Investigation of geological structures with a view to HLRW disposal, as revealed through 3D inversion of aeromagnetic and gravity data and the results of CSAMT exploration

NASA Astrophysics Data System (ADS)

An, Zhiguo; Di, Qingyun

2016-12-01

The Alxa area in Inner Mongolia has been selected as a possible site for geological disposal of high-level radioactive waste (HLRW). Based on results of a previous study on crustal stability, the Tamusu rock mass has been chosen as the target. To determine the geological structure of this rock mass, aeromagnetic and gravity data are collected and inverted. Three-dimensional (3D) inversion horizontal slices show that the internal density of the rock mass and the distribution of magnetic properties are not uniform, with fractures and fragmentation being present. To confirm this result, the controlled source audio-frequency magnetotelluric method (CSAMT) was applied to explore the geological structures, the typical CSAMT sounding curve was analyzed, and the response characteristics of the geological structure and surrounding rock are distinguished. The original data were processed and interpreted in combination with data from surface geology and drilling and logging data. It is found that the CSAMT results were consistent with those from 3D inversion of the gravity and magnetic data, confirming the existence of fractures and fragmentation in the exploration area.

The non-static effect of near-surface inhomogeneity on CSAMT data

NASA Astrophysics Data System (ADS)

Lei, Da; Fayemi, Busayo; Yang, Liangyong; Meng, Xiaohong

2017-04-01

Controlled source audio-frequency magnetotelluric (CSAMT) method has several advantages over magnetotelluric (MT) method, which includes the recording of lower noise signal and higher resolution data. However, CSAMT field data can still be distorted by the effect of near surface inhomogeneous body. It may be confused with static effect just like in MT, if three-dimensional subsurface geological body is buried under the receiver. Traditionally, the method used in static correction is adopted similar to that used in MT method for many years. In comparison, MT are the natural electric and magnetic fields in the frequency range of 0.0001 Hz to 500 Hz, while CSAMT fields are applied at frequencies ranging from 0.1 to 10 kHz. Hence, in this paper, the non-static effect of near-surface inhomogeneity in CSAMT was simulated through theoretical modeling and we summarized its characteristics. If the skin depth is much larger than the size of the near-surface inhomogeneous body that is close to the measurement point, the anomalous body causes a static effect which is represented by vertical shift in apparent resistivity curves for all frequencies from their expected values, but when the skin depth is much smaller than the size of the near-surface inhomogeneous body in the vicinity of the measurement point, the apparent resistivity curve at high frequencies remains unchanged, while at lower frequencies shift in value is observed. The near-surface effect may be confused with static effect in data processing; however, it cannot be corrected using previous static correction methods, but by using the two-dimensional inversion method. Hence, for such CSAMT data, both effective processing technique and inversion process is of great significance.

Measurement of electromagnetic fields over a small electrolytic tank

NASA Astrophysics Data System (ADS)

Caffey, T. W. H.; Morris, H. E.

1990-12-01

In 1986, Hart proposed a large, hemispherical electrolytic tank and the use of the Surface Electrical Potential method with which to study resistivity changes due to energy-extraction processes in the earth. A second method for the inference of underground resistivity changes, the Controlled Source Audio-MagnetoTelluric method, has been widely used in the field. This method uses measurements of the electromagnetic field from a surface dipole, rather than the surface potential distribution from a buried vertical electrode, as the basis of the technique. If both SEP and CSAMT could be applied to the same model structure in the same electrolytic tank, it would seem that the diagnostic information would be enhanced over the use of each technique separately. Accordingly, the specific objectives were: to determine to what radial extent the bowl could be used as a homogeneous half-space; and to demonstrate acceptable accuracy by measuring the effect of a conducting target immersed in the bowl and comparing the measurements with numerical modeling. Electromagnetic fields over an electrolytic tank have been measured by others, and this report begins with a comparative summary of both prior and present work. The next section presents the formulas for the electromagnetic fields, and explains the choice of a particular method of measuring apparent resistivity. The field theory is also used in the subsequent section to provide error estimates needed for design guidance. The following sections describe the measurements, and the considerations for a larger facility. The appendices include the derivatives of the fields, the electrolyte characteristics, a description of the apparatus, and calibration methods.

Delineation of a quick clay zone at Smørgrav, Norway, with electromagnetic methods under geotechnical constraints

NASA Astrophysics Data System (ADS)

Kalscheuer, Thomas; Bastani, Mehrdad; Donohue, Shane; Persson, Lena; Aspmo Pfaffhuber, Andreas; Reiser, Fabienne; Ren, Zhengyong

2013-05-01

In many coastal areas of North America and Scandinavia, post-glacial clay sediments have emerged above sea level due to iso-static uplift. These clays are often destabilised by fresh water leaching and transformed to so-called quick clays as at the investigated area at Smørgrav, Norway. Slight mechanical disturbances of these materials may trigger landslides. Since the leaching increases the electrical resistivity of quick clay as compared to normal marine clay, the application of electromagnetic (EM) methods is of particular interest in the study of quick clay structures. For the first time, single and joint inversions of direct-current resistivity (DCR), radiomagnetotelluric (RMT) and controlled-source audiomagnetotelluric (CSAMT) data were applied to delineate a zone of quick clay. The resulting 2-D models of electrical resistivity correlate excellently with previously published data from a ground conductivity metre and resistivity logs from two resistivity cone penetration tests (RCPT) into marine clay and quick clay. The RCPT log into the central part of the quick clay identifies the electrical resistivity of the quick clay structure to lie between 10 and 80 Ω m. In combination with the 2-D inversion models, it becomes possible to delineate the vertical and horizontal extent of the quick clay zone. As compared to the inversions of single data sets, the joint inversion model exhibits sharper resistivity contrasts and its resistivity values are more characteristic of the expected geology. In our preferred joint inversion model, there is a clear demarcation between dry soil, marine clay, quick clay and bedrock, which consists of alum shale and limestone.

Methods for enhancing mapping of thermal fronts in oil recovery

DOEpatents

Lee, D.O.; Montoya, P.C.; Wayland, J.R. Jr.

1984-03-30

A method for enhancing the resistivity contrasts of a thermal front in an oil recovery production field as measured by the controlled source audio frequency magnetotelluric (CSAMT) technique is disclosed. This method includes the steps of: (1) preparing a CSAMT-determined topological resistivity map of the production field; (2) introducing a solution of a dopant material into the production field at a concentration effective to alter the resistivity associated with the thermal front; said dopant material having a high cation exchange capacity which might be selected from the group consisting of montmorillonite, illite, and chlorite clays; said material being soluble in the conate water of the production field; (3) preparing a CSAMT-determined topological resistivity map of the production field while said dopant material is moving therethrough; and (4) mathematically comparing the maps from step (1) and step (3) to determine the location of the thermal front. This method is effective with the steam flood, fire flood and water flood techniques.

Where is the hot rock and where is the ground water – Using CSAMT to map beneath and around Mount St. Helens

USGS Publications Warehouse

Wynn, Jeff; Mosbrucker, Adam; Pierce, Herbert; Spicer, Kurt R.

2016-01-01

We have observed several new features in recent controlled-source audio-frequency magnetotelluric (CSAMT) soundings on and around Mount St. Helens, Washington State, USA. We have identified the approximate location of a strong electrical conductor at the edges of and beneath the 2004–08 dome. We interpret this conductor to be hot brine at the hot-intrusive-cold-rock interface. This contact can be found within 50 meters of the receiver station on Spine 5, which extruded between April and July of 2005. We have also mapped separate regional and glacier-dome aquifers, which lie one atop the other, out to considerable distances from the volcano.

Regularized inversion of controlled source audio-frequency magnetotelluric data in horizontally layered transversely isotropic media

NASA Astrophysics Data System (ADS)

Zhou, Jianmei; Wang, Jianxun; Shang, Qinglong; Wang, Hongnian; Yin, Changchun

2014-04-01

We present an algorithm for inverting controlled source audio-frequency magnetotelluric (CSAMT) data in horizontally layered transversely isotropic (TI) media. The popular inversion method parameterizes the media into a large number of layers which have fixed thickness and only reconstruct the conductivities (e.g. Occam's inversion), which does not enable the recovery of the sharp interfaces between layers. In this paper, we simultaneously reconstruct all the model parameters, including both the horizontal and vertical conductivities and layer depths. Applying the perturbation principle and the dyadic Green's function in TI media, we derive the analytic expression of Fréchet derivatives of CSAMT responses with respect to all the model parameters in the form of Sommerfeld integrals. A regularized iterative inversion method is established to simultaneously reconstruct all the model parameters. Numerical results show that the inverse algorithm, including the depths of the layer interfaces, can significantly improve the inverse results. It can not only reconstruct the sharp interfaces between layers, but also can obtain conductivities close to the true value.

Method for determining depth and shape of a sub-surface conductive object

NASA Astrophysics Data System (ADS)

Lee, D. O.; Montoya, P. C.; Wayland, J. R., Jr.

1984-06-01

The depth to and size of an underground object may be determined by sweeping a controlled source audio magnetotelluric (CSAMT) signal and locating a peak response when the receiver spans the edge of the object. The depth of the object is one quarter wavelength in the subsurface media of the frequency of the peak.

Detection and characterization of lightning-based sources using continuous wavelet transform: application to audio-magnetotellurics

NASA Astrophysics Data System (ADS)

Larnier, H.; Sailhac, P.; Chambodut, A.

2018-01-01

Atmospheric electromagnetic waves created by global lightning activity contain information about electrical processes of the inner and the outer Earth. Large signal-to-noise ratio events are particularly interesting because they convey information about electromagnetic properties along their path. We introduce a new methodology to automatically detect and characterize lightning-based waves using a time-frequency decomposition obtained through the application of continuous wavelet transform. We focus specifically on three types of sources, namely, atmospherics, slow tails and whistlers, that cover the frequency range 10 Hz to 10 kHz. Each wave has distinguishable characteristics in the time-frequency domain due to source shape and dispersion processes. Our methodology allows automatic detection of each type of event in the time-frequency decomposition thanks to their specific signature. Horizontal polarization attributes are also recovered in the time-frequency domain. This procedure is first applied to synthetic extremely low frequency time-series with different signal-to-noise ratios to test for robustness. We then apply it on real data: three stations of audio-magnetotelluric data acquired in Guadeloupe, oversea French territories. Most of analysed atmospherics and slow tails display linear polarization, whereas analysed whistlers are elliptically polarized. The diversity of lightning activity is finally analysed in an audio-magnetotelluric data processing framework, as used in subsurface prospecting, through estimation of the impedance response functions. We show that audio-magnetotelluric processing results depend mainly on the frequency content of electromagnetic waves observed in processed time-series, with an emphasis on the difference between morning and afternoon acquisition. Our new methodology based on the time-frequency signature of lightning-induced electromagnetic waves allows automatic detection and characterization of events in audio-magnetotelluric time-series, providing the means to assess quality of response functions obtained through processing.

Method for determining depth and shape of a sub-surface conductive object

DOEpatents

Lee, D.O.; Montoya, P.C.; Wayland, Jr.

1984-06-27

The depth to and size of an underground object may be determined by sweeping a controlled source audio magnetotelluric (CSAMT) signal and locating a peak response when the receiver spans the edge of the object. The depth of the object is one quarter wavelength in the subsurface media of the frequency of the peak. 3 figures.

Frequency and time domain three-dimensional inversion of electromagnetic data for a grounded-wire source

NASA Astrophysics Data System (ADS)

Sasaki, Yutaka; Yi, Myeong-Jong; Choi, Jihyang; Son, Jeong-Sul

2015-01-01

We present frequency- and time-domain three-dimensional (3-D) inversion approaches that can be applied to transient electromagnetic (TEM) data from a grounded-wire source using a PC. In the direct time-domain approach, the forward solution and sensitivity were obtained in the frequency domain using a finite-difference technique, and the frequency response was then Fourier-transformed using a digital filter technique. In the frequency-domain approach, TEM data were Fourier-transformed using a smooth-spectrum inversion method, and the recovered frequency response was then inverted. The synthetic examples show that for the time derivative of magnetic field, frequency-domain inversion of TEM data performs almost as well as time-domain inversion, with a significant reduction in computational time. In our synthetic studies, we also compared the resolution capabilities of the ground and airborne TEM and controlled-source audio-frequency magnetotelluric (CSAMT) data resulting from a common grounded wire. An airborne TEM survey at 200-m elevation achieved a resolution for buried conductors almost comparable to that of the ground TEM method. It is also shown that the inversion of CSAMT data was able to detect a 3-D resistivity structure better than the TEM inversion, suggesting an advantage of electric-field measurements over magnetic-field-only measurements.

Unravelling aquifer-wetland interaction using CSAMT and gravity methods: the Mollina-Camorra aquifer and the Fuente de Piedra playa-lake, southern Spain

NASA Astrophysics Data System (ADS)

Pedrera, A.; Martos-Rosillo, S.; Galindo-Zaldívar, J.; Rodríguez-Rodríguez, M.; Benavente, J.; Martín-Rodríguez, J. F.; Zúñiga-López, M. I.

2016-06-01

The hydrological regime of Fuente de Piedra playa-lake (Málaga, southern Spain) has been significantly affected by the intensive exploitation of groundwater in the area. The playa-lake is situated above clays, marls, and gypsum, and under unaltered conditions received surface-subsurface runoff within the watershed as well as groundwater discharge from two carbonate aquifers. We have analyzed the structure of the main one, the Mollina-Camorra carbonate aquifer, by combining controlled source audio magnetotellurics (CSAMT), gravity prospecting, and time-domain electromagnetic (TDEM) soundings. This geophysical information, together with new structural and hydrogeological data, was gathered to develop a new conceptual hydrogeological model. This model allows the hydrological linkage of the carbonate aquifer with the playa-lake system to be established. Moreover, the intensive exploitation in the carbonate aquifer, even outside the watershed of the playa-lake, has affected the hydrological regime of the system. This multidisciplinary work demonstrates the potential of geophysical methods for understanding wetland-aquifer interaction, having important groundwater management implications.

A field test of electromagnetic geophysical techniques for locating simulated in situ mining leach solution

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

Tweeton, D.R.; Hanson, J.C.; Friedel, M.J.

1994-01-01

The US Bureau of Mines, The University of Arizona, Sandia National Laboratories, and Zonge Engineering and Research Organization, Inc., conducted cooperative field tests of six electromagnetic (EM) geophysical methods to compare their effectiveness in locating a brine solution simulating in situ leach solution or a high-conductivity plume of contamination. The brine was approximately 160 m below the surface. The testsite was the University's San Xavier experimental mine near Tucson, AZ. Geophysical surveys using surface and surface-borehole, time-domain electromagnetic (TEM) induction; surface controlled-source audiofrequency magnetotellurics (CSAMT); surface-borehole, frequency-domain electromagnetic (FEM) induction; crosshole FEM; and surface magnetic field ellipticity were conducted beforemore » and during brine injection. The surface TEM data showed a broad decrease in resistivity. CSAMT measurements with the conventional orientation did not detect the brine, but measurements with another orientation indicated some decrease in resistivity. The surface-borehole and crosshole methods located a known fracture and other fracture zones inferred from borehole induction logs. Surface magnetic field ellipticity data showed a broad decrease in resistivity at depth following brine injection.« less

Combination of Geophysical Methods to Support Urban Geological Mapping

NASA Astrophysics Data System (ADS)

Gabàs, A.; Macau, A.; Benjumea, B.; Bellmunt, F.; Figueras, S.; Vilà, M.

2014-07-01

Urban geological mapping is a key to assist management of new developed areas, conversion of current urban areas or assessment of urban geological hazards. Geophysics can have a pivotal role to yield subsurface information in urban areas provided that geophysical methods are capable of dealing with challenges related to these scenarios (e.g., low signal-to-noise ratio or special logistical arrangements). With this principal aim, a specific methodology is developed to characterize lithological changes, to image fault zones and to delineate basin geometry in the urban areas. The process uses the combination of passive and active techniques as complementary data: controlled source audio-magnetotelluric method (CSAMT), magnetotelluric method (MT), microtremor H/V analysis and ambient noise array measurements to overcome the limitations of traditional geophysical methodology. This study is focused in Girona and Salt surrounding areas (NE of Spain) where some uncertainties in subsurface knowledge (maps of bedrock depth and the isopach maps of thickness of quaternary sediments) need to be resolved to carry out the 1:5000 urban geological mapping. These parameters can be estimated using this proposed methodology. (1) Acoustic impedance contrast between Neogene sediments and Paleogene or Paleozoic bedrock is detected with microtremor H/V analysis that provides the soil resonance frequency. The minimum value obtained is 0.4 Hz in Salt city, and the maximum value is the 9.5 Hz in Girona city. The result of this first method is a fast scanner of the geometry of basement. (2) Ambient noise array constrains the bedrock depth using the measurements of shear-wave velocity of soft soil. (3) Finally, the electrical resistivity models contribute with a good description of lithological changes and fault imaging. The conductive materials (1-100 Ωm) are associated with Neogene Basin composed by unconsolidated detrital sediments; medium resistive materials (100-400 Ωm) correspond to Paleogene, and resistive materials (600-1,000 Ωm) are related with complex basement, granite of Paleozoic. The Neogene basin-basement boundary is constrained between surface and 500 m depth, approximately. The new geophysical methodology presented is an optimized and fast tool to refine geological mapping by adding 2D information to traditional geological data and improving the knowledge of subsoil.

Geophysical Tools for an Improved Hydrogeologic Conceptual Model of the Big Chino Sub-basin, Central Arizona

NASA Astrophysics Data System (ADS)

Macy, J. P.; Kennedy, J.

2017-12-01

Water users and managers who rely on the Verde River system and its aquifers for water supplies have an intrinsic interest in developing the best possible tools for assessing the effects of groundwater withdrawals. Past, present, and future groundwater withdrawals from the Big Chino sub-basin will affect groundwater levels in the Big Chino area and groundwater discharge at the headwaters of the Verde River, specifically at the Upper Verde Springs, which is believed to be a major discharge zone of groundwater from the sub-basin. The amount and timing of reduced discharge as base flow is a function of connections between hydrogeologic (aquifer) units, aquifer storage properties and transmissivity, and proximity of withdrawal locations to discharge areas. To better define the aquifer units and aquifer storage properties, the United States Geological Survey, Cities of Prescott and Prescott Valley, and Salt River Project have initiated an ongoing geophysical study using controlled-source audio-frequency magnetotellurics (CSAMT) and repeat microgravity methods. CSAMT, a high-energy electromagnetic method sensitive to lithologic variations between rock and sediment types, is useful for defining aquifers at depths of up to 600 meters. Visual display of CSAMT profiles using Google Earth is useful for understanding and visualizing the relation between geophysics and Big Chino Sub-basin hydrogeology. Initial results from repeat microgravity surveys, which measure changes in subsurface mass (and therefore aquifer storage) over time, reveal spatial variation in the relation between aquifer storage changes and groundwater level changes. This variation reflects different confining conditions and multiple aquifer systems in different parts of the aquifer. Information about confining conditions and multiple aquifers could improve numerical groundwater models and predictions of future groundwater-level and base-flow depletion.

Audiomagnetotelluric data from Spring, Cave, and Coyote Spring Valleys, Nevada

USGS Publications Warehouse

McPhee, Darcy K.; Chuchel, Bruce A.; Pellerin, Louise

2006-01-01

Audiomagnetotelluric (AMT) data along four profiles in Spring, Cave, and Coyote Spring Valleys are presented here. The AMT method is used to estimate the electrical resistivity of the earth over depth ranges of a few meters to greater than one kilometer. This method is a valuable tool for revealing subsurface structure and stratigraphy within the Basin and Range of eastern Nevada, therefore helping to define the geohydrologic framework in this region. We collected AMT data using the Geometrics StrataGem EH4 system, a four-channel, natural and controlled- source tensor system recording in the range of 10 to 92,000 Hz. To augment the low signal in the natural field, an unpolarized transmitter comprised of two horizontal-magnetic dipoles was used from 1,000 to 70,000 Hz. Profiles were 1.4 - 12.6 km in length with station spacing of 100-400 m. Data were recorded with the electrical (E) field parallel to and perpendicular to the regional geologic strike direction. Station locations and sounding curves, showing apparent resistivity, phase data, and coherency data, are presented here.

Synthetic Modeling of A Geothermal System Using Audio-magnetotelluric (AMT) and Magnetotelluric (MT)

NASA Astrophysics Data System (ADS)

Mega Saputra, Rifki; Widodo

2017-04-01

Indonesia has 40% of the world’s potential geothermal resources with estimated capacity of 28,910 MW. Generally, the characteristic of the geothermal system in Indonesia is liquid-dominated systems, which driven by volcanic activities. In geothermal exploration, electromagnetic methods are used to map structures that could host potential reservoirs and source rocks. We want to know the responses of a geothermal system using synthetic data of Audio-magnetotelluric (AMT) and Magnetotelluric (MT). Due to frequency range, AMT and MT data can resolve the shallow and deeper structure, respectively. 1-D models have been performed using AMT and MT data. The results indicate that AMT and MT data give detailed conductivity distribution of geothermal structure.

APPLICATION OF AUDIO-MAGNETOTELLURIC SURVEYS ON SAO MIGUEL ISLAND, AZORES PORTUGAL.

USGS Publications Warehouse

Hoover, Donald; Rodrigues Da Silva, A.; Pierce, Herbert A.; Amaral, Roberto

1984-01-01

Geothermal exploration and development has been under way on Sao Miguel Island, Azores since 1975. This work had been restricted to the Fogo volcano, one of three dormant silicic volcanic centers on the island. The USGS in 1982 and 1983 conducted reconnaissance natural-source audio-magnetotelluric (AMT) surveys of all three silicic centers to evaluate the potential for geothermal systems at each and to demonstrate the utility of the method in areas of difficult terrain. Results on Fogo showed a low resistivity trend extending from the present production area upslope to the caldera boundary. The upper part of this trend is the upwelling zone of a thermal plume which supplies the production area. Further exploration and drilling are now planned for this area.

Unified physical mechanism of frequency-domain controlled-source electromagnetic exploration on land and in ocean

NASA Astrophysics Data System (ADS)

Liu, Changsheng; Lin, Jun; Zhou, Fengdao; Hu, Ruihua; Sun, Caitang

2013-12-01

The frequency-domain controlled-source electromagnetic method (FDCSEM) has played an important role in the terrestrial and oceanic exploration. However, the measuring manners and the detecting abilities in two kinds of environment are much different. This paper analyses the electromagnetic theories of the FDCSEM exploration on land and in ocean, simulates the electromagnetic responses in the two cases based on a united physical and mathematical model, and studies the physical mechanism leading to these differences. In this study, the relationship between the propagation paths and the detecting ability is illuminated and the way to improve the detecting ability of FDCSEM is brought forward. In terrestrial exploration, FDCSEM widely adopts the measuring manner of controlled-source audio-frequency magnetotelluric method (CSAMT), which records the electromagnetic fields in the far zone in the broadside direction of an electric dipole source. This manner utilizes the airwave (i.e. the Earth surface wave) and takes the stratum wave as interference. It is sensitive to the conductive target but insensitive to the resistive one. In oceanic exploration, FDCSEM usually adopts the measuring manner of marine controlled-source electromagnetic method (MCSEM), which records the electromagnetic fields, commonly the horizontal electric fields, in the in-line direction of the electric dipole source. This manner utilizes the stratum wave (i.e. the seafloor wave and the guided wave in resistive targets) and takes the airwave as interference. It is sensitive to the resistive target but relatively insensitive to the conductive one. The numerical simulation shows that both the airwave and the stratum wave contribute to the FDCSEM exploration. United utilization of them will enhance the anomalies of targets and congregate the advantages of CSAMT and MCSEM theories. At different azimuth and different offset, the contribution of the airwave and the stratum wave to electromagnetic anomaly is different. Observation at moderate offset in the in-line direction is the best choice for the exploration of resistive targets, no matter the environment is land or shallow sea. It is also the best choice for the exploration of conductive targets in terrestrial environment. As for the conductive targets in shallow sea, observation at moderate offset in the broadside direction is better. Synthetic and felicitous utilization of the airwave and the stratum wave will optimize the performance of FDCSEM.

`Earth-ionosphere' mode controlled source electromagnetic method

NASA Astrophysics Data System (ADS)

Li, Diquan; Di, Qingyun; Wang, Miaoyue; Nobes, David

2015-09-01

In traditional artificial-source electromagnetic exploration, the effects of the ionosphere and displacement current (DC) in the air were neglected, and only the geoelectrical structure of the earth's crust and upper mantle was considered, such as for controlled source audio-frequency magnetotelluric (CSAMT). By employing a transmitter (less than 30 kW) to generate source fields, the CSAMT method overcomes the problems associated with weak natural electromagnetic (EM) fields used in magnetotellurics. However, the transmitter is moved and the source-receiver offset is approximately less than 20 km, because of the limitation of emission energy. We put forward a new idea, that is, a fixed artificial source (greater than 200 kW) is used and the source location selected at a high resistivity region (to ensure a high emission efficiency), so there may be a possibility that as long as the source strength magnitude is strong enough, the artificial EM signal can be easily observed within a distance of several thousand kilometres. Previous studies have provided the evidence to support this idea; they used the `earth-ionosphere' mode in modeling the EM fields with the offset up to a thousand kilometres. Such EM fields still have a signal/noise ratio over 10-20 dB; this means that a new EM method with fixed source is feasible. However, in their calculations, the DC which plays a very important role for large offsets was neglected. This paper pays much attention to derive the formulae of the `earth-ionosphere' mode with a horizontal electric dipole source, and the DC is not neglected. We present some three layers modeling results to illustrate the basic EM field characteristics under the `earth-ionosphere' mode. As the offset increases, the contribution of the conduction current decreases, DC and ionosphere were taken into account, and the EM field attenuation decreases. We also quantitatively compare the predicted and observed data. The comparison of these results with the data reveal the excellent agreement between the experimental and theoretical results. The DC and ionosphere affects the EM fields, however impedances (ratio of E to H) are unaffected, and this means we need to include ionosphere and DC effects to accurately model the EM field amplitudes for optimal setting of measurement parameters, but we do not need to include these complications for the interpretation of the data for the Earth conductivity.

Audiomagnetotelluric data, Taos Plateau Volcanic Field, New Mexico

USGS Publications Warehouse

Ailes, Chad E.; Rodriguez, Brian D.

2011-01-01

The U.S. Geological Survey is conducting a series of multidisciplinary studies of the San Luis Basin as part of the Geologic framework of the Rio Grande Basins project. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, audiomagnetotelluric surveys, and hydrologic and lithologic data are being used to better understand the aquifers. This report describes a regional east-west audiomagnetotelluric sounding profile acquired in late July 2009 across the Taos Plateau Volcanic Field. No interpretation of the data is included.

CSAMT method for determining depth and shape of a sub-surface conductive object

DOEpatents

Lee, David O.; Montoya, Paul C.; Wayland, Jr., J. Robert

1986-01-01

The depth to and size of an underground object may be determined by sweeping a CSAMT signal and locating a peak response when the receiver spans the edge of the object. The depth of the object is one quarter wavelength in the subsurface media of the frequency of the peak.

Geoelectrical Characterization of the Punta Banda System: A Possible Structural Control for the Geothermal Anomalies

NASA Astrophysics Data System (ADS)

Arango-Galvan, C.; Flores-Marquez, E.; Prol-Ledesma, R.; Working Group, I.

2007-05-01

The lack of sufficient drinking water in México has become a very serious problem, especially in the northern desert regions of the country. In order to give a real solution to this phenomenon the IMPULSA research program has been created to develope novel technologies based on desalination of sea and brackish water using renewable sources of energy to face the problem. The Punta Banda geothermal anomaly is located towards the northern part of Baja California Peninsula (Mexico). High water temperatures in some wells along the coast depicted a geothermal anomaly. An audiomagnetotelluric survey was carried out in the area as a preliminary study, both to understand the process generating these anomalous temperatures and to assess its potential exploitation to supply hot water to desalination plants. Among the electromagnetic methods, the audiomagnetotellurics (AMT) method is appropriated for deep groundwater and geothermal studies. The survey consisted of 27 AMT stations covering a 5 km profile along the Agua Blanca Fault. The employed array allowed us to characterize the geoelectrical properties of the main structures up to 500 m depth. Two main geoelectrical zones were identified: 1) a shallow low resistivity media located at the central portion of the profile, coinciding with the Maneadero valley and 2) two high resitivity structures bordering the conductive zone possibly related to NS faulting, already identified by previous geophysical studies. These results suggest that the main geothermal anomalies are controlled by the dominant structural regime in the zone.

Imaging 2D structures by the CSAMT method: application to the Pantano di S. Gregorio Magno faulted basin (Southern Italy)

NASA Astrophysics Data System (ADS)

Troiano, Antonio; Di Giuseppe, Maria Giulia; Petrillo, Zaccaria; Patella, Domenico

2009-06-01

A controlled source audiofrequency magnetotelluric (CSAMT) survey has been undertaken in the Pantano di San Gregorio Magno faulted basin, an earthquake prone area of Southern Apennines in Italy. A dataset from 11 soundings, distributed along a nearly N-S 780 m long profile, was acquired in the basin's easternmost area, where the fewest data are available as to the faulting shallow features. A preliminary skew analysis allowed a prevailing 2D nature of the dataset to be ascertained. Then, using a single-site multi-frequency approach, Dantzig's simplex algorithm was introduced for the first time to estimate the CSAMT decomposition parameters. The simplex algorithm, freely available online, proved to be fast and efficient. By this approach, the TM and TE mode field diagrams were obtained and a N35°W ± 10° 2D strike mean direction was estimated along the profile, in substantial agreement with the fault traces within the basin. A 2D inversion of the apparent resistivity and phase curves at seven almost noise-free sites distributed along the central portion of the profile was finally elaborated, reinforced by a sensitivity analysis, which allowed the best resolved portion of the model to be imaged from the first few meters of depth down to a mean depth of 300 m b.g.l. From the inverted section, the following features have been outlined: (i) a cover layer with resistivity in the range 3-30 Ω m ascribed to the Quaternary lacustrine clayey deposits filling the basin, down to an average depth of about 35 m b.g.l., underlain by a structure with resistivity over 50 Ω m up to about 600 Ω m, ascribed to the Mesozoic carbonate bedrock; (ii) a system of two normal faults within the carbonate basement, extending down to the maximum best resolved depth of the order of 300 m b.g.l.; (iii) two wedge-shaped domains separating the opposite blocks of the faults with resistivity ranging between 30 Ω m and 50 Ω m and horizontal extent of the order of some tens of metres, likely filled with lacustrine sediments and embedded fine gravels.

Audio-magnetotelluric survey to characterize the Sunnyside porphyry copper system in the Patagonia Mountains, Arizona

USGS Publications Warehouse

Sampson, Jay A.; Rodriguez, Brian D.

2010-01-01

The Sunnyside porphyry copper system is part of the concealed San Rafael Valley porphyry system located in the Patagonia Mountains of Arizona. The U.S. Geological Survey is conducting a series of multidisciplinary studies as part of the Assessment Techniques for Concealed Mineral Resources project. To help characterize the size, resistivity, and skin depth of the polarizable mineral deposit concealed beneath thick overburden, a regional east-west audio-magnetotelluric sounding profile was acquired. The purpose of this report is to release the audio-magnetotelluric sounding data collected along that east-west profile. No interpretation of the data is included.

Methods for enhancing mapping of thermal fronts in oil recovery

DOEpatents

Lee, David O.; Montoya, Paul C.; Wayland, Jr., James R.

1987-01-01

A method for enhancing the resistivity contrasts of a thermal front in an oil recovery production field as measured by the CSAMT technique is disclosed. This method includes the steps of: (a) preparing a CSAMT-determined topological resistivity map of the production field; (b) introducing a solution of a dopant material into the production field at a concentration effective to alter the resistivity associated with the thermal front; said dopant material having a high cation exchange capacity which might be selected from the group consisting of montmorillonite, illite, and chlorite clays; said material being soluble in the connate water of the production field; (c) preparing a CSAMT-determined topological resistivity map of the production field while said dopant material is moving therethrough; and (d) mathematically comparing the maps from step (a) and step (c) to determine the location of the thermal front. This method is effective with the steam flood, fire flood and water flood techniques.

Field test of electromagnetic geophysical techniques for locating simulated in situ mining leach solution. Report of investigations/1994

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

Tweeton, D.R.; Hanson, J.C.; Friedel, M.J.

1994-01-01

The U.S. Bureau of Mines, the University of Arizona, Sandia National Laboratory, and Zonge Engineering and Research, Inc., conducted cooperative field tests of six electromagnetic geophysical methods to compare their effectiveness in locating a brine solution simulating in situ leach solution or a high-conductivity plume of contamination. The brine was approximately 160 meters below the surface. The test site was the University's San Xavier experimental mine near Tucson, Arizona. Geophysical surveys using surface and surface-borehole time-domain electromagnetics (TEM), surface controlled source audio-frequency magnetotellurics (CSAMT), surface-borehole frequency-domain electromagnetics (FEM), crosshole FEM and surface magnetic field ellipticity were conducted before and duringmore » brine injection.« less

An automatic audio-magnetotelluric equipment, controlled by microprocessor, for the telesurvellance of the volcano Momotombo (Nicaragua)

NASA Astrophysics Data System (ADS)

Clerc, G.; Décriaud, J.-P.; Doyen, G.; Halbwachs, M.; Henrotte, M.; Rémy, J.; Zhang, X.-C.

1984-07-01

A campaign of audio-magnetotelluric soundings in the crater of Momotombo has shown that the structure of this volcano is suitable to a surveillance by this method; it has an only central activity, and the resistivity versus the depth decreases suddenly at least 100 times at about 270 m. So, this technical paper describes the equipment designed and built in order to measure every 2 hr the apparent resistivity in a given direction, at seven frequencies regularly spaced from 5 to 312 Hz. The data are preprocessed to fill only 32 bytes: they are - on the one hand, printed locally for the close surveillance; - on the other hand, transmitted by an ARGOS platform and received in Garchy via satellite for searching studies

Audio-magnetotelluric data collected in the area of Beatty, Nevada

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

Williams, J.M.

1998-11-01

In the summer of 1997, electrical geophysical data was collected north of Beatty, Nevada. Audio-magnetotellurics (AMT) was the geophysical method used to collect 16 stations along two profiles. The purpose of this data collection was to determine the depth to the alluvial basement, based upon the needs of the geologists requesting the data.

An evaluation of the applicability of the telluric-electric and audio-magnetotelluric methods to mineral assessment on the Arabian Shield, Kingdom of Saudi Arabia

USGS Publications Warehouse

Flanigan, Vincent J.; Zablocki, Charles J.

1984-01-01

Feasibility studies of two electromagnetic methods were made in selected areas of the Jabal Hibshi (1:250,000) quadrangle, 26F, in the Kingdom of Saudi Arabia in March of 1983. The methods tested were the natural source-field telluricelectric and audio-magnetotelluric methods developed and extensively used in recent years by the U.S. Geological Survey in some of its domestic programs related to geothermal and mineral resource assessment. Results from limited studies in the Meshaheed district, the Jabal as Silsilah ring complex, and across a portion of the Raha fault zone clearly demonstrate the appropriateness of these sub-regional scale, reconnaissance-type studies to mineral resource assessment. The favorable results obtained are largely attributed to distinctive and large contrasts in the electrical resistivity of the major rock types encountered. It appears that the predominant controlling factor governing the rock resistivities is the amount of contained clay minerals. Accordingly, unaltered (specifically, non-argillic) igneous and metamorphic rocks have very high resistivities; metasedimentary rocks of the Murdama group that contain several percent clay minerals have intermediate values of resistivity; and highly altered rocks, containing abundant clay minerals, have very low values of resistivity. Water-filled fracture porosity may be a secondary, but important, factor in some settings. However, influences from variations in interstitial or intercrystalline, water-filled porosity are probably small because these types of porosity are generally low. It is reasonable to expect similar results in other areas within the Arabian Shield.

Audiomagnetotelluric data to characterize the Revett-type copper-silver deposits at Rock Creek in the Cabinet Mountains Wilderness, Montana

USGS Publications Warehouse

Sampson, Jay A.; Rodriguez, Brian D.

2011-01-01

The Revett-type deposits at Rock Creek are part of the concealed stratabound copper-silver deposits located in the Cabinet Mountains Wilderness of Montana. The U.S. Geological Survey is conducting a series of multidisciplinary studies as part of the Assessment Techniques for Concealed Mineral Resources project. Geologic, geochemical, geophysical, and mineral resources data are being evaluated with existing and new mineral deposit models to predict the possibility and probability of undiscovered deposits in covered terranes. To help characterize the size, resistivity, and depth of the mineral deposit concealed beneath thick overburden, a regional southwest-northeast audiomagnetotelluric sounding profile was acquired. Further studies will attempt to determine if induced polarization parameters can be extracted from the magnetotelluric data to determine the size of the mineralized area. The purpose of this report is to release the audiomagnetotelluric sounding data collected along that southwest-northeast profile. No interpretation of the data is included.

Electromagnetic outline of the Solfatara-Pisciarelli hydrothermal system, Campi Flegrei (Southern Italy)

NASA Astrophysics Data System (ADS)

Troiano, A.; Di Giuseppe, M. G.; Patella, D.; Troise, C.; De Natale, G.

2014-05-01

We describe the results from a combined controlled source audio magnetotelluric (CSAMT) and natural source magnetotelluric (MT) survey carried out in the Solfatara-Pisciarelli (S-P) area, located in the central part of the Campi Flegrei (CF) composite caldera, west of Naples, Southern Italy. The S-P area represents the most active zone within the CF caldera, in terms of hydrothermal manifestations and local seismicity. Since 1969, the CF caldera is experiencing ground deformation, seismicity and geochemical fluid changes, which are particularly evident in the S-P area. A 1 km long, nearly W-E directed CSAMT-MT profile crossing the fumarole field was carried out in the S-P area with the aim of deducting a resistivity model of the structural setting of the hydrothermal system in the first 3 km depth. An interpretation of the modelled section across the profile is given in this paper, taking advantage from already existing seismic, gravity and geochemical data in the same area. Three well distinct zones have been outlined. The first zone is a very shallow, electrically conductive body localized beneath the westernmost segment of the profile, which, within a short distance of about 100 m, dips westwards from near surface down to some hundred metres in depth. Mostly accounting for the very low resistivity (1-10 Ω m) and the exceedingly high values of vP/vS (> 4), this shallow zone has been ascribed to a water-saturated, high-pressurized geothermal reservoir. The second zone, which has been localized below the west-central portion of the CSAMT-MT transect, appears as a composite body made up of a nearly vertical plumelike structure that escapes at about 2.25 km depth from the top edge of the east side of a presumably horizontal platelike body. The plumelike structure rises up to the free surface in correspondence of the fumarole field, whereas the platelike structure deepens at least down to the 3 km of maximum exploration depth. The combined interpretation of resistivity (50-100 Ω m), body wave velocity ratio (vP/vS < 2.0), mass density contrast (Δσ < 0 g/cm3), and geochemical data indicates that the plumelike portion can likely be associated with a steam/gas-saturated column and the platelike portion with a high temperature (> 300 °C), over-pressurized, gas-saturated reservoir. Finally, the third zone, which has been localized beneath the eastern half of the transect, from about 1.2 km down to about 3 km of depth, is also characterized by very low resistivity values (1-10 Ω m). Jointly interpreted with seismic (vP/vS < 1.73) and gravity (⨂⌠ > 0 g/cm3) data, this last electrically conductive structure appears to be associated with a hydrothermally mineralized, clay-rich body.

Structural controls on ground-water conditions and estimated aquifer properties near Bill Williams Mountain, Williams, Arizona

USGS Publications Warehouse

Pierce, Herbert A.

2001-01-01

As of 1999, surface water collected and stored in reservoirs is the sole source of municipal water for the city of Williams. During 1996 and 1999, reservoirs reached historically low levels. Understanding the ground-water flow system is critical to managing the ground-water resources in this part of the Coconino Plateau. The nearly 1,000-meter-deep regional aquifer in the Redwall and Muav Limestones, however, makes studying or utilizing the resource difficult. Near-vertical faults and complex geologic structures control the ground-water flow system on the southwest side of the Kaibab Uplift near Williams, Arizona. To address the hydrogeologic complexities in the study area, a suite of techniques, which included aeromagnetic, gravity, square-array resistivity, and audiomagnetotelluric surveys, were applied as part of a regional study near Bill Williams Mountain. Existing well data and interpreted geophysical data were compiled and used to estimate depths to the water table and to prepare a potentiometric map. Geologic characteristics, such as secondary porosity, coefficient of anisotropy, and fracture-strike direction, were calculated at several sites to examine how these characteristics change with depth. The 14-kilometer-wide, seismically active northwestward-trending Cataract Creek and the northeastward-trending Mesa Butte Fault systems intersect near Bill Williams Mountain. Several north-south-trending faults may provide additional block faulting north and west of Bill Williams Mountain. Because of the extensive block faulting and regional folding, the volcanic and sedimentary rocks are tilted toward one or more of these faults. These faults provide near-vertical flow paths to the regional water table. The nearly radial fractures allow water that reaches the regional aquifer to move away from the Bill Williams Mountain area. Depth to the regional aquifer is highly variable and depends on location and local structures. On the basis of interpreted audiomagnetotelluric and square-array resistivity sounding curves and limited well data, depths to water may range from 450 to 1,300 meters.

Geophysical Electromagnetic Sounding Using HAARP

DTIC Science & Technology

2002-03-01

apparent resistivity vs. frequency can be converted into true resistivity vs. depth, This grant involved an investigation into the HAARP virtual antenna pattern out to 200 km, and its use as a CSAMT transmitter.

Test research of Surface Electromagnetic Prospecting (SEP) System in Yang-jia-zhang-zi of Liao Ning province

NASA Astrophysics Data System (ADS)

Di, Q.

2013-12-01

In recent years, deep prospecting method such as magnetotelluric and controlled source audio-frequency magnetotelluric develop rapidly, but the instruments almost monopolized by several big geophysical companies from the United States, Canada and Germany. From prospecting practice, foreign equipment adaptation on complicated geological conditions in China is unsatisfactory. As increasing of national strength, electromagnetic exploration system development independently is on the agenda. In the year of 2010, the institute of geology and geophysics, Chinese academy of sciences, took on one subject of the SinoProbe project, the research of surface Electromagnetic Prospecting (SEP) System, and has achieved some achievements. SEP is an independent research instrumentation system, which is available for MT, AMT and CSAMT soundings. After laboratory testing, in order to test SEP's performance in field, the yang-jia-zhang-zi molybdenum deposit area is selected for SEP experiment. All modules and components of SEP system have been tested, and the field ability of the whole system also has been tested. The experimental results show that SEP performance has reached the level of commercial instruments.

The potential of audiomagnetotellurics in the study of geothermal fields: A case study from the northern segment of the La Candelaria Range, northwestern Argentina

NASA Astrophysics Data System (ADS)

Barcelona, Hernan; Favetto, Alicia; Peri, Veronica Gisel; Pomposiello, Cristina; Ungarelli, Carlo

2013-01-01

Despite its reduced penetration depth, audiomagnetotelluric (AMT) studies can be used to determine a broad range of features related to little studied geothermal fields. This technique requires a stepwise interpretation of results taking into consideration diverse information (e.g. topographic, hydrological, geological and/or structural data) to constrain the characteristics of the study area. In this work, an AMT study was performed at the hot springs in the northern segment of the La Candelaria Range in order to characterize the area at depth. Geometric aspects of the shallow subsurface were determined based on the dimensional and distortion analysis of the impedance tensors. Also, the correlation between structural features and regional strikes allowed us to define two geoelectric domains, useful to determine the controls on fluid circulation. The subsurface resistivity distribution was determined through 1D and 2D models. The patterns of the 1D models were compared with the morpho-structure of the range. Shallow and deep conductive zones were defined and a possible shallow geothermal system scheme proposed. A strong correlation was found between the AMT results and the geological framework of the region, showing the relevance of using AMT in geothermal areas during the early stages of subsurface prospecting.

Magnetotelluric and Audio-magnetotelluric measurements in Alasehir Graben for geothermal exploration purposes

NASA Astrophysics Data System (ADS)

Tekesin-Cankurtaranlar, Ozge; Tuysuz, Okan; Riza Kilic, Ali

2017-04-01

In this study, we present the results of Magnetotelluric (MT) and Audio-magnetotelluric (AMT) soundings over a potential geothermal field. Study area is located in the northeasternmost part of the Alasehir (or Gediz) Graben, Western Anatolia, which is delimited by NW-SE trending fault systems and is filled by Miocene to Recent sediments. Study area is also very close to the Kula Quaternary volcanic region, a possible geothermal heat source for the region, last eruption of which was 12.000 years ago. Relatively thin crust, high heat flow values and intense tectonic activity of the Western Anatolia possibly refers to the high geothermal potential. In fact, along the southern and central part of the graben there are many productive areas reaching up to 300 degrees Celsius. By this motivation, to determine the geothermal potential of the study area MT and AMT measurements had been carried out on a total of 45 stations covering about 8 km2 area. All profiles shows higher resistivity values (>140 ohm.m) at greater depths, possibly indicating a metamorphic basement covered by Miocene to Recent sediments. This metamorphic basement gets shallower towards the North where the geothermally weathered schists and marbles crop out. Furthermore, a normal fault interface between metamorphic basement and Neogene sediments shows high resistivity contrast. Results indicate that the metamorphic basement is a less conductive block located at a depth of 1500 - 2000 m at the south and gets shallower towards the north as normal fault blocks.

Understanding the relationship between audiomagnetotelluric data and models, and borehole data in a hydrological environment

USGS Publications Warehouse

McPhee, D.K.; Pellerin, L.

2008-01-01

Audiomagnetotelluric (AMT) data and resulting models are analyzed with respect to geophysical and geological borehole logs in order to clarify the relationship between the two methodologies of investigation of a hydrological environment. Several profiles of AMT data collected in basins in southwestern United States are being used for groundwater exploration and hydrogeological framework studies. In a systematic manner, the AMT data and models are compared to borehole data by computing the equivalent one-dimensional AMT model and comparing with the two-dimensional (2-D) inverse AMT model. The spatial length is used to determine if the well is near enough to the AMT profile to quantify the relationship between the two datasets, and determine the required resolution of the AMT data and models. The significance of the quality of the borehole data when compared to the AMT data is also examined.

Three-dimensional inversion of magnetotelluric data for mineral exploration: An example from the McArthur River uranium deposit, Saskatchewan, Canada

NASA Astrophysics Data System (ADS)

Farquharson, Colin G.; Craven, James A.

2009-08-01

Shallow exploration targets are becoming scarce, meaning interest is turning towards deeper targets. The magnetotelluric method has the necessary depth capability, unlike many of the controlled-source electromagnetic prospecting techniques traditionally used. The geological setting of ore deposits is usually complex, requiring three-dimensional Earth models for their representation. An example of the applicability of three-dimensional inversion of magnetotelluric data to mineral exploration is presented here. Inversions of an audio-magnetotelluric data-set from the McArthur River uranium mine in the Athabasca Basin were carried out. A sub-set comprising data from eleven frequencies distributed over almost three decades was inverted. The form of the data used in the inversion was impedance. All four elements of the tensor were included. No decompositions of the data were done, nor rotation to a preferred strike direction, nor correction for static shifts. The inversions were successful: the observations were adequately reproduced and the main features in the conductivity model corresponded to known geological features. These included the graphitic basement fault along which the McArthur River uranium deposit is located.

Audiomagnetotelluric exploration across the Waíanae Range, Óahu, Hawaíi

NASA Astrophysics Data System (ADS)

Sigurdardottir, T. D.; Thomas, D. M.; Wallin, E.; Winchester, C.; Sinton, J. M.

2015-12-01

The audiomagnetotelluric (AMT) method is capable of providing direct evidence of a geothermal resource within the extinct Waíanae volcano, Óahu, Hawaíi. Geothermal systems are becoming an increasingly important energy source worldwide. With electric energy costs in Hawaíi the most expensive in the US (30.54 cents/kWh), it is important to investigate the potential of local geothermal resources. Slightly elevated temperature and chloride concentrations, measured in the 1970's at wells in the upper Lualualei Valley indicate the possibility of a geothermal resource. Previous geophysical investigations: self-potential, rotating quadripole resistivity, and shallow soil temperature surveys in the caldera measured low resistivity values. Resistivity is related to rock characteristics (e.g., porosity, saturation, salinity, temperature, chemistry, and the presence of weathered minerals). We are investigating the area further using the AMT method. We have collected profiles of AMT measurements across the Lualualei Valley and the Waíanae caldera boundary. Anthropogenic noise and access in this area is problematic. Electrical noise, originating from power lines along roads and very low frequency radio towers in the vicinity, add noise to the data. Limited access to sites on military lands inhibit data collection. However, preliminary results show that we have successfully imaged the expected higher resistivity values as our profiles cross the mountains bounding the caldera. As data continue to be collected across the Waíanae Caldera and Range and we begin modeling our data in two dimensions, we expect to be able to identify water table elevations, detect lateral variability between salt and fresh water saturation, estimate thickness of the freshwater lens and depth to the transition zone, image fault structures at the caldera boundary, and with enough sensitivity to conductivity, we can identify regions of elevated temperature.

The Noise Level Optimization for Induction Magnetometer of SEP System

NASA Astrophysics Data System (ADS)

Zhu, W.; Fang, G.

2011-12-01

The Surface Electromagnetic Penetration (SEP) System, subsidized by the SinoProbe Plan in China, is designed for 3D conductivity imaging in geophysical mineral exploration, underground water distribution exploration, oil and gas reservoir exploration. Both the Controlled Source Audio Magnetotellurics (CSAMT) method and Magnetotellurics (MT) method can be surveyed by SEP system. In this article, an optimization design is introduced, which can minimize the noise level of the induction magnetometer for SEP system magnetic field's acquisition. The induction magnetometer transfers the rate of the magnetic field's change to voltage signal by induction coil, and amplified it by Low Noise Amplifier The noise parts contributed to the magnetometer are: the coil's thermal noise, the equivalent input voltage and current noise of the pre-amplifier. The coil's thermal noise is decided by coil's DC resistance. The equivalent input voltage and current noise of the pre-amplifier depend on the amplifier's type and DC operation condition. The design here optimized the DC operation point of pre-amplifier, adjusted the DC current source, and realized the minimum of total noise level of magnetometer. The calculation and test results show that: the total noise is about 1pT/√Hz, the thermal noise of coils is 1.7nV/√Hz, the preamplifier equivalent input voltage and current noise is 3nV/ √Hz and 0.1pA/√Hz, the weight of the magnetometer is 4.5kg and meet the requirement of SEP system.

Evaluation of geophysical techniques for the detection of paleochannels in the Oakland area of eastern Nebraska as part of the Eastern Nebraska Water Resource Assessment

USGS Publications Warehouse

Abraham, Jared D.; Bedrosian, Paul A.; Asch, Theodore H.; Ball, Lyndsay B.; Cannia, James C.; Phillips, Jeffery D.; Lackey, Susan

2012-01-01

Surface audio-magnetotelluric and time-domain electromagnetic methods achieved sufficient depth of penetration and indicated that the paleochannel was much more complex than the original geological model. Simulated and observed gravity anomalies indicate that imaging sand and gravel aquifers near Oakland, Nebraska, would be difficult due to the complex basement density contrasts. Interpretation of the magnetic data indicates no magnetic sources from geologic units above the bedrock surface. Based upon the analysis and interpretation of the four methods evaluated, we suggest a large-scale survey using a high-powered time-domain airborne system. This is the most efficient and cost-effective path forward for the Eastern Nebraska Water Assessment group to map paleochannels that lie beneath thick clay-rich glacial tills.

Successful application of frequency-domain airborne electromagnetic system with a grounded electric source

NASA Astrophysics Data System (ADS)

Kang, L.; Lin, J.; Liu, C.; Zhou, H.; Ren, T.; Yao, Y.

2017-12-01

A new frequency-domain AEM system with a grounded electric source, which was called ground-airborne frequency-domain electromagnetic (GAFEM) system, was proposed to extend penetration depth without compromising the resolution and detection efficiency. In GAFEM system, an electric source was placed on the ground to enlarge the strength of response signals. UVA was chosen as aircraft to reduce interaction noise and improve its ability to adapt to complex terrain. Multi-source and multi-frequency emission method has been researched and applied to improve the efficiency of GAFEM system. 2n pseudorandom sequence was introduced as transmitting waveform, to ensure resolution and detection efficiency. Inversion-procedure based on full-space apparent resistivity formula was built to realize GAFEM method and extend the survey area to non-far field. Based on GAFEM system, two application was conducted in Changchun, China, to map the deep conductive structure. As shown in the results of this exploration, GAFEM system shows its effectiveness to conductive structure, obtaining a depth of about 1km with a source-receiver distance of over 6km. And it shows the same level of resolution with CSAMT method with an over 10 times of efficiency. This extended a range of important applications where the terrain is too complex to be accessed or large penetration depth is required in a large survey area.

Audiomagnetotelluric Data and Two-Dimensional Models from Spring, Snake, and Three Lakes Valleys, Nevada

USGS Publications Warehouse

McPhee, Darcy K.; Chuchel, Bruce A.; Pellerin, Louise

2007-01-01

Audiomagnetotelluric (AMT) data along thirteen profiles in Spring, Snake, and Three Lakes Valleys, and the corresponding two-dimensional (2-D) inverse models, are presented. The AMT method is a valuable tool for estimating the electrical resistivity of the Earth over depth ranges of a few meters to roughly one kilometer. It is important for revealing subsurface structure and stratigraphy within the Basin and Range province of eastern Nevada that can be used to define the geohydrologic framework of the region. We collected AMT data using the Geometrics StrataGem EH4 system. Profiles were 1.2 to 4.6 km in length with station spacing of 100-400 m. Data were recorded in a coordinate system parallel to and perpendicular to the assumed regional geologic strike direction. We show station locations, sounding curves of apparent resistivity, phase, and coherency, and 2-D models. The 2-D inverse models are computed from the transverse electric (TE), transverse magnetic (TM), and TE+TM mode data using the conjugate gradient, finite-difference method of Rodi and Mackie (2001). Preliminary interpretation of these models defines the structural framework of the basins and the resistivity contrasts between alluvial basin-fill, volcanic units, and carbonate/clastic rocks.

Numerical Simulation of Response Characteristics of Audio-magnetotelluric for Gas Hydrate in the Qilian Mountain Permafrost, China

NASA Astrophysics Data System (ADS)

Xiao, Kun; Zou, Changchun; Yu, Changqing; Pi, Jinyun

2015-10-01

Audio-magnetotelluric (AMT) method is a kind of frequency-domain sounding technique, which can be applied to gas hydrate prospecting and assessments in the permafrost region due to its high frequency band. Based on the geological conditions of gas hydrate reservoir in the Qilian Mountain permafrost, by establishing high-resistance abnormal model for gas hydrate and carrying out numerical simulation using finite element method (FEM) and nonlinear conjugate gradient (NLCG) method, this paper analyzed the application range of AMT method and the best acquisition parameters setting scheme. When porosity of gas hydrate reservoir is less than 5%, gas hydrate saturation is greater than 70%, occurrence scale is less than 50 m, or bury depth is greater than 500 m, AMT technique cannot identify and delineate the favorable gas hydrate reservoir. Survey line should be more than twice the length of probable occurrence scale, while tripling the length will make the best result. The number of stations should be no less than 6, and 11 stations are optimal. At the high frequency section (10˜1000 Hz), there should be no less than 3 frequency points, 4 being the best number.

An audio-magnetotelluric investigation in Terceira Island (Azores)

NASA Astrophysics Data System (ADS)

Monteiro Santos, Fernando A.; Trota, António; Soares, António; Luzio, Rafael; Lourenço, Nuno; Matos, Liliana; Almeida, Eugénio; Gaspar, João L.; Miranda, Jorge M.

2006-08-01

Ten audio-magnetotelluric soundings have been carried out along a profile crossing the Serra do Cume caldera in the eastern part of the Terceira Island (Azores). The main objectives of this investigation were to detect geoelectrical features related with tectonic structures and to characterize regional hydrological and hydrothermal aspects mainly those related to geothermal fluid dynamics. Three-dimensional numerical investigation showed that the data acquired at periods shorter than 1 s are not significantly affected by ocean effect. The data was analysed using the Smith's decomposition method in order to investigate possible distortions caused by superficial structures and to estimate a global regional strike. The results suggest that in general the soundings were not distorted. A regional N55°W strike was chosen for the two-dimensional data inversion. The low-resistivity zones (10-30 ohm-m) displayed in the central part of the 2-D geoelectrical model have been interpreted as caused by hydrothermal circulation. The low-resistivity anomalies at the ends of the profile might be attributed to alteration zones with interaction of seawater intrusion. High-resistivity (> 300 ohm-m) values have been related with less permeable zones in the SW of Cinco Picos and Guilherme Moniz caldera walls.

Identification the geothermal system using 1-D audio-magnetotelluric inversion in Lamongan volcano field, East Java, Indonesia

NASA Astrophysics Data System (ADS)

Ilham, N.; Niasari, S. W.

2018-04-01

Tiris village, Probolinggo, East Java, is one of geothermal potential areas in Indonesia. This area is located in a valley flank of Mount Lamongan and Argopuro volcanic complex. This research aimed to identify a geothermal system at Tiris area, particularly the fluid pathways. The geothermal potential can be seen from the presence of warm springs with temperature ranging 35-45°C. The warm spring locations are aligned in the same orientation with major fault structure in the area. The fault structure shows dominant northwest-southeast orientation. We used audio-magnetotelluric data in the frequency range of 10 Hz until 92 kHz. The total magnetotelluric sites are 6. From the data analysis, most of the data orientation were 2-D with geo-electrical direction north-south. We used 1-D inversion using Newton algorithm. The 1-D inversion resulted in low resistive anomaly that corresponds to Lamongan lavas. Additionally, the depth of the resistor are different between the area to the west (i.e. 75 m) and to the east (i.e. 25 m). This indicates that there is a fault around the aligned maar (e.g. Ranu Air).

Characterization of the Highway 95 Fault in lower Fortymile Wash using electrical and electromagnetic methods, Nye County, Nevada

USGS Publications Warehouse

Macy, Jamie P.; Kryder, Levi; Walker, Jamieson

2012-01-01

Coordinated application of electrical and electromagnetic geophysical methods provided better characterization of the Highway 95 Fault. The comparison of dipole-dipole resistivity, TEM, and CSAMT data confirm faulting of an uplifted block of resistive Paleozoic Carbonate that lies beneath a more conductive sandstone unit. A more resistive alluvial basin-fill unit is found above the sandstone unit, and it constitutes only about 150 m of the uppermost subsurface.

The Characteristics of Electromagnetic Fields Induced by Different Type Sources

NASA Astrophysics Data System (ADS)

Di, Q.; Fu, C.; Wang, R.; Xu, C.; An, Z.

2011-12-01

Controlled source audio-frequence magnetotelluric (CSAMT) method has played an important role in the shallow exploration (less than 1.5km) in the field of resources, environment and engineering geology. In order to prospect the deeper target, one has to increase the strength of the source and offset. However, the exploration is nearly impossible for the heavy larger power transmitting source used in the deeper prospecting and mountain area. So an EM method using a fixed large power source, such as long bipole current source, two perpendicular "L" shape long bipole current source and large radius circle current source, is beginning to take shape. In order to increase the strength of the source, the length of the transmitting bipole in one direction or in perpendicular directions has to be much larger, such as L=100km, or the radius of the circle current source is much larger. The electric field strength are IL2and IL2/4π separately for long bipole source and circle current source with the same wire length. Just considering the effectiveness of source, the strength of the circle current source is larger than that of long bipole source if is large enough. However, the strength of the electromagnetic signal doesn't totally depend on the transmitting source, the effect of ionosphere on the electromagnetic (EM) field should be considered when observation is carried at a very far (about several thousands kilometers) location away from the source for the long bipole source or the large radius circle current source. We firstly calculate the electromagnetic fields with the traditional controlled source (CSEM) configuration using the integral equation (IE) code developed by our research group for a three layers earth-ionosphere model which consists of ionosphere, atmosphere and earth media. The modeling results agree well with the half space analytical results because the effect of ionosphere for this small scale source can be ignorable, which means the integral equation method is reliable and effective for modeling models including ionosphere, atmosphere and earth media. In order to discuss EM fields' characters for complicate earth-ionosphere media excited by long bipole, "L" shape bipole and circle current sources in the far-field and wave-guide zones, we modeled the frequency responses and decay characters of EM fields for three layers earth-ionosphere model. Because of the effect of ionosphere, the earth-ionosphere electromagnetic fields' decay curves with given frequency show that the fields of Ex and Hy , excited by a long bipole and "L" shape bipole, can be divided into an extra wave-guide field with slower attenuation and strong amplititude than that in half space, but the EM fields of circle current source does not show the same characteristics, ionosphere makes the amplitude of the EM field weaker for the circle current source. For this reason, it is better to use long bipole source while working in the wave-guide field with a fixed large power source.

Audiomagnetotelluric Data and Preliminary Two-Dimensional Models from Spring, Dry Lake, and Delamar Valleys, Nevada

USGS Publications Warehouse

McPhee, Darcy K.; Chuchel, Bruce A.; Pellerin, Louise

2008-01-01

This report presents audiomagnetotelluric (AMT) data along fourteen profiles in Spring, Delamar, and Dry Lake Valleys, and the corresponding preliminary two-dimensional (2-D) inverse models. The AMT method is a valuable tool for estimating the electrical resistivity of the Earth over depth ranges from a few meters to less than one kilometer, and it is important for revealing subsurface structure and stratigraphy within the Basin and Range province of eastern Nevada, which can be used to define the geohydrologic framework of the region. We collected AMT data by using the Geometrics StrataGem EH4 system. Profiles were 0.7 - 3.2 km in length with station spacing of 50-400 m. Data were recorded in a coordinate system parallel to and perpendicular to the regional geologic-strike direction with Z positive down. We show AMT station locations, sounding curves of apparent resistivity, phase, and coherency, and 2-D models of subsurface resistivity along the profiles. The 2-D inverse models are computed from the transverse electric (TE), transverse magnetic (TM), and TE+TM mode data by using a conjugate gradient, finite-difference method. Preliminary interpretation of the 2-D models defines the structural framework of the basins and the resistivity contrasts between alluvial basin-fill, volcanic units, and carbonate basement rocks.

2D joint inversion of dc and scalar audio-magnetotelluric data in the evaluation of low enthalpy geothermal fields

NASA Astrophysics Data System (ADS)

Monteiro Santos, Fernando A.; Afonso, António R. Andrade; Dupis, André

2007-03-01

Audio-magnetotelluric (AMT) and resistivity (dc) surveys are often used in environmental, hydrological and geothermal evaluation. The separate interpretation of those geophysical data sets assuming two-dimensional models frequently produces ambiguous results. The joint inversion of AMT and dc data is advocated by several authors as an efficient method for reducing the ambiguity inherent to each of those methods. This paper presents results obtained from the two-dimensional joint inversion of dipole-dipole and scalar AMT data acquired in a low enthalpy geothermal field situated in a graben. The joint inverted models show a better definition of shallow and deep structures. The results show that the extension of the benefits using joint inversion depends on the number and spacing of the AMT sites. The models obtained from experimental data display a low resistivity zone (<20 Ω m) in the central part of the graben that was correlated with the geothermal reservoir. The resistivity distribution models were used to estimate the distribution of the porosity in the geothermal reservoir applying two different approaches and considering the clay minerals effect. The results suggest that the maximum porosity of the reservoir is not uniform and might be in the range of 12% to 24%.

Audio-magnetotelluric investigation of allochthonous iron formations in the Archaean Reguibat shield (Mauritania): structural and mining implications

NASA Astrophysics Data System (ADS)

Bronner, G.; Fourno, J. P.

1992-11-01

The M'Haoudat range, considered as an allochthonous unit amid the strongly metamorphosed Archaean basement (Tiris Group), belongs to the Lower Proterozoic Ijil Group, weakly metamorphosed, constituted mainly by iron quartzites including red jaspers and high grade iron ore. Audio-magnetotelluric (AMT) soundings (frequency range 1-7500 HZ) were performed together with the systematic survey of the range (SNIM mining company). The non-linear least squares method was used to perform a smoothness-constrained data model. The obvious AMT resistivity contrasts between the M'Haoudat Unit (150-3500 ohm. m) and the Archaean basement (20 000 ohm. m) allow to state precisely that the two thrust surfaces, on both sides of the range, join together at a depth which increases from North-West to South-East, as the ore bodies. Inside the steeply dipping M'Haoudat Unit, the main beds of iron quartzites (1500-3500 ohm. m), schists (1000-1500 ohm. m) and hematite ores (150-300 ohm. m) were distinguished when their thickness exceeded 30 to 50 m. The existence of an hydrostatic level (1-50 ohm. m) and the steeply dipping architecture, very likely responsible for the lack of resistivity contrast on the upper part of some profiles, complicate the interpretation at high frequencies the thin layers being poorly defined.

Audio-magnetotelluric (AMT) study to investigate the genesis of Mujil hill

NASA Astrophysics Data System (ADS)

Rahmania, Suryanto, Wiwit

2017-07-01

Gunung Mujil is an isolated hill located near Pondoworejo village, Kalibawang sub-district, Kulon Progo district, and Special Province of Yogyakarta. The hill is part of the eastern Kulon Progo mountain range extended relatively in the North-South direction. The lithology of the hill consists of andesite breccia and it's similar with the Old Andesite Formation that built the Kulon Progo Mountains. There are at least two hypothesis about the genesis and the formation mechanism of this hill, (1) it was formed by debris mass from Kulon Progo Mountains, and (2) ) it was formed by an intrusion. Our study intended to determine the subsurface resistivity below the hill and to relating those results to with the scenario of the genesis of the Mujil hill. We conducted Audio-magnetotellurics (AMT) measurements along two lines survey crossing the Mujil hill consisting of 20 measurements. Since the measurements are located near the villages, most of the data has a fair to bad quality and only one station yielded an excellent data. A 1D Forward modeling was then applied to find best-fit model of the AMT data. The results shows that the Mujil hill was built by debris mass of the Old Andesite Formation from Kulon Progo mountain which is represented by a lower resistivity value under the Mujil hill.

Audio-magnetotelluric methods in reconnaissance geothermal exploration

USGS Publications Warehouse

Hoover, D.B.; Long, C.L.

1976-01-01

and 18 600 Hz where artificial VLF sources are available. As a reconnaissance technique we use AMT surveys in conjunction with regional gravity, magnetic, and telluric surveys. The exploration depth is a function of the resistivities of the lithologic section, but typically ranges from the surface to 0.2 km in low-resistivity areas and to greater than 2 km in high-resistivity regions. Results of the initial reconnaissance AMT surveys provide a rational basis for deciding on the extent of costlier follow-up surveys. As part of the U.S. Geological Survey geothermal program, surveys were conducted in Long Valley and Surprise Valley, California; the Vale, Ore-Weiser, Idaho region; and Bruneau-Grand View, Raft River, and Island Park regions of Idaho. AMT surveys in five additional known geothermal resource areas (KGRA's) have been scheduled for completion by May 1975. In the Raft River and Bruneau-Grand View regions and Long Valley, follow-up electrical surveys substantiated the effectiveness of the AMT technique for reconnaissance surveying.

High Resolution Audiomagnetotelluric Investigation of the Porosity at the Margin of the Hudson Bay Basin, Canada

NASA Astrophysics Data System (ADS)

Craven, J. A.; Roberts, B.

2012-12-01

Seismic exploration from 1968 to 1985 within the intracratonic Hudson Bay basin in northern Canada resulted in five dry wells drilled on a structural high in the central part of the basin (Hamblin, 2008). Recent work (Bertrand and Malo, 2012) has indicated successions at margins of the basin are well within the oil and gas "window". To test this conjecture a magnetotelluric (MT) survey was carried out in the vicinity of Churchill, Manitoba, at the margin of the basin. The primary goal of the survey was to identify potential source or reservoir rocks in the Upper Ordovician section of the Palaeozoic strata. MT surveys have been utilized in the northeastern portion of the Williston basin and have successfully imaged lower Palaeozoic carbonate units (Gowan et al., 2009). The MT method provides information on the electrical conductivity of the subsurface though the measurement of the natural time-varying electric and magnetic fields at the surface. Due to the dependence of the depth of investigation of the fields on their frequency, an estimate of conductivity variation with depth can be attained. A total of 46 high frequency audio-magnetotelluric (AMT) sites were collected, 38 along one approximately N-S corridor perpendicular to the coastline and 8 in a more E-W direction closer to the town of Churchill. Simultaneous collection of broadband MT data (BBMT) at a limited number of sites was done in order to calculate a response function over a wider range of frequencies at each AMT site. The combined AMT and BBMT MT data have been edited and processed to produce response functions at all sites, and 1-D modelling has provided resistivity vs. depth curves in the top 200 m of the basin. The 1-D models have been stitched together to create a continuous, approximately N-S resistivity section. In addition, the data have been input to a 3D inversion program and preliminary 3D resistivity and conductivity volumes have been generated along with an estimate of 3-D porosity variations to a depth of approximately 200 m.

Monitoring electrical properties for improving the lithological and hydrological characterization of landslides

NASA Astrophysics Data System (ADS)

Malet, J. P.; Gance, J.; Lajaunie, M.; Gallistl, J.; Denchik, N.; Flores Orozco, A.; Ottowitz, D.; Supper, R.; Sailhac, P.; Gautier, S.; Schmutz, M.

2017-12-01

Imaging water flows in landslides is of critical importance as the distribution of pore-fluid pressures controls the dynamics (acceleration, deceleration) of the material. Detecting and imaging water is a difficult task, not only because of the complex topography and the small dimensions of the geological structures, but also because the landslide material consists of unsaturated porous and heterogeneous fractured media, leading to multi-scale water-flow properties. Further, these properties can change in time, in relation to temperature, rainfall and biological forcings. Electrical properties are relevant proxies of the sub-surface hydrological properties. In order to image water in landslide bodies, we propose to combine multi-frequency electrical and electromagnetic measurements using campaigns or permanent instruments, and surface/boreole investigations, installed on several unstable slopes in France. To evaluate the information gained from electrical properties for different geological conditions, we discuss electrical and electro-magnetic imaging results for data collected at four different landslides located in France (Super-Sauze and La Valette in the South East Alps, Lodève lin the southern border of the Massif Central Massif, and Séchilienne in the North French Alps). Time-lapse electrical DC resistivity observations, complex electrical conductivity (conduction and polarization/chargeability) measured by IP imaging methods, and controlled-source electromagnetic (CS-AMT) methods are discussed. Imaging results demonstrate an improved lithological characterization of the landslide structures (delineation of the sliding planes, identification of the fractures, discrimination of clay lenses with enhanced resolution); further, water infiltration within the soil matrix and/or the fractures is discriminated allowing better modelling of the hydrological regime of the landslides at the slope scale. This research is conducted in the frame of the project HYDROSLIDE - Hydrogeophysical Monitoring of Clay-Rich Landslides funded by the Austrian Science Fund (FWF) and the French Research Agency (ANR).

Mount St. Helens: Controlled-source audio-frequency magnetotelluric (CSAMT) data and inversions

USGS Publications Warehouse

Wynn, Jeff; Pierce, Herbert A.

2015-01-01

The apparent conductivity (or its inverse, apparent resistivity) measured by a geoelectrical system is caused by several factors. The most important of these are water-filled rock porosity and the presence of water-filled fractures; however, rock type and minerals (for instance, sulfides and clay content) also contribute to apparent conductivity. In situations with little recharge (for instance, in arid regions), variations in ionic content of water occupying pore space and fractures sampled by the measurement system must also be factored in (Wynn, 2006). Variations in ionic content may also be present in hydrothermal fluids surrounding volcanoes in wet regions. In unusual cases, temperature may also affect apparent conductivity (Keller, 1989; Palacky, 1989). There is relatively little hydrothermal alteration (and thus fewer clay minerals that might add to the apparent conductivity) in the eruptive products of Mount St. Helens (Reid and others, 2010), so conductors observed in the Fischer, Occam, and Marquardt inversion results later in this report are thus believed to map zones with significant water content. Geoelectrical surveys thus have the potential to reveal subsurface regions with significant groundwater content, including perched and regional aquifers. Reid and others (2001) and Reid (2004) have suggested that groundwater involvement may figure in both the scale and the character of some if not all volcanic edifice collapse events. Ongoing research by the U.S. Geological Survey (USGS) and others aims to better understand the contribution of groundwater to both edifice pore pressure and rock alteration as well as its direct influence on eruption processes by violent interaction with magma (Schmincke, 1998).

Applications of three-dimensional modeling in electromagnetic exploration

NASA Astrophysics Data System (ADS)

Pellerin, Louise Donna

Numerical modeling is used in geophysical exploration to understand physical mechanisms of a geophysical method, compare different exploration techniques, and interpret field data. Exploring the physics of a geophysical response enhances the geophysicist's insight, resulting in better survey design and interpretation. Comparing exploration methods numerically can eliminate the use of a technique that cannot resolve the exploration target. Interpreting field data to determine the structure of the earth is the ultimate goal of the exploration geophysicist. Applications of three-dimensional (3-D) electromagnetic (EM) modeling in mining, geothermal and environmental exploration demonstrate the importance of numerical modeling as a geophysical tool. Detection of a confined, conductive target with a vertical electric source (VES) can be an effective technique if properly used. The vertical magnetic field response is due solely to multi-dimensional structures, and current channeling is the dominant mechanism. A VES is deployed in a bore hole, hence the orientation of the hole is critical to the response. A deviation of more than a degree from the vertical can result in a host response that overwhelms the target response. Only the in-phase response at low frequencies can be corrected to a purely vertical response. The geothermal system studied consists of a near-surface clay cap and a deep reservoir. The magnetotelluric (MT), controlled-source audio magnetotelluric (CSAMT), long-offset time-domain electromagnetic (LOTEM) and central-loop transient electromagnetic (TEM) methods are appraised for their ability to detect the reservoir and delineate the cap. The reservoir anomaly is supported by boundary charges and therefore is detectable only with deep sounding electric field measurement MT and LOTEM. The cap is easily delineated with all techniques. For interpretation I developed an approximate 3-D inversion that refines a 1-D interpretation by removing lateral distortions. An iterative inverse procedure invokes EM reciprocity while operating on a localized portion of the survey area thereby greatly reducing the computational requirements. The scheme is illustrated with three synthetic data sets representative of problems in environmental geophysics.

A practical, low-noise coil system for magnetotellurics

USGS Publications Warehouse

Stanley, William D.; Tinkler, Richard D.

1983-01-01

Magnetotellurics is a geophysical technique which was developed by Cagnaird (1953) and Tikhonov (1950) and later refined by other scientists worldwide. The technique is a method of electromagnetic sounding of the Earth and is based upon the skin depth effect in conductive media. The electric and magnetic fields arising from natural sources are measured at the surface of the earth over broad frequency bands. An excellent review of the technique is provided in the paper by Vozoff (1972). The sources of the natural fields are found in two basic mechanisms. At frequencies above a few hertz, most of the energy arises from lightning in thunderstorm belts around the equatorial regions. This energy is propagated in a wave-guide formed by the earthionospheric cavity. Energy levels are higher at fundamental modes for this cavity, but sufficient energy exists over most of the audio range to be useful for sounding at these frequencies, in which case the technique is generally referred to as audio-magnetotellurics or AMT. At frequencies lower than audio, and in general below 1 Hz, the source of naturally occuring electromagnetic energy is found in ionospheric currents. Current systems flowing in the ionosphere generate EM waves which can be used in sounding of the earth. These fields generate a relatively complete spectrum of electromagnetic energy that extends from around 1 Hz to periods of one day. Figure 1 shows an amplitude spectrum characteristic of both the ionospheric and lightning sources, covering a frequency range from 0.0001 Hz to 1000 Hz. It can be seen that there is a minimum in signal levels that occurs at about 1 Hz, in the gap between the two sources, and that signal level increases with a decrease in frequency.

Understanding hydrothermal circulation patterns at a low-enthalpy thermal spring using audio-magnetotelluric data: A case study from Ireland

NASA Astrophysics Data System (ADS)

Blake, Sarah; Henry, Tiernan; Muller, Mark R.; Jones, Alan G.; Moore, John Paul; Murray, John; Campanyà, Joan; Vozar, Jan; Walsh, John; Rath, Volker

2016-09-01

Kilbrook spring is a thermal spring in east-central Ireland. The temperatures in the spring are the highest recorded for any thermal spring in Ireland (maximum of 25 °C). The temperature is elevated with respect to average Irish groundwater temperatures (9.5-10.5 °C), and represents a geothermal energy potential, which is currently under evaluation. A multi-disciplinary investigation based upon an audio-magnetotelluric (AMT) survey, and hydrochemical analysis including time-lapse temperature and chemistry measurements, has been undertaken with the aims of investigating the provenance of the thermal groundwater and characterising the geological structures facilitating groundwater circulation in the bedrock. The three-dimensional (3-D) electrical resistivity model of the subsurface at Kilbrook spring was obtained by the inversion of AMT impedances and vertical magnetic transfer functions. The model is interpreted alongside high resolution temperature and electrical conductivity measurements, and a previous hydrochemical analysis. The hydrochemical analysis and time-lapse measurements suggest that the thermal waters have a relatively stable temperature and major ion hydrochemistry, and flow within the limestones of the Carboniferous Dublin Basin at all times. The 3-D resistivity model of the subsurface reveals a prominent NNW aligned structure within a highly resistive limestone lithology that is interpreted as a dissolutionally enhanced strike-slip fault, of Cenozoic age. The karstification of this structure, which extends to depths of at least 500 m directly beneath the spring, has provided conduits that facilitate the operation of a relatively deep hydrothermal circulation pattern (likely estimated depths between 560 and 1000 m) within the limestone succession of the Dublin Basin. The results of this study support the hypothesis that the winter thermal maximum and simultaneous increased discharge at Kilbrook spring is the result of rapid infiltration, heating and re-circulation of meteoric waters within this structurally controlled hydrothermal circulation system. This paper illustrates how AMT may be useful in a multi-disciplinary investigation of an intermediate-depth (100-1000 m), low-enthalpy, geothermal target, and shows how the different strands of inquiry from a multi-disciplinary investigation may be woven together to gain a deeper understanding of a complex hydrothermal system.

A "caliper" type of controlled-source, frequency-domain, electromagnetic sounding method

NASA Astrophysics Data System (ADS)

Zhang, W.; Lin, J.; Zhou, F.; Liu, C.; Chen, J.; Xue, K.; Liu, L.; Wu, Y.

2011-12-01

We developed a special measurement manner for controlled-source, frequency-domain, electromagnetic sounding method that can improve resolution and efficiency, called as "caliper". This manner is base on our array electromagnetic system DPS-I, which consists of 53 channels and can cover 2500 m survey line at one arrangement. There are several steps to apply this method. First, a rough measurement is carried out, using large dynamic range but sparse frequencies. The ratio of adjacent frequency is set to be 2 or 4. The frequency points cover the entire frequency band that is required according to the geological environment, and are almost equidistantly distributed at logarithmic axis. Receivers array are arranged in one or more survey lines to measure the amplitude and phase of electromagnetic field components simultaneously. After all frequency points for rough measurement are measured, data in each sub-receiver are transmitted to the controller and the apparent resistivity and phase are calculated in field quickly. Then the pseudo section diagrams of apparent resistivity and phase are drew. By the pseudo section we can roughly lock the abnormal zone and determine the frequency band required for detail investigation of abnormal zone. Next, the measurement using high density of frequencies in this frequency band is carried out, which we called "detailed measurement". The ratio of adjacent frequency in this time is m which lies between 1 and 2. The exact value of m will depend on how detailed that the user expected. After "detailed measurement" is finished, the pseudo section diagrams of apparent resistivity and phase are drew in the same way with the first step. We can see more detailed information about the abnormal zone and decide whether further measurement is necessary. If it is necessary, we can repeat the second step using smaller m until the resolution meet the requirements to distinguish the target. By simulation, we know that high density of frequencies really help us to improve resolution. But we also need to say that the improvement is limited and it will do no help to add frequencies if the frequency is already dense enough. This method not only improves efficiency, but also improves the ability to distinguish the abnormal body. This measurement mode consisting of rough measurement and detailed measurement is similar to the caliper measurement of length, so called "caliper" type. It is accurate and fast. It not only can be applied to frequency-domain sounding, such as controlled source audio -frequency magnetotelluric (CSAMT), but also can be extended to the spectral induced polarization method. By using this measurement manner, high resolution and high-efficiency can be expected.

Groundwater Exploration in Baja California, Mexico, Using Audiomagnetotellurics

NASA Astrophysics Data System (ADS)

Antonio, R.; Arroyo, A.; Romo, J.; Vazquez, R.

2007-12-01

Guadalupe Valley, in Ensenada B. C. Mexico, basis of the winery industry of the region, is known by their climatic attributes for vineyard cultivation. In this place, the crop growing depends totally on underground water extracted of an aquifer contained in two separate small basins. In order to estimate the depth to water level, as well as the thickness of one of these basins, we carry out a geophysical survey using audio-magnetotellurics (AMT). We carried out five profiles in a frequency range between 1 Hz and 750 kHz to estimate the electrical conductivity of the ground. We know that this physical property is enhanced by the permeability as well as by the salinity of fluids in the aquifer. In contrast, the crystalline rocks forming the basement of the basin are very bad conductors of electricity. Based on the AMT observations we construct 2-D models of the ground resistivity distribution. Our results show a clear resistivity contrast between sediments and bedrock. The sediments have resistivity values that oscillate from 40 to 100 Ohm-m, associated with lithology and/or permeability changes. Some conductive bodies (5 to 15 Ohms-m) are observed at depths shallower that 150 m, which might be caused by the presence of water with higher salinity, or alternatively, by clay lens. The bottom of the basin has resistivity values larger than 300 Ohm-m typical of the granitic rocks composing the bedrock. The spatial variation of the basement depth suggests the presence a normal fault, in agreement with a graben structure proposed in former studies.

Geophysical techniques for low enthalpy geothermal exploration in New Zealand

NASA Astrophysics Data System (ADS)

Soengkono, Supri; Bromley, Chris; Reeves, Robert; Bennie, Stewart; Graham, Duncan

2013-05-01

Shallow warm water resources associated with low enthalpy geothermal systems are often difficult to explore using geophysical techniques, mainly because the warm water creates an insufficient physical change from the host rocks to be easily detectable. In addition, often the system also has a limited or narrow size. However, appropriate use of geophysical techniques can still help the exploration and further investigation of low enthalpy geothermal resources. We present case studies on the use of geophysical techniques for shallow warm water explorations over a variety of settings in New Zealand (mostly in the North Island) with variable degrees of success. A simple and direct method for the exploration of warm water systems is shallow temperature measurements. In some New Zealand examples, measurements of near surface temperatures helped to trace the extent of deeper thermal water. The gravity method was utilised as a structural technique for the exploration of some warm water systems in New Zealand. Our case studies show the technique can be useful in identifying basement depths and tracing fault systems associated with the occurrence of hot springs. Direct current (DC) ground resistivity measurements using a variety of electrode arrays have been the most common method for the exploration of low enthalpy geothermal resources in New Zealand. The technique can be used to detect the extent of shallow warm waters that are more electrically conductive than the surrounding cold groundwater. Ground resistivity investigations using the electromagnetic (EM) techniques of audio magnetotellurics (AMT or shallow MT), controlled source audio magnetotellurics (CSAMT) and transient electromagnetic (TEM) methods have also been used. Highly conductive clays of thermal or sedimentary origin often limit the penetration depth of the resistivity techniques and can create some interpretation difficulties. Interpretation of resistivity anomalies needs to be treated in a site specific manner.

Three-dimensional audio-magnetotelluric sounding in monitoring coalbed methane reservoirs

NASA Astrophysics Data System (ADS)

Wang, Nan; Zhao, Shanshan; Hui, Jian; Qin, Qiming

2017-03-01

Audio-magnetotelluric (AMT) sounding is widely employed in rapid resistivity delineation of objective geometry in near surface exploration. According to reservoir patterns and electrical parameters obtained in Qinshui Basin, China, two-dimensional and three-dimensional synthetic "objective anomaly" models were designed and inverted with the availability of a modular system for electromagnetic inversion (ModEM). The results revealed that 3-D full impedance inversion yielded the subsurface models closest to synthetic models. One or more conductive targets were correctly recovered. Therefore, conductive aquifers in the study area, including hydrous coalbed methane (CBM) reservoirs, were suggested to be the interpretation signs for reservoir characterization. With the aim of dynamic monitoring of CBM reservoirs, the AMT surveys in continuous years (June 2013-May 2015) were carried out. 3-D inversion results demonstrated that conductive anomalies accumulated around the producing reservoirs at the corresponding depths if CBM reservoirs were in high water production rates. In contrast, smaller conductive anomalies were generally identical with rapid gas production or stopping production of reservoirs. These analyses were in accordance with actual production history of CBM wells. The dynamic traces of conductive anomalies revealed that reservoir water migrated deep or converged in axial parts and wings of folds, which contributed significantly to formations of CBM traps. Then the well spacing scenario was also evaluated based on the dynamic production analysis. Wells distributed near closed faults or flat folds, rather than open faults, had CBM production potential to ascertain stable gas production. Therefore, three-dimensional AMT sounding becomes an attractive option with the ability of dynamic monitoring of CBM reservoirs, and lays a solid foundation of quantitative evaluation of reservoir parameters.

Audio-magnetotelluric surveys to constrain the origin of a network of narrow synclines in Eocene limestone, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Tarabees, Elhamy A.; Tewksbury, Barbara J.; Mehrtens, Charlotte J.; Younis, Abdellatif

2017-12-01

Recent work with high resolution satellite imagery has revealed a network of narrow synclines developed during the Oligocene or Miocene over tens of thousands of square kilometers in Eocene limestone of the Thebes Group in the Western Desert of Egypt. The synclines are non-tectonic, and their scale and geometry strongly resemble sag synclines in Qatar that were produced by dissolution of subsurface evaporites and resulting sag of overlying layers. Evaporite dissolution cannot explain the Egypt synclines, because subsurface evaporites of any significance have never been reported in this part of Egypt. In this study, we use audio-magnetotelluric surveys to illuminate the subsurface under the synclines in order to constrain possible models for their formation. We suspected karst dissolution at depth, and, given a modern water table depth of over 400 m, we expected that dry fracture networks and void spaces under the synclines might result in higher electrical resistivities than surrounding coherent limestone. We also anticipated a significant change from high to low resistivity at the contact between the Thebes Group and the underlying Esna Shale at depths of 400 m or more. Instead, we found localized low resistivity zones extending from about 50-100 m below the surface to depths of more than 400 m that are strongly correlated with synclines. We suggest that these localized low resistivity zones are filled with artesian groundwater that has insufficient hydraulic head to rise to the modern topographic surface and that is localized in subsurface voids and collapse breccias produced by dissolution. Sag of overlying limestone layers is a reasonable model for syncline formation but, given the Oligocene/Miocene age of the synclines, dissolution and sag would be unrelated to young groundwater processes.

Electromagnetic exploration in high-salinity groundwater zones: case studies from volcanic and soft sedimentary sites in coastal Japan

NASA Astrophysics Data System (ADS)

Suzuki, Koichi; Kusano, Yukiko; Ochi, Ryota; Nishiyama, Nariaki; Tokunaga, Tomochika; Tanaka, Kazuhiro

2017-01-01

Estimating the spatial distribution of groundwater salinity in coastal plain regions is becoming increasingly important for site characterisation and the prediction of hydrogeological environmental conditions resulting from radioactive waste disposal and underground CO2 storage. In previous studies of the freshwater-saltwater interface, electromagnetic methods were used for sites characterised by unconsolidated deposits or Neocene soft sedimentary rocks. However, investigating the freshwater-saltwater interface in hard rock sites (e.g. igneous areas) is more complex, with the permeability of the rocks greatly influenced by fractures. In this study, we investigated the distribution of high-salinity groundwater at two volcanic rock sites and one sedimentary rock site, each characterised by different hydrogeological features. Our investigations included (1) applying the controlled source audio-frequency magnetotelluric (CSAMT) method and (2) conducting laboratory tests to measure the electrical properties of rock core samples. We interpreted the 2D resistivity sections by referring to previous data on geology and geochemistry of groundwater. At the Tokusa site, an area of inland volcanic rocks, low resistivity zones were detected along a fault running through volcanic rocks and shallow sediments. The results suggest that fluids rise through the Tokusa-Jifuku Fault to penetrate shallow sediments in a direction parallel to the river, and some fluids are diluted by rainwater. At the Oki site, a volcanic island on a continental shelf, four resistivity zones (in upward succession: low, high, low and high) were detected. The results suggest that these four zones were formed during a transgression-regression cycle caused by the last glacial period. At the Saijo site, located on a coastal plain composed of thick sediments, we observed a deep low resistivity zone, indicative of fossil seawater remnant from a transgression after the last glacial period. The current coastal plain formed in historical times, following which fresh water penetrated the upper parts of the fossil seawater zone to form a freshwater aquifer ~200 m in thickness.

REMOTE-SENSING MINERAL DISCOVERIES IN THE MOJAVE DESERT OF CALIFORNIA.

USGS Publications Warehouse

Raines, Gary L.; Hoover, Donald B.; Collins, William E.

1984-01-01

As a result of remote sensing studies in the Mojave Desert of California three previously unknown stockwork molybdenum systems have been discovered. It is not known if economic deposits of molybdenum and associated minerals occur in these areas; there is, however, sufficient data to judge that these areas are worthy of further exploration. The purpose of this paper is to present case histories of two of these discoveries. These discoveries have been made from laboratory analyses of Landsat multispectral scanner images to map limonitic materials and from field reconnaissance to determine if the limonite is due to hydrothermal alteration. In those areas that seemed most promising, airborne spectrometer surveys were employed to mapped Al-OH minerals, and audio-magnetotelluric (AMT) and telluric-traversing surveys were performed to obtain information at depth.

A multi-disciplinary investigation of Irish warm springs and their potential for geothermal energy provision.

NASA Astrophysics Data System (ADS)

Blake, Sarah; Jones, Alan G.; Henry, Tiernan

2015-04-01

Irish warm springs are one of a set of several target types that are being evaluated for their geothermal energy potential during the course of the island-wide assessment of the geothermal energy potential of Ireland under the IRETHERM project (www.iretherm.ie). Forty-two warm springs and warm shallow groundwater occurrences have been recorded in Ireland; water temperatures in the springs (approx. 12-25 °C) are elevated with respect to average Irish groundwater temperatures (10-11 °C). This study focuses on warm springs in east-central Ireland found in the Carboniferous limestone of the Dublin Basin. A combination of geophysical methods (controlled source electromagnetics (CSEM) and audio-magnetotellurics (AMT)) and hydrochemical analyses (including time-lapse temperature and electrical conductivity measurements) have been utilised at several of the springs to determine the source of the heated waters at depth and the nature of the geological structures that deliver the warm waters to the surface. Using the example of St. Gorman's Well, Co. Meath, we show how the combination of these different methods of investigation and the interpretation of these various data sets enables us to better understand the physical and chemical variability of the spring through time. This will provide the basis for an assessment of the source of these thermal waters as a potential geothermal energy reservoir and will allow for more precise characterisation of the groundwater resource. We present subsurface models derived from new geophysical data collected at St. Gorman's Well in 2013. This high-resolution AMT survey consisted of a grid of 40 soundings recorded at approximately 200 m intervals centred on the spring. The aim of the survey was to image directly any (electrically conductive) fluid conduit systems that may be associated with the springs and to provide an understanding of the observed association of the Irish warm springs with major structural lineaments, such as the NE-SW Caledonian structural trend which dominates Irish geology. Seasonal hydrochemical sampling of six warm spring locations commenced in July 2013. Data loggers installed at each location measured temperature and electrical conductivity (15-minute sampling intervals) throughout the sampling period (July 2013 - early 2015). The hydrochemical results and the data from the logger at St. Gorman's Well are examined here in conjunction with regional rainfall and available hydrogeological information in order to establish the nature of the relationship between the hydrological cycle and fluctuations in the hydrochemistry of the spring.

Structural controls on geothermal circulation in Surprise Valley, California: A re-evaluation of the Lake City fault zone

USGS Publications Warehouse

Anne E. Egger,; Glen, Jonathan; McPhee, Darcy K.

2014-01-01

Faults and fractures play an important role in the circulation of geothermal fluids in the crust, and the nature of that role varies according to structural setting and state of stress. As a result, detailed geologic and geophysical mapping that relates thermal springs to known structural features is essential to modeling geothermal systems. Published maps of Surprise Valley in northeastern California suggest that the “Lake City fault” or “Lake City fault zone” is a significant structural feature, cutting obliquely across the basin and connecting thermal springs across the valley. Newly acquired geophysical data (audio-magnetotelluric, gravity, and magnetic), combined with existing geochemical and geological data, suggest otherwise. We examine potential field profiles and resistivity models that cross the mapped Lake City fault zone. While there are numerous geophysical anomalies that suggest subsurface structures, they mostly do not coincide with the mapped traces of the Lake City fault zone, nor do they show a consistent signature in gravity, magnetics, or resistivities that would suggest a through-going fault that would promote connectivity through lateral fluid flow. Instead of a single, continuous fault, we propose the presence of a deformation zone associated with the growth of the range-front Surprise Valley fault. The implication for geothermal circulation is that this is a zone of enhanced porosity but lacks length-wise connectivity that could conduct fluids across the valley. Thermal fluid circulation is most likely controlled primarily by interactions between N-S–trending normal faults.

Identification of kimberlite bodies in Brazil from a 3D audio-magnetotelluric survey

NASA Astrophysics Data System (ADS)

De Lugao, P. P.; Eric, C. D. O.; Loureiro, F. O.; Arantes, P. R.; Pastana, A. F.

2015-12-01

We report on a succesfull identification of kimberlite bodies in Brazil through the use of the electromagnetic technique audio-magnetotelluric (AMT). Macnae (1979) writes that "In one large survey in South Africa, electromagnetic (EM) techniques have proven to be remarkably effective in detecting the presence of weathered clays or epiclastic kimberlite contained within the pipes." Full tensor AMT data were acquired at 65 points (stations) in a 3D configuration with frequencies ranging from 10kHz to 1Hz. The survey was located in the NW portion of the Mato Grosso state, Brazil, in na area of thick jungle coverage. During the AMT survey, few outcrops were seen because of the dense forest cover. Usually, the occurrences found were of sand deposits, indicating the occurence of Fazenda Casa Branca and Utiariti Formations and gravel from Salto das Nuvens Formation, widely used in paving trails n this region. In the area of the survey, three main targets were confirmed/identified: Kimberlite Area 1 - a classic kimberlite in the region, with the crater facies with different clasts and distinct size. We noted the occurrence of a red-brown soil and an unusual vegetation in this area. The resistivity model provided confirmed the presence of Kimberlite Area 1 and was used to identify other two areas. Area of Interest 1 - area with atypical vegetation along a trail. There is an excavation that displays soil of white color with several blocks present, there are small quartz crystal agglomerates in these blocks. The resistivity model cleary shows a conductive body here, indicative of the presence of a kimberlite. Area of Interest 2 - the presence of a kimberlite was confirmed, not exactly where the targeted Area 2 was, but the southwest of it. Close to this area, there was a very fine rock and a few blocks of pure silica, probably indicating a kimberlitic intrusion. In summary, the 3D resistivity model in depth obtained from inversion of the AMT data confirmed and identified three targets for kimberlites quickly and at a low cost, in na otherwise region of difficult logistics due to the dense jungle cover and remote location.

Joint Audio-Magnetotelluric and Passive Seismic Imaging of the Cerdanya Basin

NASA Astrophysics Data System (ADS)

Gabàs, A.; Macau, A.; Benjumea, B.; Queralt, P.; Ledo, J.; Figueras, S.; Marcuello, A.

2016-09-01

The structure of Cerdanya Basin (north-east of Iberian Peninsula) is partly known from geological cross sections, geological maps and vintage geophysical data. However, these data do not have the necessary resolution to characterize some parts of Cerdanya Basin such as the thickness of soft soil, geometry of bedrock or geometry of geological units and associated faults. For all these reasons, the main objective of this work is to improve this deficiency carrying out a detailed study in this Neogene basin applying jointly the combination of passive seismic methods ( H/V spectral ratio and seismic array) and electromagnetic methods (audio-magnetotelluric and magnetotelluric method). The passive seismic techniques provide valuable information of geometry of basement along the profile. The maximum depth is located near Alp village with a bedrock depth of 500 m. The bedrock is located in surface at both sites of profile. The Neogene sediments present a shear-wave velocity between 400 and 1000 m/s, and the bedrock basement presents a shear-wave velocity values between 1700 and 2200 m/s. These results are used as a priori information to create a 2D resistivity initial model which constraints the inversion process of electromagnetic data. We have obtained a 2D resistivity model which is characterized by (1) a heterogeneous conductivity zone (<40 Ohm m) that corresponds to shallow part of the model up to 500 m depth in the centre of the profile. These values have been associated with Quaternary and Neogene sediments formed by silts, clays, conglomerates, sandstones and gravels, and (2) a deeper resistive zone (1000-3000 Ohm m) interpreted as Palaeozoic basement (sandstones, limestones and slates at NW and conglomerates and microconglomerates at SE). The resistive zone is truncated by a discontinuity at the south-east of the profile which is interpreted as the Alp-La Tet Fault. This discontinuity is represented by a more conductive zone (600 Ohm m approx.) and is explained as a combination of fractured rock and a fluid network. The result highlights that the support between different geophysical methods is essential in producing geophysical meaningful models.

Audiomagnetotelluric investigation of Snake Valley, eastern Nevada and western Utah

USGS Publications Warehouse

McPhee, Darcy K.; Pari, Keith; Baird, Frank

2009-01-01

As support for an exploratory well-drilling and hydraulic-testing program, AMT data were collected using a Geometrics Stratagem EH4 system along four profiles that extend roughly east-west from the southern Snake Range into Snake Valley. The profiles range from 3 to 5 kilometers in length, and station spacing was 200 to 400 meters. Two-dimensional inverse models were computed using the data from the transverse-electric (TE), transverse-magnetic (TM), and combined (TE+TM) mode using a conjugate gradient, finite-difference method. Interpretation of the 2-D AMT models defines several faults, some of which may influence ground-water flow in the basins, as well as identify underlying Paleozoic carbonate and clastic rocks and the thickness of basin-fill sediments. These AMT data and models, coupled with the geologic mapping and other surface geophysical methods, form the basis for identifying potential well sites and defining the subsurface structures and stratigraphy within Snake Valley.

Possibilities of magnetotelluric methods in geophysical exploration for ore minerals

NASA Astrophysics Data System (ADS)

Varentsov M., Iv.; Kulikov, V. A.; Yakovlev, A. G.; Yakovlev, D. V.

2013-05-01

In the past decade, the applications of magnetotelluric method in the electric prospecting for ore bodies have been rapidly progressing. In the present work, we summarize the first results on this way. We discuss the specificity of the geoelectrical models in the problems of mining prospecting for ore bodies. The state-of-the-art capabilities of the method, which rely on the synchronous observation systems and the procedure of joint inversion of magnetotelluric and magnetovariational responses, are considered in the context of ore mineral exploration. The results of modeling a typical mining audio-magnetotelluric survey for ore minerals are presented. On the basis of these simulations and the data provided by in-situ soundings, the efficient approaches to the processing, analysis, and inversion of these data are discussed and illustrated. The future trends in magnetotellurics as applied to the mining prospecting are analyzed.

Reconnaissance electrical surveys in the Coso Range, California

NASA Astrophysics Data System (ADS)

Jackson, Dallas B.; O'Donnell, James E.

1980-05-01

Telluric current, audiomagnetotelluric (AMT), and direct current (dc) methods were used to study the electrical structure of the Coso Range and Coso geothermal area. Telluric current mapping outlined major resistivity lows associated with conductive valley fill of the Rose Valley basin, the Coso Basin, and the northern extension of the Coso Basin east of Coso Hot Springs. A secondary resistivity low with a north-south trend runs through the Coso Hot Springs-Devil's Kitchen geothermal area. The secondary low in the geothermal area, best defined by the 7.5-Hz AMT map and dc soundings, is caused by a shallow conductive zone (5-30 ohm m) interpreted to be hydrothermally altered Sierra Nevada basement rocks containing saline water of a hot water geothermal system. This zone of lowest apparent resistivities over the basement rocks lies within a closed contour of a heat flow anomaly where all values are greater than 10 heat flow units.

Requirements for a multi-scale, ultra wide-band National Geoelectromagnetic Facility (Invited)

NASA Astrophysics Data System (ADS)

Schultz, A.

2009-12-01

Advances in data acquisition technology and modeling make it possible to image the electrical properties of the near surface, crust and mantle in 3D. A generation of investigators is emerging whose research depends on application of complementary methods including magnetotelluric (MT) [micro-Hz to kHz sampling frequencies], natural audio (AMT) and controlled source and radio-frequency magnetotellurics (CSAMT, RFMT) [1 Hz-300 kHz], time-domain (TDEM) EM, as well as DC resistivity, induced polarization and ground-penetrating radar. Different process studies involve different depths and spatial scales, requiring target illumination by signals of different frequency content, and application of one or more of the methods above. Current practice often assumes that near surface and deeper crustal imaging problems can be decoupled by treating shallower heterogeneities in e.g. electrical conductivity structure as surface distortions that can be dealt with either through tensor stripping techniques or thin sheet modeling. Such methods are based on parametric models with implicit or explicit assumptions that may not in all cases be satisfied by the physics of the situation. Large-scale EM imaging programs such as EarthScope/USArray's magnetotelluric (MT) component seek to reconstruct the electrical conductivity structure of the US on the crustal-to-upper mantle scale. A variety of PI-led investigations seek to increase the resolving power of this effort through a combination of targeted, finer-spaced arrays, and by pushing into a higher frequency domain. As these efforts continue, great care has to be made in dealing with the impact of near surface heterogeneities. There is no national or regional scale set of near surface conductivity maps that one could use to strip near surface effects from deeper studies. National radio propagation/absorption maps were assembled by the FCC in the 1950's, and maps of ground-penetrating radar soil suitability provide a rough guide to surface conductance. Such information is insufficient to remove near surface effects for those imaging upper-to-mid crustal electrical properties. In order to obtain field measurements that can span near-surface through crust and upper mantle problems, an initiative to establish a multi-institutional National Geoelectromagnetic Facility has been proposed as part of a Virtual Institute for EM methods. An academic-industry partnership is designing a flexible, ultra wide-band system capable of being configured to obtain most of the data types indicated above. The system is specified to to provide between 100 dB - 130 dB dynamic range for sample rates from DC up to 2.5 MHz. A hybrid magnetic field sensor employing both induction coils and fluxgates, and a flexible arrangement of electric field sensors completes the specified receivers. The systems can be configured for sustained, low-power autonomous operation, or for higher power high frequency, active source operations. A series of controlled source transmitter systems is also specified. As financial support for the National Geoelectromagnetic Facility is being aligned, an organizational framework is being developed to permit efficient scheduling, data flow and archiving of resulting data sets. Education and outreach efforts are intrinsic to this, with close interactions with SAGE and other projects planned from the outset.

Electromagnetic outline of the Solfatara-Pisciarelli hydrothermal system, Campi Flegrei (Southern Italy)

NASA Astrophysics Data System (ADS)

Troiano, Antonio; Giulia Di Giuseppe, Maria; Patella, Domenico; Troise, Claudia; De Natale, Giuseppe

2014-05-01

We describe the results from a combined CSAMT and MT survey carried out in the Solfatara-Pisciarelli area, located in the central part of the Campi Flegrei composite caldera, west of Naples, Southern Italy. The Solfatara-Pisciarelli area represents the most active zone within the CF area, in terms of hydrothermal manifestations and local seismicity. Since 1969, the caldera is experiencing ground deformation, seismicity and geochemical fluid changes, which are particularly evident in this area. A 1 km long, nearly W-E directed CSAMT-MT profile crossing the fumaroles field was carried out with the aim of deducting an EM model of the structural setting of the hydrothermal system in the first 3 km depth. An interpretation of the EM modelled section is given in this paper, taking advantage from already existing seismic, gravity and geochemical data in the same area. Three well distinct EM zones have been outlined. The first EM zone is a very shallow, electrically conductive body localized beneath the westernmost segment of the profile, which, within a short distance of about 100 m, dips westwards from near surface down to some hundred metres depth. Mostly accounting for the very low resistivity (1-10 Ωm) and the exceedingly high values of vP/vS (>4), this shallow zone has been ascribed to a water-saturated, high-pressurized geothermal reservoir. The second EM zone, which has been localized below the west-central portion of the EM transect, appears as a composite body made of a nearly vertical plumelike structure that escapes at about 2.25 km depth from the top edge of the east side of a presumably horizontal platelike body. The plumelike structure rises up to the free surface in correspondence of the fumaroles field, whereas the platelike structure deepens at least down to the 3 km of maximum EM exploration depth. The combined interpretation of resistivity, wave velocity, gravity and geochemical data indicates the plumelike portion is likely associated with a steam/gas-saturated column and the platelike portion to a high temperature (>300°C), over-pressurized, gas-saturated reservoir. Finally, the third EM zone, which has been localized beneath the eastern half of the EM transect, from about 1.2 km down to about 3 km of depth, is also characterized by the lowest resistivity values (1-10 Ωm). When jointly interpreted with seismic and gravity data, this feature can be associated to a hydrothermally mineralized, clay-rich body.

Geoelectric structure of the Gila-San Francisco Wilderness Area, Graham and Greenlee counties, Arizona from audio-magnetotelluric data

USGS Publications Warehouse

Klein, D.P.; Baer, M.J.

1983-01-01

Electromagnetic induction data using distant field sources, mostly of natural origin, in the frequency range of 4.5-27,000 Hz are analyzed to depict the geoelectric structure in an area of volcanic-rock cover located in southeastern Arizona between the Morenci and Safford porphyry copper deposits. The data for each station consist of scalar electromagnetic measurements at descrete frequencies for two-orthogonal magnetic and electric field pairs. Observations spaced about 5-km apart indicate resistivities in the range of 100-700 ohm-m for the unweathered Tertiary volcanic rocks to a depth of 200 to 500 m. Beneath this zone the data indicate resistivities in the range of 10-100 ohm-m that suggest the existence of an older volcanic rock unit. The less resistive unit appears to be displaced upward beneath Turtle Mountain, an area bounded to the northeast and southwest by mapped Basin and Range faults, and bounded to the southeast by an unmapped fault of older origin that trends northeast. Lateral changes in the resistivity of the two main geoelectric layers result in lowered resistivity in an area of known hot-springs near the confluence of the Gila and San Francisco Rivers, as well as along a north-south trending zone located on the east flank of Turtle Mountain, about 5-km (3-mi) west-northwest of the hot springs. This second anomaly is at a probable depth of 400-500 m and is interpreted to indicate a buried fault or fracture zone.

Characterising the hydrothermal circulation patterns beneath thermal springs in the limestones of the Carboniferous Dublin Basin, Ireland: a geophysical and geochemical approach.

NASA Astrophysics Data System (ADS)

Blake, Sarah; Henry, Tiernan; Muller, Mark R.; Jones, Alan G.; Moore, John Paul; Murray, John; Campanyà, Joan; Vozár, Jan; Walsh, John; Rath, Volker

2016-04-01

A hydrogeological conceptual model of the sources, circulation pathways and temporal variations of two low-enthalpy thermal springs is derived from a multi-disciplinary approach. The springs are situated in the Carboniferous limestones of the Dublin Basin, in east-central Ireland. Kilbrook spring (Co. Kildare) has the highest recorded temperatures for any thermal spring in Ireland (maximum of 25.0 °C), and St. Gorman's Well (Co. Meath) has a complex and variable temperature profile (maximum of 21.8 °C). These temperatures are elevated with respect to average Irish groundwater temperatures (9.5 - 10.5 °C), and represent a geothermal energy potential, which is currently under evaluation. A multi-disciplinary investigation based upon audio-magnetotelluric (AMT) surveys, time-lapse temperature and chemistry measurements, and hydrochemical analysis, has been undertaken with the aims of investigating the provenance of the thermal groundwater and characterising the geological structures facilitating groundwater circulation in the bedrock. The hydrochemical analysis indicates that the thermal waters flow within the limestones of the Dublin Basin, and there is evidence that Kilbrook spring receives a contribution from deep-basinal fluids. The time-lapse temperature, electrical conductivity and water level records for St. Gorman's Well indicate a strongly non-linear response to recharge inputs to the system, suggestive of fluid flow in karst conduits. The 3-D electrical resistivity models of the subsurface revealed two types of geological structure beneath the springs; (1) Carboniferous normal faults, and (2) Cenozoic strike-slip faults. These structures are dissolutionally enhanced, particularly where they intersect. The karstification of these structures, which extend to depths of at least 500 m, has provided conduits that facilitate the operation of a relatively deep hydrothermal circulation pattern (likely estimated depths between 240 and 1,000 m) within the Dublin Basin. The results of this study support a hypothesis that the thermal maximum and simultaneous increased discharge observed each winter at both springs is the result of rapid infiltration, heating and re-circulation of meteoric waters within a structurally- and recharge-controlled hydrothermal circulation system.

Magnetotelluric and audiomagnetotelluric groundwater survey along the Humu'ula portion of Saddle Road near and around the Pohakuloa Training Area, Hawaii

USGS Publications Warehouse

Pierce, Herbert A.; Thomas, Donald M.

2009-01-01

The Pohakuloa Training Area (PTA), operated by the U.S. Army on the Big Island of Hawaii, is in need of a reliable potable water supply to sustain ongoing operations by staff and trainees. In an effort to acquire baseline hydrologic data with which to develop a plan for providing that water, a series of magnetotelluric (MT) geophysical surveys was performed that spanned the Mauna Loa/Mauna Kea Saddle region of Hawaii Island. These surveys provided electrical resistivity profiles and resistivity maps at several elevations along the axis of the field measurements that can be interpreted to yield information on the depth to the water table. In 2004 a preliminary sequence of 23 audiomagnetotelluric (AMT) soundings was collected along Saddle Road extending from the Waikii Ranch area, west of the PTA, to Department of Hawaiian Home Lands Humu'ula properties east of the Mauna Kea access road. The results of those soundings showed that highly resistive rocks, consistent with dry basalts, were present to depths of at least one kilometer, the maximum depth to which the AMT technique can reliably reach in Hawaii's rocks. A second survey was conducted in 2008 using MT instruments capable of recovering resistivity data to depths of several kilometers below sea level where saturated formations are known to exist. A total of 30 MT soundings was performed along a roughly east to west transect that extended from the (recently acquired) Keamuku PTA lands on the west to as far as the County of Hawaii's upper Kaumana water supply well to the east. Inversion and processing of the field data yielded an electrical cross-section following the Saddle that roughly parallels the geologic contact between the Mauna Kea and Mauna Loa lavas. Several additional electrical sections were constructed normal to the main transect to investigate the three-dimensional nature of the contact. These resistivity data and models suggest that the elevation of saturated rock in places are 400 to 600 meters above mean sea level beneath the surveyed region. Highest elevations for water-saturated zones based upon preferred electrical models are located between training area 3 and training area 6 southwest of training area 4.

Integrated geophysical study of the geothermal system in the southern part of Nisyros Island, Greece

NASA Astrophysics Data System (ADS)

Lagios, E.; Apostolopoulos, G.

1995-10-01

The study of the high-enthalpy geothermal field of Nisyros Island is of great importance, because of the planned construction of a geothermal power station. The purpose of the applied geophysical surveys — gravity, SP, VLF and audio-magnetotelluric — in southernmost Nisyros was to investigate the major and minor faulting zones which are geothermally active, i.e. whether geothermal fluid circulation occurs in these zones. The survey lines, four parallel traverses of about 1500 m length, were chosen to be almost transverse to the main faults of the area. The SP method was the main reconnaissance technique, with the VLF and gravity measurements correlating with the "SP model". Previously proposed SP data acquisition and reduction techniques were used, followed by a 2-D interpretation of the SP map which apparently locates the position of the fracture zones (geothermally active). The SP and VLF anomalies are believed to be generated by the same source (subsurface flow of fluid, heat and ions). Hence, at the place of a vertical geothermal fluid circulation zone, the curve of SP dipole-like anomaly changes its behaviour and the curve of the VLF anomaly takes maximum values for the in-phase component and minimum values for the out-of-phase component. On the VLF map of the survey area, the zones detected with the SP interpretation coincide with the maximum values of the VLF in-phase component. The geothermal fluid circulation zones, detected by the SP method, appear to be well correlated with corresponding features derived from the gravity and the AMT surveys. In particular, the AMT soundings indicate two zones of geothermal fluid circulation instead of the one the SP method detected in the central part of the investigated area.

Hydrogeological bedrock inferred from electrical resistivity model in Taichung Basin, Taiwan

NASA Astrophysics Data System (ADS)

Chiang, C. W.; Chang, P. Y.; Chang, L. C.

2015-12-01

The four-year project of the study of groundwater hydrogeology and recharge model was indicated by Central Geological Survey, MOEA, Taiwan (R.O.C.) to evaluate recharge groundwater areas in Taiwan where included Taipei, Taichung Basins, Lanyang and Chianan Plains. The groundwater recharge models of Lanyang Plain and Taipei Basin have successfully been estimated in two years ago (2013-2014). The third year of the project integrates with geophysical, geochemistry, and hydrogeology models to estimate the groundwater recharge model in Taichung Basin region. Taichung Basin is mainly covered by Pre-Pleistocene of thick gravel, sandy and muddy sediment rocks within a joint alluvial fan, whereas the depth of the hydrological bedrock remains uncertain. Two electrical resistivity geophysical tools were carried out utilizing direct current resistivity and audio-magnetotelluric (AMT) explorations, which could ideally provide the depth resolutions from shallow to depth for evaluating the groundwater resources. The study has carried out 21 AMT stations in the southern Taichung Basin in order to delineate hydrological bedrock in the region. All the AMT stations were deployed about 24 hours and processed with remote reference technique to reduce culture noises. The quality of most stations shows acceptable in the area which two stations were excluded due to near-field source effect in the southwestern basin. The best depth resolution is identified in 500 meters for the model. The preliminary result shows that the depths of the bedrock gradually changes from southern ~20 m toward to ~400 m in central, and eastern ~20 m to 180 m in the western basin inferred from the AMT model. The investigation shows that AMT method could be a useful geophysical tool to enhance the groundwater recharge model estimation without dense loggings in the region.

Subsurface Resistivity Structures in and Around Strike-Slip Faults - Electromagnetic Surveys and Drillings Across Active Faults in Central Japan -

NASA Astrophysics Data System (ADS)

Omura, K.; Ikeda, R.; Iio, Y.; Matsuda, T.

2005-12-01

Electrical resistivity is important property to investigate the structure of active faults. Pore fluid affect seriously the electrical properties of rocks, subsurface electrical resistivity can be an indicator of the existence of fluid and distribution of pores. Fracture zone of fault is expected to have low resistivity due to high porosity and small gain size. Especially, strike-slip type fault has nearly vertical fracture zone and the fracture zone would be detected by an electrical survey across the fault. We performed electromagnetic survey across the strike-slip active faults in central Japan. At the same faults, we also drilled borehole into the fault and did downhole logging in the borehole. We applied MT or CSAMT methods onto 5 faults: Nojima fault which appeared on the surface by the 1995 Great Kobe earthquake (M=7.2), western Nagano Ohtaki area(1984 Nagano-ken seibu earthquake (M=6.8), the fault did not appeared on the surface), Neodani fault which appeared by the 1891 Nobi earthquake (M=8.0), Atera fault which seemed to be dislocated by the 1586 Tensyo earthquake (M=7.9), Gofukuji fault that is considered to have activated about 1200 years ago. The sampling frequencies of electrical and magnetic field were 2 - 1024Hz (10 frequencies) for CSAMT survey and 0.00055 - 384Hz (40 frequencies) for MT survey. The electromagnetic data were processed by standard method and inverted to 2-D resistivity structure along transects of the faults. Results of the survey were compared with downhole electrical logging data and observational descriptions of drilled cores. Fault plane of each fault were recognized as low resistivity region or boundary between relatively low and high resistivity region, except for Gofukuji fault. As for Gofukuji fault, fault was located in relatively high resistivity region. During very long elapsed time from the last earthquake, the properties of fracture zone of Gofukuji fault might changed from low resistivity properties as observed for other faults. Downhole electrical logging data were consistent to values of resistivity estimated by electromagnetic survey for each fault. The existence of relatively low and high resistivity regions in 2-D structure from electromagnetic survey was observed again by downhole logging at the correspondent portion in the borehole. Cores recovered from depthes where the electrical logging showed low resistivity were hardly fractured and altered from host rock which showed high resistivity. Results of electromagnetic survey, downhole electrical logging and observation of drilled cores were consistent to each other. In present case, electromagnetic survey is useful to explore the properties of fault fracture zone. In the further investigations, it is important to explore relationships among features of resistivity structure and geological and geophysical situations of the faults.

Audio-magnetotelluric investigation of sulfide mineralization in Proterozoic-Archean greenstone belts of Eastern Indian Craton

NASA Astrophysics Data System (ADS)

Singh, Shailendra; Maurya, Ved P.; Singh, Roshan K.; Srivastava, Shalivahan; Tripathi, Anurag; Adhikari, P. K.

2018-04-01

Greenstone belts are well known for gold occurrences at different regions of the world. The Dhanjori basin in the eastern Singhbhum region shows major characteristics of a rifted greenstone belt. Initially, we conducted 14 audio-magnetotelluric (AMT) measurements for a profile of ˜ 20 km in the frequency range of 1 kHz to 10 Hz over this rather complex geologic environment covering Dhanjori Volcanics (DhV) and Kolhan Group (KG). Subsequently, gravity and magnetic surveys were also conducted over this AMT profile. The purpose of the survey was to identify and map conductive features and to relate them to metallogeny of the area along with the mapping of the basement of Dhanjori basin. The strike analysis showed N30°W strike for DhV for all the frequencies and for sites over KG domain in the frequency range of 100-10 Hz, but for KG domain, the obtained strike in 1 kHz to 100 Hz is N45°E. As the combination of transverse electric (TE), transverse magnetic (TM) and tipper (Tzy) can recover the electrical signature in complex geological environment, we discuss the conductivity model obtained from TE+TM+Tzy only. The inversion was carried for the regional profile with 14 sites and for 7 sites over KG domain. Conductivity model shows two well resolved conductors, one each in KG and Quartz Pebble Conglomerate Dhanjori (QPCD) domains respectively showing common linked concordant features between these regional and KG profiles. The conductors are interpreted as sulfide mineralization linked with QPCD group of rocks which may host gold. These conductors are also horizontally disposed due to the intrusive younger Mayurbhanj Granite. These intrusives correlate well with the gravity modeling as well. The thickness of the Dhanjori basin at the central is about 3.0 km, similar to that from gravity modeling. The conductivity model also indicates the presence of shallow conductors, but could not be resolved due to lack of high frequency data. However, the results from the close-by drill site indicate the presence of shallow sulfide mineralization hosting gold. The deep level conductors delineated from AMT studies are associated with gravity high and low magnetic. ICP-AES results of Dhanjori samples show significant concentration of gold ˜ 5.0 g/t, which is of economic consideration. Thus, it can be inferred that the conductors have evidences of sulfide mineralization which host gold.

Audio magnetotelluric study applied to hydrogeology at Santo Tomás Valley, Baja California, México

NASA Astrophysics Data System (ADS)

Islas, A. C.; Romo, J. M.

2009-12-01

The Santo Tomás valley, located 50 km southeast of Ensenada, Baja California, is one of the most important viniculture zones in all of Mexico. Therefore, aquifer characterization is very important for the area. A geophysical study was conducted using the audio-magnetotelluric method (AMT) to determinate the electric conductivity of the basin. 82 AMT stations were measured in three profiles with a North-South orientation. Data was collected using a Stratagem EH4 (by Geometrics) in frequencies between 10 Hz to 100 kHz. To determinate basement and water table depths we made 2D ground resistivity models, using an inversion regularized algorithm. The results show a conductive zone from a few meters up to depths of 200 meters; this unit can be interpreted as the aquifer zone. The models show a less conductive zone (~1000 Ohm-m) in the first 20 meters, which is interpreted as the vadose zone. Finally, we have a very resistive unit corresponding to the basement, estimated around 200 meters depth.

On the optimization of electromagnetic geophysical data: Application of the PSO algorithm

NASA Astrophysics Data System (ADS)

Godio, A.; Santilano, A.

2018-01-01

Particle Swarm optimization (PSO) algorithm resolves constrained multi-parameter problems and is suitable for simultaneous optimization of linear and nonlinear problems, with the assumption that forward modeling is based on good understanding of ill-posed problem for geophysical inversion. We apply PSO for solving the geophysical inverse problem to infer an Earth model, i.e. the electrical resistivity at depth, consistent with the observed geophysical data. The method doesn't require an initial model and can be easily constrained, according to external information for each single sounding. The optimization process to estimate the model parameters from the electromagnetic soundings focuses on the discussion of the objective function to be minimized. We discuss the possibility to introduce in the objective function vertical and lateral constraints, with an Occam-like regularization. A sensitivity analysis allowed us to check the performance of the algorithm. The reliability of the approach is tested on synthetic, real Audio-Magnetotelluric (AMT) and Long Period MT data. The method appears able to solve complex problems and allows us to estimate the a posteriori distribution of the model parameters.

New insights into the hydrogeology of a basaltic shield volcano from a comparison between self-potential and electromagnetic data: Piton de la Fournaise, Indian ocean

NASA Astrophysics Data System (ADS)

Boubekraoui, Souad; Courteaud, Michel; Aubert, Maurice; Albouy, Yves; Coudray, Jean

1998-12-01

In order to investigate aquifers, several geophysical surveys have been carried out in the Baril area of the southern flank of Piton de la Fournaise volcano on Reunion in the Indian Ocean using audiomagnetotelluric (AMT), very-low-frequency (VLF) and self-potential (SP) methods. We present the results with emphasis on a comparison between SP data and the findings of geoelectric surveys. AMT soundings have indicated, from the surface downward, three layers: (i) resistive volcanic rocks, (ii) an intermediate resistivity layer, and (iii) a conductive basement attributed to a seawater-bearing aquifer. VLF measurements allow the mapping of the first layer apparent resistivity, and therefore its bottom, when the true resistivity is supposed to be isotropic and homogenous. When this assumption does not hold, only the SP method permits the mapping of this bottom. Because of the good agreement between the SP and electromagnetic results, we propose the SP method as the first tool that should be used in studying shallow hydrogeological structures in volcanic areas.

Magnetotelluric Data, Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nevada

USGS Publications Warehouse

Williams, Jackie M.; Sampson, Jay A.; Rodriguez, Brian D.; Asch, Theodore H.

2006-01-01

Introduction: The United States Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing ground-water contamination resulting from historical underground nuclear testing through the Environmental Management (EM) program and, in particular, the Underground Test Area (UGTA) project. During 2005, the U.S. Geological Survey (USGS), in cooperation with the DOE and NNSA-NSO, collected and processed data from twenty-six magnetotelluric (MT) and audio-magnetotelluric (AMT) sites at the Nevada Test Site. The 2005 data stations were located on and near Rainier Mesa and Shoshone Mountain to assist in characterizing the pre-Tertiary geology in those areas. These new stations extend the area of the hydrogeologic study previously conducted in Yucca Flat. The MT data presented in this report will help refine what is known about the character, thickness, and lateral extent of pre Tertiary confining units. Subsequent interpretation will include a three dimensional (3 D) character analysis and a two-dimensional (2 D) resistivity model. The purpose of this report is to release the MT sounding data. No interpretation of the data is included here.

Exploration and geology of the Karangahake and Rahu epithermal Au-Ag deposits, Hauraki Goldfield

USGS Publications Warehouse

Simpson, Mark P.; Stevens, Murray R; Mauk, Jeffrey L.; Harris, Matthew C; Stuart, Alistair G J

2016-01-01

Karangahake was the third largest gold producer in the Hauraki goldfield. In 2009, New Talisman Gold mines was granted a mining permit, and plans are underway to commence underground mine development of the Maria vein, which has a maiden Ore Reserve (consistent with the 2012 JORC Code) of 28 800 oz Au and 127 800 oz Ag. Exploration drilling at Rahu, located 2 km north of Karangahake has identified polymictic hydrothermal breccias and quartz veins that are strongly gold anomalous. Some quartz vein clasts within the breccia have up to 8.7 g/t Au, suggesting the presence of higher grade quartz vein(s) either below or directly adjacent to the breccias. A controlled source audio-frequency magnetotelluric (CSAMT) survey at Rahu revealed that strongly resistive zones extend below the Barbara and Eunice anomalies to at least 300 m depth and likely correspond to areas of increased silicification, breccias and/or veins. Future drilling will focus on these targets. Detailed geophysical, alteration and fluid inclusion studies have been undertaken at Karangahake, Rahu and Ascot (c 1 km NW of Rahu). Karangahake and Rahu both occur within a broad demagnetised zone, c 4.2 × 2.7 km, in which magnetite has been destroyed by strong hydrothermal alteration. At Karangahake, andesite and overlying minor rhyolite are replaced by adularia, chlorite, illite, pyrite, plus minor albite, epidote and calcite, which have formed from upwelling chloride waters that at depth were hotter than 280°C. At Rahu, localised adularia coupled with complex distributions of illite and interstratified illite-smectite, suggest cooler (c 180° to 240°C) and more focused fluid flow, as well as inferred cool groundwater influx. Fluid inclusion data suggest veins at Karangahake, Rahu and Ascot formed beneath palaeowater tables at 920 m, 440 m and 430 m relative to current sea level (asl), respectively. At Ascot, the presence of silica sinter at 135 m asl, which formed at the palaeosurface, is shallower compared to the fluid inclusion depth estimate and suggests that the palaeowater table here rose some 300 m during hydrothermal activity due to burial, resulting in overprinting. This overprint may also have occurred at Karangahake and Rahu, but the evidence is inconclusive; although burial during hydrothermal activity could explain the exceptional 700 m vertical range of mineralisation at Karangahake and raises the possibility of concealed mineralisation at depth elsewhere within the Karangahake alteration envelope.

Fault Zone Resistivity Structure and Monitoring at the Taiwan Chelungpu Drilling Project from AMT data

NASA Astrophysics Data System (ADS)

Chiang, C.-W.; Unsworth, M. J.; Chen, C.-S.; Chen, C.-C.; Lin, A.-T.; Hsu, H.-L.

2009-04-01

The Chi-Chi earthquake occurred on September 21st, 1999 in the Western Foothills of central Taiwan. This Mw=7.6 earthquake produced a 90 km long surface rupture and caused severe damage across Taiwan. The coseismic displacement on the Chelungpu fault was one of the largest ever observed. The Taiwan Chelungpu drilling project (TCDP) began in 2003 and resulted in a 2,000 m well that recovered cores from the fault zone at A-hole and finished in 2005 with two boreholes (A-hole and B-hole) being completed. The Chelungpu fault that caused the Chi-Chi earthquake was observed in the core at a depth of 1,111 m (FAZ1111). Another fault zone (Sanyi Fault - FAZ1710) was observed at depths of 1,500~1,710 m. Since the electrical resistivity of rocks is sensitive to the presence of fluids, geophysical methods that remotely sense sub-surface resistivity, such as Magnetotellurics (MT), can be a powerful tool in investigating the fluid distribution in the shallow crust. The effectiveness of MT in imaging fault zones has been demonstrated by studies of the San Andreas Fault zone in California, the U.S. and elsewhere. In magnetotellurics, the depth of exploration increases as the signal frequency decreases. Thus for imaging shallow fault zone structure at the TCDP site, the higher frequency audio-magnetotelluric (AMT) method is the most suitable. In this paper, AMT data collected at the TCDP site from 2004 to 2006 are presented. Spatial and temporal variations are described and interpreted in terms of the tectonic setting. Audio-magnetotelluric (AMT) measurements were used to investigate electrical resistivity structure at the TCDP site from 2004~2006. These data show a geoelectric strike direction of N15°E to N30°E. Inversion and forward modeling of the AMT data were used to generate a 1-D resistivity model that has a prominent low resistivity zone (< 10 ohm-m) between depths of 1,100 and 1,500 m. When combined with porosity measurements, the AMT measurements imply that the ground water has a resistivity of 0.55 ohm-m at the depth of the fault zone. Time variations in the measured AMT data were observed from 2004~2005 with maximum changes of 43% in apparent resistivity and 18° in phase. The change in apparent resistivity is greatest in the 1,000~100 Hz frequency band. These frequencies are sensitive to the resistivity structure of the upper 500 m of the hanging wall of the Chelungpu Fault. The decrease in resistivity over time appears to be robust and could be caused by an increase in porosity and a re-distribution of the groundwater.

Audiomagnetotellurics-Magnetotelluric (AMT-MT) survey of the Campi Flegrei inner caldera

NASA Astrophysics Data System (ADS)

Siniscalchi, Agata; Tripaldi, Simona; Romano, Gerardo; D'Auria, Luca; Improta, Luigi; Petrillo, Zaccaria

2017-04-01

In the framework of the EU project MED-SUV, an audiomagnetotellurics-magnetotelluric (AMT-MT) survey in the frequency band 0.1-100kHz was performed in the eastern border of the Campi Flegrei inner caldera comprising the area where seismicity is concentred in the last decade. This survey was aimed to provide new insights on the electrical resistivity structure of the subsoil. Among all the collected MT soundings, twenty-two, on a total of forty-three, were selected along a WSW-ENE alignment that crosses the main fumarole emissions (Solfatara, Pisciarelli and Agnano) and used for 2D regularized inversion. The obtained model is characterized by a quite narrow resistivity range that well matches typical range of enhanced geothermal environment as largely documented in the international literature. In particular focusing on the Solfatara and Pisciarelli districts the resistivity distribution clearly calls to mind the behavior of a high temperature geothermal system with a very conductive cap in the shallower part. Here the presence of gaps in this conductor just in correspondence of the main superficial emissions describes the inflow and outflow pathway of the shallow fluids circulation. A high resistive reservoir appearing at a depth of about 500 m b.s.l.. WithinWithin this region we selected a vertical resistivity profile just in correspondence of a Vp/Vs profile versus depth coming from a passive seismic tomography (Vanorio et al., 2005). The comparison of the two behaviors shows a clear anti-correlation between the two physical parameters (high resistivity and low Vp/Vs) in the depth range 500-1000 m supporting the interpretation that an over-pressurized gas bearing rocks under supercritical conditions constituting the reservoir of the enhanced geothermal system. On the eastern side of this resistive plume up to 2.5 km of depth is present a local relative conductive unit underneath the Pisciarelli area. In the same volume most of the recent (from 2005 up to date) micro-earthquake hypocenters are confined suggesting that in this volume geothermal fluid, pushed by the reservoir pressure and mixed with the powerful aquifer (testified in the well CF23), propagates in widespread pores and cracks triggering microseismicity. The present resistivity model is limited to 3 km of depth due to the adopted frequency range, thus does not investigate the magma feeding system of the Plegrean Field caldera that seismic imaging suggest to be a large magmatic sill within the basement formations at about 7.5 km of depth (Zollo et al., 2008). On the contrary it well image for the first time with higher resolution than in the past the geothermal system underneath Solfatara-Pisciarelli districts giving insights of the whole hydro-geothermal circulation.

Imaging hydrothermal systems at Furnas caldera (Azores, Portugal): Insights from Audio-Magnetotelluric data

NASA Astrophysics Data System (ADS)

Hogg, Colin; Kiyan, Duygu; Rath, Volker; Byrdina, Svetlana; Vandemeulebrouck, Jean; Silva, Catarina; Viveiros, Maria FB; Ferreira, Teresa

2016-04-01

The Furnas volcano is the eastern-most of the three active central volcanoes of Sao Miguel Island. The main caldera formed about 30 ka BP, followed by a younger eruption at 10-12 ka BP, which forms the steep topography of more than 200 m in the measuring area. It contains several very young eruptive centers, and a shallow caldera lake. Tectonic features of varying directions have been identified in the Caldera and its vicinity. In the northern part of the caldera, containing the fumarole field of Caldeiras das Furnas, a detailed map of surface CO2 emissions was recently made available. In 2015, a pilot survey of 13 AudioMagnetoTelluric soundings (AMT) and Electrical Resistivity Tomography (ERT) data were collected along two profiles in the eastern part of Furnas caldera in order to image the electrical conductivity of the subsurface. The data quality achieved by both techniques is extraordinary and first results indicate a general correlation between regions of elevated conductivity and the mapped surface CO2 emissions, suggesting that they may both be caused by the presence hydrothermal fluids. Tensor decomposition analysis using the Groom-Bailey approach produce a generalised geo-electric strike direction, 72deg East of North, for the AMT data compared to the surface geological strike derived from the major mapped fault crossing the profiles of 105deg. An analysis of the real induction arrows at certain frequencies (at depths greater than 350 m) infer that an extended conductor at depth does not exactly correspond to the degassing structures at the surface and extends outside the area of investigation. The geometry of the most conductive regions with electrical conductivities less then1 Ώm found at various depths differ from what was expected from earlier geologic and tectonic studies and possibly may not be directly related to the mapped fault systems at the surface. On the eastern profile, which seemed to be more appropriate for 2-D modelling with 72deg strike angle, a deep structure starting north of the major mapped fault crossing this profile can be found. It extends far to the south, with a top of approximately 150 m below the surface at the northern limit. A deeper conductive structure (top at about 300 m) is emerging at the southern end of the profile, though not fully resolved by the existing data. This work will focus on the processing, analysis and preliminary modelling results of the AMT data. A joint interpretation of the AMT results together with the ERT data covering the shallow regime with much higher resolution will be presented.

AMT measurements compared with gravimetry and magnetometry for structural study of a sedimentary basin: Letlhakeng-Botlhapatlou groundwater project, Botswana

NASA Astrophysics Data System (ADS)

Bourgeois, B.; Mathieu, F.; Vachette, C.; Vaubourg, P.

1994-02-01

Within the framework of hydrogeological studies for additional water supply to the main towns of Botswana, the BRGM company has carried out a multimethod geophysical survey of a large sedimentary basin in the Kalahari desert, for the purpose of assessing its water resources. On a regional scale, gravimetry, magnetometry and audio-magnetotellurics (AMT) were used to determine the structure of the basin, which is intensely faulted into horsts and grabens. Next, a number of favourable areas were selected for detailed profiling with horizontal portable loop EM (HLEM) and DC electrical arrays to locate accurately the fractured zones at the edges of grabens, the targets for exploratory drillholes. The AMT method proved to be the most effective for mapping the basement of the basin, thanks to the good resistivity contrast between the resistive basement and its conductive cover, and to the regional constancy of sedimentary organisation of the cover. The presence of the uniformly resistive Kalahari Sands at the top of the cover was also very favourable, protecting AMT data from troublesome "static" effects. These good conditions enabled a fast and innovative quantitative interpretation of AMT soundings, determined by borehole calibration and based on the reading of the apparent resistivity at a single frequency (10 Hz).

Geoelectrical image of the subsurface for CO2 geological storage in the Changhua site, Taiwan

NASA Astrophysics Data System (ADS)

Chiang, C. W.; Chiao, C. H.; Yang, M. W.; Yu, C. W.; Yang, C. H.; Chen, C. C.

2016-12-01

Global warming has recently become an important worldwide issue. Reduction of carbon dioxide (CO2) emission is recommended by Intergovernmental Panel on Climate Change, which geological storage is one of possible way to reduce the CO2 issue. The Taichung Power Plant is a coal-fired power plant operated by the Taiwan Power Company in Taichung, Taiwan, which is the largest coal-fired power station in the world. The power plant emits approximately 40 million tons annually which is also the world's largest CO2 emitter. Geophysical techniques are presented as the most useful tool to characterize the reservoir. The electrical resistivity tool was carried out applying audio-magnetotelluric (AMT) method, which could provide the depth resolution for evaluating the subsurface. A first survey of 20 AMT soundings was acquired to study the viability of the method to characterize the subsurface. Stations were deployed at approximately 500 m intervals and the data were recorded in the frequency range of 104-100 Hz. The dimensionality analysis proved the validity of the 1-D or 2-D assumption. The visualized model shows a layered electrical resistivity structure from shallow to depth of 3000 m. The preliminary result corresponds to seismic reflection and geological investigations that suggests a simple geological structure without complex geological processes in the area. It could be a suitable site for geological storage.

Joint Interpretation of Geological, Magnetic, AMT, and ERT Data for Mineral Exploration in the Northeast of Inner Mongolia, China

NASA Astrophysics Data System (ADS)

Zhang, Gang; Lü, Qing-Tian; Zhang, Gui-Bin; Lin, Ping-Rong; Jia, Zheng-Yuan; Suo, Kui

2018-03-01

The integrated interpretation of data from various technologies has the potential to obtain a more accurate estimate of subterranean earth properties. In this paper, we implement the joint interpretation of geological and geophysical data for mineral exploration in the northeastern region of Inner Mongolia, China. The joint application of several methodologies reduces the exploration risk. We first determined an approximate and large potential area for mineral exploration with geological data and magnetic data interpretation in Gaoerqi. Results from the two types of data analysis show that the ore deposit strikes roughly east in the northern part of the Gaoerqi mining area. Next, we employed the audio-magnetotelluric (AMT) method to study the subterranean electrical resistivity distribution and divide the earth into four layers. Inverted resistivity sections from the AMT data illustrate that the ore deposits are likely developed in the low-resistivity zone of the survey area from the land surface to 300-m depth. Finally, the high-resolution borehole-to-surface electrical resistivity tomography (ERT) method was employed for further investigation of the location and attitude of the potential ore deposits. Inverted resistivity sections from the ERT data show that two prospective areas for mineral exploration were observed in the west of the survey area and that the eastern portion of the survey area warrants further investigation.

Depth of the base of the Jackson aquifer, based on geophysical exploration, southern Jackson Hole, Wyoming, USA

USGS Publications Warehouse

Nolan, B.T.; Campbell, D.L.; Senterfit, R.M.

1998-01-01

A geophysical survey was conducted to determine the depth of the base of the water-table aquifer in the southern part of Jackson Hole, Wyoming, USA. Audio-magnetotellurics (AMT) measurements at 77 sites in the study area yielded electrical-resistivity logs of the subsurface, and these were used to infer lithologic changes with depth. A 100-600 ohm-m geoelectric layer, designated the Jackson aquifer, was used to represent surficial saturated, unconsolidated deposits of Quaternary age. The median depth of the base of the Jackson aquifer is estimated to be 200 ft (61 m), based on 62 sites that had sufficient resistivity data. AMT-measured values were kriged to predict the depth to the base of the aquifer throughout the southern part of Jackson Hole. Contour maps of the kriging predictions indicate that the depth of the base of the Jackson aquifer is shallow in the central part of the study area near the East and West Gros Ventre Buttes, deeper in the west near the Teton fault system, and shallow at the southern edge of Jackson Hole. Predicted, contoured depths range from 100 ft (30 m) in the south, near the confluences of Spring Creek and Flat Creek with the Snake River, to 700 ft (210 m) in the west, near the town of Wilson, Wyoming.

Application and evaluation of electromagnetic methods for imaging saltwater intrusion in coastal aquifers: Seaside Groundwater Basin, California

USGS Publications Warehouse

Nenna, Vanessa; Herckenrather, Daan; Knight, Rosemary; Odlum, Nick; McPhee, Darcy

2013-01-01

Developing effective resource management strategies to limit or prevent saltwater intrusion as a result of increasing demands on coastal groundwater resources requires reliable information about the geologic structure and hydrologic state of an aquifer system. A common strategy for acquiring such information is to drill sentinel wells near the coast to monitor changes in water salinity with time. However, installation and operation of sentinel wells is costly and provides limited spatial coverage. We studied the use of noninvasive electromagnetic (EM) geophysical methods as an alternative to installation of monitoring wells for characterizing coastal aquifers. We tested the feasibility of using EM methods at a field site in northern California to identify the potential for and/or presence of hydraulic communication between an unconfined saline aquifer and a confined freshwater aquifer. One-dimensional soundings were acquired using the time-domain electromagnetic (TDEM) and audiomagnetotelluric (AMT) methods. We compared inverted resistivity models of TDEM and AMT data obtained from several inversion algorithms. We found that multiple interpretations of inverted models can be supported by the same data set, but that there were consistencies between all data sets and inversion algorithms. Results from all collected data sets suggested that EM methods are capable of reliably identifying a saltwater-saturated zone in the unconfined aquifer. Geophysical data indicated that the impermeable clay between aquifers may be more continuous than is supported by current models.

Application of magnetotelluric in the modeling of underlying structure of Gour Oumelalen (Egere-Aleksod terrane, Central Hoggar, South of Algeria)

NASA Astrophysics Data System (ADS)

Boukhalfa, Zakaria; Abderrezak, Bouzid; Khadidja, Ouzegane; Abderrahmane, Bendaoud; Mohamed, Hamoudi; Abdeslam, Abtout; Abdelhamid, Bendekken; Sofiane Said, Bougchiche; Walid, Boukhlouf; Abdelgharfour, Boukar; Aboubakr, Deramchi; Mohamed, Bendali; Abdenaceur, Lemgharbi; Mohammed, Djeddi

2016-04-01

The results of a magnetotelluric experiment crossing Ounane granodiorite to the east until the Amadror Wadi to the West, passing through Adrar Ounane in our study area are presented. The magnetotelluric field survey was carried out in the Gour Oumelalen (GO) area during March 2015. We deployed 34 magnetotelluric sites along two parallel EW profiles of a hundred km long. Time series were collected using a V5 system 2000® of Phoenix Geophysics. The first profile located to the north is composed of 18 braodband measurement sites obtained from merging magnetotelluri with audio-magnetotelluric (AMT) data. The second one located 10 km south of the first, is composed of 15 MT sites. An inter-station distance of ~5 km provides good lateral resolution. The MT time series were recorded during about 20 hours which allows to reach a depth of 100 km or more and the AMT data 30 minutes. This allows to get broadband magnetotelluric soundings with good quality data in period range from 0.001 s to 3000 s. In this study we will use the south profile data for modeling the underlying structure of GO. The crustal part of the model shows a resistance bloc, divided by conductive parts which can be interpreted as faults, as regards the lithospheric part it less resistant the upper part, the transition crust / mantle corresponding to MOHO is estimated at more or less 35 km.

Magnetotelluric Data, Central Yucca Flat, Nevada Test Site, Nevada

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

J.M. Williams; B.D. Rodriguez, and T.H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Central Yucca Flat, Profile 1, as shown in figure 1. No interpretation of the data is included here.« less

Magnetotelluric Data, North Central Yucca Flat, Nevada Test Site, Nevada

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

J.M. Williams; B.D. Rodriguez, and T.H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for north central Yucca Flat, Profile 7, as shown in Figure 1. No interpretation of the data is included here.« less

Magnetotelluric Data, Northern Frenchman Flat, Nevada Test Site Nevada

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

J.M. Williams; B.D. Rodriguez, and T. H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Frenchman Flat Profile 3, as shown in Figure 1. No interpretation of the data is included here.« less

Magnetotelluric Data, Across Quartzite Ridge, Nevada Test Site, Nevada

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

J.M. Williams; B.D. Rodriguez, and T.H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT soundings across Quartzite Ridge, Profiles 5, 6a, and 6b, as shown in Figure 1. No interpretation of the data is included here.« less

Magnetotelluric Data, Southern Yucca Flat, Nevada Test Site, Nevada

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

J.M. Williams; B.D. Rodriguez, and T.H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Southern Yucca Flat, Profile 4, as shown in Figure 1. No interpretation of the data is included here.« less

Magnetotelluric Data, Northern Yucca Flat, Nevada Test Site, Nevada

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

J.M. Williams; B.D. Rodriguez, and T.H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Profile 2, (fig. 1), located in the northern Yucca Flat area. No interpretation of the data is included here.« less

Geophysical Investigation of the Lake City Fault Zone, Surprise Valley, California, and Implications for Geothermal Circulation

NASA Astrophysics Data System (ADS)

McPhee, D. K.; Glen, J. M.; Egger, A. E.; Chuchel, B. A.

2009-12-01

New audiomagnetotelluric (AMT), gravity, and magnetic data were collected in Surprise Valley, northwestern Basin and Range, in order to investigate the role that the Lake City Fault Zone (LCFZ) may play in controlling geothermal circulation in the area. Surprise Valley hosts an extensional geothermal system currently undergoing exploration for development on several scales. The focus of much of that exploration has been the LCFZ, a set of NW-SE-trending structures that has been suggested on the basis of (1) low-relief scarps in the NW portion of the zone, (2) dissolved mineral-rich groundwater chemistry along its length, and (3) parallelism with a strong regional fabric that includes the Brothers Fault Zone. The LCFZ extends across the valley at a topographic high, intersecting the N-S-trending basin-bounding faults where major hot springs occur. This relationship suggests that the LCFZ may be a zone of permeability for flow of hydrothermal fluids. Previous potential field data indicate that there is no vertical offset along this fault zone, and little signature at all in either the gravity or magnetic data; along with the lack of surface expression along most of its length, the subsurface geometry of the LCFZ and its influence on geothermal fluid circulation remains enigmatic. The LCFZ therefore provides an ideal opportunity to utilize AMT data, which measures subsurface resistivity and therefore - unlike potential field data - is highly sensitive to the presence of saline fluids. AMT data and additional gravity and magnetic data were collected in 2009 along 3 profiles perpendicular to the LCFZ in order to define the subsurface geometry and conductivity of the fault zone down to depths of ~ 500 m. AMT soundings were collected using the Geometrics Stratagem EH4 system, a four channel, natural and controlled-source tensor system recording in the range of 10 to 92,000 Hz. To augment the low signal in the natural field a transmitter of two horizontal-magnetic dipoles was used from 800 to 56,000 Hz. One profile extends within 200 m of hot springs and fault scarps near the northwestern end of the LCFZ. There, preliminary data show low resistivities (< 5 ohm-m) at stations closest to the hot springs suggesting that the data are sensitive to high concentrations of salts characteristic of geothermal fluids in the area. Two additional profiles extend across the LCFZ further to the southeast where it is at its widest and most diffuse. Profiles were ~ 3 km-long with station spacing of ~ 200 - 400 m, and data were recorded in a coordinate system parallel to and perpendicular to the regional geologic-strike of the LCFZ. Two-dimensional (2D) inverse models were computed using the conjugate gradient, finite-difference method of Rodi and Mackie (2001). In addition to AMT data, ground magnetic and gravity data were collected along the AMT profiles. These data, combined with the 2D resistivity models, will be used to image the LCFZ at depth and determine whether it is a single through-going fracture zone that potentially hosts hydrothermal fluids within the shallow (< 1km) subsurface or whether it is simply a set of unrelated features with little or no geophysical expression.

Multi-frequency electrical and electromagnetic measurements for imaging water flows: application to catchment and landslide hydrology.

NASA Astrophysics Data System (ADS)

Lajaunie, Myriam; Sailhac, Pascal; Malet, Jean-Philippe; Larnier, Hugo; Gance, Julien; Gautier, Stéphanie; Pierret, Marie-Claire

2017-04-01

Imaging water flows in mountainous watersheds is a difficult task, not only because of the topography and the dimensions of the existing structures, but also because the soils and rocks consist of unsaturated porous and heterogeneous fractured media, leading to multi-scale water-flow properties. In addition, these properties can change in time, in relation to temperature, rainfall and biological forcings. Electrical properties are relevant proxies of the subsurface hydrological properties. In order to image water flows, we consider measurements of the complex electrical conductivity (conduction and polarization/chargeability effects) which translate into a frequency dependance of the conductivity at the sample scale. We further discuss the combined use of electromagnetic (CS-AMT) and electric (DC and IP) measurements at the slope scale. The solving of processing, calibration and modelling issues allows the estimation of hydrological properties (i.e. permeability, soil humidity) giving master constraints for slope-scale hydrological modelling. We illustrate the application of these methods for the identification of the hydrological role of weathered structures of granitic catchments (e.g. Strengbach, Vosges mountains, ca. 80 km from Strasbourg, North East France) where new AMT processing has been developed in the AMT dead band to improve DC electrical imaging. We also illustrate the use of these methods to document the seasonal regime of the groundwater of the Lodève landslide (unstable slope located at Pégairolles, foot of the Cévennes mountain, ca. 80 km from Montpellier, South of France) where a new detailed time-lapse DC and IP setup (surface and borehole) is being tested. The works are supported by the research projects HYDROCRISZTO and HYDROSLIDE, and the large infrastructure project CRITEX.

10 CFR 835.1201 - Sealed radioactive source control.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Sealed radioactive source control. 835.1201 Section 835.1201 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Sealed Radioactive Source Control § 835.1201 Sealed radioactive source control. Sealed radioactive sources shall be used, handled, and...

10 CFR 835.1201 - Sealed radioactive source control.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Sealed radioactive source control. 835.1201 Section 835.1201 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Sealed Radioactive Source Control § 835.1201 Sealed radioactive source control. Sealed radioactive sources shall be used, handled, and...

10 CFR 835.1201 - Sealed radioactive source control.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Sealed radioactive source control. 835.1201 Section 835.1201 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Sealed Radioactive Source Control § 835.1201 Sealed radioactive source control. Sealed radioactive sources shall be used, handled, and...

10 CFR 835.1201 - Sealed radioactive source control.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Sealed radioactive source control. 835.1201 Section 835.1201 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Sealed Radioactive Source Control § 835.1201 Sealed radioactive source control. Sealed radioactive sources shall be used, handled, and...

10 CFR 835.1201 - Sealed radioactive source control.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Sealed radioactive source control. 835.1201 Section 835.1201 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Sealed Radioactive Source Control § 835.1201 Sealed radioactive source control. Sealed radioactive sources shall be used, handled, and...

Impact of Source Control in Patients With Severe Sepsis and Septic Shock.

PubMed

Martínez, María Luisa; Ferrer, Ricard; Torrents, Eva; Guillamat-Prats, Raquel; Gomà, Gemma; Suárez, David; Álvarez-Rocha, Luis; Pozo Laderas, Juan Carlos; Martín-Loeches, Ignacio; Levy, Mitchell M; Artigas, Antonio

2017-01-01

Time to clearance of pathogens is probably critical to outcome in septic shock. Current guidelines recommend intervention for source control within 12 hours after diagnosis. We aimed to determine the epidemiology of source control in the management of sepsis and to analyze the impact of timing to source control on mortality. Prospective observational analysis of the Antibiotic Intervention in Severe Sepsis study, a Spanish national multicenter educational intervention to improve antibiotherapy in sepsis. Ninety-nine medical-surgical ICUs in Spain. We enrolled 3,663 patients with severe sepsis or septic shock during three 4-month periods between 2011 and 2013. Source control and hospital mortality. A total of 1,173 patients (32%) underwent source control, predominantly for abdominal, urinary, and soft-tissue infections. Compared with patients who did not require source control, patients who underwent source control were older, with a greater prevalence of shock, major organ dysfunction, bacteremia, inflammatory markers, and lactic acidemia. In addition, compliance with the resuscitation bundle was worse in those undergoing source control. In patients who underwent source control, crude ICU mortality was lower (21.2% vs 25.1%; p = 0.010); after adjustment for confounding factors, hospital mortality was also lower (odds ratio, 0.809 [95% CI, 0.658-0.994]; p = 0.044). In this observational database analysis, source control after 12 hours was not associated with higher mortality (27.6% vs 26.8%; p = 0.789). Despite greater severity and worse compliance with resuscitation bundles, mortality was lower in septic patients who underwent source control than in those who did not. The time to source control could not be linked to survival in this observational database.

Clinical and scientific importance of source control in abdominal infections: summary of a symposium

PubMed Central

Bohnen, John M.A.; Marshall, John C.; Fry, Donald E.; Johnson, Steven B.; Solomkin, Joseph S.

1999-01-01

In May 1997, a panel of surgeon-investigators met to discuss the clinical importance and research implications of controlling the source of abdominal infections. It was concluded that source control is critical to therapeutic success and that antimicrobial therapy and other adjunctive interventions will fail if the source of infection is not controlled by resection, exteriorization or other means. The panelists presented different definitions of source control, depending on the scientific purpose of the definition. All participants agreed that failure to consider the adequacy of source control of infection has limited the value of most clinical trials of therapeutic anti-infective agents. Besides recognizing source control as an essential goal of patient care, the panelists emphasized the need for further investigative work to define, record and stratify the adequacy of source control in clinical trials of therapeutic agents for abdominal infections. PMID:10223073

Respiratory source control using a surgical mask: An in vitro study.

PubMed

Patel, Rajeev B; Skaria, Shaji D; Mansour, Mohamed M; Smaldone, Gerald C

2016-07-01

Cough etiquette and respiratory hygiene are forms of source control encouraged to prevent the spread of respiratory infection. The use of surgical masks as a means of source control has not been quantified in terms of reducing exposure to others. We designed an in vitro model using various facepieces to assess their contribution to exposure reduction when worn at the infectious source (Source) relative to facepieces worn for primary (Receiver) protection, and the factors that contribute to each. In a chamber with various airflows, radiolabeled aerosols were exhaled via a ventilated soft-face manikin head using tidal breathing and cough (Source). Another manikin, containing a filter, quantified recipient exposure (Receiver). The natural fit surgical mask, fitted (SecureFit) surgical mask and an N95-class filtering facepiece respirator (commonly known as an "N95 respirator") with and without a Vaseline-seal were tested. With cough, source control (mask or respirator on Source) was statistically superior to mask or unsealed respirator protection on the Receiver (Receiver protection) in all environments. To equal source control during coughing, the N95 respirator must be Vaseline-sealed. During tidal breathing, source control was comparable or superior to mask or respirator protection on the Receiver. Source control via surgical masks may be an important adjunct defense against the spread of respiratory infections. The fit of the mask or respirator, in combination with the airflow patterns in a given setting, are significant contributors to source control efficacy. Future clinical trials should include a surgical mask source control arm to assess the contribution of source control in overall protection against airborne infection.

Respiratory source control using a surgical mask: An in vitro study

PubMed Central

Patel, Rajeev B.; Skaria, Shaji D.; Mansour, Mohamed M.; Smaldone, Gerald C.

2016-01-01

ABSTRACT Cough etiquette and respiratory hygiene are forms of source control encouraged to prevent the spread of respiratory infection. The use of surgical masks as a means of source control has not been quantified in terms of reducing exposure to others. We designed an in vitro model using various facepieces to assess their contribution to exposure reduction when worn at the infectious source (Source) relative to facepieces worn for primary (Receiver) protection, and the factors that contribute to each. In a chamber with various airflows, radiolabeled aerosols were exhaled via a ventilated soft-face manikin head using tidal breathing and cough (Source). Another manikin, containing a filter, quantified recipient exposure (Receiver). The natural fit surgical mask, fitted (SecureFit) surgical mask and an N95-class filtering facepiece respirator (commonly known as an “N95 respirator”) with and without a Vaseline-seal were tested. With cough, source control (mask or respirator on Source) was statistically superior to mask or unsealed respirator protection on the Receiver (Receiver protection) in all environments. To equal source control during coughing, the N95 respirator must be Vaseline-sealed. During tidal breathing, source control was comparable or superior to mask or respirator protection on the Receiver. Source control via surgical masks may be an important adjunct defense against the spread of respiratory infections. The fit of the mask or respirator, in combination with the airflow patterns in a given setting, are significant contributors to source control efficacy. Future clinical trials should include a surgical mask source control arm to assess the contribution of source control in overall protection against airborne infection. PMID:26225807

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

None

This case history discusses the exploration methods used at the Momotombo Geothermal Field in western Nicaragua, and evaluates their contributions to the development of the geothermal field models. Subsequent reservoir engineering has not been synthesized or evaluated. A geothermal exploration program was started in Nicaragua in 1966 to discover and delineate potential geothermal reservoirs in western Nicaragua. Exploration began at the Momotombo field in 1970 using geological, geochemical, and geophysical methods. A regional study of thermal manifestations was undertaken and the area on the southern flank of Volcan Momotombo was chosen for more detailed investigation. Subsequent exploration by various consultantsmore » produced a number of geotechnical reports on the geology, geophysics, and geochemistry of the field as well as describing production well drilling. Geological investigations at Momotombo included photogeology, field mapping, binocular microscope examination of cuttings, and drillhole correlations. Among the geophysical techniques used to investigate the field sub-structure were: Schlumberger and electromagnetic soundings, dipole mapping and audio-magnetotelluric surveys, gravity and magnetic measurements, frequency domain soundings, self-potential surveys, and subsurface temperature determinations. The geochemical program analyzed the thermal fluids of the surface and in the wells. This report presents the description and results of exploration methods used during the investigative stages of the Momotombo Geothermal Field. A conceptual model of the geothermal field was drawn from the information available at each exploration phase. The exploration methods have been evaluated with respect to their contributions to the understanding of the field and their utilization in planning further development. Our principal finding is that data developed at each stage were not sufficiently integrated to guide further work at the field, causing inefficient use of resources.« less

Loop Heat Pipe Operation Using Heat Source Temperature for Set Point Control

NASA Technical Reports Server (NTRS)

Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

2011-01-01

The LHP operating temperature is governed by the saturation temperature of its reservoir. Controlling the reservoir saturation temperature is commonly accomplished by cold biasing the reservoir and using electrical heaters to provide the required control power. Using this method, the loop operating temperature can be controlled within +/- 0.5K. However, because of the thermal resistance that exists between the heat source and the LHP evaporator, the heat source temperature will vary with its heat output even if LHP operating temperature is kept constant. Since maintaining a constant heat source temperature is of most interest, a question often raised is whether the heat source temperature can be used for LHP set point temperature control. A test program with a miniature LHP has been carried out to investigate the effects on the LHP operation when the control temperature sensor is placed on the heat source instead of the reservoir. In these tests, the LHP reservoir is cold-biased and is heated by a control heater. Tests results show that it is feasible to use the heat source temperature for feedback control of the LHP operation. Using this method, the heat source temperature can be maintained within a tight range for moderate and high powers. At low powers, however, temperature oscillations may occur due to interactions among the reservoir control heater power, the heat source mass, and the heat output from the heat source. In addition, the heat source temperature could temporarily deviate from its set point during fast thermal transients. The implication is that more sophisticated feedback control algorithms need to be implemented for LHP transient operation when the heat source temperature is used for feedback control.

Multiple source/multiple target fluid transfer apparatus

DOEpatents

Turner, Terry D.

1997-01-01

A fluid transfer apparatus includes: a) a plurality of orifices for connection with fluid sources; b) a plurality of orifices for connection with fluid targets; c) a set of fluid source conduits and fluid target conduits associated with the orifices; d) a pump fluidically interposed between the source and target conduits to transfer fluid therebetween; e) a purge gas conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass a purge gas under pressure; f) a solvent conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass solvent, the solvent conduit including a solvent valve; g) pump control means for controlling operation of the pump; h) purge gas valve control means for controlling operation of the purge gas valve to selectively impart flow of purge gas to the fluid source conduits, fluid target conduits and pump; i) solvent valve control means for controlling operation of the solvent valve to selectively impart flow of solvent to the fluid source conduits, fluid target conduits and pump; and j) source and target valve control means for controlling operation of the fluid source conduit valves and the fluid target conduit valves to selectively impart passage of fluid between a selected one of the fluid source conduits and a selected one of the fluid target conduits through the pump and to enable passage of solvent or purge gas through selected fluid source conduits and selected fluid target conduits.

Multiple source/multiple target fluid transfer apparatus

DOEpatents

Turner, T.D.

1997-08-26

A fluid transfer apparatus includes: (a) a plurality of orifices for connection with fluid sources; (b) a plurality of orifices for connection with fluid targets; (c) a set of fluid source conduits and fluid target conduits associated with the orifices; (d) a pump fluidically interposed between the source and target conduits to transfer fluid there between; (e) a purge gas conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass a purge gas under pressure; (f) a solvent conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass solvent, the solvent conduit including a solvent valve; (g) pump control means for controlling operation of the pump; (h) purge gas valve control means for controlling operation of the purge gas valve to selectively impart flow of purge gas to the fluid source conduits, fluid target conduits and pump; (i) solvent valve control means for controlling operation of the solvent valve to selectively impart flow of solvent to the fluid source conduits, fluid target conduits and pump; and (j) source and target valve control means for controlling operation of the fluid source conduit valves and the fluid target conduit valves to selectively impart passage of fluid between a selected one of the fluid source conduits and a selected one of the fluid target conduits through the pump and to enable passage of solvent or purge gas through selected fluid source conduits and selected fluid target conduits. 6 figs.

LED lamp color control system and method

DOEpatents

Gaines, James; Clauberg, Bernd; Van Erp, Josephus A.M.

2013-02-05

An LED lamp color control system and method including an LED lamp having an LED controller 58; and a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 determines whether the LED source 80 is in a feedback controllable range, stores measured optical flux for the LED source 80 when the LED source 80 is in the feedback controllable range, and bypasses storing the measured optical flux when the LED source 80 is not in the feedback controllable range.

Interior sound field control using generalized singular value decomposition in the frequency domain.

PubMed

Pasco, Yann; Gauthier, Philippe-Aubert; Berry, Alain; Moreau, Stéphane

2017-01-01

The problem of controlling a sound field inside a region surrounded by acoustic control sources is considered. Inspired by the Kirchhoff-Helmholtz integral, the use of double-layer source arrays allows such a control and avoids the modification of the external sound field by the control sources by the approximation of the sources as monopole and radial dipole transducers. However, the practical implementation of the Kirchhoff-Helmholtz integral in physical space leads to large numbers of control sources and error sensors along with excessive controller complexity in three dimensions. The present study investigates the potential of the Generalized Singular Value Decomposition (GSVD) to reduce the controller complexity and separate the effect of control sources on the interior and exterior sound fields, respectively. A proper truncation of the singular basis provided by the GSVD factorization is shown to lead to effective cancellation of the interior sound field at frequencies below the spatial Nyquist frequency of the control sources array while leaving the exterior sound field almost unchanged. Proofs of concept are provided through simulations achieved for interior problems by simulations in a free field scenario with circular arrays and in a reflective environment with square arrays.

Mathematically trivial control of sound using a parametric beam focusing source.

PubMed

Tanaka, Nobuo; Tanaka, Motoki

2011-01-01

By exploiting a case regarded as trivial, this paper presents global active noise control using a parametric beam focusing source (PBFS). As with a dipole model, one is used for a primary sound source and the other for a control sound source, the control effect for minimizing a total acoustic power depends on the distance between the two. When the distance becomes zero, the total acoustic power becomes null, hence nothing less than a trivial case. Because of the constraints in practice, there exist difficulties in placing a control source close enough to a primary source. However, by projecting a sound beam of a parametric array loudspeaker onto the target sound source (primary source), a virtual sound source may be created on the target sound source, thereby enabling the collocation of the sources. In order to further ensure feasibility of the trivial case, a PBFS is then introduced in an effort to meet the size of the two sources. Reflected sound wave of the PBFS, which is tantamount to the virtual sound source output, aims to suppress the primary sound. Finally, a numerical analysis as well as an experiment is conducted, verifying the validity of the proposed methodology.

Distributed optimization system and method

DOEpatents

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

2003-06-10

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

Distributed Optimization System

DOEpatents

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

2004-11-30

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

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

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

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

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

Field Operations and Enforcement Manual for Air Pollution Control. Volume II: Control Technology and General Source Inspection.

ERIC Educational Resources Information Center

Weisburd, Melvin I.

The Field Operations and Enforcement Manual for Air Pollution Control, Volume II, explains in detail the following: technology of source control, modification of operations, particulate control equipment, sulfur dioxide removal systems for power plants, and control equipment for gases and vapors; inspection procedures for general sources, fuel…

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

PubMed

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

2005-05-01

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

Integrated optics reflectometer

DOEpatents

Couch, Philip R; Murphy, Kent A.; Gunther, Michael F; Gause, Charles B

2017-01-31

An apparatus includes a laser source configured to output laser light at a target frequency, and a measurement unit configured to measure a deviation between an actual frequency outputted by the laser source at a current period of time and the target frequency of the laser source. The apparatus includes a feedback control unit configured to, based on the measured deviation between the actual and target frequencies, control the laser source to maintain a constant frequency of laser output from the laser source so that the frequency of laser light transmitted from the laser source is adjusted to the target frequency. The feedback control unit can control the laser source to maintain a linear rate of change in the frequency of its laser light output, and compensate for characteristics of the measurement unit utilized for frequency measurement. A method is provided for performing the feedback control of the laser source.

Loop Heat Pipe Operation Using Heat Source Temperature for Set Point Control

NASA Technical Reports Server (NTRS)

Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

2011-01-01

Loop heat pipes (LHPs) have been used for thermal control of several NASA and commercial orbiting spacecraft. The LHP operating temperature is governed by the saturation temperature of its compensation chamber (CC). Most LHPs use the CC temperature for feedback control of its operating temperature. There exists a thermal resistance between the heat source to be cooled by the LHP and the LHP's CC. Even if the CC set point temperature is controlled precisely, the heat source temperature will still vary with its heat output. For most applications, controlling the heat source temperature is of most interest. A logical question to ask is: "Can the heat source temperature be used for feedback control of the LHP operation?" A test program has been implemented to answer the above question. Objective is to investigate the LHP performance using the CC temperature and the heat source temperature for feedback control

ISHN Ion Source Control System. First Steps Toward an EPICS Based ESS-Bilbao Accelerator Control System

NASA Astrophysics Data System (ADS)

Eguiraun, M.; Jugo, J.; Arredondo, I.; del Campo, M.; Feuchtwanger, J.; Etxebarria, V.; Bermejo, F. J.

2013-04-01

ISHN (Ion Source Hydrogen Negative) consists of a Penning type ion source in operation at ESS-Bilbao facilities. From the control point of view, this source is representative of the first steps and decisions taken towards the general control architecture of the whole accelerator to be built. The ISHN main control system is based on a PXI architecture, under a real-time controller which is programmed using LabVIEW. This system, with additional elements, is connected to the general control system. The whole system is based on EPICS for the control network, and the modularization of the communication layers of the accelerator plays an important role in the proposed control architecture.

A boundary element approach to optimization of active noise control sources on three-dimensional structures

NASA Technical Reports Server (NTRS)

Cunefare, K. A.; Koopmann, G. H.

1991-01-01

This paper presents the theoretical development of an approach to active noise control (ANC) applicable to three-dimensional radiators. The active noise control technique, termed ANC Optimization Analysis, is based on minimizing the total radiated power by adding secondary acoustic sources on the primary noise source. ANC Optimization Analysis determines the optimum magnitude and phase at which to drive the secondary control sources in order to achieve the best possible reduction in the total radiated power from the noise source/control source combination. For example, ANC Optimization Analysis predicts a 20 dB reduction in the total power radiated from a sphere of radius at a dimensionless wavenumber ka of 0.125, for a single control source representing 2.5 percent of the total area of the sphere. ANC Optimization Analysis is based on a boundary element formulation of the Helmholtz Integral Equation, and thus, the optimization analysis applies to a single frequency, while multiple frequencies can be treated through repeated analyses.

An integrated system for dynamic control of auditory perspective in a multichannel sound field

NASA Astrophysics Data System (ADS)

Corey, Jason Andrew

An integrated system providing dynamic control of sound source azimuth, distance and proximity to a room boundary within a simulated acoustic space is proposed for use in multichannel music and film sound production. The system has been investigated, implemented, and psychoacoustically tested within the ITU-R BS.775 recommended five-channel (3/2) loudspeaker layout. The work brings together physical and perceptual models of room simulation to allow dynamic placement of virtual sound sources at any location of a simulated space within the horizontal plane. The control system incorporates a number of modules including simulated room modes, "fuzzy" sources, and tracking early reflections, whose parameters are dynamically changed according to sound source location within the simulated space. The control functions of the basic elements, derived from theories of perception of a source in a real room, have been carefully tuned to provide efficient, effective, and intuitive control of a sound source's perceived location. Seven formal listening tests were conducted to evaluate the effectiveness of the algorithm design choices. The tests evaluated: (1) loudness calibration of multichannel sound images; (2) the effectiveness of distance control; (3) the resolution of distance control provided by the system; (4) the effectiveness of the proposed system when compared to a commercially available multichannel room simulation system in terms of control of source distance and proximity to a room boundary; (5) the role of tracking early reflection patterns on the perception of sound source distance; (6) the role of tracking early reflection patterns on the perception of lateral phantom images. The listening tests confirm the effectiveness of the system for control of perceived sound source distance, proximity to room boundaries, and azimuth, through fine, dynamic adjustment of parameters according to source location. All of the parameters are grouped and controlled together to create a perceptually strong impression of source location and movement within a simulated space.

21 CFR 123.28 - Source controls.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Source controls. 123.28 Section 123.28 Food and... CONSUMPTION FISH AND FISHERY PRODUCTS Raw Molluscan Shellfish § 123.28 Source controls. (a) In order to meet... molluscan shellfish harvested from growing waters approved for harvesting by a shellfish control authority...

21 CFR 123.28 - Source controls.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Source controls. 123.28 Section 123.28 Food and... CONSUMPTION FISH AND FISHERY PRODUCTS Raw Molluscan Shellfish § 123.28 Source controls. (a) In order to meet... molluscan shellfish harvested from growing waters approved for harvesting by a shellfish control authority...

21 CFR 123.28 - Source controls.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Source controls. 123.28 Section 123.28 Food and... CONSUMPTION FISH AND FISHERY PRODUCTS Raw Molluscan Shellfish § 123.28 Source controls. (a) In order to meet... molluscan shellfish harvested from growing waters approved for harvesting by a shellfish control authority...

21 CFR 123.28 - Source controls.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Source controls. 123.28 Section 123.28 Food and... CONSUMPTION FISH AND FISHERY PRODUCTS Raw Molluscan Shellfish § 123.28 Source controls. (a) In order to meet... molluscan shellfish harvested from growing waters approved for harvesting by a shellfish control authority...

Loop Heat Pipe Transient Behavior Using Heat Source Temperature for Set Point Control with Thermoelectric Converter on Reservoir

NASA Technical Reports Server (NTRS)

Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

2011-01-01

The LHP operating temperature is governed by the saturation temperature of its reservoir. Controlling the reservoir saturation temperature is commonly done by cold biasing the reservoir and using electrical heaters to provide the required control power. With this method, the loop operating temperature can be controlled within 0.5K or better. However, because the thermal resistance that exists between the heat source and the LHP evaporator, the heat source temperature will vary with its heat output even if the LHP operating temperature is kept constant. Since maintaining a constant heat source temperature is of most interest, a question often raised is whether the heat source temperature can be used for LHP set point temperature control. A test program with a miniature LHP was carried out to investigate the effects on the LHP operation when the control temperature sensor was placed on the heat source instead of the reservoir. In these tests, the LHP reservoir was cold-biased and was heated by a control heater. Test results show that it was feasible to use the heat source temperature for feedback control of the LHP operation. In particular, when a thermoelectric converter was used as the reservoir control heater, the heat source temperature could be maintained within a tight range using a proportional-integral-derivative or on/off control algorithm. Moreover, because the TEC could provide both heating and cooling to the reservoir, temperature oscillations during fast transients such as loop startup could be eliminated or substantially reduced when compared to using an electrical heater as the control heater.

Regulatory Control of Sealed Sources in Germany including Regulations Regarding Spent and Disused Sources - 13176

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

Dollan, Ralph; Haeusler, Uwe; Czarwinski, Renate

2013-07-01

Effective regulatory control is essential to ensure the safe and secure use of radioactive material and the appropriate management of radioactive waste. To ensure a sustainable control of high radioactive sources, the European Commission published the Council Directive 2003/122/EURATOM on the control of high-activity sealed radioactive sources and orphan sources, which had to be transferred into national legislation by all member states of the European Union. Major requirement of the Directive is a system to ensure traceability of high-activity sealed sources from 'cradle to grave' as well as the provision to take back disused sources by the supplier or manufacturer.more » With the Act on high-activity sealed radioactive sources Germany implemented the requirements of the Directive 2003/122/EURATOM and established a national registry of high-activity sealed sources in 2006. Currently, about 27.000 high-activity sealed sources are recorded in this national registry. (authors)« less

A wavenumber approach to analysing the active control of plane waves with arrays of secondary sources

NASA Astrophysics Data System (ADS)

Elliott, Stephen J.; Cheer, Jordan; Bhan, Lam; Shi, Chuang; Gan, Woon-Seng

2018-04-01

The active control of an incident sound field with an array of secondary sources is a fundamental problem in active control. In this paper the optimal performance of an infinite array of secondary sources in controlling a plane incident sound wave is first considered in free space. An analytic solution for normal incidence plane waves is presented, indicating a clear cut-off frequency for good performance, when the separation distance between the uniformly-spaced sources is equal to a wavelength. The extent of the near field pressure close to the source array is also quantified, since this determines the positions of the error microphones in a practical arrangement. The theory is also extended to oblique incident waves. This result is then compared with numerical simulations of controlling the sound power radiated through an open aperture in a rigid wall, subject to an incident plane wave, using an array of secondary sources in the aperture. In this case the diffraction through the aperture becomes important when its size is compatible with the acoustic wavelength, in which case only a few sources are necessary for good control. When the size of the aperture is large compared to the wavelength, and diffraction is less important but more secondary sources need to be used for good control, the results then become similar to those for the free field problem with an infinite source array.

Active Vibration Control for Helicopter Interior Noise Reduction Using Power Minimization

NASA Technical Reports Server (NTRS)

Mendoza, J.; Chevva, K.; Sun, F.; Blanc, A.; Kim, S. B.

2014-01-01

This report describes work performed by United Technologies Research Center (UTRC) for NASA Langley Research Center (LaRC) under Contract NNL11AA06C. The objective of this program is to develop technology to reduce helicopter interior noise resulting from multiple gear meshing frequencies. A novel active vibration control approach called Minimum Actuation Power (MAP) is developed. MAP is an optimal control strategy that minimizes the total input power into a structure by monitoring and varying the input power of controlling sources. MAP control was implemented without explicit knowledge of the phasing and magnitude of the excitation sources by driving the real part of the input power from the controlling sources to zero. It is shown that this occurs when the total mechanical input power from the excitation and controlling sources is a minimum. MAP theory is developed for multiple excitation sources with arbitrary relative phasing for single or multiple discrete frequencies and controlled by a single or multiple controlling sources. Simulations and experimental results demonstrate the feasibility of MAP for structural vibration reduction of a realistic rotorcraft interior structure. MAP control resulted in significant average global vibration reduction of a single frequency and multiple frequency excitations with one controlling actuator. Simulations also demonstrate the potential effectiveness of the observed vibration reductions on interior radiated noise.

Source Credibility in Tobacco Control Messaging

PubMed Central

Schmidt, Allison M.; Ranney, Leah M.; Pepper, Jessica K.; Goldstein, Adam O.

2016-01-01

Objectives Perceived credibility of a message’s source can affect persuasion. This paper reviews how beliefs about the source of tobacco control messages may encourage attitude and behavior change. Methods We conducted a series of searches of the peer-reviewed literature using terms from communication and public health fields. We reviewed research on source credibility, its underlying concepts, and its relation to the persuasiveness of tobacco control messages. Results We recommend an agenda for future research to bridge the gaps between communication literature on source credibility and tobacco control research. Our recommendations are to study the impact of source credibility on persuasion with long-term behavior change outcomes, in different populations and demographic groups, by developing new credibility measures that are topic- and organization-specific, by measuring how credibility operates across media platforms, and by identifying factors that enhance credibility and persuasion. Conclusions This manuscript reviews the state of research on source credibility and identifies gaps that are maximally relevant to tobacco control communication. Knowing first whether a source is perceived as credible, and second, how to enhance perceived credibility, can inform the development of future tobacco control campaigns and regulatory communications. PMID:27525298

GUIDE TO CLEANER TECHNOLOGIES: ORGANIC COATING REMOVAL

EPA Science Inventory

A cleaner technology is a source reduction or recycle method |applied to eliminate or significantly reduce hazardous waste generation. Source reduction includes product changes and source control. Source control can be further characterized as input material changes, technology...

40 CFR 63.42 - Program requirements governing construction or reconstruction of major sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... construction or reconstruction of major sources. 63.42 Section 63.42 Protection of Environment ENVIRONMENTAL... POLLUTANTS FOR SOURCE CATEGORIES Requirements for Control Technology Determinations for Major Sources in... achievable control technology emission limitation for new sources. [61 FR 68400, Dec. 27, 1996, as amended at...

14 CFR 27.1351 - General.

Code of Federal Regulations, 2013 CFR

2013-01-01

... generator; and (4) Each generator must have an overvoltage control designed and installed to prevent damage...) Electric power sources, their transmission cables, and their associated control and protective devices must... operation. (4) Each electric power source control must allow the independent operation of each source. (c...

14 CFR 27.1351 - General.

Code of Federal Regulations, 2014 CFR

2014-01-01

... generator; and (4) Each generator must have an overvoltage control designed and installed to prevent damage...) Electric power sources, their transmission cables, and their associated control and protective devices must... operation. (4) Each electric power source control must allow the independent operation of each source. (c...

14 CFR 27.1351 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... generator; and (4) Each generator must have an overvoltage control designed and installed to prevent damage...) Electric power sources, their transmission cables, and their associated control and protective devices must... operation. (4) Each electric power source control must allow the independent operation of each source. (c...

14 CFR 27.1351 - General.

Code of Federal Regulations, 2011 CFR

2011-01-01

... generator; and (4) Each generator must have an overvoltage control designed and installed to prevent damage...) Electric power sources, their transmission cables, and their associated control and protective devices must... operation. (4) Each electric power source control must allow the independent operation of each source. (c...

14 CFR 27.1351 - General.

Code of Federal Regulations, 2012 CFR

2012-01-01

... generator; and (4) Each generator must have an overvoltage control designed and installed to prevent damage...) Electric power sources, their transmission cables, and their associated control and protective devices must... operation. (4) Each electric power source control must allow the independent operation of each source. (c...

Survivability of Autonomous Microgrid during Overload Events

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

Du, Wei; Lasseter, Robert H.; Khalsa, Amrit S.

Grid-forming sources are voltage sources that draw necessary currents to meet any load changes. A load step can cause part or all of these sources to become overloaded in a microgrid. This paper presents an overload mitigation controller that addresses the two overload issues in a microgrid by actively controlling the sources’ frequency. When part of the sources in a microgrid is overloaded, the controller autonomously transfers the extra load to other sources by rapidly reducing its frequency. The frequency difference between sources during transient results in a change of phase angle, which redistributes the power flow. When all sourcesmore » in a microgrid are overloaded, each source keeps dropping the frequency. Therefore, under frequency load shedding can be used to trip the non-critical loads resulting in the survival of microgrid. The advantages of these concepts are that communications between sources are not needed during transient, and the robust voltage control is maintained. Lastly, simulation and field tests from CERTS/AEP microgrid test site verify that the control strategy is effective in both purely inverter-based microgrids and inverter & generator mixed microgrids.« less

Survivability of Autonomous Microgrid during Overload Events

DOE PAGES

Du, Wei; Lasseter, Robert H.; Khalsa, Amrit S.

2018-04-23

Grid-forming sources are voltage sources that draw necessary currents to meet any load changes. A load step can cause part or all of these sources to become overloaded in a microgrid. This paper presents an overload mitigation controller that addresses the two overload issues in a microgrid by actively controlling the sources’ frequency. When part of the sources in a microgrid is overloaded, the controller autonomously transfers the extra load to other sources by rapidly reducing its frequency. The frequency difference between sources during transient results in a change of phase angle, which redistributes the power flow. When all sourcesmore » in a microgrid are overloaded, each source keeps dropping the frequency. Therefore, under frequency load shedding can be used to trip the non-critical loads resulting in the survival of microgrid. The advantages of these concepts are that communications between sources are not needed during transient, and the robust voltage control is maintained. Lastly, simulation and field tests from CERTS/AEP microgrid test site verify that the control strategy is effective in both purely inverter-based microgrids and inverter & generator mixed microgrids.« less

Fast pulsed operation of a small non-radioactive electron source with continuous emission current control

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

Cochems, P.; Kirk, A. T.; Bunert, E.

Non-radioactive electron sources are of great interest in any application requiring the emission of electrons at atmospheric pressure, as they offer better control over emission parameters than radioactive electron sources and are not subject to legal restrictions. Recently, we published a simple electron source consisting only of a vacuum housing, a filament, and a single control grid. In this paper, we present improved control electronics that utilize this control grid in order to focus and defocus the electron beam, thus pulsing the electron emission at atmospheric pressure. This allows short emission pulses and excellent stability of the emitted electron currentmore » due to continuous control, both during pulsed and continuous operations. As an application example, this electron source is coupled to an ion mobility spectrometer. Here, the pulsed electron source allows experiments on gas phase ion chemistry (e.g., ion generation and recombination kinetics) and can even remove the need for a traditional ion shutter.« less

X-ray source assembly having enhanced output stability, and fluid stream analysis applications thereof

DOEpatents

Radley, Ian [Glenmont, NY; Bievenue, Thomas J [Delmar, NY; Burdett, John H [Charlton, NY; Gallagher, Brian W [Guilderland, NY; Shakshober, Stuart M [Hudson, NY; Chen, Zewu [Schenectady, NY; Moore, Michael D [Alplaus, NY

2008-06-08

An x-ray source assembly and method of operation are provided having enhanced output stability. The assembly includes an anode having a source spot upon which electrons impinge and a control system for controlling position of the anode source spot relative to an output structure. The control system can maintain the anode source spot location relative to the output structure notwithstanding a change in one or more operating conditions of the x-ray source assembly. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.

Dynamic power flow controllers

DOEpatents

Divan, Deepakraj M.; Prasai, Anish

2017-03-07

Dynamic power flow controllers are provided. A dynamic power flow controller may comprise a transformer and a power converter. The power converter is subject to low voltage stresses and not floated at line voltage. In addition, the power converter is rated at a fraction of the total power controlled. A dynamic power flow controller controls both the real and the reactive power flow between two AC sources having the same frequency. A dynamic power flow controller inserts a voltage with controllable magnitude and phase between two AC sources; thereby effecting control of active and reactive power flows between two AC sources.

10 CFR 36.31 - Control of source movement.

Code of Federal Regulations, 2014 CFR

2014-01-01

... portable radiation survey meter by a chain or cable. The lock for source control must be designed so that... 10 Energy 1 2014-01-01 2014-01-01 false Control of source movement. 36.31 Section 36.31 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Design and...

10 CFR 36.31 - Control of source movement.

Code of Federal Regulations, 2013 CFR

2013-01-01

... portable radiation survey meter by a chain or cable. The lock for source control must be designed so that... 10 Energy 1 2013-01-01 2013-01-01 false Control of source movement. 36.31 Section 36.31 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Design and...

10 CFR 36.31 - Control of source movement.

Code of Federal Regulations, 2012 CFR

2012-01-01

... portable radiation survey meter by a chain or cable. The lock for source control must be designed so that... 10 Energy 1 2012-01-01 2012-01-01 false Control of source movement. 36.31 Section 36.31 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Design and...

10 CFR 36.31 - Control of source movement.

Code of Federal Regulations, 2010 CFR

2010-01-01

... portable radiation survey meter by a chain or cable. The lock for source control must be designed so that... 10 Energy 1 2010-01-01 2010-01-01 false Control of source movement. 36.31 Section 36.31 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Design and...

10 CFR 36.31 - Control of source movement.

Code of Federal Regulations, 2011 CFR

2011-01-01

... portable radiation survey meter by a chain or cable. The lock for source control must be designed so that... 10 Energy 1 2011-01-01 2011-01-01 false Control of source movement. 36.31 Section 36.31 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Design and...

40 CFR 450.24 - New source performance standards reflecting the best available demonstrated control technology...

Code of Federal Regulations, 2011 CFR

2011-07-01

... performance standards reflecting the best available demonstrated control technology (NSPS). Any new source... 40 Protection of Environment 30 2011-07-01 2011-07-01 false New source performance standards reflecting the best available demonstrated control technology (NSPS). 450.24 Section 450.24 Protection of...

40 CFR 450.24 - New source performance standards reflecting the best available demonstrated control technology...

Code of Federal Regulations, 2010 CFR

2010-07-01

... performance standards reflecting the best available demonstrated control technology (NSPS). Any new source... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards reflecting the best available demonstrated control technology (NSPS). 450.24 Section 450.24 Protection of...

40 CFR 63.5716 - When must I conduct a performance test?

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES... for Open Molding Operations Controlled by Add-on Control Devices § 63.5716 When must I conduct a performance test? (a) If your source is an existing source, you must complete the add-on control device...

Early Versus Delayed Source Control in Open Abdomen Management for Severe Intra-abdominal Infections: A Retrospective Analysis on 111 Cases.

PubMed

Rausei, Stefano; Pappalardo, Vincenzo; Ruspi, Laura; Colella, Antonio; Giudici, Simone; Ardita, Vincenzo; Frattini, Francesco; Rovera, Francesca; Boni, Luigi; Dionigi, Gianlorenzo

2018-03-01

Time to source control plays a determinant prognostic role in patients having severe intra-abdominal infections (IAIs). Open abdomen (OA) management became an effective treatment option for peritonitis. Aim of this study was to analyze the correlation between time to source control and outcome in patients presenting with abdominal sepsis and treated by OA. We retrospectively analyzed 111 patients affected by abdominal sepsis and treated with OA from May 2007 to May 2015. Patients were classified according to time interval from first patient evaluation to source control. The end points were intra-hospital mortality and primary fascial closure rate. The in-hospital mortality rate was 21.6% (24/111), and the primary fascial closure rate was 90.9% (101/111). A time to source control ≥6 h resulted significantly associated with a poor prognosis and a lower fascial closure rate (mortality 27.0 vs 9.0%, p = 0.04; primary fascial closure 86 vs 100%, p = 0.02). We observed a direct increase in mortality (and a reduction in closure rate) for each 6-h delay in surgery to source control. Early source control using OA management significantly improves outcome of patients with severe IAIs. This damage control approach well fits to the treatment of time-related conditions, particularly in case of critically ill patients.

Power flow controller with a fractionally rated back-to-back converter

DOEpatents

Divan, Deepakraj M.; Kandula, Rajendra Prasad; Prasai, Anish

2016-03-08

A power flow controller with a fractionally rated back-to-back (BTB) converter is provided. The power flow controller provide dynamic control of both active and reactive power of a power system. The power flow controller inserts a voltage with controllable magnitude and phase between two AC sources at the same frequency; thereby effecting control of active and reactive power flows between the two AC sources. A transformer may be augmented with a fractionally rated bi-directional Back to Back (BTB) converter. The fractionally rated BTB converter comprises a transformer side converter (TSC), a direct-current (DC) link, and a line side converter (LSC). By controlling the switches of the BTB converter, the effective phase angle between the two AC source voltages may be regulated, and the amplitude of the voltage inserted by the power flow controller may be adjusted with respect to the AC source voltages.

X-ray source assembly having enhanced output stability, and fluid stream analysis applications thereof

DOEpatents

Radley, Ian; Bievenue, Thomas J.; Burdett Jr., John H.; Gallagher, Brian W.; Shakshober, Stuart M.; Chen, Zewu; Moore, Michael D.

2007-04-24

An x-ray source assembly (2700) and method of operation are provided having enhanced output stability. The assembly includes an anode (2125) having a source spot upon which electrons (2120) impinge and a control system (2715/2720) for controlling position of the anode source spot relative to an output structure. The control system can maintain the anode source spot location relative to the output structure (2710) notwithstanding a change in one or more operating conditions of the x-ray source assembly. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.

Source-Monitoring Training Facilitates Preschoolers' Eyewitness Memory Performance.

ERIC Educational Resources Information Center

Thierry, Karen L.; Spence, Melanie J.

2002-01-01

Investigated whether source-monitoring training would decrease 3- to 4-year-olds' suggestibility. After observing live or video target-events, children received source-monitoring or recognition (control) training. Found that children given source-monitoring training were more accurate than control group children in response to misleading and…

The use of an active controlled enclosure to attenuate sound radiation from a heavy radiator

NASA Astrophysics Data System (ADS)

Sun, Yao; Yang, Tiejun; Zhu, Minggang; Pan, Jie

2017-03-01

Active structural acoustical control usually experiences difficulty in the control of heavy sources or sources where direct applications of control forces are not practical. To overcome this difficulty, an active controlled enclosure, which forms a cavity with both flexible and open boundary, is employed. This configuration permits indirect implementation of active control in which the control inputs can be applied to subsidiary structures other than the sources. To determine the control effectiveness of the configuration, the vibro-acoustic behavior of the system, which consists of a top plate with an open, a sound cavity and a source panel, is investigated in this paper. A complete mathematical model of the system is formulated involving modified Fourier series formulations and the governing equations are solved using the Rayleigh-Ritz method. The coupling mechanisms of a partly opened cavity and a plate are analysed in terms of modal responses and directivity patterns. Furthermore, to attenuate sound power radiated from both the top panel and the open, two strategies are studied: minimizing the total radiated power and the cancellation of volume velocity. Moreover, three control configurations are compared, using a point force on the control panel (structural control), using a sound source in the cavity (acoustical control) and applying hybrid structural-acoustical control. In addition, the effects of boundary condition of the control panel on the sound radiation and control performance are discussed.

Development of emissions inventory and identification of sources for priority control in the middle reaches of Yangtze River Urban Agglomerations.

PubMed

Sun, Xiaowei; Cheng, Shuiyuan; Lang, Jianlei; Ren, Zhenhai; Sun, Chao

2018-06-01

This paper presents the first attempt to investigate the emission source control of the Middle Reaches of Yangtze River Urban Agglomerations (MRYRUA), one of the national urban agglomerations in China. An emission inventory of the MRYRUA was developed as inputs to the CAMx model based on county-level activity data obtained by full-coverage investigation and source-based spatial surrogates. A classification technology method for priority control of atmospheric emission sources was introduced and applied in the MRYRUA for the evaluation of the emission sources control on the region-scale and city-scale, respectively. The results demonstrated that the emission sources in the Hefei-centered urban agglomerations contributed the biggest on the mean PM 2.5 concentrations of the MRYRUA and should be taken the priority to control. The emission sources in the Ma'anshan city, Xiangtan city, Hefei city and Wuhan city were the bigger contributors on the mean PM 2.5 concentrations of the MRYRUA among the cities and should be taken the priority to control. In generally, emission sources in cities along the Yangtze River and the tributary should be given the special attention for the regional air quality target attainments. This study can give an understanding of Chinese emissions and provide a valuable preference to policy makers for finding effective mitigation measures and control strategies for reducing national and regional air pollution in China. Copyright © 2017 Elsevier B.V. All rights reserved.

21 CFR 123.28 - Source controls.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Source controls. 123.28 Section 123.28 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION FISH AND FISHERY PRODUCTS Raw Molluscan Shellfish § 123.28 Source controls. (a) In order to meet...

40 CFR 63.55 - Maximum achievable control technology (MACT) determinations for affected sources subject to case...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Maximum achievable control technology (MACT) determinations for affected sources subject to case-by-case determination of equivalent emission... Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air Act Sections...

40 CFR 63.55 - Maximum achievable control technology (MACT) determinations for affected sources subject to case...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Maximum achievable control technology (MACT) determinations for affected sources subject to case-by-case determination of equivalent emission... Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air Act Sections...

40 CFR 63.55 - Maximum achievable control technology (MACT) determinations for affected sources subject to case...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Maximum achievable control technology (MACT) determinations for affected sources subject to case-by-case determination of equivalent emission... Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air Act Sections...

40 CFR 63.55 - Maximum achievable control technology (MACT) determinations for affected sources subject to case...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Maximum achievable control technology (MACT) determinations for affected sources subject to case-by-case determination of equivalent emission... Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air Act Sections...

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

PubMed

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

2013-02-01

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

40 CFR 63.4081 - Am I subject to this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

... source or group of stationary sources located within a contiguous area and under common control that... sources located within a contiguous area and under common control that is not a major source. (b) The..., spray guns or dip tanks; (4) Application of porcelain enamel, powder coating, and asphalt interior...

40 CFR 63.4081 - Am I subject to this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

... source or group of stationary sources located within a contiguous area and under common control that... sources located within a contiguous area and under common control that is not a major source. (b) The..., spray guns or dip tanks; (4) Application of porcelain enamel, powder coating, and asphalt interior...

40 CFR 63.4081 - Am I subject to this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

... source or group of stationary sources located within a contiguous area and under common control that... sources located within a contiguous area and under common control that is not a major source. (b) The..., spray guns or dip tanks; (4) Application of porcelain enamel, powder coating, and asphalt interior...

Energy storage connection system

DOEpatents

Benedict, Eric L.; Borland, Nicholas P.; Dale, Magdelena; Freeman, Belvin; Kite, Kim A.; Petter, Jeffrey K.; Taylor, Brendan F.

2012-07-03

A power system for connecting a variable voltage power source, such as a power controller, with a plurality of energy storage devices, at least two of which have a different initial voltage than the output voltage of the variable voltage power source. The power system includes a controller that increases the output voltage of the variable voltage power source. When such output voltage is substantially equal to the initial voltage of a first one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the first one of the energy storage devices. The controller then causes the output voltage of the variable voltage power source to continue increasing. When the output voltage is substantially equal to the initial voltage of a second one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the second one of the energy storage devices.

Laser interlock system

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

Woodruff, Steven D; Mcintyre, Dustin L

2015-01-13

A method and device for providing a laser interlock having a first optical source, a first beam splitter, a second optical source, a detector, an interlock control system, and a means for producing dangerous optical energy. The first beam splitter is optically connected to the first optical source, the first detector and the second optical source. The detector is connected to the interlock control system. The interlock control system is connected to the means for producing dangerous optical energy and configured to terminate its optical energy production upon the detection of optical energy at the detector from the second opticalmore » source below a predetermined detector threshold. The second optical source produces an optical energy in response to optical energy from the first optical source. The optical energy from the second optical source has a different wavelength, polarization, modulation or combination thereof from the optical energy of the first optical source.« less

Automatic control of a negative ion source

NASA Astrophysics Data System (ADS)

Saadatmand, K.; Sredniawski, J.; Solensten, L.

1989-04-01

A CAMAC based control architecture is devised for a Berkeley-type H - volume ion source [1]. The architecture employs three 80386 TM PCs. One PC is dedicated to control and monitoring of source operation. The other PC functions with digitizers to provide data acquisition of waveforms. The third PC is used for off-line analysis. Initially, operation of the source was put under remote computer control (supervisory). This was followed by development of an automated startup procedure. Finally, a study of the physics of operation is now underway to establish a data base from which automatic beam optimization can be derived.

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

Fernandez-Gutierrez, Sulmer, E-mail: sulmer.a.fernandez.gutierrez@intel.com; Browning, Jim; Lin, Ming-Chieh

Phase-control of a magnetron is studied via simulation using a combination of a continuous current source and a modulated current source. The addressable, modulated current source is turned ON and OFF at the magnetron operating frequency in order to control the electron injection and the spoke phase. Prior simulation work using a 2D model of a Rising Sun magnetron showed that the use of 100% modulated current controlled the magnetron phase and allowed for dynamic phase control. In this work, the minimum fraction of modulated current source needed to achieve a phase control is studied. The current fractions (modulated versusmore » continuous) were varied from 10% modulated current to 100% modulated current to study the effects on phase control. Dynamic phase-control, stability, and start up time of the device were studied for all these cases showing that with 10% modulated current and 90% continuous current, a phase shift of 180° can be achieved demonstrating dynamic phase control.« less

Analytical investigation of adaptive control of radiated inlet noise from turbofan engines

NASA Technical Reports Server (NTRS)

Risi, John D.; Burdisso, Ricardo A.

1994-01-01

An analytical model has been developed to predict the resulting far field radiation from a turbofan engine inlet. A feedforward control algorithm was simulated to predict the controlled far field radiation from the destructive combination of fan noise and secondary control sources. Numerical results were developed for two system configurations, with the resulting controlled far field radiation patterns showing varying degrees of attenuation and spillover. With one axial station of twelve control sources and error sensors with equal relative angular positions, nearly global attenuation is achieved. Shifting the angular position of one error sensor resulted in an increase of spillover to the extreme sidelines. The complex control inputs for each configuration was investigated to identify the structure of the wave pattern created by the control sources, giving an indication of performance of the system configuration. It is deduced that the locations of the error sensors and the control source configuration are equally critical to the operation of the active noise control system.

Current Source Based on H-Bridge Inverter with Output LCL Filter

NASA Astrophysics Data System (ADS)

Blahnik, Vojtech; Talla, Jakub; Peroutka, Zdenek

2015-09-01

The paper deals with a control of current source with an LCL output filter. The controlled current source is realized as a single-phase inverter and output LCL filter provides low ripple of output current. However, systems incorporating LCL filters require more complex control strategies and there are several interesting approaches to the control of this type of converter. This paper presents the inverter control algorithm, which combines model based control with a direct current control based on resonant controllers and single-phase vector control. The primary goal is to reduce the current ripple and distortion under required limits and provides fast and precise control of output current. The proposed control technique is verified by measurements on the laboratory model.

Religious belief as compensatory control.

PubMed

Kay, Aaron C; Gaucher, Danielle; McGregor, Ian; Nash, Kyle

2010-02-01

The authors review experimental evidence that religious conviction can be a defensive source of compensatory control when personal or external sources of control are low. They show evidence that (a) belief in religious deities and secular institutions can serve as external forms of control that can compensate for manipulations that lower personal control and (b) religious conviction can also serve as compensatory personal control after experimental manipulations that lower other forms of personal or external control. The authors review dispositional factors that differentially orient individuals toward external or personal varieties of compensatory control and conclude that compensatory religious conviction can be a flexible source of personal and external control for relief from the anxiety associated with random and uncertain experiences.

Intelligent and robust optimization frameworks for smart grids

NASA Astrophysics Data System (ADS)

Dhansri, Naren Reddy

A smart grid implies a cyberspace real-time distributed power control system to optimally deliver electricity based on varying consumer characteristics. Although smart grids solve many of the contemporary problems, they give rise to new control and optimization problems with the growing role of renewable energy sources such as wind or solar energy. Under highly dynamic nature of distributed power generation and the varying consumer demand and cost requirements, the total power output of the grid should be controlled such that the load demand is met by giving a higher priority to renewable energy sources. Hence, the power generated from renewable energy sources should be optimized while minimizing the generation from non renewable energy sources. This research develops a demand-based automatic generation control and optimization framework for real-time smart grid operations by integrating conventional and renewable energy sources under varying consumer demand and cost requirements. Focusing on the renewable energy sources, the intelligent and robust control frameworks optimize the power generation by tracking the consumer demand in a closed-loop control framework, yielding superior economic and ecological benefits and circumvent nonlinear model complexities and handles uncertainties for superior real-time operations. The proposed intelligent system framework optimizes the smart grid power generation for maximum economical and ecological benefits under an uncertain renewable wind energy source. The numerical results demonstrate that the proposed framework is a viable approach to integrate various energy sources for real-time smart grid implementations. The robust optimization framework results demonstrate the effectiveness of the robust controllers under bounded power plant model uncertainties and exogenous wind input excitation while maximizing economical and ecological performance objectives. Therefore, the proposed framework offers a new worst-case deterministic optimization algorithm for smart grid automatic generation control.

Deep prospecting electromagnetic system and its application

NASA Astrophysics Data System (ADS)

Lin, J.; Liu, C.; Zhou, F.; Zhang, W.; Chen, J.; Xue, K.; Sun, C.; Xu, W.; Hu, R.

2011-12-01

Today mineral resource is becoming the impediment to the society development because less and less mineral resource can be available. People are trying all kinds of technological tools to find the mineral deposit concealed in deep lithosphere. Unfortunately, current technology can not meet the exploration requirement completely and it is still difficult to know whether a deep mineral deposit exists and how it is presented at a considered site. In order to meet the requirement of discovering the mineral deposit in the second mine prospecting space (500-2000m under earth surface), we developed a deep prospecting electromagnetic system (DPS-I). This system consists of an electromagnetic receiver array and a high-power transmitter. The receiver array consists of 24 sub-receivers and one controller and has up to 53 electromagnetic channels. The sub-receivers can be extended conveniently if the user would like and they communicate with the controller through a cable or wireless antenna. When the channel interval is set to typical value of 50 m, the system can cover 2500 m survey line at one arrangement with two magnetic records. Since the signals are collected at the same time some disturbances, such as time variable but space invariable noise, will be suppressed because they have almost the same effect to all channels. The transmitter is designed to be 45 KW of upper power limit so that strong signals will be detected. Series transmission technology is adopted to avoid unwieldiness of transmitter. In fact it is made of three portable transmission units and each one can work independently. The system can transmit several kinds of waves and records all samples of signals in time sequences. So it can work for different electromagnetic methods. The prior methods for our application are the combination of IP, CSAMT and MT. Utilizing joint inversion and model restriction, we can obtain more refined model at large depth than conventional exploration. We have applied this system in China to detect nickel ore, iron ore, geothermic water and formation buried in deep earth successfully with high resolution power and the largest depth of investigation exceeded 2000 m. The nickel ore is located at Hongqiling hill, Jilin province. The depth of its top surface is about 600 m and that of its bottom surface is about 900 m. The iron ore is located at Dataigou, Liaoning province. Its top surface is buried about 1200 m beneath the ground and its bottom surface is still not assured because the deepest bore didn't reach its bottom. According to the known information, the bottom surface is inferred to be deeper than 2000 m. The geothermic water is buried deeply about 1600 m beneath the ground, located at Baishan, Jilin province. A bore of 2200 m depth was dilled after our exploration and hot water flowed out from the bore. Although several power lines exist nearby the survey lines, we still observed obvious signals and find low resistivity region at the place where the ore and the water exist. These experiments show that our electromagnetic system is successful.

SOURCEBOOK: NOX CONTROL TECHNOLOGY DATA

EPA Science Inventory

The report, a compilation of available information on the control of nitrogen oxide (NOx) emissions from stationary sources, is provided to assist new source permitting activities by regulatory agencies. he sources covered are combustion turbines, internal combustion engines, non...

Design structure for in-system redundant array repair in integrated circuits

DOEpatents

Bright, Arthur A.; Crumley, Paul G.; Dombrowa, Marc; Douskey, Steven M.; Haring, Rudolf A.; Oakland, Steven F.; Quellette, Michael R.; Strissel, Scott A.

2008-11-25

A design structure for repairing an integrated circuit during operation of the integrated circuit. The integrated circuit comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The design structure provides the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The design structure further passes the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

Fate of hydrocarbon pollutants in source and non-source control sustainable drainage systems.

PubMed

Roinas, Georgios; Mant, Cath; Williams, John B

2014-01-01

Sustainable drainage (SuDs) is an established method for managing runoff from developments, and source control is part of accepted design philosophy. However, there are limited studies into the contribution source control makes to pollutant removal, especially for roads. This study examines organic pollutants, total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs), in paired source and non-source control full-scale SuDs systems. Sites were selected to cover local roads, trunk roads and housing developments, with a range of SuDs, including porous asphalt, swales, detention basins and ponds. Soil and water samples were taken bi-monthly over 12 months to assess pollutant loads. Results show first flush patterns in storm events for solids, but not for TPH. The patterns of removal for specific PAHs were also different, reflecting varying physico-chemical properties. The potential of trunk roads for pollution was illustrated by peak runoff for TPH of > 17,000 μg/l. Overall there was no significant difference between pollutant loads from source and non-source control systems, but the dynamic nature of runoff means that longer-term data are required. The outcomes of this project will increase understanding of organic pollutants behaviour in SuDs. This will provide design guidance about the most appropriate systems for treating these pollutants.

Hydrothermal reservoir beneath Taal Volcano (Philippines): Implications to volcanic activity

NASA Astrophysics Data System (ADS)

Nagao, T.; Alanis, P. B.; Yamaya, Y.; Takeuchi, A.; Bornas, M. V.; Cordon, J. M.; Puertollano, J.; Clarito, C. J.; Hashimoto, T.; Mogi, T.; Sasai, Y.

2012-12-01

Taal Volcano is one of the most active volcanoes in the Philippines. The first recorded eruption was in 1573. Since then it has erupted 33 times resulting in thousands of casualties and large damages to property. In 1995, it was declared as one of the 15 Decade Volcanoes. Beginning in the early 1990s it has experienced several phases of abnormal activity, including seismic swarms, episodes of ground deformation, ground fissuring and hydrothermal activities, which continues up to the present. However, it has been noted that past historical eruptions of Taal Volcano may be divided into 2 distinct cycles, depending on the location of the eruption center, either at Main Crater or at the flanks. Between 1572-1645, eruptions occurred at the Main Crater, in 1707 to 1731, they occurred at the flanks. In 1749, eruptions moved back to the Main Crater until 1911. During the 1965 and until the end of the 1977 eruptions, eruptive activity once again shifted to the flanks. As part of the PHIVOLCS-JICA-SATREPS Project magnetotelluric and audio-magnetotelluric surveys were conducted on Volcano Island in March 2011 and March 2012. Two-dimensional (2-D) inversion and 3-D forward modeling reveals a prominent and large zone of relatively high resistivity between 1 to 4 kilometers beneath the volcano almost directly beneath the Main Crater, surrounded by zones of relatively low resistivity. This anomalous zone of high resistivity is hypothesized to be a large hydrothermal reservoir filled with volcanic fluids. The presence of this large hydrothermal reservoir could be related to past activities of Taal Volcano. In particular we believe that the catastrophic explosion described during the 1911 eruption was the result of the hydrothermal reservoir collapsing. During the cycle of Main Crater eruptions, this hydrothermal reservoir is depleted, while during a cycle of flank eruptions this reservoir is replenished with hydrothermal fluids.

Geophysical characterization of Range-Front Faults, Snake Valley, Nevada

USGS Publications Warehouse

Asch, Theodore H.; Sweetkind, Donald S.

2010-01-01

In September 2009, the U.S. Geological Survey, in cooperation with the National Park Service, collected audiomagnetotelluric (AMT) data along two profiles on the eastern flank of the Snake Range near Great Basin National Park to refine understanding of the subsurface geology. Line 1 was collected along Baker Creek, was approximately 6.7-km long, and recorded subsurface geologic conditions to approximately 800-m deep. Line 2, collected farther to the southeast in the vicinity of Kious Spring, was 2.8-km long, and imaged to depths of approximately 600 m. The two AMT lines are similar in their electrical response and are interpreted to show generally similar subsurface geologic conditions. The geophysical response seen on both lines may be described by three general domains of electrical response: (1) a shallow (mostly less than 100-200-m deep) domain of highly variable resistivity, (2) a deep domain characterized by generally high resistivity that gradually declines eastward to lower resistivity with a steeply dipping grain or fabric, and (3) an eastern domain in which the resistivity character changes abruptly at all depths from that in the western domain. The shallow, highly variable domain is interpreted to be the result of a heterogeneous assemblage of Miocene conglomerate and incorporated megabreccia blocks overlying a shallowly eastward-dipping southern Snake Range detachment fault. The deep domain of generally higher resistivity is interpreted as Paleozoic sedimentary rocks (Pole Canyon limestone and Prospect Mountain Quartzite) and Mesozoic and Cenozoic plutonic rocks occurring beneath the detachment surface. The range of resistivity values within this deep domain may result from fracturing adjacent to the detachment, the presence of Paleozoic rock units of variable resistivities that do not crop out in the vicinity of the lines, or both. The eastern geophysical domain is interpreted to be a section of Miocene strata at depth, overlain by Quaternary alluvial fill. These deposits lie east of a steeply east-dipping normal fault that cuts all units and has about 100 m of east-side-down offset.

Basin Characterisation by Means of Joint Inversion of Electromagnetic Geophysical Data, Borehole Data and Multivariate Statistical Methods: The Loop Head Peninsula, Western Ireland, Case Study

NASA Astrophysics Data System (ADS)

Campanya, J. L.; Ogaya, X.; Jones, A. G.; Rath, V.; McConnell, B.; Haughton, P.; Prada, M.

2016-12-01

The Science Foundation Ireland funded project IRECCSEM project (www.ireccsem.ie) aims to evaluate Ireland's potential for onshore carbon sequestration in saline aquifers by integrating new electromagnetic geophysical data with existing geophysical and geological data. One of the objectives of this component of IRECCSEM is to characterise the subsurface beneath the Loop Head Peninsula (part of Clare Basin, Co. Clare, Ireland), and identify major electrical resistivity structures that can guide an interpretation of the carbon sequestration potential of this area. During the summer of 2014, a magnetotelluric (MT) survey was carried out on the Loop Head Peninsula, and data from a total of 140 sites were acquired, including audio-magnetotelluric (AMT), and broadband magnetotelluric (BBMT). The dataset was used to generate shallow three-dimensional (3-D) electrical resistivity models constraining the subsurface to depths of up to 3.5 km. The three-dimensional (3-D) joint inversions were performed using three different types of electromagnetic data: MT impedance tensor (Z), geomagnetic transfer functions (T), and inter-station horizontal magnetic transfer-functions (H). The interpretation of the results was complemented with second-derivative models of the resulting electrical resistivity models, and a quantitative comparison with borehole data using multivariate statistical methods. Second-derivative models were used to define the main interfaces between the geoelectrical structures, facilitating superior comparison with geological and seismic results, and also reducing the influence of the colour scale when interpreting the results. Specific analysis was performed to compare the extant borehole data with the electrical resistivity model, identifying those structures that are better characterised by the resistivity model. Finally, the electrical resistivity model was also used to propagate some of the physical properties measured in the borehole, when a good relation was possible between the different types of data. The final results were compared with independent geological and geophysical data for a high-quality interpretation.

Assessment of groundwater contamination by gypsum dissolution in San Luis Potosí (México) using geoelectrical characterization

NASA Astrophysics Data System (ADS)

Arango-Galvan, C.; Ramos-Leal, J. A.; Yáñez-Rodríguez, M. A.; Corbo-Camargo, F.

2017-12-01

The Cerritos and Río Verde aquifers in San Luis Potosí (central México) make up a very complex aquifer system that is seriously affected by the overexploitation and the high concentration of sulphates. Currently, it is partially closed for extraction causing a substantial decrease in per capita drinking water availability affecting to more than 50,000 inhabitants in the region. Therefore, a very comprehensive study has been proposed in order to evaluate not only the groundwater contamination distribution but also to better know the aquifer configuration and its main hydrogeological characteristics as well. These studies include a detailed geological reconnaissance, hydrogeochemical analyses and a geoelectrical characterization. The main goal is to assess the aquifer geometry and to identify the gypsum horizons causing the presence of higher concentrations of sulphates in drinking water. A total of 26 audiomagnetotelluric soundings were measured and modelled along profiles following a perpendicular direction to the NW regional trending. Two-dimensional resistivity models suggest the presence of a shallow conductive layer (C1) with resistivity values ranging from 10 to 20 Ohm.m. It is related to the upper aquifer with a very low exploitation potential. A less conductive horizon (C2; 50 Ohm.m) underlying the shallow aquifer could be related to a very fractured limestone horizon forming a confined aquifer in the middle of the valley. A very resistive layer (R1) is observed underlying C1 and C2 units. This strata shows higher resistivity values (>100 Ohm.m) and could be associated with a reefal limestone identified as El Abra Formation. Finally, a conductive layer (<100 Ohm.m) observed beneath this horizon could be related to the oldest stratigraphic unit outcropping on the region, the Guaxcamá Formation, a gypsum-enriched unit, that contributes to the presence of sulphates in the upper aquifers by dissolution processes.

EPA Air Pollution Control Cost Manual

EPA Science Inventory

EPA's Air Pollution Control Cost Manual provides guidance for the development of accurate and consistent costs for air pollution control devices. A long-standing document prepared by EPA, the Control Cost Manual focuses on point source and stationary area source air pollution con...

Solid state light source driver establishing buck or boost operation

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

Palmer, Fred

A solid state light source driver circuit that operates in either a buck convertor or a boost convertor configuration is provided. The driver circuit includes a controller, a boost switch circuit and a buck switch circuit, each coupled to the controller, and a feedback circuit, coupled to the light source. The feedback circuit provides feedback to the controller, representing a DC output of the driver circuit. The controller controls the boost switch circuit and the buck switch circuit in response to the feedback signal, to regulate current to the light source. The controller places the driver circuit in its boostmore » converter configuration when the DC output is less than a rectified AC voltage coupled to the driver circuit at an input node. The controller places the driver circuit in its buck converter configuration when the DC output is greater than the rectified AC voltage at the input node.« less

Aircraft Drag Prediction and Reduction

DTIC Science & Technology

1985-07-01

Figure 10 with their subsources. The major source groups are the airfiame noise sources, the propulsion system noise sources, and the lamirar-flow control ...the emerging areas of non -planar geometry and large-eddy alteration. Turbulent control techniques for air generally result in modest (but...17. 57. Ketchem, Jeffery J.; and Velkoff, Henry R.: An Experimental Investigation of the Effect of Electrically Induced Controlled Frequency

NicoLase—An open-source diode laser combiner, fiber launch, and sequencing controller for fluorescence microscopy

PubMed Central

Walsh, James; Böcking, Till; Gaus, Katharina

2017-01-01

Modern fluorescence microscopy requires software-controlled illumination sources with high power across a wide range of wavelengths. Diode lasers meet the power requirements and combining multiple units into a single fiber launch expands their capability across the required spectral range. We present the NicoLase, an open-source diode laser combiner, fiber launch, and software sequence controller for fluorescence microscopy and super-resolution microscopy applications. Two configurations are described, giving four or six output wavelengths and one or two single-mode fiber outputs, with all CAD files, machinist drawings, and controller source code openly available. PMID:28301563

Perception and Selection of Information Sources by Undergraduate Students: Effects of Avoidant Style, Confidence, and Personal Control in Problem-Solving

ERIC Educational Resources Information Center

Kim, Kyung-Sun; Sin, Sei-Ching Joanna

2007-01-01

A survey of undergraduate students examined how students' beliefs about their problem-solving styles and abilities (including avoidant style, confidence, and personal control in problem-solving) influenced their perception and selection of sources, as reflected in (1) perceived characteristics of sources, (2) source characteristics considered…

Monitoring Guidance for Determining the Effectiveness of Nonpoint Source Controls

EPA Pesticide Factsheets

A nonpoint source monitoring and evaluation guide written for use by those who monitor and those who evaluate monitoring proposals. It focuses on monitoring to determine the effectiveness of nonpoint source controls at the watershed and practice levels

Control Techniques for Particulate Air Pollutants.

ERIC Educational Resources Information Center

National Air Pollution Control Administration (DHEW), Washington, DC.

Included is a comprehensive review of the approaches commonly recommended for controlling the sources of particulate air pollution. Not all possible combinations of control techniques that might bring about more stringent control of each individual source are reviewed. The many agricultural, commercial, domestic, industrial, and municipal…

Method and apparatus for in-system redundant array repair on integrated circuits

DOEpatents

Bright, Arthur A [Croton-on-Hudson, NY; Crumley, Paul G [Yorktown Heights, NY; Dombrowa, Marc B [Bronx, NY; Douskey, Steven M [Rochester, MN; Haring, Rudolf A [Cortlandt Manor, NY; Oakland, Steven F [Colchester, VT; Ouellette, Michael R [Westford, VT; Strissel, Scott A [Byron, MN

2008-07-29

Disclosed is a method of repairing an integrated circuit of the type comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The method comprises the steps of providing the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The method comprises the further step of, at a given time, passing the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

Method and apparatus for in-system redundant array repair on integrated circuits

DOEpatents

Bright, Arthur A [Croton-on-Hudson, NY; Crumley, Paul G [Yorktown Heights, NY; Dombrowa, Marc B [Bronx, NY; Douskey, Steven M [Rochester, MN; Haring, Rudolf A [Cortlandt Manor, NY; Oakland, Steven F [Colchester, VT; Ouellette, Michael R [Westford, VT; Strissel, Scott A [Byron, MN

2008-07-08

Disclosed is a method of repairing an integrated circuit of the type comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The method comprises the steps of providing the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The method comprises the further step of, at a given time, passing the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

Method and apparatus for in-system redundant array repair on integrated circuits

DOEpatents

Bright, Arthur A.; Crumley, Paul G.; Dombrowa, Marc B.; Douskey, Steven M.; Haring, Rudolf A.; Oakland, Steven F.; Ouellette, Michael R.; Strissel, Scott A.

2007-12-18

Disclosed is a method of repairing an integrated circuit of the type comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The method comprises the steps of providing the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The method comprises the further step of, at a given time, passing the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

System for computer controlled shifting of an automatic transmission

DOEpatents

Patil, Prabhakar B.

1989-01-01

In an automotive vehicle having an automatic transmission that driveably connects a power source to the driving wheels, a method to control the application of hydraulic pressure to a clutch, whose engagement produces an upshift and whose disengagement produces a downshift, the speed of the power source, and the output torque of the transmission. The transmission output shaft torque and the power source speed are the controlled variables. The commanded power source torque and commanded hydraulic pressure supplied to the clutch are the control variables. A mathematical model is formulated that describes the kinematics and dynamics of the powertrain before, during and after a gear shift. The model represents the operating characteristics of each component and the structural arrangement of the components within the transmission being controlled. Next, a close loop feedback control is developed to determine the proper control law or compensation strategy to achieve an acceptably smooth gear ratio change, one in which the output torque disturbance is kept to a minimum and the duration of the shift is minimized. Then a computer algorithm simulating the shift dynamics employing the mathematical model is used to study the effects of changes in the values of the parameters established from a closed loop control of the clutch hydraulic and the power source torque on the shift quality. This computer simulation is used also to establish possible shift control strategies. The shift strategies determine from the prior step are reduced to an algorithm executed by a computer to control the operation of the power source and the transmission.

Closed loop computer control for an automatic transmission

DOEpatents

Patil, Prabhakar B.

1989-01-01

In an automotive vehicle having an automatic transmission that driveably connects a power source to the driving wheels, a method to control the application of hydraulic pressure to a clutch, whose engagement produces an upshift and whose disengagement produces a downshift, the speed of the power source, and the output torque of the transmission. The transmission output shaft torque and the power source speed are the controlled variables. The commanded power source torque and commanded hydraulic pressure supplied to the clutch are the control variables. A mathematical model is formulated that describes the kinematics and dynamics of the powertrain before, during and after a gear shift. The model represents the operating characteristics of each component and the structural arrangement of the components within the transmission being controlled. Next, a close loop feedback control is developed to determine the proper control law or compensation strategy to achieve an acceptably smooth gear ratio change, one in which the output torque disturbance is kept to a minimum and the duration of the shift is minimized. Then a computer algorithm simulating the shift dynamics employing the mathematical model is used to study the effects of changes in the values of the parameters established from a closed loop control of the clutch hydraulic and the power source torque on the shift quality. This computer simulation is used also to establish possible shift control strategies. The shift strategies determined from the prior step are reduced to an algorithm executed by a computer to control the operation of the power source and the transmission.

Note: Tormenta: An open source Python-powered control software for camera based optical microscopy.

PubMed

Barabas, Federico M; Masullo, Luciano A; Stefani, Fernando D

2016-12-01

Until recently, PC control and synchronization of scientific instruments was only possible through closed-source expensive frameworks like National Instruments' LabVIEW. Nowadays, efficient cost-free alternatives are available in the context of a continuously growing community of open-source software developers. Here, we report on Tormenta, a modular open-source software for the control of camera-based optical microscopes. Tormenta is built on Python, works on multiple operating systems, and includes some key features for fluorescence nanoscopy based on single molecule localization.

Note: Tormenta: An open source Python-powered control software for camera based optical microscopy

NASA Astrophysics Data System (ADS)

Barabas, Federico M.; Masullo, Luciano A.; Stefani, Fernando D.

2016-12-01

Until recently, PC control and synchronization of scientific instruments was only possible through closed-source expensive frameworks like National Instruments' LabVIEW. Nowadays, efficient cost-free alternatives are available in the context of a continuously growing community of open-source software developers. Here, we report on Tormenta, a modular open-source software for the control of camera-based optical microscopes. Tormenta is built on Python, works on multiple operating systems, and includes some key features for fluorescence nanoscopy based on single molecule localization.

[Effect analysis on the two total load control methods for poisonous heavy metals].

PubMed

Fu, Guo-Wei

2012-12-01

Firstly it should be made clear that implementation of source total load control for the first type of pollutants is necessary for environmental pollution control legislation and economic structure regulation. This kind of surveillance method has been more practical to be implemented since the Manual of the Industry Discharge Coefficient of First National Pollution Sources Investigation was published. The source total load control and water environment total load control are independent of each other and none of them is redundant, on the other side they can be complementary to each other. In the present, some local planning managers are blurring and confusing the contents and styles of the two surveillance methods. They just use the water total load control to manage all the pollutants, and source total load control is discarded, which results in the loss of control for the first type of pollutants especially for the drinking water source surveillance. There is a big difference between the water quality standards and the water environmental background concentration values for the first type of pollutants in the Environmental quality standard for surface water (GB 3838-88), which means that there are problems such as "relaxing the pollutant discharge permit" and "risk induced by valence state change". Taking an enterprise with 10t electrolytic lead production capacity as an example, there is a big difference between the allowable lead discharged loads by the two total load surveillance methods. In summary, it will bring a lot of harmful effects if the water total load control is implemented for the two types of pollutants, so the source total load control and water environmental total load control should be implemented strictly at the same time.

40 CFR Table 2 to Subpart V of... - Surge Control Vessels and Bottoms Receivers at New Sources

Code of Federal Regulations, 2010 CFR

2010-07-01

... Receivers at New Sources 2 Table 2 to Subpart V of Part 61 Protection of Environment ENVIRONMENTAL... POLLUTANTS National Emission Standard for Equipment Leaks (Fugitive Emission Sources) Pt. 61, Subpt. V, Table 2 Table 2 to Subpart V of Part 61—Surge Control Vessels and Bottoms Receivers at New Sources Vessel...

40 CFR Table 2 to Subpart V of... - Surge Control Vessels and Bottoms Receivers at New Sources

Code of Federal Regulations, 2011 CFR

2011-07-01

... Receivers at New Sources 2 Table 2 to Subpart V of Part 61 Protection of Environment ENVIRONMENTAL... POLLUTANTS National Emission Standard for Equipment Leaks (Fugitive Emission Sources) Pt. 61, Subpt. V, Table 2 Table 2 to Subpart V of Part 61—Surge Control Vessels and Bottoms Receivers at New Sources Vessel...

40 CFR Table 1 to Subpart V of... - Surge Control Vessels and Bottoms Receivers at Existing Sources

Code of Federal Regulations, 2010 CFR

2010-07-01

... Receivers at Existing Sources 1 Table 1 to Subpart V of Part 61 Protection of Environment ENVIRONMENTAL... POLLUTANTS National Emission Standard for Equipment Leaks (Fugitive Emission Sources) Pt. 61, Subpt. V, Table 1 Table 1 to Subpart V of Part 61—Surge Control Vessels and Bottoms Receivers at Existing Sources...

40 CFR Table 1 to Subpart V of... - Surge Control Vessels and Bottoms Receivers at Existing Sources

Code of Federal Regulations, 2011 CFR

2011-07-01

... Receivers at Existing Sources 1 Table 1 to Subpart V of Part 61 Protection of Environment ENVIRONMENTAL... POLLUTANTS National Emission Standard for Equipment Leaks (Fugitive Emission Sources) Pt. 61, Subpt. V, Table 1 Table 1 to Subpart V of Part 61—Surge Control Vessels and Bottoms Receivers at Existing Sources...

40 CFR Table 1 to Subpart V of... - Surge Control Vessels and Bottoms Receivers at Existing Sources

Code of Federal Regulations, 2014 CFR

2014-07-01

... Receivers at Existing Sources 1 Table 1 to Subpart V of Part 61 Protection of Environment ENVIRONMENTAL... POLLUTANTS National Emission Standard for Equipment Leaks (Fugitive Emission Sources) Pt. 61, Subpt. V, Table 1 Table 1 to Subpart V of Part 61—Surge Control Vessels and Bottoms Receivers at Existing Sources...

40 CFR Table 1 to Subpart V of... - Surge Control Vessels and Bottoms Receivers at Existing Sources

Code of Federal Regulations, 2013 CFR

2013-07-01

... Receivers at Existing Sources 1 Table 1 to Subpart V of Part 61 Protection of Environment ENVIRONMENTAL... POLLUTANTS National Emission Standard for Equipment Leaks (Fugitive Emission Sources) Pt. 61, Subpt. V, Table 1 Table 1 to Subpart V of Part 61—Surge Control Vessels and Bottoms Receivers at Existing Sources...

40 CFR Table 2 to Subpart V of... - Surge Control Vessels and Bottoms Receivers at New Sources

Code of Federal Regulations, 2013 CFR

2013-07-01

... Receivers at New Sources 2 Table 2 to Subpart V of Part 61 Protection of Environment ENVIRONMENTAL... POLLUTANTS National Emission Standard for Equipment Leaks (Fugitive Emission Sources) Pt. 61, Subpt. V, Table 2 Table 2 to Subpart V of Part 61—Surge Control Vessels and Bottoms Receivers at New Sources Vessel...

40 CFR Table 1 to Subpart V of... - Surge Control Vessels and Bottoms Receivers at Existing Sources

Code of Federal Regulations, 2012 CFR

2012-07-01

... Receivers at Existing Sources 1 Table 1 to Subpart V of Part 61 Protection of Environment ENVIRONMENTAL... POLLUTANTS National Emission Standard for Equipment Leaks (Fugitive Emission Sources) Pt. 61, Subpt. V, Table 1 Table 1 to Subpart V of Part 61—Surge Control Vessels and Bottoms Receivers at Existing Sources...

40 CFR Table 2 to Subpart V of... - Surge Control Vessels and Bottoms Receivers at New Sources

Code of Federal Regulations, 2014 CFR

2014-07-01

... Receivers at New Sources 2 Table 2 to Subpart V of Part 61 Protection of Environment ENVIRONMENTAL... POLLUTANTS National Emission Standard for Equipment Leaks (Fugitive Emission Sources) Pt. 61, Subpt. V, Table 2 Table 2 to Subpart V of Part 61—Surge Control Vessels and Bottoms Receivers at New Sources Vessel...

40 CFR Table 2 to Subpart V of... - Surge Control Vessels and Bottoms Receivers at New Sources

Code of Federal Regulations, 2012 CFR

2012-07-01

... Receivers at New Sources 2 Table 2 to Subpart V of Part 61 Protection of Environment ENVIRONMENTAL... POLLUTANTS National Emission Standard for Equipment Leaks (Fugitive Emission Sources) Pt. 61, Subpt. V, Table 2 Table 2 to Subpart V of Part 61—Surge Control Vessels and Bottoms Receivers at New Sources Vessel...

Optical detector calibrator system

NASA Technical Reports Server (NTRS)

Strobel, James P. (Inventor); Moerk, John S. (Inventor); Youngquist, Robert C. (Inventor)

1996-01-01

An optical detector calibrator system simulates a source of optical radiation to which a detector to be calibrated is responsive. A light source selected to emit radiation in a range of wavelengths corresponding to the spectral signature of the source is disposed within a housing containing a microprocessor for controlling the light source and other system elements. An adjustable iris and a multiple aperture filter wheel are provided for controlling the intensity of radiation emitted from the housing by the light source to adjust the simulated distance between the light source and the detector to be calibrated. The geared iris has an aperture whose size is adjustable by means of a first stepper motor controlled by the microprocessor. The multiple aperture filter wheel contains neutral density filters of different attenuation levels which are selectively positioned in the path of the emitted radiation by a second stepper motor that is also controlled by the microprocessor. An operator can select a number of detector tests including range, maximum and minimum sensitivity, and basic functionality. During the range test, the geared iris and filter wheel are repeatedly adjusted by the microprocessor as necessary to simulate an incrementally increasing simulated source distance. A light source calibration subsystem is incorporated in the system which insures that the intensity of the light source is maintained at a constant level over time.

Distributed control system for parallel-connected DC boost converters

DOEpatents

Goldsmith, Steven

2017-08-15

The disclosed invention is a distributed control system for operating a DC bus fed by disparate DC power sources that service a known or unknown load. The voltage sources vary in v-i characteristics and have time-varying, maximum supply capacities. Each source is connected to the bus via a boost converter, which may have different dynamic characteristics and power transfer capacities, but are controlled through PWM. The invention tracks the time-varying power sources and apportions their power contribution while maintaining the DC bus voltage within the specifications. A central digital controller solves the steady-state system for the optimal duty cycle settings that achieve a desired power supply apportionment scheme for a known or predictable DC load. A distributed networked control system is derived from the central system that utilizes communications among controllers to compute a shared estimate of the unknown time-varying load through shared bus current measurements and bus voltage measurements.

[Bibliometric analysis of literature regarding integrated schistosomiasis control strategy with emphasis on infectious source control].

PubMed

Qian, Yi-Li; Wang, Wei; Hong, Qing-Biao; Liang, You-Sheng

2014-12-01

To evaluate the outcomes of implementation of integrated schistosomiasis control strategy with emphasis on infectious source control using a bibliometric method. The literature pertaining to integrated schistosomiasis control strategy with emphasis on infectious source control was retrieved from CNKI, Wanfangdata, VIP, PubMed, Web of Science, BIOSIS and Google Scholar, and a bibliometric analysis of literature captured was performed. During the period from January 1, 2004 through September 30, 2014, a total of 94 publications regarding integrated schistosomiasis control strategy with emphasis on infectious source control were captured, including 78 Chinese articles (82.98%) and 16 English papers (17.02%). The Chinese literature was published in 21 national journals, and Chinese Journal of Schistosomiasis Control had the largest number of publications, consisting of 37.23% of total publications; 16 English papers were published in 12 international journals, and PLoS Neglected Tropical Diseases had the largest number of publications (3 publications). There were 37 affiliations publishing these 94 articles, and National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (16 publications), Anhui Institute of Schistosomiasis Control (12 publications) and Hunan Institute of Schistosomiasis Control (9 publications) ranked top three affiliations in number of publications. A total of 157 persons were co-authored in these 94 publications, and Wang, Zhou and Zhang ranked top 3 authors in number of publications. The integrated schistosomiasis control strategy with emphasis on infectious source control has been widely implemented in China, and the achievements obtained from the implementation of this strategy should be summarized and transmitted internationally.

Process system and method for fabricating submicron field emission cathodes

DOEpatents

Jankowski, A.F.; Hayes, J.P.

1998-05-05

A process method and system for making field emission cathodes exists. The deposition source divergence is controlled to produce field emission cathodes with height-to-base aspect ratios that are uniform over large substrate surface areas while using very short source-to-substrate distances. The rate of hole closure is controlled from the cone source. The substrate surface is coated in well defined increments. The deposition source is apertured to coat pixel areas on the substrate. The entire substrate is coated using a manipulator to incrementally move the whole substrate surface past the deposition source. Either collimated sputtering or evaporative deposition sources can be used. The position of the aperture and its size and shape are used to control the field emission cathode size and shape. 3 figs.

Process system and method for fabricating submicron field emission cathodes

DOEpatents

Jankowski, Alan F.; Hayes, Jeffrey P.

1998-01-01

A process method and system for making field emission cathodes exists. The deposition source divergence is controlled to produce field emission cathodes with height-to-base aspect ratios that are uniform over large substrate surface areas while using very short source-to-substrate distances. The rate of hole closure is controlled from the cone source. The substrate surface is coated in well defined increments. The deposition source is apertured to coat pixel areas on the substrate. The entire substrate is coated using a manipulator to incrementally move the whole substrate surface past the deposition source. Either collimated sputtering or evaporative deposition sources can be used. The position of the aperture and its size and shape are used to control the field emission cathode size and shape.

40 CFR 63.54 - Preconstruction review procedures for new affected sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... new affected sources. 63.54 Section 63.54 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air... required. (2) The permitting authority will approve an applicant's proposed control technology, or the...

Alternate energy source usage for in situ heat treatment processes

DOEpatents

Stone, Jr., Francis Marion; Goodwin, Charles R [League City, TX; Richard, Jr., James

2011-03-22

Systems, methods, and heaters for treating a subsurface formation are described herein. At least one system for providing power to one or more subsurface heaters is described herein. The system may include an intermittent power source; a transformer coupled to the intermittent power source, and a tap controller coupled to the transformer. The transformer may be configured to transform power from the intermittent power source to power with appropriate operating parameters for the heaters. The tap controller may be configured to monitor and control the transformer so that a constant voltage is provided to the heaters from the transformer regardless of the load of the heaters and the power output provided by the intermittent power source.

Systems and methods for providing power to a load based upon a control strategy

DOEpatents

Perisic, Milun; Lawrence, Christopher P; Ransom, Ray M; Kajouke, Lateef A

2014-11-04

Systems and methods are provided for an electrical system. The electrical system, for example, includes a first load, an interface configured to receive a voltage from a voltage source, and a controller configured to receive the voltage through the interface and to provide a voltage and current to the first load. The controller may be further configured to, receive information on a second load electrically connected to the voltage source, determine an amount of reactive current to return to the voltage source such that a current drawn by the electrical system and the second load from the voltage source is substantially real, and provide the determined reactive current to the voltage source.

Uninterrupted and reusable source for the controlled growth of nanowires

PubMed Central

Sugavaneshwar, R. P.; Nanda, Karuna Kar

2013-01-01

Generally, the length of the oxide nanowires grown by vapor phase transport is limited by the degradation of the source materials. Furthermore, the source material is used once for the nanowires growth. By exploiting the Si-Zn phase diagram, we have developed a simple methodology for the non-catalytic growth of ultralong ZnO nanowires in large area with controllable aspect ratio and branched structures. The insolubility of Zn in Si and the use of a Si cap on the Zn source to prevent local source oxidation of Zn (i. e. prevents the degradation of the source) are the keys to grow longer nanowires without limitations. It has been shown that the aspect ratio can be controlled by thermodynamically (temperature) and more importantly by kinetically (vapor flux). One of the interesting findings is that the same source material can be used for several depositions of oxide nanostructured materials. PMID:23412010

Adjustable ECR Ion Source Control System: Ion Source Hydrogen Positive Project

NASA Astrophysics Data System (ADS)

Arredondo, I.; Eguiraun, M.; Jugo, J.; Piso, D.; del Campo, M.; Poggi, T.; Varnasseri, S.; Feuchtwanger, J.; Bilbao, J.; Gonzalez, X.; Harper, G.; Muguira, L.; Miracoli, R.; Corres, J.; Belver, D.; Echevarria, P.; Garmendia, N.; Gonzalez, P.; Etxebarria, V.

2015-06-01

ISHP (Ion Source Hydrogen Positive) project consists of a highly versatile ECR type ion source. It has been built for several purposes, on the one hand, to serve as a workbench to test accelerator related technologies and validate in-house made developments, at the first stages. On the other hand, to design an ion source valid as the first step in an actual LINAC. Since this paper is focused on the control system of ISHP, besides the ion source, all the hardware and its control architecture is presented. Nowadays the ion source is able to generate a pulse of positive ions of Hydrogen from 2 μs to a few ms range with a repetition rate ranging from 1 Hz to 50 Hz with a maximum of 45 mA of current. Furthermore, the first experiments with White Rabbit (WR) synchronization system are presented.

Investigation of spherical loudspeaker arrays for local active control of sound.

PubMed

Peleg, Tomer; Rafaely, Boaz

2011-10-01

Active control of sound can be employed globally to reduce noise levels in an entire enclosure, or locally around a listener's head. Recently, spherical loudspeaker arrays have been studied as multiple-channel sources for local active control of sound, presenting the fundamental theory and several active control configurations. In this paper, important aspects of using a spherical loudspeaker array for local active control of sound are further investigated. First, the feasibility of creating sphere-shaped quiet zones away from the source is studied both theoretically and numerically, showing that these quiet zones are associated with sound amplification and poor system robustness. To mitigate the latter, the design of shell-shaped quiet zones around the source is investigated. A combination of two spherical sources is then studied with the aim of enlarging the quiet zone. The two sources are employed to generate quiet zones that surround a rigid sphere, investigating the application of active control around a listener's head. A significant improvement in performance is demonstrated in this case over a conventional headrest-type system that uses two monopole secondary sources. Finally, several simulations are presented to support the theoretical work and to demonstrate the performance and limitations of the system. © 2011 Acoustical Society of America

Active control of sound radiation from a vibrating rectangular panel by sound sources and vibration inputs - An experimental comparison

NASA Technical Reports Server (NTRS)

Fuller, C. R.; Hansen, C. H.; Snyder, S. D.

1991-01-01

Active control of sound radiation from a rectangular panel by two different methods has been experimentally studied and compared. In the first method a single control force applied directly to the structure is used with a single error microphone located in the radiated acoustic field. Global attenuation of radiated sound was observed to occur by two main mechanisms. For 'on-resonance' excitation, the control force had the effect of increasing the total panel input impedance presented to the nosie source, thus reducing all radiated sound. For 'off-resonance' excitation, the control force tends not significantly to modify the panel total response amplitude but rather to restructure the relative phases of the modes leading to a more complex vibration pattern and a decrease in radiation efficiency. For acoustic control, the second method, the number of acoustic sources required for global reduction was seen to increase with panel modal order. The mechanism in this case was that the acoustic sources tended to create an inverse pressure distribution at the panel surface and thus 'unload' the panel by reducing the panel radiation impedance. In general, control by structural inputs appears more effective than control by acoustic sources for structurally radiated noise.

Emission Inventory Development and Application Based On an Atmospheric Emission Source Priority Control Classification Technology Method, a Case Study in the Middle Reaches of Yangtze River Urban Agglomerations, China

NASA Astrophysics Data System (ADS)

Sun, X.; Cheng, S.

2017-12-01

This paper presents the first attempt to investigate the emission source control of the Middle Reaches of Yangtze River Urban Agglomerations (MRYRUA), one of the national urban agglomerations in China. An emission inventory of the MRYRUA was the first time to be developed as inputs to the CAMx model based on county-level activity data obtained by full-coverage investigation and source-based spatial surrogates. The emission inventory was proved to be acceptable owing to the atmospheric modeling verification. A classification technology method for atmospheric pollution source priority control was the first time to be introduced and applied in the MRYRUA for the evaluation of the emission sources control on the region-scale and city-scale. MICAPS (Meteorological Information comprehensive Analysis and Processing System) was applied for the regional meteorological condition and sensitivity analysis. The results demonstrated that the emission sources in the Hefei-center Urban Agglomerations contributed biggest on the mean PM2.5 concentrations of the MRYRUA and should be taken the priority to control. The emission sources in the Ma'anshan city, Xiangtan city, Hefei city and Wuhan city were the bigger contributors on the mean PM2.5 concentrations of the MRYRUA among the cities and should be taken the priority to control. In addition, the cities along the Yangtze River and the tributary should be given the special attention for the regional air quality target attainments. This study provide a valuable preference for policy makers to develop effective air pollution control strategies.

Characterization of ambient volatile organic compounds and their sources in Beijing, before, during, and after Asia-Pacific Economic Cooperation China 2014

NASA Astrophysics Data System (ADS)

Li, J.; Xie, S. D.; Zeng, L. M.; Li, L. Y.; Li, Y. Q.; Wu, R. R.

2015-07-01

Ambient volatile organic compounds (VOCs) were measured using an online system, gas chromatography-mass spectrometry/flame ionization detector (GC-MS/FID), in Beijing, China, before, during, and after Asia-Pacific Economic Cooperation (APEC) China 2014, when stringent air quality control measures were implemented. Positive matrix factorization (PMF) was applied to identify the major VOC contributing sources and their temporal variations. The secondary organic aerosols potential (SOAP) approach was used to estimate variations of precursor source contributions to SOA formation. The average VOC mixing ratios during the three periods were 86.17, 48.28, and 72.97 ppbv, respectively. The mixing ratios of total VOC during the control period were reduced by 44 %, and the mixing ratios of acetonitrile, halocarbons, oxygenated VOCs (OVOCs), aromatics, acetylene, alkanes, and alkenes decreased by approximately 65, 62, 54, 53, 37, 36, and 23 %, respectively. The mixing ratios of all measured VOC species decreased during control, and the most affected species were chlorinated VOCs (chloroethane, 1,1-dichloroethylene, chlorobenzene). PMF analysis indicated eight major sources of ambient VOCs, and emissions from target control sources were clearly reduced during the control period. Compared with the values before control, contributions of vehicular exhaust were most reduced, followed by industrial manufacturing and solvent utilization. Reductions of these three sources were responsible for 50, 26, and 16 % of the reductions in ambient VOCs. Contributions of evaporated or liquid gasoline and industrial chemical feedstock were slightly reduced, and contributions of secondary and long-lived species were relatively stable. Due to central heating, emissions from fuel combustion kept on increasing during the whole campaign; because of weak control of liquid petroleum gas (LPG), the highest emissions of LPG occurred in the control period. Vehicle-related sources were the most important precursor sources likely responsible for the reduction in SOA formation during this campaign.

Development of the integrated control system for the microwave ion source of the PEFP 100-MeV proton accelerator

NASA Astrophysics Data System (ADS)

Song, Young-Gi; Seol, Kyung-Tae; Jang, Ji-Ho; Kwon, Hyeok-Jung; Cho, Yong-Sub

2012-07-01

The Proton Engineering Frontier Project (PEFP) 20-MeV proton linear accelerator is currently operating at the Korea Atomic Energy Research Institute (KAERI). The ion source of the 100-MeV proton linac needs at least a 100-hour operation time. To meet the goal, we have developed a microwave ion source that uses no filament. For the ion source, a remote control system has been developed by using experimental physics and the industrial control system (EPICS) software framework. The control system consists of a versa module europa (VME) and EPICS-based embedded applications running on a VxWorks real-time operating system. The main purpose of the control system is to control and monitor the operational variables of the components remotely and to protect operators from radiation exposure and the components from critical problems during beam extraction. We successfully performed the operation test of the control system to confirm the degree of safety during the hardware performance.

Nonpoint Source Discharge Control on Non-Builtup Military Lands: Compliance Background Analysis Through October 1999

DTIC Science & Technology

2000-08-01

management for NPS. The State nonpoint Source Task Force coordinates joint watershed management efforts with SCS, USFS, BLM. Intense grazing and...nonpoint source water pollution discharges from unimproved lands, particularly military lands. Increasing emphasis at national and state levels on...lands, particularly military lands. Increasing emphasis at national and state levels on controlling pollutant discharges from nonpoint sources and

40 CFR 63.52 - Approval process for new and existing affected sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... affected sources. 63.52 Section 63.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... CATEGORIES Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air... emission reductions that can be achieved if the control technologies or work practices are installed...

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

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

Litao Wang; Jiming Hao; Kebin He

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

40 CFR 52.245 - New Source Review rules.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California §52.245 New Source Review rules. (a) Approval of the New Source Review rules for the San Joaquin Valley Unified Air Pollution Control District... Review rules for the San Joaquin Valley Unified Air Pollution Control District Rules 2020 and 2201 as...

Inductively generated streaming plasma ion source

DOEpatents

Glidden, Steven C.; Sanders, Howard D.; Greenly, John B.

2006-07-25

A novel pulsed, neutralized ion beam source is provided. The source uses pulsed inductive breakdown of neutral gas, and magnetic acceleration and control of the resulting plasma, to form a beam. The beam supplies ions for applications requiring excellent control of ion species, low remittance, high current density, and spatial uniformity.

Computer controlled fluorometer device and method of operating same

DOEpatents

Kolber, Z.; Falkowski, P.

1990-07-17

A computer controlled fluorometer device and method of operating same, said device being made to include a pump flash source and a probe flash source and one or more sample chambers in combination with a light condenser lens system and associated filters and reflectors and collimators, as well as signal conditioning and monitoring means and a programmable computer means and a software programmable source of background irradiance that is operable according to the method of the invention to rapidly, efficiently and accurately measure photosynthetic activity by precisely monitoring and recording changes in fluorescence yield produced by a controlled series of predetermined cycles of probe and pump flashes from the respective probe and pump sources that are controlled by the computer means. 13 figs.

Computer controlled fluorometer device and method of operating same

DOEpatents

Kolber, Zbigniew; Falkowski, Paul

1990-01-01

A computer controlled fluorometer device and method of operating same, said device being made to include a pump flash source and a probe flash source and one or more sample chambers in combination with a light condenser lens system and associated filters and reflectors and collimators, as well as signal conditioning and monitoring means and a programmable computer means and a software programmable source of background irradiance that is operable according to the method of the invention to rapidly, efficiently and accurately measure photosynthetic activity by precisely monitoring and recording changes in fluorescence yield produced by a controlled series of predetermined cycles of probe and pump flashes from the respective probe and pump sources that are controlled by the computer means.

Characterization of ambient volatile organic compounds and their sources in Beijing, before, during, and after Asia-Pacific Economic Cooperation China 2014

NASA Astrophysics Data System (ADS)

Li, J.; Xie, S. D.; Zeng, L. M.; Li, L. Y.; Li, Y. Q.; Wu, R. R.

2015-04-01

Ambient volatile organic compounds (VOCs) were measured using an online system, gas chromatography-mass spectrometry/flame ionization detector (GC-MS/FID), in Beijing, China, before, during and after Asia-Pacific Economic Cooperation (APEC) China 2014, when stringent air quality control measures were implemented. Positive matrix factorization (PMF) was applied to identify the major VOC contributing sources and their temporal variations. The secondary organic aerosols potential (SOAP) approach was used to estimate variations of precursor source contributions to SOA formation. The average VOC mixing ratios during the three periods were 86.17, 48.28, and 72.97 ppbv, respectively. The mixing ratios of total VOC during the control period were reduced by 44%, and the mixing ratios of acetonitrile, halocarbons, oxygenated VOCs (OVOCs), aromatics, acetylene, alkanes, and alkenes decreased by approximately 65, 62, 54, 53, 37, 36, and 23%, respectively. The mixing ratios of all measured VOC species decreased during control, and the most affected species were chlorinated VOCs (chloroethane, 1,1-dichloroethylene, chlorobenzene). PMF analysis indicated eight major sources of ambient VOCs, and emissions from target control sources were clearly reduced during the control period. Contributions of vehicular exhaust were most reduced (19.65 ppbv, the contributions before the control period minus the values after the control period), followed by industrial manufacturing (10.29 ppbv) and solvent utilization (6.20 ppbv). Contributions of evaporated or liquid gasoline and industrial chemical feedstock were slightly reduced, with values of 2.85 and 0.35 ppbv, respectively. Contributions of secondary and long-lived species were relatively stable. Due to central heating, emissions from fuel combustion kept on increasing during the whole campaign; because of weak control of liquid petroleum gas (LPG), the highest emissions of LPG occurred in the control period. Vehicle-related sources were the most important precursor sources likely responsible for the reduction in SOA formation during this campaign.

Variable pressure power cycle and control system

DOEpatents

Goldsberry, Fred L.

1984-11-27

A variable pressure power cycle and control system that is adjustable to a variable heat source is disclosed. The power cycle adjusts itself to the heat source so that a minimal temperature difference is maintained between the heat source fluid and the power cycle working fluid, thereby substantially matching the thermodynamic envelope of the power cycle to the thermodynamic envelope of the heat source. Adjustments are made by sensing the inlet temperature of the heat source fluid and then setting a superheated vapor temperature and pressure to achieve a minimum temperature difference between the heat source fluid and the working fluid.

Improved efficiency and precise temperature control of low-frequency induction-heating pure iron vapor source on ECR ion source

NASA Astrophysics Data System (ADS)

Kato, Y.; Takenaka, T.; Yano, K.; Kiriyama, R.; Kurisu, Y.; Nozaki, D.; Muramatsu, M.; Kitagawa, A.; Uchida, T.; Yoshida, Y.; Sato, F.; Iida, T.

2012-11-01

Multiply charged ions to be used prospectively are produced from solid pure material in an electron cyclotron resonance ion source (ECRIS). Recently a pure iron source is also required for the production of caged iron ions in the fullerene in order to control cells in vivo in bio-nano science and technology. We adopt directly heating iron rod by induction heating (IH) because it has non-contact with insulated materials which are impurity gas sources. We choose molybdenum wire for the IH coils because it doesn't need water cooling. To improve power efficiency and temperature control, we propose to the new circuit without previously using the serial and parallel dummy coils (SPD) for matching and safety. We made the circuit consisted of inductively coupled coils which are thin-flat and helix shape, and which insulates the IH power source from the evaporator. This coupling coils circuit, i.e. insulated induction heating coil transformer (IHCT), can be move mechanically. The secondary current can be adjusted precisely and continuously. Heating efficiency by using the IHCT is much higher than those of previous experiments by using the SPD, because leakage flux is decreased and matching is improved simultaneously. We are able to adjust the temperature in heating the vapor source around melting point. And then the vapor pressure can be controlled precisely by using the IHCT. We can control ±10K around 1500°C by this method, and also recognize to controlling iron vapor flux experimentally in the extreme low pressures. Now we come into next stage of developing induction heating vapor source for materials with furthermore high temperature melting points above 2000K with the IHCT, and then apply it in our ECRIS.

Atmospheric Particulate Matter Pollution during the 2008 Beijing Olympics

PubMed Central

WANG, WENTAO; PRIMBS, TOBY; TAO, SHU; ZHU, TONG; SIMONICH, STACI L. MASSEY

2009-01-01

Size fractionated particulate matter (PM) samples (including PM2.5 and PM10) were collected at Peking University in Northwestern Beijing, China for a 2 week period prior to the Olympics, during the 2 week period of the Olympics, and for a 4 week period following the 2008 Olympics, during both source control and non-source control period. PM10 concentrations in this study were high correlated with, but a factor of 1.3 times higher than, the Beijing Environmental Protection Bureau's PM10 concentrations at near-by sites because of differences in the measurement methods used. The mean PM2.5 and PM10 concentrations were statistically different, and lower by 31 and 35%, during the Olympic period compared to the non-Olympic period. However, the PM concentrations were not statistically different between the source control and non-source control periods. While meteorological parameters (air masses from the south and precipitation) accounted for 40% of the total variation in PM10 concentration, source control accounted for 16%, suggesting that meteorology accounted for more of the variation in PM concentration than source control measures. The PM10 concentrations in Beijing during the Olympic period were 2.9, 3.5, and 1.9 times higher than those in Atlanta, Sydney and Athens. In addition, the PM2.5 and PM10 concentrations during the Olympic period exceeded the WHO 24-hour guideline 100% and 81% of the time, respectively. Finally, the PM10 concentrations in October, November, and December 2008 were reduced by 9% to 27% compared to the same months in 2007, suggesting that the Olympic source control efforts (and possibly a down turn in the economy) have resulted in lower PM10 concentrations in Beijing. PMID:19708359

40 CFR 97.621 - Recordation of TR SO2 Group 1 allowance allocations and auction results.

Code of Federal Regulations, 2012 CFR

2012-07-01

... allocated to the TR SO2 Group 1 units at the source in accordance with § 97.611(a) for the control period in... allocated to the TR SO2 Group 1 units at the source in accordance with § 97.611(a) for the control period in... SO2 Group 1 units at the source in accordance with § 97.611(a) for the control period in 2013. (c) By...

40 CFR 97.721 - Recordation of TR SO2 Group 2 allowance allocations and auction results.

Code of Federal Regulations, 2012 CFR

2012-07-01

... allocated to the TR SO2 Group 2 units at the source in accordance with § 97.711(a) for the control period in... allocated to the TR SO2 Group 2 units at the source in accordance with § 97.711(a) for the control period in... SO2 Group 2 units at the source in accordance with § 97.711(a) for the control period in 2013. (c) By...

Active control of noise on the source side of a partition to increase its sound isolation

NASA Astrophysics Data System (ADS)

Tarabini, Marco; Roure, Alain; Pinhede, Cedric

2009-03-01

This paper describes a local active noise control system that virtually increases the sound isolation of a dividing wall by means of a secondary source array. With the proposed method, sound pressure on the source side of the partition is reduced using an array of loudspeakers that generates destructive interference on the wall surface, where an array of error microphones is placed. The reduction of sound pressure on the incident side of the wall is expected to decrease the sound radiated into the contiguous room. The method efficiency was experimentally verified by checking the insertion loss of the active noise control system; in order to investigate the possibility of using a large number of actuators, a decentralized FXLMS control algorithm was used. Active control performances and stability were tested with different array configurations, loudspeaker directivities and enclosure characteristics (sound source position and absorption coefficient). The influence of all these parameters was investigated with the factorial design of experiments. The main outcome of the experimental campaign was that the insertion loss produced by the secondary source array, in the 50-300 Hz frequency range, was close to 10 dB. In addition, the analysis of variance showed that the active noise control performance can be optimized with a proper choice of the directional characteristics of the secondary source and the distance between loudspeakers and error microphones.

40 CFR 141.716 - Source toolbox components.

Code of Federal Regulations, 2012 CFR

2012-07-01

... for Microbial Toolbox Components § 141.716 Source toolbox components. (a) Watershed control program. Systems receive 0.5-log Cryptosporidium treatment credit for implementing a watershed control program that meets the requirements of this section. (1) Systems that intend to apply for the watershed control...

40 CFR 141.716 - Source toolbox components.

Code of Federal Regulations, 2013 CFR

2013-07-01

... for Microbial Toolbox Components § 141.716 Source toolbox components. (a) Watershed control program. Systems receive 0.5-log Cryptosporidium treatment credit for implementing a watershed control program that meets the requirements of this section. (1) Systems that intend to apply for the watershed control...

40 CFR 141.716 - Source toolbox components.

Code of Federal Regulations, 2014 CFR

2014-07-01

... for Microbial Toolbox Components § 141.716 Source toolbox components. (a) Watershed control program. Systems receive 0.5-log Cryptosporidium treatment credit for implementing a watershed control program that meets the requirements of this section. (1) Systems that intend to apply for the watershed control...

ALTERNATIVE POLICIES FOR CONTROLLING NONPOINT AGRICULTURAL SOURCES OF WATER POLLUTION

EPA Science Inventory

This study of policies for controlling water pollution from nonpoint agricultural sources includes a survey of existing state and Federal programs, agencies, and laws directed to the control of soil erosion. Six policies representing a variety of approaches to this pollution prob...

THE IMPACT OF PARTICULATE EMISSIONS CONTROL ON THE CONTROL OF OTHER MWC AIR EMISSIONS

EPA Science Inventory

On December 20, 1989, the Environmental Protection Agency (EPA) proposed revised new source performance standards for new municipal waste combustion (MWC) units and guidelines for existing sources. The proposed national regulations require tighter particulate matter control and a...

Power Source Status Estimation and Drive Control Method for Autonomous Decentralized Hybrid Train

NASA Astrophysics Data System (ADS)

Furuya, Takemasa; Ogawa, Kenichi; Yamamoto, Takamitsu; Hasegawa, Hitoshi

A hybrid control system has two main functions: power sharing and equipment protection. In this paper, we discuss the design, construction and testing of a drive control method for an autonomous decentralized hybrid train with 100-kW-class fuel cells (FC) and 36-kWh lithium-ion batteries (Li-Batt). The main objectives of this study are to identify the operation status of the power sources on the basis of the input voltage of the traction inverter and to estimate the maximum traction power control basis of the power-source status. The proposed control method is useful in preventing overload operation of the onboard power sources in an autonomous decentralized hybrid system that has a flexible main circuit configuration and a few control signal lines. Further, with this method, the initial cost of a hybrid system can be reduced and the retrofit design of the hybrid system can be simplified. The effectiveness of the proposed method is experimentally confirmed by using a real-scale hybrid train system.

Controlling Nonpoint-Source Water Pollution: A Citizen's Handbook.

ERIC Educational Resources Information Center

Hansen, Nancy Richardson; And Others

Citizens can play an important role in helping their states develop pollution control programs and spurring effective efforts to deal with nonpoint-source pollution. This guide takes the reader step-by-step through the process that states must follow to comply with water quality legislation relevant to nonpoint-source pollution. Part I provides…

Beam current controller for laser ion source

DOEpatents

Okamura, Masahiro

2014-10-28

The present invention relates to the design and use of an ion source with a rapid beam current controller for experimental and medicinal purposes. More particularly, the present invention relates to the design and use of a laser ion source with a magnetic field applied to confine a plasma flux caused by laser ablation.

First Order Estimates of Energy Requirements for Pollution Control. Interagency Energy-Environment Research and Development Program Report.

ERIC Educational Resources Information Center

Barker, James L.; And Others

This U.S. Environmental Protection Agency report presents estimates of the energy demand attributable to environmental control of pollution from stationary point sources. This class of pollution source includes powerplants, factories, refineries, municipal waste water treatment plants, etc., but excludes mobile sources such as trucks, and…

40 CFR 63.1316 - PET and polystyrene affected sources-emissions control provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 12 2012-07-01 2011-07-01 true PET and polystyrene affected sources... and Resins § 63.1316 PET and polystyrene affected sources—emissions control provisions. (a) The owner or operator of an affected source producing PET using a continuous process shall comply with...

40 CFR 63.1316 - PET and polystyrene affected sources-emissions control provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 12 2013-07-01 2013-07-01 false PET and polystyrene affected sources... Polymers and Resins § 63.1316 PET and polystyrene affected sources—emissions control provisions. (a) The owner or operator of an affected source producing PET using a continuous process shall comply with...

40 CFR 63.1316 - PET and polystyrene affected sources-emissions control provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 12 2014-07-01 2014-07-01 false PET and polystyrene affected sources... Polymers and Resins § 63.1316 PET and polystyrene affected sources—emissions control provisions. (a) The owner or operator of an affected source producing PET using a continuous process shall comply with...

75 FR 3392 - Outer Continental Shelf Air Regulations Consistency Update for Alaska

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-21

... 40 CFR part 55,\\1\\ which established requirements to control air pollution from OCS sources in order... air pollution from OCS sources located within 25 miles of States' seaward boundaries that are the same... the Act requires that EPA establish requirements to control air pollution from OCS sources located...

76 FR 15898 - Outer Continental Shelf Air Regulations; Consistency Update for California

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-22

... for OCS sources for which the Santa Barbara County Air Pollution Control District (``Santa Barbara...\\ which established requirements to control air pollution from OCS sources in order to attain and maintain... Mexico west of 87.5 degrees longitude. Section 328 of the Act requires that for such sources located...

76 FR 1389 - Outer Continental Shelf Air Regulations Consistency Update for California

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-10

... for OCS sources for which the Santa Barbara County Air Pollution Control District (``Santa Barbara...\\ which established requirements to control air pollution from OCS sources in order to attain and maintain... Mexico west of 87.5 degrees longitude. Section 328 of the Act requires that for such sources located...

Energy storage requirements of dc microgrids with high penetration renewables under droop control

DOE PAGES

Weaver, Wayne W.; Robinett, Rush D.; Parker, Gordon G.; ...

2015-01-09

Energy storage is a important design component in microgrids with high penetration renewable sources to maintain the system because of the highly variable and sometimes stochastic nature of the sources. Storage devices can be distributed close to the sources and/or at the microgrid bus. In addition, storage requirements can be minimized with a centralized control architecture, but this creates a single point of failure. Distributed droop control enables a completely decentralized architecture but, the energy storage optimization becomes more difficult. Our paper presents an approach to droop control that enables the local and bus storage requirements to be determined. Givenmore » a priori knowledge of the design structure of a microgrid and the basic cycles of the renewable sources, we found that the droop settings of the sources are such that they minimize both the bus voltage variations and overall energy storage capacity required in the system. This approach can be used in the design phase of a microgrid with a decentralized control structure to determine appropriate droop settings as well as the sizing of energy storage devices.« less

77 FR 33642 - Regional Haze: Revisions to Provisions Governing Alternatives to Source-Specific Best Available...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-07

... of the Two-Pronged Test 2. Identification of Affected Class I Areas 3. Control Scenarios Examined 4... two-pronged test to the Transport Rule control scenario and the source-specific BART control scenario... approaches to identify the Class I areas ``affected'' by the Transport Rule as an alternative control program...

Effectiveness evaluation of temporary emission control action in 2016 in winter in Shijiazhuang, China

NASA Astrophysics Data System (ADS)

Liu, Baoshuang; Cheng, Yuan; Zhou, Ming; Liang, Danni; Dai, Qili; Wang, Lu; Jin, Wei; Zhang, Lingzhi; Ren, Yibin; Zhou, Jingbo; Dai, Chunling; Xu, Jiao; Wang, Jiao; Feng, Yinchang; Zhang, Yufen

2018-05-01

To evaluate the environmental effectiveness of the control measures for atmospheric pollution in Shijiazhuang, China, a large-scale controlling experiment for emission sources of atmospheric pollutants (i.e. a temporary emission control action, TECA) was designed and implemented during 1 November 2016 to 9 January 2017. Compared to the no-control action and heating period (NCAHP), under unfavourable meteorological conditions, the mean concentrations of PM2.5, PM10, SO2, NO2, and chemical species (Si, Al, Ca2+, Mg2+) in PM2.5 during the control action and heating period (CAHP) still decreased by 8, 8, 5, 19, 30.3, 4.5, 47.0, and 45.2 %, respectively, indicating that the control measures for atmospheric pollution were effective. The effects of control measures in suburbs were better than those in urban area, especially for the control effects of particulate matter sources. The control effects for emission sources of carbon monoxide (CO) were not apparent during the TECA period, especially in suburbs, likely due to the increasing usage of domestic coal in suburbs along with the temperature decreasing.The results of positive matrix factorization (PMF) analysis showed that crustal dust, secondary sources, vehicle emissions, coal combustion and industrial emissions were main PM2.5 sources. Compared to the whole year (WY) and the no-control action and no-heating period (NCANHP), the contribution concentrations and proportions of coal combustion to PM2.5 increased significantly during other stages of the TECA period. The contribution concentrations and proportions of crustal dust and vehicle emissions to PM2.5 decreased noticeably during the CAHP compared to other stages of the TECA period. The contribution concentrations and proportions of industrial emissions to PM2.5 during the CAHP decreased noticeably compared to the NCAHP. The pollutants' emission sources during the CAHP were in effective control, especially for crustal dust and vehicles. However, the necessary coal heating for the cold winter and the unfavourable meteorological conditions had an offset effect on the control measures for emission sources to some degree. The results also illustrated that the discharge of pollutants might still be enormous even under such strict control measures.The backward trajectory and potential source contribution function (PSCF) analysis in the light of atmospheric pollutants suggested that the potential source areas mainly involved the surrounding regions of Shijiazhuang, i.e. south of Hebei and north of Henan and Shanxi. The regional nature of the atmospheric pollution in the North China Plain revealed that there is an urgent need for making cross-boundary control policies in addition to local control measures given the high background level of pollutants.The TECA is an important practical exercise but it cannot be advocated for as the normalized control measures for atmospheric pollution in China. The direct cause of atmospheric pollution in China is the emission of pollutants exceeding the air environment's self-purification capacity, which is caused by an unreasonable and unhealthy pattern for economic development in China.

Programmable solid state atom sources for nanofabrication.

PubMed

Han, Han; Imboden, Matthias; Stark, Thomas; del Corro, Pablo G; Pardo, Flavio; Bolle, Cristian A; Lally, Richard W; Bishop, David J

2015-06-28

In this paper we discuss the development of a MEMS-based solid state atom source that can provide controllable atom deposition ranging over eight orders of magnitude, from ten atoms per square micron up to hundreds of atomic layers, on a target ∼1 mm away. Using a micron-scale silicon plate as a thermal evaporation source we demonstrate the deposition of indium, silver, gold, copper, iron, aluminum, lead and tin. Because of their small sizes and rapid thermal response times, pulse width modulation techniques are a powerful way to control the atomic flux. Pulsing the source with precise voltages and timing provides control in terms of when and how many atoms get deposited. By arranging many of these devices into an array, one has a multi-material, programmable solid state evaporation source. These micro atom sources are a complementary technology that can enhance the capability of a variety of nano-fabrication techniques.

Study on road surface source pollution controlled by permeable pavement

NASA Astrophysics Data System (ADS)

Zheng, Chaocheng

2018-06-01

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

PULSED ION SOURCE

DOEpatents

Martina, E.F.

1958-10-14

An improved pulsed ion source of the type where the gas to be ionized is released within the source by momentary heating of an electrode occluded with the gas is presented. The other details of the ion source construction include an electron emitting filament and a positive reference grid, between which an electron discharge is set up, and electrode means for withdrawing the ions from the source. Due to the location of the gas source behind the electrode discharge region, and the positioning of the vacuum exhaust system on the opposite side of the discharge, the released gas is drawn into the electron discharge and ionized in accurately controlled amounts. Consequently, the output pulses of the ion source may be accurately controlled.

RACT (Reasonably Available Control Technology) determination for five industry categories in Florida

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

Hawks, R.L.; Schlesser, S.P.; Loudin, D.L.

Section 172(b)(2) of the Clean Air Act as amended August 1977, requires that SIP revisions 'provide for the implementation of all reasonably available control measures as expeditiously as practicable.' The use of RACT for stationary sources is defined as the lowest emission limit that a particular source is capable of meeting by the application of control technology that is reasonably available considering technological and economic feasibility. The purpose of this report has been to identify control techniques that best represent RACT for particular emission sources in TSP nonattainment areas in the State of Florida. These sources include phosphate process operations;more » portland cement plants; electric arc furnaces; sweat or pot furnaces; materials handling, sizing, screening, crushing, and grinding operations.« less

Setting the agenda for a healthy retail environment: content analysis of US newspaper coverage of tobacco control policies affecting the point of sale, 2007-2014.

PubMed

Myers, Allison E; Southwell, Brian G; Ribisl, Kurt M; Moreland-Russell, Sarah; Lytle, Leslie A

2017-07-01

Tobacco control policies affecting the point of sale (POS) are an emerging intervention, yet POS-related news media content has not been studied. We describe news coverage of POS tobacco control efforts and assess relationships between article characteristics, including policy domains, frames, sources, localisation and evidence present, and slant towards tobacco control efforts. High circulation state (n=268) and national (n=5) newspapers comprised the sampling frame. We retrieved 917 relevant POS-focused articles in newspapers from 1 January 2007 to 31 December 2014. 5 raters screened and coded articles, 10% of articles were double coded, and mean inter-rater reliability (IRR) was 0.74. POS coverage emphasised tobacco retailer licensing (49.1% of articles) and the most common frame present was regulation (71.3%). Government officials (52.3%), followed by tobacco retailers (39.6%), were the most frequent sources. Half of articles (51.3%) had a mixed, neutral or antitobacco control slant. Articles presenting a health frame, a greater number of protobacco control sources, and statistical evidence were significantly more likely to also have a protobacco control slant. Articles presenting a political/rights or regulation frame, a greater number of antitobacco control sources, or government, tobacco industry, tobacco retailers, or tobacco users as sources were significantly less likely to also have a protobacco control slant. Stories that feature procontrol sources, research evidence and a health frame also tend to support tobacco control objectives. Future research should investigate how to use data, stories and localisation to encourage a protobacco control slant, and should test relationships between content characteristics and policy progression. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Monitoring by Control Technique - Cyclone

EPA Pesticide Factsheets

Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about cyclone control techniques used to reduce pollutant emissions.

Monitoring by Control Technique - Condensers

EPA Pesticide Factsheets

Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about condenser control techniques used to reduce pollutant emissions.

Adaptive CT scanning system

DOEpatents

Sampayan, Stephen E.

2016-11-22

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

Source apportionment of fine particulate matter organic carbon in Shenzhen, China by chemical mass balance and radiocarbon methods.

PubMed

Al-Naiema, Ibrahim M; Yoon, Subin; Wang, Yu-Qin; Zhang, Yuan-Xun; Sheesley, Rebecca J; Stone, Elizabeth A

2018-09-01

Chemical mass balance (CMB) modeling and radiocarbon measurements were combined to evaluate the sources of carbonaceous fine particulate matter (PM 2.5 ) in Shenzhen, China during and after the 2011 summer Universiade games when air pollution control measurements were implemented to achieve air quality targets. Ambient PM 2.5 filter samples were collected daily at two sampling sites (Peking University Shenzhen campus and Longgang) over 24 consecutive days, covering the controlled and uncontrolled periods. During the controlled period, the average PM 2.5 concentration was less than half of what it was after the controls were lifted. Organic carbon (OC), organic molecular markers (e.g., levoglucosan, hopanes, polycyclic aromatic hydrocarbons), and secondary organic carbon (SOC) tracers were all significantly lower during the controlled period. After pollution controls ended, at Peking University, OC source contributions included gasoline and diesel engines (24%), coal combustion (6%), biomass burning (12.2%), vegetative detritus (2%), biogenic SOC (from isoprene, α-pinene, and β-caryophyllene; 7.1%), aromatic SOC (23%), and other sources not included in the model (25%). At Longgang after the controls ended, similar source contributions were observed: gasoline and diesel engines (23%), coal combustion (7%), biomass burning (17.7%), vegetative detritus (1%), biogenic SOC (from isoprene, α-pinene, and β-caryophyllene; 5.3%), aromatic SOC (13%), and other sources (33%). The contributions of the following sources were smaller during the pollution controls: biogenic SOC (by a factor of 10-16), aromatic SOC (4-12), coal combustion (1.5-6.8), and biomass burning (2.3-4.9). CMB model results and radiocarbon measurements both indicated that fossil carbon dominated over modern carbon, regardless of pollution controls. However, the CMB model needs further improvement to apportion contemporary carbon (i.e. biomass burning, biogenic SOC) in this region. This work defines the major contributors to carbonaceous PM 2.5 in Shenzhen and demonstrates that control measures for primary emissions could significantly reduce secondary organic aerosol (SOA) formation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Combining controlled-source seismology and receiver function information to derive 3-D Moho topography for Italy

NASA Astrophysics Data System (ADS)

Spada, M.; Bianchi, I.; Kissling, E.; Agostinetti, N. Piana; Wiemer, S.

2013-08-01

The accurate definition of 3-D crustal structures and, in primis, the Moho depth, are the most important requirement for seismological, geophysical and geodynamic modelling in complex tectonic regions. In such areas, like the Mediterranean region, various active and passive seismic experiments are performed, locally reveal information on Moho depth, average and gradient crustal Vp velocity and average Vp/Vs velocity ratios. Until now, the most reliable information on crustal structures stems from controlled-source seismology experiments. In most parts of the Alpine region, a relatively large number of controlled-source seismology information are available though the overall coverage in the central Mediterranean area is still sparse due to high costs of such experiments. Thus, results from other seismic methodologies, such as local earthquake tomography, receiver functions and ambient noise tomography can be used to complement the controlled-source seismology information to increase coverage and thus the quality of 3-D crustal models. In this paper, we introduce a methodology to directly combine controlled-source seismology and receiver functions information relying on the strengths of each method and in relation to quantitative uncertainty estimates for all data to derive a well resolved Moho map for Italy. To obtain a homogeneous elaboration of controlled-source seismology and receiver functions results, we introduce a new classification/weighting scheme based on uncertainty assessment for receiver functions data. In order to tune the receiver functions information quality, we compare local receiver functions Moho depths and uncertainties with a recently derived well-resolved local earthquake tomography-derived Moho map and with controlled-source seismology information. We find an excellent correlation in the Moho information obtained by these three methodologies in Italy. In the final step, we interpolate the controlled-source seismology and receiver functions information to derive the map of Moho topography in Italy and surrounding regions. Our results show high-frequency undulation in the Moho topography of three different Moho interfaces, the European, the Adriatic-Ionian, and the Liguria-Corsica-Sardinia-Tyrrhenia, reflecting the complexity of geodynamical evolution.

77 FR 71323 - Reconsideration of Certain New Source and Startup/Shutdown Issues: National Emission Standards...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-30

... units designed for the coal >= 8300 Btu/lb (non- low rank virgin coal) subcategory. Some petitioners...-fired EGU would have the opportunity to design the primary PM control device to meet the new source... the opportunity to design the primary PM control device to meet the new source emission limit, we can...

40 CFR 63.4951 - How do I demonstrate initial compliance with the emission limitations?

Code of Federal Regulations, 2010 CFR

2010-07-01

... without add-on controls option for any individual coating operation, for any group of coating operations in the affected source, or for all the coating operations in the affected source to demonstrate... emission rate with add-on controls option for any coating operation in the affected source for which you do...

40 CFR 63.11465 - What are the standards for new and existing sources?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Metals Processing Area Sources Standards, Compliance, and Monitoring Requirements § 63.11465 What are the... through a fabric filter or baghouse that achieves a particulate matter (PM) control efficiency of at least... affected source through a fabric filter or baghouse that achieves a PM control efficiency of at least 99.5...

46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.

Code of Federal Regulations, 2011 CFR

2011-10-01

... difference in potential between the external conductors, overcurrent protection need only be at the supply of... to start. (c) Source of potential. The potential for a control, interlock, or indicator circuit must... disconnected from all sources of potential by a disconnect device independent of the motor and controller...

46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.

Code of Federal Regulations, 2014 CFR

2014-10-01

... difference in potential between the external conductors, overcurrent protection need only be at the supply of... to start. (c) Source of potential. The potential for a control, interlock, or indicator circuit must... disconnected from all sources of potential by a disconnect device independent of the motor and controller...

46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.

Code of Federal Regulations, 2013 CFR

2013-10-01

... difference in potential between the external conductors, overcurrent protection need only be at the supply of... to start. (c) Source of potential. The potential for a control, interlock, or indicator circuit must... disconnected from all sources of potential by a disconnect device independent of the motor and controller...

46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.

Code of Federal Regulations, 2012 CFR

2012-10-01

... difference in potential between the external conductors, overcurrent protection need only be at the supply of... to start. (c) Source of potential. The potential for a control, interlock, or indicator circuit must... disconnected from all sources of potential by a disconnect device independent of the motor and controller...

46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.

Code of Federal Regulations, 2010 CFR

2010-10-01

... difference in potential between the external conductors, overcurrent protection need only be at the supply of... to start. (c) Source of potential. The potential for a control, interlock, or indicator circuit must... disconnected from all sources of potential by a disconnect device independent of the motor and controller...

Assessment and control of spacecraft electromagnetic interference

NASA Technical Reports Server (NTRS)

1972-01-01

Design criteria are presented to provide guidance in assessing electromagnetic interference from onboard sources and establishing requisite control in spacecraft design, development, and testing. A comprehensive state-of-the-art review is given which covers flight experience, sources and transmission of electromagnetic interference, susceptible equipment, design procedure, control techniques, and test methods.

Augmented thermal bus

NASA Technical Reports Server (NTRS)

Schrage, Dean S. (Inventor)

1993-01-01

The present invention is directed to an augmented thermal bus. In the present design a plurity of thermo-electric heat pumps are used to couple a source plate to a sink plate. Each heat pump is individually controlled by a model based controller. The controller coordinates the heat pump to maintain isothermality in the source.

Augmented Thermal Bus

NASA Technical Reports Server (NTRS)

Schrage, Dean S. (Inventor)

1996-01-01

The present invention is directed to an augmented thermal bus. In the present design a plurality of thermo-electric heat pumps are used to couple a source plate to a sink plate. Each heat pump is individually controlled by a model based controller. The controller coordinates the heat pumps to maintain isothermality in the source.

78 FR 59263 - Outer Continental Shelf Air Regulations Consistency Update for California

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-26

... pertains to the requirements for OCS sources for which the Santa Barbara County Air Pollution Control...), EPA proposed to incorporate various Santa Barbara County APCD air pollution control requirements into... requires that EPA establish requirements to control air pollution from OCS sources located within 25 miles...

A comprehensive classification method for VOC emission sources to tackle air pollution based on VOC species reactivity and emission amounts.

PubMed

Li, Guohao; Wei, Wei; Shao, Xia; Nie, Lei; Wang, Hailin; Yan, Xiao; Zhang, Rui

2018-05-01

In China, volatile organic compound (VOC) control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were based on VOC emission amounts (EA), but never considered the significant differentiation of VOC species in terms of atmospheric chemical reactivity. This will adversely influence the effect of VOC reduction on air quality improvement. Therefore, this study attempted to develop a comprehensive classification method for typical VOC sources in the Beijing-Tianjin-Hebei region (BTH), by combining the VOC emission amounts with the chemical reactivities of VOC species. Firstly, we obtained the VOC chemical profiles by measuring 5 key sources in the BTH region and referencing another 10 key sources, and estimated the ozone formation potential (OFP) per ton VOC emission for these sources by using the maximum incremental reactivity (MIR) index as the characteristic of source reactivity (SR). Then, we applied the data normalization method to respectively convert EA and SR to normalized EA (NEA) and normalized SR (NSR) for various sources in the BTH region. Finally, the control index (CI) was calculated, and these sources were further classified into four grades based on the normalized CI (NCI). The study results showed that in the BTH region, furniture coating, automobile coating, and road vehicles are characterized by high NCI and need to be given more attention; however, the petro-chemical industry, which was designated as an important control source by air quality managers, has a lower NCI. Copyright © 2017. Published by Elsevier B.V.

An air-coupled actuator array for active modal control of timpani

NASA Astrophysics Data System (ADS)

Rollow, Douglas; Sparrow, Victor W.; Swanson, David C.

2005-09-01

The timbral characteristics of kettledrums can be described by a modal formulation of the vibration of a thin, air-loaded membrane. Modification of the modal time history can be brought about with the use of a control system which has independent influence on each structural mode. By replacing the usual kettle with a shallow chamber and a planar array of piston sources, a modal controller is created when driving the sources in appropriate linear combinations. A theoretical formulation of active control of structural vibration by means of fluid-coupled actuators is expressed, and a Boundary Element simulation provides insight to the coupled modes, independence of control, and constraints due to the geometry of the chamber. Advantages and limitations of this type of control source to general problems in actively controlled musical instruments are explored.

Monitoring by Control Technique - Catalytic Oxidizer

EPA Pesticide Factsheets

Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about catalytic oxidizer control techniques used to reduce pollutant emissions.

Monitoring by Control Technique - Thermal Oxidizer

EPA Pesticide Factsheets

Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about thermal oxidizer control techniques used to reduce pollutant emissions.

Monitoring by Control Technique - Electrostatic Precipitators

EPA Pesticide Factsheets

Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about electrostatic precipitator control techniques used to reduce pollutant emissions.

Monitoring by Control Technique - Fabric Filters

EPA Pesticide Factsheets

Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about fabric filter control techniques used to reduce pollutant emissions.

Monitoring by Control Technique - Capture Systems

EPA Pesticide Factsheets

Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about capture system control techniques used to reduce pollutant emissions.

Source Memory for Self and Other in Patients With Mild Cognitive Impairment due to Alzheimer’s Disease

PubMed Central

Deason, Rebecca G.; Budson, Andrew E.; Gutchess, Angela H.

2016-01-01

Objectives. The present study examined the role of enactment in source memory in a cognitively impaired population. As seen in healthy older adults, it was predicted that source memory in people with mild cognitive impairment due to Alzheimer’s disease (MCI-AD) would benefit from the self-reference aspect of enactment. Method. Seventeen participants with MCI-AD and 18 controls worked in small groups to pack a picnic basket and suitcase and were later tested for their source memory for each item. Results. For item memory, self-referencing improved corrected recognition scores for both MCI-AD and control participants. The MCI-AD group did not demonstrate the same benefit as controls in correct source memory for self-related items. However, those with MCI-AD were relatively less likely to misattribute new items to the self and more likely to misattribute new items to others when committing errors, compared with controls. Discussion. The enactment effect and self-referencing did not enhance accurate source memory more than other referencing for patients with MCI-AD. However, people with MCI-AD benefited in item memory and source memory, being less likely to falsely claim new items as their own, indicating some self-reference benefit occurs for people with MCI-AD. PMID:24904049

Source Memory for Self and Other in Patients With Mild Cognitive Impairment due to Alzheimer's Disease.

PubMed

Rosa, Nicole M; Deason, Rebecca G; Budson, Andrew E; Gutchess, Angela H

2016-01-01

The present study examined the role of enactment in source memory in a cognitively impaired population. As seen in healthy older adults, it was predicted that source memory in people with mild cognitive impairment due to Alzheimer's disease (MCI-AD) would benefit from the self-reference aspect of enactment. Seventeen participants with MCI-AD and 18 controls worked in small groups to pack a picnic basket and suitcase and were later tested for their source memory for each item. For item memory, self-referencing improved corrected recognition scores for both MCI-AD and control participants. The MCI-AD group did not demonstrate the same benefit as controls in correct source memory for self-related items. However, those with MCI-AD were relatively less likely to misattribute new items to the self and more likely to misattribute new items to others when committing errors, compared with controls. The enactment effect and self-referencing did not enhance accurate source memory more than other referencing for patients with MCI-AD. However, people with MCI-AD benefited in item memory and source memory, being less likely to falsely claim new items as their own, indicating some self-reference benefit occurs for people with MCI-AD. Published by Oxford University Press on behalf of the Gerontological Society of America 2014.

Open source software to control Bioflo bioreactors.

PubMed

Burdge, David A; Libourel, Igor G L

2014-01-01

Bioreactors are designed to support highly controlled environments for growth of tissues, cell cultures or microbial cultures. A variety of bioreactors are commercially available, often including sophisticated software to enhance the functionality of the bioreactor. However, experiments that the bioreactor hardware can support, but that were not envisioned during the software design cannot be performed without developing custom software. In addition, support for third party or custom designed auxiliary hardware is often sparse or absent. This work presents flexible open source freeware for the control of bioreactors of the Bioflo product family. The functionality of the software includes setpoint control, data logging, and protocol execution. Auxiliary hardware can be easily integrated and controlled through an integrated plugin interface without altering existing software. Simple experimental protocols can be entered as a CSV scripting file, and a Python-based protocol execution model is included for more demanding conditional experimental control. The software was designed to be a more flexible and free open source alternative to the commercially available solution. The source code and various auxiliary hardware plugins are publicly available for download from https://github.com/LibourelLab/BiofloSoftware. In addition to the source code, the software was compiled and packaged as a self-installing file for 32 and 64 bit windows operating systems. The compiled software will be able to control a Bioflo system, and will not require the installation of LabVIEW.

Open Source Software to Control Bioflo Bioreactors

PubMed Central

Burdge, David A.; Libourel, Igor G. L.

2014-01-01

Bioreactors are designed to support highly controlled environments for growth of tissues, cell cultures or microbial cultures. A variety of bioreactors are commercially available, often including sophisticated software to enhance the functionality of the bioreactor. However, experiments that the bioreactor hardware can support, but that were not envisioned during the software design cannot be performed without developing custom software. In addition, support for third party or custom designed auxiliary hardware is often sparse or absent. This work presents flexible open source freeware for the control of bioreactors of the Bioflo product family. The functionality of the software includes setpoint control, data logging, and protocol execution. Auxiliary hardware can be easily integrated and controlled through an integrated plugin interface without altering existing software. Simple experimental protocols can be entered as a CSV scripting file, and a Python-based protocol execution model is included for more demanding conditional experimental control. The software was designed to be a more flexible and free open source alternative to the commercially available solution. The source code and various auxiliary hardware plugins are publicly available for download from https://github.com/LibourelLab/BiofloSoftware. In addition to the source code, the software was compiled and packaged as a self-installing file for 32 and 64 bit windows operating systems. The compiled software will be able to control a Bioflo system, and will not require the installation of LabVIEW. PMID:24667828

Monitoring by Control Technique - Activated Carbon Adsorber

EPA Pesticide Factsheets

Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about Activated Carbon Adsorber control techniques used to reduce pollutant emissions.

National Management Measures to Control Nonpoint Source Pollution from Forestry

EPA Pesticide Factsheets

This report helps forest owners protect lakes and streams from polluted runoff that can result from forestry activities. The report will also help states to implement their nonpoint source control programs.

Monitoring by Control Technique - Electrified Filter Bed

EPA Pesticide Factsheets

Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about electrified filter bed control techniques used to reduce pollutant emissions.

Volume 3 - Area Sources and Area Source Method Abstracts

EPA Pesticide Factsheets

Nonpoint (area) source emission reference materials from the EIIP. Provides nonpoint source guidance on planning, emissions estimation, data collection, inventory documentation and reporting, and quality assurance/quality control.

Power system monitoring and source control of the Space Station Freedom DC power system testbed

NASA Technical Reports Server (NTRS)

Kimnach, Greg L.; Baez, Anastacio N.

1992-01-01

Unlike a terrestrial electric utility which can purchase power from a neighboring utility, the Space Station Freedom (SSF) has strictly limited energy resources; as a result, source control, system monitoring, system protection, and load management are essential to the safe and efficient operation of the SSF Electric Power System (EPS). These functions are being evaluated in the DC Power Management and Distribution (PMAD) Testbed which NASA LeRC has developed at the Power System Facility (PSF) located in Cleveland, Ohio. The testbed is an ideal platform to develop, integrate, and verify power system monitoring and control algorithms. State Estimation (SE) is a monitoring tool used extensively in terrestrial electric utilities to ensure safe power system operation. It uses redundant system information to calculate the actual state of the EPS, to isolate faulty sensors, to determine source operating points, to verify faults detected by subsidiary controllers, and to identify high impedance faults. Source control and monitoring safeguard the power generation and storage subsystems and ensure that the power system operates within safe limits while satisfying user demands with minimal interruptions. System monitoring functions, in coordination with hardware implemented schemes, provide for a complete fault protection system. The objective of this paper is to overview the development and integration of the state estimator and the source control algorithms.

Power system monitoring and source control of the Space Station Freedom dc-power system testbed

NASA Technical Reports Server (NTRS)

Kimnach, Greg L.; Baez, Anastacio N.

1992-01-01

Unlike a terrestrial electric utility which can purchase power from a neighboring utility, the Space Station Freedom (SSF) has strictly limited energy resources; as a result, source control, system monitoring, system protection, and load management are essential to the safe and efficient operation of the SSF Electric Power System (EPS). These functions are being evaluated in the dc Power Management and Distribution (PMAD) Testbed which NASA LeRC has developed at the Power System Facility (PSF) located in Cleveland, Ohio. The testbed is an ideal platform to develop, integrate, and verify power system monitoring and control algorithms. State Estimation (SE) is a monitoring tool used extensively in terrestrial electric utilities to ensure safe power system operation. It uses redundant system information to calculate the actual state of the EPS, to isolate faulty sensors, to determine source operating points, to verify faults detected by subsidiary controllers, and to identify high impedance faults. Source control and monitoring safeguard the power generation and storage subsystems and ensure that the power system operates within safe limits while satisfying user demands with minimal interruptions. System monitoring functions, in coordination with hardware implemented schemes, provide for a complete fault protection system. The objective of this paper is to overview the development and integration of the state estimator and the source control algorithms.

Active control of fan-generated plane wave noise

NASA Technical Reports Server (NTRS)

Gerhold, Carl H.; Nuckolls, William E.; Santamaria, Odillyn L.; Martinson, Scott D.

1993-01-01

Subsonic propulsion systems for future aircraft may incorporate ultra-high bypass ratio ducted fan engines whose dominant noise source is the fan with blade passage frequency less than 1000 Hz. This low frequency combines with the requirement of a short nacelle to diminish the effectiveness of passive duct liners. Active noise control is seen as a viable method to augment the conventional passive treatments. An experiment to control ducted fan noise using a time domain active adaptive system is reported. The control sound source consists of loudspeakers arrayed around the fan duct. The error sensor location is in the fan duct. The purpose of this experiment is to demonstrate that the in-duct error sensor reduces the mode spillover in the far field, thereby increasing the efficiency of the control system. In this first series of tests, the fan is configured so that predominantly zero order circumferential waves are generated. The control system is found to reduce the blade passage frequency tone significantly in the acoustic far field when the mode orders of the noise source and of the control source are the same. The noise reduction is not as great when the mode orders are not the same even though the noise source modes are evanescent, but the control system converges stably and global noise reduction is demonstrated in the far field. Further experimentation is planned in which the performance of the system will be evaluated when higher order radial and spinning modes are generated.

Systems and methods for distributing power using photovoltaic resources and a shifting battery system

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

Mammoli, Andrea A.; Lavrova, Olga; Arellano, Brian

The present invention is an apparatus and method for delivering energy using a renewable resource. The method includes providing a photovoltaic energy source and applying energy storage to the photovoltaic energy source via a battery storage unit. The energy output from the photovoltaic energy source and the battery system is controlled using a battery control system. The battery control system predicts peak load, develops a schedule that includes when to begin discharging power and when to stop discharging power, shifts power to the battery storage unit when excess power is available, and prioritizes the functionality of the battery storage unitmore » and the photovoltaic energy source.« less

Spherical loudspeaker array for local active control of sound.

PubMed

Rafaely, Boaz

2009-05-01

Active control of sound has been employed to reduce noise levels around listeners' head using destructive interference from noise-canceling sound sources. Recently, spherical loudspeaker arrays have been studied as multiple-channel sound sources, capable of generating sound fields with high complexity. In this paper, the potential use of a spherical loudspeaker array for local active control of sound is investigated. A theoretical analysis of the primary and secondary sound fields around a spherical sound source reveals that the natural quiet zones for the spherical source have a shell-shape. Using numerical optimization, quiet zones with other shapes are designed, showing potential for quiet zones with extents that are significantly larger than the well-known limit of a tenth of a wavelength for monopole sources. The paper presents several simulation examples showing quiet zones in various configurations.

Microfabricated diffusion source

DOEpatents

Oborny, Michael C [Albuquerque, NM; Frye-Mason, Gregory C [Cedar Crest, NM; Manginell, Ronald P [Albuquerque, NM

2008-07-15

A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

Indirect current control with separate IZ drop compensation for voltage source converters

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

Kanetkar, V.R.; Dawande, M.S.; Dubey, G.K.

1995-12-31

Indirect Current Control (ICC) of boost type Voltage Source Converters (VSCs) using separate compensation of line IZ voltage drop is presented. A separate bi-directional VSC is used to produce the compensation voltage. This simplifies the ICC regulator scheme as the power flow is controlled through single modulation index. Experimental verification is provided for bi-directional control of the power flow.

The Accuracy of Webcams in 2D Motion Analysis: Sources of Error and Their Control

ERIC Educational Resources Information Center

Page, A.; Moreno, R.; Candelas, P.; Belmar, F.

2008-01-01

In this paper, we show the potential of webcams as precision measuring instruments in a physics laboratory. Various sources of error appearing in 2D coordinate measurements using low-cost commercial webcams are discussed, quantifying their impact on accuracy and precision, and simple procedures to control these sources of error are presented.…

Active room compensation for sound reinforcement using sound field separation techniques.

PubMed

Heuchel, Franz M; Fernandez-Grande, Efren; Agerkvist, Finn T; Shabalina, Elena

2018-03-01

This work investigates how the sound field created by a sound reinforcement system can be controlled at low frequencies. An indoor control method is proposed which actively absorbs the sound incident on a reflecting boundary using an array of secondary sources. The sound field is separated into incident and reflected components by a microphone array close to the secondary sources, enabling the minimization of reflected components by means of optimal signals for the secondary sources. The method is purely feed-forward and assumes constant room conditions. Three different sound field separation techniques for the modeling of the reflections are investigated based on plane wave decomposition, equivalent sources, and the Spatial Fourier transform. Simulations and an experimental validation are presented, showing that the control method performs similarly well at enhancing low frequency responses with the three sound separation techniques. Resonances in the entire room are reduced, although the microphone array and secondary sources are confined to a small region close to the reflecting wall. Unlike previous control methods based on the creation of a plane wave sound field, the investigated method works in arbitrary room geometries and primary source positions.

40 CFR 52.730 - Compliance schedules.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Pollution Control Regulations Rule 203(d)(4), 203(d)(6)(B)(ii)(bb), 203(g)(1)(B), 203(g)(2), 203(g)(3), 203... operator of any stationary source subject to Illinois Air Pollution Control Regulation Rule 203(d)(4) shall... or operator of any stationary source subject to Illinois Air Pollution Control Regulation Rule 203(d...

40 CFR 52.730 - Compliance schedules.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Pollution Control Regulations Rule 203(d)(4), 203(d)(6)(B)(ii)(bb), 203(g)(1)(B), 203(g)(2), 203(g)(3), 203... operator of any stationary source subject to Illinois Air Pollution Control Regulation Rule 203(d)(4) shall... or operator of any stationary source subject to Illinois Air Pollution Control Regulation Rule 203(d...

40 CFR 52.730 - Compliance schedules.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Pollution Control Regulations Rule 203(d)(4), 203(d)(6)(B)(ii)(bb), 203(g)(1)(B), 203(g)(2), 203(g)(3), 203... operator of any stationary source subject to Illinois Air Pollution Control Regulation Rule 203(d)(4) shall... or operator of any stationary source subject to Illinois Air Pollution Control Regulation Rule 203(d...

Alternative Fuels Data Center: Maps and Data

Science.gov Websites

control systems and appliances with off-board sources of electricity, thereby reducing the need to idle trucks to power climate control systems and appliances with off-board sources of electricity, thereby

Bounded extremum seeking for angular velocity actuated control of nonholonomic unicycle

DOE PAGES

Scheinker, Alexander

2016-08-17

Here, we study control of the angular-velocity actuated nonholonomic unicycle, via a simple, bounded extremum seeking controller which is robust to external disturbances and measurement noise. The vehicle performs source seeking despite not having any position information about itself or the source, able only to sense a noise corrupted scalar value whose extremum coincides with the unknown source location. In order to control the angular velocity, rather than the angular heading directly, a controller is developed such that the closed loop system exhibits multiple time scales and requires an analysis approach expanding the previous work of Kurzweil, Jarnik, Sussmann, andmore » Liu, utilizing weak limits. We provide analytic proof of stability and demonstrate how this simple scheme can be extended to include position-independent source seeking, tracking, and collision avoidance of groups on autonomous vehicles in GPS-denied environments, based only on a measure of distance to an obstacle, which is an especially important feature for an autonomous agent.« less

Fuzzy Logic Controlled Solar Module for Driving Three- Phase Induction Motor

NASA Astrophysics Data System (ADS)

Afiqah Zainal, Nurul; Sooi Tat, Chan; Ajisman

2016-02-01

Renewable energy produced by solar module gives advantages for generated three- phase induction motor in remote area. But, solar module's ou tput is uncertain and complex. Fuzzy logic controller is one of controllers that can handle non-linear system and maximum power of solar module. Fuzzy logic controller used for Maximum Power Point Tracking (MPPT) technique to control Pulse-Width Modulation (PWM) for switching power electronics circuit. DC-DC boost converter used to boost up photovoltaic voltage to desired output and supply voltage source inverter which controlled by three-phase PWM generated by microcontroller. IGBT switched Voltage source inverter (VSI) produced alternating current (AC) voltage from direct current (DC) source to control speed of three-phase induction motor from boost converter output. Results showed that, the output power of solar module is optimized and controlled by using fuzzy logic controller. Besides that, the three-phase induction motor can be drive and control using VSI switching by the PWM signal generated by the fuzzy logic controller. This concluded that the non-linear system can be controlled and used in driving three-phase induction motor.

[Effect of schistosomiasis control strategy based on infection source control of Poyang Lake region in Yongxiu County promotion zone].

PubMed

Chen, Zhe; Rao, Xian-long; Li, Yi-feng; Gu, Xiao-nan; Xu, Mei-xin; Lin, Dan-dan

2015-12-01

To evaluate the effect of schistosomiasis control strategy with emphasis on infection source control in the Yongxiu County promotion zone of Poyang Lake region. The Wucheng Township of Yongxiu County was selected as the observation site, and the effect of the comprehensive control strategy was evaluated by using the method of field surveys combined with retrospective investigations. In 2010, there were 17 persons whose stool tests for schistosome infection were positive, and the number of calculated schistosomiasis patients was 2,331. The infection rate of cattle was 4.5%, and the area with infected Oncomelania hupensis snails was 10.00 hm². In 2011, the comprehensive control strategy was carried out, and in 2012, there were no cattle in the promotion zone. In 2013 and 2014, there were no schistosomiasis patients with positive stool tests. In 2014, no schistosome infected snails were found. The control strategy with emphasis on infection source control effectively controls the transmission of schistosomiasis in Yongxiu County promotion zone.

Solute source depletion control of forward and back diffusion through low-permeability zones

NASA Astrophysics Data System (ADS)

Yang, Minjune; Annable, Michael D.; Jawitz, James W.

2016-10-01

Solute diffusive exchange between low-permeability aquitards and high-permeability aquifers acts as a significant mediator of long-term contaminant fate. Aquifer contaminants diffuse into aquitards, but as contaminant sources are depleted, aquifer concentrations decline, triggering back diffusion from aquitards. The dynamics of the contaminant source depletion, or the source strength function, controls the timing of the transition of aquitards from sinks to sources. Here, we experimentally evaluate three archetypical transient source depletion models (step-change, linear, and exponential), and we use novel analytical solutions to accurately account for dynamic aquitard-aquifer diffusive transfer. Laboratory diffusion experiments were conducted using a well-controlled flow chamber to assess solute exchange between sand aquifer and kaolinite aquitard layers. Solute concentration profiles in the aquitard were measured in situ using electrical conductivity. Back diffusion was shown to begin earlier and produce larger mass flux for rapidly depleting sources. The analytical models showed very good correspondence with measured aquifer breakthrough curves and aquitard concentration profiles. The modeling approach links source dissolution and back diffusion, enabling assessment of human exposure risk and calculation of the back diffusion initiation time, as well as the resulting plume persistence.

Solute source depletion control of forward and back diffusion through low-permeability zones.

PubMed

Yang, Minjune; Annable, Michael D; Jawitz, James W

2016-10-01

Solute diffusive exchange between low-permeability aquitards and high-permeability aquifers acts as a significant mediator of long-term contaminant fate. Aquifer contaminants diffuse into aquitards, but as contaminant sources are depleted, aquifer concentrations decline, triggering back diffusion from aquitards. The dynamics of the contaminant source depletion, or the source strength function, controls the timing of the transition of aquitards from sinks to sources. Here, we experimentally evaluate three archetypical transient source depletion models (step-change, linear, and exponential), and we use novel analytical solutions to accurately account for dynamic aquitard-aquifer diffusive transfer. Laboratory diffusion experiments were conducted using a well-controlled flow chamber to assess solute exchange between sand aquifer and kaolinite aquitard layers. Solute concentration profiles in the aquitard were measured in situ using electrical conductivity. Back diffusion was shown to begin earlier and produce larger mass flux for rapidly depleting sources. The analytical models showed very good correspondence with measured aquifer breakthrough curves and aquitard concentration profiles. The modeling approach links source dissolution and back diffusion, enabling assessment of human exposure risk and calculation of the back diffusion initiation time, as well as the resulting plume persistence. Copyright © 2016 Elsevier B.V. All rights reserved.

Method for the production of dicarboxylic acids

DOEpatents

Nghiem, N.P.; Donnelly, M.; Millard, C.S.; Stols, L.

1999-02-09

The present invention is an economical fermentation method for the production of carboxylic acids comprising the steps of (a) inoculating a medium having a carbon source with a carboxylic acid-producing organism; (b) incubating the carboxylic acid-producing organism in an aerobic atmosphere to promote rapid growth of the organism thereby increasing the biomass of the organism; (c) controllably releasing oxygen to maintain the aerobic atmosphere; (d) controllably feeding the organism having increased biomass with a solution containing the carbon source to maintain the concentration of the carbon source within the medium of about 0.5 g/l up to about 1 g/l; (e) depriving the aerobic atmosphere of oxygen to produce an anaerobic atmosphere to cause the organism to undergo anaerobic metabolism; (f) controllably feeding the organism having increased biomass a solution containing the carbon source to maintain the concentration of the carbon source within the medium of {>=}1 g/l; and (g) converting the carbon source to carboxylic acids using the anaerobic metabolism of the organism. 7 figs.

Method for the production of dicarboxylic acids

DOEpatents

Nghiem, Nhuan Phu; Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

1999-01-01

The present invention is an economical fermentation method for the production of carboxylic acids comprising the steps of a) inoculating a medium having a carbon source with a carboxylic acid-producing organism; b) incubating the carboxylic acid-producing organism in an aerobic atmosphere to promote rapid growth of the organism thereby increasing the biomass of the organism; c) controllably releasing oxygen to maintain the aerobic atmosphere; d) controllably feeding the organism having increased biomass with a solution containing the carbon source to maintain the concentration of the carbon source within the medium of about 0.5 g/L up to about 1 g/L; e) depriving the aerobic atmosphere of oxygen to produce an anaerobic atmosphere to cause the organism to undergo anaerobic metabolism; f) controllably feeding the organism having increased biomass a solution containing the carbon source to maintain the concentration of the carbon source within the medium of .gtoreq.1 g/L; and g) converting the carbon source to carboxylic acids using the anaerobic metabolism of the organism.

Real-time multi-DSP control of three-phase current-source unity power factor PWM rectifier

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

Xiao Wang; Boon-Teck Ooi

1993-07-01

The design of a real-time multi-DSP controller for a high-quality six-valve three-phase current-source unity power factor PWM rectifier is discussed in this paper. With the decoupler preprocessor and the dynamic trilogic PWM trigger scheme, each of the three input currents can be controlled independently. Based on the a-b-c frame system model and the fast parallel computer control, the pole-placement control method is implemented successfully to achieve fast response in the ac currents. The low-frequency resonance in the ac filter L-C networks has been damped effectively. The experimental results are obtained from a 1-kVA bipolar transistor current-source PWM rectifier with amore » real-time controller using three TMS320C25 DSP's.« less

Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

NASA Technical Reports Server (NTRS)

Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

1996-01-01

An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

NASA Technical Reports Server (NTRS)

Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

1994-01-01

An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

10 CFR 835.1202 - Accountable sealed radioactive sources.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Accountable sealed radioactive sources. 835.1202 Section 835.1202 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Sealed Radioactive Source Control § 835.1202 Accountable sealed radioactive sources. (a) Each accountable sealed radioactive source...

10 CFR 835.1202 - Accountable sealed radioactive sources.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Accountable sealed radioactive sources. 835.1202 Section 835.1202 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Sealed Radioactive Source Control § 835.1202 Accountable sealed radioactive sources. (a) Each accountable sealed radioactive source...

10 CFR 835.1202 - Accountable sealed radioactive sources.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Accountable sealed radioactive sources. 835.1202 Section 835.1202 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Sealed Radioactive Source Control § 835.1202 Accountable sealed radioactive sources. (a) Each accountable sealed radioactive source...

10 CFR 835.1202 - Accountable sealed radioactive sources.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Accountable sealed radioactive sources. 835.1202 Section 835.1202 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Sealed Radioactive Source Control § 835.1202 Accountable sealed radioactive sources. (a) Each accountable sealed radioactive source...

10 CFR 835.1202 - Accountable sealed radioactive sources.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Accountable sealed radioactive sources. 835.1202 Section 835.1202 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Sealed Radioactive Source Control § 835.1202 Accountable sealed radioactive sources. (a) Each accountable sealed radioactive source...

Long-term trends of ambient particulate matter emission source contributions and the accountability of control strategies in Hong Kong over 1998-2008

NASA Astrophysics Data System (ADS)

Yuan, Zibing; Yadav, Varun; Turner, Jay R.; Louie, Peter K. K.; Lau, Alexis Kai Hon

2013-09-01

Despite extensive emission control measures targeting motor vehicles and to a lesser extent other sources, annual-average PM10 mass concentrations in Hong Kong have remained relatively constant for the past several years and for some air quality metrics, such as the frequency of poor visibility days, conditions have degraded. The underlying drivers for these long-term trends were examined by performing source apportionment on eleven years (1998-2008) of data for seven monitoring sites in the Hong Kong PM10 chemical speciation network. Nine factors were resolved using Positive Matrix Factorization. These factors were assigned to emission source categories that were classified as local (operationally defined as within the Hong Kong Special Administrative Region) or non-local based on temporal and spatial patterns in the source contribution estimates. This data-driven analysis provides strong evidence that local controls on motor vehicle emissions have been effective in reducing motor vehicle-related ambient PM10 burdens with annual-average contributions at neighborhood- and larger-scale monitoring stations decreasing by ˜6 μg m-3 over the eleven year period. However, this improvement has been offset by an increase in annual-average contributions from non-local contributions, especially secondary sulfate and nitrate, of ˜8 μg m-3 over the same time period. As a result, non-local source contributions to urban-scale PM10 have increased from 58% in 1998 to 70% in 2008. Most of the motor vehicle-related decrease and non-local source driven increase occurred over the period 1998-2004 with more modest changes thereafter. Non-local contributions increased most dramatically for secondary sulfate and secondary nitrate factors and thus combustion-related control strategies, including but not limited to power plants, are needed for sources located in the Pearl River Delta and more distant regions to improve air quality conditions in Hong Kong. PMF-resolved source contribution estimates were also used to examine differential contributions of emission source categories during high PM episodes compared to study-average behavior. While contributions from all source categories increased to some extent on high PM days, the increases were disproportionately high for the non-local sources. Thus, controls on emission sources located outside the Hong Kong Special Administrative Region will be needed to effectively decrease the frequency and severity of high PM episodes.

Techniques for Tracking, Evaluating, and Reporting the Implementation of Nonpoint Source Control Measures - Forestry

EPA Pesticide Factsheets

This guidance is intended to assist state, regional, and local environmental professionals in tracking the implementation of best management practices (BMPs) used to control nonpoint source pollution generated by forestry practices.

Monitoring by Control Technique - Wet Scrubber For Particulate Matter

EPA Pesticide Factsheets

Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about Wet Scrubber For Particulate Matter controls used to reduce pollutant emissions.

AIR POLLUTION CONTROL TECHNOLOGIES (CHAPTER 65)

EPA Science Inventory

The chapter discusses the use of technologies for reducing air pollution emissions from stationary sources, with emphasis on the control of combustion gen-erated air pollution. Major stationary sources include utility power boilers, industrial boilers and heaters, metal smelting ...

End of Life Decisions for Sealed Radioactive Sources

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

Pryor, Kathryn H.

Sealed radioactive sources are encountered in a wide variety of settings – from household smoke detectors and instrument check sources, through fixed industrial gauges, industrial radiography and well logging sources, to irradiators and medical teletherapy devices. In general, the higher the level of activity in the sealed source, the stricter the regulatory control that is applied to its use, control and ultimate disposition. Lower levels of attention and oversight can and do lead to sources ending up in the wrong place – as orphan sources in uncontrolled storage, disposed in a sanitary landfill, melted down in metal recycling operations andmore » incorporated into consumer products, or handled by an unsuspecting member of the public. There are a range of issues that contribute to the problem of improper disposal of sealed sources, and, in particular, to disused source disposal. General licensed sources and devices are particularly at risk of being disposed incorrectly. Higher activity general licensed sources, although required to be registered with the Nuclear Regulatory Commission (NRC) or Agreement State, receive limited regulatory oversight and are not tracked on a national scale. Users frequently do not consider the full life-cycle costs when procuring sources or devices and discover that they cannot afford to package, transport and dispose of their sources properly. The NRC requirements for decommissioning funding plans and financial assurance are not adequate to cover sealed source transport and disposal costs fully. While there are regulatory limits for storage of disused sources, enforcement is limited and there is no financial incentive for owners to dispose of the sources. In some cases, the lack of availability of approved Department of Transportation (DOT) Type B shipping casks also presents a barrier to sealed source disposal. The report of the Disused Sources Working Group does an excellent job of framing these issues. This article reviews both the issues and the report’s recommendations, which are designed to improve sealed source control and encourage proper disposal of disused sources.« less

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

Scheinker, Alexander

Here, we study control of the angular-velocity actuated nonholonomic unicycle, via a simple, bounded extremum seeking controller which is robust to external disturbances and measurement noise. The vehicle performs source seeking despite not having any position information about itself or the source, able only to sense a noise corrupted scalar value whose extremum coincides with the unknown source location. In order to control the angular velocity, rather than the angular heading directly, a controller is developed such that the closed loop system exhibits multiple time scales and requires an analysis approach expanding the previous work of Kurzweil, Jarnik, Sussmann, andmore » Liu, utilizing weak limits. We provide analytic proof of stability and demonstrate how this simple scheme can be extended to include position-independent source seeking, tracking, and collision avoidance of groups on autonomous vehicles in GPS-denied environments, based only on a measure of distance to an obstacle, which is an especially important feature for an autonomous agent.« less

Improved Magnetron Stability and Reduced Noise in Efficient Transmitters for Superconducting Accelerators

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

Kazakevich, G.; Johnson, R.; Lebedev, V.

State of the art high-current superconducting accelerators require efficient RF sources with a fast dynamic phase and power control. This allows for compensation of the phase and amplitude deviations of the accelerating voltage in the Superconducting RF (SRF) cavities caused by microphonics, etc. Efficient magnetron transmitters with fast phase and power control are attractive RF sources for this application. They are more cost effective than traditional RF sources such as klystrons, IOTs and solid-state amplifiers used with large scale accelerator projects. However, unlike traditional RF sources, controlled magnetrons operate as forced oscillators. Study of the impact of the controlling signalmore » on magnetron stability, noise and efficiency is therefore important. This paper discusses experiments with 2.45 GHz, 1 kW tubes and verifies our analytical model which is based on the charge drift approximation.« less

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

PubMed

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

2016-10-01

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

Illumination control apparatus for compensating solar light

NASA Technical Reports Server (NTRS)

Owens, L. J. (Inventor)

1978-01-01

An illumination control apparatus is presented for supplementing light from solar radiation with light from an artificial light source to compensate for periods of insufficient levels of solar light. The apparatus maintains a desired illumination level within an interior space comprising an artificial light source connected to an electrical power source with a switch means for selectively energizing said light source. An actuator means for controlling the on-off operation of the switch means is connected to a light sensor which responses to the illumination level of the interior space. A limit switch carried adjacent to the actuator limits the movement of the actuator within a predetermined range so as to prevent further movement thereof during detection of erroneous illumination conditions.

Photonic-powered cable assembly

DOEpatents

Sanderson, Stephen N.; Appel, Titus James; Wrye, IV, Walter C.

2013-01-22

A photonic-cable assembly includes a power source cable connector ("PSCC") coupled to a power receive cable connector ("PRCC") via a fiber cable. The PSCC electrically connects to a first electronic device and houses a photonic power source and an optical data transmitter. The fiber cable includes an optical transmit data path coupled to the optical data transmitter, an optical power path coupled to the photonic power source, and an optical feedback path coupled to provide feedback control to the photonic power source. The PRCC electrically connects to a second electronic device and houses an optical data receiver coupled to the optical transmit data path, a feedback controller coupled to the optical feedback path to control the photonic power source, and a photonic power converter coupled to the optical power path to convert photonic energy received over the optical power path to electrical energy to power components of the PRCC.

Photonic-powered cable assembly

DOEpatents

Sanderson, Stephen N; Appel, Titus James; Wrye, IV, Walter C

2014-06-24

A photonic-cable assembly includes a power source cable connector ("PSCC") coupled to a power receive cable connector ("PRCC") via a fiber cable. The PSCC electrically connects to a first electronic device and houses a photonic power source and an optical data transmitter. The fiber cable includes an optical transmit data path coupled to the optical data transmitter, an optical power path coupled to the photonic power source, and an optical feedback path coupled to provide feedback control to the photonic power source. The PRCC electrically connects to a second electronic device and houses an optical data receiver coupled to the optical transmit data path, a feedback controller coupled to the optical feedback path to control the photonic power source, and a photonic power converter coupled to the optical power path to convert photonic energy received over the optical power path to electrical energy to power components of the PRCC.

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

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-15

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

Controllable Bidirectional dc Power Sources For Large Loads

NASA Technical Reports Server (NTRS)

Tripp, John S.; Daniels, Taumi S.

1995-01-01

System redesigned for greater efficiency, durability, and controllability. Modern electronically controlled dc power sources proposed to supply currents to six electromagnets used to position aerodynamic test model in wind tunnel. Six-phase bridge rectifier supplies load with large current at voltage of commanded magnitude and polarity. Current-feedback circuit includes current-limiting feature giving some protection against overload.

Efficient Development of High Fidelity Structured Volume Grids for Hypersonic Flow Simulations

NASA Technical Reports Server (NTRS)

Alter, Stephen J.

2003-01-01

A new technique for the control of grid line spacing and intersection angles of a structured volume grid, using elliptic partial differential equations (PDEs) is presented. Existing structured grid generation algorithms make use of source term hybridization to provide control of grid lines, imposing orthogonality implicitly at the boundary and explicitly on the interior of the domain. A bridging function between the two types of grid line control is typically used to blend the different orthogonality formulations. It is shown that utilizing such a bridging function with source term hybridization can result in the excessive use of computational resources and diminishes robustness. A new approach, Anisotropic Lagrange Based Trans-Finite Interpolation (ALBTFI), is offered as a replacement to source term hybridization. The ALBTFI technique captures the essence of the desired grid controls while improving the convergence rate of the elliptic PDEs when compared with source term hybridization. Grid generation on a blunt cone and a Shuttle Orbiter is used to demonstrate and assess the ALBTFI technique, which is shown to be as much as 50% faster, more robust, and produces higher quality grids than source term hybridization.

[Demand for and the Development of Detection Techniques for Source of Schistosome Infection in China].

PubMed

Wang, Shi-ping; He, Xin; Zhou, Yun-fei

2015-12-01

Schistosomiasis is a type of zoonotic parasitosis that severely impairs human health. Rapid detection of infection sources is a key to the control of schistosomiasis. With the effective control of schistosomiasis in China, the detection techniques for infection sources have also been developed. The rate and the intensity of infection among humans and livestocks have been significantly decreased in China, as the control program has entered the transmission control stage in most of the endemic areas. Under this situation, the traditional etiological diagnosing techniques and common immunological methods can not afford rapid detection of infection sources of schistosomiasis. Instead, we are calling for detection methods with higher sensitivity, specificity and stability while being less time-consuming, more convenient and less costing. In recent years, many improved or novel detection methods have been applied for the epidemiological surveillance of schistosomiasis, such as the automatic scanning microscopic image acquisition system, PCR-ELISA, immunosensors, loop-mediated isothermal amplification, etc. The development of new monitoring techniques can facilitate rapid detection of schistosome infection sources in endemic areas.

Open-Source Syringe Pump Library

PubMed Central

Wijnen, Bas; Hunt, Emily J.; Anzalone, Gerald C.; Pearce, Joshua M.

2014-01-01

This article explores a new open-source method for developing and manufacturing high-quality scientific equipment suitable for use in virtually any laboratory. A syringe pump was designed using freely available open-source computer aided design (CAD) software and manufactured using an open-source RepRap 3-D printer and readily available parts. The design, bill of materials and assembly instructions are globally available to anyone wishing to use them. Details are provided covering the use of the CAD software and the RepRap 3-D printer. The use of an open-source Rasberry Pi computer as a wireless control device is also illustrated. Performance of the syringe pump was assessed and the methods used for assessment are detailed. The cost of the entire system, including the controller and web-based control interface, is on the order of 5% or less than one would expect to pay for a commercial syringe pump having similar performance. The design should suit the needs of a given research activity requiring a syringe pump including carefully controlled dosing of reagents, pharmaceuticals, and delivery of viscous 3-D printer media among other applications. PMID:25229451

Interpolity exchange of basalt tools facilitated via elite control in Hawaiian archaic states

PubMed Central

Kirch, Patrick V.; Mills, Peter R.; Lundblad, Steven P.; Sinton, John; Kahn, Jennifer G.

2012-01-01

Ethnohistoric accounts of late precontact Hawaiian archaic states emphasize the independence of chiefly controlled territories (ahupua‘a) based on an agricultural, staple economy. However, elite control of unevenly distributed resources, such as high-quality volcanic rock for adze production, may have provided an alternative source of economic power. To test this hypothesis we used nondestructive energy-dispersive X-ray fluorescence (ED-XRF) analysis of 328 lithic artifacts from 36 archaeological features in the Kahikinui district, Maui Island, to geochemically characterize the source groups. This process was followed by a limited sampling using destructive wavelength-dispersive X-ray fluorescence (WD-XRF) analysis to more precisely characterize certain nonlocal source groups. Seventeen geochemical groups were defined, eight of which represent extra-Maui Island sources. Although the majority of stone tools were derived from Maui Island sources (71%), a significant quantity (27%) of tools derived from extraisland sources, including the large Mauna Kea quarry on Hawai‘i Island as well as quarries on O‘ahu, Moloka‘i, and Lāna‘i islands. Importantly, tools quarried from extralocal sources are found in the highest frequency in elite residential features and in ritual contexts. These results suggest a significant role for a wealth economy based on the control and distribution of nonagricultural goods and resources during the rise of the Hawaiian archaic states. PMID:22203984

Boundary control of bidomain equations with state-dependent switching source functions in the ionic model

NASA Astrophysics Data System (ADS)

Chamakuri, Nagaiah; Engwer, Christian; Kunisch, Karl

2014-09-01

Optimal control for cardiac electrophysiology based on the bidomain equations in conjunction with the Fenton-Karma ionic model is considered. This generic ventricular model approximates well the restitution properties and spiral wave behavior of more complex ionic models of cardiac action potentials. However, it is challenging due to the appearance of state-dependent discontinuities in the source terms. A computational framework for the numerical realization of optimal control problems is presented. Essential ingredients are a shape calculus based treatment of the sensitivities of the discontinuous source terms and a marching cubes algorithm to track iso-surface of excitation wavefronts. Numerical results exhibit successful defibrillation by applying an optimally controlled extracellular stimulus.

Voltage controlled current source

DOEpatents

Casne, Gregory M.

1992-01-01

A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

NEW TECHNOLOGY FOR THE CONTROL OF AEROSOLS FROM STATIONARY SOURCES

EPA Science Inventory

The paper discusses an EPA program to develop new technologies for controlling particulate matter from stationary sources, including both electrostatically augmented fabric filtration (ESFF) and electrostatic precipitators (ESPs). The first generation ESFF system, using an electr...

FIRST ORDER ESTIMATES OF ENERGY REQUIREMENTS FOR POLLUTION CONTROL

EPA Science Inventory

This report presents estimates of the energy demand attributable to environmental control of pollution from 'stationary point sources.' This class of pollution source includes powerplants, factories, refineries, municipal waste water treatment plants, etc., but excludes 'mobile s...

The NASA Langley Research Center 0.3-meter transonic cryogenic tunnel microcomputer controller source code

NASA Technical Reports Server (NTRS)

Kilgore, W. Allen; Balakrishna, S.

1991-01-01

The 0.3 m Transonic Cryogenic Tunnel (TCT) microcomputer based controller has been operating for several thousand hours in a safe and efficient manner. A complete listing is provided of the source codes for the tunnel controller and tunnel simulator. Included also is a listing of all the variables used in these programs. Several changes made to the controller are described. These changes are to improve the controller ease of use and safety.

Acoustical Engineering Controls and Estimated Return on Investment for DoD Selected High Noise Sources: A Roadmap for Future Noise Control in Acquisition

DTIC Science & Technology

2013-04-25

Room 2A534, 1155 Defense Pentagon, Washington, DC 20301-1155 1. DOCUMENTDESCruPTION a . TYPE b. TITLE Acoustical Engineering Controls and Estimated...Return on Investment for DoD Selected Report Hil!h Noise Sources: A Roadmap for Future Noise Control in Acquisition c. PAGE COUNT d. SUBJECT AREA...175 Acoustical Engineering - Noise Control - Acquisition 2. AUTHOR/SPEAKER a . NAME (Last, First, Middlo Initial) b. RANK c. TITLE Erdman, Joy GS-15

SPiRiT Scoring Through Self-Assessment Charrettes

DTIC Science & Technology

2004-09-01

Continued) 0 Max 17 5.C5 Indoor Chemical and Pollutant Source Control 1 5.C6 Controllability of Systems 2 5.C7 Thermal Comfort 2 5.C8...Pollutant Source Control 1 5.C6 Controllability of Systems 2 5.C7 Thermal Comfort 2 5.C8 Daylight and Views 2 5.C9 Acoustic Environment...1 5.C6 Controllability of Systems 2 5.C7 Thermal Comfort 2 5.C8 Daylight and Views 2 5.C9 Acoustic Environment /Noise Control 1 5

40 CFR 424.16 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

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

Tunable Optical Sources.

DTIC Science & Technology

1980-11-01

finite aperture size 5. A. E. Siegman , "Unstable optical resonators for laser of the YAG rod, applications," Proc. IEEE 53, 217-287 (1965); "Unstable...Pumped LiNbO3 Tunable Source Radial Birefringent Element Computer Controlled Laser Attenuator Slab Configuration Laser Source 20. ABSTRACT (Continue on...have invented and demonstrated a computer controlled laser attenu- ator. .... Cont inued DD Il 7 1473 EDITION OF I NOV 01 IS OBSOLETE UNCLASSIFIEDAN

40 CFR Table 3 to Subpart Kkkk of... - Emission Limits for Affected Sources Using the Control Efficiency/Outlet Concentration Compliance...

Code of Federal Regulations, 2013 CFR

2013-07-01

... reconstructed affected source a. reduce emissions of total HAP, measured as THC (as carbon), a by 97 percent; orb. limit emissions of total HAP, measured as THC (as carbon), a to 20 ppmvd at the control device outlet and use a PTE. 2. in an existing affected source a. reduce emissions of total HAP, measured as THC...

40 CFR Table 3 to Subpart Kkkk of... - Emission Limits for Affected Sources Using the Control Efficiency/Outlet Concentration Compliance...

Code of Federal Regulations, 2012 CFR

2012-07-01

... reconstructed affected source a. reduce emissions of total HAP, measured as THC (as carbon), a by 97 percent; orb. limit emissions of total HAP, measured as THC (as carbon), a to 20 ppmvd at the control device outlet and use a PTE. 2. in an existing affected source a. reduce emissions of total HAP, measured as THC...

40 CFR Table 3 to Subpart Kkkk of... - Emission Limits for Affected Sources Using the Control Efficiency/Outlet Concentration Compliance...

Code of Federal Regulations, 2014 CFR

2014-07-01

... reconstructed affected source a. reduce emissions of total HAP, measured as THC (as carbon), a by 97 percent; orb. limit emissions of total HAP, measured as THC (as carbon), a to 20 ppmvd at the control device outlet and use a PTE. 2. in an existing affected source a. reduce emissions of total HAP, measured as THC...

40 CFR Table 3 to Subpart Kkkk of... - Emission Limits for Affected Sources Using the Control Efficiency/Outlet Concentration Compliance...

Code of Federal Regulations, 2011 CFR

2011-07-01

... affected source a. reduce emissions of total HAP, measured as THC (as carbon), a by 97 percent; orb. limit emissions of total HAP, measured as THC (as carbon), a to 20 ppmvd at the control device outlet and use a PTE. 2. in an existing affected source a. reduce emissions of total HAP, measured as THC (as carbon...

40 CFR Table 3 to Subpart Kkkk of... - Emission Limits for Affected Sources Using the Control Efficiency/Outlet Concentration Compliance...

Code of Federal Regulations, 2010 CFR

2010-07-01

... affected source a. reduce emissions of total HAP, measured as THC (as carbon), a by 97 percent; orb. limit emissions of total HAP, measured as THC (as carbon), a to 20 ppmvd at the control device outlet and use a PTE. 2. in an existing affected source a. reduce emissions of total HAP, measured as THC (as carbon...

Controlled Nuclear Fusion: Status and Outlook

ERIC Educational Resources Information Center

Rose, David J.

1971-01-01

Presents the history, current concerns and potential developments of nuclear fusion as a major energy source. Controlled fusion research is summarized, technological feasibility is discussed and environmental factors are examined. Relationships of alternative energy sources as well as energy utilization are considered. (JM)

SOURCE MANAGEMENT AND CONTROL TECHNOLOGIES

EPA Science Inventory

The options for pollution abatement in WWF can be implemented at the source by land management and pollution prevention techniques, in the collection system, offline by storage, or in a treatment plant. An integrated system that combines prevention, control, and treatment has of...

Torque coordinating robust control of shifting process for dry dual clutch transmission equipped in a hybrid car

NASA Astrophysics Data System (ADS)

Zhao, Z.-G.; Chen, H.-J.; Yang, Y.-Y.; He, L.

2015-09-01

For a hybrid car equipped with dual clutch transmission (DCT), the coordination control problems of clutches and power sources are investigated while taking full advantage of the integrated starter generator motor's fast response speed and high accuracy (speed and torque). First, a dynamic model of the shifting process is established, the vehicle acceleration is quantified according to the intentions of the driver, and the torque transmitted by clutches is calculated based on the designed disengaging principle during the torque phase. Next, a robust H∞ controller is designed to ensure speed synchronisation despite the existence of model uncertainties, measurement noise, and engine torque lag. The engine torque lag and measurement noise are used as external disturbances to initially modify the output torque of the power source. Additionally, during the torque switch phase, the torque of the power sources is smoothly transitioned to the driver's demanded torque. Finally, the torque of the power sources is further distributed based on the optimisation of system efficiency, and the throttle opening of the engine is constrained to avoid sharp torque variations. The simulation results verify that the proposed control strategies effectively address the problem of coordinating control of clutches and power sources, establishing a foundation for the application of DCT in hybrid cars.

Issues in Humanoid Audition and Sound Source Localization by Active Audition

NASA Astrophysics Data System (ADS)

Nakadai, Kazuhiro; Okuno, Hiroshi G.; Kitano, Hiroaki

In this paper, we present an active audition system which is implemented on the humanoid robot "SIG the humanoid". The audition system for highly intelligent humanoids localizes sound sources and recognizes auditory events in the auditory scene. Active audition reported in this paper enables SIG to track sources by integrating audition, vision, and motor movements. Given the multiple sound sources in the auditory scene, SIG actively moves its head to improve localization by aligning microphones orthogonal to the sound source and by capturing the possible sound sources by vision. However, such an active head movement inevitably creates motor noises.The system adaptively cancels motor noises using motor control signals and the cover acoustics. The experimental result demonstrates that active audition by integration of audition, vision, and motor control attains sound source tracking in variety of conditions.onditions.

Recognition memory, self-other source memory, and theory-of-mind in children with autism spectrum disorder.

PubMed

Lind, Sophie E; Bowler, Dermot M

2009-09-01

This study investigated semantic and episodic memory in autism spectrum disorder (ASD), using a task which assessed recognition and self-other source memory. Children with ASD showed undiminished recognition memory but significantly diminished source memory, relative to age- and verbal ability-matched comparison children. Both children with and without ASD showed an "enactment effect", demonstrating significantly better recognition and source memory for self-performed actions than other-person-performed actions. Within the comparison group, theory-of-mind (ToM) task performance was significantly correlated with source memory, specifically for other-person-performed actions (after statistically controlling for verbal ability). Within the ASD group, ToM task performance was not significantly correlated with source memory (after controlling for verbal ability). Possible explanations for these relations between source memory and ToM are considered.

40 CFR 63.1217 - What are the standards for liquid fuel boilers that burn hazardous waste?

Code of Federal Regulations, 2010 CFR

2010-07-01

... ng TEQ/dscm, corrected to 7 percent oxygen, for liquid fuel boilers equipped with a dry air pollution... by paragraph (a)(5) of this section for sources not equipped with a dry air pollution control system; (iii) A source equipped with a wet air pollution control system followed by a dry air pollution control...

40 CFR 63.1217 - What are the standards for liquid fuel boilers that burn hazardous waste?

Code of Federal Regulations, 2011 CFR

2011-07-01

... ng TEQ/dscm, corrected to 7 percent oxygen, for liquid fuel boilers equipped with a dry air pollution... by paragraph (a)(5) of this section for sources not equipped with a dry air pollution control system; (iii) A source equipped with a wet air pollution control system followed by a dry air pollution control...

Implementation and performance evaluation open-source controller for precision control of gripper

NASA Astrophysics Data System (ADS)

Lee, Seung-Yong; Ham, Un-Hyeong; Park, Young-Woo; Jung, Hak-Sang; Jung, Il-Kyun; Lim, Sun

2017-12-01

This paper proposes integrating gripper embedded operating system, which consist of external interface structure for sophisticated gripper control. This system has multiple functions that control the gripping module and measure the pose of the gripper body with respect to contact environment. A controller based on open source only for the gripper is developed and an external communication interface between robot controller and gripper controller is designed. An experimental environment for the fixed-cycle test consists of integrating magic gripper software system and hardware on commercial business. As a result, a deviation is measured approximately 2% and the system were verified for gripper control.

[Groundwater organic pollution source identification technology system research and application].

PubMed

Wang, Xiao-Hong; Wei, Jia-Hua; Cheng, Zhi-Neng; Liu, Pei-Bin; Ji, Yi-Qun; Zhang, Gan

2013-02-01

Groundwater organic pollutions are found in large amount of locations, and the pollutions are widely spread once onset; which is hard to identify and control. The key process to control and govern groundwater pollution is how to control the sources of pollution and reduce the danger to groundwater. This paper introduced typical contaminated sites as an example; then carried out the source identification studies and established groundwater organic pollution source identification system, finally applied the system to the identification of typical contaminated sites. First, grasp the basis of the contaminated sites of geological and hydrogeological conditions; determine the contaminated sites characteristics of pollutants as carbon tetrachloride, from the large numbers of groundwater analysis and test data; then find the solute transport model of contaminated sites and compound-specific isotope techniques. At last, through groundwater solute transport model and compound-specific isotope technology, determine the distribution of the typical site of organic sources of pollution and pollution status; invest identified potential sources of pollution and sample the soil to analysis. It turns out that the results of two identified historical pollution sources and pollutant concentration distribution are reliable. The results provided the basis for treatment of groundwater pollution.

Intelligent power management in a vehicular system with multiple power sources

NASA Astrophysics Data System (ADS)

Murphey, Yi L.; Chen, ZhiHang; Kiliaris, Leonidas; Masrur, M. Abul

This paper presents an optimal online power management strategy applied to a vehicular power system that contains multiple power sources and deals with largely fluctuated load requests. The optimal online power management strategy is developed using machine learning and fuzzy logic. A machine learning algorithm has been developed to learn the knowledge about minimizing power loss in a Multiple Power Sources and Loads (M_PS&LD) system. The algorithm exploits the fact that different power sources used to deliver a load request have different power losses under different vehicle states. The machine learning algorithm is developed to train an intelligent power controller, an online fuzzy power controller, FPC_MPS, that has the capability of finding combinations of power sources that minimize power losses while satisfying a given set of system and component constraints during a drive cycle. The FPC_MPS was implemented in two simulated systems, a power system of four power sources, and a vehicle system of three power sources. Experimental results show that the proposed machine learning approach combined with fuzzy control is a promising technology for intelligent vehicle power management in a M_PS&LD power system.

Heat recovery system employing a temperature controlled variable speed fan

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

Jones, W.T.

1986-05-20

A heat recovery system is described for use in recovering heat from an industrial process producing a heated fluid comprising: a source of inlet air; a housing coupled to the source and including a heat exchanger; means for passing the heated fluid through the heat exchanger; the housing including means for moving a variable volume of air adjustable over a continuous range from the source through the heat exchanger; air discharge means communicating with the housing for discharging air which has passed through the heat exchanger; a control system including first temperature sensing means for sensing the discharge temperature ofmore » the discharge air moving through the discharge means and a control circuit coupled to the first temperature sensing means and to the moving means for varying the volume of air moved in response to the sensed discharge temperature to control the temperature of discharge air passing through the discharge means at a first predetermined value; and the control system including second temperature sensing means for sensing the temperature of the source of inlet air and valve means coupled to and controlled by the control circuit to cause liquid to bypass the heat exchanger when the inlet air temperature rises above a second predetermined value.« less

Lead Exposures in U.S. Children, 2008: Implications for Prevention

PubMed Central

Levin, Ronnie; Brown, Mary Jean; Kashtock, Michael E.; Jacobs, David E.; Whelan, Elizabeth A.; Rodman, Joanne; Schock, Michael R.; Padilla, Alma; Sinks, Thomas

2008-01-01

Objective We reviewed the sources of lead in the environments of U.S. children, contributions to children’s blood lead levels, source elimination and control efforts, and existing federal authorities. Our context is the U.S. public health goal to eliminate pediatric elevated blood lead levels (EBLs) by 2010. Data sources National, state, and local exposure assessments over the past half century have identified risk factors for EBLs among U.S. children, including age, race, income, age and location of housing, parental occupation, and season. Data extraction and synthesis Recent national policies have greatly reduced lead exposure among U.S. children, but even very low exposure levels compromise children’s later intellectual development and lifetime achievement. No threshold for these effects has been demonstrated. Although lead paint and dust may still account for up to 70% of EBLs in U.S. children, the U.S. Centers for Disease Control and Prevention estimates that ≥30% of current EBLs do not have an immediate lead paint source, and numerous studies indicate that lead exposures result from multiple sources. EBLs and even deaths have been associated with inadequately controlled sources including ethnic remedies and goods, consumer products, and food-related items such as ceramics. Lead in public drinking water and in older urban centers remain exposure sources in many areas. Conclusions Achieving the 2010 goal requires maintaining current efforts, especially programs addressing lead paint, while developing interventions that prevent exposure before children are poisoned. It also requires active collaboration across all levels of government to identify and control all potential sources of lead exposure, as well as primary prevention. PMID:18941567

Research on starlight hardware-in-the-loop simulator

NASA Astrophysics Data System (ADS)

Zhang, Ying; Gao, Yang; Qu, Huiyang; Liu, Dongfang; Du, Huijie; Lei, Jie

2016-10-01

The starlight navigation is considered to be one of the most important methods for spacecraft navigation. Starlight simulation system is a high-precision system with large fields of view, designed to test the starlight navigation sensor performance on the ground. A complete hardware-in-the-loop simulation of the system has been built. The starlight simulator is made up of light source, light source controller, light filter, LCD, collimator and control computer. LCD is the key display component of the system, and is installed at the focal point of the collimator. For the LCD cannot emit light itself, so light source and light source power controller is specially designed for the brightness demanded by the LCD. Light filter is designed for the dark background which is also needed in the simulation.

HANDBOOK: CONTROL TECHNIQUES FOR HAZARDOUS AIR POLLUTANTS

EPA Science Inventory

This manual is a revision of the first (1986) edition of the Handbook: Control Technologies for Hazardous Air Pollutants, which incorporated information from numerous sources into a single, self-contained reference source focusing on the design and cost of VOC and partic...

40 CFR 63.16 - Performance Track Provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 63.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... the emission standard to which the affected source is subject is based on add-on control technology, and the affected source complies by using add-on control technology, then all required reporting...

Monitoring by Control Technique - Compliant (Low/No VOC/HAP) Inks and Coatings

EPA Pesticide Factsheets

Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about Compliant (Low/No VOC/HAP) Inks and Coatings control techniques used to reduce pollutant emissions.

NOX EMISSION CONTROL OPTIONS FOR COAL-FIRED ELECTRIC UTILITY BOILERS

EPA Science Inventory

The paper reviews NOx control options for coal-fired electric utility boilers. (NOTE: Acid Rain NOx regulations, the Ozone Transport Commission's NOx Budget Program, revision of the New Source Performance Standards (NSPS) for NOx emissions from utility sources, and Ozone Transpor...

Final Rule for Control of Hazardous Air Pollutants From Mobile Sources: Early Credit Technology Requirement Revision

EPA Pesticide Factsheets

EPA is taking final action to revise the February 26, 2007 mobile source air toxics rule’s requirements that specify which benzene control technologies a refiner may utilize to qualify to generate early benzene credits.

RECOGNIZING FARMERS' ATTITUDES AND IMPLEMENTING NONPOINT SOURCE POLLUTION CONTROL POLICIES

EPA Science Inventory

This report examines the role of farmer attitudes and corresponding communication activities in the implementation of nonpoint source water pollution control programs. The report begins with an examination of the basis for and function of attitudes in influencing behavior. The ro...

A Variable Frequency, Mis-Match Tolerant, Inductive Plasma Source

NASA Astrophysics Data System (ADS)

Rogers, Anthony; Kirchner, Don; Skiff, Fred

2014-10-01

Presented here is a survey and analysis of an inductively coupled, magnetically confined, singly ionized Argon plasma generated by a square-wave, variable frequency plasma source. The helicon-style antenna is driven directly by the class ``D'' amplifier without matching network for increased efficiency while maintaining independent control of frequency and applied power at the feed point. The survey is compared to similar data taken using a traditional exciter--power amplifier--matching network source. Specifically, the flexibility of this plasma source in terms of the independent control of electron plasma temperature and density is discussed in comparison to traditional source arrangements. Supported by US DOE Grant DE-FG02-99ER54543.

Magnetotelluric Data, Mid Valley, Nevada Test Site, Nevada

USGS Publications Warehouse

Williams, Jackie M.; Wallin, Erin L.; Rodriguez, Brian D.; Lindsey, Charles R.; Sampson, Jay A.

2007-01-01

Introduction The United States Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing ground-water contamination resulting from historical underground nuclear testing through the Environmental Management (EM) program and, in particular, the Underground Test Area (UGTA) project. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow. Ground-water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Rainier Mesa/Shoshone Mountain Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS), in cooperation with the DOE and NNSA-NSO, collected and processed data at the Nevada Test Site in and near Yucca Flat (YF) to help define the character, thickness, and lateral extent of the pre-Tertiary confining units. We collected 51 magnetotelluric (MT) and audio-magnetotelluric (AMT), stations for that research. In early 2005 we extended that research with 26 additional MT data stations, located on and near Rainier Mesa and Shoshone Mountain (RM-SM). The new stations extended the area of the hydrogeologic study previously conducted in Yucca Flat. This work was done to help refine what is known about the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal was to define the upper clastic confining unit (UCCU). The UCCU is comprised of late Devonian to Mississippian siliciclastic rocks assigned to the Eleana Formation and Chainman Shale. The UCCU underlies the Yucca Flat area and extends westward towards Shoshone Mountain, southward to Buckboard Mesa, and northward to Rainier Mesa. Late in 2005 we collected another 14 MT stations in Mid Valley and in northern Yucca Flat basin. That work was done to better determine the extent and thickness of the UCCU near the southeastern RM-SM CAU boundary with the southwestern YF CAU, and also in the northern YF CAU. The purpose of this report is to release the MT data at those 14 stations. No interpretation of the data is included here.

Deep resistivity structure of Yucca Flat, Nevada Test Site, Nevada

USGS Publications Warehouse

Asch, Theodore H.; Rodriguez, Brian D.; Sampson, Jay A.; Wallin, Erin L.; Williams, Jackie M.

2006-01-01

The Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office are addressing groundwater contamination resulting from historical underground nuclear testing through the Environmental Management program and, in particular, the Underground Test Area project. One issue of concern is the nature of the somewhat poorly constrained pre Tertiary geology and its effects on ground-water flow in the area adjacent to a nuclear test. Ground water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey, supported by the DOE and NNSA-NSO, collected and processed data from 51 magnetotelluric (MT) and audio-magnetotelluric (AMT) stations at the Nevada Test Site in and near Yucca Flat to assist in characterizing the pre-Tertiary geology in that area. The primary purpose was to refine the character, thickness, and lateral extent of pre Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (late Devonian - Mississippian-age siliciclastic rocks assigned to the Eleana Formation and Chainman Shale) in the Yucca Flat area. The MT and AMT data have been released in separate USGS Open File Reports. The Nevada Test Site magnetotelluric data interpretation presented in this report includes the results of detailed two-dimensional (2 D) resistivity modeling for each profile (including alternative interpretations) and gross inferences on the three dimensional (3 D) character of the geology beneath each station. The character, thickness, and lateral extent of the Chainman Shale and Eleana Formation that comprise the Upper Clastic Confining Unit are generally well determined in the upper 5 km. Inferences can be made regarding the presence of the Lower Clastic Confining Unit at depths below 5 km. Large fault structures such as the CP Thrust fault, the Carpetbag fault, and the Yucca fault that cross Yucca Flat are also discernable as are other smaller faults. The subsurface electrical resistivity distribution and inferred geologic structures determined by this investigation should help constrain the hydrostratigraphic framework model that is under development.

Relative Impact of Emissions Controls and Meteorology on Air Pollution Mitigation Associated with the Asia-Pacific Economic Cooperation (APEC) Conference in Beijing, China

NASA Astrophysics Data System (ADS)

Zhang, Y.; Wang, Y.; Schauer, J. J.; de Foy, B.

2016-12-01

The Beijing government and its surrounding provinces implemented a series of measures to ensure haze-free skies during the 22nd Asia-Pacific Economic Cooperation (APEC) conference (November 10th - 11th, 2014). These measures included restrictions on traffic, construction, and industrial activity. Twelve hour measurements of the concentration and composition of ambient fine particulate matter (PM2.5) were performed for 5 consecutive months near the APEC conference site before (September 11th - November 2nd, 2014), during (November 3rd - 12th, 2014) and after (November 13th, 2014 - January 31st, 2015). The measurements are used in a positive matrix factorization model to determine the contributions from seven sources of PM2.5: secondary aerosols, mobile source, industrial emission, road dust, soil dust, biomass burning and residual oil combustion. The source apportionment results are integrated with backward trajectory analysis using Weather Research and Forecast (WRF) meteorological simulations, which determine the relative influence of new regulation and meteorology upon improved air quality during the APEC conference. Data show that controls are very effective, but meteorology must be taken into account to determine the actual influence of the controls on pollution reduction. The Industry source control is the most effective for reducing concentrations, follows by secondary aerosol and biomass controls, while the least effective control is for the residual oil combustion source. The largest reductions in concentrations occur when air mass transport is from the west-northwest (Ulanqab). Secondary aerosol and mobile source reductions are most significant for air mass transport from the north-northwest (Xilingele League) origin, and least significant for northeast transport (Chifeng via Tangshan conditions). The largest reductions of soil dust, biomass burning, and industrial source are distinctly seen for Ulanqab conditions and least distinct for Xilingele League.

Proof-of-principle to unfold an angle-energy dependent source from forward and adjoint calculations

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

Pace, J.V. III

For many years there has existed a discrepancy between the measured and calculated responses from the Little Boy weapon in Hiroshima. A myriad of solutions have been proposed, but to no avail. If one can rationalize to himself that it does not really matter exactly what happened with the weapon when it exploded, and if sufficient information exist about the measurements, one should be able to unfold the source. Moreover, if a source can be unfolded in a controlled environment, then it should be possible to unfold a more complicated source, for example, the Little Boy source. This report recordsmore » the findings of a proof-of-principle test to unfold a source in the controlled environment.« less

Fiber optically isolated and remotely stabilized data transmission system

DOEpatents

Nelson, Melvin A.

1992-01-01

A fiber optically isolated and remotely stabilized data transmission system s described wherein optical data may be transmitted over an optical data fiber from a remote source which includes a data transmitter and a power supply at the remote source. The transmitter may be remotely calibrated and stabilized via an optical control fiber, and the power source may be remotely cycled between duty and standby modes via an optical control fiber.

Fiber optically isolated and remotely stabilized data transmission system

DOEpatents

Nelson, M.A.

1992-11-10

A fiber optically isolated and remotely stabilized data transmission systems described wherein optical data may be transmitted over an optical data fiber from a remote source which includes a data transmitter and a power supply at the remote source. The transmitter may be remotely calibrated and stabilized via an optical control fiber, and the power source may be remotely cycled between duty and standby modes via an optical control fiber. 3 figs.

ION SWITCH

DOEpatents

Cook, B.

1959-02-10

An ion switch capable of transferring large magnitudes of power is described. An ion switch constructed in accordance with the invention includes a pair of spaced control electrodes disposed in a highly evacuated region for connection in a conventional circuit to control the passing of power therethrough. A controllable ionic conduction path is provided directiy between the control electrodes by a source unit to close the ion switch. Conventional power supply means are provided to trigger the source unit and control the magnitude, durations and pulse repetition rate of the aforementioned ionic conduction path.

[Peritonitis in diverticulitis: the Bern concept].

PubMed

Seiler, C A; Brügger, L; Maurer, C A; Renzulli, P; Büchler, M W

1998-01-01

The colon is the most frequent origine for a diffuse peritonitis and diverticular perforation is again the most common source of a spontaneous secondary peritonitis. This paper first focuses on the treatment of peritonitis and secondly on the strategies of source control in peritonitis with special emphasis on the tactics (primary anastomosis vs. Hartmann procedure with colostomy) for surgical source control. Prospective analysis of 404 patients suffering from peritonitis (11/93-2/98), treated with an uniform treatment concept including early operation, source control and extensive intraoperative lavage (20 to 30 liters) as a standard procedure. Other treatment measures were added in special indications "on demand" only. Peritonitis was graded with the Mannheim Peritonitis Index (MPI). Tactics of source control in peritonitis due to diverticulitis were performed according to "general condition" respectively the MPI of the patient. The 404 patients averaged a MPI of 19 (0-35) in "local" peritonitis and a MPI of 26 (11-43) in "diffuse" peritonitis. The colon as a source of peritonitis resulted in MPI of 16 (0-33) in the case of "local" respectively 27 (11-43) in "diffuse" peritonitis. From 181 patients suffering from diverticulitis 144 needed an operation and in 78 (54%) peritonitis was present. Fourty-six percent (36) of the patients suffered from "local", 54% (42) from "diffuse" peritonitis. Resection with primary anastomosis was performed in 26% (20/78) whereas in 74% (58/78) of the patients a Hartmann procedure with colostomy was performed. The correlating MPI was 16 (0-28) vs. 23 (16-27) respectively. The analysis of complications and mortality based on the MPI showed a decent discrimination potential for primary anastomosis vs Hartmann procedure: morbidity 35% vs. 41%; reoperation 5% vs. 5%; mortality 0% vs. 14%. In case of peritonitis due to diverticulitis the treatment of peritonitis comes first. Thanks to advances in intensive care and improved anti-inflammatory care, a more conservative surgical concept nowadays is accepted. In the case of diverticulitis the MPI is helpful to choose between primary anastomosis vs. Hartmann procedure with colostomy as source control. The MPI includes the "general condition" of the patient into the tactical decision how to attain source control.

40 CFR 35.1605-4 - Nonpoint source.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Lakes § 35.1605-4 Nonpoint source. Pollution sources which generally are not controlled by establishing... traceable to a discrete identifiable origin, but generally result from land runoff, precipitation, drainage...

California State Implementation Plan; Proposed Approval of Revisions; Northern Sonoma County Air Pollution Control District; Stationary Source Permits

EPA Pesticide Factsheets

EPA is proposing to approve revisions to the Northern Sonoma County Air Pollution Control District (NSCAPCD) portion of the California SIP concerning NSCAPCD's PSD permitting program for new and modified sources of air pollution.

CONTROLLED FIELD STUDY ON THE USE OF NITRATE AND OXYGEN FOR BIOREMEDIATION OF A GASOLINE SOURCE ZONE

EPA Science Inventory

Controlled releases of unleaded gasoline were used to evaluate the biotransformation of the soluble aromatic hydrocarbons (benzene, toluene, ethylbenzene, xylene isomers, trimethylbenzene isomers, and naphthalene) within a source zone using nitrate and oxygen as electron accepto...

National Conference on Mining-Influenced Waters: Approaches for Characterization, Source Control and Treatment

EPA Science Inventory

The conference goal was to provide a forum for the exchange of scientific information on current and emerging approaches to assessing characterization, monitoring, source control, treatment and/or remediation on mining-influenced waters. The conference was aimed at mining remedi...

MINE WASTE TECHNOLOGY PROGRAM - UNDERGROUND MINE SOURCE CONTROL DEMONSTRATION PROJECT

EPA Science Inventory

This report presents results of the Mine Waste Technology Program Activity III, Project 8, Underground Mine Source Control Demonstration Project implemented and funded by the U. S. Environmental Protection Agency (EPA) and jointly administered by EPA and the U. S. Department of E...

MENU OF NOX EMISSION CONTROL OPTIONS FOR COAL-FIRED ELECTRIC UTILITY BOILERS

EPA Science Inventory

The paper reviews NOx control options for coal-fired electric utility boilers. (NOTE: Acid Rain NOx regulations, the Ozone Transport Commission's NOx Budget Program, revision of the New Source Performance Standards (NSPS) for NOx emissions from utility sources, and Ozone Transpor...

Proposed Rule for Control of Hazardous Air Pollutants From Mobile Sources - 40 CFR Parts 59, 80, 85, and 86

EPA Pesticide Factsheets

A proposed rule to control gasoline, passenger vehicles, and portable gasoline containers (gas cans) that would significantly reduce emissions of benzene and other hazardous air pollutants (‘‘mobile source air toxics’’).

“A significant source of isoprene aerosol controlled by acidity”

EPA Science Inventory

“A significant source of isoprene aerosol controlled by acidity” by Pye et al.Abstract: Isoprene is a significant contributor to organic aerosol in the southeastern United States where biogenic hydrocarbons mix with anthropogenic emissions. In this work, CMAQ provides explicit p...

Nonlinear optimal control policies for buoyancy-driven flows in the built environment

NASA Astrophysics Data System (ADS)

Nabi, Saleh; Grover, Piyush; Caulfield, Colm

2017-11-01

We consider optimal control of turbulent buoyancy-driven flows in the built environment, focusing on a model test case of displacement ventilation with a time-varying heat source. The flow is modeled using the unsteady Reynolds-averaged equations (URANS). To understand the stratification dynamics better, we derive a low-order partial-mixing ODE model extending the buoyancy-driven emptying filling box problem to the case of where both the heat source and the (controlled) inlet flow are time-varying. In the limit of a single step-change in the heat source strength, our model is consistent with that of Bower et al.. Our model considers the dynamics of both `filling' and `intruding' added layers due to a time-varying source and inlet flow. A nonlinear direct-adjoint-looping optimal control formulation yields time-varying values of temperature and velocity of the inlet flow that lead to `optimal' time-averaged temperature relative to appropriate objective functionals in a region of interest.

Development and program implementation of elements for identification of the electromagnet condition for movable element position control

NASA Astrophysics Data System (ADS)

Leukhin, R. I.; Shaykhutdinov, D. V.; Shirokov, K. M.; Narakidze, N. D.; Vlasov, A. S.

2017-02-01

Developing the experimental design of new electromagnetic constructions types in engineering industry enterprises requires solutions of two major problems: regulator’s parameters setup and comprehensive testing of electromagnets. A weber-ampere characteristic as a data source for electromagnet condition identification was selected. Present article focuses on development and implementation of the software for electromagnetic drive control system based on the weber-ampere characteristic measuring. The software for weber-ampere characteristic data processing based on artificial neural network is developed. Results of the design have been integrated into the program code in LabVIEW environment. The license package of LabVIEW graphic programming was used. The hardware is chosen and possibility of its use for control system implementation was proved. The trained artificial neural network defines electromagnetic drive effector position with minimal error. Developed system allows to control the electromagnetic drive powered by the voltage source, the current source and hybrid sources.

Preparation method and quality control of multigamma volume sources with different matrices.

PubMed

Listkowska, A; Lech, E; Saganowski, P; Tymiński, Z; Dziel, T; Cacko, D; Ziemek, T; Kołakowska, E; Broda, R

2018-04-01

The aim of the work was to develop new radioactive standard sources based on epoxy resins. The optimal proportions of the components and the homogeneity of the matrices were determined. The activity of multigamma sources prepared in Marinelli beakers was determined with reference to the National Standard of Radionuclides Activity in Poland. The difference of radionuclides activity values determined using calibrated gamma spectrometer and the activity of standard solutions used are in most cases significantly lower than measurement uncertainty limits. Sources production method and quality control procedure have been developed. Copyright © 2017 Elsevier Ltd. All rights reserved.

RESIDUAL RISK ASSESSMENT: MAGNETIC TAPE ...

EPA Pesticide Factsheets

This document describes the residual risk assessment for the Magnetic Tape Manufacturing source category. For stationary sources, section 112 (f) of the Clean Air Act requires EPA to assess risks to human health and the environment following implementation of technology-based control standards. If these technology-based control standards do not provide an ample margin of safety, then EPA is required to promulgate addtional standards. This document describes the methodology and results of the residual risk assessment performed for the Magnetic Tape Manufacturing source category. The results of this analyiss will assist EPA in determining whether a residual risk rule for this source category is appropriate.

40 CFR Table 2 to Subpart H of... - Surge Control Vessels and Bottoms Receivers at Existing Sources

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Surge Control Vessels and Bottoms Receivers at Existing Sources 2 Table 2 to Subpart H of Part 63 Protection of Environment ENVIRONMENTAL... Equipment Leaks Pt. 63, Subpt. H, Table 2 Table 2 to Subpart H of Part 63—Surge Control Vessels and Bottoms...

40 CFR Table 3 to Subpart H of... - Surge Control Vessels and Bottoms Receivers at New Sources

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Surge Control Vessels and Bottoms Receivers at New Sources 3 Table 3 to Subpart H of Part 63 Protection of Environment ENVIRONMENTAL... Equipment Leaks Pt. 63, Subpt. H, Table 3 Table 3 to Subpart H of Part 63—Surge Control Vessels and Bottoms...

Residential Mobility and Lung Cancer Risk: Data-Driven Exploration Using Internet Sources

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

Yoon, Hong-Jun; Tourassi, Georgia; Xu, Songhua

2015-01-01

Frequent relocation has been linked to health decline, particularly with respect to emotional and psychological wellbeing. In this paper we investigate whether there is an association between frequent relocation and lung cancer risk. For the initial investigation we leverage two online data sources to collect cancer and control subjects using web crawling and tailored text mining. The two data sources share different strengths and weaknesses in terms of the amount of detail, population representation, and sample size. One data source includes online obituaries. The second data source includes augmented LinkedIn profiles. For each data source, the subjects spatiotemporal history ismore » reconstructed from the available information provided in the obituaries and from the education and work experience provided in the LinkedIn profiles. The study shows that lung cancer subjects have higher mobility frequency than the control group. This trend is consistent for both data sources.« less

40 CFR 424.15 - Standards of performance for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... sources. 424.15 Section 424.15 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS FERROALLOY MANUFACTURING POINT SOURCE CATEGORY Open Electric Furnaces With Wet Air Pollution Control Devices Subcategory § 424.15 Standards of performance for new sources...

Inventory of U.S. 2012 dioxin emissions to atmosphere.

PubMed

Dwyer, Henri; Themelis, Nickolas J

2015-12-01

In 2006, the U.S. EPA published an inventory of dioxin emissions for the U.S. covering the period from 1987-2000. This paper is an updated inventory of all U.S. dioxin emissions to the atmosphere in the year 2012. The sources of emissions of polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), collectively referred to in this paper as "dioxins", were separated into two classes: controlled industrial and open burning sources. Controlled source emissions decreased 95.5% from 14.0 kg TEQ in 1987 to 0.6 kg in 2012. Open burning source emissions increased from 2.3 kg TEQ in 1987 to 2.9 kg in 2012. The 2012 dioxin emissions from 53 U.S. waste-to-energy (WTE) power plants were compiled on the basis of detailed data obtained from the two major U.S. WTE companies, representing 84% of the total MSW combusted (27.4 million metric tons). The dioxin emissions of all U.S. WTE plants in 2012 were 3.4 g TEQ and represented 0.54% of the controlled industrial dioxin emissions, and 0.09% of all dioxin emissions from controlled and open burning sources. Copyright © 2015. Published by Elsevier Ltd.

Conceptual design of data acquisition and control system for two Rf driver based negative ion source for fusion R&D

NASA Astrophysics Data System (ADS)

Soni, Jigensh; Yadav, R. K.; Patel, A.; Gahlaut, A.; Mistry, H.; Parmar, K. G.; Mahesh, V.; Parmar, D.; Prajapati, B.; Singh, M. J.; Bandyopadhyay, M.; Bansal, G.; Pandya, K.; Chakraborty, A.

2013-02-01

Twin Source - An Inductively coupled two RF driver based 180 kW, 1 MHz negative ion source experimental setup is initiated at IPR, Gandhinagar, under Indian program, with the objective of understanding the physics and technology of multi-driver coupling. Twin Source [1] (TS) also provides an intermediate platform between operational ROBIN [2] [5] and eight RF drivers based Indian test facility -INTF [3]. A twin source experiment requires a central system to provide control, data acquisition and communication interface, referred as TS-CODAC, for which a software architecture similar to ITER CODAC core system has been decided for implementation. The Core System is a software suite for ITER plant system manufacturers to use as a template for the development of their interface with CODAC. The ITER approach, in terms of technology, has been adopted for the TS-CODAC so as to develop necessary expertise for developing and operating a control system based on the ITER guidelines as similar configuration needs to be implemented for the INTF. This cost effective approach will provide an opportunity to evaluate and learn ITER CODAC technology, documentation, information technology and control system processes, on an operational machine. Conceptual design of the TS-CODAC system has been completed. For complete control of the system, approximately 200 Nos. control signals and 152 acquisition signals are needed. In TS-CODAC, control loop time required is within the range of 5ms - 10 ms, therefore for the control system, PLC (Siemens S-7 400) has been chosen as suggested in the ITER slow controller catalog. For the data acquisition, the maximum sampling interval required is 100 micro second, and therefore National Instruments (NI) PXIe system and NI 6259 digitizer cards have been selected as suggested in the ITER fast controller catalog. This paper will present conceptual design of TS -CODAC system based on ITER CODAC Core software and applicable plant system integration processes.

Coordinated single-phase control scheme for voltage unbalance reduction in low voltage network.

PubMed

Pullaguram, Deepak; Mishra, Sukumar; Senroy, Nilanjan

2017-08-13

Low voltage (LV) distribution systems are typically unbalanced in nature due to unbalanced loading and unsymmetrical line configuration. This situation is further aggravated by single-phase power injections. A coordinated control scheme is proposed for single-phase sources, to reduce voltage unbalance. A consensus-based coordination is achieved using a multi-agent system, where each agent estimates the averaged global voltage and current magnitudes of individual phases in the LV network. These estimated values are used to modify the reference power of individual single-phase sources, to ensure system-wide balanced voltages and proper power sharing among sources connected to the same phase. Further, the high X / R ratio of the filter, used in the inverter of the single-phase source, enables control of reactive power, to minimize voltage unbalance locally. The proposed scheme is validated by simulating a LV distribution network with multiple single-phase sources subjected to various perturbations.This article is part of the themed issue 'Energy management: flexibility, risk and optimization'. © 2017 The Author(s).

Reporting funding source or conflict of interest in abstracts of randomized controlled trials, no evidence of a large impact on general practitioners' confidence in conclusions, a three-arm randomized controlled trial.

PubMed

Buffel du Vaure, Céline; Boutron, Isabelle; Perrodeau, Elodie; Ravaud, Philippe

2014-04-28

Systematic reporting of funding sources is recommended in the CONSORT Statement for abstracts. However, no specific recommendation is related to the reporting of conflicts of interest (CoI). The objective was to compare physicians' confidence in the conclusions of abstracts of randomized controlled trials of pharmaceutical treatment indexed in PubMed. We planned a three-arm parallel-group randomized trial. French general practitioners (GPs) were invited to participate and were blinded to the study's aim. We used a representative sample of 75 abstracts of pharmaceutical industry-funded randomized controlled trials published in 2010 and indexed in PubMed. Each abstract was standardized and reported in three formats: 1) no mention of the funding source or CoI; 2) reporting the funding source only; and 3) reporting the funding source and CoI. GPs were randomized according to a computerized randomization on a secure Internet system at a 1:1:1 ratio to assess one abstract among the three formats. The primary outcome was GPs' confidence in the abstract conclusions (0, not at all, to 10, completely confident). The study was planned to detect a large difference with an effect size of 0.5. Between October 2012 and June 2013, among 605 GPs contacted, 354 were randomized, 118 for each type of abstract. The mean difference (95% confidence interval) in GPs' confidence in abstract findings was 0.2 (-0.6; 1.0) (P = 0.84) for abstracts reporting the funding source only versus no funding source or CoI; -0.4 (-1.3; 0.4) (P = 0.39) for abstracts reporting the funding source and CoI versus no funding source and CoI; and -0.6 (-1.5; 0.2) (P = 0.15) for abstracts reporting the funding source and CoI versus the funding source only. We found no evidence of a large impact of trial report abstracts mentioning funding sources or CoI on GPs' confidence in the conclusions of the abstracts. ClinicalTrials.gov identifier: NCT01679873.

Systems and methods for providing power to a load based upon a control strategy

DOEpatents

Perisic, Milun; Kajouke, Lateef A; Ransom, Ray M

2013-12-24

Systems and methods are provided for an electrical system. The electrical system includes a load, an interface configured to receive a voltage from a voltage source, and a controller configured to receive the voltage from the voltage source through the interface and to provide a voltage and current to the load. Wherein, when the controller is in a constant voltage mode, the controller provides a constant voltage to the load, when the controller is in a constant current mode, the controller provides a constant current to the load, and when the controller is in a constant power mode, the controller provides a constant power to the load.

Rechargeable Li/Li(x)CoO(2) 100 Ah/600 Ah Battery With Integral Smart Charge Control

DTIC Science & Technology

1999-03-01

Rechargeable Li/LixCo02100 Ah/600 Ah Battery with Integral Smart Charge Control By Charles J. Kelly ^ (Alliant Techsystems, Inc., Alliant Power...Rechargeable Li/LixCo02100 Ah/600 Ah Battery with Integral Smart Charge Control By Charles J. Kelly (Alliant Techsystems, Inc., Alliant Power Sources...AND SUBTITLE Rechargeable Li/LixCo02100 Ah/600 Ah Battery with Integral Smart Charge Control 6 AUTHOR(S) C. J. Kelly (Alliant Power Sources Co

Neutron Imaging Control Report: FY 2016

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

Gibson, D. J.

2016-11-30

During the 2016 fiscal year, work began on the supervision and control systems for the neutron source currently under construction in the B194 accelerator caves. This source relies on a deuteron beam colliding with a high-speed stream of deuterium gas to create neutrons, which poses significant technical challenges. To help overcome those challenges, an integrated, operator-focused control architecture is required to collect and assimilate disparate data from a variety of measurement points, as well as provide the means to remotely control the system hardware.

Variable leak gas source

DOEpatents

Henderson, Timothy M.; Wuttke, Gilbert H.

1977-01-01

A variable leak gas source and a method for obtaining the same which includes filling a quantity of hollow glass micro-spheres with a gas, storing said quantity in a confined chamber having a controllable outlet, heating said chamber above room temperature, and controlling the temperature of said chamber to control the quantity of gas passing out of said controllable outlet. Individual gas filled spheres may be utilized for calibration purposes by breaking a sphere having a known quantity of a known gas to calibrate a gas detection apparatus.

Estimated Reduction in Cancer Risk due to PAH Exposures If Source Control Measures during the 2008 Beijing Olympics Were Sustained

PubMed Central

Jia, Yuling; Stone, Dave; Wang, Wentao; Schrlau, Jill; Tao, Shu; Massey Simonich, Staci L.

2011-01-01

Background The 2008 Beijing Olympic Games provided a unique case study to investigate the effect of source control measures on the reduction in air pollution, and associated inhalation cancer risk, in a Chinese megacity. Objectives We measured 17 carcinogenic polycyclic aromatic hydrocarbons (PAHs) and estimated the lifetime excess inhalation cancer risk during different periods of the Beijing Olympic Games, to assess the effectiveness of source control measures in reducing PAH-induced inhalation cancer risks. Methods PAH concentrations were measured in samples of particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5) collected during the Beijing Olympic Games, and the associated inhalation cancer risks were estimated using a point-estimate approach based on relative potency factors. Results We estimated the number of lifetime excess cancer cases due to exposure to the 17 carcinogenic PAHs [12 priority pollutant PAHs and five high-molecular-weight (302 Da) PAHs (MW 302 PAHs)] to range from 6.5 to 518 per million people for the source control period concentrations and from 12.2 to 964 per million people for the nonsource control period concentrations. This would correspond to a 46% reduction in estimated inhalation cancer risk due to source control measures, if these measures were sustained over time. Benzo[b]fluoranthene, dibenz[a,h]anthracene, benzo[a]pyrene, and dibenzo[a,l]pyrene were the most carcinogenic PAH species evaluated. Total excess inhalation cancer risk would be underestimated by 23% if we did not include the five MW 302 PAHs in the risk calculation. Conclusions Source control measures, such as those imposed during the 2008 Beijing Olympics, can significantly reduce the inhalation cancer risk associated with PAH exposure in Chinese megacities similar to Beijing. MW 302 PAHs are a significant contributor to the estimated overall inhalation cancer risk. PMID:21632310

40 CFR 428.95 - Standards of performance for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Mechanical Reclaimed Rubber Subcategory § 428.95 Standards of performance for new sources. (a) The following standards of performance establish the quantity or quality of pollutants or pollutant properties, controlled... or quality of pollutants or pollutant properties, controlled by this section and attributable to pan...

BEST MANAGEMENT PRACTICES FOR THE CONTROL OF NUTRIENTS FROM URBAN NONPOINT SOURCES

EPA Science Inventory

While the costs and benefits associated with the point source control of nutrients are relatively well defined, considerable uncertainties remain in the efficiency and long-term costs associated with the best management practices (BMPs) used to redcuce loads from nonpoint and dif...

Open Source Software and the Intellectual Commons.

ERIC Educational Resources Information Center

Dorman, David

2002-01-01

Discusses the Open Source Software method of software development and its relationship to control over information content. Topics include digital library resources; reference services; preservation; the legal and economic status of information; technical standards; access to digital data; control of information use; and copyright and patent laws.…

The Sources of Air Pollution and Their Control.

ERIC Educational Resources Information Center

National Air Pollution Control Administration (DHEW), Arlington, VA.

The problems of air pollution and its control are discussed. Major consideration is given the sources of pollution - motor vehicles, industry, power plants, space heating, and refuse disposal. Annual emission levels of five principle pollutants - carbon monoxide, sulfur dioxide, nitrogen oxides, hydrocarbons, and particulate matter - are listed…

RELATIONSHIPS OF MEADOW VEGETATION TO GROUNDWATER DEPTH: EFFECTS OF PRECIPITATION VARIABILITY AND STREAM INCISION

EPA Science Inventory

The composition of riparian meadow vegetation is controlled by access to groundwater. Depth to groundwater is controlled by meadow architecture and water source, and changes in either meadow architecture or water source through stream incision or changes in annual precipitation c...

Systems and methods for initializing a charging system

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

Perisic, Milun; Ransonm, Ray M.; Kojouke, Lateef A.

2017-09-26

Systems and methods are provided for charging a battery. The system, for example, includes, but is not limited to a first interface configured to receive a voltage from an AC voltage source, a matrix conversion module comprising a plurality of switches electrically connected to the first interface and configured to provide a charging voltage to the battery, and a controller communicatively connected to the matrix conversion module, wherein the controller is configured to: determine a voltage of the battery, determine an angle of the AC voltage source to initiate charging of the battery based upon the voltage of the battery,more » and control the plurality of switches to provide the charging voltage to the battery between the determined angle of the AC voltage source and a subsequent zero-crossing of the AC voltage source.« less

Photochemical grid model implementation and application of VOC, NOx, and O3 source apportionment

EPA Science Inventory

For the purposes of developing optimal emissions control strategies, efficient approaches are needed to identify the major sources or groups of sources that contribute to elevated ozone (O3) concentrations. Source-based apportionment techniques implemented in photochemical grid m...

Implementation and evaluation of PM2.5 source contribution analysis in a photochemical model

EPA Science Inventory

Source culpability assessments are useful for developing effective emissions control programs. The Integrated Source Apportionment Method (ISAM) has been implemented in the Community Multiscale Air Quality (CMAQ) model to track contributions from source groups and regions to ambi...

Atmospheric deposition having been one of the major source of Pb in Jiaozhou Bay

NASA Astrophysics Data System (ADS)

Yang, Dongfang; Miao, Zhenqing; Zhang, Xiaolong; Wang, Qi; Li, Haixia

2018-03-01

Many marine bays have been polluted by Pb due to the rapid development of industry, and identifying the major source of Pb is essential to pollution control. This paper analyzed the distribution and pollution source of Pb in Jiaozhou Bay in 1988. Results showed that Pb contents in surface waters in Jiaozhou Bay in April, July and October 1988 were 5.52-24.61 μg L‑1, 7.66-38.62 μg L‑1 and 6.89-19.30 μg L‑1, respectively. The major Pb sources in this bay were atmospheric deposition, and marine current, whose source strengths were 19.30-24.61μg L‑1 and 38.62 μg L‑1, respectively. Atmospheric deposition had been one of the major Pb sources in Jiaozhou Bay, and the source strengths were stable and strong. The pollution level of Pb in this bay in 1988 was moderate to heavy, and the source control measurements were necessary.

Identifying, Visualizing, and Fusing Social Media Data to Support Nonproliferation and Arms Control Treaty Verification: Preliminary Results

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

Gastelum, Zoe N.; Cramer, Nicholas O.; Benz, Jacob M.

While international nonproliferation and arms control verification capabilities have their foundations in physical and chemical sensors, state declarations, and on-site inspections, verification experts are beginning to consider the importance of open source data to complement and support traditional means of verification. One of those new, and increasingly expanding, sources of open source information is social media, which can be ingested and understood through social media analytics (SMA). Pacific Northwest National Laboratory (PNNL) is conducting research to further our ability to identify, visualize, and fuse social media data to support nonproliferation and arms control treaty verification efforts. This paper will describemore » our preliminary research to examine social media signatures of nonproliferation or arms control proxy events. We will describe the development of our preliminary nonproliferation and arms control proxy events, outline our initial findings, and propose ideas for future work.« less

Method and apparatus for controlling carrier envelope phase

DOEpatents

Chang, Zenghu [Manhattan, KS; Li, Chengquan [Sunnyvale, CA; Moon, Eric [Manhattan, KS

2011-12-06

A chirped pulse amplification laser system. The system generally comprises a laser source, a pulse modification apparatus including first and second pulse modification elements separated by a separation distance, a positioning element, a measurement device, and a feedback controller. The laser source is operable to generate a laser pulse and the pulse modification apparatus operable to modify at least a portion of the laser pulse. The positioning element is operable to reposition at least a portion of the pulse modification apparatus to vary the separation distance. The measurement device is operable to measure the carrier envelope phase of the generated laser pulse and the feedback controller is operable to control the positioning element based on the measured carrier envelope phase to vary the separation distance of the pulse modification elements and control the carrier envelope phase of laser pulses generated by the laser source.

Control of mercury emissions from stationary coal combustion sources in China: Current status and recommendations.

PubMed

Hu, Yuanan; Cheng, Hefa

2016-11-01

Coal burning in power plants and industrial boilers is the largest combustion source of mercury emissions in China. Together, power plants and industrial boilers emit around 250 tonnes of mercury each year, or around half of atmospheric mercury emissions from anthropogenic sources in the country. Power plants in China are generally equipped with multi-pollutant control technologies, which offer the co-benefit of mercury removal, while mercury-specific control technologies have been installed in some facilities. In contrast, most industrial boilers have only basic or no flue gas cleaning. A combination of measures, including energy conservation, coal switching and blending, reducing the mercury contents of coals through washing, combustion controls, and flue gas cleaning, can be used to reduce mercury emissions from these stationary combustion sources. More stringent emission standards for the major air pollutants from coal-fired power plants and industrial boiler, along with standards for the previously unregulated mercury, were implemented recently, which is expected to bring significant reduction in their mercury emissions through the necessary upgrades of multi-pollutant and mercury-specific control technologies. Meanwhile, strong monitoring capacity and strict enforcement are necessary to ensure that the combustion sources operate in compliance with the new emission standards and achieve significant reduction in the emissions of mercury and other air pollutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quadratic Optimization in the Problems of Active Control of Sound

NASA Technical Reports Server (NTRS)

Loncaric, J.; Tsynkov, S. V.; Bushnell, Dennis M. (Technical Monitor)

2002-01-01

We analyze the problem of suppressing the unwanted component of a time-harmonic acoustic field (noise) on a predetermined region of interest. The suppression is rendered by active means, i.e., by introducing the additional acoustic sources called controls that generate the appropriate anti-sound. Previously, we have obtained general solutions for active controls in both continuous and discrete formulations of the problem. We have also obtained optimal solutions that minimize the overall absolute acoustic source strength of active control sources. These optimal solutions happen to be particular layers of monopoles on the perimeter of the protected region. Mathematically, minimization of acoustic source strength is equivalent to minimization in the sense of L(sub 1). By contrast. in the current paper we formulate and study optimization problems that involve quadratic functions of merit. Specifically, we minimize the L(sub 2) norm of the control sources, and we consider both the unconstrained and constrained minimization. The unconstrained L(sub 2) minimization is certainly the easiest problem to address numerically. On the other hand, the constrained approach allows one to analyze sophisticated geometries. In a special case, we call compare our finite-difference optimal solutions to the continuous optimal solutions obtained previously using a semi-analytic technique. We also show that the optima obtained in the sense of L(sub 2) differ drastically from those obtained in the sense of L(sub 1).

Who purchases cigarettes from cheaper sources in China? Findings from the ITC China Survey

PubMed Central

Yao, Tingting; Huang, Jidong; Sung, Hai-Yen; Ong, Michael K.; Mao, Zhengzhong; Jiang, Yuan; Fong, Geoffrey T.; Max, Wendy

2014-01-01

Objective The availability of cigarettes from cheaper sources constitutes a major challenge to public health throughout the world, including China, because it may counteract price-based tobacco control policies. The goal of this study was to identify factors associated with purchasing cigarettes from cheaper sources among adult smokers in China. Methods Data were analyzed from Waves 1–3 of the International Tobacco Control China Survey, conducted in 2006–2009 among adult smokers in six cities in China (N=7,980). One survey question asked, “In the last six months, have you purchased cheaper cigarettes than you can get from local stores for economic reasons?” We examined whether sociodemographic factors and smoking intensity were associated with purchasing cigarettes from cheaper sources using the general estimating equations (GEE) model. Sociodemographic factors considered were gender, age, marital status, monthly household income, education, employment status, and city of residence. Results 15.6% of smokers reported purchasing cigarettes from cheaper sources. After controlling for other covariates, the associations of the behavior of purchasing cigarettes from cheaper sources with age (AOR=1.49, 95% CI=1.17–3.92 for age 18–24 compared to age 55+) and with income (AOR=2.93, 95%CI=2.27–3.79 for low income compared to high income) were statistically significant, but there was no statistically significant relationship with smoking intensity. Conclusions Our findings indicate that young and low income smokers are more likely than older and high income smokers to purchase cigarettes from cheaper sources in China. Tobacco control policies that reduce the availability of cigarettes from cheaper sources could have an impact on reducing cigarette consumption among young and low income smokers in China. PMID:24078076

Who purchases cigarettes from cheaper sources in China? Findings from the ITC China Survey.

PubMed

Yao, Tingting; Huang, Jidong; Sung, Hai-Yen; Ong, Michael K; Mao, Zhengzhong; Jiang, Yuan; Fong, Geoffrey T; Max, Wendy

2014-03-01

The availability of cigarettes from cheaper sources constitutes a major challenge to public health throughout the world, including China, because it may counteract price-based tobacco control policies. The goal of this study was to identify factors associated with purchasing cigarettes from cheaper sources among adult smokers in China. Data were analysed from Waves 1 to 3 of the International Tobacco Control China Survey conducted in 2006-2009 among adult smokers in six cities in China (N=7980). One survey question asked, "In the last 6 months, have you purchased cheaper cigarettes than you can get from local stores for economic reasons?" We examined whether sociodemographic factors and smoking intensity were associated with purchasing cigarettes from cheaper sources using the general estimating equations model. Sociodemographic factors considered were gender, age, marital status, monthly household income, education, employment status and city of residence. 15.6% of smokers reported purchasing cigarettes from cheaper sources. After controlling for other covariates, the associations of the behaviour of purchasing cigarettes from cheaper sources with age (adjusted OR (AOR)=1.49, 95% CI 1.17 to 3.92 for age 18-24 compared with age 55+) and with income (AOR=2.93, 95% CI 2.27 to 3.79 for low income compared with high income) were statistically significant, but there was no statistically significant relationship with smoking intensity. Our findings indicate that young and low-income smokers are more likely than older and high-income smokers to purchase cigarettes from cheaper sources in China. Tobacco control policies that reduce the availability of cigarettes from cheaper sources could have an impact on reducing cigarette consumption among young and low-income smokers in China.

Automated control of linear constricted plasma source array

DOEpatents

Anders, Andre; Maschwitz, Peter A.

2000-01-01

An apparatus and method for controlling an array of constricted glow discharge chambers are disclosed. More particularly a linear array of constricted glow plasma sources whose polarity and geometry are set so that the contamination and energy of the ions discharged from the sources are minimized. The several sources can be mounted in parallel and in series to provide a sustained ultra low source of ions in a plasma with contamination below practical detection limits. The quality of film along deposition "tracks" opposite the plasma sources can be measured and compared to desired absolute or relative values by optical and/or electrical sensors. Plasma quality can then be adjusted by adjusting the power current values, gas feed pressure/flow, gas mixtures or a combination of some or all of these to improve the match between the measured values and the desired values.

[Regional atmospheric environment risk source identification and assessment].

PubMed

Zhang, Xiao-Chun; Chen, Wei-Ping; Ma, Chun; Zhan, Shui-Fen; Jiao, Wen-Tao

2012-12-01

Identification and assessment for atmospheric environment risk source plays an important role in regional atmospheric risk assessment and regional atmospheric pollution prevention and control. The likelihood exposure and consequence assessment method (LEC method) and the Delphi method were employed to build a fast and effective method for identification and assessment of regional atmospheric environment risk sources. This method was applied to the case study of a large coal transportation port in North China. The assessment results showed that the risk characteristics and the harm degree of regional atmospheric environment risk source were in line with the actual situation. Fast and effective identification and assessment of risk source has laid an important foundation for the regional atmospheric environmental risk assessment and regional atmospheric pollution prevention and control.

Controllability of semi-infinite rod heating by a point source

NASA Astrophysics Data System (ADS)

Khurshudyan, A.

2018-04-01

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

Palaeoenvironment and Its Control on the Formation of Miocene Marine Source Rocks in the Qiongdongnan Basin, Northern South China Sea

PubMed Central

Li, Wenhao; Zhang, Zhihuan; Wang, Weiming; Lu, Shuangfang; Li, Youchuan; Fu, Ning

2014-01-01

The main factors of the developmental environment of marine source rocks in continental margin basins have their specificality. This realization, in return, has led to the recognition that the developmental environment and pattern of marine source rocks, especially for the source rocks in continental margin basins, are still controversial or poorly understood. Through the analysis of the trace elements and maceral data, the developmental environment of Miocene marine source rocks in the Qiongdongnan Basin is reconstructed, and the developmental patterns of the Miocene marine source rocks are established. This paper attempts to reveal the hydrocarbon potential of the Miocene marine source rocks in different environment and speculate the quality of source rocks in bathyal region of the continental slope without exploratory well. Our results highlight the palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin of the northern South China Sea and speculate the hydrocarbon potential of the source rocks in the bathyal region. This study provides a window for better understanding the main factors influencing the marine source rocks in the continental margin basins, including productivity, preservation conditions, and the input of terrestrial organic matter. PMID:25401132

Variable cycle control model for intersection based on multi-source information

NASA Astrophysics Data System (ADS)

Sun, Zhi-Yuan; Li, Yue; Qu, Wen-Cong; Chen, Yan-Yan

2018-05-01

In order to improve the efficiency of traffic control system in the era of big data, a new variable cycle control model based on multi-source information is presented for intersection in this paper. Firstly, with consideration of multi-source information, a unified framework based on cyber-physical system is proposed. Secondly, taking into account the variable length of cell, hysteresis phenomenon of traffic flow and the characteristics of lane group, a Lane group-based Cell Transmission Model is established to describe the physical properties of traffic flow under different traffic signal control schemes. Thirdly, the variable cycle control problem is abstracted into a bi-level programming model. The upper level model is put forward for cycle length optimization considering traffic capacity and delay. The lower level model is a dynamic signal control decision model based on fairness analysis. Then, a Hybrid Intelligent Optimization Algorithm is raised to solve the proposed model. Finally, a case study shows the efficiency and applicability of the proposed model and algorithm.

Safety in the Chemical Laboratory--Safety Education for Chemistry Students: Hazard Control Starting at the Source.

ERIC Educational Resources Information Center

Zwaard, A. W.; And Others

1989-01-01

Presents a programed method that inventories and classifies hazards. 8iscusses the following topics: (1) student and hazard source, (2) elimination of the source, (3) adaptation of the source, (4) isolation of the source, (5) adjustment of the surroundings, (6) isolation of man, and (7) personal protective equipment. (MVL)

Impact of head models in N170 component source imaging: results in control subjects and ADHD patients

NASA Astrophysics Data System (ADS)

Beltrachini, L.; Blenkmann, A.; von Ellenrieder, N.; Petroni, A.; Urquina, H.; Manes, F.; Ibáñez, A.; Muravchik, C. H.

2011-12-01

The major goal of evoked related potential studies arise in source localization techniques to identify the loci of neural activity that give rise to a particular voltage distribution measured on the surface of the scalp. In this paper we evaluate the effect of the head model adopted in order to estimate the N170 component source in attention deficit hyperactivity disorder (ADHD) patients and control subjects, considering faces and words stimuli. The standardized low resolution brain electromagnetic tomography algorithm (sLORETA) is used to compare between the three shell spherical head model and a fully realistic model based on the ICBM-152 atlas. We compare their variance on source estimation and analyze the impact on the N170 source localization. Results show that the often used three shell spherical model may lead to erroneous solutions, specially on ADHD patients, so its use is not recommended. Our results also suggest that N170 sources are mainly located in the right occipital fusiform gyrus for faces stimuli and in the left occipital fusiform gyrus for words stimuli, for both control subjects and ADHD patients. We also found a notable decrease on the N170 estimated source amplitude on ADHD patients, resulting in a plausible marker of the disease.

[Automatic adjustment control system for DC glow discharge plasma source].

PubMed

Wan, Zhen-zhen; Wang, Yong-qing; Li, Xiao-jia; Wang, Hai-zhou; Shi, Ning

2011-03-01

There are three important parameters in the DC glow discharge process, the discharge current, discharge voltage and argon pressure in discharge source. These parameters influence each other during glow discharge process. This paper presents an automatic control system for DC glow discharge plasma source. This system collects and controls discharge voltage automatically by adjusting discharge source pressure while the discharge current is constant in the glow discharge process. The design concept, circuit principle and control program of this automatic control system are described. The accuracy is improved by this automatic control system with the method of reducing the complex operations and manual control errors. This system enhances the control accuracy of glow discharge voltage, and reduces the time to reach discharge voltage stability. The glow discharge voltage stability test results with automatic control system are provided as well, the accuracy with automatic control system is better than 1% FS which is improved from 4% FS by manual control. Time to reach discharge voltage stability has been shortened to within 30 s by automatic control from more than 90 s by manual control. Standard samples like middle-low alloy steel and tin bronze have been tested by this automatic control system. The concentration analysis precision has been significantly improved. The RSDs of all the test result are better than 3.5%. In middle-low alloy steel standard sample, the RSD range of concentration test result of Ti, Co and Mn elements is reduced from 3.0%-4.3% by manual control to 1.7%-2.4% by automatic control, and that for S and Mo is also reduced from 5.2%-5.9% to 3.3%-3.5%. In tin bronze standard sample, the RSD range of Sn, Zn and Al elements is reduced from 2.6%-4.4% to 1.0%-2.4%, and that for Si, Ni and Fe is reduced from 6.6%-13.9% to 2.6%-3.5%. The test data is also shown in this paper.

Exploring cover crops as carbon sources for anaerobic soil disinfestation in a vegetable production system

USDA-ARS?s Scientific Manuscript database

In a raised-bed plasticulture vegetable production system utilizing anaerobic soil disinfestation (ASD) in Florida field trials, pathogen, weed, and parasitic nematode control was equivalent to or better than the methyl bromide control. Molasses was used as the labile carbon source to stimulate micr...

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

Code of Federal Regulations, 2010 CFR

2010-07-01

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

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

EPA Pesticide Factsheets

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

O3 Source Contribution During a Heavy O3 Pollution Episode in Shanghai China

EPA Science Inventory

Source culpability assessments are useful for developing effective emission control strategies. The Integrated Source Apportionment Method (ISAM) has been implemented in CMAQ to track contributions from source groups and regions to ambient levels and deposited amounts of O3. CMAQ...

How Is Open Source Special?

ERIC Educational Resources Information Center

Kapor, Mitchell

2005-01-01

Open source software projects involve the production of goods, but in software projects, the "goods" consist of information. The open source model is an alternative to the conventional centralized, command-and-control way in which things are usually made. In contrast, open source projects are genuinely decentralized and transparent. Transparent…

40 CFR 52.1025 - Control strategy: Particulate matter.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the emission limitations applicable to the sources listed below or resulting from the change in the compliance date for such sources with the applicable emission limitation is hereby approved. All regulations... compliance schedule approvals and disapprovals pertaining to one or more of the sources below.) Source...

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

PubMed

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

2018-08-15

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

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

A method for environmental acoustic analysis improvement based on individual evaluation of common sources in urban areas.

PubMed

López-Pacheco, María G; Sánchez-Fernández, Luis P; Molina-Lozano, Herón

2014-01-15

Noise levels of common sources such as vehicles, whistles, sirens, car horns and crowd sounds are mixed in urban soundscapes. Nowadays, environmental acoustic analysis is performed based on mixture signals recorded by monitoring systems. These mixed signals make it difficult for individual analysis which is useful in taking actions to reduce and control environmental noise. This paper aims at separating, individually, the noise source from recorded mixtures in order to evaluate the noise level of each estimated source. A method based on blind deconvolution and blind source separation in the wavelet domain is proposed. This approach provides a basis to improve results obtained in monitoring and analysis of common noise sources in urban areas. The method validation is through experiments based on knowledge of the predominant noise sources in urban soundscapes. Actual recordings of common noise sources are used to acquire mixture signals using a microphone array in semi-controlled environments. The developed method has demonstrated great performance improvements in identification, analysis and evaluation of common urban sources. © 2013 Elsevier B.V. All rights reserved.

Network based management for multiplexed electric vehicle charging

DOEpatents

Gadh, Rajit; Chung, Ching Yen; Qui, Li

2017-04-11

A system for multiplexing charging of electric vehicles, comprising a server coupled to a plurality of charging control modules over a network. Each of said charging modules being connected to a voltage source such that each charging control module is configured to regulate distribution of voltage from the voltage source to an electric vehicle coupled to the charging control module. Data collection and control software is provided on the server for identifying a plurality of electric vehicles coupled to the plurality of charging control modules and selectively distributing charging of the plurality of charging control modules to multiplex distribution of voltage to the plurality of electric vehicles.

Source apportionments of PM2.5 organic carbon during the elevated pollution episodes in the Ordos region, Inner Mongolia, China.

PubMed

Khuzestani, Reza Bashiri; Schauer, James J; Shang, Jing; Cai, Tianqi; Fang, Dongqing; Wei, Yongjie; Zhang, Lulu; Zhang, Yuanxun

2018-05-01

The Ordos region in the southwestern part of Inner Mongolia experiences frequent PM concentrations in excess of the national PM 2.5 air quality standards. In order to determine the key sources of PM 2.5 contributing to these pollution episodes, the main sources of PM 2.5 OC during elevated PM episodes in the Inner Mongolia were analyzed and compared with non-polluted days. This will provide insight to the main sources of particulate matter pollution during the high-pollution episodes and the effective seasonal strategies to control sources of particulate matter during months and with the highest PM concentrations that need to be controlled. The PMF source contributions to OC demonstrated that the industrial/coal combustion (4762.77 ± 1061.54 versus 2726.49 ± 469.75 ng/m 3 ; p < 0.001) and mobile source factors (4651.14 ± 681.82 versus 2605.55 ± 276.50 ng/m 3 ; p value < 0.001) showed greater contributions to the elevated concentrations during the episode. The spatial analysis of secondary organic carbon (SOC) factors, regional biomass burning, and biogenic sources did not show significant difference in the pollution episodes and the non-polluted months. In addition, the bivariate polar plots and CWT maps of the industrial/coal combustion and mobile illustrated a regional long-range transport patterns from the external sources to the study area, however, adjacent areas were mostly controlling the contributions of these factors during the PM elevated episodes. The SOC sources, regional biomass burning, and biogenic sources illustrated a regional long-range transport with similar locations found during the elevated pollution episodes compared to the normal situations.

Lead exposures in U.S. Children, 2008: implications for prevention.

PubMed

Levin, Ronnie; Brown, Mary Jean; Kashtock, Michael E; Jacobs, David E; Whelan, Elizabeth A; Rodman, Joanne; Schock, Michael R; Padilla, Alma; Sinks, Thomas

2008-10-01

We reviewed the sources of lead in the environments of U.S. children, contributions to children's blood lead levels, source elimination and control efforts, and existing federal authorities. Our context is the U.S. public health goal to eliminate pediatric elevated blood lead levels (EBLs) by 2010. National, state, and local exposure assessments over the past half century have identified risk factors for EBLs among U.S. children, including age, race, income, age and location of housing, parental occupation, and season. Recent national policies have greatly reduced lead exposure among U.S. children, but even very low exposure levels compromise children's later intellectual development and lifetime achievement. No threshold for these effects has been demonstrated. Although lead paint and dust may still account for up to 70% of EBLs in U.S. children, the U.S. Centers for Disease Control and Prevention estimates that >or=30% of current EBLs do not have an immediate lead paint source, and numerous studies indicate that lead exposures result from multiple sources. EBLs and even deaths have been associated with inadequately controlled sources including ethnic remedies and goods, consumer products, and food-related items such as ceramics. Lead in public drinking water and in older urban centers remain exposure sources in many areas. Achieving the 2010 goal requires maintaining current efforts, especially programs addressing lead paint, while developing interventions that prevent exposure before children are poisoned. It also requires active collaboration across all levels of government to identify and control all potential sources of lead exposure, as well as primary prevention.

40 CFR Table 3 to Subpart Dd of... - Tank Control Levels for Tanks at Existing Affected Sources as Required by 40 CFR 63.685(b)(1)

Code of Federal Regulations, 2010 CFR

2010-07-01

... Existing Affected Sources as Required by 40 CFR 63.685(b)(1) 3 Table 3 to Subpart DD of Part 63 Protection... Hazardous Air Pollutants from Off-Site Waste and Recovery Operations Pt. 63, Subpt. DD, Table 3 Table 3 to Subpart DD of Part 63—Tank Control Levels for Tanks at Existing Affected Sources as Required by 40 CFR 63...

40 CFR Table 4 to Subpart Dd of... - Tank Control Levels for Tanks at New Affected Sources as Required by 40 CFR 63.685(b)(2)

Code of Federal Regulations, 2010 CFR

2010-07-01

... Affected Sources as Required by 40 CFR 63.685(b)(2) 4 Table 4 to Subpart DD of Part 63 Protection of... Hazardous Air Pollutants from Off-Site Waste and Recovery Operations Pt. 63, Subpt. DD, Table 4 Table 4 to Subpart DD of Part 63—Tank Control Levels for Tanks at New Affected Sources as Required by 40 CFR 63.685(b...

Redundant speed control for brushless Hall effect motor

NASA Technical Reports Server (NTRS)

Nola, F. J. (Inventor)

1973-01-01

A speed control system for a brushless Hall effect device equipped direct current (D.C.) motor is described. Separate windings of the motor are powered by separate speed responsive power sources. A change in speed, upward or downward, because of the failure of a component of one of the power sources results in a corrective signal being generated in the other power source to supply an appropriate power level and polarity to one winding to cause the motor to be corrected in speed.

Electro-mechanical energy conversion system having a permanent magnet machine with stator, resonant transfer link and energy converter controls

DOEpatents

Skeist, S. Merrill; Baker, Richard H.

2006-01-10

An electro-mechanical energy conversion system coupled between an energy source and an energy load comprising an energy converter device including a permanent magnet induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer to control the flow of power or energy through the permanent magnetic induction machine.

RESIDUAL RISK ASSESSMENT: ETHYLENE OXIDE ...

EPA Pesticide Factsheets

This document describes the residual risk assessment for the Ethylene Oxide Commercial Sterilization source category. For stationary sources, section 112 (f) of the Clean Air Act requires EPA to assess risks to human health and the environment following implementation of technology-based control standards. If these technology-based control standards do not provide an ample margin of safety, then EPA is required to promulgate addtional standards. This document describes the methodology and results of the residual risk assessment performed for the Ethylene Oxide Commercial Sterilization source category. The results of this analyiss will assist EPA in determining whether a residual risk rule for this source category is appropriate.

40 CFR 70.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... program to control air pollution from outer continental shelf sources, under section 328 of the Act; (12... other functionally-equivalent opening. General permit means a part 70 permit that meets the requirements of § 70.6(d). Major source means any stationary source (or any group of stationary sources that are...

40 CFR 70.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... program to control air pollution from outer continental shelf sources, under section 328 of the Act; (12... other functionally-equivalent opening. General permit means a part 70 permit that meets the requirements of § 70.6(d). Major source means any stationary source (or any group of stationary sources that are...

40 CFR 70.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... program to control air pollution from outer continental shelf sources, under section 328 of the Act; (12... other functionally-equivalent opening. General permit means a part 70 permit that meets the requirements of § 70.6(d). Major source means any stationary source (or any group of stationary sources that are...

75 FR 70263 - Federal Acquisition Regulation; Submission for OMB Review; Reporting Purchases From Sources...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-17

...; Submission for OMB Review; Reporting Purchases From Sources Outside the United States AGENCY: Department of... reporting purchases from sources outside the United States. Public comments are particularly invited on.... Please cite OMB Control Number 9000-0161, Reporting Purchases from Sources Outside the United States, in...

40 CFR 49.128 - Rule for limiting particulate matter emissions from wood products industry sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... emissions from wood products industry sources. 49.128 Section 49.128 Protection of Environment ENVIRONMENTAL... Rule for limiting particulate matter emissions from wood products industry sources. (a) What is the... certain wood products industry sources operating within the Indian reservation to control ground-level...

A Handbook for Determining the Sources of PCB Contamination in Sediments

DTIC Science & Technology

2012-10-01

identifying sources for initial source control to later use for remedial cost apportionment . Often, forensic investigations are successfully used to...alteration processes, source apportionment can be difficult. For instance, one can easily imagine an onshore spill or source of PCB oil that results in a...the use of Aroclor analyses for identifying contamination sources to only fresh samples (for example, PCB oils or soils with freshly spilled PCB

Controlled-source seismic interferometry with one way wave fields

NASA Astrophysics Data System (ADS)

van der Neut, J.; Wapenaar, K.; Thorbecke, J. W.

2008-12-01

In Seismic Interferometry we generally cross-correlate registrations at two receiver locations and sum over an array of sources to retrieve a Green's function as if one of the receiver locations hosts a (virtual) source and the other receiver location hosts an actual receiver. One application of this concept is to redatum an area of surface sources to a downhole receiver location, without requiring information about the medium between the sources and receivers, thus providing an effective tool for imaging below complex overburden, which is also known as the Virtual Source method. We demonstrate how elastic wavefield decomposition can be effectively combined with controlled-source Seismic Interferometry to generate virtual sources in a downhole receiver array that radiate only down- or upgoing P- or S-waves with receivers sensing only down- or upgoing P- or S- waves. For this purpose we derive exact Green's matrix representations from a reciprocity theorem for decomposed wavefields. Required is the deployment of multi-component sources at the surface and multi- component receivers in a horizontal borehole. The theory is supported with a synthetic elastic model, where redatumed traces are compared with those of a directly modeled reflection response, generated by placing active sources at the virtual source locations and applying elastic wavefield decomposition on both source and receiver side.

Multisource inverse-geometry CT. Part II. X-ray source design and prototype

PubMed Central

Neculaes, V. Bogdan; Caiafa, Antonio; Cao, Yang; De Man, Bruno; Edic, Peter M.; Frutschy, Kristopher; Gunturi, Satish; Inzinna, Lou; Reynolds, Joseph; Vermilyea, Mark; Wagner, David; Zhang, Xi; Zou, Yun; Pelc, Norbert J.; Lounsberry, Brian

2016-01-01

Purpose: This paper summarizes the development of a high-power distributed x-ray source, or “multisource,” designed for inverse-geometry computed tomography (CT) applications [see B. De Man et al., “Multisource inverse-geometry CT. Part I. System concept and development,” Med. Phys. 43, 4607–4616 (2016)]. The paper presents the evolution of the source architecture, component design (anode, emitter, beam optics, control electronics, high voltage insulator), and experimental validation. Methods: Dispenser cathode emitters were chosen as electron sources. A modular design was adopted, with eight electron emitters (two rows of four emitters) per module, wherein tungsten targets were brazed onto copper anode blocks—one anode block per module. A specialized ceramic connector provided high voltage standoff capability and cooling oil flow to the anode. A matrix topology and low-noise electronic controls provided switching of the emitters. Results: Four modules (32 x-ray sources in two rows of 16) have been successfully integrated into a single vacuum vessel and operated on an inverse-geometry computed tomography system. Dispenser cathodes provided high beam current (>1000 mA) in pulse mode, and the electrostatic lenses focused the current beam to a small optical focal spot size (0.5 × 1.4 mm). Controlled emitter grid voltage allowed the beam current to be varied for each source, providing the ability to modulate beam current across the fan of the x-ray beam, denoted as a virtual bowtie filter. The custom designed controls achieved x-ray source switching in <1 μs. The cathode-grounded source was operated successfully up to 120 kV. Conclusions: A high-power, distributed x-ray source for inverse-geometry CT applications was successfully designed, fabricated, and operated. Future embodiments may increase the number of spots and utilize fast read out detectors to increase the x-ray flux magnitude further, while still staying within the stationary target inherent thermal limitations. PMID:27487878

Multisource inverse-geometry CT. Part II. X-ray source design and prototype

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

Neculaes, V. Bogdan, E-mail: neculaes@ge.com; Caia

2016-08-15

Purpose: This paper summarizes the development of a high-power distributed x-ray source, or “multisource,” designed for inverse-geometry computed tomography (CT) applications [see B. De Man et al., “Multisource inverse-geometry CT. Part I. System concept and development,” Med. Phys. 43, 4607–4616 (2016)]. The paper presents the evolution of the source architecture, component design (anode, emitter, beam optics, control electronics, high voltage insulator), and experimental validation. Methods: Dispenser cathode emitters were chosen as electron sources. A modular design was adopted, with eight electron emitters (two rows of four emitters) per module, wherein tungsten targets were brazed onto copper anode blocks—one anode blockmore » per module. A specialized ceramic connector provided high voltage standoff capability and cooling oil flow to the anode. A matrix topology and low-noise electronic controls provided switching of the emitters. Results: Four modules (32 x-ray sources in two rows of 16) have been successfully integrated into a single vacuum vessel and operated on an inverse-geometry computed tomography system. Dispenser cathodes provided high beam current (>1000 mA) in pulse mode, and the electrostatic lenses focused the current beam to a small optical focal spot size (0.5 × 1.4 mm). Controlled emitter grid voltage allowed the beam current to be varied for each source, providing the ability to modulate beam current across the fan of the x-ray beam, denoted as a virtual bowtie filter. The custom designed controls achieved x-ray source switching in <1 μs. The cathode-grounded source was operated successfully up to 120 kV. Conclusions: A high-power, distributed x-ray source for inverse-geometry CT applications was successfully designed, fabricated, and operated. Future embodiments may increase the number of spots and utilize fast read out detectors to increase the x-ray flux magnitude further, while still staying within the stationary target inherent thermal limitations.« less

An Open Source Rapid Computer Aided Control System Design Toolchain Using Scilab, Scicos and RTAI Linux

NASA Astrophysics Data System (ADS)

Bouchpan-Lerust-Juéry, L.

2007-08-01

Current and next generation on-board computer systems tend to implement real-time embedded control applications (e.g. Attitude and Orbit Control Subsystem (AOCS), Packet Utililization Standard (PUS), spacecraft autonomy . . . ) which must meet high standards of Reliability and Predictability as well as Safety. All these requirements require a considerable amount of effort and cost for Space Sofware Industry. This paper, in a first part, presents a free Open Source integrated solution to develop RTAI applications from analysis, design, simulation and direct implementation using code generation based on Open Source and in its second part summarises this suggested approach, its results and the conclusion for further work.

Calibrated vapor generator source

DOEpatents

Davies, John P.; Larson, Ronald A.; Goodrich, Lorenzo D.; Hall, Harold J.; Stoddard, Billy D.; Davis, Sean G.; Kaser, Timothy G.; Conrad, Frank J.

1995-01-01

A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet.

REGULATOR FOR CALUTRON ION SOURCE

DOEpatents

Miller, B.F.

1958-09-01

Improvements are described in electric discharge devices and circuits for a calutron and, more specifically, presents an arc discharge regulator circuit for the ion source of the calatron. In general, the source comprises a filament which bombards a cathode with electrons, a griid control electrode between the filament and the cathode, and an anode electrode. The control electrode has a DC potential which is varied in response to changes in the anode current flow by means of a saturable reactor installed in its power supply energizing line having the anode current flowing through its control winding. In this manner the bombardment current to the cathode may be decreased when the anode current increases beyond a predetermined level.

Dynamic Control of Particle Deposition in Evaporating Droplets by an External Point Source of Vapor.

PubMed

Malinowski, Robert; Volpe, Giovanni; Parkin, Ivan P; Volpe, Giorgio

2018-02-01

The deposition of particles on a surface by an evaporating sessile droplet is important for phenomena as diverse as printing, thin-film deposition, and self-assembly. The shape of the final deposit depends on the flows within the droplet during evaporation. These flows are typically determined at the onset of the process by the intrinsic physical, chemical, and geometrical properties of the droplet and its environment. Here, we demonstrate deterministic emergence and real-time control of Marangoni flows within the evaporating droplet by an external point source of vapor. By varying the source location, we can modulate these flows in space and time to pattern colloids on surfaces in a controllable manner.

Reduction of interior sound fields in flexible cylinders by active vibration control

NASA Technical Reports Server (NTRS)

Jones, J. D.; Fuller, C. R.

1988-01-01

The mechanisms of interior sound reduction through active control of a thin flexible shell's vibrational response are presently evaluated in view of an analytical model. The noise source is a single exterior acoustic monopole. The active control model is evaluated for harmonic excitation; the results obtained indicate spatially-averaged noise reductions in excess of 20 dB over the source plane, for acoustic resonant conditions inside the cavity.

RESEARCH ON EMISSIONS AND MITIGATION OF POP'S FROM COMBUSTION SOURCES

EPA Science Inventory

Chapter summarizes EPA's research on emissions and control of persistent organic pollutants (POPS) from combustion sources, with emphasis on source characterization and measurement, formation and destruction mechanisms, formation prevention, and flue gas cleaning. Laboratory exp...

A study of interior noise levels, noise sources and transmission paths in light aircraft

NASA Technical Reports Server (NTRS)

Hayden, R. E.; Murray, B. S.; Theobald, M. A.

1983-01-01

The interior noise levels and spectral characteristics of 18 single-and twin-engine propeller-driven light aircraft, and source-path diagnosis of a single-engine aircraft which was considered representative of a large part of the fleet were studied. The purpose of the flight surveys was to measure internal noise levels and identify principal noise sources and paths under a carefully controlled and standardized set of flight procedures. The diagnostic tests consisted of flights and ground tests in which various parts of the aircraft, such as engine mounts, the engine compartment, exhaust pipe, individual panels, and the wing strut were instrumented to determine source levels and transmission path strengths using the transfer function technique. Predominant source and path combinations are identified. Experimental techniques are described. Data, transfer function calculations to derive source-path contributions to the cabin acoustic environment, and implications of the findings for noise control design are analyzed.

Locus of control, sources of motivation, and mental boundaries as antecedents of leader-member exchange quality.

PubMed

Barbuto, John E; Finch, Weltmer Dayna; Pennisi, Lisa A

2010-02-01

In this study were examined leaders' and members' scores on locus of control, sources of motivation, and mental boundaries to predict the quality of leader-member exchanges. 80 elected officials and their 388 direct reports were sampled in a field study. Analysis indicated followers' scores on locus of control, leaders' scores of self-concept internal motivation, leaders' scores on locus of control, and followers' rated goal-internalization motivation were positively related to leader-member exchanges. Implications and directions for research are discussed.

A superconducting large-angle magnetic suspension

NASA Technical Reports Server (NTRS)

Downer, James R.; Anastas, George V., Jr.; Bushko, Dariusz A.; Flynn, Frederick J.; Goldie, James H.; Gondhalekar, Vijay; Hawkey, Timothy J.; Hockney, Richard L.; Torti, Richard P.

1992-01-01

SatCon Technology Corporation has completed a Small Business Innovation Research (SBIR) Phase 2 program to develop a Superconducting Large-Angle Magnetic Suspension (LAMS) for the NASA Langley Research Center. The Superconducting LAMS was a hardware demonstration of the control technology required to develop an advanced momentum exchange effector. The Phase 2 research was directed toward the demonstration for the key technology required for the advanced concept CMG, the controller. The Phase 2 hardware consists of a superconducting solenoid ('source coils') suspended within an array of nonsuperconducting coils ('control coils'), a five-degree-of-freedom positioning sensing system, switching power amplifiers, and a digital control system. The results demonstrated the feasibility of suspending the source coil. Gimballing (pointing the axis of the source coil) was demonstrated over a limited range. With further development of the rotation sensing system, enhanced angular freedom should be possible.

A superconducting large-angle magnetic suspension

NASA Astrophysics Data System (ADS)

Downer, James R.; Anastas, George V., Jr.; Bushko, Dariusz A.; Flynn, Frederick J.; Goldie, James H.; Gondhalekar, Vijay; Hawkey, Timothy J.; Hockney, Richard L.; Torti, Richard P.

1992-12-01

SatCon Technology Corporation has completed a Small Business Innovation Research (SBIR) Phase 2 program to develop a Superconducting Large-Angle Magnetic Suspension (LAMS) for the NASA Langley Research Center. The Superconducting LAMS was a hardware demonstration of the control technology required to develop an advanced momentum exchange effector. The Phase 2 research was directed toward the demonstration for the key technology required for the advanced concept CMG, the controller. The Phase 2 hardware consists of a superconducting solenoid ('source coils') suspended within an array of nonsuperconducting coils ('control coils'), a five-degree-of-freedom positioning sensing system, switching power amplifiers, and a digital control system. The results demonstrated the feasibility of suspending the source coil. Gimballing (pointing the axis of the source coil) was demonstrated over a limited range. With further development of the rotation sensing system, enhanced angular freedom should be possible.

Translation of an Object Using Phase-Controlled Sound Sources in Acoustic Levitation

NASA Astrophysics Data System (ADS)

Matsui, Takayasu; Ohdaira, Etsuzo; Masuzawa, Nobuyoshi; Ide, Masao

1995-05-01

Acoustic levitation is used for positioning materials in the development of new materials in space where there is no gravity. This technique is applicable to materials for which electromagnetic force cannot be used. If the levitation point of the materials can be controlled freely in this application, possibilities of new applications will be extended. In this paper we report on an experimental study on controlling the levitation point of the object in an acoustic levitation system. The system fabricated and tested in this study has two sound sources with vibrating plates facing each other. Translation of the object can be achieved by controlling the phase of the energizing electrical signal for one of the sound sources. It was found that the levitation point can be moved smoothly in proportion to the phase difference between the vibrating plates.

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

Code of Federal Regulations, 2010 CFR

2010-07-01

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

40 CFR 61.126 - Monitoring of operations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... operator of any source subject to this subpart using a wet-scrubbing emission control device shall install... manufacturer to be accurate within ±250 pascal (±1 inch of water). The owner or operator of any source subject to this subpart using a wet-scrubbing emission control device shall also install, calibrate, maintain...

40 CFR 61.126 - Monitoring of operations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... operator of any source subject to this subpart using a wet-scrubbing emission control device shall install... manufacturer to be accurate within ±250 pascal (±1 inch of water). The owner or operator of any source subject to this subpart using a wet-scrubbing emission control device shall also install, calibrate, maintain...

40 CFR 63.11148 - What are the standards and compliance requirements for existing sources using batch copper...

Code of Federal Regulations, 2013 CFR

2013-07-01

... acid plant prior to discharge to the atmosphere. (iv) For each secondary capture system that is used to... practicable, maintain and operate any affected source, including associated air pollution control equipment, in a manner consistent with good air pollution control practice for minimizing emissions...

40 CFR 63.11148 - What are the standards and compliance requirements for existing sources using batch copper...

Code of Federal Regulations, 2014 CFR

2014-07-01

... acid plant prior to discharge to the atmosphere. (iv) For each secondary capture system that is used to... practicable, maintain and operate any affected source, including associated air pollution control equipment, in a manner consistent with good air pollution control practice for minimizing emissions...

40 CFR 63.11148 - What are the standards and compliance requirements for existing sources using batch copper...

Code of Federal Regulations, 2011 CFR

2011-07-01

... acid plant prior to discharge to the atmosphere. (iv) For each secondary capture system that is used to... practicable, maintain and operate any affected source, including associated air pollution control equipment, in a manner consistent with good air pollution control practice for minimizing emissions...

40 CFR 63.11148 - What are the standards and compliance requirements for existing sources using batch copper...

Code of Federal Regulations, 2010 CFR

2010-07-01

... acid plant prior to discharge to the atmosphere. (iv) For each secondary capture system that is used to... practicable, maintain and operate any affected source, including associated air pollution control equipment, in a manner consistent with good air pollution control practice for minimizing emissions...

40 CFR 63.11148 - What are the standards and compliance requirements for existing sources using batch copper...

Code of Federal Regulations, 2012 CFR

2012-07-01

... acid plant prior to discharge to the atmosphere. (iv) For each secondary capture system that is used to... practicable, maintain and operate any affected source, including associated air pollution control equipment, in a manner consistent with good air pollution control practice for minimizing emissions...