Readability of patient information pamphlets in urogynecology.

PubMed

Reagan, Krista M L; O'Sullivan, David M; Harvey, David P; Lasala, Christine A

2015-01-01

The purpose of this study was to determine the reading level of frequently used patient information pamphlets and documents in the field of urogynecology. Urogynecology pamphlets were identified from a variety of sources. Readability was determined using 4 different accepted formulas: the Flesch-Kincaid Grade Level, the simple measure of gobbledygook Index, the Coleman-Liau Index, and the Gunning Fog index. The scores were calculated using an online calculator (http://www.readability-score.com). Descriptive statistics were used for analysis. The average of the 4 scores was calculated for each pamphlet. Subsequently, Z-scores were used to standardize the averages between the reading scales. Of the 40 documents reviewed, only a single pamphlet met the National Institutes of Health-recommended reading level. This document was developed by the American Urological Association and was specifically designated as a "Low-Literacy Brochure." The remainder of the patient education pamphlets, from both industry-sponsored and academic-sponsored sources, consistently rated above the recommended reading level for maximum comprehension. The majority of patient education pamphlets, from both industry-sponsored and academic-sponsored sources, are above the reading level recommended by the National Institutes of Health for maximum patient comprehension. Future work should be done to improve the educational resources available to patients by simplifying the verbiage in these documents.

Residential exposure to air toxics is linked to lower grade point averages among school children in El Paso, Texas, USA

PubMed Central

Clark-Reyna, Stephanie E.; Grineski, Sara E.; Collins, Timothy W.

2015-01-01

Children in low-income neighborhoods tend to be disproportionately exposed to environmental toxicants. This is cause for concern because exposure to environmental toxicants negatively affect health, which can impair academic success. To date, it is unknown if associations between air toxics and academic performance found in previous school-level studies persist when studying individual children. In pairing the National Air Toxics Assessment (NATA) risk estimates for respiratory and diesel particulate matter risk disaggregated by source, with individual-level data collected through a mail survey, this paper examines the effects of exposure to residential environmental toxics on academic performance for individual children for the first time and adjusts for school-level effects using generalized estimating equations. We find that higher levels of residential air toxics, especially those from non-road mobile sources, are statistically significantly associated with lower grade point averages among fourth and fifth grade school children in El Paso (Texas, USA). PMID:27034529

Assessment of exposure to indoor air contaminants from combustion sources: methodology and application.

PubMed

Leaderer, B P; Zagraniski, R T; Berwick, M; Stolwijk, J A

1986-08-01

A methodology for assessing indoor air pollutant exposures is presented, with specific application to unvented combustion by-products. This paper describes the method as applied to a study of acute respiratory illness associated with the use of unvented kerosene space heaters in 333 residences in the New Haven, Connecticut, area from September 1982 to April 1983. The protocol serves as a prototype for a nested design of exposure assessment which could be applied to large-scale field studies of indoor air contaminant levels. Questionnaires, secondary records, and several methods of air monitoring offer a reliable method of estimating environmental exposures for assessing associations with health effects at a reasonable cost. Indoor to outdoor ratios of NO2 concentrations were found to be 0.58 +/- 0.31 for residences without known sources of NO2. Levels of NO2 were found to be comparable for homes with a kerosene heater only and those with a gas cooking stove only. Homes with a kerosene heater and a gas stove had average two-week NO2 levels approximately double those with only one source. Presence of tobacco smokers had a small but significant impact on indoor NO2 levels. Two-week average levels of indoor NO2 were found to be excellent predictors of total personal NO2 exposure for a small sample of adults. Residences with kerosene space heaters had SO2 levels corresponding to the number of hours of heater use and the sulfur content of the fuel. Formaldehyde levels were found to be low and not related to unvented combustion sources. NO2, SO2, and CO2 levels measured in some of the residences were found to exceed those levels specified in current national health standards.

Determining the Consistency of Information between Multiple Systems Used in Maritime Domain Awareness

DTIC Science & Technology

2010-07-01

In this example, the slice is made at the level of OOCL Malaysia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Figure 32...cube. The slice is made at the Ship level (OOCL Malaysia ship). The averaged consistency among sources is computed with the gray cells of the cube...reported from the sources. For example, variations such as ”OOCL Malaysia ” and ”OCCL Malaysia ”, or ”King of the sea” and ”King of sea” are common. During

An estimation of Canadian population exposure to cosmic rays.

PubMed

Chen, Jing; Timmins, Rachel; Verdecchia, Kyle; Sato, Tatsuhiko

2009-08-01

The worldwide average exposure to cosmic rays contributes to about 16% of the annual effective dose from natural radiation sources. At ground level, doses from cosmic ray exposure depend strongly on altitude, and weakly on geographical location and solar activity. With the analytical model PARMA developed by the Japan Atomic Energy Agency, annual effective doses due to cosmic ray exposure at ground level were calculated for more than 1,500 communities across Canada which cover more than 85% of the Canadian population. The annual effective doses from cosmic ray exposure in the year 2000 during solar maximum ranged from 0.27 to 0.72 mSv with the population-weighted national average of 0.30 mSv. For the year 2006 during solar minimum, the doses varied between 0.30 and 0.84 mSv, and the population-weighted national average was 0.33 mSv. Averaged over solar activity, the Canadian population-weighted average annual effective dose due to cosmic ray exposure at ground level is estimated to be 0.31 mSv.

Acoustical conditions for speech communication in active elementary school classrooms

NASA Astrophysics Data System (ADS)

Sato, Hiroshi; Bradley, John

2005-04-01

Detailed acoustical measurements were made in 34 active elementary school classrooms with typical rectangular room shape in schools near Ottawa, Canada. There was an average of 21 students in classrooms. The measurements were made to obtain accurate indications of the acoustical quality of conditions for speech communication during actual teaching activities. Mean speech and noise levels were determined from the distribution of recorded sound levels and the average speech-to-noise ratio was 11 dBA. Measured mid-frequency reverberation times (RT) during the same occupied conditions varied from 0.3 to 0.6 s, and were a little less than for the unoccupied rooms. RT values were not related to noise levels. Octave band speech and noise levels, useful-to-detrimental ratios, and Speech Transmission Index values were also determined. Key results included: (1) The average vocal effort of teachers corresponded to louder than Pearsons Raised voice level; (2) teachers increase their voice level to overcome ambient noise; (3) effective speech levels can be enhanced by up to 5 dB by early reflection energy; and (4) student activity is seen to be the dominant noise source, increasing average noise levels by up to 10 dBA during teaching activities. [Work supported by CLLRnet.

On the Non-Equilibrium Population Distribution of E-Methanol in Dark Clouds

NASA Astrophysics Data System (ADS)

Wollman, Emma

2007-12-01

The goal of this project was to determine the typical distribution of rotational level populations in the k=0 ladder of E-methanol in dark clouds in order to provide another observational test for theoretical models of pumping. We used our own observations of several sources with the 12-m ARO telescope on Kitt Peak as well as the published observational results by Slysh et al. (1999). The relative level populations (excitation temperatures) were determined from the measured intensity ratios of a series of the J(0)-J(-1) transitions of E-methanol under the assumption of spontaneous, optically thin emission. We observed the J(0)-J(-1) lines in six sources: W75N, DR21N, DR21, and three positions at DR21OH. The J=1 to J=5 lines were observed for all sources and the J=7 line was observed for W75N, DR21N, and one position in DR21OH. We also used Slysh et al.'s results for the J=1 through 4 lines in 52 sources, for the J=5 line in 50 sources, for the J=6 line in 15 sources, and for the J=7 and 8 lines in 2 sources. We determined the excitation temperatures of the involved levels in the k=0 ladder relative to the 1(0) level for each source and averaged the results over the sources. The average excitation temperatures demonstrate strong evidence of overcooling in the k=0 ladder - the excitation temperature increases linearly with increasing energy, from 8 K to 35 K. Our observations confirm this tendency of overcooling. We will discuss the agreement of these results with the predictions of the current models of methanol pumping. The author thanks the technical staff of the 12-m ARO telescope for help with the observations. This project was supported by the NSF/REU grant AST-0354056 and the Nantucket Maria Mitchell Association.

Readability of Online Patient Education Materials Related to IR.

PubMed

McEnteggart, Gregory E; Naeem, Muhammad; Skierkowski, Dorothy; Baird, Grayson L; Ahn, Sun H; Soares, Gregory

2015-08-01

To assess the readability of online patient education materials (OPEM) related to common diseases treated by and procedures performed by interventional radiology (IR). The following websites were chosen based on their average Google search return for each IR OPEM content area examined in this study: Society of Interventional Radiology (SIR), Cardiovascular and Interventional Radiological Society of Europe (CIRSE), National Library of Medicine, RadiologyInfo, Mayo Clinic, WebMD, and Wikipedia. IR OPEM content area was assessed for the following: peripheral arterial disease, central venous catheter, varicocele, uterine artery embolization, vertebroplasty, transjugular intrahepatic portosystemic shunt, and deep vein thrombosis. The following algorithms were used to estimate and compare readability levels: Flesch-Kincaid Grade Formula, Flesch Reading Ease Score, Gunning Frequency of Gobbledygook, Simple Measure of Gobbledygook, and Coleman-Liau Index. Data were analyzed using general mixed modeling. On average, online sources that required beyond high school grade-level readability were Wikipedia (15.0), SIR (14.2), and RadiologyInfo (12.4); sources that required high school grade-level readability were CIRSE (11.3), Mayo Clinic (11.0), WebMD (10.6), and National Library of Medicine (9.0). On average, OPEM on uterine artery embolization, vertebroplasty, varicocele, and peripheral arterial disease required the highest level of readability (12.5, 12.3, 12.3, and 12.2, respectively). The IR OPEM assessed in this study were written above the recommended sixth-grade reading level and the health literacy level of the average American adult. Many patients in the general public may not have the ability to read and understand health information in IR OPEM. Copyright © 2015 SIR. Published by Elsevier Inc. All rights reserved.

Identification of the sources of PM10 in a subway tunnel using positive matrix factorization.

PubMed

Park, Duckshin; Lee, Taejeong; Hwang, Doyeon; Jung, Wonseok; Lee, Yongil; Cho, KiChul; Kim, Dongsool; Lees, Kiyoung

2014-12-01

The level of particulate matter of less than 10 μm diameter (PM10) at subway platforms can be significantly reduced by installing a platform screen-door system. However, both workers and passengers might be exposed to higher PM10 levels while the cars are within the tunnel because it is a more confined environment. This study determined the PM10 levels in a subway tunnel, and identified the sources of PM10 using elemental analysis and receptor modeling. Forty-four PM10 samples were collected in the tunnel between the Gireum and Mia stations on Line 4 in metropolitan Seoul and analyzed using inductively coupled plasma-atomic emission spectrometry and ion chromatography. The major PM10 sources were identified using positive matrix factorization (PMF). The average PM10 concentration in the tunnels was 200.8 ± 22.0 μg/m3. Elemental analysis indicated that the PM10 consisted of 40.4% inorganic species, 9.1% anions, 4.9% cations, and 45.6% other materials. Iron was the most abundant element, with an average concentration of 72.5 ± 10.4 μg/m3. The PM10 sources characterized by PMF included rail, wheel, and brake wear (59.6%), soil combustion (17.0%), secondary aerosols (10.0%), electric cable wear (8.1%), and soil and road dust (5.4%). Internal sources comprising rail, wheel, brake, and electric cable wear made the greatest contribution to the PM10 (67.7%) in tunnel air. Implications: With installation of a platform screen door, PM10 levels in subway tunnels were higher than those on platforms. Tunnel PM10 levels exceeded 150 µg/m3 of the Korean standard for subway platform. Elemental analysis of PM10 in a tunnel showed that Fe was the most abundant element. Five PM10 sources in tunnel were identified by positive matrix factorization. Railroad-related sources contributed 68% of PM10 in the subway tunnel.

Effect of interventions on children's blood lead levels.

PubMed Central

Hilts, S R; Bock, S E; Oke, T L; Yates, C L; Copes, R A

1998-01-01

Trail, Canada, has been the site of an active lead/zinc smelter for nearly a century. Since 1991, the Trail Community Lead Task Force has carried out blood lead screening, case management, education programs targeted at early childhood groups and the general community, community dust abatement, exposure pathways studies, and remedial trials. From 1989 through 1996, average blood lead levels of children tested for the first time declined at an average rate of 0.6 microg/dl/year, while blood lead levels in Canadian children not living near point sources appeared to be leveling off following the phase-out of leaded gasoline. Since there was no concurrent improvement in local environmental conditions during this time, it is possible that the continuing decline in Trail blood lead levels has been at least partly due to community-wide intervention programs. One year follow-up of children whose families received in-home educational visits, as well as assistance with home-based dust control measures, found that these specific interventions produced average blood lead changes of +0.5- -4.0 microg/dl, with statistically significant declines in 3 years out of 5. Education and dust control, particularly actions targeted toward higher risk children, appear to have served as effective and appropriate interim remedial measures while major source control measures have been implemented at the smelter site. Images Figure 1 Figure 2 PMID:9435149

Chemical Composition and Source Apportionment of Size ...

EPA Pesticide Factsheets

The Cleveland airshed comprises a complex mixture of industrial source emissions that contribute to periods of non-attainment for fine particulate matter (PM 2.5 ) and are associated with increased adverse health outcomes in the exposed population. Specific PM sources responsible for health effects however are not fully understood. Size-fractionated PM (coarse, fine, and ultrafine) samples were collected using a ChemVol sampler at an urban site (G.T. Craig (GTC)) and rural site (Chippewa Lake (CLM)) from July 2009 to June 2010, and then chemically analyzed. The resulting speciated PM data were apportioned by EPA positive matrix factorization to identify emission sources for each size fraction and location. For comparisons with the ChemVol results, PM samples were also collected with sequential dichotomous and passive samplers, and evaluated for source contributions to each sampling site. The ChemVol results showed that annual average concentrations of PM, elemental carbon, and inorganic elements in the coarse fraction at GTC were ~ 2, ~7, and ~3 times higher than those at CLM, respectively, while the smaller size fractions at both sites showed similar annual average concentrat ions. Seasonal variations of secondary aerosols (e.g., high N03- level in winter and high SO42- level in summer) were observed at both sites. Source apportionment results demonstrated that the PM samples at GTC and CLM were enriched with local industrial sources (e.g., steel plant and coa

Nonlinear pulse compression stage delivering 43-W few-cycle pulses with GW peak-power at 2-μm wavelength

NASA Astrophysics Data System (ADS)

Gebhardt, Martin; Gaida, Christian; Heuermann, T.; Stutzki, F.; Jauregui, C.; Antonio-Lopez, J.; Schüuzgen, A.; Amezcua-Correa, R.; Tünnermann, A.; Limpert, J.

2018-02-01

In this contribution we demonstrate the nonlinear pulse compression of an ultrafast thulium-doped fiber laser down to 14 fs FWHM duration (sub-3 optical cycles) at a record average power of 43 W and 34.5 μJ pulse energy. To the best of our knowledge, we present the highest average power few-cycle laser source at 2 μm wavelength. This performance level in combination with GW-class peak power makes our laser source extremely interesting for driving high-harmonic generation or for generating mid-infrared frequency combs via intra-pulse frequency down-conversion at an unprecedented average power. The experiments were enabled by an ultrafast thulium-doped fiber laser delivering 110 fs pulses at high repetition rates, and an argon gas-filled antiresonant hollow-core fiber (ARHCF) with excellent transmission and weak anomalous dispersion, leading to the self-compression of the pulses. We have shown that ARHCFs are well-suited for nonlinear pulse compression around 2 μm wavelength and that this concept features excellent power handling capabilities. Based on this result, we discuss the next steps for energy and average power scaling including upscaling the fiber dimensions in order to fully exploit the capabilities of our laser system, which can deliver several GW of peak power. This way, a 100 W-class laser source with mJ-level few-cycle pulses at 2 μm wavelength is feasible in the near future.

Metrics associated with NIH funding: a high-level view.

PubMed

Boyack, Kevin W; Jordan, Paul

2011-01-01

To introduce the availability of grant-to-article linkage data associated with National Institutes of Health (NIH) grants and to perform a high-level analysis of the publication outputs and impacts associated with those grants. Articles were linked to the grants they acknowledge using the grant acknowledgment strings in PubMed using a parsing and matching process as embodied in the NIH Scientific Publication Information Retrieval & Evaluation System system. Additional data from PubMed and citation counts from Scopus were added to the linkage data. The data comprise 2,572,576 records from 1980 to 2009. The data show that synergies between NIH institutes are increasing over time; 29% of current articles acknowledge grants from multiple institutes. The median time lag to publication for a new grant is 3 years. Each grant contributes to approximately 1.7 articles per year, averaged over all grant types. Articles acknowledging US Public Health Service (PHS, which includes NIH) funding are cited twice as much as US-authored articles acknowledging no funding source. Articles acknowledging both PHS funding and a non-US government funding source receive on average 40% more citations that those acknowledging PHS funding sources alone. The US PHS is effective at funding research with a higher-than-average impact. The data are amenable to further and much more detailed analysis.

Earthquake source parameters determined using the SAFOD Pilot Hole vertical seismic array

NASA Astrophysics Data System (ADS)

Imanishi, K.; Ellsworth, W. L.; Prejean, S. G.

2003-12-01

We determined source parameters of microearthquakes occurring at Parkfield, CA, using the SAFOD Pilot Hole vertical seismic array. The array consists of 32 stations with 3-component 15 Hz geophones at 40 meter spacing (856 to 2096 m depth) The site is about 1.8 km southwest of a segment of the San Andreas fault characterized by a combination of aseismic creep and repeating microearthquakes. We analyzed seismograms recorded at sample rates of 1kHz or 2kHz. Spectra have high signal-to-noise ratios at frequencies up to 300-400 Hz, showing these data include information on source processes of microearthquakes. By comparing spectra and waveforms at different levels of the array, we observe how attenuation and scattering in the shallow crust affect high-frequency waves. We estimated spectral level (Ω 0), corner frequency (fc) and path-averaged attenuation (Q) at each level of the array by fitting an omega squared model to displacement spectra. While the spectral level changes smoothly with depth, there is significant scatter in fc and Q due to the strong trade-off between these parameters. Because we expect source parameters to vary systematically with depth, we impose a smoothness constraint on Q, Ω 0 and fc as a function of depth. For some of the nearby events, take-off angles to the different levels of the array span a significant part of the focal sphere. Therefore corner frequencies should also change with depth. We smooth measurements using a linear first-difference operator that links Q, Ω 0 and fc at one level to the levels above and below, and use Akaike_fs Bayesian Information Criterion (ABIC) to weight the smoothing operators. We applied this approach to events with high signal-to-noise ratios. For the results with the minimum ABIC, fc does not scatter and Q decreases with decreasing depth. Seismic moments were determined by the spectral level and range from 109 and 1012 Nm. Source radii were estimated from the corner frequency using the circular crack model of Sato and Hirasawa (1973). Estimated values of static stress drop were roughly 1 MPa and do not vary with seismic moment. Q values from all earthquakes were averaged at each level of the array. Average Qp and Qs range from 250 to 350 and from 300 to 400 between the top and bottom of the array, respectively. Increasing Q values as a function of depth explain well the observed decrease in high-frequency content as waves propagate toward the surface. Thus, by jointly analyzing the entire vertical array we can both accurately determine source parameters of microearthquakes and make reliable Q estimates while suppressing the trade-off between fc and Q.

Agent Reasoning Transparency: The Influence of Information Level on Automation Induced Complacency

DTIC Science & Technology

2017-06-01

ARL-TR-8044 ● JUNE 2017 US Army Research Laboratory Agent Reasoning Transparency: The Influence of Information Level on...US Army Research Laboratory Agent Reasoning Transparency: The Influence of Information Level on Automation-Induced Complacency by Julia...collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources

Ruthenium Oxide Electrochemical Super Capacitor Optimization for Pulse Power Applications

NASA Technical Reports Server (NTRS)

Merryman, Stephen A.; Chen, Zheng

2000-01-01

Electrical actuator systems are being pursued as alternatives to hydraulic systems to reduce maintenance time, weight and costs while increasing reliability. Additionally, safety and environmental hazards associated with the hydraulic fluids can be eliminated. For most actuation systems, the actuation process is typically pulsed with high peak power requirements but with relatively modest average power levels. The power-time requirements for electrical actuators are characteristic of pulsed power technologies where the source can be sized for the average power levels while providing the capability to achieve the peak requirements. Among the options for the power source are battery systems, capacitor systems or battery-capacitor hybrid systems. Battery technologies are energy dense but deficient in power density; capacitor technologies are power dense but limited by energy density. The battery-capacitor hybrid system uses the battery to supply the average power and the capacitor to meet the peak demands. It has been demonstrated in previous work that the hybrid electrical power source can potentially provide a weight savings of approximately 59% over a battery-only source. Electrochemical capacitors have many properties that make them well-suited for electrical actuator applications. They have the highest demonstrated energy density for capacitive storage (up to 100 J/g), have power densities much greater than most battery technologies (greater than 30kW/kg), are capable of greater than one million charge-discharge cycles, can be charged at extremely high rates, and have non-explosive failure modes. Thus, electrochemical capacitors exhibit a combination of desirable battery and capacitor characteristics.

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

PubMed

Jagals, P

2006-01-01

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

Distribution and Determinants of 90-Day Payments for Multilevel Posterior Lumbar Fusion: A Medicare Analysis.

PubMed

Jain, Nikhil; Phillips, Frank M; Khan, Safdar N

2018-04-01

A retrospective, economic analysis. The objective of this article is to analyze the distribution of 90-day payments, sources of variation, and reimbursement for complications and readmissions for primary ≥3-level posterior lumbar fusion (PLF) from Medicare data. A secondary objective was to identify risk factors for complications. Bundled payments represent a single payment system to cover all costs associated with a single episode of care, typically over 90 days. The dollar amount spent on different health service providers and the variation in payments for ≥3-level PLF have not been analyzed from a bundled perspective. Administrative claims data were used to study 90-day Medicare (2005-2012) reimbursements for primary ≥3-level PLF for deformity and degenerative conditions of the lumbar spine. Distribution of payments, sources of variation, and reimbursements for managing complications were studied using linear regression models. Risk factors for complications were studied by stepwise multiple-variable logistic regression analysis. Hospital payments comprised 73.8% share of total 90-day payment. Adjusted analysis identified several factors for variation in index hospital payments. The average 90-day Medicare payment for all multilevel PLFs without complications was $35,878 per patient. The additional average cost of treating complications with/without revision surgery within 90 days period ranged from $17,284 to $68,963. A 90-day bundle for ≥3-level PLF with readmission ranges from $88,648 (3 levels) to $117,215 (8+ levels). Rates and risk factors for complications were also identified. The average 90-day payment per patient from Medicare was $35,878 with several factors such as levels of surgery, comorbidities, and development of complications influencing the cost. The study also identifies the risks and costs associated with complications and readmissions and emphasize the significant effect these would have on bundled payments (additional burden of up to 192% the cost of an average uncomplicated procedure over 90 days). Level 3.

Scintillation analysis of truncated Bessel beams via numerical turbulence propagation simulation.

PubMed

Eyyuboğlu, Halil T; Voelz, David; Xiao, Xifeng

2013-11-20

Scintillation aspects of truncated Bessel beams propagated through atmospheric turbulence are investigated using a numerical wave optics random phase screen simulation method. On-axis, aperture averaged scintillation and scintillation relative to a classical Gaussian beam of equal source power and scintillation per unit received power are evaluated. It is found that in almost all circumstances studied, the zeroth-order Bessel beam will deliver the lowest scintillation. Low aperture averaged scintillation levels are also observed for the fourth-order Bessel beam truncated by a narrower source window. When assessed relative to the scintillation of a Gaussian beam of equal source power, Bessel beams generally have less scintillation, particularly at small receiver aperture sizes and small beam orders. Upon including in this relative performance measure the criteria of per unit received power, this advantageous position of Bessel beams mostly disappears, but zeroth- and first-order Bessel beams continue to offer some advantage for relatively smaller aperture sizes, larger source powers, larger source plane dimensions, and intermediate propagation lengths.

Comparison of neurological healthcare oriented educational resources for patients on the internet.

PubMed

Punia, Vineet; Dagar, Anjali; Agarwal, Nitin; He, Wenzhuan; Hillen, Machteld

2014-12-01

The internet has become a major contributor to health literacy promotion. The average American reads at 7th-8th grade level and it is recommended to write patient education materials at or below 6th grade reading level. We tried to assess the level of literacy required to read and understand online patient education materials (OPEM) for neurological diseases from various internet resources. We then compared those to an assumed reference OPEM source, namely the patient education brochures from the American Academy of Neurology (AAN), the world's largest professional association of neurologists. Disease specific patient education brochures were downloaded from the AAN website. OPEM for these diseases were also accessed from other common online sources determined using a predefined criterion. All OPEM were converted to Microsoft Word (Microsoft Corp., Redmond, WA, USA) and their reading level was analyzed using Readability Studio Professional Edition version 2012.1 (Oleander Software, Vandalia, OH, USA). Descriptive analysis and analysis of variance were used to compare reading levels of OPEM from different resources. Medline Plus, Mayo clinic and Wikipedia qualified for OPEM analysis. All OPEM from these resources, including the AAN, were written above the recommended 6th grade reading level. They were also found to be "fairly difficult", "difficult" or "confusing" on the Flesch Reading Ease scale. AAN OPEM on average needed lower reading level, with Wikipedia OPEM being significantly (p<0.01) more difficult to read compared to the other three resources. OPEM on neurological diseases are being written at a level of reading complexity higher than the average American and the recommended reading levels. This may be undermining the utility of these resources. Copyright © 2014 Elsevier Ltd. All rights reserved.

DESIGN OF A GAMMA-RAY SOURCE BASED ON INVERSE COMPTON SCATTERING AT THE FAST SUPERCONDUCTING LINAC

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

Mihalcea, D.; Jacobson, B.; Murokh, A.

2016-10-10

A watt-level average-power gamma-ray source is currently under development at the Fermilab Accelerator Science & Technology (FAST) facility. The source is based on the Inverse Compton Scattering of a high-brightness 300-MeV beam against a high-power laser beam circulating in an optical cavity. The back scattered gamma rays are expected to have photon energies up to 1.5 MeV. This paper discusses the optimization of the source, its performances, and the main challenges ahead.

Precise bearing support ditherer with piezoelectric drive means

NASA Astrophysics Data System (ADS)

Assard, G. L.; Moorcroft, A. L.

1985-06-01

A relatively solid mounting surface, which may be part of a leveling gimbal, supports a piezoelectric bearing mount which has the properties of an acoustic transducer. The transducer has electrodes thereon which are powered from multi-phase electrical sources causing the bearing mount, and a bearing jewel which is rigid therewith, to move so as to dither the jewel in a rotary or other preselected fashion, thereby reducing bearing friction. Bandwidth, level and phasing sequence of the power sources are adjustable permitting optimized average dynamic motion and corresponding increased readout accuracy.

40 CFR 141.623 - Reduced monitoring.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 141.623 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection Byproducts Requirements § 141... qualify for reduced monitoring. In addition, the source water annual average TOC level, before any...

Fluoride concentration level in rural area in Poldasht city and daily fluoride intake based on drinking water consumption with temperature.

PubMed

Mohammadi, Ali Akbar; Yousefi, Mahmood; Mahvi, Amir Hossein

2017-08-01

Long-term exposure to high level of fluoride can caused several adverse effects on human health including dental and skeletal fluorosis. We investigated all the drinking water source located in rural areas of Poldasht city, west Azerbaijan Province, North West Iran between 2014 and 2015. Fluoride concentration of water samples was measured by SPADNS method. We found that in the villages of Poldasht the average of fluoride concentration in drinking water sources (well, and the river) was in the range mg/l 0.28-10.23. The average daily received per 2 l of drinking water is in the range mg/l 0.7-16.6 per day per person. Drinking water demands cause fluorosis in the villages around the area residents and based on the findings of this study writers are announced suggestions below in order to take care of the health of area residents.

Fan Noise Source Diagnostic Test: Vane Unsteady Pressure Results

NASA Technical Reports Server (NTRS)

Envia, Edmane

2002-01-01

To investigate the nature of fan outlet guide vane pressure fluctuations and their link to rotor-stator interaction noise, time histories of vane fluctuating pressures were digitally acquired as part of the Fan Noise Source Diagnostic Test. Vane unsteady pressures were measured at seven fan tip speeds for both a radial and a swept vane configuration. Using time-domain averaging and spectral analysis, the blade passing frequency (BPF) harmonic and broadband contents of the vane pressures were individually analyzed. Significant Sound Pressure Level (SPL) reductions were observed for the swept vane relative to the radial vane for the BPF harmonics of vane pressure, but vane broadband reductions due to sweep turned out to be much smaller especially on an average basis. Cross-correlation analysis was used to establish the level of spatial coherence of broadband pressures between different locations on the vane and integral length scales of pressure fluctuations were estimated from these correlations. Two main results of this work are: (1) the average broadband level on the vane (in dB) increases linearly with the fan tip speed for both the radial and swept vanes, and (2) the broadband pressure distribution on the vane is nearly homogeneous and its integral length scale is a monotonically decreasing function of fan tip speed.

Hall Current Plasma Source Having a Center-Mounted or a Surface-Mounted Cathode

NASA Technical Reports Server (NTRS)

Martinez, Rafael A. (Inventor); Moritz, Jr., Joel A. (Inventor); Williams, John D. (Inventor); Farnell, Casey C. (Inventor)

2018-01-01

A miniature Hall current plasma source apparatus having magnetic shielding of the walls from ionized plasma, an integrated discharge channel and gas distributor, an instant-start hollow cathode mounted to the plasma source, and an externally mounted keeper, is described. The apparatus offers advantages over other Hall current plasma sources having similar power levels, including: lower mass, longer lifetime, lower part count including fewer power supplies, and the ability to be continuously adjustable to lower average power levels using pulsed operation and adjustment of the pulse duty cycle. The Hall current plasma source can provide propulsion for small spacecraft that either do not have sufficient power to accommodate a propulsion system or do not have available volume to incorporate the larger propulsion systems currently available. The present low-power Hall current plasma source can be used to provide energetic ions to assist the deposition of thin films in plasma processing applications.

Using School-Level Student Achievement to Engage in Formative Evaluation: Comparative School-Level Rates of Oral Reading Fluency Growth Conditioned by Initial Skill for Second Grade Students

ERIC Educational Resources Information Center

Cummings, Kelli D.; Stoolmiller, Michael L.; Baker, Scott K.; Fien, Hank; Kame'enui, Edward J.

2015-01-01

We present a method for data-based decision making at the school level using student achievement data. We demonstrate the potential of a national assessment database [i.e., the University of Oregon DIBELS Data System (DDS)] to provide comparative levels of school-level data on average student achievement gains. Through the DDS as a data source,…

Metrics associated with NIH funding: a high-level view

PubMed Central

Jordan, Paul

2011-01-01

Objective To introduce the availability of grant-to-article linkage data associated with National Institutes of Health (NIH) grants and to perform a high-level analysis of the publication outputs and impacts associated with those grants. Design Articles were linked to the grants they acknowledge using the grant acknowledgment strings in PubMed using a parsing and matching process as embodied in the NIH Scientific Publication Information Retrieval & Evaluation System system. Additional data from PubMed and citation counts from Scopus were added to the linkage data. The data comprise 2 572 576 records from 1980 to 2009. Results The data show that synergies between NIH institutes are increasing over time; 29% of current articles acknowledge grants from multiple institutes. The median time lag to publication for a new grant is 3 years. Each grant contributes to approximately 1.7 articles per year, averaged over all grant types. Articles acknowledging US Public Health Service (PHS, which includes NIH) funding are cited twice as much as US-authored articles acknowledging no funding source. Articles acknowledging both PHS funding and a non-US government funding source receive on average 40% more citations that those acknowledging PHS funding sources alone. Conclusion The US PHS is effective at funding research with a higher-than-average impact. The data are amenable to further and much more detailed analysis. PMID:21527408

Temporal fluctuation of the lead level in the cord blood of neonates in Taipei.

PubMed

Hwang, Y H; Wang, J D

1990-01-01

From August 1985 to September 1987, 9,502 cord blood samples were obtained from the Taipei Municipal Maternal and Child Hospital. A total of 205 cord blood samples chosen randomly from newborns without parental exposure to lead were analyzed by flameless atomic absorption spectrophotometry. The average blood lead level was .36 +/- .11 mumol/l (7.48 +/- 2.25 micrograms/dl). A similar analysis was performed on samples obtained from 160 newborns whose fathers had occupational lead exposure. In both groups, the average concentration of lead in cord blood in the summer was statistically greater than that in the winter. Air lead and total amount of lead in gasoline consumed in Taipei appeared to be associated with this seasonal fluctuation in the average lead level of cord blood. After considering alternative sources, we conclude that the seasonal fluctuation of cord blood lead is probably influenced by air lead produced from the combustion of gasoline.

Root and shoot responses of Taxodium distichum seedlings subjected to saline flooding

USGS Publications Warehouse

Krauss, K.W.; Chambers, J.L.; Allen, J.A.; Luse, B.P.; DeBosier, A.S.

1999-01-01

Variation among progeny of five half-sib family collections of baldcypress (Taxodium distichum) from three freshwater and two brackish-water seed sources subjected to saline flooding was evaluated Mini-rhizotrons (slant tubes) were used to monitor root elongation for a period of 99 days. Salinity level produced significant effects across all baldcypress half-sib families, with root elongation averaging 1594.0, 956.8, and 382.1 mm, respectively, for the 0, 4, and 6 g l-1 treatments. Combined mean root elongation for families from brackish-water seed sources was greater (1236.7 mm) than for families from freshwater seed sources (794.6 mm). Considerable variation occurred at the highest salinity treatment, however, with one freshwater family maintaining more than 28% more root growth than the average of the two brackish-water collections. Hence, results indicate that short-term evaluation of root elongation at these salinity concentrations may not be a reliable method for salt tolerance screening of baldcypress. Species-level effects for height and diameter, which were measured at day 62, were significant for both parameters. Height increment in the control (7.4 cm), for example, was approximately five times greater than height increment in the 6 g l-1 salinity treatment (1.5 cm). Family-level variation was significant only for diameter, which had an incremental range of 0.2 to 1.5 mm across all salinity levels.

Preliminary data on polybrominated diphenyl ethers (PBDEs) in farmed fish tissues (Salmo salar) and fish feed in Southern Chile.

PubMed

Montory, Mónica; Barra, Ricardo

2006-05-01

Polybrominated diphenyl ethers (PBDEs) have become an issue of global concern. Recent studies have shown that farmed salmon can accumulate high levels of brominated compounds in their tissues and consequently there is a growing concern on its industrial and public health impacts. Little information is found in the international literature on PBDEs in the biotic compartment of the Southern Hemisphere. This paper reports the levels of several PBDE congeners found in the tissues of farmed fish from five different farming areas of Southern Chile. PBDEs were analyzed by HRGC-MS. More analytical data were obtained by analyzing these same pollutants in fish feed. Our results indicate a general trend of PBDE levels averaging 1.46 ng g(-1) wet weight (wwt). The observed congeneric distribution that resulted was quite similar to data previously reported in the open literature. PBDE profiles were found to be dominated by BDE 47. No correlation was observed between levels found in the tissues and the lipid content in such tissues, although a high correlation with the fish feed data was observed indicating that this could probably be the main PDBE entry source into fish, although other sources cannot be excluded. Even though the samples were obtained from different geographical areas, they presented fairly similar profiles, indicating a potential common source. We concluded that PBDE levels in the farmed Chilean salmon are in the low average range of values published in the open literature.

Patterns and sources of personality development in old age.

PubMed

Kandler, Christian; Kornadt, Anna E; Hagemeyer, Birk; Neyer, Franz J

2015-07-01

Despite abundant evidence that personality development continues in adulthood, little is known about the patterns and sources of personality development in old age. We thus investigated mean-level trends and individual differences in change as well as the genetic and environmental sources of rank-order continuity and change in several personality traits (neuroticism, extraversion, openness, agreeableness, conscientiousness, perceived control, and affect intensity) and well-being. In addition, we analyzed the interrelation between perceived control and change in other personality traits as well as between change in personality traits and change in well-being. We analyzed data from older adult twins, aged 64-85 years at Time 1 (N = 410; 135 males and 275 females; 134 monozygotic and 63 dizygotic twin pairs), collected at 2 different time points about 5 years apart. On average, neuroticism increased, whereas extraversion, conscientiousness, and perceived control significantly decreased over time. Change in perceived control was associated with change in neuroticism and conscientiousness, pointing to particular adaptation mechanisms specific to old age. Whereas individual differences in personality traits were fairly stable due to both genetic and environmental sources, individual differences in change were primarily due to environmental sources (beyond random error) indicating plasticity in old age. Even though the average level of well-being did not significantly change over time, individual well-being tended to decrease with strongly increasing levels of neuroticism as well as decreasing extraversion, conscientiousness, and perceived control, indicating that personality traits predict well-being but not vice versa. We discuss implications for theory on personality development across the lifespan. (c) 2015 APA, all rights reserved).

Piezoelectric transducer design for a miniaturized injectable acoustic transmitter

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

Li, Huidong; Jung, Ki Won; Deng, Zhiqun D.

Acoustic telemetry has been an important tool in the last 20 years for studying fish survival and migration behaviors during and after dam passage. This technology uses implantable acoustic transmitters as tags to three-dimensionally track the movement of fish. However, the relatively large weights and sizes of commercially available transmitters limit the populations of fish that could be studied. The surgical implantation procedures required may also injure fish and also incur a significant amount of labor. Therefore, a smaller, lighter, and injectable tag was needed, and similar or better acoustic performance and service life over that provided by existing commercialmore » tags was desired. To develop such a small transmitter, a number of technical challenges, including design optimization of the piezoelectric transducer, needed to be overcome. The goal of our efforts to optimize the transducer focused on improving the average source level in the 180° range in which the transmitter was facing the receiving hydrophone, so as to increase the transmitter’s detection probability. This paper reports the techniques that were explored and developed to achieve this goal. We found that a novel off-center tube transducer improved the average source level of the front half of the transducer by 1.5 dB. An acoustic reflector attached to the back of the transducer also improved the source level by 3 dB when the transducer was pointed toward the receiving hydrophone, although the source level on the sides of the transducer was reduced. We found that too small a gap between the transducer and the component placed behind it resulted in distortion of the beam pattern. To overcome that issue, we connected a tuning inductor in series with the transducer to help optimize the source level. Furthermore, the findings and techniques developed in this work contributed to the successful development and implementation of a new injectable transmitter.« less

Piezoelectric transducer design for a miniaturized injectable acoustic transmitter

DOE PAGES

Li, Huidong; Jung, Ki Won; Deng, Zhiqun D.

2015-10-07

Acoustic telemetry has been an important tool in the last 20 years for studying fish survival and migration behaviors during and after dam passage. This technology uses implantable acoustic transmitters as tags to three-dimensionally track the movement of fish. However, the relatively large weights and sizes of commercially available transmitters limit the populations of fish that could be studied. The surgical implantation procedures required may also injure fish and also incur a significant amount of labor. Therefore, a smaller, lighter, and injectable tag was needed, and similar or better acoustic performance and service life over that provided by existing commercialmore » tags was desired. To develop such a small transmitter, a number of technical challenges, including design optimization of the piezoelectric transducer, needed to be overcome. The goal of our efforts to optimize the transducer focused on improving the average source level in the 180° range in which the transmitter was facing the receiving hydrophone, so as to increase the transmitter’s detection probability. This paper reports the techniques that were explored and developed to achieve this goal. We found that a novel off-center tube transducer improved the average source level of the front half of the transducer by 1.5 dB. An acoustic reflector attached to the back of the transducer also improved the source level by 3 dB when the transducer was pointed toward the receiving hydrophone, although the source level on the sides of the transducer was reduced. We found that too small a gap between the transducer and the component placed behind it resulted in distortion of the beam pattern. To overcome that issue, we connected a tuning inductor in series with the transducer to help optimize the source level. Furthermore, the findings and techniques developed in this work contributed to the successful development and implementation of a new injectable transmitter.« less

Peak power ratio generator

DOEpatents

Moyer, Robert D.

1985-01-01

A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

Peak power ratio generator

DOEpatents

Moyer, R.D.

A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

Comparison of the Microbial Quality of Lamb and Goat Meat Acquired from Internet and Local Retail Markets.

PubMed

Kim, Chyer; Stein, Roslyn A; Pao, Steven

2015-11-01

This study was conducted to evaluate the microbial quality of lamb and goat meat sold through local (Virginia) and Internet (U. S.) retail markets. A total of 134 frozen meat products consisting of locally purchased lamb ground (LLG) and lamb chops and Internet-procured lamb ground, goat ground, lamb chops (ILC), goat chops (IGC), lamb stew, and goat stew were tested. Significantly higher levels of aerobic mesophiles, psychrotrophs, and coliforms were found in the meat locally acquired than in the meat procured from the Internet. Similar average prevalence (27%) of Escherichia coli was observed regardless of market source. Ground meat had significantly high levels and prevalence of mesophiles, psychrotrophs, coliforms, and Listeria spp. One sample of LLG contained Campylobacter, and one sample of IGC contained Salmonella. Listeria spp. were present in 23 to 40% and 17 to 80% of samples from local and Internet markets, respectively. Pulsed-field gel electrophoresis (PFGE) of isolated E. coli strains revealed brand specificity and genomic diversity. No isolate from different brands and market sources had matching PFGE profiles. The average price of Internet meat ($23.4/kg) was about 1.2 times higher than the price of local meat, except for ILC, whose price was 2.7 times higher. This study revealed differences in microbial quality of lamb and goat meat based on market source; thus, meat products should be handled carefully regardless of market source because of the presence of high microbial levels and the high prevalence of pathogens.

Spatial and temporal variability of fine particle composition and source types in five cities of Connecticut and Massachusetts

PubMed Central

Lee, Hyung Joo; Gent, Janneane F.; Leaderer, Brian P.; Koutrakis, Petros

2011-01-01

To protect public health from PM2.5 air pollution, it is critical to identify the source types of PM2.5 mass and chemical components associated with higher risks of adverse health outcomes. Source apportionment modeling using Positive Matrix Factorization (PMF), was used to identify PM2.5 source types and quantify the source contributions to PM2.5 in five cities of Connecticut and Massachusetts. Spatial and temporal variability of PM2.5 mass, components and source contributions were investigated. PMF analysis identified five source types: regional pollution as traced by sulfur, motor vehicle, road dust, oil combustion and sea salt. The sulfur-related regional pollution and traffic source type were major contributors to PM2.5. Due to sparse ground-level PM2.5 monitoring sites, current epidemiological studies are susceptible to exposure measurement errors. The higher correlations in concentrations and source contributions between different locations suggest less spatial variability, resulting in less exposure measurement errors. When concentrations and/or contributions were compared to regional averages, correlations were generally higher than between-site correlations. This suggests that for assigning exposures for health effects studies, using regional average concentrations or contributions from several PM2.5 monitors is more reliable than using data from the nearest central monitor. PMID:21429560

Persistent organic pesticide residues in sediments of Vasai Creek near Mumbai: Assessment of sources and potential ecological risk.

PubMed

Singare, Pravin U

2015-11-15

Thirteen persistent organic pesticides were investigated in the sediments of Vasai Creek near Mumbai to evaluate their pollution levels and potential risks. It was observed that ΣOCPs level was in the range of 597-1538ng/g dw, with an average value of 1115.25ng/g dw. The level of ΣOPPs was in the range of 492-1034ng/g dw, with an average value of 798.15ng/g dw. The values o,p'-DDT/p,p'-DDT ratio gives an indication of use of technical DDT as the prime source of DDT, while the α/γ-BHC ratio indicate that BHCs in study area might have been received from fresh lindane. The results of an ecological risk assessment showed that sediment bound organic pesticides are of more ecotoxicological concern as they might create adverse ecological risk to the marine breeding habitats. These pesticides residues may get remobilize and released to overlying waters creating adverse effects on terrestrial and aquatic organisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Composition and sources of carbonaceous aerosols in Northern Europe during winter

NASA Astrophysics Data System (ADS)

Glasius, M.; Hansen, A. M. K.; Claeys, M.; Henzing, J. S.; Jedynska, A. D.; Kasper-Giebl, A.; Kistler, M.; Kristensen, K.; Martinsson, J.; Maenhaut, W.; Nøjgaard, J. K.; Spindler, G.; Stenström, K. E.; Swietlicki, E.; Szidat, S.; Simpson, D.; Yttri, K. E.

2018-01-01

Sources of elemental carbon (EC) and organic carbon (OC) in atmospheric aerosols (carbonaceous aerosols) were investigated by collection of weekly aerosol filter samples at six background sites in Northern Europe (Birkenes, Norway; Vavihill, Sweden; Risoe, Denmark; Cabauw and Rotterdam in The Netherlands; Melpitz, Germany) during winter 2013. Analysis of 14C and a set of molecular tracers were used to constrain the sources of EC and OC. During the four-week campaign, most sites (in particular those in Germany and The Netherlands) were affected by an episode during the first two weeks with high concentrations of aerosol, as continental air masses were transported westward. The analysis results showed a clear, increasing north to south gradient for most molecular tracers. Total carbon (TC = OC + EC) at Birkenes showed an average concentration of 0.5 ± 0.3 μg C m-3, whereas the average concentration at Melpitz was 6.0 ± 4.3 μg C m-3. One weekly mean TC concentration as high as 11 μg C m-3 was observed at Melpitz. Average levoglucosan concentrations varied by an order of magnitude from 25 ± 13 ng m-3 (Birkenes) to 249 ± 13 ng m-3 (Melpitz), while concentrations of tracers of fungal spores (arabitol and mannitol) and vegetative debris (cellulose) were very low, showing a minor influence of primary biological aerosol particles during the North European winter. The fraction of modern carbon generally varied from 0.57 (Melpitz) to 0.91 (Birkenes), showing an opposite trend compared to the molecular tracers and TC. Total concentrations of 10 biogenic and anthropogenic carboxylic acids, mainly of secondary origin, were 4-53 ng m-3, with the lowest concentrations observed at Birkenes and the highest at Melpitz. However, the highest relative concentrations of carboxylic acids (normalized to TC) were observed at the most northern sites. Levels of organosulphates and nitrooxy organosulphates varied more than two orders of magnitude, from 2 to 414 ng m-3, between individual sites and samples. The three sites Melpitz, Rotterdam and Cabauw, located closest to source regions in continental Europe, showed very high levels of organosulphates and nitrooxy organosulphates (up to 414 ng m-3) during the first two weeks of the study, while low levels (<7 ng m-3) were found at all sites except Melpitz during the last week. The large variation in organosulphate levels probably reflects differences in the presence of acidic sulphate aerosols, known from laboratory studies to accelerate the formation of these compounds. On average, the ratio of organic sulphate to inorganic sulphate was 1.5 ± 1.0% (range 0.1-3.4%). Latin-hypercube source apportionment techniques identified biomass burning as the major source of OC for all samples at all sites (typically >40% of TC), while use and combustion of fossil fuels was the second most important source. Furthermore, EC from biomass burning accounted for 7-16% of TC, whereas EC from fossil sources contributed to <2-23% of TC, of which the highest percentages were observed for low-concentration aerosol samples. Unresolved non-fossil sources (such as cooking and biogenic secondary organic aerosols) did not account for more than 5-12% of TC. The results confirm that wood combustion is a major source to OC and EC in Northern Europe during winter.

Open-path spectroscopic methane detection using a broadband monolithic distributed feedback-quantum cascade laser array.

PubMed

Michel, Anna P M; Kapit, Jason; Witinski, Mark F; Blanchard, Romain

2017-04-10

Methane is a powerful greenhouse gas that has both natural and anthropogenic sources. The ability to measure methane using an integrated path length approach such as an open/long-path length sensor would be beneficial in several environments for examining anthropogenic and natural sources, including tundra landscapes, rivers, lakes, landfills, estuaries, fracking sites, pipelines, and agricultural sites. Here a broadband monolithic distributed feedback-quantum cascade laser array was utilized as the source for an open-path methane sensor. Two telescopes were utilized for the launch (laser source) and receiver (detector) in a bistatic configuration for methane sensing across a 50 m path length. Direct-absorption spectroscopy was utilized with intrapulse tuning. Ambient methane levels were detectable, and an instrument precision of 70 ppb with 100 s averaging and 90 ppb with 10 s averaging was achieved. The sensor system was designed to work "off the grid" and utilizes batteries that are rechargeable with solar panels and wind turbines.

Estimating watershed degradation over the last century and its impact on water-treatment costs for the world’s large cities

PubMed Central

McDonald, Robert I.; Weber, Katherine F.; Padowski, Julie; Boucher, Tim; Shemie, Daniel

2016-01-01

Urban water systems are impacted by land use within their source watersheds, as it affects raw water quality and thus the costs of water treatment. However, global estimates of the effect of land cover change on urban water-treatment costs have been hampered by a lack of global information on urban source watersheds. Here, we use a unique map of the urban source watersheds for 309 large cities (population > 750,000), combined with long-term data on anthropogenic land-use change in their source watersheds and data on water-treatment costs. We show that anthropogenic activity is highly correlated with sediment and nutrient pollution levels, which is in turn highly correlated with treatment costs. Over our study period (1900–2005), median population density has increased by a factor of 5.4 in urban source watersheds, whereas ranching and cropland use have increased by a factor of 3.4 and 2.0, respectively. Nearly all (90%) of urban source watersheds have had some level of watershed degradation, with the average pollutant yield of urban source watersheds increasing by 40% for sediment, 47% for phosphorus, and 119% for nitrogen. We estimate the degradation of watersheds over our study period has impacted treatment costs for 29% of cities globally, with operation and maintenance costs for impacted cities increasing on average by 53 ± 5% and replacement capital costs increasing by 44 ± 14%. We discuss why this widespread degradation might be occurring, and strategies cities have used to slow natural land cover loss. PMID:27457941

Estimating watershed degradation over the last century and its impact on water-treatment costs for the world's large cities.

PubMed

McDonald, Robert I; Weber, Katherine F; Padowski, Julie; Boucher, Tim; Shemie, Daniel

2016-08-09

Urban water systems are impacted by land use within their source watersheds, as it affects raw water quality and thus the costs of water treatment. However, global estimates of the effect of land cover change on urban water-treatment costs have been hampered by a lack of global information on urban source watersheds. Here, we use a unique map of the urban source watersheds for 309 large cities (population > 750,000), combined with long-term data on anthropogenic land-use change in their source watersheds and data on water-treatment costs. We show that anthropogenic activity is highly correlated with sediment and nutrient pollution levels, which is in turn highly correlated with treatment costs. Over our study period (1900-2005), median population density has increased by a factor of 5.4 in urban source watersheds, whereas ranching and cropland use have increased by a factor of 3.4 and 2.0, respectively. Nearly all (90%) of urban source watersheds have had some level of watershed degradation, with the average pollutant yield of urban source watersheds increasing by 40% for sediment, 47% for phosphorus, and 119% for nitrogen. We estimate the degradation of watersheds over our study period has impacted treatment costs for 29% of cities globally, with operation and maintenance costs for impacted cities increasing on average by 53 ± 5% and replacement capital costs increasing by 44 ± 14%. We discuss why this widespread degradation might be occurring, and strategies cities have used to slow natural land cover loss.

Background radiation in the Albuquerque, New Mexico, U.S.A., area

NASA Astrophysics Data System (ADS)

Brookins, Douglas G.

1992-01-01

Background radiation levels in the Albuquerque, New Mexico, area are elevated when compared to much of the United States. Soil K, U, and Th are somewhat elevated compared to average values in this country and generate roughly 60 mrem per year to the average resident. Cosmic ray contribution, due to the mean elevation of 5,200 ft above sea level, is 80 mrem/yr—well over the average for the United States. Thirty percent of the homes in Albuquerque contain indoor radon levels over the EPA action level of 4 pCi/ℓ compared to 10 12 percent of homes for the entire United States. Indoor radon contributes about 100 300 mrem/yr. Food, beverages, and x-ray doses are assumed at an average-equivalent for the United States and locally yield 96 mrem/yr. Total contributions from other minor sources (color TV, coal, weapons fallout, etc.) are under 10 mrem/yr. Thus total background radiation received by Albuquerque residents is about 330 530 mrem/yr, well in excess of the rest of the United States. The spread in mrem values is due to variations in the contribution from indoor radon.

The Flux Variability of Markarian 501 in Very High Energy Gamma Rays

NASA Astrophysics Data System (ADS)

Quinn, J.; Bond, I. H.; Boyle, P. J.; Bradbury, S. M.; Breslin, A. C.; Buckley, J. H.; Burdett, A. M.; Gordo, J. Bussons; Carter-Lewis, D. A.; Catanese, M.; Cawley, M. F.; Fegan, D. J.; Finley, J. P.; Gaidos, J. A.; Hall, T.; Hillas, A. M.; Krennrich, F.; Lamb, R. C.; Lessard, R. W.; Masterson, C.; McEnery, J. E.; Moriarty, P.; Rodgers, A. J.; Rose, H. J.; Samuelson, F. W.; Sembroski, G. H.; Srinivasan, R.; Vassiliev, V. V.; Weekes, T. C.

1999-06-01

The BL Lacertae object Markarian 501 was identified as a source of γ-ray emission at the Whipple Observatory in 1995 March. Here we present a flux variability analysis on several timescales of the 233 hr data set accumulated over 213 nights (from March 1995 to July 1998) with the Whipple Observatory 10 m atmospheric Cerenkov imaging telescope. In 1995, with the exception of a single night, the flux from Markarian 501 was constant on daily and monthly timescales and had an average flux of only 10% that of the Crab Nebula, making it the weakest very high energy source detected to date. In 1996, the average flux was approximately twice the 1995 flux and showed significant month-to-month variability. No significant day-scale variations were detected. The average γ-ray flux above ~350 GeV in the 1997 observing season rose to 1.4 times that of the Crab Nebula--14 times the 1995 discovery level--allowing a search for variability on timescales shorter than 1 day. Significant hour-scale variability was present in the 1997 data, with the shortest, observed on MJD 50,607, having a doubling time of ~2 hr. In 1998 the average emission level decreased considerably from that of 1997 (to ~20% of the Crab Nebula flux), but two significant flaring events were observed. Thus the emission from Markarian 501 shows large amplitude and rapid flux variability at very high energies, as does Markarian 421. It also shows large mean flux level variations on year-to-year timescales, behavior that has not been seen from Markarian 421 so far.

Predicting Risk from Radon in Source Waters from Water Quality Parameters

EPA Science Inventory

Overall, 47 groundwater samples were collected from 45 small community water systems (CWSs) and analyzed for radon and other water quality constituents. In general, groundwater from unconsolidated deposits and sedimentary rocks had lower average radon levels (ranging from 223 to...

Index to Computer Assisted Instruction.

ERIC Educational Resources Information Center

Lekan, Helen A., Ed.

The computer assisted instruction (CAI) programs and projects described in this index are listed by subject matter. The index gives the program name, author, source, description, prerequisites, level of instruction, type of student, average completion time, logic and program, purpose for which program was designed, supplementary…

PM2.5-bound PAHs in three indoor and one outdoor air in Beijing: Concentration, source and health risk assessment.

PubMed

Chen, Ying; Li, Xinghua; Zhu, Tianle; Han, Yingjie; Lv, Dong

2017-05-15

Three indoor (residential home, dormitory, and office) and one outdoor concentrations of PM 2.5 -bound Polycyclic aromatic hydrocarbons (PAHs) were analyzed in Beijing across four seasons. The highest and lowest concentration of total PAHs for outdoor appeared in winter and in summer with averages of 200.1 and 9.1ng/m 3 respectively. The seasonal variations of total PAHs in three indoor sites were the same as outdoor. The correlation analysis between the indoor and outdoor samples showed that the annual mean I/O ratios of total PAHs in the three sites were lower than 1. Source apportionment showed vehicle exhaust, coal combustion, and biomass burning were the major contributors of indoor and outdoor PM 2.5 -bound PAHs. Indoor source, such as camphor pollution, was identified in the dormitory, while camphor pollution and cooking sources were identified in the residential home. The annual averages of Benzo[a]pyrene equivalent concentration (BaP eq ) were 7.6, 7.8, 7.7 and 12.7ng/m 3 for the dormitory, office, residential home and outdoor samples respectively, far higher than the annual limit of 1ng/m 3 regulated by European Commission. Life lung cancer risk (LLCR) in four sites across four seasons were over the acceptable cancer risk level, showing the cancer risk were at a high level in both indoor and outdoor sites in Beijing, and its level in indoor sites was much lower than in the outdoor site. The health risk assessment indicated the level of PAHs cancer risk on human for three indoor sites were similar. The results call for the development of more stringent control measures to reduce PAHs emissions. Copyright © 2017 Elsevier B.V. All rights reserved.

Outdoor radiofrequency radiation levels in the West Bank-Palestine.

PubMed

Lahham, Adnan; Hammash, Alaa

2012-05-01

This work presents the results of exposure levels to radio frequency (RF) emission from different sources in the environment of the West Bank-Palestine. These RF emitters include FM and TV broadcasting stations and mobile phone base stations. Power densities were measured at 65 locations distributed over the West Bank area. These locations include mainly centres of the major cities. Also a 24 h activity level was investigated for a mobile phone base station to determine the maximum activity level for this kind of RF emitters. All measurements were conducted at a height of 1.7 m above ground level using hand held Narda SRM 3000 spectrum analyzer with isotropic antenna capable of collecting RF signals in the frequency band from 75 MHz to 3 GHz. The average value of power density resulted from FM radio broadcasting in all investigated locations was 0.148 μW cm(-2), from TV broadcasting was 0.007 μW cm(-2) and from mobile phone base station was 0.089 μW cm(-2). The maximum total exposure evaluated at any location was 3.86 μW cm(-2). The corresponding exposure quotient calculated for this site was 0.02. This value is well below unity indicating compliance with the International Commission on non-ionising Radiation protection guidelines. Contributions from all relevant RF sources to the total exposure were evaluated and found to be ~62 % from FM radio, 3 % for TV broadcasting and 35 % from mobile phone base stations. The average total exposure from all investigated RF sources was 0.37 μW cm(-2).

Biomarkers in sedimentary sequences: Indicators to track sediment sources over decadal timescales

NASA Astrophysics Data System (ADS)

Chen, F. X.; Fang, N. F.; Wang, Y. X.; Tong, L. S.; Shi, Z. H.

2017-02-01

Long-term sedimentary sequence research can reveal how human activities and climate interact to affect catchment vegetation, flooding, soil erosion, and sediment sources. In this study, a biomarker sediment fingerprinting technique based on n-alkanes was used to identify long timescale (decadal) sediment sources in a small agricultural catchment. However, the highly saline carbonate environment and bacterial and algal activities elevated the levels of even-chain n-alkanes in the sediments, leading to an obvious even-over-odd predominance of short and middle components (C15-C26). Therefore, by analyzing three odd, long-chain n-alkanes (C27, C29 and C31) in 27 source samples from cropland, gully, and steep slope areas and one sediment sequence (one cultivated horizon and 47 flood couplets), a composite fingerprinting method and genetic algorithm optimization were applied to find the optimal source contributions to sediments. The biomarker fingerprinting results demonstrated that the primary sediment source is gullies, followed by cropland and steep slope areas. The average median source contributions associated with 47 flood couples collected from sediment core samples ranged from 0 ± 0.1% to 91.9 ± 0.4% with an average of 45.0% for gullies, 0 ± 0.4% to 95.6 ± 1.6% with an average of 38.2% for cropland, and 0 ± 2.1% to 60.7 ± 0.4% with an average of 16.8% for steep slopes. However, because farmers were highly motivated to manage the cropland after the 1980s, over half the sediments were derived from cropland in the 1980s. Biomarkers have significant advantages in the identification of sediments derived from different landscape units (e.g., gully and steep slope areas), and n-alkanes have considerable potential in high-resolution research of environmental change based on soil erosion in the hilly Loess Plateau region.

[Studies of bioavailability of different food sources of selenium in experiment].

PubMed

Egorova, E A; Gmoshinskiĭ, I V; Zorin, S I; Mazo, V K

2006-01-01

The selenium bioavailability in selenium enriched Spirulina (Arthrospira platensis), phycocyanin containing (Se-PC) protein isolate, separated from this micro algae and in sodium selenite was studied and compared in rats. The daily dose of selenium per one animal was 5 microgram in all experimental groups. The average selenium levels in blood serum and liver of animals that received sodium selenite during 14 days were the highest. The average selenium level in blood serum of animals fed with selenium enriched Spirulina platensis after 14 days of receiving was the same with the control group, but the average concentration of selenium in their liver was rather high and close to this parameter of sodium selenite animal group. The animals which were fed with Se-PC showed better results. Their average selenium level in blood serum was higher than in Spirulina group, but lower than in sodium selenite group. The average concentration of selenium in the liver of these animals was the same with sodium selenite animal group. As regards to animals that were fed with selenium enriched Spirulina, Se-PC and sodium selenite for 21 days, the average selenium levels ratio in their blood serum and liver was higher than in control group, but these results were not significantly different among each other. The concentrations of selenium in seminal glands in all groups of animals including control group both after 14 and 21 days feeding were close to each other.

29 CFR 510.21 - SIC codes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... annual Census of Manufacturing Industries as a source of average hourly wage data by industry. Industries in that census are organized by Standard Industrial Classification (SIC), the statistical... stated that data “should be at a level of specificity comparable to the four digit Standard Industry Code...

29 CFR 510.21 - SIC codes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... annual Census of Manufacturing Industries as a source of average hourly wage data by industry. Industries in that census are organized by Standard Industrial Classification (SIC), the statistical... stated that data “should be at a level of specificity comparable to the four digit Standard Industry Code...

29 CFR 510.21 - SIC codes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... annual Census of Manufacturing Industries as a source of average hourly wage data by industry. Industries in that census are organized by Standard Industrial Classification (SIC), the statistical... stated that data “should be at a level of specificity comparable to the four digit Standard Industry Code...

29 CFR 510.21 - SIC codes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... annual Census of Manufacturing Industries as a source of average hourly wage data by industry. Industries in that census are organized by Standard Industrial Classification (SIC), the statistical... stated that data “should be at a level of specificity comparable to the four digit Standard Industry Code...

Noise-induced annoyance from transportation noise: short-term responses to a single noise source in a laboratory.

PubMed

Kim, Jaehwan; Lim, Changwoo; Hong, Jiyoung; Lee, Soogab

2010-02-01

An experimental study was performed to compare the annoyances from civil-aircraft noise, military-aircraft noise, railway noise, and road-traffic noise. Two-way within-subjects designs were applied in this research. Fifty-two subjects, who were naive listeners, were given various stimuli with varying levels through a headphone in an anechoic chamber. Regardless of the frequency weighting network, even under the same average energy level, civil-aircraft noise was the most annoying, followed by military-aircraft noise, railway noise, and road-traffic noise. In particular, penalties in the time-averaged, A-weighted sound level (TAL) of about 8, 5, and 5 dB, respectively, were found in the civil-aircraft, military-aircraft, and railway noises. The reason could be clarified through the high-frequency component and the variability in the level. When people were exposed to sounds with the same maximum A-weighted level, a railway bonus of about 3 dB was found. However, transportation noise has been evaluated by the time-averaged A-weighted level in most countries. Therefore, in the present situation, the railway bonus is not acceptable for railway vehicles with diesel-electric engines.

Patient-oriented methotrexate information sites on the Internet: a review of completeness, accuracy, format, reliability, credibility, and readability.

PubMed

Thompson, Andrew E; Graydon, Sara L

2009-01-01

With continuing use of the Internet, rheumatologists are referring patients to various websites to gain information about medications and diseases. Our goal was to develop and evaluate a Medication Website Assessment Tool (MWAT) for use by health professionals, and to explore the overall quality of methotrexate information presented on common English-language websites. Identification of websites was performed using a search strategy on the search engine Google. The first 250 hits were screened. Inclusion criteria included those English-language websites from authoritative sources, trusted medical, physicians', and common health-related websites. Websites from pharmaceutical companies, online pharmacies, and where the purpose seemed to be primarily advertisements were also included. Product monographs or technical-based web pages and web pages where the information was clearly directed at patients with cancer were excluded. Two reviewers independently scored each included web page for completeness and accuracy, format, readability, reliability, and credibility. An overall ranking was provided for each methotrexate information page. Twenty-eight web pages were included in the analysis. The average score for completeness and accuracy was 15.48+/-3.70 (maximum 24) with 10 out of 28 pages scoring 18 (75%) or higher. The average format score was 6.00+/-1.46 (maximum 8). The Flesch-Kincaid Grade Level revealed an average grade level of 10.07+/-1.84, with 5 out of 28 websites written at a reading level less than grade 8; however, no web page scored at a grade 5 to 6 level. An overall ranking was calculated identifying 8 web pages as appropriate sources of accurate and reliable methotrexate information. With the enormous amount of information available on the Internet, it is important to direct patients to web pages that are complete, accurate, readable, and credible sources of information. We identified web pages that may serve the interests of both rheumatologists and patients.

Effect of dietary calcium and phosphorus levels on the total tract digestibility of innate and supplemental organic and inorganic microminerals in a corn-soybean meal based diet of grower pigs.

PubMed

Jolliff, J S; Mahan, D C

2013-06-01

The effects of Ca and P (CaP) levels and micromineral sources on mineral digestibility were evaluated in growing pigs. Treatments consisted of 2 levels of CaP and 3 trace mineral (TM) treatments arranged as a 2 × 3 factorial in a randomized complete block design with 8 replicates. The CaP levels evaluated were: 1) 0.65% Ca and 0.55% P [standard CaP (Std CaP)], and 2) 1.00% Ca and 0.85% P (High CaP). The TM treatments were: 1) Basal, without supplemental TM, 2) Basal supplemented with organic TM, and 3) Basal supplemented with inorganic TM. Both organic and inorganic TM premixes added 15 mg Cu, 150 mg Fe, 10 mg Mn, 0.3 mg Se, and 140 mg Zn/kg diet. Diets were formulated using corn soybean meal with a Ca to P ratio of 1.18 in both CaP treatments. Barrows with an initial BW of 45 kg were acclimated to stainless steel metabolism crates where diets were fed for 14 d before a 10-d collection period. Pigs within replicates were fed equivalent amounts of feed at 0800 and 1600 h each day with water provided free choice. Total feces, urine, and feed orts were collected daily. Essential macro- and microminerals were analyzed by inductively coupled plasma analysis. Increasing dietary CaP decreased the digestibility of Ca and Zn. Phosphorus digestibility did not change when the P inclusion level increased from 0.55 to 0.85% Ptotal. The High CaP level resulted in a lower urinary excretion of most minerals, particularly Cu (P < 0.05) and Mn (P < 0.05), as dietary CaP level increased but the others were not statistically significant. A summary of the ATTD for each of the experimental variables was statistically analyzed and averaged for the experiment. Although there were few statistical differences with individual minerals, they generally demonstrated a decline in digestibility when the High CaP was fed, averaging a 3% lower digestibility consistently than when the Std CaP level was fed. Organic TM averaged an approximately 5% greater digestibility than the average inorganic microminerals with the difference between minerals within each source relatively consistent. These results indicate that CaP level had the greatest effect on mineral digestibility, organic microminerals had a greater digestibility than inorganic minerals, and the innate microminerals had an average apparent digestibility of 45%.

Spatial distribution and source identification of heavy metals in surface soils in a typical coal mine city, Lianyuan, China.

PubMed

Liang, Jie; Feng, Chunting; Zeng, Guangming; Gao, Xiang; Zhong, Minzhou; Li, Xiaodong; Li, Xin; He, Xinyue; Fang, Yilong

2017-06-01

In this study, we investigated the pollution degree and spatial distribution of heavy metals and determined their sources in topsoil in a typical coal mine city, Lianyuan, Hunan Province, China. We collected 6078 soil surface samples in different land use types. And the concentrations of Zn, Cd, Cu, Hg, Pb, Sb, As, Mo, V, Mn, Fe and Cr were measured. The average contents of all heavy metals were lower than their corresponding Grade II values of Chinese Soil Quality Standard with the exception of Hg. However, average contents of twelve heavy metals, except for Mn, exceeded their background level in soils in Hunan Province. Based on one-way analysis of variance (ANOVA), the contents of Cu, Zn, Cd, Pb, Hg, Mo and V were related to the anthropogenic source and there were statistically significant differences in their concentrations among different land use patterns. The spatial variation of heavy metal was visualized by GIS. The PMF model was used to ascertain contamination sources of twelve heavy metals and apportion their source contributions in Lianyuan soils. The results showed that the source contributions of the natural source, atmospheric deposition, industrial activities and agricultural activities accounted for 33.6%, 26.05%, 23.44% and 16.91%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spatial and temporal variability of fine particle composition and source types in five cities of Connecticut and Massachusetts.

PubMed

Lee, Hyung Joo; Gent, Janneane F; Leaderer, Brian P; Koutrakis, Petros

2011-05-01

To protect public health from PM(2.5) air pollution, it is critical to identify the source types of PM(2.5) mass and chemical components associated with higher risks of adverse health outcomes. Source apportionment modeling using Positive Matrix Factorization (PMF), was used to identify PM(2.5) source types and quantify the source contributions to PM(2.5) in five cities of Connecticut and Massachusetts. Spatial and temporal variability of PM(2.5) mass, components and source contributions were investigated. PMF analysis identified five source types: regional pollution as traced by sulfur, motor vehicle, road dust, oil combustion and sea salt. The sulfur-related regional pollution and traffic source type were major contributors to PM(2.5). Due to sparse ground-level PM(2.5) monitoring sites, current epidemiological studies are susceptible to exposure measurement errors. The higher correlations in concentrations and source contributions between different locations suggest less spatial variability, resulting in less exposure measurement errors. When concentrations and/or contributions were compared to regional averages, correlations were generally higher than between-site correlations. This suggests that for assigning exposures for health effects studies, using regional average concentrations or contributions from several PM(2.5) monitors is more reliable than using data from the nearest central monitor. Copyright © 2011 Elsevier B.V. All rights reserved.

Open air mineral treatment operations and ambient air quality: assessment and source apportionment.

PubMed

Escudero, M; Alastuey, A; Moreno, T; Querol, X; Pérez, P

2012-11-01

We present a methodology for evaluating and quantifying the impact of inhalable mineral dust resuspension close to a potentially important industrial point source, in this case an open air plant producing sand, flux and kaolin in the Capuchinos district of Alcañiz (Teruel, NE Spain). PM(10) levels at Capuchinos were initially high (42 μg m(-3) as the annual average with 91 exceedances of the EU daily limit value during 2007) but subsequently decreased (26 μg m(-3) with 16 exceedances in 2010) due to a reduced demand for minerals from the ceramic industry and construction sector during the first stages of the economic crisis. Back trajectory and local wind pattern analyses revealed only limited contribution from exotic PM sources such as African dust intrusions whereas there was clearly a strong link with the mineral stockpiles of the local industry. This link was reinforced by chemical and mineral speciation and source apportionment analysis which showed a dominance of mineral matter (sum of CO(3)(2-), SiO(2), Al(2)O(3), Ca, Fe, K, Mg, P, and Ti: mostly aluminosilicates) which in 2007 contributed 76% of the PM(10) mass (44 μg m(-3) on average). The contribution from Secondary Inorganic Aerosols (SIA, sum of SO(4)(2-), NO(3)(-) and NH(4)(+)) reached 8.4 μg m(-3), accounting for 14% of the PM(10) mass, similar to the amount of calcareous road dust estimated to be present (8 μg m(-3); 13%). Organic matter and elemental carbon contributed 5.3 μg m(-3) (9%) whereas marine aerosol (Na + Cl) levels were minor with an average concentration of 0.4 μg m(-3) (1% of the PM(10) mass). Finally, chemical and mineralogical analysis of stockpile samples and comparison with filter samples confirmed the local industry to be the major source of ambient PM(10) in the area.

Echolocation clicks from killer whales (Orcinus orca) feeding on herring (Clupea harengus).

PubMed

Simon, Malene; Wahlberg, Magnus; Miller, Lee A

2007-02-01

Echolocation clicks from Norwegian killer whales feeding on herring schools were recorded using a four-hydrophone array. The clicks had broadband bimodal frequency spectra with low and high frequency peaks at 24 and 108 kHz, respectively. The -10 dB bandwidth was 35 kHz. The average source level varied from 173 to 202 dB re 1 microPa (peak-to-peak) at 1 m. This is considerably lower than source levels described for Canadian killer whales foraging on salmon. It is suggested that biosonar clicks of Norwegian killer whales are adapted for localization of prey with high target strength and acute hearing abilities.

In−Vitro and In−Vivo Noise Analysis for Optical Neural Recording

PubMed Central

Foust, Amanda J.; Schei, Jennifer L.; Rojas, Manuel J.; Rector, David M.

2008-01-01

Laser diodes (LD) are commonly used for optical neural recordings in chronically recorded animals and humans, primarily due to their brightness and small size. However, noise introduced by LDs may counteract the benefits of brightness when compared to low−noise light emitting diodes (LEDs). To understand noise sources in optical recordings, we systematically compared instrument and physiological noise profiles in two recording paradigms. A better understanding of noise sources will help improve optical recordings and make them more practical with fewer averages. We stimulated lobster nerves and rat cortex, then compared the root mean square (RMS) noise and signal−to−noise ratios (SNRs) of data obtained with LED, superluminescent diode (SLD) and LD illumination for different numbers of averages. The LED data exhibited significantly higher SNRs in fewer averages than LD data in all recordings. In the absence of tissue, LED noise increased linearly with intensity, while LD noise increased sharply in the transition to lasing and settled to noise levels significantly higher than the LED’s, suggesting that speckle noise contributed to the LD’s higher noise and lower SNRs. Our data recommend low coherence and portable light sources for in−vivo chronic neural recording applications. PMID:19021365

PUBLIC EXPOSURE TO MULTIPLE RF SOURCES IN GHANA.

PubMed

Deatanyah, P; Abavare, E K K; Menyeh, A; Amoako, J K

2018-03-16

This paper describes an effort to respond to the suggestion in World Health Organization (WHO) research agenda to better quantify potential exposure levels from a range of radiofrequency (RF) sources at 200 public access locations in Ghana. Wide-band measurements were performed-with a spectrum analyser and a log-periodic antenna using three-point spatial averaging method. The overall results represented a maximum of 0.19% of the ICNIRP reference levels for public exposure. These results were generally lower than found in some previous but were 58% (2.0 dB) greater, than found in similar work conducted in the USA. Major contributing sources of RF fields were identified to be FM broadcast and mobile base station sites. Three locations with the greatest measured RF fields could represent potential areas for epidemiological studies.

Investigation of remote sensing techniques as inputs to operational resource management models. [South Dakota

NASA Technical Reports Server (NTRS)

Schmer, F. A. (Principal Investigator); Isakson, R. E.; Eidenshink, J. C.

1977-01-01

The author has identified the following significant results. Successful operational applications of LANDSAT data were found for level 1 land use mapping, drainage network delineation, and aspen mapping. Visual LANDSAT interpretation using 1:125,000 color composite imagery was the least expensive method of obtaining timely level 1 land use data. With an average agricultural/rangeland interpretation accuracy in excess of 80%, such a data source was considered the most cost effective of those sources available to state agencies. Costs do not compare favorably with those incurred using the present method of extracting land use data from historical tabular summaries. The cost increase in advancing from the present procedure to a satellite-based data source was justified in terms of expanded data content.

Chemical composition and source apportionment of size fractionated particulate matter in Cleveland, Ohio, USA.

PubMed

Kim, Yong Ho; Krantz, Q Todd; McGee, John; Kovalcik, Kasey D; Duvall, Rachelle M; Willis, Robert D; Kamal, Ali S; Landis, Matthew S; Norris, Gary A; Gilmour, M Ian

2016-11-01

The Cleveland airshed comprises a complex mixture of industrial source emissions that contribute to periods of non-attainment for fine particulate matter (PM 2.5 ) and are associated with increased adverse health outcomes in the exposed population. Specific PM sources responsible for health effects however are not fully understood. Size-fractionated PM (coarse, fine, and ultrafine) samples were collected using a ChemVol sampler at an urban site (G.T. Craig (GTC)) and rural site (Chippewa Lake (CLM)) from July 2009 to June 2010, and then chemically analyzed. The resulting speciated PM data were apportioned by EPA positive matrix factorization to identify emission sources for each size fraction and location. For comparisons with the ChemVol results, PM samples were also collected with sequential dichotomous and passive samplers, and evaluated for source contributions to each sampling site. The ChemVol results showed that annual average concentrations of PM, elemental carbon, and inorganic elements in the coarse fraction at GTC were ∼2, ∼7, and ∼3 times higher than those at CLM, respectively, while the smaller size fractions at both sites showed similar annual average concentrations. Seasonal variations of secondary aerosols (e.g., high NO 3 - level in winter and high SO 4 2- level in summer) were observed at both sites. Source apportionment results demonstrated that the PM samples at GTC and CLM were enriched with local industrial sources (e.g., steel plant and coal-fired power plant) but their contributions were influenced by meteorological conditions and the emission source's operation conditions. Taken together the year-long PM collection and data analysis provides valuable insights into the characteristics and sources of PM impacting the Cleveland airshed in both the urban center and the rural upwind background locations. These data will be used to classify the PM samples for toxicology studies to determine which PM sources, species, and size fractions are of greatest health concern. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tracking of Pacific walruses in the Chukchi Sea using a single hydrophone.

PubMed

Mouy, Xavier; Hannay, David; Zykov, Mikhail; Martin, Bruce

2012-02-01

The vocal repertoire of Pacific walruses includes underwater sound pulses referred to as knocks and bell-like calls. An extended acoustic monitoring program was performed in summer 2007 over a large region of the eastern Chukchi Sea using autonomous seabed-mounted acoustic recorders. Walrus knocks were identified in many of the recordings and most of these sounds included multiple bottom and surface reflected signals. This paper investigates the use of a localization technique based on relative multipath arrival times (RMATs) for potential behavior studies. First, knocks are detected using a semi-automated kurtosis-based algorithm. Then RMATs are matched to values predicted by a ray-tracing model. Walrus tracks with vertical and horizontal movements were obtained. The tracks included repeated dives between 4.0 m and 15.5 m depth and a deep dive to the sea bottom (53 m). Depths at which bell-like sounds are produced, average knock production rate and source levels estimates of the knocks were determined. Bell sounds were produced at all depths throughout the dives. Average knock production rates varied from 59 to 75 knocks/min. Average source level of the knocks was estimated to 177.6 ± 7.5 dB re 1 μPa peak @ 1 m. © 2012 Acoustical Society of America

Spatial and temporal characteristics of PM2.5 and source apportionment in Wuhan

NASA Astrophysics Data System (ADS)

Hao, Hanzhou; Guo, Qianqian

2018-02-01

In order to study the pollution characteristics and sources of PM2.5, the PM2.5 in Wuhan atmosphere was sampled continuously. Inductively coupled plasma mass spectrometry (ICP-MS) were employed to measure Na, K, Mg, Ca, Al, Mn, Cu, Zn, As, Pb, Cr, Ni, Co, Cd, Fe, V, Ti, Hg, Si, while water soluble ions (Cl-, NO3-, SO4 2-) as well as carbonaceous mass (EC and OC) were analyzed using ion chromatograph(IC) and carbon analyzer, respectively. The results show: (1) In 2014 and 2015, Wuhan PM2.5 values were 81.4μg/m3and 69.2μg/m3 respectively far exceed the national standard level 2, i.e. annual average 35 μg/m3 in China, annual average limit 10 μg/m3 by the World Health Organization, the annual limit of 15 μg/m3 in the United States. (2) Taking Huaqiao and Qihao as research points, the Spring Festival effect of PM2.5 in Wuhan city is analyzed. It shows that the concentration of PM2.5 in 2014 and 2015 is before Spring Festival> during Spring Festival> after Spring Festival. As a backdrop, during the Spring Festival, Qihao PM2.5 concentration than Huaqiao average low 20 μg/m3. (3) The results of positive factor matrix factorization (PMF) analysis show that PM2.5 in Summer in Wuhan mainly comes from the automobile source, soil dust source, biomass combustion, industrial source, secondary aerosol source, combustion coal source, the contribution rate is 37.7%. 25%, 16.4%, 8.1%, 6.5%,6.4%, respectively.

Diurnal variation, vertical distribution and source apportionment of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in Chiang-Mai, Thailand.

PubMed

Pongpiachan, Siwatt

2013-01-01

Diurnal variation of particulate polycyclic aromatic hydrocarbons (PAHs) was investigated by collecting PM10 at three different sampling altitudes using high buildings in the city center of Chiang-Mai, Thailand, during the relatively cold period in late February 2008. At site-1 (12 m above ground level), B[a]P concentrations ranged from 30.3 -1,673 pg m-3 with an average of 506±477 pg m-3, contributing on average, 8.09±8.69% to ?PAHs. Ind and B[b]F concentrations varied from 54.6 to 4,579 pg m-3 and from 80.7 to 2,292 pg m-3 with the highest average of 1,187±1,058 pg m-3 and 963±656 pg m-3, contributing on average, 19.0±19.3% and 15.4±12.0% to ?PAHs, respectively. Morning maxima were predominantly detected in all observatory sites, which can be described by typical diurnal variations of traffic flow in Chiang-Mai City, showing a morning peak between 6 AM. and 9 AM. Despite the fact that most monitoring sites might be subjected to specific-site impacts, it could be seen that PAH profiles in Site-1 and Site-2 were astonishingly homogeneous. The lack of differences suggests that the source signatures of several PAHs become less distinct possibly due to the impacts of traffic and cooking emissions from ground level.

The effect of intermediate-scale motions on line formation. [sawtooth and sine motions in solar atmosphere

NASA Technical Reports Server (NTRS)

Shine, R. A.

1975-01-01

The problem of LTE and non-LTE line formation in the presence of nonthermal velocity fields with geometric scales between the microscopic and macroscopic limits is investigated in the cases of periodic sinusoidal and sawtooth waves. For a fixed source function (the LTE case), it is shown that time-averaged line profiles progress smoothly from the microscopic to the macroscopic limits as the geometric scale of the motions increases, that the sinusoidal motions produce symmetric time-averaged profiles, and that the sawtooth motions cause a redshift. In several idealized non-LTE cases, it is found that intermediate-scale velocity fields can significantly increase the surface source functions and line-core intensities. Calculations are made for a two-level atom in an isothermal atmosphere for a range of velocity scales and non-LTE coupling parameters and also for a two-level atom and a four-level representation of Na I line formation in the Harvard-Smithsonian Reference Atmosphere (1971) solar model. It is found that intermediate-scale velocity fields in the solar atmosphere could explain the central intensities of the Na I D lines and other strong absorption lines without invoking previously suggested high electron densities.

Determination of West Indian manatee vocalization levels and rate

NASA Astrophysics Data System (ADS)

Phillips, Richard; Niezrecki, Christopher; Beusse, Diedrich

2004-05-01

The West Indian manatee (Trichechus manatus latirostris) has become endangered partly because of a growing number of collisions with boats. A system to warn boaters of the presence of manatees, based upon the vocalizations of manatees, could potentially reduce these boat collisions. The feasibility of this warning system would depend mainly upon two factors: the rate at which manatees vocalize and the distance in which the manatees can be detected. The research presented in this paper verifies that the average vocalization rate of the West Indian manatee is approximately one to two times per 5-min period. Several different manatee vocalization recordings were broadcast to the manatees and their response was observed. It was found that during the broadcast periods, the vocalization rates for the manatees increased substantially when compared with the average vocalization rates during nonbroadcast periods. An array of four hydrophones was used while recording the manatees. This allowed for position estimation techniques to be used to determine the location of the vocalizing manatee. Knowing the position of the manatee, the source level was determined and it was found that the mean source level of the manatee vocalizations is approximately 112 dB (re:1 Pa) @ 1 m.

Determination of West Indian manatee vocalization levels and rate

NASA Astrophysics Data System (ADS)

Phillips, Richard; Niezrecki, Christopher; Beusse, Diedrich O.

2004-01-01

The West Indian manatee (Trichechus manatus latirostris) has become endangered partly because of a growing number of collisions with boats. A system to warn boaters of the presence of manatees, based upon the vocalizations of manatees, could potentially reduce these boat collisions. The feasibility of this warning system would depend mainly upon two factors: the rate at which manatees vocalize and the distance in which the manatees can be detected. The research presented in this paper verifies that the average vocalization rate of the West Indian manatee is approximately one to two times per 5-min period. Several different manatee vocalization recordings were broadcast to the manatees and their response was observed. It was found that during the broadcast periods, the vocalization rates for the manatees increased substantially when compared with the average vocalization rates during nonbroadcast periods. An array of four hydrophones was used while recording the manatees. This allowed for position estimation techniques to be used to determine the location of the vocalizing manatee. Knowing the position of the manatee, the source level was determined and it was found that the mean source level of the manatee vocalizations is approximately 112 dB (re 1 μPa) @ 1 m.

Application of the aeroacoustic analogy to a shrouded, subsonic, radial fan

NASA Astrophysics Data System (ADS)

Buccieri, Bryan M.; Richards, Christopher M.

2016-12-01

A study was conducted to investigate the predictive capability of computational aeroacoustics with respect to a shrouded, subsonic, radial fan. A three dimensional unsteady fluid dynamics simulation was conducted to produce aerodynamic data used as the acoustic source for an aeroacoustics simulation. Two acoustic models were developed: one modeling the forces on the rotating fan blades as a set of rotating dipoles located at the center of mass of each fan blade and one modeling the forces on the stationary fan shroud as a field of distributed stationary dipoles. Predicted acoustic response was compared to experimental data measured at two operating speeds using three different outlet restrictions. The blade source model predicted overall far field sound power levels within 5 dB averaged over the six different operating conditions while the shroud model predicted overall far field sound power levels within 7 dB averaged over the same conditions. Doubling the density of the computational fluids mesh and using a scale adaptive simulation turbulence model increased broadband noise accuracy. However, computation time doubled and the accuracy of the overall sound power level prediction improved by only 1 dB.

Marine litter on the beaches of the Adriatic and Ionian Seas: An assessment of their abundance, composition and sources.

PubMed

Vlachogianni, Thomais; Fortibuoni, Tomaso; Ronchi, Francesca; Zeri, Christina; Mazziotti, Cristina; Tutman, Pero; Varezić, Dubravka Bojanić; Palatinus, Andreja; Trdan, Štefan; Peterlin, Monika; Mandić, Milica; Markovic, Olivera; Prvan, Mosor; Kaberi, Helen; Prevenios, Michael; Kolitari, Jerina; Kroqi, Gulielm; Fusco, Marina; Kalampokis, Evangelos; Scoullos, Michael

2018-06-01

The abundance, composition and sources of marine litter were determined on beaches located in the seven countries of the Adriatic-Ionian macroregion, namely Albania, Bosnia and Herzegovina, Croatia, Greece, Italy, Montenegro and Slovenia. A total of 70,581 marine litter items were classified and recorded through one-year long surveys carried out in 31 sites. The average litter density of 0.67 items/m 2 found within this study is considered to be relatively high. The beaches investigated differed in terms of human-induced pressures; their majority is classified either as semi-urban or semi-rural, while very few beaches could be characterized as urban or remote/natural. The majority of litter items were made of artificial/anthropogenic polymer materials accounting for 91.1% of all litter. Litter from shoreline sources accounted for 33.4% of all litter collected. The amount of litter from sea-based sources ranged in the different countries from 1.54% to 14.84%, with an average of 6.30% at regional level. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of interior door position on room-to-room differences in residential pollutant concentrations after short-term releases

NASA Astrophysics Data System (ADS)

Ferro, Andrea R.; Klepeis, Neil E.; Ott, Wayne R.; Nazaroff, William W.; Hildemann, Lynn M.; Switzer, Paul

Residential interior door positions influence the pollutant concentrations that result from short-term indoor sources, such as cigarettes, candles, and incense. To elucidate this influence, we reviewed past studies and conducted new experiments in three residences: a single-story 714 m 3 ranch-style house, a 510 m 3 two-story split-level house, and a 200 m 3 two-story house. During the experiments, we released sulfur hexafluoride or carbon monoxide tracer gas over short periods (≤30 min) and measured concentrations in the source room and at least one other (receptor) room for various interior door opening positions. We found that closing a door between rooms effectively prevented transport of air pollutants, reducing the average concentration in the receptor room relative to the source room by 57-100% over exposure periods of 1-8 h. When intervening doors were partially or fully open, the reduction in average concentrations ranged from 3% to 99%, varying as a function of door opening width and the distance between source and receptor rooms.

Growth and Productivity Response of Hybrid Rice to Application of Animal Manures, Plant Residues and Phosphorus

PubMed Central

Amanullah; Khan, Shams-ul-Tamraiz; Iqbal, Asif; Fahad, Shah

2016-01-01

The objective of this research was to evaluate the impact of organic sources (animal manures vs. plant residues at the rate of 10 t ha−1 each) on the productivity of hybrid rice (Oryza sativa L.) production under different levels of phosphorus (0, 30, 60, and 90 kg P ha−1) fertilization. Two separate field experiments were conducted. In experiment (1), impact of three animal manures sources (cattle, sheep, and poultry manures) and P levels were studied along with one control plot (no animal manure and P applied) was investigated. In experiment (2), three plant residues sources (peach leaves, garlic residues, and wheat straw) and P levels were studied along with one control plot (no plant residues and P applied). Both the experiments were carried out on small land farmer field at District Swabi, Khyber Pakhtunkhwa Province (Northwest Pakistan) during summer 2015. The results revealed that in both experiments the control plot had significantly (p ≤ 0.05) less productivity than the average of all treated plots with organic sources and P level. The increase in P levels in both experiments (animal manure vs. plant residues) resulted in higher rice productivity (90 > 60 > 30 > 0 kg P ha−1). In the experiment under animal manures, application of poultry manure increased rice productivity as compared with sheep and cattle manures (poultry > sheep > cattle manures). In the experiment under plant residues, application of peach leaves or garlic residues had higher rice productivity than wheat straw (peach leaves = garlic residues > wheat straw). On average, rice grown under animal manures produced about 20% higher grain yield than rice grown under crop residues. We conclude from this study that application of 90 kg P ha−1 along with combined application of animal manures, especially poultry manure increases rice productivity. Also, the use of either garlic residues or peach leaves, never applied before as organic manures, can increase crop productivity and will help in degraded soil for sustainable soil management. PMID:27803701

Street-level noise in an urban setting: assessment and contribution to personal exposure.

PubMed

McAlexander, Tara P; Gershon, Robyn R M; Neitzel, Richard L

2015-02-28

The urban soundscape, which represents the totality of noise in the urban setting, is formed from a wide range of sources. One of the most ubiquitous and least studied of these is street-level (i.e., sidewalk) noise. Mainly associated with vehicular traffic, street level noise is hard to ignore and hard to escape. It is also potentially dangerous, as excessive noise from any source is an important risk factor for adverse health effects. This study was conducted to better characterize the urban soundscape and the role of street level noise on overall personal noise exposure in an urban setting. Street-level noise measures were obtained at 99 street sites located throughout New York City (NYC), along with data on time, location, and sources of environmental noise. The relationship between street-level noise measures and potential predictors of noise was analyzed using linear and logistic regression models, and geospatial modeling was used to evaluate spatial trends in noise. Daily durations of street-level activities (time spent standing, sitting, walking and running on streets) were estimated via survey from a sample of NYC community members recruited at NYC street fairs. Street-level noise measurements were then combined with daily exposure durations for each member of the sample to estimate exposure to street noise, as well as exposure to other sources of noise. The mean street noise level was 73.4 dBA, with substantial spatial variation (range 55.8-95.0 dBA). Density of vehicular (road) traffic was significantly associated with excessive street level noise levels. Exposure duration data for street-level noise and other common sources of noise were collected from 1894 NYC community members. Based on individual street-level exposure estimates, and in consideration of all other sources of noise exposure in an urban population, we estimated that street noise exposure contributes approximately 4% to an average individual's annual noise dose. Street-level noise exposure is a potentially important source of overall noise exposure, and the reduction of environmental sources of excessive street- level noise should be a priority for public health and urban planning.

Elemental and iron isotopic composition of aerosols collected in a parking structure.

PubMed

Majestic, Brian J; Anbar, Ariel D; Herckes, Pierre

2009-09-01

The trace metal contents and iron isotope composition of size-resolved aerosols were determined in a parking structure in Tempe, AZ, USA. Particulate matter (PM)<2.5 microm in diameter (the fine fraction) and PM>2.5 microm were collected. Several air toxics (e.g., arsenic, cadmium, and antimony) were enriched above the crustal average, implicating automobiles as an important source. Extremely high levels of fine copper (up to 1000 ng m(-3)) were also observed in the parking garage, likely from brake wear. The iron isotope composition of the aerosols were found to be +0.15+/-0.03 per thousand and +0.18+/-0.03 per thousand for the PM<2.5 microm and PM>2.5 microm fractions, respectively. The similarity of isotope composition indicates a common source for each size fraction. To better understand the source of iron in the parking garage, the elemental composition in four brake pads (two semi-metallic and two ceramic), two tire tread samples, and two waste oil samples were determined. Striking differences in the metallic and ceramic brake pads were observed. The ceramic brake pads contained 10-20% copper by mass, while the metallic brake pads contained about 70% iron, with very little copper. Both waste oil samples contained significant amounts of calcium, phosphorous, and zinc, consistent with the composition of some engine oil additives. Differences in iron isotope composition were observed between the source materials; most notably between the tire tread (average=+0.02 per thousand) and the ceramic brake linings (average=+0.65 per thousand). Differences in isotopic composition were also observed between the metallic (average=+0.18 per thousand) and ceramic brake pads, implying that iron isotope composition may be used to resolve these sources. The iron isotope composition of the metallic brake pads was found to be identical to the aerosols, implying that brake dust is the dominant source of iron in a parking garage.

Effects of source spatial partial coherence on temporal fade statistics of irradiance flux in free-space optical links through atmospheric turbulence.

PubMed

Chen, Chunyi; Yang, Huamin; Zhou, Zhou; Zhang, Weizhi; Kavehrad, Mohsen; Tong, Shoufeng; Wang, Tianshu

2013-12-02

The temporal covariance function of irradiance-flux fluctua-tions for Gaussian Schell-model (GSM) beams propagating in atmospheric turbulence is theoretically formulated by making use of the method of effective beam parameters. Based on this formulation, new expressions for the root-mean-square (RMS) bandwidth of the irradiance-flux temporal spectrum due to GSM beams passing through atmospheric turbulence are derived. With the help of these expressions, the temporal fade statistics of the irradiance flux in free-space optical (FSO) communication systems, using spatially partially coherent sources, impaired by atmospheric turbulence are further calculated. Results show that with a given receiver aperture size, the use of a spatially partially coherent source can reduce both the fractional fade time and average fade duration of the received light signal; however, when atmospheric turbulence grows strong, the reduction in the fractional fade time becomes insignificant for both large and small receiver apertures and in the average fade duration turns inconsiderable for small receiver apertures. It is also illustrated that if the receiver aperture size is fixed, changing the transverse correlation length of the source from a larger value to a smaller one can reduce the average fade frequency of the received light signal only when a threshold parameter in decibels greater than the critical threshold level is specified.

Polycyclic aromatic hydrocarbons (PAHs) in wetland soils under different land uses in a coastal estuary: toxic levels, sources and relationships with soil organic matter and water-stable aggregates.

PubMed

Xiao, Rong; Bai, Junhong; Wang, Junjing; Lu, Qiongqiong; Zhao, Qingqing; Cui, Baoshan; Liu, Xinhui

2014-09-01

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in the soils from industrial, wharf, cropland, milldam and natural wetland sites to characterize their distributions, toxic levels and possible sources in the Pearl River Estuary and identify their relationships with soil organic matter (SOM) and water-stable aggregates (WSAs). Our results indicate that the average concentration of total PAHs in this region reached a moderate pollution level, which was higher than that in other larger estuaries in Asia. The average level of total PAHs in industrial soils was 1.2, 1.5, 1.6 and 2.3 times higher than those in soils from wharf, cropland, milldam and natural wetland sites, respectively. Greater accumulation of PAHs occurred in the middle and/or bottom soil layers where 3-ring PAHs were dominant. Industrial soils also exhibited the highest toxic levels with the highest toxic equivalent concentrations of PAHs, followed by wharf and milldam soils, and the cropland and wetland soils had the lowest toxicity. The diagnostic ratios suggested that PAHs primarily originated from biomass and coal combustion at industrial and milldam sites, and petroleum combustion was determined to be the primary source of PAHs at the wharf, cropland and wetland sites. Both 3-ring and 4-ring PAHs in the milldam and wharf soils were significantly positively correlated with the SOM, whereas the 4,5,6-ring PAHs and total PAHs in industrial soils and the 2-ring PAHs in cropland soils were significantly negatively correlated with the SOM. In addition, large WSAs also exhibited a significant positive correlation with PAHs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Source contributions to PM10 and arsenic concentrations in Central Chile using positive matrix factorization

NASA Astrophysics Data System (ADS)

Hedberg, Emma; Gidhagen, Lars; Johansson, Christer

Sampling of particles (PM10) was conducted during a one-year period at two rural sites in Central Chile, Quillota and Linares. The samples were analyzed for elemental composition. The data sets have undergone source-receptor analyses in order to estimate the sources and their abundance's in the PM10 size fraction, by using the factor analytical method positive matrix factorization (PMF). The analysis showed that PM10 was dominated by soil resuspension at both sites during the summer months, while during winter traffic dominated the particle mass at Quillota and local wood burning dominated the particle mass at Linares. Two copper smelters impacted the Quillota station, and contributed to 10% and 16% of PM10 as an average during summer and winter, respectively. One smelter impacted Linares by 8% and 19% of PM10 in the summer and winter, respectively. For arsenic the two smelters accounted for 87% of the monitored arsenic levels at Quillota and at Linares one smelter contributed with 72% of the measured mass. In comparison with PMF, the use of a dispersion model tended to overestimate the smelter contribution to arsenic levels at both sites. The robustness of the PMF model was tested by using randomly reduced data sets, where 85%, 70%, 50% and 33% of the samples were included. In this way the ability of the model to reconstruct the sources initially found by the original data set could be tested. On average for all sources the relative standard deviation increased from 7% to 25% for the variables identifying the sources, when decreasing the data set from 85% to 33% of the samples, indicating that the solution initially found was very stable to begin with. But it was also noted that sources due to industrial or combustion processes were more sensitive for the size of the data set, compared to the natural sources as local soil and sea spray sources.

Rush-hour aromatic and chlorinated hydrocarbons in selected subway stations of Shanghai, China.

PubMed

Zhang, Yanli; Li, Chunlei; Wang, Xinming; Guo, Hai; Feng, Yanli; Chen, Jianmin

2012-01-01

Air samples were collected simultaneously at platform, mezzanine and outdoor in five typical stations of subway system in Shanghai, China using stainless steel canisters and analyzed by gas chromatography-mass selective detector (GC-MSD) after cryogenic preconcentration. Benzene, toluene, ethylbenzene and xylenes (BTEX) at the platforms and mezzanines inside the stations averaged (10.3 +/- 2.1), (38.7 +/- 9.0), (19.4 +/- 10.1) and (30.0 +/- 11.1) microg/m3, respectively; while trichloroethylene (TrCE), tetrachloroethylene (TeCE) and para-dichlorobenzene (pDCB), vinyl chloride and carbon tetrachloride were the most abundant chlorinated hydrocarbons inside the stations with average levels of (3.6 +/- 1.3), (1.3 +/- 0.5), (4.1 +/- 1.1), (2.2 +/- 1.1) and (1.2 +/- 0.3) microg/m3, respectively. Mean levels of major aromatic and chlorinated hydrocarbons were higher indoor (platforms and mezzanines) than outdoor with average indoor/outdoor (I/O) ratios of 1.1-9.5, whereas no significant indoor/outdoor differences were found except for benzene and TrCE. The highly significant mutual correlations (p < 0.01) for BTEX between indoor and outdoor and their significant correlation (p < 0.05) with methyl tert-butyl ether (MTBE), a marker of traffic-related emission without other indoor and outdoor sources, indicated that BTEX were introduced into the subway stations from indoor/outdoor air exchange and traffic emission should be their dominant source. TrCE and pDCB were mainly from indoor emission and TeCE might have both indoor emission sources and contribution from outdoor air, especially in the mezzanines.

Fine particle receptor modeling in the atmosphere of Mexico City.

PubMed

Vega, Elizabeth; Lowenthal, Douglas; Ruiz, Hugo; Reyes, Elizabeth; Watson, John G; Chow, Judith C; Viana, Mar; Querol, Xavier; Alastuey, Andrés

2009-12-01

Source apportionment analyses were carried out by means of receptor modeling techniques to determine the contribution of major fine particulate matter (PM2.5) sources found at six sites in Mexico City. Thirty-six source profiles were determined within Mexico City to establish the fingerprints of particulate matter sources. Additionally, the profiles under the same source category were averaged using cluster analysis and the fingerprints of 10 sources were included. Before application of the chemical mass balance (CMB), several tests were carried out to determine the best combination of source profiles and species used for the fitting. CMB results showed significant spatial variations in source contributions among the six sites that are influenced by local soil types and land use. On average, 24-hr PM2.5 concentrations were dominated by mobile source emissions (45%), followed by secondary inorganic aerosols (16%) and geological material (17%). Industrial emissions representing oil combustion and incineration contributed less than 5%, and their contribution was higher at the industrial areas of Tlalnepantla (11%) and Xalostoc (8%). Other sources such as cooking, biomass burning, and oil fuel combustion were identified at lower levels. A second receptor model (principal component analysis, [PCA]) was subsequently applied to three of the monitoring sites for comparison purposes. Although differences were obtained between source contributions, results evidence the advantages of the combined use of different receptor modeling techniques for source apportionment, given the complementary nature of their results. Further research is needed in this direction to reach a better agreement between the estimated source contributions to the particulate matter mass.

Spatial relationships between lead sources and children's blood lead levels in the urban center of Indianapolis (USA).

PubMed

Morrison, Deborah; Lin, Qing; Wiehe, Sarah; Liu, Gilbert; Rosenman, Marc; Fuller, Trevor; Wang, Jane; Filippelli, Gabriel

2013-04-01

Urban children remain disproportionately at risk of having higher blood lead levels than their suburban counterparts. The Westside Cooperative Organization (WESCO), located in Marion County, Indianapolis, Indiana, has a history of children with high blood lead levels as well as high soil lead (Pb) values. This study aims at determining the spatial relationship between soil Pb sources and children's blood lead levels. Soils have been identified as a source of chronic Pb exposure to children, but the spatial scale of the source-recipient relationship is not well characterized. Neighborhood-wide analysis of soil Pb distribution along with a furnace filter technique for sampling interior Pb accumulation for selected homes (n = 7) in the WESCO community was performed. Blood lead levels for children aged 0-5 years during the period 1999-2008 were collected. The study population's mean blood lead levels were higher than national averages across all ages, race, and gender. Non-Hispanic blacks and those individuals in the Wishard advantage program had the highest proportion of elevated blood lead levels. The results show that while there is not a direct relationship between soil Pb and children's blood lead levels at a spatial scale of ~100 m, resuspension of locally sourced soil is occurring based on the interior Pb accumulation. County-wide, the largest predictor of elevated blood lead levels is the location within the urban core. Variation in soil Pb and blood lead levels on the community level is high and not predicted by housing stock age or income. Race is a strong predictor for blood lead levels in the WESCO community.

Concentrations of volatile organic compounds, carbon monoxide, carbon dioxide and particulate matter in buses on highways in Taiwan

NASA Astrophysics Data System (ADS)

Hsu, Der-Jen; Huang, Hsiao-Lin

2009-12-01

Although airborne pollutants in urban buses have been studied in many cities globally, long-distance buses running mainly on highways have not been addressed in this regard. This study investigates the levels of volatile organic compounds (VOCs), carbon monoxide (CO), carbon dioxide (CO 2) and particulate matter (PM) in the long-distance buses in Taiwan. Analytical results indicate that pollutants levels in long-distance buses are generally lower than those in urban buses. This finding is attributable to the driving speed and patterns of long-distance buses, as well as the meteorological and geographical features of the highway surroundings. The levels of benzene, toluene, ethylbenzene and xylene (BTEX) found in bus cabins exceed the proposed indoor VOC guidelines for aromatic compounds, and are likely attributable to the interior trim in the cabins. The overall average CO level is 2.3 ppm, with higher average level on local streets (2.9 ppm) than on highways (2.2 ppm). The average CO 2 level is 1493 ppm, which is higher than the guideline for non-industrial occupied settings. The average PM level in this study is lower than those in urban buses and IAQ guidelines set by Taiwan EPA. However, the average PM 10 and PM 2.5 is higher than the level set by WHO. Besides the probable causes mentioned above, fewer passenger movements and less particle re-suspension from bus floor might also cause the lower PM levels. Measurements of particle size distribution reveal that more than 75% of particles are in submicron and smaller sizes. These particles may come from the infiltration from the outdoor air. This study concludes that air exchange rates in long-distance buses should be increased in order to reduce CO 2 levels. Future research on long-distance buses should focus on the emission of VOCs from brand new buses, and the sources of submicron particles in bus cabins.

Understanding Sources and Spatial Patterns of Atmospheric Nitrogen Deposition in the Greater Yellowstone Ecosystem

NASA Astrophysics Data System (ADS)

Hoffman, A.; Williams, D. G.; Albeke, S. E.; McMurray, J. A.

2016-12-01

Increased anthropogenic nitrogen (N) deposition can lead to N saturation of ecosystems, altering water quality, biogeochemical cycling and biodiversity. Although some N deposition (Ndep) is natural, there has been an increase in Ndep in the Greater Yellowstone Ecosystem (GYE), largely due to local and regional intensification of agricultural activity, which releases ammonia (NHx), and transportation and industrial processes, which release nitrogen oxides (NOx). The climate, topography, and sources of Ndep in the region likely create heterogeneous patterns of Ndep in the GYE, where nutrient-limited alpine ecosystems are especially susceptible to Ndep. Epiphytic lichens obtain their nutrients from the air and record local scale patterns of Ndep. The objective of our research was to understand patterns and sources of Ndep in the GYE and multiple spatial scales. We established ion exchange resin (IER) collectors during summer 2016 at 15 sites in the western GYE, where we also collected lichens (Usnea lapponica and Letharia vulpina) to establish the relationship between lichen N and IER N. We then collected lichens from across the GYE to expand the spatial extent of our understanding of variation and sources of Ndep. We expected to find higher levels of Ndep in the southwest GYE due to major agricultural sources of N in the Snake River Plains. Additionally, we expected to find higher Ndep at higher elevations, especially on western slopes, because of increased precipitation due to orographic effects. Finally we expected increased 15N in lichen tissues and IER collections with higher Ndep because anthropogenic sources of N tend to have more 15N than natural sources of nitrogen. U. lapponica samples collected in June 2016 on west facing slopes adjacent to the Snake River Plains had average δ15N values of -10.2±7.8 ‰ and on average contained 1.2±.5 %N (n=9), while those on east facing slopes had average δ15N values of -13.1±1.7 ‰ and on average contained 1.3±.3 % N (n=11). L. vulpina samples from west facing slopes on average contained 1.3±.3 %N and had δ15N values of -13.8±2.3 ‰ (n=12), while those on east facing slopes had 1.3±.3 %N and δ15N values of -11.3±1.5 ‰ (n=6).

Added sugars: consumption and associated factors among adults and the elderly. São Paulo, Brazil.

PubMed

Bueno, Milena Baptista; Marchioni, Dirce Maria Lobo; César, Chester Luis Galvão; Fisberg, Regina Mara

2012-06-01

To investigate added sugar intake, main dietary sources and factors associated with excessive intake of added sugar. A population-based household survey was carried out in São Paulo, the largest city in Brazil. Cluster sampling was performed and the study sample comprised 689 adults and 622 elderly individuals. Dietary intake was estimated based on a 24-hour food recall. Usual nutrient intake was estimated by correcting for the within-person variance of intake using the Iowa State University (ISU) method. Linear regression analysis was conducted to identify factors associated with added sugar intake. Average of energy intake (EI) from added sugars was 9.1% (95% CI: 8.9%; 9.4%) among adults and 8.4% (95% CI: 8.2%; 8.7%) among the elderly (p < 0.05). Average added sugar intake (% EI) was higher among women than among men (p < 0.05). Soft drink was the main source of added sugar among adults, while table sugar was the main source of added sugar among the elderly. Added sugar intake increased with age among adults. Moreover, higher socioeconomic level was associated with added sugar intake in the same group. Added sugar intake is higher among younger adults of higher socioeconomic level. Soft drink and table sugar accounted for more than 50% of the sugar consumed.

Antioxidant intake and cognitive function of elderly men and women: the Cache County Study.

PubMed

Wengreen, H J; Munger, R G; Corcoran, C D; Zandi, P; Hayden, K M; Fotuhi, M; Skoog, I; Norton, M C; Tschanz, J; Breitner, J C S; Welsh-Bohmer, K A

2007-01-01

We prospectively examined associations between intakes of antioxidants (vitamins C, vitamin E, and carotene) and cognitive function and decline among elderly men and women of the Cache County Study on Memory and Aging in Utah. In 1995, 3831 residents 65 years of age or older completed a baseline survey that included a food frequency questionnaire and cognitive assessment. Cognitive function was assessed using an adapted version of the Modified Mini-Mental State examination (3MS) at baseline and at three subsequent follow-up interviews spanning approximately 7 years. Multivariable-mixed models were used to estimate antioxidant nutrient effects on average 3MS score over time. Increasing quartiles of vitamin C intake alone and combined with vitamin E were associated with higher baseline average 3MS scores (p-trend = 0.013 and 0.02 respectively); this association appeared stronger for food sources compared to supplement or food and supplement sources combined. Study participants with lower levels of intake of vitamin C, vitamin E and carotene had a greater acceleration of the rate of 3MS decline over time compared to those with higher levels of intake. High antioxidant intake from food and supplement sources of vitamin C, vitamin E, and carotene may delay cognitive decline in the elderly.

Biases in Long-term NO2 Averages Inferred from Satellite Observations Due to Cloud Selection Criteria

NASA Technical Reports Server (NTRS)

Geddes, Jeffrey A.; Murphy, Jennifer G.; O'Brien, Jason M.; Celarier, Edward A.

2012-01-01

Retrievals of atmospheric trace gas column densities from space are compromised by the presence of clouds, requiring most studies to exclude observations with significant cloud fractions in the instrument's field of view. Using NO2 observations at three ground stations representing urban, suburban, and rural environments, and tropospheric vertical column densities measured by the Ozone Monitoring Instrument (OMI) over each site, we show that the observations from space represent monthly averaged ground-level pollutant conditions well (R=0.86) under relatively cloud-free conditions. However, by analyzing the ground-level data and applying the OMI cloud fraction as a filter, we show there is a significant bias in long-term averaged NO2 as a result of removing the data during cloudy conditions. For the ground-based sites considered in this study, excluding observations on days when OMI-derived cloud fractions were greater than 0.2 causes 12:00-14:00 mean summer mixing ratios to be underestimated by 12%+/-6%, 20%+/-7%, and 40%+/-10% on average (+/-1 standard deviation) at the urban, suburban, and rural sites respectively. This bias was investigated in particular at the rural site, a region where pollutant transport is the main source of NO2, and where longterm observations of NOy were also available. Evidence of changing photochemical conditions and a correlation between clear skies and the transport of cleaner air masses play key roles in explaining the bias. The magnitude of a bias is expected to vary from site to site depending on meteorology and proximity to NOx sources, and decreases when longer averaging times of ground station data (e.g. 24-h) are used for the comparison.

Consumption of freshwater fish in Kahnawake: risks and benefits.

PubMed

Chan, H M; Trifonopoulos, M; Ing, A; Receveur, O; Johnson, E

1999-02-01

Kahnawake is a Mohawk community located on the south shore of the Saint Lawrence River near Montreal. A comprehensive study was conducted in 1996-1997 to address the local concern regarding health risks of contaminant exposure associated with freshwater fish consumption. Forty-two participants, including most of the identified active fishermen (n=33), were interviewed. Walleye, perch, bullhead, and smallmouth bass were the species most consumed. Average daily intake of locally caught fish was 23 g/day. Nutrient and contaminant levels of locally collected fish were analyzed. Fish were good sources of protein, polyunsaturated fatty acids (particularly omega-3 fatty acids), calcium, zinc, and iron. Levels of cadmium, lead, arsenic, polychlorinated biphenyls (PCBs), and other chlorinated pesticides were at least 10 times lower than the guideline levels. Mercury levels of some predatory fish exceeded the guideline of 0.5 microgram/g. Average daily intakes of all contaminants were below the guideline levels by a factor of 10 except for mercury. Average mercury intake rate was about one-third that of the guideline level (200 micrograms/week). Contrary to residents' perception, Kahnawake fish were not particularly contaminated. In view of the nutritional as well as cultural benefits, fishing and fish consumption may be promoted. Copyright 1999 Academic Press.

Readability analysis of internet-based patient information regarding skull base tumors.

PubMed

Misra, Poonam; Kasabwala, Khushabu; Agarwal, Nitin; Eloy, Jean Anderson; Liu, James K

2012-09-01

Readability is an important consideration in assessing healthcare-related literature. In order for a source of information to be the most beneficial to patients, it should be written at a level appropriate for the audience. The National Institute of Health recommends that health literature be written at a maximum level of sixth grade. This is not uniformly found in current health literature, putting patients with lower reading levels at a disadvantage. In February 2012, healthcare-oriented education resources were retrieved from websites obtained using the Google search phrase skull base tumors. Of the first 25 consecutive, unique website hits, 18 websites were found to contain information for patients. Ten different assessment scales were utilized to assess the readability of the patient-specific web pages. Patient-oriented material found online for skull base tumors was written at a significantly higher level than the reading level of the average US patient. The average reading level of this material was found to be at a minimum of eleventh grade across all ten scales. Health related material related to skull base tumors available through the internet can be improved to reach a larger audience without sacrificing the necessary information. Revisions of this material can provide significant benefit for average patients and improve their health care.

Oral health literacy and information sources among adults in Tehran, Iran.

PubMed

Sistani, M M Naghibi; Yazdani, R; Virtanen, J; Pakdaman, A; Murtomaa, H

2013-09-01

To assess oral health literacy level and oral health information of Iranian adults in Tehran, and to determine the factors related to oral health literacy. A cross-sectional population study. A random sample of 1,031 adults in Tehran, Iran. Oral health literacy was measured using an oral health adult literacy questionnaire (OHL-AQ). Variation in use of information sources by socio-economic and demographic background was estimated by odds ratios. A multiple linear regression model served to determine predictor factors of OHL-AQ scores controlling for characteristics of the subjects and number of information sources. The mean OHL-AQ score was 10.5 (sd 3.0). Women (p < 0.001), younger (p < 0.001), and better educated participants (p < 0.001) had higher OHL-AQ scores. The most common sources of oral health information were dentists (52.6%), and TV/Radio (49.5%). According to the regression model, females (p = 0.001), high educational level (p < 0.001), and use of multiple information sources (two sources p = 0.01, three sources or more p = 0.002) were the main predictor factors of OHL-AQ scores. The average oral health literacy level of Iranian adults was low. Disseminating evidence-based oral health care information from multiple sources including TV/radio, dentists, and other health professionals in different settings should improve public oral health literacy.

Hydrostatic temperature calculations. [in synoptic meteorology

NASA Technical Reports Server (NTRS)

Raymond, William H.

1987-01-01

Comparisons are made between hydrostatically computed temperatures and ambient temperatures associated with nine different data sources, including analyses, forecasts and conventional observations. Five-day averages and the day-to-day variations in the root-mean-square temperature differences are presented. Several different numerical and interpolation procedures are examined. Error correction and a constrained optimum procedure that minimizes ambient minus calculated hydrostatic temperature differences are introduced. Systematic differences between ambient and hydrostatic temperatures are found to be associated with the sinoptic situation. When compared with ambient temperatures, hydrostatic temperatures at 500 mb tend to be too warm at or in front of a trough and too cold behind the trough. In the vertical direction, for the eight-level configuration tested, the average hydrostatic temperatures are too cold at low levels (850, 700 mb) and too warm at upper levels, (300, 250 mb).

A new multi-spectral feature level image fusion method for human interpretation

NASA Astrophysics Data System (ADS)

Leviner, Marom; Maltz, Masha

2009-03-01

Various different methods to perform multi-spectral image fusion have been suggested, mostly on the pixel level. However, the jury is still out on the benefits of a fused image compared to its source images. We present here a new multi-spectral image fusion method, multi-spectral segmentation fusion (MSSF), which uses a feature level processing paradigm. To test our method, we compared human observer performance in a three-task experiment using MSSF against two established methods: averaging and principle components analysis (PCA), and against its two source bands, visible and infrared. The three tasks that we studied were: (1) simple target detection, (2) spatial orientation, and (3) camouflaged target detection. MSSF proved superior to the other fusion methods in all three tests; MSSF also outperformed the source images in the spatial orientation and camouflaged target detection tasks. Based on these findings, current speculation about the circumstances in which multi-spectral image fusion in general and specific fusion methods in particular would be superior to using the original image sources can be further addressed.

High-average-power 2 μm few-cycle optical parametric chirped pulse amplifier at 100 kHz repetition rate.

PubMed

Shamir, Yariv; Rothhardt, Jan; Hädrich, Steffen; Demmler, Stefan; Tschernajew, Maxim; Limpert, Jens; Tünnermann, Andreas

2015-12-01

Sources of long wavelengths few-cycle high repetition rate pulses are becoming increasingly important for a plethora of applications, e.g., in high-field physics. Here, we report on the realization of a tunable optical parametric chirped pulse amplifier at 100 kHz repetition rate. At a central wavelength of 2 μm, the system delivered 33 fs pulses and a 6 W average power corresponding to 60 μJ pulse energy with gigawatt-level peak powers. Idler absorption and its crystal heating is experimentally investigated for a BBO. Strategies for further power scaling to several tens of watts of average power are discussed.

Assessment of general public exposure to LTE and RF sources present in an urban environment.

PubMed

Joseph, Wout; Verloock, Leen; Goeminne, Francis; Vermeeren, Günter; Martens, Luc

2010-10-01

For the first time, in situ electromagnetic field exposure of the general public to fields from long term evolution (LTE) cellular base stations is assessed. Exposure contributions due to different radiofrequency (RF) sources are compared with LTE exposure at 30 locations in Stockholm, Sweden. Total exposures (0.2-2.6 V/m) satisfy the International Commission on Non-Ionizing Radiation Protection (ICNIRP) reference levels (from 28 V/m for frequency modulation (FM), up to 61 V/m for LTE) at all locations. LTE exposure levels up to 0.8 V/m were measured, and the average contribution of the LTE signal to the total RF exposure equals 4%.

Pilot survey of subway and bus stop noise levels.

PubMed

Gershon, Robyn R M; Neitzel, Richard; Barrera, Marissa A; Akram, Muhammad

2006-09-01

Excessive noise exposure is a serious global urban health problem, adversely affecting millions of people. One often cited source of urban noise is mass transit, particularly subway systems. As a first step in determining risk within this context, we recently conducted an environmental survey of noise levels of the New York City transit system. Over 90 noise measurements were made using a sound level meter. Average and maximum noise levels were measured on subway platforms, and maximum levels were measured inside subway cars and at several bus stops for comparison purposes. The average noise level measured on the subway platforms was 86 +/- 4 dBA (decibel-A weighting). Maximum levels of 106, 112, and 89 dBA were measured on subway platforms, inside subway cars, and at bus stops, respectively. These results indicate that noise levels in subway and bus stop environments have the potential to exceed recommended exposure guidelines from the World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA), given sufficient exposure duration. Risk reduction strategies following the standard hierarchy of control measures should be applied, where feasible, to reduce subway noise exposure.

Using an epiphytic moss to identify previously unknown sources of atmospheric cadmium pollution.

PubMed

Donovan, Geoffrey H; Jovan, Sarah E; Gatziolis, Demetrios; Burstyn, Igor; Michael, Yvonne L; Amacher, Michael C; Monleon, Vicente J

2016-07-15

Urban networks of air-quality monitors are often too widely spaced to identify sources of air pollutants, especially if they do not disperse far from emission sources. The objectives of this study were to test the use of moss bio-indicators to develop a fine-scale map of atmospherically-derived cadmium and to identify the sources of cadmium in a complex urban setting. We collected 346 samples of the moss Orthotrichum lyellii from deciduous trees in December, 2013 using a modified randomized grid-based sampling strategy across Portland, Oregon. We estimated a spatial linear model of moss cadmium levels and predicted cadmium on a 50m grid across the city. Cadmium levels in moss were positively correlated with proximity to two stained-glass manufacturers, proximity to the Oregon-Washington border, and percent industrial land in a 500m buffer, and negatively correlated with percent residential land in a 500m buffer. The maps showed very high concentrations of cadmium around the two stained-glass manufacturers, neither of which were known to environmental regulators as cadmium emitters. In addition, in response to our findings, the Oregon Department of Environmental Quality placed an instrumental monitor 120m from the larger stained-glass manufacturer in October, 2015. The monthly average atmospheric cadmium concentration was 29.4ng/m(3), which is 49 times higher than Oregon's benchmark of 0.6ng/m(3), and high enough to pose a health risk from even short-term exposure. Both stained-glass manufacturers voluntarily stopped using cadmium after the monitoring results were made public, and the monthly average cadmium levels precipitously dropped to 1.1ng/m(3) for stained-glass manufacturer #1 and 0.67ng/m(3) for stained-glass manufacturer #2. Published by Elsevier B.V.

Characteristics of carbonyls: Concentrations and source strengths for indoor and outdoor residential microenvironments in China

NASA Astrophysics Data System (ADS)

Wang, B.; Lee, S. C.; Ho, K. F.

Indoor and outdoor carbonyl concentrations were measured simultaneously in 12 urban dwellings in Beijing, Shanghai, Guangzhou, and Xi'an, China in summer (from July to September in 2004) and winter (from December 2004 to February 2005). Formaldehyde was the most abundant indoor carbonyls species, while formaldehyde, acetaldehyde and acetone were found to be the most abundant outdoor carbonyls species. The average formaldehyde concentrations in summer indoor air varied widely between cities, ranging from a low of 19.3 μg m -3 in Xi'an to a high of 92.8 μg m -3 in Beijing. The results showed that the dwellings with tobacco smoke, incense burning or poor ventilation had significantly higher indoor concentrations of certain carbonyls. It was noticed that although one half of the dwellings in this study installed with low emission building materials or furniture, the carbonyls levels were still significantly high. It was also noted that in winter both the indoor and outdoor acetone concentrations in two dwellings in Guangzhou were significantly high, which were mainly caused by the usage of acetone as industrial solvent in many paint manufacturing and other industries located around Guangzhou and relatively longer lifetime of acetone for removal by photolysis and OH reaction than other carbonyls species. The indoor carbonyls levels in Chinese dwellings were higher than that in dwellings in the other countries. The levels of indoor and ambient carbonyls showed great seasonal differences. Six carbonyls species were carried out the estimation of indoor source strengths. Formaldehyde had the largest indoor source strength, with an average of 5.25 mg h -1 in summer and 1.98 mg h -1 in winter, respectively. However, propionaldehyde, crotonaldehyde and benzaldehyde had the weakest indoor sources.

Hearing Sensation Levels of Emitted Biosonar Clicks in an Echolocating Atlantic Bottlenose Dolphin

PubMed Central

Li, Songhai; Nachtigall, Paul E.; Breese, Marlee; Supin, Alexander Ya.

2012-01-01

Emitted biosonar clicks and auditory evoked potential (AEP) responses triggered by the clicks were synchronously recorded during echolocation in an Atlantic bottlenose dolphin (Tursiops truncatus) trained to wear suction-cup EEG electrodes and to detect targets by echolocation. Three targets with target strengths of −34, −28, and −22 dB were used at distances of 2 to 6.5 m for each target. The AEP responses were sorted according to the corresponding emitted click source levels in 5-dB bins and averaged within each bin to extract biosonar click-related AEPs from noise. The AEP amplitudes were measured peak-to-peak and plotted as a function of click source levels for each target type, distance, and target-present or target-absent condition. Hearing sensation levels of the biosonar clicks were evaluated by comparing the functions of the biosonar click-related AEP amplitude-versus-click source level to a function of external (in free field) click-related AEP amplitude-versus-click sound pressure level. The results indicated that the dolphin's hearing sensation levels to her own biosonar clicks were equal to that of external clicks with sound pressure levels 16 to 36 dB lower than the biosonar click source levels, varying with target type, distance, and condition. These data may be assumed to indicate that the bottlenose dolphin possesses effective protection mechanisms to isolate the self-produced intense biosonar beam from the animal's ears during echolocation. PMID:22238654

Hearing sensation levels of emitted biosonar clicks in an echolocating Atlantic bottlenose dolphin.

PubMed

Li, Songhai; Nachtigall, Paul E; Breese, Marlee; Supin, Alexander Ya

2012-01-01

Emitted biosonar clicks and auditory evoked potential (AEP) responses triggered by the clicks were synchronously recorded during echolocation in an Atlantic bottlenose dolphin (Tursiops truncatus) trained to wear suction-cup EEG electrodes and to detect targets by echolocation. Three targets with target strengths of -34, -28, and -22 dB were used at distances of 2 to 6.5 m for each target. The AEP responses were sorted according to the corresponding emitted click source levels in 5-dB bins and averaged within each bin to extract biosonar click-related AEPs from noise. The AEP amplitudes were measured peak-to-peak and plotted as a function of click source levels for each target type, distance, and target-present or target-absent condition. Hearing sensation levels of the biosonar clicks were evaluated by comparing the functions of the biosonar click-related AEP amplitude-versus-click source level to a function of external (in free field) click-related AEP amplitude-versus-click sound pressure level. The results indicated that the dolphin's hearing sensation levels to her own biosonar clicks were equal to that of external clicks with sound pressure levels 16 to 36 dB lower than the biosonar click source levels, varying with target type, distance, and condition. These data may be assumed to indicate that the bottlenose dolphin possesses effective protection mechanisms to isolate the self-produced intense biosonar beam from the animal's ears during echolocation.

Group Analysis in FieldTrip of Time-Frequency Responses: A Pipeline for Reproducibility at Every Step of Processing, Going From Individual Sensor Space Representations to an Across-Group Source Space Representation.

PubMed

Andersen, Lau M

2018-01-01

An important aim of an analysis pipeline for magnetoencephalographic (MEG) data is that it allows for the researcher spending maximal effort on making the statistical comparisons that will answer his or her questions. The example question being answered here is whether the so-called beta rebound differs between novel and repeated stimulations. Two analyses are presented: going from individual sensor space representations to, respectively, an across-group sensor space representation and an across-group source space representation. The data analyzed are neural responses to tactile stimulations of the right index finger in a group of 20 healthy participants acquired from an Elekta Neuromag System. The processing steps covered for the first analysis are MaxFiltering the raw data, defining, preprocessing and epoching the data, cleaning the data, finding and removing independent components related to eye blinks, eye movements and heart beats, calculating participants' individual evoked responses by averaging over epoched data and subsequently removing the average response from single epochs, calculating a time-frequency representation and baselining it with non-stimulation trials and finally calculating a grand average, an across-group sensor space representation. The second analysis starts from the grand average sensor space representation and after identification of the beta rebound the neural origin is imaged using beamformer source reconstruction. This analysis covers reading in co-registered magnetic resonance images, segmenting the data, creating a volume conductor, creating a forward model, cutting out MEG data of interest in the time and frequency domains, getting Fourier transforms and estimating source activity with a beamformer model where power is expressed relative to MEG data measured during periods of non-stimulation. Finally, morphing the source estimates onto a common template and performing group-level statistics on the data are covered. Functions for saving relevant figures in an automated and structured manner are also included. The protocol presented here can be applied to any research protocol where the emphasis is on source reconstruction of induced responses where the underlying sources are not coherent.

Estimation of the local and long-range contributions to particulate matter levels using continuous measurements in a single urban background site

NASA Astrophysics Data System (ADS)

Diamantopoulou, Marianna; Skyllakou, Ksakousti; Pandis, Spyros N.

2016-06-01

The Particulate Matter Source Apportionment Technology (PSAT) algorithm is used together with PMCAMx, a regional chemical transport model, to develop a simple observation-based method (OBM) for the estimation of local and regional contributions of sources of primary and secondary pollutants in urban areas. We test the hypothesis that the minimum of the diurnal average concentration profile of the pollutant is a good estimate of the average contribution of long range transport levels. We use PMCAMx to generate "pseudo-observations" for four different European cities (Paris, London, Milan, and Dusseldorf) and PSAT to estimate the corresponding "true" local and regional contributions. The predictions of the proposed OBM are compared to the "true" values for different definitions of the source area. During winter, the estimates by the OBM for the local contributions to the concentrations of total PM2.5, primary pollutants, and sulfate are within 25% of the "true" contributions of the urban area sources. For secondary organic aerosol the OBM overestimates the importance of the local sources and it actually estimates the contributions of sources within 200 km from the receptor. During summer for primary pollutants and cities with low nearby emissions (ratio of emissions in an area extending 100 km from the city over local emissions lower than 10) the OBM estimates correspond to the city emissions within 25% or so. For cities with relatively high nearby emissions the OBM estimates correspond to emissions within 100 km from the receptor. For secondary PM2.5 components like sulfate and secondary organic aerosol the OBM's estimates correspond to sources within 200 km from the receptor. Finally, for total PM2.5 the OBM provides approximately the contribution of city emissions during the winter and the contribution of sources within 100 km from the receptor during the summer.

Airborne measurements of ethene from industrial sources using laser photo-acoustic spectroscopy.

PubMed

De Gouw, J A; te Lintel Hekkert, S; Mellqvist, J; Warneke, C; Atlas, E L; Fehsenfeld, F C; Fried, A; Frost, G J; Harren, F J M; Holloway, J S; Lefer, B; Lueb, R; Meagher, J F; Parrish, D D; Patel, M; Pope, L; Richter, D; Rivera, C; Ryerson, T B; Samuelsson, J; Walega, J; Washenfelder, R A; Weibring, P; Zhu, X

2009-04-01

A laser photoacoustic spectroscopy (LPAS) instrument was developed and used for aircraft measurements of ethene from industrial sources near Houston, Texas. The instrument provided 20 s measurements with a detection limit of less than 0.7 ppbv. Data from this instrument and from the GC-FID analysis of air samples collected in flight agreed within 15% on average. Ethene fluxes from the Mt. Belvieu chemical complex to the northeast of Houston were quantified during 10 different flights. The average flux was 520 +/- 140 kg h(-1) in agreement with independent results from solar occultation flux (SOF) measurements, and roughly an order of magnitude higher than regulatory emission inventories indicate. This study shows that ethene emissions are routinely at levels that qualify as emission upsets, which need to be reported to regional air quality managers.

Measurement of greenhouse gas emissions from agricultural sites using open-path optical remote sensing method.

PubMed

Ro, Kyoung S; Johnson, Melvin H; Varma, Ravi M; Hashmonay, Ram A; Hunt, Patrick

2009-08-01

Improved characterization of distributed emission sources of greenhouse gases such as methane from concentrated animal feeding operations require more accurate methods. One promising method is recently used by the USEPA. It employs a vertical radial plume mapping (VRPM) algorithm using optical remote sensing techniques. We evaluated this method to estimate emission rates from simulated distributed methane sources. A scanning open-path tunable diode laser was used to collect path-integrated concentrations (PICs) along different optical paths on a vertical plane downwind of controlled methane releases. Each cycle consists of 3 ground-level PICs and 2 above ground PICs. Three- to 10-cycle moving averages were used to reconstruct mass equivalent concentration plum maps on the vertical plane. The VRPM algorithm estimated emission rates of methane along with meteorological and PIC data collected concomitantly under different atmospheric stability conditions. The derived emission rates compared well with actual released rates irrespective of atmospheric stability conditions. The maximum error was 22 percent when 3-cycle moving average PICs were used; however, it decreased to 11% when 10-cycle moving average PICs were used. Our validation results suggest that this new VRPM method may be used for improved estimations of greenhouse gas emission from a variety of agricultural sources.

Source of atmospheric heavy metals in winter in Foshan, China.

PubMed

Tan, Ji-Hua; Duan, Jing-Chun; Ma, Yong-Liang; Yang, Fu-Mo; Cheng, Yuan; He, Ke-Bin; Yu, Yong-Chang; Wang, Jie-Wen

2014-09-15

Foshan is a ceramics manufacturing center in the world and the most polluted city in the Pearl River Delta (PRD) in southern China measured by the levels of atmospheric heavy metals. PM2.5 samples were collected in Foshan in winter 2008. Among the 22 elements and ions analyzed, 7 heavy metals (Zn, V, Mn, Cu, As, Cd and Pb) were studied in depth for their levels, spatiotemporal variations and sources. The ambient concentrations of the heavy metals were much higher than the reported average concentrations in China. The levels of Pb (675.7 ± 378.5 ng/m(3)), As (76.6 ± 49.1 ng/m(3)) and Cd (42.6 ± 45.2 ng/m(3)) exceeded the reference values of NAAQS (GB3095-2012) and the health guidelines of the World Health Organization. Generally, the levels of atmospheric heavy metals showed spatial distribution as: downtown site (CC, Chancheng District)>urban sites (NH and SD, Nanhai and Shunde Districts)>rural site (SS, Shanshui District). Two sources of heavy metals, the ceramic and aluminum industries, were identified during the sampling period. The large number of ceramic manufactures was responsible for the high levels of atmospheric Zn, Pb and As in Chancheng District. Transport from an aluminum industry park under light north-west winds contributed high levels of Cd to the SS site (Shanshui District). The average concentration of Cd under north-west wind was 220 ng/m(3), 20.5 times higher than those under other wind directions. The high daily maximum enrichment factors (EFs) of Cd, Pb, Zn, As and Cu at all four sites indicated extremely high contamination by local emissions. Back trajectory analysis showed that the heavy metals were also closely associated with the pathway of air mass. A positive matrix factorization (PMF) method was applied to determine the source apportionment of these heavy metals. Five factors (industry including the ceramic industry and coal combustion, vehicle emissions, dust, transportation and sea salt) were identified and industry was the most important source of atmospheric heavy metals. The present paper suggests a control policy on the four heavy metals Cd, Pb, Zn, and Cu, and suggests the inclusion of As in the ceramic industry emission standard in the future. Copyright © 2014 Elsevier B.V. All rights reserved.

Spatial variation in environmental noise and air pollution in New York City.

PubMed

Kheirbek, Iyad; Ito, Kazuhiko; Neitzel, Richard; Kim, Jung; Johnson, Sarah; Ross, Zev; Eisl, Holger; Matte, Thomas

2014-06-01

Exposure to environmental noise from traffic is common in urban areas and has been linked to increased risks of adverse health effects including cardiovascular disease. Because traffic sources also produce air pollutants that increase the risk of cardiovascular morbidity, associations between traffic exposures and health outcomes may involve confounding and/or synergisms between air pollution and noise. While prior studies have characterized intraurban spatial variation in air pollution in New York City (NYC), limited data exists on the levels and spatial variation in noise levels. We measured 1-week equivalent continuous sound pressure levels (Leq) at 56 sites during the fall of 2012 across NYC locations with varying traffic intensity and building density that are routinely monitored for combustion-related air pollutants. We evaluated correlations among several noise metrics used to characterize noise exposures, including Leq during different time periods (night, day, weekday, weekend), Ldn (day-night noise), and measures of intermittent noise defined as the ratio of peak levels to median and background levels. We also examined correlations between sound pressure levels and co-located simultaneous measures of nitric oxide (NO), nitrogen dioxide (NO2), fine particulate matter (PM2.5), and black carbon (BC) as well as estimates of traffic and building density around the monitoring sites. Noise levels varied widely across the 56 monitoring sites; 1-week Leq varied by 21.6 dBA (range 59.1-80.7 dBA) with the highest levels observed during the weekday, daytime hours. Indices of average noise were well correlated with each other (r > 0.83), while indices of intermittent noise were not well correlated with average noise levels (r < 0.41). One-week Leq correlated well with NO, NO2, and EC levels (r = 0.61 to 0.68) and less so with PM2.5 levels (r = 0.45). We observed associations between 1-week noise levels and traffic intensity within 100 m of the monitoring sites (r = 0.58). The high levels of noise observed in NYC often exceed recommended guidelines for outdoor and personal exposures, suggesting unhealthy levels in many locations. Associations between noise, traffic, and combustion air pollutants suggest the possibility for confounding and/or synergism in intraurban epidemiological studies of traffic-related health effects. The different spatial pattern of intermittent noise compared to average noise level may suggest different sources.

E-Waste Informal Recycling: An Emerging Source of Lead Exposure in South America

PubMed Central

Pascale, Antonio; Sosa, Adriana; Bares, Cristina; Battocletti, Alejandra; Moll, María José; Pose, Darío; Laborde, Amalia; González, Hugo; Feola, Gabriella

2016-01-01

BACKGROUND Primitive electronic waste (e-waste) recycling creates exposures to several hazardous substances including lead. In Uruguay, primitive recycling procedures are a significant source of lead exposure. OBJECTIVES The aim of this study was to examine lead exposure in blood lead levels (BLLs) in low-income children exposed to lead through burning cables. METHODS A sample of children and adolescents exposed to lead through burning cable activities were assessed at the Department of Toxicology in Montevideo, Uruguay, between 2010 and 2014. Soil lead levels of residences were taken shortly after their assessment. FINDINGS The final sample included 69 children and adolescents (mean age 7.89 years). More than 66% of participants had an additional source of lead exposure—manual gathering of metals—and <5% were exposed to lead through landfills or paint. Average BLLs at first consultation were 9.19 ug/dL and lower at the second measurement (5.86 μg/dL). Data from soil lead levels ranged from 650 to 19,000 mg of lead/kg of soil. The interventions conducted after the assessment included family education in the clinic and at home, indoor and outdoor remediation. We found a decrease in BLLs of 6.96 μg/dL. Older children had lower BLLs (r = −0.24; P =0.05). Statistical analyses also showed that children living in areas with higher soil lead levels had significantly higher BLLs (r = 0.50; P < 0.01). Additionally, we found greater BLLs from burning cable activities when children had been exposed to lead-based paint (r = 0.23; P < 0.1). CONCLUSION Among children exposed to e-waste recycling, the most common additional source of lead exposure was the manual gathering of metals. The average BLL among children and adolescents in this study is higher than the BLLs currently suggested in medical intervention. Future research should focus on exploring effective interventions to reduce lead exposure among this vulnerable group. PMID:27325077

Are modern contraceptives acceptable to people and where do they source them from across Nigeria?

PubMed

Onwujekwe, Obinna E; Enemuoh, Jane C; Ogbonna, Chinwe; Mbachu, Chinyere; Uzochukwu, Benjamin Sc; Lawson, Agathe; Ndyanabangi, Bannet

2013-01-23

Understanding the extent that different modern contraceptives are acceptable to different populations groups and where they get the commodities from will help in developing specific interventions that will help to scale-up the availability of the contraceptives. The study took place in urban and rural sites in six states across Nigeria. Data on acceptability and sources of the contraceptives was collected from at least 770 randomly selected mostly female householders from each state respectively using a questionnaire. Acceptability of the different contraceptives was scored by the respondents on a scale of 1 (lowest) to 10 (highest). The relationships between acceptability and sources of the contraceptives with socio-economic status and geographic location of the respondents were examined. The use of modern contraceptives in general was acceptable to 87% of the respondents. Male condom was the most acceptable means of contraceptive with an average score of 5.0. It was followed by implants with and oral contraceptive pill with average scores of 4.0, whilst IUD was the least acceptable with an average score of 2.9. The private sector was the major source of contraceptives to different population groups. Both male and female condoms were mostly procured from patent medicine dealers (PMD) and pharmacy shops. Intra Uterine Devices (IUDs) and implants were mostly sourced from public and private hospitals in the urban areas, whilst injectibles were mostly sourced from private hospitals. Oral contraceptives were mostly sourced from pharmacy shops and patent medicine dealers. There were SES and geographic differences for both acceptability and sources of the contraceptives. Also, the sources of different contraceptives depended on the type of the contraceptive. The different contraceptives were acceptable to the respondents and the major source of the contraceptives was the private sector. Hence, public-private partnership arrangements should be explored so that universal coverage with contraceptives could be easily achieved. Interventions should be developed to eliminate the inequities in both acceptability and sources of different contraceptives. The acceptability of all the contraceptives should be enhanced with relevant behaviour change communication interventions especially in areas with the lowest levels of acceptability.

Are modern contraceptives acceptable to people and where do they source them from across Nigeria?

PubMed Central

2013-01-01

Background Understanding the extent that different modern contraceptives are acceptable to different populations groups and where they get the commodities from will help in developing specific interventions that will help to scale-up the availability of the contraceptives. Methods The study took place in urban and rural sites in six states across Nigeria. Data on acceptability and sources of the contraceptives was collected from at least 770 randomly selected mostly female householders from each state respectively using a questionnaire. Acceptability of the different contraceptives was scored by the respondents on a scale of 1 (lowest) to 10 (highest). The relationships between acceptability and sources of the contraceptives with socio-economic status and geographic location of the respondents were examined. Results The use of modern contraceptives in general was acceptable to 87% of the respondents. Male condom was the most acceptable means of contraceptive with an average score of 5.0. It was followed by implants with and oral contraceptive pill with average scores of 4.0, whilst IUD was the least acceptable with an average score of 2.9. The private sector was the major source of contraceptives to different population groups. Both male and female condoms were mostly procured from patent medicine dealers (PMD) and pharmacy shops. Intra Uterine Devices (IUDs) and implants were mostly sourced from public and private hospitals in the urban areas, whilst injectibles were mostly sourced from private hospitals. Oral contraceptives were mostly sourced from pharmacy shops and patent medicine dealers. There were SES and geographic differences for both acceptability and sources of the contraceptives. Also, the sources of different contraceptives depended on the type of the contraceptive. Conclusion The different contraceptives were acceptable to the respondents and the major source of the contraceptives was the private sector. Hence, public-private partnership arrangements should be explored so that universal coverage with contraceptives could be easily achieved. Interventions should be developed to eliminate the inequities in both acceptability and sources of different contraceptives. The acceptability of all the contraceptives should be enhanced with relevant behaviour change communication interventions especially in areas with the lowest levels of acceptability. PMID:23343579

Assessment of natural radioactivity in aquifer medium bearing uranium ores in Koprubasi, Turkey

NASA Astrophysics Data System (ADS)

Simsek, Celalettin

2008-10-01

Koprubasi, located within Manisa Province near the Izmir, is the biggest uranium mine where uranium ores originate from Neogene aged altered sandstone and conglomerate layers. The main objective of this study is to determine the radiation hazard associated with radioactivity levels of uranium ores, and the rocks and sediments around Koprubasi. In this regard, measured activity levels of 226Ra, 232Th and 40K were compared with world averages. The average activity levels of 226 Ra, 232Th and 40K were measured to be 5369.75, 124.78 and 10.0 Bq/kg in uranium ores, 24.32, 52.94 and 623.38 Bq/kg in gneiss, 46.24, 45.13 and 762.26 Bq/kg in sandstone and conglomerate, 73.11, 43.15 and 810.65 Bq/kg in sediments, respectively. All samples have high 226Ra and 40K levels according to world average level. As these sediments are used as construction materials and in agricultural activities within the study area, the radiation hazard are calculated by using dose rate (D), annual effective dose rate (He), radium equivalent activity (Raeq) and radiation hazard index (Iyr). All the samples have Raeq levels that are lower than the world average limit of 370 Bq/kg. On the other hand, D, He and Iyr values are higher than world average values. These results indicate that the uranium ores in the Koprubasi is the most important contributor to the natural radiation level. The radioactivity levels of sediments and rocks make them unsuitable for use as agricultural soil and as construction materials. Moreover, it is determined that shallow groundwater in sediments and deep groundwater in conglomerate rocks and also surface water sources in the Koprubasi have high 226Ra content. According to environmental radioactive baseline, some environmental protection study must be taken in Koprubasi uranium site and the environment.

Cost effectiveness of the US Geological Survey stream-gaging program in Alabama

USGS Publications Warehouse

Jeffcoat, H.H.

1987-01-01

A study of the cost effectiveness of the stream gaging program in Alabama identified data uses and funding sources for 72 surface water stations (including dam stations, slope stations, and continuous-velocity stations) operated by the U.S. Geological Survey in Alabama with a budget of $393,600. Of these , 58 gaging stations were used in all phases of the analysis at a funding level of $328,380. For the current policy of operation of the 58-station program, the average standard error of estimation of instantaneous discharge is 29.3%. This overall level of accuracy can be maintained with a budget of $319,800 by optimizing routes and implementing some policy changes. The maximum budget considered in the analysis was $361,200, which gave an average standard error of estimation of 20.6%. The minimum budget considered was $299,360, with an average standard error of estimation of 36.5%. The study indicates that a major source of error in the stream gaging records is lost or missing data that are the result of streamside equipment failure. If perfect equipment were available, the standard error in estimating instantaneous discharge under the current program and budget could be reduced to 18.6%. This can also be interpreted to mean that the streamflow data records have a standard error of this magnitude during times when the equipment is operating properly. (Author 's abstract)

Contributions to cities' ambient particulate matter (PM): A systematic review of local source contributions at global level

NASA Astrophysics Data System (ADS)

Karagulian, Federico; Belis, Claudio A.; Dora, Carlos Francisco C.; Prüss-Ustün, Annette M.; Bonjour, Sophie; Adair-Rohani, Heather; Amann, Markus

2015-11-01

For reducing health impacts from air pollution, it is important to know the sources contributing to human exposure. This study systematically reviewed and analysed available source apportionment studies on particulate matter (of diameter of 10 and 2.5 microns, PM10 and PM2.5) performed in cities to estimate typical shares of the sources of pollution by country and by region. A database with city source apportionment records, estimated with the use of receptor models, was also developed and available at the website of the World Health Organization. Systematic Scopus and Google searches were performed to retrieve city studies of source apportionment for particulate matter. Six source categories were defined. Country and regional averages of source apportionment were estimated based on city population weighting. A total of 419 source apportionment records from studies conducted in cities of 51 countries were used to calculate regional averages of sources of ambient particulate matter. Based on the available information, globally 25% of urban ambient air pollution from PM2.5 is contributed by traffic, 15% by industrial activities, 20% by domestic fuel burning, 22% from unspecified sources of human origin, and 18% from natural dust and salt. The available source apportionment records exhibit, however, important heterogeneities in assessed source categories and incompleteness in certain countries/regions. Traffic is one important contributor to ambient PM in cities. To reduce air pollution in cities and the substantial disease burden it causes, solutions to sustainably reduce ambient PM from traffic, industrial activities and biomass burning should urgently be sought. However, further efforts are required to improve data availability and evaluation, and possibly to combine with other types of information in view of increasing usefulness for policy making.

Multidimensional incremental parsing for universal source coding.

PubMed

Bae, Soo Hyun; Juang, Biing-Hwang

2008-10-01

A multidimensional incremental parsing algorithm (MDIP) for multidimensional discrete sources, as a generalization of the Lempel-Ziv coding algorithm, is investigated. It consists of three essential component schemes, maximum decimation matching, hierarchical structure of multidimensional source coding, and dictionary augmentation. As a counterpart of the longest match search in the Lempel-Ziv algorithm, two classes of maximum decimation matching are studied. Also, an underlying behavior of the dictionary augmentation scheme for estimating the source statistics is examined. For an m-dimensional source, m augmentative patches are appended into the dictionary at each coding epoch, thus requiring the transmission of a substantial amount of information to the decoder. The property of the hierarchical structure of the source coding algorithm resolves this issue by successively incorporating lower dimensional coding procedures in the scheme. In regard to universal lossy source coders, we propose two distortion functions, the local average distortion and the local minimax distortion with a set of threshold levels for each source symbol. For performance evaluation, we implemented three image compression algorithms based upon the MDIP; one is lossless and the others are lossy. The lossless image compression algorithm does not perform better than the Lempel-Ziv-Welch coding, but experimentally shows efficiency in capturing the source structure. The two lossy image compression algorithms are implemented using the two distortion functions, respectively. The algorithm based on the local average distortion is efficient at minimizing the signal distortion, but the images by the one with the local minimax distortion have a good perceptual fidelity among other compression algorithms. Our insights inspire future research on feature extraction of multidimensional discrete sources.

Source Water Management for Disinfection By-Product Control using New York City's Operations Support Tool and On-Line Monitoring

NASA Astrophysics Data System (ADS)

Weiss, W. J.; Becker, W.; Schindler, S.

2012-12-01

The United States Environmental Protection Agency's 2006 Stage 2 Disinfectant / Disinfection Byproduct Rule (DBPR) for finished drinking waters is intended to reduce overall DBP levels by limiting the levels of total trihalomethanes (TTHM) and five of the haloacetic acids (HAA5). Under Stage 2, maximum contaminant levels (MCLs), 80 μg/L for TTHM and 60 μg/L for HAA5, are based on a locational running annual average for individual sites instead of as the system-wide quarterly running annual average of the Stage 1 DBPR. This means compliance will have to be met at sampling locations of peak TTHM and HAA5 concentrations rather than an average across the entire system. Compliance monitoring under the Stage 2 DBPR began on April 1, 2012. The New York City (NYC) Department of Environmental Protection (DEP) began evaluating potential impacts of the Stage 2 DBPR on NYC's unfiltered water supply in 2002 by monitoring TTHM and HAA5 levels at various locations throughout the distribution system. Initial monitoring indicated that HAA5 levels could be of concern in the future, with the potential to intermittently violate the Stage 2 DBPR at specific locations, particularly those with high water age. Because of the uncertainty regarding the long-term prospect for compliance, DEP evaluated alternatives to ensure compliance, including operational changes (reducing chlorine dose, changing flow configurations to minimize water age, altering pH, altering source water withdrawals); changing the residual disinfectant from free chlorine to chloramines; and engineered treatment alternatives. This paper will discuss the potential for using DEP's Operations Support Tool (OST) and enhanced reservoir monitoring to support optimization of source water withdrawals to minimize finished water DBP levels. The OST is a state-of-the-art decision support system (DSS) to provide computational and predictive support for water supply operations and planning. It incorporates a water supply system simulation model (OASIS, HydroLogics, Inc.), reservoir water quality models, a near real-time monitoring network, and hydrologic forecasts to provide analytical support for both long-term planning and near-term operations. The OST helps managers and operators balance multiple objectives, including water supply reliability, water quality, and environmental and community release objectives. This paper will describe the results of initial testing to evaluate the potential to reduce DBP levels by managing source water withdrawals to minimize the transport of natural organic matter (NOM) precursors from upper reservoirs. Operating rules were developed that take advantage of selective withdrawal capabilities at some upstate reservoirs and the inherent flexibility of the overall water supply system, seeking to minimize DBPs within the larger framework of water supply, water quality, environmental, and regulatory objectives. The results demonstrated that there is substantial flexibility within the system to manage DBP levels, in some cases providing the potential for reductions of DBP precursors of nearly 10%. Additional research is underway that seeks to better understand the sources of natural organic matter in the NYC watershed to provide guidance for on-line monitoring to be used with the OST to support real-time operation support for DBP control.

Assessing product image quality for online shopping

NASA Astrophysics Data System (ADS)

Goswami, Anjan; Chung, Sung H.; Chittar, Naren; Islam, Atiq

2012-01-01

Assessing product-image quality is important in the context of online shopping. A high quality image that conveys more information about a product can boost the buyer's confidence and can get more attention. However, the notion of image quality for product-images is not the same as that in other domains. The perception of quality of product-images depends not only on various photographic quality features but also on various high level features such as clarity of the foreground or goodness of the background etc. In this paper, we define a notion of product-image quality based on various such features. We conduct a crowd-sourced experiment to collect user judgments on thousands of eBay's images. We formulate a multi-class classification problem for modeling image quality by classifying images into good, fair and poor quality based on the guided perceptual notions from the judges. We also conduct experiments with regression using average crowd-sourced human judgments as target. We compute a pseudo-regression score with expected average of predicted classes and also compute a score from the regression technique. We design many experiments with various sampling and voting schemes with crowd-sourced data and construct various experimental image quality models. Most of our models have reasonable accuracies (greater or equal to 70%) on test data set. We observe that our computed image quality score has a high (0.66) rank correlation with average votes from the crowd sourced human judgments.

Unusually loud ambient noise in tidewater glacier fjords: a signal of ice melt

USGS Publications Warehouse

Pettit, Erin C.; Lee, Kevin M.; Brann, Joel P.; Nystuen, Jeffrey A.; Wilson, Preston S.; O'Neel, Shad

2015-01-01

In glacierized fjords, the ice-ocean boundary is a physically and biologically dynamic environment that is sensitive to both glacier flow and ocean circulation. Ocean ambient noise offers insight into processes and change at the ice-ocean boundary. Here we characterize fjord ambient noise and show that the average noise levels are louder than nearly all measured natural oceanic environments (significantly louder than sea ice and non-glacierized fjords). Icy Bay, Alaska has an annual average sound pressure level of 120 dB (re 1 μPa) with a broad peak between 1000 and 3000 Hz. Bubble formation in the water column as glacier ice melts is the noise source, with variability driven by fjord circulation patterns. Measurements from two additional fjords, in Alaska and Antarctica, support that this unusually loud ambient noise in Icy Bay is representative of glacierized fjords. These high noise levels likely alter the behavior of marine mammals.

Top-Down CO Emissions Based On IASI Observations and Hemispheric Constraints on OH Levels

NASA Astrophysics Data System (ADS)

Müller, J.-F.; Stavrakou, T.; Bauwens, M.; George, M.; Hurtmans, D.; Coheur, P.-F.; Clerbaux, C.; Sweeney, C.

2018-02-01

Assessments of carbon monoxide emissions through inverse modeling are dependent on the modeled abundance of the hydroxyl radical (OH) which controls both the primary sink of CO and its photochemical source through hydrocarbon oxidation. However, most chemistry transport models (CTMs) fall short of reproducing constraints on hemispherically averaged OH levels derived from methylchloroform (MCF) observations. Here we construct five different OH fields compatible with MCF-based analyses, and we prescribe those fields in a global CTM to infer CO fluxes based on Infrared Atmospheric Sounding Interferometer (IASI) CO columns. Each OH field leads to a different set of optimized emissions. Comparisons with independent data (surface, ground-based remotely sensed, aircraft) indicate that the inversion adopting the lowest average OH level in the Northern Hemisphere (7.8 × 105 molec cm-3, ˜18% lower than the best estimate based on MCF measurements) provides the best overall agreement with all tested observation data sets.

Multispectral image fusion for target detection

NASA Astrophysics Data System (ADS)

Leviner, Marom; Maltz, Masha

2009-09-01

Various different methods to perform multi-spectral image fusion have been suggested, mostly on the pixel level. However, the jury is still out on the benefits of a fused image compared to its source images. We present here a new multi-spectral image fusion method, multi-spectral segmentation fusion (MSSF), which uses a feature level processing paradigm. To test our method, we compared human observer performance in an experiment using MSSF against two established methods: Averaging and Principle Components Analysis (PCA), and against its two source bands, visible and infrared. The task that we studied was: target detection in the cluttered environment. MSSF proved superior to the other fusion methods. Based on these findings, current speculation about the circumstances in which multi-spectral image fusion in general and specific fusion methods in particular would be superior to using the original image sources can be further addressed.

Numerical Analysis of the Cavity Flow subjected to Passive Controls Techniques

NASA Astrophysics Data System (ADS)

Melih Guleren, Kursad; Turk, Seyfettin; Mirza Demircan, Osman; Demir, Oguzhan

2018-03-01

Open-source flow solvers are getting more and more popular for the analysis of challenging flow problems in aeronautical and mechanical engineering applications. They are offered under the GNU General Public License and can be run, examined, shared and modified according to user’s requirements. SU2 and OpenFOAM are the two most popular open-source solvers in Computational Fluid Dynamics (CFD) community. In the present study, some passive control methods on the high-speed cavity flows are numerically simulated using these open-source flow solvers along with one commercial flow solver called ANSYS/Fluent. The results are compared with the available experimental data. The solver SU2 are seen to predict satisfactory the mean streamline velocity but not turbulent kinetic energy and overall averaged sound pressure level (OASPL). Whereas OpenFOAM predicts all these parameters nearly as the same levels of ANSYS/Fluent.

7 CFR 220.8 - Meal requirements for breakfasts.

Code of Federal Regulations, 2014 CFR

2014-01-01

... minimum and maximum levels. b Discretionary sources of calories (solid fats and added sugars) may be added... fluid milk as a beverage or on cereal or used partly for both; (B) A serving of fruit or vegetable or... food items School week averages Fluid milk (as a beverage, on cereal, or both) 4 fluid ounces 6 fluid...

Receptor model source attributions for Utah’s Salt Lake City airshed and the impacts of wintertime secondary ammonium nitrate and ammonium chloride aerosol.

EPA Science Inventory

Communities along Utah’s Wasatch Front are currently developing strategies to reduce daily average PM2.5 levels to below National Ambient Air Quality Standards during wintertime, persistent, multi-day stable atmospheric conditions or cold-air pools. Speciated PM2.5 data from the ...

The assessment of corruption impact on the inflow of foreign direct investment

NASA Astrophysics Data System (ADS)

Gasanova, Ayshan; Medvedev, Alexander N.; Komotskiy, Evgeny I.

2017-06-01

The aim of this paper is to investigate the impact of corruption on the inflow of foreign direct investment (FDI). The data, taken from official sources, Transparency International and the Heritage Foundation, have been treated in a special program "Deductor Studio Academic" by the method of Machine Learning (cluster analysis using Kohonen Self-Organizing Maps). There was composed a Kohonen map, in which the countries were divided into 4 clusters: countries with low levels of corruption and high level of FDI inflow, countries with low level of corruption and FDI above average, countries with average level of corruption and the average level of FDI, and countries with high level of corruption and low level of FDI. The research has shown that corruption influences the investment attractiveness of the host country. This means that in countries where the level of corruption is low and economic environment is attractive, the level of foreign direct investment is high, and in those countries where the level of corruption is high and and economic attractiveness is low - the level of investment is low. However, the study identified countries which have high level of corruption and high FDI inflow - China, India, Brazil and Russia (BRIC countries). These countries are the exception from the rule due to the wide domestic market, cheap labour, the wealth of natural resources - all these factors increase the investment attractiveness of these countries. It was found that corruption in BRIC countries has similarity being a controlled and predictable phenomenon. This allows calculating the cost of corruption for accounting it in business projects.

The strategic significance of wastewater sources to pollutant phosphorus levels in English rivers and to environmental management for rural, agricultural and urban catchments.

PubMed

Neal, Colin; Jarvie, Helen P; Withers, Paul J A; Whitton, Brian A; Neal, Margaret

2010-03-01

The relationship between soluble and particulate phosphorus was examined for 9 major UK rivers including 26 major tributaries and 68 monitoring points, covering wide-ranging rural and agricultural/urban impacted systems with catchment areas varying from 1 to 6000km(2) scales. Phosphorus concentrations in Soluble Reactive (SRP), Total Dissolved (TDP), Total (TP), Dissolved Hydrolysable (DHP) and Particulate (PP) forms correlated with effluent markers (sodium and boron) and SRP was generally dominant signifying the importance of sewage sources. Low flows were particularly enriched in SRP, TDP and TP for average SRP>100microg/l indicating low effluent dilution. At particularly low average concentrations, SRP increased with flow but effluent sources were still implicated as the effluent markers (boron in particular) increased likewise. For rural areas, DHP had proportionately high concentrations and SRP+DHP concentrations could exceed environmental thresholds currently set for SRP. Given DHP has a high bioavailability the environmental implications need further consideration. PP concentrations were generally highest at high flows but PP in the suspended solids was generally at its lowest and in general PP correlated with particulate organic carbon and more so than the suspended sediment in total. Separation of pollutant inputs solely between effluent and diffuse (agriculture) components is misleading, as part of the "diffuse" term comprises effluents flushed from the catchments during high flow. Effluent sources of phosphorus supplied directly or indirectly to the river coupled with within-river interactions between water/sediment/biota largely determine pollutant levels. The study flags the fundamental need of placing direct and indirect effluent sources and contaminated storage with interchange to/from the river at the focus for remediation strategies for UK rivers in relation to eutrophication and the WFD.

Long-term biases in geomagnetic K and aa indices

USGS Publications Warehouse

Love, J.J.

2011-01-01

Analysis is made of the geomagnetic-activity aa index and its source K-index data from groups of ground-based observatories in Britain, and Australia, 1868.0-2009.0, solar cycles 11-23. The K data show persistent biases, especially for high (low) K-activity levels at British (Australian) observatories. From examination of multiple subsets of the K data we infer that the biases are not predominantly the result of changes in observatory location, localized induced magnetotelluric currents, changes in magnetometer technology, or the modernization of K-value estimation methods. Instead, the biases appear to be artifacts of the latitude-dependent scaling used to assign K values to particular local levels of geomagnetic activity. The biases are not effectively removed by weighting factors used to estimate aa. We show that long-term averages of the aa index, such as annual averages, are dominated by medium-level geomagnetic activity levels having K values of 3 and 4. ?? 2011 Author(s).

Aerosol optical properties observation and its relationship to meteorological conditions and emission during the Chinese National Day and Spring Festival holiday in Beijing

NASA Astrophysics Data System (ADS)

Zheng, Yu; Che, Huizheng; Zhao, Tianliang; Zhao, Hujia; Gui, Ke; Sun, Tianze; An, Linchang; Yu, Jie; Liu, Chong; Jiang, Yongcheng; Zhang, Lei; Wang, Hong; Wang, Yaqiang; Zhang, Xiaoye

2017-11-01

The reduction of traffic flow in downtown areas during the Chinese National Day holiday and the fireworks during the Spring Festival provide a unique opportunity for investigating the impact of urban anthropogenic activities on aerosol optical properties during these important Chinese festivals in Beijing. The National Day in 2014 and 2015 and Spring Festival in 2015 and 2016 were selected as study periods. The aerosol optical depth (AOD) at 440 nm increased over the all holiday periods and the average AODs during the 2015 National Day, 2015 Spring Festival and 2016 Spring Festival were about 81%, 21% and 36% higher than the background levels, respectively. The average AOD in 2014 National Day holiday was lower than background level partly influenced by precipitation event. The absorption AOD (AAOD) at 440 nm showed consistent variations with the AOD and the average AAODs during the 2015 National Day, 2015 Spring Festival and 2016 Spring Festival holidays were about 75%, 19% and 23% higher than the background level, respectively. The mean values of single scattering albedo were greater than the background level during the Spring Festival holidays, whereas the values during the National Day holiday in 2015 were lower partly due to the reduction of vehicular emissions in downtown areas. Fine- and coarse-mode particle volumes during pollution periods in holidays were 0.04-0.25 μm3 and 0.03-0.15 μm3 larger than background level, respectively. The results of potential source contribution function and concentration-weighted trajectory analyses identified the areas south of Beijing as the main source regions of PM2.5 and were responsible for the extremely high PM2.5 concentrations in Beijing during the holiday periods. The findings of this study may aid understanding the effects of human activities on aerosol optical properties over Beijing area and contribute to improving regional air quality.

CO2 laser drives extreme ultraviolet nano-lithography — second life of mature laser technology

NASA Astrophysics Data System (ADS)

Nowak, K. M.; Ohta, T.; Suganuma, T.; Fujimoto, J.; Mizoguchi, H.; Sumitani, A.; Endo, A.

2013-12-01

It was shown both theoretically and experimentally that nanosecond order laser pulses at 10.6 micron wavelength were superior for driving the Sn plasma extreme ultraviolet (EUV) source for nano-lithography for the reasons of higher conversion efficiency, lower production of debris and higher average power levels obtainable in CO2 media without serious problems of beam distortions and nonlinear effects occurring in competing solid-state lasers at high intensities. The renewed interest in such pulse format, wavelength, repetition rates in excess of 50 kHz and average power levels in excess of 18 kiloWatt has sparked new opportunities for a matured multi-kiloWatt CO2 laser technology. The power demand of EUV source could be only satisfied by a Master-Oscillator-Power-Amplifier system configuration, leading to a development of a new type of hybrid pulsed CO2 laser employing a whole spectrum of CO2 technology, such as fast flow systems and diffusion-cooled planar waveguide lasers, and relatively recent quantum cascade lasers. In this paper we review briefly the history of relevant pulsed CO2 laser technology and the requirements for multi-kiloWatt CO2 laser, intended for the laser-produced plasma EUV source, and present our recent advances, such as novel solid-state seeded master oscillator and efficient multi-pass amplifiers built on planar waveguide CO2 lasers.

Identification of Major Sources of Atmospheric NH3 in an Urban Environment in Northern China During Wintertime.

PubMed

Teng, Xiaolin; Hu, Qingjing; Zhang, Leiming; Qi, Jiajia; Shi, Jinhui; Xie, Huan; Gao, Huiwang; Yao, Xiaohong

2017-06-20

To assess the relative contributions of traffic emission and other potential sources to high levels of atmospheric ammonia (NH 3 ) in urban areas in the wintertime, atmospheric NH 3 and related pollutants were measured at an urban site, ∼300 m from a major traffic road, in northern China in November and December 2015. Hourly average NH 3 varied from 0.3 to 10.8 ppb with an average of 2.4 ppb during the campaign. Contrary to the common perspective in literature, traffic emission was demonstrated to be a negligible contributor to atmospheric NH 3 . Atmospheric NH 3 correlated well with ambient water vapor during many time periods lasting from tens of hours to several days, implying NH 3 released from water evaporation is an important source. Emissions from local green space inside the urban areas were identified to significantly contribute to the observed atmospheric NH 3 during ∼60% of the sampling times. Evaporation of predeposited NH x through wet precipitation combined with emissions from local green space likely caused the spikes of atmospheric NH 3 mostly occurring 1-4 h after morning rush hours or after and during slight shower events. There are still ∼30% of the data samples with appreciable NH 3 level for which major contributors are yet to be identified.

Evaluation of the table Mountain Ronchi telescope for angular tracking

NASA Technical Reports Server (NTRS)

Lanyi, G.; Purcell, G.; Treuhaft, R.; Buffington, A.

1992-01-01

The performance of the University of California at San Diego (UCSD) Table Mountain telescope was evaluated to determine the potential of such an instrument for optical angular tracking. This telescope uses a Ronchi ruling to measure differential positions of stars at the meridian. The Ronchi technique is summarized and the operational features of the Table Mountain instrument are described. Results from an analytic model, simulations, and actual data are presented that characterize the telescope's current performance. For a star pair of visual magnitude 7, the differential uncertainty of a 5-min observation is about 50 nrad (10 marcsec), and tropospheric fluctuations are the dominant error source. At magnitude 11, the current differential uncertainty is approximately 800 nrad (approximately 170 marcsec). This magnitude is equivalent to that of a 2-W laser with a 0.4-m aperture transmitting to Earth from a spacecraft at Saturn. Photoelectron noise is the dominant error source for stars of visual magnitude 8.5 and fainter. If the photoelectron noise is reduced, ultimately tropospheric fluctuations will be the limiting source of error at an average level of 35 nrad (7 marcsec) for stars approximately 0.25 deg apart. Three near-term strategies are proposed for improving the performance of the telescope to the 10-nrad level: improving the efficiency of the optics, masking background starlight, and averaging tropospheric fluctuations over multiple observations.

Distribution and source analysis of aluminum in rivers near Xi'an City, China.

PubMed

Wang, Dongqi; He, Yanling; Liang, Jidong; Liu, Pei; Zhuang, Pengyu

2013-02-01

To study the status and source of aluminum (Al) contamination, a total of 21 sampling sites along six rivers near Xi'an City (Shaanxi province, China) were investigated during 2008-2010. The results indicated that the average concentration of total Al (Al(t)) in the six rivers increased by 1.6 times from 2008 to 2010. The spatial distribution of Al(t) concentrations in the rivers near Xi'an City was significantly different, ranged from 367 μg/L (Bahe River) to 1,978 μg/L (Taiping River). The Al(t) concentration was highest near an industrial area for pulp and paper-making (2,773 μg/L), where the Al level greatly exceeded the water quality criteria of both the USA (Criterion Continuous Concentration, 87 μg/L) and Canada (100 μg/L). The average concentration of inorganic monometric aluminum (Al(im)) was 72 μg/L which would pose threats to fishes and other aquatic lives in the rivers. The concentrations of exchangeable Al (Al(ex)) in the sediment of the Taiping River sampled were relatively high, making it to be an alternative explanation of increasing Al concentrations in the rivers near Xi'an City. Furthermore, an increasing Al level has been detected in the upstream watershed near Xi'an City in recent years, which might indicate another notable pollution source of Al.

A subsynoptic-scale kinetic energy study of the Red River Valley tornado outbreak (AVE-SESAME 1)

NASA Technical Reports Server (NTRS)

Jedlovec, G. J.; Fuelberg, H. E.

1981-01-01

The subsynoptis-scale kinetic energy balance during the Red River Valley tornado outbreak is presented in order to diagnose storm environment interactions. Area-time averaged energetics indicate that horizontal flux convergence provides the major energy source to the region, while cross contour flow provides the greatest sink. Maximum energy variability is found in the upper levels in association with jet stream activity. Area averaged energetics at individual observation times show that the energy balance near times of maximum storm activity differs considerably from that of the remaining periods. The local kinetic energy balance over Oklahoma during the formation of a limited jet streak receives special attention. Cross contour production of energy is the dominant local source for jet development. Intense convection producing the Red River Valley tornadoes may have contributed to this local development by modifying the surrounding environment.

Comparison of different Kalman filter approaches in deriving time varying connectivity from EEG data.

PubMed

Ghumare, Eshwar; Schrooten, Maarten; Vandenberghe, Rik; Dupont, Patrick

2015-08-01

Kalman filter approaches are widely applied to derive time varying effective connectivity from electroencephalographic (EEG) data. For multi-trial data, a classical Kalman filter (CKF) designed for the estimation of single trial data, can be implemented by trial-averaging the data or by averaging single trial estimates. A general linear Kalman filter (GLKF) provides an extension for multi-trial data. In this work, we studied the performance of the different Kalman filtering approaches for different values of signal-to-noise ratio (SNR), number of trials and number of EEG channels. We used a simulated model from which we calculated scalp recordings. From these recordings, we estimated cortical sources. Multivariate autoregressive model parameters and partial directed coherence was calculated for these estimated sources and compared with the ground-truth. The results showed an overall superior performance of GLKF except for low levels of SNR and number of trials.

Sources and distribution of allochthonous organic matter in surface sediment from the Seomjin River to the southern inner shelf of Korea

NASA Astrophysics Data System (ADS)

Badejo, Adegoke Olugboyega; Hyun, Sangmin; Kim, Wonnyon; Ju, Se-Jong; Song, Bareum

2017-12-01

The spatial distributions of δ13C, δ15N, and n-alkanes were investigated to determine the source and transportation of allochthonous organic matter from the mouth of the Seomjin River to the southern inner shelf break of Korea. Total organic carbon (%) ranged from 0.3% to 1.6% (average = 0.80%, n = 81), and the C/N ratio varied from 2.4 to 12.4 (average = 6.76, n = 81). The δ13C values ranged from -25.86 to -20.26‰ (average = -21.47‰, n = 81), and δ15N values ranged from 4.37‰ to 8.57‰ (average = 6.72‰, n = 81). The contribution of the terrestrial fraction of organic matter to the total ranged from 4.4% to 97.7% (average = 24.4%, n = 81), suggesting higher amounts around the catchment area and lower amounts in the offshore area. The concentration of total n-alkanes ( nC25 - nC35) was higher at the boundary between the outer bay and inner shelf break (BOBIS). Average chain length and the carbon preference index both indicated that major leaf wax n-alkanes accounted for the observed distribution of terrestrial organic matter, and were dominant in the inner shelf break (around BOBIS) and outer shelf break. Based on the spatial distribution of the total n-alkanes and the sum of nC27, nC29, and nC31, the terrestrial organic matter distribution was considered to be controlled by local oceanographic conditions, especially at the center of the BOBIS. In addition to enabling the distribution and source of terrestrial organic matter to be identified, the n-alkanes indicated that minor anthropogenic allochthonous organic materials were superimposed on the total organic materials in the central part of Yeosu Bay and the catchment area. The n-alkane indices revealed weathered petroleum contamination, with contamination levels being relatively low at the present time.

Pilot Survey of Subway and Bus Stop Noise Levels

PubMed Central

Neitzel, Richard; Barrera, Marissa A.; Akram, Muhammad

2006-01-01

Excessive noise exposure is a serious global urban health problem, adversely affecting millions of people. One often cited source of urban noise is mass transit, particularly subway systems. As a first step in determining risk within this context, we recently conducted an environmental survey of noise levels of the New York City transit system. Over 90 noise measurements were made using a sound level meter. Average and maximum noise levels were measured on subway platforms, and maximum levels were measured inside subway cars and at several bus stops for comparison purposes. The average noise level measured on the subway platforms was 86 ± 4 dBA (decibel-A weighting). Maximum levels of 106, 112, and 89 dBA were measured on subway platforms, inside subway cars, and at bus stops, respectively. These results indicate that noise levels in subway and bus stop environments have the potential to exceed recommended exposure guidelines from the World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA), given sufficient exposure duration. Risk reduction strategies following the standard hierarchy of control measures should be applied, where feasible, to reduce subway noise exposure. PMID:16802179

Quantification of allyl hexanoate in pineapple beverages and yogurts as a case study to characterise a source of uncertainty in dietary exposure assessment to flavouring substances.

PubMed

Raffo, A; D'Aloise, A; Magrì, A D; Leclercq, C

2012-01-01

One source of uncertainty in the estimation of dietary exposure to flavouring substances is the uncertainty in the occurrence and concentration levels of these substances naturally present or added to foodstuffs. The aim of this study was to assess the variability of concentration levels of allyl hexanoate, considered as a case study, in two main food categories to which it is often added: pineapple juice-based beverages and yogurts containing pineapple. Thirty-four beverages and 29 yogurts, with pineapple fruit or juice and added flavourings declared as ingredients on the package, were purchased from the local market (in Rome) and analysed. Analytical methods based on the stir bar sorptive extraction (SBSE) technique for the isolation of the target analyte, and on GC-MS analysis for final determination, were developed for the two food categories. In beverages, allyl hexanoate concentrations ranged from less than 0.01 to 16.71 mg l(-1), whereas in yogurts they ranged from 0.02 to 89.41 mg kg(-1). Average concentrations in beverages and yogurts with pineapple as the main fruit ingredient (1.91 mg l(-1) for beverages, 9.61 mg kg(-1) for yogurts) were in fair agreement with average use level data reported from industry surveys for the relevant food categories (4.5 and 6.0 mg kg(-1), respectively). Within the group of yogurts a single product was found to contain a level of allyl hexanoate more than 10-fold higher than the average reported use level. The screening techniques developed by the European Food Safety Authority (EFSA) using use level data provided by industry gave estimates of exposure that were of the same order of magnitude as the estimates obtained for regular consumers who would be loyal to the pineapple yogurt and beverage products containing the highest observed concentration of the substance of interest. In this specific case the uncertainty in the results obtained with the use of standard screening techniques for exposure assessment based on industry reported use levels is low.

Exposure to Road, Railway, and Aircraft Noise and Arterial Stiffness in the SAPALDIA Study: Annual Average Noise Levels and Temporal Noise Characteristics

PubMed Central

Eze, Ikenna C.; Schaffner, Emmanuel; Vienneau, Danielle; Héritier, Harris; Endes, Simon; Rudzik, Franziska; Thiesse, Laurie; Pieren, Reto; Schindler, Christian; Schmidt-Trucksäss, Arno; Brink, Mark; Cajochen, Christian; Marc Wunderli, Jean; Röösli, Martin; Probst-Hensch, Nicole

2017-01-01

Background: The impact of different transportation noise sources and noise environments on arterial stiffness remains unknown. Objectives: We evaluated the association between residential outdoor exposure to annual average road, railway, and aircraft noise levels, total noise intermittency (IR), and total number of noise events (NE) and brachial-ankle pulse wave velocity (baPWV) following a cross-sectional design. Methods: We measured baPWV (meters/second) in 2,775 participants (49–81 y old) at the second follow-up (2010–2011) of the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA). We assigned annual average road, railway, and aircraft noise levels (Ldensource), total day- and nighttime NEtime and IRtime (percent fluctuation=0%, none or constant noise; percent fluctuation=100%, high fluctuation) at the most exposed façade using 2011 Swiss noise models. We applied multivariable linear mixed regression models to analyze associations. Results: Medians [interquartile ranges (IQRs)] were baPWV=13.4 (3.1) m/s; Ldenair (57.6% exposed)=32.8 (8.0) dB; Ldenrail (44.6% exposed)=30.0 (8.1) dB; Ldenroad (99.7% exposed): 54.2 (10.6) dB; NEnight=123 (179); NEday=433 (870); IRnight=73% (27); and IRday=63.8% (40.3). We observed a 0.87% (95% CI: 0.31, 1.43%) increase in baPWV per IQR of Ldenrail, which was greater with IRnight>80% or with daytime sleepiness. We observed a nonsignificant positive association between Ldenroad and baPWV in urban areas and a negative tendency in rural areas. NEnight, but not NEday, was associated with baPWV. Associations were independent of the other noise sources and air pollution. Conclusions: Long-term exposure to railway noise, particularly in an intermittent nighttime noise environment, and to nighttime noise events, mainly related to road noise, may affect arterial stiffness, a major determinant of cardiovascular disease. Ascertaining noise exposure characteristics beyond average noise levels may be relevant to better understand noise-related health effects. https://doi.org/10.1289/EHP1136 PMID:28934719

Evaluation and use of U.S. Environmental Protection Agency Clean Watersheds Needs Survey data to quantify nutrient loads to surface water, 1978–2012

USGS Publications Warehouse

Ivahnenko, Tamara I.

2017-12-07

Changes in municipal and industrial point-source discharges over time have been an important factor affecting nutrient trends in many of the Nation’s streams and rivers. This report documents how three U.S. Environmental Protection Agency (EPA) national datasets—the Permit Compliance System, the Integrated Compliance Information System, and the Clean Watersheds Needs Survey—were evaluated for use in the U.S. Geological Survey National Water-Quality Assessment project to assess the causes of nutrient trends. This report also describes how a database of total nitrogen load and total phosphorous load was generated for select wastewater treatment facilities in the United States based on information reported in the EPA Clean Watersheds Needs Survey. Nutrient loads were calculated for the years 1978, 1980, 1982, 1984, 1986, 1988, 1990, 1992, 1996, 2000, 2004, 2008, and 2012 based on average nitrogen and phosphorous concentrations for reported treatment levels and on annual reported flow values.The EPA Permit Compliance System (PCS) and Integrated Compliance Information System (ICIS), which monitor point-source facility discharges, together are the Nation’s most spatially comprehensive dataset for nutrients released to surface waters. However, datasets for many individual facilities are incomplete, the PCS/ICIS historical data date back only to 1989, and historical data are available for only a limited number of facilities. Additionally, inconsistencies in facility reporting make it difficult to track or identify changes in nutrient discharges over time. Previous efforts made by the U.S. Geological Survey to “fill in” gaps in the PCS/ICIS data were based on statistical methods—missing data were filled in through the use of a statistical model based on the Standard Industrial Classification code, size, and flow class of the facility and on seasonal nutrient discharges of similar facilities. This approach was used to estimate point-source loads for a single point in time; it was not evaluated for use in generating a consistent data series over time.Another national EPA dataset that is available is the Clean Watersheds Needs Survey (CWNS), conducted every 4 years beginning 1973. The CWNS is an assessment of the capital needs of wastewater facilities to meet the water-quality goals set in the Clean Water Act. Data collected about these facilities include location and contact information for the facilities; population served; flow and treatment level of the facility; estimated capital needs to upgrade, repair, or improve facilities for water quality; and nonpoint-source best management practices.Total nitrogen and total phosphorous load calculations for each of the CWNS years were based on treatment level information and average annual outflow (in million gallons per day) from each of the facilities that had reported it. Treatment levels categories (such as Primary, Secondary, or Advanced) were substituted with average total nitrogen and total phosphorous concentrations for each treatment level based on those reported in literature. The CWNS dataset, like the PCS/ICIS dataset, has years where facilities did not report either a treatment level or an annual average outflow, or both. To fill in the data gaps, simple linear assumptions were made based on each facility’s responses to the survey in years bracketing the data gap or immediately before or after the data gap if open ended. Treatment level and flow data unique to each facility were used to complete the CWNS dataset for that facility.

[The assessment of the quality of water from sources of decentralized water supply of Ekaterinburg and surrounding areas].

PubMed

Konshina, Lidia G

2016-01-01

The availability of high-quality drinking water is currently the one out of the most acute problems in the Russian Federation. There was performed an analysis of the chemical composition of drinking water from sources of decentralized supply of inhabitants of the city of Yekaterinburg and the surrounding areas. Average values of indices of the water quality in the wells for individual use in the district of the city of Yekaterinburg not go beyond the standards, with the exception of manganese content. In some sources there were revealed elevated values of chromatic level, oxidability, hardness, content of iron, nitrates, barium, dry residue, ammonium nitrogen, silicon. Percentage of sources that do not meet hygienic requirements on a number of indices can reach 21-23%.

Spatial and seasonal distribution of polychlorinated biphenyls (PCBs) in the vicinity of an iron and steel making plant.

PubMed

Baek, Song-Yee; Choi, Sung-Deuk; Park, Hyokeun; Kang, Jung-Ho; Chang, Yoon-Seok

2010-04-15

Four consecutive passive air samplings (September 2006-July 2007) were conducted at 15 sites around an iron and steel making plant in Pohang, Korea to investigate the spatial and seasonal distributions of polychlorinated biphenyls (PCBs) and ultimately the source-receptor relationships. Annual mean values of Sigma(8)PCBs (IUPAC number 8, 28, 52, 101, 118, 138, 153, 180) were in the range of 15.1-166 pg/m(3) with an average of 53.0 pg/m(3). The spatial distribution of PCBs for each sampling period clearly suggests that the steel complex is a major source of PCBs in this area, and the prevailing winds facilitated the atmospheric transport and dispersion of PCBs from the steel complex to the surrounding areas. Seasonal patterns of PCBs were observed clearly, which were influenced by meteorological conditions; the highest levels of PCBs were observed with the highest average air temperature, and the influence of rainfall (i.e., wet scavenging) was also observed. In addition, PCB 11, a non-Aroclor congener, was detected in high concentrations at all sites, implying that the sources of PCB 11 are both unique and ubiquitous. This study confirms that passive air sampling is a useful tool to obtain seasonal and spatial distributions of time-averaged POPs data at a local scale.

Adolescent athletes and the demand and supply of drugs to improve their performance.

PubMed

Laure, Patrick; Binsinger, Caroline

2005-09-01

The aim of this study was to gather information into the principal methods and means employed to supply adolescents with doping agents and others substances used to improve their sporting performance. We conducted a nation wide study in France among adolescent athletes, using a self-completed questionnaire. Exploitable questionnaires (n = 6402) were returned, corresponding to 48.9% for the girls and 51.1% for the boys, both aged on average from 16.1 ± 2.2 years. These adolescents practise on average 10.0 ± 5.2 hours of sport per week. 21.9% participate on a national or international competition level. Of our respondents, 4.0% (95% confidence interval: 3.5% - 4.5%) say they have been enticed into using products which are prohibited for athletes. 10.3% of the adolescents say that they have received substances to improve their performance at least once from an average of two different people. It was mostly a friend, their parents and the family doctor. On average, in 33.2% of the cases, the adolescent received the product without asking for it, and in nearly half the cases (46.6%), the adolescent paid for the product. We feel that it is necessary to better understand the ways in which this black market functions: for example; the initial sources of the products sold, the number and the 'profiles' of the dealers, the general organisation of the market and the sums of money involved. Key PointsThis study confirms the existence of a 'black market' for products to improve performance, which is directed at adolescent athletes engaged in high-level competitions.This market is characterized by its ease of accessibility and also the diversity of its 'suppliers', the two main sources being friends and parents.

The protective effects of high-education levels on cognition in different stages of multiple sclerosis.

PubMed

Rimkus, Carolina de Medeiros; Avolio, Isabella Maria Bello; Miotto, Eliane Correa; Pereira, Samira Apostolos; Mendes, Maria Fernanda; Callegaro, Dagoberto; Leite, Claudia da Costa

2018-05-01

Low-education attainment is associated with worse cognitive performance in multiple sclerosis (MS) patients, and possibly with a lower cognitive reserve and/or increased inflammatory activity. Cognitive reserve refers to the capability of a source of intellectual enrichment in attenuating a negative effect of a disease-related factor; while the inflammatory activity is often related to T2-lesion load (T2-LL) increase. To disentangle the effects of cognitive reserve and an increased T2-LL in MS-patients with low-education levels. The study included 136 MS patients and 65 healthy-controls, divided in low-education (12 years or less of school education without obtaining any technical superior degree) and high-education (more than 12 years of school education with technical or superior degree) groups. An extensive battery of neuropsychological tests was applied examining intelligence quotient and six cognitive domains. Test results were z-scored and subjects with z-scores ≤ -1.5 in two or more domains were considered cognitively impaired. To test the factors associated with worse cognitive performance, regression models were applied using average cognition as target; education level, Expanded Disability Status Scale (EDSS), T2-LL, disease duration, age of disease onset, age and gender as predictors. We also tested the correlation between T2-LL and cognition in the groups. To investigate the role of education level as a source of intellectual enrichment/cognitive reserve in different stages of MS, we sub-divided the MS patients in three groups according to the disease duration (less than 5 years, between 5 and 10 years and more than 10 years). Worse average cognition was associated with low-education level, higher T2-LL and male gender. A higher frequency of cognitively impaired patients was observed in MS patients with low-education level, in all stages of the disease. In patients with a disease duration shorter than five years, there was a lower correlation between worse average cognition and T2-LL in the high-education level group, compared to the patients with low-education level; in MS patients with longer disease duration, we observed a stronger correlation between lesion burden and cognitive impairment in both groups. Education attainment is a source of intellectual enrichment and can enhance the cognitive reserve in MS patients. The protective effect of a high-education level was stronger in patients with less than five years of disease, suggesting a stronger role of cognitive reserve in short-term disease. In long-term disease we observed a greater impact of increased inflammatory activity on cognition. Copyright © 2018 Elsevier B.V. All rights reserved.

Agricultural peat lands; towards a greenhouse gas sink - a synthesis of a Dutch landscape study

NASA Astrophysics Data System (ADS)

Schrier-Uijl, A. P.; Kroon, P. S.; Hendriks, D. M. D.; Hensen, A.; Van Huissteden, J. C.; Leffelaar, P. A.; Berendse, F.; Veenendaal, E. M.

2013-06-01

It is generally known that managed, drained peatlands act as carbon sources. In this study we examined how mitigation through the reduction of management and through rewetting may affect the greenhouse gas (GHG) emission and the carbon balance of intensively managed, drained, agricultural peatlands. Carbon and GHG balances were determined for three peatlands in the western part of the Netherlands from 2005 to 2008 by considering spatial and temporal variability of emissions (CO2, CH4 and N2O). One area (Oukoop) is an intensively managed grass-on-peatland, including a dairy farm, with the ground water level at an average annual depth of 0.55 m below the soil surface. The second area (Stein) is an extensively managed grass-on-peatland, formerly intensively managed, with a dynamic ground water level at an average annual depth of 0.45 m below the soil surface. The third area is an (since 1998) rewetted former agricultural peatland (Horstermeer), close to Oukoop and Stein, with the average annual ground water level at a depth of 0.2 m below the soil surface. During the measurement campaigns we found that both agriculturally managed sites acted as carbon and GHG sources but the rewetted agricultural peatland acted as a carbon and GHG sink. The terrestrial GHG source strength was 1.4 kg CO2-eq m-2 yr-1 for the intensively managed area and 1.0 kg CO2-eq m-2 yr-1 for the extensively managed area; the unmanaged area acted as a GHG sink of 0.7 kg CO2-eq m-2 yr-1. Water bodies contributed significantly to the terrestrial GHG balance because of a high release of CH4 and the loss of DOC only played a minor role. Adding the farm-based CO2 and CH4 emissions increased the source strength for the managed sites to 2.7 kg CO2-eq m-2 yr-1 for Oukoop and 2.1 kg CO2-eq m-2 yr-1 for Stein. Shifting from intensively managed to extensively managed grass-on-peat reduced GHG emissions mainly because N2O emission and farm-based CH4 emissions decreased. Overall, this study suggests that managed peatlands are large sources of GHG and carbon, but, if appropriate measures are taken they can be turned back into GHG and carbon sinks within 15 yr of abandonment and rewetting.

Use of Tritium Accelerator Mass Spectrometry for Tree Ring Analysis

PubMed Central

LOVE, ADAM H.; HUNT, JAMES R.; ROBERTS, MARK L.; SOUTHON, JOHN R.; CHIARAPPA - ZUCCA, MARINA L.; DINGLEY, KAREN H.

2010-01-01

Public concerns over the health effects associated with low-level and long-term exposure to tritium released from industrial point sources have generated the demand for better methods to evaluate historical tritium exposure levels for these communities. The cellulose of trees accurately reflects the tritium concentration in the source water and may contain the only historical record of tritium exposure. The tritium activity in the annual rings of a tree was measured using accelerator mass spectrometry to reconstruct historical annual averages of tritium exposure. Milligram-sized samples of the annual tree rings from a Tamarix located at the Nevada Test Site are used for validation of this methodology. The salt cedar was chosen since it had a single source of tritiated water that was well-characterized as it varied over time. The decay-corrected tritium activity of the water in which the salt cedar grew closely agrees with the organically bound tritium activity in its annual rings. This demonstrates that the milligram-sized samples used in tritium accelerator mass spectrometry are suited for reconstructing anthropogenic tritium levels in the environment. PMID:12144257

Source-to-sensation level ratio of transmitted biosonar pulses in an echolocating false killer whale.

PubMed

Supin, Alexander Ya; Nachtigall, Paul E; Breese, Marlee

2006-07-01

Transmitted biosonar pulses, and the brain auditory evoked potentials (AEPs) associated with those pulses, were synchronously recorded in a false killer whale Pseudorca crassidens trained to accept suction-cup EEG electrodes and to detect targets by echolocation. AEP amplitude was investigated as a function of the transmitted biosonar pulse source level. For that, a few thousand of the individual AEP records were sorted according to the spontaneously varied amplitude of synchronously recorded biosonar pulses. In each of the sorting bins (in 5-dB steps) AEP records were averaged to extract AEP from noise; AEP amplitude was plotted as a function of the biosonar pulse source level. For comparison, AEPs were recorded to external (in free field) sound pulses of a waveform and spectrum similar to those of the biosonar pulses; amplitude of these AEPs was plotted as a function of sound pressure level. A comparison of these two functions has shown that, depending on the presence or absence of a target, the sensitivity of the whale's hearing to its own transmitted biosonar pulses was 30 to 45 dB lower than might be expected in a free acoustic field.

Mapping underwater sound noise and assessing its sources by using a self-organizing maps method.

PubMed

Rako, Nikolina; Vilibić, Ivica; Mihanović, Hrvoje

2013-03-01

This study aims to provide an objective mapping of the underwater noise and its sources over an Adriatic coastal marine habitat by applying the self-organizing maps (SOM) method. Systematic sampling of sea ambient noise (SAN) was carried out at ten predefined acoustic stations between 2007 and 2009. Analyses of noise levels were performed for 1/3 octave band standard centered frequencies in terms of instantaneous sound pressure levels averaged over 300 s to calculate the equivalent continuous sound pressure levels. Data on vessels' presence, type, and distance from the monitoring stations were also collected at each acoustic station during the acoustic sampling. Altogether 69 noise surveys were introduced to the SOM predefined 2 × 2 array. The overall results of the analysis distinguished two dominant underwater soundscapes, associating them mainly to the seasonal changes in the nautical tourism and fishing activities within the study area and to the wind and wave action. The analysis identified recreational vessels as the dominant anthropogenic source of underwater noise, particularly during the tourist season. The method demonstrated to be an efficient tool in predicting the SAN levels based on the vessel distribution, indicating also the possibility of its wider implication for marine conservation.

Quantitative assessment of source contributions to PM2.5 on the west coast of Peninsular Malaysia to determine the burden of Indonesian peatland fire

NASA Astrophysics Data System (ADS)

Fujii, Yusuke; Tohno, Susumu; Amil, Norhaniza; Latif, Mohd Talib

2017-12-01

Almost every dry season, peatland fires occur in Sumatra and Kalimantan Inlands. Dense smoke haze from Indonesian peatland fires (IPFs) causes impacts on health, visibility, transport and regional climate in Southeast Asian countries such as Indonesia, Malaysia, and Singapore. Quantitative knowledge of IPF source contribution to ambient aerosols in Southeast Asia (SEA) is so useful to make appropriate suggestions to policy makers to mitigate IPF-induced haze pollution. However, its quantitative contribution to ambient aerosols in SEA remains unclarified. In this study, the source contributions to PM2.5 were determined by the Positive Matrix Factorization (PMF) model with annual comprehensive observation data at Petaling Jaya on the west coast of Peninsular Malaysia, which is downwind of the IPF areas in Sumatra Island, during the dry (southwest monsoon: June-September) season. The average PM2.5 mass concentration during the whole sampling periods (Aug 2011-Jul 2012) based on the PMF and chemical mass closure models was determined as 20-21 μg m-3. Throughout the sampling periods, IPF contributed (on average) 6.1-7.0 μg m-3 to the PM2.5, or ∼30% of the retrieved PM2.5 concentration. In particular, the PM2.5 was dominantly sourced from IPF during the southwest monsoon season (51-55% of the total PM2.5 concentration on average). Thus, reducing the IPF burden in the PM2.5 levels would drastically improve the air quality (especially during the southwest monsoon season) around the west coast of Peninsular Malaysia.

Inputs, source apportionment, and transboundary transport of pesticides and other polar organic contaminants along the lower Red River, Manitoba, Canada.

PubMed

Challis, Jonathan K; Cuscito, Leah D; Joudan, Shira; Luong, Kim H; Knapp, Charles W; Hanson, Mark L; Wong, Charles S

2018-04-20

The Red River originates in the U.S., drains into Lake Winnipeg, and is a significant pathway for nutrients. We investigate its role as a source for pesticides, pharmaceuticals, per- and polyfluoroalkyl substances (PFASs), and microbes bearing antibiotic resistance genes (ARGs). We delineate agricultural, urban, and rural land-use for organic contaminants to determine the extent of chemical transboundary riverine fluxes, and characterize levels and trends of organic contaminants and ARGs between spring and fall 2014 and 2015. The herbicide atrazine peaked at over 500 ng/L (14-day time-weighted average) near the border, indicating that the U.S. represents the major source into Canada from the Red River. Neonicotinoid insecticides had relatively constant concentrations, suggesting more widespread agricultural use in both countries. Pesticide concentrations were greatest post-application in June and July. Mass loadings of pesticides over the sampling periods, from the river to Lake Winnipeg, ranged from approximately 800 kg of atrazine, to 120 kg of thiamethoxam and clothianidin, to 40 kg of imidacloprid. Exposure distributions for atrazine exceeded benchmark water quality guidelines for protection of aquatic life (0.2% probability of exceeding chronic benchmark) with no exceedances for neonicotinoids. Seven pharmaceuticals were detected, mostly at low ng/L levels downstream of the City of Winnipeg wastewater treatment plant. Carbamazepine, the only pharmaceutical detected consistently at all sites, contributed on average 20 kg each year into Lake Winnipeg. While minor inputs were observed all along the river, city inputs represented the greatest source of pharmaceuticals to the river. Both PFASs and ARGs were observed consistently and ubiquitously, indicative of an anthropogenically-influenced system with no indications of any single point-source signature. While transboundary flux from the U.S. was an important source of pesticides to the Red River, especially for atrazine, observed concentrations of all measured contaminants suggest that known aquatic toxicological risk is minimal. Copyright © 2018 Elsevier B.V. All rights reserved.

Monitoring of volatile organic compounds (VOCs) from an oil and gas station in northwest China for 1 year

NASA Astrophysics Data System (ADS)

Zheng, Huang; Kong, Shaofei; Xing, Xinli; Mao, Yao; Hu, Tianpeng; Ding, Yang; Li, Gang; Liu, Dantong; Li, Shuanglin; Qi, Shihua

2018-04-01

Oil and natural gas are important for energy supply around the world. The exploring, drilling, transportation and processing in oil and gas regions can release a lot of volatile organic compounds (VOCs). To understand the VOC levels, compositions and sources in such regions, an oil and gas station in northwest China was chosen as the research site and 57 VOCs designated as the photochemical precursors were continuously measured for an entire year (September 2014-August 2015) using an online monitoring system. The average concentration of total VOCs was 297 ± 372 ppbv and the main contributor was alkanes, accounting for 87.5 % of the total VOCs. According to the propylene-equivalent concentration and maximum incremental reactivity methods, alkanes were identified as the most important VOC groups for the ozone formation potential. Positive matrix factorization (PMF) analysis showed that the annual average contributions from natural gas, fuel evaporation, combustion sources, oil refining processes and asphalt (anthropogenic and natural sources) to the total VOCs were 62.6 ± 3.04, 21.5 ± .99, 10.9 ± 1.57, 3.8 ± 0.50 and 1.3 ± 0.69 %, respectively. The five identified VOC sources exhibited various diurnal patterns due to their different emission patterns and the impact of meteorological parameters. Potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) models based on backward trajectory analysis indicated that the five identified sources had similar geographic origins. Raster analysis based on CWT analysis indicated that the local emissions contributed 48.4-74.6 % to the total VOCs. Based on the high-resolution observation data, this study clearly described and analyzed the temporal variation in VOC emission characteristics at a typical oil and gas field, which exhibited different VOC levels, compositions and origins compared with those in urban and industrial areas.

Arsenic in Mexican children exposed to contaminated well water.

PubMed

Monroy-Torres, Rebeca; Macías, Alejandro E; Gallaga-Solorzano, Juan Carlos; Santiago-García, Enrique Javier; Hernández, Isabel

2009-01-01

This cross-sectional study measures the arsenic level in school children exposed to contaminated well water in a rural area in México. Arsenic was measured in hair by hydride generation atomic absorption spectrophotometry. Overall, 110 children were included (average 10 years-old). Among 55 exposed children, mean arsenic level on hair was 1.3 mg/kg (range <0.006-5.9). All unexposed children had undetectable arsenic levels. The high level of arsenic in water was associated to the level in hair. However, exposed children drank less well water at school or at home than unexposed children, suggesting that the use of contaminated water to cook beans, broths or soups may be the source of arsenic exposure.

Raman beam combining for laser brightness enhancement

DOEpatents

Dawson, Jay W.; Allen, Graham S.; Pax, Paul H.; Heebner, John E.; Sridharan, Arun K.; Rubenchik, Alexander M.; Barty, Chrisopher B. J.

2015-10-27

An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

Whistle source levels of free-ranging beluga whales in Saguenay-St. Lawrence marine park.

PubMed

Le Bot, Olivier; Simard, Yvan; Roy, Nathalie; Mars, Jérôme I; Gervaise, Cédric

2016-07-01

Wild beluga whistle source levels (SLs) are estimated from 52 three-dimensional (3D) localized calls using a 4-hydrophone array. The probability distribution functions of the root-mean-square (rms) SL in the time domain, and the peak, the strongest 3-dB, and 10-dB SLs from the spectrogram, were non-Gaussian. The average rms SL was 143.8 ± 6.7 dB re 1 μPa at 1 m. SL spectral metrics were, respectively, 145.8 ± 8 dB, 143.2 ± 7.1 dB, and 138.5 ± 6.9 dB re 1 μPa(2)·Hz(-1) at 1 m.

Level of supplemental protein does not influence the ruminally undegradable protein value.

PubMed

Legleiter, L R; Mueller, A M; Kerley, M S

2005-04-01

Two experiments were conducted to determine whether elevating the percentage of ruminally undegradable protein (RUP) in the diet would influence the RUP value of the protein feedstuff. A single-effluent, continuous-culture study was designed to test the effect of RUP inclusion rate in the diet on ruminal degradability of the protein. Treatments consisted (DM basis) of a control diet with no supplemental protein, control + 2.5% bloodmeal (BM-L), control + 5% bloodmeal (BM-H), control + 4.45% soybean meal (SBM-L), and control + 8.89% soybean meal (SBM-H). Proteolytic activity and total VFA concentration were not affected (P = 0.73 and P = 0.13) by treatment. Within protein source, dietary RUP value was not affected (P = 0.94) by level of inclusion. When corrected for control diet RUP flow, the RUP value of the blood meal (BM) protein was higher (P = 0.01) than soybean meal (SBM); however, level of supplementation did not affect (P = 0.07) the RUP value of BM or SBM. In Exp. 2, 32 British x Continental crossbred steers (276 +/- 26.3 kg) were fed for 72 d to examine the effects of balancing the AA:energy ratio, using BM as a RUP source, on ADG, G:F, and lean tissue deposition. Diets were formulated to provide increasing levels of arginine, while ruminally degradable protein and energy were held constant. Four dietary treatments provided 0.5, 1, 1.5, and 2x the required amount of arginine, whereas the control diet had no BM included. Daily DMI averaged 7.6 kg/steer and did not differ (P = 0.71) among treatments. Steers gained an average of 1.9 kg/d and average G:F was 0.260, with no differences (P = 0.60 and P = 0.97, respectively) among treatments. There was no difference (P = 0.48) in the change in 12th-rib fat depth during the study; however, change in LM area was affected quadratically as the level of BM increased in the diet, with the greatest increase in LM area occurring in steers fed the 1x and 1.5x required arginine treatments. Balancing the AA:energy ratio did not affect G:F, DMI, or ADG; however, it increased deposition of lean in the LM quadratically. Level of dietary inclusion of BM as an RUP source does not affect its RUP value or efficacy of providing postruminal AA in growing steers.

40 CFR 464.34 - New source performance standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-continuous dischargers, annual average mass standards and maximum day and maximum for monthly average concentration (mg/l) standards shall apply. Concentration standards and annual average mass standards shall only... 40 Protection of Environment 31 2012-07-01 2012-07-01 false New source performance standards. 464...

40 CFR 464.34 - New source performance standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-continuous dischargers, annual average mass standards and maximum day and maximum for monthly average concentration (mg/l) standards shall apply. Concentration standards and annual average mass standards shall only... 40 Protection of Environment 30 2014-07-01 2014-07-01 false New source performance standards. 464...

40 CFR 464.34 - New source performance standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-continuous dischargers, annual average mass standards and maximum day and maximum for monthly average concentration (mg/l) standards shall apply. Concentration standards and annual average mass standards shall only... 40 Protection of Environment 31 2013-07-01 2013-07-01 false New source performance standards. 464...

Sources and assessment of occupational stress in the police.

PubMed

Deschamps, Frédéric; Paganon-Badinier, Isabelle; Marchand, Annie-Claude; Merle, Corinne

2003-11-01

The role of the police in Western society is undergoing a transformation that reflects the economic social and technological changes in the community and the assertion of individual rights within a democracy. The aim of this study is to evaluate level of stress among a group of French policemen and to examine the association between policing, potential stressors and stress levels. The sample is drawn from a large metropolitan police force (n=617). The population extends from the first line policeman to top senior management. Each policeman is matched for age (more or less five years) and sex, to a control. Policemen and controls complete a self administered questionnaire including demographic, occupational and health characteristics, and a stress level assessment with the help of a visual analogue scale. The average age of the two groups is 40 yr. Eighty-four percent are men. The total score for average sources is not statistically significantly different for policemen and controls. Comparison of a police group with a high stress level to a police population with a low and moderate stress level is made. The comparison is done first only with men, and second with the whole population. Policemen with a high stress level (same results only for men and the whole population) belong to the following groups: more than 15 yr service, sergeant, officer and administrative employee rank, divorced experience, age over 30, no leisure-time activities and no hobbies. Multivariate analysis shows that the two last parameters are bound to the stress level. For the whole population, age over 30 has to be added, and for the group of men, length of service over five years should be noted. Stress at work is an ill-health provoking factor. Police from minority groups such as ageing subjects or police officers have been reported to experience greater stress. This population is adversely affected by lack of available manpower and long working hours. In fact sources of stress in the police population are found both in the weariness of the job and private life planning.

Comparison of Highly Resolved Model-Based Exposure ...

EPA Pesticide Factsheets

Human exposure to air pollution in many studies is represented by ambient concentrations from space-time kriging of observed values. Space-time kriging techniques based on a limited number of ambient monitors may fail to capture the concentration from local sources. Further, because people spend more time indoors, using ambient concentration to represent exposure may cause error. To quantify the associated exposure error, we computed a series of six different hourly-based exposure metrics at 16,095 Census blocks of three Counties in North Carolina for CO, NOx, PM2.5, and elemental carbon (EC) during 2012. These metrics include ambient background concentration from space-time ordinary kriging (STOK), ambient on-road concentration from the Research LINE source dispersion model (R-LINE), a hybrid concentration combining STOK and R-LINE, and their associated indoor concentrations from an indoor infiltration mass balance model. Using a hybrid-based indoor concentration as the standard, the comparison showed that outdoor STOK metrics yielded large error at both population (67% to 93%) and individual level (average bias between −10% to 95%). For pollutants with significant contribution from on-road emission (EC and NOx), the on-road based indoor metric performs the best at the population level (error less than 52%). At the individual level, however, the STOK-based indoor concentration performs the best (average bias below 30%). For PM2.5, due to the relatively low co

Radiation effects on MOS devices - dosimetry, annealing, irradiation sequence, and sources

NASA Technical Reports Server (NTRS)

Stassinopoulos, E. G.; Brucker, G. J.; Van Gunten, O.; Knudson, A. R.; Jordan, T. M.

1983-01-01

This paper reports on some investigations of dosimetry, annealing, irradiation sequences, and radioactive sources, involved in the determination of radiation effects on MOS devices. Results show that agreement in the experimental and theoretical surface to average doses support the use of thermo-luminescent dosimeters (manganese activated calcium fluoride) in specifying the surface dose delivered to thin gate insulators of MOS devices. Annealing measurements indicate the existence of at least two energy levels,,s or a activation energies, for recovery of soft oxide MOS devices after irradiation by electrons, protons, and gammas. Damage sensitivities of MOS devices were found to be independent of combinations and sequences of radiation type or energies. Comparison of various gamma sources indicated a small dependence of damage sensitivity on the Cobalt facility, but a more significant dependence in the case of the Cesium source. These results were attributed to differences in the spectral content of the several sources.

High-power multi-megahertz source of waveform-stabilized few-cycle light

PubMed Central

Pronin, O.; Seidel, M.; Lücking, F.; Brons, J.; Fedulova, E.; Trubetskov, M.; Pervak, V.; Apolonski, A.; Udem, Th.; Krausz, F.

2015-01-01

Waveform-stabilized laser pulses have revolutionized the exploration of the electronic structure and dynamics of matter by serving as the technological basis for frequency-comb and attosecond spectroscopy. Their primary sources, mode-locked titanium-doped sapphire lasers and erbium/ytterbium-doped fibre lasers, deliver pulses with several nanojoules energy, which is insufficient for many important applications. Here we present the waveform-stabilized light source that is scalable to microjoule energy levels at the full (megahertz) repetition rate of the laser oscillator. A diode-pumped Kerr-lens-mode-locked Yb:YAG thin-disk laser combined with extracavity pulse compression yields waveform-stabilized few-cycle pulses (7.7 fs, 2.2 cycles) with a pulse energy of 0.15 μJ and an average power of 6 W. The demonstrated concept is scalable to pulse energies of several microjoules and near-gigawatt peak powers. The generation of attosecond pulses at the full repetition rate of the oscillator comes into reach. The presented system could serve as a primary source for frequency combs in the mid infrared and vacuum UV with unprecedented high power levels. PMID:25939968

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

NASA Astrophysics Data System (ADS)

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

2015-05-01

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

Community Perceptions of Air Pollution and Related Health Risks in Nairobi Slums

PubMed Central

Egondi, Thaddaeus; Kyobutungi, Catherine; Ng, Nawi; Muindi, Kanyiva; Oti, Samuel; van de Vijver, Steven; Ettarh, Remare; Rocklöv, Joacim

2013-01-01

Air pollution is among the leading global risks for mortality and responsible for increasing risk for chronic diseases. Community perceptions on exposure are critical in determining people’s response and acceptance of related policies. Therefore, understanding people’ perception is critical in informing the design of appropriate intervention measures. The aim of this paper was to establish levels and associations between perceived pollution and health risk perception among slum residents. A cross-sectional study of 5,317 individuals aged 35+ years was conducted in two slums of Nairobi. Association of perceived score and individual characteristics was assessed using linear regression. Spatial variation in the perceived levels was determined through hot spot analysis using ArcGIS. The average perceived air pollution level was higher among residents in Viwandani compared to those in Korogocho. Perceived air pollution level was positively associated with perceived health risks. The majority of respondents were exposed to air pollution in their place of work with 66% exposed to at least two sources of air pollution. Less than 20% of the respondents in both areas mentioned sources related to indoor pollution. The perceived air pollution level and related health risks in the study community were lowamong the residents indicating the need for promoting awareness on air pollution sources and related health risks. PMID:24157509

Quantifying tap-to-household water quality deterioration in urban communities in Vellore, India: The impact of spatial assumptions.

PubMed

Alarcon Falconi, Tania M; Kulinkina, Alexandra V; Mohan, Venkata Raghava; Francis, Mark R; Kattula, Deepthi; Sarkar, Rajiv; Ward, Honorine; Kang, Gagandeep; Balraj, Vinohar; Naumova, Elena N

2017-01-01

Municipal water sources in India have been found to be highly contaminated, with further water quality deterioration occurring during household storage. Quantifying water quality deterioration requires knowledge about the exact source tap and length of water storage at the household, which is not usually known. This study presents a methodology to link source and household stored water, and explores the effects of spatial assumptions on the association between tap-to-household water quality deterioration and enteric infections in two semi-urban slums of Vellore, India. To determine a possible water source for each household sample, we paired household and tap samples collected on the same day using three spatial approaches implemented in GIS: minimum Euclidean distance; minimum network distance; and inverse network-distance weighted average. Logistic and Poisson regression models were used to determine associations between water quality deterioration and household-level characteristics, and between diarrheal cases and water quality deterioration. On average, 60% of households had higher fecal coliform concentrations in household samples than at source taps. Only the weighted average approach detected a higher risk of water quality deterioration for households that do not purify water and that have animals in the home (RR=1.50 [1.03, 2.18], p=0.033); and showed that households with water quality deterioration were more likely to report diarrheal cases (OR=3.08 [1.21, 8.18], p=0.02). Studies to assess contamination between source and household are rare due to methodological challenges and high costs associated with collecting paired samples. Our study demonstrated it is possible to derive useful spatial links between samples post hoc; and that the pairing approach affects the conclusions related to associations between enteric infections and water quality deterioration. Copyright © 2016 Elsevier GmbH. All rights reserved.

Sources and elemental composition of ambient PM(2.5) in three European cities.

PubMed

Vallius, M; Janssen, N A H; Heinrich, J; Hoek, G; Ruuskanen, J; Cyrys, J; Van Grieken, R; de Hartog, J J; Kreyling, W G; Pekkanen, J

2005-01-20

Source apportionment of urban fine particle mass (PM(2.5)) was performed from data collected during 1998-1999 in Amsterdam (The Netherlands), Erfurt (Germany) and Helsinki (Finland), using principal component analysis (PCA) and multiple linear regression. Six source categories of PM(2.5) were identified in Amsterdam. They were traffic-related particles (30% of the average PM(2.5)), secondary particles (34%), crustal material (7%), oil combustion (11%), industrial and incineration processes (9%), and sea salt (2%). The unidentified PM(2.5) fraction was 7% on the average. In Erfurt, four source categories were extracted with some difficulties in interpretation of source profiles. They were combustion emissions related to traffic (32%), secondary PM (32%), crustal material (21%) and industrial processes (8%). In Erfurt, 3% of PM(2.5) remained unidentified. Air pollution data and source apportionment results from the two Central European cities were compared to previously published results from Helsinki, where about 80% of average PM(2.5) was attributed to transboundary air pollution and particles from traffic and other regional combustion sources. Our results indicate that secondary particles and local combustion processes (mainly traffic) were the most important source categories in all cities; their impact on the average PM(2.5) was almost equal in Amsterdam and Erfurt whereas, in Helsinki, secondary particles made up for as much as half of the total average PM(2.5).

Vertical and horizontal variability of PM10 source contributions in Barcelona during SAPUSS

NASA Astrophysics Data System (ADS)

Brines, Mariola; Dall'Osto, Manuel; Amato, Fulvio; Cruz Minguillón, María; Karanasiou, Angeliki; Alastuey, Andrés; Querol, Xavier

2016-06-01

During the SAPUSS campaign (Solving Aerosol Problems by Using Synergistic Strategies) PM10 samples at 12-hour resolution were simultaneously collected at four monitoring sites located in the urban agglomerate of Barcelona (Spain). A total of 221 samples were collected from 20 September to 20 October 2010. The Road Site (RS) site and the Urban Background (UB) site were located at street level, whereas the Torre Mapfre (TM) and the Torre Collserola (TC) sites were located at 150 m a.s.l. by the sea side within the urban area and at 415 m a.s.l. 8 km inland, respectively. For the first time, we are able to report simultaneous PM10 aerosol measurements, allowing us to study aerosol gradients at both horizontal and vertical levels. The complete chemical composition of PM10 was determined on the 221 samples, and factor analysis (positive matrix factorisation, PMF) was applied. This resulted in eight factors which were attributed to eight main aerosol sources affecting PM10 concentrations in the studied urban environment: (1) vehicle exhaust and wear (2-9 µg m-3, 10-27 % of PM10 mass on average), (2) road dust (2-4 µg m-3, 8-12 %), (3) mineral dust (5 µg m-3, 13-26 %), (4) aged marine (3-5 µg m-3, 13-20 %), (5) heavy oil (0.4-0.6 µg m-3, 2 %), (6) industrial (1 µg m-3, 3-5 %), (7) sulfate (3-4 µg m-3, 11-17 %) and (8) nitrate (4-6 µg m-3, 17-21 %). Three aerosol sources were found to be enhanced at the ground levels (confined within the urban ground levels of the city) relative to the upper levels: (1) vehicle exhaust and wear (2.8 higher), (2) road dust (1.8 higher) and (3) local urban industries/crafts workshops (1.6 higher). Surprisingly, the other aerosol sources were relatively homogeneous at both horizontal and vertical levels. However, air mass origin and meteorological parameters also played a key role in influencing the variability of the factor concentrations. The mineral dust and aged marine factors were found to be a mixture of natural and anthropogenic components and were thus further investigated. Overall, three types of dust were identified to affect the urban study area: road dust (35 % of the mineral dust load, 2-4 µg m-3 on average), Saharan dust (28 %, 2.1 µg m-3) and background mineral dust (37 %, 2.8 µg m-3). Our results evidence that although the city of Barcelona broadly shows a homogeneous distribution of PM10 pollution sources, non-exhaust traffic, exhaust traffic and local urban industrial activities are major coarse PM10 aerosol sources.

Vertical and horizontal variability of PM10 source contributions in Barcelona during SAPUSS

NASA Astrophysics Data System (ADS)

Brines, M.; Dall'Osto, M.; Amato, F.; Minguillón, M. C.; Karanasiou, A.; Alastuey, A.; Querol, X.

2015-11-01

During the SAPUSS campaign (Solving Aerosol Problems by Using Synergistic Strategies) PM10 samples at twelve hours resolution were simultaneously collected at four monitoring sites located in the urban agglomerate of Barcelona (Spain). A total of 221 samples were collected from 20 September to 20 October 2010. The Road Site (RS) site and the Urban Background (UB) site were located at street level, whereas the Torre Mapfre (TM) and the Torre Collserola (TC) sites were located at 150 m a.s.l. by the sea side within the urban area and at 415 m a.s.l. 8 km inland, respectively. For the first time, we are able to report simultaneous PM10 aerosol measurements allowing us to study aerosol gradients at both horizontal and vertical levels. The complete chemical composition of PM10 was determined on the 221 samples, and factor analysis (Positive Matrix Factorisation, PMF) was applied. This resulted in eight factors which were attributed to eight main aerosol sources affecting PM10 concentrations in the studied urban environment: (1) vehicle exhaust and wear (2-9 μg m-3, 10-27 % of PM10 mass on average), (2) road dust (2-4 μg m-3, 8-12 %), (3) mineral dust (5 μg m-3, 13-26 %), (4) aged marine (3-5 μg m-3, 13-20 %), (5) heavy oil (0.4-0.6 μg m-3, 2 %), (6) industrial (1 μg m-3, 3-5 %), (7) sulphate (3-4 μg m-3, 11-17 %) and (8) nitrate (4-6 μg m-3, 17-21 %). Three aerosol sources were found enhanced at the ground levels (confined within the urban ground levels of the city) relative to the upper levels: (1) vehicle exhaust and wear (2.8 higher), (2) road dust (1.8 higher) and (3) local urban industries/crafts workshops (1.6 higher). Surprisingly, the other aerosol sources were relatively homogeneous at both horizontal and vertical levels. However, air mass origin and meteorological parameters also played a key role in influencing the variability of the factors concentrations. The mineral dust and aged marine factors were found to be a mixture of natural and anthropogenic components and were thus further investigated. Overall, three types of dust were identified to affect the urban study area: road dust (35 % of the mineral dust load, 2-4 μg m-3 on average), Saharan dust (28 %, 2.1 μg m-3) and background mineral dust (37 %, 2.8 μg m-3). Our results evidence that although the city of Barcelona broadly shows a homogeneous distribution of PM10 pollution sources, non-exhaust traffic, exhaust traffic and local urban industrial activities are major coarse PM10 aerosol sources.

Modeling population exposures to outdoor sources of hazardous air pollutants.

PubMed

Ozkaynak, Halûk; Palma, Ted; Touma, Jawad S; Thurman, James

2008-01-01

Accurate assessment of human exposures is an important part of environmental health effects research. However, most air pollution epidemiology studies rely upon imperfect surrogates of personal exposures, such as information based on available central-site outdoor concentration monitoring or modeling data. In this paper, we examine the limitations of using outdoor concentration predictions instead of modeled personal exposures for over 30 gaseous and particulate hazardous air pollutants (HAPs) in the US. The analysis uses the results from an air quality dispersion model (the ASPEN or Assessment System for Population Exposure Nationwide model) and an inhalation exposure model (the HAPEM or Hazardous Air Pollutant Exposure Model, Version 5), applied by the US. Environmental protection Agency during the 1999 National Air Toxic Assessment (NATA) in the US. Our results show that the total predicted chronic exposure concentrations of outdoor HAPs from all sources are lower than the modeled ambient concentrations by about 20% on average for most gaseous HAPs and by about 60% on average for most particulate HAPs (mainly, due to the exclusion of indoor sources from our modeling analysis and lower infiltration of particles indoors). On the other hand, the HAPEM/ASPEN concentration ratio averages for onroad mobile source exposures were found to be greater than 1 (around 1.20) for most mobile-source related HAPs (e.g. 1, 3-butadiene, acetaldehyde, benzene, formaldehyde) reflecting the importance of near-roadway and commuting environments on personal exposures to HAPs. The distribution of the ratios of personal to ambient concentrations was found to be skewed for a number of the VOCs and reactive HAPs associated with major source emissions, indicating the importance of personal mobility factors. We conclude that the increase in personal exposures from the corresponding predicted ambient levels tends to occur near locations where there are either major emission sources of HAPs or when individuals are exposed to either on- or nonroad sources of HAPs during their daily activities. These findings underscore the importance of applying exposure-modeling methods, which incorporate information on time-activity, commuting, and exposure factors data, for the purposes of assigning exposures in air pollution health studies.

Analysis of the readability of patient education materials from surgical subspecialties.

PubMed

Hansberry, David R; Agarwal, Nitin; Shah, Ravi; Schmitt, Paul J; Baredes, Soly; Setzen, Michael; Carmel, Peter W; Prestigiacomo, Charles J; Liu, James K; Eloy, Jean Anderson

2014-02-01

Patients are increasingly using the Internet as a source of information on medical conditions. Because the average American adult reads at a 7th- to 8th-grade level, the National Institutes of Health recommend that patient education material be written between a 4th- and 6th-grade level. In this study, we assess and compare the readability of patient education materials on major surgical subspecialty Web sites relative to otolaryngology. Descriptive and correlational design. Patient education materials from 14 major surgical subspecialty Web sites (American Society of Colon and Rectal Surgeons, American Association of Endocrine Surgeons, American Society of General Surgeons, American Society for Metabolic and Bariatric Surgery, American Association of Neurological Surgeons, American Congress of Obstetricians and Gynecologists, American Academy of Ophthalmology, American Academy of Orthopedic Surgeons, American Academy of Otolaryngology-Head and Neck Surgery, American Pediatric Surgical Association, American Society of Plastic Surgeons, Society for Thoracic Surgeons, and American Urological Association) were downloaded and assessed for their level of readability using 10 widely accepted readability scales. The readability level of patient education material from all surgical subspecialties was uniformly too high. Average readability levels across all subspecialties ranged from the 10th- to 15th-grade level. Otolaryngology and other surgical subspecialties Web sites have patient education material written at an education level that the average American may not be able to understand. To reach a broader population of patients, it might be necessary to rewrite patient education material at a more appropriate level. N/A. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Hydrogeology and water quality of the Shell Valley Aquifer, Rolette County, North Dakota

USGS Publications Warehouse

Strobel, M.L.

1997-01-01

The Shell Valley aquifer is the sole source of water for the city of Belcourt and the primary source of water for most of the Turtle Mountain Indian Reservation. The Turtle Mountain Band of Chippewa Indians is concerned about the quantity and quality of water in the Shell Valley aquifer, which underlies about 56 square miles in central Rolette County and has an average saturated thickness of about 35 feet. Water levels across most of the Shell Valley aquifer fluctuate with variations in precipitation but generally are stable. Withdrawals from the north well field decreased slightly during 1976-95, but withdrawals from the south well field increased during 1983-95. Water levels in the south well field declined as withdrawals increased. The average decline during the last 8 years was about 1.75 feet per year. The water level has reached the well screen in at least one of the production wells. Most of the water in the aquifer is a bicarbonate type and has dissolved-solids concentrations ranging from 479 to 1,510 milligrams per liter. None of the samples analyzed had detectable concentrations of pesticides, but hydrocarbons were detected in both ground- and surfacewater samples. Polycyclic aromatic hydrocarbons (PAH) were the most frequently detected hydrocarbons. Benzene, toluene, ethylbenzene, and xylene (BTEX), polychlorinated biphenyls (PCB), and pentachlorophenol (PCP) also were detected.Generally, the Shell Valley aquifer is an adequate source of water for current needs, but evaluation of withdrawals in relation to a knowledge of aquifer hydrology would be important in quantifying sustainable water supplies. Water quality in the aquifer generally is good; the Turtle Mountain Band of Chippewa Indians filters the water to reduce concentrations of dissolved constituents. Hydrocarbons, although present in the aquifer, have not been quantified and may not pose a general health risk. Further analysis of the quantity and distribution of the hydrocarbons would be useful to understand their sources and implications for water use.

Sources and Trends of Nitrogen Loading to New England Estuaries

EPA Science Inventory

A database of nitrogen (N) loading components to estuaries of the conterminous United States has been developed through application of regional SPARROW models. The original SPARROW models predict average detrended loads by source based on average flow conditions and 2002 source t...

Readability of Written Materials for CKD Patients: A Systematic Review.

PubMed

Morony, Suzanne; Flynn, Michaela; McCaffery, Kirsten J; Jansen, Jesse; Webster, Angela C

2015-06-01

The "average" patient has a literacy level of US grade 8 (age 13-14 years), but this may be lower for people with chronic kidney disease (CKD). Current guidelines suggest that patient education materials should be pitched at a literacy level of around 5th grade (age 10-11 years). This study aims to evaluate the readability of written materials targeted at patients with CKD. Systematic review. Patient information materials aimed at adults with CKD and written in English. Patient education materials designed to be printed and read, sourced from practices in Australia and online at all known websites run by relevant international CKD organizations during March 2014. Quantitative analysis of readability using Lexile Analyzer and Flesch-Kincaid tools. We analyzed 80 materials. Both Lexile Analyzer and Flesch-Kincaid analyses suggested that most materials required a minimum of grade 9 (age 14-15 years) schooling to read them. Only 5% of materials were pitched at the recommended level (grade 5). Readability formulas have inherent limitations and do not account for visual information. We did not consider other media through which patients with CKD may access information. Although the study covered materials from the United States, United Kingdom, and Australia, all non-Internet materials were sourced locally, and it is possible that some international paper-based materials were missed. Generalizability may be limited due to exclusion of non-English materials. These findings suggest that patient information materials aimed at patients with CKD are pitched above the average patient's literacy level. This issue is compounded by cognitive decline in patients with CKD, who may have lower literacy than the average patient. It suggests that information providers need to consider their audience more carefully when preparing patient information materials, including user testing with a low-literacy patient population. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Detecting the leakage source of a reservoir using isotopes.

PubMed

Yi, Peng; Yang, Jing; Wang, Yongdong; Mugwanezal, Vincent de Paul; Chen, Li; Aldahan, Ala

2018-07-01

A good monitoring method is vital for understanding the sources of a water reservoir leakage and planning for effective restoring. Here we present a combination of several tracers ( 222 Rn, oxygen and hydrogen isotopes, anions and temperature) for identification of water leakage sources in the Pushihe pumped storage power station which is in the Liaoning province, China. The results show an average 222 Rn activity of 6843 Bq/m 3 in the leakage water, 3034 Bq/m 3 in the reservoir water, and 41,759 Bq/m 3 in the groundwater. Considering that 222 Rn activity in surface water is typically less than 5000 Bq/m 3 , the low level average 222 Rn activity in the leakage water suggests the reservoir water as the main source of water. Results of the oxygen and hydrogen isotopes show comparable ranges and values in the reservoir and the leakage water samples. However, important contribution of the groundwater (up to 36%) was present in some samples from the bottom and upper parts of the underground powerhouse, while the leakage water from some other parts indicate the reservoir water as the dominant source. The isotopic finding suggests that the reservoir water is the main source of the leakage water which is confirmed by the analysis of anions (nitrate, sulfate, and chloride) in the water samples. The combination of these tracer methods for studying dam water leakage improves the accuracy of identifying the source of leaks and provide a scientific reference for engineering solutions to ensure the dam safety. Copyright © 2018 Elsevier Ltd. All rights reserved.

Using air quality modeling to study source-receptor relationships between nitrogen oxides emissions and ozone exposures over the United States.

PubMed

Tong, Daniel Q; Muller, Nicholas Z; Kan, Haidong; Mendelsohn, Robert O

2009-11-01

Human exposure to ambient ozone (O(3)) has been linked to a variety of adverse health effects. The ozone level at a location is contributed by local production, regional transport, and background ozone. This study combines detailed emission inventory, air quality modeling, and census data to investigate the source-receptor relationships between nitrogen oxides (NO(x)) emissions and population exposure to ambient O(3) in 48 states over the continental United States. By removing NO(x) emissions from each state one at a time, we calculate the change in O(3) exposures by examining the difference between the base and the sensitivity simulations. Based on the 49 simulations, we construct state-level and census region-level source-receptor matrices describing the relationships among these states/regions. We find that, for 43 receptor states, cumulative NO(x) emissions from upwind states contribute more to O(3) exposures than the state's own emissions. In-state emissions are responsible for less than 15% of O(3) exposures in 90% of U.S. states. A state's NO(x) emissions can influence 2 to 40 downwind states by at least a 0.1 ppbv change in population-averaged O(3) exposure. The results suggest that the U.S. generally needs a regional strategy to effectively reduce O(3) exposures. But the current regional emission control program in the U.S. is a cap-and-trade program that assumes the marginal damage of every ton of NO(x) is equal. In this study, the average O(3) exposures caused by one ton of NO(x) emissions ranges from -2.0 to 2.3 ppm-people-hours depending on the state. The actual damage caused by one ton of NO(x) emissions varies considerably over space.

RF Design of a High Average Beam-Power SRF Electron Source

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

Sipahi, Nihan; Biedron, Sandra; Gonin, Ivan

2016-06-01

There is a significant interest in developing high-average power electron sources, particularly in the area of electron sources integrated with Superconducting Radio Frequency (SRF) systems. For these systems, the electron gun and cathode parts are critical components for stable intensity and high-average powers. In this initial design study, we will present the design of a 9-cell accelerator cavity having a frequency of 1.3 GHz and the corresponding field optimization studies.

Test Area C-64 Range Environmental Assessment, Revision 1

DTIC Science & Technology

2010-10-01

DOI U.S. Department of the Interior DNL Day–Night Average Sound Level DU Depleted Uranium EBD Environmental Baseline Document EIAP Environmental...vulnerability, burning sensitivity, drop tests, bullet impact tests, sympathetic detonation tests, advanced warhead design tests, and depleted uranium (DU...land back to range use. Source: U.S. Air Force, 2009 DU = depleted uranium ; ERP = Environmental Restoration Program; LUC = land use control; RW

Detection and Identification of Acoustic Signatures

DTIC Science & Technology

2011-08-01

represent complex scenarios such as urban scenes with multiple sources in the soundscape and significant amount of reverberation and diffraction effects... soundscape . In either case it is necessary to understand that the probability of detection is a function of both the vehicle acoustic signature and...the acoustic masking component, or soundscape . And that both signals must be defined in greater depth than overall level, or average frequency

Three-dimensional surgical modelling with an open-source software protocol: study of precision and reproducibility in mandibular reconstruction with the fibula free flap.

PubMed

Ganry, L; Quilichini, J; Bandini, C M; Leyder, P; Hersant, B; Meningaud, J P

2017-08-01

Very few surgical teams currently use totally independent and free solutions to perform three-dimensional (3D) surgical modelling for osseous free flaps in reconstructive surgery. This study assessed the precision and technical reproducibility of a 3D surgical modelling protocol using free open-source software in mandibular reconstruction with fibula free flaps and surgical guides. Precision was assessed through comparisons of the 3D surgical guide to the sterilized 3D-printed guide, determining accuracy to the millimetre level. Reproducibility was assessed in three surgical cases by volumetric comparison to the millimetre level. For the 3D surgical modelling, a difference of less than 0.1mm was observed. Almost no deformations (<0.2mm) were observed post-autoclave sterilization of the 3D-printed surgical guides. In the three surgical cases, the average precision of fibula free flap modelling was between 0.1mm and 0.4mm, and the average precision of the complete reconstructed mandible was less than 1mm. The open-source software protocol demonstrated high accuracy without complications. However, the precision of the surgical case depends on the surgeon's 3D surgical modelling. Therefore, surgeons need training on the use of this protocol before applying it to surgical cases; this constitutes a limitation. Further studies should address the transfer of expertise. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Quantifying the contribution of long-range transport to particulate matter (PM) mass loadings at a suburban site in the north-western Indo-Gangetic Plain (NW-IGP)

NASA Astrophysics Data System (ADS)

Pawar, H.; Garg, S.; Kumar, V.; Sachan, H.; Arya, R.; Sarkar, C.; Chandra, B. P.; Sinha, B.

2015-08-01

Many sites in the densely populated Indo-Gangetic Plain (IGP) frequently exceed the national ambient air quality standard (NAAQS) of 100 μg m-3 for 24 h average PM10 and 60 μg m-3 for 24 h average PM2.5 mass loadings, exposing residents to hazardous levels of particulate matter (PM) throughout the year. We quantify the contribution of long-range transport to elevated PM levels and the number of exceedance events through a back-trajectory climatology analysis of air masses arriving at the IISER Mohali Atmospheric Chemistry facility (30.667° N, 76.729° E; 310 m a.m.s.l.) for the period August 2011-June 2013. Air masses arriving at the receptor site were classified into six clusters, which represent synoptic-scale air-mass transport patterns. Long-range transport from the west leads to significant enhancements in the average fine- and coarse-mode PM mass loadings during all seasons. The contribution of long-range transport from the west and south-west (source regions: Arabia, Thar Desert, Middle East and Afghanistan) to coarse-mode PM varied between 9 and 57 % of the total PM10-2.5 mass. Local pollution episodes (wind speed < 1 m s-1) contributed to enhanced PM2.5 mass loadings during both the winter and summer seasons and to enhanced coarse-mode PM only during the winter season. South-easterly air masses (source region: eastern IGP) were associated with significantly lower fine- and coarse-mode PM mass loadings during all seasons. The fraction of days in each season during which the PM mass loadings exceeded the national ambient air quality standard was controlled by long-range transport to a much lesser degree. For the local cluster, which represents regional air masses (source region: NW-IGP), the fraction of days during which the national ambient air quality standard (NAAQS) of 60 μg m-3 for 24 h average PM2.5 was exceeded varied between 36 % of the days associated with this synoptic-scale transport during the monsoon, and 95 % during post-monsoon and winter seasons; the fraction of days during which the NAAQS of 100 μg m-3 for the 24 h average PM10 was exceeded, varied between 48 % during the monsoon and 98 % during the post-monsoon season. Long-range transport was responsible for both, bringing air masses with a significantly lower fraction of exceedance days from the eastern IGP and air masses with a moderate increase in the fraction of exceedance days from the west (source regions: Arabia, Thar Desert, Middle East and Afghanistan). In order to bring PM mass loadings into compliance with the NAAQS and to reduce the number of exceedance days, mitigation of regional combustion sources in the NW-IGP needs to be given highest priority.

The DZERO Level 3 Data Acquisition System

NASA Astrophysics Data System (ADS)

Angstadt, R.; Brooijmans, G.; Chapin, D.; Clements, M.; Cutts, D.; Haas, A.; Hauser, R.; Johnson, M.; Kulyavtsev, A.; Mattingly, S. E. K.; Mulders, M.; Padley, P.; Petravick, D.; Rechenmacher, R.; Snyder, S.; Watts, G.

2004-06-01

The DZERO experiment began RunII datataking operation at Fermilab in spring 2001. The physics program of the experiment requires the Level 3 data acquisition (DAQ) system system to handle average event sizes of 250 kilobytes at a rate of 1 kHz. The system routes and transfers event fragments of approximately 1-20 kilobytes from 63 VME crate sources to any of approximately 100 processing nodes. It is built upon a Cisco 6509 Ethernet switch, standard PCs, and commodity VME single board computers (SBCs). The system has been in full operation since spring 2002.

Indicators reflecting local and transboundary sources of PM2.5 and PMCOARSE in Rome - Impacts in air quality

NASA Astrophysics Data System (ADS)

Dimitriou, Konstantinos; Kassomenos, Pavlos

2014-10-01

The keystone of this paper was to calculate and interpret indicators reflecting sources and air quality impacts of PM2.5 and PMCOARSE (PM10-PM2.5) in Rome (Italy), focusing on potential exogenous influences. A backward atmospheric trajectory cluster analysis was implemented. The likelihood of daily PM10 exceedances was studied in conjunction with atmospheric patterns, whereas a Potential Source Contribution Function (PSCF) based on air mass residence time was deployed on a grid of a 0.5° × 0.5° resolution. Higher PM2.5 concentrations were associated with short/medium range airflows originated from Balkan Peninsula, whereas potential PMCOARSE sources were localized across the Mediterranean and coastal North Africa, due to dust and sea spray transportation. According to the outcome of a daily Pollution Index (PI), a slightly increased degradation of air quality is induced due to the additional quantity of exogenous PM but nevertheless, average levels of PI in all trajectory clusters belong in the low pollution category. Gaseous and particulate pollutants were also elaborated by a Principal Component Analysis (PCA), which produced 4 components: [Traffic], [photochemical], [residential] and [Secondary Coarse Aerosol], reflecting local sources of air pollution. PM2.5 levels were strongly associated with traffic, whereas PMCOARSE were produced autonomously by secondary sources.

E-Waste Informal Recycling: An Emerging Source of Lead Exposure in South America.

PubMed

Pascale, Antonio; Sosa, Adriana; Bares, Cristina; Battocletti, Alejandra; Moll, María José; Pose, Darío; Laborde, Amalia; González, Hugo; Feola, Gabriella

2016-01-01

Primitive electronic waste (e-waste) recycling creates exposures to several hazardous substances including lead. In Uruguay, primitive recycling procedures are a significant source of lead exposure. The aim of this study was to examine lead exposure in blood lead levels (BLLs) in low-income children exposed to lead through burning cables. A sample of children and adolescents exposed to lead through burning cable activities were assessed at the Department of Toxicology in Montevideo, Uruguay, between 2010 and 2014. Soil lead levels of residences were taken shortly after their assessment. The final sample included 69 children and adolescents (mean age 7.89 years). More than 66% of participants had an additional source of lead exposure-manual gathering of metals-and <5% were exposed to lead through landfills or paint. Average BLLs at first consultation were 9.19 ug/dL and lower at the second measurement (5.86 μg/dL). Data from soil lead levels ranged from 650 to 19,000 mg of lead/kg of soil. The interventions conducted after the assessment included family education in the clinic and at home, indoor and outdoor remediation. We found a decrease in BLLs of 6.96 μg/dL. Older children had lower BLLs (r = -0.24; P = 0.05). Statistical analyses also showed that children living in areas with higher soil lead levels had significantly higher BLLs (r = 0.50; P < 0.01). Additionally, we found greater BLLs from burning cable activities when children had been exposed to lead-based paint (r = 0.23; P < 0.1). Among children exposed to e-waste recycling, the most common additional source of lead exposure was the manual gathering of metals. The average BLL among children and adolescents in this study is higher than the BLLs currently suggested in medical intervention. Future research should focus on exploring effective interventions to reduce lead exposure among this vulnerable group. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Ammunition is the principal source of lead accumulated by California condors re-introduced to the wild.

PubMed

Church, Molly E; Gwiazda, Roberto; Risebrough, Robert W; Sorenson, Kelly; Chamberlain, C Page; Farry, Sean; Heinrich, William; Rideout, Bruce A; Smith, Donald R

2006-10-01

The endangered California Condor (Gymnogyps californianus) was reduced to a total population of 22 birds by the end of 1982. Their captive-bred descendants are now being released back into the wild in California, Arizona, and Baja California, where monitoring indicates they may accumulate lead to toxic levels. Fragments of ammunition in the carcasses of game animals such as deer, elk, and feral pigs not retrieved by hunters or in gut piles left in the field have been considered a plausible source of the lead, though little direct evidence is available to support this hypothesis. Here, we measured lead concentrations and isotope ratios in blood from 18 condors living in the wild in central California, in 8 pre-release birds, and in diet and ammunition samples to determine the importance of ammunition as a source of exposure. Blood lead levels in pre-release condors were low (average 27.7 ng/mL, SD 4.9 ng/ mL) and isotopically similar to dietary and background environmental lead in California. In contrast, blood lead levels in free-flying condors were substantially higher (average 246 ng/mL, SD 229 ng/mL) with lead isotopic compositions that approached or matched those of the lead ammunition. A two-endmember mixing model defined by the background 207Pb/206Pb ratio of representative condor diet samples (0.8346) and the upper 207Pb/206Pb ratio of the ammunition samples (0.8184) was able to account for the blood lead isotopic compositions in 20 out of the 26 live condors sampled in this study (i.e., 77%). Finally, lead in tissues and in a serially sampled growing feather recovered postmortem from a lead-poisoned condor in Arizona evidence acute exposure from an isotopically distinct lead source. Together, these data indicate that incidental ingestion of ammunition in carcasses of animals killed by hunters is the principal source of elevated lead exposure that threatens the recovery in the wild of this endangered species.

[Indoor volatile organic compounds: concentrations, sources, variation factors].

PubMed

Palot, A; Charpin-Kadouch, C; Ercoli, J; Charpin, D

2008-06-01

Volatile organic compounds (V.O.C.) are part of urban air pollution and are also generated indoors from cleaning and maintenance products. VOC measurements are, on average, 10 times higher within homes than outside. Results of the national survey led by the Observatoire National de la Qualité de l'Air Intérieur demonstrated that up to 25% of French homes have very high or high concentrations of VOC. Indoor levels depend mainly on indoor sources. Aldehydes are included in many everyday life products. VOC originate from various household decorating and cleaning products. Some products are less detrimental to the environment and health and have special labelling. Indoor VOC levels also depend on the rate of air exchange and on household characteristics such as indoor temperature and humidity, age of the building, presence of smokers, and communication with a garage. The public may participate in maintaining good indoor air quality and the authorities should also improve regulations. VOC are part of everyday air pollution. Their sources and concentrations should be better monitored.

Source apportionment of PAHs and n-alkanes in respirable particles in Tehran, Iran by wind sector and vertical profile.

PubMed

Moeinaddini, Mazaher; Esmaili Sari, Abbas; Riyahi bakhtiari, Alireza; Chan, Andrew Yiu-Chung; Taghavi, Seyed Mohammad; Hawker, Darryl; Connell, Des

2014-06-01

The vertical concentration profiles and source contributions of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in respirable particle samples (PM4) collected at 10, 100, 200 and 300-m altitude from the Milad Tower of Tehran, Iran during fall and winter were investigated. The average concentrations of total PAHs and total n-alkanes were 16.7 and 591 ng/m(3), respectively. The positive matrix factorization (PMF) model was applied to the chemical composition and wind data to apportion the contributing sources. The five PAH source factors identified were: 'diesel' (56.3% of total PAHs on average), 'gasoline' (15.5%), 'wood combustion, and incineration' (13%), 'industry' (9.2%), and 'road soil particle' (6.0%). The four n-alkane source factors identified were: 'petrogenic' (65% of total n-alkanes on average), 'mixture of petrogenic and biomass burning' (15%), 'mixture of biogenic and fossil fuel' (11.5%), and 'biogenic' (8.5%). Source contributions by wind sector were also estimated based on the wind sector factor loadings from PMF analysis. Directional dependence of sources was investigated using the conditional probability function (CPF) and directional relative strength (DRS) methods. The calm wind period was found to contribute to 4.4% of total PAHs and 5.0% of total n-alkanes on average. Highest average concentrations of PAHs and n-alkanes were found in the 10 and 100 m samples, reflecting the importance of contributions from local sources. Higher average concentrations in the 300 m samples compared to those in the 200 m samples may indicate contributions from long-range transport. The vertical profiles of source factors indicate the gasoline and road soil particle-associated PAHs, and the mixture from biogenic and fossil fuel source-associated n-alkanes were mostly from local emissions. The smaller average contribution of diesel-associated PAHs in the lower altitude samples also indicates that the restriction of diesel-fueled vehicle use in the central area of Tehran has been effective in reducing the PAHs concentration.

Combining near- and far-field exposure for an organ-specific and whole-body RF-EMF proxy for epidemiological research: a reference case.

PubMed

Lauer, Oliver; Frei, Patrizia; Gosselin, Marie-Christine; Joseph, Wout; Röösli, Martin; Fröhlich, Jürg

2013-07-01

A framework for the combination of near-field (NF) and far-field (FF) radio frequency electromagnetic exposure sources to the average organ and whole-body specific absorption rates (SARs) is presented. As a reference case, values based on numerically derived SARs for whole-body and individual organs and tissues are combined with realistic exposure data, which have been collected using personal exposure meters during the Swiss Qualifex study. The framework presented can be applied to any study region where exposure data is collected by appropriate measurement equipment. Based on results derived from the data for the region of Basel, Switzerland, the relative importance of NF and FF sources to the personal exposure is examined for three different study groups. The results show that a 24-h whole-body averaged exposure of a typical mobile phone user is dominated by the use of his or her own mobile phone when a Global System for Mobile Communications (GSM) 900 or GSM 1800 phone is used. If only Universal Mobile Telecommunications System (UMTS) phones are used, the user would experience a lower exposure level on average caused by the lower average output power of UMTS phones. Data presented clearly indicate the necessity of collecting band-selective exposure data in epidemiological studies related to electromagnetic fields. Copyright © 2013 Wiley Periodicals, Inc.

Atmospheric measurement of point source fossil CO2 emissions

NASA Astrophysics Data System (ADS)

Turnbull, J. C.; Keller, E. D.; Baisden, T.; Brailsford, G.; Bromley, T.; Norris, M.; Zondervan, A.

2014-05-01

We use the Kapuni Gas Treatment Plant to examine methodologies for atmospheric monitoring of point source fossil fuel CO2 (CO2ff) emissions. The Kapuni plant, located in rural New Zealand, removes CO2 from locally extracted natural gas and vents that CO2 to the atmosphere, at a rate of ~0.1 Tg carbon per year. The plant is located in a rural dairy farming area, with no other significant CO2ff sources nearby, but large, diurnally varying, biospheric CO2 fluxes from the surrounding highly productive agricultural grassland. We made flask measurements of CO2 and 14CO2 (from which we derive the CO2ff component) and in situ measurements of CO2 downwind of the Kapuni plant, using a Helikite to sample transects across the emission plume from the surface up to 100 m above ground level. We also determined the surface CO2ff content averaged over several weeks from the 14C content of grass samples collected from the surrounding area. We use the WindTrax plume dispersion model to compare the atmospheric observations with the emissions reported by the Kapuni plant, and to determine how well atmospheric measurements can constrain the emissions. The model has difficulty accurately capturing the fluctuations and short-term variability in the Helikite samples, but does quite well in representing the observed CO2ff in 15 min averaged surface flask samples and in ~ one week integrated CO2ff averages from grass samples. In this pilot study, we found that using grass samples, the modeled and observed CO2ff emissions averaged over one week agreed to within 30%. The results imply that greater verification accuracy may be achieved by including more detailed meteorological observations and refining 14C sampling strategies.

The influence of street layouts and viaduct settings on daily carbon monoxide exposure and intake fraction in idealized urban canyons.

PubMed

Hang, Jian; Luo, Zhiwen; Wang, Xuemei; He, Lejian; Wang, Baomin; Zhu, Wei

2017-01-01

Environmental concerns have been raised on the adverse health effects of vehicle emissions in micro-scale traffic-crowded street canyons, especially for pedestrians and residents living in near-road buildings. Viaduct design is sometimes used to improve transportation efficiency but possibly affects urban airflow and the resultant exposure risk, which have been rarely investigated so far. The personal intake fraction (P_IF) is defined as the average fraction of total emissions that is inhaled by each person of a population (1 ppm = 1 × 10 -6 ), and the daily carbon monoxide (CO) pollutant exposure (E t ) is estimated by multiplying the average concentration of a specific micro-environment within one day. As a novelty, by considering time activity patterns and breathing rates in various micro-environments for three age groups, this paper introduces IF and E t into computational fluid dynamic (CFD) simulation to quantify the impacts of street layouts (street width/building height W/H = 1, 1.5, 2), source location, viaduct settings and noise barriers on the source-exposure correlation when realistic CO sources are defined. Narrower streets experience larger P_IF (1.51-5.21 ppm) and CO exposure, and leeward-side buildings always attain higher vehicular pollutant exposure than windward-side. Cases with a viaduct experience smaller P_IF (3.25-1.46 ppm) than cases without a viaduct (P_IF = 5.21-2.23 ppm) if the single ground-level CO source is elevated onto the viaduct. With two CO sources (both ground-level and viaduct-level), daily CO exposure rises 2.80-3.33 times but P_IF only change slightly. Noise barriers above a viaduct raise concentration between barriers, but slightly reduce vehicular exposure in near-road buildings. Because people spend most of their time indoors, vehicular pollutant exposure within near-road buildings can be 6-9 times that at pedestrian level. Although further studies are still required to provide practical guidelines, this paper provides effective methodologies to quantify the impacts of street/viaduct configurations on human exposure for urban design purpose. Copyright © 2016 Elsevier Ltd. All rights reserved.

Leading multiple teams: average and relative external leadership influences on team empowerment and effectiveness.

PubMed

Luciano, Margaret M; Mathieu, John E; Ruddy, Thomas M

2014-03-01

External leaders continue to be an important source of influence even when teams are empowered, but it is not always clear how they do so. Extending research on structurally empowered teams, we recognize that teams' external leaders are often responsible for multiple teams. We adopt a multilevel approach to model external leader influences at both the team level and the external leader level of analysis. In doing so, we distinguish the influence of general external leader behaviors (i.e., average external leadership) from those that are directed differently toward the teams that they lead (i.e., relative external leadership). Analysis of data collected from 451 individuals, in 101 teams, reporting to 25 external leaders, revealed that both relative and average external leadership related positively to team empowerment. In turn, team empowerment related positively to team performance and member job satisfaction. However, while the indirect effects were all positive, we found that relative external leadership was not directly related to team performance, and average external leadership evidenced a significant negative direct influence. Additionally, relative external leadership exhibited a significant direct positive influence on member job satisfaction as anticipated, whereas average external leadership did not. These findings attest to the value in distinguishing external leaders' behaviors that are exhibited consistently versus differentially across empowered teams. Implications and future directions for the study and management of external leaders overseeing multiple teams are discussed.

Mercury Speciation in Hair of Children in Three Communities of the Amazon, Brazil

PubMed Central

Marinho, Jamile Salim; Lima, Marcelo Oliveira; Santos, Elisabeth Conceição de Oliveira; de Jesus, Iracina Maura; Pinheiro, Maria da Conceição N.; Alves, Cláudio Nahum; Muller, Regina Celi Sarkis

2014-01-01

Children from riverside communities located downstream of gold mining areas may be chronically exposed to relatively high levels of MeHg through the consumption of fish of this region. The objective of this study was to evaluate and compare levels of THg and MeHg in hair of children less than 12 years in communities near mines in the municipality of Itaituba and in communities far from prospecting areas in the city of Abaetetuba. The communities of Itaituba (Barreiras and São Luiz do Tapajós) had THg mean levels of 5.64 ± 5.55 μg·g−1 (0.43–27.82) and 11.41 ± 7.16 μg.g−1 (1.08–28.17), respectively, and an average count of MeHg relative to THg of 92.20% and 90.27%, respectively. In the Maranhão community, the THg average concentrations results were 2.27 ± 2.11 μg·g−1 (0.13–9.54) and the average values were 93.17% for MeHg. Children of Itaituba had average levels of mercury above the limit established by the World Health Organization (10 μg·g−1) and the strong correlation coefficient between the communities (R = 0.968 and P = 0.0001) suggests the hair as an excellent biomarker of human exposure to organic mercury in riverside populations of the Tapajós, which has the intake of fish daily as main source of protein dietary. PMID:24734253

Evaluation of the effects of pharmacological zinc oxide and phosphorus source on weaned piglet growth performance, plasma minerals and mineral digestibility.

PubMed

Walk, C L; Wilcock, P; Magowan, E

2015-07-01

Crossbred pigs (n=720; average age=28±3 days and weight=9.5±0.3 kg) were used in a 20-day trial in order to determine the influence of phosphorus (P) source and various doses of pharmacological zinc (Zn) on growth performance, plasma minerals and mineral digestibility. Pigs (five intact males and five females per pen) were randomly allotted to treatments in a 3×3 factorial arrangement with three sources of dietary P (4.5 g/kg digestible P, 4.5 g/kg digestible P plus 2500 phytase units (FTU)/kg, or 5.5 g/kg digestible P) and three dietary levels of supplemental Zn (0, 1750 or 3500 mg/kg) from ZnO (82% Zn) with eight pens per treatment. Diets were formulated to exceed all nutrient requirements, including calcium (Ca), P and Zn from day 0 to 20. Zn supplementation increased (quadratic P<0.05) average daily feed intake. There was a significant Zn level×P source interaction on average daily gain and feed conversion ratio (FCR). Pigs fed 4.5 g/kg digestible P without or with 2500 FTU/kg phytase gained more per day (quadratic P<0.05) and had better FCR (quadratic P<0.05) when they were fed 1750 mg/kg supplemental Zn. However, pigs fed 5.5 g/kg digestible P gained more per day (linear P<0.05) and were more efficient (linear P<0.05) when they were fed 3500 mg/kg supplemental Zn. Plasma Zn and Zn digestibility increased (linear P<0.05) as pharmacological Zn supplementation increased from 0 to 3500 mg/kg, irrespective of P source. However, Ca, P, sodium (Na), potassium (K) and copper (Cu) digestibility were reduced (P<0.05) as pharmacological Zn supplementation increased, and this was mitigated or exacerbated by the supplementation of 5.5 g/kg digestible P or phytase. In conclusion, increasing the dietary inclusion of pharmacological Zn may impact growth performance in young pigs through the interaction with minerals such as Ca, P, Na and K. Pharmacological Zn may reduce Na or K digestibility and indirectly reduce water secretion into the lumen, resulting in an increase in faecal dry matter as pharmacological Zn supplementation in the diet increased.

Occupational Noise Reduction in CNC Striping Process

NASA Astrophysics Data System (ADS)

Mahmad Khairai, Kamarulzaman; Shamime Salleh, Nurul; Razlan Yusoff, Ahmad

2018-03-01

Occupational noise hearing loss with high level exposure is common occupational hazards. In CNC striping process, employee that exposed to high noise level for a long time as 8-hour contributes to hearing loss, create physical and psychological stress that reduce productivity. In this paper, CNC stripping process with high level noises are measured and reduced to the permissible noise exposure. First condition is all machines shutting down and second condition when all CNC machine under operations. For both conditions, noise exposures were measured to evaluate the noise problems and sources. After improvement made, the noise exposures were measured to evaluate the effectiveness of reduction. The initial average noise level at the first condition is 95.797 dB (A). After the pneumatic system with leakage was solved, the noise reduced to 55.517 dB (A). The average noise level at the second condition is 109.340 dB (A). After six machines were gathered at one area and cover that area with plastic curtain, the noise reduced to 95.209 dB (A). In conclusion, the noise level exposure in CNC striping machine is high and exceed the permissible noise exposure can be reduced to acceptable levels. The reduction of noise level in CNC striping processes enhanced productivity in the industry.

An ensemble pulsar time

NASA Technical Reports Server (NTRS)

Petit, Gerard; Thomas, Claudine; Tavella, Patrizia

1993-01-01

Millisecond pulsars are galactic objects that exhibit a very stable spinning period. Several tens of these celestial clocks have now been discovered, which opens the possibility that an average time scale may be deduced through a long-term stability algorithm. Such an ensemble average makes it possible to reduce the level of the instabilities originating from the pulsars or from other sources of noise, which are unknown but independent. The basis for such an algorithm is presented and applied to real pulsar data. It is shown that pulsar time could shortly become more stable than the present atomic time, for averaging times of a few years. Pulsar time can also be used as a flywheel to maintain the accuracy of atomic time in case of temporary failure of the primary standards, or to transfer the improved accuracy of future standards back to the present.

Sources and production of organic aerosol in Mexico City: insights from the combination of a chemical transport model (PMCAMx-2008) and measurements during MILAGRO

NASA Astrophysics Data System (ADS)

Tsimpidi, A. P.; Karydis, V. A.; Zavala, M.; Lei, W.; Bei, N.; Molina, L.; Pandis, S. N.

2010-11-01

Urban areas are large sources of organic aerosols and their precursors. Nevertheless, the contributions of primary (POA) and secondary organic aerosol (SOA) to the observed particulate matter levels have been difficult to quantify. In this study the three-dimensional chemical transport model PMCAMx-2008 is used to investigate the temporal and geographic variability of organic aerosol in the Mexico City Metropolitan Area (MCMA) during the MILAGRO campaign that took place in the spring of 2006. The organic module of PMCAMx-2008 is based on the volatility basis-set approach: both primary and secondary organic components are assumed to be semi-volatile and photochemically reactive and are distributed in logarithmically spaced volatility bins. The MCMA emission inventory is modified and the POA emissions are distributed by volatility based on dilution experiments. The model predictions are compared with observations from four different types of sites, an urban (T0), a suburban (T1), a rural (T2), and an elevated site in Pico Tres Padres (PTP). The performance of the model in reproducing organic mass concentrations in these sites was encouraging. The average predicted PM1 OA concentration in T0, T1, and T2 was 18 μg m-3, 11.7 μg m-3, and 10.5 μg m-3 respectively, while the corresponding measured values were 17.2 μg m-3, 11 μg m-3, and 9 μg m-3. The average predicted fresh primary OA concentrations were 4.4 μg m-3 at T0, 1.2 μg m-3 at T1 and 1.7 μg m-3 at PTP in reasonably good agreement with the corresponding PMF analysis estimates based on the AMS observations of 4.5, 1.3, and 2.9 μg m-3 respectively. The model reproduced reasonably well the average oxygenated OA (OOA) levels in T0 (7.5 μg m-3 predicted versus 7.5 μg m-3 measured), in T1 (6.3 μg m-3 predicted versus 4.6 μg m-3 measured) and in PTP (6.6 μg m-3 predicted versus 5.9 μg m-3 measured). Inside Mexico City, the locally produced OA is predicted to be on average 53% fresh primary (POA), 11% semi-volatile (S-SOA) and intermediate volatile (I-SOA) organic aerosol, and 36% traditional SOA from the oxidation of VOCs (V-SOA). The long range transport from biomass burning activities and other sources in Mexico is predicted to contribute on average almost as much as the local sources during the MILAGRO period.

A reassessment of the sources and importance of land-derived organic matter in surface sediments from the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Goñi, Miguel A.; Ruttenberg, Kathleen C.; Eglinton, Timothy I.

1998-09-01

Organic matter in surface sediments from two onshore-offshore transects in the northwestern Gulf of Mexico was characterized by a variety of techniques, including elemental, stable carbon, radiocarbon, and molecular-level analyses. In spite of the importance of the Mississippi River as a sediment source, there is little evidence for a significant terrigenous input based on the low carbon:nitrogen ratios (8-5) and the enriched δ 13C values of bulk sedimentary organic carbon (-19.7‰ to -21.7‰). Radiocarbon analyses, on the other hand, yield depleted Δ 14C values (-277‰ to -572‰) which indicate that a significant fraction of the sedimentary organic carbon (OC) in all these surface sediments must be relatively old and most likely of allochthonous origin. CuO oxidations yield relatively low quantities of lignin products (0.4-1.4 mg/100 mg OC) along with compounds derived from proteins, polysaccharides, and lipids. Syringyl:vanillyl and cinnamyl:vanillyl ratios (averaging 1.6 and 0.5, respectively) and acid:aldehyde ratios for both vanillyl and syringyl phenols (averaging 0.8 and 1.2, respectively) indicate that the lignin present in sediments originates from nonwoody angiosperm sources and is highly degraded. The δ 13C values of lignin phenols in shelf sediments are relatively depleted in 13C (averaging -26.3‰) but are increasingly enriched in 13C at the slope sites (averaging -17.5‰ for the two deepest stations). We interpret these molecular and isotopic compositions to indicate that a significant fraction (≥50%) of the lignin and, by inference, the land-derived organic carbon in northwestern Gulf of Mexico sediments ultimately originated from C 4 plants. The source of this material is likely to be soil organic matter eroded from the extensive grasslands of the Mississippi River drainage basin. Notably, the mixed C 4 and C 3 source and the highly degraded state of this material hampers its recognition and quantification in shelf and slope sediments. Our data are consistent with higher than previously estimated inputs of land-derived organic carbon to regions of the ocean, such as the Gulf of Mexico, with significant sources of terrigenous C 4-derived organic matter.

Mercury Levels in Women and Children from Interior Villages in Suriname, South America.

PubMed

Ouboter, Paul E; Landburg, Gwendolyn; Satnarain, Gaitrie U; Starke, Sheryl Y; Nanden, Indra; Simon-Friedt, Bridget; Hawkins, William B; Taylor, Robert; Lichtveld, Maureen Y; Harville, Emily; Wickliffe, Jeffrey K

2018-05-17

Natural sources of mercury, historical gold mining, and contemporary artisanal and small-scale gold mining (ASGM) activities have led to mercury contamination in Suriname. Our primary objective was to evaluate mercury levels in hair of women and children from interior villages in Suriname where mercury levels in fish are elevated. We also estimated blood levels of mercury using an established mathematical conversion to facilitate comparison with other biomonitoring programs in the United States. Estimated levels of mercury in the blood of participants from Suriname were significantly higher than those in women from a heavy marine fish-consuming population in southeast Louisiana and estimates of the US national average. This includes women from Surinamese villages well upstream of ASGM activities. Since residents in these areas rely heavily on local fish, this is likely the source of their exposure to mercury. The levels in hair are similar to those seen in women from longitudinal studies finding neurological impairments in children exposed pre- and postnatally. Additional biomonitoring and neurodevelopmental assessments are warranted in these areas, as well as other areas of the Suriname. Mercury levels in hair (Suriname) and blood (southeast LA USA) were determined using cold vapor atomic absorption spectroscopy (CVAAS).

Polycyclic aromatic hydrocarbons (PAHs) concentration levels, pattern, source identification and soil toxicity assessment in urban traffic soil of Dhanbad, India.

PubMed

Suman, Swapnil; Sinha, Alok; Tarafdar, Abhrajyoti

2016-03-01

Present study was carried out to assess and understand potential health risk and to examine the impact of vehicular traffic on the contamination status of urban traffic soils in Dhanbad City with respect to polycyclic aromatic hydrocarbons (PAHs). Eight urban traffic sites and two control/rural site surface soils were analyzed and the contents of 13 priority PAHs was determined. Total PAH concentration at traffic sites ranged from 1.019 μg g(-1) to 10.856 μg g(-1) with an average value of 3.488 μg g(-1). At control/rural site, average concentration of total PAHs was found to be 0.640 μg g(-1). PAH pattern was dominated by four- and five-ring PAHs (contributing >50% to the total PAHs) at all the eight traffic sites. On the other hand, rural soil showed a predominance of low molecular weight three-ring PAHs (contributing >30% to the total PAHs). Indeno[123-cd]pyrene/benz[ghi]perylene (IP/BgP) ratio indicated that PAH load at the traffic sites is predominated by the gasoline-driven vehicles. The ratio of Ant/(Ant+Phe) varied from 0.03 to 0.44, averaging 0.10; Fla/(Fla+Pyr) from 0.39 to 0.954, averaging 0.52; BaA/(BaA+Chry) from 0.156 to 0.60, averaging 0.44; and IP/(IP+BgP) from 0.176 to 0.811, averaging 0.286. The results indicated that vehicular emission was the major source for PAHs contamination with moderate effect of coal combustion and biomass combustion. Carcinogenic potency of PAH load in traffic soil was nearly 6.15 times higher as compared to the control/rural soil. Copyright © 2015 Elsevier B.V. All rights reserved.

Source investigation of personal particulates in relation to identify major routes of exposure among urban residentials

NASA Astrophysics Data System (ADS)

Gadkari, Neelima M.; Pervez, Shamsh

Multiple 24-h average outdoor, indoor and personal respirable particulate matter (RPM) measurements were made in different urban residential colonies to determine major routes of personal exposure. The study area was Bhilai-Durg, District Durg, Chhattisgarh, India. About 100 residentials from each of two selected colonies have been surveyed for consent to participate in the study and for preparation of time-activity diary. On the basis of their time-activity diary, residentials have been categorized into three types: type-A, purely residential; type-B, residents who go out, and type-C, residence who go into work, specially in industrial area. A total of 28 adult participants (14 males and 14 females; mean age 40±15, range 21-61 years) were selected and monitored longitudinally during the summer (15 March-15 June) of 2004. Participants' residential indoor RPM level and also local ambient outdoor RPM levels were measured,and these are done simultaneous with personal monitoring. Residential indoor and ambient outdoors RPM monitoring sessions were throughout the year to obtain infiltration factor more precisely. To compare RPM levels with Indian National Ambient Air Quality Standards (NAAQS) of PM 10, simultaneous measurements of PM 10 were also done with the course of ambient outdoor RPM monitoring. RPM levels in indoors were higher compared to ambient outdoors. The annual average ratio RPM/PM 10 was found to vary significantly among residential sites due to variation in surroundings. Source contribution estimates (SCE) of personal exposure to RPM in selected 12 residences (six from each colony) have been investigated using chemical mass balance model CMB8. Ambient outdoors, residential indoors, soils and road-traffic borne RPM were identified as main routes and principal sources of personal RPM. Results of model output have shown that residential indoors and soil-borne RPM are the major routes of personal exposure.

Speciated atmospheric mercury and its potential source in Guiyang, China

NASA Astrophysics Data System (ADS)

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

2011-08-01

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

Characterization of Greater-Than-Class C sealed sources. Volume 3, Sealed sources held by general licensees

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

Harris, G.

1994-09-01

This is the third volume in a series of three volumes characterizing the population of sealed sources that may become greater-than-Class C low-level radioactive waste (GTCC LLW). In this volume, those sources possessed by general licensees are discussed. General-licensed devices may contain sealed sources with significant amounts of radioactive material. However, the devices are designed to be safe to use without special knowledge of radiological safety practices. Devices containing Am-241 or Cm-244 sources are most likely to become GTCC LLW after concentration averaging. This study estimates that there are about 16,000 GTCC devices held by general licensees; 15,000 of thesemore » contain Am-241 sources and 1,000 contain Cm-244 sources. Additionally, this study estimates that there are 1,600 GTCC devices sold to general licensees each year. However, due to a lack of available information on general licensees in Agreement States, these estimates are uncertain. This uncertainty is quantified in the low and high case estimates given in this report, which span approximately an order of magnitude.« less

OH detection by Ford Motor Company

NASA Technical Reports Server (NTRS)

Wang, Charles C.

1986-01-01

Two different methods for detection of OH are presented: a low pressure flow cell system and a frequency modulation absorption measurement. Using conventional absorption spectroscopy, detection limits were quoted of 1,000,000 OH molecules per cu cm using a 30-minute averaging time on the ground, and a 3-hour averaging time in the air for present apparatus in use. With the addition of FM spectroscopy at 1 GHz, a double-beam machine should permit detectable absorption of and an OH limit of 100,000 per cu cm in a 30-minute averaging time. In the low pressure system on which experiments are ongoing nonexponential time behavior was observed after the decay had progressed to about 0.3 of its original level; this was attributed to ion emission in the photomultiplier. A flame source with OH present at high concentration levels was used as a calibration. It was estimated that within the sampling chamber, 400,000 OH could be measured. With a factor-of-2 loss at the sampling orifice, this means detectability of 5 to 8 x 100,000 cu cm at the present time. This could be reduced by a factor of 2 in one hour averaging time; improvements in laser bandwidth and energy should provide another factor of 2 in sensitivity.

OH detection by Ford Motor Company

NASA Astrophysics Data System (ADS)

Wang, Charles C.

1986-12-01

Two different methods for detection of OH are presented: a low pressure flow cell system and a frequency modulation absorption measurement. Using conventional absorption spectroscopy, detection limits were quoted of 1,000,000 OH molecules per cu cm using a 30-minute averaging time on the ground, and a 3-hour averaging time in the air for present apparatus in use. With the addition of FM spectroscopy at 1 GHz, a double-beam machine should permit detectable absorption of and an OH limit of 100,000 per cu cm in a 30-minute averaging time. In the low pressure system on which experiments are ongoing nonexponential time behavior was observed after the decay had progressed to about 0.3 of its original level; this was attributed to ion emission in the photomultiplier. A flame source with OH present at high concentration levels was used as a calibration. It was estimated that within the sampling chamber, 400,000 OH could be measured. With a factor-of-2 loss at the sampling orifice, this means detectability of 5 to 8 x 100,000 cu cm at the present time. This could be reduced by a factor of 2 in one hour averaging time; improvements in laser bandwidth and energy should provide another factor of 2 in sensitivity.

Occurrence and levels of polybrominated diphenyl ethers in surface sediments from the Yellow River Estuary, China.

PubMed

Yuan, Zijiao; Liu, Guijian; Lam, Michael Hon Wah; Liu, Houqi; Da, Chunnian

2016-05-01

A total of 21 surface sediments collected from the Yellow River Estuary, China were analyzed for 40 kinds of polybrominated diphenyl ethers (PBDEs) using gas chromatography-mass spectrometry (GC-MS). Their levels, spatial distribution, congener profiles and possible sources were investigated. Only ten congeners were detected in the sediments. The total concentrations of the lower brominated BDEs (∑PBDEslow, PBDEs excluding BDE 209) and BDE 209 ranged from 0.482 ng/g to 1.07 ng/g and 1.16-5.40 ng/g, with an average value of 0.690 and 2.79 ng/g, respectively, which were both at the low end of the global contamination level. The congener profiles were dominated by BDE 209, with the average value accounting for 79.2% of the total PBDEs in the sediment samples. Among the nine lower brominated BDE congeners, BDE 47, 99 and 183 had high abundances. Although the commercial Penta/Octa-BDE products have been banned in most countries, the residual commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds such as BDE 209 were still found to be the possible sources for the trace level of PBDEs in the present study area. In spite of the gradual removal of the commercial PBDEs in the world, the present research results further suggested that scientific attention should not be reduced on the issue of environmental contamination caused by these outdated chemical compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

Average optimal DPOAE primary tone levels in normal-hearing adults.

PubMed

Marcrum, Steven C; Kummer, Peter; Kreitmayer, Christoph; Steffens, Thomas

2016-01-01

Despite great progress towards optimizing DPOAE primary tone characteristics, factors such as stimulus and intra-subject emission variability have not been addressed. The purpose of this study was to identify optimal primary tone level relationships when these sources of variability were acknowledged, and to identify any influences of test frequency. Following coupler-based measurements assessing primary tone level stability, two experiments were conducted. In experiment 1, DPOAE test-retest reliability without probe replacement was measured for f2 = 1-6 kHz with L1 = L2 = 65 dB SPL. In experiment 2, optimal L1-L2 relationships were identified for f2 = 1-6 kHz. For 20 ≤ L2 ≤ 75 dB SPL, L1 was varied 15 dB SPL above and below the recommendation of L1 = 0.4 L2 + 39 [dB SPL]. Eleven normal-hearing adults participated in experiment 1. Thirty normal-hearing adults participated in experiment 2. Stimulus variability did not exceed 0.1 dB SPL. DPOAE reliability testing revealed an across-frequency mean standard error of measurement of 0.52 dB SPL. The average optimal L1-L2 relationship was described by L1 = 0.49 L2 + 41 [dB SPL]. A significant effect of frequency was identified for 6 kHz. Including relevant sources of variability improves internal validity of a primary tone level optimization formula.

Serum concentrations of polychlorinated dibenzo-p-dioxins among ceramicists.

PubMed

Demond, Avery; Jiang, Xiaohui; Broadwater, Kendra; Meeker, John; Luksemburg, William; Maier, Martha; Garabrant, David; Franzblau, Alfred

2015-01-01

Polychlorinated dibenzo-p-dioxins (PCDDs) occur naturally in ball clay at elevated concentrations. Thus, persons who habitually work with clay may be at risk for exposure to PCDDs. An earlier case report provided some evidence of elevated PCDD levels in serum for long-term hobby ceramicists; however, no previous study has measured serum dioxin concentrations among ceramicists. This study measured PCDD serum levels for 27 individuals involved in ceramics making. The average residual, defined as the average of the [log measured serum lipid concentration – log background serum lipid concentration], was calculated and then tested to determine whether it was significantly different from zero. The p-values for the average residuals indicated that the serum lipid concentrations for several PCDD congeners were elevated relative to background. The number of significant residuals increased dramatically if the background concentrations were adjusted to account for the fact that they were not contemporaneous with the measurements for the ceramicists. The ratio of the 1,2,3,6,7,8-HxCDD concentration to the 1,2,3,7,8,9-HxCDD concentration was greater than 1.0, unlike in ball clay, suggesting that although long-term working with ball clay elevates the PCDD levels in serum somewhat, it is not the predominant source of the PCDD body burden for ceramicists.

Cost effectiveness of the US Geological Survey's stream-gaging programs in New Hampshire and Vermont

USGS Publications Warehouse

Smath, J.A.; Blackey, F.E.

1986-01-01

Data uses and funding sources were identified for the 73 continuous stream gages currently (1984) being operated. Eight stream gages were identified as having insufficient reason to continue their operation. Parts of New Hampshire and Vermont were identified as needing additional hydrologic data. New gages should be established in these regions as funds become available. Alternative methods for providing hydrologic data at the stream gaging stations currently being operated were found to lack the accuracy that is required for their intended use. The current policy for operation of the stream gages requires a net budget of $297,000/yr. The average standard error of estimation of the streamflow records is 17.9%. This overall level of accuracy could be maintained with a budget of $285,000 if resources were redistributed among gages. Cost-effective analysis indicates that with the present budget, the average standard error could be reduced to 16.6%. A minimum budget of $278,000 is required to operate the present stream gaging program. Below this level, the gages and recorders would not receive the proper service and maintenance. At the minimum budget, the average standard error would be 20.4%. The loss of correlative data is a significant component of the error in streamflow records, especially at lower budgetary levels. (Author 's abstract)

Generation of high powers from diode pumped chromium-3+ doped colquiriites

NASA Astrophysics Data System (ADS)

Eichenholz, Jason Matthew

1998-12-01

There is considerable interest in the area of laser diode pumped solid-state lasers. Diode pumped solid-state lasers (DPSSL) operating at high average power levels are attractive light sources for various applications such as materials processing, laser radar, and fundamental physics experiments. These laser systems have become more commonplace because of their efficiency, reliability, compactness, low relative cost, and long operational lifetimes. Induced thermal effects in the solid-state laser medium hinder the scaling of DPSSL's to higher average power levels. Therefore a deep insight into the thermo-mechanical properties of the solid state laser is crucial in order to ensure a laser design which is optimized for high average power operation. A comprehensive study of the factors that contribute to thermal loading of the colquiriites was performed. A three-dimensional thermal model has been created to determine the temperature rise inside the laser crystal. This new model calculates the temperature distribution by considering quantum defect, upconversion, and upper-state lifetime quenching as heating sources. The thermally induced lensing in end pumped Cr3+ doped LiSrAlF6, LiSrGaF6, LiSrCaAlF6, and LiCaAlF6 were experimentally measured. Several diode pumped colquiriite laser systems were assembled to quantitatively observe and identify thermally induced effects. Significant differences in each of the colquiriite materials were observed. These differences are explained by the differences in the thermo-mechanical and thermo-optical properties of the material and are explained by the theoretical thermal model.

Relativistic MR–MP Energy Levels for L-shell Ions of Silicon

DOE PAGES

Santana, Juan A.; Lopez-Dauphin, Nahyr A.; Beiersdorfer, Peter

2018-01-15

Level energies are reported for Si v, Si vi, Si vii, Si viii, Si ix, Si x, Si xi, and Si xii. The energies have been calculated with the relativistic Multi-Reference Møller–Plesset Perturbation Theory method and include valence and K-vacancy states with nl up to 5f. The accuracy of the calculated level energies is established by comparison with the recommended data listed in the National Institute of Standards and Technology (NIST) online database. The average deviation of valence level energies ranges from 0.20 eV in Si v to 0.04 eV in Si xii. For K-vacancy states, the available values recommendedmore » in the NIST database are limited to Si xii and Si xiii. The average energy deviation is below 0.3 eV for K-vacancy states. The extensive and accurate data set presented here greatly augments the amount of available reference level energies. Here, we expect our data to ease the line identification of L-shell ions of Si in celestial sources and laboratory-generated plasmas, and to serve as energy references in the absence of more accurate laboratory measurements.« less

Relativistic MR–MP Energy Levels for L-shell Ions of Silicon

NASA Astrophysics Data System (ADS)

Santana, Juan A.; Lopez-Dauphin, Nahyr A.; Beiersdorfer, Peter

2018-01-01

Level energies are reported for Si V, Si VI, Si VII, Si VIII, Si IX, Si X, Si XI, and Si XII. The energies have been calculated with the relativistic Multi-Reference Møller–Plesset Perturbation Theory method and include valence and K-vacancy states with nl up to 5f. The accuracy of the calculated level energies is established by comparison with the recommended data listed in the National Institute of Standards and Technology (NIST) online database. The average deviation of valence level energies ranges from 0.20 eV in Si V to 0.04 eV in Si XII. For K-vacancy states, the available values recommended in the NIST database are limited to Si XII and Si XIII. The average energy deviation is below 0.3 eV for K-vacancy states. The extensive and accurate data set presented here greatly augments the amount of available reference level energies. We expect our data to ease the line identification of L-shell ions of Si in celestial sources and laboratory-generated plasmas, and to serve as energy references in the absence of more accurate laboratory measurements.

VizieR Online Data Catalog: Relativistic MR-MP energy levels for Si (Santana+, 2018)

NASA Astrophysics Data System (ADS)

Santana, J. A.; Lopez-Dauphin, N. A.; Beiersdorfer, P.

2018-03-01

Level energies are reported for Si V, Si VI, Si VII, Si VIII, Si IX, Si X, Si XI, and Si XII. The energies have been calculated with the relativistic Multi- Reference Moller-Plesset Perturbation Theory method and include valence and K-vacancy states with nl up to 5f. The accuracy of the calculated level energies is established by comparison with the recommended data listed in the National Institute of Standards and Technology (NIST) online database. The average deviation of valence level energies ranges from 0.20eV in SiV to 0.04eV in SiXII. For K-vacancy states, the available values recommended in the NIST database are limited to Si XII and Si XIII. The average energy deviation is below 0.3eV for K-vacancy states. The extensive and accurate data set presented here greatly augments the amount of available reference level energies. We expect our data to ease the line identification of L-shell ions of Si in celestial sources and laboratory-generated plasmas, and to serve as energy references in the absence of more accurate laboratory measurements. (1 data file).

Relativistic MR–MP Energy Levels for L-shell Ions of Silicon

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

Santana, Juan A.; Lopez-Dauphin, Nahyr A.; Beiersdorfer, Peter

Level energies are reported for Si v, Si vi, Si vii, Si viii, Si ix, Si x, Si xi, and Si xii. The energies have been calculated with the relativistic Multi-Reference Møller–Plesset Perturbation Theory method and include valence and K-vacancy states with nl up to 5f. The accuracy of the calculated level energies is established by comparison with the recommended data listed in the National Institute of Standards and Technology (NIST) online database. The average deviation of valence level energies ranges from 0.20 eV in Si v to 0.04 eV in Si xii. For K-vacancy states, the available values recommendedmore » in the NIST database are limited to Si xii and Si xiii. The average energy deviation is below 0.3 eV for K-vacancy states. The extensive and accurate data set presented here greatly augments the amount of available reference level energies. Here, we expect our data to ease the line identification of L-shell ions of Si in celestial sources and laboratory-generated plasmas, and to serve as energy references in the absence of more accurate laboratory measurements.« less

Project ArchimedeZ

DTIC Science & Technology

2015-05-18

of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering...describe the proposed content of Project ArchimedeZ, 4 ) describe incentives that Project ArchimedeZ will give to Total Force Airmen to participate and...engaged, most of the time, in some sort of PME but at a manageable level. Rather than a three- hour block, for example, Project ArchimedeZ would deliver

Source apportionment of heavy metals and their ecological risk in a tropical river basin system.

PubMed

Kumar, Balwant; Singh, Umesh Kumar

2018-06-27

Surface water and sediment samples were collected from Ajay River basin to appraise the behavior of heavy metals with surrounding environments and their inter-elemental relationships. Parameters like pH and organic carbon are having a minimal role in heavy metal distribution while some elements like Fe and Cu showed great affinity for organic matter based on linear regression analysis (LRA). Ficklin diagram justified that river basin is not contaminated through acidic pollutants. The river basin is highly enriched with Cu, Cd, Pb, and Ni which were much higher than world average values, average shale standard, effect range low (ERL), and threshold effect level (TEL). PCA and LRA verified that Cu, Cd, Pb, and Ni were mainly derived from anthropogenic inputs, and others like Fe, Mn, Zn, and Co came from geogenic sources. Pollution indices revealed that river basin is moderately to highly contaminated by Cu, Cd, and Ni. Furthermore, Ajay River basin is under strong potential ecological risk based on the obtained value of risk index and probable effect level/effect range median quotient index. However, river basin is strongly influenced by lithological properties, diversified hydrogeological settings, mineralization and mobilization of subsurface materials, and urban and industrial effluents which are controlling the heavy metals.

Initial assessment on the use of cocoa pulp in complete feed formulation: in vitro dry matter and organic matter digestibility

NASA Astrophysics Data System (ADS)

Natsir, A.; Mujnisa, A.; Mide, M. Z.; Purnomo, N.; Saade, M. F.

2018-05-01

Cocoa pulp is a by-product from cocoa industry which is produced in large quantity, but very limited study has been carried out in utilizing it as energy source in animal feed. The purpose of this study was to assess the in vitro dry matter (IVDMD) and in vitro organic matter digestibility (IVOMD) of complete feed containing different levels of cocoa pulp. The experiment was carried out according to completely randomised design consisting of four treatments and three replications. The treatments were P0 = Complete feed containing 0% cocoa pulp, P1 = Complete feed containing 5% cocoa pulp, P2 = Complete feed containing 10% cocoa pulp, and P3 = Complete feed containing 15% cocoa pulp on dry matter basis. The results of the study indicated that the average IVDMD was 567, 538, 566, and 526 g kg-1 DM, while the average IVOMD was 522, 491, 502, and 461 g/kg DM, respectively for treatment P0, P1, P2, and P3. Statistical analysis indicated that increasing levels of coca pulp in the feed significantly affected (P<0.05) the IVDMD and IVOMD of the feed. In conclusion, cocoa pulp is potential to be used up to 10% in complete feed with corn cobs as the fibre source.

Performance of one hundred watt HVM LPP-EUV source

NASA Astrophysics Data System (ADS)

Mizoguchi, Hakaru; Nakarai, Hiroaki; Abe, Tamotsu; Nowak, Krzysztof M.; Kawasuji, Yasufumi; Tanaka, Hiroshi; Watanabe, Yukio; Hori, Tsukasa; Kodama, Takeshi; Shiraishi, Yutaka; Yanagida, Tatsuya; Soumagne, Georg; Yamada, Tsuyoshi; Yamazaki, Taku; Okazaki, Shinji; Saitou, Takashi

2015-03-01

We have been developing CO2-Sn-LPP EUV light source which is the most promising solution as the 13.5nm high power light source for HVM EUVL. Unique and original technologies such as: combination of pulsed CO2 laser and Sn droplets, dual wavelength laser pulses shooting, and mitigation with magnetic field, have been developed in Gigaphoton Inc. The theoretical and experimental data have clearly showed the advantage of our proposed strategy. Based on these data we are developing first practical source for HVM - "GL200E". This data means 250W EUV power will be able to realize around 20kW level pulsed CO2 laser. We have reported engineering data from our recent test such around 43W average clean power, CE=2.0%, with 100kHz operation and other data 19). We have already finished preparation of higher average power CO2 laser more than 20kW at output power cooperate with Mitsubishi Electric Corporation 14). Recently we achieved 92W with 50kHz, 50% duty cycle operation 20). We have reported component technology progress of EUV light source system. We report promising experimental data and result of simulation of magnetic mitigation system in Proto #1 system. We demonstrated several data with Proto #2 system: (1) emission data of 140W in burst under 70kHz 50% duty cycle during 10 minutes. (2) emission data of 118W in burst under 60kHz 70% duty cycle during 10 minutes. (3) emission data of 42W in burst under 20kHz 50% duty cycle (10000pls/0.5ms OFF) during 3 hours (110Mpls). Also we report construction of Pilot #1 system. Final target is week level operation with 250W EUV power with CE=4%, more than 27kW CO2 laser power by the end of Q2 of 2015.

Normal results of post-race thallium-201 myocardial perfusion imaging in marathon runners with elevated serum MB creatine kinase levels

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

Siegel, A.J.; Silverman, L.M.; Holman, B.L.

1985-10-01

Elevated cardiac enzyme values in asymptomatic marathon runners after competition can arise from skeletal muscle through exertional rhabdomyolysis, silent injury to the myocardium, or a combined tissue source. Peak post-race levels of the MB isoenzyme of creatine kinase are similar to values in patients with acute myocardial infarction. Previously reported normal results of infarct-avid myocardial scintigraphy with technetium 99m pyrophosphate in runners after competition suggest a non-cardiac source but cannot exclude silent injury to the myocardium. Therefore, thallium 201 myocardial perfusion imaging was performed in runners immediately after competition together with determination of sequential cardiac enzyme levels. Among 15 runnersmore » tested, the average peak in serum MB creatine kinase 24 hours after the race was 128 IU/liter with a cumulative MB creatine kinase release of 117 IU/liter; these values are comparable to those in patients with acute transmural myocardial infarction. Thallium 201 myocardial scintigraphic results were normal in five runners randomly selected from those who volunteered for determination of sequential blood levels. It is concluded that elevations of serum MB creatine kinase in marathon runners arise from a skeletal muscle source and that thallium 201 myocardial scintigraphy is useful to assess runners for myocardial injury when clinical questions arise.« less

Analysis of diurnal variability of atmospheric halocarbons and CFC replacements to imply emission strength and sources at an urban site of Lukang in central Taiwan

NASA Astrophysics Data System (ADS)

Lee, Bing-Sun; Chiou, Chung-Biau; Lin, Chung-Yi

2014-12-01

Hourly atmospheric measurements of halocarbons and chlorofluorocarbon (CFC) replacements were conducted at an urban site of Lukang, Changhua, in central Taiwan from May to August, 2013. The temporal distribution of different groups of halocarbons in the Lukang urban atmosphere, including chlorofluorocarbons (CFCs), Chlorodifluoromethane (HCFC-22), Bromochlorodifluoromethane (Halon-1211), and other chlorinated compounds, is presented and discussed. The concentrations (mixing ratios) of HCFC-22, Dichlorodifluoromethane (CFC-12), Halon-1211, Trichlorofluoromethane (CFC-11), Dichloromethane (CH2Cl2), and Trichloroethylene (TCE) were enhanced with respect to the local background levels; the atmospheric mixing ratio of carbon tetrachloride (CCl4) was slightly higher than its local background level; on the other hand, 1,1,2-Trichlorotrifluoroethane (CFC-113) was relatively uniform and not very different from background atmospheric level in non-urban areas. Among these compounds, HCFC-22, Halon-1211 and the halogenated compounds, CH2Cl2 and TCE, used as solvents were strongly enhanced. The average mixing ratio of Halon-1211 was higher than the local background of ∼4.5 ppt by ∼60% although Halon-1211 production had been phased out by 1996. Hourly average mixing ratios of halocarbons (HCFC-22, CFC-12, Halon-1211, CFC-11, CH2Cl2, and TCE) illustrated a distinct diurnal cycle characterized with a pattern of elevated mixing ratio and large mixing ratio variability amplitude at night relative to that in daytime. Although emission sources of these halocarbons were complex, hourly average mixing ratios for most of these high variability halocarbons peaked at ∼5:00 AM when the hourly average wind speed reached the minimum value of the day; by contrast, the hourly average mixing ratio of CO peaked at ∼8:30 AM when the ambient atmospheric wind condition was strongly influenced by sea breezes during the traffic rush hours. This phenomenon revealed that meteorological factors predominated the distribution of halocarbon mixing ratio in the urban atmosphere and the traffic emission of CFC-12 derived from old vehicles manufactured before 1994 was insignificant to the CFC-12 mixing ratio in the urban atmosphere. The meteorological condition of nighttime atmospheric temperature inversion and low wind speed facilitated the accumulation of terrestrial airborne pollutants near the ground; consequently the hourly average mixing ratios at night were higher than those in daytime by up to ∼2% (CFC-11), ∼7% (CFC-12), ∼75% (HCFC-22), ∼72% (Halon-1211), ∼280% (CH2Cl2), and ∼155% (TCE).

Sources and behavior of perchlorate ions (ClO4-) in chalk aquifer of Champagne-Ardenne, France: preliminary results

NASA Astrophysics Data System (ADS)

Cao, Feifei; Jaunat, Jessy; Ollivier, Patrick; Cancès, Benjamin; Morvan, Xavier; Hubé, Daniel; Devos, Alain; Devau, Nicolas; Barbin, Vincent; Pannet, Pierre

2018-06-01

Perchlorate (ClO4-) is an environmental contaminant of growing concern due to its potential human health effects and widespread occurrence in surface water and groundwater. Analyses carried out in France have highlighted the presence of ClO4- in drinking water of Champagne-Ardenne (NW of France), with two potential sources suspected: a military source related to the First World War and an agricultural source related to the past use of Chilean nitrates. To determine the sources of ClO4- in groundwater, major and trace elements, 2H and 18O, ClO3- and ClO4- ions and a list of 39 explosives were analyzed from 35 surface water and groundwater sampling points in the east of the city of Reims. ClO4- ions were found in almost all sampling points (32 out of 35) with a max value of 33 µg L-1. ClO4- concentrations were highest in groundwater ranging from 0.7 to 33 µg L-1 (average value of about 6.2 µg L-1) against from < 0.5 to 10.2 µg L-1 in surface water (average value of about 2.7 µg L-1). Most of the water samples showing high ClO4- levels (> 4 µg L-1) were collected near a military camp, where huge quantities of ammunitions have been used, stored and destroyed during and after the First World War.

Sources of indoor and outdoor PM2.5 concentrations in primary schools.

PubMed

Amato, F; Rivas, I; Viana, M; Moreno, T; Bouso, L; Reche, C; Àlvarez-Pedrerol, M; Alastuey, A; Sunyer, J; Querol, X

2014-08-15

Children spend a third of their day in the classroom, where air pollution levels may differ substantially from those outdoors due to specific indoor sources. Air pollution exposure assessments based on atmospheric particle mass measured outdoors may therefore have little to do with the daily PM dose received by school children. This study aims to investigate outdoor and indoor sources of PM2.5 measured at 39 primary schools in Barcelona during 2012. On average 47% of indoor PM2.5 measured concentrations was found to be generated indoors due to continuous resuspension of soil particles (13%) and a mixed source (34%) comprising organic (skin flakes, clothes fibers, possible condensation of VOCs) and Ca-rich particles (from chalk and building deterioration). Emissions from seven outdoor sources penetrated easily indoors being responsible for the remaining 53% of measured PM2.5 indoors. Unpaved playgrounds were found to increase mineral contributions in classrooms by 5-6 μg/m(3) on average with respect to schools with paved playgrounds. Weekday traffic contributions varied considerably across Barcelona within ranges of 1-14 μg/m(3) outdoor and 1-10 μg/m(3) indoor. Indoors, traffic contributions were significantly higher (more than twofold) for classrooms with windows oriented directly to the street, rather than to the interior of the block or to playgrounds. This highlights the importance of urban planning in order to reduce children's exposure to traffic emissions. Copyright © 2014 Elsevier B.V. All rights reserved.

Readability levels of health pamphlets distributed in hospitals and health centres in Athens, Greece.

PubMed

Kondilis, B K; Akrivos, P D; Sardi, T A; Soteriades, E S; Falagas, M E

2010-10-01

Health literacy is important in the medical and social sciences due to its impact on behavioural and health outcomes. Nevertheless, little is known about it in Greece, including patients' level of understanding health brochures and pamphlets distributed in Greek hospitals and clinics. Observational study in the greater metropolitan area of Athens, Greece. Pamphlets and brochures written in the Greek language were collected from 17 hospitals and healthcare centres between the spring and autumn of 2006. Readability of pamphlets using the Flesch-Kincaid, Simple Measure of Gobbledygook (SMOG) and Fog methods was calculated based on a Greek readability software. Out of 70 pamphlets collected from 17 hospitals, 37 pamphlets met the criteria for the study. The average readability level of all scanned pamphlets was ninth to 10th grade, corresponding to a readability level of 'average'. A highly significant difference (P<0.001) was found between private and public hospitals using the Flesch-Kincaid and SMOG readability scales. Pamphlets from private hospitals were one grade more difficult than those from public hospitals. Approximately 43.7% of the Greek population aged ≥20 years would not be able to comprehend the available pamphlets, which were found to have an average readability level of ninth to 10th grade. Further research examining readability levels in the context of health literacy in Greece is warranted. This effort paves the way for additional research in the field of readability levels of health pamphlets in the Greek language, the sources of health information, and the level of understanding of key health messages by the population. Copyright © 2010 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Concentrations and Origins of Atmospheric Lead and Other Trace Species at a Rural Site in Northern China

NASA Technical Reports Server (NTRS)

Li, Can; Wen, Tianxue; Li, Zhanqing; Dickerson, Russell R.; Yang, Yongjie; Zhao, Yanan; Wang, Yuesi; Tsay, Si-Chee

2010-01-01

In this study we analyze the ambient levels of lead and other trace species in the bulk aerosol samples from a rural site approx.70 km ESE of Beijing in spring 2005. Lead (0.28+/-0.24 micro-g/cu m, average +/- standard deviation), along with several pollution \\related trace elements, was enriched by over 100 fold relative to the Earth's crust. The ambient lead levels showing large synoptic variations were well-correlated with other anthropogenic pollutants (e.g., CO and SO2). The Unmix receptor model resolved four factors in the aerosol composition data: a biomass burning source, an industrial and coal combustion source, a secondary aerosol source, and a dust source. The first three sources were strongest in weak southerly winds ahead of cold fronts, while the dust source peaked in strong northerly winds behind cold fronts. The second source, primarily representing emissions from industrial processes and relatively small \\scale coal burning such as in home and institutional heating, was identified as the main source of ambient lead in this study. Mobile sources might also contribute to this factor, but there was no distinct evidence of emissions due to combustion of leaded gasoline, despite a correlation between lead and CO. Potential source contribution function, calculated from backward trajectories and aerosol composition, further reveals that lead observed in this study was predominantly from the populated and industrialized areas to the south and SW of Xianghe, rather than Beijing to the west. Our results and several recent studies show that the lead levels in suburban areas near big cities in China, although generally lower than those in industrial districts and urban areas, are substantial (near or above 0.15 micro-g/cu m). More extensive studies on airborne lead and its emission sources in China are called for.

Elevated Lead in Drinking Water in Washington, DC, 2003–2004: The Public Health Response

PubMed Central

Guidotti, Tee L.; Calhoun, Thomas; Davies-Cole, John O.; Knuckles, Maurice E.; Stokes, Lynette; Glymph, Chevelle; Lum, Garret; Moses, Marina S.; Goldsmith, David F.; Ragain, Lisa

2007-01-01

Background In 2003, residents of the District of Columbia (DC) experienced an abrupt rise in lead levels in drinking water, which followed a change in water-disinfection treatment in 2001 and which was attributed to consequent changes in water chemistry and corrosivity. Objectives To evaluate the public health implications of the exceedance, the DC Department of Health expanded the scope of its monitoring programs for blood lead levels in children. Methods From 3 February 2004 to 31 July 2004, 6,834 DC residents were screened to determine their blood lead levels. Results Children from 6 months to 6 years of age constituted 2,342 of those tested; 65 had blood lead levels > 10 μg/dL (the “level of concern” defined by the Centers for Disease Control and Prevention), the highest with a level of 68 μg/dL. Investigation of their homes identified environmental sources of lead exposure other than tap water as the source, when the source was identified. Most of the children with elevated blood lead levels (n = 46; 70.8%) lived in homes without lead drinking-water service lines, which is the principal source of lead in drinking water in older cities. Although residents of houses with lead service lines had higher blood lead levels on average than those in houses that did not, this relationship is confounded. Older houses that retain lead service lines usually have not been rehabilitated and are more likely to be associated with other sources of exposure, particularly lead paint. None of 96 pregnant women tested showed blood lead levels > 10 μg/dL, but two nursing mothers had blood lead levels > 10 μg/dL. Among two data sets of 107 and 71 children for whom paired blood and water lead levels could be obtained, there was no correlation (r2 = –0.03142 for the 107). Conclusions The expanded screening program developed in response to increased lead levels in water uncovered the true dimensions of a continuing problem with sources of lead in homes, specifically lead paint. This study cannot be used to correlate lead in drinking water with blood lead levels directly because it is based on an ecologic rather than individualized exposure assessment; the protocol for measuring lead was based on regulatory requirements rather than estimating individual intake; numerous interventions were introduced to mitigate the effect; exposure from drinking water is confounded with other sources of lead in older houses; and the period of potential exposure was limited and variable. PMID:17520055

An analysis of the readability characteristics of oral health information literature available to the public in Tasmania, Australia.

PubMed

Barnett, Tony; Hoang, Ha; Furlan, Ashlea

2016-03-17

The effectiveness of print-based health promotion materials is dependent on their readability. This study aimed to assess the characteristics of print-based oral health information literature publically available in Tasmania, Australia. Oral health education brochures were collected from 11 dental clinics across Tasmania and assessed for structure and format, content and readability. Reading level was calculated using three widely-used measures: Flesch-Kincaid Grade Level (FKGL), Flesch Reading Ease, and Simple Measure of Gobbledygook (SMOG) reading grade level. The FKGL of the 67 brochures sampled ranged from grade 3 to 13. The grade level for government health department brochures (n = 14) ranged from grade 4 to 11 (5.6 ± 1.8). Reading levels for materials produced by commercial sources (n = 22) ranged from 3 to 13 (8.3 ± 2.1), those from professional associations (n = 22) ranged from grade 7 to 11 (8.9 ± 0.9) and brochures produced by other sources (n = 9) ranged from 5 to 10 (7.6 ± 1.5). The SMOG test was positively correlated with the FKGL (rs = 0.92, p < 0.001) though consistently rated materials 2-3 grades higher. The reading level required to comprehend brochures published by government sources were, on average, lower than those from commercial, professional and other sources. Government materials were also more likely to contain fewer words and professional jargon terms than brochures from the other sources. A range of oral health information brochures were publically available for patients in both public and private dental clinics. However, their readability characteristics differed. Many brochures required a reading skill level higher than that suited to a large proportion of the Tasmanian population. Readability and other characteristics of oral health education materials should be assessed to ensure their suitability for use with patients, especially those suspected of having low literacy skills.

A systematic analysis of PM2.5 in Beijing and its sources from 2000 to 2012

NASA Astrophysics Data System (ADS)

Lv, Baolei; Zhang, Bin; Bai, Yuqi

2016-01-01

Particulate matter with an aerodynamic diameter of 2.5 μm or less (PM2.5) is the main air pollutant in Beijing. To have a comprehensive understanding of concentrations, compositions and sources of PM2.5 in Beijing, recent studies reporting ground-based observations and source apportionment results dated from 2000 to 2012 in this typical large city of China are reviewed. Statistical methods were also used to better enable data comparison. During the last decade, annual average concentrations of PM2.5 have decreased and seasonal mean concentrations declined through autumn and winter. Generally, winter is the most polluted season and summer is the least polluted one. Seasonal variance of PM2.5 levels decreased. For diurnal variance, PM2.5 generally increases at night and decreases during the day. On average, organic matters, sulfate, nitrate and ammonium are the major compositions of PM2.5 in Beijing. Fractions of organic matters increased from 2000 to 2004, and decreased afterwards. Fractions of sulfate, nitrate and ammonium decreased in winter and remained largely unchanged in summer. Concentrations of organic carbon and elemental carbon were always higher in winter than in summer and they barely changed during the last decade. Concentrations of sulfate, nitrate and ammonium exhibited significant increasing trend in summer but in reverse in winter. On average they were higher in winter than in summer before 2005, and took a reverse after 2005. Receptor model results show that vehicle, dust, industry, biomass burning, coal combustion and secondary products were major sources and they all increased except coal combustions and secondary products. The growth was decided both changing social and economic activities in Beijing, and most likely growing emissions in neighboring Hebei province. Explicit descriptions of the spatial variations of PM2.5 concentration, better methods to estimate secondary products and ensemble source apportionments models to reduce uncertainties would remain being open questions for future studies.

Seasonal and Spatial Variations of Heavy Metals in Two Typical Chinese Rivers: Concentrations, Environmental Risks, and Possible Sources

PubMed Central

Yao, Hong; Qian, Xin; Gao, Hailong; Wang, Yulei; Xia, Bisheng

2014-01-01

Ten metals were analyzed in samples collected in three seasons (the dry season, the early rainy season, and the late rainy season) from two rivers in China. No observed toxic effect concentrations were used to estimate the risks. The possible sources of the metals in each season, and the dominant source(s) at each site, were assessed using principal components analysis. The metal concentrations in the area studied were found, using t-tests, to vary both seasonally and spatially (P = 0.05). The potential risks in different seasons decreased in the order: early rainy season > dry season > late rainy season, and Cd was the dominant contributor to the total risks associated with heavy metal pollution in the two rivers. The high population and industrial site densities in the Taihu basin have had negative influences on the two rivers. The river that is used as a source of drinking water (the Taipu River) had a low average level of risks caused by the metals. Metals accumulated in environmental media were the main possible sources in the dry season, and emissions from mechanical manufacturing enterprises were the main possible sources in the rainy season. The river in the industrial area (the Wusong River) had a moderate level of risk caused by the metals, and the main sources were industrial emissions. The seasonal and spatial distributions of the heavy metals mean that risk prevention and mitigation measures should be targeted taking these variations into account. PMID:25407421

Readability of patient education materials on the American Orthopaedic Society for Sports Medicine website.

PubMed

Eltorai, Adam E M; Han, Alex; Truntzer, Jeremy; Daniels, Alan H

2014-11-01

The recommended readability of patient education materials by the American Medical Association (AMA) and National Institutes of Health (NIH) should be no greater than a sixth-grade reading level. However, online resources may be too complex for some patients to understand, and poor health literacy predicts inferior health-related quality of life outcomes. This study evaluated whether the American Orthopaedic Society for Sports Medicine (AOSSM) website's patient education materials meet recommended readability guidelines for medical information. We hypothesized that the readability of these online materials would have a Flesch-Kincaid formula grade above the sixth grade. All 65 patient education entries of the AOSSM website were analyzed for grade level readability using the Flesch-Kincaid formula, a widely used and validated tool to evaluate the text reading level. The average (standard deviation) readability of all 65 articles was grade level 10.03 (1.44); 64 articles had a readability score above the sixth-grade level, which is the maximum level recommended by the AMA and NIH. Mean readability of the articles exceeded this level by 4.03 grade levels (95% CI, 3.7-4.4; P < 0.0001). We found post-hoc that only 7 articles had a readability score ≤ an eighth-grade level, the average reading level of US adults. Mean readability of the articles exceeded this level by 2.03 grade levels (95% CI, 1.7-2.4; P < 0.0001). The readability of online AOSSM patient education materials exceeds the readability level recommended by the AMA and NIH, and is above the average reading level of the majority of US adults. This online information may be of limited utility to most patients due to a lack of comprehension. Our study provides a clear example of the need to improve the readability of specific education material in order to maximize the efficacy of multimedia sources.

A content analysis of Internet resources about the risks of seafood consumption.

PubMed

Henderson, Heather C; Hong, Jie; Friedman, Daniela B; Porter, Dwayne E; Halfacre, Angela C; Scott, Geoffrey I; Lead, Jamie R

2016-08-01

Seafood consumption is a main source of human exposure to certain environmental contaminants. Therefore, it is valuable to assess the online health risk messages focused on this topic, as people in the US are increasingly accessing the Internet for health-related information. Previous research indicates that online health information tends to be written at a reading level that is more advanced than ability of the general population. The purpose of this research was to examine the content and readability of Internet resources targeted toward consumers in the US regarding the health risks from consumption of contaminated seafood. Sources for analysis were gathered through a targeted search of state and national government websites, as well as through a Google search. The overall mean readability level was Grade 9.21, which is slightly above the average reading level of US adults. Future research should evaluate the accuracy of the health risk messages, as well as consumer perceptions of risk.

40 CFR 406.16 - Pretreatment standards for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Corn Wet Milling Subcategory § 406.16 Pretreatment... new corn wet milling source to be discharged to the POTW (gallons per one hour for flow and pounds per day for BOD5 and TSS). Q = average existing waste load to POTW. R = average waste load for the new...

40 CFR 406.16 - Pretreatment standards for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Corn Wet Milling Subcategory § 406.16 Pretreatment... new corn wet milling source to be discharged to the POTW (gallons per one hour for flow and pounds per day for BOD5 and TSS). Q = average existing waste load to POTW. R = average waste load for the new...

40 CFR 406.16 - Pretreatment standards for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Corn Wet Milling Subcategory § 406.16 Pretreatment... new corn wet milling source to be discharged to the POTW (gallons per one hour for flow and pounds per day for BOD5 and TSS). Q = average existing waste load to POTW. R = average waste load for the new...

Identification of nitrogen sources to four small lakes in the agricultural region of Khorezm, Uzbekistan

USGS Publications Warehouse

Shanafield, M.; Rosen, M.; Saito, L.; Chandra, S.; Lamers, J.; Nishonov, Bakhriddin

2010-01-01

Pollution of inland waters by agricultural land use is a concern in many areas of the world, and especially in arid regions, where water resources are inherently scarce. This study used physical and chemical water quality and stable nitrogen isotope (δ15N) measurements from zooplankton to examine nitrogen (N) sources and concentrations in four small lakes of Khorezm, Uzbekistan, an arid, highly agricultural region, which is part of the environmentally-impacted Aral Sea Basin. During the 2-year study period, ammonium concentrations were the highest dissolved inorganic N species in all lakes, with a maximum of 3.00 mg N l−1 and an average concentration of 0.62 mg N l−1. Nitrate levels were low, with a maximum concentration of 0.46 mg N l−1 and an average of 0.05 mg N l−1 for all four lakes. The limited zooplankton δ15N values did not correlate with the high loads of synthetic fertilizer applied to local croplands during summer months. These results suggest that the N cycles in these lakes may be more influenced by regional dynamics than agricultural activity in the immediate surroundings. The Amu-Darya River, which provides the main source of irrigation water to the region, was identified as a possible source of the primary N input to the lakes.

Occurrence and sources of bromate in chlorinated tap drinking water in Metropolitan Manila, Philippines.

PubMed

Genuino, Homer C; Espino, Maria Pythias B

2012-04-01

Significant levels of potentially carcinogenic bromate were measured in chlorinated tap drinking water in Metropolitan Manila, Philippines, using an optimized ion-chromatographic method. This method can quantify bromate in water down to 4.5 μg l⁻¹ by employing a postcolumn reaction with acidic fuchsin and subsequent spectrophotometric detection. The concentration of bromate in tap drinking water samples collected from 21 locations in cities and municipalities within the 9-month study period ranged from 7 to 138 μg l⁻¹. The average bromate concentration of all tap drinking water samples was 66 μg l⁻¹ (n = 567), almost seven times greater than the current regulatory limit in the country. The levels of bromate in other water types were also determined to identify the sources of bromate found in the distribution lines and to further uncover contaminated sites. The concentration of bromate in water sourced from two rivers and two water treatment plants ranged from 15 to 80 and 12 to 101 μg l⁻¹, respectively. Rainwater did not contribute bromate in rivers but decreased bromate level by dilution. Groundwater and wastewater samples showed bromate concentrations as high as 246 and 342 μg l⁻¹, respectively. Bromate presence in tap drinking water can be linked to pollution in natural water bodies and the practice of using hypochlorite chemicals in addition to gaseous chlorine for water disinfection. This study established the levels, occurrence, and possible sources of bromate in local drinking water supplies.

Heavy metals pollution and pb isotopic signatures in surface sediments collected from Bohai Bay, North China.

PubMed

Gao, Bo; Lu, Jin; Hao, Hong; Yin, Shuhua; Yu, Xiao; Wang, Qiwen; Sun, Ke

2014-01-01

To investigate the characteristics and potential sources of heavy metals pollution, surface sediments collected from Bohai Bay, North China, were analyzed for the selected metals (Cd, Cr, Cu, Ni, Pb, and Zn). The Geoaccumulation Index was used to assess the level of heavy metal pollution. Pb isotopic compositions in sediments were also measured to effectively identify the potential Pb sources. The results showed that the average concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were 0.15, 79.73, 28.70, 36.56, 25.63, and 72.83 mg/kg, respectively. The mean concentrations of the studied metals were slightly higher than the background values. However, the heavy metals concentrations in surface sediments in Bohai Bay were below the other important bays or estuaries in China. The assessment by Geoaccumulation Index indicated that Cr, Zn, and Cd were classified as "the unpolluted" level, while Ni, Cu, and Pb were ranked as "unpolluted to moderately polluted" level. The order of pollution level of heavy metals was: Pb > Ni > Cu > Cr > Zn > Cd. The Pb isotopic ratios in surface sediments varied from 1.159 to 1.185 for (206)Pb/(207)Pb and from 2.456 to 2.482 for (208)Pb/(207)Pb. Compared with Pb isotopic radios in other sources, Pb contaminations in the surface sediments of Bohai Bay may be controlled by the mix process of coal combustion, aerosol particles deposition, and natural sources.

Variations in atmospheric PM trace metal content in Spanish towns: Illustrating the chemical complexity of the inorganic urban aerosol cocktail

NASA Astrophysics Data System (ADS)

Moreno, Teresa; Querol, Xavier; Alastuey, Andrés; Viana, Mar; Salvador, Pedro; Sánchez de la Campa, Ana; Artiñano, Begoña; de la Rosa, Jesús; Gibbons, Wes

The majority of the Spanish urban population breathe air containing inhalable ambient airborne particles at average concentrations of 30-46 μg m -3 (PM 10) and 20-30 μg m -3 (PM 2.5). Even though the average weight of inhaled urban aerosol is commonly similar, however, there can be large chemical differences between the ambient dusts from different towns, including the more bioreactive elements such as some metals. In this context, we compare the source-apportioned trace metal content of airborne PM 10 and PM 2.5 collected daily over a 1-year period from six population centres in Spain: Barcelona, Alcobendas, Llodio, Huelva, Tarragona and Las Palmas de Gran Canaria. Total average trace metal (ΣTM) PM 10 and PM 2.5 contents vary by up to a factor of around 3, reaching a maximum of ΣTM 10 811 ng m -3 and ΣTM 2.5 503 ng m -3 at Llodio, an industrial but humid site with the lowest PM 10 mass levels but high contamination by Zn, Pb, Mn, Sn, Ni and Cr. In contrast, pollution at Huelva, although another industrially influenced site, instead emphasises Cu and As, whereas Barcelona, where traffic emissions and resuspension contribute to some of the highest average PM 10 levels in Spain, has unusually raised levels of Ti, V and Ba. Such variations in both daily and annual average PM bulk chemistry, particularly in potentially toxic trace metals concentrated in the finer aerosols (such as Cd, As, Pb, Hg and Ni), predict that PM health effects on resident populations from different towns are unlikely to be the same.

Imaging of noncarious cervical lesions by means of a fast swept source optical coherence tomography system

NASA Astrophysics Data System (ADS)

Stoica, Eniko T.; Marcauteanu, Corina; Bradu, Adrian; Sinescu, Cosmin; Topala, Florin Ionel; Negrutiu, Meda Lavinia; Duma, Virgil Florin; Podoleanu, Adrian Gh.

2014-01-01

Non-carious cervical lesions (NCCL) are defined as the loss of tooth substance at the cemento-enamel junction and are caused by abrasion, erosion and/or occlusal overload. In this paper we proved that our fast swept source OCT system is a valuable tool to track the evolution of NCCL lesions in time. On several extracted bicuspids, four levels of NCCL were artificially created. After every level of induced lesion, OCT scanning was performed. B scans were acquired and 3D reconstructions were generated. The swept source OCT instrument used in this study has a central wavelength of 1050 nm, a sweeping range of 106 nm (measured at 10 dB), an average output power of 16 mW and a sweeping rate of 100 kHz. A depth resolution determined by the swept source of 12 μm in air was experimentally obtained. NCCL were measured on the B-scans as 2D images and 3D reconstructions (volumes). For quantitative evaluations of volumes, the Image J software was used. By calculating the areas of the amount of lost tissue corresponding to each difference of Bscans, the final volumes of NCCL were obtained. This swept source OCT method allows the dynamic diagnosis of NCCL in time.

Effects of wind on background particle concentrations at truck freight terminals.

PubMed

Garcia, Ronald; Hart, Jaime E; Davis, Mary E; Reaser, Paul; Natkin, Jonathan; Laden, Francine; Garshick, Eric; Smith, Thomas J

2007-01-01

Truck freight terminals are predominantly located near highways and industrial facilities. This proximity to pollution sources, coupled with meteorological conditions and wind patterns, may affect occupational exposures to particles at these work locations. To understand this process, data from an environmental sampling study of particles at U.S. trucking terminals, along with weather and geographic maps, were analyzed to determine the extent to which the transportation of particles from local pollutant sources elevated observed occupational exposures at these locations. To help identify potential upwind sources, wind direction weighted averages and speed measurements were used to construct wind roses that were superimposed on overhead photos of the terminal and examined for upwind source activity. Statistical tests were performed on these "source" and "nonsource" directions to determine whether there were significant differences in observed particle levels between the two groups. Our results provide evidence that nearby upwind pollution sources significantly elevated background concentrations at only a few of the locations sampled, whereas the majority provided little to no evidence of a significant upwind source effect.

Description and interpretation of geologic materials from shotholes drilled for the Trans-Alaska Crustal Transect project, Copper River basin, Alaska, May 1985

USGS Publications Warehouse

Odum, J.K.; Yehle, L.A.; Schmoll, H.R.; Gilbert, Chuck

1986-01-01

This map shows the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity, Florida, for May 1986. The Upper Floridan aquifer is the principal source of potable water in the area. Water level measurements were made on approximately 1,000 wells and on several springs. The potentiometric surface is shown mostly by 5-foot contour intervals. In the Fernandina Beach area of Nassau County, a 30-ft. interval is used to show a deep cone of depression. The potentiometric surface ranged from 125 feet above sea level in Polk County to 75 feet below sea level in Nassau County. Water levels in most key wells ranged from 1 to 9 feet below the May average in response to the lack of recharge from rainfall and an attendant increase in pumpage. Many levels in the district were equal to or lower than the below average levels of May 1985. Declines of about a foot from May 1985 levels were common in the eastern half of the district. However, the largest declines from May 1985 levels, as much as 7 to 9 feet, were mostly in well fields along the coastline. Levels in many wells approached, and in a few wells exceeded, record lows. (USGS)

MP3 player listening sound pressure levels among 10 to 17 year old students.

PubMed

Keith, Stephen E; Michaud, David S; Feder, Katya; Haider, Ifaz; Marro, Leonora; Thompson, Emma; Marcoux, Andre M

2011-11-01

Using a manikin, equivalent free-field sound pressure level measurements were made from the portable digital audio players of 219 subjects, aged 10 to 17 years (93 males) at their typical and "worst-case" volume levels. Measurements were made in different classrooms with background sound pressure levels between 40 and 52 dBA. After correction for the transfer function of the ear, the median equivalent free field sound pressure levels and interquartile ranges (IQR) at typical and worst-case volume settings were 68 dBA (IQR = 15) and 76 dBA (IQR = 19), respectively. Self-reported mean daily use ranged from 0.014 to 12 h. When typical sound pressure levels were considered in combination with the average daily duration of use, the median noise exposure level, Lex, was 56 dBA (IQR = 18) and 3.2% of subjects were estimated to exceed the most protective occupational noise exposure level limit in Canada, i.e., 85 dBA Lex. Under worst-case listening conditions, 77.6% of the sample was estimated to listen to their device at combinations of sound pressure levels and average daily durations for which there is no known risk of permanent noise-induced hearing loss, i.e., ≤  75 dBA Lex. Sources and magnitudes of measurement uncertainties are also discussed.

Sensitivity of a phase-sensitive optical time-domain reflectometer with a semiconductor laser source

NASA Astrophysics Data System (ADS)

Alekseev, A. E.; Tezadov, Ya A.; Potapov, V. T.

2018-06-01

In the present paper we perform, for the first time, an analysis of the average sensitivity of a coherent phase-sensitive optical time-domain reflectometer (phase-OTDR) with a semiconductor laser source to external actions. The sensitivity of this OTDR can be defined in a conventional manner via average SNR at its output, which in turn is defined by the average useful signal power and the average intensity noise power in the OTDR spatial channels in the bandwidth defined by the OTDR sampling frequency. The average intensity noise power is considered in detail in a previous paper. In the current paper we examine the average useful signal power at the output of a phase-OTDR. The analysis of the average useful signal power of a phase-OTDR is based on the study of a fiber scattered-light interferometer (FSLI) which is treated as a constituent part of a phase- OTDR. In the analysis, one of the conventional phase-OTDR schemes with a rectangular dual-pulse probe signal is considered. The FSLI which corresponds to this OTDR scheme has two scattering fiber segments with additional time delay, introduced between backscattered fields. The average useful signal power and the resulting average SNR at the output of this FSLI are determined by the degree of coherence of the semiconductor laser source, the length of the scattering fiber segments, and by the additional time delay between the scattering fiber segments. The average useful signal power characteristic of the corresponding phase-OTDR is determined by analogous parameters: the source coherence, the time durations of the parts constituting the dual-pulse, and the time interval which separates these parts. In the paper an expression for the average useful signal power of a phase-OTDR is theoretically derived and experimentally verified. Based on the found average useful signal power of a phase-OTDR and the average intensity noise power, derived in the previous paper, the average SNR of a phase-OTDR is defined. Setting the average signal SNR to 1, at a defined spectral band the minimum detectable external action amplitude for our particular phase-OTDR setup is determined. We also derive a simple relation for the average useful signal power and the average SNR which results when making the assumption that the laser source coherence is high. The results of the paper can serve as the basis for further development of the concept of phase-OTDR sensitivity.

Comparison of Indoor Mercury Vapor in Common Areas of Residential Buildings with Outdoor Levels in a Community Where Mercury Is Used for Cultural Purposes

PubMed Central

Garetano, Gary; Gochfeld, Michael; Stern, Alan H.

2006-01-01

Elemental mercury has been imbued with magical properties for millennia, and various cultures use elemental mercury in a variety of superstitious and cultural practices, raising health concerns for users and residents in buildings where it is used. As a first step in assessing this phenomenon, we compared mercury vapor concentration in common areas of residential buildings versus outdoor air, in two New Jersey cities where mercury is available and is used in cultural practices. We measured mercury using a portable atomic absorption spectrometer capable of quantitative measurement from 2 ng/m3 mercury vapor. We evaluated the interior hallways in 34 multifamily buildings and the vestibule in an additional 33 buildings. Outdoor mercury vapor averaged 5 ng/m3; indoor mercury was significantly higher (mean 25 ng/m3; p < 0.001); 21% of buildings had mean mercury vapor concentration in hallways that exceeded the 95th percentile of outdoor mercury vapor concentration (17 ng/m3), whereas 35% of buildings had a maximum mercury vapor concentration that exceeded the 95th percentile of outdoor mercury concentration. The highest indoor average mercury vapor concentration was 299 ng/m3, and the maximum point concentration was 2,022 ng/m3. In some instances, we were able to locate the source, but we could not specifically attribute the elevated levels of mercury vapor to cultural use or other specific mercury releases. However, these findings provide sufficient evidence of indoor mercury source(s) to warrant further investigation. PMID:16393659

Emergency Department Visit Forecasting and Dynamic Nursing Staff Allocation Using Machine Learning Techniques With Readily Available Open-Source Software.

PubMed

Zlotnik, Alexander; Gallardo-Antolín, Ascensión; Cuchí Alfaro, Miguel; Pérez Pérez, María Carmen; Montero Martínez, Juan Manuel

2015-08-01

Although emergency department visit forecasting can be of use for nurse staff planning, previous research has focused on models that lacked sufficient resolution and realistic error metrics for these predictions to be applied in practice. Using data from a 1100-bed specialized care hospital with 553,000 patients assigned to its healthcare area, forecasts with different prediction horizons, from 2 to 24 weeks ahead, with an 8-hour granularity, using support vector regression, M5P, and stratified average time-series models were generated with an open-source software package. As overstaffing and understaffing errors have different implications, error metrics and potential personnel monetary savings were calculated with a custom validation scheme, which simulated subsequent generation of predictions during a 4-year period. Results were then compared with a generalized estimating equation regression. Support vector regression and M5P models were found to be superior to the stratified average model with a 95% confidence interval. Our findings suggest that medium and severe understaffing situations could be reduced in more than an order of magnitude and average yearly savings of up to €683,500 could be achieved if dynamic nursing staff allocation was performed with support vector regression instead of the static staffing levels currently in use.

Measurements and source apportionment of particle-associated polycyclic aromatic hydrocarbons in ambient air in Riyadh, Saudi Arabia

NASA Astrophysics Data System (ADS)

Bian, Qijing; Alharbi, Badr; Collett, Jeffrey; Kreidenweis, Sonia; Pasha, Mohammad J.

2016-07-01

Ambient air samples were obtained in Riyadh, the capital and largest city of Saudi Arabia, during two measurement campaigns spanning September 2011 to September 2012. Sixteen particle-phase polycyclic aromatic hydrocarbons (PAH) were quantified in 167 samples. Pyrene and fluoranthene were the most abundant PAH, with average of 3.37 ± 14.01 ng m-3 and 8.00 ± 44.09 ng m-3, respectively. A dominant contribution from low molecular weight (LMW) PAH (MW < 228) suggested a large influence of industrial emissions on PAH concentrations. Monte Carlo source apportionment using diagnostic ratios showed that 80 ± 10% of the average LMW PAH concentrations were contributed by petroleum vapor emissions, while 53 ± 19% of high molecular weight (HMW) PAH were from solid fuel combustion emissions. The positive matrix factorization model estimated that oil combustion emissions dominated total PAH concentrations, accounting for on average 96%, likely due to widespread use of oil fuels in energy production (power plants and industries). Our results demonstrate the significant influence of petroleum product production and consumption on particulate-phase PAH concentrations in Riyadh, but also point to the importance of traffic and solid fuel burning, including coke burning and seasonal biomass burning, especially as they contribute to the ambient levels of HMW PAH.

STELLAR SURFACE MAGNETO-CONVECTION AS A SOURCE OF ASTROPHYSICAL NOISE. I. MULTI-COMPONENT PARAMETERIZATION OF ABSORPTION LINE PROFILES

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

Cegla, H. M.; Shelyag, S.; Watson, C. A.

2013-02-15

We outline our techniques to characterize photospheric granulation as an astrophysical noise source. A four-component parameterization of granulation is developed that can be used to reconstruct stellar line asymmetries and radial velocity shifts due to photospheric convective motions. The four components are made up of absorption line profiles calculated for granules, magnetic intergranular lanes, non-magnetic intergranular lanes, and magnetic bright points at disk center. These components are constructed by averaging Fe I 6302 A magnetically sensitive absorption line profiles output from detailed radiative transport calculations of the solar photosphere. Each of the four categories adopted is based on magnetic fieldmore » and continuum intensity limits determined from examining three-dimensional magnetohydrodynamic simulations with an average magnetic flux of 200 G. Using these four-component line profiles we accurately reconstruct granulation profiles, produced from modeling 12 Multiplication-Sign 12 Mm{sup 2} areas on the solar surface, to within {approx} {+-}20 cm s{sup -1} on a {approx}100 m s{sup -1} granulation signal. We have also successfully reconstructed granulation profiles from a 50 G simulation using the parameterized line profiles from the 200 G average magnetic field simulation. This test demonstrates applicability of the characterization to a range of magnetic stellar activity levels.« less

Comparing the relationships between noise level and annoyance in different surveys - A railway noise vs. aircraft and road traffic comparison

NASA Technical Reports Server (NTRS)

Fields, J. M.; Walker, J. G.

1982-01-01

Annoyance expressed in a railway noise survey is compared with that from two road traffic and three aircraft surveys in order to determine whether responses to various types of environmental noise are source-specific. Railway noise is found to be less annoying than other noises at any given high noise level. Railway noise annoyance rises less rapidly with increasing noise level. At high levels, this gap in reactions averages about 10 dB; it ranges from 4 dB to more than 20 dB. The methods used for comparing the surveys are examined. It is found that methodological uncertainties lead to imprecise comparisons and that different annoyance scales yield different estimates of intersurvey differences.

Identification and level of organochlorine insecticide contamination in groundwater and iridology analysis for people in Upper Citarum cascade

NASA Astrophysics Data System (ADS)

Oginawati, K.; Pratama, M. A.

2016-03-01

Organochlorines are the main pollutants in the class of persistent organic pollutants which are types of pollutants that are being questioned worldwide due to chronic persistence, toxicity and bioaccumulation. Human around the Citarum River are still using groundwater as a drinking source. It is very risky for people health that consume groundwater because in 2009 the application of organochlorine still found in the Upper Citarum watershed rice field and had potential to contaminate groundwater. Groundwater was analyzed with nine species belonging to the organochlorine pollutants Organic Peristent types. 7 types of organochlorinesAldrin was detected with an average concentration of 0.09 ppb, dieldrin with an average concentration of 24 ppb, heptaklor with an average concentration of 0.51 ppb, with concentrations of endosulfan on average 0.73 ppb, DDT with average concentration of 0.13 ppb, Lindan with an average concentration of 1.2 ppb, endrin with an average concentration of 0.03 ppb. Types with the highest concentration of organochlorine a lindan and endosulfan. Residues of aldrin, dieldrin and heptaklor in groundwater already exceeds the quality standards for drinking water Permenkes 492/2010. Based on the iridology analysis obtained several systems are expected to nervous, immune and reproductive system disorders and toxin deposits under the skin.

Changes in Sea Levels around the British Isles Revisited (Invited)

NASA Astrophysics Data System (ADS)

Teferle, F. N.; Hansen, D. N.; Bingley, R. M.; Williams, S. D.; Woodworth, P. L.; Gehrels, W. R.; Bradley, S. L.; Stocchi, P.

2009-12-01

Recently a number of new and/or updated sources for estimates of vertical land movements for the British Isles have become available allowing the relative and average changes in sea levels for this region to be revisited. The geodetic data set stems from a combination of re-processed continuous Global Positioning System (GPS) measurements from stations in the British Isles and from a global reference frame network, and absolute gravity (AG) measurements from two stations in the British Isles. The geologic data set of late Holocene sea level indicators has recently been updated, now applying corrections for the 20th century sea level rise, syphoning effect and late Holocene global ice melt, and expanded to Northern Ireland and Ireland. Several new model predictions of the glacial isostatic adjustment (GIA) process active in this region form the modelling data set of vertical land movements for the British Isles. Correcting the updated revised local reference (RLR) trends from the Permanent Service for Mean Sea Level (PSMSL) with these vertical land movement data sets, regional and averaged changes in sea levels around the British Isles have been investigated. Special focus is thereby also given to the coastal areas that have recently been identified within the UK Climate Projections 2009.

Non-sky-averaged sensitivity curves for space-based gravitational-wave observatories

NASA Astrophysics Data System (ADS)

Vallisneri, Michele; Galley, Chad R.

2012-06-01

The signal-to-noise ratio (SNR) is used in gravitational-wave observations as the basic figure of merit for detection confidence and, together with the Fisher matrix, for the amount of physical information that can be extracted from a detected signal. SNRs are usually computed from a sensitivity curve, which describes the gravitational-wave amplitude needed by a monochromatic source of given frequency to achieve a threshold SNR. Although the term ‘sensitivity’ is used loosely to refer to the detector’s noise spectral density, the two quantities are not the same: the sensitivity includes also the frequency- and orientation-dependent response of the detector to gravitational waves and takes into account the duration of observation. For interferometric space-based detectors similar to LISA, which are sensitive to long-lived signals and have constantly changing position and orientation, exact SNRs need to be computed on a source-by-source basis. For convenience, most authors prefer to work with sky-averaged sensitivities, accepting inaccurate SNRs for individual sources and giving up control over the statistical distribution of SNRs for source populations. In this paper, we describe a straightforward end-to-end recipe to compute the non-sky-averaged sensitivity of interferometric space-based detectors of any geometry. This recipe includes the effects of spacecraft motion and of seasonal variations in the partially subtracted confusion foreground from Galactic binaries, and it can be used to generate a sampling distribution of sensitivities for a given source population. In effect, we derive error bars for the sky-averaged sensitivity curve, which provide a stringent statistical interpretation for previously unqualified statements about sky-averaged SNRs. As a worked-out example, we consider isotropic and Galactic-disk populations of monochromatic sources, as observed with the ‘classic LISA’ configuration. We confirm that the (standard) inverse-rms average sensitivity for the isotropic population remains the same whether or not the LISA orbits are included in the computation. However, detector motion tightens the distribution of sensitivities, so for 50% of sources the sensitivity is within 30% of its average. For the Galactic-disk population, the average and the distribution of the sensitivity for a moving detector turn out to be similar to the isotropic case.

Characteristics and distributions of atmospheric mercury ...

EPA Pesticide Factsheets

Continuous measurements of speciated atmospheric mercury (Hg), including gaseous elemental mercury (GEM), particulate mercury (PHg), and reactive gaseous mercury (RGM) were conducted in Guizhou Province, southwestern China. Guiyang Power Plant (GPP), Guiyang Wujiang Cement Plant, Guizhou Aluminum Plant (GAP), and Guiyang Forest Park (GFP) in Guiyang were selected as study sites. Automatic Atmospheric Mercury Speciation Analyzers (Tekran 2537A) were used for GEM analysis. PHg and RGM were simultaneously collected by a manual sampling system, including elutriator, coupler/impactor, KCl-coated annular denuder, and a filter holder. Results show that different emission sources dominate different species of Hg. The highest average GEM value was 22.2 ± 28.3 ng·m−3 and the lowest 6.1 ± 3.9 ng·m−3, from samples collected at GPP and GAP, respectively. The maximum average PHg was 1984.9 pg·m−3 and the minimum average 55.9 pg·m−3, also from GPP and GAP, respectively. Similarly, the highest average RGM of 68.8 pg·m−3 was measured at GPP, and the lowest level of 20.5 pg·m−3 was found at GAP. We conclude that coal combustion sources are still playing a key role in GEM; traffic contributes significantly to PHg; and domestic pollution dominates RGM. Mercury (Hg) is a persistent hazardous pollutant with adverse effects on human health and wildlife due mainly to bioaccumulation and biomagnification in aquatic food webs (Lindqvist et al. 1991; Schroeder and Munt

Presenting SAPUSS: Solving Aerosol Problem by Using Synergistic Strategies in Barcelona, Spain

NASA Astrophysics Data System (ADS)

Dall'Osto, M.; Querol, X.; Alastuey, A.; Minguillon, M. C.; Alier, M.; Amato, F.; Brines, M.; Cusack, M.; Grimalt, J. O.; Karanasiou, A.; Moreno, T.; Pandolfi, M.; Pey, J.; Reche, C.; Ripoll, A.; Tauler, R.; Van Drooge, B. L.; Viana, M.; Harrison, R. M.; Gietl, J.; Beddows, D.; Bloss, W.; O'Dowd, C.; Ceburnis, D.; Martucci, G.; Ng, N. L.; Worsnop, D.; Wenger, J.; Mc Gillicuddy, E.; Sodeau, J.; Healy, R.; Lucarelli, F.; Nava, S.; Jimenez, J. L.; Gomez Moreno, F.; Artinano, B.; Prévôt, A. S. H.; Pfaffenberger, L.; Frey, S.; Wilsenack, F.; Casabona, D.; Jiménez-Guerrero, P.; Gross, D.; Cots, N.

2013-09-01

This paper presents the summary of the key objectives, instrumentation and logistic details, goals, and initial scientific findings of the European Marie Curie Action SAPUSS project carried out in the western Mediterranean Basin (WMB) during September-October in autumn 2010. The key SAPUSS objective is to deduce aerosol source characteristics and to understand the atmospheric processes responsible for their generations and transformations - both horizontally and vertically in the Mediterranean urban environment. In order to achieve so, the unique approach of SAPUSS is the concurrent measurements of aerosols with multiple techniques occurring simultaneously in six monitoring sites around the city of Barcelona (NE Spain): a main road traffic site, two urban background sites, a regional background site and two urban tower sites (150 m and 545 m above sea level, 150 m and 80 m above ground, respectively). SAPUSS allows us to advance our knowledge sensibly of the atmospheric chemistry and physics of the urban Mediterranean environment. This is well achieved only because of both the three dimensional spatial scale and the high sampling time resolution used. During SAPUSS different meteorological regimes were encountered, including warm Saharan, cold Atlantic, wet European and stagnant regional ones. The different meteorology of such regimes is herein described. Additionally, we report the trends of the parameters regulated by air quality purposes (both gaseous and aerosol mass concentrations); and we also compare the six monitoring sites. High levels of traffic-related gaseous pollutants were measured at the urban ground level monitoring sites, whereas layers of tropospheric ozone were recorded at tower levels. Particularly, tower level night-time average ozone concentrations (80 ± 25 μg m-3) were up to double compared to ground level ones. The examination of the vertical profiles clearly shows the predominant influence of NOx on ozone concentrations, and a source of ozone aloft. Analysis of the particulate matter (PM) mass concentrations shows an enhancement of coarse particles (PM2.5-10) at the urban ground level (+64%, average 11.7 μg m-3) but of fine ones (PM1) at urban tower level (+28%, average 14.4 μg m-3). These results show complex dynamics of the size-resolved PM mass at both horizontal and vertical levels of the study area. Preliminary modelling findings reveal an underestimation of the fine accumulation aerosols. In summary, this paper lays the foundation of SAPUSS, an integrated study of relevance to many other similar urban Mediterranean coastal environment sites.

Total particle, sulfate, and acidic aerosol emissions from kerosene space heaters

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

Leaderer, B.P.; Boone, P.M.; Hammond, S.K.

1990-06-01

Chamber studies were conducted on four unvented kerosene space heaters to assess emissions of total particle, sulfate, and acidic aerosol. The heaters tested represented four burner designs currently in use by the public. Kerosene space heaters are a potential source of fine particles ({<=} 2.5-{mu}m diameter), sulfate, and acidic aerosol indoors. Fine particle concentrations in homes in which the heaters are used may be increased in excess of 20 {mu}g/m{sup 3} over background levels. Sulfate and acidic aerosol levels in such homes could exceed average and peak outdoor concentrations. Maltuned heaters could produce exceptionally high levels of all air contaminantsmore » measured.« less

Total particle, sulfate, and acidic aerosol emissions from kerosene space heaters

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

Leaderer, B.P.; Boone, P.M.; Hammond, S.K.

1990-01-01

The article discusses chamber studies of four unvented kerosene space heaters to assess emissions of total particle, sulfate, and acidic aerosol. The heaters tested represented four burner designs currently in use by the public. Kerosene space heaters are a potential source of fine particles (= or < 2.5 micrometer diameter), sulfate, and acidic aerosol indoors. Fine particle concentrations in houses in which the heaters are used may be increased in excess of 20 micrograms/m3 over background levels. Sulfate and acidic aerosol levels in such houses could exceed average and peak outdoor concentrations. Maltuned heaters could produce exceptionally high levels ofmore » all air contaminants measured.« less

Transcriptional response of Pasteurella multocida to defined iron sources.

PubMed

Paustian, Michael L; May, Barbara J; Cao, Dongwei; Boley, Daniel; Kapur, Vivek

2002-12-01

Pasteurella multocida was grown in iron-free chemically defined medium supplemented with hemoglobin, transferrin, ferritin, and ferric citrate as iron sources. Whole-genome DNA microarrays were used to monitor global gene expression over seven time points after the addition of the defined iron source to the medium. This resulted in a set of data containing over 338,000 gene expression observations. On average, 12% of P. multocida genes were differentially expressed under any single condition. A majority of these genes encoded P. multocida proteins that were involved in either transport and binding or were annotated as hypothetical proteins. Several trends are evident when the data from different iron sources are compared. In general, only two genes (ptsN and sapD) were expressed at elevated levels under all of the conditions tested. The results also show that genes with increased expression in the presence of hemoglobin did not respond to transferrin or ferritin as an iron source. Correspondingly, genes with increased expression in the transferrin and ferritin experiments were expressed at reduced levels when hemoglobin was supplied as the sole iron source. Finally, the data show that genes that were most responsive to the presence of ferric citrate did not follow a trend similar to that of the other iron sources, suggesting that different pathways respond to inorganic or organic sources of iron in P. multocida. Taken together, our results demonstrate that unique subsets of P. multocida genes are expressed in response to different iron sources and that many of these genes have yet to be functionally characterized.

Simulation of Jet Noise with OVERFLOW CFD Code and Kirchhoff Surface Integral

NASA Technical Reports Server (NTRS)

Kandula, M.; Caimi, R.; Voska, N. (Technical Monitor)

2002-01-01

An acoustic prediction capability for supersonic axisymmetric jets was developed on the basis of OVERFLOW Navier-Stokes CFD (Computational Fluid Dynamics) code of NASA Langley Research Center. Reynolds-averaged turbulent stresses in the flow field are modeled with the aid of Spalart-Allmaras one-equation turbulence model. Appropriate acoustic and outflow boundary conditions were implemented to compute time-dependent acoustic pressure in the nonlinear source-field. Based on the specification of acoustic pressure, its temporal and normal derivatives on the Kirchhoff surface, the near-field and the far-field sound pressure levels are computed via Kirchhoff surface integral, with the Kirchhoff surface chosen to enclose the nonlinear sound source region described by the CFD code. The methods are validated by a comparison of the predictions of sound pressure levels with the available data for an axisymmetric turbulent supersonic (Mach 2) perfectly expanded jet.

Simulation of Supersonic Jet Noise with the Adaptation of Overflow CFD Code and Kirchhoff Surface Integral

NASA Technical Reports Server (NTRS)

Kandula, Max; Caimi, Raoul; Steinrock, T. (Technical Monitor)

2001-01-01

An acoustic prediction capability for supersonic axisymmetric jets was developed on the basis of OVERFLOW Navier-Stokes CFD (Computational Fluid Dynamics) code of NASA Langley Research Center. Reynolds-averaged turbulent stresses in the flow field are modeled with the aid of Spalart-Allmaras one-equation turbulence model. Appropriate acoustic and outflow boundary conditions were implemented to compute time-dependent acoustic pressure in the nonlinear source-field. Based on the specification of acoustic pressure, its temporal and normal derivatives on the Kirchhoff surface, the near-field and the far-field sound pressure levels are computed via Kirchhoff surface integral, with the Kirchhoff surface chosen to enclose the nonlinear sound source region described by the CFD code. The methods are validated by a comparison of the predictions of sound pressure levels with the available data for an axisymmetric turbulent supersonic (Mach 2) perfectly expanded jet.

Ship noise extends to frequencies used for echolocation by endangered killer whales.

PubMed

Veirs, Scott; Veirs, Val; Wood, Jason D

2016-01-01

Combining calibrated hydrophone measurements with vessel location data from the Automatic Identification System, we estimate underwater sound pressure levels for 1,582 unique ships that transited the core critical habitat of the endangered Southern Resident killer whales during 28 months between March, 2011, and October, 2013. Median received spectrum levels of noise from 2,809 isolated transits are elevated relative to median background levels not only at low frequencies (20-30 dB re 1 µPa(2)/Hz from 100 to 1,000 Hz), but also at high frequencies (5-13 dB from 10,000 to 96,000 Hz). Thus, noise received from ships at ranges less than 3 km extends to frequencies used by odontocetes. Broadband received levels (11.5-40,000 Hz) near the shoreline in Haro Strait (WA, USA) for the entire ship population were 110 ± 7 dB re 1 µPa on average. Assuming near-spherical spreading based on a transmission loss experiment we compute mean broadband source levels for the ship population of 173 ± 7 dB re 1 µPa 1 m without accounting for frequency-dependent absorption. Mean ship speed was 7.3 ± 2.0 m/s (14.1 ± 3.9 knots). Most ship classes show a linear relationship between source level and speed with a slope near +2 dB per m/s (+1 dB/knot). Spectrum, 1/12-octave, and 1/3-octave source levels for the whole population have median values that are comparable to previous measurements and models at most frequencies, but for select studies may be relatively low below 200 Hz and high above 20,000 Hz. Median source spectrum levels peak near 50 Hz for all 12 ship classes, have a maximum of 159 dB re 1 µPa(2)/Hz @ 1 m for container ships, and vary between classes. Below 200 Hz, the class-specific median spectrum levels bifurcate with large commercial ships grouping as higher power noise sources. Within all ship classes spectrum levels vary more at low frequencies than at high frequencies, and the degree of variability is almost halved for classes that have smaller speed standard deviations. This is the first study to present source spectra for populations of different ship classes operating in coastal habitats, including at higher frequencies used by killer whales for both communication and echolocation.

Personal carbon monoxide exposure in Helsinki, Finland

NASA Astrophysics Data System (ADS)

Scotto di Marco, Greta; Kephalopoulos, Stylianos; Ruuskanen, Juhani; Jantunen, Matti

Personal exposure concentrations of carbon monoxide (CO) were measured for the adult urban population of Helsinki, Finland, as part of the multi-centre European EXPOLIS study. The arithmetic mean of the 48 h average personal CO exposure concentration was 1.3 mg m -3 for participants not exposed to environmental tobacco smoke (ETS) and 1.6 mg m -3 for those exposed to ETS at any time and in any microenvironment. The maximum 8 and 1 h exposure values were 2.0 and 2.6 mg m -3, and 4.3 and 5.7 mg m -3, respectively. As tobacco smoke is one of the major sources of CO, therefore the personal mean exposures of ETS participants were higher than the non-ETS participants for all averaging times. The long- and short-term personal exposures were higher in winter than in summer for all participants. In order to analyse in more detail the correlation between the time-activity patterns and exposure levels, cluster analysis was performed using 24 h personal exposure profiles of 1 h moving averages. The results showed clearly that the major source of CO for non-ETS exposed participants are traffic emissions. The majority of the diurnal exposure profiles showed two notable exposure peaks corresponding to the morning and evening traffic rush hours. The time spent in street traffic was the most relevant factor for describing the short-term personal exposures. The more time was spent commuting by car the higher were the exposures. The long-term exposure levels were linked both to the time spent commuting and home location. People living in low-traffic suburban areas and working in downtown spent more time commuting and ended up experiencing similar long-term exposure levels than people who lived in heavy-traffic downtown areas, but spent little time commuting. For ETS exposed participants the personal exposure profiles were dominated by both tobacco smoke and traffic emissions.

Sources and geographical origins of fine aerosols in Paris (France)

NASA Astrophysics Data System (ADS)

Bressi, M.; Sciare, J.; Ghersi, V.; Mihalopoulos, N.; Petit, J.-E.; Nicolas, J. B.; Moukhtar, S.; Rosso, A.; Féron, A.; Bonnaire, N.; Poulakis, E.; Theodosi, C.

2013-12-01

The present study aims at identifying and apportioning the major sources of fine aerosols in Paris (France) - the second largest megacity in Europe -, and determining their geographical origins. It is based on the daily chemical composition of PM2.5 characterised during one year at an urban background site of Paris (Bressi et al., 2013). Positive Matrix Factorization (EPA PMF3.0) was used to identify and apportion the sources of fine aerosols; bootstrapping was performed to determine the adequate number of PMF factors, and statistics (root mean square error, coefficient of determination, etc.) were examined to better model PM2.5 mass and chemical components. Potential Source Contribution Function (PSCF) and Conditional Probability Function (CPF) allowed the geographical origins of the sources to be assessed; special attention was paid to implement suitable weighting functions. Seven factors named ammonium sulfate (A.S.) rich factor, ammonium nitrate (A.N.) rich factor, heavy oil combustion, road traffic, biomass burning, marine aerosols and metals industry were identified; a detailed discussion of their chemical characteristics is reported. They respectively contribute 27, 24, 17, 14, 12, 6 and 1% of PM2.5 mass (14.7 μg m-3) on the annual average; their seasonal variability is discussed. The A.S. and A.N. rich factors have undergone north-eastward mid- or long-range transport from Continental Europe, heavy oil combustion mainly stems from northern France and the English Channel, whereas road traffic and biomass burning are primarily locally emitted. Therefore, on average more than half of PM2.5 mass measured in the city of Paris is due to mid- or long-range transport of secondary aerosols stemming from continental Europe, whereas local sources only contribute a quarter of the annual averaged mass. These results imply that fine aerosols abatement policies conducted at the local scale may not be sufficient to notably reduce PM2.5 levels at urban background sites in Paris, suggesting instead more coordinated strategies amongst neighbouring countries. Similar conclusions might be drawn in other continental urban background sites given the transboundary nature of PM2.5 pollution.

Sources and geographical origins of fine aerosols in Paris (France)

NASA Astrophysics Data System (ADS)

Bressi, M.; Sciare, J.; Ghersi, V.; Mihalopoulos, N.; Petit, J.-E.; Nicolas, J. B.; Moukhtar, S.; Rosso, A.; Féron, A.; Bonnaire, N.; Poulakis, E.; Theodosi, C.

2014-08-01

The present study aims at identifying and apportioning fine aerosols to their major sources in Paris (France) - the second most populated "larger urban zone" in Europe - and determining their geographical origins. It is based on the daily chemical composition of PM2.5 examined over 1 year at an urban background site of Paris (Bressi et al., 2013). Positive matrix factorization (EPA PMF3.0) was used to identify and apportion fine aerosols to their sources; bootstrapping was performed to determine the adequate number of PMF factors, and statistics (root mean square error, coefficient of determination, etc.) were examined to better model PM2.5 mass and chemical components. Potential source contribution function (PSCF) and conditional probability function (CPF) allowed the geographical origins of the sources to be assessed; special attention was paid to implement suitable weighting functions. Seven factors, namely ammonium sulfate (A.S.)-rich factor, ammonium nitrate (A.N.)-rich factor, heavy oil combustion, road traffic, biomass burning, marine aerosols and metal industry, were identified; a detailed discussion of their chemical characteristics is reported. They contribute 27, 24, 17, 14, 12, 6 and 1% of PM2.5 mass (14.7 μg m-3) respectively on the annual average; their seasonal variability is discussed. The A.S.- and A.N.-rich factors have undergone mid- or long-range transport from continental Europe; heavy oil combustion mainly stems from northern France and the English Channel, whereas road traffic and biomass burning are primarily locally emitted. Therefore, on average more than half of PM2.5 mass measured in the city of Paris is due to mid- or long-range transport of secondary aerosols stemming from continental Europe, whereas local sources only contribute a quarter of the annual averaged mass. These results imply that fine-aerosol abatement policies conducted at the local scale may not be sufficient to notably reduce PM2.5 levels at urban background sites in Paris, suggesting instead more coordinated strategies amongst neighbouring countries. Similar conclusions might be drawn in other continental urban background sites given the transboundary nature of PM2.5 pollution.

Chemical characterization and source apportionment of fine and coarse particulate matter in Lahore, Pakistan

NASA Astrophysics Data System (ADS)

Stone, Elizabeth; Schauer, James; Quraishi, Tauseef A.; Mahmood, Abid

2010-03-01

Lahore, Pakistan is an emerging megacity that is heavily polluted with high levels of particle air pollution. In this study, respirable particulate matter (PM 2.5 and PM 10) were collected every sixth day in Lahore from 12 January 2007 to 19 January 2008. Ambient aerosol was characterized using well-established chemical methods for mass, organic carbon (OC), elemental carbon (EC), ionic species (sulfate, nitrate, chloride, ammonium, sodium, calcium, and potassium), and organic species. The annual average concentration (±one standard deviation) of PM 2.5 was 194 ± 94 μg m -3 and PM 10 was 336 ± 135 μg m -3. Coarse aerosol (PM 10-2.5) was dominated by crustal sources like dust (74 ± 16%, annual average ± one standard deviation), whereas fine particles were dominated by carbonaceous aerosol (organic matter and elemental carbon, 61 ± 17%). Organic tracer species were used to identify sources of PM 2.5 OC and chemical mass balance (CMB) modeling was used to estimate relative source contributions. On an annual basis, non-catalyzed motor vehicles accounted for more than half of primary OC (53 ± 19%). Lesser sources included biomass burning (10 ± 5%) and the combined source of diesel engines and residual fuel oil combustion (6 ± 2%). Secondary organic aerosol (SOA) was an important contributor to ambient OC, particularly during the winter when secondary processing of aerosol species during fog episodes was expected. Coal combustion alone contributed a small percentage of organic aerosol (1.9 ± 0.3%), but showed strong linear correlation with unidentified sources of OC that contributed more significantly (27 ± 16%). Brick kilns, where coal and other low quality fuels are burned together, are suggested as the most probable origins of unapportioned OC. The chemical profiling of emissions from brick kilns and other sources unique to Lahore would contribute to a better understanding of OC sources in this megacity.

Genetic Structure and Gene Flows within Horses: A Genealogical Study at the French Population Scale

PubMed Central

Pirault, Pauline; Danvy, Sophy; Verrier, Etienne; Leroy, Grégoire

2013-01-01

Since horse breeds constitute populations submitted to variable and multiple outcrossing events, we analyzed the genetic structure and gene flows considering horses raised in France. We used genealogical data, with a reference population of 547,620 horses born in France between 2002 and 2011, grouped according to 55 breed origins. On average, individuals had 6.3 equivalent generations known. Considering different population levels, fixation index decreased from an overall species FIT of 1.37%, to an average of −0.07% when considering the 55 origins, showing that most horse breeds constitute populations without genetic structure. We illustrate the complexity of gene flows existing among horse breeds, a few populations being closed to foreign influence, most, however, being submitted to various levels of introgression. In particular, Thoroughbred and Arab breeds are largely used as introgression sources, since those two populations explain together 26% of founder origins within the overall horse population. When compared with molecular data, breeds with a small level of coancestry also showed low genetic distance; the gene pool of the breeds was probably impacted by their reproducer exchanges. PMID:23630596

Geochemistry of placer gold, Koyukuk-Chandalar mining district, Alaska

USGS Publications Warehouse

Mosier, E.L.; Cathrall, J.B.; Antweiler, J.C.; Tripp, R.B.

1989-01-01

The Koyukuk-Chandalar mining district of the Brooks Range mineral belt in north-central Alaska contains numerous placer gold deposits but few known lode gold sources. Gold grains, collected from 46 placer localities and 6 lode gold sites in the district, were analyzed for Ag and 37 trace elements utilizing direct current-arc optical emission spectroscopy. When possible, several measurements were made on each sample and averaged. Gold content was calculated by the summation of the 38 elements determined and subtracting from 100. The objectives of our study were to characterize the deposits by defining the type and number of distinct geochemical characteristics for the Au, to determine relationships of Au in placer deposits to possible lode sources (placer and lode), to identify possible primary sources of placer gold, and to study processes of placer formation. Interpretation of results emphasize that the Au grains are almost invariably ternary (Au-Ag-Cu) alloys. The average Cu content is 0.040% and the average Ag content and fineness [(Au/Au+Ag)??1,000] are 10.5% and 893 parts per thousand, respectively, for the 46 placer localities. Six geochemically distinct types of placer gold can be identified in the Koyukuk-Chandalar mining district based on Ag and Cu values. One type with an average Ag content of 21.2%, an average Cu content of 0.007%, and 786 average fineness is found only in the eastern part of the district. Placer gold grains that have an average Ag content of 6.0%, an average Cu content of 0.276%, and 940 average fineness were found in the western part of the district. Four intermediate types generally occur in order across the district. Variations in the chemistry of the placer gold can be related to variable depositional environments at the primary gold sources. Placer gold geochemistry is important in determining the origin and depositional environment of the primary Au sources and could add to the knowledge of the thermal history of the southcentral Brooks Range. ?? 1989.

Effects of olive tree branches burning emissions on PM2.5 concentrations

NASA Astrophysics Data System (ADS)

Papadakis, G. Z.; Megaritis, A. G.; Pandis, S. N.

2015-07-01

An olive tree branches burning emission inventory for Greece is developed based on recently measured emission factors and the spatial distribution of olive trees. A three-dimensional chemical transport model (CTM), PMCAMx, is used to estimate the corresponding impact on PM2.5 concentrations during a typical winter period. Assuming that burning of olive tree branches takes place only during days with low wind speed and without precipitation, the contribution of olive tree branches burning emissions on PM2.5 levels is more significant during the most polluted days. Increases of hourly PM2.5 exceeding 50% and locally reaching up to 150% in Crete are predicted during the most polluted periods. On a monthly-average basis, the corresponding emissions are predicted to increase PM2.5 levels up to 1.5 μg m-3 (20%) in Crete and Peloponnese, where the largest fraction of olive trees is located, and by 0.4 μg m-3 (5%) on average over Greece. OA and EC levels increase by 20% and 13% respectively on average over Greece, and up to 70% in Crete. The magnitude of the effect is quite sensitive to burning practices. Assuming that burning of olive tree branches takes place during all days results in a smaller effect of burning on PM2.5 levels (9% increase instead of 20%). These results suggest that this type of agricultural waste burning is a major source of particulate pollution in the Mediterranean countries where this practice is prevalent during winter.

Occurrence of carboxylic acids in different steps of two drinking-water treatment plants using different disinfectants.

PubMed

Jurado-Sánchez, Beatriz; Ballesteros, Evaristo; Gallego, Mercedes

2014-03-15

The occurrence of 35 aliphatic and aromatic carboxylic acids within two full scale drinking-water treatment plants was evaluated for the first time in this research. At the intake of each plant (raw water), the occurrence of carboxylic acids varied according to the quality of the water source although in both cases 13 acids were detected at average concentrations of 6.9 and 4.7 μg/L (in winter). In the following steps in each treatment plant, the concentration patterns of these compounds differed depending on the type of disinfectant applied. Thus, after disinfection by chloramination, the levels of the acids remained almost constant (average concentration, 6.3 μg/L) and four new acids were formed (butyric, 2-methylbutyric, 3-hydroxybenzoic and 2-nitrobenzoic) at low levels (1.1-5 μg/L). When ozonation/chlorination was used, the total concentration of the carboxylic acids in the raw water sample (4.7 μg/L) increased up to 6 times (average concentration, 26.3 μg/L) after disinfection and 6 new acids (mainly aromatic) were produced at high levels (3.5-100 μg/L). Seasonal variations of the carboxylic acids under study showed that in both plants, maximum levels of all the analytes were reached in the coldest months (autumn and winter), aromatic acids only being found in those seasons. Copyright © 2013 Elsevier Ltd. All rights reserved.

Individuality in nutritional preferences: a multi-level approach in field crickets.

PubMed

Han, Chang S; Jäger, Heidi Y; Dingemanse, Niels J

2016-06-30

Selection may favour individuals of the same population to differ consistently in nutritional preference, for example, because optimal diets covary with morphology or personality. We provided Southern field crickets (Gryllus bimaculatus) with two synthetic food sources (carbohydrates and proteins) and quantified repeatedly how much of each macronutrient was consumed by each individual. We then quantified (i) whether individuals were repeatable in carbohydrate and protein intake rate, (ii) whether an individual's average daily intake of carbohydrates was correlated with its average daily intake of protein, and (iii) whether short-term changes in intake of carbohydrates coincided with changes in intake of protein within individuals. Intake rates were individually repeatable for both macronutrients. However, individuals differed in their relative daily intake of carbohydrates versus proteins (i.e., 'nutritional preference'). By contrast, total consumption varied plastically as a function of body weight within individuals. Body weight-but not personality (i.e., aggression, exploration behaviour)-positively predicted nutritional preference at the individual level as large crickets repeatedly consumed a higher carbohydrate to protein ratio compared to small ones. Our finding of level-specific associations between the consumption of distinct nutritional components demonstrates the merit of applying multivariate and multi-level viewpoints to the study of nutritional preference.

[Pollution Level and Source Apportionment of Atmospheric Particles PM₂.₅ in Southwest Suburb of Chengdu in Spring].

PubMed

Lin, Yu; Ye, Zhi-xiang; Yang, Huai-jin; Zhang, Ju; Yin, Wei-wen; Li, Xiao-fen

2016-05-15

In order to understand the characteristics of PM₂.₅ pollution in the atmosphere of Chengdu southwest suburb, PM₂.₅ particles in Chengdu southwest suburb were collected and analyzed from March 18 to March 31st, 2015. The results showed that the daily average concentration of PM₂.₅ in the southwest suburb of Chengdu reached 121.21 µg · m⁻³, and the average daily concentration of 24 samples in 31 PM₂.₅ samples was over 75 µg · m⁻³, the daily excessive rate was 77%, indicating the PM₂.₅ pollution in the study area was serious in March. When studying the relationship between atmospheric and meteorological factors, it was found that there was a significant index correlation between PM₂.₅ concentration and atmospheric visibility, and it had a positive correlation with temperature and humidity, but the correlation was not obvious. NH₄⁺ (16.24%), SO₄²- (12.58%) and NO₃⁻ (9.91%) were dominant in PM₂.₅ The ratio of NO₃⁻/SO₄²⁻ was 0.77, which indicated that the pollution of stationary sources in the southwest suburb was more severe than that of mobile sources. Organic carbon (OC)/elemental carbon (EC) ratios were higher than 2, which indicated the existence of second organic carbon (SOC). Using OC/EC ratio method to estimate the concentration of SOC, it was found that the average concentration of SOC in the southwest suburb of Chengdu in March was 3.49 µ · m⁻³, and the contribution rate of OC was 20.6%, which showed that the main source of OC in the southwest suburb of Chengdu was primary discharge. The correlation analysis of OC and EC showed that the correlation coefficient reached 0.95, indicating that the OC and EC sources were similar and relatively stable, and there was a great impact of local source emissions on Chengdu southwest suburb in spring, and primary discharge played a dominant role, while the contribution of SOC to OC was relatively small, which was consistent with the SOC characteristics obtained by estimation. Using principal component analysis method to analyze the sources of PM₂.₅ in the southwest of Chengdu, it was found that the main pollution sources of PM₂.₅ in southwest suburb of Chengdu were coal burning and biomass burning, secondary nitrate/sulfate, soil and dust, vehicle emissions, electronic production source, and mechanical processing source.

Sources of secondary organic aerosols over North China Plain in winter

NASA Astrophysics Data System (ADS)

Xing, L.; Li, G.; Tie, X.; Junji, C.; Long, X.

2017-12-01

Organic aerosol (OA) concentrations are simulated over the North China Plain (NCP) from 10th to 26th January, 2014 using the Weather Research and Forecasting model coupled to chemistry (WRF-CHEM), with the goal of examining the impact of heterogeneous HONO sources on atmospheric oxidation capacity and consequently on SOA formation and SOA formation from different pathways in winter. Generally, the model well reproduced the spatial and temporal distribution of PM2.5, SO2, NO2, and O3 concentrations. The heterogeneous HONO formation contributed a major part of atmospheric HONO concentrations in Beijing. The heterogeneous HONO sources significantly increased the daily maximum OH concentrations by 260% on average in Beijing, which enhanced the atmospheric oxidation capacity and consequently SOA concentrations by 80% in Beijing on average. Under severe haze pollution on January 16th 2014, the regional average HONO concentration over NCP was 0.86 ppb, which increased SOA concentration by 68% on average. The average mass fractions of ASOA (SOA from oxidation of anthropogenic VOCs), BSOA (SOA from oxidation of biogenic VOCs), PSOA (SOA from oxidation of evaporated POA), and GSOA (SOA from irreversible uptake of glyoxal and methylglyoxal) during the simulation period over NCP were 24%, 5%, 26% and 45%, respectively. GSOA contributed most to the total SOA mass over NCP in winter. The model sensitivity simulation revealed that GSOA in winter was mainly from primary residential sources. The regional average of GSOA from primary residential sources constituted 87% of total GSOA mass.

The NuSTAR Extragalactic Survey: Average Broadband X-Ray Spectral Properties of the NuSTAR-detected AGNs

NASA Astrophysics Data System (ADS)

Del Moro, A.; Alexander, D. M.; Aird, J. A.; Bauer, F. E.; Civano, F.; Mullaney, J. R.; Ballantyne, D. R.; Brandt, W. N.; Comastri, A.; Gandhi, P.; Harrison, F. A.; Lansbury, G. B.; Lanz, L.; Luo, B.; Marchesi, S.; Puccetti, S.; Ricci, C.; Saez, C.; Stern, D.; Treister, E.; Zappacosta, L.

2017-11-01

We present a study of the average X-ray spectral properties of the sources detected by the NuSTAR extragalactic survey, comprising observations of the Extended Chandra Deep Field South (E-CDFS), Extended Groth Strip (EGS), and the Cosmic Evolution Survey (COSMOS). The sample includes 182 NuSTAR sources (64 detected at 8-24 keV), with 3-24 keV fluxes ranging between {f}3{--24{keV}}≈ {10}-14 and 6 × 10-13 erg cm-2 s-1 ({f}8{--24{keV}}≈ 3× {10}-14{--}3× {10}-13 erg cm-2 s-1) and redshifts in the range of z=0.04{--}3.21. We produce composite spectra from the Chandra + NuSTAR data (E≈ 2{--}40 {keV}, rest frame) for all the sources with redshift identifications (95%) and investigate the intrinsic, average spectra of the sources, divided into broad-line (BL) and narrow-line (NL) active galactic nuclei (AGNs), and also in different bins of X-ray column density and luminosity. The average power-law photon index for the whole sample is {{Γ }}={1.65}-0.03+0.03, flatter than the {{Γ }}≈ 1.8 typically found for AGNs. While the spectral slope of BL and X-ray unabsorbed AGNs is consistent with the typical values ({{Γ }}={1.79}-0.01+0.01), a significant flattening is seen in NL AGNs and heavily absorbed sources ({{Γ }}={1.60}-0.05+0.08 and {{Γ }}={1.38}-0.12+0.12, respectively), likely due to the effect of absorption and to the contribution from the Compton reflection component to the high-energy flux (E> 10 keV). We find that the typical reflection fraction in our spectra is R≈ 0.5 (for {{Γ }}=1.8), with a tentative indication of an increase of the reflection strength with X-ray column density. While there is no significant evidence for a dependence of the photon index on X-ray luminosity in our sample, we find that R decreases with luminosity, with relatively high levels of reflection (R≈ 1.2) for {L}10{--40{keV}}< {10}44 erg s-1 and R≈ 0.3 for {L}10{--40{keV}}> {10}44 erg s-1 AGNs, assuming a fixed spectral slope of {{Γ }}=1.8.

Bayesian analyses of time-interval data for environmental radiation monitoring.

PubMed

Luo, Peng; Sharp, Julia L; DeVol, Timothy A

2013-01-01

Time-interval (time difference between two consecutive pulses) analysis based on the principles of Bayesian inference was investigated for online radiation monitoring. Using experimental and simulated data, Bayesian analysis of time-interval data [Bayesian (ti)] was compared with Bayesian and a conventional frequentist analysis of counts in a fixed count time [Bayesian (cnt) and single interval test (SIT), respectively]. The performances of the three methods were compared in terms of average run length (ARL) and detection probability for several simulated detection scenarios. Experimental data were acquired with a DGF-4C system in list mode. Simulated data were obtained using Monte Carlo techniques to obtain a random sampling of the Poisson distribution. All statistical algorithms were developed using the R Project for statistical computing. Bayesian analysis of time-interval information provided a similar detection probability as Bayesian analysis of count information, but the authors were able to make a decision with fewer pulses at relatively higher radiation levels. In addition, for the cases with very short presence of the source (< count time), time-interval information is more sensitive to detect a change than count information since the source data is averaged by the background data over the entire count time. The relationships of the source time, change points, and modifications to the Bayesian approach for increasing detection probability are presented.

High Contributions of Secondary Inorganic Aerosols to PM2.5 under Polluted Levels at a Regional Station in Northern China.

PubMed

Li, Yang; Tao, Jun; Zhang, Leiming; Jia, Xiaofang; Wu, Yunfei

2016-12-15

Daily PM 2.5 samples were collected at Shangdianzi (SDZ) regional site in Beijing-Tianjin-Hebei (BTH) region in 2015. Samples were subject to chemical analysis for organic carbon (OC), elemental carbon (EC), and major water-soluble inorganic ions. The annual average PM 2.5 mass concentration was 53 ± 36 μg·m -3 with the highest seasonal average concentration in spring and the lowest in summer. Water-soluble inorganic ions and carbonaceous aerosols accounted for 34% ± 15% and 33% ± 9%, respectively, of PM 2.5 mass on annual average. The excellent, good, lightly polluted, moderately polluted, and heavily polluted days based on the Air Quality Index (AQI) of PM 2.5 accounted for 40%, 42%, 11%, 4%, and 3%, respectively, of the year. The sum of the average concentration of sulfate, nitrate, and ammonium (SNA) increased from 4.2 ± 2.9 μg·m -3 during excellent days to 85.9 ± 22.4 μg·m -3 during heavily polluted days, and their contributions to PM 2.5 increased from 15% ± 8% to 49% ± 10% accordingly. In contrast, the average concentration of carbonaceous aerosols increased from 9.2 ± 2.8 μg·m -3 to 51.2 ± 14.1 μg·m -3 , and their contributions to PM 2.5 decreased from 34% ± 6% to 29% ± 7%. Potential source contribution function (PSCF) analysis revealed that the major sources for high PM 2.5 and its dominant chemical components were within the area mainly covering Shandong, Henan, and Hebei provinces. Regional pollutant transport from Shanxi province and Inner Mongolia autonomous region located in the west direction of SDZ was also important during the heating season.

Thyroid function and perchlorate in drinking water: an evaluation among California newborns, 1998.

PubMed

Buffler, Patricia A; Kelsh, Michael A; Lau, Edmund C; Edinboro, Charlotte H; Barnard, Julie C; Rutherford, George W; Daaboul, Jorge J; Palmer, Lynn; Lorey, Fred W

2006-05-01

Perchlorate (ClO4-) has been detected in groundwater sources in numerous communities in California and other parts of the United States, raising concerns about potential impacts on health. For California communities where ClO4- was tested in 1997 and 1998, we evaluated the prevalence of primary congenital hypothyroidism (PCH) and high thyroid-stimulating hormone (TSH) levels among the 342,257 California newborns screened in 1998. We compared thyroid function results among newborns from 24 communities with average ClO4- concentrations in drinking water>5 microg/L (n=50,326) to newborns from 287 communities with average concentrations5 microg/L were observed, with 20.4 expected [adjusted prevalence odds ratio (POR)=0.71; 95% confidence interval (CI), 0.40-1.19]. Although only 36% of all California newborns were screened before 24 hr of age in 1998, nearly 80% of newborns with high TSH were screened before 24 hr of age. Because of the physiologic postnatal surge of TSH, the results for newborns screened before 24 hr were uninformative for assessing an environmental impact. For newborns screened>or=24 hr, the adjusted POR for high TSH was 0.73 (95% CI, 0.40-1.23). All adjusted odds ratios (ORs) were controlled for sex, ethnicity, birth weight, and multiple birth status. Using an assessment of ClO4- in drinking water based on available data, we did not observe an association between estimated average ClO4- concentrations>5 microg/L in drinking water supplies and the prevalence of clinically diagnosed PCH or high TSH concentrations.

Earnings and Financial Compensation from Social Security Systems Correlate Strongly with Disability for Multiple Sclerosis Patients.

PubMed

Kavaliunas, Andrius; Wiberg, Michael; Tinghög, Petter; Glaser, Anna; Gyllensten, Hanna; Alexanderson, Kristina; Hillert, Jan

2015-01-01

Multiple sclerosis (MS) patients earn lower incomes and receive higher benefits. However, there is limited knowledge of how this is correlated with their disability. To elucidate sources and levels of income among MS patients with different disability, assessed with the Expanded Disability Status Scale. A total of 7929 MS patients aged 21-64 years and living in Sweden in 2010 were identified for this cross-sectional study. Descriptive statistics, logistic and truncated linear regression models were used to estimate differences between MS patients regarding earnings, disability pension, sickness absence, disability allowance, unemployment compensation, and social assistance. The average level of earnings was ten times lower and the average level of health- related benefits was four times higher when comparing MS patients with severe and mild disability. MS patients with severe disability had on average SEK 166,931 less annual income from earnings and SEK 54,534 more income from benefits compared to those with mild disability. The combined average income for MS patients was 35% lower when comparing patients in the same groups. The adjusted risk ratio for having earnings among MS patients with severe disability compared to the patients with mild disability was 0.33 (95% CI 0.29-0.39), while the risk ratio for having benefits was 1.93 (95% CI 1.90-1.94). Disease progression affects the financial situation of MS patients considerably. Correlations between higher disability and patient income were observed, suggesting that earnings and benefits could be used as measures of MS progression and proxies of disability.

Determination of beryllium concentrations in UK ambient air

NASA Astrophysics Data System (ADS)

Goddard, Sharon L.; Brown, Richard J. C.; Ghatora, Baljit K.

2016-12-01

Air quality monitoring of ambient air is essential to minimise the exposure of the general population to toxic substances such as heavy metals, and thus the health risks associated with them. In the UK, ambient air is already monitored under the UK Heavy Metals Monitoring Network for a number of heavy metals, including nickel (Ni), arsenic (As), cadmium (Cd) and lead (Pb) to ensure compliance with legislative limits. However, the UK Expert Panel on Air Quality Standards (EPAQS) has highlighted a need to limit concentrations of beryllium (Be) in air, which is not currently monitored, because of its toxicity. The aim of this work was to analyse airborne particulate matter (PM) sampled onto filter papers from the UK Heavy Metals Monitoring Network for quantitative, trace level beryllium determination and compare the results to the guideline concentration specified by EPAQS. Samples were prepared by microwave acid digestion in a matrix of 2% sulphuric acid and 14% nitric acid, verified by the use of Certified Reference Materials (CRMs). The digested samples were then analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The filters from the UK Heavy Metals Monitoring Network were tested using this procedure and the average beryllium concentration across the network for the duration of the study period was 7.87 pg m-3. The highest site average concentration was 32.0 pg m-3 at Scunthorpe Low Santon, which is significantly lower than levels that are thought to cause harm. However the highest levels were observed at sites monitoring industrial point sources, indicating that beryllium is being used and emitted, albeit at very low levels, from these point sources. Comparison with other metals concentrations and data from the UK National Atmospheric Emissions Inventory suggests that current emissions of beryllium may be significantly overestimated.

A novel earth observation based ecological indicator for cyanobacterial blooms

NASA Astrophysics Data System (ADS)

Anttila, Saku; Fleming-Lehtinen, Vivi; Attila, Jenni; Junttila, Sofia; Alasalmi, Hanna; Hällfors, Heidi; Kervinen, Mikko; Koponen, Sampsa

2018-02-01

Cyanobacteria form spectacular mass occurrences almost annually in the Baltic Sea. These harmful algal blooms are the most visible consequences of marine eutrophication, driven by a surplus of nutrients from anthropogenic sources and internal processes of the ecosystem. We present a novel Cyanobacterial Bloom Indicator (CyaBI) targeted for the ecosystem assessment of eutrophication in marine areas. The method measures the current cyanobacterial bloom situation (an average condition of recent 5 years) and compares this to the estimated target level for 'good environmental status' (GES). The current status is derived with an index combining indicative bloom event variables. As such we used seasonal information from the duration, volume and severity of algal blooms derived from earth observation (EO) data. The target level for GES was set by using a remote sensing based data set named Fraction with Cyanobacterial Accumulations (FCA; Kahru & Elmgren, 2014) covering years 1979-2014. Here a shift-detection algorithm for time series was applied to detect time-periods in the FCA data where the level of blooms remained low several consecutive years. The average conditions from these time periods were transformed into respective CyaBI target values to represent target level for GES. The indicator is shown to pass the three critical factors set for marine indicator development, namely it measures the current status accurately, the target setting can be scientifically proven and it can be connected to the ecosystem management goal. An advantage of the CyaBI method is that it's not restricted to the data used in the development work, but can be complemented, or fully applied, by using different types of data sources providing information on cyanobacterial accumulations.

High power industrial picosecond laser from IR to UV

NASA Astrophysics Data System (ADS)

Saby, Julien; Sangla, Damien; Pierrot, Simonette; Deslandes, Pierre; Salin, François

2013-02-01

Many industrial applications such as glass cutting, ceramic micro-machining or photovoltaic processes require high average and high peak power Picosecond pulses. The main limitation for the expansion of the picosecond market is the cost of high power picosecond laser sources, which is due to the complexity of the architecture used for picosecond pulse amplification, and the difficulty to keep an excellent beam quality at high average power. Amplification with fibers is a good technology to achieve high power in picosecond regime but, because of its tight confinement over long distances, light undergoes dramatic non linearities while propagating in fibers. One way to avoid strong non linearities is to increase fiber's mode area. Nineteen missing holes fibers offering core diameter larger than 80μm have been used over the past few years [1-3] but it has been shown that mode instabilities occur at approximately 100W average output power in these fibers [4]. Recently a new fiber design has been introduced, in which HOMs are delocalized from the core to the clad, preventing from HOMs amplification [5]. In these so-called Large Pitch Fibers, threshold for mode instabilities is increased to 294W offering robust single-mode operation below this power level [6]. We have demonstrated a high power-high efficiency industrial picosecond source using single-mode Large Pitch rod-type fibers doped with Ytterbium. Large Pitch Rod type fibers can offer a unique combination of single-mode output with a very large mode area from 40 μm up to 100μm and very high gain. This enables to directly amplify a low power-low energy Mode Locked Fiber laser with a simple amplification architecture, achieving very high power together with singlemode output independent of power level or repetition rate.

Chemical characteristics and source apportionment of PM2.5 between heavily polluted days and other days in Zhengzhou, China.

PubMed

Jiang, Nan; Li, Qiang; Su, Fangcheng; Wang, Qun; Yu, Xue; Kang, Panru; Zhang, Ruiqin; Tang, Xiaoyan

2018-04-01

PM 2.5 samples were collected in Zhengzhou during 3years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM 2.5 concentrations and annual average values exceeded the Chinese National Ambient Air Quality Daily and Annual Standards, indicating serious PM 2.5 pollution. The average concentration of water-soluble inorganic ions was 2.4 times higher in heavily polluted days (daily PM 2.5 concentrations>250μg/m 3 and visibility <3km) than that in other days, with sulfate, nitrate, and ammonium as major ions. According to the ratio of NO 3 - /SO 4 2- , stationary sources are still the dominant source of PM 2.5 and vehicle emission could not be ignored. The ratio of secondary organic carbon to organic carbon indicated that photochemical reactivity in heavily polluted days was more intense than in other days. Crustal elements were the most abundant elements, accounting for more than 60% of 23 elements. Chemical Mass Balance results indicated that the contributions of major sources (i.e., nitrate, sulfate, biomass, carbon and refractory material, coal combustion, soil dust, vehicle, and industry) of PM 2.5 were 13%, 16%, 12%, 2%, 14%, 8%, 7%, and 8% in heavily polluted days and 20%, 18%, 9%, 2%, 27%, 14%, 15%, and 9% in other days, respectively. Extensive combustion activities were the main sources of polycyclic aromatic hydrocarbons during the episode (Jan 1-9, 2015) and the total benzo[a]pyrene equivalency concentrations in heavily polluted days present significant health threat. Because of the effect of regional transport, the pollution level of PM 2.5 in the study area was aggravated. Copyright © 2017. Published by Elsevier B.V.

Temporal studies of black hole X-ray transients during outburst decay

NASA Astrophysics Data System (ADS)

Kalemci, Emrah

Galactic black holes (GBH) are a class of astrophysical sources with X-ray emission that is powered by accretion from a companion star. An important goal of GBH research is to understand the accretion structure and the nature of the variability of these systems. The GBHs sometimes show significant changes in the X-ray emission properties, and these changes are called state transitions. The transitions are believed to be caused by variation of the mass accretion rate and changes in accretion geometry. Thus, their study provides valuable information on the nature of the accretion structure. In this thesis work, I present results from studying the spectral and temporal evolution of all GBH transients that have been observed with NASA's Rossi X-ray Timing Explorer during outburst decay. I explore the physical conditions before, during and after the state transition, characterize the quasi-periodic oscillations (QPO) and continuum of power spectral density (PSD) in different energy bands, and study the correlations between spectral and temporal fit parameters. I also analyze the evolution of the cross- spectral parameters during and after the transition. I show that the appearance of the broad band variability is coincident with an increase of power-law flux. The evolution of the characteristic frequencies and the spectral parameters after the transition are consistent with retreating of the inner accretion disk. The energy dependent PSD analysis shows that the level of variability increases with energy when there is significant soft flux from the optically thick accretion disk. The variability level also increases with energy if the absorption column density to the source is high. This may be a result of small angle scatterings of lower energy X-ray photons with the ISM dust around these sources. I find global correlations between the spectral index and three temporal fit parameters: the QPO frequency, the overall level of variability and the integrated time lag. The relation between the spectral index and the time lags are interpreted within the context of the average number of Compton scatterings and the temperature of the scattering medium. During the transitions, the average lag is higher and average coherence is lower. I discuss whether a hybrid accretion model, for which the hot electron corona is the base of an optically thin outflow or a jet, can explain the physical properties during the transition.

Volatile organic compounds in a multi-storey shopping mall in guangzhou, South China

NASA Astrophysics Data System (ADS)

Tang, Jianhui; Chan, C. Y.; Wang, Xinming; Chan, L. Y.; Sheng, Guoying; Fu, Jiamo

Volatile organic compounds (VOCs) specified in the USEPA TO-14 list were analysed in microenvironments of a multi-storey shopping mall in Guangzhou city, South China. The microenvironments studied include both indoor (department store, supermarket, fast-food court, electronic games room, children's playground, gallery and book store) and outdoor ones (rooftop and ground level entrance). The characteristics and concentration of VOCs varied widely in differing microenvironments. The average concentrations of the total VOCs in the indoor microenvironments ranged from 178.5 to 457.7 μg m -3 with a maximum of 596.8 μg m -3. The fast-food court and a leather products department store had the highest concentrations of benzene, toluene, ethylbenzene, xylenes and chlorinated hydrocarbons. A high level of 1,4-dichlorobenzene was found in all indoor microenvironments with an average of 12.3 μg m -3 and a maximum of 44.3 μg m -3. The ratios of average indoor to outdoor concentrations (I/O ratio) in all indoor microenvironments fell between 1 and 3, except an average of 24.6 and a maximum of 77.8 in the fashion department store for 1,4-dichlorobenzene. Indoor emission sources of monocyclic aromatic hydrocarbons in the shopping mall might include cooking stoves, leather products and building materials. Chlorinated hydrocarbons, however, were possibly connected with their use as cleaning agents or deodorizers.

Sources and Potential Photochemical Roles of Formaldehyde in an Urban Atmosphere in South China

NASA Astrophysics Data System (ADS)

Wang, Chuan; Huang, Xiao-Feng; Han, Yu; Zhu, Bo; He, Ling-Yan

2017-11-01

Formaldehyde (HCHO) is an important intermediate in tropospheric photochemistry. However, study of its evolution characteristics under heavy pollution conditions in China is limited, especially for high temporal resolutions, making it difficult to analyze its sources and environmental impacts. In this study, ambient levels of HCHO were monitored using a proton-transfer reaction mass spectrometer at an urban site in the Pearl River Delta of China. Continuous monitoring campaigns were conducted in the spring, summer, fall, and winter in 2016. The highest averaged HCHO concentrations were observed in autumn (5.1 ± 3.1 ppbv) and summer (5.0 ± 4.4 ppbv), followed by winter (4.2 ± 2.2 ppbv) and spring (3.4 ± 1.6 ppbv). The daily maximum of HCHO occurs in the early afternoon and shows good correlations with O3 and the secondary organic aerosol tracer during the day, revealing close relationships between ambient HCHO and secondary formations in Shenzhen, especially in summer and autumn. The daytime HCHO is estimated to be the major contributor to O3 formation and OH radical production, indicating that HCHO plays a key role in the urban atmospheric photochemical reactions. Anthropogenic secondary formation was calculated to be the dominant source of HCHO using a photochemical age-based parameterization method, with an average proportion of 39%. The contributions of biogenic sources in summer (41%) and autumn (39%) are much higher than those in spring (26%) and winter (28%), while the contributions of anthropogenic primary sources in spring (20%) and winter (18%) are twice those in summer (9%) and autumn (9%).

A modeling study of coarse particulate matter pollution in Beijing: regional source contributions and control implications for the 2008 summer Olympics

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

Litao Wang; Jiming Hao; Kebin He

In the last 10 yr, Beijing has made a great effort to improve its air quality. However, it is still suffering from regional coarse particulate matter (PM10) pollution that could be a challenge to the promise of clean air during the 2008 Olympics. To provide scientific guidance on regional air pollution control, the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality Model (CMAQ) air quality modeling system was used to investigate the contributions of emission sources outside the Beijing area to pollution levels in Beijing. The contributions to the PM10 concentrations in Beijing were assessed formore » the following sources: power plants, industry, domestic sources, transportation, agriculture, and biomass open burning. In January, it is estimated that on average 22% of the PM10 concentrations can be attributed to outside sources, of which domestic and industrial sources contributed 37 and 31%, respectively. In August, as much as 40% of the PM10 concentrations came from regional sources, of which approximately 41% came from industry and 31% from power plants. However, the synchronous analysis of the hourly concentrations, regional contributions, and wind vectors indicates that in the heaviest pollution periods the local emission sources play a more important role. The implications are that long-term control strategies should be based on regional-scale collaborations, and that emission abatement of local sources may be more effective in lowering the PM10 concentration levels on the heavy pollution days. Better air quality can be attained during the Olympics by placing effective emission controls on the local sources in Beijing and by controlling emissions from industry and power plants in the surrounding regions. 44 refs., 6 figs., 3 tabs.« less

Optimizing dietary levels of menhaden and soybean oils and soybean lecithin for pre-gonadal somatic growth in juveniles of the sea urchin Lytechinus variegatus

PubMed Central

Gibbs, Victoria K.; Heflin, Laura E.; Jones, Warren T.; Powell, Mickie L.; Lawrence, Addison L.; Makowsky, Robert; Watts, Stephen A.

2015-01-01

Dietary lipids serve as important sources of energy and essential fatty acids for aquatic animals. Sources of animal and plant oils are increasingly limited as well as expensive, and dietary requirements associated with the inclusion of these oils must be carefully evaluated to facilitate sustainable and affordable formulations. In this study, we investigated quantities of menhaden oil (MO) with and without soybean lecithin or soybean oil (SO) to determine appropriate levels for optimal somatic growth for pre-gonadal juvenile Lytechinus variegatus. We prepared semi-purified diets that varied in neutral lipid content (0, 2, 4, or 8% dry matter) and soy lecithin (0 or 2%) and exchanged lipids reciprocally with purified starch while holding constant all other nutrients. We maintained laboratory-reared juvenile L. variegatus (average initial wet weight 82 ± 0.7 mg, mean ± SE , n = 9 treatment−1) in recirculating seawater systems and fed each daily a sub-satiation ration for five weeks. We assessed wet weights and test diameters every two weeks and at the end of the experiment (5 wk). Level of MO with or without soybean lecithin did not significantly affect wet weight gain; however, increasing levels of SO in the diet reduced wet weight gain and dry matter production efficiency and increased feed conversion ratio. Dry gut weight was positively correlated with level of MO. Lipid level in the gut increased with increasing dietary lipid level, regardless of source. These data suggest the composition of the SO is inhibitory for either nutrient absorption or metabolic processes associated with growth at this life stage. Diets containing total lipid levels of approximately 5 to 6% that include sources of n-3 fatty acids may support optimal growth for pre-gonadal juvenile L. variegatus. PMID:26146422

Assessing the Implications of Allowing Transgender Personnel to Serve Openly

DTIC Science & Technology

2016-01-01

their utilization estimates. Data from several sources (e.g., Sonier et al ., 2013; Gould , 2012) imply an approximate average one-to-one ratio of... et al ., 2014). Our analysis focused on the policies of the four countries—Australia, Canada, Israel, and the United Kingdom— with the most well...hor- mone levels stabilize (Hembree et al ., 2009; Elders et al ., 2014). To avoid this cost, DoD would need to either permit more flexible monitoring

Prediction of airframe noise

NASA Technical Reports Server (NTRS)

Hardin, J. C.; Fratello, D. J.; Hayden, R. E.; Kadman, Y.; Africk, S.

1975-01-01

Methods of predicting airframe noise generated by aircraft in flight under nonpowered conditions are discussed. Approaches to predictions relying on flyover data and component theoretical analyses are developed. A nondimensional airframe noise spectrum of various aircraft is presented. The spectrum was obtained by smoothing all the measured spectra to remove any peculiarities due to airframe protrusions, normalizing each spectra by its overall sound pressure level and a characteristics frequency, and averaging the spectra together. A chart of airframe noise sources is included.

Road and Roadside Feature Extraction Using Imagery and LIDAR Data for Transportation Operation

NASA Astrophysics Data System (ADS)

Ural, S.; Shan, J.; Romero, M. A.; Tarko, A.

2015-03-01

Transportation agencies require up-to-date, reliable, and feasibly acquired information on road geometry and features within proximity to the roads as input for evaluating and prioritizing new or improvement road projects. The information needed for a robust evaluation of road projects includes road centerline, width, and extent together with the average grade, cross-sections, and obstructions near the travelled way. Remote sensing is equipped with a large collection of data and well-established tools for acquiring the information and extracting aforementioned various road features at various levels and scopes. Even with many remote sensing data and methods available for road extraction, transportation operation requires more than the centerlines. Acquiring information that is spatially coherent at the operational level for the entire road system is challenging and needs multiple data sources to be integrated. In the presented study, we established a framework that used data from multiple sources, including one-foot resolution color infrared orthophotos, airborne LiDAR point clouds, and existing spatially non-accurate ancillary road networks. We were able to extract 90.25% of a total of 23.6 miles of road networks together with estimated road width, average grade along the road, and cross sections at specified intervals. Also, we have extracted buildings and vegetation within a predetermined proximity to the extracted road extent. 90.6% of 107 existing buildings were correctly identified with 31% false detection rate.

Ten-watt level picosecond parametric mid-IR source broadly tunable in wavelength

NASA Astrophysics Data System (ADS)

Vyvlečka, Michal; Novák, Ondřej; Roškot, Lukáscaron; Smrž, Martin; Mužík, Jiří; Endo, Akira; Mocek, Tomáš

2018-02-01

Mid-IR wavelength range (between 2 and 8 μm) offers perspective applications, such as minimally-invasive neurosurgery, gas sensing, or plastic and polymer processing. Maturity of high average power near-IR lasers is beneficial for powerful mid-IR generation by optical parametric conversion. We utilize in-house developed Yb:YAG thin-disk laser of 100 W average power at 77 kHz repetition rate, wavelength of 1030 nm, and about 2 ps pulse width for pumping of a ten-watt level picosecond mid-IR source. Seed beam is obtained by optical parametric generation in a double-pass 10 mm long PPLN crystal pumped by a part of the fundamental near-IR beam. Tunability of the signal wavelength between 1.46 μm and 1.95 μm was achieved with power of several tens of miliwatts. Main part of the fundamental beam pumps an optical parametric amplification stage, which includes a walk-off compensating pair of 10 mm long KTP crystals. We already demonstrated the OPA output signal and idler beam tunability between 1.70-1.95 μm and 2.18-2.62 μm, respectively. The signal and idler beams were amplified up to 8.5 W and 5 W, respectively, at 42 W pump without evidence of strong saturation. Thus, increase in signal and idler output power is expected for pump power increase.

A New Approach in Coal Mine Exploration Using Cosmic Ray Muons

NASA Astrophysics Data System (ADS)

Darijani, Reza; Negarestani, Ali; Rezaie, Mohammad Reza; Fatemi, Syed Jalil; Akhond, Ahmad

2016-08-01

Muon radiography is a technique that uses cosmic ray muons to image the interior of large scale geological structures. The muon absorption in matter is the most important parameter in cosmic ray muon radiography. Cosmic ray muon radiography is similar to X-ray radiography. The main aim in this survey is the simulation of the muon radiography for exploration of mines. So, the production source, tracking, and detection of cosmic ray muons were simulated by MCNPX code. For this purpose, the input data of the source card in MCNPX code were extracted from the muon energy spectrum at sea level. In addition, the other input data such as average density and thickness of layers that were used in this code are the measured data from Pabdana (Kerman, Iran) coal mines. The average thickness and density of these layers in the coal mines are from 2 to 4 m and 1.3 gr/c3, respectively. To increase the spatial resolution, a detector was placed inside the mountain. The results indicated that using this approach, the layers with minimum thickness about 2.5 m can be identified.

Nucleon matrix elements from lattice QCD with all-mode-averaging and a domain-decomposed solver: An exploratory study

NASA Astrophysics Data System (ADS)

von Hippel, Georg; Rae, Thomas D.; Shintani, Eigo; Wittig, Hartmut

2017-01-01

We study the performance of all-mode-averaging (AMA) when used in conjunction with a locally deflated SAP-preconditioned solver, determining how to optimize the local block sizes and number of deflation fields in order to minimize the computational cost for a given level of overall statistical accuracy. We find that AMA enables a reduction of the statistical error on nucleon charges by a factor of around two at the same cost when compared to the standard method. As a demonstration, we compute the axial, scalar and tensor charges of the nucleon in Nf = 2 lattice QCD with non-perturbatively O(a)-improved Wilson quarks, using O(10,000) measurements to pursue the signal out to source-sink separations of ts ∼ 1.5 fm. Our results suggest that the axial charge is suffering from a significant amount (5-10%) of excited-state contamination at source-sink separations of up to ts ∼ 1.2 fm, whereas the excited-state contamination in the scalar and tensor charges seems to be small.

Interplanetary medium data book, appendix

NASA Technical Reports Server (NTRS)

King, J. H.

1977-01-01

Computer generated listings of hourly average interplanetary plasma and magnetic field parameters are given. Parameters include proton temperature, proton density, bulk speed, an identifier of the source of the plasma data for the hour, average magnetic field magnitude and cartesian components of the magnetic field. Also included are longitude and latitude angles of the vector made up of the average field components, a vector standard deviation, and an identifier of the source of magnetic field data.

Night of the sirens: analysis of carbon monoxide-detector experience in suburban Chicago.

PubMed

Bizovi, K E; Leikin, J B; Hryhorczuk, D O; Frateschi, L J

1998-06-01

To determine the pattern and environmental causes of carbon monoxide (CO)-detector alarms. Data including time, location, detector manufacturer, CO measurements in the home, reported illness, cause, and actions taken were collected between July 15, 1994, and January 26, 1995, on all calls to 17 suburban Chicago fire departments for CO-detector alarms. We used univariate time-series analysis involving joint estimation of model parameters and outlier effects to analyze data and compared data on ambient CO levels from the Illinois Environmental Protection Agency to the number of calls per day. During the study period, 777 calls for sounding CO detectors were made to the fire departments in question. The median number of calls per day was three. Our univariate time series identified 3 days with a significant excess of calls (December 12, 29 calls; December 21, 69; December 22, 128; P < .001). The average ambient CO readings on these days were 0.99, 3.25, and 3.89 ppm, respectively, compared with an overall mean of 8.8 ppm. In-home CO levels among all 828 measurements taken from the 777 domestic calls ranged from 0 to 425 ppm, 0 in 249 (30%), 1 to 10 in 340 (41%), 11 to 50 in 149 (18%), 51 to 100 in 22 (9%), and more than 100 in 11 (1.3%). No measurement was taken in six cases. Cause of alarm was listed as furnace in 25 cases, auto exhaust in 24, stove/oven in 22, poor location of detector in 14, water heater in 11, outside sources in 7, and multiple sources in 7. Other sources accounted for fewer than 1% each. The participating fire departments considered 242 cases (31%) to be false alarms. Cause was not determined in 400 calls (51%). In 37 calls (4.8%), people reported illness. Above-average ambient CO levels coincided with a significant increase in the number of calls and may have contributed to the triggering of CO alarms.

[An investigation of occupational stress, social support, and happiness of junior civil servants].

PubMed

Wang, Lingfeng

2015-10-01

To investigate the current status of occupational stress, social support, and happiness in junior civil servants in northern Zhejiang Province, China, and to investigate the relationship between occupational stress, social support and happiness. A total of 360 junior civil servants from below-county-level administrative organizations in Huzhou, Jiaxing, and Hangzhou were surveyed using the job stress questionnaire and social support rating scale for civil servants. The total average score of occupational stress in junior civil servants was 2.52 ± 0.48, indicating a moderate level of occupational stress; career prospects topped the rank list of sources of occupational stress with a score of 2.90 ± 0.60; different generations showed significant differences in the sources and total average scores of occupational stress, with the scores of the 1980s, 1990s, 1970s, 1950s, and 1960s groups decreasing in the same order (P<0.01); the occupational stress of males was significantly greater than that of the females (P<0.01). The levels of social support and happiness among the junior civil servants were relatively low, with scores of 38.43 ± 8.38 and 76.88 ± 12.77, respectively; different generations also showed significant differences, with the scores of 1980s, 1990s, 1970s, 1950s, and 1960s groups increasing in the same order (P<0.01); females experienced significantly more social support and happiness than males (P<0.01). Sources of occupational stress like superior leaders, work task, tendency to perfection, and career prospects, objective and subjective support, and utilization of the support were significantly related to the happiness of junior civil servants (r=0.405~0.571, P<0.01; β=0.090~0.210, P <0.01). Occupational stress and social support are significantly related to the happiness of junior civil servants.

Fiber-based tunable repetition rate source for deep tissue two-photon fluorescence microscopy.

PubMed

Charan, Kriti; Li, Bo; Wang, Mengran; Lin, Charles P; Xu, Chris

2018-05-01

Deep tissue multiphoton imaging requires high peak power to enhance signal and low average power to prevent thermal damage. Both goals can be advantageously achieved through laser repetition rate tuning instead of simply adjusting the average power. We show that the ideal repetition rate for deep two-photon imaging in the mouse brain is between 1 and 10 MHz, and we present a fiber-based source with an arbitrarily tunable repetition rate within this range. The performance of the new source is compared to a mode-locked Ti:Sapphire (Ti:S) laser for in vivo imaging of mouse brain vasculature. At 2.5 MHz, the fiber source requires 5.1 times less average power to obtain the same signal as a standard Ti:S laser operating at 80 MHz.

40 CFR 464.44 - New source performance standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards. 464...

40 CFR 464.14 - New source performance standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 31 2013-07-01 2013-07-01 false New source performance standards. 464...

40 CFR 464.14 - New source performance standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards. 464...

40 CFR 464.44 - New source performance standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 30 2014-07-01 2014-07-01 false New source performance standards. 464...

40 CFR 464.24 - New source performance standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 31 2013-07-01 2013-07-01 false New source performance standards. 464...

40 CFR 464.24 - New source performance standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 30 2011-07-01 2011-07-01 false New source performance standards. 464...

40 CFR 464.24 - New source performance standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards. 464...

40 CFR 464.44 - New source performance standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 31 2013-07-01 2013-07-01 false New source performance standards. 464...

40 CFR 464.44 - New source performance standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 31 2012-07-01 2012-07-01 false New source performance standards. 464...

40 CFR 464.24 - New source performance standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 30 2014-07-01 2014-07-01 false New source performance standards. 464...

40 CFR 464.44 - New source performance standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 30 2011-07-01 2011-07-01 false New source performance standards. 464...

40 CFR 464.24 - New source performance standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 31 2012-07-01 2012-07-01 false New source performance standards. 464...

40 CFR 464.14 - New source performance standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 30 2014-07-01 2014-07-01 false New source performance standards. 464...

40 CFR 464.14 - New source performance standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 30 2011-07-01 2011-07-01 false New source performance standards. 464...

40 CFR 464.14 - New source performance standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., total phenols, oil and grease, and TSS. For non-continuous dischargers, annual average mass standards.... Concentration standards and annual average mass standards shall only apply to non-continuous dischargers. (a... 40 Protection of Environment 31 2012-07-01 2012-07-01 false New source performance standards. 464...

Binary encoding of multiplexed images in mixed noise.

PubMed

Lalush, David S

2008-09-01

Binary coding of multiplexed signals and images has been studied in the context of spectroscopy with models of either purely constant or purely proportional noise, and has been shown to result in improved noise performance under certain conditions. We consider the case of mixed noise in an imaging system consisting of multiple individually-controllable sources (X-ray or near-infrared, for example) shining on a single detector. We develop a mathematical model for the noise in such a system and show that the noise is dependent on the properties of the binary coding matrix and on the average number of sources used for each code. Each binary matrix has a characteristic linear relationship between the ratio of proportional-to-constant noise and the noise level in the decoded image. We introduce a criterion for noise level, which is minimized via a genetic algorithm search. The search procedure results in the discovery of matrices that outperform the Hadamard S-matrices at certain levels of mixed noise. Simulation of a seven-source radiography system demonstrates that the noise model predicts trends and rank order of performance in regions of nonuniform images and in a simple tomosynthesis reconstruction. We conclude that the model developed provides a simple framework for analysis, discovery, and optimization of binary coding patterns used in multiplexed imaging systems.

[Evaluation of environmental conditions: air, water and soil in areas of mining activity in Boyacá, Colombia].

PubMed

Agudelo-Calderón, Carlos A; Quiroz-Arcentales, Leonardo; García-Ubaque, Juan C; Robledo-Martínez, Rocío; García-Ubaque, Cesar A

2016-02-01

Objectives To determine concentrations of PM10, mercury and lead in indoor air of homes, water sources and soil in municipalities near mining operations. Method 6 points were evaluated in areas of influence and 2 in control areas. For measurements of indoor air, we used the NIOSH 600 method (PM10), NIOSH 6009 (mercury) and NIOSH 7300 (lead). For water analysis we used the IDEAM Guide for monitoring discharges. For soil analysis, we used the cold vapor technique (mercury) and atomic absorption (lead). Results In almost all selected households, the average PM10 and mercury concentrations in indoor air exceeded applicable air quality standards. Concentrations of lead were below standard levels. In all water sources, high concentrations of lead were found and in some places within the mining areas, high levels of iron, aluminum and mercury were also found. In soil, mercury concentrations were below the detection level and for lead, differences between the monitored points were observed. Conclusions The results do not establish causal relationships between mining and concentration of these pollutants in the evaluated areas because of the multiplicity of sources in the area. However, such studies provide important information, useful to agents of the environmental health system and researchers. Installation of networks for environmental monitoring to obtain continuous reports is suggested.

Taking aim at nurse stress: a call to action.

PubMed

Kashani, Mariam; Eliasson, Arn; Chrosniak, Linda; Vernalis, Marina

2010-02-01

The study investigates stress levels and related behaviors of nurses in a military medical center during wartime. In 2007, nurses completed a questionnaire survey with objective validation of data in a subsample using actigraphy over 12 weeks. Of 270 nurses, 255 (94%) returned surveys. A total of 81% reported moderately high or high stress with sources listed as work (66%) and fatigue (39%). Many reported coming to work despite feeling ill and/or stressed (13.6 days/3 months). In contrast, morale was high or moderately high in 71%. Nurses reported an average of 5.5 hours of sleep/night, 8.8 h/wk taken for self, and 3.8 h/wk for exercise. Actigraphy data showed an average of 6.0 hours of sleep/night. These findings highlight a mismatch between stress levels and coping perceptions indicating an inability to properly care for self. To manage the effects of chronic stress, nurse leaders should implement systems targeting healthy life balance.

Nearest Neighbor Averaging and its Effect on the Critical Level and Minimum Detectable Concentration for Scanning Radiological Survey Instruments that Perform Facility Release Surveys.

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

Fournier, Sean Donovan; Beall, Patrick S; Miller, Mark L

2014-08-01

Through the SNL New Mexico Small Business Assistance (NMSBA) program, several Sandia engineers worked with the Environmental Restoration Group (ERG) Inc. to verify and validate a novel algorithm used to determine the scanning Critical Level (L c ) and Minimum Detectable Concentration (MDC) (or Minimum Detectable Areal Activity) for the 102F scanning system. Through the use of Monte Carlo statistical simulations the algorithm mathematically demonstrates accuracy in determining the L c and MDC when a nearest-neighbor averaging (NNA) technique was used. To empirically validate this approach, SNL prepared several spiked sources and ran a test with the ERG 102F instrumentmore » on a bare concrete floor known to have no radiological contamination other than background naturally occurring radioactive material (NORM). The tests conclude that the NNA technique increases the sensitivity (decreases the L c and MDC) for high-density data maps that are obtained by scanning radiological survey instruments.« less

Levels of selected metals in ambient air PM10 in an urban site of Zaragoza (Spain).

PubMed

López, J M; Callén, M S; Murillo, R; García, T; Navarro, M V; de la Cruz, M T; Mastral, A M

2005-09-01

An assessment of the air quality of Zaragoza (Spain) was performed by determining the trace element content in airborne PM10 in a sampling campaign from July 2001 to July 2002. Samples were collected in a heavy traffic area with a high volume air sampler provided with a PM10 cutoff inlet. The levels of 16 elements (Al, Ba, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, V, and Zn) were quantified after collecting the PM10 on Teflon-coated glass fiber filters (GFF). Regarding the PM10, 32% exceedance of the proposed PM10 daily limit was obtained, some of them corresponding to summer and autumn periods. The limit values of toxic trace elements from US-EPA, WHO, and EC were not exceeded, considering Zaragoza as a moderately polluted city under the current air quality guidelines. The contribution of anthropogenic sources to atmospheric elemental levels was reflected by the high values of enrichment factors for Zn, Pb, and Cu compared to the average crustal composition. Statistical analyses also determined the contribution of different sources to the PM10, finding that vehicle traffic and anthropogenic emissions related to combustion and industrial processes were the main pollutant sources as well as natural sources associated with transport of dust from Africa for specific dates. Regarding the influence of meteorological conditions on PM10 and trace elements concentrations, it was found that calm weather conditions with low wind speed favor the PM10 collection and the pollution for trace elements, suggesting the influence of local sources.

Origins and trends in ethane and propane in the United Kingdom from 1993 to 2012

NASA Astrophysics Data System (ADS)

Derwent, R. G.; Field, R. A.; Dumitrean, P.; Murrells, T. P.; Telling, S. P.

2017-05-01

Continuous, high frequency in situ observations of ethane and propane began in the United Kingdom in 1993 and have continued through to the present day at a range of kerbside, urban background and rural locations. Whilst other monitored C2 - C8 hydrocarbons have shown dramatic declines in concentrations by close to or over an order of magnitude, ethane and propane levels have remained at or close to their 1993 values. Urban ethane sources appear to be dominated by natural gas leakage. Background levels of ethane associated with long range transport are rising. However, natural gas leakage is not the sole source of urban propane. Oil and gas operations lead to elevated propane levels in urban centres when important refinery operations are located nearby. Weekend versus weekday average diurnal curves for ethane and propane at an urban background site in London show the importance of natural gas leakage for both ethane and propane, and road traffic sources for propane. The road traffic source of propane was tentatively identified as arising from petrol-engined motor vehicle refuelling and showed a strong downwards trend at the long-running urban background and rural sites. The natural gas leakage source of ethane and propane in the observations exhibits an upwards trend whereas that in the UK emission inventory trends downwards. Also, inventory emissions for natural gas leakage appeared to be significantly underestimated compared with the observations. In addition, the observed ethane to propane ratio found here for natural gas leakage strongly disagreed with the inventory ratio.

A comparison of alternative methods for measuring cigarette prices.

PubMed

Chaloupka, Frank J; Tauras, John A; Strasser, Julia H; Willis, Gordon; Gibson, James T; Hartman, Anne M

2015-05-01

Government agencies, public health organisations and tobacco control researchers rely on accurate estimates of cigarette prices for a variety of purposes. Since the 1950s, the Tax Burden on Tobacco (TBOT) has served as the most widely used source of this price data despite its limitations. This paper compares the prices and collection methods of the TBOT retail-based data and the 2003 and 2006/2007 waves of the population-based Tobacco Use Supplement to the Current Population Survey (TUS-CPS). From the TUS-CPS, we constructed multiple state-level measures of cigarette prices, including weighted average prices per pack (based on average prices for single-pack purchases and average prices for carton purchases) and compared these with the weighted average price data reported in the TBOT. We also constructed several measures of tax avoidance from the TUS-CPS self-reported data. For the 2003 wave, the average TUS-CPS price was 71 cents per pack less than the average TBOT price; for the 2006/2007 wave, the difference was 47 cents. TUS-CPS and TBOT prices were also significantly different at the state level. However, these differences varied widely by state due to tax avoidance opportunities, such as cross-border purchasing. The TUS-CPS can be used to construct valid measures of cigarette prices. Unlike the TBOT, the TUS-CPS captures the effect of price-reducing marketing strategies, as well as tax avoidance practices and non-traditional types of purchasing. Thus, self-reported data like TUS-CPS appear to have advantages over TBOT in estimating the 'real' price that smokers face. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Does the Market Value Racial and Ethnic Concordance in Physician–Patient Relationships?

PubMed Central

Brown, Timothy T; Scheffler, Richard M; Tom, Sarah E; Schulman, Kevin A

2007-01-01

Objective To determine if the market-determined earnings per hour of physicians is sensitive to the degree of area-level racial/ethnic concordance (ALREC) in the local physician labor market. Data Sources 1998–1999 and 2000–2001 Community Tracking Study Physician Surveys and Household Surveys, 2000 U.S. Census, and the Area Resource File. Study Design Population-averaged regression models with area-level fixed effects were used to estimate the determinants of log earnings per hour for physicians in a two-period panel (N = 12,886). ALREC for a given racial/ethnic group is measured as the percentage of physicians who are of a given race/ethnicity less the percentage of the population who are of the corresponding race/ethnicity. Relevant control variables were included. Principal Findings Average earnings per hour for Hispanic and Asian physicians varies with the degree of ALREC that corresponds to a physician's race/ethnicity. Both Hispanic and Asian physicians earn more per hour in areas where corresponding ALREC is negative, other things equal. ALREC varies from negative to positive for all groups. ALREC for Hispanics is negative, on average, due to the small percentage of the physician workforce that is Hispanic. This results in an average 5.6 percent earnings-per-hour premium for Hispanic physicians. However, ALREC for Asians is positive, on average, due to the large percentage of the physician workforce that is Asian. This results in an average 4.0 percent earnings-per-hour discount for Asian physicians. No similar statistically significant results were found for black physicians. Conclusions The market-determined earnings per hour of Hispanic and Asian physicians are sensitive to the degree of ALREC in the local labor market. Larger sample sizes may be needed to find statistically significant results for black physicians. PMID:17362214

Investigation of natural effective gamma dose rates case study: Ardebil Province in Iran

PubMed Central

2012-01-01

Gamma rays pose enough energy to induce chemical changes that may be biologically important for the normal functioning of body cells. The external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined. In this research natural background gamma dose rates and corresponding annual effective doses were determined for selected cities of Ardebil province. Outdoor gamma dose rates were measured using an Ion Chamber Survey Meter in 105 locations in selected districts. Average absorbed doses for Ardebil, Sar-Ein, Germy, Neer, Shourabil Recreational Lake, and Kosar were determined as 265, 219, 344, 233, 352, and 358 nSv/h, respectively. Although dose rates recorded for Germi and Kosar are comparable with some areas with high natural radiation background, however, the dose rates in other districts are well below the levels reported for such locations. Average annual effective dose due to indoor and outdoor gamma radiation for Ardebil province was estimated as 1.73 (1.35–2.39) mSv, which is on average 2 times higher than the world population weighted average. PMID:23369115

Radiation exposure from consumer products and miscellaneous sources

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

Not Available

1977-01-01

This review of the literature indicates that there is a variety of consumer products and miscellaneous sources of radiation that result in exposure to the U.S. population. A summary of the number of people exposed to each such source, an estimate of the resulting dose equivalents to the exposed population, and an estimate of the average annual population dose equivalent are tabulated. A review of the data in this table shows that the total average annual contribution to the whole-body dose equivalent of the U.S. population from consumer products is less than 5 mrem; about 70 percent of this arisesmore » from the presence of naturally-occurring radionuclides in building materials. Some of the consumer product sources contribute exposure mainly to localized tissues or organs. Such localized estimates include: 0.5 to 1 mrem to the average annual population lung dose equivalent (generalized); 2 rem to the average annual population bronchial epithelial dose equivalent (localized); and 10 to 15 rem to the average annual population basal mucosal dose equivalent (basal mucosa of the gum). Based on these estimates, these sources may be grouped or classified as those that involve many people and the dose equivalent is relative large or those that involve many people but the dose equivalent is relatively small, or the dose equivalent is relatively large but the number of people involved is small.« less

Sources of osmium to the modern oceans: New evidence from the 190Pt-186Os system

USGS Publications Warehouse

McDaniel, D.K.; Walker, R.J.; Hemming, S.R.; Horan, M.F.; Becker, H.; Grauch, R.I.

2004-01-01

High precision Os isotope analysis of young marine manganese nodules indicate that whereas the composition of modern seawater is radiogenic with respect to 187Os/188Os, it has 186Os/188Os that is within uncertainty of the chondritic value. Marine Mn nodule compositions thus indicate that the average continental source of Os to modern seawater had long-term high Re/Os compared to Pt/Os. Analyses of loess and freshwater Mn nodules support existing evidence that average upper continental crust (UCC) has resolvably suprachondritic 186Os/188Os, as well as radiogenic 187Os/188Os. Modeling the composition of seawater as a two-component mixture of oceanic/cosmic Os with chondritic Os compositions and continentally-derived Os demonstrates that, insofar as estimates for the composition of average UCC are accurate, congruently weathered average UCC cannot be the sole continental source of Os to seawater. Our analysis of four Cambrian black shales confirm that organic-rich sediments can have 187Os/188Os ratios that are much higher than average UCC, but 186Os/188Os compositions that are generally between those of chondrites and average-UCC. Preferential weathering of black shales can result in dissolved Os discharged to the ocean basins that has a much lower 186Os/188Os than does average upper crust. Modeling the available data demonstrates that augmentation of estimated average UCC compositions with less than 0.1% additional black shale and 1.4% additional ultramafic rock can produce a continental end-member Os isotopic composition that satisfies the requirements imposed by the marine Mn nodule data. The interplay of these two sources provides a mechanism by which the 187Os/188Os of seawater can change as sources and weathering conditions change, yet seawater 186Os/188Os varies only minimally. ?? 2004 Elsevier Ltd.

Characterization of gigahertz (GHz) bandwidth photomultipliers

NASA Technical Reports Server (NTRS)

Abshire, J. B.; Rowe, H. E.

1977-01-01

The average impulse response, root-mean-square times jitter as a function of signal level, single photoelectron distribution, and multiphotoelectron dark-count distribution have been measured for two static crossed-field and five electrostatic photomultipliers. The optical signal source for the first three of these tests was a 30 picosecond mode-locked laser pulse at 0.53 micron. The static crossed-field detectors had 2-photoelectron resolution, less than 200 ps rise times, and rms time jitters of 30 ps at the single photoelectron level. The electrostatic photomultipliers had rise times from 1 to 2.5 nanoseconds, and rms time jitters from 160 to 650 ps at the same signal level. The two static crossed-field photomultipliers had ion-feedback-generated dark pulses to the 50-photoelectron level, whereas one electrostatic photomultiplier had dark pulses to the 30-photoelectron level.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and biphenyls (PCBs) in home-produced eggs.

PubMed

Hoogenboom, Ron L A P; Ten Dam, Guillaume; van Bruggen, Mark; Jeurissen, Suzanne M F; van Leeuwen, Stefan P J; Theelen, Rob M C; Zeilmaker, Marco J

2016-05-01

Home produced eggs from 62 addresses in the Netherlands were investigated for the levels of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and biphenyls (PCBs), both dioxin-like (dl) and non-dioxin-like (ndl). Compared to commercial eggs, levels were relatively high with a median of 4.6 pg TEQ g(-1) fat for the sum of PCDD/Fs and dl-PCBs, and a highest level of 18.9 pg TEQ g(-1) fat. A number of samples showed clearly elevated ndl-PCB levels with a median of 13 ng g(-1) fat and a highest level of 80 ng g(-1) fat. There were no clear regional differences, even though part of the samples were derived from the rather industrial Rotterdam/Rijnmond area. Based on the congener patterns, former backyard burning of waste seems the most likely source for most eggs, with two exceptions where other sources contributed to the contamination. Similar is true for the ndl-PCBs. The study shows that average levels are about ten-fold higher than commercial eggs and may substantially contribute to the intake of PCDD/Fs and dl-PCBs by consumers. Intervention measures to reduce the intake of these contaminants by laying hens are advised. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ultrafast disk technology enables next generation micromachining laser sources

NASA Astrophysics Data System (ADS)

Heckl, Oliver H.; Weiler, Sascha; Luzius, Severin; Zawischa, Ivo; Sutter, Dirk

2013-02-01

Ultrashort pulsed lasers based on thin disk technology have entered the 100 W regime and deliver several tens of MW peak power without chirped pulse amplification. Highest uptime and insensitivity to back reflections make them ideal tools for efficient and cost effective industrial micromachining. Frequency converted versions allow the processing of a large variety of materials. On one hand, thin disk oscillators deliver more than 30 MW peak power directly out of the resonator in laboratory setups. These peak power levels are made possible by recent progress in the scaling of the pulse energy in excess of 40 μJ. At the corresponding high peak intensity, thin disk technology profits from the limited amount of material and hence the manageable nonlinearity within the resonator. Using new broadband host materials like for example the sesquioxides will eventually reduce the pulse duration during high power operation and further increase the peak power. On the other hand industry grade amplifier systems deliver even higher peak power levels. At closed-loop controlled 100W, the TruMicro Series 5000 currently offers the highest average ultrafast power in an industry proven product, and enables efficient micromachining of almost any material, in particular of glasses, ceramics or sapphire. Conventional laser cutting of these materials often requires UV laser sources with pulse durations of several nanoseconds and an average power in the 10 W range. Material processing based on high peak power laser sources makes use of multi-photon absorption processes. This highly nonlinear absorption enables micromachining driven by the fundamental (1030 nm) or frequency doubled (515 nm) wavelength of Yb:YAG. Operation in the IR or green spectral range reduces the complexity and running costs of industrial systems initially based on UV light sources. Where UV wavelength is required, the TruMicro 5360 with a specified UV crystal life-time of more than 10 thousand hours of continues operation at 15W is an excellent choice. Currently this is the world's most powerful industrial sub-10 ps UV laser.

Preliminary study on assessment of lead exposure in Thai children aged between 3-7 years old who live in Umphang district, Tak Province.

PubMed

Neesanan, Naiyana; Kasemsup, Rachada; Ratanachuaeg, Suntree; Kojaranjit, Puangporn; Sakulnoom, Kim; Padungtod, Chantana

2011-08-01

Centers of Disease Control of the United States of America (CDC) informs Ministry of Public Health, Thailand that up to 13% of Burmese refugee children who are transferred to the United States of America during 2007-2009 have elevated blood lead levels (EBLL, Blood Lead Level > or = 10 microg/dl). These are children from a number of refugee camps in Tak Province; two camps are near Umphang but other camps are not. In June 2008, CDC, the result of investigation of Centers for Disease Control/Thailand Ministry of Public Health Collaboration (CDC/TUC) and International Organization for Migration, Thailand indicates that 33 of 64 children aged 6 months to 15 years (5.1%) who live in Mae La, Umpiem and Nupo camps have elevated blood lead level. However, no study on how Thai children who live nearby those camps are exposed to lead. Subsequently, Queen Sirikit National Institute of Child Health, Bangkok, Thailand contacts relevant organizations in Tak Province in order to investigate lead exposure and evaluate health status of Thai children who live close to Burmese refugee camps. 1) Evaluation of lead exposure of Thai children who live nearby Burmese refugee camps; 2) Assessment of risk factors on lead exposure of the children as mentioned above. The present study adopts a retrospective study based on information gathered from health assessment on 213 Thai children aged between 3-7 years old who live nearby Burmese refugee camps. The health assessment was conducted from April 30th, 2010 to May 5th, 2010. The information is from 3 sources. The first source is from blood sampling in order to assess lead level and ferritin level. The next source is from interview of persons who provide primary care in order to identify risk factors on lead exposure of target children. The last source is from physical examination and developmental assessment conducted by pediatricians and special nurses for child development in order to identify health and developmental problems. The population of the present study was 213 of Thai children are 3-7 years old, average age is 54.54 +/- 12.41 months-old. The average blood lead level is 7.71 +/- 4.62 microg/dl (range = 3-25 microg/dl). Elevated blood lead levels of all populations show that 57 children (26%) have blood lead level at 10 microg/dl or more. Analysis of odds by controlling all risk factors (adjusted OR) that effect on blood lead level (> or =10 microg/dl) indicates that only gender and source of drinking water are risk factors. To clarify, male children would have 2.8 times higher risk than female children. Children who drink water from tap and canal have 15 times and 72 times, respectively, higher risk than children drinking from bottle water. The result of the present study shows that 1 of 4 of Thai children at Umphang district, Tak Province who lived near Burmese refugee camps aged between 3-7 years old have blood lead level higher than concerning level. Thus, it is necessary to identify risk factors on lead exposure and policy of blood lead screening in some areas in Thailand.

Aerosol Measurements in the Mid-Atlantic: Trends and Uncertainty

NASA Astrophysics Data System (ADS)

Hains, J. C.; Chen, L. A.; Taubman, B. F.; Dickerson, R. R.

2006-05-01

Elevated levels of PM2.5 are associated with cardiovascular and respiratory problems and even increased mortality rates. In 2002 we ran two commonly used PM2.5 speciation samplers (an IMPROVE sampler and an EPA sampler) in parallel at Fort Meade, Maryland (a suburban site located in the Baltimore- Washington urban corridor). The filters were analyzed at different labs. This experiment allowed us to calculate the 'real world' uncertainties associated with these instruments. The EPA method retrieved a January average PM2.5 mass of 9.3 μg/m3 with a standard deviation of 2.8 μg/m3, while the IMPROVE method retrieved an average mass of 7.3 μg/m3 with a standard deviation of 2.1 μg/m3. The EPA method retrieved a July average PM2.5 mass of 26.4 μg/m3 with a standard deviation of 14.6 μg/m3, while the IMPROVE method retrieved an average mass of 23.3 μg/m3 with a standard deviation of 13.0 μg/m3. We calculated a 5% uncertainty associated with the EPA and IMPROVE methods that accounts for uncertainties in flow control strategies and laboratory analysis. The RMS difference between the two methods in January was 2.1 μg/m3, which is about 25% of the monthly average mass and greater than the uncertainty we calculated. In July the RMS difference between the two methods was 5.2 μg/m3, about 20% of the monthly average mass, and greater than the uncertainty we calculated. The EPA methods retrieve consistently higher concentrations of PM2.5 than the IMPROVE methods on a daily basis in January and July. This suggests a systematic bias possibly resulting from contamination of either of the sampling methods. We reconstructed the mass and found that both samplers have good correlation between reconstructed and gravimetric mass, though the IMPROVE method has slightly better correlation than the EPA method. In January, organic carbon is the largest contributor to PM2.5 mass, and in July both sulfate and organic matter contribute substantially to PM2.5. Source apportionment models suggest that regional and local power plants are the major sources of sulfate, while mobile and vegetative burning factors are the major sources of organic carbon.

Aggregation of Adenovirus 2 in Source Water and Impacts on Disinfection by Chlorine

PubMed Central

Cromeans, Theresa L.; Metcalfe, Maureen G.; Humphrey, Charles D.; Hill, Vincent R.

2016-01-01

It is generally accepted that viral particles in source water are likely to be found as aggregates attached to other particles. For this reason, it is important to investigate the disinfection efficacy of chlorine on aggregated viruses. A method to produce adenovirus particle aggregation was developed for this study. Negative stain electron microscopy was used to measure aggregation before and after addition of virus particles to surface water at different pH and specific conductance levels. The impact of aggregation on the efficacy of chlorine disinfection was also examined. Disinfection experiments with human adenovirus 2 (HAdV2) in source water were conducted using 0.2 mg/L free chlorine at 5 °C. Aggregation of HAdV2 in source water (≥3 aggregated particles) remained higher at higher specific conductance and pH levels. However, aggregation was highly variable, with the percentage of particles present in aggregates ranging from 43 to 71 %. Upon addition into source water, the aggregation percentage dropped dramatically. On average, chlorination CT values (chlorine concentration in mg/L × time in min) for 3-log10 inactivation of aggregated HAdV2 were up to three times higher than those for dispersed HAdV2, indicating that aggregation reduced the disinfection rate. This information can be used by water utilities and regulators to guide decision making regarding disinfection of viruses in water. PMID:26910058

Aggregation of Adenovirus 2 in Source Water and Impacts on Disinfection by Chlorine.

PubMed

Kahler, Amy M; Cromeans, Theresa L; Metcalfe, Maureen G; Humphrey, Charles D; Hill, Vincent R

2016-06-01

It is generally accepted that viral particles in source water are likely to be found as aggregates attached to other particles. For this reason, it is important to investigate the disinfection efficacy of chlorine on aggregated viruses. A method to produce adenovirus particle aggregation was developed for this study. Negative stain electron microscopy was used to measure aggregation before and after addition of virus particles to surface water at different pH and specific conductance levels. The impact of aggregation on the efficacy of chlorine disinfection was also examined. Disinfection experiments with human adenovirus 2 (HAdV2) in source water were conducted using 0.2 mg/L free chlorine at 5 °C. Aggregation of HAdV2 in source water (≥3 aggregated particles) remained higher at higher specific conductance and pH levels. However, aggregation was highly variable, with the percentage of particles present in aggregates ranging from 43 to 71 %. Upon addition into source water, the aggregation percentage dropped dramatically. On average, chlorination CT values (chlorine concentration in mg/L × time in min) for 3-log10 inactivation of aggregated HAdV2 were up to three times higher than those for dispersed HAdV2, indicating that aggregation reduced the disinfection rate. This information can be used by water utilities and regulators to guide decision making regarding disinfection of viruses in water.

Separating the air quality impact of a major highway and nearby sources by nonparametric trajectory analysis.

PubMed

Henry, Ronald C; Vette, Alan; Norris, Gary; Vedantham, Ram; Kimbrough, Sue; Shores, Richard C

2011-12-15

Nonparametric Trajectory Analysis (NTA), a receptor-oriented model, was used to assess the impact of local sources of air pollution at monitoring sites located adjacent to highway I-15 in Las Vegas, NV. Measurements of black carbon, carbon monoxide, nitrogen oxides, and sulfur dioxide concentrations were collected from December 2008 to December 2009. The purpose of the study was to determine the impact of the highway at three downwind monitoring stations using an upwind station to measure background concentrations. NTA was used to precisely determine the contribution of the highway to the average concentrations measured at the monitoring stations accounting for the spatially heterogeneous contributions of other local urban sources. NTA uses short time average concentrations, 5 min in this case, and constructed local back-trajectories from similarly short time average wind speed and direction to locate and quantify contributions from local source regions. Averaged over an entire year, the decrease of concentrations with distance from the highway was found to be consistent with previous studies. For this study, the NTA model is shown to be a reliable approach to quantify the impact of the highway on local air quality in an urban area with other local sources.

Spatial distribution and importance of potential perfluoroalkyl acid precursors in urban rivers and sewage treatment plant effluent--case study of Tama River, Japan.

PubMed

Ye, Feng; Tokumura, Masahiro; Islam, Md Saiful; Zushi, Yasuyuki; Oh, Jungkeun; Masunaga, Shigeki

2014-12-15

Production and use of perfluorooctane sulfonate (PFOS) is regulated worldwide. However, numerous potential precursors that eventually decompose into PFOS and other perfluoroalkyl acids (PFAAs) such as perfluorooctanoic acid (PFOA) are still being used and have not been studied in detail. Therefore, knowledge about the levels and sources of the precursors is essential. We investigated the total concentration of potential PFAA precursors in the Tama River, which is one of the major rivers flowing into the Tokyo Bay, by converting all the perfluorinated carboxylic acid (PFCA) and perfluoroalkyl sulfonic acid (PFSA) precursors into PFCAs by chemical oxidation. The importance of controlling PFAA precursors was determined by calculating the ratios of PFCAs formed by oxidation to the PFAAs originally present (ΣΔ[PFCAC4-C12]/Σ[PFAAs]before oxidation) (average = 0.28 and 0.69 for main and tributary branch rivers, respectively). Higher total concentrations of Δ[PFCAs] were found in sewage treatment plant (STP) effluents. However, the ratios found in the effluents were lower (average = 0.21) than those found in the river water samples, which implies the decomposition of some precursors into PFAAs during the treatment process. On the other hand, higher ratios were observed in the upstream water samples and the existence of emission sources other than the STP effluents was indicated. This study showed that although the treatment process converting a part of the PFAA precursors into PFAAs, STPs were important sources of precursors to the Tama River. To reduce the levels of PFAAs in the aquatic environment, it is necessary to reduce the emission of the PFAA precursors as well. Copyright © 2014 Elsevier Ltd. All rights reserved.

Global approach to reducing lead exposure and poisoning.

PubMed

Meyer, Pamela A; Brown, Mary Jean; Falk, Henry

2008-01-01

Lead poisoning is an important environmental disease that can have life-long adverse health effects. Most susceptible are children, and most commonly exposed are those who are poor and live in developing countries. Studies of children's blood-lead levels (BLLs) are showing cognitive impairment at increasingly lower BLLs. Lead is dangerous at all levels in children. The sources of lead exposure vary among and within countries depending on past and current uses. Sources of lead may be from historic contamination, recycling old lead products, or from manufacturing new products. In all countries that have banned leaded gasoline, average population BLLs have declined rapidly. In many developing countries where leaded gasoline is no longer used, many children and workers are exposed to fugitive emissions and mining wastes. Unexpected lead threats, such as improper disposal of electronics and children's toys contaminated with lead, continue to emerge. The only medical treatment available is chelation, which can save lives of persons with very high BLLs. However, chelating drugs are not always available in developing countries and have limited value in reducing the sequelae of chronic low dose lead exposure. Therefore, the best approach is to prevent exposure to lead. Because a key strategy for preventing lead poisoning is to identify and control or eliminate lead sources, this article highlights several major sources of lead poisoning worldwide. In addition, we recommend three primary prevention strategies for lead poisoning: identify sources, eliminate or control sources, and monitor environmental exposures and hazards.

Productive performance, eggshell quality, and eggshell ultrastructure of laying hens fed diets supplemented with organic trace minerals.

PubMed

Stefanello, C; Santos, T C; Murakami, A E; Martins, E N; Carneiro, T C

2014-01-01

This study was carried out with the purpose of evaluating the effect of supplementing hens' diets with trace minerals from inorganic or organic sources on the productive performance, eggshell quality, and eggshell ultrastructure of laying hens. Three hundred sixty Hy-Line W36 laying hens between 47 to 62 wk of age were used and distributed in a completely randomized experimental design with 9 treatments, 5 replicates, and 8 birds for each experimental unit. The treatments consisted of a control diet without supplementation of the trace minerals Mn, Zn, and Cu; 4 supplementation levels of these trace minerals from an inorganic source; and the same levels of supplementation from an organic source (proteinates). The supplementation levels in milligrams per kilogram for Mn, Zn, and Cu, were, respectively, 35-30-05, 65-60-10, 95-90-15, and 125-120-20. There was no effect of supplementation of trace minerals on the rate of posture, feed intake, feed conversion, specific weight, and Haugh unit of eggs. However, there was a quadratic effect (P < 0.05) of the levels of trace mineral supplementation on average egg weight and egg mass; the results did not differ regarding the source used. The increase in the levels of supplementation of Mn, Zn, and Cu provided a linear increase (P < 0.05) in the breaking strength and the percentage of eggshell. There was a linear decrease (P < 0.05) in the egg loss and the number of mammillary buttons in the shell. The best results were obtained using diets supplemented with trace minerals from an organic source because these diets provided lower egg loss, higher thickness, and increased strength of the shell. Structurally, organic Mn, Zn, and Cu provided higher thickness of the palisade layer and lower mammillary density. The trace mineral supplementation improved the structural characteristics and the quality of the eggshells.

A scale model wind tunnel study of dispersion in the Cleveland area. Laboratory simulation of lake breeze effects on diffusion from ground level emissions

NASA Technical Reports Server (NTRS)

Hoydysh, W. G.

1974-01-01

A wind tunnel simulation of the diffusion patterns in a sea breeze was attempted. The results indicate that the low level onshore flow was well simulated for neutral, stable, unstable, and elevated inversion conditions. Velocity, turbulence, shear stress, and temperature data were taken, and the spread of emissions from ground level sources was investigated. Comparison is made with theoretical predictions by E. Inoue and with the open, homogeneous plane field results of Pasquill. Agreement with the predictions by Inoue is good, and the comparison with Pasquill's results shows that the wind tunnel flows are shifted two categories towards more stable. The discrepancy may be explained as a matter of averaging time.

Future methane emissions from animals

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

Anastasi, C.; Simpson, V.J.

1993-04-20

The authors project future methane emissions from animals to the year 2025. They review the present estimated sources of methane from enteric fermentation in animals. Ruminant animals produce the highest concentrations of methane. Methane is a byproduct of anaerobic breakdown of carbohydrates by microbes in the digestive tract of herbatious animals. In general the methane production depends on the variety of animal, the quality of the feed, and the feeding level. Since cattle, sheep, and buffalo account for roughly 91% of all animal methane emission, they only study these animals in detail. Results suggest a rise in methane production ofmore » roughly 1% per year averaged through 2025. Increasing levels are found to originate from developed countries even though the feedstock levels are lower.« less

Simulated effects of irrigation on salinity in the Arkansas River Valley in Colorado

USGS Publications Warehouse

Goff, K.; Lewis, M.E.; Person, M.A.; Konikow, Leonard F.

1998-01-01

Agricultural irrigation has a substantial impact on water quantity and quality in the lower Arkansas River valley of southeastern Colorado. A two-dimensional flow and solute transport model was used to evaluate the potential effects of changes in irrigation on the quantity and quality of water in the alluvial aquifer and in the Arkansas River along an 17.7 km reach of the fiver. The model was calibrated to aquifer water level and dissolved solids concentration data collected throughout the 24 year study period (197195). Two categories of irrigation management were simulated with the calibrated model: (1) a decrease in ground water withdrawals for irrigation; and (2) cessation of all irrigation from ground water and surface water sources. In the modeled category of decreased irrigation from ground water pumping, there was a resulting 6.9% decrease in the average monthly ground water salinity, a 0.6% decrease in average monthly river salinity, and an 11.1% increase in ground water return flows to the river. In the modeled category of the cessation of all irrigation, average monthly ground water salinity decreased by 25%; average monthly river salinity decreased by 4.4%; and ground water return flows to the river decreased by an average of 64%. In all scenarios, simulated ground water salinity decreased relative to historical conditions for about 12 years before reaching a new dynamic equilibrium condition. Aquifer water levels were not sensitive to any of the modeled scenarios. These potential changes in salinity could result in improved water quality for irrigation purposes downstream from the affected area.

Characterizing large river sounds: Providing context for understanding the environmental effects of noise produced by hydrokinetic turbines

DOE PAGES

Bevelhimer, Mark S.; Deng, Z. Daniel; Scherelis, Constantin C.

2016-01-06

Underwaternoise associated with the installation and operation of hydrokinetic turbines in rivers and tidal zones presents a potential environmental concern for fish and marine mammals. Comparing the spectral quality of sounds emitted by hydrokinetic turbines to natural and other anthropogenic sound sources is an initial step at understanding potential environmental impacts. Underwater recordings were obtained from passing vessels and natural underwater sound sources in static and flowing waters. Static water measurements were taken in a lake with minimal background noise. Flowing water measurements were taken at a previously proposed deployment site for hydrokinetic turbines on the Mississippi River, where soundsmore » created by flowing water are part of all measurements, both natural ambient and anthropogenic sources. Vessel sizes ranged from a small fishing boat with 60 hp outboard motor to an 18-unit barge train being pushed upstream by tugboat. As expected, large vessels with large engines created the highest sound levels, which were, on average, 40 dB greater than the sound created by an operating hydrokinetic turbine. As a result, a comparison of sound levels from the same sources at different distances using both spherical and cylindrical sound attenuation functions suggests that spherical model results more closely approximate observed sound attenuation.« less

Performance of 100-W HVM LPP-EUV source

NASA Astrophysics Data System (ADS)

Mizoguchi, Hakaru; Nakarai, Hiroaki; Abe, Tamotsu; Nowak, Krzysztof M.; Kawasuji, Yasufumi; Tanaka, Hiroshi; Watanabe, Yukio; Hori, Tsukasa; Kodama, Takeshi; Shiraishi, Yutaka; Yanagida, Tatsuya; Soumagne, Georg; Yamada, Tsuyoshi; Yamazaki, Taku; Okazaki, Shinji; Saitou, Takashi

2015-08-01

At Gigaphoton Inc., we have developed unique and original technologies for a carbon dioxide laser-produced tin plasma extreme ultraviolet (CO2-Sn-LPP EUV) light source, which is the most promising solution for high-power high-volume manufacturing (HVM) EUV lithography at 13.5 nm. Our unique technologies include the combination of a pulsed CO2 laser with Sn droplets, the application of dual-wavelength laser pulses for Sn droplet conditioning, and subsequent EUV generation and magnetic field mitigation. Theoretical and experimental data have clearly shown the advantage of our proposed strategy. Currently, we are developing the first HVM light source, `GL200E'. This HVM light source will provide 250-W EUV power based on a 20-kW level pulsed CO2 laser. The preparation of a high average-power CO2 laser (more than 20 kW output power) has been completed in cooperation with Mitsubishi Electric Corporation. Recently, we achieved 140 W at 50 kHz and 50% duty cycle operation as well as 2 h of operation at 100 W of power level. Further improvements are ongoing. We will report the latest status and the challenge to reach stable system operation of more than 100 W at about 4% conversion efficiency with 20-μm droplets and magnetic mitigation.

Characterizing large river sounds: Providing context for understanding the environmental effects of noise produced by hydrokinetic turbines.

PubMed

Bevelhimer, Mark S; Deng, Z Daniel; Scherelis, Constantin

2016-01-01

Underwater noise associated with the installation and operation of hydrokinetic turbines in rivers and tidal zones presents a potential environmental concern for fish and marine mammals. Comparing the spectral quality of sounds emitted by hydrokinetic turbines to natural and other anthropogenic sound sources is an initial step at understanding potential environmental impacts. Underwater recordings were obtained from passing vessels and natural underwater sound sources in static and flowing waters. Static water measurements were taken in a lake with minimal background noise. Flowing water measurements were taken at a previously proposed deployment site for hydrokinetic turbines on the Mississippi River, where sounds created by flowing water are part of all measurements, both natural ambient and anthropogenic sources. Vessel sizes ranged from a small fishing boat with 60 hp outboard motor to an 18-unit barge train being pushed upstream by tugboat. As expected, large vessels with large engines created the highest sound levels, which were, on average, 40 dB greater than the sound created by an operating hydrokinetic turbine. A comparison of sound levels from the same sources at different distances using both spherical and cylindrical sound attenuation functions suggests that spherical model results more closely approximate observed sound attenuation.

Potentiometric surface of the upper Floridan Aquifer in the St. Johns Water Management District and vicinity, Florida, May 1984

USGS Publications Warehouse

Schiner, George R.; Hayes, Eugene C.

1984-01-01

This map shows the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 1984. The Upper Floridan aquifer is the principal source of potable water in the area. Water-level measurements were made on approximately 1,000 wells and on several springs. The potentiometric surface is shown mostly by 5-foot contour intervals. In the Fernandina Beach area a 40-foot interval is used to show a deep cone of depression. The potentiometric surface ranged from 126 feet above sea level in Polk County to 84 feet below sea level in Nassau County. Water levels in key wells were mostly above, or less frequently, slightly below averages for May in response to diverse area rainfall patterns. Most levels in the district were about the same, or more commonly, 1 to 2 feet lower than May 1983 levels. (USGS)

Respiratory disease associated with community air pollution and a steel mill, Utah Valley.

PubMed Central

Pope, C A

1989-01-01

This study assessed the association between hospital admissions and fine particulate pollution (PM10) in Utah Valley during the period April 1985-February 1988. This time period included the closure and reopening of the local steel mill, the primary source of PM10. An association between elevated PM10 levels and hospital admissions for pneumonia, pleurisy, bronchitis, and asthma was observed. During months when 24-hour PM10 levels exceeded 150 micrograms/m3, average admissions for children nearly tripled; in adults, the increase in admissions was 44 per cent. During months with mean PM10 levels greater than or equal to 50 micrograms/m3 average admissions for children and adults increased by 89 and 47 per cent, respectively. During the winter months when the steel mill was open, PM10 levels were nearly double the levels experienced during the winter months when the mill was closed. This occurred even though relatively stagnant air was experienced during the winter the mill was closed. Children's admissions were two to three times higher during the winters when the mill was open compared to when it was closed. Regression analysis also revealed that PM10 levels were strongly correlated with hospital admissions. They were more strongly correlated with children's admissions than with adult admissions and were more strongly correlated with admissions for bronchitis and asthma than with admissions for pneumonia and pleurisy. PMID:2495741

Geological sources of fluoride and acceptable intake of fluoride in an endemic fluorosis area, southern Iran.

PubMed

Battaleb-Looie, Sedigheh; Moore, Farid; Jacks, Gunnar; Ketabdari, Mohammad Reza

2012-10-01

The present study is the first attempt to put forward possible source(s) of fluoride in the Dashtestan area, Bushehr Province, southern Iran. In response to reports on the high incidence of dental fluorosis, 35 surface and groundwater samples were collected and analysed for fluoride. The results indicate that dissolved fluoride in the study area is above the maximum permissible limit recommended by the World Health Organization (WHO). An additional 35 soil and rock samples were also collected and analysed for fluoride, and rock samples were subjected to petrographic investigations and X-ray diffraction. The results of these analyses show that the most likely source for fluoride in the groundwater is from clay minerals (chlorite) and micas (muscovite, sericite, and biotite) in the soils and rocks in the area. We also note that due to the high average temperatures all year round and excessive water consumption in the area, the optimum fluoride dose level should be lower than that recommended by the WHO.

Infrared photometry of the black hole candidate Sagittarius A*

NASA Technical Reports Server (NTRS)

Close, Laird M.; Mccarthy, Donald W. JR.; Melia, Fulvio

1995-01-01

An infrared source has been imaged within 0.2 +/- 0.3 arcseconds of the unique Galactic center radio source Sgr A* High angular resolution (averaged value of the Full Width at Half Maximum (FWHM) approximately 0.55 arcseconds) was achieved by rapid (approximately 50 Hz) real-time images motion compensation. The source's near-infrared magnitudes (K = 12.1 +/- 0.3, H = 13.7 +/- 0.3, and J = 16.6 +/- 0.4) are consistent with a hot object reddened by the local extinction A(sub v) approximately 27). At the 3 sigma level of confidence, a time series of 80 images limits the source variability to less than 50% on timescales from 3 to 30 minutes. The photometry is consistent with the emission from a simple accretion disk model for a approximately 1 x 10(exp 6) solar mass black hole. However, the fluxes are also consistent with a hot luminous (L approximately 10(exp 3.5) to 10(exp 4-6) solar luminosity) central cluster star positionally coincident with Sgr A*.

Source origin of trace elements in PM from regional background, urban and industrial sites of Spain

NASA Astrophysics Data System (ADS)

Querol, X.; Viana, M.; Alastuey, A.; Amato, F.; Moreno, T.; Castillo, S.; Pey, J.; de la Rosa, J.; Sánchez de la Campa, A.; Artíñano, B.; Salvador, P.; García Dos Santos, S.; Fernández-Patier, R.; Moreno-Grau, S.; Negral, L.; Minguillón, M. C.; Monfort, E.; Gil, J. I.; Inza, A.; Ortega, L. A.; Santamaría, J. M.; Zabalza, J.

Despite their significant role in source apportionment analysis, studies dedicated to the identification of tracer elements of emission sources of atmospheric particulate matter based on air quality data are relatively scarce. The studies describing tracer elements of specific sources currently available in the literature mostly focus on emissions from traffic or large-scale combustion processes (e.g. power plants), but not on specific industrial processes. Furthermore, marker elements are not usually determined at receptor sites, but during emission. In our study, trace element concentrations in PM 10 and PM 2.5 were determined at 33 monitoring stations in Spain throughout the period 1995-2006. Industrial emissions from different forms of metallurgy (steel, stainless steel, copper, zinc), ceramic and petrochemical industries were evaluated. Results obtained at sites with no significant industrial development allowed us to define usual concentration ranges for a number of trace elements in rural and urban background environments. At industrial and traffic hotspots, average trace metal concentrations were highest, exceeding rural background levels by even one order of magnitude in the cases of Cr, Mn, Cu, Zn, As, Sn, W, V, Ni, Cs and Pb. Steel production emissions were linked to high levels of Cr, Mn, Ni, Zn, Mo, Cd, Se and Sn (and probably Pb). Copper metallurgy areas showed high levels of As, Bi, Ga and Cu. Zinc metallurgy was characterised by high levels of Zn and Cd. Glazed ceramic production areas were linked to high levels of Zn, As, Se, Zr, Cs, Tl, Li, Co and Pb. High levels of Ni and V (in association) were tracers of petrochemical plants and/or fuel-oil combustion. At one site under the influence of heavy vessel traffic these elements could be considered tracers (although not exclusively) of shipping emissions. Levels of Zn-Ba and Cu-Sb were relatively high in urban areas when compared with industrialised regions due to tyre and brake abrasion, respectively.

Development of a flattening filter free multiple source model for use as an independent, Monte Carlo, dose calculation, quality assurance tool for clinical trials.

PubMed

Faught, Austin M; Davidson, Scott E; Popple, Richard; Kry, Stephen F; Etzel, Carol; Ibbott, Geoffrey S; Followill, David S

2017-09-01

The Imaging and Radiation Oncology Core-Houston (IROC-H) Quality Assurance Center (formerly the Radiological Physics Center) has reported varying levels of compliance from their anthropomorphic phantom auditing program. IROC-H studies have suggested that one source of disagreement between institution submitted calculated doses and measurement is the accuracy of the institution's treatment planning system dose calculations and heterogeneity corrections used. In order to audit this step of the radiation therapy treatment process, an independent dose calculation tool is needed. Monte Carlo multiple source models for Varian flattening filter free (FFF) 6 MV and FFF 10 MV therapeutic x-ray beams were commissioned based on central axis depth dose data from a 10 × 10 cm 2 field size and dose profiles for a 40 × 40 cm 2 field size. The models were validated against open-field measurements in a water tank for field sizes ranging from 3 × 3 cm 2 to 40 × 40 cm 2 . The models were then benchmarked against IROC-H's anthropomorphic head and neck phantom and lung phantom measurements. Validation results, assessed with a ±2%/2 mm gamma criterion, showed average agreement of 99.9% and 99.0% for central axis depth dose data for FFF 6 MV and FFF 10 MV models, respectively. Dose profile agreement using the same evaluation technique averaged 97.8% and 97.9% for the respective models. Phantom benchmarking comparisons were evaluated with a ±3%/2 mm gamma criterion, and agreement averaged 90.1% and 90.8% for the respective models. Multiple source models for Varian FFF 6 MV and FFF 10 MV beams have been developed, validated, and benchmarked for inclusion in an independent dose calculation quality assurance tool for use in clinical trial audits. © 2017 American Association of Physicists in Medicine.

Quantifying Sulfur-Containing Compounds Over the Santa Barbara Channel

NASA Astrophysics Data System (ADS)

Black, J.; Hughes, S.; Blake, D. R.

2016-12-01

Carbonyl sulfide (OCS) is emitted to the atmosphere through the outgassing of ocean surface waters. OCS is also the primary source of sulfur-containing compounds in the stratosphere and contributes to the formation of the stratospheric sulfate layer. During the 2016 Student Airborne Research Program (SARP), whole air samples were collected on the NASA DC-8 aircraft over the Santa Barbara Channel. Five additional surface samples were taken at various locations along the Santa Barbara Channel. The samples were analyzed using gas chromatography in the Rowland-Blake lab at UC Irvine, and compounds such as OCS, dimethyl sulfide (DMS), carbon disulfide (CS2), bromoform (CHBr3), and methyl iodide (CH3I) associated with ocean emissions and stratospheric aerosols were analyzed. These marine sourced compounds, excluding OCS, showed expected trends of dilution with increasing altitude. The surface samples from the Santa Barbara Channel all exhibited elevated concentrations of OCS in comparison to samples taken from the aircraft, with an average of 666 ± 12 pptv, whereas the average background concentration of OCS was 587 ± 19 pptv. SARP flights from 2009-2015 over the Santa Barbara Channel saw an average OCS concentration of 548 ± 26 pptv. Elevated levels of OCS have never been detected from the aircraft during SARP flights, indicating that OCS emissions must be measured using surface sampling if emission estimates from the ocean are to be evaluated.

Atmospheric methane sources - Alaskan tundra bogs, an alpine fen, and a subarctic boreal marsh

NASA Technical Reports Server (NTRS)

Sebacher, D. I.; Harriss, R. C.; Grice, S. S.; Bartlett, K. B.; Sebacher, S. M.

1986-01-01

Methane (CH4) flux measurements from Alaska tundra bogs, an alpine fen, and a subarctic boreal marsh were obtained at field sites ranging from Prudhoe Bay on the coast of the Arctic Ocean to the Alaskan Range south of Fairbanks during August 1984. In the tundra, average CH4 emission rates varied from 4.9 mg CH4 per sq m per day (moist tundra) to 119 mg CH4 per sq m per day (waterlogged tundra). Fluxes averaged 40 mg CH4 per sq m per day from wet tussock meadows in the Brooks Range and 289 mg Ch4 per sq m per day from an alpine fen in the Alaskan Range. The boreal marsh had an average CH4 emission rate of 106 mg CH4 per sq m per day. Significant emissions were detected in tundra areas where peat temperatures were as low as 4 C, and permafrost was only 25 cm below the ground surface. Emission rates from the 17 sites sampled were found to be logarithmically related to water levels at the sites. Extrapolation of the data to an estimate of the total annual CH4 emission from all arctic and boreal wetlands suggests that these ecosystems are a major source of atmospheric CH4 and could account for up to 23 percent of global CH4 emissions from wetlands.

Spatial and temporal trends in short-chain chlorinated paraffins in Lake Ontario sediments.

PubMed

Marvin, C H; Painter, S; Tomy, G T; Stern, G A; Braekevelt, E; Muir, D C G

2003-10-15

Short-chain chlorinated paraffins (polychlorinated-[C10-C13]-n-alkanes) were measured in Lake Ontario sediments collected during a lake-wide survey to characterize spatial and temporal trends in contamination. The Lake Ontario average SCCP sediment concentration was 49 ng/g (dry wt), which was somewhat higher than the lake-wide average for sigmaDDT (32 ng/g). Individual stations in each of the depositional basins exhibited the highest concentrations, ranging from 147 ng/g (dry wt) to 410 ng/g at an index station in the Niagara (western) basin. Relative average contributions of the carbon chain groups to total SCCPs on a lake-wide basis were as follows: sigmaC10 = 24%, sigmaC11 = 35%, sigmaC12 = 34%, sigmaC13 = 6.6%. Assessment of core profiles and estimates of SCCP fluxes indicated that an area of the western end of Lake Ontario is heavily impacted (SCCP flux of 170 microg/m2 yr) and potentially influenced by local industrial sources of SCCPs. Maximum accumulation of SCCPs in this area of the western basin occurred in the mid-1970s. In contrast, SCCP concentrations in a core from a site in the central area of the lake (SCCP flux of 8.0 microg/m2 yr) were more similar to levels characteristic of remote locations primarily impacted by atmospheric sources.

Sophisticated Clean Air Strategies Required to Mitigate Against Particulate Organic Pollution

NASA Astrophysics Data System (ADS)

Grigas, T.; Ovadnevaite, J.; Ceburnis, D.; Moran, E.; McGovern, F. M.; Jennings, S. G.; O'Dowd, C.

2017-03-01

Since the 1980’s, measures mitigating the impact of transboundary air pollution have been implemented successfully as evidenced in the 1980-2014 record of atmospheric sulphur pollution over the NE-Atlantic, a key region for monitoring background northern-hemisphere pollution levels. The record reveals a 72-79% reduction in annual-average airborne sulphur pollution (SO4 and SO2, respectively) over the 35-year period. The NE-Atlantic, as observed from the Mace Head research station on the Irish coast, can be considered clean for 64% of the time during which sulphate dominates PM1 levels, contributing 42% of the mass, and for the remainder of the time, under polluted conditions, a carbonaceous (organic matter and Black Carbon) aerosol prevails, contributing 60% to 90% of the PM1 mass and exhibiting a trend whereby its contribution increases with increasing pollution levels. The carbonaceous aerosol is known to be diverse in source and nature and requires sophisticated air pollution policies underpinned by sophisticated characterisation and source apportionment capabilities to inform selective emissions-reduction strategies. Inauspiciously, however, this carbonaceous concoction is not measured in regulatory Air Quality networks.

Sophisticated Clean Air Strategies Required to Mitigate Against Particulate Organic Pollution.

PubMed

Grigas, T; Ovadnevaite, J; Ceburnis, D; Moran, E; McGovern, F M; Jennings, S G; O'Dowd, C

2017-03-17

Since the 1980's, measures mitigating the impact of transboundary air pollution have been implemented successfully as evidenced in the 1980-2014 record of atmospheric sulphur pollution over the NE-Atlantic, a key region for monitoring background northern-hemisphere pollution levels. The record reveals a 72-79% reduction in annual-average airborne sulphur pollution (SO 4 and SO 2 , respectively) over the 35-year period. The NE-Atlantic, as observed from the Mace Head research station on the Irish coast, can be considered clean for 64% of the time during which sulphate dominates PM 1 levels, contributing 42% of the mass, and for the remainder of the time, under polluted conditions, a carbonaceous (organic matter and Black Carbon) aerosol prevails, contributing 60% to 90% of the PM 1 mass and exhibiting a trend whereby its contribution increases with increasing pollution levels. The carbonaceous aerosol is known to be diverse in source and nature and requires sophisticated air pollution policies underpinned by sophisticated characterisation and source apportionment capabilities to inform selective emissions-reduction strategies. Inauspiciously, however, this carbonaceous concoction is not measured in regulatory Air Quality networks.

Environmental impact and human exposure to PCBs in Guiyu, an electronic waste recycling site in China.

PubMed

Xing, Guan Hua; Chan, Janet Kit Yan; Leung, Anna Oi Wah; Wu, Sheng Chun; Wong, M H

2009-01-01

PCB levels in fish (collected from local rivers), atmosphere and human milk samples have been studied to determine the exposure levels of PCBs for local residents and e-waste workers in Guiyu, a major electronic waste scrapping center in China. The source appointment and correlation analyses showed that homologue composition of PCBs in 7 species of fish were consistent and similar to commercial PCBs Aroclor 1248. PCB levels in air surrounding the open burning site were significantly higher than those in residential area. Inhalation exposure contributed 27% and 93% to the total body loadings (the sum of dietary and inhalation exposure) of the local residents, and e-waste workers engaged in open burning respectively. Total PCB concentrations in human milk ranged from N.D. to 57.6 ng/g lipid, with an average of 9.50 ng/g lipid. The present results indicated that commercial PCBs derived from e-waste recycling are major sources of PCBs accumulating in different environmental media, leading to the accumulation of high chlorinated biphenyls in human beings.

Wetland Resiliency: How does multi-year water table level decline and recovery influence carbon dioxide and methane fluxes?

NASA Astrophysics Data System (ADS)

Pugh, C.; Reed, D. E.; Desai, A. R.; Sulman, B. N.

2016-12-01

Wetlands play a disproportionately large role in the global carbon budget, and individual wetlands can fluctuate between carbon sinks and sources depending on factors such as hydrology, biogeochemistry, and land use. Although much research has been done on wetland biogeochemical cycles, there is a lack of experimental evidence concerning how changes in wetland hydrology influence these cycles over interannual timescales. Over a seven-year period, Sulman et al. (2009) found that a drought-induced declining water table at a shrub wetland in northern Wisconsin coincided with increased ecosystem respiration (ER) and gross ecosystem productivity (GEP) (Sulman et al. 2009). Since then, however, the average water table level at this site has begun to increase, thus allowing a unique opportunity to explore how wetland carbon storage is impacted by water table recovery. With the addition of three more years of eddy covariance observations post recovery and new methane flux observations, we found that water table level no longer had a significant correlation with GEP, ER, or methane flux. Air temperature, however, had a strong correlation with all three. Average methane flux stayed relatively constant under 14 °C, before increasing an order of magnitude from 3.7 nmol m-2 s-1 in April to 36 nmol m-2 s-1 in July. These results suggest that, over decadal timescales, temperature, rather than water level, is a stronger limiting factor for both aerobic and anaerobic respiration in shrub fen wetlands. Wetlands play a disproportionately large role in the global carbon budget, and individual wetlands can fluctuate between carbon sinks and sources depending on factors such as hydrology, biogeochemistry, and land use. Although much research has been done on wetland biogeochemical cycles, there is a lack of experimental evidence concerning how changes in wetland hydrology influence these cycles over interannual timescales. Over a seven-year period, Sulman et al. (2009) found that a drought-induced declining water table at a shrub wetland in northern Wisconsin coincided with increased ecosystem respiration (ER) and gross ecosystem productivity (GEP) (Sulman et al. 2009). Since then, however, the average water table level at this site has begun to increase, thus allowing a unique opportunity to explore how wetland carbon storage is impacted by water table recovery. With the addition of three more years of eddy covariance observations post recovery and new methane flux observations, we found that water table level no longer had a significant correlation with GEP, ER, or methane flux. Air temperature, however, had a strong correlation with all three. Average methane flux stayed relatively constant under 14 °C, before increasing an order of magnitude from 3.7 nmol m-2 s-1 in April to 36 nmol m-2 s-1 in July. These results suggest that, over decadal timescales, temperature, rather than water level, is a stronger limiting factor for both aerobic and anaerobic respiration in shrub fen wetlands.

Are Cockroaches an Important Source of Indoor Endotoxins?

PubMed

Lai, Ka Man

2017-01-18

Endotoxins are common indoor biocontaminants. Their levels have been shown to link to many sources and factors. One of them is cockroach infestation but the role of cockroaches and contamination mechanisms are unclear. We hypothesized that not only is cockroach infestation a sign of poor hygiene, but it also contributes to indoor endotoxins via fecal contamination. In this study, different cockroach species were caught in homes. The endotoxin and allergen levels and their ratios in cockroach feces were determined. To estimate the amount of indoor endotoxins that originated from cockroaches, a new approach of using these new cockroach endotoxin and allergen ratios to compare with environmental data was employed. We found that Supella (S.) longipalpa , Periplaneta (P.) australasiae , and Blattella (B.) germanica were dominant in homes. On average, P. australasiae feces had a higher level but greater variation of endotoxins. B. germanica feces had the highest levels of allergens measured. Depending on environmental bacterial load and the type of cockroaches present, cockroach endotoxins in the environment may vary greatly. Cockroaches directly contribute to indoor endotoxins rather than just being a sign of poor hygiene. The type and extent of cockroach infestation should be taken into consideration when assessing and remediating indoor endotoxin contamination.

Are Cockroaches an Important Source of Indoor Endotoxins?

PubMed Central

Lai, Ka Man

2017-01-01

Endotoxins are common indoor biocontaminants. Their levels have been shown to link to many sources and factors. One of them is cockroach infestation but the role of cockroaches and contamination mechanisms are unclear. We hypothesized that not only is cockroach infestation a sign of poor hygiene, but it also contributes to indoor endotoxins via fecal contamination. In this study, different cockroach species were caught in homes. The endotoxin and allergen levels and their ratios in cockroach feces were determined. To estimate the amount of indoor endotoxins that originated from cockroaches, a new approach of using these new cockroach endotoxin and allergen ratios to compare with environmental data was employed. We found that Supella (S.) longipalpa, Periplaneta (P.) australasiae, and Blattella (B.) germanica were dominant in homes. On average, P. australasiae feces had a higher level but greater variation of endotoxins. B. germanica feces had the highest levels of allergens measured. Depending on environmental bacterial load and the type of cockroaches present, cockroach endotoxins in the environment may vary greatly. Cockroaches directly contribute to indoor endotoxins rather than just being a sign of poor hygiene. The type and extent of cockroach infestation should be taken into consideration when assessing and remediating indoor endotoxin contamination. PMID:28106812

Fast prediction of pulsed nonlinear acoustic fields from clinically relevant sources using Time-Averaged Wave Envelope approach: comparison of numerical simulations and experimental results

PubMed Central

Wójcik, J.; Kujawska, T.; Nowicki, A.; Lewin, P.A.

2008-01-01

The primary goal of this work was to verify experimentally the applicability of the recently introduced Time-Averaged Wave Envelope (TAWE) method [1] as a tool for fast prediction of four dimensional (4D) pulsed nonlinear pressure fields from arbitrarily shaped acoustic sources in attenuating media. The experiments were performed in water at the fundamental frequency of 2.8 MHz for spherically focused (focal length F = 80 mm) square (20 × 20 mm) and rectangular (10 × 25 mm) sources similar to those used in the design of 1D linear arrays operating with ultrasonic imaging systems. The experimental results obtained with 10-cycle tone bursts at three different excitation levels corresponding to linear, moderately nonlinear and highly nonlinear propagation conditions (0.045, 0.225 and 0.45 MPa on-source pressure amplitude, respectively) were compared with those yielded using the TAWE approach [1]. The comparison of the experimental results and numerical simulations has shown that the TAWE approach is well suited to predict (to within ± 1 dB) both the spatial-temporal and spatial-spectral pressure variations in the pulsed nonlinear acoustic beams. The obtained results indicated that implementation of the TAWE approach enabled shortening of computation time in comparison with the time needed for prediction of the full 4D pulsed nonlinear acoustic fields using a conventional (Fourier-series) approach [2]. The reduction in computation time depends on several parameters, including the source geometry, dimensions, fundamental resonance frequency, excitation level as well as the strength of the medium nonlinearity. For the non-axisymmetric focused transducers mentioned above and excited by a tone burst corresponding to moderately nonlinear and highly nonlinear conditions the execution time of computations was 3 and 12 hours, respectively, when using a 1.5 GHz clock frequency, 32-bit processor PC laptop with 2 GB RAM memory, only. Such prediction of the full 4D pulsed field is not possible when using conventional, Fourier-series scheme as it would require increasing the RAM memory by at least 2 orders of magnitude. PMID:18474387

Eutrophication study at the Panjiakou-Daheiting Reservoir system, northern Hebei Province, People's Republic of China: Chlorophyll-a model and sources of phosphorus and nitrogen

USGS Publications Warehouse

Domagalski, Joseph L.; Lin, Chao; Luo, Yang; Kang, Jie; Wang, Shaoming; Brown, Larry R.; Munn, Mark D.

2007-01-01

Concentrations, loads, and sources of nitrate and total phosphorus were investigated at the Panjiakou and Daheiting Reservoir system in northern Hebei Province, People's Republic of China. The Luan He River is the primary source of water to these reservoirs, and the upstream watershed has a mix of land uses including agriculture, forest, and one large urban center. The reservoirs have a primary use for storage of drinking water and partially supply Tianjin City with its annual needs. Secondary uses include flood control and aqua culture (fish cages). The response of the reservoir system from phosphorus input, with respect to chlorophyll-a production from algae, was fitted to a model of normalized phosphorus loading that regresses the average summer-time chlorophyll-a concentration to the average annual phosphorus concentration of the reservoir. Comparison of the normalized phosphorus loading and chlorophyll-a response of this system to other reservoirs throughout the world indicate a level of eutrophication that will require up to an approximate 5–10-fold decrease in annual phosphorus load to bring the system to a more acceptable level of algal productivity. Isotopes of nitrogen and oxygen in dissolved nitrate were measured from the headwater streams and at various locations along the major rivers that provide the majority of water to these reservoirs. Those isotopic measurements indicate that the sources of nitrate change from natural background in the rivers to animal manure and septic waste upstream of the reservoir. Although the isotopic measurements suggest that animal and septic wastes are a primary source of nutrients, measurements of the molar ratio of nitrogen to phosphorus are more indicative of row-cropping practices. Options for reduction of nutrient loads include changing the management practices of the aqua culture, installation of new sewage treatment systems in the large urbanized area of the upper watershed, and agricultural management practices that would reduce the loading of nutrients and soil erosion from that land use.

Fiber-based tunable repetition rate source for deep tissue two-photon fluorescence microscopy

PubMed Central

Charan, Kriti; Li, Bo; Wang, Mengran; Lin, Charles P.; Xu, Chris

2018-01-01

Deep tissue multiphoton imaging requires high peak power to enhance signal and low average power to prevent thermal damage. Both goals can be advantageously achieved through laser repetition rate tuning instead of simply adjusting the average power. We show that the ideal repetition rate for deep two-photon imaging in the mouse brain is between 1 and 10 MHz, and we present a fiber-based source with an arbitrarily tunable repetition rate within this range. The performance of the new source is compared to a mode-locked Ti:Sapphire (Ti:S) laser for in vivo imaging of mouse brain vasculature. At 2.5 MHz, the fiber source requires 5.1 times less average power to obtain the same signal as a standard Ti:S laser operating at 80 MHz. PMID:29760989

School-based exposure to hazardous air pollutants and grade point average: A multi-level study.

PubMed

Grineski, Sara E; Clark-Reyna, Stephanie E; Collins, Timothy W

2016-05-01

The problem of environmental health hazards around schools is serious but it has been neglected by researchers and analysts. This is concerning because children are highly susceptible to the effects of chemical hazards. Some ecological studies have demonstrated that higher school-level pollution is associated with lower aggregate school-level standardized test scores likely, related to increased respiratory illnesses and/or impaired cognitive development. However, an important question remains unexamined: How do school-level exposures impact individual children's academic performance? To address this, we obtained socio-demographic and grades data from the parents of 1888 fourth and fifth grade children in the El Paso (Texas, USA) Independent School District in 2012. El Paso is located on the US-side of the Mexican border and has a majority Mexican-origin population. School-based hazardous air pollution (HAP) exposure was calculated using census block-level US Environmental Protection Agency National Air Toxics Assessment risk estimates for respiratory and diesel particulate matter (PM). School-level demographics were obtained from the school district. Multi-level models adjusting for individual-level covariates (e.g., age, sex, race/ethnicity, English proficiency, and economic deprivation) and school-level covariates (e.g., percent of students economically disadvantaged and student-teacher ratio) showed that higher school-level HAPs were associated with lower individual-level grade point averages. An interquartile range increase in school-level HAP exposure was associated with an adjusted 0.11-0.40 point decrease in individual students' grade point averages (GPAs), depending on HAP type and emission source. Respiratory risk from HAPs had a larger effect on GPA than did diesel PM risk. Non-road mobile and total respiratory risk had the largest effects on children's GPA of all HAP variables studied and only mother's level of education had a larger effect than those two variables on children's GPA. The five school-level demographic indicators were only weakly associated with GPA. The study findings indicate the need for regulations on school siting and adjacent land uses to protect children's environmental health. Copyright © 2016 Elsevier Inc. All rights reserved.

Fast, noise-free memory for photon synchronization at room temperature.

PubMed

Finkelstein, Ran; Poem, Eilon; Michel, Ohad; Lahad, Ohr; Firstenberg, Ofer

2018-01-01

Future quantum photonic networks require coherent optical memories for synchronizing quantum sources and gates of probabilistic nature. We demonstrate a fast ladder memory (FLAME) mapping the optical field onto the superposition between electronic orbitals of rubidium vapor. Using a ladder-level system of orbital transitions with nearly degenerate frequencies simultaneously enables high bandwidth, low noise, and long memory lifetime. We store and retrieve 1.7-ns-long pulses, containing 0.5 photons on average, and observe short-time external efficiency of 25%, memory lifetime (1/ e ) of 86 ns, and below 10 -4 added noise photons. Consequently, coupling this memory to a probabilistic source would enhance the on-demand photon generation probability by a factor of 12, the highest number yet reported for a noise-free, room temperature memory. This paves the way toward the controlled production of large quantum states of light from probabilistic photon sources.

Global two dimensional chemistry model and simulation of atmospheric chemical composition

NASA Astrophysics Data System (ADS)

Zhang, Renjian; Wang, Mingxing; Zeng, Qingcun

2000-03-01

A global two-dimensional zonally averaged chemistry model is developed to study the chemi-cal composition of atmosphere. The region of the model is from 90°S to 90°N and from the ground to the altitude of 20 km with a resolution of 5° x 1 km. The wind field is residual circulation calcu-lated from diabatic rate. 34 species and 104 chemical and photochemical reactions are considered in the model. The sources of CH4, CO and NOx, which are divided into seasonal sources and non-seasonal sources, are parameterized as a function of latitude and time. The chemical composi-tion of atmosphere was simulated with emission level of CH4, CO and NOx in 1990. The results are compared with observations and other model results, showing that the model is successful to simu-late the atmospheric chemical composition and distribution of CH4.

A Mars 1 Watt vortex wind energy machine

NASA Technical Reports Server (NTRS)

Ralston, Michael; Crowley, Christopher; Thomson, Ronald; Gwynne, Owen

1992-01-01

A Martian wind power generator capable of surviving impact and fulfilling the long-term (2-5 yr) low-level power requirements (1-2 W) of an unmanned surface probe is presented. Attention is given to a tornado vortex generator that was chosen on the basis of its capability to theoretically augment the available power that may be extracted for average Martian wind speeds of about 7.5 m/s. The generator offers comparable mass-to-power ratios with solar power sources.

Remedial Investigation Report Area of Contamination (AOC) 43J. Volume 1 of 2

DTIC Science & Technology

1996-02-01

produced risks within the USEPA range (1x1W05 and 3x10’, respectively). If the modified cancer slope factor (CSF) for arsenic was used to estimate excess...lifetime cancer risks for both source area and downgradient groundwater quality, then the cancer risks associated with exposure to both average and...very poorly drained; nearly level, organic; occurs in depressions and on flat areas of uplands and glacial outwash plains. Windsor Series. Deep

New X-ray Outburst in X1744-361 (A1744-36)

NASA Astrophysics Data System (ADS)

Remillard, Ronald A.

2009-11-01

The recurrent transient and accreting neutron star, X1744-361, has begun the fourth outburst observed with RXTE (see ATel #1587). The ASM data rate for this source is impeded by the angular proximity of the Sun, but the outburst appears to have begun near MJD 55145. The intensity seems to have leveled off quickly, and the the average flux during the last week is 65(7) mCrab at 2-12 keV. Followup observations are encouraged.

Co-exposure to methylmercury and inorganic arsenic in baby rice cereals and rice-containing teething biscuits.

PubMed

Rothenberg, Sarah E; Jackson, Brian P; Carly McCalla, G; Donohue, Alexis; Emmons, Alison M

2017-11-01

Rice is an important dietary source for methylmercury (MeHg), a potent neurotoxin, and inorganic arsenic (As), a human carcinogen. Rice baby cereals are a dietary source of inorganic As; however, less is known concerning MeHg concentrations in rice baby cereals and rice teething biscuits. MeHg concentrations were measured in 36 rice baby cereals, eight rice teething biscuits, and four baby cereals manufactured with oats/wheat (n = 48 total). Arsenic (As) species, including inorganic As, were determined in rice baby cereals and rice teething biscuits (n = 44/48), while total As was determined in all products (n = 48). Rice baby cereals and rice teething biscuits were on average 61 and 92 times higher in MeHg, respectively, and 9.4 and 4.7 times higher in total As, respectively, compared to wheat/oat baby cereals. For a 15-g serving of rice baby cereal, average MeHg intake was 0.0092μgday -1 (range: 0.0013-0.034μgday -1 ), while average inorganic As intake was 1.3μgday -1 (range: 0.37-2.3μgday -1 ). Inorganic As concentrations in two brands of rice baby cereal (n = 12/36 boxes of rice cereal) exceeded 100ng/g, the proposed action level from the U.S. Food and Drug Administration. Log 10 MeHg and inorganic As concentrations in rice baby cereals were strongly, positively correlated (Pearson's rho = 0.60, p < 0.001, n = 36). Rice-containing baby cereals and teething biscuits were a dietary source of both MeHg and inorganic As. Studies concerning the cumulative impacts of MeHg and inorganic As on offspring development are warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

Nitrous acid formation in a snow-free wintertime polluted rural area

NASA Astrophysics Data System (ADS)

Tsai, Catalina; Spolaor, Max; Fedele Colosimo, Santo; Pikelnaya, Olga; Cheung, Ross; Williams, Eric; Gilman, Jessica B.; Lerner, Brian M.; Zamora, Robert J.; Warneke, Carsten; Roberts, James M.; Ahmadov, Ravan; de Gouw, Joost; Bates, Timothy; Quinn, Patricia K.; Stutz, Jochen

2018-02-01

Nitrous acid (HONO) photolysis is an important source of hydroxyl radicals (OH) in the lower atmosphere, in particular in winter when other OH sources are less efficient. The nighttime formation of HONO and its photolysis in the early morning have long been recognized as an important contributor to the OH budget in polluted environments. Over the past few decades it has become clear that the formation of HONO during the day is an even larger contributor to the OH budget and additionally provides a pathway to recycle NOx. Despite the recognition of this unidentified HONO daytime source, the precise chemical mechanism remains elusive. A number of mechanisms have been proposed, including gas-phase, aerosol, and ground surface processes, to explain the elevated levels of daytime HONO. To identify the likely HONO formation mechanisms in a wintertime polluted rural environment we present LP-DOAS observations of HONO, NO2, and O3 on three absorption paths that cover altitude intervals from 2 to 31, 45, and 68 m above ground level (a.g.l.) during the UBWOS 2012 experiment in the Uintah Basin, Utah, USA. Daytime HONO mixing ratios in the 2-31 m height interval were, on average, 78 ppt, which is lower than HONO levels measured in most polluted urban environments with similar NO2 mixing ratios of 1-2 ppb. HONO surface fluxes at 19 m a.g.l., calculated using the HONO gradients from the LP-DOAS and measured eddy diffusivity coefficient, show clear upward fluxes. The hourly average vertical HONO flux during sunny days followed solar irradiance, with a maximum of (4.9 ± 0.2) × 1010 molec. cm-2 s-1 at noontime. A photostationary state analysis of the HONO budget shows that the surface flux closes the HONO budget, accounting for 63 ± 32 % of the unidentified HONO daytime source throughout the day and 90 ± 30 % near noontime. This is also supported by 1-D chemistry and transport model calculations that include the measured surface flux, thus clearly identifying chemistry at the ground as the missing daytime HONO source in this environment. Comparison between HONO surface flux, solar radiation, NO2 and HNO3 mixing ratios, and results from 1-D model runs suggest that, under high NOx conditions, HONO formation mechanisms related to solar radiation and NO2 mixing ratios, such as photo-enhanced conversion of NO2 on the ground, are most likely the source of daytime HONO. Under moderate to low NO2 conditions, photolysis of HNO3 on the ground seems to be the main source of HONO.

[Accumulation, distribution and pollution assessment of heavy metals in surface sediment of Caohai plateau wetland, Guizhou province].

PubMed

Zhang, Qing-Hai; Lin, Chang-Hu; Tan, Hong; Lin, Shao-Xia; Yang, Hong-Bo

2013-03-01

The objective of this paper is to investigate the concentrations and distribution characteristics of heavy metals in surface sediments of different areas in the Caohai plateau wetland. 16 samples of surface sediments were collected and 7 heavy metals were analyzed. Heavy metal pollution in surface sediments of different areas in the Caohai plateau wetland was estimated by the Tomlinson Pollution Load Index (PLI) method. The analyzed results indicated that the average contents of Cd, Hg, As, Pb, Cr, Cu, Zn were 0.985, 0.345, 15.8, 38.9, 38.6, 22.8 and 384 mg x kg(-1), respectively. The heavy metal distributions varied with regional environment changes, the order of average contents of Cd and Hg in different regions was E (the eastern region) > S (the southern region) > N (the northern region), the order of the average content of Pb was N > E > S, and that of Zn was S > E > N. The results also suggested a medium heavy metal pollution level in the surface sediment of the Caohai plateau wetland with the PLI(zone) reaching 1.17. The order of pollution level in surface sediments of different regions was E > S > N. The results showed medium pollution levels in E and Hg which reached the extreme intensity pollution level were also the major polluted elements in surface sediments of the Caohai plateau wetland. And also, results showed medium pollution levels of Cd and Pb in surface sediments of Caohai plateau wetland. Cluster analysis results showed similar pollution sources of Cd, Zn, Pb and Hg, which should be attached great importance in terms of the prevention of the Caohai plateau wetland.

[Pollution Level and Health Risk Assessment of Heavy Metals in Atmospheric PM₂.₅ in Nanjing Before and After the Youth Olympic Games].

PubMed

Zhang, Heng; Zhou, Zi-qiang; Zhao, Hai-yan; Xiong, Zheng-qin

2016-01-15

The influence of human activities on the atmospheric environment has attracted people's attention. This study reported the dynamic changes in PM₂.₅ concentration, its heavy metal compositions and health risk assessment from April to September, 2014 in Nanjing when the Youth Olympic Games ( YOG) was held. The results showed that the mass levels of PM₂.₅ ranged from 26.39 to 80.31 µg · m⁻³ from April to September. The mass levels of PM₂.₅ met the level II standard of ambient air quality in China (24 h average concentration, 75 µg · m⁻³) in months of April, May and July while met the level I standard (24 h average concentration, 35 µg · m⁻³) in August during the YOG. The average mass concentration of PM₂.₅ reached 76.14 µg · m⁻¹ after the YOG, showing resilience of air pollution. The variations of heavy metals were not consistent with each other throughout the observation period. Principal component analysis indicated that emission sources significantly affected the variations of PM₂.₅ and its heavy metals. PM₂.₅ and all of the heavy metals decreased to their minimum values during the YOG, indicating the effectiveness of those temporary measures for reducing atmospheric pollutant before and during the YOG. The health risks of Cd, Cu, Ni and Pb in PM₂.₅ via breathing and dermal contact exposure were all within the acceptable ranges, but potential carcinogenic risk existed for Cr in PM₂.₅. There was potential non-carcinogenic health risk for adult males via breathing of Mn and greater non-carcinogenic health risk for children via dermal contact exposures to all these 6 heavy metals.

Assessment of indoor air quality exposures and impacts on respiratory outcomes in River Rouge and Dearborn, Michigan.

PubMed

Cleary, Erika; Asher, Mary; Olawoyin, Richard; Zhang, Kuangyuan

2017-11-01

Ambient air pollution is a public health issue which could potentially exacerbate pre-existing respiratory conditions and contribute to increases in asthma incidence. This study aims to address gaps in understanding how IAQ is impacted by outdoor air quality, which was done by sampling for indoor gaseous and particulate pollutants in residence and facilities near the sources of pollution. The study areas were selected due to non-attainment status with air quality standards, as well as demographic and socioeconomic status of those residing in these areas. Samples are obtained from five locations around the study areas. The sampling procedure involves active sampling methodologies for particulate matter (PM) and gases. Average volatile organic compounds (VOC) levels of 2.71 ppm were measured at a location, while the average particulate matter (PM) concentrations in three study locations were; 15,979 pt/cc, 9533 pt/cc, 5267 pt/cc respectively, which exceeded clean background environment level of 500-2000 pt/cc. All locations had average CO concentrations above 0.3 ppm, which is potentially associated with elevated asthma symptoms. Results demonstrated that facilities in the study area have increased levels of indoor air pollutants that potentially increase asthma and respiratory issues. The study concludes that particulate and gaseous pollutant levels in the study areas are a concerning human health issue. The study outcomes have significant implications for air quality exposure modeling and potential exposure mitigation strategies, which are expected to facilitate the implementation of public policies for improved human health conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Regional propagation characteristics and source parameters of earthquakes in northeastern North America

USGS Publications Warehouse

Boatwright, John

1994-01-01

The vertical components of the S wave trains recorded on the Eastern Canadian Telemetered Network (ECTN) from 1980 through 1990 have been spectrally analyzed for source, site, and propagation characteristics. The data set comprises some 1033 recordings of 97 earthquakes whose magnitudes range from M ≈ 3 to 6. The epicentral distances range from 15 to 1000 km, with most of the data set recorded at distances from 200 to 800 km. The recorded S wave trains contain the phases S, SmS, Sn, and Lg and are sampled using windows that increase with distance; the acceleration spectra were analyzed from 1.0 to 10 Hz. To separate the source, site, and propagation characteristics, an inversion for the earthquake corner frequencies, low-frequency levels, and average attenuation parameters is alternated with a regression of residuals onto the set of stations and a grid of 14 distances ranging from 25 to 1000 km. The iteration between these two parts of the inversion converges in about 60 steps. The average attenuation parameters obtained from the inversion were Q = 1997 ± 10 and γ = 0.998 ± 0.003. The most pronounced variation from this average attenuation is a marked deamplification of more than a factor of 2 at 63 km and 2 Hz, which shallows with increasing frequency and increasing distance out to 200 km. The site-response spectra obtained for the ECTN stations are generally flat. The source spectral shape assumed in this inversion provides an adequate spectral model for the smaller events (Mo < 3 × 1021 dyne-cm) in the data set, whose Brune stress drops range from 5 to 150 bars. For the five events in the data set with Mo ≧ 1023 dyne-cm, however, the source spectra obtained by regressing the residuals suggest that an ω2 spectrum is an inadequate model for the spectral shape. In particular, the corner frequencies for most of these large events appear to be split, so that the spectra exhibit an intermediate behavior (where |ü(ω)| is roughly proportional to ω).

Airborne particulate matter in school classrooms of northern Italy.

PubMed

Rovelli, Sabrina; Cattaneo, Andrea; Nuzzi, Camilla P; Spinazzè, Andrea; Piazza, Silvia; Carrer, Paolo; Cavallo, Domenico M

2014-01-27

Indoor size-fractioned particulate matter (PM) was measured in seven schools in Milan, to characterize their concentration levels in classrooms, compare the measured concentrations with the recommended guideline values, and provide a preliminary assessment of the efficacy of the intervention measures, based on the guidelines developed by the Italian Ministry of Healthand applied to mitigate exposure to undesirable air pollutants. Indoor sampling was performed from Monday morning to Friday afternoon in three classrooms of each school and was repeated in winter 2011-2012 and 2012-2013. Simultaneously, PM2.5 samples were also collected outdoors. Two different photometers were used to collect the PM continuous data, which were corrected a posteriori using simultaneous gravimetric PM2.5 measurements. Furthermore, the concentrations of carbon dioxide (CO2) were monitored and used to determine the Air Exchange Rates in the classrooms. The results revealed poor IAQ in the school environment. In several cases, the PM2.5 and PM10 24 h concentrations exceeded the 24 h guideline values established by the World Health Organization (WHO). In addition, the indoor CO2 levels often surpassed the CO2 ASHRAE Standard. Our findings confirmed that important indoor sources (human movements, personal clouds, cleaning activities) emitted coarse particles, markedly increasing the measured PM during school hours. In general, the mean PM2.5 indoor concentrations were lower than the average outdoor PM2.5 levels, with I/O ratios generally <1. Fine PM was less affected by indoor sources, exerting a major impact on the PM1-2.5 fraction. Over half of the indoor fine particles were estimated to originate from outdoors. To a first approximation, the intervention proposed to reduce indoor particle levels did not seem to significantly influence the indoor fine PM concentrations. Conversely, the frequent opening of doors and windows appeared to significantly contribute to the reduction of the average indoor CO2 levels.

Average stopping powers for electron and photon sources for radiobiological modeling and microdosimetric applications

NASA Astrophysics Data System (ADS)

Vassiliev, Oleg N.; Kry, Stephen F.; Grosshans, David R.; Mohan, Radhe

2018-03-01

This study concerns calculation of the average electronic stopping power for photon and electron sources. It addresses two problems that have not yet been fully resolved. The first is defining the electron spectrum used for averaging in a way that is most suitable for radiobiological modeling. We define it as the spectrum of electrons entering the sensitive to radiation volume (SV) within the cell nucleus, at the moment they enter the SV. For this spectrum we derive a formula that combines linearly the fluence spectrum and the source spectrum. The latter is the distribution of initial energies of electrons produced by a source. Previous studies used either the fluence or source spectra, but not both, thereby neglecting a part of the complete spectrum. Our derived formula reduces to these two prior methods in the case of high and low energy sources, respectively. The second problem is extending electron spectra to low energies. Previous studies used an energy cut-off on the order of 1 keV. However, as we show, even for high energy sources, such as 60Co, electrons with energies below 1 keV contribute about 30% to the dose. In this study all the spectra were calculated with Geant4-DNA code and a cut-off energy of only 11 eV. We present formulas for calculating frequency- and dose-average stopping powers, numerical results for several important electron and photon sources, and tables with all the data needed to use our formulas for arbitrary electron and photon sources producing electrons with initial energies up to  ∼1 MeV.

Laser technologies for ultrasensitive groundwater dating using long-lived isotopes

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

Backus, Sterling

In this phase I work, we propose to construct and demonstrate a 103 nm laser based on resonantly enhanced and phase matched fifth harmonic generation in hollow waveguides driven by a high power, low cost and compact ultrafast fiber laser. (Figure 4) This VUV laser source can potentially produce >100 milliwatts of VUV light at 103 nm with pulse repetition-rates of 100 kHz to 100 MHz, ideal for the above-mentioned applications. This technology is state-of-the-art and potentially compact, fieldable, low-cost, and of broad interest for a variety of science and technology applications. Laser-based VUV sources in the past have exhibitedmore » low repetition rate, low efficiency, low beam quality, and are based on expensive laser sources. Our approch is to combine ultrafast fiber laser drive technology, ultrafast pulses, and our proven waveguide technology, to create a high repetition rate, high average power VUV source for producing high yield metastable Krypton. At KMLabs we have been offering EUV light sources employing the high harmonic generation (HHG) process driven by high-power femtosecond lasers for >5 years now. Recently, we have developed much smaller scale (briefcase size), but still high average power femtosecond fiber laser sources to supply other markets, and create new ones. By combining these new laser sources with our patented waveguide frequency upconversion technology, we expect to be able to obtain >20mW average power initially, with potentially much higher powers depending on wavelength, in an affordable VUV product. For comparison, our current EUV light sources based on ti:sapphire generate an average power of ~5 µW (albeit at shorter 29 nm wavelength), and we are aware of one other supplier that has developed a VUV (112 nm) light source with ~10-20 µW power.« less

Ship noise extends to frequencies used for echolocation by endangered killer whales

PubMed Central

Veirs, Val; Wood, Jason D.

2016-01-01

Combining calibrated hydrophone measurements with vessel location data from the Automatic Identification System, we estimate underwater sound pressure levels for 1,582 unique ships that transited the core critical habitat of the endangered Southern Resident killer whales during 28 months between March, 2011, and October, 2013. Median received spectrum levels of noise from 2,809 isolated transits are elevated relative to median background levels not only at low frequencies (20–30 dB re 1 µPa2/Hz from 100 to 1,000 Hz), but also at high frequencies (5–13 dB from 10,000 to 96,000 Hz). Thus, noise received from ships at ranges less than 3 km extends to frequencies used by odontocetes. Broadband received levels (11.5–40,000 Hz) near the shoreline in Haro Strait (WA, USA) for the entire ship population were 110 ± 7 dB re 1 µPa on average. Assuming near-spherical spreading based on a transmission loss experiment we compute mean broadband source levels for the ship population of 173 ± 7 dB re 1 µPa 1 m without accounting for frequency-dependent absorption. Mean ship speed was 7.3 ± 2.0 m/s (14.1 ± 3.9 knots). Most ship classes show a linear relationship between source level and speed with a slope near +2 dB per m/s (+1 dB/knot). Spectrum, 1/12-octave, and 1/3-octave source levels for the whole population have median values that are comparable to previous measurements and models at most frequencies, but for select studies may be relatively low below 200 Hz and high above 20,000 Hz. Median source spectrum levels peak near 50 Hz for all 12 ship classes, have a maximum of 159 dB re 1 µPa2/Hz @ 1 m for container ships, and vary between classes. Below 200 Hz, the class-specific median spectrum levels bifurcate with large commercial ships grouping as higher power noise sources. Within all ship classes spectrum levels vary more at low frequencies than at high frequencies, and the degree of variability is almost halved for classes that have smaller speed standard deviations. This is the first study to present source spectra for populations of different ship classes operating in coastal habitats, including at higher frequencies used by killer whales for both communication and echolocation. PMID:27004149

Health risk assessments for alumina refineries.

PubMed

Donoghue, A Michael; Coffey, Patrick S

2014-05-01

To describe contemporary air dispersion modeling and health risk assessment methodologies applied to alumina refineries and to summarize recent results. Air dispersion models using emission source and meteorological data have been used to assess ground-level concentrations (GLCs) of refinery emissions. Short-term (1-hour and 24-hour average) GLCs and annual average GLCs have been used to assess acute health, chronic health, and incremental carcinogenic risks. The acute hazard index can exceed 1 close to refineries, but it is typically less than 1 at neighboring residential locations. The chronic hazard index is typically substantially less than 1. The incremental carcinogenic risk is typically less than 10(-6). The risks of acute health effects are adequately controlled, and the risks of chronic health effects and incremental carcinogenic risks are negligible around referenced alumina refineries.

40 CFR 464.25 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Copper Casting... Maximum for monthly average kg/1000 kkg (pounds per million pounds) of metal poured Copper (T) 0.0307 0... any 1 day Maximum for monthly average kg/1,000 kkg (pounds per million pounds) of metal poured Copper...

Particle Concentrations and Effectiveness of Free-Standing Air Filters in Bedrooms of Children with Asthma in Detroit, Michigan

PubMed Central

Du, Liuliu; Batterman, Stuart; Parker, Edith; Godwin, Christopher; Chin, Jo-Yu; O'Toole, Ashley; Robins, Thomas; Brakefield-Caldwell, Wilma; Lewis, Toby

2011-01-01

Asthma can be exacerbated by environmental factors including airborne particulate matter (PM) and environmental tobacco smoke (ETS). We report on a study designed to characterize PM levels and the effectiveness of filters on pollutant exposures of children with asthma. 126 households with an asthmatic child in Detroit, Michigan, were recruited and randomized into control or treatment groups. Both groups received asthma education; the latter also received a free-standing high efficiency air filter placed in the child’s bedroom. Information regarding the home, emission sources, and occupant activities was obtained using surveys administered to the child's caregiver and a household inspection. Over a one-week period, we measured PM, carbon dioxide (CO2), environmental tobacco smoke (ETS) tracers, and air exchange rates (AERs). Filters were installed at midweek. Before filter installation, PM concentrations averaged 28 µg m−3, number concentrations averaged 70,777 and 1,471 L−1 in 0.3–1.0 and 1–5 µm size ranges, respectively, and the median CO2 concentration was 1,018 ppm. ETS tracers were detected in 23 of 38 homes where smoking was unrestricted and occupants included smokers and, when detected, PM concentrations were elevated by an average of 15 µg m−3. Filter use reduced PM concentrations by an average of 69 to 80%. Simulation models representing location conditions show that filter air flow, room volume and AERs are the key parameters affecting PM removal, however, filters can achieve substantial removal in even "worst" case applications. While PM levels in homes with asthmatic children can be high, levels can be dramatically reduced using filters. PMID:21874085

Particle Concentrations and Effectiveness of Free-Standing Air Filters in Bedrooms of Children with Asthma in Detroit, Michigan.

PubMed

Du, Liuliu; Batterman, Stuart; Parker, Edith; Godwin, Christopher; Chin, Jo-Yu; O'Toole, Ashley; Robins, Thomas; Brakefield-Caldwell, Wilma; Lewis, Toby

2011-10-01

Asthma can be exacerbated by environmental factors including airborne particulate matter (PM) and environmental tobacco smoke (ETS). We report on a study designed to characterize PM levels and the effectiveness of filters on pollutant exposures of children with asthma. 126 households with an asthmatic child in Detroit, Michigan, were recruited and randomized into control or treatment groups. Both groups received asthma education; the latter also received a free-standing high efficiency air filter placed in the child's bedroom. Information regarding the home, emission sources, and occupant activities was obtained using surveys administered to the child's caregiver and a household inspection. Over a one-week period, we measured PM, carbon dioxide (CO(2)), environmental tobacco smoke (ETS) tracers, and air exchange rates (AERs). Filters were installed at midweek. Before filter installation, PM concentrations averaged 28 µg m(-3), number concentrations averaged 70,777 and 1,471 L(-1) in 0.3-1.0 and 1-5 µm size ranges, respectively, and the median CO(2) concentration was 1,018 ppm. ETS tracers were detected in 23 of 38 homes where smoking was unrestricted and occupants included smokers and, when detected, PM concentrations were elevated by an average of 15 µg m(-3). Filter use reduced PM concentrations by an average of 69 to 80%. Simulation models representing location conditions show that filter air flow, room volume and AERs are the key parameters affecting PM removal, however, filters can achieve substantial removal in even "worst" case applications. While PM levels in homes with asthmatic children can be high, levels can be dramatically reduced using filters.

Sources and production of organic aerosol in Mexico City: insights from the combination of a chemical transport model (PMCAMx-2008) and measurements during MILAGRO

NASA Astrophysics Data System (ADS)

Tsimpidi, A. P.; Karydis, V. A.; Zavala, M.; Lei, W.; Bei, N.; Molina, L.; Pandis, S. N.

2011-06-01

Urban areas are large sources of organic aerosols and their precursors. Nevertheless, the contributions of primary (POA) and secondary organic aerosol (SOA) to the observed particulate matter levels have been difficult to quantify. In this study the three-dimensional chemical transport model PMCAMx-2008 is used to investigate the temporal and geographic variability of organic aerosol in the Mexico City Metropolitan Area (MCMA) during the MILAGRO campaign that took place in the spring of 2006. The organic module of PMCAMx-2008 includes the recently developed volatility basis-set framework in which both primary and secondary organic components are assumed to be semi-volatile and photochemically reactive and are distributed in logarithmically spaced volatility bins. The MCMA emission inventory is modified and the POA emissions are distributed by volatility based on dilution experiments. The model predictions are compared with observations from four different types of sites, an urban (T0), a suburban (T1), a rural (T2), and an elevated site in Pico de Tres Padres (PTP). The performance of the model in reproducing organic mass concentrations in these sites is encouraging. The average predicted PM1 organic aerosol (OA) concentration in T0, T1, and T2 is 18 μg m-3, 11.7 μg m-3, and 10.5 μg m-3 respectively, while the corresponding measured values are 17.2 μg m-3, 11 μg m-3, and 9 μg m-3. The average predicted locally-emitted primary OA concentrations, 4.4 μg m-3 at T0, 1.2 μg m-3 at T1 and 1.7 μg m-3 at PTP, are in reasonably good agreement with the corresponding PMF analysis estimates based on the Aerosol Mass Spectrometer (AMS) observations of 4.5, 1.3, and 2.9 μg m-3 respectively. The model reproduces reasonably well the average oxygenated OA (OOA) levels in T0 (7.5 μg m-3 predicted versus 7.5 μg m-3 measured), in T1 (6.3 μg m-3 predicted versus 4.6 μg m-3 measured) and in PTP (6.6 μg m-3 predicted versus 5.9 μg m-3 measured). The rest of the OA mass (6.1 μg m-3 and 4.2 μg m-3 in T0 and T1 respectively) is assumed to originate from biomass burning activities and is introduced to the model as part of the boundary conditions. Inside Mexico City (at T0), the locally-produced OA is predicted to be on average 60 % locally-emitted primary (POA), 6 % semi-volatile (S-SOA) and intermediate volatile (I-SOA) organic aerosol, and 34 % traditional SOA from the oxidation of VOCs (V-SOA). The average contributions of the OA components to the locally-produced OA for the entire modelling domain are predicted to be 32 % POA, 10 % S-SOA and I-SOA, and 58 % V-SOA. The long range transport from biomass burning activities and other sources in Mexico is predicted to contribute on average almost as much as the local sources during the MILAGRO period.

Near-infrared and gamma-ray monitoring of TANAMI gamma-ray bright sources

DOE PAGES

Nesci, R.; Tosti, G.; Pursimo, T.; ...

2013-06-18

Context. We present that spectral energy distribution and its variability are basic tools for understanding the physical processes operating in active galactic nuclei (AGN). Aims. In this paper we report the results of a one-year near-infrared (NIR) and optical monitoring of a sample of 22 AGN known to be gamma-ray emitters, aimed at discovering correlations between optical and gamma-ray emission. Methods. We observed our objects with the Rapid Eye Mount (REM) telescope in J,H,K, and R bands nearly twice every month during their visibility window and derived light curves and spectral indexes. We also analyzed the gamma-ray data from themore » Fermi gamma-ray Space Telescope, making weekly averages. Results. Six sources were never detected during our monitoring, proving to be fainter than their historical Two micron all sky survey (2MASS) level. All of the sixteen detected sources showed marked flux density variability, while the spectral indexes remained unchanged within our sensitivity limits. Steeper sources showed, on average, a larger variability. From the NIR light curves we also computed a variability speed index for each detected source. Only one source (PKS 0208-512) underwent an NIR flare during our monitoring. Half of the sources showed a regular flux density trend on a one-year time scale, but do not show any other peculiar characteristic. The broadband spectral index α ro appears to be a good proxy of the NIR spectral index only for BL Lac objects. No clear correlation between NIR and gamma-ray data is evident in our data, save for PKS 0537-441, PKS 0521-360, PKS 2155-304, and PKS 1424-418. In conclusion, the gamma-ray/NIR flux ratio showed a large spread, QSO being generally gamma-louder than BL Lac, with a marked correlation with the estimated peak frequency (ν peak) of the synchrotron emission.« less

Assessment of Sociodemographic and Geographic Disparities in Cancer Risk from Air Toxics in South Carolina

PubMed Central

Wilson, Sacoby; Burwell-Naney, Kristen; Jiang, Chengsheng; Zhang, Hongmei; Samantapudi, Ashok; Murray, Rianna; Dalemarre, Laura; Rice, LaShanta; Williams, Edith

2015-01-01

Populations of color and low-income communities are often disproportionately burdened by exposures to various environmental contaminants, including air pollution. Some air pollutants have carcinogenic properties that are particularly problematic in South Carolina (SC), a state that consistently has high rates of cancer mortality for all sites. The purpose of this study was to assess cancer risk disparities in SC by linking risk estimates from the U.S. Environmental Protection Agency’s 2005 National Air Toxics Assessment (NATA) with sociodemographic data from the 2000 US Census Bureau. Specifically, NATA risk data for varying risk categories were linked by tract ID and analyzed with sociodemographic variables from the 2000 census using R. The average change in cancer risk from all sources by sociodemographic variable was quantified using multiple linear regression models. Spatial methods were further employed using ArcGIS 10 to assess the distribution of all source risk and percent non-white at each census tract level. The relative risk estimates of the proportion of high cancer risk tracts (defined as the top 10% of cancer risk in SC) and their respective 95% confidence intervals (CIs) were calculated between the first and latter three quartiles defined by sociodemographic factors, while the variance in the percentage of high cancer risk between quartile groups was tested using Pearson’s chi-square. The average total cancer risk for SC was 26.8 people/million (ppl/million). The risk from on-road sources was approximately 5.8 ppl/million, higher than the risk from major, area, and non-road sources (1.8, 2.6, and 1.3 ppl/million), respectively. Based on our findings, addressing on-road sources may decrease the disproportionate cancer risk burden among low-income populations and communities of color in SC. PMID:26037107

40 CFR 60.2943 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

Code of Federal Regulations, 2010 CFR

2010-07-01

... averages into the appropriate averaging times and units? 60.2943 Section 60.2943 Protection of Environment... SOURCES Operator Training and Qualification Monitoring § 60.2943 How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units? (a) Use Equation 1 in § 60.2975 to calculate...

40 CFR 60.2943 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

Code of Federal Regulations, 2012 CFR

2012-07-01

... averages into the appropriate averaging times and units? 60.2943 Section 60.2943 Protection of Environment... SOURCES Operator Training and Qualification Monitoring § 60.2943 How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units? (a) Use Equation 1 in § 60.2975 to calculate...

40 CFR 60.2943 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

Code of Federal Regulations, 2011 CFR

2011-07-01

... averages into the appropriate averaging times and units? 60.2943 Section 60.2943 Protection of Environment... SOURCES Operator Training and Qualification Monitoring § 60.2943 How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units? (a) Use Equation 1 in § 60.2975 to calculate...

Seasonal trends, chemical speciation and source apportionment of fine PM in Tehran

NASA Astrophysics Data System (ADS)

Arhami, Mohammad; Hosseini, Vahid; Zare Shahne, Maryam; Bigdeli, Mostafa; Lai, Alexandra; Schauer, James J.

2017-03-01

Frequent air pollution episodes have been reported for Tehran, Iran, mainly because of critically high levels of fine particulate matter (PM2.5). The composition and sources of these particles are poorly known, so this study aims to identify the major components and heavy metals in PM2.5 along with their seasonal trends and associated sources. 24-hour PM2.5 samples were collected at a main residential station every 6 days for a full year from February 2014 to February 2015. The samples were analyzed for ions, organic carbon (including water-soluble and insoluble portions), elemental carbon (EC), and all detectable elements. The dominant mass components, which were determined by means of chemical mass closure, were organic matter (35%), dust (25%), non-sea salt sulfate (11%), EC (9%), ammonium (5%), and nitrate (2%). Organic matter and EC together comprised 44% of fine PM on average (increased to >70% in the colder season), which reflects the significance of anthropogenic urban sources (i.e. vehicles). The contributions of different components varied considerably throughout the year, particularly the dust component that varied from 7% in the cold season to 56% in the hot and dry season. Principal component analyses were applied, resulting in 5 major source factors that explained 85% of the variance in fine PM. Factor 1, representing soil dust, explained 53%; Factor 2 denotes heavy metals mainly found in industrial sources and accounted for 18%; and rest of factors, mainly representing combustion sources, explained 14% of the variation. The levels of major heavy metals were further evaluated, and their trends showed considerable increases during cold seasons. The results of this study provide useful insight to fine PM in Tehran, which could help in identifying their health effects and sources, and also adopting effective control strategies.

A comparative analysis of minimally invasive and open spine surgery patient education resources.

PubMed

Agarwal, Nitin; Feghhi, Daniel P; Gupta, Raghav; Hansberry, David R; Quinn, John C; Heary, Robert F; Goldstein, Ira M

2014-09-01

The Internet has become a widespread source for disseminating health information to large numbers of people. Such is the case for spine surgery as well. Given the complexity of spinal surgeries, an important point to consider is whether these resources are easily read and understood by most Americans. The average national reading grade level has been estimated to be at about the 7th grade. In the present study the authors strove to assess the readability of open spine surgery resources and minimally invasive spine surgery resources to offer suggestions to help improve the readability of patient resources. Online patient education resources were downloaded in 2013 from 50 resources representing either traditional open back surgery or minimally invasive spine surgery. Each resource was assessed using 10 scales from Readability Studio Professional Edition version 2012.1. Patient education resources representing traditional open back surgery or minimally invasive spine surgery were all found to be written at a level well above the recommended 6th grade level. In general, minimally invasive spine surgery materials were written at a higher grade level. The readability of patient education resources from spine surgery websites exceeds the average reading ability of an American adult. Revisions may be warranted to increase quality and patient comprehension of these resources to effectively reach a greater patient population.

Industrial ion source technology

NASA Technical Reports Server (NTRS)

Kaufman, H. R.

1976-01-01

A 30 cm electron bombardment ion source was designed and fabricated for micromachining and sputtering applications. This source has a multipole magnetic field that employs permanent magnets between permeable pole pieces. An average ion current density of 1 ma/sq cm with 500 eV argon ions was selected as a design operating condition. The ion beam at this operating condition was uniform and well collimated, with an average variation of plus or minus 5 percent over the center 20 cm of the beam at distances up to 30 cm from the ion source. A variety of sputtering applications were undertaken with a small 10 cm ion source to better understand the ion source requirements in these applications. The results of these experimental studies are also included.

Readability of Orthopaedic Oncology-related Patient Education Materials Available on the Internet.

PubMed

Shah, Akash K; Yi, Paul H; Stein, Andrew

2015-12-01

A person's health literacy is one of the most important indicators of a patient's health status. According to national recommendations, patient education materials should be written at no higher than the sixth- to eighth-grade reading level. The purpose of our study was to assess the readability of online patient education materials related to orthopaedic oncology on the websites of the American Academy of Orthopaedic Surgeons (AAOS), American Cancer Society (ACS), Bone and Cancer Foundation (BCF), and National Cancer Institute (NCI). We searched the online patient education libraries of the AAOS, ACS, BCF, and NCI for all articles related to orthopaedic oncology. The Flesch-Kincaid (FK) readability score was calculated for each article and compared between sources. A total of 227 articles were identified with an overall mean FK grade level of 9.8. Stratified by source, the mean FK grade levels were 10.1, 9.6, 11.1, and 9.5 for the AAOS, ACS, BCF, and NCI, respectively (P < 0.003). Only 31 articles (14%) and 1 article (0.4%) were at or below the recommended eighth- and sixth-grade levels, respectively. Online patient education materials related to orthopaedic oncology appear to be written at a level above the comprehension ability of the average patient. Copyright 2015 by the American Academy of Orthopaedic Surgeons.

Exploring the uncertainty in attributing sediment contributions in fingerprinting studies due to uncertainty in determining element concentrations in source areas.

NASA Astrophysics Data System (ADS)

Gomez, Jose Alfonso; Owens, Phillip N.; Koiter, Alex J.; Lobb, David

2016-04-01

One of the major sources of uncertainty in attributing sediment sources in fingerprinting studies is the uncertainty in determining the concentrations of the elements used in the mixing model due to the variability of the concentrations of these elements in the source materials (e.g., Kraushaar et al., 2015). The uncertainty in determining the "true" concentration of a given element in each one of the source areas depends on several factors, among them the spatial variability of that element, the sampling procedure and sampling density. Researchers have limited control over these factors, and usually sampling density tends to be sparse, limited by time and the resources available. Monte Carlo analysis has been used regularly in fingerprinting studies to explore the probable solutions within the measured variability of the elements in the source areas, providing an appraisal of the probability of the different solutions (e.g., Collins et al., 2012). This problem can be considered analogous to the propagation of uncertainty in hydrologic models due to uncertainty in the determination of the values of the model parameters, and there are many examples of Monte Carlo analysis of this uncertainty (e.g., Freeze, 1980; Gómez et al., 2001). Some of these model analyses rely on the simulation of "virtual" situations that were calibrated from parameter values found in the literature, with the purpose of providing insight about the response of the model to different configurations of input parameters. This approach - evaluating the answer for a "virtual" problem whose solution could be known in advance - might be useful in evaluating the propagation of uncertainty in mixing models in sediment fingerprinting studies. In this communication, we present the preliminary results of an on-going study evaluating the effect of variability of element concentrations in source materials, sampling density, and the number of elements included in the mixing models. For this study a virtual catchment was constructed, composed by three sub-catchments each of 500 x 500 m size. We assumed that there was no selectivity in sediment detachment or transport. A numerical excercise was performed considering these variables: 1) variability of element concentration: three levels with CVs of 20 %, 50 % and 80 %; 2) sampling density: 10, 25 and 50 "samples" per sub-catchment and element; and 3) number of elements included in the mixing model: two (determined), and five (overdetermined). This resulted in a total of 18 (3 x 3 x 2) possible combinations. The five fingerprinting elements considered in the study were: C, N, 40K, Al and Pavail, and their average values, taken from the literature, were: sub-catchment 1: 4.0 %, 0.35 %, 0.50 ppm, 5.0 ppm, 1.42 ppm, respectively; sub-catchment 2: 2.0 %, 0.18 %, 0.20 ppm, 10.0 ppm, 0.20 ppm, respectively; and sub-catchment 3: 1.0 %, 0.06 %, 1.0 ppm, 16.0 ppm, 7.8 ppm, respectively. For each sub-catchment, three maps of the spatial distribution of each element was generated using the random generator of Mejia and Rodriguez-Iturbe (1974) as described in Freeze (1980), using the average value and the three different CVs defined above. Each map for each source area and property was generated for a 100 x 100 square grid, each grid cell being 5 m x 5 m. Maps were randomly generated for each property and source area. In doing so, we did not consider the possibility of cross correlation among properties. Spatial autocorrelation was assumed to be weak. The reason for generating the maps was to create a "virtual" situation where all the element concentration values at each point are known. Simultaneously, we arbitrarily determined the percentage of sediment coming from sub-catchments. These values were 30 %, 10 % and 60 %, for sub-catchments 1, 2 and 3, respectively. Using these values, we determined the element concentrations in the sediment. The exercise consisted of creating different sampling strategies in a virtual environment to determine an average value for each of the different maps of element concentration and sub-catchment, under different sampling densities: 200 different average values for the "high" sampling density (average of 50 samples); 400 different average values for the "medium" sampling density (average of 25 samples); and 1,000 different average values for the "low" sampling density (average of 10 samples). All these combinations of possible values of element concentrations in the source areas were solved for the concentration in the sediment already determined for the "true" solution using limSolve (Soetaert et al., 2014) in R language. The sediment source solutions found for the different situations and values were analyzed in order to: 1) evaluate the uncertainty in the sediment source attribution; and 2) explore strategies to detect the most probable solutions that might lead to improved methods for constructing the most robust mixing models. Preliminary results on these will be presented and discussed in this communication. Key words: sediment, fingerprinting, uncertainty, variability, mixing model. References Collins, A.L., Zhang, Y., McChesney, D., Walling, D.E., Haley, S.M., Smith, P. 2012. Sediment source tracing in a lowland agricultural catchment in southern England using a modified procedure combining statistical analysis and numerical modelling. Science of the Total Environment 414: 301-317. Freeze, R.A. 1980. A stochastic-conceptual analysis of rainfall-runoff processes on a hillslope. Water Resources Research 16: 391-408.

Aerofoil broadband and tonal noise modelling using stochastic sound sources and incorporated large scale fluctuations

NASA Astrophysics Data System (ADS)

Proskurov, S.; Darbyshire, O. R.; Karabasov, S. A.

2017-12-01

The present work discusses modifications to the stochastic Fast Random Particle Mesh (FRPM) method featuring both tonal and broadband noise sources. The technique relies on the combination of incorporated vortex-shedding resolved flow available from Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulation with the fine-scale turbulence FRPM solution generated via the stochastic velocity fluctuations in the context of vortex sound theory. In contrast to the existing literature, our method encompasses a unified treatment for broadband and tonal acoustic noise sources at the source level, thus, accounting for linear source interference as well as possible non-linear source interaction effects. When sound sources are determined, for the sound propagation, Acoustic Perturbation Equations (APE-4) are solved in the time-domain. Results of the method's application for two aerofoil benchmark cases, with both sharp and blunt trailing edges are presented. In each case, the importance of individual linear and non-linear noise sources was investigated. Several new key features related to the unsteady implementation of the method were tested and brought into the equation. Encouraging results have been obtained for benchmark test cases using the new technique which is believed to be potentially applicable to other airframe noise problems where both tonal and broadband parts are important.

Application of ion thruster technology to a 30-cm multipole sputtering ion source

NASA Technical Reports Server (NTRS)

Robinson, R. S.; Kaufman, H. R.

1976-01-01

A 30-cm electron-bombardment ion source has been designed and fabricated for micromachining and sputtering applications. This source has a multipole magnetic field that employs permanent magnets between permeable pole pieces. An average ion current density of 1 ma/sq cm with 500-eV argon ions was selected as a design operating condition. The ion beam at this operating condition was uniform and well collimated, with an average variation of + or -5 percent over the center 20 cm of the beam at a distance up to 30 cm from the ion source.

Understanding human infectious Cryptosporidium risk in drinking water supply catchments.

PubMed

Swaffer, Brooke; Abbott, Hayley; King, Brendon; van der Linden, Leon; Monis, Paul

2018-07-01

Treating drinking water appropriately depends, in part, on the robustness of source water quality risk assessments, however quantifying the proportion of infectious, human pathogenic Cryptosporidium oocysts remains a significant challenge. We analysed 962 source water samples across nine locations to profile the occurrence, rate and timing of infectious, human pathogenic Cryptosporidium in surface waters entering drinking water reservoirs during rainfall-runoff conditions. At the catchment level, average infectivity over the four-year study period reached 18%; however, most locations averaged <5%. The maximum recorded infectivity fraction within a single rainfall runoff event was 65.4%, and was dominated by C. parvum. Twenty-two Cryptosporidium species and genotypes were identified using PCR-based molecular techniques; the most common being C. parvum, detected in 23% of water samples. Associations between landuse and livestock stocking characteristics with Cryptosporidium were determined using a linear mixed-effects model. The concentration of pathogens in water were significantly influenced by flow and dominance of land-use by commercial grazing properties (as opposed to lifestyle properties) in the catchment (p < 0.01). Inclusion of measured infectivity and human pathogenicity data into a quantitative microbial risk assessment (QMRA) could reduce the source water treatment requirements by up to 2.67 log removal values, depending on the catchment, and demonstrated the potential benefit of collating such data for QMRAs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development of a Composite Measure of State-Level Malpractice Environment

PubMed Central

Chung, Jeanette W; Sohn, Min-Woong; Merkow, Ryan P; Oh, Elissa H; Minami, Christina; Black, Bernard S; Bilimoria, Karl Y

2014-01-01

Objective To develop a composite measure of state-level malpractice environment. Data Sources Public use data from the National Practitioner Data Bank, Medical Liability Monitor, the National Conference of State Legislatures, and the American Bar Association. Study Design Principal component analysis of state-level indicators (paid claims rate, malpractice premiums, lawyers per capita, average award size, and malpractice laws), with indirect validation of the composite using receiver-operating characteristic curves to determine how accurately the composite could identify states with high-tort activity and costs. Principal Findings A single composite accounted for over 73 percent of total variance in the seven indicators and demonstrated reasonable criterion validity. Conclusion An empirical composite measure of state-level malpractice risk may offer advantages over single indicators in measuring overall risk and may facilitate cross-state comparisons of malpractice environments. PMID:24117397

Artificial light sources for simulating natural daylight and skylight.

PubMed

Grum, F

1968-01-01

A review of the literature reveals the need for reliable and stable artificial light sources that can be used as simulators of daylight and skylight. In quest of such simulators a first requirement is quantitative information on the average spectral distributions of natural sources such as daylight and skylight. Recent investigations of the spectral energy characteristics of natural daylight and skylight made it possible to determine such average conditions. With these conditions established, a search was undertaken for an artificial light source that would simulate these average natural distributions with a minimum of filtering. Certain fluorescent lamps and combinations of them were considered first, but, although it was possible to achieve fairly good visual matches of daylight and skylight, the spectral characteristics and the variability of such combinations are drawbacks to their use in critical scientific work. For this purpose, therefore, xenon arc lamps were found to be superior.

Trophic state in Voyageurs National Park lakes before and after implementation of a revised water-level management plan

USGS Publications Warehouse

Christensen, Victoria G.; Maki, Ryan P.

2015-01-01

We compiled Secchi depth, total phosphorus, and chlorophyll a (Chla) data from Voyageurs National Park lakes and compared datasets before and after a new water-level management plan was implemented in January 2000. Average Secchi depth transparency improved (from 1.9 to 2.1 m, p = 0.020) between 1977-1999 and 2000-2011 in Kabetogama Lake for August samples only and remained unchanged in Rainy, Namakan, and Sand Point Lakes, and Black Bay in Rainy Lake. Average open-water season Chla concentration decreased in Black Bay (from an average of 13 to 6.0 μg/l, p = 0.001) and Kabetogama Lake (from 9.9 to 6.2 μg/l, p = 0.006) between 1977-1999 and 2000-2011. Trophic state index decreased significantly in Black Bay from 59 to 51 (p = 0.006) and in Kabetogama Lake from 57 to 50 (p = 0.006) between 1977-1999 and 2000-2011. Trophic state indices based on Chla indicated that after 2000, Sand Point, Namakan, and Rainy Lakes remained oligotrophic, whereas eutrophication has decreased in Kabetogama Lake and Black Bay. Although nutrient inputs from inflows and internal sources are still sufficient to produce annual cyanobacterial blooms and may inhibit designated water uses, trophic state has decreased for Kabetogama Lake and Black Bay and there has been no decline in lake ecosystem health since the implementation of the revised water-level management plan.

Analysis of 4-hydroxy-1-(-3-pyridyl)-1-butanone (HPB)-releasing DNA adducts in human exfoliated oral mucosa cells by liquid chromatography-electrospray ionization-tandem mass spectrometry

PubMed Central

Stepanov, Irina; Muzic, John; Le, Chap T.; Sebero, Erin; Villalta, Peter; Ma, Bin; Jensen, Joni; Hatsukami, Dorothy; Hecht, Stephen S.

2013-01-01

Quantitation of DNA adducts could provide critical information on the relationship between exposure to tobacco smoke and cancer risk in smokers. In this study, we developed a robust and sensitive liquid chromatography-tandem mass spectrometry method for the analysis of 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB1)-releasing DNA adducts in human oral cells, a non-invasive source of DNA for biomarker studies. Isolated DNA undergoes acid hydrolysis, after which samples are purified by solid-phase extraction and analyzed by LC-ESI-MS/MS. The developed method was applied for analysis of samples obtained via collection with a commercial mouthwash from 30 smokers and 15 nonsmokers. In smokers, the levels of HPB-releasing DNA adducts averaged 12.0 pmol HPB/mg DNA (detected in 20 out of 28 samples with quantifiable DNA yield) and in nonsmokers, the levels of adducts averaged 0.23 pmol/mg DNA (detected in 3 out of 15 samples). For the 30 smoking subjects, matching buccal brushings were also analyzed and HPB-releasing DNA adducts were detected in 24 out of 27 samples with quantifiable DNA yield, averaging 44.7 pmol HPB/mg DNA. The levels of adducts in buccal brushings correlated with those in mouthwash samples of smokers (R = 0.73, p < 0.0001). Potentially the method can be applied in studies of individual susceptibility to tobacco-induced cancers in humans. PMID:23252610

Earthquake Hazard and Risk in New Zealand

NASA Astrophysics Data System (ADS)

Apel, E. V.; Nyst, M.; Fitzenz, D. D.; Molas, G.

2014-12-01

To quantify risk in New Zealand we examine the impact of updating the seismic hazard model. The previous RMS New Zealand hazard model is based on the 2002 probabilistic seismic hazard maps for New Zealand (Stirling et al., 2002). The 2015 RMS model, based on Stirling et al., (2012) will update several key source parameters. These updates include: implementation a new set of crustal faults including multi-segment ruptures, updating the subduction zone geometry and reccurrence rate and implementing new background rates and a robust methodology for modeling background earthquake sources. The number of crustal faults has increased by over 200 from the 2002 model, to the 2012 model which now includes over 500 individual fault sources. This includes the additions of many offshore faults in northern, east-central, and southwest regions. We also use the recent data to update the source geometry of the Hikurangi subduction zone (Wallace, 2009; Williams et al., 2013). We compare hazard changes in our updated model with those from the previous version. Changes between the two maps are discussed as well as the drivers for these changes. We examine the impact the hazard model changes have on New Zealand earthquake risk. Considered risk metrics include average annual loss, an annualized expected loss level used by insurers to determine the costs of earthquake insurance (and premium levels), and the loss exceedance probability curve used by insurers to address their solvency and manage their portfolio risk. We analyze risk profile changes in areas with large population density and for structures of economic and financial importance. New Zealand is interesting in that the city with the majority of the risk exposure in the country (Auckland) lies in the region of lowest hazard, where we don't have a lot of information about the location of faults and distributed seismicity is modeled by averaged Mw-frequency relationships on area sources. Thus small changes to the background rates can have a large impact on the risk profile for the area. Wellington, another area of high exposure is particularly sensitive to how the Hikurangi subduction zone and the Wellington fault are modeled. Minor changes on these sources have substantial impacts for the risk profile of the city and the country at large.

Gender and ethnic differences in young adolescents' sources of cigarettes.

PubMed

Robinson, L A; Klesges, R C; Zbikowski, S M

1998-01-01

To identify the sources used by young adolescents to obtain cigarettes. In early 1994 a survey assessing usual sources of cigarettes and characteristics of the respondents was administered in homeroom classes. A large urban, predominantly African American school system. A population-based sample of 6967 seventh graders averaging 13 years of age. Reports of usual sources of cigarettes. At this age level, young smokers were more likely to get cigarettes from friends (31.2%) than buy them in stores (14.3%). However, the odds of purchasing varied for different groups of children. Regular smokers were much more likely (48.3%) to have purchased cigarettes than experimental smokers (9.6%), p < 0.001. Girls were less likely to have bought their cigarettes than boys (p < 0.001), and black smokers were less likely to have purchased cigarettes than white children (p < 0.001). Results suggested that family members who smoke may constitute a more important source of tobacco products than previously recognised, particularly for young girls. In this middle-school sample, peers provided the major point of cigarette distribution. However, even at this age, direct purchase was not uncommon. Sources of cigarettes varied significantly with gender, ethnicity, and smoking rate.

40 CFR 80.205 - How is the annual refinery or importer average and corporate pool average sulfur level determined?

Code of Federal Regulations, 2010 CFR

2010-07-01

... average and corporate pool average sulfur level determined? 80.205 Section 80.205 Protection of... ADDITIVES Gasoline Sulfur Gasoline Sulfur Standards § 80.205 How is the annual refinery or importer average and corporate pool average sulfur level determined? (a) The annual refinery or importer average and...

40 CFR 80.205 - How is the annual refinery or importer average and corporate pool average sulfur level determined?

Code of Federal Regulations, 2011 CFR

2011-07-01

... average and corporate pool average sulfur level determined? 80.205 Section 80.205 Protection of... ADDITIVES Gasoline Sulfur Gasoline Sulfur Standards § 80.205 How is the annual refinery or importer average and corporate pool average sulfur level determined? (a) The annual refinery or importer average and...

40 CFR 80.205 - How is the annual refinery or importer average and corporate pool average sulfur level determined?

Code of Federal Regulations, 2013 CFR

2013-07-01

... average and corporate pool average sulfur level determined? 80.205 Section 80.205 Protection of... ADDITIVES Gasoline Sulfur Gasoline Sulfur Standards § 80.205 How is the annual refinery or importer average and corporate pool average sulfur level determined? (a) The annual refinery or importer average and...

40 CFR 80.205 - How is the annual refinery or importer average and corporate pool average sulfur level determined?

Code of Federal Regulations, 2014 CFR

2014-07-01

... average and corporate pool average sulfur level determined? 80.205 Section 80.205 Protection of... ADDITIVES Gasoline Sulfur Gasoline Sulfur Standards § 80.205 How is the annual refinery or importer average and corporate pool average sulfur level determined? (a) The annual refinery or importer average and...

Highly Directional Sonar Beam of Narwhals (Monodon monoceros) Measured with a Vertical 16 Hydrophone Array.

PubMed

Koblitz, Jens C; Stilz, Peter; Rasmussen, Marianne H; Laidre, Kristin L

2016-01-01

Recordings of narwhal (Monodon monoceros) echolocation signals were made using a linear 16 hydrophone array in the pack ice of Baffin Bay, West Greenland in 2013 at eleven sites. An average -3 dB beam width of 5.0° makes the narwhal click the most directional biosonar signal reported for any species to date. The beam shows a dorsal-ventral asymmetry with a narrower beam above the beam axis. This may be an evolutionary advantage for toothed whales to reduce echoes from the water surface or sea ice surface. Source level measurements show narwhal click intensities of up to 222 dB pp re 1 μPa, with a mean apparent source level of 215 dB pp re 1 μPa. During ascents and descents the narwhals perform scanning in the vertical plane with their sonar beam. This study provides valuable information for reference sonar parameters of narwhals and for the use of acoustic monitoring in the Arctic.

The use of limpets as monitor of PAHs pollution in the Cantabrian coast

NASA Astrophysics Data System (ADS)

Bartolomé, L.; Bustamante, M.; Navarro, P.; Tajadura, J.; Gorostiaga, J. M.; Díez, I.; Zuloaga, O.; Etxebarria, N.

2011-11-01

The concentrations of 24 parental and methylated polycyclic aromatic hydrocarbon (PAH) levels in common limpet ( Patella vulgata) were measured in 15 coastal localities of the southern Bay of Biscay and 2 sites per locality for 2 years (spring and autumn of 2004 and 2005, respectively). Although the average concentrations shown a wide variability among the sites and the season, several sites showed a remarkable high concentration (PAH tot>900 ng g -1 d.w.) or medium (300-800 ng g -1 d.w) levels, but in most of the cases the initial high concentrations decreased sharply from one campaign to the following. Moreover, based on ratios of individual isomers concentration, petrogenic and pyrolitic sources were distinguished suggesting more than one source. Finally, based on the results of this work and comparing with previously reported data, it can concluded that limpets can be used as sentinel organisms in coastal environmental monitoring, even when oil spills are involved.

Highly Directional Sonar Beam of Narwhals (Monodon monoceros) Measured with a Vertical 16 Hydrophone Array

PubMed Central

Koblitz, Jens C.; Stilz, Peter; Rasmussen, Marianne H.; Laidre, Kristin L.

2016-01-01

Recordings of narwhal (Monodon monoceros) echolocation signals were made using a linear 16 hydrophone array in the pack ice of Baffin Bay, West Greenland in 2013 at eleven sites. An average -3 dB beam width of 5.0° makes the narwhal click the most directional biosonar signal reported for any species to date. The beam shows a dorsal-ventral asymmetry with a narrower beam above the beam axis. This may be an evolutionary advantage for toothed whales to reduce echoes from the water surface or sea ice surface. Source level measurements show narwhal click intensities of up to 222 dB pp re 1 μPa, with a mean apparent source level of 215 dB pp re 1 μPa. During ascents and descents the narwhals perform scanning in the vertical plane with their sonar beam. This study provides valuable information for reference sonar parameters of narwhals and for the use of acoustic monitoring in the Arctic. PMID:27828956

Preliminary study on the radiological and physicochemical quality of the Umgeni Water catchments and drinking water sources in KwaZulu-Natal, South Africa.

PubMed

Manickum, T; John, W; Terry, S; Hodgson, K

2014-11-01

Raw and potable water sample sources, from the Umgeni Water catchment areas (rivers, dams, boreholes) in central KwaZulu-Natal (South Africa), were screened for Uranium concentration and alpha and beta radioactivity. Test methods used were gas flow proportional counting for alpha-beta radioactivity, and kinetic phosphorescence analysis (KPA), for Uranium. The uranium levels (median = 0.525 μg/L, range = <0.050-5.010) were well below the international World Health Organization (WHO) (2011) guideline for drinking-water quality (≤15 μg/L). The corresponding alpha and beta radioactivity was ≤0.5 Bq/L (median = 0.084, Interquartile Range (IR) = 0.038, range = 0.018-0.094), and ≤1.0 Bq/L (median = 0.114, IR = 0.096, range = 0.024-0.734), respectively, in compliance with the international WHO limits. For uranium radionuclide, the average dose level, at uranium level of ±0.525 μg/L, was 0.06 μSv/a, which complies with the WHO reference dose level for drinking water (<0.1 mSv/a). There was a distinct trend of cluster of relatively higher Uranium levels of some sources that were found to be associated with the geology/geography and groundwater sources. Overall, the radiological water quality classification, with respect to WHO, is "Blue" - ideal; additional physicochemical analyses indicated good water quality. The analytical test methods employed were found to be suitable for preliminary screening for potential radioactive "hot spots". The observed Uranium levels, and the alpha/beta radioactivity, indicate contribution largely from Naturally Occurring Radioactive Material (NORM), with no significant health risk to humans, or to the environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Primary and Recycling Sources of OH During the NACHTT-2011 Campaign: HONO as an Important OH Primary Source in the Wintertime

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

Kim, S.; VandenBoer, Trevor; Young, Cora

2014-06-10

We present OH observation results during the NACHTT-11 field campaign at the Boulder Atmospheric Observatory in Weld County, Colorado. The observed OH levels during the daytime (at noon) were ~ 2.7 × 106 molecules cm-3 at the ground level (2 m above ground level, AGL). HONO and ozone photolysis were the two dominant photochemical OH production pathways during the field campaign. However, alkene ozonolysis, found an important source for OH by two previous winter season OH observations, was a minor contribution to OH primary production (~5 %). To evaluate recycling sources of OH from HO2 and RO2, an observation constrainedmore » University of Washington Chemical Mechanism (UWCM) box model is employed to simulated ambient OH levels with different model scenarios. For the base run without constraining observed HONO, the model simulated OH significantly underestimates the observed OH level (20.8 times in the morning and 7.2 times in the daytime). This indicates that the known HONO sources incorporated in the UWCM model cannot explain the observed HONO level. Once HONO is constrained by the observation, the discrepancy between observation and model simulation improves (5.1 times in the morning and 2.1 times in the daytime) but still out of the measurement uncertainty range (35 %). We explore two possible reasons for the observed unexplainably high wintertime OH levels. First, potential roles of Cl atoms produce organic peroxy radicals from the reactions between Cl atmos and alkane compounds. However, the Cl levels during the observation period are estimated very low (~ 103 atoms cm-3) to explain the enhanced OH levels. Second, Impacts of higher HONO levels on the ground was evaluated. Strong HONO gradient towards ground was observed especially during the early morning (6 am to 8 am) was observed and the lowest level available for the HONO observation during the campaign is 5 m AGL. Once we assume the twice of the observed HONO levels averaged between 5 m to 15 m at 2 m AGL, model predicted OH levels agree well within the observation uncertainty range. Wintertime photochemistry has not been investigated as much as the summer season. The results of this study along with a limited number of winter OH observations clearly urge further investigation on tropospheric oxidation capacity in the winter season considering implications of tropospheric oxidation capacity to the short-lived climate forcers especially methane.« less

In situ, satellite measurement and model evidence on the dominant regional contribution to fine particulate matter levels in the Paris megacity

NASA Astrophysics Data System (ADS)

Beekmann, M.; Prévôt, A. S. H.; Drewnick, F.; Sciare, J.; Pandis, S. N.; Denier van der Gon, H. A. C.; Crippa, M.; Freutel, F.; Poulain, L.; Ghersi, V.; Rodriguez, E.; Beirle, S.; Zotter, P.; von der Weiden-Reinmüller, S.-L.; Bressi, M.; Fountoukis, C.; Petetin, H.; Szidat, S.; Schneider, J.; Rosso, A.; El Haddad, I.; Megaritis, A.; Zhang, Q. J.; Michoud, V.; Slowik, J. G.; Moukhtar, S.; Kolmonen, P.; Stohl, A.; Eckhardt, S.; Borbon, A.; Gros, V.; Marchand, N.; Jaffrezo, J. L.; Schwarzenboeck, A.; Colomb, A.; Wiedensohler, A.; Borrmann, S.; Lawrence, M.; Baklanov, A.; Baltensperger, U.

2015-08-01

A detailed characterization of air quality in the megacity of Paris (France) during two 1-month intensive campaigns and from additional 1-year observations revealed that about 70 % of the urban background fine particulate matter (PM) is transported on average into the megacity from upwind regions. This dominant influence of regional sources was confirmed by in situ measurements during short intensive and longer-term campaigns, aerosol optical depth (AOD) measurements from ENVISAT, and modeling results from PMCAMx and CHIMERE chemistry transport models. While advection of sulfate is well documented for other megacities, there was surprisingly high contribution from long-range transport for both nitrate and organic aerosol. The origin of organic PM was investigated by comprehensive analysis of aerosol mass spectrometer (AMS), radiocarbon and tracer measurements during two intensive campaigns. Primary fossil fuel combustion emissions constituted less than 20 % in winter and 40 % in summer of carbonaceous fine PM, unexpectedly small for a megacity. Cooking activities and, during winter, residential wood burning are the major primary organic PM sources. This analysis suggests that the major part of secondary organic aerosol is of modern origin, i.e., from biogenic precursors and from wood burning. Black carbon concentrations are on the lower end of values encountered in megacities worldwide, but still represent an issue for air quality. These comparatively low air pollution levels are due to a combination of low emissions per inhabitant, flat terrain, and a meteorology that is in general not conducive to local pollution build-up. This revised picture of a megacity only being partially responsible for its own average and peak PM levels has important implications for air pollution regulation policies.

In-situ, satellite measurement and model evidence for a~dominant regional contribution to fine particulate matter levels in the Paris Megacity

NASA Astrophysics Data System (ADS)

Beekmann, M.; Prévôt, A. S. H.; Drewnick, F.; Sciare, J.; Pandis, S. N.; Denier van der Gon, H. A. C.; Crippa, M.; Freutel, F.; Poulain, L.; Ghersi, V.; Rodriguez, E.; Beirle, S.; Zotter, P.; von der Weiden-Reinmüller, S.-L.; Bressi, M.; Fountoukis, C.; Petetin, H.; Szidat, S.; Schneider, J.; Rosso, A.; El Haddad, I.; Megaritis, A.; Zhang, Q. J.; Michoud, V.; Slowik, J. G.; Moukhtar, S.; Kolmonen, P.; Stohl, A.; Eckhardt, S.; Borbon, A.; Gros, V.; Marchand, N.; Jaffrezo, J. L.; Schwarzenboeck, A.; Colomb, A.; Wiedensohler, A.; Borrmann, S.; Lawrence, M.; Baklanov, A.; Baltensperger, U.

2015-03-01

A detailed characterization of air quality in Paris (France), a megacity of more than 10 million inhabitants, during two one month intensive campaigns and from additional one year observations, revealed that about 70% of the fine particulate matter (PM) at urban background is transported on average into the megacity from upwind regions. This dominant influence of regional sources was confirmed by in-situ measurements during short intensive and longer term campaigns, aerosol optical depth (AOD) measurements from ENVISAT, and modeling results from PMCAMx and CHIMERE. While advection of sulfate is well documented for other megacities, there was surprisingly high contribution from long-range transport for both nitrate and organic aerosol. The origin of organic PM was investigated by a comprehensive analysis of aerosol mass spectrometer (AMS), radiocarbon and tracer measurements during two intensive campaigns. Primary fossil fuel combustion emissions contributed less than 20% in winter and 40% in summer to carbonaceous fine PM, unexpectedly little for a megacity. Cooking activities and, during winter, residential wood burning are the major primary organic PM sources. This analysis suggests that the major part of secondary organic aerosol is of modern origin, i.e. from biogenic precursors and from wood burning. Black carbon concentrations are on the lower end of values encountered in megacities worldwide, but still represent an issue for air quality. These comparatively low air pollution levels are due to a combination of low emissions per inhabitant, flat terrain, and a meteorology that is in general not conducive to local pollution build-up. This revised picture of a megacity only controlling part of its own average and peak PM levels has important implications for air pollution regulation policies.

A Ten-year Survey of Giardia Cysts in Drinking Water Supplies of Seoul, the Republic of Korea

PubMed Central

Cho, Eun-Joo; Lee, Jin-Hyo; Han, Sun-Hee; Park, Yong-Sang

2011-01-01

To understand the distribution of Giardia cysts in drinking water supplies in Seoul, Korea, we collected water samples quarterly at 6 intakes in the Han River, its largest stream and 6 conventional water treatment plants (WTPs) serving drinking water, from 2000 to 2009. Giardia cysts in each of 10 L water were confirmed in 35.0% of intake water samples and the arithmetic mean was 1.65 cysts/10 L (range 0-35 cysts/10 L). The lowest cyst density was observed at Paldang and Kangbuk intakes, and the pollution level was higher at 4 intakes downstream. It seemed that these 4 intakes were under influence of Wangsuk stream at the end of which cysts were found in all samples with the mean of 140 cysts/10 L. The annual mean number of cysts was 0.21-4.21 cysts/10 L, and the cyst level at the second half of the 10 years was about 1/5 of that at first half on average. The cysts were more frequently found in winter, and their mean density was 3.74 cysts/10 L in winter and 0.80-1.08 cysts/10 L in other seasons. All finished water samples collected at 6 WTPs were negative for Giardia in each of 100 L sample for 10 years and cyst removal by physical process was average 2.9-log. It was concluded that conventional water treatment at 6 WTPs of Seoul appears to remove the cysts effectively under the present level of their source water. Domestic wastewater from the urban region could be an important source of Giardia pollution in the river. PMID:21461263

High levels of perfluoroalkyl acids in sport fish species downstream of a firefighting training facility at Hamilton International Airport, Ontario, Canada.

PubMed

Gewurtz, Sarah B; Bhavsar, Satyendra P; Petro, Steve; Mahon, Chris G; Zhao, Xiaoming; Morse, Dave; Reiner, Eric J; Tittlemier, Sheryl A; Braekevelt, Eric; Drouillard, Ken

2014-06-01

A recent study reported elevated concentrations of perfluorooctane sulfonic acid (PFOS) and other perfluoroalkyl acids (PFAAs) in surface water, snapping turtles, and amphipods in Lake Niapenco, downstream of Hamilton International Airport, Ontario, Canada. Here, our goals were to 1) determine the extent of PFAA contamination in sport fish species collected downstream of the airport, 2) explore if the airport could be a potential source, and 3) compare fish PFOS concentrations to consumption advisory benchmarks. The PFOS levels in several sport fish collected from the three locations closest to the airport (<40km) were among the highest previously published in the peer-reviewed literature and also tended to exceed consumption benchmarks. The only other fish that had comparable concentrations were collected in a region affected by inputs from a major fluorinated chemical production facility. In contrast, PFOS concentrations in the two most downstream locations (>70km) were comparable to or below the average concentrations in fish as observed in the literature and were generally below the benchmarks. With regards to perfluorocarboxylates (PFCAs), there was no significant decrease in concentrations in fish with distance from the airport and levels were comparable to or below the average concentrations observed in the literature, suggesting that the airport is not a significant source of PFCAs in these fish species. PFOS-based aqueous film-forming foam (AFFF) was used at a firefighting training facility at the airport in the 1980s to mid-1990s. Taken together, our results provide evidence that the historical use of AFFF at the airport has resulted in fish PFOS concentrations that exceed the 95th percentile concentration of values reported in the literature to date. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Ozone and TFA impacts in North America from degradation of 2,3,3,3-Tetrafluoropropene (HFO-1234yf), a potential greenhouse gas replacement.

PubMed

Luecken, Deborah J; L Waterland, Robert; Papasavva, Stella; Taddonio, Kristen N; Hutzell, William T; Rugh, John P; Andersen, Stephen O

2010-01-01

We use a regional-scale, three-dimensional atmospheric model to evaluate U.S. air quality effects that would result from replacing HFC-134a in automobile air conditioners in the U.S. with HFO-1234yf. Although HFO-1234yf produces tropospheric ozone, the incremental amount is small, averaging less than 0.01% of total ozone formed during the simulation. We show that this production of ozone could be compensated for by a modest improvement in air conditioner efficiency. Atmospheric decomposition of HFO-1234yf produces trifluoroacetic acid (TFA), which is subject to wet and dry deposition. Deposition and concentrations of TFA are spatially variable due to HFO-1234yf's short atmospheric lifetime, with more localized peaks and less global transport when compared to HFC-134a. Over the 2.5 month simulation, deposition of TFA in the continental U.S. from mobile air conditioners averages 0.24 kg km(-2), substantially higher than previous estimates from all sources of current hydrofluorocarbons. Automobile air conditioning HFO-1234yf emissions are predicted to produce concentrations of TFA in Eastern U.S. rainfall at least double the values currently observed from all sources, natural and man-made. Our model predicts peak concentrations in rainfall of 1264 ng L(-1), a level that is 80x lower than the lowest level considered safe for the most sensitive aquatic organisms.

"What do you know?"--knowledge among village doctors of lead poisoning in children in rural China.

PubMed

Huang, Ruixue; Ning, Huacheng; Baum, Carl R; Chen, Lei; Hsiao, Allen

2017-11-23

This study evaluates the extent of village doctors' knowledge of lead poisoning in children in rural China and assesses the characteristics associated with possessing accurate knowledge. A cross-sectional, questionnaire-based survey of 297 village doctors in Fenghuang County, Hunan Province, China was conducted. All village doctors were interviewed face-to-face using a "What do you know" test questionnaire focusing on prevention strategies and lead sources in rural children. A total of 287 (96.6%) village doctors completed the survey in full. Most village doctors had an appropriate degree of general knowledge of lead poisoning; however, they had relatively poor knowledge of lead sources and prevention measures. Village doctors with an undergraduate level education scored an average of 2.7 points higher than those who had a junior college level education (p = 0.033). Village doctors with an annual income ≤ 10,000 RMB yuan scored 1.03 points lower than those whose income was >10,001 RMB yuan. Ethnic Han village doctors scored 1.12 points higher, on average, than ethnic Tujia village doctors (p = 0.027). This study identified important gaps in knowledge concerning lead poisoning in children among a rural population of village doctors. There is a clear need for multifaceted interventions that target village doctors to improve their knowledge regarding lead poisoning in children. The "What do you know" questionnaire is a new tool to evaluate lead poisoning knowledge and education projects.

7 CFR 760.640 - National average market price.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false National average market price. 760.640 Section 760.640....640 National average market price. (a) The Deputy Administrator will establish the National Average Market Price (NAMP) using the best sources available, as determined by the Deputy Administrator, which...

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

PubMed

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

2015-07-01

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

Lunar rocks as a source of oxygen

NASA Technical Reports Server (NTRS)

Poole, H. G.

1963-01-01

A thermodynamic study of the thermal stability of conventional terrestrial minerals in a hypothetical lunar atmosphere has opened some interesting speculation. Much of the Earth's crust is composed of oxides of silicon, aluminum, magnesium, and related compounds. These crust components may be as much a product of the Earth's atmosphere as vegetation and animal life. Though inanimate and long considered imperishable, these materials are stable under conditions of an atmosphere equivalent to 34 ft of water at sea level and persist under adverse conditions of moisture and temperature to altitudes of roughly 29,000 ft above sea level. The oxygen content averages 21% ) and the oxygen partial pressure would be roughly 1/5 atm.

How strong is the Social Security safety net? Using the Elder Index to assess gaps in economic security.

PubMed

Mutchler, Jan E; Li, Yang; Xu, Ping

2018-04-16

Older Americans rely heavily on Social Security benefits (SSBs) to support independent lifestyles, and many have few or no additional sources of income. We establish the extent to which SSBs adequately support economic security, benchmarked by the Elder Economic Security Standard Index. We document variability across U.S. counties in the adequacy levels of SSBs among older adults. We find that the average SSBs fall short of what is required for economic security in every county in the United States, but the level of shortfall varies considerably by location. Policy implications relating to strengthening Social Security and other forms of retirement income are discussed.

Sources and physicochemical characteristics of black carbon aerosol from the southeastern Tibetan Plateau: internal mixing enhances light absorption

NASA Astrophysics Data System (ADS)

Wang, Qiyuan; Cao, Junji; Han, Yongming; Tian, Jie; Zhu, Chongshu; Zhang, Yonggang; Zhang, Ningning; Shen, Zhenxing; Ni, Haiyan; Zhao, Shuyu; Wu, Jiarui

2018-04-01

Black carbon (BC) aerosol has important effects on the climate and hydrology of the Tibetan Plateau (TP). An intensive measurement campaign was conducted at Lulang (˜ 3300 m a.s.l. - above sea level), southeastern TP, from September to October 2015, to investigate the sources and physicochemical characteristics of refractory BC (rBC) aerosol. The average rBC mass concentration was 0.31 ± 0.55 µg m-3, which is higher than most prior results for BC on the TP. A clear diurnal cycle in rBC showed high values in the morning and low values in the afternoon. A bivariate polar plot showed that rBC loadings varied with wind speed and direction, which also reflected the dominant transport direction. The estimated net surface rBC transport intensity was +0.05 ± 0.29 µg s-1 m-2, indicating stronger transport from outside the TP compared with its interior. Cluster analysis and a concentration-weighted trajectory model connected emissions from north India to the high rBC loadings, but the effects of internal TP sources should not be overlooked. The average mass median diameter (MMD) of rBC was 160 ± 23 nm, with smaller MMDs on rainy days (145 nm) compared with non-rainy days (164 nm). The average number fraction of thickly coated rBC (FrBC) was 39 ± 8 %, and it increased with the O3 mixing ratios from 10:00 to 14:00 LT, indicating that photochemical oxidation played a role in forming rBC coatings. The average rBC absorption enhancement (Eabs) was estimated to be 1.9, suggesting that light absorption by coated rBC particles was greater than for uncoated ones. The Eabs was strongly positively correlated with the FrBC, indicating an amplification of light absorption for internally mixed rBC. For rBC cores < 170 nm, Eabs was negatively correlated with MMD, but it was nearly constant for rBC cores > 170 nm. Our study provides insight into the sources and evolution of rBC aerosol on the TP, and the results should be useful for improving models of the radiative effects of carbonaceous aerosols in this area.

Application of positive matrix factorization to identify potential sources of PAHs in soil of Dalian, China.

PubMed

Wang, Degao; Tian, Fulin; Yang, Meng; Liu, Chenlin; Li, Yi-Fan

2009-05-01

Soil derived sources of polycyclic aromatic hydrocarbons (PAHs) in the region of Dalian, China were investigated using positive matrix factorization (PMF). Three factors were separated based on PMF for the statistical investigation of the datasets both in summer and winter. These factors were dominated by the pattern of single sources or groups of similar sources, showing seasonal and regional variations. The main sources of PAHs in Dalian soil in summer were the emissions from coal combustion average (46%), diesel engine (30%), and gasoline engine (24%). In winter, the main sources were the emissions from coal-fired boiler (72%), traffic average (20%), and gasoline engine (8%). These factors with strong seasonality indicated that coal combustion in winter and traffic exhaust in summer dominated the sources of PAHs in soil. These results suggested that PMF model was a proper approach to identify the sources of PAHs in soil.

Technical Note: Effect of explicit M and N-shell atomic transitions on a low-energy x-ray source

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

Watson, Peter G. F., E-mail: peter.watson@mail.mcgill.ca; Seuntjens, Jan

Purpose: In EGSnrc, atomic transitions to and from the M and N-shells are treated in an average way by default. This approach is justified in which the energy difference between explicit and average M and N-shell binding energies is less than 1 keV, and for most applications can be considered negligible. However, for simulations of low energy x-ray sources on thin, high-Z targets, characteristic x-rays can make up a significant portion of the source spectra. As of release V4-2.4.0, EGSnrc has included an option to enable a more complete algorithm of all atomic transitions available in the EADL compilation. Inmore » this paper, the effect of M and N-shell averaging on the calculation of half-value layer (HVL) and relative depth dose (RDD) curve of a 50 kVp intraoperative x-ray tube with a thin gold target was investigated. Methods: A 50 kVp miniature x-ray source with a gold target (The INTRABEAM System, Carl Zeiss, Germany) was modeled with the EGSnrc user code cavity, both with and without M and N-shell averaging. From photon fluence spectra simulations, the source HVLs were determined analytically. The same source model was then used with egs-chamber to calculate RDD curves in water. Results: A 4% increase of HVL was reported when accounting for explicit M and N-shell transitions, and up to a 9% decrease in local relative dose for normalization at 3 mm depth in water. Conclusions: The EGSnrc default of using averaged M and N-shell binding energies has an observable effect on the HVL and RDD of a low energy x-ray source with high-Z target. For accurate modeling of this class of devices, explicit atomic transitions should be included.« less

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

PubMed

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

2016-01-01

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

Echolocation signals of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) in Sanniang Bay, China.

PubMed

Fang, Liang; Li, Songhai; Wang, Kexiong; Wang, Zhitao; Shi, Wenjing; Wang, Ding

2015-09-01

While the low-frequency communication sounds of Indo-Pacific humpback dolphins (Sousa chinensis) have been reported in a number of papers, the high-frequency echolocation signals of Sousa chinensis, especially those living in the wild, have been less studied. In the current study, echolocation signals of humpback dolphins were recorded in Sanniang Bay, Guangxi Province, China, using a cross-type hydrophone array with five elements. In total, 77 candidate on-axis clicks from 77 scans were selected for analysis. The results showed that the varied peak-to-peak source levels ranged from 177.1 to 207.3 dB, with an average of 187.7 dB re: 1 μPa. The mean peak frequency was 109.0 kHz with a -3-dB bandwidth of 50.3 kHz and 95% energy duration of 22 μs. The -3-dB bandwidth was much broader than the root mean square bandwidth and exhibited a bimodal distribution. The center frequency exhibited a positive relationship with the peak-to-peak source level. The clicks of the wild Indo-Pacific humpback dolphins were short-duration, broadband, ultrasonic pulses, similar to those produced by other whistling dolphins of similar body size. However, the click source levels of the Indo-Pacific humpback dolphin appear to be lower than those of other whistling dolphins.

Evaluation of the solar conditions for the acquisitions of energy from renewable sources on the base of Sosnowiec city (Poland)

NASA Astrophysics Data System (ADS)

Sarapata, Sonia

2014-09-01

The country's energy security risk, as well as a desire to protect the environment from the pollution and degradation which are the results of conventional fuels acquisition - these was a motivation for intensive researches on the use of renewable energy sources in eco - innovative installations. Solar radiation is one of the self - renewable energy sources which can be used both as a source of electricity and heat. The area of research is Sosnowiec city located in the south of Poland in the eastern part of Silesia voivodeship. The solar radiation data covering the years 2003 to 2013 was used. The intra - annual variability of daily averaged solar radiation hesitated in a wide range from 0.6 kWh/m2 (December) to 5.2 kWh/m2 (June). Day duration varies on average from 10 hours in January, November and December to 17 hours in May, June and July. Day occupies 56% of the 8767 hours in year. On average the largest amount of energy reached the analyzed area in July: 157 kWh/m2 (15% of the annual average), while the smallest in December: 18 kWh/m2 (less than 2% of the annual average). The 75% of the average annual total of energy falls on the period from 1st March to 31th August (spring - summer). The range of the annual solar radiation was determined by the minimum of 980 kWh/m2 and the maximum of 1094 kWh/m2. In Sosnowiec the average annual irradiation total on the horizontal surface amounts to 1052 kWh/m2 (2003 - 2013)

Statistical properties of the time histories of cosmic gamma-ray bursts detected by the BATSE experiment of the Compton gamma-ray observatory

NASA Technical Reports Server (NTRS)

Sagdeev, Roald

1995-01-01

The main scientific objectives of the project were: (1) Calculation of average time history for different subsets of BATSE gamma-ray bursts; (2) Comparison of averaged parameters and averaged time history for different Burst And Transient Source Experiments (BASTE) Gamma Ray Bursts (GRB's) sets; (3) Comparison of results obtained with BATSE data with those obtained with APEX experiment at PHOBOS mission; and (4) Use the results of (1)-(3) to compare current models of gamma-ray bursts sources.

Source apportionment and pollution evaluation of heavy metals in water and sediments of Buriganga River, Bangladesh, using multivariate analysis and pollution evaluation indices.

PubMed

Bhuiyan, Mohammad Amir Hossain; Dampare, Samuel B; Islam, M A; Suzuki, Shigeyuki

2015-01-01

Concentrations of heavy metals in water and sediment samples of Buriganga River in the capital city Dhaka, Bangladesh, were studied to understand the level of heavy metals and their source apportionment. The results showed that the mean concentrations of heavy metals both in water and sediment samples were very high and, in most cases, exceeded the permissible limits recommended by the Bangladesh government and other international organizations. Significantly higher concentrations of Pb, Cr, Mn, Co, Ni, Cu, Zn, As, and Cd were found in sediment samples. However, average concentrations of metals both in water and sediment samples were above the effect range median. The heavy metal pollution index (HPI) and degree of contamination (Cd) yielded different results in water samples despite significant correlations between them. The heavy metal evaluation index (HEI) showed strong correlations with HPI and Cd and provided better assessment of pollution levels. The enrichment factor (EF) and geoaccumulation index (Igeo) showed the elevated value of Cr, Pb, and Cd in access of background values. The measured elements were subjected to positive matrix factorization (PMF) and examining correlations in order to explain the content, behavior, and source apportionment of metals. PMF resulted in a successful partitioning of variances into sources related to background geochemistry and contaminant influences. However, the PMF approach successfully demarcated the major sources of metals from tannery, paint, municipal sewage, textiles, and agricultural activities.

Hydrology and simulation of ground-water flow in the Tooele Valley ground-water basin, Tooele County, Utah

USGS Publications Warehouse

Stolp, Bernard J.; Brooks, Lynette E.

2009-01-01

Ground water is the sole source of drinking water within Tooele Valley. Transition from agriculture to residential land and water use necessitates additional understanding of water resources. The ground-water basin is conceptualized as a single interconnected hydrologic system consisting of the consolidated-rock mountains and adjoining unconsolidated basin-fill valleys. Within the basin fill, unconfined conditions exist along the valley margins and confined conditions exist in the central areas of the valleys. Transmissivity of the unconsolidated basin-fill aquifer ranges from 1,000 to 270,000 square feet per day. Within the consolidated rock of the mountains, ground-water flow largely is unconfined, though variability in geologic structure, stratigraphy, and lithology has created some areas where ground-water flow is confined. Hydraulic conductivity of the consolidated rock ranges from 0.003 to 100 feet per day. Ground water within the basin generally moves from the mountains toward the central and northern areas of Tooele Valley. Steep hydraulic gradients exist at Tooele Army Depot and near Erda. The estimated average annual ground-water recharge within the basin is 82,000 acre-feet per year. The primary source of recharge is precipitation in the mountains; other sources of recharge are irrigation water and streams. Recharge from precipitation was determined using the Basin Characterization Model. Estimated average annual ground-water discharge within the basin is 84,000 acre-feet per year. Discharge is to wells, springs, and drains, and by evapotranspiration. Water levels at wells within the basin indicate periods of increased recharge during 1983-84 and 1996-2000. During these periods annual precipitation at Tooele City exceeded the 1971-2000 annual average for consecutive years. The water with the lowest dissolved-solids concentrations exists in the mountain areas where most of the ground-water recharge occurs. The principal dissolved constituents are calcium and bicarbonate. Dissolved-solids concentration increases in the central and northern parts of Tooele Valley, at the distal ends of the ground-water flow paths. Increased concentration is due mainly to greater amounts of sodium and chloride. Deuterium and oxygen-18 values indicate water recharged primarily from precipitation occurs throughout the ground-water basin. Ground water with the highest percentage of recharge from irrigation exists along the eastern margin of Tooele Valley, indicating negligible recharge from the adjacent consolidated rock. Tritium and tritiogenic helium-3 concentrations indicate modern water exists along the flow paths originating in the Oquirrh Mountains between Settlement and Pass Canyons and extending between the steep hydraulic gradient areas at Tooele Army Depot and Erda. Pre-modern water exists in areas east of Erda and near Stansbury Park. Using the change in tritium along the flow paths originating in the Oquirrh Mountains, a first-order estimate of average linear ground-water velocity for the general area is roughly 2 to 5 feet per day. A numerical ground-water flow model was developed to simulate ground-water flow in the Tooele Valley ground-water basin and to test the conceptual understanding of the ground-water system. Simulating flow in consolidated rock allows recharge and withdrawal from wells in or near consolidated rock to be simulated more accurately. In general, the model accurately simulates water levels and water-level fluctuations and can be considered an adequate tool to help determine the valley-wide effects on water levels of additional ground-water withdrawal and changes in water use. The simulated increase in storage during a projection simulation using 2003 withdrawal rates and average recharge indicates that repeated years of average precipitation and recharge conditions do not completely restore the system after multiple years of below-normal precipitation. In the similar case where precipitation is 90

Micronutrient Intake among Children in Puerto Rico: Dietary and Multivitamin-Multimineral Supplement Sources.

PubMed

Lopez-Cepero, Andrea; Torres, Roxana; Elias, Augusto; Rosal, Milagros C; Palacios, Cristina

2015-12-01

Micronutrients are critical for healthy growth and development of children. Micronutrient intake from dietary sources is inadequate among some children and may be improved by use of multivitamin and multimineral (MVMM) supplements. To assess micronutrient intake from dietary and MVMM supplement sources among 12-year-old children in Puerto Rico. A representative sample of 732 children enrolled in an oral health study in Puerto Rico, who completed dietary and MVMM assessments through one 24-h recall, were included in this analysis. Micronutrient intake sources were described and compared to the Dietary Reference Intakes (DRIs) using the Estimated Average Requirement when available (used Adequate Intake for vitamin K and pantothenic acid). Micronutrient profiles of MVMM users and non-users were compared using t-tests. Mean intakes of vitamins A, D, E, and K, pantothenic acid, calcium, and magnesium from food and beverage sources were below the DRIs. From food and beverage sources, MVMM users had higher intakes of riboflavin and folate compared to non-users (p < 0.05). When MVMM supplements were taken into account, users had higher intakes of all nutrients except vitamin K. With the help of MVMM, users increased intake of vitamins E, A, D, and pantothenic acid to IOM-recommended levels but calcium, magnesium, and vitamin K remained below guidelines. Micronutrient intake from diet was below the IOM-recommended levels in the total sample. MVMM use improved intake of selected micronutrients and facilitated meeting recommendations for some nutrients. Public health measures to improve micronutrient intake among children in Puerto Rico are needed.

Assessment of indoor radon, thoron concentrations, and their relationship with seasonal variation and geology of Udhampur district, Jammu & Kashmir, India.

PubMed

Kumar, Ajay; Sharma, Sumit; Mehra, Rohit; Narang, Saurabh; Mishra, Rosaline

2017-07-01

Background The inhalation doses resulting from the exposure to radon, thoron, and their progeny are important quantities in estimating the radiation risk for epidemiological studies as the average global annual effective dose due to radon and its progeny is 1.3 mSv as compared to that of 2.4 mSv due to all other natural sources of ionizing radiation. Objectives The annual inhalation dose has been assessed with an aim of investigating the health risk to the inhabitants of the studied region. Methods Time integrated deposition based 222 Rn/ 220 Rn sensors have been used to measure concentrations in 146 dwellings of Udhampur district, Jammu and Kashmir. An active smart RnDuo monitor has also been used for comparison purposes. Results The range of indoor radon/thoron concentrations is found to vary from 11 to 58 Bqm -3 with an average value of 29 ± 9 Bqm -3 and from 25 to 185 Bqm -3 with an average value of 83 ± 32 Bqm -3 , respectively. About 10.7% dwellings have higher values than world average of 40 Bqm -3 prescribed by UNSCEAR. The relationship of indoor radon and thoron levels with different seasons, ventilation conditions, and different geological formations have been discussed. Conclusions The observed values of concentrations and average annual effective dose due to radon, thoron, and its progeny in the study area have been found to be below the recommended level of ICRP. The observed concentrations of 222 Rn and 220 Rn measured with active and passive techniques are found to be in good agreement.

Audible and infrasonic noise levels in the cabins of modern agricultural tractors--does the risk of adverse, exposure-dependent effects still exist?

PubMed

Bilski, Bartosz

2013-06-01

The agricultural tractor is one of the most commonly used vehicles on farms and one of the most prominent sources of noise. This article presents an exemplary assessment of the audible and infrasonic noise levels in the cabins of selected modern wheeled agricultural tractors. Operator-perceived audible and infrasonic noise levels in the cabins were examined for 20 types of modern tractors during typical conditions of work. The tractors had been in use for no longer than 3 years, with rated power between 96 kW and 227 kW, designed and produced by world-renowned companies. Noise level measurements were performed in accordance with PN-EN ISO 9612:2011 (ISO 9612:2009). Audible noise levels (A-weighted) ranged from 62.1 to 87.4 dB-A (average: 68.2 to 83.8 dB-A) for different work tasks. The factors influencing noise levels include performed tasks, soil, weather conditions and the skills of individual drivers. In spectrum analysis, the highest noise levels occurred at frequencies 250 Hz, 1 and 2 kHz. Infrasound noise levels (G-weighted) ranged from 87.3 to 111.3 dB-G. The driver-experienced exposure to infrasound was found to increase significantly when the vehicle was in motion. Average audible noise levels have no potential to adversely affect the hearing organ during tasks performed inside the closed cabins of the analysed modern agricultural tractors. Due to the relatively low audible noise levels inside the cabins of modern agricultural tractors, non-auditory effects are the only adverse symptoms that can develop. Modern agricultural tractors emit considerable infrasonic noise levels. All tractors introduced into the market should be subjected to tests with regard to infrasonic noise levels.

The indoor volatile organic compound (VOC) characteristics and source identification in a new university campus in Tianjin, China.

PubMed

Kang, Jian; Liu, Junjie; Pei, Jingjing

2017-06-01

This study investigates the volatile organic compounds (VOCs) constituents and concentration levels on a new university campus, where all of the buildings including classrooms and student dormitories were newly built and decorated within 1 year. Investigated indoor environments include dormitories, classrooms, and the library. About 30 dormitory buildings with different furniture loading ratios were measured. The characteristics of the indoor VOCs species are analyzed and possible sources are identified. The VOCs were analyzed with gas chromatography-mass spectroscopy (GC-MS). It was found that the average total VOC (TVOC) concentration can reach 2.44 mg/m 3 . Alkenes were the most abundant VOCs in dormitory rooms, contributing up to 86.5% of the total VOCs concentration. The concentration of α-pinene is the highest among the alkenes. Unlike the dormitory rooms, there is almost no room with TVOC concentration above 0.6 mg/m 3 in classroom and library buildings. Formaldehyde concentration in the dormitory rooms increased about 23.7% after the installation of furniture, and the highest level reached 0.068 mg/m 3 . Ammonia released from the building antifreeze material results in an average indoor concentration of 0.28 mg/m 3 , which is 100% over the threshold and should be seriously considered. Further experiments were conducted to analyze the source of the α-pinene and some alkanes in dormitory rooms. The results showed that the α-pinene mainly comes from the bed boards, while the wardrobes are the main sources of alkanes. The contribution of the pinewood bed boards to the α-pinene and TVOC concentration can reach up to above 90%. The same type rooms were sampled 1 year later and the decay rate of α-pinene is quite high, close to 100%, so that it almost cannot be detected in the sampled rooms. Analysis of indoor volatile organic compounds (VOCs) in newly built campus buildings in China identified the specific constituents of indoor VOCs contaminants exposed to Chinese college students. The main detected substances α-pinene, β-pinene, and 3-carene originated from solid wood bed boards and should be seriously considered. In addition, the contribution rates of building structure materials and furniture to specific VOCs constituents are quantitative calculated. Also, the decay rates of these specific constituents within 1 year are also quantitative calculated in this paper. This study can help us to better understand the sources and concentration levels of VOC contaminants in campus buildings, and to help select appropriate materials in buildings.

Sexual behaviour and sexual and reproductive health education: a cross-sectional study in Romania.

PubMed

Rada, Cornelia

2014-06-23

Up-to-date, genuine sexual and reproductive health (SRH) education programmes have been possible in Romania only since communism collapsed in 1990. Since 2006, Romania has had no national strategy in this field. Under current global circumstances (high labour mobility, internationally mixed marriages), issues previously considered solely national have become worldwide concerns. In 2011-2012, 1215 respondents homogeneously distributed on background, gender, educational level and age group (18-74) were sampled. This article uses a 96-item questionnaire about family and SRH, presenting results on nine items: first intercourse (FI), virginity, knowing first sexual partner, safe sex, number of sexual partners and sexual education. The data were analysed using Pearson chi-square tests and latent class analysis. Some participants (7.2%) engaged in FI at age 15 or earlier. The average age at FI was lower for men (18.08), for individuals with a lower education level (18.07) and for those in rural areas (18.27), compared with that for women, those with more education and those in urban areas, respectively. The average age at FI was over 2.5 years lower for people aged 18-24 (16.99) than for those aged 60-74 (p < 0.001). More than 60% were not married or partnered with their FI partner, and 17.8% engaged in FI less than a month after meeting their partner. Less than one-fourth practiced safe sex at FI, with higher proportions for the urban sample, those with an average level of education and those aged 18-35 (p < 0.001). Higher average numbers of sexual partners were found among men (6.56, compared with 2.37 among women), in urban areas (5.07, compared with 3.75 in rural areas) and among those with higher levels of education (p < 0.005). On average, subjects first received information on SRH at 15.39 years of age, with only 10% listing the school, doctors or medics as a source. Unsafe sex, early initiation of sexual activity and poor SRH education from schools, experts and parents require a multidisciplinary approach within prevention programmes, especially among the populations at risk: rural residents, those with low levels of education and youth.

Sexual behaviour and sexual and reproductive health education: a cross-sectional study in Romania

PubMed Central

2014-01-01

Background Up-to-date, genuine sexual and reproductive health (SRH) education programmes have been possible in Romania only since communism collapsed in 1990. Since 2006, Romania has had no national strategy in this field. Under current global circumstances (high labour mobility, internationally mixed marriages), issues previously considered solely national have become worldwide concerns. Methods In 2011–2012, 1215 respondents homogeneously distributed on background, gender, educational level and age group (18–74) were sampled. This article uses a 96-item questionnaire about family and SRH, presenting results on nine items: first intercourse (FI), virginity, knowing first sexual partner, safe sex, number of sexual partners and sexual education. The data were analysed using Pearson chi-square tests and latent class analysis. Results Some participants (7.2%) engaged in FI at age 15 or earlier. The average age at FI was lower for men (18.08), for individuals with a lower education level (18.07) and for those in rural areas (18.27), compared with that for women, those with more education and those in urban areas, respectively. The average age at FI was over 2.5 years lower for people aged 18–24 (16.99) than for those aged 60–74 (p < 0.001). More than 60% were not married or partnered with their FI partner, and 17.8% engaged in FI less than a month after meeting their partner. Less than one-fourth practiced safe sex at FI, with higher proportions for the urban sample, those with an average level of education and those aged 18–35 (p < 0.001). Higher average numbers of sexual partners were found among men (6.56, compared with 2.37 among women), in urban areas (5.07, compared with 3.75 in rural areas) and among those with higher levels of education (p < 0.005). On average, subjects first received information on SRH at 15.39 years of age, with only 10% listing the school, doctors or medics as a source. Conclusions Unsafe sex, early initiation of sexual activity and poor SRH education from schools, experts and parents require a multidisciplinary approach within prevention programmes, especially among the populations at risk: rural residents, those with low levels of education and youth. PMID:24957900

Characterizations of atmospheric fungal aerosol in Beijing, China

NASA Astrophysics Data System (ADS)

Liang, Linlin; Engling, Guenter; He, Kebin; Du, Zhenyu

2013-04-01

Fungal aerosols constitute the most abundant fraction of biological aerosols in the atmosphere, influencing human health, the biosphere, atmospheric chemistry and climate. However, the total abundance of fungal spores in the atmosphere is still poorly understood and quantified. PM10 and PM2.5 samples were collected by high volume samplers simultaneously at a rural site (MY) and an urban site (THU) in Beijing, China. Various carbohydrates were quantified by high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), including the sugar alcohols mannitol and arabitol, proposed as molecular tracers for fungal aerosol. The annual average concentrations of arabitol in PM2.5 and PM10 at the THU site were 7.4±9.4 ng/m3 and 10.3±9.5 ng/m3, and the respective mannitol concentrations were 21.0±20.4 ng/m3 and 31.9±26.9 ng/m3. Compared to PM10, the monthly average concentrations of arabitol and mannitol in PM2.5 did not vary significantly and were present at nearly consistent levels in the different seasons. Moreover, during summer and autumn higher arabitol and mannitol levels than during spring and winter were observed in coarse particles, probably due to different dominant sources of fungal spores in different seasons. In the dry period (i.e., winter and spring) in Beijing, probably only the suspension from exposed surfaces, (e.g., soil resuspension, transported dust, etc.) can be regarded as the main sources for fungal aerosols. On the other hand, in summer and autumn, fungal spores in the atmosphere can be derived from more complex sources, including plants, vegetation decomposition and agricultural activity, such as ploughing; these fungal spore sources may contribute more to coarse PM. Mannitol and arabitol correlated well with each other, both in PM10 (R2 = 0.71) and PM2.5 (R2 = 0.81). Although fungal spore levels at rural sites were consistently higher than those at urban sites in other studies, the findings in our study were reversed, indicating a high abundance of fungal spores in the urban area of Beijing, China. Meteorological conditions were shown to have complex effects on the ambient concentrations of fungal spores: the concentrations of arabitol exhibited positive correlation with temperature below 30.0 °C, negative correlation with wind speed higher than 0.6 m/s, no relationship with solar radiation and the highest arabitol levels were mainly associated with RH in the range of 51-70%.

Use of computer code for dose distribution studies in A 60CO industrial irradiator

NASA Astrophysics Data System (ADS)

Piña-Villalpando, G.; Sloan, D. P.

1995-09-01

This paper presents a benchmark comparison between calculated and experimental absorbed dose values tor a typical product, in a 60Co industrial irradiator, located at ININ, México. The irradiator is a two levels, two layers system with overlapping product configuration with activity around 300kCi. Experimental values were obtanied from routine dosimetry, using red acrylic pellets. Typical product was Petri dishes packages, apparent density 0.13 g/cm3; that product was chosen because uniform size, large quantity and low density. Minimum dose was fixed in 15 kGy. Calculated values were obtained from QAD-CGGP code. This code uses a point kernel technique, build-up factors fitting was done by geometrical progression and combinatorial geometry is used for system description. Main modifications for the code were related with source sumilation, using punctual sources instead of pencils and an energy and anisotropic emission spectrums were included. Results were, for maximum dose, calculated value (18.2 kGy) was 8% higher than experimental average value (16.8 kGy); for minimum dose, calculated value (13.8 kGy) was 3% higher than experimental average value (14.3 kGy).

The binaural performance of a cross-talk cancellation system with matched or mismatched setup and playback acoustics.

PubMed

Akeroyd, Michael A; Chambers, John; Bullock, David; Palmer, Alan R; Summerfield, A Quentin; Nelson, Philip A; Gatehouse, Stuart

2007-02-01

Cross-talk cancellation is a method for synthesizing virtual auditory space using loudspeakers. One implementation is the "Optimal Source Distribution" technique [T. Takeuchi and P. Nelson, J. Acoust. Soc. Am. 112, 2786-2797 (2002)], in which the audio bandwidth is split across three pairs of loudspeakers, placed at azimuths of +/-90 degrees, +/-15 degrees, and +/-3 degrees, conveying low, mid, and high frequencies, respectively. A computational simulation of this system was developed and verified against measurements made on an acoustic system using a manikin. Both the acoustic system and the simulation gave a wideband average cancellation of almost 25 dB. The simulation showed that when there was a mismatch between the head-related transfer functions used to set up the system and those of the final listener, the cancellation was reduced to an average of 13 dB. Moreover, in this case the binaural interaural time differences and interaural level differences delivered by the simulation of the optimal source distribution (OSD) system often differed from the target values. It is concluded that only when the OSD system is set up with "matched" head-related transfer functions can it deliver accurate binaural cues.

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

Logue, Jennifer M; Singer, Brett

Range hood use during residential cooking is essential to maintaining good indoor air quality. However, widespread use will impact the energy demand of the U.S. housing stock. This paper describes a modeling study to determine site energy, source energy, and consumer costs for comprehensive range hood use. To estimate the energy impacts for all 113 million homes in the U.S., we extrapolated from the simulation of a representative weighted sample of 50,000 virtual homes developed from the 2009 Residential Energy Consumption Survey database. A physics-based simulation model that considered fan energy, energy to condition additional incoming air, and the effectmore » on home heating and cooling due to exhausting the heat from cooking was applied to each home. Hoods performing at a level common to hoods currently in U.S. homes would require 19?33 TWh [69?120 PJ] of site energy, 31?53 TWh [110-190 PJ] of source energy; and would cost consumers $1.2?2.1 billion (U.S.$2010) annually in the U.S. housing stock. The average household would spend less than $15 annually. Reducing required airflow, e.g. with designs that promote better pollutant capture has more energy saving potential, on average, than improving fan efficiency.« less

Surveillance system for air pollutants by combination of the decision support system COMPAS and optical remote sensing systems

NASA Astrophysics Data System (ADS)

Flassak, Thomas; de Witt, Helmut; Hahnfeld, Peter; Knaup, Andreas; Kramer, Lothar

1995-09-01

COMPAS is a decision support system designed to assist in the assessment of the consequences of accidental releases of toxic and flammable substances. One of the key elements of COMPAS is a feedback algorithm which allows us to calculate the source term with the aid of concentration measurements. Up to now the feedback technique is applied to concentration measurements done with test tubes or conventional point sensors. In this paper the extension of the actual method is presented which is the combination of COMPAS and an optical remote sensing system like the KAYSER-THREDE K300 FTIR system. Active remote sensing methods based on FTIR are, among other applications, ideal for the so-called fence line monitoring of the diffuse emissions and accidental releases from industrial facilities, since from the FTIR spectra averaged concentration levels along the measurement path can be achieved. The line-averaged concentrations are ideally suited as on-line input for COMPAS' feedback technique. Uncertainties in the assessment of the source term related with both shortcomings of the dispersion model itself and also problems of a feedback strategy based on point measurements are reduced.

Sources of groundwater and characteristics of surface-water recharge at Bell, White, and Suwannee Springs, Florida, 2012–13

USGS Publications Warehouse

Stamm, John F.; McBride, W. Scott

2016-12-21

Discharge from springs in Florida is sourced from aquifers, such as the Upper Floridan aquifer, which is overlain by an upper confining unit that locally can have properties of an aquifer. Water levels in aquifers are affected by several factors, such as precipitation, recharge, and groundwater withdrawals, which in turn can affect discharge from springs. Therefore, identifying groundwater sources and recharge characteristics can be important in assessing how these factors might affect flows and water levels in springs and can be informative in broader applications such as groundwater modeling. Recharge characteristics include the residence time of water at the surface, apparent age of recharge, and recharge water temperature.The groundwater sources and recharge characteristics of three springs that discharge from the banks of the Suwannee River in northern Florida were assessed for this study: Bell Springs, White Springs, and Suwannee Springs. Sources of groundwater were also assessed for a 150-foot-deep well finished within the Upper Floridan aquifer, hereafter referred to as the UFA well. Water samples were collected for geochemical analyses in November 2012 and October 2013 from the three springs and the UFA well. Samples were analyzed for a suite of major ions, dissolved gases, and isotopes of sulfur, strontium, oxygen, and hydrogen. Daily means of water level and specific conductance at White Springs were continuously recorded from October 2012 through December 2013 by the Suwannee River Water Management District. Suwannee River stage at White Springs was computed on the basis of stage at a U.S. Geological Survey streamgage about 2.4 miles upstream. Water levels in two wells, located about 2.5 miles northwest and 13 miles southeast of White Springs, were also used in the analyses.Major ion concentrations were used to differentiate water from the springs and Upper Floridan aquifer into three groups: Bell Springs, UFA well, and White and Suwannee Springs. When considered together, evidence from water-level, specific conductance, major-ion concentration, and isotope data indicated that groundwater at Bell Springs and the UFA well was a mixture of surface water and groundwater from the upper confining unit, and that groundwater at White and Suwannee Springs was a mixture of surface water, groundwater from the upper confining unit, and groundwater from the Upper Floridan aquifer. Higher concentrations of magnesium in groundwater samples at the UFA well than in samples at Bell Springs might indicate less mixing with surface water at the UFA well than at Bell Springs. Characteristics of surface-water recharge, such as residence time at the surface, apparent age, and recharge water temperature, were estimated on the basis of isotopic ratios, and dissolved concentrations of gases such as argon, tritium, and sulfur hexafluoride. Oxygen and deuterium isotopic ratios were consistent with rapid recharge by rainwater for samples collected in 2012, and longer residence time at the surface (ponding) for samples collected in 2013. Apparent ages of groundwater samples, computed on the basis of tritium activity and sulfur hexafluoride concentration, indicated groundwater recharge occurred after the late 1980s; however, the estimated apparent ages likely represent the average of ages of multiple sources. Recharge since the 1980s is consistent with groundwater from shallow sources, such as the upper confining unit and Upper Floridan aquifer. Recharge water temperature computed for the three springs and UFA well averaged 20.1 degrees Celsius, which is similar to the mean annual air temperature of 20.6 degrees Celsius at a nearby weather station for 1960–2014.

50 CFR 218.120 - Specified activity and geographical area.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the following mid-frequency active sonar (MFAS) sources, high-frequency active sonar (HFAS) sources...-mounted active sonar)—up to 2,890 hours over the course of 5 years (an average of 578 hours per year); (ii) AN/SQS-56 (hull-mounted active sonar)—up to 260 hours over the course of 5 years (an average of 52...

50 CFR 218.120 - Specified activity and geographical area.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the following mid-frequency active sonar (MFAS) sources, high-frequency active sonar (HFAS) sources...-mounted active sonar)—up to 2,890 hours over the course of 5 years (an average of 578 hours per year); (ii) AN/SQS-56 (hull-mounted active sonar)—up to 260 hours over the course of 5 years (an average of 52...

50 CFR 218.120 - Specified activity and geographical area.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the following mid-frequency active sonar (MFAS) sources, high-frequency active sonar (HFAS) sources...-mounted active sonar)—up to 2,890 hours over the course of 5 years (an average of 578 hours per year); (ii) AN/SQS-56 (hull-mounted active sonar)—up to 260 hours over the course of 5 years (an average of 52...

50 CFR 218.120 - Specified activity and geographical area.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the following mid-frequency active sonar (MFAS) sources, high-frequency active sonar (HFAS) sources...-mounted active sonar)—up to 2,890 hours over the course of 5 years (an average of 578 hours per year); (ii) AN/SQS-56 (hull-mounted active sonar)—up to 260 hours over the course of 5 years (an average of 52...

Experimental study of outdoor propagation of spherically speading periodic acoustic waves of finite amplitude

NASA Technical Reports Server (NTRS)

Theobald, M. A.

1977-01-01

The outdoor propagation of spherically spreading sound waves of finite amplitude was investigated. The main purpose of the experiments was to determine the extent to which the outdoor environment, mainly random inhomogeneity of the medium, affects finite amplitude propagation. Periodic sources with fundamental frequencies in the range 6 to 8 kHz and source levels SPLlm from 140 to 149 dB were used. The sources were an array of 7 to 10 horn drivers and a siren. The propagation path was vertical and parallel to an 85 m tower, whose elevator carried the traveling microphone. The general conclusions drawn from the experimental results were as follows. The inhomogeneities caused significant fluctuations in the instantaneous acoustic signal, but with sufficient time averaging of the measured harmonic levels, the results were comparable to results expected for propagation in a quiet medium. Propagation data for the fundamental of the siren approached within 1 dB of the weak shock saturation levels. Extra attenuation on the order of 8 dB was observed. The measurements generally confirmed the predictions of several theoretical models. The maximum propagation distance was 36 m. The narrowbeam arrays were much weaker sources. Nonlinear propagation distortion was produced, but the maximum value of extra attenuation measured was 1.5 dB. The maximum propagation distance was 76 m. The behavior of the asymetric waveforms received in one experiment qualitatively suggested that beam type diffraction effects were present. The role of diffraction of high intensity sound waves in radiation from a single horn was briefly investigated.

Compact Tunable Narrowband Terahertz-Wave Source Based on Difference Frequency Generation Pumped by Dual Fiber Lasers in MgO:LiNbO3

NASA Astrophysics Data System (ADS)

Wada, Yoshio; Satoh, Takumi; Higashi, Yasuhiro; Urata, Yoshiharu

2017-12-01

We demonstrate a high-average-power, single longitudinal-mode, and tunable terahertz (THz)-wave source based on difference frequency generation (DFG) in a MgO:LiNbO3 (MgO:LN) crystal. The waves for DFG are generated using a pair of Yb-doped pulsed fiber lasers with a master oscillator power fiber amplifier configuration. The average power of the THz-wave output reaches 450 μW at 1.07 THz (280 μm) at a linewidth of 7.2 GHz, and the tunability ranges from 0.35 to 1.07 THz under the pulse repetition frequency of 500 kHz. A short burn-in test of the THz wave is also carried out, and the output power stability is within ± 5% of the averaged power without any active stabilizing technique. The combination of MgO:LN-DFG and stable and robust fiber laser sources is highly promising for the development of high-average-power THz-wave sources, particularly in the high transmission sub-THz region. This approach may enable new applications of THz-wave spectroscopy in imaging and remote sensing.

Predictors of Human Immunodeficiency Virus Knowledge among Jordanian Youths

PubMed Central

Al-Khasawneh, Esra M.; Ismayilova, Leyla; Seshan, Vidya; Hmoud, Olimat; El-Bassel, Nabila

2013-01-01

Objectives: Understanding factors associated with the level of human immunodeficiency virus (HIV) knowledge acquisition is crucial to inform preventative programmes for young people. This study examines predictors of HIV knowledge among Jordanian youths. Methods: A cross-sectional survey was conducted among 8,129 youths aged between 14 and 25 years randomly selected from schools representing each of the 12 governorates of Jordan. A total of 50% of respondents were female and, on average, 17 years old. Participants completed a self-administered questionnaire covering sociodemographic characteristics, HIV knowledge, gender awareness, exposure to and favourable attitudes toward risky behaviours. Results: On a 13-item HIV knowledge test, participants answered an average of 7 questions correctly (mean = 7.21; standard deviation = 2.63). Female respondents from rural areas demonstrated significantly lower levels of HIV knowledge, while college and university students demonstrated higher levels. HIV knowledge differed significantly by sources of information, with peer-acquired information associated with more accuracy, while HIV information from parents or health centres was associated with a lower score. Youths with more egalitarian gender views also demonstrated higher knowledge levels, whereas youths approving of drug use showed lower levels of HIV knowledge. Conclusion: HIV education programmes in Jordan should focus on females and youths living in rural areas. Educational institutions have been shown to be effective in providing accurate information to students, while parents and health professionals should also be included in HIV prevention programmes in order to reduce misconceptions and raise the level of HIV knowledge among Jordanian youths. PMID:23862028

Respiratory disease associated with community air pollution and a steel mill, Utah Valley

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

Pope, C.A. III

This study assessed the association between hospital admissions and fine particulate pollution (PM10) in Utah Valley during the period April 1985-February 1988. This time period included the closure and reopening of the local steel mill, the primary source of PM10. An association between elevated PM10 levels and hospital admissions for pneumonia, pleurisy, bronchitis, and asthma was observed. During months when 24-hour PM10 levels exceeded 150 micrograms/m3, average admissions for children nearly tripled; in adults, the increase in admissions was 44 per cent. During months with mean PM10 levels greater than or equal to 50 micrograms/m3 average admissions for children andmore » adults increased by 89 and 47 per cent, respectively. During the winter months when the steel mill was open, PM10 levels were nearly double the levels experienced during the winter months when the mill was closed. This occurred even though relatively stagnant air was experienced during the winter the mill was closed. Children's admissions were two to three times higher during the winters when the mill was open compared to when it was closed. Regression analysis also revealed that PM10 levels were strongly correlated with hospital admissions. They were more strongly correlated with children's admissions than with adult admissions and were more strongly correlated with admissions for bronchitis and asthma than with admissions for pneumonia and pleurisy.« less

Fugitive emissions from nanopowder manufacturing

NASA Astrophysics Data System (ADS)

Trompetter, W. J.; Ancelet, T.; Davy, P. K.; Kennedy, J.

2016-07-01

In response to health and safety questions and concerns regarding particulate matter emissions from equipment used for synthesizing NiFe and TiO2 nanopowders, a study was undertaken to assess their impact on the air quality inside and outside a laboratory where the manufacturing equipment is operated. Elemental concentrations determined by ion beam analysis (IBA) of air particulate matter (PM) samples collected hourly with a StreakerTM sampler were used to identify possible sources and estimate contributions from nanopowder production and other sources. The fugitive nanopowder emissions were the highest at the indoor sampling location when powders were being manufactured. Average fugitive emissions of 210 ng m-3 (1-h average) (maximum 2163 ng m-3 1-h average) represented 2 % (maximum 20 %) of the average PM collected (9359 ng m-3 1-h average). The measured NiFe alloy or TiO2 PM concentrations were much smaller than the 8-h time-weighted average (TWA) workplace exposure standards (WES) for these materials (≥1,000,000 ng m-3). Most PM was found to be from infiltrated outdoor ambient sources. This suggests that nanopowder production in the laboratory is not likely to have adverse health effects on individuals using the equipment, although further improvements can be made to further limit exposure.

High Contributions of Secondary Inorganic Aerosols to PM2.5 under Polluted Levels at a Regional Station in Northern China

PubMed Central

Li, Yang; Tao, Jun; Zhang, Leiming; Jia, Xiaofang; Wu, Yunfei

2016-01-01

Daily PM2.5 samples were collected at Shangdianzi (SDZ) regional site in Beijing–Tianjin–Hebei (BTH) region in 2015. Samples were subject to chemical analysis for organic carbon (OC), elemental carbon (EC), and major water-soluble inorganic ions. The annual average PM2.5 mass concentration was 53 ± 36 μg·m−3 with the highest seasonal average concentration in spring and the lowest in summer. Water-soluble inorganic ions and carbonaceous aerosols accounted for 34% ± 15% and 33% ± 9%, respectively, of PM2.5 mass on annual average. The excellent, good, lightly polluted, moderately polluted, and heavily polluted days based on the Air Quality Index (AQI) of PM2.5 accounted for 40%, 42%, 11%, 4%, and 3%, respectively, of the year. The sum of the average concentration of sulfate, nitrate, and ammonium (SNA) increased from 4.2 ± 2.9 μg·m−3 during excellent days to 85.9 ± 22.4 μg·m−3 during heavily polluted days, and their contributions to PM2.5 increased from 15% ± 8% to 49% ± 10% accordingly. In contrast, the average concentration of carbonaceous aerosols increased from 9.2 ± 2.8 μg·m−3 to 51.2 ± 14.1 μg·m−3, and their contributions to PM2.5 decreased from 34% ± 6% to 29% ± 7%. Potential source contribution function (PSCF) analysis revealed that the major sources for high PM2.5 and its dominant chemical components were within the area mainly covering Shandong, Henan, and Hebei provinces. Regional pollutant transport from Shanxi province and Inner Mongolia autonomous region located in the west direction of SDZ was also important during the heating season. PMID:27983711

Very Luminous X-ray Point Sources in Starburst Galaxies

NASA Astrophysics Data System (ADS)

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

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

Health Risk Assessments for Alumina Refineries

PubMed Central

Coffey, Patrick S.

2014-01-01

Objective: To describe contemporary air dispersion modeling and health risk assessment methodologies applied to alumina refineries and to summarize recent results. Methods: Air dispersion models using emission source and meteorological data have been used to assess ground-level concentrations (GLCs) of refinery emissions. Short-term (1-hour and 24-hour average) GLCs and annual average GLCs have been used to assess acute health, chronic health, and incremental carcinogenic risks. Results: The acute hazard index can exceed 1 close to refineries, but it is typically less than 1 at neighboring residential locations. The chronic hazard index is typically substantially less than 1. The incremental carcinogenic risk is typically less than 10−6. Conclusions: The risks of acute health effects are adequately controlled, and the risks of chronic health effects and incremental carcinogenic risks are negligible around referenced alumina refineries. PMID:24806721

Frequency Measurements of Superradiance from the Strontium Clock Transition

NASA Astrophysics Data System (ADS)

Norcia, Matthew A.; Cline, Julia R. K.; Muniz, Juan A.; Robinson, John M.; Hutson, Ross B.; Goban, Akihisa; Marti, G. Edward; Ye, Jun; Thompson, James K.

2018-04-01

We present the first characterization of the spectral properties of superradiant light emitted from the ultranarrow, 1-mHz-linewidth optical clock transition in an ensemble of cold Sr 87 atoms. Such a light source has been proposed as a next-generation active atomic frequency reference, with the potential to enable high-precision optical frequency references to be used outside laboratory environments. By comparing the frequency of our superradiant source to that of a state-of-the-art cavity-stabilized laser and optical lattice clock, we observe a fractional Allan deviation of 6.7 (1 )×10-16 at 1 s of averaging, establish absolute accuracy at the 2-Hz (4 ×10-15 fractional frequency) level, and demonstrate insensitivity to key environmental perturbations.

Scale and legacy controls on catchment nutrient export regimes

NASA Astrophysics Data System (ADS)

Howden, N. J. K.; Burt, T.; Worrall, F.

2017-12-01

Nutrient dynamics in river catchments are complex: water and chemical fluxes are highly variable in low-order streams, but this variability declines as fluxes move through higher-order reaches. This poses a major challenge for process understanding as much effort is focussed on long-term monitoring of the main river channel (a high-order reach), and therefore the data available to support process understanding are predominantly derived from sites where much of the transient response of nutrient export is masked by the effect of averaging over both space and time. This may be further exacerbated at all scales by the accumulation of legacy nutrient sources in soils, aquifers and pore waters, where historical activities have led to nutrient accumulation where the catchment system is transport limited. Therefore it is of particular interest to investigate how the variability of nutrient export changes both with catchment scale (from low to high-order catchment streams) and with the presence of legacy sources, such that the context of infrequent monitoring on high-order streams can be better understood. This is not only a question of characterising nutrient export regimes per se, but also developing a more thorough understanding of how the concepts of scale and legacy may modify the statistical characteristics of observed responses across scales in both space and time. In this paper, we use synthetic data series and develop a model approach to consider how space and timescales combine with impacts of legacy sources to influence observed variability in catchment export. We find that: increasing space and timescales tend to reduce the observed variance in nutrient exports, due to an increase in travel times and greater mixing, and therefore averaging, of sources; increasing the influence of legacy sources inflates the variance, with the level of inflation dictated by the residence time of the respective sources.

Interannual Variations in Aerosol Sources and Their Impact on Orographic Precipitation over California's Central Sierra Nevada

NASA Astrophysics Data System (ADS)

Creamean, J.; Ault, A. P.; White, A. B.; Neiman, P. J.; Minnis, P.; Prather, K. A.

2014-12-01

Aerosols that serve as cloud condensation nuclei (CCN) and ice nuclei (IN) have the potential to profoundly influence precipitation processes. Furthermore, changes in orographic precipitation have broad implications for reservoir storage and flood risks. As part of the CalWater I field campaign (2009-2011), the impacts of aerosol sources on precipitation were investigated in the California Sierra Nevada Mountains. In 2009, the precipitation collected on the ground was influenced by both local biomass burning and long-range transported dust and biological particles, while in 2010, by mostly local sources of biomass burning and pollution, and in 2011 by mostly long-range transport of dust and biological particles from distant sources. Although vast differences in the sources of residues were observed from year-to-year, dust and biological residues were omnipresent (on average, 55% of the total residues combined) and were associated with storms consisting of deep convective cloud systems and larger quantities of precipitation initiated in the ice phase. Further, biological residues were dominant during storms with relatively warm cloud temperatures (up to -15°C), suggesting biological components were more efficient IN than mineral dust. On the other hand, when precipitation quantities were lower, local biomass burning and pollution residues were observed (on average 31% and 9%, respectively), suggesting these residues potentially served as CCN at the base of shallow cloud systems and that lower level polluted clouds of storm systems produced less precipitation than non-polluted (i.e., marine) clouds. The direct connection of the sources of aerosols within clouds and precipitation type and quantity can be used in models to better assess how local emissions versus long-range transported dust and biological aerosols play a role in impacting regional weather and climate, ultimately with the goal of more accurate predictive weather forecast models and water resource management.

Hydrology of Northern Utah Valley, Utah County, Utah, 1975-2005

USGS Publications Warehouse

Cederberg, Jay R.; Gardner, Philip M.; Thiros, Susan A.

2009-01-01

The ground-water resources of northern Utah Valley, Utah, were assessed during 2003-05 to describe and quantify components of the hydrologic system, determine a hydrologic budget for the basin-fill aquifer, and evaluate changes to the system relative to previous studies. Northern Utah Valley is a horst and graben structure with ground water occurring in both the mountain-block uplands surrounding the valley and in the unconsolidated basin-fill sediments. The principal aquifer in northern Utah Valley occurs in the unconsolidated basin-fill deposits where a deeper unconfined aquifer occurs near the mountain front and laterally grades into multiple confined aquifers near the center of the valley. Sources of water to the basin-fill aquifers occur predominantly as either infiltration of streamflow at or near the interface of the mountain front and valley or as subsurface inflow from the adjacent mountain blocks. Sources of water to the basin-fill aquifers were estimated to average 153,000 (+/- 31,500) acre-feet annually during 1975-2004 with subsurface inflow and infiltration of streamflow being the predominant sources. Discharge from the basin-fill aquifers occurs in the valley lowlands as flow to waterways, drains, ditches, springs, as diffuse seepage, and as discharge from flowing and pumping wells. Ground-water discharge from the basin-fill aquifers during 1975-2004 was estimated to average 166,700 (+/- 25,900) acre-feet/year where discharge to wells for consumptive use and discharge to waterways, drains, ditches, and springs were the principal sources. Measured water levels in wells in northern Utah Valley declined an average of 22 feet from 1981 to 2004. Water-level declines are consistent with a severe regional drought beginning in 1999 and continuing through 2004. Water samples were collected from 36 wells and springs throughout the study area along expected flowpaths. Water samples collected from 34 wells were analyzed for dissolved major ions, nutrients, and stable isotopes of hydrogen and oxygen. Water samples from all 36 wells were analyzed for dissolved-gas concentration including noble gases and tritium/helium-3. Within the basin fill, dissolved-solids concentration generally increases with distance along flowpaths from recharge areas, and shallower flowpaths tend to have higher concentrations than deeper flowpaths. Nitrate concentrations generally are at or below natural background levels. Dissolved-gas recharge temperature data support the conceptual model of the basin-fill aquifers and highlight complexities of recharge patterns in different parts of the valley. Dissolved-gas data indicate that the highest elevation recharge sources for the basin-fill aquifer are subsurface inflow derived from recharge in the adjacent mountain block between the mouths of American Fork and Provo Canyons. Apparent ground-water ages in the basin-fill aquifer, as calculated using tritium/helium-3 data, range from 2 to more than 50 years. The youngest waters in the valley occur near the mountain fronts with apparent ages generally increasing near the valley lowlands and discharge area around Utah Lake. Flowpaths are controlled by aquifer properties and the location of the predominant recharge sources, including subsurface inflow and recharge along the mountain front. Subsurface inflow is distributed over a larger area across the interface of the subsurface mountain block and basin-fill deposits. Subsurface inflow occurs at a depth deeper than that at which mountain-front recharge occurs. Recharge along the mountain front is often localized and focused over areas where streams and creeks enter the valley, and recharge is enhanced by the associated irrigation canals.

Atmospheric mercury measurements at a suburban site in the Mid-Atlantic United States: Inter-annual, seasonal and diurnal variations and source-receptor relationships

NASA Astrophysics Data System (ADS)

Ren, Xinrong; Luke, Winston T.; Kelley, Paul; Cohen, Mark D.; Artz, Richard; Olson, Mark L.; Schmeltz, David; Puchalski, Melissa; Goldberg, Daniel L.; Ring, Allison; Mazzuca, Gina M.; Cummings, Kristin A.; Wojdan, Lisa; Preaux, Sandra; Stehr, Jeff W.

2016-12-01

Different atmospheric mercury forms have been measured at a suburban site in Beltsville, Maryland in the Mid-Atlantic United States since 2007 to investigate their inter-annual, seasonal and diurnal variabilities. Average concentrations and standard deviations of hourly measurements from 2007 to 2015 were 1.41 ± 0.23 ng m-3 for gaseous elemental mercury (GEM), 4.6 ± 33.7 pg m-3 for gaseous oxidized mercury (GOM), and 8.6 ± 56.8 pg m-3 for particulate-bound mercury (PBM). Observations show that on average, the rates of decrease were 0.020 ± 0.007 ng m-3 yr-1 (or 1.3 ± 0.5% yr-1, statistically significant, p-value < 0.01) for GEM, 0.54 ± 0.19 pg m-3 yr-1 (or 7.3 ± 2.6% yr-1, statistically significant, p-value < 0.01) for GOM, and 0.15 ± 0.35 pg m-3 yr-1 (or 1.6 ± 3.8% yr-1, statistically insignificant, p-value > 0.01) for PBM over this nine-year period. In addition, the collocated annual mercury wet deposition decreased at a rate of 0.51 ± 0.24 μg m-2 yr-2 (or 4.2 ± 1.9% yr-1, statistically insignificant, p-value > 0.01). Diurnal variation of GEM shows a slight peak in the morning, likely due to the shallow boundary layer. Seasonal variation of GEM shows lower levels in fall. Both diurnal variations of GOM and PBM show peaks in the afternoon likely due to the photochemical production of reactive mercury from the oxidation of GEM and the influence of boundary layer processes. Seasonally, GOM measurements show high levels in spring and constant low levels in the other three seasons, while PBM measurements exhibit higher levels from late fall to early spring and lower levels from late spring to fall. These measurement data were analyzed using the HYSPLIT back trajectory model in order to examine possible source-receptor relationships at this suburban site. Trajectory frequency analysis shows that high GEM/GOM/PBM events were generally associated with high frequencies of the trajectories passing through areas with high mercury emissions, while low GEM/GOM/PBM levels were largely associated the trajectories passing through relatively clean areas. This study indicates that local and regional sources appear to have a significant impact on the site and these impacts appear to have changed over time, as the local/regional emissions have been reduced.

[Dietary exposure assessment of aflatoxin of foodstuff and edible oil from Shenzhen residents].

PubMed

Li, Ke; Qiu, Fen; Jiang, Lixin; Yang, Mei

2014-07-01

To assess the dietary exposure aflatoxin B1 and total aflatoxins of foodstuff and edible oil in Shenzhen residents. Aflatoxins in the samples were determined by the immuno-affinity column clean-up plus UPLC. The aflatoxin B1 and aflatoxins dietary exposure were calculated by the level of aflatoxins contamination in the food and consumption of dietary. The average diary aflatoxin B1 dietary exposure of the man of the 2 to 6, 7 to 14, 15 to 50 and > 50 age group in Shenzhen were 0.320, 0.385, 0.401 and 0.398 ng/(kg BW x d), the results of the woman were 0.282, 0.222, 0.367 and 0.470 ng/(kg BW x d) respectively. The total average daily dietary aflatoxin B1 exposure of the man were 0.012, 0.015, 0.016 and 0.016 ng/(kg BW x d) about each age group. The results of the woman were 78.4, 167, 113 and 103 ng/(kg BW d). According to the the average levels of consumption and the high levels of consumption, the risk of AFB, of the man were 0.012,0.015, 0.016, 0. 016 and 3.0, 8.2, 4.1, 4.4 cancer patient per one hundred thousand, respectively. The results of the woman were 0.010, 0.009, 0.014, 0.018 and 2.9, 6.7, 4.4, 4.0 cancer patient per one hundred thousand, respectively. 7 to 14 age group compared with adults age group face higher exposure levels. The rice and peanut oil are most primary aflatoxin dietary exposure sources in Shenzhen.

Interrupted time series analysis of children’s blood lead levels: A case study of lead hazard control program in Syracuse, New York

PubMed Central

Shao, Liyang; Zhang, Lianjun; Zhen, Zhen

2017-01-01

Children’s blood lead concentrations have been closely monitored over the last two decades in the United States. The bio-monitoring surveillance data collected in local agencies reflected the local temporal trends of children’s blood lead levels (BLLs). However, the analysis and modeling of the long-term time series of BLLs have rarely been reported. We attempted to quantify the long-term trends of children’s BLLs in the city of Syracuse, New York and evaluate the impacts of local lead poisoning prevention programs and Lead Hazard Control Program on reducing the children’s BLLs. We applied interrupted time series analysis on the monthly time series of BLLs surveillance data and used ARMA (autoregressive and moving average) models to measure the average children’s blood lead level shift and detect the seasonal pattern change. Our results showed that there were three intervention stages over the past 20 years to reduce children’s BLLs in the city of Syracuse, NY. The average of children’s BLLs was significantly decreased after the interventions, declining from 8.77μg/dL to 3.94μg/dL during1992 to 2011. The seasonal variation diminished over the past decade, but more short term influences were in the variation. The lead hazard control treatment intervention proved effective in reducing the children’s blood lead levels in Syracuse, NY. Also, the reduction of the seasonal variation of children’s BLLs reflected the impacts of the local lead-based paint mitigation program. The replacement of window and door was the major cost of lead house abatement. However, soil lead was not considered a major source of lead hazard in our analysis. PMID:28182688

Interrupted time series analysis of children's blood lead levels: A case study of lead hazard control program in Syracuse, New York.

PubMed

Shao, Liyang; Zhang, Lianjun; Zhen, Zhen

2017-01-01

Children's blood lead concentrations have been closely monitored over the last two decades in the United States. The bio-monitoring surveillance data collected in local agencies reflected the local temporal trends of children's blood lead levels (BLLs). However, the analysis and modeling of the long-term time series of BLLs have rarely been reported. We attempted to quantify the long-term trends of children's BLLs in the city of Syracuse, New York and evaluate the impacts of local lead poisoning prevention programs and Lead Hazard Control Program on reducing the children's BLLs. We applied interrupted time series analysis on the monthly time series of BLLs surveillance data and used ARMA (autoregressive and moving average) models to measure the average children's blood lead level shift and detect the seasonal pattern change. Our results showed that there were three intervention stages over the past 20 years to reduce children's BLLs in the city of Syracuse, NY. The average of children's BLLs was significantly decreased after the interventions, declining from 8.77μg/dL to 3.94μg/dL during1992 to 2011. The seasonal variation diminished over the past decade, but more short term influences were in the variation. The lead hazard control treatment intervention proved effective in reducing the children's blood lead levels in Syracuse, NY. Also, the reduction of the seasonal variation of children's BLLs reflected the impacts of the local lead-based paint mitigation program. The replacement of window and door was the major cost of lead house abatement. However, soil lead was not considered a major source of lead hazard in our analysis.

THE CELESTIAL REFERENCE FRAME AT 24 AND 43 GHz. II. IMAGING

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

Charlot, P.; Boboltz, D. A.; Fey, A. L.

2010-05-15

We have measured the submilliarcsecond structure of 274 extragalactic sources at 24 and 43 GHz in order to assess their astrometric suitability for use in a high-frequency celestial reference frame (CRF). Ten sessions of observations with the Very Long Baseline Array have been conducted over the course of {approx}5 years, with a total of 1339 images produced for the 274 sources. There are several quantities that can be used to characterize the impact of intrinsic source structure on astrometric observations including the source flux density, the flux density variability, the source structure index, the source compactness, and the compactness variability.more » A detailed analysis of these imaging quantities shows that (1) our selection of compact sources from 8.4 GHz catalogs yielded sources with flux densities, averaged over the sessions in which each source was observed, of about 1 Jy at both 24 and 43 GHz, (2) on average the source flux densities at 24 GHz varied by 20%-25% relative to their mean values, with variations in the session-to-session flux density scale being less than 10%, (3) sources were found to be more compact with less intrinsic structure at higher frequencies, and (4) variations of the core radio emission relative to the total flux density of the source are less than 8% on average at 24 GHz. We conclude that the reduction in the effects due to source structure gained by observing at higher frequencies will result in an improved CRF and a pool of high-quality fiducial reference points for use in spacecraft navigation over the next decade.« less

Spatial distribution and metal contamination in the coastal sediments of Al-Khafji area, Arabian Gulf, Saudi Arabia.

PubMed

Alharbi, Talal; Alfaifi, Hussain; Almadani, Sattam A; El-Sorogy, Abdelbaset

2017-11-13

To document the spatial distribution and metal contamination in the coastal sediments of the Al-Khafji area in the northern part of the Saudi Arabian Gulf, 27 samples were collected for Al, V, Cr, Mn, Cu, Zn, Cd, Pb, Hg, Sr, As, Fe, Co, and Ni analysis using inductively coupled plasma-mass spectrometer (ICP-MS). The results revealed the following descending order of the metal concentrations: Sr > Fe > Al > As > Mn > Ni > V > Zn > Cr > Cu > Pb > Co > Hg > Cd. Average levels of enrichment factor of Sr, As, Hg, Cd, Ni, V, Cu, Co, and Pb were higher than 2 (218.10, 128.50, 80.94, 41.50, 12.31, 5.66, 2.95, 2.90, and 2.85, respectively) and that means the anthropogenic sources of these metals, while Al, Zn, Cr and Mn have enrichment factor less than 2, which implies natural sources. Average values of Sr, Hg, Cd, Cr, Ni, and As in the coastal sediments of Al-Khafji area were mostly higher than the values recorded from the background shale and earth crust and from those results along coasts of the Caspian Sea and the Mediterranean Sea. The highest levels of Cu in the northern part of the studied coastline might be due to Al-Khafji desalination plant, while levels of Al, Ni, Cr, Fe, Mn, Pb, and Zn in the central part may be a result of landfilling and industrial sewage. The highest levels of As, Cd, Co, Cu, Hg, and V in the southern part seem to be due to oil pollutants from Khafji Joint Operations (KJO). The higher values of Sr in the studied sediments in general and particularly in locality 7 could relate to the hypersalinity and aragonitic composition of the scleractinian corals abundant in that area.

Earthquake stress via event ratio levels: Application to the 2011 and 2016 Oklahoma seismic sequences

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

Walter, William R.; Yoo, Seung -Hoon; Mayeda, Kevin

Here, we develop a new methodology for determining earthquake stress drop and apparent stress values via spectral ratio asymptotic levels. With sufficient bandwidth, the stress ratio for a pair of events can be directly related to these low- and high-frequency levels. This avoids the need to assume a particular spectral model and derive stress drop from cubed corner frequency measures. The method can be applied to spectral ratios for any pair of closely related earthquakes and is particularly well suited for coda envelope methods that provide good azimuthally averaged, point-source measures. We apply the new method to the 2011 Praguemore » and 2016 Pawnee earthquake sequences in Oklahoma. The sequences show stress scaling with size and depth, with the largest events having apparent stress levels near 1 MPa and smaller and/or shallower events having systematically lower stress values.« less

Earthquake stress via event ratio levels: Application to the 2011 and 2016 Oklahoma seismic sequences

DOE PAGES

Walter, William R.; Yoo, Seung -Hoon; Mayeda, Kevin; ...

2017-04-03

Here, we develop a new methodology for determining earthquake stress drop and apparent stress values via spectral ratio asymptotic levels. With sufficient bandwidth, the stress ratio for a pair of events can be directly related to these low- and high-frequency levels. This avoids the need to assume a particular spectral model and derive stress drop from cubed corner frequency measures. The method can be applied to spectral ratios for any pair of closely related earthquakes and is particularly well suited for coda envelope methods that provide good azimuthally averaged, point-source measures. We apply the new method to the 2011 Praguemore » and 2016 Pawnee earthquake sequences in Oklahoma. The sequences show stress scaling with size and depth, with the largest events having apparent stress levels near 1 MPa and smaller and/or shallower events having systematically lower stress values.« less

Evaluation of noise level in architecture department building in University of Sumatera Utara

NASA Astrophysics Data System (ADS)

Amran, Novrial; Damanik, Novita Hillary Christy

2018-03-01

Noise is one the comfort factors that need to be noticed, particularly in an educational environment. Hearing a high noise in a period can affect students’ learning performance. The aims of this study were to know the noise level and get an appropriate design to reduce noise in Architecture Department building in the University of Sumatera Utara, considering that architecture students often spend most of their time inside the room. The measurement was conducted in four rooms for two days each from 09:00 – 12:00 and from 13:00 – 16:00 by using Sound Level Meter that placed near the noise source of the room. The result indicated that the average of noise level exceeded the 55 dB(A) so it still needs the appropriate design to reduce the noise that occurs in the building.

Combustion of available fossil fuel resources sufficient to eliminate the Antarctic Ice Sheet

PubMed Central

Winkelmann, Ricarda; Levermann, Anders; Ridgwell, Andy; Caldeira, Ken

2015-01-01

The Antarctic Ice Sheet stores water equivalent to 58 m in global sea-level rise. We show in simulations using the Parallel Ice Sheet Model that burning the currently attainable fossil fuel resources is sufficient to eliminate the ice sheet. With cumulative fossil fuel emissions of 10,000 gigatonnes of carbon (GtC), Antarctica is projected to become almost ice-free with an average contribution to sea-level rise exceeding 3 m per century during the first millennium. Consistent with recent observations and simulations, the West Antarctic Ice Sheet becomes unstable with 600 to 800 GtC of additional carbon emissions. Beyond this additional carbon release, the destabilization of ice basins in both West and East Antarctica results in a threshold increase in global sea level. Unabated carbon emissions thus threaten the Antarctic Ice Sheet in its entirety with associated sea-level rise that far exceeds that of all other possible sources. PMID:26601273

Combustion of available fossil-fuel resources sufficient to eliminate the Antarctic Ice Sheet

NASA Astrophysics Data System (ADS)

Winkelmann, R.; Levermann, A.; Ridgwell, A.; Caldeira, K.

2015-12-01

The Antarctic Ice Sheet stores water equivalent to 58 meters in global sea-level rise. Here we show in simulations with the Parallel Ice Sheet Model that burning the currently attainable fossil-fuel resources is sufficient to eliminate the ice sheet. With cumulative fossil-fuel emissions of 10 000 GtC, Antarctica is projected to become almost ice-free with an average contribution to sea-level rise exceeding 3 meters per century during the first millennium. Consistent with recent observations and simulations, the West Antarctic Ice Sheet becomes unstable with 600 to 800 GtC of additional carbon emissions. Beyond this additional carbon release, the destabilization of ice basins in both West- and East Antarctica results in a threshold-increase in global sea level. Unabated carbon emissions thus threaten the Antarctic Ice Sheet in its entirety with associated sea-level rise that far exceeds that of all other possible sources.

Combustion of available fossil fuel resources sufficient to eliminate the Antarctic Ice Sheet.

PubMed

Winkelmann, Ricarda; Levermann, Anders; Ridgwell, Andy; Caldeira, Ken

2015-09-01

The Antarctic Ice Sheet stores water equivalent to 58 m in global sea-level rise. We show in simulations using the Parallel Ice Sheet Model that burning the currently attainable fossil fuel resources is sufficient to eliminate the ice sheet. With cumulative fossil fuel emissions of 10,000 gigatonnes of carbon (GtC), Antarctica is projected to become almost ice-free with an average contribution to sea-level rise exceeding 3 m per century during the first millennium. Consistent with recent observations and simulations, the West Antarctic Ice Sheet becomes unstable with 600 to 800 GtC of additional carbon emissions. Beyond this additional carbon release, the destabilization of ice basins in both West and East Antarctica results in a threshold increase in global sea level. Unabated carbon emissions thus threaten the Antarctic Ice Sheet in its entirety with associated sea-level rise that far exceeds that of all other possible sources.

Line profiles and turbulence generated by acoustic waves in the solar chromosphere. II - Contours of the Ca II and Mg II K lines

NASA Technical Reports Server (NTRS)

Shine, R. A.; Oster, L.

1973-01-01

Making use of the time-averaged absorption profiles derived by Oster and Ulmschneider, non-LTE line formation in the context of a two-level atom is investigated for an isothermal atmosphere and for the Ca II and Mg II K lines in the solar chromosphere as represented by the Harvard-Smithsonian Reference Atmosphere. Source functions and emergent line profiles are computed for a variety of assumptions concerning the acoustically broadened profiles and the solar velocity fields.

Rapid Evaluation of Radioactive Contamination in Rare Earth Mine Mining

NASA Astrophysics Data System (ADS)

Wang, N.

2017-12-01

In order to estimate the current levels of environmental radioactivity in Bayan Obo rare earth mine and to study the rapid evaluation methods of radioactivity contamination in the rare earth mine, the surveys of the in-situ gamma-ray spectrometry and gamma dose rate measurement were carried out around the mining area and living area. The in-situ gamma-ray spectrometer was composed of a scintillation detector of NaI(Tl) (Φ75mm×75mm) and a multichannel analyzer. Our survey results in Bayan Obo Mine display: (1) Thorium-232 is the radioactive contamination source of this region, and uranium-238 and potassium - 40 is at the background level. (2) The average content of thorium-232 in the slag of the tailings dam in Bayan Obo is as high as 276 mg/kg, which is 37 times as the global average value of thorium content. (3) We found that the thorium-232 content in the soil in the living area near the mining is higher than that in the local soil in Guyang County. The average thorium-232 concentrations in the mining areas of the Bayan Obo Mine and the living areas of the Bayan Obo Town were 18.7±7.5 and 26.2±9.1 mg/kg, respectively. (4) It was observed that thorium-232 was abnormal distributed in the contaminated area near the tailings dam. Our preliminary research results show that the in-situ gamma-ray spectrometry is an effective approach of fast evaluating rare earths radioactive pollution, not only can the scene to determine the types of radioactive contamination source, but also to measure the radioactivity concentration of thorium and uranium in soil. The environmental radioactive evaluation of rare earth ore and tailings dam in open-pit mining is also needed. The research was supported by National Natural Science Foundation of China (No. 41674111).

Heavy metals in soils of Hechuan County in the upper Yangtze (SW China): Comparative pollution assessment using multiple indices with high-spatial-resolution sampling.

PubMed

Ni, Maofei; Mao, Rong; Jia, Zhongmin; Dong, Ruozhu; Li, Siyue

2018-02-01

In order to assess heavy metals (HMs) in soils of the upper Yangtze Basin, a very high-spatial-resolution sampling (582 soil samples) was conducted from Hechuan County, an important agricultural practice area in the Southwest China. Multiple indices including geoaccumulation index (I geo ), enrichment factor (EF), sediment pollution index (SPI) and risk index (RI), as well as multivariate statistics were employed for pollution assessment and source identification of HMs in soils. Our results demonstrated that the averages of eight HMs decreased in the following order: Zn (82.8 ± 15.9) > Cr (71.6 ± 12.2) > Ni (32.1 ± 9.89) > Pb (27.6 ± 13.8) > Cu (25.9 ± 11.8) > As (5.48 ± 3.42) > Cd (0.30 ± 0.077) > Hg (0.082 ± 0.092). Averages of HMs except Cd were lower than threshold value of Environmental Quality Standard for Soils, while 43% of total samples had Cd concentration exceeding the national standard, 1% of samples for Hg and 5% samples for Ni, moreover, Cd and Hg averages were much higher than their background levels. I geo and EF indicated that their levels decreased as follows: Cd > Hg > Zn > Pb > Ni > Cu > Cr > As, with moderate enrichments of Cd and Hg. RI indicated that 61.7% of all samples showed moderate risk, while 6.5% of samples with greater than considerable risk due to human activities should be paid more attention. Multivariate analysis showed lithogenic source of Cu, Cr, Ni and Zn, while Cd and Hg were largely contributed by anthropogenic activities such as agricultural practices. Our study would be helpful for improving soil environmental quality in SW, China, as well as supplying modern approaches for other areas with soil HM pollution. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of demographic factors and information sources on United States consumer perceptions of animal welfare.

PubMed

McKendree, M G S; Croney, C C; Widmar, N J O

2014-07-01

As consumers have become more interested in understanding how their food is produced, scrutiny and criticism have increased regarding intensified food animal production methods. Resolution of public concerns about animal agricultural practices depends on understanding the myriad factors that provide the basis for concerns. An online survey of 798 U.S. households was conducted to investigate relationships between household characteristics (demographics, geographic location, and experiences) and level of concern for animal welfare as well as sources used to obtain information on the subject. Because recent media attention has focused on animal care practices used in the U.S. swine industry, respondents were also asked specific questions pertaining to their perceptions of pig management practices and welfare issues and their corresponding pork purchasing behavior. Respondents reporting higher levels of concern about animal welfare were more frequently female, younger, and self-reported members of the Democratic Party. Fourteen percent of respondents reported reduction in pork consumption because of animal welfare concerns with an average reduction of 56%. Over half of the respondents (56%) did not have a primary source for animal welfare information; those who identified a primary information source most commonly used information provided by animal protection organizations, the Humane Society of the United States (HSUS), and People for the Ethical Treatment of Animals (PETA). Midwest participants were significantly, at the 5% significance level, less concerned about domestic livestock animal welfare and more frequently reported not having a source for animal welfare information than those from other regions of the United States. Overall, the U.S. livestock and poultry industries and other organizations affiliated with animal agriculture appear to be less used public sources of information on animal welfare than popular animal protection organizations. Improved understanding of the factors that contribute to consumers' evolving perceptions of the care and welfare of farm animals is an essential step toward enhanced sustainability and social responsibility in contemporary food production systems.

A Critical Review of Naphthalene Sources and Exposures Relevant to Indoor and Outdoor Air

PubMed Central

Jia, Chunrong; Batterman, Stuart

2010-01-01

Both the recent classification of naphthalene as a possible human carcinogen and its ubiquitous presence motivate this critical review of naphthalene’s sources and exposures. We evaluate the environmental literature on naphthalene published since 1990, drawing on nearly 150 studies that report emissions and concentrations in indoor, outdoor and personal air. While naphthalene is both a volatile organic compound and a polycyclic aromatic hydrocarbon, concentrations and exposures are poorly characterized relative to many other pollutants. Most airborne emissions result from combustion, and key sources include industry, open burning, tailpipe emissions, and cigarettes. The second largest source is off-gassing, specifically from naphthalene’s use as a deodorizer, repellent and fumigant. In the U.S., naphthalene’s use as a moth repellant has been reduced in favor of para-dichlorobenzene, but extensive use continues in mothballs, which appears responsible for some of the highest indoor exposures, along with off-label uses. Among the studies judged to be representative, average concentrations ranged from 0.18 to 1.7 μg m−3 in non-smoker’s homes, and from 0.02 to 0.31 μg m−3 outdoors in urban areas. Personal exposures have been reported in only three European studies. Indoor sources are the major contributor to (non-occupational) exposure. While its central tendencies fall well below guideline levels relevant to acute health impacts, several studies have reported maximum concentrations exceeding 100 μg m−3, far above guideline levels. Using current but draft estimates of cancer risks, naphthalene is a major environmental risk driver, with typical individual risk levels in the 10−4 range, which is high and notable given that millions of individuals are exposed. Several factors influence indoor and outdoor concentrations, but the literature is inconsistent on their effects. Further investigation is needed to better characterize naphthalene’s sources and exposures, especially for indoor and personal measurements. PMID:20717549

Monitoring alert and drowsy states by modeling EEG source nonstationarity

NASA Astrophysics Data System (ADS)

Hsu, Sheng-Hsiou; Jung, Tzyy-Ping

2017-10-01

Objective. As a human brain performs various cognitive functions within ever-changing environments, states of the brain characterized by recorded brain activities such as electroencephalogram (EEG) are inevitably nonstationary. The challenges of analyzing the nonstationary EEG signals include finding neurocognitive sources that underlie different brain states and using EEG data to quantitatively assess the state changes. Approach. This study hypothesizes that brain activities under different states, e.g. levels of alertness, can be modeled as distinct compositions of statistically independent sources using independent component analysis (ICA). This study presents a framework to quantitatively assess the EEG source nonstationarity and estimate levels of alertness. The framework was tested against EEG data collected from 10 subjects performing a sustained-attention task in a driving simulator. Main results. Empirical results illustrate that EEG signals under alert versus drowsy states, indexed by reaction speeds to driving challenges, can be characterized by distinct ICA models. By quantifying the goodness-of-fit of each ICA model to the EEG data using the model deviation index (MDI), we found that MDIs were significantly correlated with the reaction speeds (r  =  -0.390 with alertness models and r  =  0.449 with drowsiness models) and the opposite correlations indicated that the two models accounted for sources in the alert and drowsy states, respectively. Based on the observed source nonstationarity, this study also proposes an online framework using a subject-specific ICA model trained with an initial (alert) state to track the level of alertness. For classification of alert against drowsy states, the proposed online framework achieved an averaged area-under-curve of 0.745 and compared favorably with a classic power-based approach. Significance. This ICA-based framework provides a new way to study changes of brain states and can be applied to monitoring cognitive or mental states of human operators in attention-critical settings or in passive brain-computer interfaces.

Sophisticated Clean Air Strategies Required to Mitigate Against Particulate Organic Pollution

PubMed Central

Grigas, T.; Ovadnevaite, J.; Ceburnis, D.; Moran, E.; McGovern, F. M.; Jennings, S. G.; O’Dowd, C.

2017-01-01

Since the 1980’s, measures mitigating the impact of transboundary air pollution have been implemented successfully as evidenced in the 1980–2014 record of atmospheric sulphur pollution over the NE-Atlantic, a key region for monitoring background northern-hemisphere pollution levels. The record reveals a 72–79% reduction in annual-average airborne sulphur pollution (SO4 and SO2, respectively) over the 35-year period. The NE-Atlantic, as observed from the Mace Head research station on the Irish coast, can be considered clean for 64% of the time during which sulphate dominates PM1 levels, contributing 42% of the mass, and for the remainder of the time, under polluted conditions, a carbonaceous (organic matter and Black Carbon) aerosol prevails, contributing 60% to 90% of the PM1 mass and exhibiting a trend whereby its contribution increases with increasing pollution levels. The carbonaceous aerosol is known to be diverse in source and nature and requires sophisticated air pollution policies underpinned by sophisticated characterisation and source apportionment capabilities to inform selective emissions-reduction strategies. Inauspiciously, however, this carbonaceous concoction is not measured in regulatory Air Quality networks. PMID:28303958

Study of MPLNET-Derived Aerosol Climatology over Kanpur, India, and Validation of CALIPSO Level 2 Version 3 Backscatter and Extinction Products

NASA Technical Reports Server (NTRS)

Misra, Amit; Tripathi, S. N.; Kaul, D. S.; Welton, Ellsworth J.

2012-01-01

The level 2 aerosol backscatter and extinction profiles from the NASA Micropulse Lidar Network (MPLNET) at Kanpur, India, have been studied from May 2009 to September 2010. Monthly averaged extinction profiles from MPLNET shows high extinction values near the surface during October March. Higher extinction values at altitudes of 24 km are observed from April to June, a period marked by frequent dust episodes. Version 3 level 2 Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) aerosol profile products have been compared with corresponding data from MPLNET over Kanpur for the above-mentioned period. Out of the available backscatter profiles, the16 profiles used in this study have time differences less than 3 h and distances less than 130 km. Among these profiles, four cases show good comparison above 400 m with R2 greater than 0.7. Comparison with AERONET data shows that the aerosol type is properly identified by the CALIOP algorithm. Cloud contamination is a possible source of error in the remaining cases of poor comparison. Another source of error is the improper backscatter-to-extinction ratio, which further affects the accuracy of extinction coefficient retrieval.

Residents’ Preferences for Household Kitchen Waste Source Separation Services in Beijing: A Choice Experiment Approach

PubMed Central

Yuan, Yalin; Yabe, Mitsuyasu

2014-01-01

A source separation program for household kitchen waste has been in place in Beijing since 2010. However, the participation rate of residents is far from satisfactory. This study was carried out to identify residents’ preferences based on an improved management strategy for household kitchen waste source separation. We determine the preferences of residents in an ad hoc sample, according to their age level, for source separation services and their marginal willingness to accept compensation for the service attributes. We used a multinomial logit model to analyze the data, collected from 394 residents in Haidian and Dongcheng districts of Beijing City through a choice experiment. The results show there are differences of preferences on the services attributes between young, middle, and old age residents. Low compensation is not a major factor to promote young and middle age residents accept the proposed separation services. However, on average, most of them prefer services with frequent, evening, plastic bag attributes and without instructor. This study indicates that there is a potential for local government to improve the current separation services accordingly. PMID:25546279

The Scaling of Broadband Shock-Associated Noise with Increasing Temperature

NASA Technical Reports Server (NTRS)

Miller, Steven A. E.

2013-01-01

A physical explanation for the saturation of broadband shock-associated noise (BBSAN) intensity with increasing jet stagnation temperature has eluded investigators. An explanation is proposed for this phenomenon with the use of an acoustic analogy. To isolate the relevant physics, the scaling of BBSAN peak intensity level at the sideline observer location is examined. The equivalent source within the framework of an acoustic analogy for BBSAN is based on local field quantities at shock wave shear layer interactions. The equivalent source combined with accurate calculations of the propagation of sound through the jet shear layer, using an adjoint vector Green's function solver of the linearized Euler equations, allows for predictions that retain the scaling with respect to stagnation pressure and allows for saturation of BBSAN with increasing stagnation temperature. The sources and vector Green's function have arguments involving the steady Reynolds- Averaged Navier-Stokes solution of the jet. It is proposed that saturation of BBSAN with increasing jet temperature occurs due to a balance between the amplication of the sound propagation through the shear layer and the source term scaling.

Arsenic and heavy metals contamination, risk assessment and their source in drinking water of the Mardan District, Khyber Pakhtunkhwa, Pakistan.

PubMed

Gul, Nida; Shah, Mohammad Tahir; Khan, Sardar; Khattak, Nimat Ullah; Muhammad, Said

2015-12-01

The present study was conducted to investigate the physico-chemical characteristics in drinking water of Mardan District, Pakistan. Furthermore, water quality was evaluated for the risk assessment of arsenic and heavy metals (HMs) and their contamination sources. Representative groundwater samples of shallow and deep sources were collected in the study area. These samples were analyzed for physical parameters, anions, light metals (LMs) and HMs. Results were compared with the drinking water guideline values set by the World Health Organization and the US Environmental Protection Agency. Average concentrations of anions, LMs and HMs were found within the maximum allowable contaminant levels except for bicarbonates, Fe, Cu, and Pb. Results revealed that hazard quotients >1 were observed for shallow groundwater for 10% samples only, suggesting potential health risk from water consumption. Correlation analysis and principal component analysis showed a relationship among various physico-chemical parameters in both shallow and deep groundwater. Statistical analyses suggested the geogenic and anthropogenic sources for possible enhancement of various physico-chemical parameters in the aquifer system of the study area.

Landslides and Volcanoes: Fingerprinting Erosional Processes on a tropical island, Dominica, Lesser Antilles

NASA Astrophysics Data System (ADS)

Tomenchok, K.; Hill, M.; Jimerson, C.; Talbot-Wendlandt, , H.; Schmidt, A.; Frey, H. M.

2017-12-01

With 9 active volcanic centers, frequent tropical storms, and widespread landslides, the topography of Dominica is rugged and dynamic. This study aims to fingerprint sediment source dynamics in this relatively unstudied region with fallout radionuclides, clay mineralogy, and acid-extractable grain coating concentration measured in detrital sediments. We also aim to measure basin average erosion rates and determine river incision rates into the underlying ignimbrites. Baseline data on the effects of volcanoes, landslides, land use, and topography in setting erosional dynamics will be established. We sampled outlets of 20 large (>10 km2) rivers as well as 11 points in the Roseau River watershed for a network analysis. Block and ash flows and ignimbrites underlie 89% of the study area. Steep topography (mean slope = 19.6˚) and high levels of rainfall (mean annual rainfall = 1981.41 mm) are consistent throughout the 89% forested island. 934 landslides affect 13% of the study area. We hypothesize that basin average parameters and landslide frequency will correlate with erosion rates and fallout radionuclide activities. In addition, we used topographic data and published ignimbrite ages to calculate river incision rates that ranged from 0.448 - 113.9 mm/yr in the north and 0.86 - 44 mm/yr in the south. Basin average erosion rates will be compared to incision rates to quantify differences between basin wide erosional and river incision processes. We will fingerprint sediment sources with 7Be, 210Pbex, and 137Cs, concentration of grain coatings, and clay mineralogy. We hypothesize that watersheds with erosion from stabilizing landslide scars will have high 7Be, low 210Pbex and 137Cs, low concentrations of grain coatings, and less weathered clays. Watersheds with river bank/scarp erosion or active landslides will have little 7Be, 210Pbex, and 137Cs, less weathered clays, and low concentrations of grain coatings. Watersheds with widespread surface erosion will have high activities, weathered clays, and high concentrations of grain coatings. We will correlate basin average statistics with measured fingerprints to provide a better understanding of sediment source dynamics in an understudied region of the world. With the potential for future landslides, further information will advance hazard mitigation in Dominica.

Processes Driving Natural Acidification of Western Pacific Coral Reef Waters

NASA Astrophysics Data System (ADS)

Shamberger, K. E.; Cohen, A. L.; Golbuu, Y.; McCorkle, D. C.; Lentz, S. J.; Barkley, H. C.

2013-12-01

Rising levels of atmospheric carbon dioxide (CO2) are acidifying the oceans, reducing seawater pH, aragonite saturation state (Ωar) and the availability of carbonate ions (CO32-) that calcifying organisms use to build coral reefs. Today's most extensive reef ecosystems are located where open ocean CO32- concentration ([CO32-]) and Ωar exceed 200 μmol kg-1 and 3.3, respectively. However, high rates of biogeochemical cycling and long residence times of water can result in carbonate chemistry conditions within coral reef systems that differ greatly from those of nearby open ocean waters. In the Palauan archipelago, water moving across the reef platform is altered by both biological and hydrographic processes that combine to produce seawater pH, Ωar, [CO32-] significantly lower than that of open ocean source water. Just inshore of the barrier reefs, average Ωar values are 0.2 to 0.3 and pH values are 0.02 to 0.03 lower than they are offshore, declining further as water moves across the back reef, lagoon and into the meandering bays and inlets that characterize the Rock Islands. In the Rock Island bays, coral communities inhabit seawater with average Ωar values of 2.7 or less, and as low as 1.9. Levels of Ωar as low as these are not predicted to occur in the western tropical Pacific open ocean until near the end of the century. Calcification by coral reef organisms is the principal biological process responsible for lowering Ωar and pH, accounting for 68 - 99 % of the difference in Ωar between offshore source water and reef water at our sites. However, in the Rock Island bays where Ωar is lowest, CO2 production by net respiration contributes between 17 - 30 % of the difference in Ωar between offshore source water and reef water. Furthermore, the residence time of seawater in the Rock Island bays is much longer than at the well flushed exposed sites, enabling calcification and respiration to drive Ωar to very low levels despite lower net ecosystem calcification rates in the Rock Island bays than on the barrier reef.

Estimating rupture distances without a rupture

USGS Publications Warehouse

Thompson, Eric M.; Worden, Charles

2017-01-01

Most ground motion prediction equations (GMPEs) require distances that are defined relative to a rupture model, such as the distance to the surface projection of the rupture (RJB) or the closest distance to the rupture plane (RRUP). There are a number of situations in which GMPEs are used where it is either necessary or advantageous to derive rupture distances from point-source distance metrics, such as hypocentral (RHYP) or epicentral (REPI) distance. For ShakeMap, it is necessary to provide an estimate of the shaking levels for events without rupture models, and before rupture models are available for events that eventually do have rupture models. In probabilistic seismic hazard analysis, it is often convenient to use point-source distances for gridded seismicity sources, particularly if a preferred orientation is unknown. This avoids the computationally cumbersome task of computing rupture-based distances for virtual rupture planes across all strikes and dips for each source. We derive average rupture distances conditioned on REPI, magnitude, and (optionally) back azimuth, for a variety of assumed seismological constraints. Additionally, we derive adjustment factors for GMPE standard deviations that reflect the added uncertainty in the ground motion estimation when point-source distances are used to estimate rupture distances.

Public Exposure from Indoor Radiofrequency Radiation in the City of Hebron, West Bank-Palestine.

PubMed

Lahham, Adnan; Sharabati, Afefeh; ALMasri, Hussien

2015-08-01

This work presents the results of measured indoor exposure levels to radiofrequency (RF) radiation emitting sources in one of the major cities in the West Bank-the city of Hebron. Investigated RF emitters include FM, TV broadcasting stations, mobile telephony base stations, cordless phones [Digital Enhanced Cordless Telecommunications (DECT)], and wireless local area networks (WLAN). Measurements of power density were conducted in 343 locations representing different site categories in the city. The maximum total power density found at any location was about 2.3 × 10 W m with a corresponding exposure quotient of about 0.01. This value is well below unity, indicating compliance with the guidelines of the International Commission on Non-ionizing Radiation Protection (ICNIRP). The average total exposure from all RF sources was 0.08 × 10 W m. The relative contributions from different sources to the total exposure in terms of exposure quotient were evaluated and found to be 46% from FM radio, 26% from GSM900, 15% from DECT phones, 9% from WLAN, 3% from unknown sources, and 1% from TV broadcasting. RF sources located outdoors contribute about 73% to the population exposure indoors.

Sound source identification and sound radiation modeling in a moving medium using the time-domain equivalent source method.

PubMed

Zhang, Xiao-Zheng; Bi, Chuan-Xing; Zhang, Yong-Bin; Xu, Liang

2015-05-01

Planar near-field acoustic holography has been successfully extended to reconstruct the sound field in a moving medium, however, the reconstructed field still contains the convection effect that might lead to the wrong identification of sound sources. In order to accurately identify sound sources in a moving medium, a time-domain equivalent source method is developed. In the method, the real source is replaced by a series of time-domain equivalent sources whose strengths are solved iteratively by utilizing the measured pressure and the known convective time-domain Green's function, and time averaging is used to reduce the instability in the iterative solving process. Since these solved equivalent source strengths are independent of the convection effect, they can be used not only to identify sound sources but also to model sound radiations in both moving and static media. Numerical simulations are performed to investigate the influence of noise on the solved equivalent source strengths and the effect of time averaging on reducing the instability, and to demonstrate the advantages of the proposed method on the source identification and sound radiation modeling.

A comparison of speciated atmospheric mercury at an urban center and an upwind rural location

USGS Publications Warehouse

Rutter, A.P.; Schauer, J.J.; Lough, G.C.; Snyder, D.C.; Kolb, C.J.; Von Klooster, S.; Rudolf, T.; Manolopoulos, H.; Olson, M.L.

2008-01-01

Gaseous elemental mercury (GEM), particulate mercury (PHg) and reactive gaseous mercury (RGM) were measured every other hour at a rural location in south central Wisconsin (Devil's Lake State Park, WI, USA) between April 2003 and March 2004, and at a predominantly downwind urban site in southeastern Wisconsin (Milwaukee, WI, USA) between June 2004 and May 2005. Annual averages of GEM, PHg, and RGM at the urban site were statistically higher than those measured at the rural site. Pollution roses of GEM and reactive mercury (RM; sum of PHg and RGM) at the rural and urban sites revealed the influences of point source emissions in surrounding counties that were consistent with the US EPA 1999 National Emission Inventory and the 2003-2005 US EPA Toxics Release Inventory. Source-receptor relationships at both sites were studied by quantifying the impacts of point sources on mercury concentrations. Time series of GEM, PHg, and RGM concentrations were sorted into two categories; time periods dominated by impacts from point sources, and time periods dominated by mercury from non-point sources. The analysis revealed average point source contributions to GEM, PHg, and RGM concentration measurements to be significant over the year long studies. At the rural site, contributions to annual average concentrations were: GEM (2%; 0.04 ng m-3); and, RM (48%; 5.7 pg m-3). At the urban site, contributions to annual average concentrations were: GEM (33%; 0.81 ng m-3); and, RM (64%; 13.8 pg m-3). ?? The Royal Society of Chemistry.

Suspended particulate matter in railway coaches

NASA Astrophysics Data System (ADS)

Leutwyler, M.; Siegmann, K.; Monn, Ch

Measurements of particles <10 μm (PM 10) and particle-bound polycyclic aromatic hydrocarbons (pPAH) were performed in different passenger train coaches between Zürich and Berne, the most busy intercity connection in Switzerland. All trains are electrified and the indoor air quality is regulated by a mechanical ventilation system. In the smoker sections, pPAH levels were on average about 250 ng m -3, PM 10 levels about 950 μg m -3. In the non-smoker section, pPAH levels were about 45 ng m -3 and PM 10 levels about 210 μg m -3. Our observations suggest that smoking is the most important source of pPAH and PM 10. The spatial variation within the coaches indicates that pPAHs spread out from the smoker compartments into the non-smoker compartments. For PM 10, resuspended material may also be a source of airborne PM 10 but the contribution within this non-stop connection with most of the passengers being seated all the time was probably small. The influence of outdoor PM 10 and pPAH on indoor levels was negligible. Both pollutants, pPAH and PM 10 were largely elevated in the smoker as well as in the non-smoker compartments. Despite this fact, a questionnaire on the quality of travelling showed that most of the passengers felt well and only a small proportion felt uneasy.

Assessment of Indoor Air Pollution in Homes with Infants

PubMed Central

Pickett, Anna Ruth; Bell, Michelle L.

2011-01-01

Infants spend most of their indoor time at home; however, residential air quality is poorly understood. We investigated the air quality of infants’ homes in the New England area of the U.S. Participants (N = 53) were parents of infants (0–6 months) who completed telephone surveys to identify potential pollutant sources in their residence. Carbon monoxide (CO), carbon dioxide (CO2), particulate matter with aerodynamic diameter ≤0.5 µm (PM0.5), and total volatile organic compounds (TVOCs) were measured in 10 homes over 4–7 days, and levels were compared with health-based guidelines. Pollutant levels varied substantially across homes and within homes with overall levels for some homes up to 20 times higher than for other homes. Average levels were 0.85 ppm, 663.2 ppm, 18.7 µg/m3, and 1626 µg/m3 for CO, CO2, PM0.5, and TVOCs, respectively. CO2, TVOCs, and PM0.5 levels exceeded health-based indoor air quality guidelines. Survey results suggest that nursery renovations and related potential pollutant sources may be associated with differences in urbanicity, income, and presence of older children with respiratory ailments, which could potentially confound health studies. While there are no standards for indoor residential air quality, our findings suggest that additional research is needed to assess indoor pollution exposure for infants, which may be a vulnerable population. PMID:22408586

A six-year descriptive analysis of hospitalisations for ambulatory care sensitive conditions among people born in refugee-source countries.

PubMed

Correa-Velez, Ignacio; Ansari, Zahid; Sundararajan, Vijaya; Brown, Kaye; Gifford, Sandra M

2007-10-03

Hospitalisation for ambulatory care sensitive conditions (ACSHs) has become a recognised tool to measure access to primary care. Timely and effective outpatient care is highly relevant to refugee populations given the past exposure to torture and trauma, and poor access to adequate health care in their countries of origin and during flight. Little is known about ACSHs among resettled refugee populations. With the aim of examining the hypothesis that people from refugee backgrounds have higher ACSHs than people born in the country of hospitalisation, this study analysed a six-year state-wide hospital discharge dataset to estimate ACSH rates for residents born in refugee-source countries and compared them with the Australia-born population. Hospital discharge data between 1 July 1998 and 30 June 2004 from the Victorian Admitted Episodes Dataset were used to assess ACSH rates among residents born in eight refugee-source countries, and compare them with the Australia-born average. Rate ratios and 95% confidence levels were used to illustrate these comparisons. Four categories of ambulatory care sensitive conditions were measured: total, acute, chronic and vaccine-preventable. Country of birth was used as a proxy indicator of refugee status. When compared with the Australia-born population, hospitalisations for total and acute ambulatory care sensitive conditions were lower among refugee-born persons over the six-year period. Chronic and vaccine-preventable ACSHs were largely similar between the two population groups. Contrary to our hypothesis, preventable hospitalisation rates among people born in refugee-source countries were no higher than Australia-born population averages. More research is needed to elucidate whether low rates of preventable hospitalisation indicate better health status, appropriate health habits, timely and effective care-seeking behaviour and outpatient care, or overall low levels of health care-seeking due to other more pressing needs during the initial period of resettlement. It is important to unpack dimensions of health status and health care access in refugee populations through ad-hoc surveys as the refugee population is not a homogenous group despite sharing a common experience of forced displacement and violence-related trauma.

Temporal variation of fine and coarse particulate matter sources in Jeddah, Saudi Arabia

PubMed Central

Lim, Chris C.; Thurston, George D.; Shamy, Magdy; Alghamdi, Mansour; Khoder, Mamdouh; Mohorjy, Abdullah M.; Alkhalaf, Abdulrahman K.; Brocato, Jason; Chen, Lung Chi; Costa, Max

2017-01-01

This study provides the first comprehensive analysis of the seasonal variations and weekday/weekend differences in fine (PM2.5) and coarse (PM2.5–10) particulate matter mass concentrations, elemental constituents, and potential source origins in Jeddah, Saudi Arabia. Air quality samples were collected over one year, from June 2011 to May 2012 at a frequency of three times per week, and analyzed. The average mass concentrations of PM2.5 (21.9 µg/m3) and PM10 (107.8 µg/m3) during the sampling period exceeded the recommended annual average levels by the World Health Organization (WHO) for PM2.5 (10 µg/m3) and PM10 (20 µg/m3), respectively. Similar to other Middle Eastern locales, PM2.5–10 is the prevailing mass component of atmospheric particulate matter at Jeddah, accounting for approximately 80% of the PM10 mass. Considerations of enrichment factors, absolute principal component analysis (APCA), concentration roses, and backward trajectories identified the following source categories for both PM2.5 and PM2.5–10: 1) soil/road dust; 2) incineration; and 3) traffic; and for PM2.5 only, 4) residual oil burning. Soil/road dust accounted for a major portion of both the PM2.5 (27%) and PM2.5–10 (77%) mass, and the largest source contributor for PM2.5 was from residual oil burning (63%). Temporal variations of PM2.5–10 and PM2.5 were observed, with the elevated concentration levels observed for mass during the spring (due to increased dust storm frequency), and on weekdays (due to increased traffic). The predominant role of windblown soil and road dust in both the PM2.5 and PM2.5–10 masses in this city may have implications regarding the toxicity of these particles versus those in the western world where most PM health assessments have been made in the past. These results support the need for region-specific epidemiological investigations to be conducted and considered in future PM standard setting. PMID:28635552

Human Excreta as a Stable and Important Source of Atmospheric Ammonia in the Megacity of Shanghai

PubMed Central

Chang, Yunhua; Deng, Congrui; Dore, Anthony J.; Zhuang, Guoshun

2015-01-01

Although human excreta as a NH3 source has been recognized globally, this source has never been quantitatively determined in cities, hampering efforts to fully assess the causes of urban air pollution. In the present study, the exhausts of 15 ceiling ducts from collecting septic tanks in 13 buildings with 6 function types were selected to quantify NH3 emission rates in the megacity of Shanghai. As a comparison, the ambient NH3 concentrations across Shanghai were also measured at 13 atmospheric monitoring sites. The concentrations of NH3 in the ceiling ducts (2809−2661+5803 μg m-3) outweigh those of the open air (~10 μg m-3) by 2–3 orders of magnitude, and there is no significant difference between different seasons. δ15N values of NH3 emitted from two ceiling ducts are also seasonally consistent, suggesting that human excreta may be a stable source of NH3 in urban areas. The NH3 concentration levels were variable and dependent on the different building types and the level of human activity. NH3 emission rates of the six residential buildings (RBNH3) were in agreement with each other. Taking occupation time into account, we confined the range of the average NH3 emission factor for human excreta to be 2–4 times (with the best estimate of 3 times) of the averaged RBNH3 of 66.0±58.9 g NH3 capita-1 yr-1. With this emission factor, the population of ~21 million people living in the urban areas of Shanghai annually emitted approximately 1386 Mg NH3, which corresponds to over 11.4% of the total NH3 emissions in the Shanghai urban areas. The spatial distribution of NH3 emissions from human excreta based on population data was calculated for the city of Shanghai at a high-resolution (100×100 m). Our results demonstrate that human excreta should be included in official ammonia emission inventories. PMID:26656636

Kinetic parameters and renal clearances of plasma adenosine 3′,5′-monophosphate and guanosine 3′,5′-monophosphate in man

PubMed Central

Broadus, Arthur E.; Kaminsky, Neil I.; Hardman, Joel G.; Sutherland, Earl W.; Liddle, Grant W.

1970-01-01

Kinetic parameters and the renal clearances of plasma adenosine 3′,5′-monophosphate (cyclic AMP) and guanosine 3′,5′-monophosphate (cyclic GMP) were evaluated in normal subjects using tritium-labeled cyclic nucleotides. Each tracer was administered both by single, rapid intravenous injection and by constant intravenous infusion, and the specific activities of the cyclic nucleotides in plasma and urine were determined. Both cyclic AMP and cyclic GMP were cleared from plasma by glomerular filtration. The kidney was found to add a variable quantity of endogenous cyclic AMP to the tubular urine, amounting to an average of approximately one-third of the total level of cyclic AMP excreted. Plasma was the source of virtually all of the cyclic GMP excreted. Plasma levels of the cyclic nucleotides appeared to be in dynamic steady state. The apparent volumes of distribution of both nucleotides exceeded extracellular fluid volume, averaging 27 and 38% of body weight for cyclic AMP and cyclic GMP, respectively. Plasma production rates ranged from 9 to 17 nmoles/min for cyclic AMP and from 7 to 13 nmoles/min for cyclic GMP. Plasma clearance rates averaged 668 ml/min for cyclic AMP and 855 ml/min for cyclic GMP. Approximately 85% of the elimination of the cyclic nucleotides from the circulation was due to extrarenal clearance. PMID:5480849