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1

Ground vegetation monitoring in Swiss forests: comparison of survey methods and implications for trend assessments  

Microsoft Academic Search

At Swiss long-term forest ecosystem research sites, ground vegetation was assessed during the period 1994–2003\\/2008 following\\u000a two approaches: (1) visual assessment of the cover of species occurring in sixteen 1 m2 quadrats, distributed over a 43 × 43 m area, and (2) phytosociological relevés in concentric circular plots of 30, 200, and\\u000a 500 m2. We first compared the two approaches with respect to

Anne Thimonier; Peter Kull; Walter Keller; Barbara Moser; Thomas Wohlgemuth

2011-01-01

2

METHOD OF LOCATING GROUNDS  

DOEpatents

ABS>This patent presents a method for locating a ground in a d-c circult having a number of parallel branches connected across a d-c source or generator. The complete method comprises the steps of locating the ground with reference to the mildpoint of the parallel branches by connecting a potentiometer across the terminals of the circuit and connecting the slider of the potentiometer to ground through a current indicating instrument, adjusting the slider to right or left of the mildpoint so as to cause the instrument to indicate zero, connecting the terminal of the network which is farthest from the ground as thus indicated by the potentiometer to ground through a condenser, impressing a ripple voltage on the circuit, and then measuring the ripple voltage at the midpoint of each parallel branch to find the branch in which is the lowest value of ripple voltage, and then measuring the distribution of the ripple voltage along this branch to determine the point at which the ripple voltage drops off to zero or substantially zero due to the existence of a ground. The invention has particular application where a circuit ground is present which will disappear if the normal circuit voltage is removed.

Macleish, K.G.

1958-02-11

3

Site survey method and apparatus  

DOEpatents

The disclosure of the invention is directed to a site survey ground vehicle based apparatus and method for automatically detecting source materials, such as radioactivity, marking the location of the source materials, such as with paint, and mapping the location of the source materials on a site. The apparatus of the invention is also useful for collecting and analyzing samples. The apparatus includes a ground vehicle, detectors mounted at the front of the ground vehicle, and individual detector supports which follow somewhat irregular terrain to allow consistent and accurate detection, and autolocation equipment.

Oldham, James G. (Albuquerque, NM); Spencer, Charles R. (Boise, ID); Begley, Carl L. (Albuquerque, NM); Meyer, H. Robert (Albuquerque, NM)

1991-06-18

4

Site survey method and apparatus  

DOEpatents

The disclosure of the invention is directed to a site survey ground vehicle based apparatus and method for automatically detecting source materials, such as radioactivity, marking the location of the source materials, such as with paint, and mapping the location of the source materials on a site. The apparatus of the invention is also useful for collecting and analyzing samples. The apparatus includes a ground vehicle, detectors mounted at the front of the ground vehicle, and individual detector supports which follow somewhat irregular terrain to allow consistent and accurate detection, and autolocation equipment. 19 figures.

Oldham, J.G.; Spencer, C.R.; Begley, C.L.; Meyer, H.R.

1991-06-18

5

618-11 Burial Ground USRADS radiological surveys  

Microsoft Academic Search

This report summarizes and documents the results of the radiological surveys conducted from February 4 through February 10, 1993 over the 618-11 Burial Ground, Hanford Site, Richland, Washington. In addition, this report explains the survey methodology using the Ultrasonic Ranging and Data System (USRADS). The 618-11 Burial Ground radiological survey field task consisted of two activities: characterization of the specific

Wendling

1994-01-01

6

618-10 Burial Ground USRADS radiological surveys  

Microsoft Academic Search

This report summarizes and documents the results of the radiological surveys conducted from February 11 through February 17 and March 30, 1993 over the 618-10 Burial Ground, Hanford Site, Richland, Washington. In addition, this report explains the survey methodology using the Ultrasonic Ranging and Data System (USRADS). The 618-10 Burial Ground radiological survey field task consisted of two activities: characterization

Wendling

1994-01-01

7

618-10 Burial Ground USRADS radiological surveys.  

National Technical Information Service (NTIS)

This report summarizes and documents the results of the radiological surveys conducted from February 11 through February 17 and March 30, 1993 over the 618-10 Burial Ground, Hanford Site, Richland, Washington. In addition, this report explains the survey ...

M. Wendling

1994-01-01

8

618-11 Burial Ground USRADS radiological surveys.  

National Technical Information Service (NTIS)

This report summarizes and documents the results of the radiological surveys conducted from February 4 through February 10, 1993 over the 618-11 Burial Ground, Hanford Site, Richland, Washington. In addition, this report explains the survey methodology us...

M. A. Wendling

1994-01-01

9

Earthing - grounding methods: a primer  

Microsoft Academic Search

Grounding and its design is a complex subject encompassing personnel safety, lightning or static protection, electrical power system earthing and computer system grounding. One must define the purpose to be achieved, as each system may accomplish the objective by different means. The paper lists and defines the more common earthing-grounding terms. A brief history of early attempts at grounding electrical

D. W. Zipse

2002-01-01

10

618-11 Burial Ground USRADS radiological surveys  

SciTech Connect

This report summarizes and documents the results of the radiological surveys conducted from February 4 through February 10, 1993 over the 618-11 Burial Ground, Hanford Site, Richland, Washington. In addition, this report explains the survey methodology using the Ultrasonic Ranging and Data System (USRADS). The 618-11 Burial Ground radiological survey field task consisted of two activities: characterization of the specific background conditions and the radiological survey of the area. The radiological survey of the 618-11 Burial Ground, along with the background study, were conducted by Site Investigative Surveys Environmental Restoration Health Physics Organization of the Westinghouse Hanford Company. The survey methodology was based on utilization of the Ultrasonic Ranging and Data System (USRADS) for automated recording of the gross gamma radiation levels at or near six (6) inches and at three (3) feet from the surface soil.

Wendling, M.A.

1994-05-26

11

618-10 Burial Ground USRADS radiological surveys  

SciTech Connect

This report summarizes and documents the results of the radiological surveys conducted from February 11 through February 17 and March 30, 1993 over the 618-10 Burial Ground, Hanford Site, Richland, Washington. In addition, this report explains the survey methodology using the Ultrasonic Ranging and Data System (USRADS). The 618-10 Burial Ground radiological survey field task consisted of two activities: characterization of the specific background conditions and the radiological survey of the area. The radiological survey of the 618-10 Burial Ground, along with the background study, were conducted by Site Investigative Surveys Environmental Restoration Health Physics Organization of the Westinghouse Hanford Company. The survey methodology was based on utilization of the Ultrasonic Ranging and Data System (USRADS) for automated recording of the gross gamma radiation levels at or near six (6) inches and at three (3) feet from the surface soil.

Wendling, M.

1994-05-26

12

Ground-Cover Measurements: Assessing Correlation Among Aerial and Ground-Based Methods  

NASA Astrophysics Data System (ADS)

Wyoming’s Green Mountain Common Allotment is public land providing livestock forage, wildlife habitat, and unfenced solitude, amid other ecological services. It is also the center of ongoing debate over USDI Bureau of Land Management’s (BLM) adjudication of land uses. Monitoring resource use is a BLM responsibility, but conventional monitoring is inadequate for the vast areas encompassed in this and other public-land units. New monitoring methods are needed that will reduce monitoring costs. An understanding of data-set relationships among old and new methods is also needed. This study compared two conventional methods with two remote sensing methods using images captured from two meters and 100 meters above ground level from a camera stand (a ground, image-based method) and a light airplane (an aerial, image-based method). Image analysis used SamplePoint or VegMeasure software. Aerial methods allowed for increased sampling intensity at low cost relative to the time and travel required by ground methods. Costs to acquire the aerial imagery and measure ground cover on 162 aerial samples representing 9000 ha were less than 3000. The four highest correlations among data sets for bare ground—the ground-cover characteristic yielding the highest correlations (r)—ranged from 0.76 to 0.85 and included ground with ground, ground with aerial, and aerial with aerial data-set associations. We conclude that our aerial surveys are a cost-effective monitoring method, that ground with aerial data-set correlations can be equal to, or greater than those among ground-based data sets, and that bare ground should continue to be investigated and tested for use as a key indicator of rangeland health.

Booth, D. Terrance; Cox, Samuel E.; Meikle, Tim; Zuuring, Hans R.

2008-12-01

13

Ground-cover measurements: assessing correlation among aerial and ground-based methods.  

PubMed

Wyoming's Green Mountain Common Allotment is public land providing livestock forage, wildlife habitat, and unfenced solitude, amid other ecological services. It is also the center of ongoing debate over USDI Bureau of Land Management's (BLM) adjudication of land uses. Monitoring resource use is a BLM responsibility, but conventional monitoring is inadequate for the vast areas encompassed in this and other public-land units. New monitoring methods are needed that will reduce monitoring costs. An understanding of data-set relationships among old and new methods is also needed. This study compared two conventional methods with two remote sensing methods using images captured from two meters and 100 meters above ground level from a camera stand (a ground, image-based method) and a light airplane (an aerial, image-based method). Image analysis used SamplePoint or VegMeasure software. Aerial methods allowed for increased sampling intensity at low cost relative to the time and travel required by ground methods. Costs to acquire the aerial imagery and measure ground cover on 162 aerial samples representing 9000 ha were less than $3000. The four highest correlations among data sets for bare ground--the ground-cover characteristic yielding the highest correlations (r)--ranged from 0.76 to 0.85 and included ground with ground, ground with aerial, and aerial with aerial data-set associations. We conclude that our aerial surveys are a cost-effective monitoring method, that ground with aerial data-set correlations can be equal to, or greater than those among ground-based data sets, and that bare ground should continue to be investigated and tested for use as a key indicator of rangeland health. PMID:18446407

Booth, D Terrance; Cox, Samuel E; Meikle, Tim; Zuuring, Hans R

2008-04-30

14

Enhanced analysis methods to derive the spatial distribution of 131I deposition on the ground by airborne surveys at an early stage after the Fukushima Daiichi nuclear power plant accident.  

PubMed

This paper applies both new and well tested analysis methods to aerial radiological surveys to extract the I ground concentrations present after the March 2011 Fukushima Daiichi nuclear power plant (NPP) accident. The analysis provides a complete map of I deposition, an important quantity incalculable at the time of the accident due to the short half-life of I and the complexity of the analysis. A map of I deposition is the first step in conducting internal exposure assessments, population dose reconstruction, and follow-up epidemiological studies. The short half-life of I necessitates the use of aerial radiological surveys to cover the large area quickly, thoroughly, and safely. Teams from the U.S. Department of Energy National Nuclear Security Administration (DOE/NNSA) performed aerial radiological surveys to provide initial maps of the dispersal of radioactive material in Japan. This work reports on analyses performed on a subset of the initial survey data by a joint Japan-U.S. collaboration to determine I ground concentrations. The analytical results show a high concentration of I northwest of the NPP, consistent with the previously reported radioactive cesium deposition, but also shows a significant I concentration south of the plant, which was not observed in the original cesium analysis. The difference in the radioactive iodine and cesium patterns is possibly the result of differences in the ways these materials settle out of the air. PMID:23799504

Torii, Tatsuo; Sugita, Takeshi; Okada, Colin E; Reed, Michael S; Blumenthal, Daniel J

2013-08-01

15

Using grounded theory for method engineering  

Microsoft Academic Search

Grounded theory is a qualitative research approach that can be used to build theory from empirical data in an explorative fashion. Although the field of method engineering is a relatively mature research area, a lack of empirical grounding can be attested since method engineering is commonly based on literature reviews and follows a deductive, construction-ori ented engineering process. Particularly, the

Stefanie Looso; Rene Borner; Matthias Goeken

2011-01-01

16

Ground radan survey of a geothermal area in Hawaii  

SciTech Connect

Rates of ground radon emanation, in the Puna geothermal area on the lower east rift of Kilauea volcano, were measured by alpha particle sensitive cellulose nitrate films. The survey successfully defined an area of thermal significance associated with the rift structure, and suggests that a thermally driven ground gas convection system exists within, and peripheral to, the rift. This type of survey was found suitable for the basaltic island environmnet characteristic of Hawaii and is now used in Hawaii as a routine geothermal exploration technique.

Cox, M.E.

1980-04-01

17

Quantifying Stream Habitat: Relative Effort Versus Quality of Competing Remote Sensing & Ground-Based Survey Techniques  

NASA Astrophysics Data System (ADS)

Numerous field and analytical methods exist to assist in the quantification of the quantity and quality of in-stream habitat for salmonids. These methods range from field sketches or ‘tape and stick’ ground-based surveys, through to spatially explicit topographic and aerial photographic surveys from a mix of ground-based and remotely sensed airborne platforms. Although some investigators have assessed the quality of specific individual survey methods, the inter-comparison of competing techniques across a diverse range of habitat conditions (wadeable headwater channels to non-wadeable mainstem channels) has not yet been elucidated. In this study, we seek to quantify relative quality (i.e. accuracy, precision, extent) of habitat metrics and inventories derived from different ground-based and remotely sensed surveys of varying degrees of sophistication, as well as enumerate the effort and cost in completing the surveys. Over the summer of 2010, seven sample reaches of varying habitat complexity were surveyed in the Lemhi River Basin, Idaho, USA. Three different traditional (“stick and tape”) survey techniques were used, including a variant using map-grade GPS. Complete topographic/bathymetric surveys were attempted at each site using separate rtkGPS, total station, ground-based LiDaR, boat-based echo-sounding (w/ ADCP), traditional airborne LiDaR, and imagery-based spectral methods. Separate, georectified aerial imagery surveys were acquired using a tethered blimp, a drone UAV, and a traditional fixed-wing aircraft. Preliminary results from the surveys highlight that no single technique works across the full range of conditions where stream habitat surveys are needed. The results are helpful for understanding the strengths and weaknesses of each approach in specific conditions, and how a hybrid of data acquisition methods can be used to build a more complete quantification of habitat conditions in rivers.

Bangen, S. G.; Wheaton, J. M.; Bouwes, N.

2010-12-01

18

106. Historic American Buildings Survey ORIGINAL DRAWING OF GROUND FLOOR ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

106. Historic American Buildings Survey ORIGINAL DRAWING OF GROUND FLOOR PLAN PHOTOCOPY OF PLATE FROM IRVIN L. SCOTT, 'MARALAGO', THE AMERICAN ARCHITECT (JUNE 20, 1928), P. 798 - Mar-a-Lago, 1100 South Ocean Boulevard, Palm Beach, Palm Beach County, FL

19

Survey of ground antenna systems for solar power satellite application  

NASA Astrophysics Data System (ADS)

The purpose of this work is to survey ground based antenna systems, specifically rectifying antennas (rectennas) for space solar powered application of Microwave Wireless Power Transfer (MWPT). The ground rectenna along with its circuit components (a receiving antenna, an input Low-Pass Filter (LPF), a rectifying circuit, and an output smoothing filter) is the basic building block of the high-power receiving array that is designed to capture and then convert the microwave energy into Direct Current (DC). Once in DC form, the energy is used for various human applications on earth.

Bergsrud, Corey; Noghanian, Sima

20

Solar Flare Impulse Broadening from Gamma Ground Survey Network  

NASA Astrophysics Data System (ADS)

Inexpensive gamma detectors with GPS and wireless communications have been developed and installed to provide a ground survey network for detection of unintended gamma radiation along transport routes. Signals from pedestrian borne and vehicle borne radiation sources have pulse widths that range three orders of magnitude in time from millseconds to seconds. Information collected during the 24/7 operation of this network generated unexpected signals lasting over an hour. These longer time responses have been traced to solar flare events. This paper will discuss the time and intensity correlations with known satellite sensor data. These terrestrial gamma ray flashes will be analysed further as real-time data continues to be collected.

Litz, Marc; Burns, David; Carroll, James; Pereira, Nino

2012-03-01

21

40 CFR 141.401 - Sanitary surveys for ground water systems.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Sanitary surveys for ground water systems. 141.401 Section 141.401...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2013-07-01

22

Earthing-grounding methods: a primer  

Microsoft Academic Search

Grounding and its design is a complex subject encompassing personnel safety, lightning or static protection, electrical power system earthing and computer system grounding. One must define the purpose to be achieved, as each system may accomplish the objective by different means. The paper lists and defines the more common earthing-grounding terms. A brief history of early attempts at grounding electrical

Donald W. Zipse

2001-01-01

23

Galaxy Surveys in the Era of Large Ground-Based Telescopes  

Microsoft Academic Search

I review the observing strategies and recent results of various galaxy surveys over a wide range in redshift in the new era of large, ground-based telescopes. These surveys are compared to two major galaxy surveys currently being proposed for the GTC: OTELO and COSMOS. Both surveys focus on a region of the observational parameter space that has not been explored

R. Guzmán

2005-01-01

24

Space Station Freedom ground systems program - A survey  

NASA Astrophysics Data System (ADS)

The key facilities identified to support Space Station Freedom Program (SSFP) integrated operations and their SSFP roles are described in detail. The ground infrastructure, which must be able to support both assembly and long-term operations, will consist of ground facilities, support systems, and the associated planning and management procedures. During 1992 the SSFP is conducting a major program review of the ground infrastructure including the definition of all facility and support system functional capabilities, interfaces, and data-flow requirements. Operations functionality and interface verification tests are being identified, and operations readiness dates are being set.

Accola, A.; Paules, G.; Faulkner, J.; Giampalmo, G.; Kozawa, H.

1992-08-01

25

Eighth Conference on Health Survey Research Methods.  

National Technical Information Service (NTIS)

The purpose of this conference was to continue a series of conferences on health survey research methods that began in 1975, bringing together researchers from academic disciplines who conduct and use data from surveys, researchers and administrators from...

T. P. Johnson D. O'Rourke

2004-01-01

26

Magnetic ground survey of Slovakia for the 2007.5 epoch - accuracy of geomagnetic elements distribution maps  

NASA Astrophysics Data System (ADS)

Magnetic ground or repeat station surveys are performed to determine the geomagnetic field (GMF) spatial distribution, which is of great importance for scientific purposes as well as for many applications, for instance the aerial navigation. In for the information about the GMF distribution to be complete, the accuracy of the geomagnetic maps need to be known. It is a custom in the papers dealing with magnetic surveys that the precision of the instruments employed for the measurements are listed there. However, such information is not sufficient to answer the question about the quality of the geomagnetic maps because our experience shows that the spatial variations at a distance of several kilometers often exceed the precisions of the instruments. In the paper we proposed a simple method for the evaluation of the accuracy of the GMF distribution maps. We applied it to the maps which were the results of the magnetic ground survey carried out in Slovakia in the 2007.5 epoch. The method is based on the following procedure which is accomplished for each observation point of the magnetic ground survey network: A single point drops out of the data base, then the map is generated in a standard way, whereupon the observed value of the geomagnetic element for the dropped out observation point is compared with the value of the geomagnetic element which is determined from the map. Thus the image of the accuracy of the complete map can be tagged together for the surveyed territory

Dolinský, Peter; Valach, Fridrich; Váczyová, Magdaléna

2013-03-01

27

Ground water survey of the Texas Gulf Coastal Plain  

Microsoft Academic Search

The purpose of this investigation is to determine the availability of ground-water resources of the Gulf Coast Region, Texas, with particular reference to the sources of water suitable for the development of geothermal energy utilization for generation of electric power. For this purpose the availability of water resources is important for heat rejection. The expected characteristics of the geopressured geothermal

Gary K. Underhill; Ronald A. Carlson; William A. Clendinning; Jozsef Erdos; John Gault; James W. Hall; Robert L. Jones; Herbert K. Michael; Paul H. Powell; Carl F. Riemann; Lorenzo Rios-Castellon; Burchard P. Shepherd; John S. Wilson

1976-01-01

28

Research opportunities in interdisciplinary ground-water science in the U.S. Geological Survey  

USGS Publications Warehouse

This report is written for the scientifically literate reader but is not limited to those who are involved in ground-water science. The report is intended to encourage U.S. Geological Survey scientists to develop a sense of excitement about ground-water science in the agency, to inform scientists about existing and potential ground-water science opportunities, and to engage scientists and managers in interdisciplinary discussions and collaboration. The report is intended for use by U.S. Geological Survey and Department of the Interior management to formulate long-term ground-water science programs and to continue sustained support of ground-water monitoring and research, some of which may not have an immediate impact. Finally, the report can be used to communicate the U.S. Geological Survey's vision of ground-water science to Congress, partners, other agencies, and the research community at large with the goals of enhancing collaborative opportunities, sharing information, and maintaining dialogue regarding the directions of U.S. Geological Survey ground-water science.

Sanford, W. E.; Caine, J. S.; Wilcox, D. A.; McWreath, H. C.; Nicholas, J. R.

2006-01-01

29

NCES Handbook of Survey Methods.  

National Technical Information Service (NTIS)

This publication presents explanations of how each survey program in NCES obtains and prepares the data it publishes. The Handbook aims to provide users of NCES data with the information necessary to evaluate the suitability of the statistics for their ne...

2011-01-01

30

An analysis of the ground-penetrating radar direct ground wave method for soil water content measurement  

Microsoft Academic Search

The spatial variability of soil water content can be measured with the ground wave velocity of ground-penetrating radar (GPR) using short antenna offsets, but picking the correct ground wave arrival time is rather difficult. In applying the GPR ground wave method to soil water content estimation it is also important to know the effective sampling depth of the method. Uniform

L. W. Galagedara; G. W. Parkin; J. D. Redman

2003-01-01

31

GWM: A Ground-Water Management Process for the U.S. Geological Survey Modular Ground-Water Model (MODFLOW-2000).  

National Technical Information Service (NTIS)

GWM is a Ground-Water Management Process for the U.S. Geological Survey modular three-dimensional ground-water model, MODFLOW-2000. GWM uses a response-matrix approach to solve several types of linear, nonlinear, and mixed-binary linear ground-water manag...

D. P. Ahlfeld P. M. Barlow A. E. Mulligan

2005-01-01

32

Survey of rule extraction methods  

Microsoft Academic Search

Computational intelligence methods such as Artificial Neural Networks (ANN) are gaining popularity for their power and ease of use. ANN learning methods provide a robust and non-linear approach to approximating the target function for many classification, regression and clustering problems. The ability to learn and generalize from data, which mimics the human capability of learning from experience, makes ANNs a

Ahamed Salihe Kuttiyil

2004-01-01

33

The ground support computer and in-orbit survey data analysis program for the SEEP experiment  

Microsoft Academic Search

The ground support computer equipment (GSE) and production survey plot and analysis software are described for the Stimulated Emissions of Energetic Particles (SEEP) experiment on the S81-1 satellite. A general purpose satellite data acquisition circuit was developed based on a Z-80 portable microcomputer. By simply changing instrument control software and electrical connectors, automatic testing and control of the various SEEP

H. D. Voss; D. W. Datlowe; J. Mobilia; S. N. Roselle

1985-01-01

34

Airborne and Ground Electrical Surveys for Subsurface Mapping of the Arbuckle Aquifer, Central Oklahoma  

Microsoft Academic Search

Airborne and ground electrical surveys have been conducted to map the subsurface hydrogeologic character of the Arbuckle-Simpson aquifer in south central Oklahoma. An understanding of the geologic framework and hydrogeologic characteristics is necessary to evaluate groundwater flow through the highly faulted, structurally complex, carbonate aquifer. Results from this research will further understanding of the aquifer and will assist in managing

D. Smith; B. D. Smith; C. D. Blome; N. Osborn

2008-01-01

35

Hybrid Identification Method for Multistory Buildings with Unknown Ground Motion  

Microsoft Academic Search

Simultaneous identification of both structural parameters and ground motion of an earthquake-excited structure by using measured structural response time histories only has received great interests in recent years. A hybrid identification method is proposed in this paper for the problem concerned. The hybrid identification method first identifies the structural parameters above the first floor of a multi-story shear building using

Y. L. Xu; X. Zhao; J. Chen; J. Li

36

Exoplanets -New Results from Space and Ground-based Surveys  

NASA Astrophysics Data System (ADS)

The exploration of the outer solar system and in particular of the giant planets and their environments is an on-going process with the Cassini spacecraft currently around Saturn, the Juno mission to Jupiter preparing to depart and two large future space missions planned to launch in the 2020-2025 time frame for the Jupiter system and its satellites (Europa and Ganymede) on the one hand, and the Saturnian system and Titan on the other hand [1,2]. Titan, Saturn's largest satellite, is the only other object in our Solar system to possess an extensive nitrogen atmosphere, host to an active organic chemistry, based on the interaction of N2 with methane (CH4). Following the Voyager flyby in 1980, Titan has been intensely studied from the ground-based large telescopes (such as the Keck or the VLT) and by artificial satellites (such as the Infrared Space Observatory and the Hubble Space Telescope) for the past three decades. Prior to Cassini-Huygens, Titan's atmospheric composition was thus known to us from the Voyager missions and also through the explorations by the ISO. Our perception of Titan had thus greatly been enhanced accordingly, but many questions remained as to the nature of the haze surrounding the satellite and the composition of the surface. The recent revelations by the Cassini-Huygens mission have managed to surprise us with many discoveries [3-8] and have yet to reveal more of the interesting aspects of the satellite. The Cassini-Huygens mission to the Saturnian system has been an extraordinary success for the planetary community since the Saturn-Orbit-Insertion (SOI) in July 2004 and again the very successful probe descent and landing of Huygens on January 14, 2005. One of its main targets was Titan. Titan was revealed to be a complex world more like the Earth than any other: it has a dense mostly nitrogen atmosphere and active climate and meteorological cycles where the working fluid, methane, behaves under Titan conditions the way that water does on Earth. Its geology, from lakes and seas to broad river valleys and mountains, while carved in ice is, in its balance of processes, again most like Earth. Beneath this panoply of Earth-like processes an ice crust floats atop what appears to be a liquid water ocean. Titan is also rich in organic molecules—more so in its surface and atmosphere than anyplace in the solar system, including Earth [4]. These molecules were formed in the atmosphere, deposited on the surface and, in coming into contact with liquid water may undergo an aqueous chemistry that could replicate aspects of life's origins. I will discuss our current understanding of Titan's complex environment in view of recent exploration, in particular on the atmospheric structure (temperature and composition), and the surface nature. I will show how these and other elements can give us clues as to the origin and evolution of the satellite, and how they connect to the observations of the planet and the other satellites and rings. Future space missions to Titan can help us understand the kronian and also our Solar System as a whole. In particular, I will describe the future exploration of Titan and the Saturnian System with TSSM, a mission studied jointly by ESA and NASA in 2008 [1] and prioritized second for a launch around 2023-2025. TSSM comprises a Titan Orbiter provided by NASA that would carry two Titan in situ elements provided by ESA: a montgolfiere and a lake-landing lander. The mission would arrive 9 years later for a 4-year duration in the Saturn system. Following delivery of the ESA in situ elements to Titan, the Titan Orbiter would explore the Saturn system via a 2-year tour that includes Enceladus and Titan flybys. The montgolfiere would last at least 6 months at Titan and the lake lander 8-10 hours. Following the Saturn system tour, the Titan Orbiter would culminate in a —2-year orbit around Titan. References 1. TSSM and EJSM NASA/ESA Joint Summary Report, 16 January 2009 2. Coustenis et al. (2008). TandEM: Titan and Enceladus mission. Experimenta( Astron-omy, 23, 893-946. 3. Coustenis, A.,

Udry, Stephane

37

Ground penetrating radar methods used in surface-water discharge measurements  

Microsoft Academic Search

The U.S. Geological Survey (USGS) operates a network of about 7,000 streamflow-gaging stations that monitor open-channel water discharge at locations throughout the United States. The expense, technical difficulties, and concern for the safety of operational personnel under some field conditions have led to the search for alternate measurement methods. Ground- penetrating radar (GPR) has been used by the USGS in

F. P. Haeni; Marc L. Buursink; John E. Costa; Nick B. Melcher; Ralph T. Cheng; William J. Plant

2000-01-01

38

GROUND-PENETRATING RADAR METHODS USED IN SURFACE-WATER DISCHARGE MEASUREMENTS  

Microsoft Academic Search

The U.S. Geological Survey (USGS) operates a network of about 7,000 streamflow-gaging stations that monitor open-channel water discharge at locations throughout the United States. The expense, technical difficulties, and concern for the safety of operational personnel under some field conditions have led to the search for alternate measurement methods. Ground-penetrating radar (GPR) has been used by the USGS in hydrologic,

F. P. Haeni; Marc L. Buursink; John E. Costa; Nick B. Melcher; Ralph T. Cheng

39

Comparison of two retrieval methods for ground reflectance  

NASA Astrophysics Data System (ADS)

A comparison of two retrieval methods is presented to calculate ground reflectance from Landsat Thematic Mapper satellite data. The first method is based on a modified two-stream approximation to simulate the radiative transfer above an inhomogeneous surface. The atmosphere is parametrized by the optical depth and the single scattering albedo. The theory of fractal geometry is employed to compute the structure measures of a scene, from which the ground variability is estimated. By a linear regression, the ground variability can be related to the atmospheric optical depth. The independent second method is based on model ATCOR (including LOWTRAN-7). Here, a priori knowledge is used (shape of spectral reflectance curve for vegetation, water, bare soil) to determine the unknown atmospheric parameters like optical depth and type of aerosol (single scattering albedo). The adjacency effect, which describes the influence of atmospheric crosstalk in modifying the radiances of adjacent fields of different reflectance, is taken into account by both procedures. Typically, deviations between both methods are up to 2% in reflectance for low to medium reflection (< 30%) targets and up to 4% for high reflectance (> 40%) targets of Landsat imagery. In view of the independent approaches, this level of agreement in retrieved ground reflectance is fairly good. The new method is particularly valuable if no a-priori knowledge is available and if the scene has a large dynamic range of spatial frequencies.

Tornow, Carmen; Richter, Rudolf

1992-08-01

40

Buoyancy Distribution Around Ice Sheet Grounding Zones in the Western Amundsen Sea Embayment, Antarctica: Results from the AGASEA Survey  

NASA Astrophysics Data System (ADS)

Exposed grounding lines abutting Antarctica's relatively warm Amundsen Sea may represent an important locus of ice sheet erosion. Recent satellite remote sensing has indicated both expansion and retreat of active grounding lines in the region, with implications for global sea level change. As part of the 2004/05 AGASEA project, the University of Texas Institute for Geophysics (UTIG) surveyed Thwaites Glacier and Smith Glacier, two major marine outlet glaciers on the Amundsen Sea coast, using an aerogeophysical platform configured for simultaneous glaciological and geological investigations. The primary glaciological tools were a high-power coherent radar sounder and a laser altimeter, positioned by dual carrier phase GPS. Coverage of the Thwaites Glacier grounding line includes nine longitudinal radar and laser altimetry profiles collected by UTIG, two longitudinal radar profiles collected by the British Antarctic Survey, and three transverse radar and laser altimetry profiles collected by UTIG. Grid spacings for Thwaites Glacier were ~15km. The Smith Glacier grounding line location is constrained by two converging longitudinal profiles and three transverse lines at 15 km spacing, all five of which are UTIG radar and laser altimetry profiles.Surface elevations and ice thicknesses were derived from these data. These laser/radar profiles allow us to analyze buoyancy across the Smith Glacier and Thwaites Glacier grounding line zones. We use laser altimetry across sea ice to establish local sealevel to within a meter, and using this reference, predict from glacier surface elevations apparent hydrostatic compensation depths. Correspondence between the apparent compensation depth and the observed ice thickness allow us to identify floating ice, and thus allow a direct determination of the upstream limit of hydrostatic equilibrium. We compare this result to published tidal hinge lines delineated by satellite-based interferomic imaging radar between 1992 and 2000. The two methods match at the center of main trunk, but diverge considerably at the shear margins, which other work has suggested may be actively migrating. The reason for this divergence may be substantial retreat of the grounding line at the shear margins since 2000. An alternative explanation may be a systematic seaward offset of the tidal hinge line from the grounding line in thinner ice. The main trunk of Thwaites Glacier floats at a relatively shallow depth, and a broad lateral sill appears to localize the grounding line. Smith Glacier's grounding line is much deeper, and lacks a confining sill.

Young, D. A.; Blankenship, D. D.; Vaughan, D. G.; Holt, J. W.

2005-12-01

41

Storage and retrieval of ground-water data at the U.S. Geological Survey  

USGS Publications Warehouse

The U.S. Geological Survey maintains a computerized Ground-Water Site-Inventory (GWSI) file that contains information about wells and springs at sites from all States of the United States. This file contains data collected by U.S. Geological Survey personnel and personnel of cooperating State, local and Federal agencies. The file is easily accessible to members or users of the National Water Data Exchange. Since the establishment of the GWSI file in 1974, the data base has grown 19% per year and contains information on about 770,000 sites as of February 1981. (USGS)

Mercer, Maria W.; Morgan, Charles O.

1982-01-01

42

Y-STR Frequency Surveying Method: A critical reappraisal.  

PubMed

Reasonable formalized methods to estimate the frequencies of DNA profiles generated from lineage markers have been proposed in the past years and were discussed in the forensic community. Recently, collections of population data on the frequencies of variations in Y chromosomal STR profiles have reached a new quality with the establishment of the comprehensive neatly quality-controlled reference database YHRD. Grounded on such unrivalled empirical material from hundreds of populations studies the core assumption of the Haplotype Frequency Surveying Method originally described 10 years ago can be tested and improved. Here we provide new approaches to calculate the parameters used in the frequency surveying method: a maximum likelihood estimation of the regression parameters (r(1), r(2), s(1) and s(2)) and a revised Frequency Surveying framework with variable binning and a database preprocessing to take the population sub-structure into account. We found good estimates for 11 metapopulations using both approaches and demonstrate that the statistical basis of the method is well supported and independent of the population under study. The results of the estimation process are reliable and robust if the underlying datasets are large and representative and show small average and pairwise genetic distances. PMID:21094108

Willuweit, Sascha; Caliebe, Amke; Andersen, Mikkel Meyer; Roewer, Lutz

2010-11-19

43

MODFLOW-2005 : the U.S. Geological Survey modular ground-water model--the ground-water flow process  

USGS Publications Warehouse

This report presents MODFLOW-2005, which is a new version of the finite-difference ground-water model commonly called MODFLOW. Ground-water flow is simulated using a block-centered finite-difference approach. Layers can be simulated as confined or unconfined. Flow associated with external stresses, such as wells, areal recharge, evapotranspiration, drains, and rivers, also can be simulated. The report includes detailed explanations of physical and mathematical concepts on which the model is based, an explanation of how those concepts are incorporated in the modular structure of the computer program, instructions for using the model, and details of the computer code. The modular structure consists of a MAIN Program and a series of highly independent subroutines. The subroutines are grouped into 'packages.' Each package deals with a specific feature of the hydrologic system that is to be simulated, such as flow from rivers or flow into drains, or with a specific method of solving the set of simultaneous equations resulting from the finite-difference method. Several solution methods are incorporated, including the Preconditioned Conjugate-Gradient method. The division of the program into packages permits the user to examine specific hydrologic features of the model independently. This also facilitates development of additional capabilities because new packages can be added to the program without modifying the existing packages. The input and output systems of the computer program also are designed to permit maximum flexibility. The program is designed to allow other capabilities, such as transport and optimization, to be incorporated, but this report is limited to describing the ground-water flow capability. The program is written in Fortran 90 and will run without modification on most computers that have a Fortran 90 compiler.

Harbaugh, Arlen W.

2005-01-01

44

Airborne and Ground Electrical Surveys for Subsurface Mapping of the Arbuckle Aquifer, Central Oklahoma  

NASA Astrophysics Data System (ADS)

Airborne and ground electrical surveys have been conducted to map the subsurface hydrogeologic character of the Arbuckle-Simpson aquifer in south central Oklahoma. An understanding of the geologic framework and hydrogeologic characteristics is necessary to evaluate groundwater flow through the highly faulted, structurally complex, carbonate aquifer. Results from this research will further understanding of the aquifer and will assist in managing the water resources of the region. The major issues include water quality, the allocation of water rights, and the potential impacts of pumping on springs and stream. Four areas in the Hunton anticline area, with distinctly different geology, were flown with a frequency domain helicopter electromagnetic system (HEM) in March, 2007. Ground electrical studies include dc resistivity imaging and natural field audiomagnetotelluric (AMT), and magnetotelluric (MT) surveys. The HEM resistivity and total field magnetic survey was flown in four blocks, A through D, mostly with a line spacing of 400 m. Block A extends from the Chickasaw National Recreational Area (CHIC) to Mill Creek on the west side of the anticline. The surface geology of this block is mostly dolomitic limestone of the Arbuckle Group that is in fault contact with younger Paleozoic clastic rocks. The flight line spacing was 800 meters in the western half of the block and 400 meters in the eastern part. Airborne magnetic data indicate that the Sulphur fault bends south to merge with the Mill Creek fault which substantiates an earlier hypothesis first made from interpretation of gravity data. Block B, located on the north side of the anticline consists of mostly of Arbuckle and Simpson Group rocks. Block C, covering most of the Clarita horst on the east side of the anticline, consists of the Upper Ordovician to the Lower Pennsylvanian shales. Block D, which was flown to include a deep test well site at Spears ranch, consisted of eight lines spaced at 400 meters. The HEM data are being used to more precisely locate faults, refine the lithostratigraphic units, and to map the depth and extent of shallow epikarst. The MT and AMT data revealed deep structural contacts and a transition between fresh and highly mineralized ground water between springs in the CHIC. The dc resistivity survey has greatly helped in mapping major faults both within dolomitic limestone and clastic units. Ground resistivity surveys also suggest that, in places, the faults within limestone are zones of lower resistivity and map low resistivity surficial epikarst a several meters thick. Ground penetrometer data also has been used to define the depth extent of epikarst in selected areas and the data correlate well with the dc resistivity and HEM resistivity depth sections.

Smith, D.; Smith, B. D.; Blome, C. D.; Osborn, N.

2008-12-01

45

Development of Grounded Electrical Source Airborne Transient EM (GREATEM) Survey System and Its Application to Investigating a Volcano Structure  

NASA Astrophysics Data System (ADS)

We have developed an airborne EM system that uses a grounded electrical source and an airborne magnetic field receiver to increase the depth of investigation. Using a grounded source, we can apply a large source moment with a long transmitter-receiver distance, thus we expect to obtain a greater depth of investigation. However, the area of survey is limited with this type of method, but it has some advantages such as little effect of flight level etc. We believe that a repeated survey in active area such as volcano or fault area is effective for monitoring activity in the whole area. By using the airborne survey, we will be able to make repeated survey rapidly in volcano area where it is difficult to enter by a ground survey. The initial stage of the development was reported at Mogi et al. (1998) and the survey system was named as GREATEM (Grounded electrical source airborne transient EM). Time domain data acquisition has an advantage to the deep exploration because it avoids near source field effects that occur in frequency domain measurements. To realize the method, we should overcome mainly two problems: monitoring and filtering the motion noise of the receiver and canceling the natural magnetic field variation and cultural noise without stacking in the time domain data. We prepared high accuracy fiber optic gyros to monitor the pitch and roll of the magnetic sensor in the bird to monitor the motion and also manufactured an electromagnetic receiver that can detect three components of magnetic field and a tilt meter with MI sensor which can detect up to_ 100,000 nT with a sensitivity of 0.04 mV/nT. These receiver and tilt meter are installed on a gimbal in a bird. Data acquisition system is installed in the helicopter cabin with high precision GPS synchronized with the same type GPS set in the transmitter. In this system, we designed to analyze full wave data in time-domain for investigating deep to shallow underground resistivity structure. The measured data of three-component magnetic filed, tilting, time and positioning are digitized at 25 kHz for 10 channels. We have also developed a 3D modeling scheme to investigate magnetic field responses in the air for complicated subsurface structure and topography. We carried out GREATEM surveys at Aso Volcano, southwest Japan to test the survey system and clarify the subsurface structure of the volcano. We computed the transient response of the magnetic field in the air by removing motion noise and other EM noise using special digital filters. Finally we obtained resistivity structure, assuming horizontal layer structure. The depth of investigation of present survey was estimated about 800m deep.

Mogi, T.; Jomori, A.; Jomori, N.; Azuma, Y.; Fomenko, E. Y.

2005-12-01

46

Surveying method for locating target subterranean bodies  

SciTech Connect

This patent describes a method of drilling a relief well for intersection with a blowout well for the purpose of killing the blowout well. It comprises: collecting survey data relating to the blowout wellbore surface location and the borehole path of the blowout wellbore; determining a first set of error coefficients for the survey data for the blowout wellbore; collecting survey data relating to the surface location of a relief wellbore and the borehole path of the relief wellbore; determining a second set of error coefficients for the survey data for the relief wellbore; using the first and second sets of error coefficients to calculate a relative probable location distribution describing the location of the blowout wellbore relative to the location of the relief wellbore at successive depths; using the relative probable location distribution at the successive depths to calculate an integral probability of find for each the depth, the integral probability of find being the probability of locating the blowout wellbore using a search tool in the relief wellbore; and drilling the relief wellbore along a path having a maximum integral probability of find, such that the relief wellbore intersects the blowout wellbore.

Patton, B.J.; Foster, C.M.

1990-09-18

47

Development of Grounded Electrical Source Airborne Transient EM (GREATEM) Survey System and Its Application to Investigating a Volcano Structure  

Microsoft Academic Search

We have developed an airborne EM system that uses a grounded electrical source and an airborne magnetic field receiver to increase the depth of investigation. Using a grounded source, we can apply a large source moment with a long transmitter-receiver distance, thus we expect to obtain a greater depth of investigation. However, the area of survey is limited with this

T. Mogi; A. Jomori; N. Jomori; Y. Azuma; E. Y. Fomenko

2005-01-01

48

Buoyancy Distribution Around Ice Sheet Grounding Zones in the Western Amundsen Sea Embayment, Antarctica: Results from the AGASEA Survey  

Microsoft Academic Search

Exposed grounding lines abutting Antarctica's relatively warm Amundsen Sea may represent an important locus of ice sheet erosion. Recent satellite remote sensing has indicated both expansion and retreat of active grounding lines in the region, with implications for global sea level change. As part of the 2004\\/05 AGASEA project, the University of Texas Institute for Geophysics (UTIG) surveyed Thwaites Glacier

D. A. Young; D. D. Blankenship; D. G. Vaughan; J. W. Holt

2005-01-01

49

Assessment of some important factors affecting the singing-ground survey  

USGS Publications Warehouse

A brief history of the procedures used to analyze singing-ground survey data is outlined. Some weaknesses associated with the analytical procedures are discussed, and preliminary results of efforts to improve the procedures are presented. The most significant finding to date is that counts made by new observers need not be omitted when calculating an index of the woodcock population. Also, the distribution of woodcock heard singing, with respect to time after sunset, affirms the appropriateness of recommended starting times for counting woodcock. Woodcock count data fit the negative binomial probability distribution.

Tautin, J.

1982-01-01

50

Method of drilling with fluid comprising peanut hulls ground to a powder  

SciTech Connect

This patent describes a method of carrying out operations wherein a fluid is circulated in a well extending into the ground. It comprises: taking peanut hulls which have been ground to a powder form, adding the ground peanut hulls to a fluid, and circulating the fluid, with the ground peanut hulls added thereto, in the well.

Forrest, G.T.

1992-02-11

51

Grounded Theory Method (GTM) and the Abductive Research Strategy (ARS): a critical analysis of their differences  

Microsoft Academic Search

This paper addresses some important differences between Grounded Theory Method (GTM) and the Abductive Research Strategy (ARS). The early parts of the paper review Grounded Theory Method – both Glaser and Strauss’s (Corbin’s) Objectivist Grounded Theory Method (OGTM) and Charmaz’s Constructivist Grounded Theory Method (CGTM) – and Blaikie’s Abductive Research Strategy (ARS). It then discusses three distinctive differences between GTM

Beng Kok Ong

2012-01-01

52

Grounded Theory Method (GTM) and the Abductive Research Strategy (ARS): a critical analysis of their differences  

Microsoft Academic Search

This paper addresses some important differences between Grounded Theory Method (GTM) and the Abductive Research Strategy (ARS). The early parts of the paper review Grounded Theory Method – both Glaser and Strauss’s (Corbin’s) Objectivist Grounded Theory Method (OGTM) and Charmaz’s Constructivist Grounded Theory Method (CGTM) – and Blaikie’s Abductive Research Strategy (ARS). It then discusses three distinctive differences between GTM

Beng Kok Ong

2011-01-01

53

Revisions to the U.S. Geological Survey's MODFLOW Lake Package for Simulation of Ground-Water Interactions With Lakes  

NASA Astrophysics Data System (ADS)

Several revisions were made to the U.S. Geological Survey's MODFLOW Lake Package as part of the integration of the Precipitation-Runoff Modeling System with MODFLOW. The integrated model, named GSFLOW, is designed for the simultaneous simulation of ground-water and surface-water flow. Revisions to the Lake Package resulted in changing: (1) the numerical solution to simultaneously solve for lake stage and outflow to streams; (2) the method of calculating lake-water budgets to maintain a budget when a lake is empty; and (3) the calculation of leakage across the lakebed in areas where the water table is below the lakebed. The first change was done to reduce numerical instabilities in the calculation of lake outflow to streams. The second change was done to allow for intermittent lakes to refill on the basis of surface water inflow and to limit leakage across the lakebed to the surface-water inflow when the lake is empty. The third change was done to account for flow through an unsaturated zone beneath lakes. These revisions allow for greater flexibility in the simulation of ground-water interactions with lakes. Possible new applications for the revised Lake Package include the simulation of ground-water interaction with: (1) intermittent lakes that fill and drain as a result of seasonal changes in surface-water inflow; (2) reservoirs that fill during wet periods and are drained during droughts; (3) flood plains of streams that are inundated periodically by floods; (4) anastomosing flood plains where larger channels correspond to more than one MODFLOW cell; and (5) areas beneath lakes that are separated from ground water by an unsaturated zone.

Prudic, D. E.; Niswonger, R. G.

2006-12-01

54

Novel integrated system calibration method for impulse ground penetrating radar  

NASA Astrophysics Data System (ADS)

This paper proposes a new method of integrated system calibration that uses the transmitting and receiving signals from the impulse ground penetrating radar itself. In order to eliminate the influence from each subsystem or part including antenna, transmitter, receiver, signal processing circuits and transmission cables, two new calibration parameters that are different from the conventional S-parameters are introduced. The characteristic and influence of all parts in the transmitting and receiving channels are incorporated into the calibration equation through the new parameters. The calibration results of the radar detection data show that the new integrated system calibration can improve the quality of the data greatly in many aspects. It removes direct coupled waves, suppresses wave distortion and tail oscillation, and improves the quality of waveform and signal-clutter-ratios. It also compresses the pulse width and enhances resolution.

Huang, Chunlin; Lu, Min; Zhu, Shiping

2011-11-01

55

A comparison of vibration damping methods for ground based telescopes  

NASA Astrophysics Data System (ADS)

Vibration is becoming a more important element in design of telescope structures as these structures become larger and more compliant and include higher bandwidth actuation systems. This paper describes vibration damping methods available for current and future implementation and compares their effectiveness for a model of the Large Synoptic Survey Telescope (LSST), a structure that is actually stiffer than most large telescopes. Although facility and mount design, structural stiffening and occasionally vibration isolation have been adequate in telescopes built to date, vibration damping offers a mass-efficient means of reducing vibration response, whether the vibration results from external wind disturbances, telescope slewing, or other internal disturbances from translating or rotating components. The paper presents several damping techniques including constrained layer viscoelastics, viscous and magnetorheological (MR) fluid devices, passive and active piezoelectric dampers, tuned mass dampers (vibration absorbers) and active resonant dampers. Basic architectures and practical implementation considerations are discussed and expected performance is assessed using a finite element model of the LSST. With a goal of reducing settling time during the telescope's surveys, and considering practicalities of integration with the telescope structure, two damping methods were identified as most appropriate: passive tuned mass dampers and active electromagnetic resonant dampers.

Anderson, Eric H.; Glaese, Roger M.; Neill, Douglas

2008-08-01

56

30 CFR 75.701-3 - Approved methods of grounding metallic frames, casings and other enclosures of electric equipment...  

Code of Federal Regulations, 2010 CFR

...direct current power systems with one polarity grounded. 75.701-3 Section 75...direct current power systems with one polarity grounded. For the purpose of grounding...direct-current power system with one polarity grounded, the following methods of...

2009-07-01

57

30 CFR 75.701-3 - Approved methods of grounding metallic frames, casings and other enclosures of electric equipment...  

Code of Federal Regulations, 2010 CFR

...direct current power systems with one polarity grounded. 75.701-3 Section 75...direct current power systems with one polarity grounded. For the purpose of grounding...direct-current power system with one polarity grounded, the following methods of...

2010-07-01

58

Improved pipe-to-soil potential survey methods  

SciTech Connect

In 1988, the Corrosion Supervisory Committee of the Pipeline Research Committee initiated PR-186-807 titled Improved Pipe-to-Soil Potential Survey Methods.'' The primary purpose of PR-186-807 was to establish the portion of pipe sampled during a ground level pipe-to-soil potential measurement. The overall objective of this program was to improve the ability to perform and interpret close interval on- and off-potential surveys. This program included both large-scale field experiments utilizing 290 feet of 24 and 20-inch diameter pipe ranging from bare to well coated. The field measurements were primarily utilized to verify finite element analysis modeling. The modeling effort was performed to provide general statements on the area of pipe sampled as opposed to the very specific conditions present in the field measurements. This project was performed over a three year period from 1988 through 1990. The first two years examined bare pipe conditions and the third year examined coated pipe conditions. In the following sections, the results for the bare pipe and the coated pipe portions of this project are presented under separate headings.

Thompson, N.G.; Lawson, K.M.

1991-04-30

59

Sampling Methods for Web and E-mail Surveys  

Microsoft Academic Search

This chapter is a comprehensive overview of sampling methods for web and e-mail ('Internet- based') surveys. It reviews the various types of sampling method - both probability and non- probability - and examines their applicability to Internet-based surveys. Issues related to Internet- based survey sampling are discussed, including dif- ficulties assembling sampling frames for probability sampling, coverage issues, and nonresponse

Ronald D. F ricker

60

Ecological survey of M-Field, Edgewood Area Aberdeen Proving Ground, Maryland  

SciTech Connect

An ecological survey was conducted on M-Field, at the Edgewood Area, Aberdeen Proving Ground, Maryland. M-Field is used routinely to test army smokes and obscurants, including brass flakes, carbon fibers, and fog oils. The field has been used for testing purposes for the past 40 years, but little documented history is available. Under current environmental regulations, the test field must be assessed periodically to document the presence or potential use of the area by threatened and endangered species. The M-Field area is approximately 370 acres and is part of the US Army`s Edgewood Area at Aberdeen Proving Ground in Harford County, Maryland. The grass-covered field is primarily lowlands with elevations from about 1.0 to 8 m above sea level, and several buildings and structures are present on the field. The ecological assessment of M-Field was conducted in three stages, beginning with a preliminary site visit in May to assess sampling requirements. Two field site visits were made June 3--7, and August 12--15, 1991, to identify the biota existing on the site. Data were gathered on vegetation, small mammals, invertebrates, birds, large mammals, amphibians, and reptiles.

Downs, J.L.; Eberhardt, L.E.; Fitzner, R.E.; Rogers, L.E.

1991-12-01

61

Ecological survey of M-Field, Edgewood Area Aberdeen Proving Ground, Maryland  

SciTech Connect

An ecological survey was conducted on M-Field, at the Edgewood Area, Aberdeen Proving Ground, Maryland. M-Field is used routinely to test army smokes and obscurants, including brass flakes, carbon fibers, and fog oils. The field has been used for testing purposes for the past 40 years, but little documented history is available. Under current environmental regulations, the test field must be assessed periodically to document the presence or potential use of the area by threatened and endangered species. The M-Field area is approximately 370 acres and is part of the US Army's Edgewood Area at Aberdeen Proving Ground in Harford County, Maryland. The grass-covered field is primarily lowlands with elevations from about 1.0 to 8 m above sea level, and several buildings and structures are present on the field. The ecological assessment of M-Field was conducted in three stages, beginning with a preliminary site visit in May to assess sampling requirements. Two field site visits were made June 3--7, and August 12--15, 1991, to identify the biota existing on the site. Data were gathered on vegetation, small mammals, invertebrates, birds, large mammals, amphibians, and reptiles.

Downs, J.L.; Eberhardt, L.E.; Fitzner, R.E.; Rogers, L.E.

1991-12-01

62

In-situ high-resolution gamma-spectrometric survey of burial ground-monitoring wells  

SciTech Connect

In situ high resolution gamma-ray spectrometry with an intrinsic germanium detector assembly of special design surveyed the burial ground monitoring wells to locate and identify gamma emitters that may have migrated from the burial trenches toward the water table. Gamma-ray spectra were acquired as a function of depth in each well and recorded on magnetic tape. These spectra were reduced by a series of computer programs to produce count rate versus depth profiles for natural and man-made activities. The original spectra and the profiles have been archived on magnetic tape for comparison with similar future surveys. Large amounts of man-made activities were observed in some of the burial trenches; however, below the trench bottoms, only very low but detectable amounts of /sup 60/Co and /sup 137/Cs were observed in eleven wells. The highest level of man-made gamma activity observed below the trench bottoms has a count rate roughly equal to that observed for uranium daughter activities which are natural to the subsoil.

Bowman, W.W.

1981-09-01

63

Multivariate methods for ground-level ozone modeling  

NASA Astrophysics Data System (ADS)

The aim of this study is to apply multivariate statistical methods in predicting ozone (O3) concentrations at the ground level of the troposphere as the function of pollution and meteorological parameters. PM10, SO2, NO, NO2, CO, O3, CH4, NMHC, temperature, rainfall, humidity, pressure, wind direction, wind speed and solar radiation were measured hourly for one year period in order to predict O3 concentrations of 1 h later. In the study, relationships between O3 data and other variables were investigated by bivariate correlation analysis. CH4, NMHC, NO2 exhibited considerable negative correlations with O3 described with the Pearson correlation coefficients of - 0.67, - 0.55, - 0.51, respectively whereas highest positive correlation was noted for temperature with correlation coefficient of 0.60. Multiple regression analysis (MLR) was used for modeling annual and seasonal O3 concentrations. Adjusted R2 values were determined as 0.90, 0.85 and 0.92 respectively for annual period, cooling and warming seasons. In order to decrease the number of input variables principle component analysis (PCA) was applied by using annual data. MLR analysis was repeated using four principle components and new adjusted R2 was calculated as 0.63.

Özbay, Bilge; Keskin, Gül?en Ayd?n; Do?ruparmak, ?enay Çetin; Ayberk, Sava?

2011-10-01

64

Remaining consistent with method? An analysis of grounded theory research in accounting  

Microsoft Academic Search

Purpose – The paper revisits the intellectual roots of grounded theory and aims to analyze the consistency of the method used in grounded theory research in accounting. About 23 papers are identified and analysed. Design\\/methodology\\/approach – The paper is an analytical review of the research literature. It uses four fundamental canons of grounded theory to analyze accounting research. Findings –

Bruce Gurd

2008-01-01

65

Apparatus and method for grounding compressed fuel fueling operator  

DOEpatents

A safety system for grounding an operator at a fueling station prior to removing a fuel fill nozzle from a fuel tank upon completion of a fuel filling operation is provided which includes a fuel tank port in communication with the fuel tank for receiving and retaining the nozzle during the fuel filling operation and a grounding device adjacent to the fuel tank port which includes a grounding switch having a contact member that receives physical contact by the operator and where physical contact of the contact member activates the grounding switch. A releasable interlock is included that provides a lock position wherein the nozzle is locked into the port upon insertion of the nozzle into the port and a release position wherein the nozzle is releasable from the port upon completion of the fuel filling operation and after physical contact of the contact member is accomplished.

Cohen, Joseph Perry (Bethlehem, PA); Farese, David John (Riegelsville, PA); Xu, Jianguo (Wrightstown, PA)

2002-06-11

66

30 CFR 75.700-1 - Approved methods of grounding.  

Code of Federal Regulations, 2013 CFR

...borehole casing having low resistance to earth; (b) A solid connection to metal waterlines having low resistance to earth; (c) A solid connection to a grounding...between such metallic enclosures and the...

2013-07-01

67

30 CFR 77.700-1 - Approved methods of grounding.  

Code of Federal Regulations, 2013 CFR

...a) A solid connection to metal waterlines having low resistance to earth; (b) A solid connection to a grounding conductor, other than...no difference in potential between such metallic enclosures and the...

2013-07-01

68

Proximity morality in medical school - medical students forming physician morality "on the job": Grounded theory analysis of a student survey  

PubMed Central

Background The value of ethics education have been questioned. Therefore we did a student survey on attitudes about the teaching of ethics in Swedish medical schools. Methods Questionnaire survey on attitudes to ethics education with 409 Swedish medical students participating. We analyzed > 8000 words of open-ended responses and multiple-choice questions using classic grounded theory procedures. Results In this paper we suggest that medical students take a proximity morality stance towards their ethics education meaning that they want to form physician morality "on the job". This involves comprehensive ethics courses in which quality lectures provide "ethics grammar" and together with attitude exercises and vignette reflections nurture tutored group discussions. Goals of forming physician morality are to develop a professional identity, handling diversity of religious and existential worldviews, training students described as ethically naive, processing difficult clinical experiences, and desisting negative role modeling from physicians in clinical or teaching situations, some engaging in "ethics suppression" by controlling sensitive topic discussions and serving students politically correct attitudes. Conclusion We found that medical students have a proximity morality attitude towards ethics education. Rather than being taught ethics they want to form their own physician morality through tutored group discussions in comprehensive ethics courses.

Thulesius, Hans O; Sallin, Karl; Lynoe, Niels; Lofmark, Rurik

2007-01-01

69

Eighth Conference on Health Survey Research Methods.  

National Technical Information Service (NTIS)

Contents: Foreword; Acknowledgments; Session 1: Capturing Diversity and Change in a Dynamic Population; Session 2: Community Participation and Community Benefit; Session 3: Cross-Cultural Challenges in Health Survey Research; Session 4: How to Conduct Hea...

2004-01-01

70

An Innovative, Effective and Cost Effective Survey Method Using a Survey-Check Response Format  

Microsoft Academic Search

Maximizing the response rate to surveys involves thoughtful choices about survey design, sampling and collection methods.\\u000a This paper describes an innovative survey method, to provide immediate reinforcement for responding and to minimize the response\\u000a cost. This method involves using a questionnaire printed as checks on security (anti-fraud) paper with questions and responses\\u000a separated using a perforated tear off section. Once

Edward G. Feil; Herbert Severson; Ted K. Taylor; Shawn Boles; David A. Albert; Jason Blair

2007-01-01

71

Antenna characteristics and air-ground interface de-embedding methods for stepped-frequency ground-penetrating radar measurements  

NASA Astrophysics Data System (ADS)

The result form field-tests using a Stepped-Frequency Ground Penetrating Radar (SF-GPR) and promising antenna and air- ground deembedding methods for a SF-GPR is presented. A monostatic S-band rectangular waveguide antenna was used in the field-tests. The advantages of the SF-GPR, e.g., amplitude and phase information in the SF-GPR signal, is used to deembed the characteristics of the antenna. We propose a new air-to-ground interface deembedding technique based on Principal Component Analysis which enables enhancement of the SF-GPR signal from buried objects, e.g., anti-personal landmines. The methods are successfully evaluate on field-test data obtained from measurements on a large-scale in-door test field.

Karlsen, Brian; Larsen, Jan; Jakobsen, Kaj B.; Sorensen, Helge B.; Abrahamson, Steffan

2000-08-01

72

New results from Nevada: A test of Newton's law using the BREN tower and a high density ground gravity survey.  

National Technical Information Service (NTIS)

We report new results from the LLNL test of Newton's law of gravity being conducted at the Nevada Test Site with a stable 465-m tower and a denser ground gravity survey than any used to date (823 locations within 4 km of the tower). Measurements of gravit...

J. Kammeraad P. Kasameyer O. Fackler D. Felske R. Harris

1990-01-01

73

A survey of microbial levels for incoming raw beef, environmental sources, and ground beef in a red meat processing plant  

Microsoft Academic Search

A microbial survey was performed for a midwestern red meat processing plant that produces retail cuts and ground beef. Samples were obtained from incoming ingredients, beef during processing, finished product, food contact and environmental surfaces, and the air. Aerobic plate count (APC), coliform count (CC), andEscherichia colicount (ECC) were determined for each sample. Product samples (25 g) were taken from

W. G. Eisel; R. H. Linton; P. M. Muriana

1997-01-01

74

Recognition of magnetic anomalies in Ground Conductivity Meter soil surveys: a high-resolution field experiment  

NASA Astrophysics Data System (ADS)

Ground conductivity measurements are widely used in soil surveys, where the objective is to map an element or property, which gives a strong conductive signal compared to the surroundings. It can be used in mapping of soil contamination, mineral exploration and soil mapping, where properties like porosity, clay-content and salinity of groundwater are explored. However, interpretations get poor, when too many variables, e.g. metals, affect the measurements. To improve interpretation of the GCM dataset, we investigated confounding signals from buried metals as magnetic anomalies by a magnetometer. The small field test site in Illerup Ådal, Denmark (2 ha) was situated on peat and clayey soil, where buried metal was expected due to previous archaeological investigations. Both GCM and magnetometer measurements were on-the-go behind an ATV and logged together with DGPS positioning. Instruments were a DUALEM-21 and a Geometrics G-858 Caesium magnetometer. Data were collected in separately runs, since close proximity of the instruments can affect the magnetometer data. Data were collected on 12 lines, which were spaced 5 m apart. The frequency of readings was 4 times s-1 at a speed of approximately 12 km h-1. A 1D multi-layer model was used for the inversion of EM data, providing detailed information of the resistivity structure in the upper 2-3 m of the soil. All 12 lines were driven in both directions during sampling of magnetic data, to check if measurements are influenced by the direction of the magnetometer. Time for collecting both datasets was 90 minutes. The combined dataset showed one area (200 m2) with a magnetic anomaly, which correlated with a relatively low apparent resistivity (approximately 27 Ohm m), while the adjacent areas had a higher apparent resistivity (>50 Ohm m). The inversion model showed that a relatively low resistivity (20-30 Ohm m) was present at all depths in the area with the magnetic anomaly. However, the model showed even lower resistivity in other areas of the site (10-20 Ohm m) in all of the modelled layers. Therefore, this area would easily be interpreted wrong in GCM surveys, since it does not appear as an outlier in the EMI dataset. By making a combined survey with both EMI and magnetic susceptibility measurements, it is possible to identify small areas with high magnetic anomalies. Here caution should be taken in interpretation of GCM survey in relation to the element or property of interest.

Søe, Niels Emil; Bjergsted Pedersen, Jesper; Auken, Esben; Humlekrog Greve, Mogens; Nørgaard, Henrik; Tjelldén, Anna K. E.; Munch Kristiansen, Søren

2013-04-01

75

NATIONAL SURFACE WATER SURVEY, WESTERN LAKE SURVEY (PHASE 1 - SYNOPTIC CHEMISTRY) ANALYTICAL METHODS MANUAL  

EPA Science Inventory

The Analytical Methods Manual for the Western Lake Survey - Phase I is a supplement to the Analytical Methods Manual for the Eastern Lake Survey Phase I. The supplement provides a general description of the analytical methods that are used by the field laboratories and by the ana...

76

Study of calculating ground-reflected Fresnel zone by definition method  

Microsoft Academic Search

ical analysis and practical test show that the traditional ground-renected Fresnel zone calculating method has error with the actual situation. The method of calculating traditional ground-renected Fresnel zone and the error sources are studied at the beginning of this paper, Then a new calculation method of the definition of ground-renected Fresnel zone is derived from the definition of Huygens -Fresnel

Xie Fei; Jin Weitong; Li Hongling

2011-01-01

77

Field studies of the GPR ground wave method for estimating soil water content during irrigation and drainage  

Microsoft Academic Search

Knowledge of ground wave penetration depth and methods for facilitating ground wave velocity analysis are important practical aspects to consider when measuring soil water content with surface ground penetrating radar. A field study was conducted to optimize the wide angle reflection and refraction and fixed offset methods of measuring the ground wave velocity and to find the effective ground wave

L. W. Galagedara; G. W. Parkin; J. D. Redman; P. von Bertoldi; A. L. Endres

2005-01-01

78

MODFLOW-2000, The U.S. Geological Survey Modular Ground-Water Model - User Guide to Modularization Concepts and the Ground-Water Flow Process  

USGS Publications Warehouse

MODFLOW is a computer program that numerically solves the three-dimensional ground-water flow equation for a porous medium by using a finite-difference method. Although MODFLOW was designed to be easily enhanced, the design was oriented toward additions to the ground-water flow equation. Frequently there is a need to solve additional equations; for example, transport equations and equations for estimating parameter values that produce the closest match between model-calculated heads and flows and measured values. This report documents a new version of MODFLOW, called MODFLOW-2000, which is designed to accommodate the solution of equations in addition to the ground-water flow equation. This report is a user's manual. It contains an overview of the old and added design concepts, documents one new package, and contains input instructions for using the model to solve the ground-water flow equation.

Harbaugh, Arlen W.; Banta, Edward R.; Hill, Mary C.; McDonald, Michael G.

2000-01-01

79

Magnetic and ground penetrating radar surveys for the research of Medieval settlements in the inland of the Marche Region (Italy)  

NASA Astrophysics Data System (ADS)

This work was carried out in the framework of the R.I.M.E.M. project (Research on Medieval settlements in the inland of the Marche Region, Italy.) leaded by the Universities of Macerata and Udine and having the aim to produce a significant contribution for the comprehension of the settlement process in the Central and Southern Italy during the Late Roman Period and Early Middle Ages. Then, an extensive gradiometric survey were carried out, by using a vapour caesium magnetometer, in the area included amongst the municipal districts of Caldarola, Cessapalombo and San Ginesio, sited in the area closed to Macerata between the valleys of Chienti and Fiastra rivers. Moreover, in the most interesting areas, a 400 MHz 3D ground penetrating radar (GPR)survey was carried out in order to get the precise overlapping with the magnetic method. The Magnetic method is now a standard practice in the archaeological research taken into great consideration for its non-destructivity and quickness and its capability of mapping wide areas in quite a short lapse of time (Bavusi et al., 2008). Moreover the method provides an information well correlable with remote sensing data (Gallo et al, 2008). The GPR method is extremely useful for archaeologists thanks to its non-destructivity and capability of giving real-time and high-resolution data (Basile et al., 2000). Today the effectiveness of this method was improved by powerful 3D visualisation methods as well as 3D space, time or depth slices and iso-amplitude surfaces, too (Nuzzo et al., 2002). The integrations of several geophysical methods are usual (Sambuelli et al.1999, De Domenico et al., 2001; Chianese et al., 2004) particularly when a simple comparison in cross section along the same profiles can be performed. In this work the overlapping between two kinds of data was complicated by different outputs coming from two methods: maps for the magnetic method and cross sections for the GPR one. The 3D survey design for the GPR survey and a complex processing routine was carried out in order to get both data volumes and time slices, more easily comparable with magnetic maps. Magnetic data processing included spike removal and destripe. Finally, the results revealed the presence of several target of archaeological interest and, where two methods were carried out, the results are consistent. M. Bavusi , A. Giocoli, e. Rizzo, v. Lapenna (2008). Geophysical characterisation of Carlo' s V Castle (Crotone, Italy). Journal of Applied Geophysics. DOI: 10.1016/j.jappgeo.2008.09.002. Basile V., Carrozzo M.T., Negri S., Nuzzo L., Quarta T., Villani A.V., (2000). A ground-penetrating radar survey for archaeological investigations in an urban area - Lecce, Italy. Journal of Applied Geophysics, 44, 15-32. Chianese D., D'Emilio M., Di Salvia S., Lapenna V., Ragosta M., Rizzo E. (2004). Magnetic Mapping, Ground Penetrating Radar Surveys and Magnetic Susceptibility Measurements for the Study of the Archaeological Site of Serra di Vaglio (Southern Italy). Journal of Archaeological Science, 31, 633-643. De Domenico D., Giannino F., Marino A., Nuzzo L., Rizzo E., (2001). Indagini elettriche e radar: integrazione dei metodi nello studio dei resti sepolti del monastero normanno in s. Marco D'Alunzio (Messina). Atti del 21° Convegno Nazionale del GNGTS, 351-353. GalloD., Ciminale M., Beckerb H. and Masini N. (2008). Remote sensing techniques for reconstructing a vast Neolithic settlement in Southern Italy. Journal of Archaeological Science, DOI:10.1016/j.jas.2008.07.002. Nuzzo L., Leucci, G . Negri S., Carrozzo M. T. and Quarta T., (2002). Application of 3D visualization techniques in the analysis of GPR data for archaeology. Annals of Geophysics, 45 (2), 321-337. Sambuelli L., Socco L.V., Brecciaroli L., (1999). Acquisition and processing of electric, magnetic and GPR data on a Roman site(Victimulae, Salussola, Biella), Journal of Applied Geophysics, 41, 189-204

Bavusi, M.; Giocoli, A.; Balasco, M.; Favulli, G.; Moscatelli, U.; Minguzzi, S.; Gnesi, D.; Virgili, S.

2009-04-01

80

Drug use surveys: method and madness.  

PubMed

There are many measurement problems inherent in the drug survey field, e.g., defining dosages and choosing user categories. This paper discusses the pros and cons of interview techniques, mailed questionnaires, and group-administered questionnaires. The particular importance of the social psychology of the data gathering process is noted, including the provision of anonymity for the respondents and the establishment of credibility for the investigators. Means for dealing with these and also for improving reliability and validity are discussed, along with reasons for performing a survey, the nature and intent of the questions asked, and some other political and ethical issues. PMID:863567

Stanton, M D

1977-02-01

81

Emergency Survey Methods in Acute Cryptosporidiosis Outbreak  

PubMed Central

In August 2003, a communitywide outbreak of cryptosporidiosis occurred in Kansas. We conducted a case-control study to assess risk factors associated with Cryptosporidium infection by using the telephone survey infrastructure of the Behavioral Risk Factor Surveillance System. Using existing state-based infrastructure provides an innovative means for investigating acute outbreaks.

Ocfemia, M. Cheryl Banez; Hunt, D. Charles; Blackburn, Brian G.; Neises, Daniel; Kent, W. Kay; Beach, Michael J.; Pezzino, Gianfranco

2005-01-01

82

METHOD OF ESTIMATING DOSAGE TO GROUND FROM A RADIOACTIVE CLOUD  

Microsoft Academic Search

Beginning with Sutton's diffusion equation, the authors develop ; mathematical expressions for the radiation dose to a point on the ground ; following the instantaneous emission of a point source of radiation. From a ; knowledge of weather conditions, reactor running history, and the power . of ; the runawav, one can compute the beta and gamma dose to be

C. C. Gamertsfelder; R. L. Waterfield

1955-01-01

83

GROUNDED THEORY AS FOUNDATIONS FOR METHODS IN APPLIED ONTOLOGY  

Microsoft Academic Search

Research into domain specific ontologies is difficult to treat empirically. This is because it is difficult to ground domain ontology while simultaneously being true to its guiding philosophy or theory. Further, ontology generation is often introspective and reflective or relies on experts for ontology generation. Even those relying on expert generation lack rigour and tend to be more ad-hoc. We

John W Lamp; Simon K Milton

84

Combination of corrosion-survey methods improves protection  

SciTech Connect

Combining the three most widely used aboveground-survey procedures for evaluating coating integrity and cathodic protection adequacy can overcome the technical and economic penalties of choosing a single survey method. A review of each method and of several case histories shows how the procedures complement each other.

Allen, M.D.; Barnes, N.R.

1988-02-29

85

Prediction of ground surface temperature and soil moisture content by the force-restore method  

Microsoft Academic Search

The parsimonoy and computational efficiency offered by the force-restore approximation of the diffusion equation have motivated its widespread application in modeling ground surface temperature. Different assumptions regarding the definition of ground surface temperature have resulted in different versions of the force-restore method. Here, four existing versions of the force-restore method for ground surface temperature are compared and contrasted. An improved

Zhenglin Hu; Shafiqul Islam

1995-01-01

86

Radiological Surveys Performed in Support of the Demolition and Bulk Disposal Decommissioning Method  

SciTech Connect

Connecticut Yankee Atomic Power Company is decommissioning the Haddam Neck Plant using the 'Demolition and Bulk Disposal' method, or commonly referred to as 'Rip and Ship'. In general, completing the project using this method entails the removal of all irradiated fuel and highly contaminated systems and components, and the subsequent demolition of the above ground portions of most site structures. Since most structures are removed from site, cost and time savings are realized by virtually eliminating the need for remediation. However, this method of decommissioning creates more waste, both radiological and non-radiological, which must be segregated, packaged and disposed of properly. Prior to demolition, various types of radiological surveys must be performed and work controls put into place to minimize the spread of contamination to other areas of the site, and to prevent the inadvertent release of radioactive materials from the site. This paper will discuss the various types of radiological surveys performed, and controls implemented, in support of the demolition and bulk material disposal decommissioning method, with the emphasis on pre-demolition surveys. Details will be provided on the release criteria, survey design, survey implementation and data analysis on each of the various surveys, as well as a discussion on the controls implemented to prevent the various wastes from inadvertently being shipped to an inappropriate disposal facility. This paper will also strive to provide lessons learned for future projects that utilize the demolition and bulk disposal decommissioning method. (authors)

Yetter, R.F. [Babcock Services, Inc., 1840 Terminal Drive, Richland, WA 99352 (United States); Newson, C.T. [Connecticut Yankee Atomic Power Company, 362 Injun Hollow Road, East Hampton, CT 06424 (United States)

2006-07-01

87

Corrosion control survey methods for offshore pipelines  

SciTech Connect

Construction, operation, and maintenance of offshore pipelines and other facilities are expensive. The consequences of an offshore corrosion failure can be devastating. For these reasons, cathodic protection (CP) has become a universally applied technique for mitigating corrosion. Marine pipelines are typically provided with CP by bracelet anodes of zinc or aluminum. Impressed current systems at platforms or onshore are also used as well as hybrid systems that use a combination of the two. In this paper survey techniques are described and evaluated.

Weldon, C.P.; Kroon, D. (Corrpro Co. Inc., North, Spring, TX (US))

1992-02-01

88

Frequency response method for terrain classification in autonomous ground vehicles  

Microsoft Academic Search

Many autonomous ground vehicle (AGV) missions, such as those related to agricultural applications, search and rescue, or reconnaissance\\u000a and surveillance, require the vehicle to operate in difficult outdoor terrains such as sand, mud, or snow. To ensure the safety\\u000a and performance of AGVs on these terrains, a terrain-dependent driving and control system can be implemented. A key first\\u000a step in

Edmond M. Dupont; Carl A. Moore; Emmanuel G. Collins Jr.; Eric Coyle

2008-01-01

89

MODFLOW-2000, The U.S. Geological Survey Modular Ground-Water Model-User Guide to Modularization Concepts and the Ground-Water Flow Process.  

National Technical Information Service (NTIS)

MODFLOW is a computer program that numerically solves the three-dimensional ground-water flow equation for a porous medium by using a finite-difference method. Although MODFLOW was designed to be easily enhanced, the design was oriented toward additions t...

A. W. Harbaugh E. R. Banta M. C. Hill M. G. McDonald

2000-01-01

90

Movement and fate of creosote waste in ground water, Pensacola, Florida; U.S. Geological Survey toxic waste--ground-water contamination program  

USGS Publications Warehouse

In 1983, the U.S. Geological Survey, Office of Hazardous Waste Hydrology, selected the former American Creosote Works site near Pensacola, Florida as a national research demonstration area. Seventy-nine years (1902-81) of seepage from unlined discharge impoundments had released creosote, diesel fuel, and pentachlorophenol (since 1950) wastes into the ground-water system. A cluster of from 2 to 5 wells constructed at different depths at 9 sites yielded water which revealed contamination 600 feet downgradient and to a depth of 100 feet below land surface near the site. The best cross-sectional representation of the contaminant plume was obtained from samples collected and analyzed for oxidation-reduction sensitive inorganic chemical constituents. Energy dispersive x-ray fluorescence detected recently formed iron carbonate in soil samples from highly reducing ground-water zones. Approximately eighty specific organic contaminants were isolated from ground-water samples by gas-chromotography/mass spectrometry. Column studies indicate the dimethyl phenols are not sorbed or degraded by the sand-and-gravel aquifer materials. Five of nineteen individual phenolic and related compounds are biodegradable based on anaerobic digestor experiments with ACW site bacterial populations. The potential impacts in the nearby Pensacola Bay biotic community are being evaluated. (USGS)

edited by Mattraw, H. C., Jr.; Franks, B. J.

1984-01-01

91

Electromagnetic survey of the K1070A burial ground at the Oak Ridge K-25 Site, Oak Ridge, Tennessee  

SciTech Connect

The K1070A burial ground, located at the K-25 Site on the Oak Ridge Reservation, received chemical and radioactive wastes from the late 1940s until 1975. Analysis of water samples collected from nearby monitoring wells indicates that contamination is migrating offsite. In November 1991, Oak Ridge National Laboratory (ORNL) personnel collected high-resolution electrical terrain conductivity data at the K1070A burial ground. A Model EM31 terrain conductivity meter manufactured by Geonics Limited was used in conjunction with the ORNL-developed Ultrasonic Ranging and Data System (USRADS) to perform the survey. The purposeof the survey was to provide Environmental Restoration (ER) staff with a detailed map of the spatial variation of the apparent electrical conductivity of the shallow subsurface (upper 3 m) to assist them in siting future monitoring wells closer to the waste area without drilling into the buried waste.

Nyquist, J.E.; Emery, M.S.

1993-01-01

92

Ground Motion Simulation Using the Hybrid Empirical Method: Issues and Insights  

Microsoft Academic Search

\\u000a The widespread application of the hybrid empirical method (HEM) has made it a viable approach for developing ground motion\\u000a prediction equations (GMPEs) in regions where there are few strong motion recordings but ample weak motion data from small-to-moderate\\u000a magnitude earthquakes. The HEM uses empirical estimates of ground motion in a host region\\u000a to provide estimates of ground motion in a

K. W. Campbell

93

BOREHOLE SENSING METHODS FOR GROUND-WATER INVESTIGATIONS AT HAZARDOUS WASTE SITES  

EPA Science Inventory

Geophysical methods are becoming a cost effective approach to providing answers to hydrogeologic questions associated with ground-water contamination. Geophysical methods applicable to hazardous waste site investigations can be broken into two categories: surface and subsurface m...

94

MODFLOW-2000, The U.S. Geological Survey Modular Ground-Water Model -- GMG Linear Equation Solver Package Documentation  

USGS Publications Warehouse

A geometric multigrid solver (GMG), based in the preconditioned conjugate gradient algorithm, has been developed for solving systems of equations resulting from applying the cell-centered finite difference algorithm to flow in porous media. This solver has been adapted to the U.S. Geological Survey ground-water flow model MODFLOW-2000. The documentation herein is a description of the solver and the adaptation to MODFLOW-2000.

Wilson, John D.; Naff, Richard L.

2004-01-01

95

Revisions to the U.S. Geological Survey's MODFLOW Lake Package for Simulation of Ground-Water Interactions With Lakes  

Microsoft Academic Search

Several revisions were made to the U.S. Geological Survey's MODFLOW Lake Package as part of the integration of the Precipitation-Runoff Modeling System with MODFLOW. The integrated model, named GSFLOW, is designed for the simultaneous simulation of ground-water and surface-water flow. Revisions to the Lake Package resulted in changing: (1) the numerical solution to simultaneously solve for lake stage and outflow

D. E. Prudic; R. G. Niswonger

2006-01-01

96

Techniques and methods in ground-based observation of Mercury  

NASA Astrophysics Data System (ADS)

Modern telescopes and equipments have permitted excellent ground-based observations of Mercury, despite its proximity to the Sun. This is one of the main reasons why it has been observed using different techniques from high-resolution spectroscopy to high-resolution imaging from visible to infrared up to radio wavelengths. Because there is no obscuration from a thick atmosphere, the surface and exosphere have been imaged and the surface studied by infrared spectroscopy. This manuscript describes the techniques used to obtain information and new data of Mercury giving an overview of advantages and difficulties, and describes important scientific discoveries made with specific telescopic instrumentation.

Cremonese, G.; Warell, J.; Harmon, J. K.; Leblanc, F.; Mendillo, M.; Sprague, A. L.

2010-01-01

97

COMPARISON OF METHODS FOR ESTIMATING GROUND-WATER RECHARGE AND BASE FLOW AT A SMALL WATERSHED UNDERLAIN BY FRACTURED BEDROCK IN THE EASTERN UNITED STATES  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study by the U.S. Geological Survey, in cooperation with the Agricultural Research Service (ARS), U.S. Department of Agriculture, compared multiple methods for estimating ground-water recharge and base flow (as a proxy for recharge) at sites in east-central Pennsylvania underlain by fractured b...

98

Comparison of applied Geophysical Methods for detecting high alpine ground ice  

NASA Astrophysics Data System (ADS)

The detection of ground ice in the higher regions of the Alps is an important aim of alpine studies. Geophysical research in this field is important for alpine risk, infrastructure and climate change studies. Because of the complexity of detecting ground ice, the database of permafrost maps is currently not very well evaluated for wide areas of the Alps. The research for this project was conducted at Lazaun rockglacier (Schnalstal, Italy) and Rofenberg (Ötztal, Austria). This area was chosen because of good network of BTS (Base Temperature of Snowcover) measurements and terrain changes from ALS (Airbourne Laser Scanning) data which could possibly indicate permafrost degradation. Georadar, geoelectric and seismic methods were used to detect permafrost, with each geophysical method being applied on all profile lines. This parallel application enabled us to compare and cross-validate the results of the three techniques. After the analyses of the single datasets, a tomography including all results was created. At Rofenberg, three profiles were measured at a height of about 3200 meters. Two of them were parallel and one was crossing them both. Each profile had a length of about 100 m. The spacing of the electrodes was 2 meters for geoelectrical measurements using Schlumberger and Wenner geometries. The geophone spacing for seismic measurements was about 4 meters and a shot spacing of 4 meters was applied. For georadar measurements 50 MHz, 100 MHz and 200 MHz antennas were used and CMP measurements with the 200 MHz antenna were accomplished as well. A further profile line was investigated at the Lazaun rockglacier at an elevation of about 2800 meters. This profile was more difficult to measure because of rugged and impassable terrain. First analyses at Rofenberg show good results for two of the profiles. Permafrost is assumed at a depth between 2 meters and 8 meters and similar ground structures can be spotted for every method. At Lazaun, the interpretation is much more difficult due to a low signal to noise ratio. Data from two boreholes in direct neighborhood considerably facilitate the interpretation. The combined data show both the difficulties and the high potential of multi-method geophysical permafrost surveys in high-alpine terrain.

Ott, P.; Mössinger, M.; Sailer, R.; Sass, O.

2012-04-01

99

Seasonal changes in groundwater storage estimated by absolute ground gravity and MRS surveys in West Africa  

NASA Astrophysics Data System (ADS)

Important and fast groundwater storage changes occur in tropical monsoon regions in response to seasonal rainfall and subsequent surface water redistribution. In West Africa, one main goal of the GHYRAF experiment (Gravity and Hydrology in Africa, 2008-2010) is to compare absolute gravimetric measurements with dense hydrological surveys to better estimate and model water storage changes at various time scales. Magnetic Resonance Sounding (MRS) is a non-invasive geophysical method having a signal directly related to groundwater quantity. In SW Niger, MRS surveys were performed concurrently with gravimetric (FG5) measurements for monitoring seasonal changes in groundwater storage. Water table levels were recorded on a 4-piezometers profile (~500 m) near a temporary pond (area ~2 ha) fed by sandy gullies. The volume of water drained from the pond to the phreatic aquifer was computed to be ~100,000 m3/yr. Large piezometric fluctuations (3-6 m) occurred in response to indirect recharge through the pond during the 2008 rainy season (July-Sept.), with stronger water table fluctuations recorded near the pond. Absolute gravimetric (FG5) measurements were performed at a distance of 150 m from the pond, in order to minimize the influence of 2D effects on gravimetric records. The increase in absolute gravity measured between two dates (July-Sept.) was 8.7 ± 2.6 µGal; for the same period, the measured water table rise was +3.0 m. Considering these values, a first estimate of the groundwater storage increase is 0.2 m, corresponding to a porosity filled up by the water table rise of ~7%. Repeated MRS surveys were performed at the same location for different dates (three soundings in Sept., one in Dec.). The MRS water content was 13%, with little variation in space (±3%) along the piezometric profile. In response to a 3 metres drop in the water table (Sept- Dec), there was no significant recorded change in the MRS water content and/or in the estimated MRS water table depth. MRS and absolute gravimetry are two independent methods that could be sensitive to changes in groundwater reserves. However, because MRS is integrative of the whole saturated thickness of the aquifer (here, a few tens of metres), it was shown to be comparatively less sensitive to groundwater storage fluctuations occurring at the water table. These methods provide complementary data on aquifer characteristics, MRS being useful for quantifying lateral changes in aquifer properties, whereas gravimetric measurements helped in characterizing groundwater recharge and porosity. Both methods bring pieces of information that could be used to better constrain transient groundwater modelling at site scale.

Favreau, G.; Boucher, M.; Luck, B.; Pfeffer, J.; Genthon, P.; Hinderer, J.

2009-04-01

100

Survey research methods in evaluation and case-control studies.  

PubMed

Survey research methods are widely used in two types of analytic studies: evaluation studies that measure the effects of interventions; and population-based case-control studies that investigate the effects of various risk factors on the presence of disease. This paper provides a broad overview of some design and analysis issues related to such studies, illustrated with examples. The lack of random assignment to treatment and control groups in many evaluation studies makes controlling for confounders critically important. Confounder control can be achieved by matching in the design and by various alternative methods in the analysis. One popular analytic method of controlling for confounders is propensity scoring, which bears a close resemblance to survey weighting. The use of population-based controls has become common in case-control studies. For reasons of cost, population-based controls are often identified by telephone surveys using random digit dialling (RDD) sampling methods. However, RDD surveys are now experiencing serious problems with response rates. A recent alternative approach is to select controls from frames such as driver license lists that contain valuable demographic information for use in matching. Methods of analysis developed in the survey sampling literature are applicable, at least to some degree, in the analyses of evaluation and population-based case-control studies. In particular, the effects of complex sample designs can be taken into account using survey sampling variance estimation methods. Several survey analysis software packages are available for carrying out the computations. PMID:17278183

Kalton, Graham; Piesse, Andrea

2007-04-15

101

A Survey of the Microbial Flora of Ground Beef, Textured Soy Protein and Textured Soy Protein Extended Ground Beef after 3 Days' and 10 Days' Storage at 4 C.  

National Technical Information Service (NTIS)

A survey of the microbial populations of 31 samples of ground beef (GB), textured soy protein (TSP) and TSP extended ground beef (SGB) after 3 days' and 10 days' storage at 4 C was performed. Analyses included aerobic plate count (APC), psychrotrophic pla...

J. F. Foster J. L. Fowler J. T. Fruin L. S. Guthertz E. L. Shroyer

1977-01-01

102

TESTING GROUND BASED GEOPHYSICAL TECHNIQUES TO REFINE ELECTROMAGNETIC SURVEYS NORTH OF THE 300 AREA HANFORD WASHINGTON  

Microsoft Academic Search

Airborne electromagnetic (AEM) surveys were flown during fiscal year (FY) 2008 within the 600 Area in an attempt to characterize the underlying subsurface and to aid in the closure and remediation design study goals for the 200-PO-1 Groundwater Operable Unit (OU). The rationale for using the AEM surveys was that airborne surveys can cover large areas rapidly at relatively low

PETERSEN SW

2010-01-01

103

Simulation of strong ground motions based on recorded accelerograms and the stochastic method  

Microsoft Academic Search

Considering the strong influence of severe ground motions of shear waves on the dynamic behavior of buildings and civil structures, these shear wave motions are simulated by using the recorded accelerograms under the surface of the ground which is regarded as a base rock in Osaka, Japan, and by using the stochastic method which can easily introduce higher frequency contents

Sanshiro Suzuki; Koji Hada; Koichiro Asano

1998-01-01

104

‘How?’ and ‘Why?’: Theory emergence and using the grounded theory method to determine levels of analysis  

Microsoft Academic Search

The grounded theory method is more appropriate than just a grounded theory “approach,” for teasing out the detail of the level of analysis of constructs. Also, triangulation is important to this kind of research, but the methodological distinctions between qualitative and quantitative data and qualitative and quantitative analysis need to be made clear when mapping out a methodology. The contention

Ken Parry

2003-01-01

105

Grounded Theory as a "Family of Methods": A Genealogical Analysis to Guide Research  

ERIC Educational Resources Information Center

This study traces the evolution of grounded theory from a nuclear to an extended family of methods and considers the implications that decision-making based on informed choices throughout all phases of the research process has for realizing the potential of grounded theory for advancing adult education theory and practice. [This paper was…

Babchuk, Wayne A.

2011-01-01

106

Survey of Nonglycol and Reduced Glycol Aircraft Deicing Methods.  

National Technical Information Service (NTIS)

This survey of no glycol and low-glycol aircraft deicing practices, methods, and procedures used by the world's airlines, including cargo carriers, was conducted under contract to the Federal Aviation Administration (FAA) william J. Hughes Technical Cente...

J. Cornish F. Eyre

1999-01-01

107

Applied Survey Methods for Development Projects.  

National Technical Information Service (NTIS)

Scientific sampling methods can reduce the need for detailed recordkeeping, reporting, and accounting, and can provide useful data to project personnel. This step-by-step illustrative guide is thus designed to familiarize A.I.D. personnel responsible for ...

1981-01-01

108

Autonomous and Remote-Controlled Airborne and Ground-Based Robotic Platforms for Adaptive Geophysical Surveying  

NASA Astrophysics Data System (ADS)

Low-cost autonomous and remote-controlled robotic platforms have opened the door to precision-guided geophysical surveying. Over the past two years, the U.S. Geological Survey, Senseta, NASA Ames Research Center, and Carnegie Mellon University Silicon Valley, have developed and deployed small autonomous and remotely controlled vehicles for geophysical investigations. The purpose of this line of investigation is to 1) increase the analytical capability, resolution, and repeatability, and 2) decrease the time, and potentially the cost and map-power necessary to conduct near-surface geophysical surveys. Current technology has advanced to the point where vehicles can perform geophysical surveys autonomously, freeing the geoscientist to process and analyze the incoming data in near-real time. This has enabled geoscientists to monitor survey parameters; process, analyze and interpret the incoming data; and test geophysical models in the same field session. This new approach, termed adaptive surveying, provides the geoscientist with choices of how the remainder of the survey should be conducted. Autonomous vehicles follow pre-programmed survey paths, which can be utilized to easily repeat surveys on the same path over large areas without the operator fatigue and error that plague man-powered surveys. While initial deployments with autonomous systems required a larger field crew than a man-powered survey, over time operational experience costs and man power requirements will decrease. Using a low-cost, commercially available chassis as the base for autonomous surveying robotic systems promise to provide higher precision and efficiency than human-powered techniques. An experimental survey successfully demonstrated the adaptive techniques described. A magnetic sensor was mounted on a small rover, which autonomously drove a prescribed course designed to provide an overview of the study area. Magnetic data was relayed to the base station periodically, processed and gridded. A target was located in the subsurface, and a second, higher-resolution survey was programmed and executed to give detailed data over the newly-found target.

Spritzer, J. M.; Phelps, G. A.

2011-12-01

109

Numerical Calculation Method for Prediction of Ground-borne Vibration near Subway Tunnel  

NASA Astrophysics Data System (ADS)

This paper describes the development of prediction method for ground-borne vibration from railway tunnels. Field measurement was carried out both in a subway shield tunnel, in the ground and on the ground surface. The generated vibration in the tunnel was calculated by means of the train/track/tunnel interaction model and was compared with the measurement results. On the other hand, wave propagation in the ground was calculated utilizing the empirical model, which was proposed based on the relationship between frequency and material damping coefficient ? in order to predict the attenuation in the ground in consideration of frequency characteristics. Numerical calculation using 2-dimensinal FE analysis was also carried out in this research. The comparison between calculated and measured results shows that the prediction method including the model for train/track/tunnel interaction and that for wave propagation is applicable to the prediction of train-induced vibration propagated from railway tunnel.

Tsuno, Kiwamu; Furuta, Masaru; Abe, Kazuhisa

110

GWM-a ground-water management process for the U.S. Geological Survey modular ground-water model (MODFLOW-2000)  

USGS Publications Warehouse

GWM is a Ground?Water Management Process for the U.S. Geological Survey modular three?dimensional ground?water model, MODFLOW?2000. GWM uses a response?matrix approach to solve several types of linear, nonlinear, and mixed?binary linear ground?water management formulations. Each management formulation consists of a set of decision variables, an objective function, and a set of constraints. Three types of decision variables are supported by GWM: flow?rate decision variables, which are withdrawal or injection rates at well sites; external decision variables, which are sources or sinks of water that are external to the flow model and do not directly affect the state variables of the simulated ground?water system (heads, streamflows, and so forth); and binary variables, which have values of 0 or 1 and are used to define the status of flow?rate or external decision variables. Flow?rate decision variables can represent wells that extend over one or more model cells and be active during one or more model stress periods; external variables also can be active during one or more stress periods. A single objective function is supported by GWM, which can be specified to either minimize or maximize the weighted sum of the three types of decision variables. Four types of constraints can be specified in a GWM formulation: upper and lower bounds on the flow?rate and external decision variables; linear summations of the three types of decision variables; hydraulic?head based constraints, including drawdowns, head differences, and head gradients; and streamflow and streamflow?depletion constraints. The Response Matrix Solution (RMS) Package of GWM uses the Ground?Water Flow Process of MODFLOW to calculate the change in head at each constraint location that results from a perturbation of a flow?rate variable; these changes are used to calculate the response coefficients. For linear management formulations, the resulting matrix of response coefficients is then combined with other components of the linear management formulation to form a complete linear formulation; the formulation is then solved by use of the simplex algorithm, which is incorporated into the RMS Package. Nonlinear formulations arise for simulated conditions that include water?table (unconfined) aquifers or head?dependent boundary conditions (such as streams, drains, or evapotranspiration from the water table). Nonlinear formulations are solved by sequential linear programming; that is, repeated linearization of the nonlinear features of the management problem. In this approach, response coefficients are recalculated for each iteration of the solution process. Mixed?binary linear (or mildly nonlinear) formulations are solved by use of the branch and bound algorithm, which is also incorporated into the RMS Package. Three sample problems are provided to demonstrate the use of GWM for typical ground?water flow management problems. These sample problems provide examples of how GWM input files are constructed to specify the decision variables, objective function, constraints, and solution process for a GWM run. The GWM Process runs with the MODFLOW?2000 Global and Ground?Water Flow Processes, but in its current form GWM cannot be used with the Observation, Sensitivity, Parameter?Estimation, or Ground?Water Transport Processes. The GWM Process is written with a modular structure so that new objective functions, constraint types, and solution algorithms can be added.

Ahlfeld, David P.; Barlow, Paul M.; Mulligan, Anne E.

2005-01-01

111

A survey of modern authorship attribution methods  

Microsoft Academic Search

Authorship attribution supported by statistical or computational methods has a long history starting from 19th century and marked by the seminal study of Mosteller and Wallace (1964) on the authorship of the disputed Federalist Papers. During the last decade, this scientific field has been developed substantially taking advantage of research advances in areas such as machine learning, information retrieval, and

Efstathios Stamatatos

2009-01-01

112

Diversity creation methods: a survey and categorisation  

Microsoft Academic Search

Ensemble approaches to classication and regression have attracted a great deal of interest in recent years. These methods can be shown both theoretically and empirically to outperform single predictors on a wide range of tasks. One of the elements required for accurate prediction when using an ensemble is recognised to be error \\\\diversity\\

Gavin Brown; Jeremy L. Wyatt; Rachel Harris; Xin Yao

2005-01-01

113

Well treating methods using temperature surveys  

Microsoft Academic Search

A method is described of treating wells to stimulate production from or to increase acceptance of fluids in the well strata by controlled selective treatment of the formations of the well in conjunction with temperature evaluation. Blocking and propping agents are utilized to block off each zone or strata as it is treated. Temperature gradient curves and temperature differential curves

J. H. Guinn; W. S. Wright

1969-01-01

114

Methods and Indicators for Assessment of Regional Ground-Water Conditions in the Southwestern United States  

USGS Publications Warehouse

Monitoring the status and trends in the availability of the Nation's ground-water supplies is important to scientists, planners, water managers, and the general public. This is especially true in the semiarid to arid southwestern United States where rapid population growth and limited surface-water resources have led to increased use of ground-water supplies and water-level declines of several hundred feet in many aquifers. Individual well observations may only represent aquifer conditions in a limited area, and wells may be screened over single or multiple aquifers, further complicating single-well interpretations. Additionally, changes in ground-water conditions may involve time scales ranging from days to many decades, depending on the timing of recharge, soil and aquifer properties, and depth to the water table. The lack of an easily identifiable ground-water property indicative of current conditions, combined with differing time scales of water-level changes, makes the presentation of ground-water conditions a difficult task, particularly on a regional basis. One approach is to spatially present several indicators of ground-water conditions that address different time scales and attributes of the aquifer systems. This report describes several methods and indicators for presenting differing aspects of ground-water conditions using water-level observations in existing data-sets. The indicators of ground-water conditions developed in this study include areas experiencing water-level decline and water-level rise, recent trends in ground-water levels, and current depth to ground water. The computer programs written to create these indicators of ground-water conditions and display them in an interactive geographic information systems (GIS) format are explained and results illustrated through analyses of ground-water conditions for selected alluvial basins in the Lower Colorado River Basin in Arizona.

Tillman, Fred D; Leake, Stanley A.; Flynn, Marilyn E.; Cordova, Jeffrey T.; Schonauer, Kurt T.; Dickinson, Jesse E.

2008-01-01

115

Method of utilizing possible alternative energy sources in ground transportation  

SciTech Connect

This work discusses the magnitude of the problem of depleting world oil reserves and their impact on ground-transportation systems. One of several possible solutions is postulated and analyzed. The solution examined is one in which energy from various sources, both renewable and nonrenewable, is converted to electricity and distributed throughout the roadway network for use by vehicles. The energy is transferred to the vehicle via an on-board noncontacting, inductively coupled, pickup. The power-distribution system is fully compatible with existing vehicles and with pedestrians. A Hedonic Choice Model is developed to predict the market penetration of electric vehicles thru the year 2030. A life-cycle-cost optimization model and a system-simulation model are developed to analyze a system for the Denver metropolitan area. Results indicate that such a system is both economically and technically feasible. About 3600 lane miles of roadway would need to be electrified. This system would serve about 90% of all metro trips and would cost less than two billion dollars The system could provide mobility equivalent to that we presently experience through the foreseeable future.

Hamilton, W.R.

1987-01-01

116

The National Criminal Justice Treatment Practices survey: Multilevel survey methods and procedures?  

PubMed Central

The National Criminal Justice Treatment Practices (NCJTP) survey provides a comprehensive inquiry into the nature of programs and services provided to adult and juvenile offenders involved in the justice system in the United States. The multilevel survey design covers topics such as the mission and goals of correctional and treatment programs; organizational climate and culture for providing services; organizational capacity and needs; opinions of administrators and staff regarding rehabilitation, punishment, and services provided to offenders; treatment policies and procedures; and working relationships between correctional and other agencies. The methodology generates national estimates of the availability of programs and services for offenders. This article details the methodology and sampling frame for the NCJTP survey, response rates, and survey procedures. Prevalence estimates of juvenile and adult offenders under correctional control are provided with externally validated comparisons to illustrate the veracity of the methodology. Limitations of the survey methods are also discussed.

Taxman, Faye S.; Young, Douglas W.; Wiersema, Brian; Rhodes, Anne; Mitchell, Suzanne

2007-01-01

117

A survey of interval methods for differential equations  

Microsoft Academic Search

A brief introduction to the basic concepts, methods, and applications of interval analysis will be followed by a broad survey of interval methods for differential equations. We can obtain rigorous upper and lower bounds on sets of solutions corresponding to bounded sets of input data (initial values, boundary values, coefficients or parameters in the differential equations). The methods apply to

R. E. Moore

1984-01-01

118

A survey of quantum Lyapunov control methods.  

PubMed

The condition of a quantum Lyapunov-based control which can be well used in a closed quantum system is that the method can make the system convergent but not just stable. In the convergence study of the quantum Lyapunov control, two situations are classified: nondegenerate cases and degenerate cases. For these two situations, respectively, in this paper the target state is divided into four categories: the eigenstate, the mixed state which commutes with the internal Hamiltonian, the superposition state, and the mixed state which does not commute with the internal Hamiltonian. For these four categories, the quantum Lyapunov control methods for the closed quantum systems are summarized and analyzed. Particularly, the convergence of the control system to the different target states is reviewed, and how to make the convergence conditions be satisfied is summarized and analyzed. PMID:23766732

Cong, Shuang; Meng, Fangfang

2013-05-27

119

Evaluation of Two Methods for Determining Middle Atmosphere Composition from the Ground.  

National Technical Information Service (NTIS)

For retrieving middle atmosphere composition from ground-based solar absorption spectrum, two methods have been provided, ie transmission measurements with pressure co-ordinate and differential transmission measurements. In this paper, their information c...

W. Ying-Jian

1983-01-01

120

Methods of Minimizing Ground-Water Contamination from In situ Leach Uranium Mining: Final Report.  

National Technical Information Service (NTIS)

This is the final report of a research project dealing with methods of minimizing ground-water contamination from in situ leach uranium mining. Field work and laboratory experiments were conducted to identify excursion indicators for monitoring purposes d...

W. J. Deutsch W. J. Martin L. E. Eary R. J. Serne

1985-01-01

121

[Historical survey of modern reversible contraceptive methods].  

PubMed

Because of contraception, pregnancy need not be viewed by women as punishment for sexual activity but as a planned and desired event. Most of the contraceptive methods used in developing countries at present were introduced during the 1960s, but use of contraception has a long history and some methods date back to antiquity. Contraceptive pills were already used around 2000 BC in the form of mercury and arsenic tablets. Their effectiveness was questionable. The role of hormones in human reproduction began to be understood only in the early 1900s. The discovery of progesterone in a Mexican iguana in the 1940s permitted production of progesterone on a large scale. Estrogens had been identified around 1930. Human trials of a contraceptive pill beginning in 1956 in Puerto Rico demonstrated that progestins could prevent pregnancy by suppressing ovulation. Later on, estrogen was added to reduce menstrual irregularities. The 1st generation of combined oral contraceptives contained very high levels of hormones associated with high rates of side effects. Numerous formulations with lower hormonal contents became available beginning around 1970 and constitute the principal formulations in use today. A number of long acting hormonal methods based on progestins have been developed, including injectables, some IUDs and vaginal rings, and implants. The 1st commercially available injectable, norethisterone enanthate, did not acquire the wide distribution of medroxyprogesterone acetate, sold as Depo Provera and used to treat various pathological conditions as well as for contraception. The 1st true IUDs were small stones placed within the uteri of camels by nomads to prevent pregnancy during long caravans. An IUD was developed in 1909 by Richter, and the 2 most widely used models before 1960 were the Grafenberg and Ota silver rings. Use of the 2 rings became rare for medical reasons after 1935 despite their efficacy. Safe plastic IUDs which appeared beginning in the early 1960s were flexible and capable of returning to their original shape after insertion. The Lippes loop was the 1st highly successful IUD. Bioactive IUDs containing copper were developed in the 1970s. Research is underway to develop IUDs which will resist expulsion, reduce bleeding, be more appropriate for multiparas, and last longer. IUDs are used to treat intrauterine adhesions as well as for contraception. A gummy substance used to block the cervix was described in Egypt in 1850 BC. Japanese and Chinese prostitutes of antiquity placed oiled bamboo paper at the cervical opening for contraception. Diaphragms and cervical caps were developed in the 19th century in Germany. Large scale production became possible after 1880 with the development of better, more durable, and cheaper rubber. An Egyptian writing in 3500 BC began the study of spermicides. Numerous substances such as lemon juice and honey have been placed in the vagina to avoid pregnancy. Such substances are available to all women and some were reasonably effective. Current research is directed toward development of spermicides which will also prevent sexually transmitted diseases. The 1st condoms were made of animal skins by an English physician to prevent transmission of venereal diseases. Rubber condoms appeared in the early 20th century and are widely utilized in some family planning programs. Pregnancy vaccines and a reversible hormonal method for men are among methods under development. PMID:12268230

Mbabajende, V

1986-04-01

122

Verification of 50cm-ground-temperature method by idealized numerical experiments  

NASA Astrophysics Data System (ADS)

"50cm-ground-temperature method", or GT50 method is one of the technique for detecting the lower boundary of permafrost distribution in a mountainous terrain, which is based on the change in ground-temperature lapse rates at 50-cm depth during summer. The basic idea behind this method is that the 50-cm depth ground temperature is generally controlled by the balance of mean daily air temperature and ground heat flux, and this balance is affected by latent heat from permafrost as well within permafrost zone. This effect from permafrost causes the bend in lapse-rate plot along the slope, which can be interpreted as a lower boundary of permafrost zone. The method is suitable for the field work which has difficulties in logistics, especially for remote region or steep mountain (Fukui et al., 2006; Fujii et al., 1999; Fujii and Higuchi, 1972). Although useful, the method should have certain limits of application, because it depends on the variation of ground heat flux, the amount of latent heat, etc. The aim of this study is to verify this GT50 method quantitatively, to investigate necessary conditions and rooms for improvements. The distributed 1-D ground temperature calculation was made in a idealized semi-infinite slope, assuming uniform atmosphere-land energy exchange. For the first step, temperature profile of equilibrium state was calculated, 50-cm ground temperature was plotted against the altitude. As a preliminary results, the plot shows the dependence to the grand water content, and the method cannot detect the boundary if the permafrost is very dry (volumetric water content < 1%). Other results for different ground water content, diurnal variation, thermal conductivities will be shown in the presentation.

Sueyoshi, Tetsuo

2010-05-01

123

A Comprehensive Survey of Neighborhood-based Recommendation Methods  

Microsoft Academic Search

Among collaborative recommendation approaches, methods based on nearest-neighbors still enjoy a huge amount of popularity, due to their simplicity, their efficiency, and their ability to produce accurate and personalized recommenda- tions. This chapter presents a comprehensive survey of neighborhood-based meth- ods for the item recommendation problem. In particular, the main benefits of such methods, as well as their principal characteristics,

Christian Desrosiers; George Karypis

2011-01-01

124

A survey of kernel and spectral methods for clustering  

Microsoft Academic Search

Clustering algorithms are a useful tool to explore data structures and have been employed in many disciplines. The focus of this paper is the partitioning clustering problem with a special interest in two recent approaches: kernel and spectral methods. The aim of this paper is to present a survey of kernel and spectral clustering methods, two approaches able to produce

Maurizio Filippone; Francesco Camastra; Francesco Masulli; Stefano Rovetta

2008-01-01

125

Scenistic Methods in Training: Definitions and Theory Grounding  

ERIC Educational Resources Information Center

Purpose: The aim of this article is to describe the scenistic approach to training with corresponding activities and the theory bases that support the approach. Design/methodology/approach: Presented is the definition of the concept of scenistic training along with the step-by-step details of the implementation of the approach. Scenistic methods,…

Lyons, Paul

2010-01-01

126

Ground penetrating radar methods used in surface-water discharge measurements  

NASA Astrophysics Data System (ADS)

The U.S. Geological Survey (USGS) operates a network of about 7,000 streamflow-gaging stations that monitor open-channel water discharge at locations throughout the United States. The expense, technical difficulties, and concern for the safety of operational personnel under some field conditions have led to the search for alternate measurement methods. Ground- penetrating radar (GPR) has been used by the USGS in hydrologic, geologic, environmental, and bridge-scour studies by floating antennas on water or mounting antennas in boats. GPR methods were developed to measure and monitor remotely the cross-sectional area of rivers by suspending a 100-megahertz (MHz) radar antenna from a cableway car or bridge at four unstable streams that drained the slopes of Mount St. Helens in Washington. Based on the success of these initial efforts, an experiment was conducted in 1999 to see if a combination of complementary radar methods could be used to calculate the discharge of a river without having any of the measuring equipment in the water. The cross-sectional area of the 183- meter (m) wide Skagit River in Washington State was measured using a GPR system with a single 100-MHz antenna suspended 0.5 to 3 m above the water surface from a cableway car. A van- mounted, side-looking pulsed-Doppler (10 gigahertz) radar system was used to collect water-surface velocity data across the same section of the river. The combined radar data sets were used to calculate the river discharge and the results compared closely to the discharge measurement made by using the standard in-water measurement techniques. The depth to the river bottom, which was determined from the GPR data by using a radar velocity of 0.04 meters per nanosecond in water, was about 3 m, which was within 0.25 m of the manually measured values.

Haeni, F. P.; Buursink, Marc L.; Costa, John E.; Melcher, Nick B.; Cheng, Ralph T.; Plant, William J.

2000-04-01

127

The application of air and ground based laser mapping systems to transmission line corridor surveys  

Microsoft Academic Search

The ability to reliably and accurately locate and survey objects while moving or without physically occupying them is the key to the productivity of the FLI-MAP and TruckMAP laser mapping systems. These advanced technology systems incorporate OTF kinematic GPS, GPS-aided attitude, and reflectorless laser range finding sensors into complete remote sensing survey platforms. The FLI-MAP system is a helicopter-based laser

Morgan D. Reed; Connie E. Landry; Kenneth C. Werther

1996-01-01

128

Retina Lesion and Microaneurysm Segmentation using Morphological Reconstruction Methods with Ground-Truth Data  

SciTech Connect

In this work we report on a method for lesion segmentation based on the morphological reconstruction methods of Sbeh et. al. We adapt the method to include segmentation of dark lesions with a given vasculature segmentation. The segmentation is performed at a variety of scales determined using ground-truth data. Since the method tends to over-segment imagery, ground-truth data was used to create post-processing filters to separate nuisance blobs from true lesions. A sensitivity and specificity of 90% of classification of blobs into nuisance and actual lesion was achieved on two data sets of 86 images and 1296 images.

Karnowski, Thomas Paul [ORNL; Govindaswamy, Priya [Oak Ridge National Laboratory (ORNL); Tobin Jr, Kenneth William [ORNL; Chaum, Edward [University of Tennessee, Knoxville (UTK); Abramoff, M.D. [University of Iowa

2008-01-01

129

High resolution TEC monitoring method using permanent ground GPS receivers  

NASA Astrophysics Data System (ADS)

In this paper we propose a new and simple method for obtaining the ionospheric Total Electron Content (TEC) variations from GPS permanent station data, in a very precise manner and with high temporal and spatial resolution. The key idea is to use of the resonant period of 1 sidereal day between the Earth's rotation and the GPS satellite orbit periods, in order to obtain one TEC variation estimate directly from each ionospheric observation. This new strategy can be applied on both global and local scales, for instance to one single station. Its capabilities are shown in the application performed with the data gathered on 17, 18 and 19 October 1995 from 95 GPS permanent stations and 9 and 10 January 1997 (180 stations), coinciding with two major geomagnetic storms.

Hernández-Pajares, M.; Juan, J. M.; Sanz, J.

130

REVIEWS OF TOPICAL PROBLEMS: Sky surveys and deep fields of ground-based and space telescopes  

NASA Astrophysics Data System (ADS)

Selected results obtained in major observational sky surveys (DSS, 2MASS, 2dF, SDSS) and deep field observations (HDF, GOODS, UHDF, etc.) are reviewed. Modern surveys provide information on the characteristics and space distribution of millions of galaxies. Deep fields allow one to study galaxies at the stage of formation and to trace their evolution over billions of years. The wealth of observational data is altering the face of modern astronomy: the formulation of problems and their solutions are changing and all the previous knowledge, from planetary studies in the solar system to the most distant galaxies and quasars, is being revised.

Reshetnikov, Vladimir P.

2005-11-01

131

Comparison of geostatistical methods for estimating virus inactivation rates in ground water  

SciTech Connect

Enteric viruses are responsible for a large number of ground-waterborne disease outbreaks every year. Septic tanks are the most frequently cited causes of ground-water contamination in disease outbreaks. Controlling the placement of septic tanks such that all viruses would be non-infective by the time the effluent reached drinking water wells would likely reduce the number of waterborne viral-disease outbreaks. The study compares different geostatistical techniques (kriging, cokriging, and combined kriging and regression) that estimate virus inactivation rates in ground water. These estimates were used with the regional ground-water flow characteristics to estimate septic tank setback distances over a city-wide area. Combined kriging and regression, which eliminates the need for laboratory values of virus inactivation rates by using the linear regression relationship between temperature and inactivation rates, produced comparable results to the other two methods, yet reduced the cost of the analysis considerably.

Yates, M.V.; Yates, S.R.

1987-01-01

132

A Survey of Monte Carlo Tree Search Methods  

Microsoft Academic Search

Monte Carlo tree search (MCTS) is a recently proposed search method that combines the precision of tree search with the generality of random sampling. It has received considerable interest due to its spectacular success in the difficult problem of computer Go, but has also proved beneficial in a range of other domains. This paper is a survey of the literature

Cameron B. Browne; Edward Powley; Daniel Whitehouse; Simon M. Lucas; Peter I. Cowling; Philipp Rohlfshagen; Stephen Tavener; Diego Perez; Spyridon Samothrakis; Simon Colton

2012-01-01

133

Movement and fate of creosote waste in ground water, Pensacola, Florida; U.S. Geological Survey toxic waste-ground-water contamination program  

USGS Publications Warehouse

Ground- and surface-water contamination by pesticides used in the wood-preserving industry is widespread in the United States. Pine poles were treated with wood preservatives from 1902 to 1981 at a creosote works near Pensacola, Florida. Diesel fuel, creosote, and pentachlorophenol were discharged to two unlined impoundments that had a direct hydraulic connection to the sand-and-gravel aquifer. Evidence of wood-preserving waste contamination appears to be confined to the upper 30 meters of the aquifer. The waste plume extends downgradient approximately 300 meters south toward Pensacola Bay. In 1983, the creosote works site was selected by the U.S. Geological Survey's Office of Hazardous Waste Hydrology as a national research demonstration area to apply the latest techniques for characterizing hazardous waste problems. The multidisciplinary research effort is aimed at studying processes that affect the occurrence, transport, transformations, and fate of the toxic contaminants associated with wood preservatives in the environment. Clusters of two to five wells were constructed at different depths at nine sites to define the depth of contamination. Research studies are investigating sorption, dispersion, dilution, chemical reactions, bacterially mediated transformations, quality assurance, plume hydrodynamics, and the ultimate fate of these complex organic wastes.

edited by Mattraw, Harold C., Jr.; Franks, Bernard J.

1986-01-01

134

Tornado Damage at the Grand Gulf, Mississippi Nuclear Power Plant Site: Aerial and Ground Surveys.  

National Technical Information Service (NTIS)

A tornado struck the Grand Gulf nuclear power generating station, Port Gibson, Mississippi, about 11:30 p.m. on April 17, 1978. Storm damage investigators from the University of Chicago and Texas Tech University were dispatched to survey the damage. The m...

T. T. Fujita J. R. McDonald

1978-01-01

135

Seasonal changes in groundwater storage estimated by absolute ground gravity and MRS surveys in West Africa  

Microsoft Academic Search

Important and fast groundwater storage changes occur in tropical monsoon regions in response to seasonal rainfall and subsequent surface water redistribution. In West Africa, one main goal of the GHYRAF experiment (Gravity and Hydrology in Africa, 2008-2010) is to compare absolute gravimetric measurements with dense hydrological surveys to better estimate and model water storage changes at various time scales. Magnetic

G. Favreau; M. Boucher; B. Luck; J. Pfeffer; P. Genthon; J. Hinderer

2009-01-01

136

Little Common Ground for Magazine Editors and Professors Surveyed on Journalism Curriculum  

Microsoft Academic Search

This study was designed to fill a gap in the literature by analyzing the attitudes of magazine editors and educators toward various skills that job applicants should exhibit. The survey results detail significant differences between the editors and educators on eighteen of twenty-three skills. Open-ended questions also indicated that editors appeared to value nonskills such as cheerfulness, while overlooking a

Carolyn Lepre; Glen L. Bleske

2005-01-01

137

Prenotification, Incentives, and Survey Modality: An Experimental Test of Methods to Increase Survey Response Rates of School Principals  

ERIC Educational Resources Information Center

Teacher and principal surveys are among the most common data collection techniques employed in education research. Yet there is remarkably little research on survey methods in education, or about the most cost-effective way to raise response rates among teachers and principals. In an effort to explore various methods for increasing survey response…

Jacob, Robin Tepper; Jacob, Brian

2012-01-01

138

Approximate policy iteration: a survey and some new methods  

Microsoft Academic Search

We consider the classical policy iteration method of dynamic programming (DP), where approximations and simulation are used\\u000a to deal with the curse of dimensionality. We survey a number of issues: convergence and rate of convergence of approximate\\u000a policy evaluation methods, singularity and susceptibility to simulation noise of policy evaluation, exploration issues, constrained\\u000a and enhanced policy iteration, policy oscillation and chattering,

Dimitri P. Bertsekas

2011-01-01

139

Tomographic surveys for mineral exploration using complex resistivity method  

NASA Astrophysics Data System (ADS)

Complex resistive method is a kind of induced polarization (IP) method which all the measurement is made in frequency domain. It transmits the current with the specified frequency through current electrodes, and measure the amplitude and phase to the transmitted current at receiver electrodes. It is also called SIP (Spectral IP) method when multi-frequency measurements are involved. Our research group has been developing the methodology and interpretation technique for SIP survey for several years, and already developed 2/3D inversion algorithms and extended them to the simultaneous inversion of multi-frequency IP data. Recently we are developing mining evaluation technique by relating the inverted property of field IP data to the measured one in the laboratory through geo-statistical relationship. L1-norm inversion using IRLS (iterative reweighted least squares) method is introduced to overcome the problem of noise sensitive characteristics of complex resistivity data, especially in phase data and effectively applied to the field data. The L1-norm inversion improves the noise characteristics of complex resistivity survey. However complex resistivity method is used only for the surface survey because it require special electrode like porous pot and layout of cables to minimize the interference between transmitters and receivers. In this study, we applied complex resistivity method to the tomographic survey using boreholes and interpret data using L1-norm inversion technique to verify applicability without special electrode and layout of cables. Survey was done for the boreholes drilled in the tunnel for prospecting possible mineralized zone. Zeta system based on GDP multi-function receiver manufactured by Zonge was used in this survey and tomographic data measurement was made for two frequencies, 0.25 and 1 Hz. 30 electrodes respectively for two boreholes, a total of 60 electrodes were used in this survey and electrode spacing was 10 meter. Quality of measured data was not good, especially in in-line measurement due to the borehole effect. Inversion was tried after removing bad data. Conductive region was identified near the ore zone which was identified by core logging in the inverted resistivity section. It was also identified in the normal resistivity tomography done for the same boreholes. Comparing these two results, section from complex resistivity shows much smoother image than normal resistivity because complex resistivity data was edited more due to its lower data quality. Similar anomaly pattern was identified in the inverted phase section because the mineralized zone was supposed to have strong IP characteristics. Proper survey cable and electrodes were crucial to get reliable complex resistivity data. But it might be a hurdle to extend its applicability to the real survey and should be treated in a proper way someday. Through the test survey, we found its usefulness for mineral exploration again even for tomographic survey and some problems on the measurement. We will continue the related study to solve this problem.

Son, J.; Park, S.; Kim, J.

2011-12-01

140

Apparatus for and method of testing an electrical ground fault circuit interrupt device  

DOEpatents

An apparatus for testing a ground fault circuit interrupt device includes a processor, an input device connected to the processor for receiving input from an operator, a storage media connected to the processor for storing test data, an output device connected to the processor for outputting information corresponding to the test data to the operator, and a calibrated variable load circuit connected between the processor and the ground fault circuit interrupt device. The ground fault circuit interrupt device is configured to trip a corresponding circuit breaker. The processor is configured to receive signals from the calibrated variable load circuit and to process the signals to determine a trip threshold current and/or a trip time. A method of testing the ground fault circuit interrupt device includes a first step of providing an identification for the ground fault circuit interrupt device. Test data is then recorded in accordance with the identification. By comparing test data from an initial test with test data from a subsequent test, a trend of performance for the ground fault circuit interrupt device is determined. 17 figs.

Andrews, L.B.

1998-08-18

141

Detection methods for stealth radio signals: A literature survey  

NASA Astrophysics Data System (ADS)

In military radio communication systems, a central feature is often the ability to avoid discovery by some hostile interceptor. Therefore, when designing such a stealth radio system, it is naturally important to have knowledge of the different existing signal detection methods, i.e., the threats to a stealth radio system. This report is a literature survey of some of the most interesting methods of detecting different types of digitally modulated radio communication signals. The methods covered are wide-band radiometer detection, optimum detection and cyclic-feature detection. Comparisons between the different methods are also performed.

Andersson, G.

1993-08-01

142

U.S. Geological Survey ground-water studies in Florida  

USGS Publications Warehouse

The first groundwater study by the U.S. Geological Survey (USGS) in Florida began in 1910. In 1930, a cooperative program of study was started with the Florida Geological Survey, and in 1938, the first groundwater office of the USGS was established in Miami. In fiscal year 1987, the USGS program in Florida included 35 active groundwater studies, all of which dealt with at least one of the principal groundwater issues. The 35 active studies were divided among the issues as follows: groundwater quality management, 9 studies; groundwater availability, 12 studies; seawater intrusion, 3 studies; contamination from wastewater disposal, 6 studies; contamination from landfills and hazardous waste sites, 3 studies; and contamination from agricultural practices, 2 studies. (Lantz-PTT)

Vecchioli, John

1988-01-01

143

Survey of ground state neutron spectroscopic factors from Li to Cr isotopes  

NASA Astrophysics Data System (ADS)

The success of the Shell Model has prompted many measurements to extract the spectroscopic factors which describe the configuration of single particle orbitals. We have extracted the ground state to ground state neutron spectroscopic factors for 79 nuclei ranging in Z from 3 to 24 by analyzing the past measurements of the angular distributions of (d,p) and (p,d) reactions in a systematic and consistent manner [1]. For the Ca isotopes from ^40Ca to ^48Ca, the spectroscopic factors follow the predictions of the single particle model predictions as well as predictions from shell model suggesting Ca isotopes have good spherical cores with well defined valence nucleons. For the 59 nuclei where modern shell model calculations [Oxbash] are available, with the exception of the deformed F and Ne isotopes, the experimental spectroscopic factors for most nuclei agree with predictions from modern day shell model to within 20%. This work is supported by the NSF Grant No. NSF-PHY-01-10253 and SURE. Reference: [1] X.D.Liu, M.A.Famiano,W.G.Lynch,M.B.Tsang,and J.A.Tostevin, Phys. Rev. C69 (2004) 1.

Lee, Hui-Ching; Tsang, Betty

2005-04-01

144

General method for finding ground state manifold of classical Heisenberg model  

NASA Astrophysics Data System (ADS)

What is the ground state manifold of a classical Heisenberg model for an infinite crystal? It sounds simple, but the intuitive approach gets stuck for more general interaction patterns and higher crystal dimensions. In this paper we present an essentially analytical method that can deal with all systems with one-spin unit cells and a broad class of systems with multi-spin unit cells. We also prove a theorem that guarantees that these systems must have some ``spiral ground states,'' which are co-planar. The method can be applied to classify all such systems, so that one can read off the ground state manifold of a Hamiltonian from some of its ``spectral properties.'' It can also be generalized to XY models, finite crystals, and anisotropic couplings, and may be helpful for quantum anomalous Hall effect and spin liquids.

Xiong, Zhaoxi; Wen, Xiao-Gang

2013-03-01

145

Finding common ground in team-based qualitative research using the convergent interviewing method.  

PubMed

Research councils, agencies, and researchers recognize the benefits of team-based health research. However, researchers involved in large-scale team-based research projects face multiple challenges as they seek to identify epistemological and ontological common ground. Typically, these challenges occur between quantitative and qualitative researchers but can occur between qualitative researchers, particularly when the project involves multiple disciplinary perspectives. The authors use the convergent interviewing technique in their multidisciplinary research project to overcome these challenges. This technique assists them in developing common epistemological and ontological ground while enabling swift and detailed data collection and analysis. Although convergent interviewing is a relatively new method described primarily in marketing research, it compares and contrasts well with grounded theory and other techniques. The authors argue that this process provides a rigorous method to structure and refine research projects and requires researchers to identify and be accountable for developing a common epistemological and ontological position. PMID:16954531

Driedger, S Michelle; Gallois, Cindy; Sanders, Carrie B; Santesso, Nancy

2006-10-01

146

Mixing Web and Mail Methods in a Survey of Physicians  

PubMed Central

Objective To assess the effects of two different mixed-mode (mail and web survey) combinations on response rates, response times, and nonresponse bias in a sample of primary care and specialty internal medicine physicians. Data Sources/Study Setting Primary data were collected from 500 physicians with an appointment in the Mayo Clinic Department of Medicine (DOM) between February and March 2005. Study Design Physicians were randomly assigned to receive either an initial mailed survey evaluating the Electronic Medical Record (EMR) with a web survey follow-up to nonrespondents or its converse—an initial web survey followed by a mailed survey to nonrespondents. Response rates for each condition were calculated using standard formula. Response times were determined as well. Nonresponse bias was measured by comparing selected characteristics of survey respondents to similar characteristics in the full sample frame. In addition, the distributions of results on key outcome variables were compared overall and by data collection condition and phase. Principal Findings Overall response rates were somewhat higher in the mail/web condition (70.5 percent) than in the web/mail condition (62.9 percent); differences were more pronounced before the mode switch prior to the mailing to nonrespondents. Median response time was 2 days faster in the web/mail condition than in the mail/web (median=5 and 7 days, respectively) but there was evidence of under-representation of specialist physicians and those who used the EMR a half a day or less each day in the web/mail condition before introduction of the mailed component. This did not translate into significant inconsistencies or differences in the distributions of key outcome variables, however. Conclusions A methodology that uses an initial mailing of a self-administered form followed by a web survey to nonrespondents provides slightly higher response rates and a more representative sample than one that starts with web and ends with a mailed survey. However, if the length of the data collection period is limited and rapid response is important, perhaps the web survey followed by a mailed questionnaire is to be preferred. Key outcome variables appear to be unaffected by the data collection method.

Beebe, Timothy J; Locke, G Richard; Barnes, Sunni A; Davern, Michael E; Anderson, Kari J

2007-01-01

147

Using Airborne and Ground Electromagnetic Surveys and DC Resistivity Surveys to Delineate a Plume of Conductive Water at an In-Channel Coalbed Methane Produced Water Impoundment Near the Powder River, Wyoming  

NASA Astrophysics Data System (ADS)

Development of coal bed methane (CBM) in the Powder River Basin of Wyoming and Montana has significantly increased since 1997. Production of CBM involves withdrawing groundwater from the coal bed to lower the hydrostatic pressure thereby allowing methane to desorb from the coal. The water co-produced with CBM is managed by storing it in impoundments until it can infiltrate to the groundwater, be used for beneficial purposes, or be discharged to surface streams. Skewed Reservoir was constructed as a research site to evaluate disposal of CBM water through infiltration ponds constructed by damming ephemeral streams. Geochemical data collected from monitoring wells placed downgradient of the reservoir detected a plume of water with total dissolved solids concentrations an order of magnitude higher than the CBM water stored in the impoundment. Infiltrating CBM water is suspected to have dissolved salts that were present in the unconsolidated materials beneath the reservoir. A geophysical investigation of the Skewed Reservoir area was conducted in July of 2004 to map the horizontal and vertical extent of the plume and to possibly identify the source of solutes to the infiltrating water. The Department of Energy's National Energy Technology Laboratory contracted Fugro Airborne Surveys to fly their RESOLVE frequency domain airborne electromagnetic (AEM) system with 50-m line spacing at the site. A ground investigation was completed at the same time as the airborne survey. Five 2-D dipole-dipole resistivity surveys and one 3-D pole-dipole survey were conducted using the AGI SuperSting R8/IP multi-channel resistivity imaging system. Additionally, ground conductivity measurements were recorded along each resistivity line using a Geophex GEM-2 multi-frequency ground conductivity meter. All geoelectrical measurements were inverted to obtain the subsurface conductivity distribution. Inversions were constrained using results of downhole borehole induction logs. Results were compared to geological and geochemical data collected from on-site monitoring wells. The geophysical methods accurately delineated the CBM water plume. Differences in the inversion results were observed and are discussed. The AEM data may also prove useful in identifying potential problem areas for locating future in-channel storage impoundments.

Lipinski, B. A.; Harbert, W.; Hammack, R.; Sams, J.; Veloski, G.; Smith, B. D.

2004-12-01

148

Method of Using Satellite and Ground Information When Researching Catastrophes with an Atmospheric Origin  

Microsoft Academic Search

A new method is discussed for research of thematic data bases from satellite and ground information which serve to solve problems about the research of the physical conditions of genesis and evolution of the atmospheric catastrophes. The basic experimental complexity of the created atmospheric situation, which forms a transition from a normal turbulent condition of the atmosphere to a state

Stiliyan Stoyanov; Angel Manev

149

A method for the mapping of the apparent ground brightness using visible images from geostationary satellites  

Microsoft Academic Search

This paper deals with a method for mapping the apparent ground brightness on a pixel basis. It makes use of geostationary satellite visible data and generalizes the earlier work of Cano (1982). The detection of clouds larger than one pixel is performed in a time series by comparing the cloud-induced sensor response to the signal which would occur if the

G. Moussu; L. Diabate; D. Obrecht; L. Wald

1989-01-01

150

Misused and missed use — Grounded Theory and Objective Hermeneutics as methods for research in industrial marketing  

Microsoft Academic Search

Since qualitative research methods have always found strong representation within sociology it is warranted to look at the sociological discussion in order to challenge and enrich qualitative research in industrial marketing. With this mission in mind, we discuss two sociological concepts that constitute influential schools within the German-speaking sociology of language community: Grounded Theory and Objective Hermeneutics. The analysis of

Stephan M. Wagner; Peter Lukassen; Matthias Mahlendorf

2010-01-01

151

The elementary current method for calculating ionospheric current systems from multisatellite and ground magnetometer data  

Microsoft Academic Search

The recently launched Cluster II mission provides for the first time the possibility to instantaneously obtain spatially distributed measurements of field-aligned currents from a fleet of satellites. We present the ``elementary current method'' that combines such measurements mapped to the ionosphere with two-dimensional ground magnetic data, to calculate actual (not equivalent) ionospheric currents, without the need of further assumptions. If

O. Amm

2001-01-01

152

GROUND WATER MONITORING AND SAMPLING: MULTI-LEVEL VERSUS TRADITIONAL METHODS WHATS WHAT?  

EPA Science Inventory

After years of research and many publications, the question still remains: What is the best method to collect representative ground water samples from monitoring wells? Numerous systems and devices are currently available for obtaining both multi-level samples as well as traditi...

153

Methods of minimizing ground-water contamination from in situ leach uranium mining. Final report  

Microsoft Academic Search

This is the final report of a research project designed to study methods of minimizing ground-water contamination from in situ leach uranium mining. Fieldwork and laboratory experiments were conducted to identify excursion indicators for monitoring purposes during mining, and to evaluate effective aquifer restoration techniques following mining. Many of the solution constituents were found to be too reactive with the

W. J. Deutsch; W. J. Martin; L. E. Eary; R. J. Serne

1985-01-01

154

A Forest Biomass Survey by Bitterlich Method With an Electronic Relascope for Satellite Data Validation  

NASA Astrophysics Data System (ADS)

For the better understanding of the carbon cycle in the global ecosystem, an investigation on the spatio- temporal variation of the carbon stock which is stored as vegetation biomass should be important. "PALSAR (Phased Array type L-band Synthetic Aperture Radar)", an onboard sensor of the polar orbiting satellite "ALOS (Advanced Land Observing Satellite)" launched in January 2006, provides the information which can be used for the above-ground biomass estimation. It is expected that ALOS/PALSAR provides us a great opportunity to analyze the biomass dynamics over extensive regions. To derive the biomass from the ALOS/PALSAR measurement, it is inevitable to acquire in situ biomass measurement by ground-based forest surveys. Moreover, it is required to obtain such ground-based information at as possible many sites, because the region targeted by satellite remote sensing is extensive and the forest structure in that region is various. Therefore, a quick forest survey will be required to measure the biomass at as possible many sites. For the quick measurement of the forest above-ground biomass, we propose a way that is a combination of Bitterlich angle count sampling method and sampled-tree measuring method. First, a tree which has wider trunk than the basal area factor (BAF) angle is identified by the relascope from a representative point in the target forest. Next, the tree height and the breast height diameter (DBH) of the sampled tree are measured. The biomass of the tree is estimate by the allometric equation with the tree height and DBH measurements. Through these processes, the biomass density of the sampled tree per the forest area defined by the BAF is estimated. By sampling and measuring all trees (usually around 20 trees), the biomass of the forest can be estimate. A brand-new electronic relascope (Criterion RD 1000, Laser Technology Inc.) and laser range finder (TruPulse 200, Laser Technology Inc.) are used for the tree height and DBH measurements to shorten the time required for measuring. A preliminary forest survey was conducted in a Pinus densiflora forest around Fujiyoshida, Yamanashi, Japan, and examined the adaptability of this way.

Suzuki, R.; Ishii, R.; Takao, G.; Nakano, T.; Yasuda, T.

2006-12-01

155

A survey on statistical methods for health care fraud detection  

Microsoft Academic Search

Fraud and abuse have led to significant additional expense in the health care system of the United States. This paper aims\\u000a to provide a comprehensive survey of the statistical methods applied to health care fraud detection, with focuses on classifying\\u000a fraudulent behaviors, identifying the major sources and characteristics of the data based on which fraud detection has been\\u000a conducted, discussing

Jing Li; Kuei-Ying Huang; Jionghua Jin; Jianjun Shi

2008-01-01

156

Fourth national outdoor action conference on aquifer restoration, ground water monitoring and geophysical methods  

SciTech Connect

The Outdoor Action Conference on Aquifer Restoration, Ground Water Monitoring and Geophysical Methods is a multidimensional educational program. The meeting features technical paper presentations, indoor and outdoor workshops, outdoor demonstrations and an exposition of equipment used in the ground water monitoring industry. The Fourth National Outdoor Action Conference was held May 14-17, 1990, in Las Vegas, Nevada. More than 100 technical papers were presented during the four-day program. The following topics were addressed: innovative technology, monitoring well engineering, soil gas sampling, monitoring techniques, air stripping, vapor extraction, remediation investigations, bioremediation, geophysics, site characterization, and risk assessment. This bound volume is a compilation of papers presented at the meeting.

Not Available

1990-01-01

157

A method for spatial estimation of peak ground acceleration in dense arrays  

NASA Astrophysics Data System (ADS)

A methodology for the interpolation of peak ground acceleration (PGA) from discrete array stations is developed. Limited number of accelerometers or difficulty of monitoring at unreachable locations often has a negative impact on the generation of the maps of shaking after an earthquake. In locations with no recordings, PGA is inferred from interpolation of recorded PGA. The presented methodology estimates PGA at an arbitrary set of closely spaced points, in a way that is statistically compatible with known or prescribed PGA at other locations. The observed data recorded by strong motion stations of Istanbul Earthquake Rapid Response System are used for the development and validation of the new numerical method. The estimated and recorded PGAs are compared. Biased ground motion prediction equations are also considered at the comparisons. Ground motion prediction equations underestimated both observed and estimated PGAs. It has been found that the methodology is very effective for highly vulnerable mega-cities and urban areas.

Harmandar, Ebru; ?akt?, Eser; Erdik, Mustafa

2012-12-01

158

A Method for Emphasizing Reflection Waves from Buried Objects by Using Ground-penetrating Radar  

NASA Astrophysics Data System (ADS)

Ground-penetrating radar (GPR) is a useful tool for performing subsurface imaging by using radar pulses. In previous paper, we proposed a method for denoising GPR signals by using 2D Gabor wavelet transforms. In this paper, we present a new method for emphasizing GPR reflected waves from buried objects. We can evaluate the results of the time-frequency analysis of the reflection waves on the basis of the Markov Chain Monte Carlo (MCMC) and the Infinite Gaussian Mixture Model (IGMM) methods. Our proposed methods are effective as pre-processing method for detecting the positions of buried metal pipes.

Kobayashi, Makoto; Nakano, Kazushi

159

Tropospheric ozone profiles from a ground-based ultraviolet spectrometer: a new retrieval method  

Microsoft Academic Search

We present, to the best of our knowledge, a new method to retrieve tropospheric ozone (O3) profiles from ground-based ultraviolet spectroscopic measurements. This method utilizes radiance spectra in the Huggins bands (i.e., 300-340 nm) measured at three off-axis angles (e.g., 45°,75°, and 85°) normalized to direct-Sun irradiances or zenith-sky radiances with the total column O3 derived from direct-Sun or zenith-sky

Xiong Liu; Kelly Chance; Christopher E. Sioris; Michael J. Newchurch; Thomas P. Kurosu

2006-01-01

160

A study of the ground state of quantum wires using the finite difference method  

Microsoft Academic Search

We use the finite difference method to calculate the ground state of V-shaped, rectangular and square quantum wires. The reliability of the method is tested studying the influence of the wire’s environment, experimental characteristics, and the characteristic parameters of the grid on the results. For quantum wires of equal cross-sectional area and different shapes we study the effect of the

Maria Tsetseri; Georgios P Triberis

2002-01-01

161

The Application of a Combined Geophysical Survey (Ground-Penetrating Radar and Seismic Refraction) for mapping Sinkholes in Ghor Al-Haditha Area, Jordan  

NASA Astrophysics Data System (ADS)

Earth subsidence and sinkholes are natural phenomena that occur in certain geological environments and are associated with surface, subsurface, local and regional processes. The natural solution cavities are common in carbonate rocks and other geological environments, which characterized by the presence of large volumes of evaporates. Subsidence and or sinkholes follow the creation of subsurface caverns, especially if the overlying material consists of soft or poorly cemented sediments. The water circulation and fluctuations play a major role in the creation of caverns as well as causing the triggering of the failure of the overlying earth material. Tectonic and seism tectonic processes have a major role in forming the subsidence and sinkholes particularly in tectonic-active zones such as the Dead Sea region that characterized by the presence of many local and regional subsurface salt features. The study area, Ghor Al Haditha form a part of the southern Dead Sea basin, where subsidences and sinkholes are representing natural phenomena. The occurrence of these phenomena in the area dates back to many years. But since the transfer of the Jordan River in the 1960s and the subsequent lowering of the Dead Sea level, the problem started to occur in a rather serious manner with a noticeable correlation with the fluctuations in the level of the Dead Sea. . Geophysical surveys were carried out in the study area. The aim is to perform a geophysical map of the subsurface layers and to infer its physical properties. Deployed geophysical methods are Ground Penetrating Radar (GPR) and Seismic Refraction technique. The results of the ground penetrating radar (GPR) indicate the presence of cavities and cracks, which may verify drainage of water at surface and actually affirms the formation of sinkholes. The seismic refraction survey support the idea of a possible regional subsurface fault in a NNE direction. The highest recorded P-velocity for subsurface layers is 3948 m/sec which may represent salt intrusions at 70m depth.

Abueladas, A. A.; Al-Zoubi, A. S.

2004-12-01

162

An experimental comparison of in-situ gamma spectrometric methods for quantifying Cs137 radioactive contamination in the ground  

Microsoft Academic Search

In-situ gamma spectrometry is a potentially powerful method for rapid quantification of radioactive contamination in the ground using an above-ground detector. The accuracy of the technique, however, depends on having information on the activity variation with depth. Three methods have previously been proposed for deriving this information using information obtained in the field. This paper describes these methods and models

J. MacDonald; C. J. Gibson; P. J. Fish; D. J. Assinder

1999-01-01

163

Surveying the seismic hazard by using ground based analysis of the Earth's electromagnetic data  

NASA Astrophysics Data System (ADS)

Previous studies have shown that there are some electromagnetic (EM) effects in the crust and upper mantle caused by the major natural hazard activities such as earthquake events. Despite these prolific results of observation, earthquake related EM signals, in particular those at pre-seismic stage, have not yet been completely accepted as real physical quantities. Majority of proposed mechanisms attribute pre-seismic signals/parameters to effects such as piezo-electric, electro-kinetic, charged dislocations, exo-electrons and lithospheric conductivity changes due to the fluid migration through faulting system, being induced by stress changes and fracturing processes in the last stage of EQ preparation, respectively. In this respect, our goal is to develop a multi-parametric approach to assessing the Earth's electromagnetic field related to the intermediate depth seismic activity studies, taking into account that EQs are accompanied by intensified propagation of the electric charges along the specific sensitivity paths, in the lithosphere. These processes lead to generation of internal electric/magnetic field, into and nearby the seismogenic volume (Vrancea zone, Romania), producing the modification of the electrical conductivity in the intermediate depth interval (70-150km.). The methodology is focused on ground based multi-parametric continuous measurements of the geomagnetic field, in the frequency range DC- 1kHz, using the MAG-03 DAM system able to collect the data from the three axis magnetic field sensor MAG-03 MSL and a computer for real time data storage and processing. For a two-dimensional structure, this approach describes the physical coupling between the both vertical geomagnetic component (Bz) and horizontal geomagnetic component perpendicular to the geotectonic strike (Bperp), by using anomalous behavior of the normalized functions Bzn = Bz/Bperp and Ron = Ropar/ Roz as precursory parameters related to the intermediate depth EQs. Our results show that simultaneous analysis of these normalized functions and seismic events occurred in Vrancea zone it could provide monitoring capabilities of the earthquake precursors.

Stanica, D.; Stanica, D. A.; Vladimirescu, N.

2009-04-01

164

Efficient numerical methods for computing ground states of spin-1 Bose-Einstein condensates based on their characterizations  

NASA Astrophysics Data System (ADS)

In this paper, we propose efficient numerical methods for computing ground states of spin-1 Bose-Einstein condensates (BECs) with/without the Ioffe-Pritchard magnetic field B(x). When B(x)?0, a numerical method is introduced to compute the ground states and it is also applied to study properties of ground states. Numerical results suggest that the densities of mF=±1 components in ground states are identical for any nonzero B(x). In particular, if B(x)?B?0 is a constant, the ground states satisfy the single-mode approximation. When B(x)?0, efficient and simpler numerical methods are presented to solve the ground states of spin-1 BECs based on their ferromagnetic/antiferromagnetic characterizations. Numerical simulations show that our methods are more efficient than those in the literature. In addition, some conjectures are made from our numerical observations.

Bao, Weizhu; Chern, I.-Liang; Zhang, Yanzhi

2013-11-01

165

Hybrid identification method for multi-story buildings with unknown ground motion: theory  

NASA Astrophysics Data System (ADS)

Simultaneous identification of both structural parameters and ground motion of an earthquake-excited structure by using measured structural response time histories only has received great interests in recent years. However, this paper demonstrates through a multi-story shear building that the structural parameters and the ground motion cannot be uniquely identified when the absolute forced structural response time histories are used directly. A hybrid identification method is thus proposed for the problem concerned. The hybrid identification method first identifies the structural parameters above the first floor of a multi-story shear building using the least-squares method after the corresponding parametric identification equation is established. The minimum modal information is then introduced to find the structural parameter of the first floor of the building to eliminate the non-uniqueness problem. After all the structural parameters are identified, the unknown earthquake-induced ground motion is finally constructed by solving a first-order differentiation equation. To enhance the capability of the hybrid identification method against measurement noise, an amplitude-selective filtering procedure is also proposed. Numerical example demonstrates the feasibility and efficiency of the hybrid identification method and the effectiveness of the amplitude-selective filtering procedure. The restriction of the proposed methodology in real application and future research on this topic are also pointed out.

Zhao, X.; Xu, Y. L.; Li, J.; Chen, J.

2006-03-01

166

A Denoising Method for Detecting Reflected Waves from Buried Objects by Ground-penetrating Radar  

NASA Astrophysics Data System (ADS)

Ground-penetrating radar is a tool for imaging the subsurfaces with radar pulses. Since a variety of media including buried objects give different dielectric constants, the positions of the buried objects can be detected on the basis of variations in the reflected return signals. This paper presents a denoising method based on the 2D-Gabor wavelet transform method to solve the pending problems in extracting the signals reflected from buried objects. The validity of our method is demonstrated by comparing it with the f-k filtering method.

Kobayashi, Makoto; Nakano, Kazushi

167

Long-Term Behavior of a Slow-Moving Landslide Inferred From Ground-Based Surveys and Analysis of Digital Terrain Models  

Microsoft Academic Search

Movement of Minor Creek landslide in Humboldt County, northwestern California, has been monitored for almost thirty years. We report movement patterns and sediment yields derived from repetitive ground-based surveys and supplement them with inferences from analysis of digital terrain models (DTMs) created from aerial photographs taken in 1982 and 2001. The landslide consists predominantly of gravelly, sandy clay, has earthflow-like

L. E. Mark; R. M. Iverson; J. A. Messerich

2002-01-01

168

Reassessment of the 4 N+ 2 CH 3 ground state reaction by quantum chemistry methods  

Microsoft Academic Search

The 4N+2CH3 ground-state reaction involved in the chemistry of planetary atmospheres has been investigated by several high-level quantum chemistry computation methods of molecular orbital and density functional types. Attention has been drawn to space and symmetry constraints, convergence of the energy differences computed with respect to the size of the basis set and the nature of the correlation treatment. The

I. Hadjebar; M Nait Achour; A Boucekkine; G Berthier

2001-01-01

169

Fermi-hypernetted-chain methods and the ground state of fermion matter  

Microsoft Academic Search

The convergence properties of the Fermi-hypernetted-chain method as originated by Fantoni and Rosati are investigated. Numerical results are reported for liquid ³He and two model fermion liquids. It turns out that for not too high densities and not too long-ranged correlation functions the convergence to an upper bound for the ground-state energy is excellent, but that for higher densities and\\/or

John Zabolitzky

1977-01-01

170

Methods Used to Streamline the CAHPS(R) Hospital Survey  

PubMed Central

Objective To identify a parsimonious subset of reliable, valid, and consumer-salient items from 33 questions asking for patient reports about hospital care quality. Data Source CAHPS® Hospital Survey pilot data were collected during the summer of 2003 using mail and telephone from 19,720 patients who had been treated in 132 hospitals in three states and discharged from November 2002 to January 2003. Methods Standard psychometric methods were used to assess the reliability (internal consistency reliability and hospital-level reliability) and construct validity (exploratory and confirmatory factor analyses, strength of relationship to overall rating of hospital) of the 33 report items. The best subset of items from among the 33 was selected based on their statistical properties in conjunction with the importance assigned to each item by participants in 14 focus groups. Principal Findings Confirmatory factor analysis (CFA) indicated that a subset of 16 questions proposed to measure seven aspects of hospital care (communication with nurses, communication with doctors, responsiveness to patient needs, physical environment, pain control, communication about medication, and discharge information) demonstrated excellent fit to the data. Scales in each of these areas had acceptable levels of reliability to discriminate among hospitals and internal consistency reliability estimates comparable with previously developed CAHPS instruments. Conclusion Although half the length of the original, the shorter CAHPS hospital survey demonstrates promising measurement properties, identifies variations in care among hospitals, and deals with aspects of the hospital stay that are important to patients' evaluations of care quality.

Keller, San; O'Malley, A James; Hays, Ron D; Matthew, Rebecca A; Zaslavsky, Alan M; Hepner, Kimberly A; Cleary, Paul D

2005-01-01

171

Quantum Monte Carlo method for the ground state of many-boson systems.  

PubMed

We formulate a quantum Monte Carlo (QMC) method for calculating the ground state of many-boson systems. The method is based on a field-theoretical approach, and is closely related to existing fermion auxiliary-field QMC methods which are applied in several fields of physics. The ground-state projection is implemented as a branching random walk in the space of permanents consisting of identical single-particle orbitals. Any single-particle basis can be used, and the method is in principle exact. We illustrate this method with a trapped atomic boson gas, where the atoms interact via an attractive or repulsive contact two-body potential. We choose as the single-particle basis a real-space grid. We compare with exact results in small systems and arbitrarily sized systems of untrapped bosons with attractive interactions in one dimension, where analytical solutions exist. We also compare with the corresponding Gross-Pitaevskii (GP) mean-field calculations for trapped atoms, and discuss the close formal relation between our method and the GP approach. Our method provides a way to systematically improve upon GP while using the same framework, capturing interaction and correlation effects with a stochastic, coherent ensemble of noninteracting solutions. We discuss various algorithmic issues, including importance sampling and the back-propagation technique for computing observables, and illustrate them with numerical studies. We show results for systems with up to N approximately 400 bosons. PMID:15600791

Purwanto, Wirawan; Zhang, Shiwei

2004-11-09

172

Computer program for simulation of variable recharge with the U. S. Geological Survey modular finite-difference ground-water flow model (MODFLOW)  

USGS Publications Warehouse

The Variable-Recharge Package is a computerized method designed for use with the U.S. Geological Survey three-dimensional finitedifference ground-water flow model (MODFLOW-88) to simulate areal recharge to an aquifer. It is suitable for simulations of aquifers in which the relation between ground-water levels and land surface can affect the amount and distribution of recharge. The method is based on the premise that recharge to an aquifer cannot occur where the water level is at or above land surface. Consequently, recharge will vary spatially in simulations in which the Variable- Recharge Package is applied, if the water levels are sufficiently high. The input data required by the program for each model cell that can potentially receive recharge includes the average land-surface elevation and a quantity termed ?water available for recharge,? which is equal to precipitation minus evapotranspiration. The Variable-Recharge Package also can be used to simulate recharge to a valley-fill aquifer in which the valley fill and the adjoining uplands are explicitly simulated. Valley-fill aquifers, which are the most common type of aquifer in the glaciated northeastern United States, receive much of their recharge from upland sources as channeled and(or) unchanneled surface runoff and as lateral ground-water flow. Surface runoff in the uplands is generated in the model when the applied water available for recharge is rejected because simulated water levels are at or above land surface. The surface runoff can be distributed to other parts of the model by (1) applying the amount of the surface runoff that flows to upland streams (channeled runoff) to explicitly simulated streams that flow onto the valley floor, and(or) (2) applying the amount that flows downslope toward the valley- fill aquifer (unchanneled runoff) to specified model cells, typically those near the valley wall. An example model of an idealized valley- fill aquifer is presented to demonstrate application of the method and the type of information that can be derived from its use. Documentation of the Variable-Recharge Package is provided in the appendixes and includes listings of model code and of program variables. Comment statements in the program listings provide a narrative of the code. Input-data instructions and printed model output for the package are included.

Kontis, A. L.

2001-01-01

173

Testing alternative ground water models using cross-validation and other methods  

USGS Publications Warehouse

Many methods can be used to test alternative ground water models. Of concern in this work are methods able to (1) rank alternative models (also called model discrimination) and (2) identify observations important to parameter estimates and predictions (equivalent to the purpose served by some types of sensitivity analysis). Some of the measures investigated are computationally efficient; others are computationally demanding. The latter are generally needed to account for model nonlinearity. The efficient model discrimination methods investigated include the information criteria: the corrected Akaike information criterion, Bayesian information criterion, and generalized cross-validation. The efficient sensitivity analysis measures used are dimensionless scaled sensitivity (DSS), composite scaled sensitivity, and parameter correlation coefficient (PCC); the other statistics are DFBETAS, Cook's D, and observation-prediction statistic. Acronyms are explained in the introduction. Cross-validation (CV) is a computationally intensive nonlinear method that is used for both model discrimination and sensitivity analysis. The methods are tested using up to five alternative parsimoniously constructed models of the ground water system of the Maggia Valley in southern Switzerland. The alternative models differ in their representation of hydraulic conductivity. A new method for graphically representing CV and sensitivity analysis results for complex models is presented and used to evaluate the utility of the efficient statistics. The results indicate that for model selection, the information criteria produce similar results at much smaller computational cost than CV. For identifying important observations, the only obviously inferior linear measure is DSS; the poor performance was expected because DSS does not include the effects of parameter correlation and PCC reveals large parameter correlations. ?? 2007 National Ground Water Association.

Foglia, L.; Mehl, S. W.; Hill, M. C.; Perona, P.; Burlando, P.

2007-01-01

174

The cepstrum - A viable method for the removal of ground reflections  

NASA Astrophysics Data System (ADS)

Cepstrum analysis is applied to noise recording on open air test sites to eliminate the ground reflection effects from the recorded noise data. Results are presented on data from three sources: (1) a model jet in an anechoic chamber, (2) a spinning rig - high level microphones, and (3) the Viper 11 engine - high and low level microphones. Comparisons are made between the spectra before and after cepstrum-liftering and free-field spectra obtained from ground level microphones, or, in the case of anechoic chamber, without the reflecting board. It is shown that cepstrum analysis is a satisfactory method of removing the effects of the reflected signal from the power spectrum and producing a free field spectrum.

Syed, A. A.; Brown, J. D.; Oliver, M. J.; Hills, S. A.

1980-07-01

175

A STUDY OF LIFT-OFF TEST METHOD OF GROUND ANCHORS  

NASA Astrophysics Data System (ADS)

Ground anchors (hereinafter anchors) are important to do the maintenance after construction. Residual tensile strength of anchors are generally confirmed by lift-off test that pulls an anchor using a hydraulic jack. However, the lift-off test has not been established a proper testing method. Therefore, it may not have been proper maintenance from measurement variability. In this paper, we conducted various lift-off test at cut slope of the expressway, and made proposals on proper lift-off test method.

Fujiwara, Yuu; Sakai, Toshinori

176

Surveying abandoned mine shafts with Remote Radio Transmitter EM methods and Selfpotential  

NASA Astrophysics Data System (ADS)

Abandoned near subsurface mining constructions from the 19th and early 20th century in urbanized areas placed upon former ore mines near the city of Aachen (Germany), as well as in many other regions of the world, provide hazardous risks concerning possible collapses. In many cases, the exact locations of such constructions are not known anymore. For instance, to map covered shafts of one meter diameter on large survey areas, high resolution methods with rapid measurement progress are necessary. Enhanced developments of the traditional Very Low Frequency (VLF) technique such as VLF-gradient and Radiomagnetotellurics (RMT) fulfill these requirements. Continuous ground-contactless VLF-gradient survey quickly provides maps indicating the lateral electric resistivity heterogeneity distribution. Inversions of RMT data provide 2D-resistivity-depth sections and also the interpretation of Self-Potential data gives information about the nature of the VLF-gradient anomalies. The successful combination of the three methods for detecting mineshafts near to the city if Aachen is presented for both an electromagnetic undisturbed and noisy location.

Bosch, F. P.; Gurk, M.

2009-04-01

177

Quantifying Differences in Beach Volume Change Between 2-D and 3-D Survey Methods  

Microsoft Academic Search

RTK-GPS surveys are the most widely used method of beach surveying for engineers and researchers, but new 3-D methods are gaining popularity because of their increased efficiency and accuracy in topographic and volumetric analysis. The utility of these new methods in comparison to traditional GPS surveys remains poorly understood. This study seeks to assess the differences in volume change calculations

E. J. Theuerkauf; A. B. Rodriguez

2010-01-01

178

Transport survey calculations using the spectral collocation method  

SciTech Connect

A novel transport survey code has been developed and is being used to study the sensitivity of stellarator reactor performance to various transport assumptions. Instead of following one of the usual approaches, the steady-state transport equation are solved in integral form using the spectral collocation method. This approach effectively combine the computational efficiency of global models with the general nature of 1-D solutions. A compact torsatron reactor test case was used to study the convergence properties and flexibility of the new method. The heat transport model combined Shaing's model for ripple-induced neoclassical transport, the Chang-Hinton model for axisymmetric neoclassical transport, and neoalcator scaling for anomalous electron heat flux. Alpha particle heating, radiation losses, classical electron-ion heat flow, and external heating were included. For the test problem, the method exhibited some remarkable convergence properties. As the number of basis functions was increased, the maximum, pointwise error in the integrated power balance decayed exponentially until the numerical noise level as reached. Better than 10% accuracy in the globally-averaged quantities was achieved with only 5 basis functions; better than 1% accuracy was achieved with 10 basis functions. The numerical method was also found to be very general. Extreme temperature gradients at the plasma edge which sometimes arise from the neoclassical models and are difficult to resolve with finite-difference methods were easily resolved. 8 refs., 6 figs.

Painter, S.L.; Lyon, J.F.

1989-01-01

179

Research methods of the Youth Smoking Survey (YSS).  

PubMed

This paper describes the survey development, design and data collection protocol for the 2008/2009 Youth Smoking Survey (YSS) and the changes to the YSS survey and protocols across the 5 survey cycles (1994, 2002, 2004/2005, 2006/2007, 2008/2009). Canada's Youth Smoking Survey is a nationally representative school-based survey of students (grades 6 to 12 in 2008/2009) from randomly sampled public and private schools in the ten provinces. The main objective of the YSS is to provide benchmark data on national smoking prevalence rates for youth. Key features of the 2008/2009 YSS include consistent measures across survey cycles, a survey team of researchers and non-governmental organizations, a link to school and student level measures, provision of tailored feedback reports to schools and publicly available datasets. PMID:22153176

Elton-Marshall, T; Leatherdale, S T; Manske, S R; Wong, K; Ahmed, R; Burkhalter, R

2011-12-01

180

The cause of false operating of the rotor ground fault protection based on the AC injection method  

Microsoft Academic Search

In this paper we tackle the issues of the protection of a synchronous generator field winding in the case of the first ground fault. We analyze the reasons of false operation of the rotor ground fault protection based on the AC injection method on the synchronous machine with a static excitation system. This paper presents the results of the measurements

A. Belan; Z. Eleschova; F. Janicek

2005-01-01

181

Reactions to reading “Remaining consistent with method? An analysis of grounded theory research in accounting” : A comment on Gurd  

Microsoft Academic Search

Purpose – The purpose of this paper is to provide a commentary on “Remaining consistent with method? An analysis of grounded theory research in accounting”, a paper by Gurd. Design\\/methodology\\/approach – Like Gurd, the authors conducted a bibliographic study on prior pieces of research claiming the use of grounded theory. Findings – The authors found a large diversity of ways

Vassili Joannidès; Nicolas Berland

2008-01-01

182

Ground-based measurements of total ozone content by the infrared method  

NASA Astrophysics Data System (ADS)

To interpret the ground-based measurements of the spectra of direct solar infrared radiation with the help of a Brucker Fourier-spectrometer, a technique for determining the total ozone content (TOC) was developed and implemented. The TOC was determined using six spectral intervals of an ozone-absorption band of 9.6 ?m and the shortwave panel of a carbon-dioxide-absorption band of 15 ?m, where the impact of other atmospheric parameters on the measured solar radiation was reduced to a minimum. The potential errors of the infrared method for determining the TOC for the chosen spectral scheme with the influence of measurement errors and vertical profiles of temperature are less than 1% for different signal-to-noise ratios and zenith angles of the sun. We analyzed 269 high-resolution (0.005-0.008 cm-1) spectra of solar infrared radiation measured in Peterhof over 52 days from March to November, 2009. The resulting values of TOC were compared with the results of independent ground-based TOC measurements in Voeikovo (Main Geophysical Observatory) using a Dobson spectrophotometer and an M-124 ozonometer, as well as with the Ozone Monitoring Instrument (OMI) satellite data. The mean errors between the results of TOC measurements with the help of the three ground-based probes constitute no more than 0.4%. The rms errors between data obtained by the Brucker spectrometer and the given satellite and ground-based probes constitute 3-4%. A comparison between different series of measurements indicated that the upper estimate for the error of TOC measurements by the Brucker spectrometer was 2.5-3% (when the possible spatial and temporal errors in measurements are disregarded). An analysis of the diurnal variations in the TOC measurements for stable atmospheric conditions yields an upper estimate of ˜3 DU (around 1%) for the random component of error in TOC measurements by the Brucker spectrometer.

Virolainen, Ya. A.; Timofeev, Yu. M.; Ionov, D. V.; Poberovskii, A. V.; Shalamyanskii, A. M.

2011-08-01

183

A simple, low-cost method to monitor duration of ground water pumping.  

PubMed

Monitoring ground water withdrawals for agriculture is a difficult task, while agricultural development leads frequently to overexploitation of the aquifers. To fix the problem, sustainable management is required based on the knowledge of water uses. This paper introduces a simple and inexpensive direct method to determine the duration of pumping of a well by measuring the temperature of its water outlet pipe. A pumping phase is characterized by a steady temperature value close to ground water temperature. The method involves recording the temperature of the outlet pipe and identifying the different stages of pumping. It is based on the use of the low-cost and small-size Thermochron iButton temperature logger and can be applied to any well, provided that a water outlet pipe is accessible. The temperature time series are analyzed to determine the duration of pumping through manual and automatic posttreatments. The method was tested and applied in South India for irrigation wells using electricity-powered pumps. The duration of pumping obtained by the iButton method is fully consistent with the duration of power supply (1.5% difference). PMID:19016895

Massuel, S; Perrin, J; Wajid, M; Mascre, C; Dewandel, B

2008-11-07

184

Ground penetrating radar survey on the cross-stratified overbank deposits from the 2006 eruption of Tungurahua volcano, Ecuador.  

NASA Astrophysics Data System (ADS)

The deposits of the 2006 pyroclastic density currents (PDCs) at Tungurahua are organized as 1) massive, coarse-grained deposits confined to valleys of the drainage network and 2) cross-stratified, ash-dominated overbank deposits from dilute PDCs. These overbank deposits are exceptionally well preserved and show dune bedforms shaping the surface of the outcrops. In order to gain insights into the depositional mechanisms of the latter, we combined a terrestrial laser scanner (TLS) survey with a ground penetrating radar (GPR) dense network of profiles. The GPR survey permits to look at the internal cross stratification patterns in a non-destructive way. Three antennas with frequencies at 250, 500 and 800 MHz, respectively, permitted to image down to 10, 7 and 3 m depth. While the 800 MHz antenna was found to be very efficient to image cross-lamination, the 250 MHz antenna permitted to recognize major flow units. The GPR dataset profits from the TLS topography data, which are integrated in the processing of the data. From a dense array (profiles at 10 cm spacing) over different types of dune bedforms with the 800 MHz antenna, we manage to reconstruct the 3D internal patterns. Using the 250 MHz antenna, >50 profiles (20-80 m length) over a zone ca. 300*300 m permit to reconstruct and follow the major flow units on the overbanks and their 3D evolution as well as the pre-eruptive paleosoil. Notable results are: (1) the revelation of several units of dense pyroclastic flow deposits below the dilute PDC deposits on the overbanks. This may indicate that the valleys were filled by the time of deposition of the dune bedforms, a result not inferred in previous studies. Moreover, the number of units is greater than previously accessed. (2) For dune bedforms, the root of a structure is found to be located deeper than expected with striking spatial stability during the whole deposition stage, indicating that these bedforms are triggered by basal topographic disturbance. (3) Looking at their 3D patterns, most dune bedforms have a monotone profile, ruling out genesis from currents with different orientations. (4) In some outcrops however, cross-stratifications evolve laterally from stoss-erosive through aggrading to stoss-aggrading, implying that a single dune bedform can show both downstream and upstream migrating crests during the same stage of the flow. (5) Several structures cannibalized by a larger one show proof that the bed rapidly accommodates temporal changes in the dynamics of the currents.

Amin Douillet, Guilhem; Abolghasem, Amir; Rémi Dujardin, Jean; Kueppers, Ulrich; Hall, Jonathan; Mothes, Patricia; Dingwell, Donald

2013-04-01

185

Electromagnetic survey of the K1070A burial ground at the Oak Ridge K-25 Site, Oak Ridge, Tennessee. Environmental Restoration Program  

SciTech Connect

The K1070A burial ground, located at the K-25 Site on the Oak Ridge Reservation, received chemical and radioactive wastes from the late 1940s until 1975. Analysis of water samples collected from nearby monitoring wells indicates that contamination is migrating offsite. In November 1991, Oak Ridge National Laboratory (ORNL) personnel collected high-resolution electrical terrain conductivity data at the K1070A burial ground. A Model EM31 terrain conductivity meter manufactured by Geonics Limited was used in conjunction with the ORNL-developed Ultrasonic Ranging and Data System (USRADS) to perform the survey. The purposeof the survey was to provide Environmental Restoration (ER) staff with a detailed map of the spatial variation of the apparent electrical conductivity of the shallow subsurface (upper 3 m) to assist them in siting future monitoring wells closer to the waste area without drilling into the buried waste.

Nyquist, J.E.; Emery, M.S.

1993-01-01

186

Helicopter-borne and ground-towed radar surveys of the Fourcade Glacier on King George Island, Antarctica  

Microsoft Academic Search

To determine subglacial topography and internal features of the Fourcade Glacier on King George Island in Antarctica, helicopter-borne and ground-towed ground-penetrating radar (GPR) data were recorded along four profiles in November 2006. Signature deconvolution, f-k migration velocity analysis, and finite-difference depth migration applied to the mixed-phase, single-channel, ground-towed data, were effective in increasing vertical resolution, obtaining the velocity function, and

K. Y. Kim; J. Lee; M. H. Hong; J. K. Hong; H. Shon

2010-01-01

187

Evaluation of Electronic and Fax Methods for Survey Research  

Microsoft Academic Search

In an effort to improve the efficiency and cost effectiveness of written surveys, we compared our experiences with distribution of surveys through e-mail and FAX to our earlier uses of surveys mailed in the traditional manner. We used a sample list of dietetic educators that provided e-mail addresses for about two-thirds of the members. If there was no functional e-mail

J. E. Quinn; L. C. Robinson; E. S. Parham

1998-01-01

188

A comparison of several surface finish measurement methods as applied to ground ceramic and metal surfaces  

SciTech Connect

Surface finish is one of the most common measures of surface quality of ground ceramics and metal parts and a wide variety of methods and parameters have been developed to measure it. The purpose of this investigation was to compare the surface roughness parameters obtained on the same two specimens from three different types of measuring instruments: a traditional mechanical stylus system, a non-contact laser scanning system, and the atomic force microscope (two different AFM systems were compared). The same surface-ground silicon nitride and Inconel 625 alloy specimens were used for all measurements in this investigation. Significant differences in arithmetic average roughness, root-mean-square roughness, and peak-to-valley roughness were obtained when comparing data from the various topography measuring instruments. Non-contact methods agreed better with the others on the metal specimen than on the ceramic specimen. Reasons for these differences include the effective dimensions and geometry of the probe with respect to the surface topography; the reflectivity of the surface, and the type of filtering scheme Results of this investigation emphasize the importance of rigorously specifying the manner of surface roughness measurement when either reporting roughness data or when requesting that roughness data be provided.

Blau, P.J.; Martin, R.L.; Riester, L.

1996-01-01

189

Understanding Sample Surveys: Selective Learning about Social Science Research Methods  

ERIC Educational Resources Information Center

|We investigate differences in what students learn about survey methodology in a class on public opinion presented in two critically different ways: with the inclusion or exclusion of an original research project using a random-digit-dial telephone survey. Using a quasi-experimental design and data obtained from pretests and posttests in two…

Currin-Percival, Mary; Johnson, Martin

2010-01-01

190

Correction method for obtaining the variationally best ground-state pair density  

SciTech Connect

We present a correction method for the pair density (PD) to get close to the ground-state one. The PD is corrected to be a variationally best PD within the search region that is extended by adding the uniformly scaled PDs to its elements. The corrected PD is kept N-representable and satisfies the virial relation rigorously. The validity of the present method is confirmed by numerical calculations of neon atom. It is shown that the root-mean-square error of the electron-electron interaction and external potential energies, which is a good benchmark for the error of the PD, is reduced by 69.7% without additional heavy calculations.

Higuchi, Masahiko; Higuchi, Katsuhiko [Department of Physics, Faculty of Science, Shinshu University, Matsumoto 390-8621 (Japan); Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan)

2011-10-15

191

Proposed expansion of the City of Albuquerque/U.S. Geological Survey ground-water-level monitoring network for the middle Rio Grande Basin, New Mexico  

USGS Publications Warehouse

The Middle Rio Grande Basin in central New Mexico, extending from Cochiti Lake on the north to San Acacia on the south, covers an area of about 3,060 square miles. Ground-water withdrawals in the basin are concentrated in and around the city of Albuquerque. Because of rapid increases in population and associated ground-water pumpage, a network of wells was established cooperatively by the City of and the U.S. Geological Survey between April 1982 and September 1983 to monitor changes in ground-water levels throughout the basin. Expansion of this network has been identified as an essential element in plans to study the relation between surface water and ground water in the basin. An inventory of existing wells in the Albuquerque metropolitan area has brought together information on about 400 wells that either are being monitored for water levels or would be good candidates for monitoring. About 115 wells or well sites are proposed as additions to the current 128-well ground-water-level monitoring network for the Middle Rio Grande Basin. Despite the extensive network that would be created by the addition of the proposed existing wells, however, certain parts of the Albuquerque metropolitan area would remain without adequate coverage areally and/or with depth in the Santa Fe Group aquifer until the installation of the proposed new monitoring wells.

Bexfield, L. M.

1998-01-01

192

40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.  

Code of Federal Regulations, 2010 CFR

...2011-07-01 2011-07-01 false Ground water source microbial monitoring and analytical...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2011-07-01

193

40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Ground water source microbial monitoring and analytical...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2013-07-01

194

A multi-method high-resolution geophysical survey in the Machado de Castro museum, central Portugal  

NASA Astrophysics Data System (ADS)

Restoration of historical buildings is a delicate operation as they are often built over more ancient and important structures. The Machado de Castro Museum, Coimbra, Central Portugal, has suffered several interventions in historical times and lies over the ancient Roman forum of Coimbra. This building went through a restoration project. These works were preceded by an extensive geophysical survey that aimed at investigating subsurface stratigraphy, including archeological remains, and the internal structure of the actual walls. Owing to the needs of the project, geophysical data interpretation required not only integration but also high resolution. The study consisted of data acquisition over perpendicular planes and different levels that required detailed survey planning and integration of data from different locations that complement images of the surveyed area. Therefore a multi-method, resistivity imaging and a 3D ground probing radar (GPR), high-resolution geophysical survey was done inside the museum. Herein, radargrams are compared with the revealed stratigraphy so that signatures are interpreted, characterized and assigned to archeological structures. Although resistivity and GPR have different resolution capabilities, their data are overlapped and compared, bearing in mind the specific characteristics of this survey. It was also possible to unravel the inner structure of the actual walls, to establish connections between walls, foundations and to find older remains with the combined use and spatial integration of the GPR and resistivity imaging data.

Grangeia, Carlos; Matias, Manuel; Figueiredo, Fernando; Hermozilha, Hélder; Carvalho, Pedro; Silva, Ricardo

2011-06-01

195

Relative efficiency of four parameter-estimation methods in steady-state and transient ground-water flow models  

USGS Publications Warehouse

Parameters in numerical ground-water flow models have been successfully estimated using nonlinear-optimization methods such as the modified Gauss-Newton (GN) method and conjugate-direction methods. This paper investigates the relative efficiency of GN and three conjugate-direction parameter-estimation methods on two-dimensional, steady-state and transient ground-water flow test cases. The steady-state test cases are included to compare the performance of the algorithm with published examples. The three conjugate-direction methods are the Fletcher-Reeves (FR) and quasi-Newton (QN) regression methods, and combination Fletcher-Reeves quasi-Newton (FR-QN). All three are combined with Newton's method of calculating step size. The numerical ground-water flow model is described by McDonald and Harbaugh.

Hill, M. C.

1990-01-01

196

Effects of land use on ground-water quality in central Florida - Preliminary results: U. S. Geological Survey Toxic Waste - Ground-Water Contamination Program  

SciTech Connect

Activities of man in areas of recharge to the Floridian aquifer system that may be affecting groundwater quality include: (1) the use of drainage wells for stormwater disposal in urban areas, (2) the use of pesticides and fertilizers in citrus groves, and (3) the mining and processing of phosphate ore in mining areas. Preliminary findings about the impact of these land uses on groundwater quality are presented. Drainage wells convey excess urban stormwater directly to the Upper Floridian aquifer. The volatile organic compounds are the most common contaminants in ground water. Trace elements such as chromium and lead are entering the aquifer but their movement is apparently attenuated by precipitation reactions associated with high pH or by cation-exchange reactions. Among the trace elements and organic chemicals, most ground-water contamination in citrus production areas is caused by pesticide; other contaminants include benzene, toluene, naphthalene, and indene compounds. In the phosphate mining area, constituents of concern are arsenic, selenium, and mercury, and secondarily lead, chromium, cadmium, and others. Organic compounds such as fluorene, naphthalene, di-n-butyl phthalate, alkylated benzenes and naphthalenes, and indene compounds also are entering groundwater. 29 refs., 13 figs., 16 tabs.

Rutledge, A.T.

1987-01-01

197

Methods to reduce radiation from split ground planes in RF and mixed signal packaging structures  

Microsoft Academic Search

Split ground planes are sometimes used in RF and mixed signal packages in order to isolate the RF and analog circuits from the digital circuits. Undesired radiation in a packaging environment may occur when a signal trace is routed over a slot in the ground plane. This paper examines and investigates ways to eliminate signal coupling into split ground plane

Tamir E. Moran; Kathleen L. Virga; G. Aguirre; J. L. Prince

2002-01-01

198

Analysis of Discontinuous Finite Element Methods for Ground Water\\/Surface Water Coupling  

Microsoft Academic Search

We derive and analyze new numerical approaches for modeling coupled ground water\\/surface water flow. In this coupled model, surface water flow is described by the depth- averaged shallow water equations, while ground water is modeled by saturated Darcy flow. The coupling between the two models assumes continuity of pressure and water flux across the ground water\\/surface water interface. The coupled

Clint Dawson

2006-01-01

199

Adopting a Grounded Theory Approach to Cultural-Historical Research: Conflicting Methodologies or Complementary Methods?  

Microsoft Academic Search

Grounded theory has long been regarded as a valuable way to conduct social and educational research. However, recent constructivist and postmodern insights are challenging long-standing assumptions, most notably by suggesting that grounded theory can be flexibly integrated with existing theories. This move hinges on repositioning grounded theory from a methodology with positivist underpinnings to an approach that can be used

Jayson Seaman

200

Evaluation of three methods for sampling ground-dwelling Ants in the Brazilian Cerrado.  

PubMed

Few studies have evaluated the efficiency of methods for sampling ants, especially in regions with highly variable vegetation physiognomies such as the Cerrado region of central Brazil. Here we compared three methods to collect ground-dwelling ants: pitfall traps, sardine baits, and the Winkler litter extractor. Our aim was to determine which method would be most appropriate to characterize the ant assemblages inhabiting different vegetation types. More species were collected with pitfall traps and with the Winkler extractor than with sardine baits. Pitfall traps collected more species in the cerrado (savanna) physiognomies, particularly in those with a poor litter cover, whereas the Winlker extractor was more efficient in the forest physiognomies, except the one subject to periodic inundations. There was a low similarity in species composition between forest and cerrado physiognomies, and this pattern was detected regardless of the method used to sampling ants. Therefore, even the use of a single, relatively selective method of collection can be enough for studies comparing highly distinct habitats and/or conditions. However, if the purpose of the sampling is to produce a more thoroughly inventory of the ant fauna, we suggest the use of a combination of methods, particularly pitfall traps and the Winkler extractor. Therefore, the Ants of the Leaf-Litter (ALL) Sampling Protocol appear to be an adequate protocol for sampling ants in the highly-threatened Brazilian cerrado biome. PMID:18813741

Lopes, Cauê T; Vasconcelos, Heraldo L

201

A validation of extraction methods for noninvasive sampling of glucocorticoids in free-living ground squirrels.  

PubMed

Fecal hormone assays provide a powerful tool for noninvasive monitoring of endocrine status in wild animals. In this study we validated a protocol for extracting and measuring glucocorticoids in free-living and captive Belding's ground squirrels (Spermophilus beldingi). We first compared two commonly used extraction protocols to determine which performed better with commercially available antibodies. We next verified the preferred extraction method by correlating circulating and fecal glucocorticoid measures from a group of individuals over time. For this comparison, we used both a cortisol and a corticosterone antibody to determine which had greater affinity to the fecal metabolites. Cortisol was the primary circulating glucocorticoid, but both hormones were present in well above detectable concentrations in the blood, which does not occur in other sciurids. In addition, the cortisol antibody showed greater binding with the fecal extracts than did the corticosterone antibody. Finally, we used adrenocorticotropic hormone and dexamethasone challenges to demonstrate that changes in adrenal functioning are reflected in changing fecal corticoid levels. These results suggest that our extraction protocol provides a fast, reliable assay of stress hormones in free-living ground squirrels without the confounding influence of short-term rises in glucocorticoid concentrations caused by handling and restraint stress and that it can facilitate ecological and evolutionary studies of stress in wild species. PMID:16228945

Mateo, Jill M; Cavigelli, Sonia A

2005-09-26

202

Computation of one-dimensional consolidation of double layered ground using differential quadrature method.  

PubMed

The authors give the solution to the problem of one-dimensional consolidation of double-layered ground with the use of the differential quadrature method. Case studies showed that the computational results for pore-water pressure in soil layer agreed with those of analytical solution; and that in the computational results for the interface of soil layer also agreed with those of the analytical solution except for the small discrepancies during shortly after the start of computation. The advantages of the solution presented in this paper are that compared with the analytical solution, it avoids the cumbersome work in solving the transcendental equation for eigenvalues, and in the case of the Laplace transform solution, it can resolve the precision problem in the numerical solution of long time inverse Laplace transform. Because of the matrix form of the solution in this paper, it is convenient for formulating computational program for engineering practice. The formulas for calculating double-layered ground consolidation may be easily extended to the case of multi-layered soils. PMID:12659234

Wang, Hong-Zhi; Chen, Yun-Min; Huang, Bo

203

A Validation of Extraction Methods for Noninvasive Sampling of Glucocorticoids in Free-Living Ground Squirrels  

PubMed Central

Fecal hormone assays provide a powerful tool for noninvasive monitoring of endocrine status in wild animals. In this study we validated a protocol for extracting and measuring glucocorticoids in free-living and captive Belding’s ground squirrels (Spermophilus beldingi). We first compared two commonly used extraction protocols to determine which performed better with commercially available antibodies. We next verified the preferred extraction method by correlating circulating and fecal glucocorticoid measures from a group of individuals over time. For this comparison, we used both a cortisol and a corticosterone antibody to determine which had greater affinity to the fecal metabolites. Cortisol was the primary circulating glucocorticoid, but both hormones were present in well above detectable concentrations in the blood, which does not occur in other sciurids. In addition, the cortisol antibody showed greater binding with the fecal extracts than did the corticosterone antibody. Finally, we used adrenocorticotropic hormone and dexamethasone challenges to demonstrate that changes in adrenal functioning are reflected in changing fecal corticoid levels. These results suggest that our extraction protocol provides a fast, reliable assay of stress hormones in free-living ground squirrels without the confounding influence of short-term rises in glucocorticoid concentrations caused by handling and restraint stress and that it can facilitate ecological and evolutionary studies of stress in wild species.

Mateo, Jill M.; Cavigelli, Sonia A.

2008-01-01

204

Methods for Using Ground-Water Model Predictions to Guide Hydrogeologic Data Collection, with Applications to the Death Valley Regional Ground-Water Flow System  

SciTech Connect

Calibrated models of ground-water systems can provide substantial information for guiding data collection. This work considers using such models to guide hydrogeologic data collection for improving model predictions, by identifying model parameters that are most important to the predictions. Identification of these important parameters can help guide collection of field data about parameter values and associated flow-system features that can lead to improved predictions. Methods for identifying parameters important to predictions include prediction scaled sensitivities (PSS), which account for uncertainty on individual parameters as well as prediction sensitivity to parameters, and a new ''value of improved information'' (VOII) method, which includes the effects of parameter correlation in addition to individual parameter uncertainty and prediction sensitivity. The PSS and VOII methods are demonstrated using a model of the Death Valley regional ground-water flow system. The predictions of interest are advective-transport paths originating at sites of past underground nuclear testing. Results show that for two paths evaluated, the most important parameters include a subset of five or six of the 23 defined model parameters. Some of the parameters identified as most important are associated with flow-system attributes that do not lie in the immediate vicinity of the paths. Results also indicate that the PSS and VOII methods can identify different important parameters. Because the methods emphasize somewhat different criteria for parameter importance, it is suggested that parameters identified by both methods be carefully considered in subsequent data collection efforts aimed at improving model predictions.

Claire R. Tiedeman; M.C. Hill; F.A. D'Agnese; C.C. Faunt

2001-07-31

205

A systematic method for characterizing the time-range performance of ground penetrating radar  

NASA Astrophysics Data System (ADS)

The fundamental performance of ground penetrating radar (GPR) is linked to the ability to measure the signal time-of-flight in order to provide an accurate radar-to-target range estimate. Having knowledge of the actual time range and timing nonlinearities of a trace is therefore important when seeking to make quantitative range estimates. However, very few practical methods have been formally reported in the literature to characterize GPR time-range performance. This paper describes a method to accurately measure the true time range of a GPR to provide a quantitative assessment of the timing system performance and detect and quantify the effects of timing nonlinearity due to timing jitter. The effect of varying the number of samples per trace on the true time range has also been investigated and recommendations on how to minimize the effects of timing errors are described. The approach has been practically applied to characterize the timing performance of two commercial GPR systems. The importance of the method is that it provides the GPR community with a practical method to readily characterize the underlying accuracy of GPR systems. This in turn leads to enhanced target depth estimation as well as facilitating the accuracy of more sophisticated GPR signal processing methods.

Strange, A. D.

2013-06-01

206

Conference on Health Survey Research Methods (7th). Held in Williamsburg, Virginia on September 24-27, 1999.  

National Technical Information Service (NTIS)

The Seventh Conference on Health Survey Research Methods (HSRM) was held in Williamsburg, Virginia, on September 2427, 1999, continuing a series of meetings that began in 1975 to discuss new, innovative survey research methods to improve health survey res...

M. L. Cynamon R. A. Kulka

2001-01-01

207

Real-time prediction of ground motion by Kirchhoff-Fresnel boundary integral equation method: Extended front detection method for Earthquake Early Warning  

NASA Astrophysics Data System (ADS)

A method of real-time prediction of ground motion is proposed for application for the Earthquake Early Warning (EEW). In many methods of the present EEW systems, hypocenter and magnitude are determined quickly, after which ground motions are predicted. Although these methods can predict the strength of ground motions by using a few parameters (e.g., hypocenter, magnitude, and site factors), error in the parameters leads directly to error in the prediction, and it is not easy to take the effects of rupture directivity and source extent into account. During the aftershock activity of the 2011Tohoku earthquake (Mw 9.0), multiple events occurred simultaneously, which made it difficult to accurately determine the hypocenters and magnitudes, and led to some false alarms. To address these problems, a new method is proposed that applies the Kirchhoff-Fresnel boundary integral equation. Ground motion is predicted from real-time ground motion observation at front stations in the direction of incoming seismic waves. The real-time monitoring of wavefield and propagation direction are important for this method, but a hypocenter and magnitude are not required. It is possible to predict ground motion without a hypocenter and magnitude, and the precision of the prediction is not affected by error in the source parameters. The effects of rupture directivity, source extent, and simultaneous multiple events are substantially included in this method. The method is a quantitative extension of the front detection technique of EEW.

Hoshiba, Mitsuyuki

2013-03-01

208

Methods of Gas Phase Capture of Iodine from Fuel Reprocessing Off-Gas: A Literature Survey.  

National Technical Information Service (NTIS)

A literature survey was conducted to collect information and summarize the methods available to capture iodine from fuel reprocessing off-gases. Techniques were categorized as either wet scrubbing or solid adsorbent methods, and each method was generally ...

D. R. Haefner T. J. Tranter

2007-01-01

209

Evaluation of shallow subsurface models with microtremor survey method for earthquake disaster prevention  

NASA Astrophysics Data System (ADS)

Most of Japanese local governments have been estimating whole picture of quake damage under scenario earthquakes to reduce both casualties and physical damage. Saitama prefectural government, which is adjacent to north of Tokyo, have already made the estimation four times since 1970's. This estimation requires precise mathematical models of subsurface structures for calculating ground surface accelerations during massive quakes. The models have been updated with every new research. In the early models, the shallow layers had been created with applying geological layers of typical 241 types to the whole prefecture. On the other hand, in the current models, the shallow layers are created with the results of drilling surveys under public works. This update on the models allows us to estimate the quake damage more precisely in every 250m square throughout the prefecture. However even the current models are not complete yet. Because the drilling surveys have not been done enough in rural areas compared with urban areas. The models of shallow layers in rural areas have therefore been created by interpolating with considering terrains among the locations of drilling surveys. Thereby accuracy of the models depends on that of the interpolations. Against this background authors have examined the accuracy of the models by making comparisons of phase velocity dispersions between observed velocities through spatial autocorrelation (SPAC) technique and calculated velocities from the models. Two types of SPAC arrays with radii of 3m, 30m are deployed and data acquisition time is 30min for each array. The result shows that the subsurface structures of urban areas are well modeled, because both the dispersion curves are almost agreed, furthermore amplitude responses of the models are in good agreement with the responses determined by the results of microtremor survey method (MSM). In contrast, the subsurface structures of rural areas include cases that have not been modeled with sufficient accuracy, and the dominant frequency in amplitude responses show differences between the models and the MSM results. This suggests that the existing models of rural areas need to be improved further, and it is confirmed that the models, especially in the shallow layers, can be updated efficiently by using the MSM.

Shiraishi, H.; Sasaka, K.; Hamamoto, H.; Hachinohe, S.; Ishiyama, T.

2011-12-01

210

U.S. Geological Survey laboratory method for methyl tert-Butyl ether and other fuel oxygenates  

USGS Publications Warehouse

Methyl tert-butyl ether (MTBE) was found in shallow ground-water samples in a study of 8 urban and 20 agricultural areas throughout the United States in 1993 and 1994 (Squillace and others, 1995, p. 1). The compound is added to gasoline either seasonally or year round in many parts of the United States to increase the octane level and to reduce carbon monoxide and ozone levels in the air. The U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL), near Denver, uses state-of-the-art technology to analyze samples for MTBE as part of the USGS water-quality studies. In addition, the NWQL offers custom analyses to determine two other fuel oxygenates--ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME). The NWQL was not able to obtain a reference standard for tert-amyl ethyl ether (TAEE), another possible fuel oxygenate (Shelley and Fouhy, 1994, p. 63). The shallow ground-water samples were collected as part of the USGS National Water-Quality Assessment Program. These samples were collected from 211 urban wells or springs and 562 agricultural wells sampled by the USGS in 1993 and 1994. The wells were keyed to specific land-use areas to assess the effects of different uses on ground-water quality (Squillace and others, 1995, p. 2). Ground-water samples were preserved on site to pH less than or equal to 2 with a solution of 1:1 hydrochloric acid. All samples were analyzed at the NWQL within 2 weeks after collection. The purpose of this fact sheet is to explain briefly the analytical method implemented by the USGS for determining MTBE and other fuel oxygenates. The scope is necessarily limited to an overview of the analytical method (instrumentation, sample preparation, calibration and quantitation, identification, and preservation of samples) and method performance (reagent blanks, accuracy, and precision).

Raese, Jon W.; Rose, Donna L.; Sandstrom, Mark W.

1995-01-01

211

Application of a method for the automatic detection and Ground-Based Velocity Track Display (GBVTD) analysis of a tornado crossing the Hong Kong International Airport  

NASA Astrophysics Data System (ADS)

A weak tornado with a maximum Doppler velocity shear of about 40 m s - 1 moved across the Hong Kong International Airport (HKIA) during the evening of 20 May 2002. The tornado caused damage equivalent to F0 on the Fujita Scale, based on a damage survey. The Doppler velocity data from the Hong Kong Terminal Doppler Weather Radar (TDWR) are studied using the Ground-Based Velocity Track Display (GBVTD) method of single Doppler analysis. The GBVTD analysis is able to clearly depict the development and decay of the tornado though it appears to underestimate its magnitude. In the pre-tornadic state, the wind field is characterized by inflow toward the center near the ground and upward motion near the center. When the tornado attains its maximum strength, an eye-like structure with a downdraft appears to form in the center. Several minutes later the tornado begins to decay and outflow dominates at low levels. Assuming cyclostrophic balance, the pressure drop 200 m from the center of the tornado at its maximum strength is calculated to be about 6 hPa. To estimate the maximum ground-relative wind speed of the tornado, the TDWR's Doppler velocities are adjusted for the ratio of the sample-volume size of the radar and the radius of the tornado, resulting in a peak wind speed of 28 m s - 1 , consistent with the readings from a nearby ground-based anemometers and the F0 damage observed. An automatic tornado detection algorithm based on Doppler velocity difference (delta-V) and temporal and spatial continuity is applied to this event. The locations and the core flow radii of the tornado as determined by the automatic method and by subjective analysis agree closely.

Chan, P. W.; Wurman, J.; Shun, C. M.; Robinson, P.; Kosiba, K.

2012-03-01

212

A Socratic Method for Surveying Students' Readiness to Study Evolution  

ERIC Educational Resources Information Center

|Before beginning a series of presentations on evolution, it would be prudent to survey the general level of students' understanding of prerequisite basic concepts of reproduction, heredity, ontology, and phenotypic diversity so that teachers can avoid devoting time to well-known subjects of general knowledge and can spend more time on subjects…

Stansfield, William D.

2013-01-01

213

FOREST SURVEY METHODS USED IN THE USDA FOREST SERVICE  

EPA Science Inventory

There has been an increasing need for forest resource inventory data to contribute to various objectives of different agencies and organizations. Monitoring forest health is one area of interest for which existing forest survey data may be useful. There are many different samplin...

214

Perspective ground-based method for diagnostics of the lower ionosphere and the neutral atmosphere  

NASA Astrophysics Data System (ADS)

We present a new perspective ground-based method for diagnostics of the ionosphere and atmosphere parameters. The method uses one of the numerous physical phenomena observed in the ionosphere illuminated by high-power radio waves. It is a generation of the artificial periodic irregularities (APIs) in the ionospheric plasma. The APIs were found while studying the effects of ionospheric high-power HF modification. It was established that the APIs are formed by a standing wave that occurs due to interference between the upwardly radiated radio wave and its reflection off the ionosphere. The API studies are based upon observation of the Bragg backscatter of the pulsed probe radio wave from the artificial periodic structure. Bragg backscatter occurs if the spatial period of the irregularities is equal to half a wavelength of the probe signal. The API techniques makes it possible to obtain the following information: the profiles of electron density from the lower D-region up to the maximum of the F-layer; the irregular structure of the ionosphere including split of the regular E-layer, the sporadic layers; the vertical velocities in the D- and E-regions of the ionosphere; the turbulent velocities, turbulent diffusion coefficients and the turbopause altitude; the neutral temperatures and densities at the E-region altitudes; the parameters of the internal gravity waves and their spectral characteristics; the relative concentration of negative oxygen ions in the D-region. Some new results obtained by the API technique are discussed .

Bakhmetieva, N. V.; Grigoriev, G. I.; Tolmacheva, A. V.

215

Sparse ground-penetrating radar imaging method for off-the-grid target problem  

NASA Astrophysics Data System (ADS)

Spatial sparsity of the target space in subsurface or through-the-wall imaging applications has been successfully used within the compressive-sensing framework to decrease the data acquisition load in practical systems, while also generating high-resolution images. The developed techniques in this area mainly discretize the continuous target space into grid points and generate a dictionary of model data that is used in image-reconstructing optimization problems. However, for targets that do not coincide with the computation grid, imaging performance degrades considerably. This phenomenon is known as the off-grid problem. This paper presents a novel sparse ground-penetrating radar imaging method that is robust for off-grid targets. The proposed technique is an iterative orthogonal matching pursuit-based method that uses gradient-based steepest ascent-type iterations to locate the off-grid target. Simulations show that robust results with much smaller reconstruction errors are obtained for multiple off-grid targets compared to standard sparse reconstruction techniques.

Gurbuz, Ali Cafer; Teke, Oguzhan; Arikan, Orhan

2013-04-01

216

Influence of load and carrying methods on gait phase and ground reactions in children's stair walking.  

PubMed

The study investigated the effects of carrying methods and loads on gait phase and ground reaction force during stair ascent and descent in children. The carrying methods that were examined included the backpack and one-strap athletic bag. The load weights included 0%, 10%, 15%, and 20% of body weight. Thirteen school children aged 12.21 +/- 0.98 years were recruited as subjects. A Novel Pedar System was used to record and analyze the insole pressure during stair walking with different loads. The load that caused a significant increase in the peak force in each bag and stair mode was 15% of body weight, except for stair ascent carrying the athletic bag, where the load was 10% of body weight. The maximum peak force that was induced by this load in stair descent was 1.25 times that in descent with no load, 1.89 times that in ascent with the same load, and 2.19 times that in ascent with no load. The force-to-time ratio in descent was about three times that in ascent. PMID:15996594

Hong, Youlian; Li, Jing Xian

2005-08-01

217

Nickel and chromium in ground water samples as influenced by well construction and sampling methods  

Microsoft Academic Search

An investigation of elevated concentrations of nickel and chromium in certain ground water samples collected at Williams Air Force Base (AFB) indicated that type 304 stainless steel well materials are the source. Chloride in the ground water has apparently caused crevice corrosion of the stainless steel well screens installed during site characterization. An evaluation of site geochemistry suggested that chromium

D. Oakley; N. E. Korte

1996-01-01

218

A survey of content and teaching methods in high school summer debate workshops  

Microsoft Academic Search

Workshop directors, students, and the students' high school teacher?coaches were surveyed to determine the content and teaching methods used at summer debate workshops and the attitudes of the students and teachers toward the content and methods used. Overall, the survey indicated that the expectations of students and high school debate coaches involved in workshops were met. The article concludes with

Richard L. Shoen; Ronald J. Matlon

1974-01-01

219

Surveying Ground Water Level Using Remote Sensing: An Example over the Seco and Hondo Creek Watershed in Texas  

Microsoft Academic Search

The Normalized Difference Vegetation Index (NDVI) derived from satellite data has been applied to various vegetation studies. The objective of this study was to assess the feasibility of using the NDVI response to plant water content to predict ground water level over a watershed located in the Edwards Aquifer of Texas, USA. Results showed that the precipitation data collected inside

Pei-yu Chen; Jeffrey G. Arnold; Raghavan Srinivasan; Martin Volk; Peter M. Allen

2006-01-01

220

The effect of survey method on survey participation: Analysis of data from the Health Survey for England 2006 and the Boost Survey for London  

Microsoft Academic Search

BACKGROUND: There is a need for local level health data for local government and health bodies, for health surveillance and planning and monitoring of policies and interventions. The Health Survey for England (HSE) is a nationally-representative survey of the English population living in private households, but sub-national analyses can be performed only at a regional level because of sample size.

Jennifer S Mindell; Sarah Tipping; Kevin Pickering; Steven Hope; Marilyn A Roth; Bob Erens

2010-01-01

221

The plate candidates and tiling method for LAMOST pilot survey  

NASA Astrophysics Data System (ADS)

A LAMOST survey observation plate should have a bright star in the center for Shack-Hartmann wave front estimation. Given the plate position, there should be at least one proper guide star on each guide CCD after a small angle focal plate rotation. The detailed requirements vary according to different observation condition. As a consequence, the plate center cannot be placed arbitrarily. Using the HIPMAIN star catalog as the initial candidates and the USNO-B1.0 catalog for neighbor star reference, several lists of acceptable survey plate centers are generated for different observation conditions. The sky area coverage is tested with each plate list. Tiling algorithms using these finite plate centers are optimized for the purpose of evenly sampling and catalog completeness. The tiling is much easier for dark nights than bright nights as there are more optional plate centers. The result is applied in the LAMOST pilot survey for verification and feedback is used to update the lists retentively.

Yuan, Hailong; Zhang, Haotong; Lei, Yajuan; Dong, Yiqiao

2012-09-01

222

A method to automate the radiological survey process  

SciTech Connect

This document describes the USRAD system, a hardware/software ranging and data transmission system, that provides real-time position data and combines it with other portable instrument measurements. Live display of position data and onsite data reduction, presentation, and formatting for reports and automatic transfer into databases are among the unusual attributes of USRADS. Approximately 25% of any survey-to-survey report process is dedicated to data recording and formatting, which is eliminated by USRADS. Cost savings are realized by the elimination of manual transcription of instrument readout in the field and clerical formatting of data in the office. Increased data reliability is realized by ensuring complete survey coverage of an area in the field, by elimination of mathematical errors in conversion of instrument readout to unit concentration, and by elimination of errors associated with transcribing data from the field into report format. The USRAD system can be adapted to measure other types of pollutants or physical/chemical/geological/biological conditions in which portable instrumentation exists. 2 refs., 2 figs.

Berven, B.A.; Blair, M.S.

1987-01-01

223

Evaluation of the walkthrough survey method for detection of volatile organic compound leaks. Final report  

SciTech Connect

During 1978 and 1979, the Emission Standards and Engineering Division of EPA's Office of Air Quality Planning and Standards conducted a fugitive volatile organic compound (VOC) emission sampling program in organic chemical manufacturing plants and petroleum refineries. As a part of their sampling program, several 'walkthrough surveys,' also called 'unit area surveys,' were conducted. The assistance of EPA's Industrial Environmental Research Laboratory, Cincinnati was requested in the analysis of the walkthrough survey data. Fourteen walkthrough surveys were analyzed, from four plants. The analysis reported here focuses on the variability and reproducibility of the survey method. One indicator of variability which was studied was the coefficient of variation (CV). The CV's ranged from 55% to 408%, for each pair of walkthrough surveys. Further, the linear correlation coefficients for each set of surveys ranged from 0.046 to 0.98. No attempt was made to evaluate the sources of the variability.

Weber, R.C.; Mims, K.

1981-04-01

224

Investigation of ground target detection methods in fully polarimetric wide angle synthetic aperture radar images  

NASA Astrophysics Data System (ADS)

Target detection is a high priority of the Air Force for the purpose of reconnaissance and bombardment. This research investigates and develops methods to distinguish ground targets from clutter (i.e. foliage, landscape etc.) in Wide Angle Synthetic Aperture Radar (WASAR) images. WASAR uses multiple aspect angle SAR images of the same target scene. The WASAR data was generated from a pre-release software package (XPATCH-ES) provided by the sponsor (WL-AARA). A statistical analysis and feature extraction is performed on the XPATCH-ES data. Polarimetric and wide angle covariance matrices are estimated and analyzed. From an analysis of the wide angle covariance matrix it is shown that natural clutter has in general a uniform radar return for changing aspect angles, whereas the radar return for a target varies. Based on this analysis, two new wide angle algorithms, the WASAR Whitening Filter and the Adaptive WASAR Whitening Filter (AWWF) are developed. The target detection performance of polarimetric and multi aspect angle image combining algorithms are quantified using Receiver Operating Characteristic curves and target to clutter ratios. It is shown that wide angle processing provides superior target detection performance over polarimetric processing. Combinations of wide angle and polarimetric algorithms were used to achieve a 13.7 dB processing gain in target to clutter ratio when compared to unprocessed images of the target scene. This represents a significant improvement in target detection capabilities.

Laggan, Wayne B.

1995-03-01

225

Ground-based methods reproduce space-flight experiments and show that weak vibrations trigger microtubule self-organisation.  

PubMed

The effect of weightlessness on physical and biological systems is frequently studied by experiments in space. However, on the ground, gravity effects may also be strongly attenuated using methods such as magnetic levitation and clinorotation. Under suitable conditions, in vitro preparations of microtubules, a major element of the cytoskeleton, self-organise by a process of reaction-diffusion: self-organisation is triggered by gravity and samples prepared in space do not self-organise. Here, we report experiments carried out with ground-based methods of clinorotation and magnetic levitation. The behaviour observed closely resembles that of the space-flight experiment and suggests that many space experiments could be carried out equally well on the ground. Using clinorotation, we find that weak vibrations also trigger microtubule self-organisation and have an effect similar to gravity. Thus, in some in vitro biological systems, vibrations are a countermeasure to weightlessness. PMID:16380203

Glade, Nicolas; Beaugnon, Eric; Tabony, James

2005-12-27

226

Research of Stability Problems on Ankara-Konya High Speed Railway Line (Turkey) using Ground Penetrating Radar and Petrographical Methods  

NASA Astrophysics Data System (ADS)

The aim of the study is to research the stability problems according to rock properties and their discontinuities such as fractures, faults and karstic cavities on the new high-speed railway line between the capital city Ankara and the largest city Konya in Turkey. The Ankara-Konya high speed railway including a tunnel managed from The Turkish State Railways (TCDD). Geological surveys, polarizing microscope and confocal Raman spectrometry studies were used to determine rock properties. Ground penetrating radar (GPR) method was used to determine faults, fractures and karstic cavities. The railway line has been mainly constructed on inner Tauride Ocean suture of the Central Anatolia. The basement unit of the railway line mainly has been composed of ophiolitic complex of the inner Tauride Ocean. The main lithology of this ophiolitic complex has been formed by radiolarite, pelagic sediments, dolarite, gabbro, serpentinized peridotite and limestone blocks. The Jurassic alloctonous limestone which has been thrust on the ophiolitic complex. Neogene cover young units with minor amount of Alluvium deposits have been formed by the upper litholgy in the region. The serpentinite and altered radiolarite formation are formed by lubricous ground for the railway line in the region. A RAMAC CUII GPR system was used with a bi-static 100 MHz center band shielded antenna to acquire profile data. Totaly 35 km was surveyed on different parts of the railway line by considering the results of the geologic research and petrograpical studies. When we started to study, rail construction of some parts of the line had already been completed. Therefore, during studies, we gathered the data on the backfilled way on the three parallel profiles spaced 1m apart or on the service way next to the railway line. There was a tunnel on the line. We also gathered two parallel profiles data on the tunnel and four profiles data next to the tunnel to evaluate the stability according to the discontinuities. The petrographical studies and GPR results indicated that the areas with Jurassic alloctonous limestones thrusted on the ophiolitic rocks had deep and large fractures and cavities. The resulted radargrams indicated the thrust fault locations under the rail line. This limestone did not have a root and did not have big thickness. Therefore, the limestone could be move on the ophiolitic serpentinite unit. There were approximately horizontal and thin fracture segments under some parts of the tunnel nearly 8m in depth. There was an important collapsed zone filled up before. At the same time, there were thin and short fractures in the Jurassic limestone under the tunnel which was seen clearly on the radargrams. However, it was appeared that the hazard could not me removed completely because of the horizontal fracture. The areas with lacustrine limestones included disordered small fractures. Finally some areas had terra rossa because of the results of a large karstification. These areas could cause soil liquefaction during rainy season. The stability of these areas has to be controlled with ordered small periods.

Kadioglu, S.; Kadioglu, Y. K.

2012-04-01

227

First National Survey of Lead and Allergens in Housing: survey design and methods for the allergen and endotoxin components.  

PubMed Central

From July 1998 to August 1999, the U.S. Department of Housing and Urban Development and the National Institute of Environmental Health Sciences conducted the first National Survey of Lead and Allergens in Housing. The purpose of the survey was to assess children's potential household exposure to lead, allergens, and bacterial endotoxins. We surveyed a sample of 831 homes, representing 96 million permanently occupied, noninstitutional housing units that permit resident children. We administered questionnaires to household members, made home observations, and took environmental samples. This article provides general background information on the survey, an overview of the survey design, and a description of the data collection and laboratory methods pertaining to the allergen and endotoxin components. We collected dust samples from a bed, the bedroom floor, a sofa or chair, the living room floor, the kitchen floor, and a basement floor and analyzed them for cockroach allergen Bla g 1, the dust mite allergens Der f 1 and Der p 1, the cat allergen Fel d 1, the dog allergen Can f 1, the rodent allergens Rat n 1 and mouse urinary protein, allergens of the fungus Alternaria alternata, and endotoxin. This article provides the essential context for subsequent reports that will describe the prevalence of allergens and endotoxin in U.S. households, their distribution by various housing characteristics, and their associations with allergic diseases such as asthma and rhinitis.

Vojta, Patrick J; Friedman, Warren; Marker, David A; Clickner, Robert; Rogers, John W; Viet, Susan M; Muilenberg, Michael L; Thorne, Peter S; Arbes, Samuel J; Zeldin, Darryl C

2002-01-01

228

Radiative Transfer and Error Analysis Methods for the MSL REMS Ground Temperature Sensors  

NASA Astrophysics Data System (ADS)

The Rover Environmental Monitoring Station (REMS) on the Mars Science Laboratory (MSL) offers the opportunity to explore the near surface atmospheric boundary layer (ABL) over an extended region of the Martian surface. The atmospheric boundary layer plays an important role in the general circulation and the local atmospheric dynamics of Mars. In both cases, the ABL controls the coupling of the atmosphere and the surface [Zurek, et al., 1992]. This coupling is exhibited in the energy exchange between the near surface regolith and the near surface atmosphere and is driven by the solar insolation. Ground temperature sensors (GTS) on REMS provide the data needed to study both the thermal inertia properties of the regolith and rocks beneath the MSL rover and to study the conditions for convection in the near surface atmospheric boundary layer. The GTS includes three thermopile detectors, with infrared bands of 8-14 µm, 15 µm, and 16-20 µm [Gómez-Elvira et al., 2009]. The three sensors are clustered in a single location on the MSL mast and have a common field of view on the surface of Mars allowing the three sensors to be used in combination. The 15 µm sounds the atmosphere between the sensors and the surface. With a calibrated weighting function, this sensor will measure the temperature of the atmosphere just above the surface. The 8-14 µm and 16-20 µm sensors both measure the surface temperature, but by working on both sides of the 15 µm CO2 band, the variation in emissivity of the surface minerals across the thermal wavelengths can be factored into the surface temperature calculations. Using the Full Transfer By Optimized LINe-by-line (FUTBOLIN) code [Martin-Torres and Mlynczak, 2005] we have developed an energy balance and radiative transfer retrieval method for the REMS GTS. With the Mars Weather Research and Forcasting (MarsWRF) model, we run large eddy simulations (LES) to model ground temperatures and near surface air temperatures. Using these LES temperatures, we can test the GTS retrieval process, including an assessment of the sources of errors in the retrieval process. By using the LES temperatures as synthetic data, we assess the perfomance of the REMS GTS as well as determine, through the error analysis, the calibration data critical path in the spectral retrieval process. Reference: Martin-Torres, F. J. and M. G. Mlynczak, Application of FUTBOLIN (FUll Transfer By Ordinary Line-by-Line) to the analysis of the solar system and extrasolar planetary atmospheres, Bulletin of the American Astronomical Society, Vol. 37, p.1566, 2005

Soto, Alejandro; Martin-Torres, F. Javier; McEwan, Ian; Richardson, Mark

2010-05-01

229

Measuring galaxy [O ii] emission line doublet with future ground-based wide-field spectroscopic surveys  

NASA Astrophysics Data System (ADS)

The next generation of wide-field spectroscopic redshift surveys will map the large-scale galaxy distribution in the redshift range 0.7 ? z ? 2 to measure baryonic acoustic oscillations (BAO). The primary optical signature used in this redshift range comes from the [Oii] emission line doublet, which provides a unique redshift identification that can minimize confusion with other single emission lines. To derive the required spectrograph resolution for these redshift surveys, we simulate observations of the [Oii] (?? 3727, 3729) doublet for various instrument resolutions, and line velocities. We foresee two strategies for the choice of the resolution for future spectrographs for BAO surveys. For bright [Oii] emitter surveys ([Oii] flux ~30 × 10-17 erg cm-2 s-1 like SDSS-IV/eBOSS), a resolution of R ~ 3300 allows the separation of 90 percent of the doublets. The impact of the sky lines on the completeness in redshift is less than 6 percent. For faint [Oii] emitter surveys ([Oii] flux ~10 × 10-17 erg cm-2 s-1 like DESi), the detection improves continuously with resolution, so we recommend the highest possible resolution, the limit being given by the number of pixels (4k by 4k) on the detector and the number of spectroscopic channels (2 or 3).

Comparat, Johan; Kneib, Jean-Paul; Bacon, Roland; Mostek, Nick J.; Newman, Jeffrey A.; Schlegel, David J.; Yèche, Christophe

2013-11-01

230

Comparing Coral Reef Survey Methods. Unesco Reports in Marine Science No. 21 Report of a Regional Unesco/UNEP Workshop on Coral Reef Survey Management and Assessment Methods in Asia and the Pacific (Phuket, Thailand, December 13-17, 1982).  

ERIC Educational Resources Information Center

|This report includes nine papers prepared for a workshop on coral reef survey management and assessment methods in Asia and the Pacific. The papers are: "A Contrast in Methodologies between Surveying and Testing" (Charles Birkeland); "Coral Reef Survey Methods in the Andaman Sea" (Hansa Chansang); "A Review of Coral Reef Survey and Management…

United Nations Educational, Scientific, and Cultural Organization, Paris (France). Div. of Marine Sciences.

231

Suitability of the Respirometric Bod Oxitop Method for Determining the Biodegradability of Oils in Ground Water using Forestry Hydraulic Oils as Model Compounds  

Microsoft Academic Search

Different forestry hydraulic oils were used as model compounds for evaluating the applicability of the respirometric BOD Oxitop method in following the progress of biodegradation of oils in ground water. It is obvious that the biodegradability values of substances depend on the measurement medium used. In this study the same ground water was used in all the ground water experiments.

Toivo Kuokkanen; Pekka Vähäoja; Ilkka Välimäki; Risto Lauhanen

2004-01-01

232

Alcohol Advertising and Advertising Bans: A Survey of Research Methods, Results, and Policy Implications  

Microsoft Academic Search

This chapter surveys the literatures on advertising bans and alcohol consumption or abuse, and advertising expenditures and alcohol consumption. Studies of state-level bans of billboards are examined as well as studies of international bans that cover broadcasting media. For expenditures, the survey concentrates on econometric methods and the existence of an industry advertising-sales response function. Selected results from survey-research studies

Jon P. Nelson

2001-01-01

233

Methods and Strategies: The Common Ground -- A rationale for integrating science and reading  

NSDL National Science Digital Library

Building on the common ground between subjects through integration helps teachers address learning goals in both subjects without compromising either. This article addresses ways to integrate science with language arts objectives.

Royce, Christine A.; Wiley, David A.

2005-02-01

234

Method for Calculating the Probability of Successfully Completing a Rocket Propulsion Ground Test.  

National Technical Information Service (NTIS)

Propulsion ground test facilities face the daily challenge of scheduling multiple customers into limited facility space and successfully completing their propulsion test projects. Over the last decade NASA s propulsion test facilities have performed hundr...

B. Messer

2007-01-01

235

Long-Term Behavior of a Slow-Moving Landslide Inferred From Ground-Based Surveys and Analysis of Digital Terrain Models  

NASA Astrophysics Data System (ADS)

Movement of Minor Creek landslide in Humboldt County, northwestern California, has been monitored for almost thirty years. We report movement patterns and sediment yields derived from repetitive ground-based surveys and supplement them with inferences from analysis of digital terrain models (DTMs) created from aerial photographs taken in 1982 and 2001. The landslide consists predominantly of gravelly, sandy clay, has earthflow-like morphology, an average surface slope of 15 degrees, is 800 m long, averages 100 m wide, and is vegetated primarily by grasses and scattered trees. Its thickness, inferred from inclinometer data, ranges from 3 to more than 8 m. The landslide moves each winter rainy season in response to rising pore-water pressures, and movement ceases during the dry summer months (see Iverson and Major, GSA Bulletin, 99, 579-594, 1987). Annual downslope surface displacements measured by ground surveys average 0.42 m. Deviations from average surface displacement occur in both time and space: three large pulses of displacement (during winters of 1973-74, 1983-84, and 1997-98), averaging 1.7 m each, account for 64% of the total displacement between 1973 and 2000. Movement pulses are pronounced in the middle and lower portion of the landslide, whereas near the head of the landslide, pulses are less pronounced, and the pace of movement more uniform. Surface displacements at the toe of the landslide, which is relatively thin and abuts Minor Creek, average 280% of those elsewhere. On the basis of measured surface displacements and subsurface deformation, we estimate a net flux of 4000 m3 of landslide sediment into Minor Creek between 1973 and 2000. While ground-based surveying provides excellent resolution of landslide movement at a finite number of pre-determined survey locations, differencing of high-resolution (0.65-m cell size) DTMs constructed from 1982 and 2001 aerial photographs provides a quantitative picture of the spatial distribution of vertical displacements and the complex pattern of landslide movement. Much of the headscarp and toe areas of the landslide exhibited significant surface lowering between 1982 and 2001, and an area about 150 m downslope from the headscarp showed a significant increase in elevation over this same time period. Although the DTMs provide a good spatial picture of changes in landslide topography, their vertical accuracy is not sufficient to reliably quantify the relatively small changes in landslide sediment volume, which represent a 5 cm elevation decrease averaged over the landslide surface area. Thus the DTMs do not provide good resolution of the landslide sediment flux to Minor Creek over this 19-year period.

Mark, L. E.; Iverson, R. M.; Messerich, J. A.

2002-12-01

236

MODFLOW-2000, the U.S. Geological Survey modular ground-water model : user guide to the LMT6 package, the linkage with MT3DMS for multi-species mass transport modeling  

USGS Publications Warehouse

MODFLOW-2000, the newest version of MODFLOW, is a computer program that numerically solves the three-dimensional ground-water flow equation for a porous medium using a finite-difference method. MT3DMS, the successor to MT3D, is a computer program for modeling multi-species solute transport in three-dimensional ground-water systems using multiple solution techniques, including the finite-difference method, the method of characteristics (MOC), and the total-variation-diminishing (TVD) method. This report documents a new version of the Link-MT3DMS Package, which enables MODFLOW-2000 to produce the information needed by MT3DMS, and also discusses new visualization software for MT3DMS. Unlike the Link-MT3D Packages that coordinated previous versions of MODFLOW and MT3D, the new Link-MT3DMS Package requires an input file that, among other things, provides enhanced support for additional MODFLOW sink/source packages and allows list-directed (free) format for the flow model produced flow-transport link file. The report contains four parts: (a) documentation of the Link-MT3DMS Package Version 6 for MODFLOW-2000; (b) discussion of several issues related to simulation setup and input data preparation for running MT3DMS with MODFLOW-2000; (c) description of two test example problems, with comparison to results obtained using another MODFLOW-based transport program; and (d) overview of post-simulation visualization and animation using the U.S. Geological Survey?s Model Viewer.

Zheng, Chunmiao; Hill, Mary Catherine; Hsieh, Paul A.

2001-01-01

237

Collaborative study of a method for the extraction of light filth from whole, cracked, or flaked and ground spices.  

PubMed

An improved method has been developed for the extraction of light filth from whole, cracked, or flaked spices (basil, bay leaves, clery leaves, chervil, chives, dill weed, mint flakes, parsley, rosemary, sage, tarragon, thyme, and vegetable flakes) and from ground spices (cloves, cumin, marjoram, mustard seed, oregano, sage, and thyme). The method involves a chloroform or isopropanol defatting, followed by a direct flotation from 40% isopropanol with Tween 80-EDTA (1+1) and mineral oil-heptane (85+15). Collaborative results show that the proposed method is more rapid to perform and yields better filth recoveries than the official first action methods for ground spices, 44.116, and whole, cracked, or flaked spices, 44.129. The method has been adopted as official first action. PMID:1170162

Glaze, L E

1975-05-01

238

Using grounded theory method for theory building in operations management research : A study on inter-firm relationship governance  

Microsoft Academic Search

Purpose – Qualitative theory building approaches, such as grounded theory method (GTM), are still not very widespread and rigorously applied in operations management (OM) research. Yet it is agreed that more systematic observation of current industrial phenomena is necessary to help managers deal with their problems. The purpose of this paper is to provide an example to help guide other

Mario Binder; John S. Edwards

2010-01-01

239

Evaluation of an optical microbiological method for rapidly estimating populations of aerobic bacteria, coliforms, and Escherichia coli from ground pork.  

PubMed

The BioSys optical methods for estimating populations of aerobic bacteria, coliforms, and Escherichia coli from ground pork were evaluated. Ground pork samples were analyzed immediately, after temperature abuse at 25 degrees C for various periods of time, or after temperature abuse and dilution by mixing with pork that was prepared by grinding whole muscles that had the outer portion excised using a sterile scalpel. Each ground pork sample was tested using standard methods such as aerobic plate counts (APC), violet red bile (VRB) agar plate counts (coliforms), and three-tube most probable numbers (MPN--E. coli). Each sample was tested using the BioSys for total viable counts (TVC) by placing 2 ml of ground pork homogenate (25 g into 225 ml of sterile 1% buffered peptone water) into 8 ml of nutrient medium containing brom-cresol purple in a test vial and monitoring at 35 degrees C. Coliforms were enumerated by placing 5 ml of ground pork homogenate into 5 ml of coliform medium (CM) in a test vial and monitoring at 35 degrees C. E. coli were enumerated by placing 5 ml of ground pork homogenate into 5 ml of double-strength CM with 2% dextrose in a test vial and monitoring at 42 degrees C. The correlation coefficients for the regression lines comparing APC to BioSys TVC detection times (DT), VRB to BioSys coliform DT, and MPN to BioSys E. coli DT were -0.95, -0.94, and -0.93, and the line equations were logl0 CFU/ml = 8.94 - 0.40(DT), log10 CFU/ml = 8.77 - 0.43(DT), and log10 CFU/ml = 8.96 - 0.81(DT), respectively. These methods may allow pork producers to monitor equipment surfaces and products in less than 16 h and obtain microbiological results prior to shipment. PMID:11347998

Russell, S M

2001-05-01

240

Long Period Ground Motion Prediction Of Linked Tonankai And Nankai Subduction Earthquakes Using 3D Finite Difference Method  

NASA Astrophysics Data System (ADS)

There is high possibility of the occurrence of the Tonankai and Nankai earthquakes which are capable of causing immense damage. During these huge earthquakes, long period ground motions may strike mega-cities Osaka and Nagoya located inside the Osaka and Nobi basins in which there are many long period and low damping structures (such as tall buildings and oil tanks). It is very important for the earthquake disaster mitigation to predict long period strong ground motions of the future Tonankai and Nankai earthquakes that are capable of exciting long-period strong ground motions over a wide area. In this study, we tried to predict long-period ground motions of the future Tonankai and Nankai earthquakes using 3D finite difference method. We construct a three-dimensional underground structure model including not only the basins but also propagation field from the source to the basins. Resultantly, we can point out that the predominant periods of pseudo-velocity response spectra change basin by basin. Long period ground motions with periods of 5 to 8 second are predominant in the Osaka basin, 3 to 6 second in the Nobi basin and 2 to 5 second in the Kyoto basin. These characteristics of the long-period ground motions are related with the thicknesses of the sediments of the basins. The duration of long period ground motions inside the basin are more than 5 minutes. These results are very useful for the earthquake disaster mitigation of long period structures such as tall buildings and oil tanks.

Kawabe, H.; Kamae, K.

2005-12-01

241

A new signal processing method using multiple-input adaptive digital filter for pulsar surveys  

Microsoft Academic Search

There is a plan to survey millisecond pulsars using the radio telescope consisting of 8×8 elements array antenna and an FFT apparatus in Waseda University. For this purpose, this paper describes the method of signal processing for pulsars using an ADF (adaptive digital filter). It is shown that the two important parameters in the surveys of pulsars can easily be

N. Mikami; T. Daishido

1995-01-01

242

User-centered design methods in practice: a survey of the state of the art  

Microsoft Academic Search

This paper reports the results of a recent survey involving over one hundred leading professionals of user-centered design (UCD). The survey covered a broad range of issues ranging from the profile of a typical UCD project including the percentage of total budget on UCD, organizational impact of UCD, measures of UCD success, and the most widely used methods and techniques.

Ji-Ye Mao; Karel Vredenburg; Paul W. Smith; Tom Carey

2001-01-01

243

Novel survey method finds dramatic decline of wild cotton-top tamarin population  

Microsoft Academic Search

The cotton-top tamarin (Saguinus oedipus) is a critically endangered primate, endemic to the tropical forests of Colombia. Population monitoring is essential to evaluate the success of conservation efforts, yet standard survey methods are ineffective because animals flee silently before they are seen. We developed a novel technique that combines the use of playbacks of territorial vocalizations with traditional transect surveys.

Len Thomas; Katherine A. Leighty; Luis H. Soto; Felix S. Medina; Anne Savage

2010-01-01

244

New electromagnetic surveying/ranging method for drilling parallel horizontal twin wells  

SciTech Connect

An electromagnetic source was used in conjunction with a measurement-while-drilling (MWD) survey instrument to drill two parallel horizontal wells with a vertical separation of 9 {+-} 2 m over a length of 600 m in Amoco`s Wolf Lake field for steam-assisted gravity drainage of heavy oil. Existing wellbore survey methods are incapable of this level of precision because of cumulative survey error and associated position uncertainty. Using this new electromagnetic ranging technique, the twin wells were placed with better than 10 times the accuracy of gyro surveys.

Kuckes, A.F.; Hay, R.T.; McMahon, J.; Nord, A.G.; Schilling, D.A.; Morden, J.

1996-06-01

245

Comparing electromagnetic induction and ground penetrating radar techniques for estimating soil moisture content  

Microsoft Academic Search

Previous studies have demonstrated the capacity of electromagnetic geophysical methods for estimating soil moisture content. In this study, electromagnetic induction (EMI) and ground-penetrating radar (GPR) measurements were coincidently collected along a fixed survey line to evaluate temporal changes in apparent electrical conductivity and electromagnetic direct ground wave velocity, respectively; surveys were collected at three sites (i.e., sand, sandy loam and

Cameron W. Toy; Colby M. Steelman; Anthony L. Endres

2010-01-01

246

Mobile phones are a viable option for surveying young Australian women: a comparison of two telephone survey methods  

PubMed Central

Background Households with fixed-line telephones have decreased while mobile (cell) phone ownership has increased. We therefore sought to examine the feasibility of recruiting young women for a national health survey through random digit dialling mobile phones. Methods Two samples of women aged 18 to 39 years were surveyed by random digit dialling fixed and mobile numbers. We compared participation rates and responses to a questionnaire between women surveyed by each contact method. Results After dialling 5,390 fixed-lines and 3,697 mobile numbers, 140 and 128 women were recruited respectively. Among women contacted and found to be eligible, participation rates were 74% for fixed-lines and 88% for mobiles. Taking into account calls to numbers where eligibility was unknown (e.g. unanswered calls) the estimated response rates were 54% and 45% respectively. Of women contacted by fixed-line, 97% reported having a mobile while 61% of those contacted by mobile reported having a fixed-line at home. After adjusting for age, there were no significant differences between mobile-only and fixed-line responders with respect to education, residence, and various health behaviours; however compared to those with fixed-lines, mobile-only women were more likely to identify as Indigenous (OR 4.99, 95%CI 1.52-16.34) and less likely to live at home with their parents (OR 0.09, 95%CI 0.03-0.29). Conclusions Random digit dialling mobile phones to conduct a health survey in young Australian women is feasible, gives a comparable response rate and a more representative sample than dialling fixed-lines only. Telephone surveys of young women should include mobile dialling.

2011-01-01

247

Modelling of ground deformation and gravity fields using finite element method: an application to Etna volcano  

NASA Astrophysics Data System (ADS)

Elastic finite element models are applied to investigate the effects of topography and medium heterogeneities on the surface deformation and the gravity field produced by volcanic pressure sources. Changes in the gravity field cannot be interpreted only in terms of gain of mass disregarding the ground deformation of the rocks surrounding the source. Contributions to gravity changes depend also on surface and subsurface mass redistribution driven by dilation of the volcanic source. Both ground deformation and gravity changes were firstly evaluated by solving a coupled axisymmetric problem to estimate the effects of topography and medium heterogeneities. Numerical results show significant discrepancies in the ground deformation and gravity field compared to those predicted by analytical solutions, which disregard topography, elastic heterogeneities and density subsurface structures. With this in mind, we reviewed the expected gravity changes accompanying the 1993-1997 inflation phase on Mt Etna by setting up a fully 3-D finite element model in which we used the real topography, to include the geometry, and seismic tomography, to infer the crustal heterogeneities. The inflation phase was clearly detected by different geodetic techniques (EDM, GPS, SAR and levelling data) that showed a uniform expansion of the overall volcano edifice. When the gravity data are integrated with ground deformation data and a coupled FEM modelling was solved, a mass intrusion could have occurred at depth to justify both ground deformation and gravity observations.

Currenti, Gilda; Del Negro, Ciro; Ganci, Gaetana

2007-05-01

248

Surveys  

Cancer.gov

Behavioral Risk Factor Surveillance System (BRFSS) The world's largest, on-going telephone health survey system, tracking health conditions and risk behaviors in the United States yearly since 1984. Currently, data are collected monthly in all 50 states, the District of Columbia, Puerto Rico, the U.S. Virgin Islands, and Guam.

249

MODFLOW-2005, the U.S. Geological Survey modular ground-water model - documentation of shared node local grid refinement (LGR) and the boundary flow and head (BFH) package  

USGS Publications Warehouse

This report documents the addition of shared node Local Grid Refinement (LGR) to MODFLOW-2005, the U.S. Geological Survey modular, transient, three-dimensional, finite-difference ground-water flow model. LGR provides the capability to simulate ground-water flow using one block-shaped higher-resolution local grid (a child model) within a coarser-grid parent model. LGR accomplishes this by iteratively coupling two separate MODFLOW-2005 models such that heads and fluxes are balanced across the shared interfacing boundary. LGR can be used in two-and three-dimensional, steady-state and transient simulations and for simulations of confined and unconfined ground-water systems. Traditional one-way coupled telescopic mesh refinement (TMR) methods can have large, often undetected, inconsistencies in heads and fluxes across the interface between two model grids. The iteratively coupled shared-node method of LGR provides a more rigorous coupling in which the solution accuracy is controlled by convergence criteria defined by the user. In realistic problems, this can result in substantially more accurate solutions and require an increase in computer processing time. The rigorous coupling enables sensitivity analysis, parameter estimation, and uncertainty analysis that reflects conditions in both model grids. This report describes the method used by LGR, evaluates LGR accuracy and performance for two- and three-dimensional test cases, provides input instructions, and lists selected input and output files for an example problem. It also presents the Boundary Flow and Head (BFH) Package, which allows the child and parent models to be simulated independently using the boundary conditions obtained through the iterative process of LGR.

Mehl, Steffen W.; Hill, Mary C.

2006-01-01

250

A Survey and Empirical Comparison of Object Ranking Methods  

NASA Astrophysics Data System (ADS)

Ordered lists of objects are widely used as representational forms. Such ordered objects include Web search results or bestseller lists. In spite of their importance, methods of processing orders have received little attention. However, research concerning orders has recently become common; in particular, researchers have developed various methods for the task of Object Ranking to acquire functions for object sorting from example orders. Here, we give a unified view of these methods and compare their merits and demerits.

Kamishima, Toshihiro; Kazawa, Hideto; Akaho, Shotaro

251

A survey of data mining methods for linkage disequilibrium mapping  

PubMed Central

Data mining methods are gaining more interest as potential tools in mapping and identification of complex disease loci. The methods are well suited to large numbers of genetic marker loci produced by high-throughput laboratory analyses, but also might be useful for clarifying the phenotype definitions prior to more traditional mapping analyses. Here, the current data mining-based methods for linkage disequilibrium mapping and phenotype analyses are reviewed.

2006-01-01

252

Ground penetrating radar survey finalized to the recovery of the “S. Agata alla Badia” church in Catania (eastern Sicily, Italy)  

Microsoft Academic Search

Numerous archaeological sites dating to the greek-roman period have been found in the underground of the city of Catania (eastern\\u000a Sicily, Italy). Their presence is a testimony of the several settlements that have followed in this area over time. In this\\u000a work we have conducted electromagnetic surveys, consisting of ten georadar profiles, inside the church of “S. Agata alla Badia”,

S. Imposa; F. Barone; S. Gresta; A. Leone

2009-01-01

253

The Application of Identification Method of Ground Surfacesusing Fractal Dimension to Millimeter Wave Radar Altimeter  

NASA Astrophysics Data System (ADS)

Data of scattering coefficient on vertical incidence against ground surface at U-band are obtained by Millimeter Wave Radar Altimeter using FM-CW ranging. Noise suppression by wavelet shrinkage can be utilized to extract feature parameter in high spatial frequency band, in which level of fractal noise is dominated by that of white noise. We propose approximate algorithm for estimation of local fractal dimension in high spatial frequency band which is the most effective parameter for identification for classification of ground surfaces such as vegetation, town area and rice field.

Araki, Kan

254

A Survey on Digital Camera Image Forensic Methods  

Microsoft Academic Search

There are two main interests in Digital Camera Image Forensics, namely source identification and forgery detection. In this paper, we first briefly provide an introduction to the major processing stages inside a digital camera and then review several methods for source digital camera identification and forgery detection. Existing methods for source identification explore the various processing stages inside a digital

Tran Van Lanh; Kai-sen Chong; Sabu Emmanuel; Mohan S. Kankanhalli

2007-01-01

255

Application of nonlinear-regression methods to a ground-water flow model of the Albuquerque Basin, New Mexico  

USGS Publications Warehouse

This report documents the application of nonlinear-regression methods to a numerical model of ground-water flow in the Albuquerque Basin, New Mexico. In the Albuquerque Basin, ground water is the primary source for most water uses. Ground-water withdrawal has steadily increased since the 1940's, resulting in large declines in water levels in the Albuquerque area. A ground-water flow model was developed in 1994 and revised and updated in 1995 for the purpose of managing basin ground- water resources. In the work presented here, nonlinear-regression methods were applied to a modified version of the previous flow model. Goals of this work were to use regression methods to calibrate the model with each of six different configurations of the basin subsurface and to assess and compare optimal parameter estimates, model fit, and model error among the resulting calibrations. The Albuquerque Basin is one in a series of north trending structural basins within the Rio Grande Rift, a region of Cenozoic crustal extension. Mountains, uplifts, and fault zones bound the basin, and rock units within the basin include pre-Santa Fe Group deposits, Tertiary Santa Fe Group basin fill, and post-Santa Fe Group volcanics and sediments. The Santa Fe Group is greater than 14,000 feet (ft) thick in the central part of the basin. During deposition of the Santa Fe Group, crustal extension resulted in development of north trending normal faults with vertical displacements of as much as 30,000 ft. Ground-water flow in the Albuquerque Basin occurs primarily in the Santa Fe Group and post-Santa Fe Group deposits. Water flows between the ground-water system and surface-water bodies in the inner valley of the basin, where the Rio Grande, a network of interconnected canals and drains, and Cochiti Reservoir are located. Recharge to the ground-water flow system occurs as infiltration of precipitation along mountain fronts and infiltration of stream water along tributaries to the Rio Grande; subsurface flow from adjacent regions; irrigation and septic field seepage; and leakage through the Rio Grande, canal, and Cochiti Reservoir beds. Ground water is discharged from the basin by withdrawal; evapotranspiration; subsurface flow; and flow to the Rio Grande, canals, and drains. The transient, three-dimensional numerical model of ground-water flow to which nonlinear-regression methods were applied simulates flow in the Albuquerque Basin from 1900 to March 1995. Six different basin subsurface configurations are considered in the model. These configurations are designed to test the effects of (1) varying the simulated basin thickness, (2) including a hypothesized hydrogeologic unit with large hydraulic conductivity in the western part of the basin (the west basin high-K zone), and (3) substantially lowering the simulated hydraulic conductivity of a fault in the western part of the basin (the low-K fault zone). The model with each of the subsurface configurations was calibrated using a nonlinear least- squares regression technique. The calibration data set includes 802 hydraulic-head measurements that provide broad spatial and temporal coverage of basin conditions, and one measurement of net flow from the Rio Grande and drains to the ground-water system in the Albuquerque area. Data are weighted on the basis of estimates of the standard deviations of measurement errors. The 10 to 12 parameters to which the calibration data as a whole are generally most sensitive were estimated by nonlinear regression, whereas the remaining model parameter values were specified. Results of model calibration indicate that the optimal parameter estimates as a whole are most reasonable in calibrations of the model with with configurations 3 (which contains 1,600-ft-thick basin deposits and the west basin high-K zone), 4 (which contains 5,000-ft-thick basin de

Tiedeman, C. R.; Kernodle, J. M.; McAda, D. P.

1998-01-01

256

1992 nendo chinetsu kaihatsu sokushin chosa. 37. Chijo chosa hokokusho (Motomiya chiiki). (1992 survey for geothermal development promotion. 37. Report on ground survey (Motomiya area)).  

National Technical Information Service (NTIS)

An electromagnetic investigation (CSAMT method) was made to analyze underground structure and geothermal structure in the Motomiya area, Higashi-Muro Province, an eastern part of Wakayama Prefecture. The investigation with the CSAMT method was carried out...

1993-01-01

257

Comparison of visual survey and seining methods for estimating abundance of an endangered, benthic stream fish  

USGS Publications Warehouse

We compared visual survey and seining methods for estimating abundance of endangered Okaloosa darters, Etheostoma okaloosae, in 12 replicate stream reaches during August 2001. For each 20-m stream reach, two divers systematically located and marked the position of darters and then a second crew of three to five people came through with a small-mesh seine and exhaustively sampled the same area. Visual surveys required little extra time to complete. Visual counts (24.2 ?? 12.0; mean ?? one SD) considerably exceeded seine captures (7.4 ?? 4.8), and counts from the two methods were uncorrelated. Visual surveys, but not seines, detected the presence of Okaloosa darters at one site with low population densities. In 2003, we performed a depletion removal study in 10 replicate stream reaches to assess the accuracy of the visual survey method. Visual surveys detected 59% of Okaloosa darters present, and visual counts and removal estimates were positively correlated. Taken together, our comparisons indicate that visual surveys more accurately and precisely estimate abundance of Okaloosa darters than seining and more reliably detect presence at low population densities. We recommend evaluation of visual survey methods when designing programs to monitor abundance of benthic fishes in clear streams, especially for threatened and endangered species that may be sensitive to handling and habitat disturbance. ?? 2007 Springer Science+Business Media, Inc.

Jordan, F.; Jelks, H. L.; Bortone, S. A.; Dorazio, R. M.

2008-01-01

258

Comparison of practical vertical ground heat exchanger sizing methods to a Fort Polk data/model benchmark  

SciTech Connect

The results of five practical vertical ground heat exchanger sizing programs are compared against a detailed simulation model that has been calibrated to monitored data taken from one military family housing unit at Fort Polk, Louisiana. The calibration of the detailed model to data is described in a companion paper. The assertion that the data/detailed model is a useful benchmark for practical sizing methods is based on this calibration. The results from the comparisons demonstrate the current level of agreement between vertical ground heat exchanger sizing methods in common use. It is recommended that the calibration and comparison exercise be repeated with data sets from additional sites in order to build confidence in the practical sizing methods.

Thornton, J.W.; McDowell, T.P.; Hughes, P.J.

1997-09-01

259

Short Survey on Ten Years Interior Point Methods.  

National Technical Information Service (NTIS)

The introduction of Karmarkar's polynomial algorithm for linear programming (LP) in 1984 has influenced wide areas in the field of optimization. While in 80s emphasis was on developing and implementing efficient variants of interior point methods for LP, ...

B. Jansen C. Roos T. Terlaky

1995-01-01

260

Evaluation of In-Service Education: A Survey of Methods  

ERIC Educational Resources Information Center

|The following methods of evaluation of inservice programs are very briefly discussed: a) behavioral objectives; b) diagnosis; c) learner outcomes; d) effects on teachers; e) classroom observation, and f) questionnaires following inservice activity. (HMD)|

Wehmeyer, Lillian M.

1974-01-01

261

Survey of methods for secure connection to the internet  

NASA Astrophysics Data System (ADS)

This paper describes a study of a security method of protecting inside network computers against outside miscreants and unwelcome visitors and a control method when these computers are connected with the Internet. In the present Internet, a method to encipher all data cannot be used, so that it is necessary to utilize PEM (Privacy Enhanced Mail) capable of the encipherment and conversion of secret information. For preventing miscreant access by eavesdropping password, one-time password is effective. The most cost-effective method is a firewall system. This system lies between the outside and inside network. By limiting computers that directly communicate with the Internet, control is centralized and inside network security is protected. If the security of firewall systems is strictly controlled under correct setting, security within the network can be secured even in open networks such as the Internet.

Matsui, Shouichi

1994-04-01

262

SHORT SURVEY OF THE SEPARATION METHODS FOR ZIRCONIUM AND HAFNIUM  

Microsoft Academic Search

After a discussion of the essential ways to use zircondum as a ; construction material for nuclear reactors, a critical review is given of the ; most common chemical methods for separation of zirconium and hafnium. (auth);

Getoff

1958-01-01

263

Nanofiltration as a treatment method for the removal of pesticides from ground waters  

Microsoft Academic Search

A major problem in the drinking water production is the presence of pesticides in raw water, not only in surface waters, but also in ground waters. Concentrations of several ?g\\/l have been found. Traditionally, pesticides are removed using granular or powdered activated carbon, which is an expensive process. The cost is enhanced by competition of pesticides and natural organic matter

B. Van der Bruggen; J. Schaep; W. Maes; D. Wilms; C. Vandecasteele

1998-01-01

264

A Simple Method for Measuring Ground-Level Ozone in the Atmosphere  

ERIC Educational Resources Information Center

|An iodometric assay that allows the ground-level ozone concentration to be determined with an inexpensive sampling apparatus and a homemade photometer is described. This laboratory experiment applies a variety of different fundamental concepts including oxidation-reduction chemistry, the ideal gas law, and spectroscopic analysis and also provides…

Seeley, John V.; Seeley, Stacy K.; Bull, Arthur W.; Fehir, Richard J., Jr.; Cornwall, Susan; Knudsen, Gabriel A.

2005-01-01

265

Exact Image Method for Field Calculation in Horizontally Layered Medium Above a Conducting Ground Plane.  

National Technical Information Service (NTIS)

In layered medium performing the Mittag-Leffler expansion for the Fourier domain reflection coefficient, it is shown that the inverse Laplace transform of it can be easily derived in geometries where between infinite halfspace and ground plane there are l...

E. Alanen I. V. Lindell

1985-01-01

266

A simplified grounding damage prediction method and its application in modern damage stability requirements  

Microsoft Academic Search

This paper presents the analyses and results aimed at developing damage stability requirements which take into account the structural vulnerability to grounding damage, i.e. the kinetic energy available to generate damage and the structural resistance. The paper presents analysis of new damage statistics in order to determine impact scenarios, in particular in terms of impact speed, impact location, and width

Bo Cerup-Simonsen; Rikard Törnqvist; Marie Lützen

2009-01-01

267

WAVEFRONT RECONSTRUCTION METHODS FOR ADAPTIVE OPTICS SYSTEMS ON GROUND-BASED TELESCOPES  

Microsoft Academic Search

The earth's atmosphere is not a perfect media through which to view objects in outer- space; turbulence in the atmospheric temperature distribution results in refractive index variations that interfere with the propagation of light. As a result, wavefronts are non-planar when they reach the ground. The deviation from planarity of a wavefront is known as phase error, and it is

JOHNATHAN M. BARDSLEYyz

268

Wavefront Reconstruction Methods for Adaptive Optics Systems on Ground-Based Telescopes  

Microsoft Academic Search

The earth's atmosphere is not a perfect media through which to view objects in outer- space; turbulence in the atmospheric temperature distribution results in refractive index variations that interfere with the propagation of light. As a result, wavefronts are non-planar when they reach the ground. The deviation from planarity of a wavefront is known as phase error, and it is

Johnathan M. Bardsley

2008-01-01

269

Application of the harmonic balance method to ground moling machines operating in periodic regimes  

Microsoft Academic Search

A new system for ground moling has been patented by the University of Aberdeen and licensed world-wide. This new system is based on vibro-impact dynamics and offers significant advantages over existing systems in terms of penetrative capability and reduced soil disturbance. This paper describes current research into the mathematical modelling of the system. Periodic response is required to achieve the

Ko-Choong Woo; Albert A. Rodger; Richard D. Neilson; Marian Wiercigroch

2000-01-01

270

Celestial Exoplanet Survey Occulter: A Concept for Direct Imaging of Extrasolar Earth-like Planets from the Ground  

NASA Astrophysics Data System (ADS)

We present a new concept for detecting and characterizing extrasolar planets down to Earth size or smaller through direct imaging. The New Worlds Observer (NWO) occulter developed by Cash and coworkers is placed in a particular geometrical setup in which fuel requirements are small and the occulter is used in combination with ground-based telescopes, presumably leading to an extreme cost efficiency compared to other concepts with similar science goals. We investigate the various aspects of the given geometry, such as the dynamics and radiation environment of the occulter, and construct a detailed example target list to ensure that an excellent science case can be maintained despite the limited sky coverage. It is found that more than 200 systems can be observed with two to three visits per system, using only a few tons of fuel. For each system, an Earth-sized planet with an Earth-like albedo can be found in the habitable zone in less than 2 hr.

Janson, M.

2007-02-01

271

Methods and Sources of Data Used to Develop Selected Water-Quality Indicators for Streams and Ground Water for EPA's 2007 Report on the Environment: Science Report  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) was one of numerous governmental agencies, private organizations, and the academic community that provided data and interpretations for the U.S. Environmental Protection Agency?s (USEPA) 2007 Report on the Environment: Science Report. This report documents the sources of data and methods used to develop selected water?quality indicators for the 2007 edition of the report compiled by USEPA. Stream and ground?water?quality data collected nationally in a consistent manner as part of the USGS?s National Water?Quality Assessment Program (NAWQA) were provided for several water?quality indicators, including Nitrogen and Phosphorus in Streams in Agricultural Watersheds; Pesticides in Streams in Agricultural Watersheds; and Nitrate and Pesticides in Shallow Ground Water in Agricultural Watersheds. In addition, the USGS provided nitrate (nitrate plus nitrite) and phosphorus riverine load estimates calculated from water?quality and streamflow data collected as part of its National Stream Water Quality Accounting Network (NASQAN) and its Federal?State Cooperative Program for the Nitrogen and Phosphorus Discharge from Large Rivers indicator.

Baker, Nancy T.; Wilson, John T.; Moran, Michael J.

2008-01-01

272

Assessing the oral health of an ageing population: methods, challenges and predictors of survey participation  

PubMed Central

Assessing the oral health of an ageing population: methods, challenges and predictors of survey participation Objectives To examine predictors of participation and to describe the methodological considerations of conducting a two-stage population-based oral health survey. Methods An observational, cross-sectional survey (telephone interview and clinical oral examination) of community-dwelling adults aged 45–64 and ?65 living in Nova Scotia, Canada was conducted. Results The survey response rate was 21% for the interview and 13.5% for the examination. A total of 1141 participants completed one or both components of the survey. Both age groups had higher levels of education than the target population; the age 45–64 sample also had a higher proportion of females and lower levels of employment than the target population. Completers (participants who completed interview and examination) were compared with partial completers (who completed only the interview), and stepwise logistic regression was performed to examine predictors of completion. Identified predictors were as follows: not working, post-secondary education and frequent dental visits. Conclusion Recruitment, communications and logistics present challenges in conducting a province-wide survey. Identification of employment, education and dental visit frequency as predictors of survey participation provide insight into possible non-response bias and suggest potential for underestimation of oral disease prevalence in this and similar surveys. This potential must be considered in analysis and in future recruitment strategies.

Matthews, Debora C; Brillant, Martha G S; Clovis, Joanne B; McNally, Mary E; Filiaggi, Mark J; Kotzer, Robert D; Lawrence, Herenia P

2012-01-01

273

A Comparison of Web-Based and Paper-Based Survey Methods: Testing Assumptions of Survey Mode and Response Cost  

ERIC Educational Resources Information Center

Web-based surveys have become more prevalent in areas such as evaluation, research, and marketing research to name a few. The proliferation of these online surveys raises the question, how do response rates compare with traditional surveys and at what cost? This research explored response rates and costs for Web-based surveys, paper surveys, and…

Greenlaw, Corey; Brown-Welty, Sharon

2009-01-01

274

A Comparison of Web-Based and Paper-Based Survey Methods: Testing Assumptions of Survey Mode and Response Cost  

ERIC Educational Resources Information Center

|Web-based surveys have become more prevalent in areas such as evaluation, research, and marketing research to name a few. The proliferation of these online surveys raises the question, how do response rates compare with traditional surveys and at what cost? This research explored response rates and costs for Web-based surveys, paper surveys, and…

Greenlaw, Corey; Brown-Welty, Sharon

2009-01-01

275

A data input program (MFI2K) for the U.S. Geological Survey modular ground-water model (MODFLOW-2000)  

USGS Publications Warehouse

MFI2K is a data-input (entry) program for the U.S. Geological Survey modular three-dimensional finite-difference ground-water model, MODFLOW-2000. MFI2K runs on personal computers. MFI2K supports the solute transport and parameter-estimation capabilities that are incorporated in MODFLOW-2000. Data for MODPATH, a particle-tracking program for use with MODFLOW-2000, also can be entered using MFI2K. MFI2K is designed to be easy to use; data are entered interactively through a series of display screens. MFI2K also can be used in conjunction with other data-input programs so that the different parts of a model dataset can be entered using the most suitable program. MFI2K interfaces to an external program for entering or editing two-dimensional arrays and lists of stress data. This report provides instructions for using MFI2K.

Harbaugh, Arlen W.

2002-01-01

276

A Survey of Methods in the Human Potential Movement  

ERIC Educational Resources Information Center

|Training methods which affect the mind, body consciousness, values, and purpose of life, according to this article, include biofeedback, extrasensory perception, Yoga, transcendental meditation, and Zen. The article describes some elements common to these systems, lists a number of the systems with their costs, and gives some considerations in…

Margolis, Fredric

1977-01-01

277

A survey of forensic characterization methods for physical devices  

Microsoft Academic Search

This paper describes methods for forensic characterization of physical devices. This is important in verifying the trust and authenticity of data and the device that created it. Current forensic identification techniques for digital cameras, printers, and RF devices are presented. It is also shown how these techniques can fit into a general forensic characterization framework, which can be generalized for

Nitin Khanna; Aravind K. Mikkilineni; Anthony F. Martone; Gazi N. Ali; George T.-C. Chiu; Jan P. Allebach; Edward J. Delp

2006-01-01

278

A survey of forensic characterization methods for physical devices5  

Microsoft Academic Search

This paper describes methods for forensic characterization of physical devices. This is important in verifying the trust and authenticity of data and the device that created it. Current forensic identification techniques for digital cameras, printers, and RF devices are presented. It is also shown how these techniques can fit into a general forensic charac- terization framework, which can be generalized

Nitin Khanna; Aravind K. Mikkilineni; Anthony F. Martone; Gazi N. Ali; Jan P. Allebach; Edward J. Delp

279

Computational methods for Traditional Chinese Medicine: A survey  

Microsoft Academic Search

Traditional Chinese Medicine (TCM) has been actively researched through various approaches, including computational techniques. A review on basic elements of TCM is provided to illuminate various challenges and progresses in its study using computational methods. Information on various TCM formulations, in particular resources on databases of TCM formulations and their integration to Western medicine, are analyzed in several facets, such

Suryani Lukman; Yulan He; Siu-Cheung Hui

2007-01-01

280

The Catch-Survey Analysis (CSA) method of fish stock assessment: an evaluation using simulated data  

Microsoft Academic Search

The Catch-Survey Analysis (CSA) method of assessment aims at estimating stock abundance from relative indices by filtering measurement error in the latter through a simple two-stage population dynamics model. The method is not widely used and the associated literature is still limited. The objective of this work is to improve current understanding of the properties of the method, using data

Benoit Mesnil

2003-01-01

281

A survey of numerical methods for shock physics applications  

SciTech Connect

Hydrocodes or more accurately, shock physics analysis packages, have been widely used in the US Department of Energy (DOE) laboratories and elsewhere around the world for over 30 years. Initial applications included weapons effects studies where the pressure levels were high enough to disregard the material strength, hence the term hydrocode. Over the last 30 years, Sandia has worked extensively to develop and apply advanced hydrocodes to armor/anti-armor interactions, warhead design, high explosive initiation, and nuclear weapon safety issues. The needs of the DOE have changed over the last 30 years, especially over the last decade. A much stronger emphasis is currently placed on the details of material deformation and high explosive initiation phenomena. The hydrocodes of 30 years ago have now evolved into sophisticated analysis tools that can replace testing in some situations and complement it in all situations. A brief history of the development of hydrocodes in the US will be given. The author also discusses and compares the four principal methods in use today for the solution of the conservation equations of mass, momentum, and energy for shock physics applications. The techniques discussed are the Eulerian methods currently employed by the Sandia multi-dimensional shock physics analysis package known as CTH; the element based Lagrangian method currently used by codes like DYNA; the element free Lagrangian method (also known as smooth particle hydrodynamics) used by codes like the Los Alamos code SPHINX; and the Arbitrary Lagrangian Eulerian methods used by codes like the Lawrence Livermore code CALE or the Sandia code ALEGRA.

Hertel, E.S. Jr.

1997-10-01

282

Exact ground state Monte Carlo method for Bosons without importance sampling  

NASA Astrophysics Data System (ADS)

Generally ``exact'' quantum Monte Carlo computations for the ground state of many bosons make use of importance sampling. The importance sampling is based either on a guiding function or on an initial variational wave function. Here we investigate the need of importance sampling in the case of path integral ground state (PIGS) Monte Carlo. PIGS is based on a discrete imaginary time evolution of an initial wave function with a nonzero overlap with the ground state, which gives rise to a discrete path which is sampled via a Metropolis-like algorithm. In principle the exact ground state is reached in the limit of an infinite imaginary time evolution, but actual computations are based on finite time evolutions and the question is whether such computations give unbiased exact results. We have studied bulk liquid and solid 4He with PIGS by considering as initial wave function a constant, i.e., the ground state of an ideal Bose gas. This implies that the evolution toward the ground state is driven only by the imaginary time propagator, i.e., there is no importance sampling. For both phases we obtain results converging to those obtained by considering the best available variational wave function (the shadow wave function) as initial wave function. Moreover we obtain the same results even by considering wave functions with the wrong correlations, for instance, a wave function of a strongly localized Einstein crystal for the liquid phase. This convergence is true not only for diagonal properties such as the energy, the radial distribution function, and the static structure factor, but also for off-diagonal ones, such as the one-body density matrix. This robustness of PIGS can be traced back to the fact that the chosen initial wave function acts only at the beginning of the path without affecting the imaginary time propagator. From this analysis we conclude that zero temperature PIGS calculations can be as unbiased as those of finite temperature path integral Monte Carlo. On the other hand, a judicious choice of the initial wave function greatly improves the rate of convergence to the exact results.

Rossi, M.; Nava, M.; Reatto, L.; Galli, D. E.

2009-10-01

283

Tracking micro reentering USV with TDRS and ground stations using adaptive IMM method  

Microsoft Academic Search

In this paper, a tracking system with multi-sensors is presented, in which a sub-orbit USV (unmanned space vehicle) of wave-rider shape is tracked by a TDRS (Tracking and Data Relay Satellite) and ground stations. Because of high lift-drag ratio and maneuverability, the vehicle, once is used in reentering purpose, a complicated trajectory will be produced and cause big challenges for

Li-Qiang Hou; Heng-Nian Li; Fu-Ming Huang; Pu Huang

2011-01-01

284

Transparent 3D Visualization of Archaeological Remains in Roman Site in Ankara-Turkey with Ground Penetrating Radar Method  

Microsoft Academic Search

Transparent 3D Visualization of Archaeological Remains in Roman Site in Ankara-Turkey with Ground Penetrating Radar Method Selma KADIOGLU Ankara University, Faculty of Engineering, Department of Geophysical Engineering, 06100 Tandogan\\/ANKARA-TURKEY kadioglu@eng.ankara.edu.tr Anatolia has always been more the point of transit, a bridge between West and East. Anatolia has been a home for ideas moving from all directions. So it is that

S. Kadioglu

2009-01-01

285

GBFEL-TIE (Ground-Based Free Electron Laser Technology Experiment) sample survey on White Sands Missile Range, New Mexico: The NASA, Stallion, and Orogrande Alternatives. Final report  

SciTech Connect

Three locations on White Sands Missile Range, New Mexico, are under consideration as alternatives for the proposed Ground-Based Free-Electron Laser Technology Integration Experiment (GBFEL-TIE). The study conducted jointly by Prewitt and Associates, Inc., and the Office of Contract Archeology, was designed to provide input into the GBFEL-TIE Draft Environmental Impact Statement concerning the potential impact of the proposed project on cultural resources in each of the alternatives. The input consists of a series of predictions based on data gathered from two sources: (1) a cultural resource sample survey (15%) of two alternatives conducted as part of this study, and (2) from a previous survey of the third alternative. A predictive model was devleoped and applied using these data that estimated the potential impact of the GBFEL-TIE facility on the cultural resources within each alternative. The predictions indicate that the NASA alternatives, by far, the least favorable location for the facility followed by the Orogrande and Stallion Alternatives.

Seaman, T.J.; Doleman, W.H.

1988-09-30

286

Warm and cold gas in low-mass protostars : Herschel Space Observatory and ground-based surveys  

NASA Astrophysics Data System (ADS)

The primary focus of this thesis is the formation of low-mass protostars, specifically the earliest deeply embedded phase, when material from the collapsing envelope is still accreted onto the growing young star. Rotational transitions of CO and O2 data are obtained by the Herschel Space Observatory key projects, WISH and HOP, together with ground-based observations from APEX and the JCMT. We have found that CO and its isotopologs have different line profiles tracing different materials in the protostellar regions. Our new high-J rotational transitons of CO is key to characterize the warmer parts of the protostellar envelope and quantify feedback of the protostars on their surroundings in terms of shocks, ultraviolet (UV) heating, photodissociation, and outflow dispersal. Radiative transfer modeling was performed to determine the CO abundance structure in the envelope, showing evidence for significant freeze-out in the coldest regions in the parts of the envelope where the temperature exceeds 25 K. A tentative detection of O2 is reported toward the source position of a protostar, which originates from the surrounding cloud. These kind of detailed studies of the physical and chemical structure of low-mass protostars are important for a complete understanding of the evolution of young stellar objects (YSOs).

Yildiz, Umut

2013-05-01

287

Microgravimetric and ground penetrating radar geophysical methods to map the shallow karstic cavities network in a coastal area (Marina Di Capilungo, Lecce, Italy)  

NASA Astrophysics Data System (ADS)

The coastal area Marina di Capilungo located ~50km south-west of Lecce (Italy) is one of the sites at greatest geological risk in the Salento peninsula. In the past few decades, Marina di Capilungo has been affected by a series of subsidence events, which have led in some cases to the partial collapse of buildings and road surfaces. These events had both social repercussions, causing alarm and emergency situations, and economic ones in terms of the funds for restoration. With the aim of mapping the subsurface karstic features, and so to assess the dimensions of the phenomena in order to prevent and/or limit the ground subsidence events, integrated geophysical surveys were undertaken in an area of ~70000m2 at Marina di Capilungo. Large volume voids such as karstic cavities are excellent targets for microgravity surveys. The absent mass of the void creates a quantifiable disturbance in the earth's gravitational field, with the magnitude of the disturbance directly proportional to the volume of the void. Smaller shallow voids can be detected using ground-penetrating radar (GPR). Microgravimetric and GPR geophysical methods were therefore used. An accurate interpretation was obtained using small station spacing and accurate geophysical data processing. The interpretation was facilitated by combining the modelling of the data with the geological and topographic information for explored caves. The GPR method can complement the microgravimetric technique in determining cavity depths and in verifying the presence of off-line features and numerous areas of small cavities, which may be difficult to be resolved with only microgravimetric data. However, the microgravimetric can complement GPR in delineating with accuracy the shallow cavities in a wide area where GPR measurements are difficult. Furthermore, microgravity surveys in an urban environment require effective and accurate consideration of the effects given by infrastructures, such as buildings, as well as those given by topography, near a gravity station. The acquired negative anomaly in the residual Bouguer anomalies field suggested the presence of possible void features. GPR and modelling data were used to estimate the depth and shape of the anomalous source.

Leucci, Giovanni; De Giorgi, Lara

2010-06-01

288

Determination of land subsidence related to ground-water-level declines using Global Positioning System and leveling surveys in Antelope Valley, Los Angeles and Kern counties, California, 1992  

USGS Publications Warehouse

A large-scale, land-subsidence monitoring network for Antelope Valley, California, was established, and positions and elevations for 85 stations were measured using Global Positioning System geodetic surveying in spring 1992. The 95-percent confidence (2@) level of accuracy for the elevations calculated for a multiple-constraint adjustment generally ranged from +0.010 meter (0.032 foot) to +0.024 meter (0.078 foot). The magnitudes and rates of land subsidence as of 1992 were calculated for several periods for 218 bench marks throughout Antelope Valley. The maximum measured magnitude of land subsidence that occurred between 1926 and 1992 was 6.0 feet (1.83 meters) at BM 474 near Avenue I and Sierra Highway. Measured or estimated subsidence of 2-7 feet (.61-2.l3 meters) had occurred in a 210- square-mile (542-square-kilometer) area of Antelope Valley, generally bounded by Avenue K, Avenue A, 90th Street West, and 120th Street East, during the same period. Land subsidence in Antelope Valley is caused by aquifer-system compaction, which is related to ground-water-level declines and the presence of fine-grained, compressible sediments. Comparison of potentiomethric-surface, water-level decline, and subsidence-rate maps for several periods indicated a general correlation between water-level declines and the distribution and rate of subsidence in the Lancaster ground-water subbasin. A conservative estimate of the amount of the reduction in storage capacity of the aquifer system in the Lancaster subbasin is about 50,000 acre-feet in the area that has been affected by more than one foot (.30 meters) of subsidence as of 1992. Information on the history of ground-water levels and the distribution and thickness of fine-grained compressible sediments can be used to mitigate continued land subsidence. Future monitoring of ground-water levels and land-surface elevations in subsidence-sensitive regions of Antelope Valley may be an effective means to manage land subsidence.

Ikehara, M. E.; Phillips, S. P.

1994-01-01

289

The Hybrid Finite Element Mixing Cell Method: A New Flexible Method for Modelling Mine Ground Water Problems  

Microsoft Academic Search

Dewatering operations often stop at mine closure. The ground water rebound can have undesirable consequences, which numerical\\u000a models can help one understand and manage. However, classical modelling techniques are relatively unsuitable to these contexts.\\u000a While spatially distributed and physically based models suffer difficulties due to the lack of data and the complexity of\\u000a geological and hydrogeological conditions, black-box models are

Serge Brouyère; Ph. Orban; S. Wildemeersch; J. Couturier; N. Gardin; A. Dassargues

2009-01-01

290

New applications of hydroacoustic methods for monitoring shallow water aquatic ecosystems: the case of mussel culture grounds  

Microsoft Academic Search

The development of acoustics tools and methods for monitoring anthropized ecosystems represents a new field for the application of acoustics. Monitoring such an environment was not possible with single vertical echo sounders, due to the fact that the artificial structures and the natural targets were not distinguishable. Monitoring data were collected along the French Mediterranean coastline, during five short surveys

Patrice Brehmer; François Gerlotto; Jean Guillard; Fabien Sanguinède; Yvon Guénnegan; Dominique Buestel

2003-01-01

291

High-Order Coupled Cluster Method (CCM) Calculations for Quantum Magnets with Valence-Bond Ground States  

NASA Astrophysics Data System (ADS)

In this article, we prove that exact representations of dimer and plaquette valence-bond ket ground states for quantum Heisenberg antiferromagnets may be formed via the usual coupled cluster method (CCM) from independent-spin product (e.g. Néel) model states. We show that we are able to provide good results for both the ground-state energy and the sublattice magnetization for dimer and plaquette valence-bond phases within the CCM. As a first example, we investigate the spin-half J 1- J 2 model for the linear chain, and we show that we are able to reproduce exactly the dimerized ground (ket) state at J 2/ J 1=0.5. The dimerized phase is stable over a range of values for J 2/ J 1 around 0.5, and results for the ground-state energies are in good agreement with the results of exact diagonalizations of finite-length chains in this regime. We present evidence of symmetry breaking by considering the ket- and bra-state correlation coefficients as a function of J 2/ J 1. A radical change is also observed in the behavior of the CCM sublattice magnetization as we enter the dimerized phase. We then consider the Shastry-Sutherland model and demonstrate that the CCM can span the correct ground states in both the Néel and the dimerized phases. Once again, very good results for the ground-state energies are obtained. We find CCM critical points of the bra-state equations that are in agreement with the known phase transition point for this model. The results for the sublattice magnetization remain near to the "true" value of zero over much of the dimerized regime, although they diverge exactly at the critical point. Finally, we consider a spin-half system with nearest-neighbor bonds for an underlying lattice corresponding to the magnetic material CaV4O9 (CAVO). We show that we are able to provide excellent results for the ground-state energy in each of the plaquette-ordered, Néel-ordered, and dimerized regimes of this model. The exact plaquette and dimer ground states are reproduced by the CCM ket state in their relevant limits. Furthermore, we estimate the range over which the Néel order is stable, and we find the CCM result is in reasonable agreement with the results obtained by other methods. Our new approach has the dual advantages that it is simple to implement and that existing CCM codes for independent-spin product model states may be used from the outset. Furthermore, it also greatly extends the range of applicability to which the CCM may be applied. We believe that the CCM now provides an excellent choice of method for the study of systems with valence-bond quantum ground states.

Farnell, D. J. J.; Richter, J.; Zinke, R.; Bishop, R. F.

2009-04-01

292

A thermal profile method to identify potential ground-water discharge areas and preferred salmonid habitats for long river reaches  

USGS Publications Warehouse

The thermal regime of riverine systems is a major control on aquatic ecosystems. Ground water discharge is an important abiotic driver of the aquatic ecosystem because it provides preferred thermal structure and habitat for different types of fish at different times in their life history. In large diverse river basins with an extensive riverine system, documenting the thermal regime and ground-water discharge is difficult and problematic. A method was developed to thermally profile long (5-25 kilometers) river reaches by towing in a Lagrangian framework one or two probes that measure temperature, depth, and conductivity. One probe is towed near the streambed and, if used, a second probe is towed near the surface. The probes continuously record data at 1-3-second intervals while a Global Positioning System logs spatial coordinates. The thermal profile provides valuable information about spatial and temporal variations in habitat, and, notably, indicates ground-water discharge areas. This method was developed and tested in the Yakima River Basin, Washington, in summer 2001 during low flows in an extreme drought year. The temperature profile comprehensively documents the longitudinal distribution of a river's temperature regime that cannot be captured by fixed station data. The example profile presented exhibits intra-reach diversity that reflects the many factors controlling the temperature of a parcel of water as it moves downstream. Thermal profiles provide a new perspective on riverine system temperature regimes that represent part of the aquatic habitat template for lotic community patterns.

Vaccaro, J. J.; Maloy, K. J.

2006-01-01

293

A Survey of Proton Spectra and Fluences above 1 GV in Ground-Level Enhanced (GLE) Solar Particle Events  

NASA Astrophysics Data System (ADS)

Proton acceleration to energies above ~500 MeV is a controversial and poorly understood aspect of solar energetic particle (SEP) physics, even though these very high-energy events have been observed with neutron monitors in Ground Level Enhancements (GLEs) for more than 50 years. For 40 of the 66 GLEs reported since 1956, we have derived absolutely-normalized event-integrated proton spectra, using data from the world-wide neutron-monitor network and published neutron-yield functions (Clem & Dorman 2000), under the assumption that the proton spectra can be represented as power-laws in rigidity. We believe this analysis to be the most extensive catalogue of GLE spectra ever assembled. As a check on our results, we have compared the fluences derived from our neutron-monitor analyses to satellite measurements at ~300-700 MeV available from IMP8, SAMPEX, and/or GOES for 28 of the events. We generally find very good agreement (i.e., to within ~50%) with the satellite fluence-measurements. We also find reasonable agreement with time-dependent spectral indices that have been published previously for some of the events (e.g., Lovell et al. 1999, Lockwood et al. 2002, and Plainaki et al. 2007). Compared to spectral indices below ~0.4 GV (~100 MeV), we find no evidence for spectral hardening above ~1 GV, something that might be expected if two independent acceleration mechanisms dominated particle production in these two rigidity ranges. We present distributions of event properties above 1 GV, including event size, spectral indices, and the degree of spectral steepening relative to lower energies. These results should be useful constraints in developing and testing theoretical models of proton acceleration in GLEs. We also briefly discuss the implications of these results for the design of astronaut storm shelters, whose efficacy has often been evaluated assuming spectral shapes that are much softer than the ones we derive from the neutron-monitor data. Supported by the Office of Naval Research and by NASA DPR NNG06EC55I.

Tylka, A. J.; Dietrich, W. F.

2008-05-01

294

Method and appartus for converting static in-ground vehicle scales into weigh-in-motion systems  

DOEpatents

An apparatus and method for converting in-ground static weighing scales for vehicles to weigh-in-motion systems. The apparatus upon conversion includes the existing in-ground static scale, peripheral switches and an electronic module for automatic computation of the weight. By monitoring the velocity, tire position, axle spacing, and real time output from existing static scales as a vehicle drives over the scales, the system determines when an axle of a vehicle is on the scale at a given time, monitors the combined weight output from any given axle combination on the scale(s) at any given time, and from these measurements automatically computes the weight of each individual axle and gross vehicle weight by an integration, integration approximation, and/or signal averaging technique.

Muhs, Jeffrey D. (Lenior City, TN); Scudiere, Matthew B. (Oak Ridge, TN); Jordan, John K. (Oak Ridge, TN)

2002-01-01

295

Tensors-structured numerical methods in scientific computing: Survey on recent advances  

Microsoft Academic Search

In the present paper, we give a survey of the recent results and outline future prospects of the tensor-structured numerical methods in applications to multidimensional problems in scientific computing. The guiding principle of the tensor methods is an approximation of multivariate functions and operators relying on a certain separation of variables. Along with the traditional canonical and Tucker models, we

Boris N. Khoromskij

296

Informetric Theories and Methods for Exploring the Internet: An Analytical Survey of Recent Research Literature.  

ERIC Educational Resources Information Center

|Presents a selective review of research based on the Internet, using bibliometric and informetric methods and tools. Highlights include data collection methods on the Internet, including surveys, logging, and search engines; and informetric analysis, including citation analysis and content analysis. (Contains 78 references.) (Author/LRW)|

Bar-Ilan, Judit; Peritz, Bluma C.

2002-01-01

297

A survey of IGBT fault diagnostic methods for three-phase power inverters  

Microsoft Academic Search

Fault diagnostics of power converters have drawn increasing attentions due to the widespread adoption of advanced power control devices, such as motor drives and uninterruptible power supplies. This paper presents a literature survey on existing methods for fault diagnosis and protection of IGBTpsilas, with special focus on those used in three-phase power inverters. Eleven methods for open-circuit faults and ten

Bin Lu; Santosh Sharma

2008-01-01

298

Methods for evaluating ground dislocations in mining areas / Metoda oceny przemieszcze? budowli na terenie górniczym  

NASA Astrophysics Data System (ADS)

Underground exploitation of natural resources results in disturbance of the original equilibrium in the strata and leads to the emergence of the so-called subsidence troughs on the ground surface (Florkowska, 2010). Due to ground distortion, buildings located in these areas suffer damages and deformations, including angular tilts. An instrument for measuring constructions' angles of slope is known as an inclinometer. The prototypical vibrating wire inclinometer discussed in the present paper has three wires (each of them cooperating with one electromagnet) on which a weight - attached to an arm - is suspended. Thanks to this, it comes of use in a range of procedures, such as measuring object inclines, or determining the angle between the plane of the incline and the assumed reference direction. As any other vibrating wire transducer, an inclinometer cooperates with a proper electronic device which makes it possible to measure the vibration period for each wire separately. The device is also used for the inclinometer's calibration. Additionally, the paper provides an example of an inclinometer's use in measuring the angular tilt of a historical church tower located in the area affected by underground mining operations connected with exploitation of hard coal.

Kanciruk, Adam

2012-12-01

299

A NEW METHOD FOR THE DETERMINATION OF THE GROWTH RATE FROM GALAXY REDSHIFT SURVEYS  

SciTech Connect

Given a redshift survey of galaxies with measurements of apparent magnitudes, we present a novel method for measuring the growth rate f({Omega}) of cosmological linear perturbations. We use the galaxy distribution within the survey to solve for the peculiar velocity field which depends in linear perturbation theory on {beta} = f({Omega})/b, where b is the bias factor of the galaxy distribution. The recovered line-of-sight peculiar velocities are subtracted from the redshifts to derive the distances, which thus allows an estimate of the absolute magnitude of each galaxy. A constraint on {beta} is then found by minimizing the spread of the estimated magnitudes from their distribution function. We apply the method to the all sky K = 11.25 2MASS Redshift Survey and derive {beta} = 0.35 {+-} 0.1 at z {approx} 0, remarkably consistent with our previous estimate from the velocity-velocity comparison. The method could easily be applied to subvolumes extracted from the Sloan Digital Sky Survey to derive the growth rate at z {approx} 0.1. Further, it should also be applicable to ongoing and future spectroscopic redshift surveys to trace the evolution of f({Omega}) to z {approx} 1. Constraints obtained from this method are entirely independent from those obtained from the two-dimensional distortion of {xi}(s) and provide an important check on f({Omega}), as alternative gravity models predict observable differences.

Nusser, Adi [Physics Department and the Asher Space Science Institute-Technion, Haifa 32000 (Israel); Branchini, Enzo [Department of Physics, Universita Roma Tre, Via della Vasca Navale 84, 00146, Rome (Italy); Davis, Marc, E-mail: adi@physics.technion.ac.il, E-mail: branchin@fis.uniroma3.it, E-mail: mdavis@berkeley.edu [Departments of Astronomy and Physics, University of California, Berkeley, CA 94720 (United States)

2012-01-10

300

New land-based method for surveying sandy shores and extracting DEMs: the INSHORE system.  

PubMed

The INSHORE system (INtegrated System for High Operational REsolution in shore monitoring) is a land-base survey system designed and developed for the specific task of monitoring the evolution in time of sandy shores. This system was developed with two main objectives: (1) to produce highly accurate 3D coordinates of surface points (in the order of 0.02 to 0.03 m); and (2) to be extremely efficient in surveying a beach stretch of several kilometres. Previous tests have demonstrated that INSHORE systems fulfil such objectives. Now, the usefulness of the INSHORE system as a survey tool for the production of Digital Elevation Models (DEMs) of sandy shores is demonstrated. For this purpose, the comparison of DEMs obtained with the INSHORE system and with other relevant survey techniques is presented. This comparison focuses on the final DEM accuracy and also on the survey efficiency and its impact on the costs associated with regular monitoring programmes. The field survey method of the INSHORE system, based on profile networks, has a productivity of about 30 to 40 ha/h, depending on the beach surface characteristics. The final DEM precision, after interpolation of the global positioning system profile network, is approximately 0.08 to 0.12 m (RMS), depending on the profile network's density. Thus, this is a useful method for 3D representation of sandy shore surfaces and can permit, after interpolation, reliable calculations of volume and other physical parameters. PMID:21301958

Baptista, Paulo; Cunha, Telmo R; Matias, Ana; Gama, Cristina; Bernardes, Cristina; Ferreira, Oscar

2011-02-09

301

A comparison of web-based and paper-based survey methods: testing assumptions of survey mode and response cost.  

PubMed

Web-based surveys have become more prevalent in areas such as evaluation, research, and marketing research to name a few. The proliferation of these online surveys raises the question, how do response rates compare with traditional surveys and at what cost? This research explored response rates and costs for Web-based surveys, paper surveys, and mixed-mode surveys. The participants included evaluators from the American Evaluation Association (AEA). Results included that mixed-mode, while more expensive, had higher response rates. PMID:19605623

Greenlaw, Corey; Brown-Welty, Sharon

2009-07-15

302

A method of increasing the sensitivity of protection from single-phase short-circuits to ground in the 6 - 10 kV network  

SciTech Connect

A method of increasing the sensitivity of protection from single-phase short-circuits to ground by acting on the signal with brief dummy grounding of the neutral is described. After determining the damage, the neutral is again grounded through a high resistance and an arc-quenching reactor. An increase in the protection sensitivity is thereby obtained, the damage detection time is shortened, and the probability of the single-phase short-circuit to ground converting into double and multipoint earth faults is reduced.

Manilov, A. M.; Mel'nik, D. A. [PC 'MC 'Metropoliya' (Ukraine)

2012-07-15

303

Multidisciplinary Studies of the Fate and Transport of Contaminants in Ground Water at the U.S. Geological Survey Cape Cod Toxic Substances Hydrology Program Research Site, Massachusetts  

NASA Astrophysics Data System (ADS)

The U.S. Geological Survey conducts multidisciplinary research on the physical, chemical, and microbiological processes affecting ground-water contaminants of global concern at its Cape Cod Toxic Substances Hydrology Program site in Massachusetts, USA. The work centers on a 6-kilometer-long plume of treated wastewater in a glacial sand and gravel aquifer. The plume is characterized by distinct geochemical zones caused by the biodegradation of organic materials in treated wastewater that was disposed to the aquifer by rapid infiltration during the period 1936-95. A core group of hydrogeologists, geochemists, microbiologists, and geophysicists has been involved in the research effort for more than two decades. The effort has been enhanced by stable funding, a readily accessible site, a relatively simple hydrologic setting, and logistical support from an adjacent military base. The research team uses a three-part approach to plan and conduct research at the site. First, detailed spatial and temporal monitoring of the plume since the late 1970s provides field evidence of important contaminant-transport processes and provides the basis for multidisciplinary, process-oriented studies. Second, ground-water tracer experiments are conducted in various geochemical zones in the plume to study factors that control the rate and extent of contaminant transport. Several arrays of multilevel sampling devices, including an array with more than 15,000 individual sampling points, are used to conduct these experiments. Plume-scale (kilometers) and tracer-test-scale (1- 100 meters) studies are complemented by laboratory experiments and mathematical modeling of flow and reactive transport. Third, results are applied to the treated-wastewater plume, other contaminant plumes at the military base, and other sites nationally to evaluate the applicability of the findings and to point toward further research. Examples of findings to date include that (1) macrodispersivity can be related to hydraulic- conductivity variations as predicted by stochastic models; (2) mobile and attached bacteria and protists comprise a microbial community that plays a predominant role in geochemical processes in the subsurface, (3) estimated rates of geochemical processes are dependent on measurement scale (for example, laboratory columns versus field tracer tests); and (4) geochemical zones in a contaminant plume can persist for decades after the contaminant source has been removed and conservative species have been flushed from the area by natural ground-water flow.

Leblanc, D. R.; Smith, R. L.; Kent, D. B.; Barber, L. B.; Harvey, R. W.

2008-12-01

304

Geology and Geophysical Surveys to Infer the Structure of the Upper San Pedro River Basin, Sonora, Mexico for Use in a Ground-Water-Flow Model  

NASA Astrophysics Data System (ADS)

Data on geology and geophysics in the San Pedro River Basin in Sonora, Mexico were combined to develop a three-dimensional conceptual model of the alluvial-fill aquifer in the basin that is being used to construct a regional ground-water-flow model. In Mexico, the headwater region of the river encompasses approximately 1,800 square kilometers of an ungaged catchment system. This feeds a 58 kilometer-long series of intermittent and perennial stream reaches in the United States that extend from just north of the international border to the town of St. David, Arizona. The river forms part of a north-south riparian corridor that provides habitat for more than 100 resident and 250 migratory bird species. Ground water in the basin is used extensively on both sides of the border and information on basin structure and composition will help to address questions regarding ground- and surface-water sustainability and planning. Interpretations of bedrock and alluvial-fill geometry indicate that a significant portion of the catchment area in Mexico is underlain by bedrock composed of highly indurated (compacted) Cretaceous sedimentary, volcanic, volcano-sedimentary, and granitic intrusive rocks. Aeromagnetic surveys were used to estimate depth to bedrock underlying alluvial sediments. Satellite photographs, older geologic maps, and recent field observations were used to delineate the boundaries between bedrock and alluvium. About 655 square kilometers, or 36 percent, of the Mexican portion of the river basin is underlain by alluvial fill. In the southern part of the study area, detailed information on thickness and composition of subsurface layers to depths of 500 meters was derived from drill logs. An extensive network of vertical electrical soundings covering much of the central part of the basin allowed for estimates of the location and thickness of clay layers that are confining units within the aquifer system. Across much of the area, the thickness of the silt and confining units was difficult to determine because of problems in distinguishing between these layers and underlying, electrically-conductive Cretaceous siltstone and mudstone. In general, two hydraulically connected sub-basins were identified: one in the southern part of the study area and one in the northern part.

Pool, D.; Gray, F.; Callegary, J. B.

2005-05-01

305

Polynomial combinatorial optimization methods for analysing the ground states of disordered systems  

NASA Astrophysics Data System (ADS)

We discuss the application of polynomial combinatorial optimization algorithms to extract the universal zero-temperature properties of various disordered systems. Dijkstras algorithm is used for models of non-directed elastic lines on general regular graphs with isotropically correlated random potentials. The successive shortest path algorithm for minimum-cost-flow problems is applied for the study of ground state properties and the entanglement of many elastic lines in a disordered environment and the disorder-induced loop percolation transition in a vortex glass model. The pre-flow-push algorithm for minimum-cut-maximum-flow problems is used for the investigation of a roughening transition occurring in a model for elastic manifolds in a periodic potential in the presence of point disorder.

Rieger, Heiko

2003-10-01

306

Grounding electrode and method of reducing the electrical resistance of soils  

DOEpatents

A first solution of an electrolyte is injected underground into a volume of soil having negative surface charges on its particles. A cationic surfactant suspended in this solution neutralizes these surface charges of the soil particles within the volume. Following the first solution, a cationic asphalt emulsion suspended in a second solution is injected into the volume. The asphalt emulsion diffuses through the volume and electrostatically bonds with additional soil surrounding the volume such that an electrically conductive water repellant shell enclosing the volume is formed. This shell prevents the leaching of electrolyte from the volume into the additional soil. The second solution also contains a dissolved deliquescent salt which draws water into the volume prior to the formation of the shell. When electrically connected to an electrical installation such as a power line tower, the volume constitutes a grounding electrode for the tower.

Koehmstedt, Paul L. (Richland, WA)

1980-01-01

307

Different Views on Inquiry: A Survey of Science and Mathematics Methods Instructors  

NSDL National Science Digital Library

The national science standards encourage the use of inquiry-based instruction to teach difficult scientific concepts. As part of a larger study to investigate teachers' views on the nature of inquiry-based instruction, a survey was administered to Science and Mathematics methods course instructors to determine their views on inquiry, as well as to explore the success and difficulties associated with teaching this difficult concept. In addition, we wished to obtain their views on the "5 E's" method, an inquiry method specifically designed to promote conceptual change that is often taught as "the" method to utilize. Initial survey data suggests there are many different views among Science and Mathematics methods course instructors about the nature of inquiry. This paper discusses the difficulties encountered with the "5 E's" and teaching inquiry-based methods to teachers.

Withee, Thomas; Lindell, Rebecca S.

2009-07-13

308

A ground electromagnetic survey used to map sulfides and acid sulfate ground waters at the abandoned Cabin Branch Mine, Prince William Forest Park, northern Virginia gold-pyrite belt  

USGS Publications Warehouse

INTRODUCTION AND BACKGROUND: Prince William Forest Park is situated at the northeastern end of the Virginia Gold-Pyrite belt northwest of the town of Dumfries, VA. The U. S. Marine Corps Reservation at Quantico borders the park on the west and south, and occupies part of the same watershed. Two abandoned mines are found within the park: the Cabin Branch pyrite mine, a historic source of acid mine drainage, and the Greenwood gold mine, a source of mercury contamination. Both are within the watershed of Quantico Creek (Fig.1). The Cabin Branch mine (also known as the Dumfries mine) lies about 2.4 km northwest of the town of Dumfries. It exploited a 300 meter-long, lens-shaped body of massive sulfide ore hosted by metamorphosed volcanic rocks; during its history over 200,000 tons of ore were extracted and processed locally. The site became part of the National Capitol Region of the National Park Service in 1940 and is currently managed by the National Park Service. In 1995 the National Park Service, in cooperation with the Virginia Department of Mines, Minerals, and Energy reclaimed the Cabin Branch site. The Virginia Gold-Pyrite belt, also known as the central Virginia volcanic-plutonic belt, is host to numerous abandoned metal mines (Pavlides and others, 1982), including the Cabin Branch deposit. The belt itself extends from its northern terminus near Cabin Branch, about 50 km south of Washington, D.C., approximately 175 km to the southwest into central Virginia. It is underlain by metamorphosed volcanic and clastic (non-carbonate) sedimentary rocks, originally deposited approximately 460 million years ago during the Ordovician Period (Horton and others, 1998). Three kinds of deposits are found in the belt: volcanic-associated massive sulfide deposits, low-sulfide quartz-gold vein deposits, and gold placer deposits. The massive sulfide deposits such as Cabin Branch were historically mined for their sulfur, copper, zinc, and lead contents, but also yielded byproduct gold and silver. The environmental impact of massive sulfide deposits can be substantial. These deposits are characterized by high concentrations of heavy-metal sulfide minerals, hosted by silicate rocks. Thus, weathering of these deposits and their mine wastes has the potential to generate heavy-metal laden sulfuric acid that can have negative impacts on aquatic ecosystems. In addition, lead associated with solid mine wastes has the potential for human health impacts through ingestion. The heavy metals that are encountered in these deposits and are most likely to cause environmental impacts include copper, zinc, lead, cadmium, and arsenic. In addition, the weathering of pyrite releases large amounts of iron, and the acid generated attacks the country rocks and causes the release of large amounts of aluminum, which also can severely impact aquatic ecosystems. A reclamation attempt was made at the site in 1995, including construction of storm-water diversion trenches around the abandoned mine area, grading tailings away from the stream bank, addition of pulverized limestone and topsoil, and revegetation. The post-reclamation chemistry of shallow groundwaters (<3 meters deep) shows a neutral pH on the southwestern bank of the stream but pH of 4.1 to 4.5 on the northeastern bank. The dominant ions are Fe2+ and SO42- (Seal, Haffner, Meier, and Pollio, 1999) A ground electromagnetic survey was conducted over the site in 1999 as part of a wider study ( Seal, Haffner, and Meier, 1998a,b, 1999). It was hoped that a 3-D map of the soil conductivity derived from the survey could provide insight into the distribution of the mobilized sulfides present under the ground. This study was conducted in cooperation with the National Park Service

Wynn, Jeffrey C.

2000-01-01

309

Grounding Ring for Ground Adapters.  

National Technical Information Service (NTIS)

The present invention relates to a grounding ring which may be used in ground adapters. The grounding ring has a structure resembling a miniature box girder with an irregular hexagonal cross section and a hollow toroidal configuration. The grounding ring ...

N. F. Schade

1991-01-01

310

Comparison of ground-based measurements of natural radiation to airborne radiation survey data on transects from coastal California to the Colorado Plateau  

NASA Astrophysics Data System (ADS)

Natural gamma radiation measurements were collected with a hand-held Geiger counter at nearly 400 locations on two general transects across the southwestern United States. The data are used to provide ground-truth comparison to published airborne radiation surveys of the region. The first transect was collected by high school students in the SF-ROCKS program at San Francisco State University in the summer of 2008 starting in San Francisco. Data were collected across the Sierra Nevada Range on I-80, and across Highway 50 in Nevada, and I-70 in Utah. Data were collected in and around Great Basin, Arches, Capitol Reef, Bryce, and Zion National Parks, and Grand Staircase-Escalante National Monument. A second transect extends from San José, California to Flagstaff, Arizona and includes the Mojave National Reserve, Death Valley region, and locations throughout the Navajo Reservation region in northern Arizona and western New Mexico. Radiation data (with GPS reference) were collected from all the major sedimentary rock formations and igneous rocks of the Colorado Plateau and from many igneous and metamorphic rocks throughout the Great Basin and southern California deserts. Anomalously high localized levels were noted in selected sedimentary units associated with uranium exploration targets in the Colorado Plateau region, and in caverns and rock fissures where radon gas (and accumulation of derivative fission products) are the inferred sources.

Stoffer, P. W.; Hernández, L.; Messina, P.; Dearaujo, J.; Li, A.; Hicks, A.; White, L.

2008-12-01

311

Evaluation of preservation methods for selected nutrients in ground water at the Idaho National Engineering Laboratory, Idaho  

SciTech Connect

Water from 28 wells completed in the Snake River Plain aquifer at the Idaho National Engineering Laboratory (INEL) was sampled as part of the US Geological Survey`s quality-assurance program to determine the effect of different preservation methods on nutrient concentrations. Samples were preserved with filtration and with mercuric chloride and chilling, chilling only, or sulfuric acid and chilling. The samples were analyzed for ammonia, nitrite, nitrite plus nitrate, and orthophosphate by the US Geological Survey National Water Quality Laboratory. The study was done in cooperation with the US Department of Energy. The comparison between samples preserved with mercuric chloride and chilling and samples preserved by chilling only showed that all sample pairs were in statistical agreement. Results for ammonia and nitrite plus nitrate samples preserved with sulfuric acid and chilling were within the 95 percent confidence level of the results for the samples preserved by the other two methods and can be considered equivalent to them. Results of this study indicate that discontinuing the use of mercuric chloride as a preservation method for nutrients in water samples will not affect the comparability of data collected at the INEL before and after October 1, 1994.

Bartholomay, R.C.; Williams, L.M.

1996-10-01

312

Chloride mass-balance method for estimating ground water recharge in arid areas: Examples from western Saudi Arabia  

USGS Publications Warehouse

The chloride mass-balance method, which integrates time and aerial distribution of ground water recharge, was applied to small alluvial aquifers in the wadi systems of the Asir and Hijaz mountains in western Saudi Arabia. This application is an extension of the method shown to be suitable for estimating recharge in regional aquifers in semi-arid areas. Because the method integrates recharge in time and space it appears to be, with certain assumptions, particularly well suited for and areas with large temporal and spatial variation in recharge. In general, recharge was found to be between 3 to 4% of precipitation - a range consistent with recharge rates found in other arid and semi-arid areas of the earth.

Bazuhair, A. S.; Wood, W. W.

1996-01-01

313

Random Qualitative Validation: A Mixed-Methods Approach to Survey Validation  

ERIC Educational Resources Information Center

The purpose of this paper is to introduce the process and value of Random Qualitative Validation (RQV) in the development and interpretation of survey data. RQV is a method of gathering clarifying qualitative data that improves the validity of the quantitative analysis. This paper is concerned with validity in relation to the participants'…

Van Duzer, Eric

2012-01-01

314

National Survey of Psychologists' Test Feedback Training, Supervision, and Practice: A Mixed Methods Study  

Microsoft Academic Search

In this empirical, mixed methods study, we explored test feedback training, supervision, and practice among psychologists, focusing specifically on how feedback is provided to clients and whether feedback skills are taught in graduate programs. Based on a 48.5% return rate, this national survey of clinical, counseling, and school psychologists' suggests psychologists provide test feedback to clients but inconsistently. Most respondents,

Kyle T. Curry; William E. Hanson

2010-01-01

315

Environmental Impact Analysis Process. Environmental Review Starlab Site On Antigua; Phase II Archeological Surveys of Proposed Ground Calibration Sites on Antigua, West Indies.  

National Technical Information Service (NTIS)

This Environmental Review has been prepared to identify and evaluate potential environmental issues associated with the proposed construction and operation of a ground calibration site on the Island of Antigua in the Caribbean. The ground calibration site...

1990-01-01

316

Methods of Gas Phase Capture of Iodine from Fuel Reprocessing Off-Gas: A Literature Survey  

SciTech Connect

A literature survey was conducted to collect information and summarize the methods available to capture iodine from fuel reprocessing off-gases. Techniques were categorized as either wet scrubbing or solid adsorbent methods, and each method was generally described as it might be used under reprocessing conditions. Decontamination factors are quoted only to give a rough indication of the effectiveness of the method. No attempt is made to identify a preferred capture method at this time, although activities are proposed that would provide a consistent baseline that would aid in evaluating technologies.

Daryl Haefner

2007-02-01

317

A Seven Month Survey for the Detection of E. coli O157:H7 from Ground Beef Samples in the Markets of Turkey  

Microsoft Academic Search

3 Abstract: A seven month period from the beginning October to the end of April 2004, a total of 126 ground beef samples were analyzed to determine the incidence of Escherichia coli (E. coli) O157:H7. Among the sampling months, the incidence of EHEC serotypes were only observed in April. Of the 126 ground beef samples, only one ground beef sample

2005-01-01

318

Survey of systems safety analysis methods and their application to nuclear waste management systems  

NASA Astrophysics Data System (ADS)

This report reviews system safety analysis methods and examines their application to nuclear waste management systems. The safety analysis methods examined include expert opinion, maximum credible accident approach, design basis accidents approach, hazard indices, preliminary hazards analysis, failure modes and effects analysis, fault trees, event trees, cause consequence diagrams, GO methodology, Markov modeling, and a general category of consequence analysis models. Previous and ongoing studies on the safety of waste management systems are discussed along with their limitations and potential improvements. The major safety methods and waste management safety related studies are surveyed. This survey provides information on what safety methods are available, what waste management safety areas have been analyzed, and what are potential areas for future study.

Pelto, P. J.; Winegardner, W. K.; Gallucci, R. H. V.

1981-11-01

319

Exploration of a lignite-bearing basin in Northern Ireland using ground magnetic and VLF-EM methods  

SciTech Connect

In an exploration technique feasibility study, a detailed magnetic and VLF-EM survey was carried out on the poorly exposed, lignite-bearing Crumlin subbasin within the Lough Neagh Basin, Co. Antrim, Northern Ireland. The faulted and onlapped margins of the basin, as well as lithological units and structures within the basin, were delineated by simple processing techniques applied to the data. The combination of the two methods overcomes the limitations of each method when it is used alone. These techniques could be successfully applied to other lignite-bearing basins sited on strongly magnetic basement worldwide.

McCaffrey, R.J.; McElroy, W.J.; Leslie, A.G. [Queen`s Univ. of Belfast (United Kingdom)

1995-03-01

320

Method of and apparatus for analyzing data from an electromagnetic survey  

US Patent & Trademark Office Database

A method is provided for analyzing data from an electromagnetic survey of a region so as to indicate the presence of a hydrocarbon reservoir. The survey provides vertical magnetic dipole data and electric dipole data, or provides measurement data from which these dipole data may be determined. The amplitude of the vertical magnetic dipole data is determined, optionally after normalising the data with reference date relating to the same region. Similarly, the amplitude of the electric dipole data is determined, optionally after similarly being normalised. The amplitudes are then compared to provide an indication of the likelihood of the presence of hydrocarbons in the region.

Amundsen; Lasse (Trondheim, NO)

2012-11-20

321

Incidence of heartrot in harvest-age Acacia mangium in Indonesia, using a rapid survey method  

Microsoft Academic Search

The potential to use plantation-grown Acacia mangium for solid-timber products is limited by heartrot, caused by decay fungi. A rapid method of surveying logs stacked in the plantation following harvest was developed which is an alternative to time-consuming whole tree destructive assessments. Logs were randomly chosen from the stacks using a transect method, the cut-ends of the logs were assessed

K. M. Barry; R. S. B. Irianto; E. Santoso; M Turjaman; E Widyati; I Sitepu; C. L Mohammed

2004-01-01

322

40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.  

Code of Federal Regulations, 2010 CFR

...D, 9222 B, or 9222 C. 8 EPA Method 1600: Enterococci in Water by Membrane Filtration Using membrane-Enterococcus Indoxyl-β-D-Glucoside Agar (mEI) EPA 821-R-02-022 (September 2002) is an approved variation of Standard Method...

2010-07-01

323

Wind load design methods for ground-based heliostats and parabolic dish collectors  

Microsoft Academic Search

The purpose of this design method is to define wind loads on flat heliostat and parabolic dish collectors in a simplified form. Wind loads are defined for both mean and peak loads accounting for the protective influence of upwind collectors, wind protective fences, or other wind-blockage elements. The method used to define wind loads was to generalize wind load data

J. A. Peterka; R. G. Derickson

1992-01-01

324

The decremented average ground-temperature method for predicting the thermal performance of underground walls  

Microsoft Academic Search

At present, the only accurate method for predicting the thermal performance of underground structures is through the use of large computer models and finite difference equations. Due to the prohibitively high cost of setting up and running these computer models, thermal analysis of subsurface buildings is inaccessible to many prospective users. The existing manual methods for calculating loads on underground

J. M. Ackridge; J. F. J. Poulos

1983-01-01

325

Geostatistical, sensitivity, and uncertainty methods for ground-water flow and radionuclide transport modeling: Proceedings  

Microsoft Academic Search

The overall theme of the DOE\\/AECL '87 conference was the application of statistical methods for sensitivity and uncertainty analysis to nuclear waste disposal flow and transport modeling. The conference was organized into six technical sessions dealing with different topics in that theme: the role of statistical methods in the nuclear waste repository performance assessment plans of several waste disposal programs,

1989-01-01

326

A non-destructive method for estimating above-ground forest biomass in threatened woodlands  

Microsoft Academic Search

Current techniques for calculation of biomass in agroforestry require felling of many trees. Such methods are not well suited to the natural environment, especially if the environment is subject to anthropic degradation and if the wood supply to local populations is at stake. The method we describe here was used in a socioeconomic and ecological study of the biomass of

N. Montès; T. Gauquelin; W. Badri; V. Bertaudière; El H. Zaoui

2000-01-01

327

A method to identify cosmic-ray nuclei in the knee region using high-resolution Cerenkov cameras on the ground  

Microsoft Academic Search

A new method for making high-resolution ground-based measurements of the energy and charge of cosmic ray primaries in the region of the knee is presented. The method works by measuring the component of Cerenkov radiation (i.e., ``Direct Cerenkov'') emitted directly by cosmic ray nuclei prior to their first hadronic interaction in the atmosphere. A dedicated ground-based Direct Cerenkov detector could

Scott P. Wakely

2007-01-01

328

GROUND-WATER QUALITY CLASSIFICATION FOR THE VALLEY-FILL AQUIFER IN SPANISH VALLEY, GRAND AND SAN JUAN COUNTIES, UTAH --A BASIS FOR PRESERVING HIGH QUALITY GROUND-WATER RESOURCES, UTAH GEOLOGICAL SURVEY  

EPA Science Inventory

The proposed study will consist of an evaluation of current ground-water quality using the Utah Water Quality Board's ground-water-quality classification system based mostly on total-dissolved-solids concentrations as follows: class 1A (Pristine), less than 500 mg/L; class 2 (dr...

329

A method for simulating transient ground-water recharge in deep water-table settings in central Florida by using a simple water-balance/transfer-function model  

USGS Publications Warehouse

A relatively simple method is needed that provides estimates of transient ground-water recharge in deep water-table settings that can be incorporated into other hydrologic models. Deep water-table settings are areas where the water table is below the reach of plant roots and virtually all water that is not lost to surface runoff, evaporation at land surface, or evapotranspiration in the root zone eventually becomes ground-water recharge. Areas in central Florida with a deep water table generally are high recharge areas; consequently, simulation of recharge in these areas is of particular interest to water-resource managers. Yet the complexities of meteorological variations and unsaturated flow processes make it difficult to estimate short-term recharge rates, thereby confounding calibration and predictive use of transient hydrologic models. A simple water-balance/transfer-function (WBTF) model was developed for simulating transient ground-water recharge in deep water-table settings. The WBTF model represents a one-dimensional column from the top of the vegetative canopy to the water table and consists of two components: (1) a water-balance module that simulates the water storage capacity of the vegetative canopy and root zone; and (2) a transfer-function module that simulates the traveltime of water as it percolates from the bottom of the root zone to the water table. Data requirements include two time series for the period of interest?precipitation (or precipitation minus surface runoff, if surface runoff is not negligible) and evapotranspiration?and values for five parameters that represent water storage capacity or soil-drainage characteristics. A limiting assumption of the WBTF model is that the percolation of water below the root zone is a linear process. That is, percolating water is assumed to have the same traveltime characteristics, experiencing the same delay and attenuation, as it moves through the unsaturated zone. This assumption is more accurate if the moisture content, and consequently the unsaturated hydraulic conductivity, below the root zone does not vary substantially with time. Results of the WBTF model were compared to those of the U.S. Geological Survey variably saturated flow model, VS2DT, and to field-based estimates of recharge to demonstrate the applicability of the WBTF model for a range of conditions relevant to deep water-table settings in central Florida. The WBTF model reproduced independently obtained estimates of recharge reasonably well for different soil types and water-table depths.

O'Reilly, Andrew M.

2004-01-01

330

Enumeration of Salmonella and Escherichia coli O157:H7 in ground beef, cattle carcass, hide and faecal samples using direct plating methods  

Microsoft Academic Search

Aim: To develop and validate high throughput methods for the direct enumer- ation of viable and culturable Salmonella and Escherichia coli O157:H7 in ground beef, carcass, hide and faecal (GCHF) samples from cattle. Methods and Results: The hydrophobic grid membrane filtration (HGMF) method and the spiral plate count method (SPCM) were evaluated as rapid tools for the estimation of pathogen

D. M. Brichta-Harhay; T. M. Arthur; J. M. Bosilevac; M. N. Guerini; N. Kalchayanand; M. Koohmaraie

2007-01-01

331

An evaluation of various plastic embedding methods for preparing ground sections from calcified tissue with the Logitech system for light microscopy.  

PubMed

Three plastic processing methods for preparing ground sections from hard tissue applicable to light microscopy are reviewed. The requirement for production of high quality ground sections of tooth and bone for pathological diagnosis is discussed and a new machine system technology, namely the LP 30 Lapping Machine (Logitech Ltd., Dunbartonshire, Scotland) which meets these requirements is described. The new approach is justified by the results, since sections of quality are produced with increased efficiency, while the operator's working conditions are distinctly improved. Ground sections, 10-20 microns, are being produced from glycol methacrylate impregnated specimens with the employment of the Leitz diamond saw and the Logitech section grounding system. Good GMA ground sections form an invaluable aid to microscopic diagnosis of many disorders of enamel as well as metabolic bone diseases. PMID:3937594

Wong, F T

1985-12-01

332

EVALUATION OF SAMPLING AND FIELD FILTRATION METHODS FOR THE ANALYSIS OF TRACE METALS IN GROUND WATER  

EPA Science Inventory

Selected groundwater sampling and filtering methods were evaluated to determine their effects on field parameters and trace metal concentrations in samples collected under several types of field conditions. he study focused on sampling in conventional standpipe monitoring wells u...

333

A non-destructive method for estimating above-ground forest biomass in threatened woodlands  

Microsoft Academic Search

Abstract Current techniques for calculation of biomass,in agroforestry require felling of many,trees. Such methods,are not well suited to the natural environment, especially if the environment is subject to anthropic degradation and if the wood supply to local populations is at stake. The method,we describe here was used in a socioeconomic,and ecological study of the biomass of a thuriferous juniper woodland,(Juniperus

N. Monte S; T. Gauquelin; V. Bertaudie Re; El H. Zaoui

334

Prediction of broadband ground-motion time histories: Hybrid low/high-frequency method with correlated random source parameters  

USGS Publications Warehouse

We present a new method for calculating broadband time histories of ground motion based on a hybrid low-frequency/high-frequency approach with correlated source parameters. Using a finite-difference method we calculate low-frequency synthetics (< ???1 Hz) in a 3D velocity structure. We also compute broadband synthetics in a 1D velocity model using a frequency-wavenumber method. The low frequencies from the 3D calculation are combined with the high frequencies from the 1D calculation by using matched filtering at a crossover frequency of 1 Hz. The source description, common to both the 1D and 3D synthetics, is based on correlated random distributions for the slip amplitude, rupture velocity, and rise time on the fault. This source description allows for the specification of source parameters independent of any a priori inversion results. In our broadband modeling we include correlation between slip amplitude, rupture velocity, and rise time, as suggested by dynamic fault modeling. The method of using correlated random source parameters is flexible and can be easily modified to adjust to our changing understanding of earthquake ruptures. A realistic attenuation model is common to both the 3D and 1D calculations that form the low- and high-frequency components of the broadband synthetics. The value of Q is a function of the local shear-wave velocity. To produce more accurate high-frequency amplitudes and durations, the 1D synthetics are corrected with a randomized, frequency-dependent radiation pattern. The 1D synthetics are further corrected for local site and nonlinear soil effects by using a 1D nonlinear propagation code and generic velocity structure appropriate for the site's National Earthquake Hazards Reduction Program (NEHRP) site classification. The entire procedure is validated by comparison with the 1994 Northridge, California, strong ground motion data set. The bias and error found here for response spectral acceleration are similar to the best results that have been published by others for the Northridge rupture.

Liu, P.; Archuleta, R. J.; Hartzell, S. H.

2006-01-01

335

A new method to obtain ground control points based on SRTM data  

NASA Astrophysics Data System (ADS)

The GCPs are widely used in remote sense image registration and geometric correction. Normally, the DRG and DOM are the major data source from which GCPs are extracted. But the high accuracy products of DRG and DOM are usually costly to obtain. Some of the production are free, yet without any guarantee. In order to balance the cost and the accuracy, the paper proposes a method of extracting the GCPs from SRTM data. The method consist of artificial assistance, binarization, data resample and reshape. With artificial assistance to find out which part of SRTM data could be used as GCPs, such as the islands or sharp coast line. By utilizing binarization algorithm , the shape information of the region is obtained while other information is excluded. Then the binary data is resampled to a suitable resolution required by specific application. At last, the data would be reshaped according to satellite imaging type to obtain the GCPs which could be used. There are three advantages of the method proposed in the paper. Firstly, the method is easy for implementation. Unlike the DRG data or DOM data that charges a lot, the SRTM data is totally free to access without any constricts. Secondly, the SRTM has a high accuracy about 90m that is promised by its producer, so the GCPs got from it can also obtain a high quality. Finally, given the SRTM data covers nearly all the land surface of earth between latitude -60° and latitude +60°, the GCPs which are produced by the method can cover most important regions of the world. The method which obtain GCPs from SRTM data can be used in meteorological satellite image or some situation alike, which have a relative low requirement about the accuracy. Through plenty of simulation test, the method is proved convenient and effective.

Wang, Pu; An, Wei; Deng, Xin-pu; Zhang, Xi

2013-09-01

336

New methods for engineering site characterization using reflection and surface wave seismic survey  

NASA Astrophysics Data System (ADS)

This study presents two new seismic testing methods for engineering application, a new shallow seismic reflection method and Time Filtered Analysis of Surface Waves (TFASW). Both methods are described in this dissertation. The new shallow seismic reflection was developed to measure reflection at a single point using two to four receivers, assuming homogeneous, horizontal layering. It uses one or more shakers driven by a swept sine function as a source, and the cross-correlation technique to identify wave arrivals. The phase difference between the source forcing function and the ground motion due to the dynamic response of the shaker-ground interface was corrected by using a reference geophone. Attenuated high frequency energy was also recovered using the whitening in frequency domain. The new shallow seismic reflection testing was performed at the crest of Porcupine Dam in Paradise, Utah. The testing used two horizontal Vibroseis sources and four receivers for spacings between 6 and 300 ft. Unfortunately, the results showed no clear evidence of the reflectors despite correction of the magnitude and phase of the signals. However, an improvement in the shape of the cross-correlations was noticed after the corrections. The results showed distinct primary lobes in the corrected cross-correlated signals up to 150 ft offset. More consistent maximum peaks were observed in the corrected waveforms. TFASW is a new surface (Rayleigh) wave method to determine the shear wave velocity profile at a site. It is a time domain method as opposed to the Spectral Analysis of Surface Waves (SASW) method, which is a frequency domain method. This method uses digital filtering to optimize bandwidth used to determine the dispersion curve. Results from testings at three different sites in Utah indicated good agreement with the dispersion curves measured using both TFASW and SASW methods. The advantage of TFASW method is that the dispersion curves had less scatter at long wavelengths as a result from wider bandwidth used in those tests.

Chaiprakaikeow, Susit

337

Fast Electron Correlation Methods for Molecular Clusters in the Ground and Excited States  

SciTech Connect

An efficient and accurate electronic structure method for clusters of weakly interacting molecules has been proposed, on the basis of the pair-interaction method of Kitaura et al., and combined with density functional, many-body perturbation, coupled-cluster, equation-of-motion coupled-cluster, configuration-interaction singles, and time-dependent density functional theories. The method retains the one- and two-body Coulomb, exchange, and correlation energies exactly and higher-order Coulomb energies in the leading order of multipole expansion (hence the dipole polarization effects). It typically recovers the total energies within 0.001 %, binding energies within a few kilocalories per mole, and excitation energies within a few hundredths of an electron volt of the conventional implementations. The size dependence of the computational cost of the method is asymptotically linear for total energies and constant for excitation energies. The method has been applied to the total energies of water clusters, to the total energies of zwitterionic and neutral glycine/water clusters, and to the excitation energies of formaldehyde/water clusters. The largest calculation was performed at an equation-of-motion coupled-cluster singles and doubles level for a formaldehyde?(H2O)81 cluster containing 247 atoms that predicted the solvatochromic shift of 1360 cm?1 in the lowest transition energy of formaldehyde in water.

Hirata, So; Valiev, Marat; Dupuis, Michel; Xantheas, Sotiris S.; Sugiki, Sin-Ichirou; Sekino, Hideo

2005-08-10

338

Geophysical Surveys at the Adams Birthplaces National Historic Site.  

National Technical Information Service (NTIS)

This document presents detailed information on the method and theory, interpretations and conclusions drawn from the use of two forms of geophysical survey techniques--resistivity and ground penetrating radar--employed as an aid to archeological investiga...

1980-01-01

339

Grid-Search Location Methods for Ground-Truth Collection From Local and Regional Seismic Networks  

SciTech Connect

This project investigated new techniques for improving seismic event locations derived from regional and local networks. The technqiues include a new approach to empirical travel-time calibration that simultaneously fits data from multiple stations and events, using a generalization of the kriging method, and predicts travel-time corrections for arbitrary event-station paths. We combined this calibration approach with grid-search event location to produce a prototype new multiple-event location method that allows the use of spatially well-distributed events and takes into account correlations between the travel-time corrections from proximate event-station paths. Preliminary tests with a high quality data set from Nevada Test Site explosions indicated that our new calibration/location method offers improvement over the conventional multiple-event location methods now in common use, and is applicable to more general event-station geometries than the conventional methods. The tests were limited, however, and further research is needed to fully evaluate, and improve, the approach. Our project also demonstrated the importance of using a realistic model for observational errors in an event location procedure. We took the initial steps in developing a new error model based on mixture-of-Gaussians probability distributions, which possess the properties necessary to characterize the complex arrival time error processes that can occur when picking low signal-to-noise arrivals. We investigated various inference methods for fitting these distributions to observed travel-time residuals, including a Markov Chain Monte Carlo technique for computing Bayesian estimates of the distribution parameters.

William Rodi; Craig A. Schultz; Gardar Johannesson; Stephen C. Myers

2005-05-13

340

Role of dynamics in interacting fermion systems: The Strutinsky method and ground state properties of quantum dots  

NASA Astrophysics Data System (ADS)

We investigate nano-structure quantum dots which show conductance peak oscillations in the Coulomb blockade regime. Although a random matrix theoretical approach (RMT) has made successful predictions, the statistical behaviors of the peak spacings remain mysterious, indicating the necessity of a more subtle treatment of the residual interaction. We pursue a many-body framework, which explicitly includes electron-electron interaction in the context of density functional theory. Based on the idea of the Strutinsky shell correction method, the ground state energy is expressed by an approximate series expansion in the fluctuation part of the density functional, and the physical interpretation of each successive term is analyzed. We identify the energy contribution of the residual interaction due to the screened Coulomb potential. Given that irregularly shaped quantum clots consist of quasiparticles interacting through a screened Coulomb interaction, we employ the two-dimensional coupled quartic oscillator as an effective confinement. The advantage of employing the quartic oscillator is that the degree of chaos can be tuned continuously from integrability to pure chaos, allowing us to study how the nature of the dynamics influences the single-particle orbital occupancies when spin is taken into account. In the analysis of the ground state configuration and spin polarization, the conductance peak spacings are reproduced and the electron orbital occupations are observed to depend upon the nature of the dynamics. The greater the chaos, the less effective the residual interaction in altering the occupations.

Nagano, Tatsuro

341

Examining the Potential of Combining the Methods of Grounded Theory and Narrative Inquiry: A Comparative Analysis  

ERIC Educational Resources Information Center

Increasingly, qualitative researchers are combining methods, processes, and principles from two or more methodologies over the course of a research study. Critics charge that researchers adopting combined approaches place too little attention on the historical, epistemological, and theoretical aspects of the research design. Rather than…

Lal, Shalini; Suto, Melinda; Ungar, Michael

2012-01-01

342

40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.  

Code of Federal Regulations, 2010 CFR

...D, 9222 B, or 9222 C. \\8\\ EPA Method 1600: Enterococci in Water by Membrane Filtration Using membrane-Enterococcus Indoxyl-[beta]-D-Glucoside Agar (mEI) EPA 821-R- 02-022 (September 2002) is an approved variation of Standard...

2009-07-01

343

Assessment of Two Methods of Sequencing Ground Trainer Practice for Undergraduate Pilot Training.  

ERIC Educational Resources Information Center

|The study was an operational evaluation of two methods of instruction sequencing for the T-38 phase of Undergraduate Pilot Training. Scheduling of concentrated trainer phases prior to aircraft flight improved student performance for early aircraft rides as compared with an intermixed trainer and aircraft schedule. Although grade differences…

Reid, Gary B.; And Others

344

Computing the Accuracy of Complex NonRandom Sampling Methods: The Case of the Bank of Canada's Business Outlook Survey  

Microsoft Academic Search

A number of central banks publish their own business conditions survey based on non-random sampling methods. The results of these surveys influence monetary policy decisions and thus affect expectations in financial markets. To date, however, no one has computed the statistical accuracy of these surveys because their respective non-random sampling method renders this assessment non-trivial. This paper describes a methodology

Daniel de Munnik; David Dupuis; Mark Illing

2009-01-01

345

Multiscale seismic attributes: a wavelet-based method and its application to high-resolution seismic and ground truth data  

NASA Astrophysics Data System (ADS)

We propose a wavelet-based method to characterize acoustic impedance discontinuities from a multiscale analysis of seismic reflected waves. Our approach relies on the analysis of ridge functions which contain most of the information of the wavelet transform in a sparse support. This method falls in the framework of the wavelet response (WR) introduced by Le Gonidec et al. which analyses the impedance multiscale behaviour by propagating dilated wavelets into the medium. We further extend the WR by considering its application to broad-band seismic data. We take into account the bandpass filter effect related to the limited frequency range of the seismic source. We apply the method to a deep-water seismic experiment performed in 2008 during the ERIG3D cruise to demonstrate the potential of ridge functions as multiscale seismic attributes. In conjunction to the analysis of seismic data acquired by the deep-towed SYSIF system (200-2200 Hz), we use ground truth data to characterize the fine scale structure of superficial sediments by using the continuous wavelet transform (CWT). The availability of in situ measurements allows to validate the relationship between CWT and WR and to estimate the attenuation of seismic waves into the sediments. Once validated, the method is applied on a whole seismic profile and WR ridge functions are computed for two particular reflectors. The reflector thicknesses fall below the resolution limit of the seismic experiment making the WR seismic attributes a super-resolution method.

Ker, S.; Le Gonidec, Y.; Gibert, D.; Marsset, B.

2011-11-01

346

Efficient Hybrid Grid Synthesis Method Based on Genetic Algorithm for Power/Ground Network Optimization with Dynamic Signal Consideration  

NASA Astrophysics Data System (ADS)

This paper proposes an efficient design algorithm for power/ground (P/G) network synthesis with dynamic signal consideration, which is mainly caused by Ldi/dt noise and Cdv/dt decoupling capacitance (DECAP) current in the distribution network. To deal with the nonlinear global optimization under synthesis constraints directly, the genetic algorithm (GA) is introduced. The proposed GA-based synthesis method can avoid the linear transformation loss and the restraint condition complexity in current SLP, SQP, ICG, and random-walk methods. In the proposed Hybrid Grid Synthesis algorithm, the dynamic signal is simulated in the gene disturbance process, and Trapezoidal Modified Euler (TME) method is introduced to realize the precise dynamic time step process. We also use a hybrid-SLP method to reduce the genetic execute time and increase the network synthesis efficiency. Experimental results on given power distribution network show the reduction on layout area and execution time compared with current P/G network synthesis methods.

Yang, Yun; Kimura, Shinji

347

MOST COMMON METHODS USED IN COMBINATION TO DETECT SPINAL SUBLUXATION: A Survey of Chiropractors in Victoria.  

PubMed

The objective of this research was to identify the most common combination of methods used by chiropractors in Victoria to identify manipulable lesions or subluxations. A postal survey of chiropractors in Victoria achieved an 85% response rate and revealed that eight methods are commonly used in combination to detect subluxation. They are: visual posture analysis, pain description of the patient, plain static erect x-rays, leg length discrepancy, neurological tests, motion palpation, static palpation, orthopaedic tests. These methods have also been found to be used commonly and regarded as reliable. PMID:17987160

Walker, B F

1998-11-01

348

Moment method analysis of infinite stripline-fed tapered slot antenna arrays with a ground plane  

Microsoft Academic Search

A full-wave method of moments solution for infinite arrays of stripline-fed tapered slot antennas is described. The formulation of the problem is sufficiently general to permit performance evaluation of most of the geometries that have been proposed for stripline-fed antennas as well as of several other types of array antennas. Computed results for some well-known antenna arrays are presented to

Daniel H. Schaubert; Jon Anders Aas; Michael E. Cooley; N. E. Buris

1994-01-01

349

Installation restoration research program: Assessment of geophysical methods for subsurface geologic mapping, cluster 13, Edgewood Area, Aberdeen Proving Ground, Maryland. Final report  

SciTech Connect

Seismic refraction, electrical resistivity, and transient electromagnetic surveys were conducted at a portion of Cluster 13, Edgewood Area of Aberdeen Proving Ground, Maryland. Seismic refraction cross sections map the topsoil layer and the water table (saturated zone). The water table elevations from the seismic surveys correlate closely with water table elevations in nearby monitoring wells. Electrical resistivity cross sections reveal a very complicated distribution of sandy and clayey facies in the upper 10 - 15 m of the subsurface. A continuous surficial (topsoil) layer correlates with the surficial layer of the seismic section and nearby boring logs. The complexity and details of the electrical resistivity cross section correlate well with boring and geophysical logs from nearby wells. The transient electromagnetic surveys map the Pleistocene-Cretaceous boundary, the saprolite, and the top of the Precambrian crystalline rocks. Conducting the transient electromagnetic surveys on a grid pattern allows the construction of a three-dimensional representation of subsurface geology (as represented by variations of electrical resistivity). Thickness and depth of the saprolitic layer and depth to top of the Precambrian rocks are consistent with generalized geologic cross sections for the Edgewood Area and depths projected from reported depths at the Aberdeen Proving Ground NW boundary using regional dips.

Butler, D.K.; Sharp, M.K.; Sjostrom, K.J.; Simms, J.E.; Llopis, J.L.

1996-10-01

350

Using an orbital method and GPS measurements of the ground control points in georeference of space images  

NASA Astrophysics Data System (ADS)

Approximation and extrapolation of the orbit of the satellite is made, using an orbital method, for obtaining the space geocentric coordinates rk=(X,Y,Z)kT at the moment tk when the photograph of the Earth's surface was taken. In the first stage, by using the values thus defined and the GPS-measured space geocentric coordinates of the known ground control points (GCP) (Xi, Yi, Zi), the output elements of the images - the extrapolated coordinates of the satellite (X,Y,Z)k and the Euler's angles (?, i, ?) are differentially determined. A powerpul mathematical model is used in the second stage for the time-coordinate georeference of the space (topographic) image to the equatric geocentric system, and the determination of the space coordinates of the needed GCP, on the basis of which the space geometrical distortions are eliminated.

Georgiev, Nikola; Nedkov, Rumen; Nedelcheva, Dora

351

Regression Method for Estimating Long-Term Mean Annual Ground-Water Recharge Rates from Base Flow in Pennsylvania  

USGS Publications Warehouse

A method was developed for making estimates of long-term, mean annual ground-water recharge from streamflow data at 80 streamflow-gaging stations in Pennsylvania. The method relates mean annual base-flow yield derived from the streamflow data (as a proxy for recharge) to the climatic, geologic, hydrologic, and physiographic characteristics of the basins (basin characteristics) by use of a regression equation. Base-flow yield is the base flow of a stream divided by the drainage area of the basin, expressed in inches of water basinwide. Mean annual base-flow yield was computed for the period of available streamflow record at continuous streamflow-gaging stations by use of the computer program PART, which separates base flow from direct runoff on the streamflow hydrograph. Base flow provides a reasonable estimate of recharge for basins where streamflow is mostly unaffected by upstream regulation, diversion, or mining. Twenty-eight basin characteristics were included in the exploratory regression analysis as possible predictors of base-flow yield. Basin characteristics found to be statistically significant predictors of mean annual base-flow yield during 1971-2000 at the 95-percent confidence level were (1) mean annual precipitation, (2) average maximum daily temperature, (3) percentage of sand in the soil, (4) percentage of carbonate bedrock in the basin, and (5) stream channel slope. The equation for predicting recharge was developed using ordinary least-squares regression. The standard error of prediction for the equation on log-transformed data was 9.7 percent, and the coefficient of determination was 0.80. The equation can be used to predict long-term, mean annual recharge rates for ungaged basins, providing that the explanatory basin characteristics can be determined and that the underlying assumption is accepted that base-flow yield derived from PART is a reasonable estimate of ground-water recharge rates. For example, application of the equation for 370 hydrologic units in Pennsylvania predicted a range of ground-water recharge from about 6.0 to 22 inches per year. A map of the predicted recharge illustrates the general magnitude and variability of recharge throughout Pennsylvania.

Risser, Dennis W.; Thompson, Ronald E.; Stuckey, Marla H.

2008-01-01

352

Measuring Public Access to the Shoreline: The Boat-Based Offset Survey Method  

Microsoft Academic Search

As cities redevelop underutilized waterfronts, opportunities exist to promote public access to the shoreline. However, planning for access is hampered by a lack of reliable data on how people utilize a specific shoreline. The boat-based offset transect survey (B-BOTS) method allows researchers to accurately record, map, and analyze shoreline access. This article discusses the use of B-BOTS along the northern

Robert Thompson; Tracy Dalton

2010-01-01

353

A new reference method for the validation of the nutrient profiling schemes using dietary surveys  

Microsoft Academic Search

Nutrient profiles of foods are increasingly used as the scientific basis of nutritional labeling, health claims, or nutritional\\u000a education. Nutrient profiling schemes are based on sets of rules, scores, or thresholds applied to the nutritional composition\\u000a of foods. However, there is a lack of scientific validation of nutritional profiling schemes. To develop a reference method\\u000a using existing dietary surveys, to

Jean-Luc Volatier; Anja Biltoft-Jensen; Stefaan De Henauw; Michael J. Gibney; Inge Huybrechts; Sinéad N. McCarthy; Jennifer L. O’Neill; Caroline Quinio; Aida Turrini; Inge Tetens

2007-01-01

354

Algorithms and R Codes for the Pseudo Empirical Likelihood Method in Survey Sampling  

Microsoft Academic Search

We present computational algorithms for the recently proposed pseudo empirical likelihood method for the analysis of complex survey data. Several key algorithms for computing the maximum pseudo empirical likelihood estimators and for constructing the pseudo empirical likelihood ratio confidence intervals are implemented using the popular statistical software R and S-PLUS. Major codes are written in the form of R\\/S-PLUS functions

Changbao Wu

2005-01-01

355

Methods and representativeness of a European survey in children and adolescents: the KIDSCREEN study  

PubMed Central

Background The objective of the present study was to compare three different sampling and questionnaire administration methods used in the international KIDSCREEN study in terms of participation, response rates, and external validity. Methods Children and adolescents aged 8–18 years were surveyed in 13 European countries using either telephone sampling and mail administration, random sampling of school listings followed by classroom or mail administration, or multistage random sampling of communities and households with self-administration of the survey materials at home. Cooperation, completion, and response rates were compared across countries and survey methods. Data on non-respondents was collected in 8 countries. The population fraction (PF, respondents in each sex-age, or educational level category, divided by the population in the same category from Eurostat census data) and population fraction ratio (PFR, ratio of PF) and their corresponding 95% confidence intervals were used to analyze differences by country between the KIDSCREEN samples and a reference Eurostat population. Results Response rates by country ranged from 18.9% to 91.2%. Response rates were highest in the school-based surveys (69.0%–91.2%). Sample proportions by age and gender were similar to the reference Eurostat population in most countries, although boys and adolescents were slightly underrepresented (PFR <1). Parents in lower educational categories were less likely to participate (PFR <1 in 5 countries). Parents in higher educational categories were overrepresented when the school and household sampling strategies were used (PFR = 1.78–2.97). Conclusion School-based sampling achieved the highest overall response rates but also produced slightly more biased samples than the other methods. The results suggest that the samples were sufficiently representative to provide reference population values for the KIDSCREEN instrument.

Berra, Silvina; Ravens-Sieberer, Ulrike; Erhart, Michael; Tebe, Cristian; Bisegger, Corinna; Duer, Wolfgang; von Rueden, Ursula; Herdman, Michael; Alonso, Jordi; Rajmil, Luis

2007-01-01

356

A comparison of three survey methods to obtain data for community mental health program planning  

Microsoft Academic Search

A perennial problem for mental health planners is assessing community needs and existing services. The three most common methods used to obtain this data are the telephone survey, the mail-out questionnaire, and the face-to-face interview. However, there are advantages and disadvantages associated with each approach in terms of sampling, response rates, and economic costs. The present study utilized all three

Andrew Lee Hinkle; Glen D. King

1978-01-01

357

The 2005 Chios ancient shipwreck survey: New methods for underwater archaeology  

Microsoft Academic Search

In 2005 a Greek and American interdisciplinary team investigated two shipwrecks off the coast of Chios dating to the 4th-century b.c. and the 2nd\\/1st century. The project pioneered archaeological methods of precision acoustic, digital image, and chemical survey using an autonomous underwater vehicle (AUV) and in-situ sensors, increasing the speed of data acquisition while decreasing costs. The AUV recorded data

Brendan P. Foley; Katerina DellaPorta; Dimitris Sakellariou; Brian S. Bingham; Richard Camilli; Ryan M. Eustice; Dionysis Evagelistis; Vicki L. Ferrini; Kostas Katsaros; Dimitris Kourkoumelis; Aggelos Mallios; Paraskevi Micha; David A. Mindell; Christopher Roman; Hanumant Singh; David S. Switzer; Theotokis Theodoulou

2009-01-01

358

Classical and non-classical kinematic fields of two-dimensional penetration tests on granular ground by discrete element method analyses  

Microsoft Academic Search

The penetration test is a widely used in-situ test in geotechnical engineering which mechanism is very important to geomechanics.\\u000a This paper presents a numerical study on both classic and non-classic kinematic fields in penetration tests on granular ground.\\u000a A two-dimensional Discrete Element Method (DEM) has been used to simulate penetration tests on a full-size granular ground\\u000a that is under an

M. J. Jiang; H. H. Zhu; D. Harris

2008-01-01

359

Cascade connection serial parallel hybrid acquisition synchronization method for DS-FHSS in air-ground data link  

NASA Astrophysics Data System (ADS)

In air-ground tactical data link system, a kind of primary anti jamming technology adopted is direct sequence - frequency hopping spread spectrum (DS-FHSS) technology. However, how to implement the quick synchronization of DS-FHSS is an important technology problem, which could influence the whole communication capability of system. Thinking of the application demand of anti jamming technology in actual, a kind of cascade connection serial parallel hybrid acquisition synchronization method is given for the DS-FHSS system. The synchronization consists of two stages. The synchronization of FH communication is adopted at the first stage, and the serial parallel hybrid structure is adopted for the DS PN code synchronization at the secondary stage. Through calculating the detect probability of the FH synchronization acquisition and the acquisition time of DS code chip synchronization, the contribution to the synchronization capability of system by this method in this paper is analyzed. Finally, through simulating on computer, the performance estimate about this cascade connection serial parallel hybrid acquisition synchronization method is given.

Wang, Feng; Zhou, Desuo

2007-11-01

360

Automatic Vehicle Location (avl) and Road Survey With Placer/dr GPS Method  

NASA Astrophysics Data System (ADS)

Pisa University belongs to the National Research Projects lead by Prof. George Manzoni of Trieste University. Pisa University has completed the preparation of its own cross-country motor vehicle (Fiat Panda 4x4 van) with a new low-cost navigational GPS + Inertial Navigation System (odometer and gyroscope). The searching activity carried out now is aimed to survey road axis in zones with numeric cartography, to record GPS+INS data and to study reability and precision of the system in urban and extra-urban environment. The results of the first road surveys in urban environment are good and they are showed by a commercial GIS, with a vectorial map and it is possible to see where the system recorded with GPS 2D-3D method or with INS method. The research program foresees the integration of the vehicle position data with those coming from: - specific environmental sensors (e.g. atmospheric pollution sensors, electromagnetics sensors ... - other topographical instrumentations (e.g. laser scanners, ..) - georeferenced images acquired with cameras and/or television cameras set on the vehicle, but also with those from high definition satellite images. The data acquired by the vehicle in a first time will be elaborated through post- processing, and only after the testing of the instrumentations and the checking of their well-operation, the survey will be experimented in real time.

Caroti, G.

361

Virtual and super - virtual refraction method: Application to synthetic data and 2012 of Karangsambung survey data  

NASA Astrophysics Data System (ADS)

Seismic refraction survey is one of geophysical method useful for imaging earth interior, definitely for imaging near surface. One of the common problems in seismic refraction survey is weak amplitude due to attenuations at far offset. This phenomenon will make it difficult to pick first refraction arrival, hence make it challenging to produce the near surface image. Seismic interferometry is a new technique to manipulate seismic trace for obtaining Green's function from a pair of receiver. One of its uses is for improving first refraction arrival quality at far offset. This research shows that we could estimate physical properties such as seismic velocity and thickness from virtual refraction processing. Also, virtual refraction could enhance the far offset signal amplitude since there is stacking procedure involved in it. Our results show super - virtual refraction processing produces seismic image which has higher signal-to-noise ratio than its raw seismic image. In the end, the numbers of reliable first arrival picks are also increased.

Nugraha, Andri Dian; Adisatrio, Philipus Ronnie

2013-09-01

362

MODFLOW-2000 : the U.S. Geological Survey modular ground-water model--documentation of the Advective-Transport Observation (ADV2) Package  

USGS Publications Warehouse

Observations of the advective component of contaminant transport in steady-state flow fields can provide important information for the calibration of ground-water flow models. This report documents the Advective-Transport Observation (ADV2) Package, version 2, which allows advective-transport observations to be used in the three-dimensional ground-water flow parameter-estimation model MODFLOW-2000. The ADV2 Package is compatible with some of the features in the Layer-Property Flow and Hydrogeologic-Unit Flow Packages, but is not compatible with the Block-Centered Flow or Generalized Finite-Difference Packages. The particle-tracking routine used in the ADV2 Package duplicates the semi-analytical method of MODPATH, as shown in a sample problem. Particles can be tracked in a forward or backward direction, and effects such as retardation can be simulated through manipulation of the effective-porosity value used to calculate velocity. Particles can be discharged at cells that are considered to be weak sinks, in which the sink applied does not capture all the water flowing into the cell, using one of two criteria: (1) if there is any outflow to a boundary condition such as a well or surface-water feature, or (2) if the outflow exceeds a user specified fraction of the cell budget. Although effective porosity could be included as a parameter in the regression, this capability is not included in this package. The weighted sum-of-squares objective function, which is minimized in the Parameter-Estimation Process, was augmented to include the square of the weighted x-, y-, and z-components of the differences between the simulated and observed advective-front locations at defined times, thereby including the direction of travel as well as the overall travel distance in the calibration process. The sensitivities of the particle movement to the parameters needed to minimize the objective function are calculated for any particle location using the exact sensitivity-equation approach; the equations are derived by taking the partial derivatives of the semi-analytical particle-tracking equation with respect to the parameters. The ADV2 Package is verified by showing that parameter estimation using advective-transport observations produces the true parameter values in a small but complicated test case when exact observations are used. To demonstrate how the ADV2 Package can be used in practice, a field application is presented. In this application, the ADV2 Package is used first in the Sensitivity-Analysis mode of MODFLOW-2000 to calculate measures of the importance of advective-transport observations relative to head-dependent flow observations when either or both are used in conjunction with hydraulic-head observations in a simulation of the sewage-discharge plume at Cape Cod, Massachusetts. The ADV2 Package is then used in the Parameter-Estimation mode of MODFLOW-2000 to determine best-fit parameter values. It is concluded that, for this problem, advective-transport observations improved the calibration of the model and the estimation of ground-water flow parameters, and the use of formal parameter-estimation methods and related techniques produced significant insight into the physical system.

Anderman, Evan R.; Hill, Mary Catherine

2001-01-01

363

Pencil-Beam Surveys for Trans-Neptunian Objects: Novel Methods for Optimization and Characterization  

NASA Astrophysics Data System (ADS)

Digital co-addition of astronomical images is a common technique for increasing signal-to-noise ratio (S/N) and image depth. A modification of this simple technique has been applied to the detection of minor bodies in the solar system: first stationary objects are removed through the subtraction of a high-S/N template image, then the sky motion of the solar system bodies of interest is predicted and compensated for by shifting pixels in software prior to the co-addition step. This "shift-and-stack" approach has been applied with great success in directed surveys for minor solar system bodies. In these surveys, the shifts have been parameterized in a variety of ways. However, these parameterizations have not been optimized and in most cases cannot be effectively applied to data sets with long observation arcs due to objects' real trajectories diverging from linear tracks on the sky. This paper presents two novel probabilistic approaches for determining a near-optimum set of shift vectors to apply to any image set given a desired region of orbital space to search. The first method is designed for short observational arcs, and the second for observational arcs long enough to require nonlinear shift vectors. Using these techniques and other optimizations, we derive optimized grids for previous surveys that have used "shift-and-stack" approaches to illustrate the improvements that can be made with our method, and at the same time derive new limits on the range of orbital parameters these surveys searched. We conclude with a simulation of a future application for this approach with LSST, and show that combining multiple nights of data from such next-generation facilities is within the realm of computational feasibility.

Parker, Alex H.; Kavelaars, J. J.

2010-05-01

364

Positive deviance control-case life history: a method to develop grounded hypotheses about successful long-term avoidance of infection  

Microsoft Academic Search

BACKGROUND: Prevalence rates for long-term injection drug users in some localities surpass 60% for HIV and 80% for HCV. We describe methods for developing grounded hypotheses about how some injectors avoid infection with either virus. METHODS: Subjects: 25 drug injectors who have injected drugs 8 – 15 years in New York City. 17 remain without antibody to either HIV or

Samuel R Friedman; Pedro Mateu-Gelabert; Milagros Sandoval; Holly Hagan; Don Jarlais

2008-01-01

365

Ground Motion Simulation for a Large Active Fault System using Empirical Green's Function Method and the Strong Motion Prediction Recipe - a Case Study of the Noubi Fault Zone -  

Microsoft Academic Search

The 1995 Hyogo-ken Nambu Earthquake (1995) near Kobe, Japan, spurred research on strong motion prediction. To mitigate damage caused by large earthquakes, a highly precise method of predicting future strong motion waveforms is required. In this study, we applied empirical Green's function method to forward modeling in order to simulate strong ground motion in the Noubi Fault zone and examine

M. Kuriyama; T. Kumamoto; M. Fujita

2005-01-01

366

Comparison of methods for estimating ground-water recharge and base flow at a small watershed underlain by fractured bedrock in the Eastern United States  

USGS Publications Warehouse

This study by the U.S. Geological Survey (USGS), in cooperation with the Agricultural Research Service (ARS), U.S. Department of Agriculture, compared multiple methods for estimating ground-water recharge and base flow (as a proxy for recharge) at sites in east-central Pennsylvania underlain by fractured bedrock and representative of a humid-continental climate. This study was one of several within the USGS Ground-Water Resources Program designed to provide an improved understanding of methods for estimating recharge in the eastern United States. Recharge was estimated on a monthly and annual basis using four methods?(1) unsaturated-zone drainage collected in gravity lysimeters, (2) daily water balance, (3) water-table fluctuations in wells, and (4) equations of Rorabaugh. Base flow was estimated by streamflow-hydrograph separation using the computer programs PART and HYSEP. Estimates of recharge and base flow were compared for an 8-year period (1994-2001) coinciding with operation of the gravity lysimeters at an experimental recharge site (Masser Recharge Site) and a longer 34-year period (1968-2001), for which climate and streamflow data were available on a 2.8-square-mile watershed (WE-38 watershed). Estimates of mean-annual recharge at the Masser Recharge Site and WE-38 watershed for 1994-2001 ranged from 9.9 to 14.0 inches (24 to 33 percent of precipitation). Recharge, in inches, from the various methods was: unsaturated-zone drainage, 12.2; daily water balance, 12.3; Rorabaugh equations with PULSE, 10.2, or RORA, 14.0; and water-table fluctuations, 9.9. Mean-annual base flow from streamflow-hydrograph separation ranged from 9.0 to 11.6 inches (21-28 percent of precipitation). Base flow, in inches, from the various methods was: PART, 10.7; HYSEP Local Minimum, 9.0; HYSEP Sliding Interval, 11.5; and HYSEP Fixed Interval, 11.6. Estimating recharge from multiple methods is useful, but the inherent differences of the methods must be considered when comparing results. For example, although unsaturated-zone drainage from the gravity lysimeters provided the most direct measure of potential recharge, it does not incorporate spatial variability that is contained in watershed-wide estimates of net recharge from the Rorabaugh equations or base flow from streamflow-hydrograph separation. This study showed that water-level fluctuations, in particular, should be used with caution to estimate recharge in low-storage fractured-rock aquifers because of the variability of water-level response among wells and sensitivity of recharge to small errors in estimating specific yield. To bracket the largest range of plausible recharge, results from this study indicate that recharge derived from RORA should be compared with base flow from the Local-Minimum version of HYSEP.

Risser, Dennis W.; Gburek, William J.; Folmar, Gordon J.

2005-01-01

367

Intelligence-based automatic detection and classification of ground collapses using object-based image analysis method: a case study in Paitan of Pearl River delta  

NASA Astrophysics Data System (ADS)

In this paper, a new method is proposed by applying case-based reasoning technique for detecting the ground collapses. The study demonstrates that the high resolution remote sensing images are suitable for monitoring the ground collapses in the study area with karst relief. With the help of object-based image analysis method, the generic algorithm (GA) for optimizing the spatial, shape, spectral, hierarchy and textural features was used in the multi-scale image segmentation with the good fitness value, and then the case library was built for detecting the collapse. The case library is reusable for place-independent detection. The proposed method has been tested in the Pearl River Delta in south China. The result of ground-collapse detection is well.

Dou, Jie; Zheng, Xiao-zhan; Qian, Jun-ping; Liu, Rui-hua; Wu, Qi-tao

2009-10-01

368

Teaching Intercultural Communication in a Basic Technical Writing Course: A Survey of Our Current Practices and Methods  

ERIC Educational Resources Information Center

This research article reports the results of an online survey distributed among technical writing instructors in 2006. The survey aimed to examine how we teach intercultural communication in basic technical writing courses: our current practices and methods. The article discusses three major challenges that instructors may face when teaching about…

Matveeva, Natalia

2008-01-01

369

Methods for rapidly processing angular masks of next-generation galaxy surveys  

NASA Astrophysics Data System (ADS)

As galaxy surveys become larger and more complex, keeping track of the completeness, magnitude limit and other survey parameters as a function of direction on the sky becomes an increasingly challenging computational task. For example, typical angular masks of the Sloan Digital Sky Survey contain about N = 300000 distinct spherical polygons. Managing masks with such large numbers of polygons becomes intractably slow, particularly for tasks that run in time with a naive algorithm, such as finding which polygons overlap each other. Here we present a `divide-and-conquer' solution to this challenge: we first split the angular mask into pre-defined regions called `pixels', such that each polygon is in only one pixel, and then perform further computations, such as checking for overlap, on the polygons within each pixel separately. This reduces tasks to , and also reduces the important task of determining in which polygon(s) a point on the sky lies from to , resulting in significant computational speedup. Additionally, we present a method to efficiently convert any angular mask to and from the popular HEALPIX format. This method can be generically applied to convert to and from any desired spherical pixelization. We have implemented these techniques in a new version of the MANGLE software package, which is freely available at http://space.mit.edu/home/tegmark/mangle/, along with complete documentation and example applications. These new methods should prove quite useful to the astronomical community, and since MANGLE is a generic tool for managing angular masks on a sphere, it has the potential to benefit terrestrial mapmaking applications as well.

Swanson, M. E. C.; Tegmark, Max; Hamilton, Andrew J. S.; Hill, J. Colin

2008-07-01

370

Topographical surveys: Classical method versus 3D laser scanning. Case study - An application in civil engineering  

NASA Astrophysics Data System (ADS)

The paper describes an experiment which took place in Iasi town, Romania, consisted in two different topographical survey techniques applied for one and the same objective placed in a block within the city (western part) - a thermal power station. The purpose was to compare those methods and to determine which one is proper to be used in this domain in terms of fastness, optimization and speed of data processing. First technique applied for our survey was the classical one, with a total station. Using the CAD technique, we obtained a final product (a dwg file) and a list of coordinates (a text file). The second method, which we focused our attention more, was the measurement with a very precise 3D laser scanstation, also very suitable in archeology. The data obtained were processed with special software. Result was a 3D model of the thermal power plant composed of measurable cloud point data. Finally, analyzing the advantages and disadvantages of each method, we came to the conclusion that the 3D laser scanning which we used matches well the application, in this case civil engineering, but the future of accepting and implementing this technique is in the hands of Romanian authorities.

Grigora?, I.-R.; Cov?snianu, A.; Ple?u, G.; Benedict, B.

2009-04-01

371

HD isotope effect of methyl internal rotation for acetaldehyde in ground state as calculated from a multicomponent molecular orbital method.  

PubMed

We have analyzed the differences in the methyl internal rotation induced by the HD isotope effect for acetaldehyde (CH(3)CHO) and deuterated acetaldehyde (CD(3)CDO) in ground state by means of the multicomponent molecular orbital (MC_MO) method, which directly accounts for the quantum effects of protons and deuterons. The rotational constant of CH(3)CHO was in reasonable agreement with experimental one due to the adequate treatment of the protonic quantum effect by the MC_MO method. The C-D bond distances were about 0.007 A shorter than the C-H distances because of the effect of anharmonicity of the potential. The Mulliken population for CD(3) in CD(3)CDO is larger than that for CH(3) in CH(3)CHO because the distribution of wavefunctions for the deuterons was more localized than that for the protons. The barrier height obtained by the MC_MO method for CH(3)CHO was estimated as 401.4 cm(-1), which was in excellent agreement with the experimentally determined barrier height. We predicted the barrier height of CD(3)CDO as 392.5 cm(-1). We suggest that the internal rotation of the CD(3) group was more facile than that of the CH(3) group because the C-D bond distance was observed to be shorter than the C-H distance. Additionally the localized electrons surrounding the CD(3) group in CD(3)CDO caused the extent of hyperconjugation between the CD(3) and CDO groups to be smaller than that in the case of CH(3)CHO, which may have also contributed to the observed differences in methyl internal rotation. The differences in bond distances and electronic populations induced by the H/D isotope effect were controlled by the difference in the distribution of wavefunctions between the protons and deuterons. PMID:18532814

Ishimoto, Takayoshi; Ishihara, Yasuyuki; Teramae, Hiroyuki; Baba, Masaaki; Nagashima, Umpei

2008-05-14

372

Development of Ground Coils with Low Eddy Current Loss by Applying the Compression Molding Method after the Coil Winding  

NASA Astrophysics Data System (ADS)

In a magnetically levitated transportation (MAGLEV) system, a huge number of ground coils will be required because they must be laid for the whole line. Therefore, stable performance and reduced cost are essential requirements for the ground coil development. On the other hand, because the magnetic field changes when the superconducting magnet passes by, an eddy current will be generated in the conductor of the ground coil and will result in energy loss. The loss not only increases the magnetic resistance for the train running but also brings an increase in the ground coil temperature. Therefore, the reduction of the eddy current loss is extremely important. This study examined ground coils in which both the eddy current loss and temperature increase were small. Furthermore, quantitative comparison for the eddy current loss of various magnet wire samples was performed by bench test. On the basis of the comparison, a round twisted wire having low eddy current loss was selected as an effective ground coil material. In addition, the ground coils were manufactured on trial. A favorable outlook to improve the size accuracy of the winding coil and uneven thickness of molded resin was obtained without reducing the insulation strength between the coil layers by applying a compression molding after winding.

Suzuki, Masao; Aiba, Masayuki; Takahashi, Noriyuki; Ota, Satoru; Okada, Shigenori

373

Methods and applications of electrical simulation in ground-water studies in the lower Arkansas and Verdigris River Valleys, Arkansas and Oklahoma  

USGS Publications Warehouse

The Arkansas River Multiple-Purpose Plan will provide year-round navigation on the Arkansas River from near its mouth to Muskogee, Okla., and on the Verdigris River from Muskogee to Catoosa, Okla. The altered regimen in the Arkansas and Verdigris Rivers will affect ground-water conditions in the adjacent alluvial aquifers. In 1957 the U.S. Geological Survey and U.S. Army Corps of Engineers entered into a cooperative agreement for a comprehensive ground-water study of the lower Arkansas and Verdigris River valleys. At the request of the Corps of Engineers, the Geological Survey agreed to provide (1) basic ground-water data before, during, and after construction of the Multiple-Purpose Plan and (2) interpretation and projections of postconstruction ground-water conditions. The data collected were used by the Corps of Engineers in preliminary foundation and excavation estimates and by the Geological Survey as the basis for defining the hydrologic properties of, and the ground-water conditions in, the aquifer. The projections of postconstruction ground-water conditions were used by the Corps of Engineers in the planning, design, construction, and operation of the Multiple-Purpose Plan. Analysis and projections of ground-water conditions were made by use of electrical analog models. These models use the analogy between the flow of electricity in a resistance-capacitance circuit and the flow of a liquid in a porous and permeable medium. Verification provides a test of the validity of the analog to perform as the aquifer would, within the range of historic forces. The verification process consists of simulating the action of historic forces which have acted upon the aquifer and of duplicating the aquifer response with the analog. The areal distribution of accretion can be treated as an unknown and can be determined by analog simulation of the piezometric surface in an aquifer. Comparison of accretion with depth to piezometric surface below land surface shows that accretion decreases with decreasing depth to water level. The decrease in accretion is attributed mostly to the increase in evapotranspiration from the aquifer, and where water levels are very near the land surface, to the rejection of recharge. The maximum accretion and the decrease in accretion with the decrease in depth to water are dependent upon the climate and the thickness and lithology of the fine-grained material overlying the aquifer. Dams on the Arkansas and Verdigris Rivers will impose a direct change in water levels in the aquifers adjacent to the rivers. This change will be attenuated by the resultant change in accretion to the aquifer. The analogs of aquifers in the valleys were used to determine the change in ground-water level from preconstruction to postconstruction conditions.

Bedinger, M. S.; Reed, J. E.; Wells, C. J.; Swafford, B. F.

1970-01-01

374

30 CFR 75.703-3 - Approved methods of grounding offtrack mobile, portable and stationary direct-current machines.  

Code of Federal Regulations, 2013 CFR

...portable and stationary direct-current machines. 75.703-3 Section 75.703-3...portable and stationary direct-current machines. In grounding offtrack direct-current machines and the enclosures of their component...

2013-07-01

375

30 CFR 75.701-1 - Approved methods of grounding of equipment receiving power from ungrounded alternating current...  

Code of Federal Regulations, 2013 CFR

...borehole casing having low resistance to earth; (c) A solid connection to metal waterlines having low resistance to earth; (d) A solid connection to a grounding...potential between such metal enclosures and the...

2013-07-01

376

30 CFR 75.703-3 - Approved methods of grounding offtrack mobile, portable and stationary direct-current machines.  

Code of Federal Regulations, 2010 CFR

...medium; or, (d) The use of silicon diodes; however, the installation of such devices...requirements: (1) Installation of silicon diodes shall be restricted to electric equipment...polarity grounded; (2) Where such diodes are used on circuits having a...

2009-07-01

377

30 CFR 75.703-3 - Approved methods of grounding offtrack mobile, portable and stationary direct-current machines.  

Code of Federal Regulations, 2010 CFR

...medium; or, (d) The use of silicon diodes; however, the installation of such devices...requirements: (1) Installation of silicon diodes shall be restricted to electric equipment...polarity grounded; (2) Where such diodes are used on circuits having a...

2010-07-01

378

A comparison of two methods for surveying mortality of beached birds in British Columbia.  

PubMed Central

Systematic surveys of beached birds are often limited in their ability to classify the causes of death of the carcasses recovered. Two methods of determining the cause of death of seabirds encountered during surveys of beaches of southwestern Vancouver Island, British Columbia, are compared. Birds were either subjected to external visual examinations by volunteer beach surveyors or submitted for gross postmortem examination by a veterinarian. The reliance on external examination of birds on beaches often prevented the accurate classification of the reproductive status and cause of death of the birds collected, but was valuable for describing the species, locations, and numbers of birds affected. The use of gross postmortem examinations of carcasses allowed for a more refined classification of the cause of death, as well as providing reliable descriptions of the bodily condition and sex of the birds examined. However, almost one half of the carcasses encountered were unsuitable for necropsy because of scavenging and decomposition. It is concluded that a combination of field and necropsy observations provides a useful method with which to monitor the pattern of mortality of beached seabirds.

Stephen, C; Burger, A E

1994-01-01

379

A comparison of methods for converting rhizotron root length measurements into estimates of root mass production per unit ground area  

Microsoft Academic Search

Rhizotrons provide valuable information about plant root production, but measurements are usually made in units of root length\\u000a per unit surface area of observation window surface. These measurement units are not easily comparable to above-ground plant\\u000a growth. To address this deficiency, several techniques have been developed to convert rhizotron measurement units into root\\u000a mass production per unit ground area. In

D. B. Metcalfe; P. Meir; M. Williams

2007-01-01

380

Mixing a Grounded Theory Approach with a Randomized Controlled Trial Related to Intimate Partner Violence: What Challenges Arise for Mixed Methods Research?  

PubMed Central

Little is known about how to systematically integrate complex qualitative studies within the context of randomized controlled trials. A two-phase sequential explanatory mixed methods study was conducted in Canada to understand how women decide to disclose intimate partner violence in emergency department settings. Mixing a RCT (with a subanalysis of data) with a grounded theory approach required methodological modifications to maintain the overall rigour of this mixed methods study. Modifications were made to the following areas of the grounded theory approach to support the overall integrity of the mixed methods study design: recruitment of participants, maximum variation and negative case sampling, data collection, and analysis methods. Recommendations for future studies include: (1) planning at the outset to incorporate a qualitative approach with a RCT and to determine logical points during the RCT to integrate the qualitative component and (2) consideration for the time needed to carry out a RCT and a grounded theory approach, especially to support recruitment, data collection, and analysis. Data mixing strategies should be considered during early stages of the study, so that appropriate measures can be developed and used in the RCT to support initial coding structures and data analysis needs of the grounded theory phase.

Catallo, Cristina; Jack, Susan M.; Ciliska, Donna; MacMillan, Harriet L.

2013-01-01

381

Efficacy of Pitfall Trapping, Winkler and Berlese Extraction Methods for Measuring Ground-Dwelling Arthropods in Moist-Deciduous Forests in the Western Ghats  

PubMed Central

The present study provides data to decide on the most appropriate method for sampling of ground-dwelling arthropods measured in a moist-deciduous forest in the Western Ghats in South India. The abundance of ground-dwelling arthropods was compared among large numbers of samples obtained using pitfall trapping, Berlese and Winkler extraction methods. Highest abundance and frequency of most of the represented taxa indicated pitfall trapping as the ideal method for sampling of ground-dwelling arthropods. However, with possible bias towards surface-active taxa, pitfall-trapping data is inappropriate for quantitative studies, and Berlese extraction is the better alternative. Berlese extraction is the better method for quantitative measurements than the other two methods, whereas pitfall trapping would be appropriate for qualitative measurements. A comparison of the Berlese and Winkler extraction data shows that in a quantitative multigroup approach, Winkler extraction was inferior to Berlese extraction because the total number of arthropods caught was the lowest; and many of the taxa that were caught from an identical sample via Berlese extraction method were not caught. Significantly a greater frequency and higher abundance of arthropods belonging to Orthoptera, Blattaria, and Diptera occurred in pitfall-trapped samples and Psocoptera and Acariformes in Berlese-extracted samples than that were obtained in the other two methods, indicating that both methods are useful, one complementing the other, eliminating a chance for possible under-representation of taxa in quantitative studies.

Sabu, Thomas K.; Shiju, Raj T.

2010-01-01

382

Survey of ochratoxin A in UK retail coffees  

Microsoft Academic Search

A new method providing sensitivity to low concentrations was developed for the analysis of ochratoxin A in roast and ground and soluble coffee and a survey has been carried out to determine levels of ochratoxin A (OTA) in 100 samples of retail coffees available in the UK. The survey covered 80 soluble coffees (granulated, powdered, freeze?dried), of which nine products

S. Patel; C. M. Hazel; A. G. M. Winterton; A. E. Gleadle

1997-01-01

383

Laboratory methods for detection of Chlamydia trachomatis: survey of laboratories in Washington State.  

PubMed Central

The last decade has witnessed the development of a wide variety of diagnostic tests for Chlamydia trachomatis. In order to determine what laboratory methods are being used to detect C. trachomatis infections in Washington State and to identify factors influencing test selection, between April 1995 and October 1995 we conducted a mailed questionnaire survey of all 112 laboratories certified to do chlamydia testing. Of these, 20 had discontinued testing for C. trachomatis, and responses were obtained from 89 (97%) of the remaining 92 laboratories. Surprisingly, 38 (43%) of the 89 laboratories used rapid tests such as Clearview and Surecell, making such tests the most commonly used laboratory tests. Laboratories which used rapid tests had lower test volumes, less experience performing tests for C. trachomatis, less frequent attendance at professional meetings, and greater reliance on manufacturers for information compared with laboratories which used other methods. Confirmation of non-culture-positive results was provided by 28 (34%) of the 82 laboratories doing non-culture-based tests. Forty-one (47%) of 88 laboratories reported having compared their method with another method. Test volume was the strongest predictor of laboratories which confirmed positive non-culture-based test results and which had performed a laboratory comparison of methods. We conclude that rapid tests for C. trachomatis are often being used inappropriately and that efforts are needed to improve effective implementation and quality assurance of laboratory testing for C. trachomatis.

Suchland, K L; Counts, J M; Stamm, W E

1997-01-01

384

Comparison and survey of finite difference methods for pricing American options under finite activity jump-diffusion models  

Microsoft Academic Search

Partial integro-differential formulations are often used for pricing American options under jump-diffusion models. A survey on such formulations and their numerical methods is presented. A detailed description of six efficient methods based on a linear complementarity formulation and finite difference discretizations is given. Numerical experiments compare the performance of these methods for pricing American put options under finite activity jump

Santtu Salmi; Jari Toivanen

2012-01-01

385

Methods and Data Used to Investigate Polonium-210 as a Source of Excess Gross-Alpha Radioactivity in Ground Water, Churchill County, Nevada  

USGS Publications Warehouse

Ground water is the major source of drinking water in the Carson River Basin, California and Nevada. Previous studies have shown that uranium and gross-alpha radioactivities in ground water can be greater than U.S. Environmental Protection Agency Maximum Contaminant Levels, particularly in the Carson Desert, Churchill County, Nevada. Studies also have shown that the primary source of the gross-alpha radioactivity and alpha-emitting radionuclides in ground water is the dissolution of uranium-rich granitic rocks and basin-fill sediments that have their origins in the Sierra Nevada. However, ground water sampled from some wells in the Carson Desert had gross-alpha radioactivities greater than could be accounted for by the decay of dissolved uranium. The occurrence of polonium-210 (Po-210) was hypothesized to explain the higher than expected gross-alpha radioactivities. This report documents and describes the study design, field and analytical methods, and data used to determine whether Po-210 is the source of excess gross-alpha radioactivity in ground water underlying the Carson Desert in and around Fallon, Nevada. Specifically, this report presents: 1) gross alpha and uranium radioactivities for 100 wells sampled from June to September 2001; and 2) pH, dissolved oxygen, specific conductance, and Po-210 radioactivity for 25 wells sampled in April and June 2007. Results of quality-control samples for the 2007 dataset are also presented.

Seiler, Ralph L.

2007-01-01

386

A New Method for the Detection of Galaxy Clusters in X-Ray Surveys  

SciTech Connect

For many years the power of counting clusters of galaxies as a function of their mass has been recognized as a powerful cosmological probe; however, we are only now beginning to acquire data from dedicated surveys with sufcient sky coverage and sensitivity to measure the cluster population out to distances where the dark energy came to dominate the Universe’s evolution. One such survey uses the XMM X-ray telescope to scan a large area of sky, detecting the X-ray photons from the hot plasma that lies in the deep potential wells of massive clusters of galaxies. These clusters appear as extended (not point-like) objects, each providing just a few hundred photons in a typical observation. The detection of extended sources in such a low signal-to-noise situation is an important problem in astrophysics: we attempt to solve it by using as much prior information as possible, translating our experience with wellmeasured clusters to define a “template” cluster that can be varied and matched to the features seen in the XMM images. In this work we adapt an existing Monte Carlo analysis code for this problem. Two detection templates were dened and their suitability explored using simulated data; the method was then applied to a publically avalable XMM observation of a “blank” field. Presented are the encouraging results of this series of experiments, suggesting that this approach continue to be developed for future cluster-identication endeavours.

Piacentine, J.M.; Marshall, P.J.; Peterson, J.R.; Andersson, K.E.

2005-01-01

387

Assessment of survey radiography as a method for diagnosis of congenital cardiac disease in dogs.  

PubMed

In order to assess the diagnostic accuracy of survey radiography for canine congenital cardiac anomalies, thoracic radiographs of 57 dogs with congenital cardiac anomalies, 31 normal dogs and 27 dogs with acquired cardiac disease were mixed, and reviewed by two independent observers, who were blinded to any patient information. The congenital anomalies were aortic stenosis (n=25), pulmonic stenosis (n=10), patent ductus arteriosus (n=9), ventricular septal defect (n=8), tricuspid dysplasia (n=3) and mitral dysplasia (n=2). Both observers were moderately accurate at identifying dogs with cardiac disease. Their ability to distinguish dogs with congenital versus acquired cardiac disease was poorer and this assessment was probably influenced by the recognition of patients that were skeletally immature, which biased observers towards a diagnosis of congenital cardiac anomaly. The diagnosis rate for specific congenital anomalies was also poor (the differential list included a correct diagnosis in only 40 and 37 per cent of cases). Radiographic signs of specific cardiac chamber enlargement or pulmonary vascular abnormalities were recognised by both observers in only 20 per cent of instances in which they might be expected. They were, however, recognised more frequently in dogs with anomalies that imposed a volume load on the heart than in dogs with anomalies that induced a pressure load on the organ. It is concluded that survey radiography is an inaccurate method for diagnosis of canine congenital cardiac anomalies because of the difficulty of recognising radiographic signs, which are not present in many cases. PMID:11721982

Lamb, C R; Boswood, A; Volkman, A; Connolly, D J

2001-11-01

388

Ground Effect in Flight  

Microsoft Academic Search

The present paper aims to analyze the propulsion of birds and fishes undergoing the ground effect as well as the lift of high-speed ground vehicle. Applying the analytical method which was developed for flutter of a soft plate placed at an arbitrary position in subsonic channel flows, calculations are carried out first for non-oscillatory case in compressible flow and then

Yoshimichi Tanida

2001-01-01

389

Cross-Cultural Issues of Intra- and Inter-Organisational Cooperation in Space Operations: A Survey Study with Ground Personnel of the European Space Agency  

NASA Astrophysics Data System (ADS)

Today's space operations often involve close co-working of people with different ethnical, professional and organizational backgrounds. The aim of the study was to examine the implications of cultural diversity for efficient collaboration within the European Space Agency (ESA), and between ESA employees and representatives from other agencies. Methods: A web-based survey was answered by 905 employees at the European Astronaut Centre and at the European Space Technology Centre. An adapted version of the Flight Management Attitude Questionnaire by Helmreich and Merrit was used. Personnel were also asked about interpersonal and operational issues that interfered with efficient co-working within ESA and in relation to other space agencies. Results: Collaboration within ESA: A descriptive analysis was conducted of the rank orders of challenges perceived by members of different nationalities (the Netherlands (N=68), German (N=138), Italian (N=135), French (N=124), British (N=84) and Scandinavian (27).Rank orders show a surprisingly uniformity across nationalities. Most respondents perceived differences in the preferred leadership style as the main challenge for co-working in multi-national groups followed by differences in dealing with conflicts and misunderstandings. In contrast communication problems due different languages and differences in non-verbal behaviour, as well as differences in gender stereotypes were among the lowest rated issues. However, Scandinavian respondents showed a different pattern from other nationalities. Collaboration between agencies: The most significant issues reported to interfere with the efficiency of inter-agency collaboration varied. Most difficulties were reported in relation to clarity of communication, insufficient sharing of task related information, understanding the process of decision making in partner organization, and authoritarian leadership style in the partner organization Conclusion: Cultural differences in leadership and decision making processes are salient challenges in cooperation both within ESA and between ESA employees and representatives from other agencies. The importance given to these factors is consistent with results from the broader area of work and organizational psychology. Potential implications for safety operations are discussed

Mjeldheim Sandal, Gro; Mjeldheim Sandal, Gro; Manzey, Dietrich

390

Mapping Spatial Attributes in Survey Research for Natural Resource Management: Methods and Applications  

Microsoft Academic Search

Traditional survey research measures attributes such as opinions, attitudes, beliefs, values, norms, and preferences. Few public surveys have attempted to map perceived spatial attributes of places and landscapes, a subject of increasing importance to environmental and natural resource management. For the past 5 years, this researcher has included spatial measures of landscape values and attributes in five separate surveys of

Gregory Brown

2004-01-01

391

77 FR 24684 - Proposed Information Collection; Comment Request; 2013-2015 American Community Survey Methods...  

Federal Register 2010, 2011, 2012, 2013

...different notifications of an Internet option in the survey invitations. Based on...the later part of the survey. The Internet tests in 2013-2015 will...will ask them to use the Internet to respond to the survey. If they have not...

2012-04-25

392

Linking qualitative and quantitative methods in cross-cultural survey research: Techniques from cognitive science  

Microsoft Academic Search

Survey research with diverse cultural and ethnic minority groups is a complex and challenging endeavor that confronts the researcher with problems related to linguistic and conceptual equivalence and measurement as well as problems related to difficulties that respondents have with the sociocultural dimensions of the survey\\/interview process. One way to improve the quality of cross-cultural surveys and to insure that

Alice M. Hines

1993-01-01

393

Cross-sectional survey methods to assess retrospectively mortality in humanitarian emergencies.  

PubMed

Since the rates and causes of mortality are critical indicators of the overall health of a population, it is important to evaluate mortality even where no complete vital statistics reporting exists. Such settings include humanitarian emergencies. Experience in cross-sectional survey methods to assess retrospectively crude, age-specific, and maternal mortality in stable settings has been gained over the past 40 years, and methods appropriate to humanitarian emergencies have been developed. In humanitarian emergencies, crude and age-specific mortality can be gauged using methods based on the enumeration of individuals resident in randomly selected households-frequently referred to as a household census. Under-five mortality can also be assessed through a modified prior birth history method in which a representative sample of reproductive-aged women are questioned about dates of child births and deaths. Maternal mortality can be appraised via the initial identification of maternal deaths in the study population and a subsequent investigation to determine the cause of each death. PMID:19500327

Cairns, K Lisa; Woodruff, Bradley A; Myatt, Mark; Bartlett, Linda; Goldberg, Howard; Roberts, Les

2009-02-12

394

Transparent 3D Visualization of Archaeological Remains in Roman Site in Ankara-Turkey with Ground Penetrating Radar Method  

NASA Astrophysics Data System (ADS)

Transparent 3D Visualization of Archaeological Remains in Roman Site in Ankara-Turkey with Ground Penetrating Radar Method Selma KADIOGLU Ankara University, Faculty of Engineering, Department of Geophysical Engineering, 06100 Tandogan/ANKARA-TURKEY kadioglu@eng.ankara.edu.tr Anatolia has always been more the point of transit, a bridge between West and East. Anatolia has been a home for ideas moving from all directions. So it is that in the Roman and post-Roman periods the role of Anatolia in general and of Ancyra (the Roman name of Ankara) in particular was of the greatest importance. Now, the visible archaeological remains of Roman period in Ankara are Roman Bath, Gymnasium, the Temple of Augustus of Rome, Street, Theatre, City Defence-Wall. The Caesar Augustus, the first Roman Emperor, conquered Asia Minor in 25 BC. Then a marble temple was built in Ancyra, the administrative capital of province, today the capital of Turkish Republic, Ankara. This monument was consecrated to the Empreror and to the Goddess Rome. This temple is supposed to have built over an earlier temple dedicated to Kybele and Men between 25 -20 BC. After the death of the Augustus in 14AD, a copy of the text of "Res Gestae Divi Augusti" was inscribed on the interior of the pronaos in Latin, whereas a Greek translation is also present on an exterior wall of the cella. In the 5th century, it was converted in to a church by the Byzantines. The aim of this study is to determine old buried archaeological remains in the Augustus temple, Roman Bath and in the governorship agora in Ulus district. These remains were imaged with transparent three dimensional (3D) visualization of the ground penetrating radar (GPR) data. Parallel two dimensional (2D) GPR profile data were acquired in the study areas, and then a 3D data volume were built using parallel 2D GPR data. A simplified amplitude-colour range and appropriate opacity function were constructed and transparent 3D image were obtained to activate buried remains. Interactive interpretation was done by using sub-blocks of the transparent 3D volume. The opacity function coefficients were increased while deep sub-blocks were visualized. Therefore amplitudes of electromagnetic wave field were controlled by changing opacity coefficients with depth. The transparent 3D visualization provided to identify the archaeological remains on native locations with depth in a 3D volume. According to the visualization results, in the governorship agora, the broken Roman Street was identified under the remnants of Ottoman, Seljuk's and Byzantine periods respectively at 4m depths and a colonnaded portico was determined in the governorship garden. Diggings encouraged the 3D image results. In the Augustus temple, very complex remnant structures including cubbies were determined in front of the east wall of the temple. The remnant walls very near to the surface were continued so deep in the 3D image. The transparent 3D visualization results overlapped with the digging results of the Augustus temple.

Kadioglu, S.

2009-04-01

395

Effects of two telephone survey methods on the level of reported risk behaviours  

PubMed Central

Objective: Reporting bias due to social desirability is an important consideration in carrying out surveys on sensitive issues. The study compared the frequency of self reported sensitive behaviours and response rates between the conventional "telephone interviewer method" (TIM) and a combined interviewer and computerised data capturing method (telephone interviewer and computerised questionnaire method, or TICQM). Methods: A total of 580 males and 582 females were recruited and randomly assigned to either of the two methods in a cross sectional study. The overall response rate was about 51.6%. Results: While the two methods both had high completion and low item non-response rates, the TICQM respondents reported higher frequencies of sensitive risk behaviours. Sexually active female respondents interviewed by the TICQM were more likely to report that their sex partners were their steady boyfriend, instead of their husband; and were also more likely to admit that they had had "one night stand" experiences or had undergone an HIV antibody test, when compared with their counterparts in the TIM group. Similar contrasts were observed for sexually active male respondents, that the TICQM group were more likely to report that they had had sexual intercourse with female sex workers or non-regular sex partners. Sex differences in the strength of association were observed between some studied behaviours (for example, HIV testing and substance abuse) and modes of data collection. Conclusion: The choice of data collection method has a significant impact on the results of sensitive studies; special attention should be given to designing the study and interpreting the results.

Lau, J; Tsui, H; Wang, Q

2003-01-01

396

A cross-sectional survey of condom use in conjunction with other contraceptive methods.  

PubMed

A cross-sectional survey of 3,136 women attending family planning clinics in Texas was conducted to examine past use of and future plans for use of condoms by partners during sexual intercourse for disease prevention in conjunction with other contraceptive methods. Following the receipt of clinical services, including counseling about family planning and disease prevention, both contraceptive and planned condom use reporting increased for the majority of subjects. However 22% of the sample indicated that they intended to reduce condom use in the future and instead use a contraceptive which protects from pregnancy but not from disease. Condom use was indicated more frequently for those who reported at least one risk factor for HIV, but 17% of those at risk indicated lower future condom use than past use. This suggests that without changes in risk behavior, these women will be at increased risk of HIV or another sexually transmitted disease. PMID:8585224

Frank, M L; Poindexter, A N; Cox, C A; Bateman, L

1995-01-01

397

Multi-method Geophysical Surveys for the Study of Holocene Landslide Deposits  

NASA Astrophysics Data System (ADS)

This paper integrates the results of a geophysical investigation of two Holocene landslides in the Cypress Hills, Alberta, Canada. Seismic refraction, ground penetrating radar (GPR) and electrical resistivity imaging (ERI) were used to retrieve information about the type and morphometry of the landslide surfaces and boundaries. The earlier event occurred about 9,400 years ago and produced the East Slump Block (ESB); the West Slump Block (WSB) dates from mid- to late Holocene. The debris surfaces were encountered in boreholes at 6.5 m on the ESB and at 1.5 m on the WSB. The geological and geomorphological settings suggest a simplified 3-layer model: soil and post-landslide deposits of varying thickness, landslide mass, and bedrock or channel fill depending on elevation. Previous research suggests that the landslides evolved in a conglomerates formation. GPR profiling was used to characterize the first few meters of the subsurface, as the depth of penetration was limited due to highly attenuating lithologies. Stratigraphic elements were inferred from changes in the propagation velocity of the ground wave, the presence of diffraction events and weak, discontinuous reflectors from depths greater than 10 m. The envelopes of strong diffractions at a depth of 6-8 meters can be interpreted as the top of the landslide. Seismic refraction complements the GPR measurements, as it can generally provide data from greater depth. Sites at the toe of the landslides produced an interface at depths less than 8 meters for the ESB and less than 2 m for the WSB. For sites located nearer to the scarp, the characteristic element is an interface at average depth of 15 m. ERI is in principle the most appropriate method for clay-rich deposits. A number of 2D sections were obtained parallel to main seismic and GPR profiles. Electrical images provide information about the structure of the upper 30 meters of the subsurface and generally reinforce the results from other methods. GPR, seismic refraction and ERI were found suitable to analyze the shallow internal structure of the landslide mass. These geophysical techniques could therefore become standard tools for the characterization of ancient landslide deposits.

Cutlac, O.; Maillol, J.

2005-05-01

398

Bathymetric Survey of the Nearshore from Belle Pass to Caminada Pass, Louisiana: Methods and Data Report  

USGS Publications Warehouse

The U.S. Geological Survey (USGS), in cooperation with the University of New Orleans (UNO) and the Louisiana Department of Natural Resources (LDNR), conducted a high-resolution, single-beam bathymetric survey along the southern Louisiana coastal zone from Belle Pass to Caminada Pass. The survey consisted of 483 line-kilometers of data acquired in July and August of 2005. This report outlines the methodology and provides the data from the survey. Analysis of the data and comparison to a similar bathymetric survey completed in 1989 show significant loss of seafloor and shoreline retreat, which is consistent with previously published estimates of shoreline change in the study area.

DeWitt, Nancy T.; Flocks, James G.; Hansen, Mark; Kulp, Mark; Reynolds, B. J.

2007-01-01

399

EXPERIMENTAL STUDY ON CLASSIFICATION OF LAYOUT METHODS OF A STEEL PLATE AND EFFECT OF DECREASE IN ACTING PRESSURE ON BEARING GROUND THROUGH THE CRAWLERS OF DRILL RIGS.  

NASA Astrophysics Data System (ADS)

Drill rigs are large pieces of construction machinery, used to build pile foundations and improve ground stability. In recent years, there have been several reports of accidents where drill rigs have toppled over. Two potential causes for these accidents are related to drill rigs becoming unstable. One cause is structural instability, where the body is composed of a top heavy weight distribution. The other is concerned with the supporting ground. During the construction process, rig sites are excavated and overlaid by reclaimed soil. These works produce uneven surfaces, as well as a distribution of different stiffnesses in the supporting ground. In this study, we first classify layout methods of a steel plate and conduct loading tests with several layout patterns while decreasing the acting pressure on the bearing ground through the crawlers. Secondly, a series of experimental simulations using a 1/25 scale model of a drill rig are performed in a centrifuge, in order to investigate the cause of drill rig instability with motion-image sequence analysis. Finally, we discuss the optimum layout methods of the steel plate.

Hori, Tomohito; Tamate, Satoshi; Kikkawa, Naotaka; Itoh, Kazuya

400

Combination of different seismic methods and geotechnical sounding for a rapid characterization of the near-surface ground  

NASA Astrophysics Data System (ADS)

For economical and feasible seismic exploration of the near-surface ground, an approach has been developed for the joint application of reflection and refraction seismics as well as multi-channel analysis of surface waves (MASW). The measuring concept was tested within the research project COMEXTECH, dealing with the exploration of construction ground. Besides the overall characterization of the subsurface by refraction and reflection seismics, the MASW can be used for the derivation of relevant soil parameters such as soil stiffness. The centre of the measuring concept represents a land streamer, pulled by a vehicle equipped with the seismic source. The 24-channel land streamer may be tipped with different geophones, according to the focus of investigation. We used three fully equipped land streamers with 72 channels at all at the test site Nauen close to Berlin, Germany. The first 24 positions of the land streamer nearby the seismic source were filled with 4.5 Hz geophones. The next two land streamers were tipped with 14 Hz geophones, respectively. The idea behind this arrangement is that the positions close to the shot point, which are not utilisable for reflection seismics, can be used for the interpretation of surface waves. The signal was given with an accelerated weight drop mounted on a cross-country vehicle. Shots were arranged every meter, and four shots per shot point were executed for an increased signal/noise ratio. Three registration units (GeodeTM by Geometrics) were connected in series for signal recording. At the site, a profile of 164 m length was investigated in bidirectional manner in combination with geotechnical exploration technique. The purpose of bidirectional recording is to check the reliability and sensitivity of the seismic array and to increase the resolution of the image of the subsurface. By using the same shot points forth and back, a multiple overlap rate for certain common depth points (CDP) can be achieved, which is thought to result in an increased data quality. Geotechnical investigations comprise the use of Cone Penetrating Tests (CPT) for characterization of properties of the subsurface. Thereby the lithology may be derived by means of the friction ratio, which represents the ratio of the in-situ determined parameters of sleeve friction and cone resistance during CPT soundings. First results of data processing are available for the interpolated shear wave velocities (Vs) of the analysis of the Rayleigh-type surface waves on a multichannel record (MASW) by using the program SURFSEIS. The velocities are more or less laterally layered with zones of lower velocities (<180 m/s) in the upper subsurface and in about 5 m depth at the southern part of the profile. The strong increase of shear-wave velocities in 10 m depth and below (>250 m/s) is supposed to correspondent to a glacial moraine underlying the sandy sediments. The characterization of the near-surface ground by MASW corresponds well with the results of the nearby CPT soundings. By comparing the MASW results of the forward and backward recording of the profile, however, it turns out that the methodical approach of bidirectional seismic measurements still needs some tests. The produced 2-D Vs profiles show some marginal differences in the Vs-distribution in detail. Processing of seismic refraction and reflection data are in progress yet. In summery, the land streamer has the real advantage of fast data recording with a variable geophone array for different applications. The slight loss in quality of seismic data does not limit the use of the land streamer even on arable land. If carefully performed, geophones fitted on the land streamer still record data in an adequate quality for a feasible characterization of the subsurface, as shown in our study. Especially along long profiles the employment of a land streamer outplays stuck geophones by the fast progress in data recording due to the pulled array of geophones in a fixed geometry.

Dietrich, P.; Kretschmer, F.; Vienken, T.; Popp, S.

2009-04-01

401

EVALUATION OF CULTURE- AND PCR-BASED DETECTION METHODS FOR ESCHERICHIA COLI O157:H7 IN INOCULATED GROUND BEEF  

Technology Transfer Automated Retrieval System (TEKTRAN)

E. coli O157:H7 is a foodborne pathogen of significant concern to the beef processing industry. This pathogen is characterized by a low infective dose and ability to cause severe disease. Several antimicrobial intervention technologies have been implemented to eliminate contamination of ground bee...

402

USING CONCEPT MAPPING TO CONSTRUCT NEW KNOWLEDGE WHILE ANALYZING RESEARCH DATA: THE CASE OF THE GROUNDED THEORY METHOD  

Microsoft Academic Search

The paper exemplifies the use of concept mapping during the analysis of qualitative research data, and demonstrates the advantage of concept mapping to derive a grounded theory by highlighting the macrostructure of the research data. Concept mapping serves here to construct new knowledge within the framework of research data analysis and it functions as a model map, in which the

Lea Kozminsky; Beer Sheva; Israel Ely Kozminsky

403

A method of prediction of strong ground motion by stochastic green function considering 3-D attenuation structure  

Microsoft Academic Search

The 3-D attenuation structure is a big problem to evaluate seismic ground motion when the seismic motion that uses a statistical Green function in the great earthquake such as Tonankai earthquake generated along subduction zone. On the other hand, Q structure analysis results (ex, Nakamura and Uetake,2004) of the short period beneath the Japanese Islands show strong inhomogeneity. Therefore, We

R. Nakamura

2004-01-01

404

A theoretical survey of atomic structure and forbidden transitions in the 4pk and 4dk ground configurations of tungsten ions W29 + through W43 +  

Microsoft Academic Search

Energy levels, wavelengths and radiative decay rates have been calculated for states within the 4pk (k = 1–5) and 4dk (k = 1–9) ground configurations in highly charged tungsten ions. Magnetic dipole (M1) and electric quadrupole (E2) transition probabilities have been obtained using the fully relativistic multiconfiguration Dirac–Fock (MCDF) approach including the correlations within the n = 4 complex, some

Pascal Quinet

2012-01-01

405

Shallow subsurface temperature surveys in the basin and range province-II. Ground temperatures in the upsal hogback geothermal area, West-Central Nevada, U.S.A.  

USGS Publications Warehouse

Numerous temperature surveys at a depth of 1 m were made in 1973-1985 in the Upsal Hogback and Soda Lakes geothermal areas in west-central Nevada. Whereas the surveys effectively delineated temperature at depth and heat flow within the relatively intense Soda Lakes thermal anomaly, they were not effective at the diffuse Upsal Hogback anomaly, where several perturbing factors that affect shallow subsurface temperatures are exceedingly variable. Albedo is the most important factor in the Upsal Hogback area, even at a depth of 30 m. All possible perturbing factors should be considered when designing a shallow temperature-based prospecting scheme. ?? 1986.

Olmsted, F. H.; Ingebritsen, S. E.

1986-01-01

406

Evaluating Evapotranspiration of Pine Forest, Switchgrass, and Pine- Switchgrass Intercroppings using Remote Sensing and Ground-based Methods  

NASA Astrophysics Data System (ADS)

Vast areas of the land in the Southeastern United States are under pine forests managed primarily for timber and related byproducts. Evapotranspiration (ET) is the major loss in the water balance of this forest ecosystem. A long-term (1988-2008) study to evaluate hydrologic and nutrient balance during a life cycle of a pine stand was just completed. The study used both monitoring and modeling approaches to evaluate hydrologic and water quality effects of silvicultural and water management treatments on three 25 ha experimental watersheds in eastern North Carolina (NC). The research was extended in 2009 to include a dedicated energy crop, switchgrass (Panicum virgatum), by adding an adjacent 25 ha watershed. These multiple watersheds are being used to evaluate the hydrologic and water quality effects of switchgrass alone, young pine with natural understory, and young pine with switchgrass intercropping compared to the control (pine stand with a natural understory). The biofuels study has been further expanded to two other southern states, Alabama (AL) and Mississippi (MS). Each has five small watersheds (< 25 ha size) consisting of the above treatments and an additional woody biomass removal treatment. In this presentation we provide methods for estimating ET for these treatment watersheds in all three states (NC, AL, and MS) using remote sensing based spatial high resolution multispectral satellite imagery data with ground truthing, where possible, together with sensor technology. This technology is making ET parameter estimation a reality for various crops and vegetation surfaces. Slope-based vegetation indices like Normalized Difference Vegetation Index (NDVI) and Green Vegetation Index (GVI) and distance-based vegetation indices like Soil Adjusted Vegetation Index (SAVI) and Perpendicular Vegetation Index (PVI) will be developed using the R and NIR bands, vegetation density, and background soil reflectance as necessary. Landsat and high resolution aerial imageries of vegetation and soils will be used. IDRISI Taiga software will be used for the indices development. The forested vegetation health will be correlated to the leaf chlorophyll content for determining the vegetation health with a subsequent derivation of available plant water for radiation. Models will be developed to correlate the plant and soil available water to different vegetation indices. Correlation models will also be developed to obtain information on climatic parameters like surface air temperature, net radiation, albedo, soil moisture content, and stomatal water availability from Landsat imageries. On-site weather parameters used for the PET estimates will be combined with other vegetation parameters like leaf area index (LAI) obtained using LIDAR data and NAIP orthophotos of different seasons. That will also help detect the upper and understory vegetation. The LIDAR data will be processed to obtain the volume of vegetation to correctly estimate the total ET for each treatment.

Amatya, D. M.; Panda, S.; Chescheir, G. M.; Nettles, J. E.; Appelboom, T.; Skaggs, R. W.

2011-12-01

407

Monitoring and Prediction of the Fall Flight of Wood Ducks ('AIX SPONSA') in Michigan: An Investigation of Survey Methods.  

National Technical Information Service (NTIS)

Direct estimates of wood duck (Aix sponsa) numbers and production are difficult to derive and improved methods are needed to estimate fall flight. The goal of this project is to evaluate survey methods that might provide a finer scale of monitoring wood d...

L. A. Briggs H. H. Prince

2000-01-01

408

Enhancing Dillman's total design method for mailed\\/ telephone surveys using current technology to maximise cost-benefit ratios  

Microsoft Academic Search

Sample survey using mailed questionnaires is an important research tool often limited by low response rates. In the late 1970s, Dillman developed a highly successful approach to ensuring high response rates called the 'total design method' (TDM). TDM was designed prior to widespread use of personal computers, word processing, graphic software, laser printing and new commun ication methods. This experimental

Rita Axford; Barbara Carter; Gary Grunwald

1997-01-01

409

Social constructivist teaching methods in Australian universities – reported uptake and perceived learning effects: a survey of lecturers  

Microsoft Academic Search

Pragmatic social constructivist teaching methods require students to construct knowledge by engaging collaboratively with realistic problems, cases or projects. It is hypothesised that they are more effective than traditional didactic teaching methods in developing undergraduate students’: (1) theoretical knowledge; (2) profession?specific skills; and (3) knowledge creation capacity. Results of a survey show the second and third learning effects to be

James M. Hanson; Kenneth E. Sinclair

2008-01-01

410

Examination of the Equivalence of Self-Report Survey-Based Paper-and-Pencil and Internet Data Collection Methods  

ERIC Educational Resources Information Center

|Self-report survey-based data collection is increasingly carried out using the Internet, as opposed to the traditional paper-and-pencil method. However, previous research on the equivalence of these methods has yielded inconsistent findings. This may be due to methodological and statistical issues present in much of the literature, such as…

Weigold, Arne; Weigold, Ingrid K.; Russell, Elizabeth J.

2013-01-01

411

A survey of the methods used in shelter and rescue programs to identify feral and frightened pet cats  

Microsoft Academic Search

Despite the lack of validated methods for differentiating feral from frightened socialized cats upon intake to animal welfare agencies, these organizations must make handling and disposition decisions for millions of cats each year based on their presumed socialization status. We conducted a nationwide survey of feline welfare stakeholders to learn about methods used to evaluate and categorize incoming cats, amount

Margaret R. Slater; Katherine A. Miller; Emily Weiss; Kathleen V. Makolinski; Lila A. M. Weisbrot

2010-01-01

412

Contraceptive Failure, Method-Related Discontinuation And Resumption of Use: Results from the 1995 National Survey of Family Growth  

Microsoft Academic Search

Context: Half of all pregnancies in the United States are unintended. Of these, half occur to women who were practicing contraception in the month they conceived, and others occur when couples stop use because they find their method difficult or inconvenient to use. Methods: Data from the 1995 National Survey of Family Growth were used to compute life-table probabilities of

James Trussell; Barbara Vaughan

413

User guide for the farm process (FMP1) for the U.S. Geological Survey's modular three-dimensional finite-difference ground-water flow model, MODFLOW-2000  

USGS Publications Warehouse

There is a need to estimate dynamically integrated supply-and-demand components of irrigated agriculture as part of the simulation of surface-water and ground-water flow. To meet this need, a computer program called the Farm Process (FMP1) was developed for the U.S. Geological Survey three-dimensional finite-difference modular ground-water flow model, MODFLOW- 2000 (MF2K). The FMP1 allows MF2K users to simulate conjunctive use of surface- and ground water for irrigated agriculture for historical and future simulations, water-rights issues and operational decisions, nondrought and drought scenarios. By dynamically integrating farm delivery requirement, surface- and ground-water delivery, as well as irrigation-return flow, the FMP1 allows for the estimation of supplemental well pumpage. While farm delivery requirement and irrigation return flow are simulated by the FMP1, the surface-water delivery to the farm can be simulated optionally by coupling the FMP1 with the Streamflow Routing Package (SFR1) and the farm well pumping can be simulated optionally by coupling the FMP1 to the Multi-Node Well (MNW) Package. In addition, semi-routed deliveries can be specified that are associated with points of diversion in the SFR1 stream network. Nonrouted surface-water deliveries can be specified independently of any stream network. The FMP1 maintains a dual mass balance of a farm budget and as part of the ground-water budget. Irrigation demand, supply, and return flow are in part subject to head-dependent sources and sinks such as evapotranspiration from ground water and leakage between the conveyance system and the aquifer. Farm well discharge and farm net recharge are source/sink terms in the FMP1, which depend on transpiration uptake from ground water and other head dependent consumptive use components. For heads rising above the bottom of the root zone, the actual transpiration is taken to vary proportionally with the depth of the active root zone, which can be restricted by anoxia or wilting. Depths corresponding to anoxia- or wilting-related pressure heads within the root zone are found using analytical solutions of a vertical pseudo steady-state pressure- head distribution over the depth of the total root zone (Consumptive Use Concept 1). Alternatively, a simpler, conceptual model is available, which defines how consumptive use (CU) components vary with changing head (CU Concept 2). Subtracting the ground water and precipitation transpiration components from the total transpiration yields a transpiratory irrigation requirement for each cell. The total farm delivery requirement (TFDR) then is determined as cumulative transpiratory and evaporative irrigation requirements of all farm cells and increased sufficiently to compensate for inefficient use from irrigation with respect to plant consumption. The TFDR subsequently is satisfied with surface- and ground-water delivery, respectively constrained by allotments, water rights, or maximum capacities. Five economic and noneconomic drought response policies can be applied optionally, if the potential supply of surface water and ground water is insufficient to meet the crop demand: acreage-optimization with or without a water conservation pool, deficit irrigation with or without water-stacking, and zero policy.

Schmid, Wolfgang; Hanson, R. T.; Maddock, Thomas, III; Leake, S. A.

2006-01-01

414

E-BOSS: an Extensive stellar BOw Shock Survey. I. Methods and first catalogue  

NASA Astrophysics Data System (ADS)

Context. Bow shocks are produced by many astrophysical objects where shock waves are present. Stellar bow shocks, generated by runaway stars, have been previously detected in small numbers and well-studied. Along with progress in model development and improvements in observing instruments, our knowledge of the emission produced by these objects and its origin can now be more clearly understood. Aims: We produce a stellar bow-shock catalogue by applying uniform search criteria and a systematic search process. This catalogue is a starting point for statistical studies, to help us address fundamental questions such as, for instance, the conditions under wich a stellar bow shock is detectable. Methods: By using the newest infrared data releases, we carried out a search for bow shocks produced by early-type runaway stars. We first explored whether a set of known IRAS bow shock candidates are visible in the most recently available IR data, which has much higher resolution and sensitivity. We then carried out a selection of runaway stars from the latest, large runaway catalogue available. In this first release, we focused on OB stars and searched for bow-shaped features in the vicinity of these stars. Results: We provide a bow-shock candidate survey that gathers a total of 28 members, which we call the Extensive stellar BOw Shock Survey (E-BOSS). We derive the main bow-shock parameters, and present some preliminary statistical results on the detected objects. Conclusions: Our analysis of the initial sample and the newly detected objects yields a bow-shock detectability around OB stars of ~10 per cent. The detections do not seem to depend particularly on either stellar mass, age or position. The extension of the E-BOSS sample, with upcoming IR data, and by considering, for example, other spectral types as well, will allow us to perform a more detailed study of the findings.

Peri, C. S.; Benaglia, P.; Brookes, D. P.; Stevens, I. R.; Isequilla, N. L.

2012-02-01

415

The DEEP2 Galaxy Redshift Survey: The Voronoi-Delaunay Method Catalog of Galaxy Groups  

SciTech Connect

We use the first 25% of the DEEP2 Galaxy Redshift Survey spectroscopic data to identify groups and clusters of galaxies in redshift space. The data set contains 8370 galaxies with confirmed redshifts in the range 0.7 {<=} z {<=} 1.4, over one square degree on the sky. Groups are identified using an algorithm (the Voronoi-Delaunay Method) that has been shown to accurately reproduce the statistics of groups in simulated DEEP2-like samples. We optimize this algorithm for the DEEP2 survey by applying it to realistic mock galaxy catalogs and assessing the results using a stringent set of criteria for measuring group-finding success, which we develop and describe in detail here. We find in particular that the group-finder can successfully identify {approx}78% of real groups and that {approx}79% of the galaxies that are true members of groups can be identified as such. Conversely, we estimate that {approx}55% of the groups we find can be definitively identified with real groups and that {approx}46% of the galaxies we place into groups are interloper field galaxies. Most importantly, we find that it is possible to measure the distribution of groups in redshift and velocity dispersion, n({sigma}, z), to an accuracy limited by cosmic variance, for dispersions greater than 350 km s{sup -1}. We anticipate that such measurements will allow strong constraints to be placed on the equation of state of the dark energy in the future. Finally, we present the first DEEP2 group catalog, which assigns 32% of the galaxies to 899 distinct groups with two or more members, 153 of which have velocity dispersions above 350 km s{sup -1}. We provide locations, redshifts and properties for this high-dispersion subsample. This catalog represents the largest sample to date of spectroscopically detected groups at z {approx} 1.

Gerke, Brian F.; /UC, Berkeley; Newman, Jeffrey A.; /LBNL, NSD; Davis, Marc; /UC, Berkeley /UC, Berkeley, Astron.Dept.; Marinoni, Christian; /Brera Observ.; Yan, Renbin; Coil, Alison L.; Conroy, Charlie; Cooper, Michael C.; /UC, Berkeley, Astron.Dept.; Faber, S.M.; /Lick Observ.; Finkbeiner, Douglas P.; /Princeton U. Observ.; Guhathakurta, Puragra; /Lick Observ.; Kaiser, Nick; /Hawaii U.; Koo, David C.; Phillips, Andrew C.; /Lick Observ.; Weiner, Benjamin J.; /Maryland U.

2012-02-14

416

Combined processing of IR and MW radiometric data in the ice reconnaissance during the survey for the harp seal puppy grounds in the White sea  

Microsoft Academic Search

Studied is the question on correlation of the IR and MW radiometer data, as well as on the expedi- ency of using MW radiometry to solve the specific problems of ice aerial reconnaissance. During a number of years, the Laboratory of Remote Sens- ing (PINRO) has been conducting multispectral aerial surveys for puppy areas of the White Sea harp seal

V. A. Tereshchenko

417

Delineate subsurface structures with ground penetrating radar  

SciTech Connect

High resolution ground penetrating radar (GPR) surveys were conducted at the Savannah River Site in South Carolina in late 1991 to demonstrate the radar techniques in imaging shallow utility and soil structures. Targets of interest at two selected sites, designated as H- and D-areas, were a buried backfilled trench, buried drums, geologic stratas, and water table. Multiple offset 2-D and single offset 3-D survey methods were used to acquire high resolution radar data. This digital data was processed using standard seismic processing software to enhance signal quality and improve resolution. Finally, using a graphics workstation, the 3D data was interpreted. In addition, a small 3D survey was acquired in The Woodlands, Texas, with very dense spatial sampling. This data set adequately demonstrated the potential of this technology in imaging subsurface features.

Wyatt, D.E. (Westinghouse Savannah River Co., Aiken, SC (United States)); Hu, L.Z. (New Wave Technology, Houston, TX (United States)); Ramaswamy, M. (Houston Advanced Research Center, Woodlands, TX (United States)); Sexton, B.G. (Microseeps, Inc., Pittsburgh, PA (United States))

1992-01-01

418

Delineate subsurface structures with ground penetrating radar  

SciTech Connect

High resolution ground penetrating radar (GPR) surveys were conducted at the Savannah River Site in South Carolina in late 1991 to demonstrate the radar techniques in imaging shallow utility and soil structures. Targets of interest at two selected sites, designated as H- and D-areas, were a buried backfilled trench, buried drums, geologic stratas, and water table. Multiple offset 2-D and single offset 3-D survey methods were used to acquire high resolution radar data. This digital data was processed using standard seismic processing software to enhance signal quality and improve resolution. Finally, using a graphics workstation, the 3D data was interpreted. In addition, a small 3D survey was acquired in The Woodlands, Texas, with very dense spatial sampling. This data set adequately demonstrated the potential of this technology in imaging subsurface features.

Wyatt, D.E. [Westinghouse Savannah River Co., Aiken, SC (United States); Hu, L.Z. [New Wave Technology, Houston, TX (United States); Ramaswamy, M. [Houston Advanced Research Center, Woodlands, TX (United States); Sexton, B.G. [Microseeps, Inc., Pittsburgh, PA (United States)

1992-10-01

419

A Survey of \\delta18O and \\delta15N Ratios in Ground Water from an Agricultural Community in the San Joaquin Valley, California  

NASA Astrophysics Data System (ADS)

We studied ground water samples from domestic and monitoring wells in an agricultural community in the eastern side of the San Joaquin Valley, California. The study area is rich in alluvial soils creating an extremely fertile farmland. Livestock farms and agricultural fields are abundant in the area. Fifty-four ground water samples were analyzed for \\delta18O and \\delta15N in dissolved nitrate, in addition to nutrients and major minerals. Nitrate concentration levels in groundwater are elevated and affected by agricultural and other activities. Possible sources of nutrients include: a municipal waste-water treatment facility, a raisin processing plant, a meat processing plant, a turkey farm, diary operations, and agricultural fields. However, except for the turkey farm and a diary, we found no statistical significant contribution of nitrate from the other facilities as compared to the rest of the area. The \\delta18O versus \\delta15N ratios plot of dissolved ground water nitrate shows most samples clustered around an area consistent with soil organic nitrogen. In addition, the rest of the samples show a trend that is indicative of denitrification process. Generally, high \\delta15N values are associated with low nitrate concentrations. The isotopic signal of denitrification is particularly pronounced in samples in the vicinity of the waste water treatment facility, where the highest values of \\delta15N and the lowest nitrate concentrations are observed. However, these samples also have elevated chloride concentrations indicating a waste-water source. These data suggest that the denitrification in the subsurface may have been enhanced by bacteria species introduced by the effluence of the plant. [This study was performed with the collaboration of Steven R Silva of USGS, Menlo Park, and Iris Yamagata and Holly Jo Ferrin of California Department of Water Resources.

Glowacki, S. D.; Suen, C. J.

2004-12-01

420

Above-ground biomass assessments and first cutting cycle production in willow ( Salix sp.) coppice—a comparison between destructive and non-destructive methods  

Microsoft Academic Search

To assess non-destructive above-ground biomass measurements in comparison to destructive measurements in willow (Salix sp.) coppice plantations, individual plant weights of twelve 4-year old willow clones (Salix viminalis L., S. dasyclados Wimm.) were estimated by constructing allometric relationships between stem diameter and shoot dry weight. The plants were also measured with a destructive method, i.e. harvest, weighing, and determination of

Nils-Erik Nordh; Theo Verwijst

2004-01-01

421

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of the total phosphorus by a Kjeldahl digestion method and an automated colorimetric finish that includes dialysis  

USGS Publications Warehouse

A method to determine total phosphorus (TP) in the same digests prepared for total Kjeldahl nitrogen (TKN) determinations is desribed. The batch, high-temperature (block digester), HG(II)-catalyzed digestion step is similar to U.S. Geological Survey methods I-2552-85/I-4552-85 and U.S. Environmental Protection Agency method 365.4 except that sample and reagent volumes are halved. Prepared digests are desolvated at 220 degrees Celsius and digested at 370 degrees Celsius in separate block digesters set at these temperatures, rather than in a single, temperature-programmed block digester. This approach is used in the method escribed here, which permits 40 calibrants, reference waters, and smaples to be digested and resolvated in about an hour. Orthophosphate ions originally present in samples, along with those released during the digestion step, are determined colorimetrically at a rate of 90 tests per hour by an automated version of the phosphoantimonylmolybdenum blue procedure. About 100 microliters of digest are required per determination. The upper concentration limit is 2 milligrams per liter (mg/L) with a method detection limt of 0.01 mg/L. Repeatability for a sample containing approximately 1.6 mg/L of TP in a high suspended-solids matrix is 0.7 percent. Between-day precision for the same sample is 5.0 percent. A dialyzer in the air-segmented continuous flow analyzer provides on-line digest cleanup, eliminated particulates that otherwise would interfere in the colorimetric finish. An single-channel analyzer can process the resolvated digests from two pairs of block digesters each hour. Paired t-test analysis of TP concentrations for approximately 1,600 samples determined by the new method (U.S. Geologial Survey methods I-2610-91 and I-4610-91) and the old method (U.S. Geological Survey methods I-2600-85 and I-4600-85) revealed positive bias in the former of 0.02 to 0.04 mg/L for surface-water samples in agreement with previous studies. Concentrations of total phosphorus detemrined for ground-water samples by both methods were statistically equivalent.

Patton, Charles J.; Truitt, Earl P.

1992-01-01

422