Iterative methods for tomography problems: implementation to a cross-well tomography problem
NASA Astrophysics Data System (ADS)
Karadeniz, M. F.; Weber, G. W.
2018-01-01
The velocity distribution between two boreholes is reconstructed by cross-well tomography, which is commonly used in geology. In this paper, iterative methods, Kaczmarz’s algorithm, algebraic reconstruction technique (ART), and simultaneous iterative reconstruction technique (SIRT), are implemented to a specific cross-well tomography problem. Convergence to the solution of these methods and their CPU time for the cross-well tomography problem are compared. Furthermore, these three methods for this problem are compared for different tolerance values.
Fang, Sinan; Pan, Heping; Du, Ting; Konaté, Ahmed Amara; Deng, Chengxiang; Qin, Zhen; Guo, Bo; Peng, Ling; Ma, Huolin; Li, Gang; Zhou, Feng
2016-01-01
This study applied the finite-difference time-domain (FDTD) method to forward modeling of the low-frequency crosswell electromagnetic (EM) method. Specifically, we implemented impulse sources and convolutional perfectly matched layer (CPML). In the process to strengthen CPML, we observed that some dispersion was induced by the real stretch κ, together with an angular variation of the phase velocity of the transverse electric plane wave; the conclusion was that this dispersion was positively related to the real stretch and was little affected by grid interval. To suppress the dispersion in the CPML, we first derived the analytical solution for the radiation field of the magneto-dipole impulse source in the time domain. Then, a numerical simulation of CPML absorption with high-frequency pulses qualitatively amplified the dispersion laws through wave field snapshots. A numerical simulation using low-frequency pulses suggested an optimal parameter strategy for CPML from the established criteria. Based on its physical nature, the CPML method of simply warping space-time was predicted to be a promising approach to achieve ideal absorption, although it was still difficult to entirely remove the dispersion. PMID:27585538
Phase and amplitude inversion of crosswell radar data
Ellefsen, Karl J.; Mazzella, Aldo T.; Horton, Robert J.; McKenna, Jason R.
2011-01-01
Phase and amplitude inversion of crosswell radar data estimates the logarithm of complex slowness for a 2.5D heterogeneous model. The inversion is formulated in the frequency domain using the vector Helmholtz equation. The objective function is minimized using a back-propagation method that is suitable for a 2.5D model and that accounts for the near-, intermediate-, and far-field regions of the antennas. The inversion is tested with crosswell radar data collected in a laboratory tank. The model anomalies are consistent with the known heterogeneity in the tank; the model’s relative dielectric permittivity, which is calculated from the real part of the estimated complex slowness, is consistent with independent laboratory measurements. The methodologies developed for this inversion can be adapted readily to inversions of seismic data (e.g., crosswell seismic and vertical seismic profiling data).
Multi-crosswell profile 3D imaging and method
Washbourne, John K.; Rector, III, James W.; Bube, Kenneth P.
2002-01-01
Characterizing the value of a particular property, for example, seismic velocity, of a subsurface region of ground is described. In one aspect, the value of the particular property is represented using at least one continuous analytic function such as a Chebychev polynomial. The seismic data may include data derived from at least one crosswell dataset for the subsurface region of interest and may also include other data. In either instance, data may simultaneously be used from a first crosswell dataset in conjunction with one or more other crosswell datasets and/or with the other data. In another aspect, the value of the property is characterized in three dimensions throughout the region of interest using crosswell and/or other data. In still another aspect, crosswell datasets for highly deviated or horizontal boreholes are inherently useful. The method is performed, in part, by fitting a set of vertically spaced layer boundaries, represented by an analytic function such as a Chebychev polynomial, within and across the region encompassing the boreholes such that a series of layers is defined between the layer boundaries. Initial values of the particular property are then established between the layer boundaries and across the subterranean region using a series of continuous analytic functions. The continuous analytic functions are then adjusted to more closely match the value of the particular property across the subterranean region of ground to determine the value of the particular property for any selected point within the region.
Frequency domain, waveform inversion of laboratory crosswell radar data
Ellefsen, Karl J.; Mazzella, Aldo T.; Horton, Robert J.; McKenna, Jason R.
2010-01-01
A new waveform inversion for crosswell radar is formulated in the frequency-domain for a 2.5D model. The inversion simulates radar waves using the vector Helmholtz equation for electromagnetic waves. The objective function is minimized using a backpropagation method suitable for a 2.5D model. The inversion is tested by processing crosswell radar data collected in a laboratory tank. The estimated model is consistent with the known electromagnetic properties of the tank. The formulation for the 2.5D model can be extended to inversions of acoustic and elastic data.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, Jihoon; Um, Evan; Moridis, George
2014-12-01
We investigate fracture propagation induced by hydraulic fracturing with water injection, using numerical simulation. For rigorous, full 3D modeling, we employ a numerical method that can model failure resulting from tensile and shear stresses, dynamic nonlinear permeability, leak-off in all directions, and thermo-poro-mechanical effects with the double porosity approach. Our numerical results indicate that fracture propagation is not the same as propagation of the water front, because fracturing is governed by geomechanics, whereas water saturation is determined by fluid flow. At early times, the water saturation front is almost identical to the fracture tip, suggesting that the fracture is mostlymore » filled with injected water. However, at late times, advance of the water front is retarded compared to fracture propagation, yielding a significant gap between the water front and the fracture top, which is filled with reservoir gas. We also find considerable leak-off of water to the reservoir. The inconsistency between the fracture volume and the volume of injected water cannot properly calculate the fracture length, when it is estimated based on the simple assumption that the fracture is fully saturated with injected water. As an example of flow-geomechanical responses, we identify pressure fluctuation under constant water injection, because hydraulic fracturing is itself a set of many failure processes, in which pressure consistently drops when failure occurs, but fluctuation decreases as the fracture length grows. We also study application of electromagnetic (EM) geophysical methods, because these methods are highly sensitive to changes in porosity and pore-fluid properties due to water injection into gas reservoirs. Employing a 3D finite-element EM geophysical simulator, we evaluate the sensitivity of the crosswell EM method for monitoring fluid movements in shaly reservoirs. For this sensitivity evaluation, reservoir models are generated through the coupled flow-geomechanical simulator and are transformed via a rock-physics model into electrical conductivity models. It is shown that anomalous conductivity distribution in the resulting models is closely related to injected water saturation, but not closely related to newly created unsaturated fractures. Our numerical modeling experiments demonstrate that the crosswell EM method can be highly sensitive to conductivity changes that directly indicate the migration pathways of the injected fluid. Accordingly, the EM method can serve as an effective monitoring tool for distribution of injected fluids (i.e., migration pathways) during hydraulic fracturing operations« less
Acquisition of Crosswell Seismic Monitoring Data
DOE Office of Scientific and Technical Information (OSTI.GOV)
Daley, T.M.; Niu, F.; Silver, P.G.
2008-02-15
Crosswell seismic acquisition provides an ideal geometry for monitoring travel time changes in the subsurface. Analysis of delay time in terms of a characteristic frequency allows us to estimate optimal acquisition parameters (frequency and distance). We have deployed standard data acquisition equipment for continuous monitoring of crosswell travel time in two separate field experiments, with well spacing of 3 and 30 m. The acquisition hardware used for the field experiments is described, along with environmental effects (such as temperature) that influence the measurements. Two field experiments are described that correlate changes in travel time (and therefore velocity) with changes inmore » barometric pressure. The results from the two field sites show a pressure sensitivity for velocity of 10{sup -6}/Pa to 10{sup -8}/Pa.« less
Improving resolution of crosswell seismic section based on time-frequency analysis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Luo, H.; Li, Y.
1994-12-31
According to signal theory, to improve resolution of seismic section is to extend high-frequency band of seismic signal. In cross-well section, sonic log can be regarded as a reliable source providing high-frequency information to the trace near the borehole. In such case, what to do is to introduce this high-frequency information into the whole section. However, neither traditional deconvolution algorithms nor some new inversion methods such as BCI (Broad Constraint Inversion) are satisfied because of high-frequency noise and nonuniqueness of inversion results respectively. To overcome their disadvantages, this paper presents a new algorithm based on Time-Frequency Analysis (TFA) technology whichmore » has been increasingly received much attention as an useful signal analysis too. Practical applications show that the new method is a stable scheme to improve resolution of cross-well seismic section greatly without decreasing Signal to Noise Ratio (SNR).« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Marchesini, Pierpaolo; Daley, Thomas; Ajo-Franklin, Jonathan
Monitoring of time-varying reservoir properties, such as the state of stress, is a primary goal of geophysical investigations, including for geological sequestration of CO 2, enhanced hydrocarbon recovery (EOR), and other subsurface engineering activities. In this work, we used Continuous Active-Source Seismic Monitoring (CASSM), with cross-well geometry, to measure variation in seismic coda amplitude, as a consequence of effective stress change (in the form of changes in pore fluid pressure). To our knowledge, the presented results are the first in-situ example of such crosswell measurement at reservoir scale and in field conditions. Data compliment the findings of our previous workmore » which investigated the relationship between pore fluid pressure and seismic velocity (velocity-stress sensitivity) using the CASSM system at the same field site (Marchesini et al., 2017, in review). We find that P-wave coda amplitude decreases with decreasing pore pressure (increasing effective stress).« less
NASA Astrophysics Data System (ADS)
Commer, M.; Kowalsky, M. B.; Dafflon, B.; Wu, Y.; Hubbard, S. S.
2013-12-01
Geologic carbon sequestration is being evaluated as a means to mitigate the effects of greenhouse gas emissions. Efforts are underway to identify adequate reservoirs and to evaluate the behavior of injected CO2 over time; time-lapse geophysical methods are considered effective tools for these purposes. Pilot studies have shown that the invasion of CO2 into a background pore fluid can alter the electrical resistivity, with increases from CO2 in the super-critical or gaseous phase, and decreases from CO2 dissolved in groundwater (especially when calcite dissolution is occurring). Because of their sensitivity to resistivity changes, electrical and electromagnetic (EM) methods have been used in such studies for indirectly assessing CO2 saturation changes. While the electrical resistance tomography (ERT) method is a well-established technique for both crosswell and surface applications, its usefulness is limited by the relatively low-resolution information it provides. Controlled-source EM methods, including both frequency-domain and time-domain (transient EM) methods, can offer improved resolution. We report on three studies that aim to maximize the information content of electrical and electromagnetic measurements in inverse modeling applications that target the monitoring of resistivity changes due to CO2 migration and/or leakage. The first study considers a three-dimensional crosswell data set collected at an analogue site used for investigating CO2 distribution and geochemical reactivity within a shallow formation. We invert both resistance and phase data using a gradient-weighting method for descent-based inversion algorithms. This method essentially steers the search direction in the model space using low-cost non-linear conjugate gradient methods towards the more computationally expensive Gauss-Newton direction. The second study involves ERT data that were collected at the SECARB Cranfield site near Natchez, Mississippi, at depths exceeding 3000 m. We employ a ratio data inversion scheme, where the time-lapse input data are given by the measured ERT data normalized by their baseline values. We investigate whether three-dimensional time-lapse inversions yield improved results compared to two-dimensional results that were previously reported. Finally, we present a synthetic study that investigates a novel time-domain controlled-source EM method that has the potential for exploiting the resolution properties of vertically oriented source antennas while avoiding their logistical difficulties. A vertical source is replaced by an array of multiple horizontal dipoles arranged in a circle such that all dipoles have a common endpoint in the center. Overall, this study presents significant advances in developing adequate geophysical techniques to monitor CO2 migration and/or potential leaks in geological reservoirs.
Three-dimensional inversion of multisource array electromagnetic data
NASA Astrophysics Data System (ADS)
Tartaras, Efthimios
Three-dimensional (3-D) inversion is increasingly important for the correct interpretation of geophysical data sets in complex environments. To this effect, several approximate solutions have been developed that allow the construction of relatively fast inversion schemes. One such method that is fast and provides satisfactory accuracy is the quasi-linear (QL) approximation. It has, however, the drawback that it is source-dependent and, therefore, impractical in situations where multiple transmitters in different positions are employed. I have, therefore, developed a localized form of the QL approximation that is source-independent. This so-called localized quasi-linear (LQL) approximation can have a scalar, a diagonal, or a full tensor form. Numerical examples of its comparison with the full integral equation solution, the Born approximation, and the original QL approximation are given. The objective behind developing this approximation is to use it in a fast 3-D inversion scheme appropriate for multisource array data such as those collected in airborne surveys, cross-well logging, and other similar geophysical applications. I have developed such an inversion scheme using the scalar and diagonal LQL approximation. It reduces the original nonlinear inverse electromagnetic (EM) problem to three linear inverse problems. The first of these problems is solved using a weighted regularized linear conjugate gradient method, whereas the last two are solved in the least squares sense. The algorithm I developed provides the option of obtaining either smooth or focused inversion images. I have applied the 3-D LQL inversion to synthetic 3-D EM data that simulate a helicopter-borne survey over different earth models. The results demonstrate the stability and efficiency of the method and show that the LQL approximation can be a practical solution to the problem of 3-D inversion of multisource array frequency-domain EM data. I have also applied the method to helicopter-borne EM data collected by INCO Exploration over the Voisey's Bay area in Labrador, Canada. The results of the 3-D inversion successfully delineate the shallow massive sulfides and show that the method can produce reasonable results even in areas of complex geology and large resistivity contrasts.
High-Frequency, Crosswell Radar Data Collected in a Laboratory Tank
Peters, Bas; Moulton, Craig W.; Ellefsen, Karl J.; Horton, Robert J.; McKenna, Jason R.
2010-01-01
Crosswell radar data were collected among three wells in a laboratory tank filled with dry sand. Embedded within the sand was a long plastic box, which was the target for the data collection. Two datasets were collected between each pair of wells, making a total of six datasets. The frequencies in the data ranged from 0.5 to 1.5 gigahertz, and the peak frequency was 0.9 gigahertz. The data are well suited for evaluating various processing algorithms, and the data linearly scale to typical field conditions.
Frozen Gaussian approximation for 3D seismic tomography
NASA Astrophysics Data System (ADS)
Chai, Lihui; Tong, Ping; Yang, Xu
2018-05-01
Three-dimensional (3D) wave-equation-based seismic tomography is computationally challenging in large scales and high-frequency regime. In this paper, we apply the frozen Gaussian approximation (FGA) method to compute 3D sensitivity kernels and seismic tomography of high-frequency. Rather than standard ray theory used in seismic inversion (e.g. Kirchhoff migration and Gaussian beam migration), FGA is used to compute the 3D high-frequency sensitivity kernels for travel-time or full waveform inversions. Specifically, we reformulate the equations of the forward and adjoint wavefields for the purpose of convenience to apply FGA, and with this reformulation, one can efficiently compute the Green’s functions whose convolutions with source time function produce wavefields needed for the construction of 3D kernels. Moreover, a fast summation method is proposed based on local fast Fourier transform which greatly improves the speed of reconstruction as the last step of FGA algorithm. We apply FGA to both the travel-time adjoint tomography and full waveform inversion (FWI) on synthetic crosswell seismic data with dominant frequencies as high as those of real crosswell data, and confirm again that FWI requires a more sophisticated initial velocity model for the convergence than travel-time adjoint tomography. We also numerically test the accuracy of applying FGA to local earthquake tomography. This study paves the way to directly apply wave-equation-based seismic tomography methods into real data around their dominant frequencies.
NASA Astrophysics Data System (ADS)
Park, Chanho; Nguyen, Phung K. T.; Nam, Myung Jin; Kim, Jongwook
2013-04-01
Monitoring CO2 migration and storage in geological formations is important not only for the stability of geological sequestration of CO2 but also for efficient management of CO2 injection. Especially, geophysical methods can make in situ observation of CO2 to assess the potential leakage of CO2 and to improve reservoir description as well to monitor development of geologic discontinuity (i.e., fault, crack, joint, etc.). Geophysical monitoring can be based on wireline logging or surface surveys for well-scale monitoring (high resolution and nallow area of investigation) or basin-scale monitoring (low resolution and wide area of investigation). In the meantime, crosswell tomography can make reservoir-scale monitoring to bridge the resolution gap between well logs and surface measurements. This study focuses on reservoir-scale monitoring based on crosswell seismic tomography aiming describe details of reservoir structure and monitoring migration of reservoir fluid (water and CO2). For the monitoring, we first make a sensitivity analysis on crosswell seismic tomography data with respect to CO2 saturation. For the sensitivity analysis, Rock Physics Models (RPMs) are constructed by calculating the values of density and P and S-wave velocities of a virtual CO2 injection reservoir. Since the seismic velocity of the reservoir accordingly changes as CO2 saturation changes when the CO2 saturation is less than about 20%, while when the CO2 saturation is larger than 20%, the seismic velocity is insensitive to the change, sensitivity analysis is mainly made when CO2 saturation is less than 20%. For precise simulation of seismic tomography responses for constructed RPMs, we developed a time-domain 2D elastic modeling based on finite difference method with a staggered grid employing a boundary condition of a convolutional perfectly matched layer. We further make comparison between sensitivities of seismic tomography and surface measurements for RPMs to analysis resolution difference between them. Moreover, assuming a similar reservoir situation to the CO2 storage site in Nagaoka, Japan, we generate time-lapse tomographic data sets for the corresponding CO2 injection process, and make a preliminary interpretation of the data sets.
Lane, John W.; Day-Lewis, Frederick D.; Versteeg, Roelof J.; Casey, Clifton C.
2004-01-01
Crosswell radar methods can be used to dynamically image ground-water flow and mass transport associated with tracer tests, hydraulic tests, and natural physical processes, for improved characterization of preferential flow paths and complex aquifer heterogeneity. Unfortunately, because the raypath coverage of the interwell region is limited by the borehole geometry, the tomographic inverse problem is typically underdetermined, and tomograms may contain artifacts such as spurious blurring or streaking that confuse interpretation.We implement object-based inversion (using a constrained, non-linear, least-squares algorithm) to improve results from pixel-based inversion approaches that utilize regularization criteria, such as damping or smoothness. Our approach requires pre- and post-injection travel-time data. Parameterization of the image plane comprises a small number of objects rather than a large number of pixels, resulting in an overdetermined problem that reduces the need for prior information. The nature and geometry of the objects are based on hydrologic insight into aquifer characteristics, the nature of the experiment, and the planned use of the geophysical results.The object-based inversion is demonstrated using synthetic and crosswell radar field data acquired during vegetable-oil injection experiments at a site in Fridley, Minnesota. The region where oil has displaced ground water is discretized as a stack of rectangles of variable horizontal extents. The inversion provides the geometry of the affected region and an estimate of the radar slowness change for each rectangle. Applying petrophysical models to these results and porosity from neutron logs, we estimate the vegetable-oil emulsion saturation in various layers.Using synthetic- and field-data examples, object-based inversion is shown to be an effective strategy for inverting crosswell radar tomography data acquired to monitor the emplacement of vegetable-oil emulsions. A principal advantage of object-based inversion is that it yields images that hydrologists and engineers can easily interpret and use for model calibration.
Seismic data acquisition through tubing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Buettner, H M; Jervis, M
1999-07-01
We have collected good quality crosswell seismic data through production tubing in active oil fields at realistic interwell distances (300 ft). The data were collected at the Aera Cymric field (1998) and at a Chevron site (1997); both located in the Central Valley of California. The Aera data were used to produce travel-time tomographic images of the interwell region. Both sites have similar geology, namely siliceous shale (diatomite) with moderate to highly attenuating reservoir rocks. In addition we confirmed modeling predictions that typical tubing attenuation losses are on the order of 12 dB. We expect that the use of strongermore » sources and tube wave suppression will allow for crosswell imaging at realistic distances even for low Q or high noise situations. We are searching for an industrial partner now for a data collection in the gas wells of the San Juan Basin or South Texas.« less
NASA Astrophysics Data System (ADS)
Bauer, K.; Haberland, Ch.; Pratt, R. G.; Ryberg, T.; Weber, M. H.; Mallik Working Group
2003-04-01
We present crosswell seismic data from the Mallik 2002 Production Research Well Program, an international research project on Gas Hydrates in the Northwest Territories of Canada. The program participants include 8 partners; The Geological Survey of Canada (GSC), The Japan National Oil Corporation (JNOC), GeoForschungsZentrum Potsdam (GFZ), United States Geological Survey (USGS), United States Department of the Energy (USDOE), India Ministry of Petroleum and Natural Gas (MOPNG)/Gas Authority of India (GAIL) and the Chevron-BP-Burlington joint venture group. The crosswell seismic measurements were carried out by making use of two 1160 m deep observation wells (Mallik 3L-38 and 4L-38) both 45 m from and co-planar with the 1188 m deep production research well (5L-38). A high power piezo-ceramic source was used to generate sweeped signals with frequencies between 100 and 2000 Hz recorded with arrays of 8 hydrophones per depth level. A depth range between 800 and 1150 m was covered, with shot and receiver spacings of 0.75 m. High quality data could be collected during the survey which allow for application of a wide range of crosswell seismic methods. The initial data analysis included suppression of tube wave energy and picking of first arrivals. A damped least-squares algorithm was used to derive P-wave velocities from the travel time data. Next, t* values were derived from the decay of the amplitude spectra, which served as input parameters for a damped least-squares attenuation tomography. The initial results of the P-wave velocity and attenuation tomography reveal significant features reflecting the stratigraphic environment and allow for detection and eventually quantification of gas hydrate bearing sediments. A prominent correlation between P velocity and attenuation was found for the gas hydrate layers. This contradicts to the apparently more meaningful inverse correlation as it was determined for the gas hydrates at the Blake Ridge but supports the results from the Mallik 2L-38 sonic log data. The P velocities and attenuation values, if combined with other information can be important for the quantitative evaluation of the gas hydrate saturation, and may further constrain petrophysical models of the hydrate bearing sediment formation.
Commer, Michael; Doetsch, Joseph; Dafflon, Baptiste; ...
2016-06-01
In this study, we advance the understanding of three-dimensional (3-D) electrical resistivity tomography (ERT) for monitoring long-term CO 2 storage by analyzing two previously published field time-lapse data sets. We address two important aspects of ERT inversion-the issue of resolution decay, a general impediment to the ERT method, and the issue of potentially misleading imaging artifacts due to 2-D model assumptions. The first study analyzes data from a shallow dissolved-CO 2 injection experiment near Escatawpa (Mississippi), where ERT data were collected in a 3-D crosswell configuration. Here, we apply a focusing approach designed for crosswell configurations to counteract resolution lossmore » in the inter-wellbore area, with synthetic studies demonstrating its effectiveness. The 3-D field data analysis reveals an initially southwards-trending flow path development and a dispersing plume development in the downgradient inter-well region. The second data set was collected during a deep (over 3 km) injection of supercritical CO 2 near Cranfield (Mississippi). Comparative 2-D and 3-D inversions reveal the projection of off-planar anomalies onto the cross-section, a typical artifact introduced by 2-D model assumptions. Conforming 3-D images from two different algorithms support earlier hydrological investigations, indicating a conduit system where flow velocity variations lead to a circumvention of a close observation well and an onset of increased CO 2 saturation downgradient from this well. We relate lateral permeability variations indicated by an independently obtained hydrological analysis to this consistently observed pattern in the CO 2 spatial plume evolution.« less
Energy and Water Efficiency on Campus | NREL
Energy and Water Efficiency on Campus Energy and Water Efficiency on Campus NREL ensures the resiliency of our future energy and water systems through energy efficiency strategies and technologies , renewable energy, and water efficiency on the NREL campus. FY17 Energy Intensity. The South Table Mountain
Time-Lapse Joint Inversion of Cross-Well DC Resistivity and Seismic Data: A Numerical Investigation
Time-lapse joint inversion of geophysical data is required to image the evolution of oil reservoirs during production and enhanced oil recovery, CO2 sequestration, geothermal fields during production, and to monitor the evolution of contaminant plumes. Joint inversion schemes red...
Energy Efficient Building Management | Climate Neutral Research Campuses |
NREL Efficient Building Management Energy Efficient Building Management As campuses complete generate the greatest climate impact. Energy efficient management in the existing stock of buildings is the following links go to sections that describe how an energy buildings management and maintenance program may
NREL Inks Technology Agreement for High Efficiency Multijunction Solar
) multijunction solar cells. While high-efficiency multijunction solar cells are commonly used for space Devices is excited to now be commercializing IMM solar cells for high-performance space and UAV Cells | News | NREL Inks Technology Agreement for High Efficiency Multijunction Solar Cells
World's Most Efficient Solar Cell
on the cost effectiveness and revenue-generating capabilities of high-power space satellites over the ) and Spectrolab. The high efficiency makes the cells attractive for use in solar concentrator systems ." Similar high-efficiency solar cells - invented and developed over 10 years at NREL before being
Robotics Intern Retrofits Home Appliance to Operate in New, More-Efficient
Ways | News | NREL Robotics Intern Retrofits Home Appliance to Operate in New, More-Efficient Ways Robotics Intern Retrofits Home Appliance to Operate in New, More-Efficient Ways November 2, 2017 Energy's Energy Efficiency and Renewable Energy Robotics Internship Program. Photo courtesy of Jamie Santos
NASA Astrophysics Data System (ADS)
Hopkins, M. A.; Allsopp, D. W. E.; Kappers, M. J.; Oliver, R. A.; Humphreys, C. J.
2017-12-01
The efficiency of light emitting diodes (LEDs) remains a topic of great contemporary interest due to their potential to reduce the amount of energy consumed in lighting. The current consensus is that electrons and holes distribute themselves through the emissive region by a drift-diffusion process which results in a highly non-uniform distribution of the light emission and can reduce efficiency. In this paper, the measured variations in the external quantum efficiency of a range of InGaN/GaN LEDs with different numbers of quantum wells (QWs) are shown to compare closely with the predictions of a revised ABC model, in which it is assumed that the electrically injected electrons and holes are uniformly distributed through the multi-quantum well (MQW) region, or nearly so, and hence carrier recombination occurs equally in all the quantum wells. The implications of the reported results are that drift-diffusion plays a far lesser role in cross-well carrier transport than previously thought; that the dominant cause of efficiency droop is intrinsic to the quantum wells and that reductions in the density of non-radiative recombination centers in the MQW would enable the use of more QWs and thereby reduce Auger losses by spreading carriers more evenly across a wider emissive region.
NREL/PG&E Condensation System Increases Geothermal Power Plant Efficiency
. Geothermal power plants like The Geysers produce energy by collecting steam from underground reservoirs and NREL/PG&E Condensation System Increases Geothermal Power Plant Efficiency For more information world's largest producer of geothermal power has improved its power production efficiency thanks to a new
Lower HVAC Costs | Efficient Windows Collaborative
system. Smaller HVAC systems cost less and as such can offset some of the cost of the efficient windows dehumidification. First cost savings - Smaller HVAC units cost less. If, for example, down-sizing the HVAC system by half a ton saves $275, the cost premium of energy-efficient windows does not present as big an up
Cities-LEAP Analysis Reveals Findings on the Most Efficient and Least
Polluting Cities in the U.S. | State, Local, and Tribal Governments | NREL Cities-LEAP Analysis Reveals Findings on the Most Efficient and Least Polluting Cities in the U.S. Cities-LEAP Analysis Reveals Findings on the Most Efficient and Least Polluting Cities in the U.S. September 12, 2016 by Megan Day
NASA Astrophysics Data System (ADS)
Hu, Rui; Hu, Linwei; Brauchler, Ralf
2017-04-01
Hydraulic tomography (HT) has been developed for more than twenty years, which is mainly used for providing the spatial information of hydraulic parameters in the subsurface. Similar to geophysical tomography, HT utilizes hydraulic tests as the sources, and head measurements in different locations (receivers) are recorded for inverting hydraulic parameters. Among various inversion algrithoms, hydraulic traveltime based method is comparably efficient, as the inversion does not require complete head readings. However, in the practical aspect, to find out traveltime diagnostics can be readily hampered by data noise during the in-situ hydraulic tests, such as pumping tests. In this study, we use the data from recovery tests to complement and improve the original method. In order to examine hydraulic traveltimes derived from both pumping and recovery tests, we first simulate multilevel pumping and recovery tests in several three-dimensional synthetic models with different heterogeneity degree. Simulation results show that hydraulic traveltimes obtained from pumping tests are equal to which from recovery tests, in the case that pumping reaches to quasi-steady/steady state. Sebquentially, we derive hydraulic traveltimes from the crosswell pumping and recovery tests in a real field site, Stegemühle, in Göttingen, Germany, and then invert these traveltimes to deplict the distribution of hydraulic conductivity and specific storage in the aquifer. Results with and without traveltimes from recovery tests imply that adding more traveltimes from recovery tests into the inversion procedure could improve the resolution and reduce result uncertainty. Finally, we compare the HT results with several previous electrical resistance tomography (ERT) results. Comparison indicates that, in general, the aquifer structures from HT and ERT are similar. Nevertheless, HT has higher resolution due to the denser tomographic arrays. Moreover, values of hydraulic conductivity and specific storage derived from HT are more accurate than ERT, as HT directly relates to these hydraulic parameters.
Alternative Fuels Data Center: College Students Engineer Efficient Vehicles
in EcoCAR 2 CompetitionA> College Students Engineer Efficient Vehicles in EcoCAR 2 Competition to someone by E-mail Share Alternative Fuels Data Center: College Students Engineer Efficient Vehicles in EcoCAR 2 Competition on Facebook Tweet about Alternative Fuels Data Center: College Students Engineer
Alternative Fuels Data Center: County Fleet Goes Big on Idle Reduction,
Ethanol Use, Fuel Efficiency County Fleet Goes Big on Idle Reduction, Ethanol Use, Fuel , Ethanol Use, Fuel Efficiency on Facebook Tweet about Alternative Fuels Data Center: County Fleet Goes Big on Idle Reduction, Ethanol Use, Fuel Efficiency on Twitter Bookmark Alternative Fuels Data Center
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schiller, Steven R.; Schwartz, Lisa C.
Demand-side energy efficiency (efficiency) represents a low-cost opportunity to reduce electricity consumption and demand and provide a wide range of non-energy benefits, including avoiding air pollution. Efficiency-related energy and non-energy impacts are determined and documented by implementing evaluation, measurement and verification (EM&V) systems. This technical brief describes efficiency EM&V coordination strategies that Western states can consider taking on together, outlines EM&V-related products that might be appropriate for multistate coordination, and identifies some implications of coordination. Coordinating efficiency EM&V activities can save both time and costs for state agencies and stakeholders engaged in efficiency activities and can be particularly beneficial formore » multiple states served by the same utility. First, the brief summarizes basic information on efficiency, its myriad potential benefits and EM&V for assessing those benefits. Second, the brief introduces the concept of multistate EM&V coordination in the context of assessing such benefits, including achievement of state and federal goals to reduce air pollutants.1 Next, the brief presents three coordination strategy options for efficiency EM&V: information clearinghouse/exchange, EM&V product development, and a regional energy efficiency tracking system platform. The brief then describes five regional EM&V products that could be developed on a multistate basis: EM&V reporting formats, database of consistent deemed electricity savings values, glossary of definitions and concepts, efficiency EM&V methodologies, and EM&V professional standards or accreditation processes. Finally, the brief discusses options for next steps that Western states can take to consider multistate coordination on efficiency EM&V. Appendices provide background information on efficiency and EM&V, as well as definitions and suggested resources on the covered topics. This brief is intended to inform state public utility commissions, boards for public and consumer-owned utilities, state energy offices and air agencies, and other organizations involved in discussions about the use of efficiency EM&V.« less
University of Maryland Energy Research Center |
ENERGY MICRO POWER SYSTEMS ENERGY EFFICIENCY SMART GRID POWER ELECTRONICS RENEWABLE ENERGY NUCLEAR ENERGY most efficient use of our natural resources while minimizing environmental impacts and our dependence
Co-Optima Targets Maximum Transportation Sector Efficiency, Energy
Independence and Industry Growth | News | NREL Co-Optima Targets Maximum Transportation Sector Efficiency, Energy Independence and Industry Growth Co-Optima Targets Maximum Transportation Sector Efficiency, Energy Independence and Industry Growth February 6, 2017 Report cover on Co-Optima Year in Review
FASTSim: Future Automotive Systems Technology Simulator | Transportation
on light-, medium-, and heavy-duty vehicle efficiency, performance, cost, and battery life. This < 10 seconds to estimate vehicle efficiency, fuel economy, acceleration, battery life, and cost < ; 5 minutes to perform powertrain comparisons of efficiency and cost. FASTSim models a wide variety of
NREL: Renewable Resource Data Center - Webmaster
Version RReDC Home Biomass Resource Information Geothermal Resource Information Solar Resource Information laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. NREL U.S. Department of Energy Office of Energy Efficiency
Mechanical and Thermal Engineering Sciences | Research | NREL
. Geothermal Energy Developing cost-competitive technologies to advance the use of geothermal energy areas of energy efficiency, sustainable transportation, and renewable power. We provide engineering and scientific expertise to a variety of federal agencies, including the DOE Office of Energy Efficiency and
Alternative Fuels Data Center: Ten Ways You Can Implement Alternative Fuels
and Energy-Efficient Vehicle Technologies Ten Ways You Can Implement Alternative Fuels and Energy-Efficient Vehicle Technologies to someone by E-mail Share Alternative Fuels Data Center: Ten Ways You Can Implement Alternative Fuels and Energy-Efficient Vehicle Technologies on Facebook Tweet about
Dan Says - Continuum Magazine | NREL
efficiency of residential and commercial buildings. At first glance, energy efficiency may not seem as and commercial structures account for more than 70% of all electricity used in the United States. That end of the decade. That is why improving the energy efficiency of our homes and commercial buildings
NREL Fuels and Engines R&D Revs Up Vehicle Efficiency, Performance (Text
Version) | News | NREL Fuels and Engines R&D Revs Up Vehicle Efficiency, Performance (Text Version) NREL Fuels and Engines R&D Revs Up Vehicle Efficiency, Performance (Text Version) NREL's combustion to the evolution of how fuels interact with engine and vehicle design. This is a text version of
High Performance Computing Meets Energy Efficiency - Continuum Magazine |
NREL High Performance Computing Meets Energy Efficiency High Performance Computing Meets Energy turbines. Simulation by Patrick J. Moriarty and Matthew J. Churchfield, NREL The new High Performance Computing Data Center at the National Renewable Energy Laboratory (NREL) hosts high-speed, high-volume data
AFV special license plate, which are available from the Arizona Department of Transportation (ADOT license plate. ADOT has reached its maximum limit of 10,000 vehicles and the issuance of Energy Efficient Alternative Fuel Vehicle (AFV) and Energy Efficient Plate Programs Dedicated AFVs qualify for an
High vertical resolution crosswell seismic imaging
Lazaratos, Spyridon K.
1999-12-07
A method for producing high vertical resolution seismic images from crosswell data is disclosed. In accordance with one aspect of the disclosure, a set of vertically spaced, generally horizontally extending continuous layers and associated nodes are defined within a region between two boreholes. The specific number of nodes is selected such that the value of a particular characteristic of the subterranean region at each of the nodes is one which can be determined from the seismic data. Once values are established at the nodes, values of the particular characteristic are assigned to positions between the node points of each layer based on the values at node within that layer and without regard to the values at node points within any other layer. A seismic map is produced using the node values and the assigned values therebetween. In accordance with another aspect of the disclosure, an approximate model of the region is established using direct arrival traveltime data. Thereafter, the approximate model is adjusted using reflected arrival data. In accordance with still another aspect of the disclosure, correction is provided for well deviation. An associated technique which provides improvements in ray tracing is also disclosed.
Integration of crosswell seismic data for simulating porosity in a heterogeneous carbonate aquifer
NASA Astrophysics Data System (ADS)
Emery, Xavier; Parra, Jorge
2013-11-01
A challenge for the geostatistical simulation of subsurface properties in mining, petroleum and groundwater applications is the integration of well logs and seismic measurements, which can provide information on geological heterogeneities at a wide range of scales. This paper presents a case study conducted at the Port Mayaca aquifer, located in western Martin County, Florida, in which it is of interest to simulate porosity, based on porosity logs at two wells and high-resolution crosswell seismic measurements of P-wave impedance. To this end, porosity and impedance are transformed into cross-correlated Gaussian random fields, using local transformations. The model parameters (transformation functions, mean values and correlation structure of the transformed fields) are inferred and checked against the data. Multiple realizations of porosity can then be constructed conditionally to the impedance information in the interwell region, which allow identifying one low-porosity structure and two to three flow units that connect the two wells, mapping heterogeneities within these units and visually assessing fluid paths in the aquifer. In particular, the results suggest that the paths in the lower flow units, formed by a network of heterogeneous conduits, are not as smooth as in the upper flow unit.
Transient and chaotic low-energy transfers in a system with bistable nonlinearity
DOE Office of Scientific and Technical Information (OSTI.GOV)
Romeo, F., E-mail: francesco.romeo@uniroma1.it; Manevitch, L. I.; Bergman, L. A.
2015-05-15
The low-energy dynamics of a two-dof system composed of a grounded linear oscillator coupled to a lightweight mass by means of a spring with both cubic nonlinear and negative linear components is investigated. The mechanisms leading to intense energy exchanges between the linear oscillator, excited by a low-energy impulse, and the nonlinear attachment are addressed. For lightly damped systems, it is shown that two main mechanisms arise: Aperiodic alternating in-well and cross-well oscillations of the nonlinear attachment, and secondary nonlinear beats occurring once the dynamics evolves solely in-well. The description of the former dissipative phenomenon is provided in a two-dimensionalmore » projection of the phase space, where transitions between in-well and cross-well oscillations are associated with sequences of crossings across a pseudo-separatrix. Whereas the second mechanism is described in terms of secondary limiting phase trajectories of the nonlinear attachment under certain resonance conditions. The analytical treatment of the two aformentioned low-energy transfer mechanisms relies on the reduction of the nonlinear dynamics and consequent analysis of the reduced dynamics by asymptotic techniques. Direct numerical simulations fully validate our analytical predictions.« less
High-Performance Computing Data Center Efficiency Dashboard | Computational
recovery water (ERW) loop Heat exchanger for energy recovery Thermosyphon Heat exchanger between ERW loop and cooling tower loop Evaporative cooling towers Learn more about our energy-efficient facility
NREL, Swiss Scientists Power Past Solar Efficiency Records | NREL | News |
of these multijunction silicon-based solar cells, at least in the near term, is the cost. Assuming 30 % efficiency, the researchers estimated the GaInP-based cell would cost $4.85 per watt and the GaAs-based cell would cost $7.15 per watt. But as manufacturing ramps up and the efficiencies of these types of cells
Benefits of Efficient Windows | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Low-Cost III-V Solar Cells | Photovoltaic Research | NREL
Low-Cost III-V Solar Cells Low-Cost III-V Solar Cells At present, the cost of III-V solar cells is to drastically lower the cost of these devices, while maintaining their conversion efficiency, thus costs in the production of high-efficiency III-V devices: the cost of the epitaxy and the single-crystal
NREL Solar Research Garners Two Prestigious R&D 100 Awards | News | NREL
efficient bulk power generator that produces 40 percent more energy than conventional fixed photovoltaic panels. The 53-kilowatt photovoltaic power generator is based on the MegaModule, a turnkey unit pairing a wafers more efficient and a mammoth power generator that sets a new standard for the production of solar
Three-dimensional inverse modelling of damped elastic wave propagation in the Fourier domain
NASA Astrophysics Data System (ADS)
Petrov, Petr V.; Newman, Gregory A.
2014-09-01
3-D full waveform inversion (FWI) of seismic wavefields is routinely implemented with explicit time-stepping simulators. A clear advantage of explicit time stepping is the avoidance of solving large-scale implicit linear systems that arise with frequency domain formulations. However, FWI using explicit time stepping may require a very fine time step and (as a consequence) significant computational resources and run times. If the computational challenges of wavefield simulation can be effectively handled, an FWI scheme implemented within the frequency domain utilizing only a few frequencies, offers a cost effective alternative to FWI in the time domain. We have therefore implemented a 3-D FWI scheme for elastic wave propagation in the Fourier domain. To overcome the computational bottleneck in wavefield simulation, we have exploited an efficient Krylov iterative solver for the elastic wave equations approximated with second and fourth order finite differences. The solver does not exploit multilevel preconditioning for wavefield simulation, but is coupled efficiently to the inversion iteration workflow to reduce computational cost. The workflow is best described as a series of sequential inversion experiments, where in the case of seismic reflection acquisition geometries, the data has been laddered such that we first image highly damped data, followed by data where damping is systemically reduced. The key to our modelling approach is its ability to take advantage of solver efficiency when the elastic wavefields are damped. As the inversion experiment progresses, damping is significantly reduced, effectively simulating non-damped wavefields in the Fourier domain. While the cost of the forward simulation increases as damping is reduced, this is counterbalanced by the cost of the outer inversion iteration, which is reduced because of a better starting model obtained from the larger damped wavefield used in the previous inversion experiment. For cross-well data, it is also possible to launch a successful inversion experiment without laddering the damping constants. With this type of acquisition geometry, the solver is still quite effective using a small fixed damping constant. To avoid cycle skipping, we also employ a multiscale imaging approach, in which frequency content of the data is also laddered (with the data now including both reflection and cross-well data acquisition geometries). Thus the inversion process is launched using low frequency data to first recover the long spatial wavelength of the image. With this image as a new starting model, adding higher frequency data refines and enhances the resolution of the image. FWI using laddered frequencies with an efficient damping schemed enables reconstructing elastic attributes of the subsurface at a resolution that approaches half the smallest wavelength utilized to image the subsurface. We show the possibility of effectively carrying out such reconstructions using two to six frequencies, depending upon the application. Using the proposed FWI scheme, massively parallel computing resources are essential for reasonable execution times.
NREL's III-V Team Demonstrates Record Efficiency Dual-Junction Solar Cell |
-junction solar cell, surpassing the previous mark by a full percentage. Under one sun of illumination, the . Department of Energy's National Renewable Energy Laboratory (NREL) have set a record efficiency for a dual lattice-mismatched, 1.1-eV GaInAs bottom cell, grown monolithically by atmospheric pressure metal-organic
Institute for Atom-Efficient Chemical Transformations Energy Frontier
Synthesis Search Argonne ... Search Argonne Home > Institute for Atom-Efficient Chemical Transformations Synthesis Characterization Computational Studies Evaluation and Mechanisms/Catalytic Experimentation Using
NREL: News - 15 Home Builders Earn Energyvalue Awards
builders who voluntarily integrate energy and resource efficiency into the design, construction and successful approaches to resource-efficient construction. The 2002 EVHA winners are: Tierra Concrete Homes , Sioux City, IA Artistic Homes, Albuquerque, NM Chuck Miller Construction, Hidden Springs ID Enviro
Department of Economic and Community Affairs provides low-interest energy efficiency loans through its Local Government Energy Loan program to local governments and educational institutions. Eligible energy efficiency conversion costs. Local governments and public colleges and universities can borrow up to $350,000; K-12
Perovskite Solar Cells | Photovoltaic Research | NREL
& Devices pages: High-Efficiency Crystalline PV Polycrystalline Thin-Film PV Perovskite and Organic -Defect Hybrid Organic/Inorganic Perovskite Films as PV Absorbers. (FY 2015FY 2016). In collaboration with organic metal halide perovskite (see article). Ultrahigh-Efficiency and Low-Cost Polycrystalline Halide
Publications | Grid Modernization | NREL
Photovoltaics: Trajectories and Challenges Cover of Efficient Relaxations for Joint Chance Constrained AC Optimal Power Flow publication Efficient Relaxations for Joint Chance Constrained AC Optimal Power Flow
they have high Illumina design scores or have worked in other experiments. For Golden Gate experiments design files returned by Illumina. Efficient SNP selection: The most efficient way to select your SNPs is to get Illumina design scores on all of your possible SNPs prior to narrowing down your list. You can
Dan Says - Continuum Magazine | NREL
transportation system-from developing more efficient electric and hydrogen fuel-cell vehicles to inventing infrastructure are more daunting than those we are overcoming in developing and integrating renewable electricity more efficient, and developing the technology needed to put more electric and biofuel vehicles on the
ACHP | Sustainability and Historic Preservation Links
Energy) Realizing the Energy Efficiency Potential of Small Buildings: Saving Energy, Money and Jobs Improving the Energy Efficiency of Historic Buildings (National Park Service) Saving Windows, Saving Money
Nanoscale Confinement Leads to New All-inorganic Perovskite with
research into perovskites has centered on a hybrid organic-inorganic structure. Since research into climbed steadily and now shows greater than 22 percent power conversion efficiency. However, the organic unstable organic component and open the door to high-efficiency quantum dot optoelectronics that can be
High-Efficiency Crystalline Photovoltaics | Photovoltaic Research | NREL
. We are key players in developing low-cost, manufacturable techniques for further increasing the also a driving force in two industry-relevant areas: low-cost III-V photovoltaic cells for 1-sun and are developing a >23%-efficiency, low-cost industrial-size cell on n-Cz wafer by 2018. Silicon
Work with Us | State, Local, and Tribal Governments | NREL
take advantage of our policy, market, and technical expertise. Here's how you can work with us to meet (STAT)-solar market expertise and policy best practices Energy Efficiency Technical Assistance Team -energy efficiency policy and program expertise for states Tribal energy decision support-resources and
NREL, LiquidCool Solutions Partner on Energy-Efficient Cooling for
denser and generate more heat. Liquid cooling, including the LiquidCool Solutions technology, offers a more energy-efficient solution that also allows for effective reuse of the heat rejected by the water, depending on the coolant temperature and heat exchanger specifications. These water temperatures
Travel-time-based thermal tracer tomography
NASA Astrophysics Data System (ADS)
Somogyvári, Márk; Bayer, Peter; Brauchler, Ralf
2016-05-01
Active thermal tracer testing is a technique to get information about the flow and transport properties of an aquifer. In this paper we propose an innovative methodology using active thermal tracers in a tomographic setup to reconstruct cross-well hydraulic conductivity profiles. This is facilitated by assuming that the propagation of the injected thermal tracer is mainly controlled by advection. To reduce the effects of density and viscosity changes and thermal diffusion, early-time diagnostics are used and specific travel times of the tracer breakthrough curves are extracted. These travel times are inverted with an eikonal solver using the staggered grid method to reduce constraints from the pre-defined grid geometry and to improve the resolution. Finally, non-reliable pixels are removed from the derived hydraulic conductivity tomograms. The method is applied to successfully reconstruct cross-well profiles as well as a 3-D block of a high-resolution fluvio-aeolian aquifer analog data set. Sensitivity analysis reveals a negligible role of the injection temperature, but more attention has to be drawn to other technical parameters such as the injection rate. This is investigated in more detail through model-based testing using diverse hydraulic and thermal conditions in order to delineate the feasible range of applications for the new tomographic approach.
Traveltime inversion and error analysis for layered anisotropy
NASA Astrophysics Data System (ADS)
Jiang, Fan; Zhou, Hua-wei
2011-02-01
While tilted transverse isotropy (TTI) is a good approximation of the velocity structure for many dipping and fractured strata, it is still challenging to estimate anisotropic depth models even when the tilted angle is known. With the assumption of weak anisotropy, we present a TTI traveltime inversion approach for models consisting of several thickness-varying layers where the anisotropic parameters are constant for each layer. For each model layer the inversion variables consist of the anisotropic parameters ɛ and δ, the tilted angle φ of its symmetry axis, layer velocity along the symmetry axis, and thickness variation of the layer. Using this method and synthetic data, we evaluate the effects of errors in some of the model parameters on the inverted values of the other parameters in crosswell and Vertical Seismic Profile (VSP) acquisition geometry. The analyses show that the errors in the layer symmetry axes sensitively affect the inverted values of other parameters, especially δ. However, the impact of errors in δ on the inversion of other parameters is much less than the impact on δ from the errors in other parameters. Hence, a practical strategy is first to invert for the most error-tolerant parameter layer velocity, then progressively invert for ɛ in crosswell geometry or δ in VSP geometry.
Disaster Resiliency and Recovery Example Project: Galena, Alaska |
Emergency Management Agency (FEMA) to identify energy-efficient rebuilding solutions, including measures to potential for water and energy efficiency measures, as well as appropriate on site renewable energy
Alternative Fuels Data Center: Efficient Driving Behaviors to Conserve Fuel
Energy Futures Series: Effects of Travel Reduction and Efficient Driving on Transportation: Energy Use and Greenhouse Gas Emissions Transportation Energy Futures Series: Effects of the Built Environment on
Energy Efficient Demonstration Proves Powerful in Home Retrofits -
project team that included key Navy stakeholders at the regional and Naval Base Guam installation levels was Naval Base Guam in Apra Harbor, which has 1,369 houses for its active-duty Navy and family members millions." Given Naval Base Guam's high electricity rates of $0.50 per kilowatt hour, the efficiency
NREL's Capabilities Boost a Wide Range of Innovative ARPA-E Research | News
the United States reach its energy goals." ARPA-E announced its OPEN 2015 program awards under a highly competitive, open solicitation. Awards fund a broad spectrum of projects from across the country achieving greater than 30 percent solar conversion efficiency. This can open new markets to high-efficiency
High-Performance Computing Data Center Water Usage Efficiency |
cooler-an advanced dry cooler that uses refrigerant in a passive cycle to dissipate heat-was installed at efficiency-using wet cooling when it's hot and dry cooling when it's not. Learn more about NREL's partnership
World-Record Solar Cell a Step Closer to Cheap Solar Energy
envelope of solar-cell efficiency, we can begin to visualize the day when energy from the sun will be in efficiency translates into lower costs for harnessing energy from the sun. The cell's excellent
pick_xwell, a program for interactive picking of crosswell seismic and radar data
Ellefsen, K.J.
1999-01-01
travel times can be plotted on the computer screen or printed to a file in postscript format. The program is written in the IDL programming language, and it is executed, in command-line mode, within the IDL program. The IDL program must be run from an X-window terminal that is connected to a computer with the Unix operating system. The data must be in the SU format.
NREL and CSEM Jointly Set New Efficiency Record with Dual-Junction Solar
converting non-concentrated (1-sun) sunlight into electricity using a dual-junction III-V/Si solar cell. The 29.8 percent one-sun efficiency," which details the steps taken to break the previous record. His
Geostatistics applied to cross-well reflection seismic for imaging carbonate aquifers
NASA Astrophysics Data System (ADS)
Parra, Jorge; Emery, Xavier
2013-05-01
Cross-well seismic reflection data, acquired from a carbonate aquifer at Port Mayaca test site near the eastern boundary of Lake Okeechobee in Martin County, Florida, are used to delineate flow units in the region intercepted by two wells. The interwell impedance determined by inversion from the seismic reflection data allows us to visualize the major boundaries between the hydraulic units. The hydraulic (flow) unit properties are based on the integration of well logs and the carbonate structure, which consists of isolated vuggy carbonate units and interconnected vug systems within the carbonate matrix. The vuggy and matrix porosity logs based on Formation Micro-Imager (FMI) data provide information about highly permeable conduits at well locations. The integration of the inverted impedance and well logs using geostatistics helps us to assess the resolution of the cross-well seismic method for detecting conduits and to determine whether these conduits are continuous or discontinuous between wells. A productive water zone of the aquifer outlined by the well logs was selected for analysis and interpretation. The ELAN (Elemental Log Analysis) porosity from two wells was selected as primary data and the reflection seismic-based impedance as secondary data. The direct and cross variograms along the vertical wells capture nested structures associated with periodic carbonate units, which correspond to connected flow units between the wells. Alternatively, the horizontal variogram of impedance (secondary data) provides scale lengths that correspond to irregular boundary shapes of flow units. The ELAN porosity image obtained by cokriging exhibits three similar flow units at different depths. These units are thin conduits developed in the first well and, at about the middle of the interwell separation region, these conduits connect to thicker flow units that are intercepted by the second well. In addition, a high impedance zone (low porosity) at a depth of about 275 m, after being converted to ELAN porosity, is characterized as a more confined low porosity structure. This continuous zone corresponds to a permeability barrier in the carbonate aquifer that separates the three connected conduits observed in the cokriging image. In the zones above and below this permeability barrier, the water production is very high, which agrees with water well observations at the Port Mayaca aquifer.
manufacturing, buildings efficiency, concentrating solar power, geothermal energy, transportation, water power Integration Facility Geothermal Energy Grid Modernization Hydrogen & Fuel Cells Integrated Energy Research Research Researching energy systems and technologies-and the science behind them-for a
on the formation of higher efficiency formamidinium lead triiodide-based solar cells," Chem -0003-2019-4298 Dr. Mengjin Yang received his Ph.D. in Materials Science from the University of Pittsburgh, where he investigated nanomaterials for solar energy conversion under the supervision of Prof
Optimal design of focused experiments and surveys
NASA Astrophysics Data System (ADS)
Curtis, Andrew
1999-10-01
Experiments and surveys are often performed to obtain data that constrain some previously underconstrained model. Often, constraints are most desired in a particular subspace of model space. Experiment design optimization requires that the quality of any particular design can be both quantified and then maximized. This study shows how the quality can be defined such that it depends on the amount of information that is focused in the particular subspace of interest. In addition, algorithms are presented which allow one particular focused quality measure (from the class of focused measures) to be evaluated efficiently. A subclass of focused quality measures is also related to the standard variance and resolution measures from linearized inverse theory. The theory presented here requires that the relationship between model parameters and data can be linearized around a reference model without significant loss of information. Physical and financial constraints define the space of possible experiment designs. Cross-well tomographic examples are presented, plus a strategy for survey design to maximize information about linear combinations of parameters such as bulk modulus, κ =λ+ 2μ/3.
State Code Guides | Efficient Windows Collaborative
CO-2012 Connecticut CT-2018 CT-2015 CT-2012 Delaware DE-2018 DE-2015 DE-2012 District of Columbia DC LA-2018 LA-2015 LA-2012 Maine ME-2018 ME-2015 ME-2012 Maryland MD-2018 MD-2015 MD-2012 Massachusetts
energy efficiency technologies and managing the commercial building energy assessment trainings that NREL detection and diagnostics for commercial buildings Commercial building energy audits and photovoltaic system
the energy efficiency of both residential and commercial buildings, and to accelerate the integration Commercial Buildings team focuses on providing large institutional and private sector commercial building
Silicon Materials and Devices R&D | Photovoltaic Research | NREL
" and "Si-based Tandem Solar Cells"), Next Generation Photovoltaics (NextGen PV III), and devices, especially for photovoltaic (PV) cell applications. PV Research Other Materials & Devices pages: High-Efficiency Crystalline PV Polycrystalline Thin-Film PV Perovskite and Organic PV Advanced PV
NREL: Renewable Resource Data Center - Geothermal Resource Information
Energy's Office of Energy Efficiency and Renewable Energy Geothermal Technologies Program. Its collection , and thermal springs. View NREL's Geothermal resource maps as well as maps for other renewable energy Geothermal Resource Information Geothermal Prospector Start exploring U.S. geothermal resources
Tools & Resources | Efficient Windows Collaborative
Selection Tool Mobile App Window Selection Tool Mobile App Use the Window Selection Tool Mobile App for new Window Selection Tool Mobile App. LBNL's RESFEN RESFEN RESFEN is used for calculating the heating and
Geothermal Heat Pump Basics | NREL
a free source of hot water. Geothermal heat pumps use much less energy than conventional heating resources: Geothermal Heat Pumps U.S. Department of Energy's Office of Energy Efficiency and Renewable Heat Pump Basics Geothermal Heat Pump Basics Geothermal heat pumps take advantage of the nearly
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schiller Consulting, Inc.; Schiller, Steven R.; Goldman, Charles A.
2011-02-04
This report is a scoping study that identifies issues associated with developing a national evaluation, measurement and verification (EM&V) standard for end-use, non-transportation, energy efficiency activities. The objectives of this study are to identify the scope of such a standard and define EM&V requirements and issues that will need to be addressed in a standard. To explore these issues, we provide and discuss: (1) a set of definitions applicable to an EM&V standard; (2) a literature review of existing guidelines, standards, and 'initiatives' relating to EM&V standards as well as a review of 'bottom-up' versus 'top-down' evaluation approaches; (3) amore » summary of EM&V related provisions of two recent federal legislative proposals (Congressman Waxman's and Markey's American Clean Energy and Security Act of 2009 and Senator Bingaman's American Clean Energy Leadership Act of 2009) that include national efficiency resource requirements; (4) an annotated list of issues that that are likely to be central to, and need to be considered when, developing a national EM&V standard; and (5) a discussion of the implications of such issues. There are three primary reasons for developing a national efficiency EM&V standard. First, some policy makers, regulators and practitioners believe that a national standard would streamline EM&V implementation, reduce costs and complexity, and improve comparability of results across jurisdictions; although there are benefits associated with each jurisdiction setting its own EM&V requirements based on their specific portfolio and evaluation budgets and objectives. Secondly, if energy efficiency is determined by the US Environmental Protection Agency to be a Best Available Control Technology (BACT) for avoiding criteria pollutant and/or greenhouse gas emissions, then a standard can be required for documenting the emission reductions resulting from efficiency actions. The third reason for a national EM&V standard is that such a standard is likely to be required as a result of future federal energy legislation that includes end-use energy efficiency, either as a stand-alone energy-efficiency resource standard (EERS) or as part of a clean energy or renewable energy standard. This study is focused primarily on this third reason and thus explores issues associated with a national EM&V standard if energy efficiency is a qualifying resource in federal clean energy legislation. Developing a national EM&V standard is likely to be a lengthy process; this study focuses on the critical first step of identifying the issues that must be addressed in a future standard. Perhaps the most fundamental of these issues is 'how good is good enough?' This has always been the fundamental issue of EM&V for energy efficiency and is a result of the counter-factual nature of efficiency. Counter-factual in that savings are not measured, but estimated to varying degrees of accuracy by comparing energy consumption after a project (program) is implemented with what is assumed to have been the consumption of energy in the absence of the project (program). Therefore, the how good is good enough question is a short version of asking how certain does one have to be of the energy savings estimate that results from EM&V activities and is that level of certainty properly balanced against the amount of effort (resources, time, money) that is utilized to obtain that level of certainty. The implication is that not only should energy efficiency investments be cost-effective, but EM&V investments should consider risk management principles and thus also balance the costs and value of information derived from EM&V (EM&V should also be cost-effective).« less
Concentrating Solar Power Projects - Crescent Dunes Solar Energy Project |
: None Thermal Storage Storage Type: 2-tank direct Storage Capacity: 10 hours Thermal Storage Description : Thermal energy storage achieved by raising salt temperature from 550 to 1050 F. Thermal storage efficiency
Replacement Windows for Existing Homes Homes | Efficient Windows
Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Selection Tool will take you through a series of design conditions pertaining to your design and location
Energy Sources | Climate Neutral Research Campuses | NREL
. Common systems include: Biomass Deep Water Cooling Fuel Cells Geothermal Energy Ground-Source Heat Pumps Sources Energy Sources Many opportunities exist to improve the efficiency of energy supply systems and to incorporate renewable energy, especially at large research campuses with many facilities
Small Community Training & Education
training and adult education professionals. Â National Technical Information Service (NTIS) This U.S residents of New Jersey and beyond through education and public service. Â Operator Training Committee of Water Wastewater Training Security Conservation & Water Efficiency Water for All Americans Water We
NREL: International Activities - Bilateral Partnerships
development and use of renewable energy and energy efficiency technologies: Algeria Angola Argentina Australia sufficiently accurate information for national-level strategic energy planning. China NREL manages renewable energy cooperation with China under the U.S.-China Renewable Energy Partnership program. This program was
On-Farm Biofuel Production Grants The Governor's Office of Agricultural Policy provides grants through the County Agricultural Investment Program for on-farm energy efficiency and renewable energy Agricultural Development Fund
Computing Project, Marc develops high-fidelity turbulence models to enhance simulation accuracy and efficient numerical algorithms for future high performance computing hardware architectures. Research Interests High performance computing High order numerical methods for computational fluid dynamics Fluid
! Boating Safety Beach Hazards Rip Currents Hypothermia Hurricanes Thunderstorms Lightning Coastal Flooding Maritime Distress and Safety System (GMDSS) are to provide more effective and efficient emergency and safety communications and disseminate Maritime Safety Information (MSI) to all ships on the world's
Window Selection Tool | Efficient Windows Collaborative
Sacramento CA San Diego CA San Francisco CO Denver CO Grand Junction CT Hartford DC Washington DE Wilmington Louisville LA Lake Charles LA New Orleans LA Shreveport MA Boston MD Baltimore ME Portland MI Detroit MI
tour through NREL's campus. NREL's 327-acre campus in Golden, Colorado, houses many research projects. Explore the ESIF's interactive illustration to learn more. Photo of NREL's Research Support Facility. Research Support Facility Completed in 2010, NREL's ultra-high-efficiency Research Support
Maximize Energy Efficiency in Buildings | Climate Neutral Research Campuses
Buildings on a research campus, especially laboratory buildings, often represent the most cost-effective plans, campuses can evaluate the following: Energy Management Building Management New Buildings Design
SUNREL Energy Simulation Software | Buildings | NREL
SUNREL Energy Simulation Software SUNREL Energy Simulation Software SUNREL® is a hourly building energy simulation program that aids in the design of small energy-efficient buildings where the loads are
Grid Data and Tools | Grid Modernization | NREL
technologies and strategies, including renewable resource data sets and models of the electric power system . Renewable Resource Data A library of resource information to inform the design of efficient, integrated
Center at NREL. Otto has been involved in the design, construction, and operation of energy efficient energy use campus and community design. Mr. Van Geet was one of the founding members of the Labs21 and assessment, passive solar building design, use of design tools, photovoltaic (PV) system design
the desired vehicle technology. PHEV-x means a plug-in hybrid electric vehicle with x miles of all hybrids, or more efficient conventional vehicles. To explore the effect of adding vehicles to your fleet , change the current number of vehicles to zero and enter a number of new vehicles. Petroleum and
NREL: News - NREL Wins Research and Development Awards
and chemicals, energy-efficient buildings, advanced vehicle design, geothermal energy and hydrogen the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) are among this year's 100 components in geothermal power plants; a solar power system that produces electricity while still allowing
Jeff Maguire Photo of Jeff Maguire Jeff Maguire Research Engineer Jeff.Maguire@nrel.gov | 303-275 -4309 Jeff joined NREL in 2012 after working as a graduate student since 2010. His research focuses on simulations to determine the impact of use and climate on water heater efficiency. Jeff specializes in
Glossary | Efficient Windows Collaborative
double-hung windows as a means of counterbalancing the weight of the sash during opening and closing. Bay a fixed sash or a double-hung window. Also referred to as bead stop. Blackbody. The ideal, perfect member of the lower sash which meet at the middle of a double-hung window. Clerestory. A window in the
Fuel-Efficient Green Fleets Policy and Fleet Management Program Development The Alabama Green Fleets Review Committee (Committee) established a Green Fleets Policy (Policy) outlining a procedure for managers must classify their vehicle inventory for compliance with the Policy and submit annual plans for
Impacts on Conventional Generators | Energy Analysis | NREL
Impacts on Conventional Generators Impacts on Conventional Generators NREL is working to understand and quantify the impacts of increased penetrations of solar and wind generation on conventional plant efficiency and emissions. NREL's analyses of impacts of renewable electricity generation on
Fuels Performance | Transportation Research | NREL
Chemistry. (2014) Saturated Monoglyceride Effects on Low-Temperature Performance of Biodiesel Blends. G.M more energy-efficient vehicles on the road to displace oil consumption, decrease greenhouse gas . (2013) Ignition Quality Tester (IQT) Investigation of the Negative Temperature Coefficient Region of
heating, ventilation and air conditioning (HVAC) systems, structural insulated panels to improve products and systems. NREL building engineers estimate the combination of advanced products and design Building America program manager George James. "All of the technologies and systems used in this house
Multi-Wind Heat Smart Grid Project. Advancing Energy Solutions in Alaska NREL provides analysis mission to transfer knowledge and innovation to solve the nation's energy challenges. The goal of this transportation energy efficiency and reduce transportation energy costs State Technical Assistance-solar market
Design Considerations | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Gas Fills | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Understanding Windows | Efficient Windows Collaborative
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Books & Publications | Efficient Windows Collaborative
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Defense.gov Special Report: Fiscal Budget
Request for Fiscal Year 2012 Air Force Budget Targets Efficiencies, Balance Budget Summary Summary of the Transcripts Gates' Opening Summary Secretary Gates Under Secretary Hale and Lt. Gen. Spencer Army Maj. Gen
Resources | Efficient Windows Collaborative
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Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
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Reducing Condensation | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Reduced Fading | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
EWC Membership | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Visible Transmittance | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
EWC Members | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Financing & Incentives | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Solar Energy Research Facility | Photovoltaic Research | NREL
-efficiency crystalline solar cells. Laboratories in the center module are used to fabricate prototype solar cells and analyze the semiconductor material used to make solar cells, as well as to research hydrogen
simulation methods for materials physics and chemistry, with particular expertise in post-DFT, high accuracy methods such as the GW approximation for electronic structure and random phase approximation (RPA) total the art in computational methods, including efficient methods for including the effects of substrates
High-Concentration III-V Multijunction Solar Cells | Photovoltaic Research
| NREL High-Concentration III-V Multijunction Solar Cells High-Concentration III-V transfer to the high-efficiency cell industry, and the invention and development of the inverted metamorphic multijunction (IMM) cell technology. PV Research Other Materials & Devices pages: High
URBANopt Advanced Analytics Platform | Buildings | NREL
-use districts, different buildings may peak in energy consumption at different times. In certain cases applications. Districts, Neighborhoods, and Campuses For districts with different building types and mixed-use buildings? How does energy consumption vary depending on different building efficiency scenarios (e.g
Organic Photovoltaic Solar Cells | Photovoltaic Research | NREL
Organic Photovoltaic Solar Cells Organic Photovoltaic Solar Cells The National Center for Photovoltaics (NCPV) at NREL has strong complementary research capabilities in organic photovoltaic (OPV) cells pages: High-Efficiency Crystalline PV Polycrystalline Thin-Film PV Perovskite and Organic PV Advanced PV
solar cells for concentrator systems. One of his early focuses after joining the group was to adapt the J. Friedman Photo of Daniel J. Friedman. Daniel Friedman Group Research Manager III-Physics manager of the High Efficiency Crystalline Photovoltaics Group. He received his doctorate in applied
Science Photo of person viewing 3D visualization of a wind turbine The NREL Computational Science challenges in fields ranging from condensed matter physics and nonlinear dynamics to computational fluid dynamics. NREL is also home to the most energy-efficient data center in the world, featuring Peregrine-the
Alternative Fuels Data Center: Hydrogen Related Links
to promote understanding of hydrogen technology and to create a marketplace for pollution-free make a swift transition to pollution-free renewable energy sources and clean, petroleum-free of fuel cells and related pollution-free, efficient energy generation, storage and utilization
Proper Installation of New Windows | Efficient Windows Collaborative
airtight fit and avoid water leakage. Always follow manufacturers installation guidelines and use trained professionals for window installation. Proper installation will: Protect from water damage. Windows should form a continuous water barrier where they meet the wall. With improper installation, water may penetrate
ACHP | Sustainability and Historic Preservation
efficiency and community livability, and are protected from climate impacts. The ACHP is working to help impacts, such as storm damage, flooding, coastal erosion, drought and associated wildfires, melting be more resilient to climate impacts, including impacts to historic properties. Good introductions to
researches new methods and technologies for energy-efficient air conditioning systems. He has tested more -6155 Eric joined NREL in 2002 and is a member of the Commercial Buildings Research Group. Eric recommendations. He uses tools such as CAD, Matlab, Engineer Equation Solver, Excel, and statistical software to
Brent Olson - Director, Office of Internal Audit | NREL
improve the effectiveness and efficiency of governance, risk management, and control processes. Using this the Treadway Commission's 2013 Internal Control Framework, Standards for Internal Control in the additional certifications from IIA including Certified Internal Auditor (CIA); Certification in Control Self
state-of-the-art and unique equipment for analyzing a wide spectrum of building energy efficiency building's energy use and make adjustments. Low-Energy Parking Structure Photo of the parking structure on structure in February 2012. The structure's estimated energy use is 42 kilowatt-hours per parking stall
Disaster Resiliency and Recovery Example Project: New Orleans, Louisiana |
Integrated Energy Solutions | NREL Orleans, Louisiana Disaster Resiliency and Recovery Example . NREL, with funding from the U.S. Department of Energy (DOE), provided technical assistance to help the city incorporate energy efficiency and renewable energy into rebuilding homes and schools, and
Supernova Survey: An Intensive HST Survey for z>1 Type Ia Supernovae by Targeting Galaxy Clusters Survey new survey strategy to discover and study high redshift Type Ia supernovae (SNe Ia) using the Hubble improvement in the efficiency of finding SNe compared to an HST field survey and a factor of three improvement
Grid-Integrated Electric Drive Analysis for The Ohio State University |
thermal management analysis and simulations on a high-performance, high-speed drive-developed by The Ohio as a pilot study for the future generation of energy efficient, high power density, high-speed integrated medium/high-voltage drive systems. If successful, the proposed project will significantly advance
Window Frame Types | Efficient Windows Collaborative
metal frames. Metal Frames Metal Frame with Thermal Break Non-metal Frames Non-metal There is a variety of non-metal framing materials for windows including, wood, wood with metal/vinyl cladding, vinyl disadvantages. Non-metal Frames Non-metal Frame, Thermally Improved Does frame material type matter? The
New Solar Cell Is More Efficient, Less Costly | News | NREL
rules for solar cells. Credit: Dennis Schroeder American innovators still have some cards to play when significant cost advantage when it comes to high-volume manufacturing. "It's a potentially disruptive . solar manufacturing when the approach hits the assembly line next year. The innovative design, simple
Window Operator Types | Efficient Windows Collaborative
Types Casement Casement Casement windows are hinged at the sides. Hinged windows such as casements operating types to consider. Traditional operable window types include the projected or hinged types such as casement, awning, and hopper, and the sliding types such as double- and single-hung and horizontal sliding
Long-term electrical resistivity monitoring of recharge-induced contaminant plume behavior.
Gasperikova, Erika; Hubbard, Susan S; Watson, David B; Baker, Gregory S; Peterson, John E; Kowalsky, Michael B; Smith, Meagan; Brooks, Scott
2012-11-01
Geophysical measurements, and electrical resistivity tomography (ERT) data in particular, are sensitive to properties that are related (directly or indirectly) to hydrological processes. The challenge is in extracting information from geophysical data at a relevant scale that can be used to gain insight about subsurface behavior and to parameterize or validate flow and transport models. Here, we consider the use of ERT data for examining the impact of recharge on subsurface contamination at the S-3 ponds of the Oak Ridge Integrated Field Research Challenge (IFRC) site in Tennessee. A large dataset of time-lapse cross-well and surface ERT data, collected at the site over a period of 12 months, is used to study time variations in resistivity due to changes in total dissolved solids (primarily nitrate). The electrical resistivity distributions recovered from cross-well and surface ERT data agrees well, and both of these datasets can be used to interpret spatiotemporal variations in subsurface nitrate concentrations due to rainfall, although the sensitivity of the electrical resistivity response to dilution varies with nitrate concentration. Using the time-lapse surface ERT data interpreted in terms of nitrate concentrations, we find that the subsurface nitrate concentration at this site varies as a function of spatial position, episodic heavy rainstorms (versus seasonal and annual fluctuations), and antecedent rainfall history. These results suggest that the surface ERT monitoring approach is potentially useful for examining subsurface plume responses to recharge over field-relevant scales. Published by Elsevier B.V.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Parra, J.; Collier, H.; Angstman, B.
In low porosity, low permeability zones, natural fractures are the primary source of permeability which affect both production and injection of fluids. The open fractures do not contribute much to porosity, but they provide an increased drainage network to any porosity. An important approach to characterizing the fracture orientation and fracture permeability of reservoir formations is one based upon the effects of such conditions on the propagation of acoustic and seismic waves in the rock. We present the feasibility of using seismic measurement techniques to map the fracture zones between wells spaced 2400 ft at depths of about 1000 ft.more » For this purpose we constructed computer models (which include azimuthal anisotropy) using Lodgepole reservoir parameters to predict seismic signatures recorded at the borehole scale, crosswell scale, and 3 D seismic scale. We have integrated well logs with existing 2D surfaces seismic to produce petrophysical and geological cross sections to determine the reservoir parameters and geometry for the computer models. In particular, the model responses are used to evaluate if surface seismic and crosswell seismic measurements can capture the anisotropy due to vertical fractures. Preliminary results suggested that seismic waves transmitted between two wells will propagate in carbonate fracture reservoirs, and the signal can be received above the noise level at the distance of 2400 ft. In addition, the large velocities contrast between the main fracture zone and the underlying unfractured Boundary Ridge Member, suggested that borehole reflection imaging may be appropriate to map and fracture zone thickness variation and fracture distributions in the reservoir.« less
Increased Light & View | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Windows for New Construction | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Performance Standards for Windows | Efficient Windows Collaborative
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Window Selection Tool | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Air Leakage (AL) | Efficient Windows Collaborative
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State Fact Sheets | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Fact Sheets & Publications | Efficient Windows Collaborative
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Condensation Resistance (CR) | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Assessing Window Replacement Options | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
National Fenestration Rating Council (NFRC) | Efficient Windows
Collaborative Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring
Low Conductance Spacers | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Energy & Cost Savings | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
U-Factor (U-value) | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Culture Practices Improving Production Efficiency of Warmwater Aquaculture Species Through Nutrition Crustaceans Effect of Nutrition on Body Composition and Subsequent Storage Quality of Farm-Raised Channel
Alternative Fuels Data Center: Natural Gas Vehicles Make a Difference in
District built a clean fuel alliance for natural gas vehicles in Tennessee. For information about this car. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a TennesseeA> Natural Gas Vehicles Make a Difference in Tennessee to someone by E-mail Share
Alternative Fuels Data Center: Yellowstone Park Recycles Vehicle Batteries
school bus Michigan Transports Students in Hybrid Electric School Buses Jan. 4, 2014 Photo of a natural of a school bus. California School District Creates First-of-Its-Kind Zero-Emissions Bus Dec. 20 , 2014 Photo of an electric car. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug
Market Demonstration: NREL Helps Transformative Technologies Go Mainstream
the 60% efficiency potential. Clearly, NREL is making an impact-in areas as varied as military bases power to help meet the Navy's ambitious energy targets and reduce energy costs, as well as providing military energy use. Working for DOE, an NREL team had examined the site for net-zero energy potential-that
Selection Process for New Windows | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Design Guidance for New Windows | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Selection Process for Replacement Windows | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Design Guidance for Replacement Windows | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Solar Heat Gain Coefficient (SHGC) | Efficient Windows Collaborative
Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards
Sustainable Mobility | Transportation Research | NREL
both safety and energy efficiency. Sustainable Mobility Initiative Takes Systems-Based Approach to of its Sustainable Mobility Initiative, approaching sustainable transportation as an intelligent Transportation Sector Initiative and DOE's Transportation Energy Futures project identify emerging and disruptive
NREL Collaborates with Trucking Industry to Prioritize R&D Opportunities |
Department drive decision-making and improve efficiency, informing long-term, high-risk research such as the Rosa Using Data to Drive Decision Making NREL's fleet test and evaluation team conducts real-world 21CTP an example of NREL's data evaluation and decision support capabilities. Using data collected in
for Energy Simulation Energy Simulation Games ElectroCity Environmental Science Electro Energy Simulation Games Energy Efficiency Energy Audit Conducting a School Energy Audit presentation Exploration of
; standardization, process improvement, monitoring and reporting; energy-water-food nexus project implementation efficiency and innovative renewable energy programs and policies Community solar; Energy-water-food nexus
renewable energy and energy efficiency into local planning, zoning, and permitting practices; residential and commercial sector solar financing; and resilience planning. Education Master's, Urban and Regional
Staff | Computational Science | NREL
develops and leads laboratory-wide efforts in high-performance computing and energy-efficient data centers Professional IV-High Perf Computing Jim.Albin@nrel.gov 303-275-4069 Ananthan, Shreyas Senior Scientist - High -Performance Algorithms and Modeling Shreyas.Ananthan@nrel.gov 303-275-4807 Bendl, Kurt IT Professional IV-High
EEBA || The Energy & Environmental Building Alliance || EEBA
Mechanical Selling High Performance Homes Water Efficiency Zero Energy Homes Upcoming Sessions HERS Associate Search High Performance Home Summit October 16-18, 2018 - San Diego, CA High Performance Home Summit Join collaboration with high performance building professionals from across the United States and Canada. More
New Design Tool Can Help Cut building Energy Use
help almost any architect or engineer evaluate passive solar and efficiency design strategies in a tool that enables them to walk through the design process and understand the consequences of design , a feature that tells designers how large of a heating, ventilation and air conditioning (HVAC
ResStock Analysis Tool | Buildings | NREL
Energy and Cost Savings for U.S. Homes Contact Eric Wilson to learn how ResStock can benefit your approach to large-scale residential energy analysis by combining: Large public and private data sources uncovered $49 billion in potential annual utility bill savings through cost-effective energy efficiency
Alternative Fuels Data Center: Widgets
Efficiency and Renewable Energy Get Widget Code à Widget Code Select All Close Vehicle Cost Calculator Share a tool to calculate annual fuel cost and greenhouse gas emissions for alternative fuel and advanced technology vehicles. Vehicle Cost Calculator Choose a vehicle to compare fuel cost and emissions with a
Office of the Under Secretary of Defense (Comptroller)
provide all of the information you need to understand the budget and financial management policy of the functionalStatements OUSD(C) History FMR Budget Materials Budget Execution Financial Management Improving Financial will also find information about the Department's ongoing effort to improve efficiency and
Fuel Cell Electric Vehicle Evaluations | Hydrogen and Fuel Cells | NREL
Electric Vehicle Evaluations Fuel Cell Electric Vehicle Evaluations NREL's technology validation include commercial FCEVs for the first time. Current fuel cell electric vehicle evaluations build on the seven-year FCEV Learning Demonstration and focus on fuel cell stack durability and efficiency, vehicle
Proper Installation of Replacement Windows | Efficient Windows
. Quality installation is critical for an airtight fit and a continuous water barrier to prevent drafts , water damage and condensation. The complexity of the installation depends on whether you are considering and specifications. Install level, plumb, and square. Install water tight: water must be prevented
ACHP | News | Federal Highway Administration wins Chairman's Award for
major source of federal funding for local and state historic preservation efforts." The award was Intermodal Surface Transportation Efficiency Act began to find an appropriate balance by creating and funding largest single source of federal funding for historic preservation. The funding is provided through a
, building energy efficiency, solar industrial process heat, geothermal power, and concentrating solar power . He is an American Solar Energy Society (ASES) Fellow and served as the ASES Chair in 2000-2001. He is editor of the 200-page ASES report, Tackling Climate Change in the U.S., which details how energy
Technology and Performance Analysis Tools | Energy Analysis | NREL
optimize renewable energy and energy efficiency technologies for your project. Many of these tools can be the consumer or energy professional. Biomass Scenario Model (BSM) Determine which supply chain changes (BLCC) Analyze capital investments in buildings. Includes the Energy Escalation Rate Calculator 2.0-15
Improved Comfort | Efficient Windows Collaborative
temperature; how low the glass temperature drops depends on the window's insulating quality. If people are exposed to the effects of a cold surface, they can experience significant radiant heat loss to that cold surface and they feel uncomfortable, even if the room air temperature is comfortable. When the interior
Asetek's Warm-Water Liquid Cooling System Yields Energy Cost Savings at
NREL | Energy Systems Integration Facility | NREL Asetek Asetek's Warm-Water Liquid Cooling System Yields Energy Cost Savings at NREL Asetek's RackCDU liquid cooling system was installed and tested at the Energy Systems Integration Facility's (ESIF's) ultra-energy-efficient high-performance
6 News Releases Access news stories about the laboratory and renewable energy and energy efficiency Facility Slashes Energy Use by 66 Percent - (10/3/96) Agreement Moves Nevada Solar Plant Step Closer to Converter Wins National Award - (7/25/96) Solar Energy to Help Heat Major Commercial Facility - (6/21/96
Data Products | Energy Analysis | NREL
Project Finance Provides information on the Solar Access to Public Capital working group, Market Insights in the NSRDB Viewer. Open EI (Open Energy Information) OpenEI is a knowledge sharing online community efficiency. The Open PV Project A collaborative effort between government, industry, and the public to
Energy Efficient Window Coatings that Please the Eye - Continuum Magazine
voltage polarity reverses the lithium-ion flow, decreasing the glass tint and allowing more light to be transparent contact layers bookending a counterelectrode layer, ion-conducting layer, and electrochromic layer . Low voltage applied across the stacked layers causes lithium ions to migrate out of the
FAQ | Efficient Windows Collaborative
climate and your pocketbook. Sometimes a homeowner feels more comfortable with a particular contractor contractor to describe the installation process. Make sure your contractor knows as much about ENERGY STAR , you will have to work with the builder or a contractor to correct the problem. If the leak is between
] Cervero, Robert; Kockelman, Kara. (1997). "Travel demand and the 3Ds: Density, diversity, and design efficient design of sustainable goods and services." The International Journal of Life Cycle Assessment . Upper Saddle River, NJ: FT Press. [202] Das, Sujit. (2004). "A Comparative Assessment of
High-Performance Computing Unlocks Innovation at NREL - Video Text Version
scales, data visualizations and large-scale modeling provide insights and test new ideas. But this type most energy-efficient data center in the world. NREL and Hewlett-Packard won an R&D 100 award-the
technologies and operational practices which increase fuel efficiency and reduce emissions from goods movement . EPA provides partners with performance benchmarking tools, fleet management best practices, technology is working with partners to test and verify advanced technologies and operational practices that save
-performance, high-reliability systems that use concentrated sunlight to generate power. Recently, Robert has been involved developing a high-efficiency solar selective absorber and anti-corrosion coatings
Commercial Buildings Research Group. Steve's areas of expertise are electric power distribution systems, DC techniques for maximizing the energy efficiency of electrical distribution systems in commercial buildings
efficiency in buildings Low emission development strategies Greenhouse gas accounting and mitigation analysis -102014-4462. A. Carpenter, E. Hotchkiss, A. Kandt. 2013. Interagency Pilot of Greenhouse Gas Accounting
Upcoming Events | Argonne National Laboratory
IACTInstitute for Atom-Efficient Chemical Transformations IGSBInstitute for Genomics and Systems Biology Engineering RISCRisk and Infrastructure Science Center SBCStructural Biology Center Energy.gov U.S. Department
Publications | Buildings | NREL
Documents Efficiency of Mini-Split Heat Pumps (Fact Sheet). NREL Highlights, Research & Development . Christensen, D.; Fang, X.; Tomerlin, J.; Winkler, J.; Hancock, E. (2011). Field Monitoring Protocol: Mini
Science and Technology Highlights | NREL
Leads to Enhanced Upgrading Methods NREL's efforts to standardize techniques for bio-oil analysis inform enhanced modeling capability and affordable methods to increase energy efficiency. December 2012 NREL Meets Performance Demands of Advanced Lithium-ion Batteries Novel surface modification methods are
High-Performance Computing Systems and Operations | Computational Science |
NREL Systems and Operations High-Performance Computing Systems and Operations NREL operates high-performance computing (HPC) systems dedicated to advancing energy efficiency and renewable energy technologies. Capabilities NREL's HPC capabilities include: High-Performance Computing Systems We operate
Sustainability through Dynamic Energy Management - Continuum Magazine |
NREL Sustainability through Dynamic Energy Management Sustainability through Dynamic Energy Management Integrating behavior change with advanced building systems is the new model in energy efficiency , it's necessary to integrate dynamic energy management with occupant behavior change. As plans were
Nome Offshore Mining Information
Lands Coal Regulatory Program Large Mine Permits Mineral Property and Rights Mining Index Land potential safety concerns, prevent overcrowding, and provide for efficient processing of the permits and Regulatory Program Large Mine Permitting Mineral Property Management Mining Fact Sheets Mining Forms APMA
Alternative Fuels Data Center: Managing Workplace Charging
able to address challenges swiftly and efficiently. Additional areas to consider when developing attendants, security personnel, or employee self-monitoring. When considering enforcement and security stations after regular business hours when the identified enforcement personnel may not be available
Sustainable Mobility Initiative | Transportation Research | NREL
optimize mobility and significantly reduce related energy consumption. This concept of an intelligent measures to explore these technologies' effects on transportation energy use, emissions, and overall system . Efficient driving with smoother starts, stops, and accelerations to reduce energy consumption and
Jacob.Kruger@nrel.gov | 303-275-4081 Research Interests Algal growth systems targeting high-efficiency Hydrotalcite Catalysts," ACS Catalysis (2016) "Aqueous-Phase Fructose Dehydration Using Brønsted ) "Elucidating the Roles of Zeolite H-BEA in Aqueous-Phase Fructose Dehydration and HMF Rehydration
area, which includes work on whole building energy modeling, cost-based optimization, model accuracy optimization tool used to provide support for the Building America program's teams and energy efficiency goals Colorado graduate student exploring enhancements to building optimization in terms of robustness and speed
Aviation Weather Program is to couple the art and science of meteorology to enhance the safe and efficient significant weather forecasts crossing international boundaries. Keeping Our National Airspace System Safe The System Newsletter Aviation Weather Center (AWC) Alaska Aviation Weather Unit (AAWU) Space Environment
Fuel Combustion and Engine Performance | Transportation Research | NREL
. Through modeling, simulation, and experimental validation, researchers examine what happens to fuel inside combustion and engine research activities include: Developing experimental and simulation research platforms develop and refine accurate, efficient kinetic mechanisms for fuel ignition Investigating low-speed pre
Alternative Fuels Data Center: Batteries for Hybrid and Plug-In Electric
most portable consumer electronics such as cell phones and laptops because of their high energy per unit mass relative to other electrical energy storage systems. They also have a high power-to-weight ratio, high energy efficiency, good high-temperature performance, and low self-discharge. Most
Hybrid Tandem Solar Cells | Photovoltaic Research | NREL
Hybrid Tandem Solar Cells Hybrid Tandem Solar Cells To achieve aggressive cost reductions in photovoltaics (PV) beyond the 6¢/kWh SunShot Initiative 2020 goal, module efficiency must be increased beyond on a silicon platform and that aim to provide viable prototypes for commercialization. PV Research
Alternative Fuels Data Center: New Jersey Utility Saves With Alternative
electric car. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a FuelA> Jersey Utility Saves With Alternative Fuel to someone by E-mail Share Alternative Fuels . For information about this project, contact New Jersey Clean Cities Coalition. Download QuickTime
Alternative Fuels Data Center: Colorado Airport Relies on Natural Gas
electric car. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a Fueling StationsA> Colorado Airport Relies on Natural Gas Fueling Stations to someone by E-mail system. For information about this project, contact Denver Metro Clean Cities Coalition. Download
Alternative Fuels Data Center: Phoenix Utility Fleet Drives Smarter with
electric car. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a BiodieselA> Phoenix Utility Fleet Drives Smarter with Biodiesel to someone by E-mail Share ... Aug. 26, 2017 Phoenix Utility Fleet Drives Smarter with Biodiesel Watch how a utility company in
to the most energy-efficient data center in the world. Learn more. Our People Our employees embody conscientious people, meet some NRELians. The team of people here are constantly pushing me. They're some of the most intelligent and passionate people I've ever worked with, and they encourage me every day to be my
NREL Scientists Demonstrate Remarkable Stability in Perovskite Solar Cells
environmentally stable, high-efficiency perovskite solar cell, bringing the emerging technology a step closer to needed to make the devices durable enough for long-term use. NREL's unencapsulated solar cell-a cell used Unencapsulated Perovskite Solar Cells for >1000 Hours of Operational Stability." "A solar cell in
Labs21 Approach to Climate Neutral Campuses | Climate Neutral Research
Campuses | NREL Labs21 Approach to Climate Neutral Campuses Labs21 Approach to Climate Neutral included a whole-building approach to energy efficiency in laboratory buildings. This website takes that approach a step further in carrying out campus-wide energy- and carbon-reduction strategies. The
and Vehicle Efficiency Fees Beginning January 1, 2020, all-electric vehicle (EV) owners must pay an annual fee of $110. Beginning January 1, 2022, EV owners must pay a fee of $115. Medium-speed EV owners must pay an annual fee of $58. All other vehicles must pay an annual fee in the following amounts
Alternative Fuels Data Center: Active Transit
: Active Transit on AddThis.com... More in this section... Idle Reduction Parts & Equipment Maintenance Reduction Parts & Equipment Maintenance Driving Behavior Fleet Rightsizing System Efficiency Locate
Tables Fuel-Efficient Vehicle Acquisition Requirements The Maine State Purchasing Agent may not purchase purposes the State Purchasing Agent designates are exempt from this requirement. (Reference Maine Revised
Use and Fuel-Efficient Vehicle Requirements State-owned vehicle fleets must implement petroleum by petroleum displaced through the use of biodiesel, ethanol, other alternative fuels, the use of
laboratory's understanding of capacity value in modern power systems and enjoys applying probabilistic systems efficiency and load management opportunities Education M.E.S. in Environment and Resource Studies, University
EERE: Alternative Fuels Data Center Home Page
facility safe with a first-of-its-kind CNG Maintenance Facility Modifications Handbook. Find Fleet & Equipment Maintenance Driving Behavior Fleet Rightsizing System Efficiency Locate Stations Search
Sustainable Transportation - Continuum Magazine | NREL
revolutionize fleet sustainability and energy efficiency. Putting On the Brakes to Protect America's Natural Treasures Putting On the Brakes to Protect America's Natural Treasures National Parks Initiative greens
Big Data | Transportation Research | NREL
Designs Leveraging Fleet DNA data to characterize real-world duty cycles for urban delivery vehicles, NREL -extended electric vehicles for urban delivery applications, targeting efficiency improvements of 50
Energy, operated by the Alliance for Sustainable Energy, LLC. NREL U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Alliance for Sustainable Energy, LLC Content Last Updated
Wide Bandgap Technology Enhances Performance of Electric-Drive Vehicles |
, WBG materials/devices enable lighter, more compact, and more efficient power electronics for vehicles, and increased electric vehicle adoption by consumers. Wide bandgap power electronics devices power electronics component size and potentially reduce system or component-level cost, while improving
Fuels and Engines | Transportation Research | NREL
technologies can influence vehicle efficiency and use through changes in vehicle designs, driving habits, and -compound cetane number data through December 2016, including previously unpublished values that are results and agricultural waste, for use in transportation applications in California. Techno-economic analyses
Energy Systems Integration Facility | NREL
influence how electric power systems operate far into the future. LEARN MORE Sharing Knowledge Recent 2017 Journal Article Wind and Solar Resource Data Sets Technical Report Innovation Incubator , Liquid Submerged Server for High-Efficiency Data Centers News and Announcements News More News News
Defense.gov Special Report: Hagel Bids Farewell
Nuclear Enterprise Military Health System POW/MIA Accounting Military Justice System Staff Efficiencies receiving mental health care. POW/MIA Accounting Hagel directed the consolidation of three DoD entities concerned with personnel accounting responsibilities into one organization. This will help the department
Interactions between human behavior and the environment Environmental and energy market impacts of energy and environmental policy Impacts of climate change on global energy supply and demand Education M.E.Sc Environmental . 2014. State Energy Efficiency Resource Standards design, status, and impacts. Golden, CO: National
SUNREL Related Links | Buildings | NREL
SUNREL Related Links SUNREL Related Links DOE Simulation Software Tools Directory a directory of 301 building software tools for evaluation of energy efficiency, renewable energy, and sustainability in buildings. TREAT Software Program a computer program that uses SUNREL and is designed to provide
Materials and Chemical Science and Technology | Research | NREL
Applications and Performance Developing high-efficiency crystalline PV, measuring PV cell/module performance Cells and Hydrogen Program Developing, integrating, and demonstrating hydrogen production/delivery /storage through core programs and EFRCs Point of Contact Bill Tumas MCST Research Advisors/Fellows Senior
Video: NREL and Buildings Research - Continuum Magazine | NREL
solutions to improve the energy efficiency of both residential and commercial buildings, and to accelerate the integration of clean energy technologies with buildings. NREL's commercial buildings research focuses on providing large institutional and private sector commercial building owners with tools
efficiency and renewable energy projects. His patent on the Renewable Energy Optimization (REO) method of distribution function for time-series simulation Analytical and numerical optimization Project delivery with System Operations and Maintenance: 2nd Edition, 2016, NREL/Sandia/Sunspec Alliance SuNLaMP PV O&M
Hammond Photo of Steven Hammond Steve Hammond Center Director II-Technical Steven.Hammond@nrel.gov | 303-275-4121 Steve Hammond is director of the Computational Science Center at the National Renewable includes leading NREL's efforts in energy efficient data centers. Prior to NREL, Steve managed the
Isothermal Battery Calorimeters | Transportation Research | NREL
only calorimeters in the world capable of providing the precise thermal measurements needed for safer battery energy efficiency with 98% accuracy and provide precise measurements through complete thermal make it possible for battery developers to predict thermal performance before installing batteries in
Wind-to-Hydrogen Project | Hydrogen and Fuel Cells | NREL
. Research Focus NREL's research focuses on: Exploring system-level integration issues related to multiple to enable cost evaluations/reductions and efficiency improvements Exploring operational challenges
Photoluminescence Spectroscopy | Photovoltaic Research | NREL
capabilities include: various excitation wavelengths that allow for varying levels of volume excitation; a efficiency. Impurity Levels and Defect Detection. The PL spectrum at low sample temperatures often reveals
Reduced Registration Fee for Fuel-Efficient Vehicles A new motor vehicle with a U.S. Environmental . For more information, see the District of Columbia Department of Motor Vehicles website. (Reference
and combustion kinetics, fuel effects on engine efficiency, and the impact of new fuels on air , and fuel effects on pollutant emissions Education Ph.D., Chemical Engineering, University of Wyoming
Argonne partners with industry on nuclear reactor work | Argonne National
October 18, 2017 Next article: Researchers create successful predictions of combustion reaction rates  CRIChain Reaction Innovations CIComputation Institute IACTInstitute for Atom-Efficient Chemical
NREL: News - Expo to Show Consumers How to Cut Energy Use
Expo to Show Consumers How to Cut Energy Use Golden, Colo., June 6, 2002 Consumers can learn how to save energy and money at home from experts who specialize in energy efficient and renewable energy products and services at the Consumer Energy Expo June 21 - 22. The Expo is hosted by the U.S. Department
Alternative Fuels Data Center: Driving Tips for MPG
Corporation Adds Propane Buses to Its Fleet Nov. 11, 2016 Photo of a man charging a car. Sacramento Powers up with Electric Vehicles Oct. 3, 2016 Photo of a car. Cleveland Car Dealership Working Toward a More Corridor Now Open Feb. 21, 2015 Photo of an electric car. College Students Engineer Efficient Vehicles in
Job Priorities on Peregrine | High-Performance Computing | NREL
allocation when run with qos=high. Requesting a Node Reservation If you are doing work that requires real scheduler more efficiently plan resources for larger jobs. When projects reach their allocation limit, jobs associated with those projects will run at very low priority, which will ensure that these jobs run only when
Alternative Fuels Data Center: Yellow Cab Converts Taxis to Propane in
electric car. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a Columbus, OhioA> Yellow Cab Converts Taxis to Propane in Columbus, Ohio to someone by E-mail how Yellow Cab is overhauling their fleet in Columbus, Ohio, with propane power. For information about
Alternative Fuels Data Center: MedCorp Fuels Emergency Vehicles With
. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a police Propane in OhioA> MedCorp Fuels Emergency Vehicles With Propane in Ohio to someone by E-mail Television Related Videos Photo of a car Hydrogen Powers Fuel Cell Vehicles in California Nov. 18, 2017 Photo
Alternative Fuels Data Center: Los Angeles Public Works Fleet Converts to
electric car. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a Natural GasA> Los Angeles Public Works Fleet Converts to Natural Gas to someone by E-mail Share . For information about this project, contact Los Angeles Clean Cities Coalition. Download QuickTime
High-Performance Computing Data Center Cooling System Energy Efficiency |
approaches involve a cooling distribution unit (CDU) (2), which interfaces with the facility cooling loop and to the energy recovery water (ERW) loop (5), which is a closed-loop system. There are three heat rejection options for this IT load: When possible, heat energy from the energy recovery loop is transferred
Breakdown Breakthrough: NREL Finds Easier Ways to Deconstruct Biomass |
soften biomass. Photo by Dennis Schroeder, NREL If there's an easier, more efficient method, science will Dennis Schroeder, NREL The process normally used to deconstruct biomass, called simultaneous in NREL's Biosciences Center. Photo by Dennis Schroeder, NREL New Technology Could Provide Boost to
Computer-Aided Design Speeds Development of Safe, Affordable, and Efficient
Systems Integration Facility's 3-D visualization room. Photo by Dennis Schroeder, NREL 41705 Computer from industry, academia, national laboratories, and other research institutions. Photo by Dennis Dennis Schroeder, NREL 41483 Bringing CAEBAT to the Next Level CAEBAT teams are now working to
Partnerships Drive New Transportation Solutions | News | NREL
efficiency challenges. Photo by Dennis Schroeder, NREL Hybrid car sales have taken off in recent years, with by Dennis Schroeder, NREL "NREL's connection to the marketplace and deployment, its strong Systems Integration Facility. Photo by Dennis Schroeder, NREL NREL leverages partnerships to deepen its
Accomplishments in Photovoltaic Manufacturing R&D | Photovoltaic Research |
made that significantly reduced the cost of solar modules while increasing their reliability and -area efficiency. Manufacturing Processes Half the cost of producing a solar module is incurred in wafer project partners marked significant progress in module cost reduction. A few notable examples follow
Quantum and Carbon Nanomaterials | Chemistry and Nanoscience Research |
acceptors in composites with thiophene-based conjugated polymers, ultimately determining that the free interface to efficiently dissociate excitons and spatially separate long-lived free carriers, but pointed toward a dependence of the free-carrier yield on the energetic driving force at the interface. By tuning
Not Too Hot, Not Too Cold - Continuum Magazine | NREL
management technologies increase vehicle energy efficiency and performance while reducing costs. Mythological automobiles. Issues with thermal management cause some of these limitations. A photo of a white disk submerged sector petroleum consumption. Manufacturers and operators alike are looking to new thermal management
High-Performance Computing Data Center Warm-Water Liquid Cooling |
Computational Science | NREL Warm-Water Liquid Cooling High-Performance Computing Data Center Warm-Water Liquid Cooling NREL's High-Performance Computing Data Center (HPC Data Center) is liquid water Liquid cooling technologies offer a more energy-efficient solution that also allows for effective
South Coast Air Quality Management District Truck Testing | Transportation
movement of cargo containers, also known as drayage, creates substantial air pollution in the vicinity of and U.S. Hybrid Corporation, transport cargo containers between the port complex and local rail yards and distribution centers. Utilizing advanced batteries and high-efficiency components, the electric
greenhouse effect. Hydrogen has very high energy for its weight, but very low energy for its volume, so new make a hydrogen economy a reality include: Fuel Cells - Improving fuel cell technology and materials needed for fuel cells. Production - Developing technology to efficiently and cost-effectively make
up zip code Case Studies Weatherization: Improving Home Safety and Reducing Your Energy Bill home energy efficient? Your House is a System Living Off The Sun, Or, No Electricity Bill Kermit was Cottage Energy Blogs 5 Most Effective Ways to Save on Your Energy Bill Updating Guest Bathroom With Energy
NREL Partners with California to Accelerate Advanced Energy Communities |
, heating, and or cooling Smart energy management systems for residential, commercial and industrial the residences, commercial and industrial buildings. Visit the NREL website to learn about how NREL's efficiency of both residential and commercial buildings, communities, and districts. -Linh Truong Mission
Energy Systems Integration News | Energy Systems Integration Facility |
for its novel approach to energy reduction. The ultra-efficient ESIF data center features a chiller "chips to bricks" approach to sustainability integrates the data center into the facility systems, rather than trying to optimize each in isolation. Key to the approach was collaboration with
Alternative Fuels Data Center: Electricity
efficiency. Using electricity to power vehicles can have significant energy security and emissions benefits . Icon of an information sign. Basics Find information about using electricity as a vehicle fuel Considerations Explore the benefits and considerations of using electricity as a vehicle fuel. Icon of a fueling
career at NREL in 1995 by conducting scanning tunneling microscope (STM) studies of the atomic structure revealed a new strain-induced step structure and contributed to the development of world-record-efficiency NREL's Computational Materials Science team, probing the atomic structure of dislocations in III-V
Energy Storage | Transportation Research | NREL
, and safe energy storage systems to power the next generation of electric-drive vehicles (EDVs). While lasting, safe, and operate at maximum efficiency in a wide range of driving conditions and climates. The Consumers, Industry, and the Environment As manufacturers develop new electric-drive vehicles, NREL acts as
Marine, Tropical, and Tsunami Services
essential to the conduct of safe and efficient maritime operations and for the protection of the marine - Managed by National Data Buoy Center (NDBC) Awareness Weeks: Tsunami Preparedness Campaigns National Safe Prepared and Stay Safe! Tsunami Preparedness: Applying Lessons from the Past Pacific Tsunami Warning Center
Technical Assistance for States | State, Local, and Tribal Governments |
on energy efficiency and renewable energy policies and issues for state and local government decision issues for state and local government decision makers. The expert assistance is intended to support legislators, regulators, state agencies, and their staff members in making informed decisions about solar
years and has contributed greatly to world-record efficiencies in various photovoltaic technologies is a world-renowned expert in the fields of multijunction PV, concentrator PV, and PV reliability Publications Photo of Mark O'Malley Mark O'Malley SENIOR RESEARCH FELLOW Mark O'Malley is a world authority on
NREL Leads Energy Systems Integration - Continuum Magazine | NREL
performance data to manage and optimize campus energy use. Integrated Solutions for a Complex Energy World 03 Integrated Solutions for a Complex Energy World Energy systems integration optimizes the design and efficient data centers in the world. Sustainability through Dynamic Energy Management Sustainability through
About Us - Employment | Alaska Division of Geological & Geophysical Surveys
Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska researching Alaska's geology and implementing technological tools to efficiently collect, interpret, publish
Alternative Fuels Data Center: Transportation System Efficiency
energy use. Transportation planners and corporate decision makers can implement combinations of these corporate decision makers can help employees telework to conserve fuel. Maps & Data Average Annual Fuel
and the environment. The Guide provides basic information about the properties of uranium compounds understand the unique challenges involved in managing DOE's inventory of depleted UF6 in a safe and efficient
Alternative Fuels Data Center: Hybrid Electric Horsepower for Kentucky
efficiency and be environmentally conscious. [It] will also provide students with learning opportunities said. "This project will also provide students with learning opportunities across many subject
(HVPE) growth of III-V materials for high-efficiency 1-sun to low-concentration solar cell applications growth, 2011. Timothy, J.C., D.L. Young, and T.A. Gessert, Modeling, Characterization, and Properties of
Levi is an expert in ocean turbulence, tidal processes, and surface waves. He has more than 10 years of the state identify renewable energy and energy efficiency opportunities that fit the climate and met
Mountain Retail Stores Become Showcase for Solar Energy
-seam metal roof, a transpired solar collector (solar wall), daylighting, energy efficient windows and during daytime hours. The Bighorn Center's final design includes clerestory windows for daylighting and a
Parade of Homes Display Features Energy-Saving Ideas
Parade of Homes Display Features Energy-Saving Ideas For more information contact: George Douglas Energy's (DOE) National Renewable Energy Laboratory will showcase energy efficient and solar energy ideas
Operational Changes Are Enhancing System Flexibility | Energy Analysis |
) improves system efficiency, reduces the amount of reserves required to balance the system, and enables balance. In addition, expanded balancing footprints can enhance the benefits of faster dispatch, reducing
Clean Energy Technologies Ready for Climate Change Challenge
environmental problems is well founded, the director of the National Renewable Energy Laboratory said today renewable energy and energy efficiency technologies in solving environmental problems is clear, Truly said
NREL: News - Innovative Utility Takes to the Wind
dependence on fossil fuels. Each Iowa Energy Tag represents the environmental benefits of 2,500 kilowatt , energy efficient buildings, geothermal energy and hydrogen fuel cells. For more information, please
Estimation of flow properties using surface deformation and head data: A trajectory-based approach
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vasco, D.W.
2004-07-12
A trajectory-based algorithm provides an efficient and robust means to infer flow properties from surface deformation and head data. The algorithm is based upon the concept of an ''arrival time'' of a drawdown front, which is defined as the time corresponding to the maximum slope of the drawdown curve. The technique involves three steps: the inference of head changes as a function of position and time, the use of the estimated head changes to define arrival times, and the inversion of the arrival times for flow properties. Trajectories, computed from the output of a numerical simulator, are used to relatemore » the drawdown arrival times to flow properties. The inversion algorithm is iterative, requiring one reservoir simulation for each iteration. The method is applied to data from a set of 14 tiltmeters, located at the Raymond Quarry field site in California. Using the technique, I am able to image a high-conductivity channel which extends to the south of the pumping well. The presence of th is permeable pathway is supported by an analysis of earlier cross-well transient pressure test data.« less
Alternative Fuels Data Center: Central Ohio Turns Trash Into Natural Gas
electric car. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a Authority of Central Ohio turns trash into compressed natural gas for fleet fuel. For information about this FuelEconomy.gov. Provided by Maryland Public Television Related Videos Photo of a car Electric Vehicles Charge up
NREL Establishes World Record for Solar Hydrogen Production | News | News |
acid/water solution (electrolyte) where the water-splitting reaction occurs to form hydrogen and oxygen efficiency and to partially protect the critical underlying layers from the corrosive electrolyte solution
Energy Saving Buildings Win National and Local Honors
for its 1997 Energy Efficiency Award in the New Construction category. The award recognizes the annual energy consumption by 30-70 percent. The building's design and construction were a collaborative
Solar Market Research and Analysis | Solar Research | NREL
stakeholder engagement, NREL's Solar Market Research and Analysis efforts further solar technologies' role in technologies' role in supporting a more efficient and better performing U.S. electricity system. Learn more
Pacific Gas & Electric Plug-In Hybrid Electric Utility Truck Testing |
improving efficiency and decreasing emissions during various modes of operation NREL results will help issues and requirements associated with vehicle operation, and fine-tune the design of such vehicles
for a variety of energy efficiency improvements, including AFV conversions and incremental costs, with cover up to 100% of the project costs ranging from $50,000 to $1 million and must be repaid after one
Materials Flow through Industry Supply Chain Modeling Tool | Advanced
efficiency. It also performs supply chain scale analyses to quantify the impacts and benefits of next , read Evaluating opportunities to improve material and energy impacts in commodity supply chains
(HEVs). FFVs are defined as automobiles or light trucks that operate on either gasoline or 85% ethanol (E85) fuel. Fuel-efficient HEVs are defined as automobiles or light trucks that use a gasoline or
Alternative Fuels Data Center: Natural Gas Fueling Station Locations
or ZIP code or along a route in the United States. Loading alternative fueling station locator Fleet Rightsizing System Efficiency Locate Stations Search by Location Map a Route Laws & Incentives
NREL: News - Energy Secretary Abraham Welcomes College Students Who will
is a team competition among universities to design and build the most energy-efficient solar-powered Decathlon, a team must blend aesthetics and modern conveniences with maximum energy production and National Mall marks a significant step forward in innovative residential design, and advanced, energy
NREL Engineer Gets Lifetime Achievement Award
the design of energy efficient buildings. Douglas Balcomb has been selected to receive the 1998 ;The Coming Revolution in Building Design." Balcomb was chosen for the PLEA honor for his contribution over 20 years to the literature in the field of passive solar, low-energy building design. He also
Photovoltaics | Chemistry and Nanoscience Research | NREL
Office of Energy Efficiency and Renewable Energy. Specific areas of active research include: Organic performance and lifetime of organic solar cells. We have had an ongoing focus on developing new contact different duty cycles. Learn more about NREL's research on organic PV. Perovskites We are seeking to make
Berkeley Lab - Materials Sciences Division
demonstrated a way to make it work. New Discovery Could Improve Organic Solar Cell Performance MSD's Center for lead to gains in efficiency for organic solar cells Rob Ritchie featured in Nature Communications Discover Material Ideal for Smart Photovoltaic Windows â² New Discovery Could Improve Organic Solar Cell
NREL Solar Technology Will Warm Air at 'Home' | News | NREL
. "That's one of those moments when you realized you are obviously going in the right direction when efficient solar collectors," Chuck Kutscher, principal engineer and group manager of the Thermal Systems Group, said. "These collectors can get 75 to 80 percent of the energy of the sunlight
ResStock - Targeting Energy and Cost Savings for U.S. Homes | NREL
ResStock - Targeting Energy and Cost Savings for U.S. Homes Science and Technology Highlights Highlights in Research & Development ResStock - Targeting Energy and Cost Savings for U.S. Homes Key discovered $49 billion in potential annual utility bill savings through cost-effective energy efficiency
NREL to Lead New Consortium to Improve Reliability and Performance of Solar
for photovoltaics (PV) and lower the cost of electricity generated by solar power. The Durable Module the cost of electricity from photovoltaics." The Energy Department's Office of Energy Efficiency , DuraMat will address the substantial opportunities that exist for durable, high-performance, low-cost
Well-Designed Wholesale Electricity Markets Support System Flexibility |
electricity markets drive efficient solutions to meet reliability needs in a least-cost manner, and they can service (which is typically provided by conventional generators as a part of interconnection through cost variable generation and load (net load) economically and reducing use of regulating reserves-cost
Alternative Fuels Data Center: Alternative Fuels Help Ensure America's
key players from the start. For example, a strategic partnership with Black Bear Solar Institute led is replacing its fleet vehicles with efficient and alternative fuel vehicles. For example, in recent deploying seven propane mowers, thanks to a donation from the Propane Education & Research Council (PERC
NREL Bridges Fuels and Engines R&D to Maximize Vehicle Efficiency and
innovation-from fuel chemistry, conversion, and combustion to the evaluation of advanced fuels in actual -cylinder engine for advanced compression ignition fuels research will be installed and commissioned in the vehicle performance and emissions research, two engine dynamometer test cells for advanced fuels research
High-Performance Computing Data Center | Computational Science | NREL
liquid cooling to achieve its very low PUE, then captures and reuses waste heat as the primary heating dry cooler that uses refrigerant in a passive cycle to dissipate heat-is reducing onsite water Measuring efficiency through PUE Warm-water liquid cooling Re-using waste heat from computing components
NREL and Partners Highlight Collaboration and Explore Future During Partner
districts, exascale computing, more efficient photovoltaics, and next-generation wind turbine blades, to blades on site? What does this do to our grid?" At sessions across NREL's South Table Mountain as the Solar Energy Research Institute (SERI), the lab and its research partners have helped shape
Zion's New Visitor Center a Model of Energy Efficiency
million people a year visit the park, overwhelming the scenic canyon with traffic, frustrating park-goers comes in through clerestory and other windows. When there is not enough sunlight, the building's energy the windows from the summer sun. When the clerestory windows are open, cooler air naturally flows
Perovskite Patent Portfolio | Photovoltaic Research | NREL
deposition of high-quality perovskite films. These techniques have been published in multiple peer-reviewed substrates that are suitable for high-throughput manufacturing and that can maximize the yield of the % to 3% increase in conversion efficiency when compared to a MAPbI3 film prepared with a standard
Alternative Fuels Data Center: Availability of Hybrid and Plug-In Electric
AddThis.com... More in this section... Electricity Basics Benefits & Considerations Stations Vehicles electricity to improve fuel efficiency. Pre-Owned Vehicles Learn about buying and selling pre-owned and plug-in electric vehicles. Learn more about the benefits and considerations of electricity as a
NREL, SPI Solar and Trimark Optimize Parabolic Trough Receiver Performance
(CSP) plants. Photo of parabolic trough receiver equipment in a laboratory Photo by Dennis Schroeder Receivers in CSP plants take a lot of abuse, from dramatic temperature changes to numerous mechanical conditions can lead to big improvements in the overall efficiency of CSP plants
NREL Fuels and Engines Research: Maximizing Vehicle Efficiency and
Laboratory, we analyze the effects of fuel chemistry on ignition and the potential emissions impacts. Our lab research. It can be used to investigate fuel chemistry effects on current and near-term engine technology , independent control allows for deeper interrogation of fuel effects on future-generation engine strategies
Maryland | Midmarket Solar Policies in the United States | Solar Research |
(RECs). Meter aggregation: Virtual net metering is allowed for agricultural customers, non-profits, and solar PV technology. Mathias Agricultural Energy Efficiency Grant Program Maryland Energy Administration Farms and agricultural businesses are eligible for grants of up to 50% of the system cost, capped at
Alternative Fuels Data Center: Biodiesel Offers an Easy Alternative for
substantial petroleum reductions and cost savings. The University has also purchased a mobile fueling station , particularly because the university chose to implement a relatively unique mobile trailer to fuel their shuttle . The mobile fueling station was the only upfront cost, but Worku says the resulting time efficiencies
;Utilization of Tabula Rasa to stabilize bulk lifetimes in n-Cz silicon for high-performance solar cell /SiOx/pc-Si passivated contacts to n-type Si solar cells." Presented at the 40th IEEE Photovoltaic , and P. Stradins. "Heterojunction rear passivated contact for high efficiency n-Cz Si solar cells
Berkeley Lab - Lawrence Berkeley National Laboratory
nanoparticles that could make solar panels more efficient by converting light usually missed by solar cells into of Methane's Increasing Greenhouse Effect A Berkeley Lab research team tracked a rise in the warming effect of methane - one of the most important greenhouse gases for the Earth's atmosphere - over a 10
| 303-384-7528 Paul is the principal engineer for the Commercial Buildings Research Group and has been at the NREL for 19 years. Prior to this role, he was the group manager for the Commercial Buildings articles related to energy efficiency and zero-energy commercial buildings. Among his many awards, Paul has
Colorado | Midmarket Solar Policies in the United States | Solar Research |
-generators. Systems >10 kW must use a second meter to measure the output. Commercial customers can measures, including solar PV. Colorado Commercial Property Assessed Clean Energy (PACE) Local authorities Colorado: Commercial Rebates for My Business Renewable Energy and Energy Efficiency for Schools Loan
NREL Validates Plug-In Hybrid Truck for Pacific Gas and Electric Company |
Energy Systems Integration Facility | NREL Pacific Gas and Electric Company NREL Validates Plug -In Hybrid Truck for Pacific Gas and Electric Company NREL is evaluating and analyzing a Pacific Gas and Electric Company (PG&E) plug-in hybrid electric utility truck developed by Efficient
NREL Joins Initiative to Boost Power Electronics Energy Efficiency and Job
Electronics and Electric Machines team, which focuses on vehicle component research and development (R&D current silicon-based components in the next five years. The institute will bring partners together to power electronics thermal management and reliability R&D, NREL's research in this area focuses on
MRI, Battelle and Bechtel to Manage National Renewable Energy Lab
Research Institute (MRI), Battelle Memorial Institute and Bechtel Corp. "We believe this new team had won the competition to manage and operate NREL for the next five years. The contract signing next five years, depending on congressional appropriations for renewable energy and energy efficiency
New NREL Research Facility Slashes Energy Use by 66 Percent
Thermal Test Facility, which serves as a showcase of energy-saving features and the home of NREL's cutting technologies now being developed at the Thermal Test Facility will help us reach this goal." The facility energy-efficient building design, NREL's Thermal Test Facility houses sophisticated equipment for
EM&V for Energy Efficiency Policies and Initiatives
Learn how representatives of jurisdictions, companies, and other entities can use evaluation, measurement, and verification (EM&V) in demand-side energy efficiency (EE) investments to achieve intended environmental, energy, and economic goals.
Advanced Vehicles and Fuels Basics | NREL
different ways. For example, we can create designs that will lower a vehicle's weight and aerodynamic drag tires. We can improve the combustion efficiency of the engine. And we can use a different propulsion
procedures to promote the cost-effective use of non-petroleum fuel vehicles and other fleet efficiency improvements. The policies must strive for the use of non-petroleum based fuels at least 90% of the time when
NREL to Assist in Development and Evaluation of Class 6 Plug-in Hybrid
, and emissions, as well as the potential impacts on life-cycle costs, barriers to implementation, and application and maximizing potential energy efficiency, emissions, economic, and performance impacts."
Electric Power Systems Are Profoundly Changing | Energy Analysis | NREL
. Advances in efficiency and smart grid technologies also have the potential to change historical demand installations are increasing. NREL works within these currents of change, and helps shape them to enhance our
NREL/Boeing Spectrolab Team Wins Research and Development Award | News |
approach represents a powerful new technology for designing super-efficient multi-junction solar cells. The results in superior electrical performance. But, with the HEMM approach, the atoms are unevenly spaced
Alternative Fuels Data Center: Hydrogen Basics
; Incentives Hydrogen Basics Hydrogen (H2) is an alternative fuel that can be produced from diverse domestic for domestic production, its fast filling time, and the fuel cell's high efficiency. In fact, a fuel
An assessment of emergency medicine residents' ability to perform in a multitasking environment.
Ledrick, David; Fisher, Susan; Thompson, Justin; Sniadanko, Mark
2009-09-01
Multitasking (MT) is a term often applied to emergency medicine (EM), but it is still poorly understood. In an effort to facilitate MT research in EM, the authors conducted this pilot study to describe EM residents' scores on a Multi-Tasking Assessment Tool (MTAT) and compare these scores with the residents' work efficiency in the emergency department. The authors administered a previously developed test of MT ability to EM residents. They performed a multiple regression analysis to determine the effect of MT ability on resident work efficiency, defining efficiency as the number of relative value units billed per hour. They controlled the analysis for year of training and medical knowledge using as a standard the in-service exam administered by the American Board of Emergency Medicine. Complete data for 35 residents were available for analysis. Work efficiency was multivariately correlated with MTAT scores and year of training (P < .05). Whereas year of training explained the majority of the variance, a resident's MT ability accounted for a smaller but still significant portion. This pilot study further validates the MTAT and lays the groundwork for further research in MT in EM. Resident year of training and MTAT scores explain the variability in resident work efficiency significantly more than medical knowledge. Understanding MT ability may ultimately help in resident selection, education, and remediation as well as career counseling and improvement of practice systems in EM.
27-Year R&D 100 Awards Winning Streak - Continuum Magazine | NREL
the real-time quantum efficiency system. Photo by Dennis Schroeder, NREL 27-Year R&D 100 Awards Mehta, and Peter Rupnowski at the controls of the Optical Cavity Furnace. Photo by Dennis Schroeder signals in solar cells used with Innovalight's Silicon Ink. Photo by Dennis Schroeder, NREL Problem: For
New Ultra-Efficient HPC Data Center Debuts | News | NREL
. Credit: Dennis Schroeder Scientists and researchers at the U.S. Department of Energy's National Renewable supports the HPC data center and ties its waste heat to the rest of the ESIF. Credit: Dennis Schroeder Warm will be accomplished using NREL's HPC. Credit: Dennis Schroeder Expanding NREL's View into the Unseen
Decades After Developing Technology, NREL Sets New Solar-to-Hydrogen Record
recently achieved 16.2% solar-to-hydrogen conversion efficiency. Photo by Dennis Schroeder Innovation is to split water into hydrogen and oxygen. Photo by Dennis Schroeder Photo shows a photoelectrochemical device to split water into hydrogen and oxygen. Photo by Dennis Schroeder Second Look Leads to Record
Window Glazing Types | Efficient Windows Collaborative
of glass. Single Clear Single Tint Double Glazing The following sections on high-performance double fills. Double Clear Double Tint Double High-Solar-Gain Low-E Double Medium-Solar-Gain Low-E Double Low -Solar-Gain Low-E Double High-Solar-Gain Low-E with Roomside (4th surface) Low-E Double Medium-Solar-Gain
NREL's Research Support Facility Certified LEED® Platinum | News | NREL
to sustainable building design and construction. At 222,000 square-feet, the RSF is a model for sustainable, high performance building design that leverages the best in energy efficiency and environmental energy use in commercial buildings that were incorporated in the design of the RSF. NREL researchers are
Alternative Fuels Data Center: Maps and Data
View Graph Graph Download Data Generated_thumb20140811-21276-p5mcbz Average Fuel Economy at Different Road Grades Generated_thumb20140811-21276-p5mcbz Trend of Fuel Economy and Consumption at different at Various Driving Speeds Generated_thumb20170119-11720-1o8tesk Trend of fuel efficiency at different
NREL Technique Leads to Improved Perovskite Solar Cells | News | NREL
), devised a method to improve perovskite solar cells, making them more efficient and reliable with higher according to the skills of the researchers making perovskites at different laboratories, to somewhere cell. The scientists from NREL and SJTU came up with a better method, using what's called the Ostwald
NREL Research Earns Three Prestigious R&D 100 Awards | News | NREL
more cost-effective lithium-ion batteries. "The IBC allows for the development of new thermal battery life and improve safety at an affordable cost. With forecasts of more than half a million hybrid Peter Ralbovsky, Jean-Francois Mauger, and Gilles Widawski. TetraSun's High-Efficiency, Cost-Effective
Inaugural History of the National Center for Photovoltaics | Photovoltaic
technology and disseminating information about photovoltaics (PV) in the United States. When created, the NCPV's long-term goals were for PV modules and systems to reach still higher efficiencies with improved , industry, and other federal programs into a united effort and accelerating the advance of PV as an industry
NREL, Hewlett-Packard Developed Ultra-Efficient, High-Performance Computing
and allows the heat captured from the supercomputer to provide all the heating needs for the Energy Systems Integration Facility. And there's even enough heat left over to melt snow outside on sidewalks during the winter. During the summer, the unused heat can be rejected via cooling towers. R&D
Alternative Fuels Data Center: Natural Gas Fuels School Buses and Refuse
Efficiency March 8, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of a school bus Buses Help Kansas City Save Money Nov. 12, 2011 Metropolitan Utilities District Fuels Vehicles With Electric Shuttle Buses Offer Free Rides in Maryland June 18, 2010 Fisher Coachworks Develops Plug-In
Alternative Fuels Data Center: Biodiesel and Propane Fuel Buses for Dallas
Leads in Alternative Fuel Use and Public Transit Efficiency March 8, 2014 Renzenberger Inc Saves Money Vehicles March 31, 2012 Natural Gas School Buses Help Kansas City Save Money Nov. 12, 2011 Metropolitan Electric Shuttle Buses Offer Free Rides in Maryland June 18, 2010 Fisher Coachworks Develops Plug-In
Alternative Fuels Data Center: South Florida Fleet Fuels with Propane
Alternative Fuel Use and Public Transit Efficiency March 8, 2014 Renzenberger Inc Saves Money With Propane Electric Vehicles March 31, 2012 Natural Gas School Buses Help Kansas City Save Money Nov. 12, 2011 Free Rides in Maryland June 18, 2010 Fisher Coachworks Develops Plug-In Electric Bus in Michigan June 3
IMM Solar Cell Shows Its Versatility - Continuum Magazine | NREL
. Inventing a new type of solar cell is one thing. Setting efficiency records with it and winning major awards add to the achievement. But when one of the world's leading manufacturers of compound semiconductor thin metal foil, and the substrate that the cell was grown on is removed. One advantage of this
Claims for Solar Cell Efficiency Put to Test at NREL | News | NREL
cell. The record was confirmed by AIST. NREL and the other the laboratories testing these high containers with zero oxygen and zero water vapor, and were sealed in chambers that maintained zero oxygen , zero water," Emery said. "As soon as we opened the containers the cells started degrading, so
Emilio Segrè and Spontaneous Fission
fissioned instead. The discovery of fission led in turn to the discovery of the chain reaction that, if material apart before it had a chance to undergo an efficient chain reaction. The possibility of chain reaction. If a similar rate was found in plutonium, it might rule out the use of that element as
Provide Natural Light | Efficient Windows Collaborative
illumination when desired. Providing Balanced Lighting A balance of light is important both for visual comfort protected from excessive light levels. The balance of light in a space depends on the overall number and furnishings. An improved balance of light can be created by providing light from at least two directions, such
Colin A. McMillan Photo of Colin A. McMillan. Colin McMillan Researcher IV-Operations Research Econometrics Research Interests Systems-level energy efficiency analysis Material and energy flows in economies ; Journal of Industrial Ecology 17, no. 5 (October 2013): 700-11. doi:10.1111/jiec.12050 McMillan, C.A., S.J
Solar Home Tour and Exhibitor Showcase Open Doors to Renewable Energy
Information Home Tour and Exhibitor Showcase Open Doors to Renewable Energy Information Golden energy efficiency products and services. The Exhibitor Showcase is open for two days at the NREL Visitors . Oct. 13. The Exhibitor Showcase is free and open to the public. The Denver-area self-guided home tour
Energy Department Launches National Fuel Cell Technology Evaluation Center
technologies by strengthening data collection from fuel cell systems and components operating under real-world also houses one of the most energy efficient data centers in the world. NFCTEC will use a secure work proprietary hydrogen and fuel cell technologies in real-world operation since 2004. To date, NREL has
Senior Research Fellow Wins Major International Science Award | News | NREL
generation (MEG) in semiconductor nanocrystals, also called quantum dots, and recently found efficient MEG in silicon quantum dots. He shares the award with Stefan W. Glunz of the Fraunhofer Institute in Germany
Analysis Reveals Impact of Road Grade on Vehicle Energy Use | News | NREL
of modern automobiles is essential for designing increasingly efficient powertrains. In recent years more information, refer to the conference paper-Contribution of Road Grade to the Energy Use of Modern
Energy Savers brochure reaches milestone and laboratory record
circulation across the country. The cost of printing Energy Savers  which is free to consumers  has been systems. Free copies of Energy Savers are available by calling DOE's Energy Efficiency and Renewable
Alternative Fuels Data Center: Clean Cities Helps the National Mall Cut
Transit Efficiency March 8, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of a Yellowstone National Park Commits to Alternative Fuels Oct. 16, 2010 Propane Buses Save Money for Virginia
Two NREL Scientists Named to Highly Cited Researcher List | News | NREL
photocurrent that has an external quantum efficiency greater than 100 percent when excited with photons from the high energy region of the solar spectrum. Nozik and his NREL colleagues employed quantum dots that
NREL Solar Research Gains Two R&D 100 Awards | News | NREL
Awards July 17, 2008 An ultra-light, highly efficient solar cell and use of ink-jet printing to cells are manufactured in layers by using ink-jet and ultrasonic technology to precisely apply metal
Alternative Fuels Data Center: Utah Paperbox Adds Workplace Charging to
Finance, Utah Paperbox Utah Paperbox (UPB) in Salt Lake City has a strong commitment to energy efficiency purchase each month," said Teri Jensen, vice president of finance for UPB. "And I am not the only
Computing Advances Enable More Efficient Buildings - Continuum Magazine |
-and to visualize and react to the data that's available to them," says Brackney. One example of to tell occupants when to open and close their windows. A screen shot of the Building Agent, showing it has been launched. One of the visualization tools is a floor plan that shows which parts of the
Lightening Soldiers' Loads by Lifting PV Cells onto Flexible Surfaces |
efficiency of cells grown on thick-glass substrates. Reese's challenge has been to combine the best of both CdTe solar cells on flexible glass. "When you grow a CdTe cell, you need to grow it for highest glass, which can withstand high temperatures, was promising, this approach had a drawback. Even flexible
New Buildings Design | Climate Neutral Research Campuses | NREL
over a building's lifetime, energy efficiency represents the lowest cost strategy for reducing energy (ft2*yr) to $16/ft2*yr. This means that if you are designing a new 100,000-ft2 building, it could cost as much as $1.6 million per year to operate. Given this baseline, life cycle cost calculations are
NREL Develops Switchable Solar Window | News | NREL
electricity at a high efficiency have been developed by scientists at the U.S. Department of Energy's National reversibly absorbed into the device. When solar energy heats up the device, the molecules are driven out, and the device is darkened. When the sun is not shining, the device is cooled back down, and the molecules
NREL's Work for the U.S. Navy Illuminates Energy and Cost Savings | News
load controls and whole-building energy efficiency retrofits as good investments for the Navy. " Program Director Steve Gorin said. Advanced power strips, a plug load control technology that cuts power and an office building with capacity for roughly 100 staff. While plug load savings depend on what can
Alternative Fuels Data Center: Propane Powers School Buses in Tuscaloosa,
Efficiency March 8, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of a school bus and Plug-In Electric Vehicles March 31, 2012 Natural Gas School Buses Help Kansas City Save Money Nov Electric Shuttle Buses Offer Free Rides in Maryland June 18, 2010 Electric Trolley Boosts Business in
Alternative Fuels Data Center: Boston Public Schools Moves to Propane
Efficiency March 8, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of a school bus to Alternative Fuel Vehicles June 8, 2012 Natural Gas School Buses Help Kansas City Save Money Nov National Park Commits to Alternative Fuels Oct. 16, 2010 Propane Buses Save Money for Virginia Schools Feb
Alternative Fuels Data Center: New Hampshire Cleans up with Biodiesel Buses
Public Transit Efficiency March 8, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo Help Kansas City Save Money Nov. 12, 2011 Electric Trucks Deliver at Kansas City Schools Sept. 17, 2011 Shuttle Buses Offer Free Rides in Maryland June 18, 2010 Fisher Coachworks Develops Plug-In Electric Bus
Provide Fresh Air | Efficient Windows Collaborative
wall - 22% 23% two openings in adjacent walls 37-45% 37-45% 40-51% two openings in opposite walls 35-42 taller the windows and the higher the ceiling, the more pronounced is this effect. Operable skylights or effect, letting hot air escape from the ceiling level where it accumulates and causing cooler air to be
NREL Manages Program to Transform Mexico's Power Sector | Integrated Energy
. Through 21CPP, NREL is helping Mexico with: Long-range planning of the power system for transmission , generation, and integration of renewable energy How best to operate the electric grid as Mexico increases the deep energy efficiency and smart grid solutions. Impact Mexico is on the brink of a major energy reform
NASA Astrophysics Data System (ADS)
Niu, F.; Taira, T.; Daley, T. M.; Marchesini, P.; Robertson, M.; Wood, T.
2017-12-01
Recent field and laboratory experiments identify seismic velocity changes preceding microearthquakes and rock failure (Niu et al., 2008, Nature; Scuderi et al., 2016, NatureGeo), which indicates that a continuous monitoring of seismic velocity might provide a mean of understanding of the earthquake nucleation process. Crosswell Continuous Active-Source Seismic Monitoring (CASSM) using borehole sources and sensors has proven to be an effective tool for measurements of seismic velocity and its temporal variation at seismogenic depth (Silver, et al, 2007, BSSA; Daley, et al, 2007, Geophysics). To expand current efforts on the CASSM development, in June 2017 we have begun to conduct a year-long CASSM field experiment at the San Andreas Fault Observatory at Depth (SAFOD) in which the preceding field experiment detected the two sudden velocity reductions approximately 10 and 2 hours before microearthquakes (Niu et al., 2008, Nature). We installed a piezoelectric source and a three-component accelerometer at the SAFOD pilot and main holes ( 1 km depth) respectively. A seismic pulse was fired from the piezoelectric source four times per second. Each waveform was recorded 150-ms-long data with a sampling rate of 48 kHz. During this one-year experiment, we expect to have 10-15 microearthquakes (magnitude 1-3) occurring near the SAFOD site, and the data collected from the new experiment would allow us to further explore a relation between velocity changes and the Parkfield seismicity. Additionally, the year-long data provide a unique opportunity to study long-term velocity changes that might be related to seasonal stress variations at Parkfield (Johnson et al., 2017, Science). We will report on initial results of the SAFOD CASSM experiment and operational experiences of the CASSM development.
NASA Astrophysics Data System (ADS)
Zhang, J.; Revil, A.
2015-04-01
The early detection of the oil-water encroachment front is of prime interest during the water flooding of an oil reservoir to maximize the production of oil and to avoid the oil-water encroachment front to come too close to production wells. We propose a new 4-D inversion approach based on the Gauss-Newton approach to invert cross-well resistance data. The goal of this study is to image the position of the oil-water encroachment front in a heterogeneous clayey sand reservoir. This approach is based on explicitly connecting the change of resistivity to the petrophysical properties controlling the position of the front (porosity and permeability) and to the saturation of the water phase through a petrophysical resistivity model accounting for bulk and surface conductivity contributions and saturation. The distributions of the permeability and porosity are also inverted using the time-lapse resistivity data in order to better reconstruct the position of the oil water encroachment front. In our synthetic test case, we get a better position of the front with the by-products of porosity and permeability inferences near the flow trajectory and close to the wells. The numerical simulations show that the position of the front is recovered well but the distribution of the recovered porosity and permeability is only fair. A comparison with a commercial code based on a classical Gauss-Newton approach with no information provided by the two-phase flow model fails to recover the position of the front. The new approach could be used for the time-lapse monitoring of various processes in both geothermal fields and oil and gas reservoirs using a combination of geophysical methods.
NASA Astrophysics Data System (ADS)
Morency, Christina; Luo, Yang; Tromp, Jeroen
2011-05-01
The key issues in CO2 sequestration involve accurate monitoring, from the injection stage to the prediction and verification of CO2 movement over time, for environmental considerations. '4-D seismics' is a natural non-intrusive monitoring technique which involves 3-D time-lapse seismic surveys. Successful monitoring of CO2 movement requires a proper description of the physical properties of a porous reservoir. We investigate the importance of poroelasticity by contrasting poroelastic simulations with elastic and acoustic simulations. Discrepancies highlight a poroelastic signature that cannot be captured using an elastic or acoustic theory and that may play a role in accurately imaging and quantifying injected CO2. We focus on time-lapse crosswell imaging and model updating based on Fréchet derivatives, or finite-frequency sensitivity kernels, which define the sensitivity of an observable to the model parameters. We compare results of time-lapse migration imaging using acoustic, elastic (with and without the use of Gassmann's formulae) and poroelastic models. Our approach highlights the influence of using different physical theories for interpreting seismic data, and, more importantly, for extracting the CO2 signature from seismic waveforms. We further investigate the differences between imaging with the direct compressional wave, as is commonly done, versus using both direct compressional (P) and shear (S) waves. We conclude that, unlike direct P-wave traveltimes, a combination of direct P- and S-wave traveltimes constrains most parameters. Adding P- and S-wave amplitude information does not drastically improve parameter sensitivity, but it does improve spatial resolution of the injected CO2 zone. The main advantage of using a poroelastic theory lies in direct sensitivity to fluid properties. Simulations are performed using a spectral-element method, and finite-frequency sensitivity kernels are calculated using an adjoint method.
NASA Astrophysics Data System (ADS)
Zhang, R.; Borgia, A.; Daley, T. M.; Oldenburg, C. M.; Jung, Y.; Lee, K. J.; Doughty, C.; Altundas, B.; Chugunov, N.; Ramakrishnan, T. S.
2017-12-01
Subsurface permeable faults and fracture networks play a critical role for enhanced geothermal systems (EGS) by providing conduits for fluid flow. Characterization of the permeable flow paths before and after stimulation is necessary to evaluate and optimize energy extraction. To provide insight into the feasibility of using CO2 as a contrast agent to enhance fault characterization by seismic methods, we model seismic monitoring of supercritical CO2 (scCO2) injected into a fault. During the CO2 injection, the original brine is replaced by scCO2, which leads to variations in geophysical properties of the formation. To explore the technical feasibility of the approach, we present modeling results for different time-lapse seismic methods including surface seismic, vertical seismic profiling (VSP), and a cross-well survey. We simulate the injection and production of CO2 into a normal fault in a system based on the Brady's geothermal field and model pressure and saturation variations in the fault zone using TOUGH2-ECO2N. The simulation results provide changing fluid properties during the injection, such as saturation and salinity changes, which allow us to estimate corresponding changes in seismic properties of the fault and the formation. We model the response of the system to active seismic monitoring in time-lapse mode using an anisotropic finite difference method with modifications for fracture compliance. Results to date show that even narrow fault and fracture zones filled with CO2 can be better detected using the VSP and cross-well survey geometry, while it would be difficult to image the CO2 plume by using surface seismic methods.
Multiscale Modeling of Plasmon-Enhanced Power Conversion Efficiency in Nanostructured Solar Cells.
Meng, Lingyi; Yam, ChiYung; Zhang, Yu; Wang, Rulin; Chen, GuanHua
2015-11-05
The unique optical properties of nanometallic structures can be exploited to confine light at subwavelength scales. This excellent light trapping is critical to improve light absorption efficiency in nanoscale photovoltaic devices. Here, we apply a multiscale quantum mechanics/electromagnetics (QM/EM) method to model the current-voltage characteristics and optical properties of plasmonic nanowire-based solar cells. The QM/EM method features a combination of first-principles quantum mechanical treatment of the photoactive component and classical description of electromagnetic environment. The coupled optical-electrical QM/EM simulations demonstrate a dramatic enhancement for power conversion efficiency of nanowire solar cells due to the surface plasmon effect of nanometallic structures. The improvement is attributed to the enhanced scattering of light into the photoactive layer. We further investigate the optimal configuration of the nanostructured solar cell. Our QM/EM simulation result demonstrates that a further increase of internal quantum efficiency can be achieved by scattering light into the n-doped region of the device.
Approximate, computationally efficient online learning in Bayesian spiking neurons.
Kuhlmann, Levin; Hauser-Raspe, Michael; Manton, Jonathan H; Grayden, David B; Tapson, Jonathan; van Schaik, André
2014-03-01
Bayesian spiking neurons (BSNs) provide a probabilistic interpretation of how neurons perform inference and learning. Online learning in BSNs typically involves parameter estimation based on maximum-likelihood expectation-maximization (ML-EM) which is computationally slow and limits the potential of studying networks of BSNs. An online learning algorithm, fast learning (FL), is presented that is more computationally efficient than the benchmark ML-EM for a fixed number of time steps as the number of inputs to a BSN increases (e.g., 16.5 times faster run times for 20 inputs). Although ML-EM appears to converge 2.0 to 3.6 times faster than FL, the computational cost of ML-EM means that ML-EM takes longer to simulate to convergence than FL. FL also provides reasonable convergence performance that is robust to initialization of parameter estimates that are far from the true parameter values. However, parameter estimation depends on the range of true parameter values. Nevertheless, for a physiologically meaningful range of parameter values, FL gives very good average estimation accuracy, despite its approximate nature. The FL algorithm therefore provides an efficient tool, complementary to ML-EM, for exploring BSN networks in more detail in order to better understand their biological relevance. Moreover, the simplicity of the FL algorithm means it can be easily implemented in neuromorphic VLSI such that one can take advantage of the energy-efficient spike coding of BSNs.
Sequenced sorghum mutant library- an efficient platform for discovery of causal gene mutations
USDA-ARS?s Scientific Manuscript database
Ethyl methanesulfonate (EMS) efficiently generates high-density mutations in genomes. We applied whole-genome sequencing to 256 phenotyped mutant lines of sorghum (Sorghum bicolor L. Moench) to 16x coverage. Comparisons with the reference sequence revealed >1.8 million canonical EMS-induced G/C to A...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Messenger, Mike; Bharvirkar, Ranjit; Golemboski, Bill
Public and private funding for end-use energy efficiency actions is expected to increase significantly in the United States over the next decade. For example, Barbose et al (2009) estimate that spending on ratepayer-funded energy efficiency programs in the U.S. could increase frommore » $3.1 billion in 2008 to $$7.5 and 12.4 billion by 2020 under their medium and high scenarios. This increase in spending could yield annual electric energy savings ranging from 0.58% - 0.93% of total U.S. retail sales in 2020, up from 0.34% of retail sales in 2008. Interest in and support for energy efficiency has broadened among national and state policymakers. Prominent examples include {approx}$$18 billion in new funding for energy efficiency programs (e.g., State Energy Program, Weatherization, and Energy Efficiency and Conservation Block Grants) in the 2009 American Recovery and Reinvestment Act (ARRA). Increased funding for energy efficiency should result in more benefits as well as more scrutiny of these results. As energy efficiency becomes a more prominent component of the U.S. national energy strategy and policies, assessing the effectiveness and energy saving impacts of energy efficiency programs is likely to become increasingly important for policymakers and private and public funders of efficiency actions. Thus, it is critical that evaluation, measurement, and verification (EM&V) is carried out effectively and efficiently, which implies that: (1) Effective program evaluation, measurement, and verification (EM&V) methodologies and tools are available to key stakeholders (e.g., regulatory agencies, program administrators, consumers, and evaluation consultants); and (2) Capacity (people and infrastructure resources) is available to conduct EM&V activities and report results in ways that support program improvement and provide data that reliably compares achieved results against goals and similar programs in other jurisdictions (benchmarking). The National Action Plan for Energy Efficiency (2007) presented commonly used definitions for EM&V in the context of energy efficiency programs: (1) Evaluation (E) - The performance of studies and activities aimed at determining the effects and effectiveness of EE programs; (2) Measurement and Verification (M&V) - Data collection, monitoring, and analysis associated with the calculation of gross energy and demand savings from individual measures, sites or projects. M&V can be a subset of program evaluation; and (3) Evaluation, Measurement, and Verification (EM&V) - This term is frequently seen in evaluation literature. EM&V is a catchall acronym for determining both the effectiveness of program designs and estimates of load impacts at the portfolio, program and project level. This report is a scoping study that assesses current practices and methods in the evaluation, measurement and verification (EM&V) of ratepayer-funded energy efficiency programs, with a focus on methods and practices currently used for determining whether projected (ex-ante) energy and demand savings have been achieved (ex-post). M&V practices for privately-funded energy efficiency projects (e.g., ESCO projects) or programs where the primary focus is greenhouse gas reductions were not part of the scope of this study. We identify and discuss key purposes and uses of current evaluations of end-use energy efficiency programs, methods used to evaluate these programs, processes used to determine those methods; and key issues that need to be addressed now and in the future, based on discussions with regulatory agencies, policymakers, program administrators, and evaluation practitioners in 14 states and national experts in the evaluation field. We also explore how EM&V may evolve in a future in which efficiency funding increases significantly, innovative mechanisms for rewarding program performance are adopted, the role of efficiency in greenhouse gas mitigation is more closely linked, and programs are increasingly funded from multiple sources often with multiple program administrators and intended to meet multiple purposes.« less
Active electromagnetic invisibility cloaking and radiation force cancellation
NASA Astrophysics Data System (ADS)
Mitri, F. G.
2018-03-01
This investigation shows that an active emitting electromagnetic (EM) Dirichlet source (i.e., with axial polarization of the electric field) in a homogeneous non-dissipative/non-absorptive medium placed near a perfectly conducting boundary can render total invisibility (i.e. zero extinction cross-section or efficiency) in addition to a radiation force cancellation on its surface. Based upon the Poynting theorem, the mathematical expression for the extinction, radiation and amplification cross-sections (or efficiencies) are derived using the partial-wave series expansion method in cylindrical coordinates. Moreover, the analysis is extended to compute the self-induced EM radiation force on the active source, resulting from the waves reflected by the boundary. The numerical results predict the generation of a zero extinction efficiency, achieving total invisibility, in addition to a radiation force cancellation which depend on the source size, the distance from the boundary and the associated EM mode order of the active source. Furthermore, an attractive EM pushing force on the active source directed toward the boundary or a repulsive pulling one pointing away from it can arise accordingly. The numerical predictions and computational results find potential applications in the design and development of EM cloaking devices, invisibility and stealth technologies.
Zhu, Yanan; Ouyang, Qi; Mao, Youdong
2017-07-21
Single-particle cryo-electron microscopy (cryo-EM) has become a mainstream tool for the structural determination of biological macromolecular complexes. However, high-resolution cryo-EM reconstruction often requires hundreds of thousands of single-particle images. Particle extraction from experimental micrographs thus can be laborious and presents a major practical bottleneck in cryo-EM structural determination. Existing computational methods for particle picking often use low-resolution templates for particle matching, making them susceptible to reference-dependent bias. It is critical to develop a highly efficient template-free method for the automatic recognition of particle images from cryo-EM micrographs. We developed a deep learning-based algorithmic framework, DeepEM, for single-particle recognition from noisy cryo-EM micrographs, enabling automated particle picking, selection and verification in an integrated fashion. The kernel of DeepEM is built upon a convolutional neural network (CNN) composed of eight layers, which can be recursively trained to be highly "knowledgeable". Our approach exhibits an improved performance and accuracy when tested on the standard KLH dataset. Application of DeepEM to several challenging experimental cryo-EM datasets demonstrated its ability to avoid the selection of un-wanted particles and non-particles even when true particles contain fewer features. The DeepEM methodology, derived from a deep CNN, allows automated particle extraction from raw cryo-EM micrographs in the absence of a template. It demonstrates an improved performance, objectivity and accuracy. Application of this novel method is expected to free the labor involved in single-particle verification, significantly improving the efficiency of cryo-EM data processing.
The prehospital emergency care system in Mexico City: a system's performance evaluation.
Peralta, Luis Mauricio Pinet
2006-01-01
Mexico City has one of the highest mortality rates in Mexico, with non-intentional injuries as a leading cause of death among persons 1-44 years of age. Emergency medical services (EMS) in Mexico can achieve high levels of efficiency by offering high quality medical care at a low cost through adequate system design. The objective of this study was to determine whether the prehospital EMS system in Mexico City meets the criteria standards established by the American Ambulance Association Guide for Contracting Emergency Medical Services (AAA Guide) for highly efficient EMS systems. This retrospective, descriptive study, evaluated the structure of Mexico City's EMS system and analyzed EMS response times, clinical capacity, economic efficiency, and customer satisfaction. These results were compared with the AAA guide, according to the soc ial, economic, and political context in Mexico. This paper describes the healthcare system structure in Mexico, followed by a description of the basic structure of EMS in Mexico City, and of each tenet described in the AAA guide. The p aper includesdata obtained from official documents and databases of government agencies, and operative and administrative data from public and private EMS providers. The quality of the data for response times (RT) were insufficient and widely varied among providers, with a minimum RT of 6.79 minutes (min) and a maximum RT of 61 min. Providers did not define RT clearly, and measured it with averages, which can hide potentially poor performance practices. Training institutions are not required to follow a standardized curriculum. Certifications are the responsibility of the individual training centers and have no government regulation. There was no evidence of active medical control involvement in direct patient care, and providers did not report that quality assurance programs were in place. There also are limited career advancement opportunities for EMS personnel. Small economies of scale may not allow providers to be economically efficient, unit hours are difficult to calculate, and few economic data are available. There is no evidence of customer satisfaction data. Emergency medical services in Mexico City did not meet the AAA requirements for high-quality, prehospital, emergency care. Coordination among EMS providers is difficult to achieve, due, in part, to the lack of: (1) an authoritative structure; (2) sound system design; and (3) appropriate legislation. The government, EMS providers, stakeholders, and community members should work together to build a high quality EMS system at the lowest possible cost.
Isolation of midgut escape mutants of two American genotype dengue 2 viruses from Aedes aegypti
2013-01-01
Background Several studies have shown that American genotype dengue 2 viruses (DENV2) have reduced viral fitness in the mosquito vector, Aedes aegypti, compared to other DENV2 genotypes. Diminished replication efficiency or inability to efficiently traverse membrane barriers encompassing organs such as the midgut or salivary glands are considered major factors negatively impacting viral fitness in the mosquito. Results We analyzed the vector competence of Ae. aegypti for two American DENV2 strains, QR94 and PR159 originating from Mexico and Puerto-Rico, respectively. Both strains infected mosquito midguts following acquisition of infectious bloodmeals. However, DENV2-QR94 and DENV2-PR159 poorly disseminated from the midgut at 7 or 14 days post-bloodmeal (pbm). We detected one virus isolate, EM33, among 31 DENV2-QR94 infected mosquitoes, and one isolate, EM41, among 121 DENV2-PR159 infected mosquitoes, generating high virus titers in mosquito carcasses at 7 days pbm. In oral challenge experiments, EM33 and EM41 showed midgut dissemination rates of 40-50%. Replication efficiency of EM41 in secondary mosquito tissue was similar to that of a dissemination-competent control strain, whereas the replication efficiency of EM33 was significantly lower than that of the control virus. The genome sequence of DENV2-QR94 encoded seven unique amino acids (aa), which were not found in 100 of the most closely related DENV2 strains. EM33 had one additional aa change, E202K, in the E protein. DENV2-PR159 encoded four unique aa residues, one of them E202K, whereas EM41 had two additional aa substitutions, Q77E in the E protein and E93D in NS3. Conclusions Our results indicate that the midgut of Ae. aegypti acts as a selective sieve for DENV2 in which genetically distinct, dissemination-competent virus variants are rapidly selected from the viral quasispecies to be transmitted to vertebrates. PMID:23937713
Reactive Transport Modeling and Geophysical Monitoring of Bioclogging at Reservoir Scale
NASA Astrophysics Data System (ADS)
Surasani, V.; Commer, M.; Ajo Franklin, J. B.; Li, L.; Hubbard, S. S.
2012-12-01
In Microbial-Enhanced-Hydrocarbon-Recovery (MEHR), preferential bioclogging targets the growth of the biofilms (def. immobilized biopolymers with active cells embodied in it) in highly permeable thief zones to enhance sweep efficiency in oil reservoirs. During MEHR, understanding and controlling bioclogging is hindered by the lack of advanced modeling and monitoring tools; these deficiencies contribute to suboptimal performance. Our focus in this study was on developing a systematic approach to understand and monitor bioclogging at the reservoir scale using a combination of reactive transport modeling and geophysical imaging tools (EM & seismic). In this study, we created a realistic reservoir model from a heterogeneous gas reservoir in the Southern Sacramento basin, California; the model well (Citizen Green #1) was characterized using sonic, electrical, nuclear, and NMR logs for hydrologic and geophysical properties. From the simplified 2D log data model, a strip of size 150m x75m with several high permeability streaks is identified for bioclogging simulation experiments. From the NMR log data it is observed that a good linear correlation exist between logarithmic permeability (0.55- 3.34 log (mD)) versus porosity (0.041-0.28). L. mesenteroides was chosen as the model bacteria. In the presence of sucrose, it enzymatically catalyzes the production of dextran, a useful bioclogging agent. Using microbial kinetics from our laboratory experiment and reservoir heterogeneity, a reactive transport model (RTM) is established for two kinds of bioclogging treatments based on whether microbes are present in situ or are supplied externally. In both cases, sucrose media (1.5 M) is injected at the rate of 1 liter/s for 20 days into the center of high permeable strip to stimulate microbes. Simulations show that the high dextran production was deep into the formation from the injection well. This phenomenon can be explained precisely with bacterial kinetics and injection rate. In the in situ treatment, dextran contributes to a maximum porosity reduction of 9.2%, while in the exogenous microbes treatment, the dextran contributes to a maximum of 10.9% porosity reduction. After RTM, the potential geophysical signature of the treatment was evaluated using previously developed experimental rock physics models and realistic forward modeling approaches. Seismic experiments during dextran production performed by Kwan & Ajo-Franklin (2011) were combined with full waveform viscoelastic modeling to yield a predicted attenuation response from the dextran distributions modeled using RTM. The response suggests that crosswell attenuation tomography may be a viable approach for in situ monitoring of the bioclogging process. Modeling the EM response involved the induced polarization (IP) method, where the simulated resistance amplitude and phase changes can be attributed to porosity reduction. Our studies suggest that the IP signals provide a valuable additional indicator. Both geophysical data methods in a joint imaging approach potentially increase the resolution of each geophysical attribute change. Likewise, reactive transport modeling and geophysical monitoring can provide a powerful tool for predicting different bioclogging scenarios in subsurface. The combination may enhance our capabilities of controlling and monitoring the MEHR bioclogging process at reservoir scale.
NASA Astrophysics Data System (ADS)
Will, R. A.; Balch, R. S.
2015-12-01
The Southwest Partnership on Carbon Sequestration is performing seismic based characterization and monitoring activities at an active CO2 EOR project at Farnsworth Field, Texas. CO2 is anthropogenically sourced from a fertilizer and an ethanol plant. The field has 13 CO2 injectors and has sequestered 302,982 metric tonnes of CO2 since October 2013. The field site provides an excellent laboratory for testing a range of monitoring technologies in an operating CO2 flood since planned development is sequential and allows for multiple opportunities to record zero CO2 baseline data, mid-flood data, and fully flooded data. The project is comparing and contrasting several scales of seismic technologies in order to determine best practices for large scale commercial sequestration projects. Characterization efforts include an 85 km2 3D surface seismic survey, baseline and repeat 3D VSP surveys centered on injection wells, cross-well tomography baseline and repeat surveys between injector/producer pairs, and a borehole passive seismic array to monitor induced seismicity. All surveys have contributed to detailed geologic models which were then used for fluid flow and risk assessment simulations. 3D VSP and cross-well data with repeat surveys have allowed for direct comparisons of the reservoir prior to CO2 injection and at eight months into injection, with a goal of imaging the CO2 plume as it moves away from injection wells. Additional repeat surveys at regular intervals will continue to refine the plume. The goal of this work is to demonstrate seismic based technologies to monitor CO2 sequestration projects, and to contribute to best practices manuals for commercial scale CO2 sequestration projects. In this talk the seismic plan will be outlined, progress towards goals enumerated, and preliminary results from baseline and repeat seismic data will be discussed. Funding for this project is provided by the U.S. Department of Energy under Award No. DE-FC26-05NT42591.
Li, Xueming; Zheng, Shawn; Agard, David A.; Cheng, Yifan
2015-01-01
Newly developed direct electron detection cameras have a high image output frame rate that enables recording dose fractionated image stacks of frozen hydrated biological samples by electron cryomicroscopy (cryoEM). Such novel image acquisition schemes provide opportunities to analyze cryoEM data in ways that were previously impossible. The file size of a dose fractionated image stack is 20 ~ 60 times larger than that of a single image. Thus, efficient data acquisition and on-the-fly analysis of a large number of dose-fractionated image stacks become a serious challenge to any cryoEM data acquisition system. We have developed a computer-assisted system, named UCSFImage4, for semi-automated cryo-EM image acquisition that implements an asynchronous data acquisition scheme. This facilitates efficient acquisition, on-the-fly motion correction, and CTF analysis of dose fractionated image stacks with a total time of ~60 seconds/exposure. Here we report the technical details and configuration of this system. PMID:26370395
NASA Astrophysics Data System (ADS)
Kruglyakov, Mikhail; Kuvshinov, Alexey
2018-05-01
3-D interpretation of electromagnetic (EM) data of different origin and scale becomes a common practice worldwide. However, 3-D EM numerical simulations (modeling)—a key part of any 3-D EM data analysis—with realistic levels of complexity, accuracy and spatial detail still remains challenging from the computational point of view. We present a novel, efficient 3-D numerical solver based on a volume integral equation (IE) method. The efficiency is achieved by using a high-order polynomial (HOP) basis instead of the zero-order (piecewise constant) basis that is invoked in all routinely used IE-based solvers. We demonstrate that usage of the HOP basis allows us to decrease substantially the number of unknowns (preserving the same accuracy), with corresponding speed increase and memory saving.
Wang, Huping; Han, Wenyu; Takagi, Junichi; Cong, Yao
2018-05-11
Cryo-electron microscopy (cryo-EM) has been established as one of the central tools in the structural study of macromolecular complexes. Although intermediate- or low-resolution structural information through negative staining or cryo-EM analysis remains highly valuable, we lack general and efficient ways to achieve unambiguous subunit identification in these applications. Here, we took advantage of the extremely high affinity between a dodecapeptide "PA" tag and the NZ-1 antibody Fab fragment to develop an efficient "yeast inner-subunit PA-NZ-1 labeling" strategy that when combined with cryo-EM could precisely identify subunits in macromolecular complexes. Using this strategy combined with cryo-EM 3D reconstruction, we were able to visualize the characteristic NZ-1 Fab density attached to the PA tag inserted into a surface-exposed loop in the middle of the sequence of CCT6 subunit present in the Saccharomyces cerevisiae group II chaperonin TRiC/CCT. This procedure facilitated the unambiguous localization of CCT6 in the TRiC complex. The PA tag was designed to contain only 12 amino acids and a tight turn configuration; when inserted into a loop, it usually has a high chance of maintaining the epitope structure and low likelihood of perturbing the native structure and function of the target protein compared to other tagging systems. We also found that the association between PA and NZ-1 can sustain the cryo freezing conditions, resulting in very high occupancy of the Fab in the final cryo-EM images. Our study demonstrated the robustness of this strategy combined with cryo-EM in efficient and accurate subunit identification in challenging multi-component complexes. Copyright © 2018 Elsevier Ltd. All rights reserved.
Hirshon, Jon Mark; Galvagno, Samuel M; Comer, Angela; Millin, Michael G; Floccare, Douglas J; Alcorta, Richard L; Lawner, Benjamin J; Margolis, Asa M; Nable, Jose V; Bass, Robert R
2016-03-01
Helicopter emergency medical services (EMS) has become a well-established component of modern trauma systems. It is an expensive, limited resource with potential safety concerns. Helicopter EMS activation criteria intended to increase efficiency and reduce inappropriate use remain elusive and difficult to measure. This study evaluates the effect of statewide field trauma triage changes on helicopter EMS use and patient outcomes. Data were extracted from the helicopter EMS computer-aided dispatch database for in-state scene flights and from the state Trauma Registry for all trauma patients directly admitted from the scene or transferred to trauma centers from July 1, 2000, to June 30, 2011. Computer-aided dispatch flights were analyzed for periods corresponding to field triage protocol modifications intended to improve system efficiency. Outcomes were separately analyzed for trauma registry patients by mode of transport. The helicopter EMS computer-aided dispatch data set included 44,073 transports. There was a statewide decrease in helicopter EMS usage for trauma patients of 55.9%, differentially affecting counties closer to trauma centers. The Trauma Registry data set included 182,809 patients (37,407 helicopter transports, 128,129 ambulance transports, and 17,273 transfers). There was an increase of 21% in overall annual EMS scene trauma patients transported; ground transports increased by 33%, whereas helicopter EMS transports decreased by 49%. Helicopter EMS patient acuity increased, with an attendant increase in patient mortality. However, when standardized with W statistics, both helicopter EMS- and ground-transported trauma patients showed sustained improvement in mortality. Modifications to state protocols were associated with decreased helicopter EMS use and overall improved trauma patient outcomes. Copyright © 2015 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.
Adaptation and Promotion of Emergency Medical Service Transportation for Climate Change
Pan, Chih-Long; Chiu, Chun-Wen; Wen, Jet-Chau
2014-01-01
Abstract The purpose of this study is to find a proper prehospital transportation scenario planning of an emergency medical service (EMS) system for possible burdensome casualties resulting from extreme climate events. This project focuses on one of the worst natural catastrophic events in Taiwan, the 88 Wind-caused Disasters, caused by the Typhoon Morakot; the case of the EMS transportation in the Xiaolin village is reviewed and analyzed. The sequential-conveyance method is designed to promote the efficiency of all the ambulance services related to transportation time and distance. Initially, a proposed mobile emergency medical center (MEMC) is constructed in a safe location near the area of the disaster. The ambulances are classified into 2 categories: the first-line ambulances, which reciprocate between the MEMC and the disaster area to save time and shorten the working distances and the second-line ambulances, which transfer patients in critical condition from the MEMC to the requested hospitals for further treatment. According to the results, the sequential-conveyance method is more efficient than the conventional method for EMS transportation in a mass-casualty incident (MCI). This method improves the time efficiency by 52.15% and the distance efficiency by 56.02%. This case study concentrates on Xiaolin, a mountain village, which was heavily destroyed by a devastating mudslide during the Typhoon Morakot. The sequential-conveyance method for the EMS transportation in this research is not only more advantageous but also more rational in adaptation to climate change. Therefore, the findings are also important to all the decision-making with respect to a promoted EMS transportation, especially in an MCI. PMID:25501065
Adaptation and promotion of emergency medical service transportation for climate change.
Pan, Chih-Long; Chiu, Chun-Wen; Wen, Jet-Chau
2014-12-01
The purpose of this study is to find a proper prehospital transportation scenario planning of an emergency medical service (EMS) system for possible burdensome casualties resulting from extreme climate events. This project focuses on one of the worst natural catastrophic events in Taiwan, the 88 Wind-caused Disasters, caused by the Typhoon Morakot; the case of the EMS transportation in the Xiaolin village is reviewed and analyzed. The sequential-conveyance method is designed to promote the efficiency of all the ambulance services related to transportation time and distance. Initially, a proposed mobile emergency medical center (MEMC) is constructed in a safe location near the area of the disaster. The ambulances are classified into 2 categories: the first-line ambulances, which reciprocate between the MEMC and the disaster area to save time and shorten the working distances and the second-line ambulances, which transfer patients in critical condition from the MEMC to the requested hospitals for further treatment. According to the results, the sequential-conveyance method is more efficient than the conventional method for EMS transportation in a mass-casualty incident (MCI). This method improves the time efficiency by 52.15% and the distance efficiency by 56.02%. This case study concentrates on Xiaolin, a mountain village, which was heavily destroyed by a devastating mudslide during the Typhoon Morakot. The sequential-conveyance method for the EMS transportation in this research is not only more advantageous but also more rational in adaptation to climate change. Therefore, the findings are also important to all the decision-making with respect to a promoted EMS transportation, especially in an MCI.
Development of the Multi-Level Seismic Receiver (MLSR)
NASA Astrophysics Data System (ADS)
Sleefe, G. E.; Engler, B. P.; Drozda, P. M.; Franco, R. J.; Morgan, Jeff
1995-02-01
The Advanced Geophysical Technology Department (6114) and the Telemetry Technology Development Department (2664) have, in conjunction with the Oil Recovery Technology Partnership, developed a Multi-Level Seismic Receiver (MLSR) for use in crosswell seismic surveys. The MLSR was designed and evaluated with the significant support of many industry partners in the oil exploration industry. The unit was designed to record and process superior quality seismic data operating in severe borehole environments, including high temperature (up to 200 C) and static pressure (10,000 psi). This development has utilized state-of-the-art technology in transducers, data acquisition, and real-time data communication and data processing. The mechanical design of the receiver has been carefully modeled and evaluated to insure excellent signal coupling into the receiver.
An integrated approach to characterization of fractured reservoirs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Datta-Gupta, A.; Majer, E.; Vasco, D.
1995-12-31
This paper summarizes an integrated hydrologic and seismic characterization of a fractured limestone formation at the Conoco Borehole Test Facility (CBTF) in Kay County, Oklahoma. Transient response from pressure interference tests were first inverted in order to identify location and orientation of dominant fractures at the CBTF. Subsequently, high resolution (1000 to 10000 Hz) cross-well and single-well seismic surveys were conducted to verify the preferential slow paths indicated by hydrologic analysis. Seismic surveys were conducted before and after an air injection in order to increase the visibility of the fracture zone to seismic imaging. Both Seismic and hydrologic analysis weremore » found to yield consistent results in detecting the location of a major fracture zone.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Michael; Dietsch, Niko
2018-01-01
This guide describes frameworks for evaluation, measurement, and verification (EM&V) of utility customer–funded energy efficiency programs. The authors reviewed multiple frameworks across the United States and gathered input from experts to prepare this guide. This guide provides the reader with both the contents of an EM&V framework, along with the processes used to develop and update these frameworks.
[Standardized investigation on medicinal nature of ethnomedicine].
Li, Zhi-Yong; Yang, Yong-Qiang; Li, Lin-Sen; Li, Yan-Wen; Lin, Ling; Cheng, Yang-Yang
2016-06-01
This article recorded the analysis and comparison between the medicinal nature theory of traditional Chinese medicine(TCM) and ethnomedicine(EM). The vocabulary of "medicinal nature" was suggested to indicate the properties of ethnomedicine. Based on the influence of TCM medicinal nature theory on EM in China, the application of medicinal nature theory in EM was divided into 3 classes, and the standardizing principles for EM medicinal nature were proposed. It was suggested that medicinal quality, flavor, tendency, tropism, degree and efficiency can be used for the classification standard for EM medicinal nature. Copyright© by the Chinese Pharmaceutical Association.
Development of Solar Grade Silicon (SoG-Si) Feedstock by Recycling SoG-Si Wastes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lifeng Zhang; Anping Dong; Lucas Nana Wiredu Damoah
2013-01-24
Experiment results of EM separation show that the non-metallic inclusions were successfully pushed to the boundary layer of the crucible under EM force. Larger frequency and smaller current generate smaller thickness of accumulated inclusions. More detailed EM separation experiments are undergoing to investigate the factors that affect the removal efficient of inclusions from SoG-Si
Regenerative fuel cell energy storage system for a low earth orbit space station
NASA Technical Reports Server (NTRS)
Martin, R. E.; Garow, J.; Michaels, K. B.
1988-01-01
A study was conducted to define characteristics of a Regenerative Fuel Cell System (RFCS) for low earth orbit Space Station missions. The RFCS's were defined and characterized based on both an alkaline electrolyte fuel cell integrated with an alkaline electrolyte water electrolyzer and an alkaline electrolyte fuel cell integrated with an acid solid polymer electrolyte (SPE) water electrolyzer. The study defined the operating characteristics of the systems including system weight, volume, and efficiency. A maintenance philosophy was defined and the implications of system reliability requirements and modularization were determined. Finally, an Engineering Model System was defined and a program to develop and demonstrate the EMS and pacing technology items that should be developed in parallel with the EMS were identified. The specific weight of an optimized RFCS operating at 140 F was defined as a function of system efficiency for a range of module sizes. An EMS operating at a nominal temperature of 180 F and capable of delivery of 10 kW at an overall efficiency of 55.4 percent is described. A program to develop the EMS is described including a technology development effort for pacing technology items.
NASA Astrophysics Data System (ADS)
Lee, Kyunghoon
To evaluate the maximum likelihood estimates (MLEs) of probabilistic principal component analysis (PPCA) parameters such as a factor-loading, PPCA can invoke an expectation-maximization (EM) algorithm, yielding an EM algorithm for PPCA (EM-PCA). In order to examine the benefits of the EM-PCA for aerospace engineering applications, this thesis attempts to qualitatively and quantitatively scrutinize the EM-PCA alongside both POD and gappy POD using high-dimensional simulation data. In pursuing qualitative investigations, the theoretical relationship between POD and PPCA is transparent such that the factor-loading MLE of PPCA, evaluated by the EM-PCA, pertains to an orthogonal basis obtained by POD. By contrast, the analytical connection between gappy POD and the EM-PCA is nebulous because they distinctively approximate missing data due to their antithetical formulation perspectives: gappy POD solves a least-squares problem whereas the EM-PCA relies on the expectation of the observation probability model. To juxtapose both gappy POD and the EM-PCA, this research proposes a unifying least-squares perspective that embraces the two disparate algorithms within a generalized least-squares framework. As a result, the unifying perspective reveals that both methods address similar least-squares problems; however, their formulations contain dissimilar bases and norms. Furthermore, this research delves into the ramifications of the different bases and norms that will eventually characterize the traits of both methods. To this end, two hybrid algorithms of gappy POD and the EM-PCA are devised and compared to the original algorithms for a qualitative illustration of the different basis and norm effects. After all, a norm reflecting a curve-fitting method is found to more significantly affect estimation error reduction than a basis for two example test data sets: one is absent of data only at a single snapshot and the other misses data across all the snapshots. From a numerical performance aspect, the EM-PCA is computationally less efficient than POD for intact data since it suffers from slow convergence inherited from the EM algorithm. For incomplete data, this thesis quantitatively found that the number of data missing snapshots predetermines whether the EM-PCA or gappy POD outperforms the other because of the computational cost of a coefficient evaluation, resulting from a norm selection. For instance, gappy POD demands laborious computational effort in proportion to the number of data-missing snapshots as a consequence of the gappy norm. In contrast, the computational cost of the EM-PCA is invariant to the number of data-missing snapshots thanks to the L2 norm. In general, the higher the number of data-missing snapshots, the wider the gap between the computational cost of gappy POD and the EM-PCA. Based on the numerical experiments reported in this thesis, the following criterion is recommended regarding the selection between gappy POD and the EM-PCA for computational efficiency: gappy POD for an incomplete data set containing a few data-missing snapshots and the EM-PCA for an incomplete data set involving multiple data-missing snapshots. Last, the EM-PCA is applied to two aerospace applications in comparison to gappy POD as a proof of concept: one with an emphasis on basis extraction and the other with a focus on missing data reconstruction for a given incomplete data set with scattered missing data. The first application exploits the EM-PCA to efficiently construct reduced-order models of engine deck responses obtained by the numerical propulsion system simulation (NPSS), some of whose results are absent due to failed analyses caused by numerical instability. Model-prediction tests validate that engine performance metrics estimated by the reduced-order NPSS model exhibit considerably good agreement with those directly obtained by NPSS. Similarly, the second application illustrates that the EM-PCA is significantly more cost effective than gappy POD at repairing spurious PIV measurements obtained from acoustically-excited, bluff-body jet flow experiments. The EM-PCA reduces computational cost on factors 8 ˜ 19 compared to gappy POD while generating the same restoration results as those evaluated by gappy POD. All in all, through comprehensive theoretical and numerical investigation, this research establishes that the EM-PCA is an efficient alternative to gappy POD for an incomplete data set containing missing data over an entire data set. (Abstract shortened by UMI.)
Spectral unmixing of urban land cover using a generic library approach
NASA Astrophysics Data System (ADS)
Degerickx, Jeroen; Lordache, Marian-Daniel; Okujeni, Akpona; Hermy, Martin; van der Linden, Sebastian; Somers, Ben
2016-10-01
Remote sensing based land cover classification in urban areas generally requires the use of subpixel classification algorithms to take into account the high spatial heterogeneity. These spectral unmixing techniques often rely on spectral libraries, i.e. collections of pure material spectra (endmembers, EM), which ideally cover the large EM variability typically present in urban scenes. Despite the advent of several (semi-) automated EM detection algorithms, the collection of such image-specific libraries remains a tedious and time-consuming task. As an alternative, we suggest the use of a generic urban EM library, containing material spectra under varying conditions, acquired from different locations and sensors. This approach requires an efficient EM selection technique, capable of only selecting those spectra relevant for a specific image. In this paper, we evaluate and compare the potential of different existing library pruning algorithms (Iterative Endmember Selection and MUSIC) using simulated hyperspectral (APEX) data of the Brussels metropolitan area. In addition, we develop a new hybrid EM selection method which is shown to be highly efficient in dealing with both imagespecific and generic libraries, subsequently yielding more robust land cover classification results compared to existing methods. Future research will include further optimization of the proposed algorithm and additional tests on both simulated and real hyperspectral data.
Hydrodynamics of ozone contactors have a crucial impact on efficient inactivation of pathogens such as Cryptosporidium as well as control of disinfection byproducts such as bromate. Improper mixing behaviors including short-circuiting, internal recirculation and presence...
Efficient EM Simulation of GCPW Structures Applied to a 200-GHz mHEMT Power Amplifier MMIC
NASA Astrophysics Data System (ADS)
Campos-Roca, Yolanda; Amado-Rey, Belén; Wagner, Sandrine; Leuther, Arnulf; Bangert, Axel; Gómez-Alcalá, Rafael; Tessmann, Axel
2017-05-01
The behaviour of grounded coplanar waveguide (GCPW) structures in the upper millimeter-wave range is analyzed by using full-wave electromagnetic (EM) simulations. A methodological approach to develop reliable and time-efficient simulations is proposed by investigating the impact of different simplifications in the EM modelling and simulation conditions. After experimental validation with measurements on test structures, this approach has been used to model the most critical passive structures involved in the layout of a state-of-the-art 200-GHz power amplifier based on metamorphic high electron mobility transistors (mHEMTs). This millimeter-wave monolithic integrated circuit (MMIC) has demonstrated a measured output power of 8.7 dBm for an input power of 0 dBm at 200 GHz. The measured output power density and power-added efficiency (PAE) are 46.3 mW/mm and 4.5 %, respectively. The peak measured small-signal gain is 12.7 dB (obtained at 196 GHz). A good agreement has been obtained between measurements and simulation results.
Numerous studies have demonstrated the efficiency of ultraviolet (UV) radiation for the inactivation of oocysts of Cryptosporidium parvum. In these studies inactivation is measured as reduction in oocysts. A primary goal is to estimate the UV radiation required to achiev...
AN INTEGRAL EQUATION REPRESENTATION OF WIDE-BAND ELECTROMAGNETIC SCATTERING BY THIN SHEETS
An efficient, accurate numerical modeling scheme has been developed, based on the integral equation solution to compute electromagnetic (EM) responses of thin sheets over a wide frequency band. The thin-sheet approach is useful for simulating the EM response of a fracture system ...
Gold reflective metallic gratings with high absorption efficiency
NASA Astrophysics Data System (ADS)
Zhang, Zhaojian; Liang, Linmei; Yang, Junbo
2017-10-01
Electromagnetic (EM) wave absorbers are devices in which the incident radiation at the operating wavelengths can be efficiently absorbed and then transformed into ohmic heat or other forms of energy. Especially, EM absorbers based on metallic structures have distinct advantages in comparison with the traditional counterparts. Thus, they have different potential applications at different frequency ranges such as absorbing devices in solar energy harvesting systems. The reflective metallic grating is a kind of metallic EM absorbers and has the fascinating property of efficiently absorbing the incident light due to the excitation of surface plasmon polaritons (SPPs), consequently drawing more and more attention. In this paper, the absorption effect of a reflective metallic grating made of gold is studied by changing grating parameters such as the period, polarization direction of the incident light and so on. We use finite difference time-domain (FDTD) method to design the grating, and simulate the process and detect the absorption spectrum. In our design, the grating has rectangular shaped grooves and has the absorption efficiency 99% for the vertically incident transverse magnetic (TM) light at the wavelength of 818nm with the period of 800 nm, the width of 365 nm and the height of 34 nm. And then we find that the absorption spectrum is blue-shifted about 87 nm with decreasing period from 800 nm to700 nm and red-shifted about 14 nm with increasing the width of the block from 305 nm to 405 nm. The absorption becomes gradually weaker from 98% to almost zero with the polarization angle from 0° to 90°. Finally, we make a theoretical explanation to these phenomena in details. It is believed that the results may provide useful guidance for the design of EM wave absorbers with high absorption efficiency.
Parallel goal-oriented adaptive finite element modeling for 3D electromagnetic exploration
NASA Astrophysics Data System (ADS)
Zhang, Y.; Key, K.; Ovall, J.; Holst, M.
2014-12-01
We present a parallel goal-oriented adaptive finite element method for accurate and efficient electromagnetic (EM) modeling of complex 3D structures. An unstructured tetrahedral mesh allows this approach to accommodate arbitrarily complex 3D conductivity variations and a priori known boundaries. The total electric field is approximated by the lowest order linear curl-conforming shape functions and the discretized finite element equations are solved by a sparse LU factorization. Accuracy of the finite element solution is achieved through adaptive mesh refinement that is performed iteratively until the solution converges to the desired accuracy tolerance. Refinement is guided by a goal-oriented error estimator that uses a dual-weighted residual method to optimize the mesh for accurate EM responses at the locations of the EM receivers. As a result, the mesh refinement is highly efficient since it only targets the elements where the inaccuracy of the solution corrupts the response at the possibly distant locations of the EM receivers. We compare the accuracy and efficiency of two approaches for estimating the primary residual error required at the core of this method: one uses local element and inter-element residuals and the other relies on solving a global residual system using a hierarchical basis. For computational efficiency our method follows the Bank-Holst algorithm for parallelization, where solutions are computed in subdomains of the original model. To resolve the load-balancing problem, this approach applies a spectral bisection method to divide the entire model into subdomains that have approximately equal error and the same number of receivers. The finite element solutions are then computed in parallel with each subdomain carrying out goal-oriented adaptive mesh refinement independently. We validate the newly developed algorithm by comparison with controlled-source EM solutions for 1D layered models and with 2D results from our earlier 2D goal oriented adaptive refinement code named MARE2DEM. We demonstrate the performance and parallel scaling of this algorithm on a medium-scale computing cluster with a marine controlled-source EM example that includes a 3D array of receivers located over a 3D model that includes significant seafloor bathymetry variations and a heterogeneous subsurface.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Marchesini, P; Ajo-Franklin, JB; Daley, TM
2017-09-01
© 2017 Society of Exploration Geophysicists. The ability to characterize time-varying reservoir properties, such as the state of stress, has fundamental implications in subsurface engineering, relevant to geologic sequestration of CO2. Stress variation, here in the form of changes in pore fluid pressure, is one factor known to affect seismic velocity. Induced variations in velocity have been used in seismic studies to determine and monitor changes in the stress state. Previous studies conducted to determine velocity-stress sensitivity at reservoir conditions rely primarily on laboratory measurements of core samples or theoretical relationships. We have developed a novel field-scale experiment designed tomore » study the in situ relationship between pore-fluid pressure and seismic velocity using a crosswell continuous active-source seismic monitoring (CASSM) system. At the Cranfield, Mississippi, CO2 sequestration field site, we actively monitored seismic response for five days with a temporal resolution of 5 min; the target was a 26 m thick injection zone at approximately 3.2 km depth in a fluvial sandstone formation (lower Tuscaloosa Formation). The variation of pore fluid pressure was obtained during discrete events of fluid withdrawal from one of the two wells and monitored with downhole pressure sensors. The results indicate a correlation between decreasing CASSM time delay (i.e., velocity change for a raypath in the reservoir) and periods of reduced fluid pore pressure. The correlation is interpreted as the velocity-stress sensitivity measured in the reservoir. This observation is consistent with published laboratory studies documenting a velocity (V) increase with an effective stress increase. A traveltime change (dt) of 0.036 ms is measured as the consequence of a change in pressure of approximately 2.55 MPa (dPe). For T 1/4 13 ms total traveltime, the velocity-stress sensitivity is dV/V/dPe 1/4 dt/T/dPe 1/4 10.9 × 10-4/MPa. The overall results suggest that CASSM measurements represent a valid technique for in situ determination of velocity-stress sensitivity in field-scale monitoring studies.« less
Sheng, Weitian; Zhou, Chenming; Liu, Yang; Bagci, Hakan; Michielssen, Eric
2018-01-01
A fast and memory efficient three-dimensional full-wave simulator for analyzing electromagnetic (EM) wave propagation in electrically large and realistic mine tunnels/galleries loaded with conductors is proposed. The simulator relies on Muller and combined field surface integral equations (SIEs) to account for scattering from mine walls and conductors, respectively. During the iterative solution of the system of SIEs, the simulator uses a fast multipole method-fast Fourier transform (FMM-FFT) scheme to reduce CPU and memory requirements. The memory requirement is further reduced by compressing large data structures via singular value and Tucker decompositions. The efficiency, accuracy, and real-world applicability of the simulator are demonstrated through characterization of EM wave propagation in electrically large mine tunnels/galleries loaded with conducting cables and mine carts. PMID:29726545
Characterizing the Weeks Island Salt Dome drilling of and seismic measurements from boreholes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sattler, A.R.; Harding, R.S.; Jacobson, R.D.
1996-10-01
A sinkhole 36 ft across, 30 ft deep was first observed in the alluvium over the Weeks Island Salt Dome (salt mine converted for oil storage by US Strategic Petroleum Reserve) May 1992. Four vertical, two slanted boreholes were drilled for diagnostics. Crosswell seismic data were generated; the velocity images suggest that the sinkhole collapse is complicated, not a simple vertical structure. The coring operation was moderately difficult; limited core was obtained through the alluvium, and the quality of the salt core from the first two vertical wells was poor. Core quality improved with better bit selection, mud, and drillingmore » method. The drilling fluid program provided fairly stable holes allowing open hole logs to be run. All holes were cemented successfully (although it took 3 attempts in one case).« less
The use of emergency manuals in perioperative crisis management: a cautious approach.
Szabo, Ashley; August, David A; Klainer, Suzanne; Miller, Andrew D; Kaye, Alan D; Raemer, Daniel B; Urman, Richard D
2015-01-01
When an unexpected perioperative crisis arises, simulation studies have suggested that the use of an emergency manual (EM) may offset the large cognitive load involved in crisis management, facilitating the efficient performance of key steps in treatment. However, little is known about how well EMs will translate into actual practice and what is required to use them optimally. While EMs are a promising tool in the management of perioperative critical events, more research is needed to define best practices and their limitations. In the interim, cautious use of these cognitive aids is recommended, especially when the diagnosis is not straightforward, falls "in between" sections of the EM, or falls outside of the EM itself. Further research should focus on the efficacy of EMs as measured by the percentage of critical steps correctly performed by their users in scenarios that do not closely mirror one of the listed EM scenarios from the beginning or as the situation evolves.
Cyberwarfare and Operational Art
2017-05-25
Electronic Attack EMS Electro Magnetic Spectrum FM Field Manual FSB Federal Security Service (Russian Federation) GAO General Accounting Office GRU...Warfare, (Cambridge, MA: O’Reilly Media Inc., 2012), 74. 2 "The Bombe developed in Bletchley by Turing and Welshman and Babbage - all luminaries of...cyberspace domain’s fundamental characteristics. First, cyberspace requires the Electro Magnetic Spectrum ( EMS ) to propagate efficiently. Second
The federal standard for the presence of asbestos in drinking water mandates the use of transmission electron microscopy (TEM) as the only acceptable testing method. The July 17, 1992 Federal Register (57 FR 31839, Section 141.23(k)(4)) specifies that the analysis for as...
Shi, Yin-Ze; Chen, Jiann-Chu; Chen, Yu-Yuan; Kuo, Yi-Hsuan; Li, Hui-Fang
2018-05-01
White shrimp Litopenaeus vannamei haemocytes receiving immunostimulating Sargassum oligocystum extract (SE) caused necrosis in haemocyte cells, which released endogenous EM-SE molecules. This study examined the immune response of white shrimp L. vannamei receiving SE and EM-SE in vitro and in vivo. Shrimp haemocytes receiving SE exhibited degranulation, changes in cell size and cell viability, necrosis and a release of EM-SE. Shrimp haemocytes receiving SE, EM-SE, and the SE + EM-SE mixture (SE + EM-SE) increased their phenoloxidase (PO) activity which was significantly higher in shrimp haemocytes receiving the SE + EM-SE mixture. Furthermore, shrimp haemocytes receiving EM-SE showed degranulation and changes in cell size and cell viability. Shrimp receiving SE, EM-SE, and SE + EM-SE all increased their immune parameters, phagocytic activity, clearance efficiency and resistance to Vibrio alginolyticus, being significantly higher in shrimp receiving SE + EM-SE. Meanwhile, the recombinant lipopolysaccharide- and β-1,3-glucan binding protein of L. vannamei (rLvLGBP) was bound to SE, EM-SE, and SE + EM-SE. We conclude that in shrimp haemocytes receiving a non-self molecule, SE in dying cells released EM-SE which led to downstream activation and synergization of the immune response. This study demonstrated that the innate immunity of shrimp was elicited and enhanced by a mixture of endogenous molecules and exogenous substances (or immunostimulants). Copyright © 2018 Elsevier Ltd. All rights reserved.
Navigating 3D electron microscopy maps with EM-SURFER.
Esquivel-Rodríguez, Juan; Xiong, Yi; Han, Xusi; Guang, Shuomeng; Christoffer, Charles; Kihara, Daisuke
2015-05-30
The Electron Microscopy DataBank (EMDB) is growing rapidly, accumulating biological structural data obtained mainly by electron microscopy and tomography, which are emerging techniques for determining large biomolecular complex and subcellular structures. Together with the Protein Data Bank (PDB), EMDB is becoming a fundamental resource of the tertiary structures of biological macromolecules. To take full advantage of this indispensable resource, the ability to search the database by structural similarity is essential. However, unlike high-resolution structures stored in PDB, methods for comparing low-resolution electron microscopy (EM) density maps in EMDB are not well established. We developed a computational method for efficiently searching low-resolution EM maps. The method uses a compact fingerprint representation of EM maps based on the 3D Zernike descriptor, which is derived from a mathematical series expansion for EM maps that are considered as 3D functions. The method is implemented in a web server named EM-SURFER, which allows users to search against the entire EMDB in real-time. EM-SURFER compares the global shapes of EM maps. Examples of search results from different types of query structures are discussed. We developed EM-SURFER, which retrieves structurally relevant matches for query EM maps from EMDB within seconds. The unique capability of EM-SURFER to detect 3D shape similarity of low-resolution EM maps should prove invaluable in structural biology.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kurnik, Charles W.; Romberger, Jeff
The HVAC Controls Evaluation Protocol is designed to address evaluation issues for direct digital controls/energy management systems/building automation systems (DDC/EMS/BAS) that are installed to control heating, ventilation, and air-conditioning (HVAC) equipment in commercial and institutional buildings. (This chapter refers to the DDC/EMS/BAS measure as HVAC controls.) This protocol may also be applicable to industrial facilities such as clean rooms and labs, which have either significant HVAC equipment or spaces requiring special environmental conditions.
Internalized compartments encapsulated nanogels for targeted drug delivery
NASA Astrophysics Data System (ADS)
Yu, Jicheng; Zhang, Yuqi; Sun, Wujin; Wang, Chao; Ranson, Davis; Ye, Yanqi; Weng, Yuyan; Gu, Zhen
2016-04-01
Drug delivery systems inspired by natural particulates hold great promise for targeted cancer therapy. An endosome formed by internalization of plasma membrane has a massive amount of membrane proteins and receptors on the surface, which is able to specifically target the homotypic cells. Herein, we describe a simple method to fabricate an internalized compartments encapsulated nanogel with endosome membrane components (EM-NG) from source cancer cells. Following intracellular uptake of methacrylated hyaluronic acid (m-HA) adsorbed SiO2/Fe3O4 nanoparticles encapsulating a crosslinker and a photoinitiator, EM-NG was readily prepared through in situ crosslinking initiated under UV irradiation after internalization. The resulting nanogels loaded with doxorubicin (DOX) displayed enhanced internalization efficiency to the source cells through a specific homotypic affinity in vitro. However, when treated with the non-source cells, the EM-NGs exhibited insignificant difference in therapeutic efficiency compared to a bare HA nanogel with DOX. This study illustrates the potential of utilizing an internalized compartments encapsulated formulation for targeted cancer therapy, and offers guidelines for developing a natural particulate-inspired drug delivery system.Drug delivery systems inspired by natural particulates hold great promise for targeted cancer therapy. An endosome formed by internalization of plasma membrane has a massive amount of membrane proteins and receptors on the surface, which is able to specifically target the homotypic cells. Herein, we describe a simple method to fabricate an internalized compartments encapsulated nanogel with endosome membrane components (EM-NG) from source cancer cells. Following intracellular uptake of methacrylated hyaluronic acid (m-HA) adsorbed SiO2/Fe3O4 nanoparticles encapsulating a crosslinker and a photoinitiator, EM-NG was readily prepared through in situ crosslinking initiated under UV irradiation after internalization. The resulting nanogels loaded with doxorubicin (DOX) displayed enhanced internalization efficiency to the source cells through a specific homotypic affinity in vitro. However, when treated with the non-source cells, the EM-NGs exhibited insignificant difference in therapeutic efficiency compared to a bare HA nanogel with DOX. This study illustrates the potential of utilizing an internalized compartments encapsulated formulation for targeted cancer therapy, and offers guidelines for developing a natural particulate-inspired drug delivery system. Electronic supplementary information (ESI) available: Synthesis of m-HA; synthesis of rhodamine-HA derivative; supplementary data on relative fluorescence intensity of DOX-EN-NGs on HeLa cells. See DOI: 10.1039/c5nr08895j
Okabe, Yoshihiro; Asamizu, Erika; Saito, Takeshi; Matsukura, Chiaki; Ariizumi, Tohru; Brès, Cécile; Rothan, Christophe; Mizoguchi, Tsuyoshi; Ezura, Hiroshi
2011-01-01
To accelerate functional genomic research in tomato, we developed a Micro-Tom TILLING (Targeting Induced Local Lesions In Genomes) platform. DNA pools were constructed from 3,052 ethyl methanesulfonate (EMS) mutant lines treated with 0.5 or 1.0% EMS. The mutation frequency was calculated by screening 10 genes. The 0.5% EMS population had a mild mutation frequency of one mutation per 1,710 kb, whereas the 1.0% EMS population had a frequency of one mutation per 737 kb, a frequency suitable for producing an allelic series of mutations in the target genes. The overall mutation frequency was one mutation per 1,237 kb, which affected an average of three alleles per kilobase screened. To assess whether a Micro-Tom TILLING platform could be used for efficient mutant isolation, six ethylene receptor genes in tomato (SlETR1–SlETR6) were screened. Two allelic mutants of SlETR1 (Sletr1-1 and Sletr1-2) that resulted in reduced ethylene responses were identified, indicating that our Micro-Tom TILLING platform provides a powerful tool for the rapid detection of mutations in an EMS mutant library. This work provides a practical and publicly accessible tool for the study of fruit biology and for obtaining novel genetic material that can be used to improve important agronomic traits in tomato. PMID:21965606
Wang, Xiangqian; Wu, Chao; Liu, Nan; Li, Sujing; Li, Wei; Chen, Jianmeng; Chen, Dongzhi
2015-04-01
A Pseudomonas sp. strain WL2 that is able to efficiently metabolize ethyl mercaptan (EM) into diethyl disulfide (DEDS) through enzymatic oxidation was isolated from the activated sludge of a pharmaceutical wastewater plant. One hundred percent removal of 113.5 mg L(-1) EM and 110.3 mg L(-1) DEDS were obtained within 14 and 32 h, respectively. A putative EM degradation pathway that involved the catabolism via DEDS was proposed, which indicated DEDS were further mineralized into carbon dioxide (CO2), bacterial cells, and sulfate (SO4 (2-)) through the transformation of element sulfur and ethyl aldehyde. Degradation kinetics for EM and DEDS with different initial concentrations by strain WL2 were evaluated using Haldane-Andrews model with maximum specific degradation rates of 3.13 and 1.33 g g(-1) h(-1), respectively, and maximum degradation rate constants of 0.522 and 0.175 h(-1) using pseudo-first-order kinetic model were obtained. Results obtained that aerobic degradation of EM by strain WL2 was more efficient than those from previous studies. Substrate range studies of strain WL2 demonstrated its ability to degrade several mercaptans, disulfides, aldehydes, and methanol. All the results obtained highlight the potential of strain WL2 for the use in the biodegradation of volatile organic sulfur compounds (VOSCs).
Okabe, Yoshihiro; Asamizu, Erika; Saito, Takeshi; Matsukura, Chiaki; Ariizumi, Tohru; Brès, Cécile; Rothan, Christophe; Mizoguchi, Tsuyoshi; Ezura, Hiroshi
2011-11-01
To accelerate functional genomic research in tomato, we developed a Micro-Tom TILLING (Targeting Induced Local Lesions In Genomes) platform. DNA pools were constructed from 3,052 ethyl methanesulfonate (EMS) mutant lines treated with 0.5 or 1.0% EMS. The mutation frequency was calculated by screening 10 genes. The 0.5% EMS population had a mild mutation frequency of one mutation per 1,710 kb, whereas the 1.0% EMS population had a frequency of one mutation per 737 kb, a frequency suitable for producing an allelic series of mutations in the target genes. The overall mutation frequency was one mutation per 1,237 kb, which affected an average of three alleles per kilobase screened. To assess whether a Micro-Tom TILLING platform could be used for efficient mutant isolation, six ethylene receptor genes in tomato (SlETR1-SlETR6) were screened. Two allelic mutants of SlETR1 (Sletr1-1 and Sletr1-2) that resulted in reduced ethylene responses were identified, indicating that our Micro-Tom TILLING platform provides a powerful tool for the rapid detection of mutations in an EMS mutant library. This work provides a practical and publicly accessible tool for the study of fruit biology and for obtaining novel genetic material that can be used to improve important agronomic traits in tomato.
Schwein, Adeline; Kramer, Ben; Chinnadurai, Ponraj; Walker, Sean; O'Malley, Marcia; Lumsden, Alan; Bismuth, Jean
2017-02-01
One limitation of the use of robotic catheters is the lack of real-time three-dimensional (3D) localization and position updating: they are still navigated based on two-dimensional (2D) X-ray fluoroscopic projection images. Our goal was to evaluate whether incorporating an electromagnetic (EM) sensor on a robotic catheter tip could improve endovascular navigation. Six users were tasked to navigate using a robotic catheter with incorporated EM sensors in an aortic aneurysm phantom. All users cannulated two anatomic targets (left renal artery and posterior "gate") using four visualization modes: (1) standard fluoroscopy mode (control), (2) 2D fluoroscopy mode showing real-time virtual catheter orientation from EM tracking, (3) 3D model of the phantom with anteroposterior and endoluminal view, and (4) 3D model with anteroposterior and lateral view. Standard X-ray fluoroscopy was always available. Cannulation and fluoroscopy times were noted for every mode. 3D positions of the EM tip sensor were recorded at 4 Hz to establish kinematic metrics. The EM sensor-incorporated catheter navigated as expected according to all users. The success rate for cannulation was 100%. For the posterior gate target, mean cannulation times in minutes:seconds were 8:12, 4:19, 4:29, and 3:09, respectively, for modes 1, 2, 3 and 4 (P = .013), and mean fluoroscopy times were 274, 20, 29, and 2 seconds, respectively (P = .001). 3D path lengths, spectral arc length, root mean dimensionless jerk, and number of submovements were significantly improved when EM tracking was used (P < .05), showing higher quality of catheter movement with EM navigation. The EM tracked robotic catheter allowed better real-time 3D orientation, facilitating navigation, with a reduction in cannulation and fluoroscopy times and improvement of motion consistency and efficiency. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
Time Management and the Woman Library Manager.
ERIC Educational Resources Information Center
Gothberg, Helen M.
1987-01-01
Discusses how women library managers can use efficient time management techniques to help them make the best of both career and home work environments. Nine basic steps to greater efficiency are presented, and external and internal time wasters are listed. (EM)
Li, Wen-Tao; Xu, Zi-Xiao; Shuang, Chen-Dong; Zhou, Qing; Li, Hai-Bo; Li, Ai-Min
2016-03-01
The efficiency and mechanism of anion exchange resin Nanda Magnetic Polymer (NDMP) for removal of fluorescent dissolved organic matter in biologically treated textile effluents were studied. The bench-scale experiments showed that as well as activated carbon, anion exchange resin could efficiently remove both aniline-like and humic-like fluorescent components, which can be up to 40 % of dissolved organic matter. The humic-like fluorescent component HS-Em460-Ex3 was more hydrophilic than HS-Em430-Ex2 and contained fewer alkyl chains but more acid groups. As a result, HS-Em460-Ex3 was eliminated more preferentially by NDMP anion exchange. However, compared with adsorption resins, the polarity of fluorescent components had a relatively small effect on the performance of anion exchange resin. The long-term pilot-scale experiments showed that the NDMP anion exchange process could remove approximately 30 % of the chemical oxygen demand and about 90 % of color from the biologically treated textile effluents. Once the issue of waste brine from resin desorption is solved, the NDMP anion exchange process could be a promising alternative for the advanced treatment of textile effluents.
Integrated thermal and energy management of plug-in hybrid electric vehicles
NASA Astrophysics Data System (ADS)
Shams-Zahraei, Mojtaba; Kouzani, Abbas Z.; Kutter, Steffen; Bäker, Bernard
2012-10-01
In plug-in hybrid electric vehicles (PHEVs), the engine temperature declines due to reduced engine load and extended engine off period. It is proven that the engine efficiency and emissions depend on the engine temperature. Also, temperature influences the vehicle air-conditioner and the cabin heater loads. Particularly, while the engine is cold, the power demand of the cabin heater needs to be provided by the batteries instead of the waste heat of engine coolant. The existing energy management strategies (EMS) of PHEVs focus on the improvement of fuel efficiency based on hot engine characteristics neglecting the effect of temperature on the engine performance and the vehicle power demand. This paper presents a new EMS incorporating an engine thermal management method which derives the global optimal battery charge depletion trajectories. A dynamic programming-based algorithm is developed to enforce the charge depletion boundaries, while optimizing a fuel consumption cost function by controlling the engine power. The optimal control problem formulates the cost function based on two state variables: battery charge and engine internal temperature. Simulation results demonstrate that temperature and the cabin heater/air-conditioner power demand can significantly influence the optimal solution for the EMS, and accordingly fuel efficiency and emissions of PHEVs.
Economic efficiency of environmental management system operation in industrial companies
NASA Astrophysics Data System (ADS)
Dukmasova, N.; Ershova, I.; Plastinina, I.; Boyarinov, A.
2017-06-01
The article examines the issue of the efficiency of the environmental management system (EMS) implementation in the Russian machine-building companies. The analysis showed that Russia clearly lags behind other developed and developing countries in terms of the number of ISO 14001 certified companies. According to the authors, the main cause of weak system implementation activity is attributed to the lack of interest in ISO 14001 certification on the Russian market. Five-year primary (field) research aimed at the analysis of the environmental priorities of the civilians suggests that the image component of the economic benefits ensures the increase in economic and financial performance of the company due to the increase in customers’ loyalty to the products of the EMS adopter. To quantify economic benefits obtained from EMS implementation, a methodological approach with regard to the image component and the decrease in semi-fixed costs due to the increase in the production scale has been developed. This approach has been tested in a machine-building electrical equipment manufacturer in Ekaterinburg. This approach applied to data processing yields the conclusion that EMS gives a good additional competitive advantage to its adopters.
Code of Federal Regulations, 2014 CFR
2014-07-01
... the implementation plan for efficiency credits to the Administrator for review and approval no later... level adjusted by applying the efficiency credits earned, lb per million Btu steam output (or lb per MWh) for the affected boiler. Em = Emissions measured during the performance test, lb per million Btu steam...
Code of Federal Regulations, 2013 CFR
2013-07-01
... the implementation plan for efficiency credits to the Administrator for review and approval no later... level adjusted by applying the efficiency credits earned, lb per million Btu steam output (or lb per MWh) for the affected boiler. Em = Emissions measured during the performance test, lb per million Btu steam...
Dang, Zhisheng; Feng, Jinchao; Yagi, Kinpei; Sugimoto, Chihiro; Li, Wei; Oku, Yuzaburo
2012-01-01
Studies have shown that a bacterial fibronectin attachment protein (FAP) is able to stimulate strong systemic and mucosal antibody responses when it is used alone or co-administrated with other antigens (Ags). Thus, it has been suggested to be a promising adjuvant candidate for the development of efficient vaccines. However, the co-administered Ags and FAP were cloned, expressed and purified individually to date. In a recent study, we first evaluated the adjuvanticity of a fibronectin-binding peptide (FBP, 24 amino acids) of Mycobacterium avium FAP fused with Echinococcus multilocularis tetraspanin 3 (Em-TSP3) by detecting systemic and local antibody responses in intranasally (i.n.) immunized BALB/c mice. Em-TSP3 and FBP fragments were linked with a GSGGSG linker and expressed as a single fusion protein (Em-TSP3-FBP) using the pBAD/Thio-TOPO expression vector. BALB/c mice were immunized i.n. with recombinant Em-TSP3-FBP (rEm-TSP3-FBP) and rEm-TSP3+CpG and the systemic and local antibody responses were detected by ELISA. The results showed that both rEm-TSP3-FBP and rEm-TSP3+CpG evoked strong serum IgG (p<0.001) and IgG1 responses (p<0.001), whereas only the latter induced a high level IgG2α production (p<0.001), compared to that of rEm-TSP3 alone without any adjuvant. There were no significant differences in IgG and IgG1 production between the groups. Low level of serum IgA and IgM were detected in both groups. The tendency of Th1 and Th2 cell immune responses were assessed via detecting the IgG1/IgG2α ratio after the second and third immunizations. The results indicated that i.n. immunization with rEm-TSP3-FBP resulted in an increased IgG1/IgG2α ratio (a Th2 tendency), while rEm-TSP3+CpG caused a rapid Th1 response that later shifted to a Th2 response. Immunization with rEm-TSP3-FBP provoked significantly stronger IgA antibody responses in intestine (p<0.05), lung (p<0.001) and spleen (p<0.001) compared to those by rEm-TSP3+CpG. Significantly high level IgA antibodies were detected in nasal cavity (p<0.05) and liver (p<0.05) samples from both groups when compared to rEm-TSP3 alone without any adjuvant, with no significant difference between them. I.n. administration of rEm-TSP3-FBP can induce strong systemic and mucosal antibody responses in immunized BALB/c mice, suggesting that fusion of Em-TSP3 with FBP is a novel, prospective strategy for developing safe and efficient human mucosal vaccines against alveolar echinococcosis (AE).
Jiang, Yannan; Wang, Lei; Wang, Jiao; Akwuruoha, Charles Nwakanma; Cao, Weiping
2017-10-30
The polarization conversion of electromagnetic (EM) waves, especially linear-to-circular (LTC) polarization conversion, is of great significance in practical applications. In this study, we propose an ultra-wideband high-efficiency reflective LTC polarization converter based on a metasurface in the terahertz regime. It consists of periodic unit cells, each cell of which is formed by a double split resonant square ring, dielectric layer, and fully reflective gold mirror. In the frequency range of 0.60 - 1.41 THz, the magnitudes of the reflection coefficients reach approximately 0.7, and the phase difference between the two orthogonal electric field components of the reflected wave is close to 90° or -270°. The results indicate that the relative bandwidth reaches 80% and the efficiency is greater than 88%, thus, ultra-wideband high-efficiency LTC polarization conversion has been realized. Finally, the physical mechanism of the polarization conversion is revealed. This converter has potential applications in antenna design, EM measurement, and stealth technology.
Yu, Wenya; Lv, Yipeng; Hu, Chaoqun; Liu, Xu; Chen, Haiping; Xue, Chen; Zhang, Lulu
2018-01-01
Emergency medical system for mass casualty incidents (EMS-MCIs) is a global issue. However, China lacks such studies extremely, which cannot meet the requirement of rapid decision-support system. This study aims to realize modeling EMS-MCIs in Shanghai, to improve mass casualty incident (MCI) rescue efficiency in China, and to provide a possible method of making rapid rescue decisions during MCIs. This study established a system dynamics (SD) model of EMS-MCIs using the Vensim DSS program. Intervention scenarios were designed as adjusting scales of MCIs, allocation of ambulances, allocation of emergency medical staff, and efficiency of organization and command. Mortality increased with the increasing scale of MCIs, medical rescue capability of hospitals was relatively good, but the efficiency of organization and command was poor, and the prehospital time was too long. Mortality declined significantly when increasing ambulances and improving the efficiency of organization and command; triage and on-site first-aid time were shortened if increasing the availability of emergency medical staff. The effect was the most evident when 2,000 people were involved in MCIs; however, the influence was very small under the scale of 5,000 people. The keys to decrease the mortality of MCIs were shortening the prehospital time and improving the efficiency of organization and command. For small-scale MCIs, improving the utilization rate of health resources was important in decreasing the mortality. For large-scale MCIs, increasing the number of ambulances and emergency medical professionals was the core to decrease prehospital time and mortality. For super-large-scale MCIs, increasing health resources was the premise.
Fredette, Jenna; O'Brien, Corinne; Poole, Christy; Nomura, Jason
2015-04-01
Experiential learning theory and the Kolb Learning Style Inventory (Kolb LSI) have influenced educators worldwide for decades. Knowledge of learning styles can create efficient learning environments, increase information retention, and improve learner satisfaction. Learning styles have been examined in medicine previously, but not specifically with Emergency Medicine (EM) residents and attendings. Using the Kolb LSI, the learning styles of Emergency Medicine residents and attendings were assessed. The findings showed that the majority of EM residents and attendings shared the accommodating learning style. This result was different than prior studies that found the majority of medical professionals had a converging learning style and other studies that found attendings often have different learning styles than residents. The issue of learning styles among emergency medical residents and attendings is important because learning style knowledge may have an impact on how a residency program structures curriculum and how EM residents are successfully, efficiently, and creatively educated.
Field Testing of Downgradient Uranium Mobility at an In-Situ Recovery Uranium Mine
NASA Astrophysics Data System (ADS)
Reimus, P. W.; Clay, J. T.; Rearick, M.; Perkins, G.; Brown, S. T.; Basu, A.; Chamberlain, K.
2015-12-01
In-situ recovery (ISR) mining of uranium involves the injection of O2 and CO2 (or NaHCO3) into saturated roll-front deposits to oxidize and solubilize the uranium, which is then removed by ion exchange at the surface and processed into U3O8. While ISR is economical and environmentally-friendly relative to conventional mining, one of the challenges of extracting uranium by this process is that it leaves behind a geochemically-altered aquifer that is exceedingly difficult to restore to pre-mining geochemical conditions, a regulatory objective. In this research, we evaluated the ability of the aquifer downgradient of an ISR mining area to attenuate the transport of uranium and other problem constituents that are mobilized by the mining process. Such an evaluation can help inform both regulators and the mining industry as to how much restoration of the mined ore zone is necessary to achieve regulatory compliance at various distances downgradient of the mining zone even if complete restoration of the ore zone proves to be difficult or impossible. Three single-well push-pull tests and one cross-well test were conducted in which water from an unrestored, previously-mined ore zone was injected into an unmined ore zone that served as a geochemical proxy for the downgradient aquifer. In all tests, non-reactive tracers were injected with the previously-mined ore zone water to allow the transport of uranium and other constituents to be compared to that of the nonreactive species. In the single-well tests, it was shown that the recovery of uranium relative to the nonreactive tracers ranged from 12-25%, suggesting significant attenuation capacity of the aquifer. In the cross-well test, selenate, molybdate and metavanadate were injected with the unrestored water to provide information on the transport of these potentially-problematic anionic constituents. In addition to the species-specific transport information, this test provided valuable constraints on redox conditions within the system, as redox couples involving these species collectively bracket the predicted transition redox potential for the U(VI)/U(IV) couple. Reduction should provide much longer-lasting immobilization of constituents than adsorption, especially given the inherent reducing characteristics of roll-front systems.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pasquale R. Perri
2003-05-15
This report describes the evaluation, design, and implementation of a DOE funded CO{sub 2} pilot project in the Lost Hills Field, Kern County, California. The pilot consists of four inverted (injector-centered) 5-spot patterns covering approximately 10 acres, and is located in a portion of the field, which has been under waterflood since early 1992. The target reservoir for the CO{sub 2} pilot is the Belridge Diatomite. The pilot location was selected based on geologic considerations, reservoir quality and reservoir performance during the waterflood. A CO{sub 2} pilot was chosen, rather than full-field implementation, to investigate uncertainties associated with CO{sub 2}more » utilization rate and premature CO{sub 2} breakthrough, and overall uncertainty in the unproven CO{sub 2} flood process in the San Joaquin Valley. A summary of the design and objectives of the CO{sub 2} pilot are included along with an overview of the Lost Hills geology, discussion of pilot injection and production facilities, and discussion of new wells drilled and remedial work completed prior to commencing injection. Actual CO{sub 2} injection began on August 31, 2000 and a comprehensive pilot monitoring and surveillance program has been implemented. Since the initiation of CO{sub 2} injection, the pilot has been hampered by excessive sand production in the pilot producers due to casing damage related to subsidence and exacerbated by the injected CO{sub 2}. Therefore CO{sub 2} injection was very sporadic in 2001 and 2002 and we experienced long periods of time with no CO{sub 2} injection. As a result of the continued mechanical problems, the pilot project was terminated on January 30, 2003. This report summarizes the injection and production performance and the monitoring results through December 31, 2002 including oil geochemistry, CO{sub 2} injection tracers, crosswell electromagnetic surveys, crosswell seismic, CO{sub 2} injection profiling, cased hole resistivity, tiltmetering results, and corrosion monitoring results. Although the Lost Hills CO{sub 2} pilot was not successful, the results and lessons learned presented in this report may be applicable to evaluate and design other potential San Joaquin Valley CO{sub 2} floods.« less
Developing 3D SEM in a broad biological context
Kremer, A; Lippens, S; Bartunkova, S; Asselbergh, B; Blanpain, C; Fendrych, M; Goossens, A; Holt, M; Janssens, S; Krols, M; Larsimont, J-C; Mc Guire, C; Nowack, MK; Saelens, X; Schertel, A; Schepens, B; Slezak, M; Timmerman, V; Theunis, C; Van Brempt, R; Visser, Y; GuÉRin, CJ
2015-01-01
When electron microscopy (EM) was introduced in the 1930s it gave scientists their first look into the nanoworld of cells. Over the last 80 years EM has vastly increased our understanding of the complex cellular structures that underlie the diverse functions that cells need to maintain life. One drawback that has been difficult to overcome was the inherent lack of volume information, mainly due to the limit on the thickness of sections that could be viewed in a transmission electron microscope (TEM). For many years scientists struggled to achieve three-dimensional (3D) EM using serial section reconstructions, TEM tomography, and scanning EM (SEM) techniques such as freeze-fracture. Although each technique yielded some special information, they required a significant amount of time and specialist expertise to obtain even a very small 3D EM dataset. Almost 20 years ago scientists began to exploit SEMs to image blocks of embedded tissues and perform serial sectioning of these tissues inside the SEM chamber. Using first focused ion beams (FIB) and subsequently robotic ultramicrotomes (serial block-face, SBF-SEM) microscopists were able to collect large volumes of 3D EM information at resolutions that could address many important biological questions, and do so in an efficient manner. We present here some examples of 3D EM taken from the many diverse specimens that have been imaged in our core facility. We propose that the next major step forward will be to efficiently correlate functional information obtained using light microscopy (LM) with 3D EM datasets to more completely investigate the important links between cell structures and their functions. Lay Description Life happens in three dimensions. For many years, first light, and then EM struggled to image the smallest parts of cells in 3D. With recent advances in technology and corresponding improvements in computing, scientists can now see the 3D world of the cell at the nanoscale. In this paper we present the results of high resolution 3D imaging in a number of diverse cells and tissues from multiple species. 3D reconstructions of cell structures often revealed them to be significantly more complex when compared to extrapolations made from 2D studies. Correlating functional 3D LM studies with 3D EM results opens up the possibility of making new strides in our understanding of how cell structure is connected to cell function. PMID:25623622
DOE Office of Scientific and Technical Information (OSTI.GOV)
Don, S; Cormack, R; Viswanathan, A
Purpose: To present a programmable robotic system for the accurate and fast deployment of an electromagnetic (EM) sensor for brachytherapy catheter localization. Methods: A robotic system for deployment of an EM sensor was designed and built. The system was programmed to increment the sensor position at specified time and space intervals. Sensor delivery accuracy was measured in a phantom using the localization of the EM sensor and tested in different environmental conditions. Accuracy was tested by measuring the distance between the physical locations reached by the sensor (measured by the EM tracker) and the intended programmed locations. Results: The systemmore » consisted of a stepper motor connected to drive wheels (that grip the cable to move the sensor) and a series of guides to connect to a brachytherapy transfer tube, all controlled by a programmable Arduino microprocessor. The total cost for parts was <$300. The positional accuracy of the sensor location was within 1 mm of the expected position provided by the motorized guide system. Acquisition speed to localize a brachytherapy catheter with 20 cm of active length was 10 seconds. The current design showed some cable slip and warping depending on environment temperature. Conclusion: The use of EM tracking for the localization of brachytherapy catheters has been previously demonstrated. Efficient data acquisition and artifact reduction requires fast and accurate deployment of an EM sensor in consistent, repeatable patterns, which cannot practically be achieved manually. The design of an inexpensive, programmable robot allowing for the precise deployment of stepping patterns was presented, and a prototype was built. Further engineering is necessary to ensure that the device provides efficient independent localization of brachytherapy catheters. This research was funded by the Kaye Family Award.« less
USDA-ARS?s Scientific Manuscript database
Chemical mutagenesis efficiently generates phenotypic variation in otherwise homogeneous genetic backgrounds, enabling functional analysis of genes. Advances in mutation detection have brought the utility of induced mutant populations on par with those produced by insertional mutagenesis, but system...
STEME: A Robust, Accurate Motif Finder for Large Data Sets
Reid, John E.; Wernisch, Lorenz
2014-01-01
Motif finding is a difficult problem that has been studied for over 20 years. Some older popular motif finders are not suitable for analysis of the large data sets generated by next-generation sequencing. We recently published an efficient approximation (STEME) to the EM algorithm that is at the core of many motif finders such as MEME. This approximation allows the EM algorithm to be applied to large data sets. In this work we describe several efficient extensions to STEME that are based on the MEME algorithm. Together with the original STEME EM approximation, these extensions make STEME a fully-fledged motif finder with similar properties to MEME. We discuss the difficulty of objectively comparing motif finders. We show that STEME performs comparably to existing prominent discriminative motif finders, DREME and Trawler, on 13 sets of transcription factor binding data in mouse ES cells. We demonstrate the ability of STEME to find long degenerate motifs which these discriminative motif finders do not find. As part of our method, we extend an earlier method due to Nagarajan et al. for the efficient calculation of motif E-values. STEME's source code is available under an open source license and STEME is available via a web interface. PMID:24625410
Reliability and Validity of Nonsymbolic and Symbolic Comparison Tasks in School-Aged Children.
Castro, Danilka; Estévez, Nancy; Gómez, David; Dartnell, Pablo Ricardo
2017-12-04
Basic numerical processing has been regularly assessed using numerical nonsymbolic and symbolic comparison tasks. It has been assumed that these tasks index similar underlying processes. However, the evidence concerning the reliability and convergent validity across different versions of these tasks is inconclusive. We explored the reliability and convergent validity between two numerical comparison tasks (nonsymbolic vs. symbolic) in school-aged children. The relations between performance in both tasks and mental arithmetic were described and a developmental trajectories' analysis was also conducted. The influence of verbal and visuospatial working memory processes and age was controlled for in the analyses. Results show significant reliability (p < .001) between Block 1 and 2 for nonsymbolic task (global adjusted RT (adjRT): r = .78, global efficiency measures (EMs): r = .74) and, for symbolic task (adjRT: r = .86, EMs: r = .86). Also, significant convergent validity between tasks (p < .001) for both adjRT (r = .71) and EMs (r = .70) were found after controlling for working memory and age. Finally, it was found the relationship between nonsymbolic and symbolic efficiencies varies across the sample's age range. Overall, these findings suggest both tasks index the same underlying cognitive architecture and are appropriate to explore the Approximate Number System (ANS) characteristics. The evidence supports the central role of ANS in arithmetic efficiency and suggests there are differences across the age range assessed, concerning the extent to which efficiency in nonsymbolic and symbolic tasks reflects ANS acuity.
Efficient sequential and parallel algorithms for finding edit distance based motifs.
Pal, Soumitra; Xiao, Peng; Rajasekaran, Sanguthevar
2016-08-18
Motif search is an important step in extracting meaningful patterns from biological data. The general problem of motif search is intractable and there is a pressing need to develop efficient, exact and approximation algorithms to solve this problem. In this paper, we present several novel, exact, sequential and parallel algorithms for solving the (l,d) Edit-distance-based Motif Search (EMS) problem: given two integers l,d and n biological strings, find all strings of length l that appear in each input string with atmost d errors of types substitution, insertion and deletion. One popular technique to solve the problem is to explore for each input string the set of all possible l-mers that belong to the d-neighborhood of any substring of the input string and output those which are common for all input strings. We introduce a novel and provably efficient neighborhood exploration technique. We show that it is enough to consider the candidates in neighborhood which are at a distance exactly d. We compactly represent these candidate motifs using wildcard characters and efficiently explore them with very few repetitions. Our sequential algorithm uses a trie based data structure to efficiently store and sort the candidate motifs. Our parallel algorithm in a multi-core shared memory setting uses arrays for storing and a novel modification of radix-sort for sorting the candidate motifs. The algorithms for EMS are customarily evaluated on several challenging instances such as (8,1), (12,2), (16,3), (20,4), and so on. The best previously known algorithm, EMS1, is sequential and in estimated 3 days solves up to instance (16,3). Our sequential algorithms are more than 20 times faster on (16,3). On other hard instances such as (9,2), (11,3), (13,4), our algorithms are much faster. Our parallel algorithm has more than 600 % scaling performance while using 16 threads. Our algorithms have pushed up the state-of-the-art of EMS solvers and we believe that the techniques introduced in this paper are also applicable to other motif search problems such as Planted Motif Search (PMS) and Simple Motif Search (SMS).
USDA-ARS?s Scientific Manuscript database
Ethyl methanesulfonate (EMS) efficiently generates high-density mutations in genomes. Conventionally, these mutations are identified by techniques that can detect single-nucleotide mismatches in heteroduplexes of individual PCR amplicons. We applied whole-genome sequencing to 256-phenotyped mutant l...
Liu, Xu; Chen, Haiping; Xue, Chen
2018-01-01
Objectives Emergency medical system for mass casualty incidents (EMS-MCIs) is a global issue. However, China lacks such studies extremely, which cannot meet the requirement of rapid decision-support system. This study aims to realize modeling EMS-MCIs in Shanghai, to improve mass casualty incident (MCI) rescue efficiency in China, and to provide a possible method of making rapid rescue decisions during MCIs. Methods This study established a system dynamics (SD) model of EMS-MCIs using the Vensim DSS program. Intervention scenarios were designed as adjusting scales of MCIs, allocation of ambulances, allocation of emergency medical staff, and efficiency of organization and command. Results Mortality increased with the increasing scale of MCIs, medical rescue capability of hospitals was relatively good, but the efficiency of organization and command was poor, and the prehospital time was too long. Mortality declined significantly when increasing ambulances and improving the efficiency of organization and command; triage and on-site first-aid time were shortened if increasing the availability of emergency medical staff. The effect was the most evident when 2,000 people were involved in MCIs; however, the influence was very small under the scale of 5,000 people. Conclusion The keys to decrease the mortality of MCIs were shortening the prehospital time and improving the efficiency of organization and command. For small-scale MCIs, improving the utilization rate of health resources was important in decreasing the mortality. For large-scale MCIs, increasing the number of ambulances and emergency medical professionals was the core to decrease prehospital time and mortality. For super-large-scale MCIs, increasing health resources was the premise. PMID:29440876
NASA Astrophysics Data System (ADS)
Rabenok, L.; Grimalsky, V.; De La Hidalga-W., J.
2006-09-01
The report is devoted to applications of the microwave therapy. 50 patients with acute purulent-inflammatory diseases of the hand were examined with using our method of treatment with electromagnetic (EM) microwave field in an outpatient clinic. We used a portable apparatus that operates in the millimeter (mm) wave range in 4 regimes. The intensity of EM radiation was 2-10 mW/cm2. A peculiarity of the method was an absence of any antibacterial medicine during the treatment. We conclude that using EM microwave fields seems very efficient in a complex treatment of acute purulent-inflammatory diseases of the hand in an outpatient clinic. An interpretation of the obtained results is given due to the resonant character of the interaction of EM radiation with molecular and cellular structures.
2012-01-01
Background Elementary mode (EM) analysis is ideally suited for metabolic engineering as it allows for an unbiased decomposition of metabolic networks in biologically meaningful pathways. Recently, constrained minimal cut sets (cMCS) have been introduced to derive optimal design strategies for strain improvement by using the full potential of EM analysis. However, this approach does not allow for the inclusion of regulatory information. Results Here we present an alternative, novel and simple method for the prediction of cMCS, which allows to account for boolean transcriptional regulation. We use binary linear programming and show that the design of a regulated, optimal metabolic network of minimal functionality can be formulated as a standard optimization problem, where EM and regulation show up as constraints. We validated our tool by optimizing ethanol production in E. coli. Our study showed that up to 70% of the predicted cMCS contained non-enzymatic, non-annotated reactions, which are difficult to engineer. These cMCS are automatically excluded by our approach utilizing simple weight functions. Finally, due to efficient preprocessing, the binary program remains computationally feasible. Conclusions We used integer programming to predict efficient deletion strategies to metabolically engineer a production organism. Our formulation utilizes the full potential of cMCS but adds additional flexibility to the design process. In particular our method allows to integrate regulatory information into the metabolic design process and explicitly favors experimentally feasible deletions. Our method remains manageable even if millions or potentially billions of EM enter the analysis. We demonstrated that our approach is able to correctly predict the most efficient designs for ethanol production in E. coli. PMID:22898474
NASA Technical Reports Server (NTRS)
Estes, Lyndon D.; Beukes, Hein; Bradley, Bethany A.; Debats, Stephanie R.; Oppenheimer, Michael; Ruane, Alex C.; Schulze, Roland; Tadross, Mark
2013-01-01
Crop model-specific biases are a key uncertainty affecting our understanding of climate change impacts to agriculture. There is increasing research focus on intermodel variation, but comparisons between mechanistic (MMs) and empirical models (EMs) are rare despite both being used widely in this field. We combined MMs and EMs to project future (2055) changes in the potential distribution (suitability) and productivity of maize and spring wheat in South Africa under 18 downscaled climate scenarios (9 models run under 2 emissions scenarios). EMs projected larger yield losses or smaller gains than MMs. The EMs' median-projected maize and wheat yield changes were 3.6% and 6.2%, respectively, compared to 6.5% and 15.2% for the MM. The EM projected a 10% reduction in the potential maize growing area, where the MM projected a 9% gain. Both models showed increases in the potential spring wheat production region (EM = 48%, MM = 20%), but these results were more equivocal because both models (particularly the EM) substantially overestimated the extent of current suitability. The substantial water-use efficiency gains simulated by the MMs under elevated CO2 accounted for much of the EMMM difference, but EMs may have more accurately represented crop temperature sensitivities. Our results align with earlier studies showing that EMs may show larger climate change losses than MMs. Crop forecasting efforts should expand to include EMMM comparisons to provide a fuller picture of crop-climate response uncertainties.
Emergency medicine as a specialty in Asia
Ho, Hiu Fai; Ramakrishnan, T. V.; Jamaluddin, Sabariah Faizah; Mesa‐Gaerlan, Faith Joan C.; Tiru, Mohan; Hwang, Sung Oh; Choi, Wai‐Mau; Kanchanasut, Somchai; Khruekarnchana, Pairoj; Avsarogullari, Levent; Shimazu, Takeshi; Hori, Shingo
2015-01-01
Aim We aim to examine the similarities and differences in areas of EM development, workload, workforce, and capabilities and support in the Asia region. Emerging challenges faced by our EM community are also discussed. Methods The National Societies for Emergency Medicine of Hong Kong, India, Japan, Malaysia, Philippines, Singapore, South Korea, Taiwan, Thailand and Turkey participated in the joint Japanese Association of Acute Medicine (JAAM) and Asian Conference of Emergency Medicine (ACEM) Special Symposium held in October 2013 at Tokyo, Japan. The findings are reviewed in this paper. Results Emergency medicine (EM) has over the years evolved into a distinct and recognized medical discipline requiring a unique set of cognitive, administrative and technical skills for managing all types of patients with acute illness or injury. EM has contributed to healthcare by providing effective, safe, efficient and cost‐effective patient care. Integrated systems have developed to allow continuity of emergency care from the community into emergency departments. Structured training curriculum for undergraduates, and specialty training programs for postgraduates are in place to equip trainees with the knowledge and skills required for the unique practice of EM. Conclusion The practice of EM still varies among the Asian countries. However, as a region, we strive to continue in our efforts to develop the specialty and improve the delivery of EM. PMID:29123755
ATOMIC RESOLUTION CRYO ELECTRON MICROSCOPY OF MACROMOLECULAR COMPLEXES
ZHOU, Z. HONG
2013-01-01
Single-particle cryo electron microscopy (cryoEM) is a technique for determining three-dimensional (3D) structures from projection images of molecular complexes preserved in their “native,” noncrystalline state. Recently, atomic or near-atomic resolution structures of several viruses and protein assemblies have been determined by single-particle cryoEM, allowing ab initio atomic model building by following the amino acid side chains or nucleic acid bases identifiable in their cryoEM density maps. In particular, these cryoEM structures have revealed extended arms contributing to molecular interactions that are otherwise not resolved by the conventional structural method of X-ray crystallography at similar resolutions. High-resolution cryoEM requires careful consideration of a number of factors, including proper sample preparation to ensure structural homogeneity, optimal configuration of electron imaging conditions to record high-resolution cryoEM images, accurate determination of image parameters to correct image distortions, efficient refinement and computation to reconstruct a 3D density map, and finally appropriate choice of modeling tools to construct atomic models for functional interpretation. This progress illustrates the power of cryoEM and ushers it into the arsenal of structural biology, alongside conventional techniques of X-ray crystallography and NMR, as a major tool (and sometimes the preferred one) for the studies of molecular interactions in supramolecular assemblies or machines. PMID:21501817
Emergency medicine as a specialty in Asia.
Pek, Jen Heng; Lim, Swee Han; Ho, Hiu Fai; Ramakrishnan, T V; Jamaluddin, Sabariah Faizah; Mesa-Gaerlan, Faith Joan C; Tiru, Mohan; Hwang, Sung Oh; Choi, Wai-Mau; Kanchanasut, Somchai; Khruekarnchana, Pairoj; Avsarogullari, Levent; Shimazu, Takeshi; Hori, Shingo
2016-04-01
We aim to examine the similarities and differences in areas of EM development, workload, workforce, and capabilities and support in the Asia region. Emerging challenges faced by our EM community are also discussed. The National Societies for Emergency Medicine of Hong Kong, India, Japan, Malaysia, Philippines, Singapore, South Korea, Taiwan, Thailand and Turkey participated in the joint Japanese Association of Acute Medicine (JAAM) and Asian Conference of Emergency Medicine (ACEM) Special Symposium held in October 2013 at Tokyo, Japan. The findings are reviewed in this paper. Emergency medicine (EM) has over the years evolved into a distinct and recognized medical discipline requiring a unique set of cognitive, administrative and technical skills for managing all types of patients with acute illness or injury. EM has contributed to healthcare by providing effective, safe, efficient and cost-effective patient care. Integrated systems have developed to allow continuity of emergency care from the community into emergency departments. Structured training curriculum for undergraduates, and specialty training programs for postgraduates are in place to equip trainees with the knowledge and skills required for the unique practice of EM. The practice of EM still varies among the Asian countries. However, as a region, we strive to continue in our efforts to develop the specialty and improve the delivery of EM.
Applications of hybrid genetic algorithms in seismic tomography
NASA Astrophysics Data System (ADS)
Soupios, Pantelis; Akca, Irfan; Mpogiatzis, Petros; Basokur, Ahmet T.; Papazachos, Constantinos
2011-11-01
Almost all earth sciences inverse problems are nonlinear and involve a large number of unknown parameters, making the application of analytical inversion methods quite restrictive. In practice, most analytical methods are local in nature and rely on a linearized form of the problem equations, adopting an iterative procedure which typically employs partial derivatives in order to optimize the starting (initial) model by minimizing a misfit (penalty) function. Unfortunately, especially for highly non-linear cases, the final model strongly depends on the initial model, hence it is prone to solution-entrapment in local minima of the misfit function, while the derivative calculation is often computationally inefficient and creates instabilities when numerical approximations are used. An alternative is to employ global techniques which do not rely on partial derivatives, are independent of the misfit form and are computationally robust. Such methods employ pseudo-randomly generated models (sampling an appropriately selected section of the model space) which are assessed in terms of their data-fit. A typical example is the class of methods known as genetic algorithms (GA), which achieves the aforementioned approximation through model representation and manipulations, and has attracted the attention of the earth sciences community during the last decade, with several applications already presented for several geophysical problems. In this paper, we examine the efficiency of the combination of the typical regularized least-squares and genetic methods for a typical seismic tomography problem. The proposed approach combines a local (LOM) and a global (GOM) optimization method, in an attempt to overcome the limitations of each individual approach, such as local minima and slow convergence, respectively. The potential of both optimization methods is tested and compared, both independently and jointly, using the several test models and synthetic refraction travel-time date sets that employ the same experimental geometry, wavelength and geometrical characteristics of the model anomalies. Moreover, real data from a crosswell tomographic project for the subsurface mapping of an ancient wall foundation are used for testing the efficiency of the proposed algorithm. The results show that the combined use of both methods can exploit the benefits of each approach, leading to improved final models and producing realistic velocity models, without significantly increasing the required computation time.
Knapp, Jenny; Sako, Yasuhito; Grenouillet, Frédéric; Bresson-Hadni, Solange; Richou, Carine; Gbaguidi-Haore, Houssein; Ito, Akira; Millon, Laurence
2014-01-01
Serological diagnosis of alveolar echinococcosis (AE) is a key element for efficient patient treatment management. A rapid immunochromatography test kit (ICT) using the recombinant Em18 antigen (rEm18) was recently developed. The aim of our study was to assess this test on a panel of sera from French patients with alveolar echinococcosis and control patients. In a blind test, a total of 112 serum samples were tested including samples of AE (n = 30), cystic echinococcosis [CE] (n = 15), and polycystic echinococcosis [PE] (n = 1). For the comparison, 66 sera from patients with hepatocarcinoma, fascioliasis, toxocariasis, Caroli’s disease, or autoimmune chronic active hepatitis were used. The diagnostic test sets we used were the rEm18-ICT and two validated ELISAs with rEm18 and Em2-Em18 antigens, respectively. For the ICT, 27/30 sera from AE patients, 4/15 sera from CE patients and the PE patient serum were positive. One serum from the control panel (toxocariasis) was positive for the ICT. The rEm18-ICT sensitivity (90.0%) and specificity (92.7%) for detection of Em18-specific antibodies confirmed it as a relevant tool for AE diagnosis. The rEm18-ELISA had a sensitivity of 86.7% and specificity of 91.5%, and the Em2-Em18-ELISA had a sensitivity of 96.7% and specificity of 87.8%. However, when AE patient sera are recorded as weak in intensity with the ICT, we recommend a double reading and use of a reference sample if the ICT is used for patient follow-up. PMID:25058754
Knapp, Jenny; Sako, Yasuhito; Grenouillet, Frédéric; Bresson-Hadni, Solange; Richou, Carine; Gbaguidi-Haore, Houssein; Ito, Akira; Millon, Laurence
2014-01-01
Serological diagnosis of alveolar echinococcosis (AE) is a key element for efficient patient treatment management. A rapid immunochromatography test kit (ICT) using the recombinant Em18 antigen (rEm18) was recently developed. The aim of our study was to assess this test on a panel of sera from French patients with alveolar echinococcosis and control patients. In a blind test, a total of 112 serum samples were tested including samples of AE (n = 30), cystic echinococcosis [CE] (n = 15), and polycystic echinococcosis [PE] (n = 1). For the comparison, 66 sera from patients with hepatocarcinoma, fascioliasis, toxocariasis, Caroli's disease, or autoimmune chronic active hepatitis were used. The diagnostic test sets we used were the rEm18-ICT and two validated ELISAs with rEm18 and Em2-Em18 antigens, respectively. For the ICT, 27/30 sera from AE patients, 4/15 sera from CE patients and the PE patient serum were positive. One serum from the control panel (toxocariasis) was positive for the ICT. The rEm18-ICT sensitivity (90.0%) and specificity (92.7%) for detection of Em18-specific antibodies confirmed it as a relevant tool for AE diagnosis. The rEm18-ELISA had a sensitivity of 86.7% and specificity of 91.5%, and the Em2-Em18-ELISA had a sensitivity of 96.7% and specificity of 87.8%. However, when AE patient sera are recorded as weak in intensity with the ICT, we recommend a double reading and use of a reference sample if the ICT is used for patient follow-up. © J. Knapp et al., published by EDP Sciences, 2014.
2011-07-27
Ion Battery Packs Advanced Chemistry Batteries EM Armor Power Brick 8 UNCLASSIFIED Concepts Platform Simulation Component Development Vehicle...Advanced Turbocharging, Supercharging, OPOC Efficient Powertrain Technologies Electrified Accessories Energy Harvesting SiC Electronics Lithium
Processing of Cryo-EM Movie Data.
Ripstein, Z A; Rubinstein, J L
2016-01-01
Direct detector device (DDD) cameras dramatically enhance the capabilities of electron cryomicroscopy (cryo-EM) due to their improved detective quantum efficiency (DQE) relative to other detectors. DDDs use semiconductor technology that allows micrographs to be recorded as movies rather than integrated individual exposures. Movies from DDDs improve cryo-EM in another, more surprising, way. DDD movies revealed beam-induced specimen movement as a major source of image degradation and provide a way to partially correct the problem by aligning frames or regions of frames to account for this specimen movement. In this chapter, we use a self-consistent mathematical notation to explain, compare, and contrast several of the most popular existing algorithms for computationally correcting specimen movement in DDD movies. We conclude by discussing future developments in algorithms for processing DDD movies that would extend the capabilities of cryo-EM even further. © 2016 Elsevier Inc. All rights reserved.
Next Generation Electromagnetic Pump Analysis Tools (PLM DOC-0005-2188). Final Report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stregy, Seth; Dasilva, Ana; Yilmaz, Serkan
2015-10-29
This report provides the broad historical review of EM Pump development and details of MATRIX development under this project. This report summarizes the efforts made to modernize the legacy performance models used in previous EM Pump designs and the improvements made to the analysis tools. This report provides information on Tasks 1, 3, and 4 of the entire project. The research for Task 4 builds upon Task 1: Update EM Pump Databank and Task 3: Modernize the Existing EM Pump Analysis Model, which are summarized within this report. Where research for Task 2: Insulation Materials Development and Evaluation identified parametersmore » applicable to the analysis model with Task 4, the analysis code was updated, and analyses were made for additional materials. The important design variables for the manufacture and operation of an EM Pump that the model improvement can evaluate are: space constraints; voltage capability of insulation system; maximum flux density through iron; flow rate and outlet pressure; efficiency and manufacturability. The development of the next-generation EM Pump analysis tools during this two-year program provides information in three broad areas: Status of analysis model development; Improvements made to older simulations; and Comparison to experimental data.« less
Preseismic Velocity Changes Observed from Active Source Monitoringat the Parkfield SAFOD Drill Site
DOE Office of Scientific and Technical Information (OSTI.GOV)
Daley, Thomas; Niu, Fenglin; Silver, Paul G.
2008-06-10
Measuring stress changes within seismically active fault zones has been a long-sought goal of seismology. Here we show that such stress changes are measurable by exploiting the stress dependence of seismic wave speed from an active source cross-well experiment conducted at the SAFOD drill site. Over a two-month period we observed an excellent anti-correlation between changes in the time required for an S wave to travel through the rock along a fixed pathway--a few microseconds--and variations in barometric pressure. We also observed two large excursions in the traveltime data that are coincident with two earthquakes that are among those predictedmore » to produce the largest coseismic stress changes at SAFOD. Interestingly, the two excursions started approximately 10 and 2 hours before the events, respectively, suggesting that they may be related to pre-rupture stress induced changes in crack properties, as observed in early laboratory studies.« less
NASA Astrophysics Data System (ADS)
Letu, H.; Ishimoto, H.; Riedi, J.; Nakajima, T. Y.; -Labonnote, L. C.; Baran, A. J.; Nagao, T. M.; Skiguchi, M.
2015-11-01
Various ice particle habits are investigated in conjunction with inferring the optical properties of ice cloud for the Global Change Observation Mission-Climate (GCOM-C) satellite program. A database of the single-scattering properties of five ice particle habits, namely, plates, columns, droxtals, bullet-rosettes, and Voronoi, is developed. The database is based on the specification of the Second Generation Global Imager (SGLI) sensor onboard the GCOM-C satellite, which is scheduled to be launched in 2017 by Japan Aerospace Exploration Agency (JAXA). A combination of the finite-difference time-domain (FDTD) method, Geometric Optics Integral Equation (GOIE) technique, and geometric optics method (GOM) are applied to compute the single-scattering properties of the selected ice particle habits at 36 wavelengths, from the visible-to-infrared spectral region, covering the SGLI channels for the size parameter, which is defined with respect to the equivalent-volume radius sphere, which ranges between 6 and 9000. The database includes the extinction efficiency, absorption efficiency, average geometrical cross-section, single-scattering albedo, asymmetry factor, size parameter of an equivalent volume sphere, maximum distance from the center of mass, particle volume, and six non-zero elements of the scattering phase matrix. The characteristics of the calculated extinction efficiency, single-scattering albedo, and asymmetry factor of the five ice particle habits are compared. Furthermore, the optical thickness and spherical albedo of ice clouds using the five ice particle habit models are retrieved from the Polarization and Directionality of the Earth's Reflectances-3 (POLDER-3) measurements on board the Polarization and Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar (PARASOL). The optimal ice particle habit for retrieving the SGLI ice cloud properties was investigated by adopting the spherical albedo difference (SAD) method. It is found that the SAD, for bullet-rosette particle, with radii of equivalent volume spheres (r~) ranging between 6 to 10 μm, and the Voronoi particle, with r~ ranging between 28 to 38 μm, and 70 to 100 μm, is distributed stably as the scattering angle increases. It is confirmed that the SAD of small bullet rosette and all sizes of voronoi particles has a low angular dependence, indicating that the combination of the bullet-rosette and Voronoi models are sufficient for retrieval of the ice cloud spherical albedo and optical thickness as an effective habit models of the SGLI sensor. Finally, SAD analysis based on the Voronoi habit model with moderate particles (r~ = 30 μm) is compared to the conventional General Habit Mixture (GHM), Inhomogeneous Hexagonal Monocrystal (IHM), 5-plate aggregate and ensemble ice particle model. It is confirmed that the Voronoi habit model has an effect similar to the counterparts of some conventional models on the retrieval of ice cloud properties from space-borne radiometric observations.
Technology Catalogue. First edition
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1994-02-01
The Department of Energy`s Office of Environmental Restoration and Waste Management (EM) is responsible for remediating its contaminated sites and managing its waste inventory in a safe and efficient manner. EM`s Office of Technology Development (OTD) supports applied research and demonstration efforts to develop and transfer innovative, cost-effective technologies to its site clean-up and waste management programs within EM`s Office of Environmental Restoration and Office of Waste Management. The purpose of the Technology Catalogue is to provide performance data on OTD-developed technologies to scientists and engineers assessing and recommending technical solutions within the Department`s clean-up and waste management programs, asmore » well as to industry, other federal and state agencies, and the academic community. OTD`s applied research and demonstration activities are conducted in programs referred to as Integrated Demonstrations (IDs) and Integrated Programs (IPs). The IDs test and evaluate.systems, consisting of coupled technologies, at specific sites to address generic problems, such as the sensing, treatment, and disposal of buried waste containers. The IPs support applied research activities in specific applications areas, such as in situ remediation, efficient separations processes, and site characterization. The Technology Catalogue is a means for communicating the status. of the development of these innovative technologies. The FY93 Technology Catalogue features technologies successfully demonstrated in the field through IDs and sufficiently mature to be used in the near-term. Technologies from the following IDs are featured in the FY93 Technology Catalogue: Buried Waste ID (Idaho National Engineering Laboratory, Idaho); Mixed Waste Landfill ID (Sandia National Laboratories, New Mexico); Underground Storage Tank ID (Hanford, Washington); Volatile organic compound (VOC) Arid ID (Richland, Washington); and VOC Non-Arid ID (Savannah River Site, South Carolina).« less
Biceps brachii muscle oxygenation in electrical muscle stimulation.
Muthalib, Makii; Jubeau, Marc; Millet, Guillaume Y; Maffiuletti, Nicola A; Ferrari, Marco; Nosaka, Kazunori
2010-09-01
The purpose of this study was to compare between electrical muscle stimulation (EMS) and maximal voluntary (VOL) isometric contractions of the elbow flexors for changes in biceps brachii muscle oxygenation (tissue oxygenation index, TOI) and haemodynamics (total haemoglobin volume, tHb = oxygenated-Hb + deoxygenated-Hb) determined by near-infrared spectroscopy (NIRS). The biceps brachii muscle of 10 healthy men (23-39 years) was electrically stimulated at high frequency (75 Hz) via surface electrodes to evoke 50 intermittent (4-s contraction, 15-s relaxation) isometric contractions at maximum tolerated current level (EMS session). The contralateral arm performed 50 intermittent (4-s contraction, 15-s relaxation) maximal voluntary isometric contractions (VOL session) in a counterbalanced order separated by 2-3 weeks. Results indicated that although the torque produced during EMS was approximately 50% of VOL (P<0.05), there was no significant difference in the changes in TOI amplitude or TOI slope between EMS and VOL over the 50 contractions. However, the TOI amplitude divided by peak torque was approximately 50% lower for EMS than VOL (P<0.05), which indicates EMS was less efficient than VOL. This seems likely because of the difference in the muscles involved in the force production between conditions. Mean decrease in tHb amplitude during the contraction phases was significantly (P<0.05) greater for EMS than VOL from the 10th contraction onwards, suggesting that the muscle blood volume was lower in EMS than VOL. It is concluded that local oxygen demand of the biceps brachii sampled by NIRS is similar between VOL and EMS.
Coupled geophysical-hydrological modeling of controlled NAPL spill
NASA Astrophysics Data System (ADS)
Kowalsky, M. B.; Majer, E.; Peterson, J. E.; Finsterle, S.; Mazzella, A.
2006-12-01
Past studies have shown reasonable sensitivity of geophysical data for detecting or monitoring the movement of non-aqueous phase liquids (NAPLs) in the subsurface. However, heterogeneity in subsurface properties and in NAPL distribution commonly results in non-unique data interpretation. Combining multiple geophysical data types and incorporating constraints from hydrological models will potentially decrease the non-uniqueness in data interpretation and aid in site characterization. Large-scale laboratory experiments have been conducted over several years to evaluate the use of various geophysical methods, including ground-penetrating radar (GPR), seismic, and electrical methods, for monitoring controlled spills of tetrachloroethylene (PCE), a hazardous industrial solvent that is pervasive in the subsurface. In the current study, we consider an experiment in which PCE was introduced into a large tank containing a heterogeneous distribution of sand and clay mixtures, and allowed to migrate while time-lapse geophysical data were collected. We consider two approaches for interpreting the surface GPR and crosswell seismic data. The first approach involves (a) waveform inversion of the surface GPR data using a non-gradient based optimization algorithm to estimate the dielectric constant distributions and (b) conversion of crosswell seismic travel times to acoustic velocity distributions; the dielectric constant and acoustic velocity distributions are then related to NAPL saturation using appropriate petrophysical models. The second approach takes advantage of a recently developed framework for coupled hydrological-geophysical modeling, providing a hydrological constraint on interpretation of the geophysical data and additionally resulting in quantitative estimates of the most relevant hydrological parameters that determine NAPL behavior in the system. Specifically, we simulate NAPL migration using the multiphase multicomponent flow simulator TOUGH2 with a 2-D radial model that takes advantage of radial symmetry in the experimental setup. The flow model is coupled to forward models for simulating the GPR and seismic measurements, and joint inversion of the multiple data types results in images of time-varying NAPL saturation distributions. Comparison of the two approaches with results of the post-experiment excavation indicate that combining geophysical data types and incorporating hydrological constraints improves estimates of NAPL saturation relative to the conventional interpretation of the geophysical data sets. Notice: Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect the official Agency policy. Mention of trade names or commercial products does not constitute endorsement or recommendation by EPA for use. This work was supported, in part, by the U.S. Dept. of Energy under Contract No. DE-AC02- 05CH11231.
Metasurface Salisbury screen: achieving ultra-wideband microwave absorption.
Zhou, Ziheng; Chen, Ke; Zhao, Junming; Chen, Ping; Jiang, Tian; Zhu, Bo; Feng, Yijun; Li, Yue
2017-11-27
The metasurfaces have recently been demonstrated to provide full control of the phase responses of electromagnetic (EM) wave scattering over subwavelength scales, enabling a wide range of practical applications. Here, we propose a comprehensive scheme for the efficient and flexible design of metasurface Salisbury screen (MSS) capable of absorbing the impinging EM wave in an ultra-wide frequency band. We show that properly designed reflective metasurface can be used to substitute the metallic ground of conventional Salisbury screen for generating diverse resonances in a desirable way, thus providing large controllability over the absorption bandwidth. Based on this concept, we establish an equivalent circuit model to qualitatively analysis the resonances in MSS and design algorithms to optimize the overall performance of the MSS. Experiments have been carried out to demonstrate that the absorption bandwidth from 6 GHz to 30 GHz with an efficiency higher than 85% can be achieved by the proposal, which is apparently much larger than that of conventional Salisbury screen (7 GHz - 17 GHz). The proposed concept of MSS could offer opportunities for flexibly designing thin electromagnetic absorbers with simultaneously ultra-wide bandwidth, polarization insensitivity, and wide incident angle, exhibiting promising potentials for many applications such as in EM compatibility, stealth technique, etc.
NASA Technical Reports Server (NTRS)
Deshpande, Manohar
2011-01-01
A precise knowledge of the interior structure of asteroids, comets, and Near Earth Objects (NEO) is important to assess the consequences of their impacts with the Earth and develop efficient mitigation strategies. Knowledge of their interior structure also provides opportunities for extraction of raw materials for future space activities. Low frequency radio sounding is often proposed for investigating interior structures of asteroids and NEOs. For designing and optimizing radio sounding instrument it is advantageous to have an accurate and efficient numerical simulation model of radio reflection and transmission through large size bodies of asteroid shapes. In this presentation we will present electromagnetic (EM) scattering analysis of electrically large size asteroids using (1) a weak form formulation and (2) also a more accurate hybrid finite element method/method of moments (FEM/MOM) to help estimate their internal structures. Assuming the internal structure with known electrical properties of a sample asteroid, we first develop its forward EM scattering model. From the knowledge of EM scattering as a function of frequency and look angle we will then present the inverse scattering procedure to extract its interior structure image. Validity of the inverse scattering procedure will be presented through few simulation examples.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Seyedhosseini, Mojtaba; Kumar, Ritwik; Jurrus, Elizabeth R.
2011-10-01
Automated neural circuit reconstruction through electron microscopy (EM) images is a challenging problem. In this paper, we present a novel method that exploits multi-scale contextual information together with Radon-like features (RLF) to learn a series of discriminative models. The main idea is to build a framework which is capable of extracting information about cell membranes from a large contextual area of an EM image in a computationally efficient way. Toward this goal, we extract RLF that can be computed efficiently from the input image and generate a scale-space representation of the context images that are obtained at the output ofmore » each discriminative model in the series. Compared to a single-scale model, the use of a multi-scale representation of the context image gives the subsequent classifiers access to a larger contextual area in an effective way. Our strategy is general and independent of the classifier and has the potential to be used in any context based framework. We demonstrate that our method outperforms the state-of-the-art algorithms in detection of neuron membranes in EM images.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
P. H. Titus, S. Avasaralla, A.Brooks, R. Hatcher
2010-09-22
The National Spherical Torus Experiment (NSTX) project is planning upgrades to the toroidal field, plasma current and pulse length. This involves the replacement of the center-stack, including the inner legs of the TF, OH, and inner PF coils. A second neutral beam will also be added. The increased performance of the upgrade requires qualification of the remaining components including the vessel, passive plates, and divertor for higher disruption loads. The hardware needing qualification is more complex than is typically accessible by large scale electromagnetic (EM) simulations of the plasma disruptions. The usual method is to include simplified representations of componentsmore » in the large EM models and attempt to extract forces to apply to more detailed models. This paper describes a more efficient approach of combining comprehensive modeling of the plasma and tokamak conducting structures, using the 2D OPERA code, with much more detailed treatment of individual components using ANSYS electromagnetic (EM) and mechanical analysis. This capture local eddy currents and resulting loads in complex details, and allows efficient non-linear, and dynamic structural analyses.« less
Jamshaid, Anila; Ather, M Hammad; Hussain, Ghazi; Khawaja, Karim B
2008-11-01
This study compared the efficacy and safety profile of electrohydraulic (EH) and electromagnetic (EM) lithotriptors in the treatment of 10- to 20-mm renal and proximal ureteric stones at a single center and by a single operator. Between January 2001 and December 2006, we sequentially treated patients meeting study inclusion criteria with MPL 9000 Dornier EH for the first 3 years, followed by the EM Siemens Modularis shockwave lithotripsy (SWL) unit. A single operator performed all SWL treatments under the supervision of an admitting urologist. We analyzed the demographic features and stone- and treatment-related parameters including complications for both groups. In each group, the stone-free rate and efficiency quotient was determined at 1-3 months. Of 274 patients, we sequentially treated 112 using the EH lithotriptor, and 162 the EM lithotriptor. The pre-SWL patients and stone-related parameters were similar in the two groups, except for diagnostic imaging modalities. The mean number of SWL sessions, need for ancillary procedure, retreatment rate, stone location, stone-free rate, and efficiency quotient were not significantly different between groups. The mean number of shockwaves required for complete fragmentation was 2977 and 6044 (P < .000) for the EH and EM groups, respectively. Single center, single operator experience with two types of lithotriptor indicated that both are equally efficacious, with similar safety profiles. The only significant difference was that the EH lithotriptor required fewer shockwaves for fragmentation.
High-performance terahertz wave absorbers made of silicon-based metamaterials
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yin, Sheng; Zhu, Jianfei; Jiang, Wei
2015-08-17
Electromagnetic (EM) wave absorbers with high efficiency in different frequency bands have been extensively investigated for various applications. In this paper, we propose an ultra-broadband and polarization-insensitive terahertz metamaterial absorber based on a patterned lossy silicon substrate. Experimentally, a large absorption efficiency more than 95% in a frequency range of 0.9–2.5 THz was obtained up to a wave incident angle as large as 70°. Much broader absorption bandwidth and excellent oblique incidence absorption performance are numerically demonstrated. The underlying mechanisms due to the combination of a waveguide cavity mode and impedance-matched diffraction are analyzed in terms of the field patternsmore » and the scattering features. The monolithic THz absorber proposed here may find important applications in EM energy harvesting systems such as THz barometer or biosensor.« less
Broadband unidirectional cloaks based on flat metasurface focusing lenses
NASA Astrophysics Data System (ADS)
Li, Yongfeng; Zhang, Jieqiu; Qu, Shaobo; Wang, Jiafu; Pang, Yongqiang; Xu, Zhuo; Zhang, Anxue
2015-08-01
Bandwidth extension and thickness reduction are now the two key issues of cloaks. In this paper, we propose to achieve broadband, thin uni-directional electromagnetic (EM) cloaks using metasurfaces. To this end, a wideband flat focusing lens is firstly devised based on high-efficiency transmissive metasurfaces. Due to the nearly dispersionless parabolic phase profile along the metasurface in the operating band, incident plane waves can be focused efficiently after passing through the metasurface. Broadband unidirectional EM cloaks were then designed by combining two identical flat lenses. Upon illumination, the incident plane waves are firstly focused by one lens and then are restored by the other lens, avoiding the cloaked region. Both simulation and experiment results verify the broadband unidirectional cloak. The broad bandwidth and small thickness of such cloaks have potential applications in achieving invisibility for electrically large objects.
Automatic segmentation and centroid detection of skin sensors for lung interventions
NASA Astrophysics Data System (ADS)
Lu, Kongkuo; Xu, Sheng; Xue, Zhong; Wong, Stephen T.
2012-02-01
Electromagnetic (EM) tracking has been recognized as a valuable tool for locating the interventional devices in procedures such as lung and liver biopsy or ablation. The advantage of this technology is its real-time connection to the 3D volumetric roadmap, i.e. CT, of a patient's anatomy while the intervention is performed. EM-based guidance requires tracking of the tip of the interventional device, transforming the location of the device onto pre-operative CT images, and superimposing the device in the 3D images to assist physicians to complete the procedure more effectively. A key requirement of this data integration is to find automatically the mapping between EM and CT coordinate systems. Thus, skin fiducial sensors are attached to patients before acquiring the pre-operative CTs. Then, those sensors can be recognized in both CT and EM coordinate systems and used calculate the transformation matrix. In this paper, to enable the EM-based navigation workflow and reduce procedural preparation time, an automatic fiducial detection method is proposed to obtain the centroids of the sensors from the pre-operative CT. The approach has been applied to 13 rabbit datasets derived from an animal study and eight human images from an observation study. The numerical results show that it is a reliable and efficient method for use in EM-guided application.
2-D modelling and simulation of EM brake for liquid steel
NASA Astrophysics Data System (ADS)
Aslan, Necdet; Senturk, Kenan; Tessarotto, Massimo
2003-11-01
The problem of EM control of bottom tapping in steelmaking metallurgy is an old and well known challenge not only from the technological viewpoint but also, potentially, an interesting and still open theoretical problem, from the viewpoint of the investigation of the detailed MHD phenomena occurring in EM braking devices [1]. Purpose of the present work is the formulation of a 2-D MHD model for a DC EM braking device, which includes the consistent modelization of inductive EM fields produced by the conductive fluid, large scale turbulence, boundary conditions for the EM fields and thermal effects. The mathematical model has been implemented in a new 2-D MHD code developed for this purpose [2], based on the so-called fluctuation splitting and dual-time stepping methods, respectively, to advance in time the fluid fields and satisfy the relevant incompressibility-solenoidality conditions for the fluid mass velocity and the magnetic field. Main goal of the investigation is the analysis of the nonlinear phenomena occurring in the process of slowing down of a column of liquid steel under the action of the EM brake, and in particular the detailed description of the effects of large scale turbulence produced by the action of Lorentz force on the fluid, their influence on the magnitude of the inductive EM fields and the performance of the EM brake itself. REFERENCES [1] A.Codutti, A.Martinis, M.Pavlicevic, M.Tessarotto and D.Batic, Proc. 3rd International Symposium on EMP (Nagoya, Japan, April 2000), p.530 (2000). [2] N.Aslan, K.Senturk and M.Tessarotto, Efficient 2-D solver for incompressible magnefluids, communication at this Conference (2003).
An Open-Source Storage Solution for Cryo-Electron Microscopy Samples.
Ultee, Eveline; Schenkel, Fred; Yang, Wen; Brenzinger, Susanne; Depelteau, Jamie S; Briegel, Ariane
2018-02-01
Cryo-electron microscopy (cryo-EM) enables the study of biological structures in situ in great detail and to solve protein structures at Ångstrom level resolution. Due to recent advances in instrumentation and data processing, the field of cryo-EM is a rapidly growing. Access to facilities and national centers that house the state-of-the-art microscopes is limited due to the ever-rising demand, resulting in long wait times between sample preparation and data acquisition. To improve sample storage, we have developed a cryo-storage system with an efficient, high storage capacity that enables sample storage in a highly organized manner. This system is simple to use, cost-effective and easily adaptable for any type of grid storage box and dewar and any size cryo-EM laboratory.
Hybridization-induced broadband terahertz wave absorption with graphene metasurfaces.
Mou, Nanli; Sun, Shulin; Dong, Hongxing; Dong, Shaohua; He, Qiong; Zhou, Lei; Zhang, Long
2018-04-30
Electromagnetic (EM) wave absorption plays a vital role in photonics. While metasurfaces are proposed to absorb EM waves efficiently, most of them exhibit limited bandwidth and fixed functionalities. Here, we propose a broadband and tunable terahertz (THz) absorber based on a graphene-based metasurface, which is constructed by a single layer of closely patterned graphene concentric double rings and a metallic mirror separated by an ultrathin SiO 2 layer. Plasmonic hybridization between two graphene rings significantly enlarges the absorption bandwidth, which can be further tuned by gating the graphene. Moreover, the specific design also makes our device insensitive to the incident angle and polarization state of impinging EM waves. Our results may inspire certain wave-modulation-related applications, such as THz imaging, smart absorber, tunable sensor, etc.
Preconditioned Alternating Projection Algorithms for Maximum a Posteriori ECT Reconstruction
Krol, Andrzej; Li, Si; Shen, Lixin; Xu, Yuesheng
2012-01-01
We propose a preconditioned alternating projection algorithm (PAPA) for solving the maximum a posteriori (MAP) emission computed tomography (ECT) reconstruction problem. Specifically, we formulate the reconstruction problem as a constrained convex optimization problem with the total variation (TV) regularization. We then characterize the solution of the constrained convex optimization problem and show that it satisfies a system of fixed-point equations defined in terms of two proximity operators raised from the convex functions that define the TV-norm and the constrain involved in the problem. The characterization (of the solution) via the proximity operators that define two projection operators naturally leads to an alternating projection algorithm for finding the solution. For efficient numerical computation, we introduce to the alternating projection algorithm a preconditioning matrix (the EM-preconditioner) for the dense system matrix involved in the optimization problem. We prove theoretically convergence of the preconditioned alternating projection algorithm. In numerical experiments, performance of our algorithms, with an appropriately selected preconditioning matrix, is compared with performance of the conventional MAP expectation-maximization (MAP-EM) algorithm with TV regularizer (EM-TV) and that of the recently developed nested EM-TV algorithm for ECT reconstruction. Based on the numerical experiments performed in this work, we observe that the alternating projection algorithm with the EM-preconditioner outperforms significantly the EM-TV in all aspects including the convergence speed, the noise in the reconstructed images and the image quality. It also outperforms the nested EM-TV in the convergence speed while providing comparable image quality. PMID:23271835
Preconditioned alternating projection algorithms for maximum a posteriori ECT reconstruction
NASA Astrophysics Data System (ADS)
Krol, Andrzej; Li, Si; Shen, Lixin; Xu, Yuesheng
2012-11-01
We propose a preconditioned alternating projection algorithm (PAPA) for solving the maximum a posteriori (MAP) emission computed tomography (ECT) reconstruction problem. Specifically, we formulate the reconstruction problem as a constrained convex optimization problem with the total variation (TV) regularization. We then characterize the solution of the constrained convex optimization problem and show that it satisfies a system of fixed-point equations defined in terms of two proximity operators raised from the convex functions that define the TV-norm and the constraint involved in the problem. The characterization (of the solution) via the proximity operators that define two projection operators naturally leads to an alternating projection algorithm for finding the solution. For efficient numerical computation, we introduce to the alternating projection algorithm a preconditioning matrix (the EM-preconditioner) for the dense system matrix involved in the optimization problem. We prove theoretically convergence of the PAPA. In numerical experiments, performance of our algorithms, with an appropriately selected preconditioning matrix, is compared with performance of the conventional MAP expectation-maximization (MAP-EM) algorithm with TV regularizer (EM-TV) and that of the recently developed nested EM-TV algorithm for ECT reconstruction. Based on the numerical experiments performed in this work, we observe that the alternating projection algorithm with the EM-preconditioner outperforms significantly the EM-TV in all aspects including the convergence speed, the noise in the reconstructed images and the image quality. It also outperforms the nested EM-TV in the convergence speed while providing comparable image quality.
A general probabilistic model for group independent component analysis and its estimation methods
Guo, Ying
2012-01-01
SUMMARY Independent component analysis (ICA) has become an important tool for analyzing data from functional magnetic resonance imaging (fMRI) studies. ICA has been successfully applied to single-subject fMRI data. The extension of ICA to group inferences in neuroimaging studies, however, is challenging due to the unavailability of a pre-specified group design matrix and the uncertainty in between-subjects variability in fMRI data. We present a general probabilistic ICA (PICA) model that can accommodate varying group structures of multi-subject spatio-temporal processes. An advantage of the proposed model is that it can flexibly model various types of group structures in different underlying neural source signals and under different experimental conditions in fMRI studies. A maximum likelihood method is used for estimating this general group ICA model. We propose two EM algorithms to obtain the ML estimates. The first method is an exact EM algorithm which provides an exact E-step and an explicit noniterative M-step. The second method is an variational approximation EM algorithm which is computationally more efficient than the exact EM. In simulation studies, we first compare the performance of the proposed general group PICA model and the existing probabilistic group ICA approach. We then compare the two proposed EM algorithms and show the variational approximation EM achieves comparable accuracy to the exact EM with significantly less computation time. An fMRI data example is used to illustrate application of the proposed methods. PMID:21517789
Piezoelectric Motors and Transformers
NASA Astrophysics Data System (ADS)
Uchino, K.
Piezoelectric ceramics forms a new field between electronic and structural ceramics [1-4]. Application fields are classified into three categories: positioners, motors, and vibration suppressors. From the market research result for 80 Japanese component industries in 1992, tiny motors in the range of 5-8 mm are required in large numbers for office and portable equipment; the conventional electromagnetic (EM) motors are rather difficult to produce in this size with sufficient energy efficiency, while Silicon MEMS actuators are too small to be used in practice. Piezoelectric ultrasonic motors whose efficiency is insensitive to size are superior in the millimeter motor area. The manufacturing precision of optical instruments such as lasers and cameras, and the positioning accuracy for fabricating semiconductor chips are of the order of 0.1μm which is much smaller than the backlash of the EM motors. Vibration suppression in space structures and military vehicles also require compact but mighty piezoelectric actuators.
Methodology for the development of a Canadian national EMS research agenda
2011-01-01
Background Many health care disciplines use evidence-based decision making to improve patient care and system performance. While the amount and quality of emergency medical services (EMS) research in Canada has increased over the past two decades, there has not been a unified national plan to enable research, ensure efficient use of research resources, guide funding decisions and build capacity in EMS research. Other countries have used research agendas to identify barriers and opportunities in EMS research and define national research priorities. The objective of this project is to develop a national EMS research agenda for Canada that will: 1) explore what barriers to EMS research currently exist, 2) identify current strengths and opportunities that may be of benefit to advancing EMS research, 3) make recommendations to overcome barriers and capitalize on opportunities, and 4) identify national EMS research priorities. Methods/Design Paramedics, educators, EMS managers, medical directors, researchers and other key stakeholders from across Canada will be purposefully recruited to participate in this mixed methods study, which consists of three phases: 1) qualitative interviews with a selection of the study participants, who will be asked about their experience and opinions about the four study objectives, 2) a facilitated roundtable discussion, in which all participants will explore and discuss the study objectives, and 3) an online Delphi consensus survey, in which all participants will be asked to score the importance of each topic discovered during the interviews and roundtable as they relate to the study objectives. Results will be analyzed to determine the level of consensus achieved for each topic. Discussion A mixed methods approach will be used to address the four study objectives. We anticipate that the keys to success will be: 1) ensuring a representative sample of EMS stakeholders, 2) fostering an open and collaborative roundtable discussion, and 3) adhering to a predefined approach to measure consensus on each topic. Steps have been taken in the methodology to address each of these a priori concerns. PMID:21961624
A workflow for the automatic segmentation of organelles in electron microscopy image stacks
Perez, Alex J.; Seyedhosseini, Mojtaba; Deerinck, Thomas J.; Bushong, Eric A.; Panda, Satchidananda; Tasdizen, Tolga; Ellisman, Mark H.
2014-01-01
Electron microscopy (EM) facilitates analysis of the form, distribution, and functional status of key organelle systems in various pathological processes, including those associated with neurodegenerative disease. Such EM data often provide important new insights into the underlying disease mechanisms. The development of more accurate and efficient methods to quantify changes in subcellular microanatomy has already proven key to understanding the pathogenesis of Parkinson's and Alzheimer's diseases, as well as glaucoma. While our ability to acquire large volumes of 3D EM data is progressing rapidly, more advanced analysis tools are needed to assist in measuring precise three-dimensional morphologies of organelles within data sets that can include hundreds to thousands of whole cells. Although new imaging instrument throughputs can exceed teravoxels of data per day, image segmentation and analysis remain significant bottlenecks to achieving quantitative descriptions of whole cell structural organellomes. Here, we present a novel method for the automatic segmentation of organelles in 3D EM image stacks. Segmentations are generated using only 2D image information, making the method suitable for anisotropic imaging techniques such as serial block-face scanning electron microscopy (SBEM). Additionally, no assumptions about 3D organelle morphology are made, ensuring the method can be easily expanded to any number of structurally and functionally diverse organelles. Following the presentation of our algorithm, we validate its performance by assessing the segmentation accuracy of different organelle targets in an example SBEM dataset and demonstrate that it can be efficiently parallelized on supercomputing resources, resulting in a dramatic reduction in runtime. PMID:25426032
Zhao, Zhi Yuan; Zheng, Wei; Liu, Jie; Ma, Peng Yi; Li, Zi Yan; Zhai, Bing Nian; Wang, Zhao Hui
2018-04-01
To evaluate the variations of soil moisture under different water and fertilizer treatments in apple orchard in the Weibei dryland, a field experiment was carried out in 2013-2016 at Tianjiawa Village, Baishui County, Shaanxi Province. There were three treatments, i.e., farmers traditional model (only addition of NPK chemical fertilizer, FM), extension model (swine manure and NPK chemical fertilizer combined with black plastic film in tree row space, EM), and optimized model (swine manure and NPK chemical fertilizer combined with black plastic film in tree row space and planting rape in the inter-row of apple trees, OM). The results showed that OM treatment significantly increased soil water storage capacity in 0-200 cm soil layer. Water content of 0-100 cm soil layer was increased by 5.6% and 15.3% in the dry season compared with FM and EM treatment, respectively. Moreover, the soil water relative deficit index of OM was lower than that of EM in 200-300 cm soil layer. The rainfall infiltration in the dry year could reach 300 cm depth under OM. Meanwhile, OM stabilized soil water content and efficiently alleviated the desiccation in deep soil layer. Compared with FM and EM, the 4-year average yield of OM was increased by 36.6% and 22.5%, respectively. In summary, OM could increase water use efficiency through increasing the contents of available soil water and improving the soil water condition in shallow and deep layers, which help alleviate the soil deficit in deep layer and increase yield.
High efficiency magnetic bearings
NASA Technical Reports Server (NTRS)
Studer, Philip A.; Jayaraman, Chaitanya P.; Anand, Davinder K.; Kirk, James A.
1993-01-01
Research activities concerning high efficiency permanent magnet plus electromagnet (PM/EM) pancake magnetic bearings at the University of Maryland are reported. A description of the construction and working of the magnetic bearing is provided. Next, parameters needed to describe the bearing are explained. Then, methods developed for the design and testing of magnetic bearings are summarized. Finally, a new magnetic bearing which allows active torque control in the off axes directions is discussed.
Vasudevan, Vinod; Singh, Preeti; Basu, Samyajit
2016-10-02
India has been slow in implementing a central emergency medical services (EMS) system across the country. "108 services" is one of the most popular services that is functional under the public-private partnership model. Limited available literature shows that despite access to services, many traffic crash victims are transported using private vehicles. The objective of this study is to understand the effectiveness of 108 services from a traffic safety perspective. A questionnaire survey is conducted to understand the awareness of EMS and their function. Using traffic-related fatalities as the dependent variable, a fixed effect panel data model is developed to analyze the effectiveness of the 108 services in improving the traffic safety. The results from the survey show that, in general, people are not aware of the 108 services. A majority of the population prefers taking victims to the hospital using their personal vehicles or any other vehicles available compared to calling an ambulance. Results from panel data analysis show that despite having an efficient system, these services failed to make significant improvement in the safety of road users in the states in which their services were subscribed. The lack of awareness of an important safety service is alarming. This could be a major reason for lower utilization of 108 services for transporting victims of traffic crashes. This article shows the importance of having efficient awareness campaigns to improve the efficiency of any similar programs that are aimed to enhance the safety of a region.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Krahn, John; Reed, Claude; Loewen, Eric
Final Technical Report: Electromagnetic Pump Insulation Materials Development and Testing (Report # DOEGEHB00613) summarizes the information gathered from the analysis of the 160 m3/min EM Pump insulation that was tested in 2000-2002 and additional evaluations of new resilient, engineered insulation system evaluated and tested at both GRC and ANL. This report provides information on Tasks 1 and 2 of the entire project. This report also provides information in three broad areas: Historical and current data; Conclusions based on test data; and Insulation specifications for use in EM Pumps. The research for Task 2 builds upon Task 1: Update EM Pumpmore » Databank, which is summarized within this report. Where research for Task 3 and 4 Next-Generation EM Pump Analysis Tools identified parameters or analysis model that benefits Task 2 research, those items are noted within this report. The important design variables for the manufacture and operation of an EM Pump that the insulation research can evaluate are: space constraints; voltage capability of insulation system; maximum flux density through iron; flow rate and outlet pressure; efficiency and manufacturability. The development summary of the Electromagnetic Pump Insulation Materials Development and Testing was completed to include: Historical and current data; Conclusions based on test data; and Insulation specifications for use in EM Pumps.« less
NASA Astrophysics Data System (ADS)
Koziel, Slawomir; Bekasiewicz, Adrian
2018-02-01
In this article, a simple yet efficient and reliable technique for fully automated multi-objective design optimization of antenna structures using sequential domain patching (SDP) is discussed. The optimization procedure according to SDP is a two-step process: (i) obtaining the initial set of Pareto-optimal designs representing the best possible trade-offs between considered conflicting objectives, and (ii) Pareto set refinement for yielding the optimal designs at the high-fidelity electromagnetic (EM) simulation model level. For the sake of computational efficiency, the first step is realized at the level of a low-fidelity (coarse-discretization) EM model by sequential construction and relocation of small design space segments (patches) in order to create a path connecting the extreme Pareto front designs obtained beforehand. The second stage involves response correction techniques and local response surface approximation models constructed by reusing EM simulation data acquired in the first step. A major contribution of this work is an automated procedure for determining the patch dimensions. It allows for appropriate selection of the number of patches for each geometry variable so as to ensure reliability of the optimization process while maintaining its low cost. The importance of this procedure is demonstrated by comparing it with uniform patch dimensions.
NASA Astrophysics Data System (ADS)
Li, Kesai; Gao, Jie; Ju, Xiaodong; Zhu, Jun; Xiong, Yanchun; Liu, Shuai
2018-05-01
This paper proposes a new tool design of ultra-deep azimuthal electromagnetic (EM) resistivity logging while drilling (LWD) for deeper geosteering and formation evaluation, which can benefit hydrocarbon exploration and development. First, a forward numerical simulation of azimuthal EM resistivity LWD is created based on the fast Hankel transform (FHT) method, and its accuracy is confirmed under classic formation conditions. Then, a reasonable range of tool parameters is designed by analyzing the logging response. However, modern technological limitations pose challenges to selecting appropriate tool parameters for ultra-deep azimuthal detection under detectable signal conditions. Therefore, this paper uses grey relational analysis (GRA) to quantify the influence of tool parameters on voltage and azimuthal investigation depth. After analyzing thousands of simulation data under different environmental conditions, the random forest is used to fit data and identify an optimal combination of tool parameters due to its high efficiency and accuracy. Finally, the structure of the ultra-deep azimuthal EM resistivity LWD tool is designed with a theoretical azimuthal investigation depth of 27.42-29.89 m in classic different isotropic and anisotropic formations. This design serves as a reliable theoretical foundation for efficient geosteering and formation evaluation in high-angle and horizontal (HA/HZ) wells in the future.
Tzimas, G; Collins, M D; Nau, H
1995-07-01
In mice and rats, 13-cis-retinoic acid (13-cis-RA) has a much lower teratogenic potency than all-trans-retinoic acid (all-trans-RA). Previous studies on Gestational Day (GD) 11 or 12 (in mice or rats, respectively) showed a limited transfer of 13-cis-RA to the embryo, in contrast to the efficient transplacental passage of all-trans-RA. In the present study we examined if the distribution between maternal circulation and embryo of 13-cis- and all-trans-RA as well as their metabolites is different at gestational times when the placenta is developing from a choriovitelline to a chorioallantoic type. In the first experiment, 13-cis-RA was administered orally to pregnant rats (75 mg/kg/day) daily, from either GD 7 to 12 or 11 to 16. In the second experiment, 13-cis-RA or all-trans-RA was given orally to pregnant mice once on either GD 11 or 14, at two dose levels (10 and 100 mg/kg). HPLC analysis of plasma and embryo samples collected at various time points post-treatment showed that 13-cis-RA was predominantly metabolized to its beta-glucuronide (13-cis-RAG) while all-trans-RA was primarily biotransformed to all-trans-4-oxo-RA and to a lesser extent to all-trans-RAG. 13-cis-RA showed a more efficient transplacental passage to the rat embryo on GD 16 than on GD 12, as indicated by higher ratios of embryonic to maternal plasma concentrations (E/M concentration ratio) on GD 16 vs. GD 12 and its E/M ratio of area-under-the-concentration-time-curve values (E/M AUC ratio; twofold higher on GD 16 vs. GD 12). In the mouse, the E/M concentration ratio of 13-cis-RA was significantly higher on GD 14 than on GD 11 only at the low dose. On the other hand, all-trans-RA and all-trans-4-oxo-RA showed an efficient transfer to the mouse embryo at both gestational times. In both species, 13-cis- and all-trans-RAG embryonic concentrations on the later gestational days exceeded significantly the corresponding ones on the earlier gestational days which resulted in far higher E/M concentration and AUC ratios for each of these metabolites on the later vs earlier gestational days. This may result from a more efficient placental transfer of the RAGs during later gestational stages and/or higher capacity of the late embryo or other conceptal tissues to biotransform RAs in situ to their glucuronides.(ABSTRACT TRUNCATED AT 400 WORDS)
Evaluation of Effective Microorganisms on home scale organic waste composting.
Fan, Yee Van; Lee, Chew Tin; Klemeš, Jiří Jaromír; Chua, Lee Suan; Sarmidi, Mohamad Roji; Leow, Chee Woh
2018-06-15
Home composting can be an effective way to reduce the volume of municipal solid waste. The aim of this study is to evaluate the effect of Effective Microorganism™ (EM) for the home scale co-composting of food waste, rice bran and dried leaves. A general consensus is lacking regarding the efficiency of inoculation composting. Home scale composting was carried out with and without EM (control) to identify the roles of EM. The composting parameters for both trials showed a similar trend of changes during the decomposition. As assayed by Fourier Transform Infrared Spectroscopy (FTIR), the functional group of humic acid was initially dominated by aliphatic structure but was dominated by the aromatic in the final compost. The EM compost has a sharper peak of aromatic CC bond presenting a better degree of humification. Compost with EM achieved a slightly higher temperature at the early stage, with foul odour suppressed, enhanced humification process and a greater fat reduction (73%). No significant difference was found for the final composts inoculated with and without EM. The properties included pH (∼7), electric conductivity (∼2), carbon-to-nitrogen ratio (C: N < 14), colour (dark brown), odour (earthy smell), germination index (>100%), humic acid content (4.5-4.8%) and pathogen content (no Salmonella, <1000 Most Probable Number/g E. coli). All samples were well matured within 2 months. The potassium and phosphate contents in both cases were similar however the EM compost has a higher nitrogen content (+1.5%). The overall results suggested the positive effect provided by EM notably in odour control and humification. Copyright © 2017 Elsevier Ltd. All rights reserved.
Diabetes mellitus treatment-Related medical knowledge among health care providers.
Shahla, Leena; Vasudev, Rahul; Chitturi, Chandrika; Rodriguez, Cindy; Paul, Namrata
To compare the knowledge of physicians, residents and medical students in diagnosis, use of insulin and oral medication in management of Type 2 Diabetes Mellitus (DM) working in different healthcare specialties. A cross sectional survey of faculty, residents and medical students of different subspecialties in a single center was conducted. Questionnaire consisting of 20 questions was used. These questions were designed to assess knowledge about diagnosis, nomenclature of different insulin/oral medications and management of DM. There were 4 answers to every question with only one correct answer based on ADA guidelines and most recent literature. The overall percentage correctly answered questions was ∼74% for IM faculty, 64% for EM faculty, 71% for IM residents, 60% for FM residents, 56% for EM residents and 59% for students. Questions based on knowledge of insulin nomenclature and characteristics were answered correctly 74% of the time by IM faculty, 62% by EM faculty, 66% by IM residents, 69% by FM residents, 45% by EM residents and 49% by medical students. Questions on the use of insulin and inpatient DM management were answered correctly 66% for IM faculty, 54% for EM faculty, 66% for IM residents, 46% for FM residents, 55% for EM Residents, and 44% medical students. Questions based on oral medications and DM diagnosis were answered correctly by 81% for IM faculty, 73% for EM faculty, 78% for IM Resident, 76% FM Resident, 64% for EM residents and 79% for students. This study demonstrates the need for focused educational initiatives required in all subspecialties involved in management of diabetes mellitus for safe and efficient management of diabetes mellitus. Copyright © 2016 Diabetes India. Published by Elsevier Ltd. All rights reserved.
Singh, Kulvir; Rathore, Pankaj
2015-07-01
Field experiments were conducted during Kharif 2012 and 2013 to evaluate the efficacy of different herbicides for weed management in cotton. Highest seed cotton yield (3537.3 kg ha(-1)) was recorded in weed free plots followed by pendimethalin @1.0 kg a.i ha(-1) as Pre.em.+quizalofopethyl @50 g a.i ha(-1) post-em at 2-4 weed leaf stage + one hoeing (3318.9 kg ha") owing to improved number of bolls per plant and boll weight. Statistically least yield was recorded underweedy check (1435.4 kg ha(-1)). Application of pyrithiobac sodium could not express any visible toxic effect on crop indicating its selectivity for cotton, although none of the tested new chemicals i.e., pyrithiobac sodium@ 62.5g a.i ha(-1) and quizalofopethyl @50g a.i ha(-1) when applied alone could not outperform the existing recommended chemicals for weed management. Yield losses to the extent of 6.2-59.4% were recorded due to weed competition. Weed control efficiency (WCE) was highest under weed free check (86.8%) followed by pendimethalin @1.0 kg a.i ha(-1) as Pre. em.+quizalofopethyl @50g a.i ha(-1), at 2-4 weed leaf stage + one hoeing (73.7%), whereas minimum values were for weedy check (24.7%). Though net returns (r94660 ha(-1)) were highest for weed free check but higher B:C ratio (2:11) was observed for pendimethalin @1.0 kg a.i ha(-1) as Pre em.+quizalofopethyl @50 g a.i ha(-1) post-em at 2-4 weed leaf stage+one hoeing. Therefore, for reasons such as labor shortage besides their timely availability, using these herbicides in combination with cultural practices could be the practical solution foreconomically efficient and effective weed management.
Viewing Angle Classification of Cryo-Electron Microscopy Images Using Eigenvectors
Singer, A.; Zhao, Z.; Shkolnisky, Y.; Hadani, R.
2012-01-01
The cryo-electron microscopy (cryo-EM) reconstruction problem is to find the three-dimensional structure of a macromolecule given noisy versions of its two-dimensional projection images at unknown random directions. We introduce a new algorithm for identifying noisy cryo-EM images of nearby viewing angles. This identification is an important first step in three-dimensional structure determination of macromolecules from cryo-EM, because once identified, these images can be rotationally aligned and averaged to produce “class averages” of better quality. The main advantage of our algorithm is its extreme robustness to noise. The algorithm is also very efficient in terms of running time and memory requirements, because it is based on the computation of the top few eigenvectors of a specially designed sparse Hermitian matrix. These advantages are demonstrated in numerous numerical experiments. PMID:22506089
NASA Astrophysics Data System (ADS)
Pan, Diankun; Ma, Benbiao; Dai, Fuhong
2017-03-01
In this work, a bi-stable vibration energy harvester is presented to scavenge energy from ambient vibrations over a wide frequency range. This bi-stable harvester consists of a bi-stable hybrid composite plate as host structure and several pieces of piezoelectric ceramics. Three linear harvesters with the same geometry were employed as the control samples to illustrate the advantages of this bi-stable harvester. The voltage-frequency responses were measured with different g-level excitations, and the output powers across various resistances were measured at different frequencies and accelerations. Unlike the linear harvesters which are effective only near their natural frequencies, the obvious nonlinearities of this bi-stable harvester broaden its working bandwidth. Additionally, the characteristics of this bi-stable host structure contribute to the output power. Under the same condition, when this bi-stable harvester is under cross-well oscillation pattern the maximum output powers are several times higher than those of the linear harvesters. The measured highest output power of this bi-stable harvester is 36.2 mW with 38 Hz frequency and 5g acceleration (g = 9.8 m s-2).
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sattler, A.R.
1996-06-01
Six boreholes were drilled during the geologic characterization and diagnostics of the Weeks Island sinkhole that is over the two-tiered salt mine which was converted for oil storage by the U.S. Strategic Petroleum Reserve. These holes were drilled to provide for geologic characterization of the Weeks Island Salt Dome and its overburden in the immediate vicinity of the sinkhole (mainly through logs and core); to establish a crosswell configuration for seismic tomography; to establish locations for hydrocarbon detection and tracer injection; and to provide direct observations of sinkhole geometry and material properties. Specific objectives of the logging program were to:more » (1) identify the top of and the physical state of the salt dome; (2) identify the water table; (3) obtain a relative salinity profile in the aquifer within the alluvium, which ranges from the water table directly to the top of the Weeks Island salt dome; and (4) identify a reflecting horizon seen on seismic profiles over this salt dome. Natural gamma, neutron, density, sonic, resistivity and caliper logs were run.« less
Optimizing Gas Generator Efficiency in a Forward Operating Base Using an Energy Management System
2013-06-01
Navy, Bethesda, MD. [4] E. Shields, B. Newell , “Current power and energy requirements of forward Deployed USMC Locations,” Released January 2012...kW and t0 was 6 hours, which resulted in Etotal=64.8 MJ . EMS logic remained the same as in Chapter IV with one exception. If the EMS sensed a...Battery Load (kW) Intial Capacity ( MJ ) Energy Drawn ( MJ ) Remaining Capacity ( MJ ) Initial SoC Final SoC 1 5 1.5 64.8 27.0 37.8 100.0% 58.3% 2 5 1.1
Enhanced absorption of light by charged nanoparticles.
Rosenkrantz, Etai; Arnon, Shlomi
2010-04-15
We found that various charged nanoparticles (NPs) can raise the attenuation of electromagnetic (EM) radiation over 30 times more efficiently during resonance in comparison to equivalent noncharged particles for a given set of parameters. A condition that indicates a state of resonance between the incident EM radiation and the NP surface excitations is mathematically derived. Our results shed light on the mechanism responsible for the strong absorption of light by such charged NPs. The outcome of this research could help to design a new generation of communication devices as well as a new technique for biological cell imaging.
Not extinct yet: innovations in frequency domain HEM triggered by sea ice studies
NASA Astrophysics Data System (ADS)
Pfaffhuber, Andreas A.; Hendricks, Stefan
2015-10-01
The last 15 years have brought major innovations in helicopter towed time domain electromagnetics (EM), while few further developments have been made within the classic frequency domain segment. Operational use of frequency domain EM for sea ice thickness mapping acted as a driving force to develop new concepts such as the system under our consideration. Since its introduction we have implemented new concepts aiming at noise reduction and drift elimination. We decreased signal noise base levels by one to two orders of magnitude with changes to the signal transmission concept. Further, we increased the receiver coil dynamic range creating an EM setup without the need for primary field bucking. Finally, we implemented control signals inside the receiver coils to potentially eliminate system drift. Ground tests demonstrate the desired noise reduction and demonstrate drift control, leading to essentially drift free data. Airborne field data confirm these results, yet also show that the procedures can still be improved. The remaining quest is whether these specialised system improvements could also be implemented in exploration helicopter EM (HEM) systems to increase accuracy and efficiency.
GABA action in immature neocortical neurons directly depends on the availability of ketone bodies.
Rheims, Sylvain; Holmgren, Carl D; Chazal, Genevieve; Mulder, Jan; Harkany, Tibor; Zilberter, Tanya; Zilberter, Yuri
2009-08-01
In the early postnatal period, energy metabolism in the suckling rodent brain relies to a large extent on metabolic pathways alternate to glucose such as the utilization of ketone bodies (KBs). However, how KBs affect neuronal excitability is not known. Using recordings of single NMDA and GABA-activated channels in neocortical pyramidal cells we studied the effects of KBs on the resting membrane potential (E(m)) and reversal potential of GABA-induced anionic currents (E(GABA)), respectively. We show that during postnatal development (P3-P19) if neocortical brain slices are adequately supplied with KBs, E(m) and E(GABA) are both maintained at negative levels of about -83 and -80 mV, respectively. Conversely, a KB deficiency causes a significant depolarization of both E(m) (>5 mV) and E(GABA) (>15 mV). The KB-mediated shift in E(GABA) is largely determined by the interaction of the NKCC1 cotransporter and Cl(-)/HCO3 transporter(s). Therefore, by inducing a hyperpolarizing shift in E(m) and modulating GABA signaling mode, KBs can efficiently control the excitability of neonatal cortical neurons.
A multiscale quantum mechanics/electromagnetics method for device simulations.
Yam, ChiYung; Meng, Lingyi; Zhang, Yu; Chen, GuanHua
2015-04-07
Multiscale modeling has become a popular tool for research applying to different areas including materials science, microelectronics, biology, chemistry, etc. In this tutorial review, we describe a newly developed multiscale computational method, incorporating quantum mechanics into electronic device modeling with the electromagnetic environment included through classical electrodynamics. In the quantum mechanics/electromagnetics (QM/EM) method, the regions of the system where active electron scattering processes take place are treated quantum mechanically, while the surroundings are described by Maxwell's equations and a semiclassical drift-diffusion model. The QM model and the EM model are solved, respectively, in different regions of the system in a self-consistent manner. Potential distributions and current densities at the interface between QM and EM regions are employed as the boundary conditions for the quantum mechanical and electromagnetic simulations, respectively. The method is illustrated in the simulation of several realistic systems. In the case of junctionless field-effect transistors, transfer characteristics are obtained and a good agreement between experiments and simulations is achieved. Optical properties of a tandem photovoltaic cell are studied and the simulations demonstrate that multiple QM regions are coupled through the classical EM model. Finally, the study of a carbon nanotube-based molecular device shows the accuracy and efficiency of the QM/EM method.
NASA Astrophysics Data System (ADS)
Bai, Chao-Ying; Huang, Guo-Jiao; Li, Xiao-Ling; Zhou, Bing; Greenhalgh, Stewart
2013-11-01
To overcome the deficiency of some current grid-/cell-based ray tracing algorithms, which are only able to handle first arrivals or primary reflections (or conversions) in anisotropic media, we have extended the functionality of the multistage irregular shortest-path method to 2-D/3-D tilted transversely isotropic (TTI) media. The new approach is able to track multiple transmitted/reflected/converted arrivals composed of any kind of combinations of transmissions, reflections and mode conversions. The basic principle is that the seven parameters (five elastic parameters plus two polar angles defining the tilt of the symmetry axis) of the TTI media are sampled at primary nodes, and the group velocity values at secondary nodes are obtained by tri-linear interpolation of the primary nodes across each cell, from which the group velocities of the three wave modes (qP, qSV and qSH) are calculated. Finally, we conduct grid-/cell-based wave front expansion to trace multiple transmitted/reflected/converted arrivals from one region to the next. The results of calculations in uniform anisotropic media indicate that the numerical results agree with the analytical solutions except in directions of SV-wave triplications, at which only the lowest velocity value is selected at the singularity points by the multistage irregular shortest-path anisotropic ray tracing method. This verifies the accuracy of the methodology. Several simulation results show that the new method is able to efficiently and accurately approximate situations involving continuous velocity variations and undulating discontinuities, and that it is suitable for any combination of multiple transmitted/reflected/converted arrival tracking in TTI media of arbitrary strength and tilt. Crosshole synthetic traveltime tomographic tests have been performed, which highlight the importance of using such code when the medium is distinctly anisotropic.
NASA Astrophysics Data System (ADS)
Lindsey, Martin Forrester
Sustained hypersonic flight using scramjet propulsion is the key technology bridging the gap between turbojets and the exoatmospheric environment where a rocket is required. Recent efforts have focused on electromagnetic (EM) flow control to mitigate the problems of high thermomechanical loads and low propulsion efficiencies associated with scramjet propulsion. This research effort is the first flight-scale, three-dimensional computational analysis of a realistic scramjet to determine how EM flow control can improve scramjet performance. Development of a quasi-one dimensional design tool culminated in the first open source geometry of an entire scramjet flowpath. This geometry was then tested extensively with the Air Force Research Laboratory's three-dimensional Navier-Stokes and EM coupled computational code. As part of improving the model fidelity, a loosely coupled algorithm was developed to incorporate thermochemistry. This resulted in the only open-source model of fuel injection, mixing and combustion in a magnetogasdynamic (MGD) flow controlled engine. In addition, a control volume analysis tool with an electron beam ionization model was presented for the first time in the context of the established computational method used. Local EM flow control within the internal inlet greatly impacted drag forces and wall heat transfer but was only marginally successful in raising the average pressure entering the combustor. The use of an MGD accelerator to locally increase flow momentum was an effective approach to improve flow into the scramjet's isolator. Combustor-based MGD generators proved superior to the inlet generator with respect to power density and overall engine efficiency. MGD acceleration was shown to be ineffective in improving overall performance, with all of the bypass engines having approximately 33% more drag than baseline and none of them achieving a self-powered state.
NASA Astrophysics Data System (ADS)
Yuan, Chengxun; Tian, Ruihuan; Eliseev, S. I.; Bekasov, V. S.; Bogdanov, E. A.; Kudryavtsev, A. A.; Zhou, Zhongxiang
2018-03-01
In this paper, we present investigation of a direct-current discharge with a gridded anode from the point of view of using it as a means of creating plasma coating that could efficiently absorb incident electromagnetic (EM) waves. A single discharge cell consists of two parallel plates, one of which (anode) is gridded. Electrons emitted from the cathode surface are accelerated in the short interelectrode gap and are injected into the post-anode space, where they lose acquired energy on ionization and create plasma. Numerical simulations were used to investigate the discharge structure and obtain spatial distributions of plasma density in the post-anode space. The numerical model of the discharge was based on a simple hybrid approach which takes into account non-local ionization by fast electrons streaming from the cathode sheath. Specially formulated transparency boundary conditions allowed performing simulations in 1D. Simulations were carried out in air at pressures of 10 Torr and higher. Analysis of the discharge structure and discharge formation is presented. It is shown that using cathode materials with lower secondary emission coefficients can allow increasing the thickness of plasma slabs for the same discharge current, which can potentially enhance EM wave absorption. Spatial distributions of electron density obtained during simulations were used to calculate attenuation of an incident EM wave propagating perpendicularly to the plasma slab boundary. It is shown that plasma created by means of a DC discharge with a gridded anode can efficiently absorb EM waves in the low frequency range (6-40 GHz). Increasing gas pressure results in a broader range of wave frequencies (up to 500 GHz) where a considerable attenuation is observed.
Emerging organizational structures in the ambulance industry in the United States.
Narad, R A
2000-01-01
This analysis seeks to identify emerging forms of organizations in emergency medical services (EMS) in the United States, to provide examples of them, to relate them to changes in healthcare generally, and to apply a classification scheme. Public policy issues related to these new forms of organizations and lessons from other areas of the healthcare system are identified. Recent changes in the healthcare system in the United States have been marked by modifications in the structure of organizations that provide and pay for health services. New forms of organizations and alliances among existing organizations have emerged in an effort to improve the efficiency of the services provided and to improve organizations' market positions. Reflecting increased competition within EMS and the demands of the changing health-care delivery system, several types of organizations have begun to emerge in EMS that resemble those occurring in health care generally. These include forms of horizontal integration, such as consolidated ambulance services and various models of ambulance service networks; and forms of vertical integration, such as demand management programs and public-private joint ventures. The ultimate end might be complete integration with a carve-out of all non-scheduled care. Although changes in EMS organizations result largely from marketplace decisions by sellers and purchasers, this does not mean that there is no public policy role. While new organizational forms may increase the ambulance industry's efficiency, public policy makers must be concerned about quality and access as well. Some policy responses will promote marketplace changes, others will accept them generally, but will seek to correct problems, and a third group will attempt to restrain the market.
Correlation-based regularization and gradient operators for (joint) inversion on unstructured meshes
NASA Astrophysics Data System (ADS)
Jordi, Claudio; Doetsch, Joseph; Günther, Thomas; Schmelzbach, Cedric; Robertsson, Johan
2017-04-01
When working with unstructured meshes for geophysical inversions, special attention should be paid to the design of the operators that are used for regularizing the inverse problem and coupling of different property models in joint inversions. Regularization constraints for inversions on unstructured meshes are often defined in a rather ad-hoc manner and usually only involve the cell to which the operator is applied and its direct neighbours. Similarly, most structural coupling operators for joint inversion, such as the popular cross-gradients operator, are only defined in the direct neighbourhood of a cell. As a result, the regularization and coupling length scales and strength of these operators depend on the discretization as well as cell sizes and shape. Especially for unstructured meshes, where the cell sizes vary throughout the model domain, the dependency of the operator on the discretization may lead to artefacts. Designing operators that are based on a spatial correlation model allows to define correlation length scales over which an operator acts (called footprint), reducing the dependency on the discretization and the effects of variable cell sizes. Moreover, correlation-based operators can accommodate for expected anisotropy by using different length scales in horizontal and vertical directions. Correlation-based regularization operators also known as stochastic regularization operators have already been successfully applied to inversions on regular grids. Here, we formulate stochastic operators for unstructured meshes and apply them in 2D surface and 3D cross-well electrical resistivity tomography data inversion examples of layered media. Especially for the synthetic cross-well example, improved inversion results are achieved when stochastic regularization is used instead of a classical smoothness constraint. For the case of cross-gradients operators for joint inversion, the correlation model is used to define the footprint of the operator and weigh the contributions of the property values that are used to calculate the cross-gradients. In a first series of synthetic-data tests, we examined the mesh dependency of the cross-gradients operators. Compared to operators that are only defined in the direct neighbourhood of a cell, the dependency on the cell size of the cross-gradients calculation is markedly reduced when using operators with larger footprints. A second test with synthetic models focussed on the effect of small-scale variabilities of the parameter value on the cross-gradients calculation. Small-scale variabilities that are superimposed on a global trend of the property value can potentially degrade the cross-gradients calculation and destabilize joint inversion. We observe that the cross-gradients from operators with footprints larger than the length scale of the variabilities are less affected compared to operators with a small footprint. In joint inversions on unstructured meshes, we thus expect the correlation-based coupling operators to ensure robust coupling on a physically meaningful scale.
The peak electromagnetic power radiated by lightning return strokes
NASA Technical Reports Server (NTRS)
Krider, E. P.; Guo, C.
1983-01-01
Estimates of the peak electromagnetic (EM) power radiated by return strokes have been made by integrating the Poynting vector of measured fields over an imaginary hemispherical surface that is centered on the lightning source, assuming that ground losses are negligible. Values of the peak EM power from first and subsequent strokes have means and standard deviations of 2 + or - 2 x 10 to the 10th and 3 + or - 4 x 10 to the 9th W, respectively. The average EM power that is radiated by subsequent strokes, at the time of the field peak, is about 2 orders of magnitude larger than the optical power that is radiated by these strokes in the wavelength interval from 0.4 to 1.1 micron; hence an upper limit to the radiative efficiency of a subsequent stroke is of the order of 1 percent or less at this time.
Making structured metals transparency for broadband and wide-incidence-angle electromagnetic waves
NASA Astrophysics Data System (ADS)
Fan, Renhao; Peng, Ruwen; Huang, Xianrong; Wang, Mu
2014-03-01
Very recently, we have demonstrated that one-dimensional metallic gratings can become transparent and completely antireflective for extremely broadband electromagnetic (EM) waves under oblique incidence. However, the oblique-incidence geometry, is inconvenient for the technological applications. To overcome this drawback, here we instead use oblique metal gratings with optimal tilt angles to achieve normal-incidence broadband transparence for EM waves. Further we use two-dimensional periodic metallic cuboids to achieve broadband and broad-angle high transmission and antireflection. By introducing such metallic cuboids arrays into silicon solar cells, we find that high performance of light trapping in the cells can be obtained with a significant enhancement of the ultimate quantum efficiency. The structured metals, which achieve broadband and broad-angle high transmission for EM waves, may have many other potential applications, such as transparent conducting panels, white-beam polarizers, and stealth objects.
A parallel graded-mesh FDTD algorithm for human-antenna interaction problems.
Catarinucci, Luca; Tarricone, Luciano
2009-01-01
The finite difference time domain method (FDTD) is frequently used for the numerical solution of a wide variety of electromagnetic (EM) problems and, among them, those concerning human exposure to EM fields. In many practical cases related to the assessment of occupational EM exposure, large simulation domains are modeled and high space resolution adopted, so that strong memory and central processing unit power requirements have to be satisfied. To better afford the computational effort, the use of parallel computing is a winning approach; alternatively, subgridding techniques are often implemented. However, the simultaneous use of subgridding schemes and parallel algorithms is very new. In this paper, an easy-to-implement and highly-efficient parallel graded-mesh (GM) FDTD scheme is proposed and applied to human-antenna interaction problems, demonstrating its appropriateness in dealing with complex occupational tasks and showing its capability to guarantee the advantages of a traditional subgridding technique without affecting the parallel FDTD performance.
Chen, Ming-Wei; You, Sizhu; Suslick, Kenneth S; Dlott, Dana D
2014-02-01
We have observed and characterized hot spot formation and hot-spot ignition of energetic materials (EM), where hot spots were created by ultrasonic or long-wavelength infrared (LWIR) exposure, and were detected by high-speed thermal microscopy. The microscope had 15-20 μm spatial resolution and 8.3 ms temporal resolution. LWIR was generated by a CO2 laser (tunable near 10.6 μm or 28.3 THz) and ultrasound by a 20 kHz acoustic horn. Both methods of energy input created spatially homogeneous energy fields, allowing hot spots to develop spontaneously due to the microstructure of the sample materials. We observed formation of hot spots which grew and caused the EM to ignite. The EM studied here consisted of composite solids with 1,3,5-trinitroperhydro-1,3,5-triazine crystals and polymer binders. EM simulants based on sucrose crystals in binders were also examined. The mechanisms of hot spot generation were different with LWIR and ultrasound. With LWIR, hot spots were most efficiently generated within the EM crystals at LWIR wavelengths having longer absorption depths of ∼25 μm, suggesting that hot spot generation mechanisms involved localized absorbing defects within the crystals, LWIR focusing in the crystals or LWIR interference in the crystals. With ultrasound, hot spots were primarily generated in regions of the polymer binder immediately adjacent to crystal surfaces, rather than inside the EM crystals.
NASA Astrophysics Data System (ADS)
Zhdanov, M. S.; Cuma, M.; Black, N.; Wilson, G. A.
2009-12-01
The marine controlled source electromagnetic (MCSEM) method has become widely used in offshore oil and gas exploration. Interpretation of MCSEM data is still a very challenging problem, especially if one would like to take into account the realistic 3D structure of the subsurface. The inversion of MCSEM data is complicated by the fact that the EM response of a hydrocarbon-bearing reservoir is very weak in comparison with the background EM fields generated by an electric dipole transmitter in complex geoelectrical structures formed by a conductive sea-water layer and the terranes beneath it. In this paper, we present a review of the recent developments in the area of large-scale 3D EM forward modeling and inversion. Our approach is based on using a new integral form of Maxwell’s equations allowing for an inhomogeneous background conductivity, which results in a numerically effective integral representation for 3D EM field. This representation provides an efficient tool for the solution of 3D EM inverse problems. To obtain a robust inverse model of the conductivity distribution, we apply regularization based on a focusing stabilizing functional which allows for the recovery of models with both smooth and sharp geoelectrical boundaries. The method is implemented in a fully parallel computer code, which makes it possible to run large-scale 3D inversions on grids with millions of inversion cells. This new technique can be effectively used for active EM detection and monitoring of the subsurface targets.
Anderson, Lorinda K
2017-01-01
Immunolocalization using either fluorescence for light microscopy (LM) or gold particles for electron microscopy (EM) has become a common tool to pinpoint proteins involved in recombination during meiotic prophase. Each method has its advantages and disadvantages. For example, LM immunofluorescence is comparatively easier and higher throughput compared to immunogold EM localization. In addition, immunofluorescence has the advantages that a faint signal can often be enhanced by longer exposure times and colocalization using two (or more) probes with different absorbance and emission spectra is straightforward. However, immunofluorescence is not useful if the object of interest does not label with an antibody probe and is below the resolution of the LM. In comparison, immunogold EM localization is higher resolution than immunofluorescent LM localization, and individual nuclear structures, such as recombination nodules, can be identified by EM regardless of whether they are labeled or not. However, immunogold localization has other disadvantages including comparatively low signal-to-noise ratios, more difficult colocalization using gold particles of different sizes, and the inability to evaluate labeling efficiency before examining the sample using EM (a more expensive and time-consuming technique than LM). Here we describe a method that takes advantage of the good points of both immunofluorescent LM and EM to analyze two classes of late recombination nodules (RNs), only one of which labels with antibodies to MLH1 protein, a marker of crossovers. The method can be used readily with other antibodies to analyze early recombination nodules or other prophase I structures.
NASA Astrophysics Data System (ADS)
Qiu, Sihang; Chen, Bin; Wang, Rongxiao; Zhu, Zhengqiu; Wang, Yuan; Qiu, Xiaogang
2018-04-01
Hazardous gas leak accident has posed a potential threat to human beings. Predicting atmospheric dispersion and estimating its source become increasingly important in emergency management. Current dispersion prediction and source estimation models cannot satisfy the requirement of emergency management because they are not equipped with high efficiency and accuracy at the same time. In this paper, we develop a fast and accurate dispersion prediction and source estimation method based on artificial neural network (ANN), particle swarm optimization (PSO) and expectation maximization (EM). The novel method uses a large amount of pre-determined scenarios to train the ANN for dispersion prediction, so that the ANN can predict concentration distribution accurately and efficiently. PSO and EM are applied for estimating the source parameters, which can effectively accelerate the process of convergence. The method is verified by the Indianapolis field study with a SF6 release source. The results demonstrate the effectiveness of the method.
Orthogonalizing EM: A design-based least squares algorithm.
Xiong, Shifeng; Dai, Bin; Huling, Jared; Qian, Peter Z G
We introduce an efficient iterative algorithm, intended for various least squares problems, based on a design of experiments perspective. The algorithm, called orthogonalizing EM (OEM), works for ordinary least squares and can be easily extended to penalized least squares. The main idea of the procedure is to orthogonalize a design matrix by adding new rows and then solve the original problem by embedding the augmented design in a missing data framework. We establish several attractive theoretical properties concerning OEM. For the ordinary least squares with a singular regression matrix, an OEM sequence converges to the Moore-Penrose generalized inverse-based least squares estimator. For ordinary and penalized least squares with various penalties, it converges to a point having grouping coherence for fully aliased regression matrices. Convergence and the convergence rate of the algorithm are examined. Finally, we demonstrate that OEM is highly efficient for large-scale least squares and penalized least squares problems, and is considerably faster than competing methods when n is much larger than p . Supplementary materials for this article are available online.
A Unique BSL-3 Cryo-Electron Microscopy Laboratory at UTMB
Sherman, Michael B.; Freiberg, Alexander N.; Razmus, Dennis; Yazuka, Shintaro; Koht, Craig; Hilser, Vincent J.; Lemon, Stanley M.; Brocard, Anne-Sophie; Zimmerman, Dee; Chiu, Wah; Watowich, Stanley J.; Weaver, Scott C.
2010-01-01
This article describes a unique cryo-electron microscopy (CryoEM) facility to study the three-dimensional organization of viruses at biological safety level 3 (BSL-3). This facility, the W. M. Keck Center for Virus Imaging, has successfully operated for more than a year without incident and was cleared for select agent studies by the Centers for Disease Control and Prevention (CDC). Standard operating procedures for the laboratory were developed and implemented to ensure its safe and efficient operation. This facility at the University of Texas Medical Branch (Galveston, TX) is the only such BSL-3 CryoEM facility approved for select agent research. PMID:21852942
Evaluation of the Thorax of Manduca sexta for Flapping Wing Micro Air Vehicle Applications
2012-03-01
input (Pi) by the muscle efficiency (Em). Estimates for muscular efficiency in insects are based on measurements of oxygen consumption which can be...34 Effects of Operating Frequency and Temperature on Mechanical Power Output form Moth Flight Muscle." Journal of Experimental Biology 149 (1990): 61...they will teach you, or the birds in the sky, and they will tell you; or speak to the earth, and it will teach you, or let the fish in the sea inform
Mishra, Varsha; Puthucheri, Smitha; Singh, Dharmendra
2018-05-07
As a preventive measure against the electromagnetic (EM) wave exposure to human body, EM radiation regulatory authorities such as ICNIRP and FCC defined the value of specific absorption rate (SAR) for the human head during EM wave exposure from mobile phone. SAR quantifies the absorption of EM waves in the human body and it mainly depends on the dielectric properties (ε', σ) of the corresponding tissues. The head part of the human body is more susceptible to EM wave exposure due to the usage of mobile phones. The human head is a complex structure made up of multiple tissues with intermixing of many layers; thus, the accurate measurement of permittivity (ε') and conductivity (σ) of the tissues of the human head is still a challenge. For computing the SAR, researchers are using multilayer model, which has some challenges for defining the boundary for layers. Therefore, in this paper, an attempt has been made to propose a method to compute effective complex permittivity of the human head in the range of 0.3 to 3.0 GHz by applying De-Loor mixing model. Similarly, for defining the thermal effect in the tissue, thermal properties of the human head have also been computed using the De-Loor mixing method. The effective dielectric and thermal properties of equivalent human head model are compared with the IEEE Std. 1528. Graphical abstract ᅟ.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Michael; Haeri, Hossein; Reynolds, Arlis
This chapter provides a set of model protocols for determining energy and demand savings that result from specific energy efficiency measures implemented through state and utility efficiency programs. The methods described here are approaches that are or are among the most commonly used and accepted in the energy efficiency industry for certain measures or programs. As such, they draw from the existing body of research and best practices for energy efficiency program evaluation, measurement, and verification (EM&V). These protocols were developed as part of the Uniform Methods Project (UMP), funded by the U.S. Department of Energy (DOE). The principal objectivemore » for the project was to establish easy-to-follow protocols based on commonly accepted methods for a core set of widely deployed energy efficiency measures.« less
Full PIC simulations of solar radio emission
NASA Astrophysics Data System (ADS)
Sgattoni, A.; Henri, P.; Briand, C.; Amiranoff, F.; Riconda, C.
2017-12-01
Solar radio emissions are electromagnetic (EM) waves emitted in the solar wind plasma as a consequence of electron beams accelerated during solar flares or interplanetary shocks such as ICMEs. To describe their origin, a multi-stage model has been proposed in the 60s which considers a succession of non-linear three-wave interaction processes. A good understanding of the process would allow to infer the kinetic energy transfered from the electron beam to EM waves, so that the radio waves recorded by spacecraft can be used as a diagnostic for the electron beam.Even if the electrostatic problem has been extensively studied, full electromagnetic simulations were attempted only recently. Our large scale 2D-3V electromagnetic PIC simulations allow to identify the generation of both electrostatic and EM waves originated by the succession of plasma instabilities. We tested several configurations varying the electron beam density and velocity considering a background plasma of uniform density. For all the tested configurations approximately 105 of the electron-beam kinetic energy is transfered into EM waves emitted in all direction nearly isotropically. With this work we aim to design experiments of laboratory astrophysics to reproduce the electromagnetic emission process and test its efficiency.
The Emergency Medical System in Greece: Opening Aeolus’ Bag of Winds
Kotsiou, Ourania S.; Srivastava, David S.; Kotsios, Panagiotis; Exadaktylos, Aristomenis K.; Gourgoulianis, Konstantinos I.
2018-01-01
An Emergency Medical Service (EMS) system must encompass a spectrum of care, with dedicated pre-hospital and in-hospital medical facilities. It has to be organised in such a way as to include all necessary services—such as triage accurate initial assessment, prompt resuscitation, efficient management of emergency cases, and transport to definitive care. The global economic downturn has had a direct effect on the health sector and poses additional threats to the healthcare system. Greece is one of the hardest-hit countries. This manuscript aims to present the structure of the Greek EMS system and the impact of the current economic recession on it. Nowadays, primary care suffers major shortages in crucial equipment, unmet health needs, and ineffective central coordination. Patients are also facing economic limitations that lead to difficulties in using healthcare services. The multi-factorial problem of in-hospital EMS overcrowding is also evident and has been linked with potentially poorer clinical outcomes. Furthermore, the ongoing refugee crisis challenges the national EMS. Adoption of a triage scale, expansion of the primary care network, and an effective primary–hospital continuum of care are urgently needed in Greece to provide comprehensive, culturally competent, and high-quality health care. PMID:29652816
The Emergency Medical System in Greece: Opening Aeolus' Bag of Winds.
Kotsiou, Ourania S; Srivastava, David S; Kotsios, Panagiotis; Exadaktylos, Aristomenis K; Gourgoulianis, Konstantinos I
2018-04-13
An Emergency Medical Service (EMS) system must encompass a spectrum of care, with dedicated pre-hospital and in-hospital medical facilities. It has to be organised in such a way as to include all necessary services—such as triage accurate initial assessment, prompt resuscitation, efficient management of emergency cases, and transport to definitive care. The global economic downturn has had a direct effect on the health sector and poses additional threats to the healthcare system. Greece is one of the hardest-hit countries. This manuscript aims to present the structure of the Greek EMS system and the impact of the current economic recession on it. Nowadays, primary care suffers major shortages in crucial equipment, unmet health needs, and ineffective central coordination. Patients are also facing economic limitations that lead to difficulties in using healthcare services. The multi-factorial problem of in-hospital EMS overcrowding is also evident and has been linked with potentially poorer clinical outcomes. Furthermore, the ongoing refugee crisis challenges the national EMS. Adoption of a triage scale, expansion of the primary care network, and an effective primary–hospital continuum of care are urgently needed in Greece to provide comprehensive, culturally competent, and high-quality health care.
Ashtiani, Dariush; Venugopal, Hari; Belousoff, Matthew; Spicer, Bradley; Mak, Johnson; Neild, Adrian; de Marco, Alex
2018-04-06
Cryo-Electron Microscopy (cryo-EM) has become an invaluable tool for structural biology. Over the past decade, the advent of direct electron detectors and automated data acquisition has established cryo-EM as a central method in structural biology. However, challenges remain in the reliable and efficient preparation of samples in a manner which is compatible with high time resolution. The delivery of sample onto the grid is recognized as a critical step in the workflow as it is a source of variability and loss of material due to the blotting which is usually required. Here, we present a method for sample delivery and plunge freezing based on the use of Surface Acoustic Waves to deploy 6-8 µm droplets to the EM grid. This method minimises the sample dead volume and ensures vitrification within 52.6 ms from the moment the sample leaves the microfluidics chip. We demonstrate a working protocol to minimize the atomised volume and apply it to plunge freeze three different samples and provide proof that no damage occurs due to the interaction between the sample and the acoustic waves. Copyright © 2018 Elsevier Inc. All rights reserved.