Using game engine for 3D terrain visualisation of GIS data: A review

NASA Astrophysics Data System (ADS)

Che Mat, Ruzinoor; Shariff, Abdul Rashid Mohammed; Nasir Zulkifli, Abdul; Shafry Mohd Rahim, Mohd; Hafiz Mahayudin, Mohd

2014-06-01

This paper reviews on the 3D terrain visualisation of GIS data using game engines that are available in the market as well as open source. 3D terrain visualisation is a technique used to visualise terrain information from GIS data such as a digital elevation model (DEM), triangular irregular network (TIN) and contour. Much research has been conducted to transform the 2D view of map to 3D. There are several terrain visualisation softwares that are available for free, which include Cesium, Hftool and Landserf. This review paper will help interested users to better understand the current state of art in 3D terrain visualisation of GIS data using game engines.

Parallelization of a Fully-Distributed Hydrologic Model using Sub-basin Partitioning

NASA Astrophysics Data System (ADS)

Vivoni, E. R.; Mniszewski, S.; Fasel, P.; Springer, E.; Ivanov, V. Y.; Bras, R. L.

2005-12-01

A primary obstacle towards advances in watershed simulations has been the limited computational capacity available to most models. The growing trend of model complexity, data availability and physical representation has not been matched by adequate developments in computational efficiency. This situation has created a serious bottleneck which limits existing distributed hydrologic models to small domains and short simulations. In this study, we present novel developments in the parallelization of a fully-distributed hydrologic model. Our work is based on the TIN-based Real-time Integrated Basin Simulator (tRIBS), which provides continuous hydrologic simulation using a multiple resolution representation of complex terrain based on a triangulated irregular network (TIN). While the use of TINs reduces computational demand, the sequential version of the model is currently limited over large basins (>10,000 km2) and long simulation periods (>1 year). To address this, a parallel MPI-based version of the tRIBS model has been implemented and tested using high performance computing resources at Los Alamos National Laboratory. Our approach utilizes domain decomposition based on sub-basin partitioning of the watershed. A stream reach graph based on the channel network structure is used to guide the sub-basin partitioning. Individual sub-basins or sub-graphs of sub-basins are assigned to separate processors to carry out internal hydrologic computations (e.g. rainfall-runoff transformation). Routed streamflow from each sub-basin forms the major hydrologic data exchange along the stream reach graph. Individual sub-basins also share subsurface hydrologic fluxes across adjacent boundaries. We demonstrate how the sub-basin partitioning provides computational feasibility and efficiency for a set of test watersheds in northeastern Oklahoma. We compare the performance of the sequential and parallelized versions to highlight the efficiency gained as the number of processors increases. We also discuss how the coupled use of TINs and parallel processing can lead to feasible long-term simulations in regional watersheds while preserving basin properties at high-resolution.

Numerical simulation of distributed snow processes in complex terrain utilizing triangulated irregular networks (TINs)

NASA Astrophysics Data System (ADS)

Rinehart, A. J.; Vivoni, E. R.

2005-12-01

Snow processes play a significant role in the hydrologic cycle of mountainous and high-latitude catchments in the western United States. Snowmelt runoff contributes to a large percentage of stream runoff while snow covered regions remain highly localized to small portions of the catchment area. The appropriate representation of snow dynamics at a given range of spatial and temporal scales is critical for adequately predicting runoff responses in snowmelt-dominated watersheds. In particular, the accurate depiction of snow cover patterns is important as a range of topographic, land-use and geographic parameters create zones of preferential snow accumulation or ablation that significantly affect the timing of a region's snow melt and the persistence of a snow pack. In this study, we present the development and testing of a distributed snow model designed for simulations over complex terrain. The snow model is developed within the context of the TIN-based Real-time Integrated Basin Simulator (tRIBS), a fully-distributed watershed model capable of continuous simulations of coupled hydrological processes, including unsaturated-saturated zone dynamics, land-atmosphere interactions and runoff generation via multiple mechanisms. The use of triangulated irregular networks as a domain discretization allows tRIBS to accurately represent topography with a reduced number of computational nodes, as compared to traditional grid-based models. This representation is developed using a Delauney optimization criterion that causes areas of topographic homogeneity to be represented at larger spatial scales than the original grid, while more heterogeneous areas are represented at higher resolutions. We utilize the TIN-based terrain representation to simulate microscale (10-m to 100-m) snow pack dynamics over a catchment. The model includes processes such as the snow pack energy balance, wind and bulk redistribution, and snow interception by vegetation. For this study, we present tests from a distributed one-layer energy balance model as applied to a northern New Mexico hillslope in a ponderosa pine forest using both synthetic and real meteorological forcing. We also provide tests of the model's capability to represent spatial patterns within a small watershed in the Jemez Mountain region. Finally, we discuss the interaction of the tested snow process module with existing components in the watershed model and additional applications and capabilities under development.

The development of a hydrologic-hydraulic representation of an urbanscape: the case study of Nashville, Tennessee

NASA Astrophysics Data System (ADS)

Sedlar, F.; Ivanov, V. Y.; Shao, J.; Narayan, U.; Nardi, F.; Adams, T. E.; Merwade, V.; Wright, D. B.; Kim, J.; Fatichi, S.; Rakhmatulina, E.

2013-12-01

Incorporating elevation data into coupled hydraulic and hydrologic models with the use of triangulated irregular networks (TINs) provides a detailed and highly customizable representation of the original domain. Until recently the resolution of such digital elevation models was 1 or 1/3 arc second (10-30 meters). Aided by the use of LiDAR, digital elevation models are now available at the 1/9 arc second resolution (1-3 meters). With elevation data at this level of resolution watershed details that are overlooked at a 10-30 meter resolution can now be resolved and incorporated into the TIN. For urban flood modeling this implies that street level features can be resolved. However to provide a useful picture of the flooding as a whole, this data would need to be integrated across a citywide scale. To prove the feasibility, process, and capabilities of generating such a detailed and large scale TIN, we present a case study of Nashville, TN, USA, during the May 1-2, 2010 flooding, a 1,000 year storm event. With the use of ArcGIS, HEC-RAS, Triangle, and additionally developed processing methodologies, an approach is developed to generate a hydrologically relevant and detailed TIN of the entire urbanscape of Nashville. This TIN incorporates three separate aspects; the watershed, the floodplain, and the city. The watershed component contains the elevation data for the delineated watershed, roughly 1,000 km2 at 1-3 meter resolution. The floodplain encompasses over 300 channel cross sections of the Cumberland River and a delineated floodplain. The city element comprises over 500,000 buildings and all major roadways within the watershed. Once generated, the resulting triangulation of the TIN is optimized with the Triangle software for input to the coupled hydraulic and hydrological model, tRIBS-OFM. Hydrologically relevant areas such as the floodplain are densified and constraints are set on the minimum triangle area for the entire TIN. Upon running the coupled hydraulic and hydrological model with the appropriate forcings, the spatial dynamics of the flooding will then be resolved at a street level across the entire city. The analysis capabilities afforded at this resolution and across such a large area will facilitate urban flood predictions coupled with hydrologic forecasts as well as a better understanding of the spatial dynamics of urban flooding.

Research on optimal DEM cell size for 3D visualization of loess terraces

NASA Astrophysics Data System (ADS)

Zhao, Weidong; Tang, Guo'an; Ji, Bin; Ma, Lei

2009-10-01

In order to represent the complex artificial terrains like loess terraces in Shanxi Province in northwest China, a new 3D visual method namely Terraces Elevation Incremental Visual Method (TEIVM) is put forth by the authors. 406 elevation points and 14 enclosed constrained lines are sampled according to the TIN-based Sampling Method (TSM) and DEM Elevation Points and Lines Classification (DEPLC). The elevation points and constrained lines are used to construct Constrained Delaunay Triangulated Irregular Networks (CD-TINs) of the loess terraces. In order to visualize the loess terraces well by use of optimal combination of cell size and Elevation Increment Value (EIV), the CD-TINs is converted to Grid-based DEM (G-DEM) by use of different combination of cell size and EIV with linear interpolating method called Bilinear Interpolation Method (BIM). Our case study shows that the new visual method can visualize the loess terraces steps very well when the combination of cell size and EIV is reasonable. The optimal combination is that the cell size is 1 m and the EIV is 6 m. Results of case study also show that the cell size should be at least smaller than half of both the terraces average width and the average vertical offset of terraces steps for representing the planar shapes of the terraces surfaces and steps well, while the EIV also should be larger than 4.6 times of the terraces average height. The TEIVM and results above is of great significance to the highly refined visualization of artificial terrains like loess terraces.

76 FR 38129 - Applications for New Awards; Americans With Disabilities Act (ADA) National Network Knowledge...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-29

...) number and a Taxpayer Identification Number (TIN); b. Register both your DUNS number and TIN with the... number and TIN on your application; and d. Maintain an active CCR registration with current information... a TIN from the Internal Revenue Service. If you are an individual, you can obtain a TIN from the...

Pechini process-derived tin oxide and tin oxide-graphite composites for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Zhang, R.; Lee, Jim Y.; Liu, Z. L.

The Pechini process [Ceram. Bull. 68 (1989) 1002] is used to obtain fine tin oxide powders that reduce the specific volume change in Li + insertion and extraction reactions. The suitability of these tin oxides as active materials for negative electrodes in lithium-ion batteries is investigated. From elemental analysis, it is found that the templating polymer network is almost completely obliterated after heating at 500 °C. The best tin oxide does not exhibit extensive crystallization of tin atoms even after 30 cycles of alloying and de-alloying reactions with Li. The structure and the specific capacity of the oxides are dependent on the heat treatment and remnants of the polymeric CH network can impose an unfavorable outcome. A capacity of 600 mAh g -1, which is unchanged for 30 cycles, can be obtained from tin oxide heat treated at 1000 °C. Composites of graphite and SnO 2 are also prepared and exhibit synergistic interactions between graphite and tin oxide which are similar to those reported previously [Electrochem. Solid State Lett. 3 (2000) 167].

High resolution diffraction imaging of crystals grown in microgravity and closely related terrestrial crystals

NASA Technical Reports Server (NTRS)

Steiner, B.; Dobbyn, R.; Black, D.; Burdette, H.; Kuriyama, M.; Spal, R.; Vandenberg, L.; Fripp, A.; Simchick, R.; Lal, R.

1991-01-01

Irregularities found in three crystals grown in space, in four crystals grown entirely on the ground were examined and compared. Irregularities were observed in mercuric iodide, lead tin telluride, triglycine sulfate, and gallium arsenide by high resolution synchrotron x radiation diffraction imaging. Radiation detectors made from mercuric iodide crystals grown in microgravity were reported to perform far better than conventional detectors grown from the same material under full gravity. Effort is now underway to reproduce these 'space' crystals, optimize their properties, and extend comparable superiority to other types of materials.

Crystal regularity with high-resolution synchrotron X-radiation diffraction imaging

NASA Technical Reports Server (NTRS)

Steiner, Bruce; Dobbyn, Ronald C.

1991-01-01

New, high-resolution sources of X-radiation such as monochromatic synchrotron radiation beams with subarcsec divergence allow observation of regularities in a range of crystals with sufficient clarity for comprehensive analyses, whose results can deepen understanding of the nature of various crystal irregularities, their sources, and their effects on device performance. An account is presented of the results thus achievable with irregularities encountered in lattice orientation and strain, grain and subgrain boundaries, dislocations, domain boundaries, additional phases, and surface scratches. Significant achievements to date encompass the observation of critical anomalies in lead tin telluride, the reconciliation of disparate observations of GaAs, the determination of the performance effects of irregularities in mercuric iodide, and the characterization of the origins of crystal growth in bismuth silicon oxide.

Estimating network parameters from combined dynamics of firing rate and irregularity of single neurons.

PubMed

Hamaguchi, Kosuke; Riehle, Alexa; Brunel, Nicolas

2011-01-01

High firing irregularity is a hallmark of cortical neurons in vivo, and modeling studies suggest a balance of excitation and inhibition is necessary to explain this high irregularity. Such a balance must be generated, at least partly, from local interconnected networks of excitatory and inhibitory neurons, but the details of the local network structure are largely unknown. The dynamics of the neural activity depends on the local network structure; this in turn suggests the possibility of estimating network structure from the dynamics of the firing statistics. Here we report a new method to estimate properties of the local cortical network from the instantaneous firing rate and irregularity (CV(2)) under the assumption that recorded neurons are a part of a randomly connected sparse network. The firing irregularity, measured in monkey motor cortex, exhibits two features; many neurons show relatively stable firing irregularity in time and across different task conditions; the time-averaged CV(2) is widely distributed from quasi-regular to irregular (CV(2) = 0.3-1.0). For each recorded neuron, we estimate the three parameters of a local network [balance of local excitation-inhibition, number of recurrent connections per neuron, and excitatory postsynaptic potential (EPSP) size] that best describe the dynamics of the measured firing rates and irregularities. Our analysis shows that optimal parameter sets form a two-dimensional manifold in the three-dimensional parameter space that is confined for most of the neurons to the inhibition-dominated region. High irregularity neurons tend to be more strongly connected to the local network, either in terms of larger EPSP and inhibitory PSP size or larger number of recurrent connections, compared with the low irregularity neurons, for a given excitatory/inhibitory balance. Incorporating either synaptic short-term depression or conductance-based synapses leads many low CV(2) neurons to move to the excitation-dominated region as well as to an increase of EPSP size.

Bathymetry of Ashokan, Cannonsville, Neversink, Pepacton, Rondout, and Schoharie Reservoirs, New York, 2013–15

USGS Publications Warehouse

Nystrom, Elizabeth A.

2018-02-01

Drinking water for New York City is supplied from several large reservoirs, including a system of reservoirs west of the Hudson River. To provide updated reservoir capacity tables and bathymetry maps of the City’s six West of Hudson reservoirs, bathymetric surveys were conducted by the U.S. Geological Survey from 2013 to 2015. Depths were surveyed with a single-beam echo sounder and real-time kinematic global positioning system along planned transects at predetermined intervals for each reservoir. A separate quality assurance dataset of echo sounder points was collected along transects at oblique angles to the main transects for accuracy assessment. Field-survey data were combined with water surface elevations in a geographic information system to create three-dimensional surfaces in the form of triangulated irregular networks (TINs) representing the elevations of the reservoir geomorphology. The TINs were linearly enforced to better represent geomorphic features within the reservoirs. The linearly enforced TINs were then used to create raster surfaces and 2-foot-interval contour maps of the reservoirs. Elevation-area-capacity tables were calculated at 0.01-foot intervals. The results of the surveys show that the total capacity of the West of Hudson reservoirs has decreased by 11.5 billion gallons (Ggal), or 2.3 percent, since construction, and the useable capacity (the volume above the minimum operating level required to deliver full flow for drinking water supply) has decreased by 7.9 Ggal (1.7 percent). The available capacity (the volume between the spillway elevation and the lowest intake or sill elevation used for drinking water supply) decreased by 9.6 Ggal (2.0 percent), and dead storage (the volume below the lowest intake or sill elevation) decreased by 1.9 Ggal (11.6 percent).

A Physically-based Model For Rainfall-triggered Landslides At A Regional Scale

NASA Astrophysics Data System (ADS)

Teles, V.; Capolongo, D.; Bras, R. L.

Rainfall has long been recognized as a major cause of landslides. Historical records have shown that large rainfall can generate hundreds of landslides over hundreds of square kilometers. Although a great body of work has documented the morphology and mechanics of individual slope failure, few studies have considered the process at basin and regional scale. A landslide model is integrated in the landscape evolution model CHILD and simulates rainfall-triggered events based on a geotechnical index, the factor of safety, which takes into account the slope, the soil effective cohesion and weight, the friction angle, the regolith thickness and the saturated thickness. The stat- urated thickness is represented by the wetness index developed in the TOPMODEL. The topography is represented by a Triangulated Irregular Network (TIN). The factor of safety is computed at each node of the TIN. If the factor of safety is lower than 1, a landslide is intiated at this node. The regolith is then moved downstream. We applied the model to the Fortore basin whose valley cuts the flysch terrain that constitute the framework of the so called "sub-Apennines" chain that is the most eastern part of the Southern Apennines (Italy). We will discuss its value according to its sensitivity to the used parameters and compare it to the actual data available for this basin.

Experimental observations on the links between surface perturbation parameters and shock-induced mass ejection

NASA Astrophysics Data System (ADS)

Monfared, S. K.; Oró, D. M.; Grover, M.; Hammerberg, J. E.; LaLone, B. M.; Pack, C. L.; Schauer, M. M.; Stevens, G. D.; Stone, J. B.; Turley, W. D.; Buttler, W. T.

2014-08-01

We have assembled together our ejecta measurements from explosively shocked tin acquired over a period of about ten years. The tin was cast at 0.99995 purity, and all of the tin targets or samples were shocked to loading pressures of about 27 GPa, allowing meaningful comparisons. The collected data are markedly consistent, and because the total ejected mass scales linearly with the perturbations amplitudes they can be used to estimate how much total Sn mass will be ejected from explosively shocked Sn, at similar loading pressures, based on the surface perturbation parameters of wavelength and amplitude. Most of the data were collected from periodic isosceles shapes that approximate sinusoidal perturbations. Importantly, however, we find that not all periodic perturbations behave similarly. For example, we observed that sawtooth (right triangular) perturbations eject more mass than an isosceles perturbation of similar depth and wavelength, demonstrating that masses ejected from irregular shaped perturbations cannot be normalized to the cross-sectional areas of the perturbations.

Using a Calculated Pulse Rate with an Artificial Neural Network to Detect Irregular Interbeats.

PubMed

Yeh, Bih-Chyun; Lin, Wen-Piao

2016-03-01

Heart rate is an important clinical measure that is often used in pathological diagnosis and prognosis. Valid detection of irregular heartbeats is crucial in the clinical practice. We propose an artificial neural network using the calculated pulse rate to detect irregular interbeats. The proposed system measures the calculated pulse rate to determine an "irregular interbeat on" or "irregular interbeat off" event. If an irregular interbeat is detected, the proposed system produces a danger warning, which is helpful for clinicians. If a non-irregular interbeat is detected, the proposed system displays the calculated pulse rate. We include a flow chart of the proposed software. In an experiment, we measure the calculated pulse rates and achieve an error percentage of < 3% in 20 participants with a wide age range. When we use the calculated pulse rates to detect irregular interbeats, we find such irregular interbeats in eight participants.

Filling the voids in the SRTM elevation model — A TIN-based delta surface approach

NASA Astrophysics Data System (ADS)

Luedeling, Eike; Siebert, Stefan; Buerkert, Andreas

The Digital Elevation Model (DEM) derived from NASA's Shuttle Radar Topography Mission is the most accurate near-global elevation model that is publicly available. However, it contains many data voids, mostly in mountainous terrain. This problem is particularly severe in the rugged Oman Mountains. This study presents a method to fill these voids using a fill surface derived from Russian military maps. For this we developed a new method, which is based on Triangular Irregular Networks (TINs). For each void, we extracted points around the edge of the void from the SRTM DEM and the fill surface. TINs were calculated from these points and converted to a base surface for each dataset. The fill base surface was subtracted from the fill surface, and the result added to the SRTM base surface. The fill surface could then seamlessly be merged with the SRTM DEM. For validation, we compared the resulting DEM to the original SRTM surface, to the fill DEM and to a surface calculated by the International Center for Tropical Agriculture (CIAT) from the SRTM data. We calculated the differences between measured GPS positions and the respective surfaces for 187,500 points throughout the mountain range (ΔGPS). Comparison of the means and standard deviations of these values showed that for the void areas, the fill surface was most accurate, with a standard deviation of the ΔGPS from the mean ΔGPS of 69 m, and only little accuracy was lost by merging it to the SRTM surface (standard deviation of 76 m). The CIAT model was much less accurate in these areas (standard deviation of 128 m). The results show that our method is capable of transferring the relative vertical accuracy of a fill surface to the void areas in the SRTM model, without introducing uncertainties about the absolute elevation of the fill surface. It is well suited for datasets with varying altitude biases, which is a common problem of older topographic information.

Synergistic Effect of Nitrogen and Refractory Material on TiN Formation and Equiaxed Grain Structure of Ferritic Stainless Steel

NASA Astrophysics Data System (ADS)

Lee, Mun Hyung; Park, Joo Hyun

2018-06-01

The effect of nitrogen content on the formation of an equiaxed solidification structure of Fe-16Cr steel was investigated. Moreover, two different kinds of refractory materials, i.e., alumina and magnesia, were employed to control the type of oxide inclusion. The characteristics of TiN(-oxide) inclusions were quantitatively analyzed in both molten steel and solidified samples. When the melting was carried out in the alumina refractory, the grain size continuously decreased with increasing nitrogen content. However, a minimum grain size was observed at a specific nitrogen content (approx. 150 ppm) when the steel was melted in the magnesia refractory. Most of the single TiN particles had a cuboidal shape and fine irregularly shaped particles were located along the grain boundary due to the microsegregation of Ti at the grain boundary during solidification. The type of TiN-oxide hybrid inclusion was strongly affected by the refractory material where Al2O3-TiN and MgAl2O4-TiN hybrid-type inclusions were obtained in the alumina and magnesia refractory experiments, respectively. The formation of oxide inclusions was well predicted by thermochemical computations and it was commonly found that oxide particles were initially formed, followed by the nucleation and growth of TiN. When the nitrogen content increased, the number density of TiN linearly increased in the alumina refractory experiments. However, the number of TiN exhibits a maximum at about [N] = 150 ppm, at which a minimum grain size was obtained in the magnesia refractory experiments. Therefore, the larger the number density of TiN, the smaller the primary grain size after solidification. The number density of TiN in the steel melted in the magnesia refractory was greater than that in the steel melted in the alumina refractory at given Ti and N contents, which was due to the lower planar lattice disregistry of MgAl2O4-TiN interface rather than that of Al2O3-TiN interface. When Δ T TiN (= difference between the TiN precipitation temperature and the liquidus of the steel) was 20 K to 40 K, the number density of effective TiN was maximized and thus, the grain size was minimized after solidification. Finally, although most of the TiN particles were smaller than 1 μm in the molten steel samples irrespective of the nitrogen content, TiN particles larger than 10 μm were observed in the solidified samples when the nitrogen content was greater than 150 ppm. The growth of TiN particles during melting and solidification was well predicted by the combinatorial simulation of the `Ostwald ripening model' based on the Lifshitz-Slyozov-Wagner theory in conjunction with the `Diffusion controlled model' using Ohnaka's microsegregation equation.

Synergistic Effect of Nitrogen and Refractory Material on TiN Formation and Equiaxed Grain Structure of Ferritic Stainless Steel

NASA Astrophysics Data System (ADS)

Lee, Mun Hyung; Park, Joo Hyun

2018-03-01

The effect of nitrogen content on the formation of an equiaxed solidification structure of Fe-16Cr steel was investigated. Moreover, two different kinds of refractory materials, i.e., alumina and magnesia, were employed to control the type of oxide inclusion. The characteristics of TiN(-oxide) inclusions were quantitatively analyzed in both molten steel and solidified samples. When the melting was carried out in the alumina refractory, the grain size continuously decreased with increasing nitrogen content. However, a minimum grain size was observed at a specific nitrogen content (approx. 150 ppm) when the steel was melted in the magnesia refractory. Most of the single TiN particles had a cuboidal shape and fine irregularly shaped particles were located along the grain boundary due to the microsegregation of Ti at the grain boundary during solidification. The type of TiN-oxide hybrid inclusion was strongly affected by the refractory material where Al2O3-TiN and MgAl2O4-TiN hybrid-type inclusions were obtained in the alumina and magnesia refractory experiments, respectively. The formation of oxide inclusions was well predicted by thermochemical computations and it was commonly found that oxide particles were initially formed, followed by the nucleation and growth of TiN. When the nitrogen content increased, the number density of TiN linearly increased in the alumina refractory experiments. However, the number of TiN exhibits a maximum at about [N] = 150 ppm, at which a minimum grain size was obtained in the magnesia refractory experiments. Therefore, the larger the number density of TiN, the smaller the primary grain size after solidification. The number density of TiN in the steel melted in the magnesia refractory was greater than that in the steel melted in the alumina refractory at given Ti and N contents, which was due to the lower planar lattice disregistry of MgAl2O4-TiN interface rather than that of Al2O3-TiN interface. When ΔT TiN (= difference between the TiN precipitation temperature and the liquidus of the steel) was 20 K to 40 K, the number density of effective TiN was maximized and thus, the grain size was minimized after solidification. Finally, although most of the TiN particles were smaller than 1 μm in the molten steel samples irrespective of the nitrogen content, TiN particles larger than 10 μm were observed in the solidified samples when the nitrogen content was greater than 150 ppm. The growth of TiN particles during melting and solidification was well predicted by the combinatorial simulation of the `Ostwald ripening model' based on the Lifshitz-Slyozov-Wagner theory in conjunction with the `Diffusion controlled model' using Ohnaka's microsegregation equation.

Electrochemical mechanism of tin membrane electrodeposition under ultrasonic waves.

PubMed

Nan, Tianxiang; Yang, Jianguang; Chen, Bing

2018-04-01

Tin was electrodeposited from chloride solutions using a membrane cell under ultrasonic waves. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CHR), and chronopotentiometry were applied to investigate the electrochemical mechanism of tin electrodeposition under ultrasonic field. Chronoamperometry curves showed that the initial process of tin electrodeposition followed the diffusion controlled three-dimensional nucleation and grain growth mechanism. The analysis of the cyclic voltammetry and linear sweep voltammetry diagrams showed that the application of ultrasound can change the tin membrane electro-deposition reaction from diffusion to electrochemical control, and the optimum parameters for tin electrodeposition were H + concentration 3.5 mol·L -1 , temperature 35 °C and ultrasonic power 100 W. The coupling ultrasonic field played a role in refining the grain in this process. The growth of tin crystals showed no orientation preferential, and the tin deposition showed a tendency to form a regular network structure after ultrasonic coupling. While in the absence of ultrasonic coupling, the growth of tin crystals has a high preferential orientation, and the tin deposition showed a tendency to form tin whiskers. Ultrasonic coupling was more favorable for obtaining a more compact and smoother cathode tin layer. Copyright © 2017 Elsevier B.V. All rights reserved.

Irregular behavior in an excitatory-inhibitory neuronal network

NASA Astrophysics Data System (ADS)

Park, Choongseok; Terman, David

2010-06-01

Excitatory-inhibitory networks arise in many regions throughout the central nervous system and display complex spatiotemporal firing patterns. These neuronal activity patterns (of individual neurons and/or the whole network) are closely related to the functional status of the system and differ between normal and pathological states. For example, neurons within the basal ganglia, a group of subcortical nuclei that are responsible for the generation of movement, display a variety of dynamic behaviors such as correlated oscillatory activity and irregular, uncorrelated spiking. Neither the origins of these firing patterns nor the mechanisms that underlie the patterns are well understood. We consider a biophysical model of an excitatory-inhibitory network in the basal ganglia and explore how specific biophysical properties of the network contribute to the generation of irregular spiking. We use geometric dynamical systems and singular perturbation methods to systematically reduce the model to a simpler set of equations, which is suitable for analysis. The results specify the dependence on the strengths of synaptic connections and the intrinsic firing properties of the cells in the irregular regime when applied to the subthalamopallidal network of the basal ganglia.

Effect of protective release coatings on the basis of superdispersersed zirconium oxide powder on the formation of gas defects in bronze casting

NASA Astrophysics Data System (ADS)

Martyushev, Nikita V.; Risto, Nikolay A.

2014-10-01

This paper investigates the use of nanopowders in the composition of foundry coatings when casting leaded tin bronzes. Influence of the composition of the applied protective coating on surface finish is studied. The effects of the coatings of the following compositions are compared: non-stick coating (a mixture of low-dispersed chromium oxide powder and heat-treated vegetable oil); non-stick lubricant ASPF-2/RgU on the basis of low- dispersed graphite powder and heat-treated vegetable oil; patent #2297300 (a mixture of superdispersed zirconium dioxide powder with industrial oil). It is demonstrated that application of foundry coatings containing superdispersed metal oxide powders with low thermal conductivity makes it possible to significantly reduce irregularities and eliminate gas porosity on the surface of tin-leaded bronze castings.

Propagating waves can explain irregular neural dynamics.

PubMed

Keane, Adam; Gong, Pulin

2015-01-28

Cortical neurons in vivo fire quite irregularly. Previous studies about the origin of such irregular neural dynamics have given rise to two major models: a balanced excitation and inhibition model, and a model of highly synchronized synaptic inputs. To elucidate the network mechanisms underlying synchronized synaptic inputs and account for irregular neural dynamics, we investigate a spatially extended, conductance-based spiking neural network model. We show that propagating wave patterns with complex dynamics emerge from the network model. These waves sweep past neurons, to which they provide highly synchronized synaptic inputs. On the other hand, these patterns only emerge from the network with balanced excitation and inhibition; our model therefore reconciles the two major models of irregular neural dynamics. We further demonstrate that the collective dynamics of propagating wave patterns provides a mechanistic explanation for a range of irregular neural dynamics, including the variability of spike timing, slow firing rate fluctuations, and correlated membrane potential fluctuations. In addition, in our model, the distributions of synaptic conductance and membrane potential are non-Gaussian, consistent with recent experimental data obtained using whole-cell recordings. Our work therefore relates the propagating waves that have been widely observed in the brain to irregular neural dynamics. These results demonstrate that neural firing activity, although appearing highly disordered at the single-neuron level, can form dynamical coherent structures, such as propagating waves at the population level. Copyright © 2015 the authors 0270-6474/15/351591-15$15.00/0.

State-of-the-Art: DTM Generation Using Airborne LIDAR Data

PubMed Central

Chen, Ziyue; Gao, Bingbo; Devereux, Bernard

2017-01-01

Digital terrain model (DTM) generation is the fundamental application of airborne Lidar data. In past decades, a large body of studies has been conducted to present and experiment a variety of DTM generation methods. Although great progress has been made, DTM generation, especially DTM generation in specific terrain situations, remains challenging. This research introduces the general principles of DTM generation and reviews diverse mainstream DTM generation methods. In accordance with the filtering strategy, these methods are classified into six categories: surface-based adjustment; morphology-based filtering, triangulated irregular network (TIN)-based refinement, segmentation and classification, statistical analysis and multi-scale comparison. Typical methods for each category are briefly introduced and the merits and limitations of each category are discussed accordingly. Despite different categories of filtering strategies, these DTM generation methods present similar difficulties when implemented in sharply changing terrain, areas with dense non-ground features and complicated landscapes. This paper suggests that the fusion of multi-sources and integration of different methods can be effective ways for improving the performance of DTM generation. PMID:28098810

A technique for inferring zonal irregularity drift from single-station GNSS measurements of intensity (S4) and phase (σφ) scintillations

NASA Astrophysics Data System (ADS)

Carrano, Charles S.; Groves, Keith M.; Rino, Charles L.; Doherty, Patricia H.

2016-08-01

The zonal drift of ionospheric irregularities at low latitudes is most commonly measured by cross-correlating observations of a scintillating satellite signal made with a pair of closely spaced antennas. The Air Force Research Laboratory-Scintillation Network Decision Aid (AFRL-SCINDA) network operates a small number of very high frequency (VHF) spaced-receiver systems at low latitudes for this purpose. A far greater number of Global Navigation Satellite System (GNSS) scintillation monitors are operated by the AFRL-SCINDA network (25-30) and the Low-Latitude Ionospheric Sensor Network (35-50), but the receivers are too widely separated from each other for cross-correlation techniques to be effective. In this paper, we present an alternative approach that leverages the weak scatter scintillation theory to infer the zonal irregularity drift from single-station GNSS measurements of S4, σφ, and the propagation geometry. Unlike the spaced-receiver technique, this approach requires assumptions regarding the height of the scattering layer (which introduces a bias in the drift estimates) and the spectral index of the irregularities (which affects the spread of the drift estimates about the mean). Nevertheless, theory and experiment suggest that the ratio of σφ to S4 is less sensitive to these parameters than it is to the zonal drift. We validate the technique using VHF spaced-receiver measurements of zonal irregularity drift obtained from the AFRL-SCINDA network. While the spaced-receiver technique remains the preferred way to monitor the drift when closely spaced antenna pairs are available, our technique provides a new opportunity to monitor zonal irregularity drift using regional or global networks of widely separated GNSS scintillation monitors.

Possibility of using NURBS for surface plotting by survey data

NASA Astrophysics Data System (ADS)

Pravdina, E. A.; Lepikhina, O. J.

2018-05-01

Different methods of surface plotting were discussed in this article. Constructing the surface with the help of the Delaunay triangulation algorithm is described. The TIN-surfaces (triangles irregular net) method is used in the entire CAD software. This type of surfaces is plotting by results of laser scanning and stadia surveying. Possibility of using spline surfaces (NURBS) for surface plotting is studied. For a defined number of points by Mathcad software, the curvilinear function that described two-dimensional spline surfaces was calculated and plotted.

Layered structures of organic/inorganic hybrid halide perovskites

NASA Astrophysics Data System (ADS)

Huan, Tran Doan; Tuoc, Vu Ngoc; Minh, Nguyen Viet

2016-03-01

Organic-inorganic hybrid halide perovskites, in which the A cations of an ABX3 perovskite are replaced by organic cations, may be used for photovoltaic and solar thermoelectric applications. In this contribution, we systematically study three lead-free hybrid perovskites, i.e., methylammonium tin iodide CH3NH3SnI3 , ammonium tin iodide NH4SnI3 , and formamidnium tin iodide HC (NH2)2SnI3 by first-principles calculations. We find that in addition to the commonly known motif in which the corner-shared SnI6 octahedra form a three-dimensional network, these materials may also favor a two-dimensional (layered) motif formed by alternating layers of the SnI6 octahedra and the organic cations. These two motifs are nearly equal in free energy and are separated by low barriers. These layered structures features many flat electronic bands near the band edges, making their electronic structures significantly different from those of the structural phases composed of three-dimension networks of SnI6 octahedra. Furthermore, because the electronic structures of HC (NH2)2SnI3 are found to be rather similar to those of CH3NH3SnI3 , formamidnium tin iodide may also be promising for the applications of methylammonium tin iodide.

Combining Cluster Analysis and Small Unmanned Aerial Systems (sUAS) for Accurate and Low-cost Bathymetric Surveying

NASA Astrophysics Data System (ADS)

Maples, B. L.; Alvarez, L. V.; Moreno, H. A.; Chilson, P. B.; Segales, A.

2017-12-01

Given that classical in-situ direct surveying for geomorphological subsurface information in rivers is time-consuming, labor-intensive, costly, and often involves high-risk activities, it is obvious that non-intrusive technologies, like UAS-based, LIDAR-based remote sensing, have a promising potential and benefits in terms of efficient and accurate measurement of channel topography over large areas within a short time; therefore, a tremendous amount of attention has been paid to the development of these techniques. Over the past two decades, efforts have been undertaken to develop a specialized technique that can penetrate the water body and detect the channel bed to derive river and coastal bathymetry. In this research, we develop a low-cost effective technique for water body bathymetry. With the use of a sUAS and a light-weight sonar, the bathymetry and volume of a small reservoir have been surveyed. The sUAS surveying approach is conducted under low altitudes (2 meters from the water) using the sUAS to tow a small boat with the sonar attached. A cluster analysis is conducted to optimize the sUAS data collection and minimize the standard deviation created by under-sampling in areas of highly variable bathymetry, so measurements are densified in regions featured by steep slopes and drastic changes in the reservoir bed. This technique provides flexibility, efficiency, and free-risk to humans while obtaining high-quality information. The irregularly-spaced bathymetric survey is then interpolated using unstructured Triangular Irregular Network (TIN)-based maps to avoid re-gridding or re-sampling issues.

On the Longitudinal Morphology of Zonal Irregularity Drift Measured using Networks of GPS Scintillation Monitors

NASA Astrophysics Data System (ADS)

Carrano, C. S.; Groves, K. M.; Valladares, C. E.; Delay, S. H.

2014-12-01

A complete characterization of field-aligned ionospheric irregularities responsible for the scintillation of satellite signals includes not only their spectral properties (power spectral strength, spectral index, anisotropy ratio, and outer-scale) but also their horizontal drift velocity. From a system impacts perspective, the horizontal drift velocity is important in that it dictates the rate of signal fading and also, to an extent, the level of phase fluctuations encountered by the receiver. From a physics perspective, studying the longitudinal morphology of zonal irregularity may lead to an improved understanding of the F region dynamo and regional electrodynamics at low latitudes. The irregularity drift at low latitudes is predominantly zonal and is most commonly measured by cross-correlating observations of satellite signals made by a pair of closely-spaced antennas. The AFRL-SCINDA network operates a small number of VHF spaced-antenna systems at low latitude stations for this purpose. A far greater number of GPS scintillation monitors are operated by AFRL-SCINDA (25-30) and the Low Latitude Ionospheric Sensor Network (35-50), but the receivers are situated too far apart to monitor the drift using cross-correlation techniques. In this paper, we present an alternative approach that leverages the weak scatter scintillation theory (Rino, Radio Sci., 1979) to infer the zonal irregularity drift from single-station GPS measurements of S4, sigma-phi, and the propagation geometry alone. Unlike the spaced-receiver technique, this technique requires assumptions for the height of the scattering layer (which introduces a bias in the drift estimates) and the spectral index of the irregularities (which affects the spread of the drift estimates about the mean). Nevertheless, theory and experiment show that the ratio of sigma-phi to S4 is less sensitive to these parameters than it is to the zonal drift, and hence the zonal drift can be estimated with reasonable accuracy. In this talk, we first validate the technique using spaced VHF-antenna measurements of zonal irregularity drift from the AFRL-SCINDA network. Next, we discuss preliminary results from our investigation into the longitudinal morphology of zonal irregularity drift using the AFRL-SCINDA and LISN networks of GPS scintillation monitors.

Digital floodplain mapping and an analysis of errors involved

USGS Publications Warehouse

Hamblen, C.S.; Soong, D.T.; Cai, X.

2007-01-01

Mapping floodplain boundaries using geographical information system (GIS) and digital elevation models (DEMs) was completed in a recent study. However convenient this method may appear at first, the resulting maps potentially can have unaccounted errors. Mapping the floodplain using GIS is faster than mapping manually, and digital mapping is expected to be more common in the future. When mapping is done manually, the experience and judgment of the engineer or geographer completing the mapping and the contour resolution of the surface topography are critical in determining the flood-plain and floodway boundaries between cross sections. When mapping is done digitally, discrepancies can result from the use of the computing algorithm and digital topographic datasets. Understanding the possible sources of error and how the error accumulates through these processes is necessary for the validation of automated digital mapping. This study will evaluate the procedure of floodplain mapping using GIS and a 3 m by 3 m resolution DEM with a focus on the accumulated errors involved in the process. Within the GIS environment of this mapping method, the procedural steps of most interest, initially, include: (1) the accurate spatial representation of the stream centerline and cross sections, (2) properly using a triangulated irregular network (TIN) model for the flood elevations of the studied cross sections, the interpolated elevations between them and the extrapolated flood elevations beyond the cross sections, and (3) the comparison of the flood elevation TIN with the ground elevation DEM, from which the appropriate inundation boundaries are delineated. The study area involved is of relatively low topographic relief; thereby, making it representative of common suburban development and a prime setting for the need of accurately mapped floodplains. This paper emphasizes the impacts of integrating supplemental digital terrain data between cross sections on floodplain delineation. ?? 2007 ASCE.

Bathymetric survey of Carroll Creek Tributary to Lake Tuscaloosa, Tuscaloosa County, Alabama, 2010

USGS Publications Warehouse

Lee, K.G.; Kimbrow, D.R.

2011-01-01

The U.S. Geological Survey, in cooperation with the City of Tuscaloosa, conducted a bathymetric survey of Carroll Creek, on May 12-13, 2010. Carroll Creek is one of the major tributaries to Lake Tuscaloosa and contributes about 6 percent of the surface drainage area. A 3.5-mile reach of Carroll Creek was surveyed to prepare a current bathymetric map, determine storage capacities at specified water-surface elevations, and compare current conditions to historical cross sections. Bathymetric data were collected using a high-resolution interferometric mapping system consisting of a phase-differencing bathymetric sonar, navigation and motion-sensing system, and a data acquisition computer. To assess the accuracy of the interferometric mapping system and document depths in shallow areas of the study reach, an electronic total station was used to survey 22 cross sections spaced 50 feet apart. The data were combined and processed and a Triangulated Irregular Network (TIN) and contour map were generated. Cross sections were extracted from the TIN and compared with historical cross sections. Between 2004 and 2010, the area (cross section 1) at the confluence of Carroll Creek and the main run of LakeTuscaloosa showed little to no change in capacity area. Another area (cross section 2) showed a maximum change in elevation of 4 feet and an average change of 3 feet. At the water-surface elevation of 224 feet (National Geodetic Vertical Datum of 1929), the cross-sectional area has changed by 260 square feet for a total loss of 28 percent of cross-sectional storage area. The loss of area may be attributed to sedimentation in Carroll Creek and (or) the difference in accuracy between the two surveys.

Automatic drawing for traffic marking with MMS LIDAR intensity

NASA Astrophysics Data System (ADS)

Takahashi, G.; Takeda, H.; Shimano, Y.

2014-05-01

Upgrading the database of CYBER JAPAN has been strategically promoted because the "Basic Act on Promotion of Utilization of Geographical Information", was enacted in May 2007. In particular, there is a high demand for road information that comprises a framework in this database. Therefore, road inventory mapping work has to be accurate and eliminate variation caused by individual human operators. Further, the large number of traffic markings that are periodically maintained and possibly changed require an efficient method for updating spatial data. Currently, we apply manual photogrammetry drawing for mapping traffic markings. However, this method is not sufficiently efficient in terms of the required productivity, and data variation can arise from individual operators. In contrast, Mobile Mapping Systems (MMS) and high-density Laser Imaging Detection and Ranging (LIDAR) scanners are rapidly gaining popularity. The aim in this study is to build an efficient method for automatically drawing traffic markings using MMS LIDAR data. The key idea in this method is extracting lines using a Hough transform strategically focused on changes in local reflection intensity along scan lines. However, also note that this method processes every traffic marking. In this paper, we discuss a highly accurate and non-human-operator-dependent method that applies the following steps: (1) Binarizing LIDAR points by intensity and extracting higher intensity points; (2) Generating a Triangulated Irregular Network (TIN) from higher intensity points; (3) Deleting arcs by length and generating outline polygons on the TIN; (4) Generating buffers from the outline polygons; (5) Extracting points from the buffers using the original LIDAR points; (6) Extracting local-intensity-changing points along scan lines using the extracted points; (7) Extracting lines from intensity-changing points through a Hough transform; and (8) Connecting lines to generate automated traffic marking mapping data.

High resolution synchrotron X-radiation diffraction imaging of crystals grown in microgravity and closely related terrestrial crystals

NASA Technical Reports Server (NTRS)

Steiner, Bruce; Dobbyn, Ronald C.; Black, David; Burdette, Harold; Kuriyama, Masao; Fripp, Archibald; Simchik, Richard

1991-01-01

Irregularities in three crystals grown in space and in four terrestrial crystals grown under otherwise comparable conditions have been observed in high resolution diffraction imaging. The images provide important new clues to the nature and origins of irregularities in each crystal. For two of the materials, mercuric iodide and lead tin telluride, more than one phase (an array of non-diffracting inclusions) was observed in terrestrial samples; but the formation of these multiple phases appears to have been suppressed in directly comparable crystals grown in microgravity. The terrestrial seed crystal of triglycine sulfate displayed an unexpected layered structure, which propagated during directly comparable space growth. Terrestrial Bridgman regrowth of gallium arsenide revealed a mesoscopic structure substantially different from that of the original Czochralski material. A directly comparable crystal is to be grown shortly in space.

Bouquet-Like Mn2SnO4 Nanocomposite Engineered with Graphene Sheets as an Advanced Lithium-Ion Battery Anode.

PubMed

Rehman, Wasif Ur; Xu, Youlong; Sun, Xiaofei; Ullah, Inam; Zhang, Yuan; Li, Long

2018-05-30

Volume expansion is a major challenge associated with tin oxide (SnO x ), which causes poor cyclability in lithium-ion battery anode. Bare tin dioxide (SnO 2 ), tin dioxide with graphene sheets (SnO 2 @GS), and bouquet-like nanocomposite structure (Mn 2 SnO 4 @GS) are prepared via hydrothermal method followed by annealing. The obtained composite material presents a bouquet structure containing manganese and tin oxide nanoparticle network with graphene sheets. Benefiting from this porous nanostructure, in which graphene sheets provide high electronic pathways to enhance the electronic conductivity, uniformly distributed particles offer accelerated kinetic reaction with lithium ion and reduced volume deviation in the tin dioxide (SnO 2 ) particle during charge-discharge testing. As a consequence, ternary composite Mn 2 SnO 4 @GS showed a high rate performance and outstanding cyclability of anode material for lithium-ion batteries. The electrode achieved a specific capacity of about 1070 mA h g -1 at a current density of 400 mA g -1 after 200 cycles; meanwhile, the electrode still delivered a specific capacity of about 455 mA h g -1 at a high current density of 2500 mA g -1 . Ternary Mn 2 SnO 4 @GS material could facilitate fabrication of unique structure and conductive network as advanced lithium-ion battery.

Investigating the Social Interactions of Beginning Teachers Using a Video Annotation Tool

ERIC Educational Resources Information Center

Ellis, Joshua; McFadden, Justin; Anwar, Tasneem; Roehrig, Gillian

2015-01-01

This study examines the use of a digital video annotation tool used by beginning in-service secondary science and mathematics teachers in the Teacher Induction Network (TIN). TIN is an online induction program in its ninth year of existence and has served over 180 teachers. The need to provide spaces for beginning teachers to reflect on their…

Nanoengineering of 2D tin sulfide nanoflake arrays incorporated on polyaniline nanofibers with boosted capacitive behavior

NASA Astrophysics Data System (ADS)

Wang, Huanhuan; Chao, DongLiang; Liu, Jilei; Lin, Jianyi; Shen, Ze Xiang

2018-07-01

Nanoscale engineering plays an important role in designing novel electrode architecture and boosting energy storage in supercapacitors. Herein, we demonstrate the fabrication of freestanding tin sulfide based supercapacitor electrode using facile nucleation substrate control, i.e. polyaniline network. This is the first time that tin sulfide based material is fabricated as a binder-free electrode for supercapacitors. The first combination of tin sulfide and polyaniline also evokes synergistic effect to enhance the performance as the polyaniline nanofibers facilitate the growth of tin sulfide flakes in nanosize which is further proved helpful for improving the capacity and stability of the electrode. The as-obtained electrode of tin sulfide nanoflake arrays incorporated on polyaniline nanofibers (365 F g‑1 at 10 mV s‑1) exhibits superior electrochemical performance compared with micro-scaled tin sulfide (32 F g‑1 at 10 mV s‑1). The significantly improved pseudocapacitive and diffusive contributions of polyaniline nanofibers incorporated electrode are identified by quantitative kinetics analysis due to greatly decreased particle size and introduced mesopores, nanoclusters, and exposed edges. Profited from effective nanostructure engineering, a Na+ intercalation mechanism is also pointed out in boosting the electrochemical performance.

Irregular Collective Behavior of Heterogeneous Neural Networks

NASA Astrophysics Data System (ADS)

Luccioli, Stefano; Politi, Antonio

2010-10-01

We investigate a network of integrate-and-fire neurons characterized by a distribution of spiking frequencies. Upon increasing the coupling strength, the model exhibits a transition from an asynchronous regime to a nontrivial collective behavior. Numerical simulations of large systems indicate that, at variance with the Kuramoto model, (i) the macroscopic dynamics stays irregular and (ii) the microscopic (single-neuron) evolution is linearly stable.

Ergodic properties of spiking neuronal networks with delayed interactions

NASA Astrophysics Data System (ADS)

Palmigiano, Agostina; Wolf, Fred

The dynamical stability of neuronal networks, and the possibility of chaotic dynamics in the brain pose profound questions to the mechanisms underlying perception. Here we advance on the tractability of large neuronal networks of exactly solvable neuronal models with delayed pulse-coupled interactions. Pulse coupled delayed systems with an infinite dimensional phase space can be studied in equivalent systems of fixed and finite degrees of freedom by introducing a delayer variable for each neuron. A Jacobian of the equivalent system can be analytically obtained, and numerically evaluated. We find that depending on the action potential onset rapidness and the level of heterogeneities, the asynchronous irregular regime characteristic of balanced state networks loses stability with increasing delays to either a slow synchronous irregular or a fast synchronous irregular state. In networks of neurons with slow action potential onset, the transition to collective oscillations leads to an increase of the exponential rate of divergence of nearby trajectories and of the entropy production rate of the chaotic dynamics. The attractor dimension, instead of increasing linearly with increasing delay as reported in many other studies, decreases until eventually the network reaches full synchrony

Modelling of Rainfall Induced Landslides in Puerto Rico

NASA Astrophysics Data System (ADS)

Lepore, C.; Arnone, E.; Sivandran, G.; Noto, L. V.; Bras, R. L.

2010-12-01

We performed an island-wide determination of static landslide susceptibility and hazard assessment as well as dynamic modeling of rainfall-induced shallow landslides in a particular hydrologic basin. Based on statistical analysis of past landslides, we determined that reliable prediction of the susceptibility to landslides is strongly dependent on the resolution of the digital elevation model (DEM) employed and the reliability of the rainfall data. A distributed hydrology model, Triangulated Irregular Network (TIN)-based Real-time Integrated Basin Simulator with VEGetation Generator for Interactive Evolution (tRIBS-VEGGIE), tRIBS-VEGGIE, has been implemented for the first time in a humid tropical environment like Puerto Rico and validated against in-situ measurements. A slope-failure module has been added to tRIBS-VEGGIE’s framework, after analyzing several failure criterions to identify the most suitable for our application; the module is used to predict the location and timing of landsliding events. The Mameyes basin, located in the Luquillo Experimental Forest in Puerto Rico, was selected for modeling based on the availability of soil, vegetation, topographical, meteorological and historic landslide data. Application of the model yields a temporal and spatial distribution of predicted rainfall-induced landslides.

The potential of high resolution airborne laser scanning for deriving geometric properties of single trees

NASA Astrophysics Data System (ADS)

Morsdorf, F.; Meier, E.; Koetz, B.; Nüesch, D.; Itten, K.; Allgöwer, B.

2003-04-01

The potential of airborne laserscanning for mapping forest stands has been intensively evaluated in the past few years. Algorithms deriving structural forest parameters in a stand-wise manner from laser data have been successfully implemented by a number of researchers. However, with very high point density laser (>20 points/m^2) data we pursue the approach of deriving these parameters on a single-tree basis. We explore the potential of delineating single trees from laser scanner raw data (x,y,z- triples) and validate this approach with a dataset of more than 2000 georeferenced trees, including tree height and crown diameter, gathered on a long term forest monitoring site by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL). The accuracy of the laser scanner is evaluated trough 6 reference targets, being 3x3 m^2 in size and horizontally plain, for validating both the horizontal and vertical accuracy of the laser scanner by matching of triangular irregular networks (TINs). Single trees are segmented by a clustering analysis in all three coordinate dimensions and their geometric properties can then be derived directly from the tree cluster.

A Coarse-to-Fine Geometric Scale-Invariant Feature Transform for Large Size High Resolution Satellite Image Registration

PubMed Central

Chang, Xueli; Du, Siliang; Li, Yingying; Fang, Shenghui

2018-01-01

Large size high resolution (HR) satellite image matching is a challenging task due to local distortion, repetitive structures, intensity changes and low efficiency. In this paper, a novel matching approach is proposed for the large size HR satellite image registration, which is based on coarse-to-fine strategy and geometric scale-invariant feature transform (SIFT). In the coarse matching step, a robust matching method scale restrict (SR) SIFT is implemented at low resolution level. The matching results provide geometric constraints which are then used to guide block division and geometric SIFT in the fine matching step. The block matching method can overcome the memory problem. In geometric SIFT, with area constraints, it is beneficial for validating the candidate matches and decreasing searching complexity. To further improve the matching efficiency, the proposed matching method is parallelized using OpenMP. Finally, the sensing image is rectified to the coordinate of reference image via Triangulated Irregular Network (TIN) transformation. Experiments are designed to test the performance of the proposed matching method. The experimental results show that the proposed method can decrease the matching time and increase the number of matching points while maintaining high registration accuracy. PMID:29702589

Integrating Metal-Oxide-Decorated CNT Networks with a CMOS Readout in a Gas Sensor

PubMed Central

Lee, Hyunjoong; Lee, Sanghoon; Kim, Dai-Hong; Perello, David; Park, Young June; Hong, Seong-Hyeon; Yun, Minhee; Kim, Suhwan

2012-01-01

We have implemented a tin-oxide-decorated carbon nanotube (CNT) network gas sensor system on a single die. We have also demonstrated the deposition of metallic tin on the CNT network, its subsequent oxidation in air, and the improvement of the lifetime of the sensors. The fabricated array of CNT sensors contains 128 sensor cells for added redundancy and increased accuracy. The read-out integrated circuit (ROIC) was combined with coarse and fine time-to-digital converters to extend its resolution in a power-efficient way. The ROIC is fabricated using a 0.35 μm CMOS process, and the whole sensor system consumes 30 mA at 5 V. The sensor system was successfully tested in the detection of ammonia gas at elevated temperatures. PMID:22736966

Modelling and prediction for chaotic fir laser attractor using rational function neural network.

PubMed

Cho, S

2001-02-01

Many real-world systems such as irregular ECG signal, volatility of currency exchange rate and heated fluid reaction exhibit highly complex nonlinear characteristic known as chaos. These chaotic systems cannot be retreated satisfactorily using linear system theory due to its high dimensionality and irregularity. This research focuses on prediction and modelling of chaotic FIR (Far InfraRed) laser system for which the underlying equations are not given. This paper proposed a method for prediction and modelling a chaotic FIR laser time series using rational function neural network. Three network architectures, TDNN (Time Delayed Neural Network), RBF (radial basis function) network and the RF (rational function) network, are also presented. Comparisons between these networks performance show the improvements introduced by the RF network in terms of a decrement in network complexity and better ability of predictability.

Calculating electronic tunnel currents in networks of disordered irregularly shaped nanoparticles by mapping networks to arrays of parallel nonlinear resistors

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

Aghili Yajadda, Mir Massoud

2014-10-21

We have shown both theoretically and experimentally that tunnel currents in networks of disordered irregularly shaped nanoparticles (NPs) can be calculated by considering the networks as arrays of parallel nonlinear resistors. Each resistor is described by a one-dimensional or a two-dimensional array of equal size nanoparticles that the tunnel junction gaps between nanoparticles in each resistor is assumed to be equal. The number of tunnel junctions between two contact electrodes and the tunnel junction gaps between nanoparticles are found to be functions of Coulomb blockade energies. In addition, the tunnel barriers between nanoparticles were considered to be tilted at highmore » voltages. Furthermore, the role of thermal expansion coefficient of the tunnel junction gaps on the tunnel current is taken into account. The model calculations fit very well to the experimental data of a network of disordered gold nanoparticles, a forest of multi-wall carbon nanotubes, and a network of few-layer graphene nanoplates over a wide temperature range (5-300 K) at low and high DC bias voltages (0.001 mV–50 V). Our investigations indicate, although electron cotunneling in networks of disordered irregularly shaped NPs may occur, non-Arrhenius behavior at low temperatures cannot be described by the cotunneling model due to size distribution in the networks and irregular shape of nanoparticles. Non-Arrhenius behavior of the samples at zero bias voltage limit was attributed to the disorder in the samples. Unlike the electron cotunneling model, we found that the crossover from Arrhenius to non-Arrhenius behavior occurs at two temperatures, one at a high temperature and the other at a low temperature.« less

Research on hardness and tensile properties of A390 alloy with tin addition

NASA Astrophysics Data System (ADS)

Si, Yi

2018-03-01

The effect of tin content on hardness and tensile properties of A390 alloys has been discussed. The microstructure of the A390 alloy with tin addition has been surveyed by OM and investigated by SEM. Research showed that β-Sn in the alloy precipitation forms were mainly small blocks and thin strips, particles within the Al2Cu network or large blocks consisting of β-Sn and Al2Cu on Al/Si interfaces or α-Al grain boundaries. Spheroidization of the primary and eutectic silicon was improved due to Sn accretion. With the augment of element tin, hardness of casting alloy is much higher than that of alloy after heat treatment. The elongation and ultimate tensile strength (UTS) were increased in Sn addition from 0 to 1%, which is attributed to the multiple action of Sn.

Telecommunications Information Network: A Model for On-Demand Transfer of Medical Information. Annual Report.

ERIC Educational Resources Information Center

Lorenzi, Nancy M.; And Others

This report describes and evaluates the first year of a demonstration project to develop an on-demand telecommunications network linking four remote hospitals in southwestern Ohio to the University of Cincinnati Medical Center. The Telecommunications Information Network (TIN) is designed to allow health care professionals at those hospitals to…

A Control Simulation Method of High-Speed Trains on Railway Network with Irregular Influence

NASA Astrophysics Data System (ADS)

Yang, Li-Xing; Li, Xiang; Li, Ke-Ping

2011-09-01

Based on the discrete time method, an effective movement control model is designed for a group of highspeed trains on a rail network. The purpose of the model is to investigate the specific traffic characteristics of high-speed trains under the interruption of stochastic irregular events. In the model, the high-speed rail traffic system is supposed to be equipped with the moving-block signalling system to guarantee maximum traversing capacity of the railway. To keep the safety of trains' movements, some operational strategies are proposed to control the movements of trains in the model, including traction operation, braking operation, and entering-station operation. The numerical simulations show that the designed model can well describe the movements of high-speed trains on the rail network. The research results can provide the useful information not only for investigating the propagation features of relevant delays under the irregular disturbance but also for rerouting and rescheduling trains on the rail network.

Roll-to-Roll Production of Transparent Silver-Nanofiber-Network Electrodes for Flexible Electrochromic Smart Windows.

PubMed

Lin, Sen; Bai, Xiaopeng; Wang, Haiyang; Wang, Haolun; Song, Jianan; Huang, Kai; Wang, Chang; Wang, Ning; Li, Bo; Lei, Ming; Wu, Hui

2017-11-01

Electrochromic smart windows (ECSWs) are considered as the most promising alternative to traditional dimming devices. However, the electrode technology in ECSWs remains stagnant, wherein inflexible indium tin oxide and fluorine-doped tin oxide are the main materials being used. Although various complicated production methods, such as high-temperature calcination and sputtering, have been reported, the mass production of flexible and transparent electrodes remains challenging. Here, a nonheated roll-to-roll process is developed for the continuous production of flexible, extralarge, and transparent silver nanofiber (AgNF) network electrodes. The optical and mechanical properties, as well as the electrical conductivity of these products (i.e., 12 Ω sq -1 at 95% transmittance) are comparable with those AgNF networks produced via high-temperature sintering. Moreover, the as-prepared AgNF network is successfully assembled into an A4-sized ECSW with short switching time, good coloration efficiency, and flexibility. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Role of GABAergic inhibition in hippocampal network oscillations.

PubMed

Mann, Edward O; Paulsen, Ole

2007-07-01

Physiological rhythmic activity in cortical circuits relies on GABAergic inhibition to balance excitation and control spike timing. With a focus on recent experimental progress in the hippocampus, here we review the mechanisms by which synaptic inhibition can control the precise timing of spike generation, by way of effects of GABAergic events on membrane conductance ('shunting' inhibition) and membrane potential ('hyperpolarizing' inhibition). Synaptic inhibition itself can be synchronized by way of interactions within networks of GABAergic neurons, and by excitatory neurons. The importance of GABAergic mechanisms for generation of cortical rhythms is now well established. What remains to be resolved is how such inhibitory control of spike timing can be harnessed for long-range fast synchronization, and the relevance of these mechanisms to network function. This review is part of the INMED/TINS special issue Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com).

Integration of remote sensing technique and hydrologic model for monitoring tidal flat dynamics of Juiduansha in Shanghai

NASA Astrophysics Data System (ADS)

Zheng, Zongsheng; Zhou, Yunxuan; Jiang, Xuezhong

2007-06-01

Ground survey is restricted by the difficulty of access to wide-range and dynamic salt marsh. Waterline method and hydrodynamic model were investigated to construct Digital Elevation Model (DEM) at Jiudunasha Shoals. A series of waterlines were extracted from multi-temporal remotely sensing images collected over the period of 2000-2004. The assignment of an elevation to each waterline at the satellite overpass was performed according to hydrodynamic model. The corrected waterlines labeled elevations were used to construct Triangulated Irregular Networks (TINs). Then an interpolation for each grid elevation was performed in accordance with the associated triangle. This initial DEM, produced using the corrected waterline set, was then used to refine the topography in the intertidal zone, and the model was re-run to produce improved water levels and a new DEM. This procedure was iterated by comparing modeled and actual waterlines until no further improvement occurred. Three DEMs of different intervals were built by this approach and were compared to evaluate the effect of Deep Water Channel Project (DWCP) at the north of Jiuduansha Island. Waterline method combined with numerical model, is an effective tool for constructing digital elevation model of mudflats. The result can provide invaluable information for coastal land use and engineer construction.

Individual Tree Crown Delineation Using Multi-Wavelength Titan LIDAR Data

NASA Astrophysics Data System (ADS)

Naveed, F.; Hu, B.

2017-10-01

The inability to detect the Emerald Ash Borer (EAB) at an early stage has led to the enumerable loss of different species of ash trees. Due to the increasing risk being posed by the EAB, a robust and accurate method is needed for identifying Individual Tree Crowns (ITCs) that are at a risk of being infected or are already diseased. This paper attempts to outline an ITC delineation method that employs airborne multi-spectral Light Detection and Ranging (LiDAR) to accurately delineate tree crowns. The raw LiDAR data were initially pre-processed to generate the Digital Surface Models (DSM) and Digital Elevation Models (DEM) using an iterative progressive TIN (Triangulated Irregular Network) densification method. The DSM and DEM were consequently used for Canopy Height Model (CHM) generation, from which the structural information pertaining to the size and shape of the tree crowns was obtained. The structural information along with the spectral information was used to segment ITCs using a region growing algorithm. The availability of the multi-spectral LiDAR data allows for delineation of crowns that have otherwise homogenous structural characteristics and hence cannot be isolated from the CHM alone. This study exploits the spectral data to derive initial approximations of individual tree tops and consequently grow those regions based on the spectral constraints of the individual trees.

Release of a 10-m-resolution DEM for the whole Italian territory: a new, freely available resource for research purposes

NASA Astrophysics Data System (ADS)

Tarquini, S.; Nannipieri, L.; Favalli, M.; Fornaciai, A.; Vinci, S.; Doumaz, F.

2012-04-01

Digital elevation models (DEMs) are fundamental in any kind of environmental or morphological study. DEMs are obtained from a variety of sources and generated in several ways. Nowadays, a few global-coverage elevation datasets are available for free (e.g., SRTM, http://www.jpl.nasa.gov/srtm; ASTER, http://asterweb.jpl.nasa.gov/). When the matrix of a DEM is used also for computational purposes, the choice of the elevation dataset which better suits the target of the study is crucial. Recently, the increasing use of DEM-based numerical simulation tools (e.g. for gravity driven mass flows), would largely benefit from the use of a higher resolution/higher accuracy topography than those available at planetary scale. Similar elevation datasets are neither easily nor freely available for all countries worldwide. Here we introduce a new web resource which made available for free (for research purposes only) a 10 m-resolution DEM for the whole Italian territory. The creation of this elevation dataset was presented by Tarquini et al. (2007). This DEM was obtained in triangular irregular network (TIN) format starting from heterogeneous vector datasets, mostly consisting in elevation contour lines and elevation points derived from several sources. The input vector database was carefully cleaned up to obtain an improved seamless TIN refined by using the DEST algorithm, thus improving the Delaunay tessellation. The whole TINITALY/01 DEM was converted in grid format (10-m cell size) according to a tiled structure composed of 193, 50-km side square elements. The grid database consists of more than 3 billions of cells and occupies almost 12 GB of disk memory. A web-GIS has been created (http://tinitaly.pi.ingv.it/ ) where a seamless layer of images in full resolution (10 m) obtained from the whole DEM (both in color-shaded and anaglyph mode) is open for browsing. Accredited navigators are allowed to download the elevation dataset.

Neural substrates of sublexical processing for spelling.

PubMed

DeMarco, Andrew T; Wilson, Stephen M; Rising, Kindle; Rapcsak, Steven Z; Beeson, Pélagie M

2017-01-01

We used fMRI to examine the neural substrates of sublexical phoneme-grapheme conversion during spelling in a group of healthy young adults. Participants performed a writing-to-dictation task involving irregular words (e.g., choir), plausible nonwords (e.g., kroid), and a control task of drawing familiar geometric shapes (e.g., squares). Written production of both irregular words and nonwords engaged a left-hemisphere perisylvian network associated with reading/spelling and phonological processing skills. Effects of lexicality, manifested by increased activation during nonword relative to irregular word spelling, were noted in anterior perisylvian regions (posterior inferior frontal gyrus/operculum/precentral gyrus/insula), and in left ventral occipito-temporal cortex. In addition to enhanced neural responses within domain-specific components of the language network, the increased cognitive demands associated with spelling nonwords engaged domain-general frontoparietal cortical networks involved in selective attention and executive control. These results elucidate the neural substrates of sublexical processing during written language production and complement lesion-deficit correlation studies of phonological agraphia. Copyright © 2016 Elsevier Inc. All rights reserved.

Neural Substrates of Sublexical Processing for Spelling

PubMed Central

Wilson, Stephen M.; Rising, Kindle; Rapcsak, Steven Z.; Beeson, Pélagie M.

2016-01-01

We used fMRI to examine the neural substrates of sublexical phoneme-grapheme conversion during spelling in a group of healthy young adults. Participants performed a writing-to-dictation task involving irregular words (e.g., choir), plausible nonwords (e.g., kroid), and a control task of drawing familiar geometric shapes (e.g., squares). Written production of both irregular words and nonwords engaged a left-hemisphere perisylvian network associated with reading/spelling and phonological processing skills. Effects of lexicality, manifested by increased activation during nonword relative to irregular word spelling, were noted in anterior perisylvian regions (posterior inferior frontal gyrus/operculum/precentral gyrus/insula), and in left ventral occipito-temporal cortex. In addition to enhanced neural responses within domain-specific components of the language network, the increased cognitive demands associated with spelling nonwords engaged domain-general frontoparietal cortical networks involved in selective attention and executive control. These results elucidate the neural substrates of sublexical processing during written language production and complement lesion-deficit correlation studies of phonological agraphia. PMID:27838547

Telecommunications Information Network: A Model for On-Demand Transfer of Medical Information. Final Report.

ERIC Educational Resources Information Center

Lorenzi, Nancy M.; And Others

This report summarizes the third phase of the Telecommunications Information Network (TIN), which provides a telecommunications link between four remote southwest Ohio hospitals and the University of Cincinnati Medical Center, thereby reducing the isolation of healthcare providers at the remote hospitals. A description of the system explains the…

Embedded Carbon Nanotube Networks for Damage Precursor Detection

DTIC Science & Technology

2014-01-01

3Thostenson, E. T.; Chou, T.-W. Carbon Nanotube Networks: Sensing of Distributed Strain and Damage for Life Prediction and Self - Healing . Advanced...3 Figure 2. Rubber dogbone mold...room temperature vulcanizing rubber to create the final mold. The rubber was mixed with Tin NW Catalyst at a 10:1 ratio. The viscous liquid rubber

Synthesis of irregular graphene oxide tubes using green chemistry and their potential use as reinforcement materials for biomedical applications.

PubMed

Serrano-Aroca, Ángel; Deb, Sanjukta

2017-01-01

Micrometer length tubes of graphene oxide (GO) with irregular form were synthesised following facile and green metal complexation reactions. These materials were obtained by crosslinking of GO with calcium, zinc or strontium chlorides at three different temperatures (24, 34 and 55°C) using distilled water as solvent for the compounds and following a remarkably simple and low-cost synthetic method, which employs no hazardous substances and is conducted without consumption of thermal or sonic energy. These irregular continuous GO networks showed a very particular interconnected structure by Field Emission Scanning Electron Microscopy with Energy-Disperse X-Ray Spectroscopy for elemental analysis and High-resolution Transmission Electron Microscopy with Scanning Transmission Electron Microscope Dark Field Imaging, and were analysed by Raman Spectroscopy. To demonstrate the potential use of these 3D GO networks as reinforcement materials for biomedical applications, two composites of calcium alginate with irregular tubes of GO and with single GO nanosheets were prepared with the same amount of GO and divalent atoms and analysed. Thus, the dynamic-mechanical modulus of the composites synthesised with the 3D crosslinked GO networks showed a very significant mechanical improvement due to marked microstructural changes confirmed by confocal microscopy, differential scanning calorimetry and Fourier transform infrared spectroscopy.

Synthesis of irregular graphene oxide tubes using green chemistry and their potential use as reinforcement materials for biomedical applications

PubMed Central

Deb, Sanjukta

2017-01-01

Micrometer length tubes of graphene oxide (GO) with irregular form were synthesised following facile and green metal complexation reactions. These materials were obtained by crosslinking of GO with calcium, zinc or strontium chlorides at three different temperatures (24, 34 and 55°C) using distilled water as solvent for the compounds and following a remarkably simple and low-cost synthetic method, which employs no hazardous substances and is conducted without consumption of thermal or sonic energy. These irregular continuous GO networks showed a very particular interconnected structure by Field Emission Scanning Electron Microscopy with Energy-Disperse X-Ray Spectroscopy for elemental analysis and High-resolution Transmission Electron Microscopy with Scanning Transmission Electron Microscope Dark Field Imaging, and were analysed by Raman Spectroscopy. To demonstrate the potential use of these 3D GO networks as reinforcement materials for biomedical applications, two composites of calcium alginate with irregular tubes of GO and with single GO nanosheets were prepared with the same amount of GO and divalent atoms and analysed. Thus, the dynamic-mechanical modulus of the composites synthesised with the 3D crosslinked GO networks showed a very significant mechanical improvement due to marked microstructural changes confirmed by confocal microscopy, differential scanning calorimetry and Fourier transform infrared spectroscopy. PMID:28934354

Effect of TiN Addition on 3Y-TZP Ceramics with Emphasis on Making EDM-Able Bodies

NASA Astrophysics Data System (ADS)

Khosravifar, Mahnoosh; Mirkazemi, Seyyed Mohammad; Taheri, Mahdiar; Golestanifard, Farhad

2018-05-01

In this study, to produce electrically conductive ceramics, rapid hot press (RHP) sintering of 3 mol.% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) and 3Y-TZP/TiN composites with TiN amounts of 25, 35, and 45 vol.% was performed at 1300, 1350, and 1400 °C. Interestingly, the toughness and hardness were improved in the presence of TiN up to 35 vol.% and maximum fracture toughness and hardness of 5.40 ± 0.05 MPa m1/2 and 14.50 ± 0.06 GPa, respectively, were obtained. However, the bending strength was decreased which could be attributed to the rather weak interfaces of nitride and oxide phases. Regarding the zirconia matrix, the effect of grain size on fracture toughness of the samples has been studied using x-ray diffraction and field emission scanning electron microscope (FESEM) analysis. It was also found that electrical resistivity decreased to the value of 6.88 × 10-6 Ω m at 45 vol.% of TiN. It seems the TiN grains form a network to impose conductivity on the ZrO2 body; however, below 35 vol.% TiN, due to lack of percolation effect, this conductivity could not be maintained according to FESEM studies. Finally, electrically conductive samples were successfully machined by electrical discharge machining (EDM).

A spiking network model of cerebellar Purkinje cells and molecular layer interneurons exhibiting irregular firing

PubMed Central

Lennon, William; Hecht-Nielsen, Robert; Yamazaki, Tadashi

2014-01-01

While the anatomy of the cerebellar microcircuit is well-studied, how it implements cerebellar function is not understood. A number of models have been proposed to describe this mechanism but few emphasize the role of the vast network Purkinje cells (PKJs) form with the molecular layer interneurons (MLIs)—the stellate and basket cells. We propose a model of the MLI-PKJ network composed of simple spiking neurons incorporating the major anatomical and physiological features. In computer simulations, the model reproduces the irregular firing patterns observed in PKJs and MLIs in vitro and a shift toward faster, more regular firing patterns when inhibitory synaptic currents are blocked. In the model, the time between PKJ spikes is shown to be proportional to the amount of feedforward inhibition from an MLI on average. The two key elements of the model are: (1) spontaneously active PKJs and MLIs due to an endogenous depolarizing current, and (2) adherence to known anatomical connectivity along a parasagittal strip of cerebellar cortex. We propose this model to extend previous spiking network models of the cerebellum and for further computational investigation into the role of irregular firing and MLIs in cerebellar learning and function. PMID:25520646

Long-Term Memory Stabilized by Noise-Induced Rehearsal

PubMed Central

Wei, Yi

2014-01-01

Cortical networks can maintain memories for decades despite the short lifetime of synaptic strengths. Can a neural network store long-lasting memories in unstable synapses? Here, we study the effects of ongoing spike-timing-dependent plasticity (STDP) on the stability of memory patterns stored in synapses of an attractor neural network. We show that certain classes of STDP rules can stabilize all stored memory patterns despite a short lifetime of synapses. In our model, unstructured neural noise, after passing through the recurrent network connections, carries the imprint of all memory patterns in temporal correlations. STDP, combined with these correlations, leads to reinforcement of all stored patterns, even those that are never explicitly visited. Our findings may provide the functional reason for irregular spiking displayed by cortical neurons and justify models of system memory consolidation. Therefore, we propose that irregular neural activity is the feature that helps cortical networks maintain stable connections. PMID:25411507

Plasma Irregularities on the Leading and Trailing Edges of Polar Cap Patches

NASA Astrophysics Data System (ADS)

Lamarche, L. J.; Varney, R. H.; Gillies, R.; Chartier, A.; Mitchell, C. N.

2017-12-01

Plasma irregularities in the polar cap have often been attributed to the gradient drift instability (GDI). Traditional fluid theories of GDI predicts irregularity growth only on the trailing edge of polar patches, where the plasma density gradient is parallel to the plasma drift velocity, however many observations show irregularities also form on the leading edge of patches. We consider decameter-scale irregularities detected by polar-latitude SuperDARN (Super Dual Auroral Radar Network) radars with any relationship between the background density gradients and drift velocity. Global electron density from the Multi-Instrument Data Analysis System (MIDAS), a GPS tomography routine, is used to provide context for where irregularities are observed relative to polar patches and finer-scale background density gradients are found from 3D imaging from both the North and Canada faces of the Resolute Bay Incoherent Scatter Radars (RISR-N and RISR-C) jointly. Shear-based instabilities are considered as mechanisms by which plasma irregularities could form on the leading edge of patches. Theoretical predictions of instability growth from both GDI and shear instabilities are compared with irregularity observations for the October 13, 2016 storm.

Dynamics of self-sustained asynchronous-irregular activity in random networks of spiking neurons with strong synapses

PubMed Central

Kriener, Birgit; Enger, Håkon; Tetzlaff, Tom; Plesser, Hans E.; Gewaltig, Marc-Oliver; Einevoll, Gaute T.

2014-01-01

Random networks of integrate-and-fire neurons with strong current-based synapses can, unlike previously believed, assume stable states of sustained asynchronous and irregular firing, even without external random background or pacemaker neurons. We analyze the mechanisms underlying the emergence, lifetime and irregularity of such self-sustained activity states. We first demonstrate how the competition between the mean and the variance of the synaptic input leads to a non-monotonic firing-rate transfer in the network. Thus, by increasing the synaptic coupling strength, the system can become bistable: In addition to the quiescent state, a second stable fixed-point at moderate firing rates can emerge by a saddle-node bifurcation. Inherently generated fluctuations of the population firing rate around this non-trivial fixed-point can trigger transitions into the quiescent state. Hence, the trade-off between the magnitude of the population-rate fluctuations and the size of the basin of attraction of the non-trivial rate fixed-point determines the onset and the lifetime of self-sustained activity states. During self-sustained activity, individual neuronal activity is moreover highly irregular, switching between long periods of low firing rate to short burst-like states. We show that this is an effect of the strong synaptic weights and the finite time constant of synaptic and neuronal integration, and can actually serve to stabilize the self-sustained state. PMID:25400575

Dynamics of self-sustained asynchronous-irregular activity in random networks of spiking neurons with strong synapses.

PubMed

Kriener, Birgit; Enger, Håkon; Tetzlaff, Tom; Plesser, Hans E; Gewaltig, Marc-Oliver; Einevoll, Gaute T

2014-01-01

Random networks of integrate-and-fire neurons with strong current-based synapses can, unlike previously believed, assume stable states of sustained asynchronous and irregular firing, even without external random background or pacemaker neurons. We analyze the mechanisms underlying the emergence, lifetime and irregularity of such self-sustained activity states. We first demonstrate how the competition between the mean and the variance of the synaptic input leads to a non-monotonic firing-rate transfer in the network. Thus, by increasing the synaptic coupling strength, the system can become bistable: In addition to the quiescent state, a second stable fixed-point at moderate firing rates can emerge by a saddle-node bifurcation. Inherently generated fluctuations of the population firing rate around this non-trivial fixed-point can trigger transitions into the quiescent state. Hence, the trade-off between the magnitude of the population-rate fluctuations and the size of the basin of attraction of the non-trivial rate fixed-point determines the onset and the lifetime of self-sustained activity states. During self-sustained activity, individual neuronal activity is moreover highly irregular, switching between long periods of low firing rate to short burst-like states. We show that this is an effect of the strong synaptic weights and the finite time constant of synaptic and neuronal integration, and can actually serve to stabilize the self-sustained state.

Designing Next Generation Massively Multithreaded Architectures for Irregular Applications

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

Tumeo, Antonino; Secchi, Simone; Villa, Oreste

Irregular applications, such as data mining or graph-based computations, show unpredictable memory/network access patterns and control structures. Massively multi-threaded architectures with large node count, like the Cray XMT, have been shown to address their requirements better than commodity clusters. In this paper we present the approaches that we are currently pursuing to design future generations of these architectures. First, we introduce the Cray XMT and compare it to other multithreaded architectures. We then propose an evolution of the architecture, integrating multiple cores per node and next generation network interconnect. We advocate the use of hardware support for remote memory referencemore » aggregation to optimize network utilization. For this evaluation we developed a highly parallel, custom simulation infrastructure for multi-threaded systems. Our simulator executes unmodified XMT binaries with very large datasets, capturing effects due to contention and hot-spotting, while predicting execution times with greater than 90% accuracy. We also discuss the FPGA prototyping approach that we are employing to study efficient support for irregular applications in next generation manycore processors.« less

A Participatory Modeling Application of a Distributed Hydrologic Model in Nuevo Leon, Mexico for the 2010 Hurricane Alex Flood Event

NASA Astrophysics Data System (ADS)

Baish, A. S.; Vivoni, E. R.; Payan, J. G.; Robles-Morua, A.; Basile, G. M.

2011-12-01

A distributed hydrologic model can help bring consensus among diverse stakeholders in regional flood planning by producing quantifiable sets of alternative futures. This value is acute in areas with high uncertainties in hydrologic conditions and sparse observations. In this study, we conduct an application of the Triangulated Irregular Network (TIN)-based Real-time Integrated Basin Simulator (tRIBS) in the Santa Catarina basin of Nuevo Leon, Mexico, where Hurricane Alex in July 2010 led to catastrophic flooding of the capital city of Monterrey. Distributed model simulations utilize best-available information on the regional topography, land cover, and soils obtained from Mexican government agencies or analysis of remotely-sensed imagery from MODIS and ASTER. Furthermore, we developed meteorological forcing for the flood event based on multiple data sources, including three local gauge networks, satellite-based estimates from TRMM and PERSIANN, and the North American Land Data Assimilation System (NLDAS). Remotely-sensed data allowed us to quantify rainfall distributions in the upland, rural portions of the Santa Catarina that are sparsely populated and ungauged. Rural areas had significant contributions to the flood event and as a result were considered by stakeholders for flood control measures, including new reservoirs and upland vegetation management. Participatory modeling workshops with the stakeholders revealed a disconnect between urban and rural populations in regard to understanding the hydrologic conditions of the flood event and the effectiveness of existing and potential flood control measures. Despite these challenges, the use of the distributed flood forecasts developed within this participatory framework facilitated building consensus among diverse stakeholders and exploring alternative futures in the basin.

Analysis of dynamic brain oscillations: methodological advances.

PubMed

Le Van Quyen, Michel; Bragin, Anatol

2007-07-01

In recent years, new recording technologies have advanced such that, at high temporal and spatial resolutions, oscillations of neuronal networks can be identified from simultaneous, multisite recordings. However, because of the deluge of multichannel data generated by these experiments, achieving the full potential of parallel neuronal recordings also depends on the development of new mathematical methods that can extract meaningful information relating to time, frequency and space. Here, we aim to bridge this gap by focusing on up-to-date recording techniques for measurement of network oscillations and new analysis tools for their quantitative assessment. In particular, we emphasize how these methods can be applied, what property might be inferred from neuronal signals and potentially productive future directions. This review is part of the INMED and TINS special issue, Physiogenic and pathogenic oscillations: the beauty and the beast, derived from presentations at the annual INMED and TINS symposium (http://inmednet.com).

Molecular basis and quantitative assessment of TRF1 and TRF2 protein interactions with TIN2 and Apollo peptides.

PubMed

Kalathiya, Umesh; Padariya, Monikaben; Baginski, Maciej

2017-03-01

Shelterin is a six-protein complex (TRF1, TRF2, POT1, RAP1, TIN2, and TPP1) that also functions in smaller subsets in regulation and protection of human telomeres. Two closely related proteins, TRF1 and TRF2, make high-affinity contact directly with double-stranded telomeric DNA and serve as a molecular platform. Protein TIN2 binds to TRF1 and TRF2 dimer-forming domains, whereas Apollo makes interaction only with TRF2. To elucidate the molecular basis of these interactions, we employed molecular dynamics (MD) simulations of TRF1 TRFH -TIN2 TBM and TRF2 TRFH -TIN2 TBM /Apollo TBM complexes and of the isolated proteins. MD enabled a structural and dynamical comparison of protein-peptide complexes including H-bond interactions and interfacial residues that may regulate TRF protein binding to the given peptides, especially focusing on interactions described in crystallographic data. Residues with a selective function in both TRF1 TRFH and TRF2 TRFH and forming a stable hydrogen bond network with TIN2 TBM or Apollo TBM peptides were traced. Our study revealed that TIN2 TBM forms a well-defined binding mode with TRF1 TRFH as compared to TRF2 TRFH , and that the binding pocket of TIN2 TBM is deeper for TRF2 TRFH protein than Apollo TBM . The MD data provide a basis for the reinterpretation of mutational data obtained in crystallographic work for the TRF proteins. Together, the previously determined X-ray structure and our MD provide a detailed view of the TRF-peptide binding mode and the structure of TRF1/2 binding pockets. Particular TRF-peptide interactions are very specific for the formation of each protein-peptide complex, identifying TRF proteins as potential targets for the design of inhibitors/drugs modulating telomere machinery for anticancer therapy.

A balanced memory network.

PubMed

Roudi, Yasser; Latham, Peter E

2007-09-01

A fundamental problem in neuroscience is understanding how working memory--the ability to store information at intermediate timescales, like tens of seconds--is implemented in realistic neuronal networks. The most likely candidate mechanism is the attractor network, and a great deal of effort has gone toward investigating it theoretically. Yet, despite almost a quarter century of intense work, attractor networks are not fully understood. In particular, there are still two unanswered questions. First, how is it that attractor networks exhibit irregular firing, as is observed experimentally during working memory tasks? And second, how many memories can be stored under biologically realistic conditions? Here we answer both questions by studying an attractor neural network in which inhibition and excitation balance each other. Using mean-field analysis, we derive a three-variable description of attractor networks. From this description it follows that irregular firing can exist only if the number of neurons involved in a memory is large. The same mean-field analysis also shows that the number of memories that can be stored in a network scales with the number of excitatory connections, a result that has been suggested for simple models but never shown for realistic ones. Both of these predictions are verified using simulations with large networks of spiking neurons.

Distributed Wavelet Transform for Irregular Sensor Network Grids

DTIC Science & Technology

2005-01-01

implement it in a multi-hop, wireless sensor network ; and illustrate with several simulations. The new transform performs on par with conventional wavelet methods in a head-to-head comparison on a regular grid of sensor nodes.

Mapping to Irregular Torus Topologies and Other Techniques for Petascale Biomolecular Simulation

PubMed Central

Phillips, James C.; Sun, Yanhua; Jain, Nikhil; Bohm, Eric J.; Kalé, Laxmikant V.

2014-01-01

Currently deployed petascale supercomputers typically use toroidal network topologies in three or more dimensions. While these networks perform well for topology-agnostic codes on a few thousand nodes, leadership machines with 20,000 nodes require topology awareness to avoid network contention for communication-intensive codes. Topology adaptation is complicated by irregular node allocation shapes and holes due to dedicated input/output nodes or hardware failure. In the context of the popular molecular dynamics program NAMD, we present methods for mapping a periodic 3-D grid of fixed-size spatial decomposition domains to 3-D Cray Gemini and 5-D IBM Blue Gene/Q toroidal networks to enable hundred-million atom full machine simulations, and to similarly partition node allocations into compact domains for smaller simulations using multiple-copy algorithms. Additional enabling techniques are discussed and performance is reported for NCSA Blue Waters, ORNL Titan, ANL Mira, TACC Stampede, and NERSC Edison. PMID:25594075

Long-term memory stabilized by noise-induced rehearsal.

PubMed

Wei, Yi; Koulakov, Alexei A

2014-11-19

Cortical networks can maintain memories for decades despite the short lifetime of synaptic strengths. Can a neural network store long-lasting memories in unstable synapses? Here, we study the effects of ongoing spike-timing-dependent plasticity (STDP) on the stability of memory patterns stored in synapses of an attractor neural network. We show that certain classes of STDP rules can stabilize all stored memory patterns despite a short lifetime of synapses. In our model, unstructured neural noise, after passing through the recurrent network connections, carries the imprint of all memory patterns in temporal correlations. STDP, combined with these correlations, leads to reinforcement of all stored patterns, even those that are never explicitly visited. Our findings may provide the functional reason for irregular spiking displayed by cortical neurons and justify models of system memory consolidation. Therefore, we propose that irregular neural activity is the feature that helps cortical networks maintain stable connections. Copyright © 2014 the authors 0270-6474/14/3415804-12$15.00/0.

Reconfigurable optical interconnections via dynamic computer-generated holograms

NASA Technical Reports Server (NTRS)

Liu, Hua-Kuang (Inventor); Zhou, Shaomin (Inventor)

1994-01-01

A system is proposed for optically providing one-to-many irregular interconnections, and strength-adjustable many-to-many irregular interconnections which may be provided with strengths (weights) w(sub ij) using multiple laser beams which address multiple holograms and means for combining the beams modified by the holograms to form multiple interconnections, such as a cross-bar switching network. The optical means for interconnection is based on entering a series of complex computer-generated holograms on an electrically addressed spatial light modulator for real-time reconfigurations, thus providing flexibility for interconnection networks for largescale practical use. By employing multiple sources and holograms, the number of interconnection patterns achieved is increased greatly.

Low-Cost Photogrammetric Technique Used to Measure Dome Growth at Mount St. Helens Volcano, 2007-2007

NASA Astrophysics Data System (ADS)

Diefenbach, A. K.; Crider, J. G.; Schilling, S. P.; Dzurisin, D.

2007-12-01

We describe a low-cost application of digital photogrammetry using commercial grade software, an off-the-shelf digital camera, a laptop computer and oblique photographs to reconstruct volcanic dome morphology during the on-going eruption at Mount St. Helens, Washington. Renewed activity at Mount St. Helens provides a rare opportunity to devise and test new methods for better understanding and predicting volcanic events, because the new method can be validated against other observations on this well-instrumented volcano. Uncalibrated, oblique aerial photographs (snap shots) taken from a helicopter are the raw data. Twelve sets of overlapping digital images of the dome taken during 2004-2007 were used to produce digital elevation models (DEMs) from which dome height, eruption volume and extrusion rate can be derived. Analyses of the digital images were carried out using PhotoModeler software, which produces three dimensional coordinates of points identified in multiple photos. The steps involved include: (1) calibrating the digital camera using this software package, (2) establishing control points derived from existing DEMs, (3) identifying tie points located in each photo of any given model date, and (4) identifying points in pairs of photos to build a three dimensional model of the evolving dome at each photo date. Text files of three-dimensional points encompassing the dome at each date were imported into ArcGIS and three-dimensional models (triangulated irregular network or TINs) were generated. TINs were then converted to 2 m raster DEMs. The evolving morphology of the growing dome was modeled by comparison of successive DEMs. The volume of extruded lava visible in each DEM was calculated using the 1986 pre-eruption crater floor topography as a basal surface. Results were validated by comparing volume measurements derived from traditional aerophotogrammetric surveys run by the USGS Cascades Volcano Observatory. Our new "quick and cheap" technique yields estimates of eruptive volume consistently within 5% of the volumes estimated with traditional surveys. The end result of this project is a new technique that provides an inexpensive, rapid assessment tool for tracking lava dome growth or other topographic changes at restless volcanoes.

The Civil Side of Irregular Warfare

DTIC Science & Technology

2014-05-22

Burj al -Shimali.52 While Musa al Sadr is not the founder of Hezbollah, his work resulted in the network of connections and the recasting of Shia...Center AMAL afwaj al -muqawama al -lubnaniya (Lebanese Resistance Regiments) = amal (Hope) CA Civil Affairs CAO Civil Affairs Operations CGSC US Army...HAMAS Harakat al -Muqawama al -Islamiyya (the Islamic Resistance Movement) IDF Israel Defense Forces IGO Intergovernmental Organization IW Irregular

Network model of chemical-sensing system inspired by mouse taste buds.

PubMed

Tateno, Katsumi; Igarashi, Jun; Ohtubo, Yoshitaka; Nakada, Kazuki; Miki, Tsutomu; Yoshii, Kiyonori

2011-07-01

Taste buds endure extreme changes in temperature, pH, osmolarity, so on. Even though taste bud cells are replaced in a short span, they contribute to consistent taste reception. Each taste bud consists of about 50 cells whose networks are assumed to process taste information, at least preliminarily. In this article, we describe a neural network model inspired by the taste bud cells of mice. It consists of two layers. In the first layer, the chemical stimulus is transduced into an irregular spike train. The synchronization of the output impulses is induced by the irregular spike train at the second layer. These results show that the intensity of the chemical stimulus is encoded as the degree of the synchronization of output impulses. The present algorithms for signal processing result in a robust chemical-sensing system.

A Balanced Memory Network

PubMed Central

Roudi, Yasser; Latham, Peter E

2007-01-01

A fundamental problem in neuroscience is understanding how working memory—the ability to store information at intermediate timescales, like tens of seconds—is implemented in realistic neuronal networks. The most likely candidate mechanism is the attractor network, and a great deal of effort has gone toward investigating it theoretically. Yet, despite almost a quarter century of intense work, attractor networks are not fully understood. In particular, there are still two unanswered questions. First, how is it that attractor networks exhibit irregular firing, as is observed experimentally during working memory tasks? And second, how many memories can be stored under biologically realistic conditions? Here we answer both questions by studying an attractor neural network in which inhibition and excitation balance each other. Using mean-field analysis, we derive a three-variable description of attractor networks. From this description it follows that irregular firing can exist only if the number of neurons involved in a memory is large. The same mean-field analysis also shows that the number of memories that can be stored in a network scales with the number of excitatory connections, a result that has been suggested for simple models but never shown for realistic ones. Both of these predictions are verified using simulations with large networks of spiking neurons. PMID:17845070

Estimating dynamic permeability in fractal pore network saturated by Maxwellian fluid

NASA Astrophysics Data System (ADS)

Sun, W.

2017-12-01

The frequency dependent flow of fluid in porous media is an important issue in geophysical prospecting. Oscillating flow in pipe leads to frequency dependent dynamic permeability and has been studied in pore network containing Newtonian fluid. But there is little work on oscillating complex fluid in pipe network, especially in irregular network. Here we formulated frequency dependent permeability for Maxwellian fluid and estimated the permeability in three-dimensional fractal network model. We consider an infinitely long cylindrical pipe with rigid solid wall. The pipe is filled with Maxwellian fluids. Based on the mass conservation equation, the equilibrium equation of force and Maxwell constitutive relationship, we formulated the flux by integration of axial velocity component over the pipe's cross section. Then we extend single pipe formulation to a 3D irregular network. Flux balance condition yields a set of linear equations whose unknowns are the fluid pressure at each node. By evaluating the total flow flux through the network, the dynamic permeability can be calculated.We investigated the dynamic permeability of brine and CPyCl/NaSal in a 3D porous sample with a cubic side length 1 cm. The pore network is created by a Voronoi cell filling method. The porosity, i.e., volume ratio between pore/pipe network and the overall cubic, is set as 0.1. The irregular pore network has a fractal structure. The dimension d of the pore network is defined by the relation between node number M within a sphere and the radius r of the sphere,M=rd.The results show that both brine and Maxwellian fluid's permeability maintain a stable value at low frequency, then decreases with fluctuating peaks. The dynamic permeability in pore networks saturated by Maxwellian fluid (CPyCl/NaSal (60 mM)) show larger peaks during the decline process at high frequency, which represents the typical resonance behavior. Dynamic permeability shows clear dependence on the dimension of the fractal network. Small-scale network has higher dimension than large-scale networks. The reason is that in larger networks pore and inter-pore connections are so dense that the probability P(r) to have a neighboring pore at distance r decays faster. The proposed model may be used to explain velocity dispersion in unconventional reservoir rocks observed in laboratory.

Construction of a stochastic model of track geometry irregularities and validation through experimental measurements of dynamic loading

NASA Astrophysics Data System (ADS)

Panunzio, Alfonso M.; Puel, G.; Cottereau, R.; Simon, S.; Quost, X.

2017-03-01

This paper describes the construction of a stochastic model of urban railway track geometry irregularities, based on experimental data. The considered irregularities are track gauge, superelevation, horizontal and vertical curvatures. They are modelled as random fields whose statistical properties are extracted from a large set of on-track measurements of the geometry of an urban railway network. About 300-1000 terms are used in the Karhunen-Loève/Polynomial Chaos expansions to represent the random fields with appropriate accuracy. The construction of the random fields is then validated by comparing on-track measurements of the contact forces and numerical dynamics simulations for different operational conditions (train velocity and car load) and horizontal layouts (alignment, curve). The dynamics simulations are performed both with and without randomly generated geometrical irregularities for the track. The power spectrum densities obtained from the dynamics simulations with the model of geometrical irregularities compare extremely well with those obtained from the experimental contact forces. Without irregularities, the spectrum is 10-50 dB too low.

JAK/Stat signaling regulates heart precursor diversification in Drosophila

PubMed Central

Johnson, Aaron N.; Mokalled, Mayssa H.; Haden, Tom N.; Olson, Eric N.

2011-01-01

Intercellular signal transduction pathways regulate the NK-2 family of transcription factors in a conserved gene regulatory network that directs cardiogenesis in both flies and mammals. The Drosophila NK-2 protein Tinman (Tin) was recently shown to regulate Stat92E, the Janus kinase (JAK) and Signal transducer and activator of transcription (Stat) pathway effector, in the developing mesoderm. To understand whether the JAK/Stat pathway also regulates cardiogenesis, we performed a systematic characterization of JAK/Stat signaling during mesoderm development. Drosophila embryos with mutations in the JAK/Stat ligand upd or in Stat92E have non-functional hearts with luminal defects and inappropriate cell aggregations. Using strong Stat92E loss-of-function alleles, we show that the JAK/Stat pathway regulates tin expression prior to heart precursor cell diversification. tin expression can be subdivided into four phases and, in Stat92E mutant embryos, the broad phase 2 expression pattern in the dorsal mesoderm does not restrict to the constrained phase 3 pattern. These embryos also have an expanded pericardial cell domain. We show the E(spl)-C gene HLHm5 is expressed in a pattern complementary to tin during phase 3 and that this expression is JAK/Stat dependent. In addition, E(spl)-C mutant embryos phenocopy the cardiac defects of Stat92E embryos. Mechanistically, JAK/Stat signals activate E(spl)-C genes to restrict Tin expression and the subsequent expression of the T-box transcription factor H15 to direct heart precursor diversification. This study is the first to characterize a role for the JAK/Stat pathway during cardiogenesis and identifies an autoregulatory circuit in which tin limits its own expression domain. PMID:21965617

Reconfigurable Optical Interconnections Via Dynamic Computer-Generated Holograms

NASA Technical Reports Server (NTRS)

Liu, Hua-Kuang (Inventor); Zhou, Shao-Min (Inventor)

1996-01-01

A system is presented for optically providing one-to-many irregular interconnections, and strength-adjustable many-to-many irregular interconnections which may be provided with strengths (weights) w(sub ij) using multiple laser beams which address multiple holograms and means for combining the beams modified by the holograms to form multiple interconnections, such as a cross-bar switching network. The optical means for interconnection is based on entering a series of complex computer-generated holograms on an electrically addressed spatial light modulator for real-time reconfigurations, thus providing flexibility for interconnection networks for large-scale practical use. By employing multiple sources and holograms, the number of interconnection patterns achieved is increased greatly.

Recurrent Neural Network Applications for Astronomical Time Series

NASA Astrophysics Data System (ADS)

Protopapas, Pavlos

2017-06-01

The benefits of good predictive models in astronomy lie in early event prediction systems and effective resource allocation. Current time series methods applicable to regular time series have not evolved to generalize for irregular time series. In this talk, I will describe two Recurrent Neural Network methods, Long Short-Term Memory (LSTM) and Echo State Networks (ESNs) for predicting irregular time series. Feature engineering along with a non-linear modeling proved to be an effective predictor. For noisy time series, the prediction is improved by training the network on error realizations using the error estimates from astronomical light curves. In addition to this, we propose a new neural network architecture to remove correlation from the residuals in order to improve prediction and compensate for the noisy data. Finally, I show how to set hyperparameters for a stable and performant solution correctly. In this work, we circumvent this obstacle by optimizing ESN hyperparameters using Bayesian optimization with Gaussian Process priors. This automates the tuning procedure, enabling users to employ the power of RNN without needing an in-depth understanding of the tuning procedure.

Carbon nanofibers with highly dispersed tin and tin antimonide nanoparticles: Preparation via electrospinning and application as the anode materials for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Li, Zhi; Zhang, Jiwei; Shu, Jie; Chen, Jianping; Gong, Chunhong; Guo, Jianhui; Yu, Laigui; Zhang, Jingwei

2018-03-01

One-dimensional carbon nanofibers with highly dispersed tin (Sn) and tin antimonide (SnSb) nanoparticles are prepared by electrospinning in the presence of antimony-doped tin oxide (denoted as ATO) wet gel as the precursor. The effect of ATO dosage on the microstructure and electrochemical properties of the as-fabricated Sn-SnSb/C composite nanofibers is investigated. Results indicate that ATO wet gel as the precursor can effectively improve the dispersion of Sn nanoparticles in carbon fiber and prevent them from segregation during the electrospinning and subsequent calcination processes. The as-prepared Sn-SnSb/C nanofibers as the anode materials for lithium-ion batteries exhibit high reversible capacity and stable cycle performance. Particularly, the electrode made from Sn-SnSb/C composite nanofibers obtained with 0.9 g of ATO gel has a high specific capacity of 779 mAh·g-1 and 378 mAh·g-1 at the current density of 50 mA·g-1 and 5 A·g-1, respectively, and it exhibits a capacity retention of 97% after 1200 cycles under the current density of 1 A·g-1. This is because the carbon nanofibers can form a continuous conductive network to buffer the volume change of the electrodes while Sn and Sn-SnSb nanoparticles uniformly distributed in the carbon nanofibers are free of segregation, thereby contributing to electrochemical performances of the electrodes.

Morpho-physiological Characteristics of Dorsal Subicular Network in Mice after Pilocarpine Induced Status Epilepticus

PubMed Central

He, De Fu; Ma, Dong Liang; Tang, Yong Cheng; Engel, Jerome; Bragin, Anatol; Tang, Feng Ru

2010-01-01

The goal of this study was to examine morpho-physiological changes in the dorsal subiculum network in the mouse model of temporal lobe epilepsy using extracellular recording, juxtacellular and immunofluorescence double labeling, and anterograde tracing methods. A significant loss of total dorsal subicular neurons, particularly calbindin, parvalbumin (PV), and immunopositive interneurons, was found at 2 months after pilocarpine-induced status epilepticus (SE). However, the sprouting of axons from lateral entorhinal cortex (LEnt) was observed to contact with surviving subicular neurons. These neurons had two predominant discharge patterns: bursting and fast irregular discharges. The bursting neurons were mainly pyramidal cells, and their dendritic spine density and bursting discharge rates were increased significantly in SE mice compared to the control group. Fast irregular discharge neurons were PV-immunopositive interneurons, and had less dendritic spines in SE mice when compared to control mice. When LEnt was stimulated, bursting and fast irregular discharge neurons had much shorter latency and stronger excitatory response in SE mice compared to the control group. Our results illustrate that morpho-physiological changes in the dorsal subiculum could be part of a multilevel pathological network that occurs simultaneously in many brain areas to contribute to the generation of epileptiform activity. PMID:19298597

Synaptic Plasticity Enables Adaptive Self-Tuning Critical Networks

PubMed Central

Stepp, Nigel; Plenz, Dietmar; Srinivasa, Narayan

2015-01-01

During rest, the mammalian cortex displays spontaneous neural activity. Spiking of single neurons during rest has been described as irregular and asynchronous. In contrast, recent in vivo and in vitro population measures of spontaneous activity, using the LFP, EEG, MEG or fMRI suggest that the default state of the cortex is critical, manifested by spontaneous, scale-invariant, cascades of activity known as neuronal avalanches. Criticality keeps a network poised for optimal information processing, but this view seems to be difficult to reconcile with apparently irregular single neuron spiking. Here, we simulate a 10,000 neuron, deterministic, plastic network of spiking neurons. We show that a combination of short- and long-term synaptic plasticity enables these networks to exhibit criticality in the face of intrinsic, i.e. self-sustained, asynchronous spiking. Brief external perturbations lead to adaptive, long-term modification of intrinsic network connectivity through long-term excitatory plasticity, whereas long-term inhibitory plasticity enables rapid self-tuning of the network back to a critical state. The critical state is characterized by a branching parameter oscillating around unity, a critical exponent close to -3/2 and a long tail distribution of a self-similarity parameter between 0.5 and 1. PMID:25590427

GEMAS: Spatial pattern analysis of Ni by using digital image processing techniques on European agricultural soil data

NASA Astrophysics Data System (ADS)

Jordan, Gyozo; Petrik, Attila; De Vivo, Benedetto; Albanese, Stefano; Demetriades, Alecos; Sadeghi, Martiya

2017-04-01

Several studies have investigated the spatial distribution of chemical elements in topsoil (0-20 cm) within the framework of the EuroGeoSurveys Geochemistry Expert Group's 'Geochemical Mapping of Agricultural and Grazing Land Soil' project . Most of these studies used geostatistical analyses and interpolated concentration maps, Exploratory and Compositional Data and Analysis to identify anomalous patterns. The objective of our investigation is to demonstrate the use of digital image processing techniques for reproducible spatial pattern recognition and quantitative spatial feature characterisation. A single element (Ni) concentration in agricultural topsoil is used to perform the detailed spatial analysis, and to relate these features to possible underlying processes. In this study, simple univariate statistical methods were implemented first, and Tukey's inner-fence criterion was used to delineate statistical outliers. The linear and triangular irregular network (TIN) interpolation was used on the outlier-free Ni data points, which was resampled to a 10*10 km grid. Successive moving average smoothing was applied to generalise the TIN model and to suppress small- and at the same time enhance significant large-scale features of Nickel concentration spatial distribution patterns in European topsoil. The TIN map smoothed with a moving average filter revealed the spatial trends and patterns without losing much detail, and it was used as the input into digital image processing, such as local maxima and minima determination, digital cross sections, gradient magnitude and gradient direction calculation, second derivative profile curvature calculation, edge detection, local variability assessment, lineament density and directional variogram analyses. The detailed image processing analysis revealed several NE-SW, E-W and NW-SE oriented elongated features, which coincide with different spatial parameter classes and alignment with local maxima and minima. The NE-SW oriented linear pattern is the dominant feature to the south of the last glaciation limit. Some of these linear features are parallel to the suture zone of the Iapetus Ocean, while the others follow the Alpine and Carpathian Chains. The highest variability zones of Ni concentration in topsoil are located in the Alps and in the Balkans where mafic and ultramafic rocks outcrop. The predominant NE-SW oriented pattern is also captured by the strong anisotropy in the semi-variograms in this direction. A single major E-W oriented north-facing feature runs along the southern border of the last glaciation zone. This zone also coincides with a series of local maxima in Ni concentration along the glaciofluvial deposits. The NW-SE elongated spatial features are less dominant and are located in the Pyrenees and Scandinavia. This study demonstrates the efficiency of systematic image processing analysis in identifying and characterising spatial geochemical patterns that often remain uncovered by the usual visual map interpretation techniques.

Topographic lidar survey of the Chandeleur Islands, Louisiana, February 6, 2012

USGS Publications Warehouse

Guy, Kristy K.; Plant, Nathaniel G.; Bonisteel-Cormier, Jamie M.

2014-01-01

This Data Series Report contains lidar elevation data collected February 6, 2012, for Chandeleur Islands, Louisiana. Point cloud data in lidar data exchange format (LAS) and bare earth digital elevation models (DEMs) in ERDAS Imagine raster format (IMG) are available as downloadable files. The point cloud data—data points described in three dimensions—were processed to extract bare earth data; therefore, the point cloud data are organized into the following classes: 1– and 17–unclassified, 2–ground, 9–water, and 10–breakline proximity. Digital Aerial Solutions, LLC, (DAS) was contracted by the U.S. Geological Survey (USGS) to collect and process these data. The lidar data were acquired at a horizontal spacing (or nominal pulse spacing) of 0.5 meters (m) or less. The USGS conducted two ground surveys in small areas on the Chandeleur Islands on February 5, 2012. DAS calculated a root mean square error (RMSEz) of 0.034 m by comparing the USGS ground survey point data to triangulated irregular network (TIN) models built from the lidar elevation data. This lidar survey was conducted to document the topography and topographic change of the Chandeleur Islands. The survey supports detailed studies of Louisiana, Mississippi and Alabama barrier islands that resolve annual and episodic changes in beaches, berms and dunes associated with processes driven by storms, sea-level rise, and even human restoration activities. These lidar data are available to Federal, State and local governments, emergency-response officials, resource managers, and the general public.

Erosion and Channel Incision Analysis with High-Resolution Lidar

NASA Astrophysics Data System (ADS)

Potapenko, J.; Bookhagen, B.

2013-12-01

High-resolution LiDAR (LIght Detection And Ranging) provides a new generation of sub-meter topographic data that is still to be fully exploited by the Earth science communities. We make use of multi-temporal airborne and terrestrial lidar scans in the south-central California and Santa Barbara area. Specifically, we have investigated the Mission Canyon and Channel Islands regions from 2009-2011 to study changes in erosion and channel incision on the landscape. In addition to gridding the lidar data into digital elevation models (DEMs), we also make use of raw lidar point clouds and triangulated irregular networks (TINs) for detailed analysis of heterogeneously spaced topographic data. Using recent advancements in lidar point cloud processing from information technology disciplines, we have employed novel lidar point cloud processing and feature detection algorithms to automate the detection of deeply incised channels and gullies, vegetation, and other derived metrics (e.g. estimates of eroded volume). Our analysis compares topographically-derived erosion volumes to field-derived cosmogenic radionuclide age and in-situ sediment-flux measurements. First results indicate that gully erosion accounts for up to 60% of the sediment volume removed from the Mission Canyon region. Furthermore, we observe that gully erosion and upstream arroyo propagation accelerated after fires, especially in regions where vegetation was heavily burned. The use of high-resolution lidar point cloud data for topographic analysis is still a novel method that needs more precedent and we hope to provide a cogent example of this approach with our research.

Watershed Complexity Impacts on Rainfall-Runoff Modeling

NASA Astrophysics Data System (ADS)

Goodrich, D. C.; Grayson, R.; Willgoose, G.; Palacios-Velez, O.; Bloeschl, G.

2002-12-01

Application of distributed hydrologic watershed models fundamentally requires watershed partitioning or discretization. In addition to partitioning the watershed into modeling elements, these elements typically represent a further abstraction of the actual watershed surface and its relevant hydrologic properties. A critical issue that must be addressed by any user of these models prior to their application is definition of an acceptable level of watershed discretization or geometric model complexity. A quantitative methodology to define a level of geometric model complexity commensurate with a specified level of model performance is developed for watershed rainfall-runoff modeling. In the case where watershed contributing areas are represented by overland flow planes, equilibrium discharge storage was used to define the transition from overland to channel dominated flow response. The methodology is tested on four subcatchments which cover a range of watershed scales of over three orders of magnitude in the USDA-ARS Walnut Gulch Experimental Watershed in Southeastern Arizona. It was found that distortion of the hydraulic roughness can compensate for a lower level of discretization (fewer channels) to a point. Beyond this point, hydraulic roughness distortion cannot compensate for topographic distortion of representing the watershed by fewer elements (e.g. less complex channel network). Similarly, differences in representation of topography by different model or digital elevation model (DEM) types (e.g. Triangular Irregular Elements - TINs; contour lines; and regular grid DEMs) also result in difference in runoff routing responses that can be largely compensated for by a distortion in hydraulic roughness.

On the spatial distribution of decameter‒scale subauroral ionospheric irregularities observed by SuperDARN radars

NASA Astrophysics Data System (ADS)

Larquier, S.; Ponomarenko, P.; Ribeiro, A. J.; Ruohoniemi, J. M.; Baker, J. B. H.; Sterne, K. T.; Lester, M.

2013-08-01

The midlatitude Super Dual Auroral Radar Network (SuperDARN) radars regularly observe nighttime low‒velocity Sub‒Auroral Ionospheric Scatter (SAIS) from decameter‒scale ionospheric density irregularities during quiet geomagnetic conditions. To establish the origin of the density irregularities responsible for low‒velocity SAIS, it is necessary to distinguish between the effects of high frequency (HF) propagation and irregularity occurrence itself on the observed backscatter distribution. We compare range, azimuth, and elevation data from the Blackstone SuperDARN radar with modeling results from ray tracing coupled with the International Reference Ionosphere assuming a uniform irregularity distribution. The observed and modeled distributions are shown to be very similar. The spatial distribution of backscattering is consistent with the requirement that HF rays propagate nearly perpendicular to the geomagnetic field lines (aspect angle ≤1°). For the first time, the irregularities responsible for low‒velocity SAIS are determined to extend between 200 and 300 km altitude, validating previous assumptions that low‒velocity SAIS is an F‒region phenomenon. We find that the limited spatial extent of this category of ionospheric backscatter within SuperDARN radars' fields‒of‒view is a consequence of HF propagation effects and the finite vertical extent of the scattering irregularities. We conclude that the density irregularities responsible for low‒velocity SAIS are widely distributed horizontally within the midlatitude ionosphere but are confined to the bottom‒side F‒region.

The surface morphology of crystals melting under solutions of different densities

NASA Technical Reports Server (NTRS)

Fang, Dacheng; Hellawell, A.

1988-01-01

Examples of solids melting beneath liquids are described for cases where the bulk liquid volume is stabilized against convection by a positive vertical temperature gradient, either with, or without local density inversion at the melting interface. The examples include ice melting beneath brine or methanol solutions and tin or lead melting under molten Sn-20 wt pct Pb or Pb-20 wt pct Sn, respectively. Without density inversion the melting is slow, purely diffusion controlled and the interfaces are smooth; with convection assisted melting the rate increases by some two orders of magnitude and the interfaces develop a rough profile - in the case of ice both irregular and quasi-steady state features are observed. The observations are discussed in terms of prevailing temperature and concentration gradients.

Defining Tolerance: Impacts of Delay and Disruption when Managing Challenged Networks

NASA Technical Reports Server (NTRS)

Birrane, Edward J. III; Burleigh, Scott C.; Cerf, Vint

2011-01-01

Challenged networks exhibit irregularities in their communication performance stemming from node mobility, power constraints, and impacts from the operating environment. These irregularities manifest as high signal propagation delay and frequent link disruption. Understanding those limits of link disruption and propagation delay beyond which core networking features fail is an ongoing area of research. Various wireless networking communities propose tools and techniques that address these phenomena. Emerging standardization activities within the Internet Research Task Force (IRTF) and the Consultative Committee for Space Data Systems (CCSDS) look to build upon both this experience and scalability analysis. Successful research in this area is predicated upon identifying enablers for common communication functions (notably node discovery, duplex communication, state caching, and link negotiation) and how increased disruptions and delays affect their feasibility within the network. Networks that make fewer assumptions relating to these enablers provide more universal service. Specifically, reliance on node discovery and link negotiation results in network-specific operational concepts rather than scalable technical solutions. Fundamental to this debate are the definitions, assumptions, operational concepts, and anticipated scaling of these networks. This paper presents the commonalities and differences between delay and disruption tolerance, including support protocols and critical enablers. We present where and how these tolerances differ. We propose a set of use cases that must be accommodated by any standardized delay-tolerant network and discuss the implication of these on existing tool development.

Reflections on a Strategic Vision for Computer Network Operations

DTIC Science & Technology

2010-05-25

either a traditional or an irregular war. It cannot include the disarmament or destruction of enemy forces or the occupation of its geographic territory...Washington, DC: Chairman of the Joint Chiefs of Staff, 15 August 2007), GL-7. 34 Mr. John Mense , Basic Computer Network Operations Planners Course

Plasma Irregularity Production in the Polar Cap F-Region Ionosphere

NASA Astrophysics Data System (ADS)

Lamarche, Leslie

Plasma in the Earth's ionosphere is highly irregular on scales ranging between a few centimeters and hundreds of kilometers. Small-scale irregularities or plasma waves can scatter radio waves resulting in a loss of signal for navigation and communication networks. The polar region is particularly susceptible to strong disturbances due to its direct connection with the Sun's magnetic field and energetic particles. In this thesis, factors that contribute to the production of decameter-scale plasma irregularities in the polar F region ionosphere are investigated. Both global and local control of irregularity production are studied, i.e. we consider global solar control through solar illumination and solar wind as well as much more local control by plasma density gradients and convection electric field. In the first experimental study, solar control of irregularity production is investigated using the Super Dual Auroral Radar Network (SuperDARN) radar at McMurdo, Antarctica. The occurrence trends for irregularities are analyzed statistically and a model is developed that describes the location of radar echoes within the radar's field-of-view. The trends are explained through variations in background plasma density with solar illumination affecting radar beam propagation. However, it is found that the irregularity occurrence during the night is higher than expected from ray tracing simulations based on a standard ionospheric density model. The high occurrence at night implies an additional source of plasma density and it is proposed that large-scale density enhancements called polar patches may be the source of this density. Additionally, occurrence maximizes around the terminator due to different competing irregularity production processes that favor a more or less sunlit ionosphere. The second study is concerned with modeling irregularity characteristics near a large-scale density gradient reversal, such as those expected near polar patches, with a particular focus on the asymmetry of the irregularity growth rate across the gradient reversal. Directional dependencies on the plasma density gradient, plasma drift, and wavevector are analyzed in the context of the recently developed general fluid theory of the gradient-drift instability. In the ionospheric F region, the strongest asymmetry is found when an elongated structure is oriented along the radar's boresight and moving perpendicular to its direction of elongation. These results have important implications for finding optimal configurations for oblique-scanning ionospheric radars such as SuperDARN to observe gradient reversals. To test the predictions of the developed model and the general theory of the gradient-drift instability, an experimental investigation is presented focusing on decameter-scale irregularities near a polar patch and the previously uninvestigated directional dependence of irregularity characteristics. Backscatter power and occurrence of irregularities are analyzed using measurements from the SuperDARN radar at Rankin Inlet, Canada, while background density gradients and convection electric fields are found from the north face of the Resolute Bay Incoherent Scatter Radar. It is shown that irregularity occurrence tends to follow the expected trends better than irregularity power, suggesting that while the gradient-drift instability may be a dominant process in generating small-scale irregularities, other mechanisms such as a shear-driven instability or nonlinear process may exert greater control over their intensity. It is concluded from this body of work that the production of small-scale plasma irregularities in the polar F-region ionosphere is controlled both by global factors such as solar illumination as well as local plasma density gradients and electric fields. In general, linear gradient-drift instability theory describes small-scale irregularity production well, particularly for low-amplitude perturbations. The production of irregularities is complex, and while ground-based radars are invaluable tools to study the ionosphere, care must be taken to interpret results correctly.

Holocene monsoon variability as resolved in small complex networks from palaeodata

NASA Astrophysics Data System (ADS)

Rehfeld, K.; Marwan, N.; Breitenbach, S.; Kurths, J.

2012-04-01

To understand the impacts of Holocene precipitation and/or temperature changes in the spatially extensive and complex region of Asia, it is promising to combine the information from palaeo archives, such as e.g. stalagmites, tree rings and marine sediment records from India and China. To this end, complex networks present a powerful and increasingly popular tool for the description and analysis of interactions within complex spatially extended systems in the geosciences and therefore appear to be predestined for this task. Such a network is typically constructed by thresholding a similarity matrix which in turn is based on a set of time series representing the (Earth) system dynamics at different locations. Looking into the pre-instrumental past, information about the system's processes and thus its state is available only through the reconstructed time series which -- most often -- are irregularly sampled in time and space. Interpolation techniques are often used for signal reconstruction, but they introduce additional errors, especially when records have large gaps. We have recently developed and extensively tested methods to quantify linear (Pearson correlation) and non-linear (mutual information) similarity in presence of heterogeneous and irregular sampling. To illustrate our approach we derive small networks from significantly correlated, linked, time series which are supposed to capture the underlying Asian Monsoon dynamics. We assess and discuss whether and where links and directionalities in these networks from irregularly sampled time series can be soundly detected. Finally, we investigate the role of the Northern Hemispheric temperature with respect to the correlation patterns and find that those derived from warm phases (e.g. Medieval Warm Period) are significantly different from patterns found in cold phases (e.g. Little Ice Age).

Images of Bottomside Irregularities Observed at Topside Altitudes

NASA Technical Reports Server (NTRS)

Burke, William J.; Gentile, Louise C.; Shomo, Shannon R.; Roddy, Patrick A.; Pfaff, Robert F.

2012-01-01

We analyzed plasma and field measurements acquired by the Communication/ Navigation Outage Forecasting System (C/NOFS) satellite during an eight-hour period on 13-14 January 2010 when strong to moderate 250 MHz scintillation activity was observed at nearby Scintillation Network Decision Aid (SCINDA) ground stations. C/NOFS consistently detected relatively small-scale density and electric field irregularities embedded within large-scale (approx 100 km) structures at topside altitudes. Significant spectral power measured at the Fresnel (approx 1 km) scale size suggests that C/NOFS was magnetically conjugate to bottomside irregularities similar to those directly responsible for the observed scintillations. Simultaneous ion drift and plasma density measurements indicate three distinct types of large-scale irregularities: (1) upward moving depletions, (2) downward moving depletions, and (3) upward moving density enhancements. The first type has the characteristics of equatorial plasma bubbles; the second and third do not. The data suggest that both downward moving depletions and upward moving density enhancements and the embedded small-scale irregularities may be regarded as Alfvenic images of bottomside irregularities. This interpretation is consistent with predictions of previously reported theoretical modeling and with satellite observations of upward-directed Poynting flux in the low-latitude ionosphere.

Exploring Manycore Multinode Systems for Irregular Applications with FPGA Prototyping

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

Ceriani, Marco; Palermo, Gianluca; Secchi, Simone

We present a prototype of a multi-core architecture implemented on FPGA, designed to enable efficient execution of irregular applications on distributed shared memory machines, while maintaining high performance on regular workloads. The architecture is composed of off-the-shelf soft-core cores, local interconnection and memory interface, integrated with custom components that optimize it for irregular applications. It relies on three key elements: a global address space, multithreading, and fine-grained synchronization. Global addresses are scrambled to reduce the formation of network hot-spots, while the latency of the transactions is covered by integrating an hardware scheduler within the custom load/store buffers to take advantagemore » from the availability of multiple executions threads, increasing the efficiency in a transparent way to the application. We evaluated a dual node system irregular kernels showing scalability in the number of cores and threads.« less

Transcriptional interference networks coordinate the expression of functionally related genes clustered in the same genomic loci

PubMed Central

Boldogköi, Zsolt

2012-01-01

The regulation of gene expression is essential for normal functioning of biological systems in every form of life. Gene expression is primarily controlled at the level of transcription, especially at the phase of initiation. Non-coding RNAs are one of the major players at every level of genetic regulation, including the control of chromatin organization, transcription, various post-transcriptional processes, and translation. In this study, the Transcriptional Interference Network (TIN) hypothesis was put forward in an attempt to explain the global expression of antisense RNAs and the overall occurrence of tandem gene clusters in the genomes of various biological systems ranging from viruses to mammalian cells. The TIN hypothesis suggests the existence of a novel layer of genetic regulation, based on the interactions between the transcriptional machineries of neighboring genes at their overlapping regions, which are assumed to play a fundamental role in coordinating gene expression within a cluster of functionally linked genes. It is claimed that the transcriptional overlaps between adjacent genes are much more widespread in genomes than is thought today. The Waterfall model of the TIN hypothesis postulates a unidirectional effect of upstream genes on the transcription of downstream genes within a cluster of tandemly arrayed genes, while the Seesaw model proposes a mutual interdependence of gene expression between the oppositely oriented genes. The TIN represents an auto-regulatory system with an exquisitely timed and highly synchronized cascade of gene expression in functionally linked genes located in close physical proximity to each other. In this study, we focused on herpesviruses. The reason for this lies in the compressed nature of viral genes, which allows a tight regulation and an easier investigation of the transcriptional interactions between genes. However, I believe that the same or similar principles can be applied to cellular organisms too. PMID:22783276

Transcriptional interference networks coordinate the expression of functionally related genes clustered in the same genomic loci.

PubMed

Boldogköi, Zsolt

2012-01-01

The regulation of gene expression is essential for normal functioning of biological systems in every form of life. Gene expression is primarily controlled at the level of transcription, especially at the phase of initiation. Non-coding RNAs are one of the major players at every level of genetic regulation, including the control of chromatin organization, transcription, various post-transcriptional processes, and translation. In this study, the Transcriptional Interference Network (TIN) hypothesis was put forward in an attempt to explain the global expression of antisense RNAs and the overall occurrence of tandem gene clusters in the genomes of various biological systems ranging from viruses to mammalian cells. The TIN hypothesis suggests the existence of a novel layer of genetic regulation, based on the interactions between the transcriptional machineries of neighboring genes at their overlapping regions, which are assumed to play a fundamental role in coordinating gene expression within a cluster of functionally linked genes. It is claimed that the transcriptional overlaps between adjacent genes are much more widespread in genomes than is thought today. The Waterfall model of the TIN hypothesis postulates a unidirectional effect of upstream genes on the transcription of downstream genes within a cluster of tandemly arrayed genes, while the Seesaw model proposes a mutual interdependence of gene expression between the oppositely oriented genes. The TIN represents an auto-regulatory system with an exquisitely timed and highly synchronized cascade of gene expression in functionally linked genes located in close physical proximity to each other. In this study, we focused on herpesviruses. The reason for this lies in the compressed nature of viral genes, which allows a tight regulation and an easier investigation of the transcriptional interactions between genes. However, I believe that the same or similar principles can be applied to cellular organisms too.

Evolution of microstructure and grain boundary character distribution of a tin bronze annealed at different temperatures

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

Huang, Weijiu; Chongqing Municipal Key Laboratory of Institutions of Higher Education for Mould Technology, Chongqing University of Technology, Chongqing 400054; Chai, Linjiang, E-mail: chailinjiang@cqut.edu.cn

2016-04-15

Specimens cut from a rolled tin bronze sheet were annealed at 400–800 °C for 1 h and evolution of their microstructures was then characterized in details by electron channeling contrast imaging and electron backscatter diffraction techniques. Particularly, statistics on special boundaries (SBs) with Σ ≤ 29 and network connectivity of random high angle boundaries (HABs) in the annealed specimens were examined to probe optimization potentials of grain boundary character distribution (GBCD) for this material. Results show that the deformed microstructure in the as-received material begins to be recrystallized when the annealing temperature increase to 500 °C and average grain sizesmore » surge with further increasing temperatures. As a result of the recrystallization, a large number of annealing twins (with Σ3 misorientation) are produced, leading to remarkably increased fractions of SBs (f{sub SBs}). Thanks to preexisting dense low angle boundaries, the majority of SBs in the 500 °C specimen with only partial recrystallization are Σ3{sub ic} (incoherent) boundaries, which effectively disrupt connectivity of random HABs network. Although the f{sub SBs} can be further increased (up to 72.5%) in specimens with full recrystallization (at higher temperatures), the Σ3{sub ic} boundaries would be replaced to some extent by Σ3{sub c} (coherent) boundaries which do not contribute directly to optimizing the GBCD. This work should be able to provide clear suggestions on applying the concept of grain boundary engineering to tin bronze alloys. - Highlights: • The rolled tin bronze begins to be recrystallized as temperature increases to 500 °C. • A lot of SBs are produced after recrystallization and the highest f{sub SBs} is 72.5%. • Partially recrystallized specimen has the optimum GBCD due to more Σ3{sub ic} boundaries. • The Σ3{sub ic} boundaries are replaced by Σ3{sub c} boundaries after full recrystallization.« less

New Media: The Key to Influence in Irregular Warfare

DTIC Science & Technology

2013-05-20

Pew-Internet-Social-Networking-full-detail.aspx. 13 May 2013. 5 Most Global Internet Users Turn to the Web for Emails (85%) and Social Networking Sites (62...sent from within Libya on various social networking sites after his friends within Libya had recorded them on his cell phone. 33 When cell...to the Web for Emails (85%) and Social Networking Sites (62%), New York, http://www.ipsos-na.com/news- polls/pressrelease.aspx?id=5564. May 4, 2013

The relevance of network micro-structure for neural dynamics.

PubMed

Pernice, Volker; Deger, Moritz; Cardanobile, Stefano; Rotter, Stefan

2013-01-01

The activity of cortical neurons is determined by the input they receive from presynaptic neurons. Many previous studies have investigated how specific aspects of the statistics of the input affect the spike trains of single neurons and neurons in recurrent networks. However, typically very simple random network models are considered in such studies. Here we use a recently developed algorithm to construct networks based on a quasi-fractal probability measure which are much more variable than commonly used network models, and which therefore promise to sample the space of recurrent networks in a more exhaustive fashion than previously possible. We use the generated graphs as the underlying network topology in simulations of networks of integrate-and-fire neurons in an asynchronous and irregular state. Based on an extensive dataset of networks and neuronal simulations we assess statistical relations between features of the network structure and the spiking activity. Our results highlight the strong influence that some details of the network structure have on the activity dynamics of both single neurons and populations, even if some global network parameters are kept fixed. We observe specific and consistent relations between activity characteristics like spike-train irregularity or correlations and network properties, for example the distributions of the numbers of in- and outgoing connections or clustering. Exploiting these relations, we demonstrate that it is possible to estimate structural characteristics of the network from activity data. We also assess higher order correlations of spiking activity in the various networks considered here, and find that their occurrence strongly depends on the network structure. These results provide directions for further theoretical studies on recurrent networks, as well as new ways to interpret spike train recordings from neural circuits.

Transformation of Context-dependent Sensory Dynamics into Motor Behavior

PubMed Central

Latorre, Roberto; Levi, Rafael; Varona, Pablo

2013-01-01

The intrinsic dynamics of sensory networks play an important role in the sensory-motor transformation. In this paper we use conductance based models and electrophysiological recordings to address the study of the dual role of a sensory network to organize two behavioral context-dependent motor programs in the mollusk Clione limacina. We show that: (i) a winner take-all dynamics in the gravimetric sensory network model drives the typical repetitive rhythm in the wing central pattern generator (CPG) during routine swimming; (ii) the winnerless competition dynamics of the same sensory network organizes the irregular pattern observed in the wing CPG during hunting behavior. Our model also shows that although the timing of the activity is irregular, the sequence of the switching among the sensory cells is preserved whenever the same set of neurons are activated in a given time window. These activation phase locks in the sensory signals are transformed into specific events in the motor activity. The activation phase locks can play an important role in motor coordination driven by the intrinsic dynamics of a multifunctional sensory organ. PMID:23459114

Investigation of the role of plasma wave cascading processes in the formation of midlatitude irregularities utilizing GPS and radar observations

NASA Astrophysics Data System (ADS)

Eltrass, A.; Scales, W. A.; Erickson, P. J.; Ruohoniemi, J. M.; Baker, J. B. H.

2016-06-01

Recent studies reveal that midlatitude ionospheric irregularities are less understood due to lack of models and observations that can explain the characteristics of the observed wave structures. In this paper, the cascading processes of both the temperature gradient instability (TGI) and the gradient drift instability (GDI) are investigated as the cause of these irregularities. Based on observations obtained during a coordinated experiment between the Millstone Hill incoherent scatter radar and the Blackstone Super Dual Auroral Radar Network radar, a time series for the growth rate of both TGI and GDI is calculated for observations in the subauroral ionosphere under both quiet and disturbed geomagnetic conditions. Recorded GPS scintillation data are analyzed to monitor the amplitude scintillations and to obtain the spectral characteristics of irregularities producing ionospheric scintillations. Spatial power spectra of the density fluctuations associated with the TGI from nonlinear plasma simulations are compared with both the GPS scintillation spectral characteristics and previous in situ satellite spectral measurements. The spectral comparisons suggest that initially, TGI or/and GDI irregularities are generated at large-scale size (kilometer scale), and the dissipation of the energy associated with these irregularities occurs by generating smaller and smaller (decameter scale) irregularities. The alignment between experimental, theoretical, and computational results of this study suggests that in spite of expectations from linear growth rate calculations, cascading processes involving TGI and GDI are likely responsible for the midlatitude ionospheric irregularities associated with GPS scintillations during disturbed times.

Design and test of an object-oriented GIS to map plant species in the Southern Rockies

NASA Technical Reports Server (NTRS)

Morain, Stanley A.; Neville, Paul R. H.; Budge, Thomas K.; Morrison, Susan C.; Helfrich, Donald A.; Fruit, Sarah

1993-01-01

Elevational and latitudinal shifts occur in the flora of the Rocky Mountains due to long term climate change. In order to specify which species are successfully migrating with these changes, and which are not, an object-oriented, image-based geographic information system (GIS) is being created to animate evolving ecological regimes of temperature and precipitation. Research at the Earth Data Analysis Center (EDAC) is developing a landscape model that includes the spatial, spectral and temporal domains. It is designed to visualize migratory changes in the Rocky Mountain flora, and to specify future community compositions. The object-oriented database will eventually tag each of the nearly 6000 species with a unique hue, intensity, and saturation value, so their movements can be individually traced. An associated GIS includes environmental parameters that control the distribution of each species in the landscape, and satellite imagery is used to help visualize the terrain. Polygons for the GIS are delineated as landform facets that are static in ecological time. The model manages these facets as a triangular irregular net (TIN), and their analysis assesses the gradual progression of species as they migrate through the TIN. Using an appropriate climate change model, the goal will be to stop the modeling process to assess both the rate and direction of species' change and to specify the changing community composition of each landscape facet.

SuperDARN HF Scattering and Propagation in the Presence of Polar Patches Imaged Using RISR

NASA Astrophysics Data System (ADS)

Gillies, R. G.; Perry, G. W.; Varney, R. H.; Gillies, D. M.; Donovan, E.

2017-12-01

The global array of High Frequency (HF) Super Dual Auroral Radar Network (SuperDARN) radars continuously monitors ionospheric convection in the middle-to-high latitude region. The radars measure coherent backscatter from decameter scale field-aligned irregularities. One of the main generation mechanisms for these field-aligned irregularities is the gradient drift instability (GDI). The edges of ionospheric density structures, such as polar cap patches, provide ideal locations for GDI growth. The geometry required for GDI growth results in irregularities forming on the trailing edge of polar patches. However, irregularities generated by the non-linear evolution of the GDI can become prevalent throughout the patch within minutes. Modelling the irregularity growth and measurements of backscatter within patches have both confirmed this. One aspect that has often been overlooked in studies of coherent backscatter within patches is the effect of HF propagation on echo location. This study examines HF echo locations in the vicinity of patches that were imaged using the Resolute Bay Incoherent Scatter Radars (RISR). The effect of both vertical and lateral refraction of the HF wave on echo location is examined.

Air and moisture stable covalently-bonded tin(ii) coordination polymers.

PubMed

de Lima, G M; Walton, R I; Clarkson, G J; Bitzer, R S; Ardisson, J D

2018-06-05

Four covalently-bonded tin(ii) coordination polymers, (1)-(4), were hydrothermally prepared in aqueous alkaline media by the reactions of SnSO4 with 1,2,4,5-benzenetetracarboxylic acid (1), 1,3,5-benzenetricarboxylic acid (2), 4-hydroxypyridine-2,6-dicarboxylic acid (3), and 1,3,5-cyclohexanetricarboxylic acid (4). All products were structurally authenticated by single-crystal X-ray diffraction, and the number of different tin centres and their oxidation states were confirmed by 119Sn Mössbauer spectroscopy. In addition, the comparison between experimental and simulated X-ray powder diffraction patterns confirmed the authenticity of the samples. Our crystallographic results for (1)-(4) show that the Sn(ii) centres are tetracoordinated and exhibit distorted disphenoidal geometries, corroborating the presence of one stereochemically active lone electron pair at each metal site. Products (1) and (2) display bi-dimensional polymeric structures, (3) exhibits a one-dimensional architecture, whereas (4) shows a remarkable three-dimensional coordination network. Hirshfeld surface and supramolecular analyses for the repeating units of (1)-(4) were also performed in order to identify structurally important non-covalent interactions.

Beginning Science Teachers' Use of a Digital Video Annotation Tool to Promote Reflective Practices

ERIC Educational Resources Information Center

McFadden, Justin; Ellis, Joshua; Anwar, Tasneem; Roehrig, Gillian

2014-01-01

The development of teachers as reflective practitioners is a central concept in national guidelines for teacher preparation and induction (National Council for Accreditation of Teacher Education 2008). The Teacher Induction Network (TIN) supports the development of reflective practice for beginning secondary science teachers through the creation…

Distributed Hydrologic Modeling of Semiarid Basins in Arizona: A Platform for Land Cover and Climate Change Assessments

NASA Astrophysics Data System (ADS)

Hawkins, G. A.; Vivoni, E. R.

2011-12-01

Watershed management is challenged by rising concerns over climate change and its potential to interact with land cover alterations to impact regional water supplies and hydrologic processes. The inability to conduct experimental manipulations that address climate and land cover change at watershed scales limits the capacity of water managers to make decisions to protect future supplies. As a result, spatially-explicit, physically-based models possess value for predicting the possible consequences on watershed hydrology. In this study, we apply a distributed watershed model, the Triangulated Irregular Network (TIN)-based Real-time Integrated Basin Simulator (tRIBS), to the Beaver Creek basin in Arizona. This sub-basin of the Verde River is representative of the regional topography, land cover, soils distribution and availability of hydrologic data in forested regions of northern Arizona. As such, it can serve as a demonstration study in the broader region to illustrate the utility of distributed models for change assessment studies. Through a model application to summertime conditions, we compare the hydrologic response from three sources of meteorological input: (1) an available network of ground-based stations, (2) weather radar rainfall estimates, and (3) the North American Land Data Assimilation System (NLDAS). Comparisons focus on analysis of spatiotemporal distributions of precipitation, soil moisture, runoff generation, evapotranspiration and recharge from the root zone at high resolution for an assessment of sustainable water supplies for agricultural and domestic purposes. We also present a preliminary analysis of the impact of vegetation change arising from historical treatments in the Beaver Creek to inform the hydrologic consequences in the form of soil moisture and evapotranspiration patterns with differing degrees of proposed forest thinning. Our results are discussed in the context of improved hydrologic predictions for sustainability and decision-making under the uncertainties induced by combined climate and land cover change.

High-resolution seismic data regularization and wavefield separation

NASA Astrophysics Data System (ADS)

Cao, Aimin; Stump, Brian; DeShon, Heather

2018-04-01

We present a new algorithm, non-equispaced fast antileakage Fourier transform (NFALFT), for irregularly sampled seismic data regularization. Synthetic tests from 1-D to 5-D show that the algorithm may efficiently remove leaked energy in the frequency wavenumber domain, and its corresponding regularization process is accurate and fast. Taking advantage of the NFALFT algorithm, we suggest a new method (wavefield separation) for the detection of the Earth's inner core shear wave with irregularly distributed seismic arrays or networks. All interfering seismic phases that propagate along the minor arc are removed from the time window around the PKJKP arrival. The NFALFT algorithm is developed for seismic data, but may also be used for other irregularly sampled temporal or spatial data processing.

Efficient Usage of Dense GNSS Networks in Central Europe for the Visualization and Investigation of Ionospheric TEC Variations

PubMed Central

Zanimonskiy, Yevgen M.; Yampolski, Yuri M.; Figurski, Mariusz

2017-01-01

The technique of the orthogonal projection of ionosphere electronic content variations for mapping total electron content (TEC) allows us to visualize ionospheric irregularities. For the reconstruction of global ionospheric characteristics, numerous global navigation satellite system (GNSS) receivers located in different regions of the Earth are used as sensors. We used dense GNSS networks in central Europe to detect and investigate a special type of plasma inhomogeneities, called travelling ionospheric disturbances (TID). Such use of GNSS sensors allows us to reconstruct the main TID parameters, such as spatial dimensions, velocities, and directions of their movement. The paper gives examples of the restoration of dynamic characteristics of ionospheric irregularities for quiet and disturbed geophysical conditions. Special attention is paid to the dynamics of ionospheric disturbances stimulated by the magnetic storms of two St. Patrick’s Days (17 March 2013 and 2015). Additional opportunities for the remote sensing of the ionosphere with the use of dense regional networks of GNSS receiving sensors have been noted too. PMID:28994718

Efficient Usage of Dense GNSS Networks in Central Europe for the Visualization and Investigation of Ionospheric TEC Variations.

PubMed

Nykiel, Grzegorz; Zanimonskiy, Yevgen M; Yampolski, Yuri M; Figurski, Mariusz

2017-10-10

The technique of the orthogonal projection of ionosphere electronic content variations for mapping total electron content (TEC) allows us to visualize ionospheric irregularities. For the reconstruction of global ionospheric characteristics, numerous global navigation satellite system (GNSS) receivers located in different regions of the Earth are used as sensors. We used dense GNSS networks in central Europe to detect and investigate a special type of plasma inhomogeneities, called travelling ionospheric disturbances (TID). Such use of GNSS sensors allows us to reconstruct the main TID parameters, such as spatial dimensions, velocities, and directions of their movement. The paper gives examples of the restoration of dynamic characteristics of ionospheric irregularities for quiet and disturbed geophysical conditions. Special attention is paid to the dynamics of ionospheric disturbances stimulated by the magnetic storms of two St. Patrick's Days (17 March 2013 and 2015). Additional opportunities for the remote sensing of the ionosphere with the use of dense regional networks of GNSS receiving sensors have been noted too.

Crystal surface analysis using matrix textural features classified by a probabilistic neural network

NASA Astrophysics Data System (ADS)

Sawyer, Curry R.; Quach, Viet; Nason, Donald; van den Berg, Lodewijk

1991-12-01

A system is under development in which surface quality of a growing bulk mercuric iodide crystal is monitored by video camera at regular intervals for early detection of growth irregularities. Mercuric iodide single crystals are employed in radiation detectors. A microcomputer system is used for image capture and processing. The digitized image is divided into multiple overlapping sub-images and features are extracted from each sub-image based on statistical measures of the gray tone distribution, according to the method of Haralick. Twenty parameters are derived from each sub-image and presented to a probabilistic neural network (PNN) for classification. This number of parameters was found to be optimal for the system. The PNN is a hierarchical, feed-forward network that can be rapidly reconfigured as additional training data become available. Training data is gathered by reviewing digital images of many crystals during their growth cycle and compiling two sets of images, those with and without irregularities.

Birth of an Abstraction: A Dynamical Systems Account of the Discovery of an Elsewhere Principle in a Category Learning Task

ERIC Educational Resources Information Center

Tabor, Whitney; Cho, Pyeong W.; Dankowicz, Harry

2013-01-01

Human participants and recurrent ("connectionist") neural networks were both trained on a categorization system abstractly similar to natural language systems involving irregular ("strong") classes and a default class. Both the humans and the networks exhibited staged learning and a generalization pattern reminiscent of the…

Forecasting the Appearance and Evolution of Ionospheric Irregularities and Structures: Their Effects on AF Systems

DTIC Science & Technology

2015-08-21

building (right) hosting the electronic unit, USB power sully and the wireless network . Figure 48. Ionosonde Field Site at Maseno, Kenya Figure 49... wireless 3G network . Continuous access to the system requires regular purchasing of data bundles. Web data repository Boston College has also...support of ionospheric instruments that have been deployed around the world in support of the SCINDA and LISN Networks . 15. SUBJECT TERMS Total

Estimation of the geothermal potential of the Caldara di Manziana site in the Mts Sabatini Volcanic District (Central Italy) by integrating geochemical data and 3D-GIS modelling.

NASA Astrophysics Data System (ADS)

Ranaldi, Massimo; Lelli, Matteo; Tarchini, Luca; Carapezza, Maria Luisa; Patera, Antonio

2016-04-01

High-enthalpy geothermal fields of Central Italy are hosted in deeply fractured carbonate reservoirs occurring in thermally anomalous and seismically active zones. However, the Mts. Sabatini volcanic district, located north of Rome, has an interesting deep temperatures (T), but it is characterized by low to very low seismicity and permeability in the reservoir rocks (mostly because of hydrothermal self-sealing processes). Low PCO2 facilitates the complete sealing of the reservoir fractures, preventing hot fluids rising and, determining a low CO2 flux at the surface. Conversely, high CO2 flux generally reflects a high pressure of CO2, suggesting that an active geothermal reservoir is present at depth. In Mts. Sabatini district, the Caldara of Manziana (CM) is the only zone characterized by a very high CO2 flux (188 tons/day) from a surface of 0.15 km2) considering both the diffuse and viscous CO2 emission. This suggests the likely presence of an actively degassing geothermal reservoir at depth. Emitted gas is dominated by CO2 (>97 vol.%). Triangular irregular networks (TINs) have been used to represent the morphology of the bottom of the surficial volcanic deposits, the thickness of the impervious formation and the top of the geothermal reservoir. The TINs, integrated by T-gradient and deep well data, allowed to estimate the depth and the temperature of the top of the geothermal reservoir, respectively to ~-1000 m from the surface and to ~130°C. These estimations are fairly in agreement with those obtained by gas chemistry (818

The effect of catchment discretization on rainfall-runoff model predictions

NASA Astrophysics Data System (ADS)

Goodrich, D.; Grayson, R.; Willgoose, G.; Palacios-Valez, O.; Bloschl, G.

2003-04-01

Application of distributed hydrologic watershed models fundamentally requires watershed partitioning or discretization. In addition to partitioning the watershed into modelling elements, these elements typically represent a further abstraction of the actual watershed surface and its relevant hydrologic properties. A critical issue that must be addressed by any user of these models prior to their application is definition of an acceptable level and type of watershed discretization or geometric model complexity. A quantitative methodology to define a level of geometric model complexity commensurate with a specified level of model performance is developed for watershed rainfall-runoff modelling. The methodology is tested on four subcatchments which cover a range of watershed scales of over three orders of magnitude in the USDA-ARS Walnut Gulch Experimental Watershed in Southeastern Arizona. It was found that distortion of the hydraulic roughness can compensate for a lower level of discretization (fewer channels) to a point. Beyond this point, hydraulic roughness distortion cannot compensate for the topographic distortion of representing the watershed by fewer elements (e.g. less complex channel network). Similarly, differences in representation of topography by different model or digital elevation model (DEM) types (e.g. Triangular Irregular Elements - TINs; contour lines; and regular grid DEMs) also result in difference in runoff routing responses that can be largely compensated for by a distortion in hydraulic roughness or path length. To put the effect of these discretization models in context it will be shown that relatively small non-compliance with Peclet number restrictions on timestep size can overwhelm the relatively modest differences resulting from the type of representation of topography.

Tree Stumps, Manhole Covers and Rubbish Tins: The Invisible Play-Lines of a Primary School Playground

ERIC Educational Resources Information Center

Factor, June

2004-01-01

The physical features of a primary school playground - dimensions, textures, furnishings, etc. - are incorporated and adapted for their own purposes by children in their free play. Youngsters create an intricate network of usage, play-lines invisible but known to every child at the school. Unfortunately, the general adult indifference to…

Powering the Network: The Forgotten Infrastructure.

ERIC Educational Resources Information Center

Learn, Larry L., Ed.

1995-01-01

Discusses systems that power the telecommunications infrastructure. Highlights include power for central telephone company offices; private branch exchange systems; power interruptions and power irregularities; uninterruptible power systems; problems in the systems; and photovoltaic systems. (LRW)

Pathological synchronization in Parkinson's disease: networks, models and treatments.

PubMed

Hammond, Constance; Bergman, Hagai; Brown, Peter

2007-07-01

Parkinson's disease is a common and disabling disorder of movement owing to dopaminergic denervation of the striatum. However, it is still unclear how this denervation perverts normal functioning to cause slowing of voluntary movements. Recent work using tissue slice preparations, animal models and in humans with Parkinson's disease has demonstrated abnormally synchronized oscillatory activity at multiple levels of the basal ganglia-cortical loop. This excessive synchronization correlates with motor deficit, and its suppression by dopaminergic therapies, ablative surgery or deep-brain stimulation might provide the basic mechanism whereby diverse therapeutic strategies ameliorate motor impairment in patients with Parkinson's disease. This review is part of the INMED/TINS special issue, Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com/).

Incorporation of Tin on copper clad laminate to increase the interface adhesion for signal loss reduction of high-frequency PCB lamination

NASA Astrophysics Data System (ADS)

Wang, Chong; Wen, Na; Zhou, Guoyun; Wang, Shouxu; He, Wei; Su, Xinhong; Hu, Yongsuan

2017-11-01

A novel method of improving the adhesion between copper and prepreg in high frequency PCB was proposed and studied in this work. This process which aimed to decrease the IEP (isoelectric point) of the copper to obtain higher adhesion, was achieved by depositing a thin tin layer with lower IEP on copper. It was characterized by scanning electron microscopy (SEM), 3D microscope, peel strength test, X-Ray thickness test, grazing incidence X-ray diffraction (GXRD), X-ray photoelectron spectroscopy (XPS), Agilent vector network analyzer (VNA), which confirmed its excellent adhesion performance and outstanding electrical properties in high-frequency signal transmission compared with traditional brown oxide method. Moreover, the mechanism of achieving high adhesion for this method was also investigated.

A canonical neural mechanism for behavioral variability

NASA Astrophysics Data System (ADS)

Darshan, Ran; Wood, William E.; Peters, Susan; Leblois, Arthur; Hansel, David

2017-05-01

The ability to generate variable movements is essential for learning and adjusting complex behaviours. This variability has been linked to the temporal irregularity of neuronal activity in the central nervous system. However, how neuronal irregularity actually translates into behavioural variability is unclear. Here we combine modelling, electrophysiological and behavioural studies to address this issue. We demonstrate that a model circuit comprising topographically organized and strongly recurrent neural networks can autonomously generate irregular motor behaviours. Simultaneous recordings of neurons in singing finches reveal that neural correlations increase across the circuit driving song variability, in agreement with the model predictions. Analysing behavioural data, we find remarkable similarities in the babbling statistics of 5-6-month-old human infants and juveniles from three songbird species and show that our model naturally accounts for these `universal' statistics.

The Occurrence of Small-scale Irregularities in the Mid-latitude Ionosphere from SuperDARN HF Radar Observations

NASA Astrophysics Data System (ADS)

Ruohoniemi, J. M.; Baker, J. B.; Maimaiti, M.; Oksavik, K.; Erickson, P. J.; Scales, W.; Eltrass, A.

2017-12-01

The mid-latitude radars of the SuperDARN network routinely observe backscatter from nighttime decameter-scale F region irregularities at latitudes well equatorward of the auroral boundary. This Sub-Auroral Ionospheric Scatter (SAIS) is strongly distinguished from auroral and SAPS backscatter by low Doppler velocities ( tens m/s) and stable, long-lived ( hours) occurrence in discrete events that are extended in both latitude and longitude. Statistical and event studies of SAIS with the SuperDARN radars indicate that the subauroral F region ionosphere is replete with irregularities during events, at least poleward of the 50° Λ horizon of the North American mid-latitude radars, and that radar observation of SAIS backscatter is then primarily limited by the magnetic aspect condition. Joint experiments with incoherent scatter radar have furnished sets of plasma measurements suitable for testing theories of plasma instability. Modeling work stimulated by the observations has explored the temperature-gradient instability (TGI) and the gradient drift instability (GDI) as possible sources of the irregularities. In this talk we review the findings on the occurrence of the SAIS category of mid-latitude F region irregularities, summarize the results of the modeling work, and discuss future research directions.

Topologically invariant macroscopic statistics in balanced networks of conductance-based integrate-and-fire neurons.

PubMed

Yger, Pierre; El Boustani, Sami; Destexhe, Alain; Frégnac, Yves

2011-10-01

The relationship between the dynamics of neural networks and their patterns of connectivity is far from clear, despite its importance for understanding functional properties. Here, we have studied sparsely-connected networks of conductance-based integrate-and-fire (IF) neurons with balanced excitatory and inhibitory connections and with finite axonal propagation speed. We focused on the genesis of states with highly irregular spiking activity and synchronous firing patterns at low rates, called slow Synchronous Irregular (SI) states. In such balanced networks, we examined the "macroscopic" properties of the spiking activity, such as ensemble correlations and mean firing rates, for different intracortical connectivity profiles ranging from randomly connected networks to networks with Gaussian-distributed local connectivity. We systematically computed the distance-dependent correlations at the extracellular (spiking) and intracellular (membrane potential) levels between randomly assigned pairs of neurons. The main finding is that such properties, when they are averaged at a macroscopic scale, are invariant with respect to the different connectivity patterns, provided the excitatory-inhibitory balance is the same. In particular, the same correlation structure holds for different connectivity profiles. In addition, we examined the response of such networks to external input, and found that the correlation landscape can be modulated by the mean level of synchrony imposed by the external drive. This modulation was found again to be independent of the external connectivity profile. We conclude that first and second-order "mean-field" statistics of such networks do not depend on the details of the connectivity at a microscopic scale. This study is an encouraging step toward a mean-field description of topological neuronal networks.

10 CFR Appendix C to Part 20 - Quantities 1 of Licensed Material Requiring Labeling

Code of Federal Regulations, 2012 CFR

2012-01-01

... Indium-115 100 Indium-116m 1,000 Indium-117m 1,000 Indium-117 1,000 Indium-119m 1,000 Tin-110 100 Tin-111 1,000 Tin-113 100 Tin-117m 100 Tin-119m 100 Tin-121m 100 Tin-121 1,000 Tin-123m 1,000 Tin-123 10 Tin-125 10 Tin-126 10 Tin-127 1,000 Tin-128 1,000 Antimony-115 1,000 Antimony-116m 1,000 Antimony-116 1...

GPS and GLONASS 1 Hz phase rate observations to study high latitudes ionospheric irregularities

NASA Astrophysics Data System (ADS)

Ghoddousi-Fard, R.; Prikryl, P.; Jacobsen, K. S.; Lahaye, F.

2016-12-01

It has been shown that dual frequency 1 Hz GPS phase rate observations can serve as a promising proxy for phase scintillation over high latitudes (see e.g. Ghoddousi-Fard et al., 2013, 2015). However signals from other GNSS constellations including GLONASS have been available and widely used for positioning applications. Usage of additional GNSS constellations should allow improved sampling of the ionosphere, a critical advantage to study small scale ionospheric irregularities over high latitudes. Migration of global GPS networks to multi-GNSS are now underway such as International GNSS Service (IGS) Multi-GNSS Experiment (MGEX) and other national, public and private sector networks. In this presentation, GPS and GLONASS observations from high latitude MGEX stations as well as a dense regional network over Norway are used to map high latitude ionospheric irregularities by means of standard deviation of phase rate variations. Occurrence of GPS phase irregularities as a function of magnetic latitude and local time are compared with those from both GPS and GLONASS. By including 1 Hz GLONASS measurements at about 185 stations over Norway during geomagnetic storm of March 17-18, 2015, this study complements a recently submitted paper that examined the GPS phase scintillation occurrence in the context of solar wind coupling to the magnetosphere-ionosphere system and auroral electrojet currents (Prikryl et al., 2016). Ghoddousi-Fard et al. (2013). GPS phase difference variation statistics: A comparison between phase scintillation index and proxy indices. Adv. Space Res., 52, 1397-1405, doi: 10.1016/j.asr.2013.06.035. Ghoddousi-Fard et al. (2015). Analysis of GPS phase rate variations in response to geomagnetic field perturbations over the Canadian auroral region. Adv. Space Res., 55, 1372-1381, doi: 10.1016/j.asr.2014.12.021. Prikryl et al. (2016). GPS phase scintillation at high latitudes during the geomagnetic storm of March 17-18, 2015, submitted to J. Geophys. Res. ESS contribution number: 20160112

Importance of Laser Scanning Resolution in the Process of Recreating the Architectural Details of Historical Buildings

NASA Astrophysics Data System (ADS)

Pawłowicz, Joanna A.

2017-10-01

The TLS method (Terrestrial Laser Scanning) may replace the traditional building survey methods, e.g. those requiring the use measuring tapes or range finders. This technology allows for collecting digital data in the form of a point cloud, which can be used to create a 3D model of a building. In addition, it allows for collecting data with an incredible precision, which translates into the possibility to reproduce all architectural features of a building. This data is applied in reverse engineering to create a 3D model of an object existing in a physical space. This study presents the results of a research carried out using a point cloud to recreate the architectural features of a historical building with the application of reverse engineering. The research was conducted on a two-storey residential building with a basement and an attic. Out of the building’s façade sticks a veranda featuring a complicated, wooden structure. The measurements were taken at the medium and the highest resolution using a ScanStation C10 laser scanner by Leica. The data obtained was processed using specialist software, which allowed for the application of reverse engineering, especially for reproducing the sculpted details of the veranda. Following digitization, all redundant data was removed from the point cloud and the cloud was subjected to modelling. For testing purposes, a selected part of the veranda was modelled by means of two methods: surface matching and Triangulated Irregular Network. Both modelling methods were applied in the case of data collected at medium and the highest resolution. Creating a model based on data obtained at medium resolution, both by means of the surface matching and the TIN method, does not allow for a precise recreation of architectural details. The study presents certain sculpted elements recreated based on the highest resolution data with superimposed TIN juxtaposed against a digital image. The resulting model is very precise. Creating good models requires highly accurate field data. It is important to properly choose the distance between the measuring station and the measured object in order to ensure that the angles of incidence (horizontal and vertical) of the laser beam are as straight as possible. The model created based on medium resolution offers very poor quality of details, i.e. only the bigger, basic elements of each detail are clearly visible, while the smaller ones are blurred. This is why in order to obtain data sufficient to reproduce architectural details laser scanning should be performed at the highest resolution. In addition, modelling by means of the surface matching method should be avoided - a better idea is to use the TIN method. In addition to providing a realistically-looking visualization, the method has one more important advantage - it is 4 times faster than the surface matching method.

A comparison of TEC fluctuations and scintillations at Ascension Island

NASA Astrophysics Data System (ADS)

Basu, S.; Groves, K. M.; Quinn, J. M.; Doherty, P.

1999-11-01

With increasing reliance on space-based platforms for global navigation and communication, concerns about the impact of ionospheric scintillation on these systems have become a high priority. Recently, the Air Force Research Laboratory (AFRL) performed amplitude scintillation measurements of L1 (1.575 MHz) signals from GPS satellites at Ascension Island (14.45° W, 7.95° S; magnetic latitude 16° S) during February-April, 1998, to compare amplitude scintillations with fluctuations of the total electron content (TEC). Ascension Island is located in the South Atlantic under the southern crest of the equatorial anomaly of F2 ionization where scintillations will be much enhanced during the upcoming solar maximum period. Ascension Island is included in the global network of the International GPS Service (IGS) and the GPS receivers in this network report the carrier to noise (C/N) ratio, the dual frequency carrier phase and pseudorange data at 30-s intervals. Such data with a sampling interval of 30 s were analyzed to determine TEC, the rate of change of TEC (ROT) and also ROTI, defined as the standard deviation of ROT. The spatial scale of ROTI, sampled at 30 s interval, will correspond to 6 km when the vector sum of the ionospheric projection of the satellite velocity and the irregularity drift orthogonal to the propagation path is of the order of 100 m/s. On the other hand, the scale-length of the amplitude scintillation index corresponds to the Fresnel dimension which is about 400 m for the GPS L1 frequency and an ionospheric height of 400 km. It is shown that, in view of the co-existence of large and small scale irregularities in equatorial irregularity structures, during the early evening hours, and small magnitude of irregularity drifts, ROTI measurements can be used to predict the presence of scintillation causing irregularities. The quantitative relationship between ROTI and S4, however, varies considerably due to variations of the ionospheric projection of the satellite velocity and the ionospheric irregularity drift. During the post-midnight period, due to the decay of small scale irregularities leading to a steepening of irregularity power spectrum, ROTI, on occasions, may not be associated with detectable levels of scintillation. In view of the power law type of irregularity power spectrum, ROTI will, in general, be larger than S4 and the ratio, ROTI/S4, in the present dataset is found to vary between 2 and 10. At high latitudes, where the ionospheric motion, driven by large electric fields of magnetospheric origin, is much enhanced during magnetically active periods, ROTI/S4 may be considerably larger than that in the equatorial region.

Single-Stroke Synthesis of Tin Sulphide/Oxide Nanocomposites Within Engineering Thermoplastic and Their Humidity Response.

PubMed

Adkar, Dattatraya; Adhyapak, Parag; Mulik, Uttamrao; Jadkar, Sandesh; Vutova, Katia; Amalnerkar, Dinesh

2018-05-01

SnS nanostructured materials have attracted enormous interest due to their important properties and potential application in low cost solar energy conversion systems and optical devices. From the perspective of SnS based device fabrication, we offer single-stroke in-situ technique for the generation of Sn based sulphide and oxide nanostructures inside the polymer network via polymer-inorganic solid state reaction route. In this method, polyphenylene sulphide (PPS)-an engineering thermoplastic-acts as chalcogen source as well as stabilizing matrix for the resultant nano products. Typical solid state reaction was accomplished by simply heating the physical admixtures of the tin salts (viz. tin acetate/tin chloride) with PPS at the crystalline melting temperature (285 °C) of PPS in inert atmosphere. The synthesized products were characterized by using various physicochemical characterization techniques. The prima facie observations suggest the concurrent formation of nanocrystalline SnS with extraneous oxide phase. The TEM analysis revealed formation of nanosized particles of assorted morphological features with polydispersity confined to 5 to 50 nm. However, agglomerated particles of nano to submicron size were also observed. The humidity sensing characterization of these nanocomposites was also performed. The resistivity response with the level of humidity (20 to 85% RH) was compared for these nanocomposites. The linear response was obtained for both the products. Nevertheless, the nanocomposite product obtained from acetate precursor showed higher sensitivity towards the humidity than that of one prepared from chloride precursor.

Prediction of heart abnormality using MLP network

NASA Astrophysics Data System (ADS)

Hashim, Fakroul Ridzuan; Januar, Yulni; Mat, Muhammad Hadzren; Rizman, Zairi Ismael; Awang, Mat Kamil

2018-02-01

Heart abnormality does not choose gender, age and races when it strikes. With no warning signs or symptoms, it can result to a sudden death of the patient. Generally, heart's irregular electrical activity is defined as heart abnormality. Via implementation of Multilayer Perceptron (MLP) network, this paper tries to develop a program that allows the detection of heart abnormality activity. Utilizing several training algorithms with Purelin activation function, an amount of heartbeat signals received through the electrocardiogram (ECG) will be employed to condition the MLP network.

Research in Knowledge Representation for Natural Language Understanding

DTIC Science & Technology

1980-11-01

artificial intelligence, natural language understanding , parsing, syntax, semantics, speaker meaning, knowledge representation, semantic networks...TinB PAGE map M W006 1Report No. 4513 L RESEARCH IN KNOWLEDGE REPRESENTATION FOR NATURAL LANGUAGE UNDERSTANDING Annual Report 1 September 1979 to 31... understanding , knowledge representation, and knowledge based inference. The work that we have been doing falls into three classes, successively motivated by

Predawn plasma bubble cluster observed in Southeast Asia

NASA Astrophysics Data System (ADS)

Watthanasangmechai, Kornyanat; Yamamoto, Mamoru; Saito, Akinori; Tsunoda, Roland; Yokoyama, Tatsuhiro; Supnithi, Pornchai; Ishii, Mamoru; Yatini, Clara

2016-06-01

Predawn plasma bubble was detected as deep plasma depletion by GNU Radio Beacon Receiver (GRBR) network and in situ measurement onboard Defense Meteorological Satellite Program F15 (DMSPF15) satellite and was confirmed by sparse GPS network in Southeast Asia. In addition to the deep depletion, the GPS network revealed the coexisting submesoscale irregularities. A deep depletion is regarded as a primary bubble. Submesoscale irregularities are regarded as secondary bubbles. Primary bubble and secondary bubbles appeared together as a cluster with zonal wavelength of 50 km. An altitude of secondary bubbles happened to be lower than that of the primary bubble in the same cluster. The observed pattern of plasma bubble cluster is consistent with the simulation result of the recent high-resolution bubble (HIRB) model. This event is only a single event out of 76 satellite passes at nighttime during 3-25 March 2012 that significantly shows plasma depletion at plasma bubble wall. The inside structure of the primary bubble was clearly revealed from the in situ density data of DMSPF15 satellite and the ground-based GRBR total electron content.

Network and intrinsic cellular mechanisms underlying theta phase precession of hippocampal neurons.

PubMed

Maurer, Andrew P; McNaughton, Bruce L

2007-07-01

Hippocampal 'place cells' systematically shift their phase of firing in relation to the theta rhythm as an animal traverses the 'place field'. These dynamics imply that the neural ensemble begins each theta cycle at a point in its state-space that might 'represent' the current location of the rat, but that the ensemble 'looks ahead' during the rest of the cycle. Phase precession could result from intrinsic cellular dynamics involving interference of two oscillators of different frequencies, or from network interactions, similar to Hebb's 'phase sequence' concept, involving asymmetric synaptic connections. Both models have difficulties accounting for all of the available experimental data, however. A hybrid model, in which the look-ahead phenomenon implied by phase precession originates in superficial entorhinal cortex by some form of interference mechanism and is enhanced in the hippocampus proper by asymmetric synaptic plasticity during sequence encoding, seems to be consistent with available data, but as yet there is no fully satisfactory theoretical account of this phenomenon. This review is part of the INMED/TINS special issue Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com).

Thalamic synchrony and dynamic regulation of global forebrain oscillations.

PubMed

Huguenard, John R; McCormick, David A

2007-07-01

The circuitry within the thalamus creates an intrinsic oscillatory unit whose function depends critically on reciprocal synaptic connectivity between excitatory thalamocortical relay neurons and inhibitory thalamic reticular neurons along with a robust post-inhibitory rebound mechanism in relay neurons. Feedforward and feedback connections between cortex and thalamus reinforce the thalamic oscillatory activity into larger thalamocortical networks to generate sleep spindles and spike-wave discharge of generalized absence epilepsy. The degree of synchrony within the thalamic network seems to be crucial in determining whether normal (spindle) or pathological (spike-wave) oscillations occur, and recent studies show that regulation of excitability in the reticular nucleus leads to dynamical modulation of the state of the thalamic circuit and provide a basis for explaining how a variety of unrelated genetic alterations might lead to the spike-wave phenotype. In addition, given the central role of the reticular nucleus in generating spike-wave discharge, these studies have suggested specific interventions that would prevent seizures while still allowing normal spindle generation to occur. This review is part of the INMED/TINS special issue Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com).

Ionospheric irregularities and acoustic/gravity wave activity above low-latitude thunderstorms

DOE PAGES

Lay, Erin H.

2017-12-18

Ionospheric irregularities due to plasma bubbles, scintillation, and acoustic/gravity waves are studied in the low-latitude ionosphere in relation to thunderstorm activity. Ionospheric total electron content (TEC) measurements from the Low Latitude Ionospheric Sensor Network (LISN) and lightning measurements from the World-Wide Lightning Location Network (WWLLN) are compared during two summer months and two winter months in 2013. Large amplitude fluctuations in TEC are found to have a strongly-peaked diurnal pattern in the late evening and nighttime summer ionosphere. The maximum magnitude and coverage area of these fluctuations increases as thunderstorm area increases. Summertime mid-amplitude fluctuations do not exhibit the samemore » diurnal variation, but do increase in magnitude and coverage area as thunderstorm area increases. Wintertime ionospheric fluctuations do not appear to be related to thunderstorm activity. Lastly, these findings show that thunderstorms have an observable effect on magnitude and coverage area of ionospheric fluctuations.« less

Sparse matrix-vector multiplication on network-on-chip

NASA Astrophysics Data System (ADS)

Sun, C.-C.; Götze, J.; Jheng, H.-Y.; Ruan, S.-J.

2010-12-01

In this paper, we present an idea for performing matrix-vector multiplication by using Network-on-Chip (NoC) architecture. In traditional IC design on-chip communications have been designed with dedicated point-to-point interconnections. Therefore, regular local data transfer is the major concept of many parallel implementations. However, when dealing with the parallel implementation of sparse matrix-vector multiplication (SMVM), which is the main step of all iterative algorithms for solving systems of linear equation, the required data transfers depend on the sparsity structure of the matrix and can be extremely irregular. Using the NoC architecture makes it possible to deal with arbitrary structure of the data transfers; i.e. with the irregular structure of the sparse matrices. So far, we have already implemented the proposed SMVM-NoC architecture with the size 4×4 and 5×5 in IEEE 754 single float point precision using FPGA.

Ionospheric irregularities and acoustic/gravity wave activity above low-latitude thunderstorms

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

Lay, Erin H.

Ionospheric irregularities due to plasma bubbles, scintillation, and acoustic/gravity waves are studied in the low-latitude ionosphere in relation to thunderstorm activity. Ionospheric total electron content (TEC) measurements from the Low Latitude Ionospheric Sensor Network (LISN) and lightning measurements from the World-Wide Lightning Location Network (WWLLN) are compared during two summer months and two winter months in 2013. Large amplitude fluctuations in TEC are found to have a strongly-peaked diurnal pattern in the late evening and nighttime summer ionosphere. The maximum magnitude and coverage area of these fluctuations increases as thunderstorm area increases. Summertime mid-amplitude fluctuations do not exhibit the samemore » diurnal variation, but do increase in magnitude and coverage area as thunderstorm area increases. Wintertime ionospheric fluctuations do not appear to be related to thunderstorm activity. Lastly, these findings show that thunderstorms have an observable effect on magnitude and coverage area of ionospheric fluctuations.« less

Ionospheric Irregularities and Acoustic/Gravity Wave Activity Above Low-Latitude Thunderstorms

NASA Astrophysics Data System (ADS)

Lay, Erin H.

2018-01-01

Ionospheric irregularities due to plasma bubbles, scintillation, and acoustic/gravity waves are studied in the low-latitude ionosphere in relation to thunderstorm activity. Ionospheric total electron content (TEC) measurements from the Low Latitude Ionospheric Sensor Network and lightning measurements from the World-Wide Lightning Location Network are compared during two summer months and two winter months in 2013. Large amplitude fluctuations in TEC are found to have a strongly peaked diurnal pattern in the late evening and nighttime summer ionosphere. The maximum magnitude and coverage area of these fluctuations increases as thunderstorm area increases. Summertime midamplitude fluctuations do not exhibit the same diurnal variation but do increase in magnitude and coverage area as thunderstorm area increases. Wintertime ionospheric fluctuations do not appear to be related to thunderstorm activity. These findings show that thunderstorms have an observable effect on magnitude and coverage area of ionospheric fluctuations.

SATSIN System Manual

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

Livingston, R.C.

1995-01-01

This report outlines the design, functions and operation of the HAARP Diagnostic Satellite Scintillation (SATSIN) system that will be used to characterize the structure and dynamics of F region ionospheric irregularities created during HF heating. When in routine operation, the SATSIN system will be located so that the propagation path from satellite radio beacons passes through the heated volume created by HAARP. The signal, altered in phase and amplitude by the irregularities, is received by the SATSIN array of eight antennas and is processed to extract the spatial and temporal characteristics of the scintillation. From this information, the strength, shapemore » and motion of the in situ irregularities generated by HAARP can be implied. The hardware and software components of the system are reviewed, and the installation and operation in conjunction with the HAARP network are outlined.« less

A canonical neural mechanism for behavioral variability

PubMed Central

Darshan, Ran; Wood, William E.; Peters, Susan; Leblois, Arthur; Hansel, David

2017-01-01

The ability to generate variable movements is essential for learning and adjusting complex behaviours. This variability has been linked to the temporal irregularity of neuronal activity in the central nervous system. However, how neuronal irregularity actually translates into behavioural variability is unclear. Here we combine modelling, electrophysiological and behavioural studies to address this issue. We demonstrate that a model circuit comprising topographically organized and strongly recurrent neural networks can autonomously generate irregular motor behaviours. Simultaneous recordings of neurons in singing finches reveal that neural correlations increase across the circuit driving song variability, in agreement with the model predictions. Analysing behavioural data, we find remarkable similarities in the babbling statistics of 5–6-month-old human infants and juveniles from three songbird species and show that our model naturally accounts for these ‘universal' statistics. PMID:28530225

GPS TEC Fluctuations in the Low and High Latitudes During the 2015 St. Patrick`s Day Storm

NASA Astrophysics Data System (ADS)

Chung, Jong-Kyun; Hong, Junseok; Yoo, Sung-Moon; Kim, Jeong-Han; Jee, Geonhwa; Hegai, Valery V.

2017-12-01

As a part of collaborative efforts to understand ionospheric irregularities, the Korea ionospheric scintillation sites (KISS) network has been built based on global positioning system (GPS) receivers with sampling rates higher than 1 Hz. We produce the rate of TEC index (ROTI) to represent GPS TEC fluctuations related to ionospheric irregularities. In the KISS network, two ground-based GPS sites at Kiruna (marker: KIRN; geographic: 67.9° N, 21.4° E; geomagnetic: 65.2° N) and Chuuk (marker: CHUK; geographic: 7.5° N, 151.9° E; geomagnetic: 0.4° N) were selected to evaluate the ROTI value for ionospheric irregularities during the occurrence of the 2015 St. Patrick’s Day storm. The KIRN ROTI values in the aurora region appear to be generally much higher than the CHUK ROTI values in the EIA region. The CHUK ROTI values increased to 0.5 TECU/min around UT=13:00 (LT=23:00) on March 16 in the quiet geomagnetic condition. On March 17, 2015, CHUK ROTI values more than 1.0 TECU/min were measured between UT=9:00 and 12:00 (LT=19:00 and 22:00) during the first main phase of the St. Patrick’s Day storm. This may be due to ionospheric irregularities by increased pre-reversal enhancement (PRE) after sunset during the geomagnetic storm. Post-midnight, the CHUK ROTI showed two peaks of 0.5 TECU/min and 0.3 TECU/min near UT=15:00 (LT=01:00) and UT=18:00 (LT=04:00) at the second main phase. The KIRN site showed significant peaks of ROTI around geomagnetic latitude=63.3° N and MLT=15:40 on the same day. These can be explained by enhanced ionospheric irregularities in the auroral oval at the maximum of AE index

Nanocrystalline tin oxide nanofibers deposited by a novel focused electrospinning method. Application to the detection of TATP precursors.

PubMed

Santos, José Pedro; Fernández, Maria Jesús; Fontecha, José Luis; Matatagui, Daniel; Sayago, Isabel; Horrillo, Maria Carmen; Gracia, Isabel

2014-12-16

A new method of depositing tin dioxide nanofibers in order to develop chemical sensors is presented. It involves an electrospinning process with in-plane electrostatic focusing over micromechanized substrates. It is a fast and reproducible method. After an annealing process, which can be performed by the substrate heaters, it is observed that the fibers are intertwined forming porous networks that are randomly distributed on the substrate. The fiber diameters oscillate from 100 nm to 200 nm and fiber lengths reach several tens of microns. Each fiber has a polycrystalline structure with multiple nano-grains. The sensors have been tested for the detection of acetone and hydrogen peroxide (precursors of the explosive triacetone triperoxide, TATP) in air in the ppm range. High and fast responses to these gases have been obtained.

Characterization of the low latitude plasma density irregularities observed using C/NOFS and SCINDA data

NASA Astrophysics Data System (ADS)

Andima, Geoffrey; Amabayo, Emirant B.; Jurua, Edward; Cilliers, Pierre J.

2018-01-01

Complex electrodynamic processes over the low latitude region often result in post sunset plasma density irregularities which degrade satellite communication and navigation. In order to forecast the density irregularities, their occurrence time, duration and location need to be quantified. Data from the Communication/Navigation Outage Forecasting System (C/NOFS) satellite was used to characterize the low latitude ion density irregularities from 2011 to 2013. This was supported by ground based data from the SCIntillation Network Decision Aid (SCINDA) receivers at Makerere (Geographic coordinate 32.6°E, 0.3°N, and dip latitude -9.3°N) and Nairobi (Geographic coordinate 36.8°E, -1.3°N, and dip latitude -10.8°N). The results show that irregularities in ion density have a daily pattern with peaks from 20:00 to 24:00 Local Time (LT). Scintillation activity at L band and VHF over East Africa peaked in 2011 and 2012 from 20:00 to 24:00 LT, though in many cases scintillation at VHF persisted longer than that at L band. A longitudinal pattern in ion density irregularity occurrence was observed with peaks over 135-180°E and 270-300°E. The likelihood of ion density irregularity occurrence decreased with increasing altitude. Analysis of C/NOFS zonal ion drift velocities showed that the largest nighttime and daytime drifts were in 270-300°E and 300-330°E longitude regions respectively. Zonal irregularity drift velocities over East Africa were for the first time estimated from L-band scintillation indices. The results show that the velocity of plasma density irregularities in 2011 and 2012 varied daily, and hourly in the range of 50-150 m s-1. The zonal drift velocity estimates from the L-band scintillation indices had good positive correlation with the zonal drift velocities derived from VHF receivers by the spaced receiver technique.

Characterizing the 10 November 2004 storm-time middle-latitude plasma bubble event in Southeast Asia using multi-instrument observations

NASA Astrophysics Data System (ADS)

Li, Guozhu; Ning, Baiqi; Zhao, Biqiang; Liu, Libo; Wan, Weixing; Ding, Feng; Xu, J. S.; Liu, J. Y.; Yumoto, K.

2009-07-01

The development and dynamics of ionospheric plasma bubble (PB) irregularity during the super storm of 7-11 November 2004 are investigated using the data from a multi-instrument network operated in Southeast Asia. Analysis of fluctuations in Global Positioning System total electron content (GPS TEC), ionosonde, GPS scintillation, and in situ satellite density data indicates a series of intense PB-associated irregularities at equatorial, low, and middle latitudes in the Japanese longitude on 10 November. However, in the Chinese sector, the scintillations and PB irregularities are confined within the range of 20-50°N in geographic latitude and 110-125°E in geographic longitude. The absence of equatorial PB irregularities in this sector shows a major difference from that in the close-by longitude Japanese sector. In the Southern Hemisphere Australian sector, the irregularities occurrence is present as a symmetrical distribution at conjugate latitudes. Combined analysis of the data from Osan and Wuhan ionosondes illustrates that the middle-latitude spread F irregularities initially develop at the lower part of the F region and then distribute in the whole F region. This initiation of spread F at lower altitudes indicates that the middle-latitude PB-associated irregularities are locally generated. These results together with the irregularities occurrence sequence from higher to lower latitudes, and the onset time delay of several hours implies that the presence of PB-associated irregularities within a latitude range of 20-50°N in the Chinese sector cannot be attributed to the effects of prompt penetration electric fields (PPEFs), although the equatorial PBs in the close-by longitude are seen to be associated with PPEFs. The possible mechanism is the F region plasma instabilities triggered by wave structures, which act as an external driving force and seed active plasma dynamics and instability growth at middle latitude.

The C-Terminal Extension Unique to the Long Isoform of the Shelterin Component TIN2 Enhances Its Interaction with TRF2 in a Phosphorylation- and Dyskeratosis Congenita Cluster-Dependent Fashion.

PubMed

Nelson, Nya D; Dodson, Lois M; Escudero, Laura; Sukumar, Ann T; Williams, Christopher L; Mihalek, Ivana; Baldan, Alessandro; Baird, Duncan M; Bertuch, Alison A

2018-06-15

TIN2 is central to the shelterin complex, linking the telomeric proteins TRF1 and TRF2 with TPP1/POT1. Mutations in TINF2 , which encodes TIN2, that are found in dyskeratosis congenita (DC) result in very short telomeres and cluster in a region shared by the two TIN2 isoforms, TIN2S (short) and TIN2L (long). Here we show that TIN2L, but not TIN2S, is phosphorylated. TRF2 interacts more with TIN2L than TIN2S, and both the DC cluster and phosphorylation promote this enhanced interaction. The binding of TIN2L, but not TIN2S, is affected by TRF2-F120, which is also required for TRF2's interaction with end processing factors such as Apollo. Conversely, TRF1 interacts more with TIN2S than with TIN2L. A DC-associated mutation further reduces TIN2L-TRF1, but not TIN2S-TRF1, interaction. Cells overexpressing TIN2L or phosphomimetic TIN2L are permissive to telomere elongation, whereas cells overexpressing TIN2S or phosphodead TIN2L are not. Telomere lengths are unchanged in cell lines in which TIN2L expression has been eliminated by clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9-mediated mutation. These results indicate that TIN2 isoforms are biochemically and functionally distinguishable and that shelterin composition could be fundamentally altered in patients with TINF2 mutations. Copyright © 2018 Nelson et al.

Identification of Abnormal System Noise Temperature Patterns in Deep Space Network Antennas Using Neural Network Trained Fuzzy Logic

NASA Technical Reports Server (NTRS)

Lu, Thomas; Pham, Timothy; Liao, Jason

2011-01-01

This paper presents the development of a fuzzy logic function trained by an artificial neural network to classify the system noise temperature (SNT) of antennas in the NASA Deep Space Network (DSN). The SNT data were classified into normal, marginal, and abnormal classes. The irregular SNT pattern was further correlated with link margin and weather data. A reasonably good correlation is detected among high SNT, low link margin and the effect of bad weather; however we also saw some unexpected non-correlations which merit further study in the future.

Atmospheric pressure, density, temperature and wind variations between 50 and 200 km

NASA Technical Reports Server (NTRS)

Justus, C. G.; Woodrum, A.

1972-01-01

Data on atmospheric pressure, density, temperature and winds between 50 and 200 km were collected from sources including Meteorological Rocket Network data, ROBIN falling sphere data, grenade release and pitot tube data, meteor winds, chemical release winds, satellite data, and others. These data were analyzed by a daily difference method and results on the distribution statistics, magnitude, and spatial structure of the irregular atmospheric variations are presented. Time structures of the irregular variations were determined by the analysis of residuals from harmonic analysis of time series data. The observed height variations of irregular winds and densities are found to be in accord with a theoretical relation between these two quantities. The latitude variations (at 50 - 60 km height) show an increasing trend with latitude. A possible explanation of the unusually large irregular wind magnitudes of the White Sands MRN data is given in terms of mountain wave generation by the Sierra Nevada range about 1000 km west of White Sands. An analytical method is developed which, based on an analogy of the irregular motion field with axisymmetric turbulence, allows measured or model correlation or structure functions to be used to evaluate the effective frequency spectra of scalar and vector quantities of a spacecraft moving at any speed and at any trajectory elevation angle.

From Fob to Noc: A Pathway to a Cyber Career for Combat Veterans

DTIC Science & Technology

2014-06-01

Assurance Certifications GS general schedule HSAC Homeland Security Advisory Council IDS intrusion detection system IP internet protocol IPS...NIPRNET non-secure internet protocol router network NIST National Institute for Standards and Technology NOC network operations center NSA National...twice a day on an irregular schedule or during contact with the enemy to keep any observing enemy wary of the force protection 13 condition at any

Fin whale tracks recorded by a seismic network on the Juan de Fuca Ridge, Northeast Pacific Ocean.

PubMed

Soule, Dax C; Wilcock, William S D

2013-03-01

Fin whale calls recorded from 2003 to 2004 by a seafloor seismic network on the Endeavour segment of the Juan de Fuca Ridge were analyzed to determine tracks and calling patterns. Over 150 tracks were obtained with a total duration of ~800 h and swimming speeds from 1 to 12 km/h. The dominant inter-pulse interval (IPI) is 24 s and the IPI patterns define 4 categories: a 25 s single IPI and 24/30 s dual IPI produced by single calling whales, a 24/13 s dual IPI interpreted as two calling whales, and an irregular IPI interpreted as groups of calling whales. There are also tracks in which the IPI switches between categories. Call rates vary seasonally with all the tracks between August and April. From August to October tracks are dominated by the irregular IPI and are predominantly headed to the northwest, suggesting that a portion of the fin whale population does not migrate south in the fall. The other IPI categories occur primarily from November to March. These tracks have slower swimming speeds, tend to meander, and are predominantly to the south. The distribution of fin whales around the network is non-random with more calls near the network and to the east and north.

First results of registering ionospheric disturbances obtained with SibNet network of GNSS receivers in active space experiments

NASA Astrophysics Data System (ADS)

Ishin, Artem; Perevalova, Natalia; Voeykov, Sergey; Khakhinov, Vitaliy

2017-12-01

Global and regional networks of GNSS receivers have been successfully used for geophysical research for many years; the number of continuous GNSS stations in the world is steadily growing. The article presents the first results of the use of a new regional network of GNSS stations (SibNet) in active space experiments. The Institute of Solar-Terrestrial Physics of Siberian Branch of Russian Academy of Sciences (ISTP SB RAS) has established this network in the South Baikal region. We describe in detail SibNet, characteristics of receivers in use, parameters of antennas and methods of their installation. We also present the general structure of observation site and the plot of coverage of the receiver operating zone at 50-55° latitudes by radio paths. It is shown that the selected location of receivers allows us to detect ionospheric irregularities of various scales. The purpose of the active space experiments was to reveal and record parameters of the ionospheric irregu larities caused by effects from jet streams of Progress cargo spacecraft. The mapping technique enabled us to identify weak, vertically localized ionospheric irregularities and associate them with the Progress spacecraft engine impact. Thus, it has been shown that SibNet deployed in the Southern Baikal region is an effective instrument for monitoring ionospheric conditions.

Hybrid aerogel-derived Sn-Ni alloy immobilized within porous carbon/graphene dual matrices for high-performance lithium storage.

PubMed

Zhang, Hao; Zhang, Mengru; Zhang, Meiling; Zhang, Lin; Zhang, Anping; Zhou, Yiming; Wu, Ping; Tang, Yawen

2017-09-01

Nanoporous networks of tin-based alloys immobilized within carbon matrices possess unique structural and compositional superiorities toward lithium-storage, and are expected to manifest improved strain-accommodation and charge-transport capabilities and thus desirable anodic performance for advanced lithium-ion batteries (LIBs). Herein, a facile and scalable hybrid aerogel-derived thermal-autoreduction route has been developed for the construction of nanoporous network of SnNi alloy immobilized within carbon/graphene dual matrices (SnNi@C/G network). When applied as an anode material for LIBs, the SnNi@C/G network manifests desirable lithium-storage performances in terms of specific capacities, cycle life, and rate capability. The facile aerogel-derived route and desirable Li-storage performance of the SnNi@C/G network facilitate its practical application as a high-capacity, long-life, and high-rate anode material for advanced LIBs. Copyright © 2017 Elsevier Inc. All rights reserved.

A dual-scale metal nanowire network transparent conductor for highly efficient and flexible organic light emitting diodes.

PubMed

Lee, Jinhwan; An, Kunsik; Won, Phillip; Ka, Yoonseok; Hwang, Hyejin; Moon, Hyunjin; Kwon, Yongwon; Hong, Sukjoon; Kim, Changsoon; Lee, Changhee; Ko, Seung Hwan

2017-02-02

Although solution processed metal nanowire (NW) percolation networks are a strong candidate to replace commercial indium tin oxide, their performance is limited in thin film device applications due to reduced effective electrical areas arising from the dimple structure and percolative voids that single size metal NW percolation networks inevitably possess. Here, we present a transparent electrode based on a dual-scale silver nanowire (AgNW) percolation network embedded in a flexible substrate to demonstrate a significant enhancement in the effective electrical area by filling the large percolative voids present in a long/thick AgNW network with short/thin AgNWs. As a proof of concept, the performance enhancement of a flexible phosphorescent OLED is demonstrated with the dual-scale AgNW percolation network compared to the previous mono-scale AgNWs. Moreover, we report that mechanical and oxidative robustness, which are critical for flexible OLEDs, are greatly increased by embedding the dual-scale AgNW network in a resin layer.

The underlying biological mechanisms of biocompatibility differences between bare and TiN-coated NiTi alloys.

PubMed

Lifeng, Zhao; Yan, Hong; Dayun, Yang; Xiaoying, Lü; Tingfei, Xi; Deyuan, Zhang; Ying, Hong; Jinfeng, Yuan

2011-04-01

TiN coating has been demonstrated to improve the biocompatibility of bare NiTi alloys; however, essential biocompatibility differences between NiTi alloys before and after TiN coating are not known so far. In this study, to explore the underlying biological mechanisms of biocompatibility differences between them, the changes of bare and TiN-coated NiTi alloys in surface chemical composition, morphology, hydrophilicity, Ni ions release, cytotoxicity, apoptosis, and gene expression profiles were compared using energy-dispersive spectroscopy, scanning electron microscopy, contact angle, surface energy, Ni ions release analysis, the methylthiazoltetrazolium (MTT) method, flow cytometry and microarray methods, respectively. Pathways binding to networks and real-time polymerase chain reaction (PCR) were employed to analyze and validate the microarray data, respectively. It was found that, compared with the bare NiTi alloys, TiN coating significantly decreased Ni ions content on the surfaces of the NiTi alloys and reduced the release of Ni ions from the alloys, attenuated the inhibition of Ni ions to the expression of genes associated with anti-inflammatory, and also suppressed the promotion of Ni ions to the expression of apoptosis-related genes. Moreover, TiN coating distinctly improved the hydrophilicity and uniformity of the surfaces of the NiTi alloys, and contributed to the expression of genes participating in cell adhesion and other physiological activities. These results indicate that the TiN-coated NiTi alloys will help overcome the shortcomings of NiTi alloys used in clinical application currently, and can be expected to be a replacement of biomaterials for a medical device field.

Self-sustained asynchronous irregular states and Up-Down states in thalamic, cortical and thalamocortical networks of nonlinear integrate-and-fire neurons.

PubMed

Destexhe, Alain

2009-12-01

Randomly-connected networks of integrate-and-fire (IF) neurons are known to display asynchronous irregular (AI) activity states, which resemble the discharge activity recorded in the cerebral cortex of awake animals. However, it is not clear whether such activity states are specific to simple IF models, or if they also exist in networks where neurons are endowed with complex intrinsic properties similar to electrophysiological measurements. Here, we investigate the occurrence of AI states in networks of nonlinear IF neurons, such as the adaptive exponential IF (Brette-Gerstner-Izhikevich) model. This model can display intrinsic properties such as low-threshold spike (LTS), regular spiking (RS) or fast-spiking (FS). We successively investigate the oscillatory and AI dynamics of thalamic, cortical and thalamocortical networks using such models. AI states can be found in each case, sometimes with surprisingly small network size of the order of a few tens of neurons. We show that the presence of LTS neurons in cortex or in thalamus, explains the robust emergence of AI states for relatively small network sizes. Finally, we investigate the role of spike-frequency adaptation (SFA). In cortical networks with strong SFA in RS cells, the AI state is transient, but when SFA is reduced, AI states can be self-sustained for long times. In thalamocortical networks, AI states are found when the cortex is itself in an AI state, but with strong SFA, the thalamocortical network displays Up and Down state transitions, similar to intracellular recordings during slow-wave sleep or anesthesia. Self-sustained Up and Down states could also be generated by two-layer cortical networks with LTS cells. These models suggest that intrinsic properties such as adaptation and low-threshold bursting activity are crucial for the genesis and control of AI states in thalamocortical networks.

Tansig activation function (of MLP network) for cardiac abnormality detection

NASA Astrophysics Data System (ADS)

Adnan, Ja'afar; Daud, Nik Ghazali Nik; Ishak, Mohd Taufiq; Rizman, Zairi Ismael; Rahman, Muhammad Izzuddin Abd

2018-02-01

Heart abnormality often occurs regardless of gender, age and races. This problem sometimes does not show any symptoms and it can cause a sudden death to the patient. In general, heart abnormality is the irregular electrical activity of the heart. This paper attempts to develop a program that can detect heart abnormality activity through implementation of Multilayer Perceptron (MLP) network. A certain amount of data of the heartbeat signals from the electrocardiogram (ECG) will be used in this project to train the MLP network by using several training algorithms with Tansig activation function.

Constructing Precisely Computing Networks with Biophysical Spiking Neurons.

PubMed

Schwemmer, Michael A; Fairhall, Adrienne L; Denéve, Sophie; Shea-Brown, Eric T

2015-07-15

While spike timing has been shown to carry detailed stimulus information at the sensory periphery, its possible role in network computation is less clear. Most models of computation by neural networks are based on population firing rates. In equivalent spiking implementations, firing is assumed to be random such that averaging across populations of neurons recovers the rate-based approach. Recently, however, Denéve and colleagues have suggested that the spiking behavior of neurons may be fundamental to how neuronal networks compute, with precise spike timing determined by each neuron's contribution to producing the desired output (Boerlin and Denéve, 2011; Boerlin et al., 2013). By postulating that each neuron fires to reduce the error in the network's output, it was demonstrated that linear computations can be performed by networks of integrate-and-fire neurons that communicate through instantaneous synapses. This left open, however, the possibility that realistic networks, with conductance-based neurons with subthreshold nonlinearity and the slower timescales of biophysical synapses, may not fit into this framework. Here, we show how the spike-based approach can be extended to biophysically plausible networks. We then show that our network reproduces a number of key features of cortical networks including irregular and Poisson-like spike times and a tight balance between excitation and inhibition. Lastly, we discuss how the behavior of our model scales with network size or with the number of neurons "recorded" from a larger computing network. These results significantly increase the biological plausibility of the spike-based approach to network computation. We derive a network of neurons with standard spike-generating currents and synapses with realistic timescales that computes based upon the principle that the precise timing of each spike is important for the computation. We then show that our network reproduces a number of key features of cortical networks including irregular, Poisson-like spike times, and a tight balance between excitation and inhibition. These results significantly increase the biological plausibility of the spike-based approach to network computation, and uncover how several components of biological networks may work together to efficiently carry out computation. Copyright © 2015 the authors 0270-6474/15/3510112-23$15.00/0.

Changes in functional connectivity within the fronto-temporal brain network induced by regular and irregular Russian verb production

PubMed Central

Kireev, Maxim; Slioussar, Natalia; Korotkov, Alexander D.; Chernigovskaya, Tatiana V.; Medvedev, Svyatoslav V.

2015-01-01

Functional connectivity between brain areas involved in the processing of complex language forms remains largely unexplored. Contributing to the debate about neural mechanisms underlying regular and irregular inflectional morphology processing in the mental lexicon, we conducted an fMRI experiment in which participants generated forms from different types of Russian verbs and nouns as well as from nonce stimuli. The data were subjected to a whole brain voxel-wise analysis of context dependent changes in functional connectivity [the so-called psychophysiological interaction (PPI) analysis]. Unlike previously reported subtractive results that reveal functional segregation between brain areas, PPI provides complementary information showing how these areas are functionally integrated in a particular task. To date, PPI evidence on inflectional morphology has been scarce and only available for inflectionally impoverished English verbs in a same-different judgment task. Using PPI here in conjunction with a production task in an inflectionally rich language, we found that functional connectivity between the left inferior frontal gyrus (LIFG) and bilateral superior temporal gyri (STG) was significantly greater for regular real verbs than for irregular ones. Furthermore, we observed a significant positive covariance between the number of mistakes in irregular real verb trials and the increase in functional connectivity between the LIFG and the right anterior cingulate cortex in these trails, as compared to regular ones. Our results therefore allow for dissociation between regularity and processing difficulty effects. These results, on the one hand, shed new light on the functional interplay within the LIFG-bilateral STG language-related network and, on the other hand, call for partial reconsideration of some of the previous findings while stressing the role of functional temporo-frontal connectivity in complex morphological processes. PMID:25741262

Disturbance dynamo effects over low-latitude F region: A study by network of VHF spaced receivers

NASA Astrophysics Data System (ADS)

Kakad, B.; Surve, G.; Tiwari, P.; Yadav, V.; Bhattacharyya, A.

2017-05-01

Generation of equatorial spread F (ESF) irregularities resulting from magnetic disturbance is known for past few decades. However, better prediction models for this phenomenon are still lacking. Magnetic storms also affects the F region plasma drifts. In this work we examined variability in (i) occurrence of such freshly generated ESF and (ii) low-latitude F region zonal plasma drifts over Indian longitude. For this purpose simultaneous observations of amplitude scintillations on 251 MHz signal, recorded by a network of spaced receivers located at low-latitude stations, are utilized. Observational stations are situated such that it longitudinally (latitudinally) covers an area of 5.6° (13°). Here effect of disturbance dynamo (DD) electric field at low-latitude F region and its variability are studied for three magnetic storms occurring in 2011. These magnetic storms are having nearly similar type characteristics except their start time. We find that as time difference (i.e., ΔT) between local sunset and start of magnetic activity decreases, the DD effects seen at low-latitude F region zonal irregularity drift around midnight becomes stronger. For a given magnetic storm the DD effect on F region zonal irregularity drifts is found to be only marginally stronger at dip equator in comparison to off-equatorial stations. Although effect of DD on F region zonal irregularity drifts are felt simultaneously, generation of fresh ESF is variable within a smaller longitudinal belt of 5.6°. It is attributed to the presence of LSWS at the bottomside of F region, as initiation of ESF is highly likely (unlikely) in the vicinity of crest (trough) of such LSWS.

Scaling Irregular Applications through Data Aggregation and Software Multithreading

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

Morari, Alessandro; Tumeo, Antonino; Chavarría-Miranda, Daniel

Bioinformatics, data analytics, semantic databases, knowledge discovery are emerging high performance application areas that exploit dynamic, linked data structures such as graphs, unbalanced trees or unstructured grids. These data structures usually are very large, requiring significantly more memory than available on single shared memory systems. Additionally, these data structures are difficult to partition on distributed memory systems. They also present poor spatial and temporal locality, thus generating unpredictable memory and network accesses. The Partitioned Global Address Space (PGAS) programming model seems suitable for these applications, because it allows using a shared memory abstraction across distributed-memory clusters. However, current PGAS languagesmore » and libraries are built to target regular remote data accesses and block transfers. Furthermore, they usually rely on the Single Program Multiple Data (SPMD) parallel control model, which is not well suited to the fine grained, dynamic and unbalanced parallelism of irregular applications. In this paper we present {\\bf GMT} (Global Memory and Threading library), a custom runtime library that enables efficient execution of irregular applications on commodity clusters. GMT integrates a PGAS data substrate with simple fork/join parallelism and provides automatic load balancing on a per node basis. It implements multi-level aggregation and lightweight multithreading to maximize memory and network bandwidth with fine-grained data accesses and tolerate long data access latencies. A key innovation in the GMT runtime is its thread specialization (workers, helpers and communication threads) that realize the overall functionality. We compare our approach with other PGAS models, such as UPC running using GASNet, and hand-optimized MPI code on a set of typical large-scale irregular applications, demonstrating speedups of an order of magnitude.« less

Silver Nanowires Modified with PEDOT: PSS and Graphene for Organic Light-Emitting Diodes Anode

PubMed Central

Xu, Yilin; Wei, Xiang; Wang, Cong; Cao, Jin; Chen, Yigang; Ma, Zhongquan; You, Ying; Wan, Jixiang; Fang, Xiaohong; Chen, Xiaoyuan

2017-01-01

Silver nanowires (AgNWs) networks are promising candidates for the replacement of indium tin oxide (ITO). However, the surface roughness of the AgNWs network is still too high for its application in optoelectronic devices. In this work, we have reduced the surface roughness of the AgNWs networks to 6.4 nm, compared to 33.9 nm of the as-deposited AgNWs network through the hot-pressing process, treatment with poly (3,4ethylenedioxythiophene)–poly (styrenesulfanate), and covered with graphene films. Using this method, we are able to produce AgNWs/PEDOT: PSS/SLG composite films with the transmittance and sheet resistance of 88.29% and 30 Ω/□, respectively. The OLEDs based on the AgNWs/PEDOT: PSS/SLG anodes are comparable to those based on ITO anodes. PMID:28349990

Modeling the distributed effects of forest thinning on the long-term water balance and streamflow extremes for a semi-arid basin in the southwestern US

NASA Astrophysics Data System (ADS)

Moreno, Hernan A.; Gupta, Hoshin V.; White, Dave D.; Sampson, David A.

2016-03-01

To achieve water resource sustainability in the water-limited southwestern US, it is critical to understand the potential effects of proposed forest thinning on the hydrology of semi-arid basins, where disturbances to headwater catchments can cause significant changes in the local water balance components and basinwise streamflows. In Arizona, the Four Forest Restoration Initiative (4FRI) is being developed with the goal of restoring 2.4 million acres of ponderosa pine along the Mogollon Rim. Using the physically based, spatially distributed triangulated irregular network (TIN)-based Real-time Integrated Basin Simulator (tRIBS) model, we examine the potential impacts of the 4FRI on the hydrology of Tonto Creek, a basin in the Verde-Tonto-Salt (VTS) system, which provides much of the water supply for the Phoenix metropolitan area. Long-term (20-year) simulations indicate that forest removal can trigger significant shifts in the spatiotemporal patterns of various hydrological components, causing increases in net radiation, surface temperature, wind speed, soil evaporation, groundwater recharge and runoff, at the expense of reductions in interception and shading, transpiration, vadose zone moisture and snow water equivalent, with south-facing slopes being more susceptible to enhanced atmospheric losses. The net effect will likely be increases in mean and maximum streamflow, particularly during El Niño events and the winter months, and chiefly for those scenarios in which soil hydraulic conductivity has been significantly reduced due to thinning operations. In this particular climate, forest thinning can lead to net loss of surface water storage by vegetation and snowpack, increasing the vulnerability of ecosystems and populations to larger and more frequent hydrologic extreme conditions on these semi-arid systems.

Digital Elevation Models of the Pre-Eruption 2000 Crater and 2004-07 Dome-Building Eruption at Mount St. Helens, Washington, USA

USGS Publications Warehouse

Messerich, J.A.; Schilling, S.P.; Thompson, R.A.

2008-01-01

Presented in this report are 27 digital elevation model (DEM) datasets for the crater area of Mount St. Helens. These datasets include pre-eruption baseline data collected in 2000, incremental model subsets collected during the 2004-07 dome building eruption, and associated shaded-relief image datasets. Each dataset was collected photogrammetrically with digital softcopy methods employing a combination of manual collection and iterative compilation of x,y,z coordinate triplets utilizing autocorrelation techniques. DEM data points collected using autocorrelation methods were rigorously edited in stereo and manually corrected to ensure conformity with the ground surface. Data were first collected as a triangulated irregular network (TIN) then interpolated to a grid format. DEM data are based on aerotriangulated photogrammetric solutions for aerial photograph strips flown at a nominal scale of 1:12,000 using a combination of surveyed ground control and photograph-identified control points. The 2000 DEM is based on aerotriangulation of four strips totaling 31 photographs. Subsequent DEMs collected during the course of the eruption are based on aerotriangulation of single aerial photograph strips consisting of between three and seven 1:12,000-scale photographs (two to six stereo pairs). Most datasets were based on three or four stereo pairs. Photogrammetric errors associated with each dataset are presented along with ground control used in the photogrammetric aerotriangulation. The temporal increase in area of deformation in the crater as a result of dome growth, deformation, and translation of glacial ice resulted in continual adoption of new ground control points and abandonment of others during the course of the eruption. Additionally, seasonal snow cover precluded the consistent use of some ground control points.

Root niche separation can explain avoidance of seasonal drought stress and vulnerability of overstory trees to extended drought in a mature Amazonian forest

NASA Astrophysics Data System (ADS)

Ivanov, Valeriy Y.; Hutyra, Lucy R.; Wofsy, Steven C.; Munger, J. William; Saleska, Scott R.; de Oliveira, Raimundo C., Jr.; de Camargo, Plínio B.

2012-12-01

Large areas of Amazonian evergreen forest experience seasonal droughts extending for three or more months, yet show maximum rates of photosynthesis and evapotranspiration during dry intervals. This apparent resilience is belied by disproportionate mortality of the large trees in manipulations that reduce wet season rainfall, occurring after 2-3 years of treatment. The goal of this study is to characterize the mechanisms that produce these contrasting ecosystem responses. A mechanistic model is developed based on the ecohydrological framework of TIN (Triangulated Irregular Network)-based Real Time Integrated Basin Simulator + Vegetation Generator for Interactive Evolution (tRIBS+VEGGIE). The model is used to test the roles of deep roots and soil capillary flux to provide water to the forest during the dry season. Also examined is the importance of "root niche separation," in which roots of overstory trees extend to depth, where during the dry season they use water stored from wet season precipitation, while roots of understory trees are concentrated in shallow layers that access dry season precipitation directly. Observational data from the Tapajós National Forest, Brazil, were used as meteorological forcing and provided comprehensive observational constraints on the model. Results strongly suggest that deep roots with root niche separation adaptations explain both the observed resilience during seasonal drought and the vulnerability of canopy-dominant trees to extended deficits of wet season rainfall. These mechanisms appear to provide an adaptive strategy that enhances productivity of the largest trees in the face of their disproportionate heat loads and water demand in the dry season. A sensitivity analysis exploring how wet season rainfall affects the stability of the rainforest system is presented.

Prediction of River Flooding using Geospatial and Statistical Analysis in New York, USA and Kent, UK

NASA Astrophysics Data System (ADS)

Marsellos, A.; Tsakiri, K.; Smith, M.

2014-12-01

Flooding in the rivers normally occurs during periods of excessive precipitation (i.e. New York, USA; Kent, UK) or ice jams during the winter period (New York, USA). For the prediction and mapping of the river flooding, it is necessary to evaluate the spatial distribution of the water (volume) in the river as well as study the interaction between the climatic and hydrological variables. Two study areas have been analyzed; one in Mohawk River, New York and one in Kent, United Kingdom (UK). A high resolution Digital Elevation Model (DEM) of the Mohawk River, New York has been used for a GIS flooding simulation to determine the maximum elevation value of the water that cannot continue to be restricted in the trunk stream and as a result flooding in the river may be triggered. The Flooding Trigger Level (FTL) is determined by incremental volumetric and surface calculations from Triangulated Irregular Network (TIN) with the use of GIS software and LiDAR data. The prediction of flooding in the river can also be improved by the statistical analysis of the hydrological and climatic variables in Mohawk River and Kent, UK. A methodology of time series analysis has been applied for the decomposition of the hydrological (water flow and ground water data) and climatic data in both locations. The KZ (Kolmogorov-Zurbenko) filter is used for the decomposition of the time series into the long, seasonal, and short term components. The explanation of the long term component of the water flow using the climatic variables has been improved up to 90% for both locations. Similar analysis has been performed for the prediction of the seasonal and short term component. This methodology can be applied for flooding of the rivers in multiple sites.

Are corticothalamic 'up' states fragments of wakefulness?

PubMed

Destexhe, Alain; Hughes, Stuart W; Rudolph, Michelle; Crunelli, Vincenzo

2007-07-01

The slow (<1 Hz) oscillation, with its alternating 'up' and 'down' states in individual neurons, is a defining feature of the electroencephalogram (EEG) during slow-wave sleep (SWS). Although this oscillation is well preserved across mammalian species, its physiological role is unclear. Electrophysiological and computational evidence from the cortex and thalamus now indicates that slow-oscillation 'up' states and the 'activated' state of wakefulness are remarkably similar dynamic entities. This is consistent with behavioural experiments suggesting that slow-oscillation 'up' states provide a context for the replay, and possible consolidation, of previous experience. In this scenario, the T-type Ca(2+) channel-dependent bursts of action potentials that initiate each 'up' state in thalamocortical (TC) neurons might function as triggers for synaptic and cellular plasticity in corticothalamic networks. This review is part of the INMED/TINS special issue Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com).

Consolidation of tin sulfide chalcogels and xerogels with and without adsorbed iodine

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

Riley, Brian J.; Pierce, David A.; Lepry, William C.

Tin sulfide (Sn2S3) chalcogels are one of the most effective non-oxide aerogels evaluated to date for iodine gas capture. This is attributed to the fact that the Sn within the gel network has a strong affinity for chemisorption of iodine to form SnI4. This study demonstrates an approach for consolidating the raw and iodine-sorbed Sn2S3 chalcogels into a chalcogenide glass using GeS2 as a glass forming additive. The system with both iodine-sorbed and iodine-free Sn2S3 chalcogels provides better glass-forming characteristics than Sn-S or Sn-S-I alone, and the quantity of iodine measured in the bulk glass of the consolidated iodine-sorbed Sn2S3more » chalcogel was at ~45 mass%. Additional experiments were also conducted using microwave sintering and hot isostatic pressing with Sn2S3 xerogels.« less

Synthesis and Characterization of Tin(IV) Oxide Obtained by Chemical Vapor Deposition Method

NASA Astrophysics Data System (ADS)

Nagirnyak, Svitlana V.; Lutz, Victoriya A.; Dontsova, Tatiana A.; Astrelin, Igor M.

2016-07-01

The effect of precursors on the characteristics of tin oxide obtained by chemical vapor deposition (CVD) method was investigated. The synthesis of nanosized tin(IV) oxide was carried out with the use of two different precursors: tin(II) oxalate obtained using tin chloride(II) and oxalic acid; tin(II) oxalate obtained using tin chloride(II); and ammonium oxalate. The synthesized tin(IV) oxide samples were studied by electron microscopy, X-ray diffraction and optical spectra. The lattice parameters of tin(IV) oxide samples were defined, the bandgap of samples were calculated.

Complete graph model for community detection

NASA Astrophysics Data System (ADS)

Sun, Peng Gang; Sun, Xiya

2017-04-01

Community detection brings plenty of considerable problems, which has attracted more attention for many years. This paper develops a new framework, which tries to measure the interior and the exterior of a community based on a same metric, complete graph model. In particular, the exterior is modeled as a complete bipartite. We partition a network into subnetworks by maximizing the difference between the interior and the exterior of the subnetworks. In addition, we compare our approach with some state of the art methods on computer-generated networks based on the LFR benchmark as well as real-world networks. The experimental results indicate that our approach obtains better results for community detection, is capable of splitting irregular networks and achieves perfect results on the karate network and the dolphin network.

International strategic minerals inventory summary report; tin

USGS Publications Warehouse

Sutphin, D.M.; Sabin, A.E.; Reed, B.L.

1990-01-01

The International Strategic Minerals Inventory tin inventory contains records for 56 major tin deposits and districts in 21 countries. These countries accounted for 98 percent of the 10 million metric tons of tin produced in the period 1934-87. Tin is a good alloying metal and is generally nontoxic, and its chief uses are as tinplate for tin cans and as solder in electronics. The 56 locations consist of 39 lode deposits and 17 placers and contain almost 7.5 million metric tons of tin in identified economic resources (R1E) and another 1.5 million metric tons of tin in other resource categories. Most of these resources are in major deposits that have been known for over a hundred years. Lode deposits account for 44 percent of the R1E and 87 percent of the resources in other categories. Placer deposits make up the remainder. Low-income and middle-income countries, including Bolivia and Brazil and countries along the Southeast Asian Tin Belt such as Malaysia, Thailand, and Indonesia account for 91 percent of the R1E resources of tin and for 61 percent of resources in other categories. The United States has less than 0.05 percent of the world's tin R1E in major deposits. Available data suggest that the Soviet Union may have about 4 percent of resources in this category. The industrial market economy countries of the United States, Japan, Federal Republic of Germany, and the United Kingdom are major consumers of tin, whereas the major tin-producing countries generally consume little tin. The Soviet Union and China are both major producers and consumers of tin. At the end of World War II, the four largest tin-producing countries (Bolivia, the Belgian Congo (Zaire), Nigeria, and Malaysia) produced over 80 percent of the world's tin. In 1986, the portion of production from the four largest producers (Malaysia, Brazil, Soviet Union, Indonesia) declined to about 55 percent, while the price of tin rose from about $1,500 to $18,000 per metric ton. In response to tin shortages during World War II, the United States began stockpiling refined tin metal from approximately 1946 to 1953 to ensure a strategic supply in the event of another war. Since World War II, there have been six International Tin Agreements to maintain price and supply stability between tin producers and consumers. Artificially high prices set by the tin-producing members and a tin glut brought on by independent producers like Brazil caused the collapse of the world tin market in late 1985; the International Tin Council exhausted its credit to support the market price. By the year 2025, Bolivia's underground lode mines will likely have insignificant production, as will those in the United Kingdom. Tin mines in the Southeast Asian Tin Belt will still be active. Brazil, which has risen from the eighth-ranked tin-producing country in 1982 to the largest producer in 1988, will likely be a major influence on world tin production well into the 21st century. The future mining activity of deposits presently inactive in Australia is impossible to predict.

Conditional bistability, a generic cellular mnemonic mechanism for robust and flexible working memory computations.

PubMed

Rodriguez, Guillaume; Sarazin, Matthieu; Clemente, Alexandra; Holden, Stephanie; Paz, Jeanne T; Delord, Bruno

2018-04-30

Persistent neural activity, the substrate of working memory, is thought to emerge from synaptic reverberation within recurrent networks. However, reverberation models do not robustly explain fundamental dynamics of persistent activity, including high-spiking irregularity, large intertrial variability, and state transitions. While cellular bistability may contribute to persistent activity, its rigidity appears incompatible with persistent activity labile characteristics. Here, we unravel in a cellular model a form of spike-mediated conditional bistability that is robust, generic and provides a rich repertoire of mnemonic computations. Under asynchronous synaptic inputs of the awakened state, conditional bistability generates spiking/bursting episodes, accounting for the irregularity, variability and state transitions characterizing persistent activity. This mechanism has likely been overlooked because of the sub-threshold input it requires and we predict how to assess it experimentally. Our results suggest a reexamination of the role of intrinsic properties in the collective network dynamics responsible for flexible working memory. SIGNIFICANCE STATEMENT This study unravels a novel form of intrinsic neuronal property, i.e. conditional bistability. We show that, thanks of its conditional character, conditional bistability favors the emergence of flexible and robust forms of persistent activity in PFC neural networks, in opposition to previously studied classical forms of absolute bistability. Specifically, we demonstrate for the first time that conditional bistability 1) is a generic biophysical spike-dependent mechanism of layer V pyramidal neurons in the PFC and that 2) it accounts for essential neurodynamical features for the organisation and flexibility of PFC persistent activity (the large irregularity and intertrial variability of the discharge and its organization under discrete stable states), which remain unexplained in a robust fashion by current models. Copyright © 2018 the authors.

Fabrication and characterization of highly transparent and conductive indium tin oxide films made with different solution-based methods

NASA Astrophysics Data System (ADS)

Xia, N.; Gerhardt, R. A.

2016-11-01

Solution-based fabrication methods can greatly reduce the cost and broaden the applications of transparent conducting oxides films, such as indium tin oxide (ITO) films. In this paper, we report on ITO films fabricated by spin coating methods on glass substrates with two different ITO sources: (1) a commercial ITO nanopowder water dispersion and (2) a sol-gel ITO solution. A simple and fast air annealing process was used to treat as-coated ITO films on a controlled temperature hot plate. Thermogravimetric analysis and x-ray diffraction showed that highly crystalline ITO films were formed after the annealing steps. The final ITO films had a good combination of optical properties and electrical properties, especially for films made from five layers of sol-gel ITO (92.66% transmittance and 8.7 × 10-3 Ω cm resistivity). The surface morphology and conducting network on the ITO films were characterized by non-contact and current atomic force microscopy. It was found that conducting paths were only partially connected for the nanoparticle ITO dispersion films, whereas the sol-gel ITO films had a more uniformly distributed conducting network on the surface. We also used the sol-gel ITO films to fabricate a simple liquid crystal display (LCD) device to demonstrate the excellent properties of our films.

40 CFR 421.290 - Applicability: Description of the secondary tin subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... secondary tin subcategory. 421.290 Section 421.290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Tin Subcategory § 421.290 Applicability: Description of the secondary tin subcategory. The provisions of this subpart are applicable to discharges resulting from the production of tin at secondary tin...

40 CFR 421.290 - Applicability: Description of the secondary tin subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... secondary tin subcategory. 421.290 Section 421.290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Tin Subcategory § 421.290 Applicability: Description of the secondary tin subcategory. The provisions of this subpart are applicable to discharges resulting from the production of tin at secondary tin...

40 CFR 421.290 - Applicability: Description of the secondary tin subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... secondary tin subcategory. 421.290 Section 421.290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Tin Subcategory § 421.290 Applicability: Description of the secondary tin subcategory. The provisions of this subpart are applicable to discharges resulting from the production of tin at secondary tin...

40 CFR 421.290 - Applicability: Description of the secondary tin subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... secondary tin subcategory. 421.290 Section 421.290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Tin Subcategory § 421.290 Applicability: Description of the secondary tin subcategory. The provisions of this subpart are applicable to discharges resulting from the production of tin at secondary tin...

40 CFR 421.290 - Applicability: Description of the secondary tin subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... secondary tin subcategory. 421.290 Section 421.290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Tin Subcategory § 421.290 Applicability: Description of the secondary tin subcategory. The provisions of this subpart are applicable to discharges resulting from the production of tin at secondary tin...

Comparative assessment of gastrointestinal irritant potency in man of tin(II) chloride and tin migrated from packaging.

PubMed

Boogaard, Peter J; Boisset, Michel; Blunden, Steve; Davies, Scot; Ong, Teng Jin; Taverne, Jean-Pierre

2003-12-01

Tin is present in low concentrations in most canned foods and beverages, the highest levels being found in products packaged in unlacquered or partially lacquered tinplate cans. A limited number of case-reports of acute gastrointestinal disorders after consumption of food containing 100-500 mg/kg tin have been reported, but these reports suffer many insufficiencies. Controlled clinical studies on acute effects of tin migrated from packaging suggest a threshold concentration for adverse effects (AEs) of >730 mg/kg. Two separate randomised, single-centre, double-blind, crossover studies, enabling comparison of the tolerability of tin added as tin(II) chloride at concentrations of <0.5, 161, 264 and 529 mg/kg in 250 ml tomato juice in 20 volunteers (Study 1) and tin migrated from packaging at concentrations of <0.5, 201 and 267 mg/kg in 250 ml tomato soup in 24 volunteers (Study 2) were carried out. Distribution studies were conducted to get insight in the acute AEs of low molecular weight (<1000 Da) tin species in the soluble fraction of food products. Results show that the chemical form of tin and not the elemental concentration per se determines the severity of AEs. A clear dose-response relationship was only observed when tin was added as tin(II) chloride in tomato juice. No clinically significant AEs were reported in Study 2 and comparison of the incidence of tin-related AEs showed no difference between the dose levels (including control). Tin species of low molecular weight in supernatant represented 31-32% of total tin in canned tomato soup versus 56-61% in juice freshly spiked with tin(II) chloride. Differences in the incidence of AEs following administration of tomato juice with 161 and 264 mg of tin per kg and tomato soup with 201 and 267 mg of tin per kg likely results from differences in the concentration of low molecular weight tin species and in the nature of tin complexes formed. The results of this work demonstrate that tin levels up to 267 mg/kg in canned food cause no AEs in healthy adults and support the currently proposed tin levels of 200 mg/kg and 250 mg/kg for canned beverages and canned foods, respectively, as safe levels for adults in the general population.

Stimulus features underlying reduced tremor suppression with temporally patterned deep brain stimulation

PubMed Central

Birdno, Merrill J.; Kuncel, Alexis M.; Dorval, Alan D.; Turner, Dennis A.; Gross, Robert E.

2012-01-01

Deep brain stimulation (DBS) provides dramatic tremor relief when delivered at high-stimulation frequencies (more than ∼100 Hz), but its mechanisms of action are not well-understood. Previous studies indicate that high-frequency stimulation is less effective when the stimulation train is temporally irregular. The purpose of this study was to determine the specific characteristics of temporally irregular stimulus trains that reduce their effectiveness: long pauses, bursts, or irregularity per se. We isolated these characteristics in stimulus trains and conducted intraoperative measurements of postural tremor in eight volunteers. Tremor varied significantly across stimulus conditions (P < 0.015), and stimulus trains with pauses were significantly less effective than stimulus trains without (P < 0.002). There were no significant differences in tremor between trains with or without bursts or between trains that were irregular or periodic. Thus the decreased effectiveness of temporally irregular DBS trains is due to long pauses in the stimulus trains, not the degree of temporal irregularity alone. We also conducted computer simulations of neuronal responses to the experimental stimulus trains using a biophysical model of the thalamic network. Trains that suppressed tremor in volunteers also suppressed fluctuations in thalamic transmembrane potential at the frequency associated with cerebellar burst-driver inputs. Clinical and computational findings indicate that DBS suppresses tremor by masking burst-driver inputs to the thalamus and that pauses in stimulation prevent such masking. Although stimulation of other anatomic targets may provide tremor suppression, we propose that the most relevant neuronal targets for effective tremor suppression are the afferent cerebellar fibers that terminate in the thalamus. PMID:21994263

Effect of Downscaled Forcings and Soil Texture Properties on Hyperresolution Hydrologic Simulations in a Regional Basin in Northwest Mexico

NASA Astrophysics Data System (ADS)

Ko, A.; Mascaro, G.; Vivoni, E. R.

2017-12-01

Hyper-resolution (< 1 km) hydrological modeling is expected to support a range of studies related to the terrestrial water cycle. A critical need for increasing the utility of hyper-resolution modeling is the availability of meteorological forcings and land surface characteristics at high spatial resolution. Unfortunately, in many areas these datasets are only available at coarse (> 10 km) scales. In this study, we address some of the challenges by applying a parallel version of the Triangulated Irregular Network (TIN)-based Real Time Integrated Basin Simulator (tRIBS) to the Rio Sonora Basin (RSB) in northwest Mexico. The RSB is a large, semiarid watershed ( 21,000 km2) characterized by complex topography and a strong seasonality in vegetation conditions, due to the North American monsoon. We conducted simulations at an average spatial resolution of 88 m over a decadal (2004-2013) period using spatially-distributed forcings from remotely-sensed and reanalysis products. Meteorological forcings were derived from the North American Land Data Assimilation System (NLDAS) at the original resolution of 12 km and were downscaled at 1 km with techniques accounting for terrain effects. Two grids of soil properties were created from different sources, including: (i) CONABIO (Comisión Nacional para el Conocimiento y Uso de la Biodiversidad) at 6 km resolution; and (ii) ISRIC (International Soil Reference Information Centre) at 250 m. Time-varying vegetation parameters were derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) composite products. The model was first calibrated and validated through distributed soil moisture data from a network of 20 soil moisture stations during the monsoon season. Next, hydrologic simulations were conducted with five different combinations of coarse and downscaled forcings and soil properties. Outputs in the different configurations were then compared with independent observations of soil moisture, and with estimates of land surface temperature (1 km, daily) and evapotranspiration (1 km, monthly) from MODIS. This study is expected to support the community involved in hyper-resolution hydrologic modeling by identifying the crucial factors that, if available at higher resolution, lead to the largest improvement of the simulation prognostic capability.

Telomere dysfunction and cell survival: roles for distinctTIN2-containing complexes

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

Kim, Sahn-Ho; Davalos, Albert R.; Heo, Seok-Jin

Telomeres are maintained by three DNA binding proteins, TRF1, TRF2 and POT1, and several associated factors. One factor, TIN2, binds TRF1 and TRF2 directly and POT1 indirectly. These and two other proteins form a soluble complex that may be the core telomere-maintenance complex. It is not clear whether subcomplexes exist or function in vivo. Here, we provide evidence for two TIN2 subcomplexes with distinct functions in human cells. TIN2 ablation by RNA interference caused telomere uncapping and p53-independent cell death in all cells tested. However, we isolated two TIN2 complexes from cell lysates, each selectively sensitive to a TIN2 mutantmore » (TIN2-13, TIN2-15C). In cells with wild-type p53 function, TIN2-15C was more potent than TIN2-13 in causing telomere uncapping and eventual growth arrest. In cells lacking p53 function, TIN215C more than TIN2-13 caused genomic instability and cell death. Thus, TIN2 subcomplexes likely have distinct functions in telomere maintenance, and may provide selective targets for eliminating cells with mutant p53.« less

Optimal design approach for heating irregular-shaped objects in three-dimensional radiant furnaces using a hybrid genetic algorithm-artificial neural network method

NASA Astrophysics Data System (ADS)

Darvishvand, Leila; Kamkari, Babak; Kowsary, Farshad

2018-03-01

In this article, a new hybrid method based on the combination of the genetic algorithm (GA) and artificial neural network (ANN) is developed to optimize the design of three-dimensional (3-D) radiant furnaces. A 3-D irregular shape design body (DB) heated inside a 3-D radiant furnace is considered as a case study. The uniform thermal conditions on the DB surfaces are obtained by minimizing an objective function. An ANN is developed to predict the objective function value which is trained through the data produced by applying the Monte Carlo method. The trained ANN is used in conjunction with the GA to find the optimal design variables. The results show that the computational time using the GA-ANN approach is significantly less than that of the conventional method. It is concluded that the integration of the ANN with GA is an efficient technique for optimization of the radiant furnaces.

A spatially distributed and physically based tool to modelling rainfall-triggered landslides

NASA Astrophysics Data System (ADS)

Arnone, E.; Noto, L. V.; Lepore, C.; Bras, R. L.

2009-09-01

Landslides are a serious threat to lives and property throughout the world. Over the last few years the need to provide consistent tools and support to decision-makers and land managers have led to significant progress in the analysis and understanding of the occurrence of landslides. The causes of landslides are varied. Multiple dynamic processes are involved in driving slope failures. One of these causes is prolonged rainfall, which affect slope stability in different ways. Water entering the ground beneath a slope always causes a rise of the piezometric surface, which in turn involves an increase of the pore-water pressure and a decrease of the soil shear resistance. For this reason, knowledge of spatio-temporal dynamics of soil water content, groundwater and infiltration processes is of considerable importance in the understanding and prediction of landslides dynamics. Many methods and techniques have been proposed to estimate when and where rainfall could trigger slope failure. In this paper a spatially distributed and physically based approach is presented, which integrates of a failure model with an hydrological one. The hydrological model used in the study is the tRIBS model (Triangulated Irregular Network (TIN-based) Real-Time Integrated Basin Simulator) that allows simulation of spatial and temporal hydrological dynamics influencing the landsliding, in particular infiltration, evapotranspiration, groundwater dynamics and soil moisture conditions. In order to evaluate the slope stability, the infinite slope model has been implemented in tRIBS, making up a new component of the model. For each computational element, the model is able to verify the stability condition as a function of the safety factor, splitting between the unconditionally stable and the conditionally stable computational cells. The amount of detached soil and its possible path are also estimated. The variations in elevation due to the landslides modify the basin morphology. The computational TIN is updated when a threshold related to the changes in elevation is exceeded. Model performance has been evaluated carrying out a setup case in a small catchment with very steep slopes, located in the northern part of Sicily (Italy). The test has been useful to highlight weaknesses and strengths of the model as well as to enhance the formulation. Another validation test is being carried out using landslides data recorded in the island of Puerto Rico, a US territory, where landslide triggered by rainfall are the most common type with one or two events per year.

Design and synthesis of inorganic/organic hybrid electrochemical materials

NASA Astrophysics Data System (ADS)

Harreld, John H.

An ambient pressure method for drying sol-gel materials is developed to synthesize high porosity (80--90%), high surface area vanadium oxide and silica aerogel materials (150--300 and 1000 m2/g for vanadium pentoxide and silica, respectively). The synthesis approach uses liquid exchange to replace the pore fluid with a low surface tension, nonpolar solvent which reduces the capillary pressures developed during drying. The Good-Girifalco interaction parameter is used to calculate pore stresses resulting from drying silica gels from various liquids. Vanadium oxide/polypyrrole hybrid aerogels are prepared using three strategies. These approaches focus on either sequential or consecutive polymerization of the inorganic and organic networks. Microcomposite aerogels are synthesized by encapsulating a dispersion of preformed polypyrrole in a vanadium pentoxide gel. In the second approach, pyrrole is polymerized and doped within the pore volume of preformed vanadium pentoxide gel. When the inorganic and organic precursors are polymerized simultaneously, the resulting gels exhibited a nanometer scaled microstructure with homogeneous distributions of either phases. Through this route, a suitable microstructure and composition for a lithium secondary battery cathode is obtained. Lithiated aerogels of hydrated nickel, cobalt, and mixed nickel-cobalt oxides are synthesized from lithium hydroxide and transition metal acetate precursors. The XRD analyses indicate that the nickel containing gels exhibit a lithium deficiency (less than 1 Li/transition metal. By increasing the concentration of the lithium precursor the lithium content in nickel oxides is increased, and additional base solution is no longer required to catalyze gelation. A non-hydrolytic sol-gel approach is utilized to create tin oxide and tin-aluminum binary oxide aerogels with high porosity (90%) and high surface area (300 m2/g). XRD data from single phase tin oxide aerogel indicates the growth of SnO2 crystallites between 150--400°C in air, accompanied by a reduction in surface area (30 m2/g). Heated tin oxide aerogel exhibits comparable reversible specific capacity (390 mAh/g) as that of commercial SnO2 (420 mAh/g). Amorphous tin oxide aerogel is stabilized to higher temperatures when aluminum oxide is incorporated into the structure. The tin oxide phase remains electrochemically active towards lithium insertion and exhibits excellent reversibility during cycling.

Tin

USGS Publications Warehouse

Kamilli, Robert J.; Kimball, Bryn E.; Carlin, James F.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Tin (Sn) is one of the first metals to be used by humans. Almost without exception, tin is used as an alloy. Because of its hardening effect on copper, tin was used in bronze implements as early as 3500 B.C. The major uses of tin today are for cans and containers, construction materials, transportation materials, and solder. The predominant ore mineral of tin, by far, is cassiterite (SnO2).In 2015, the world’s total estimated mine production of tin was 289,000 metric tons of contained tin. Total world reserves at the end of 2016 were estimated to be 4,700,000 metric tons. China held about 24 percent of the world’s tin reserves and accounted for 38 percent of the world’s 2015 production of tin.The proportion of scrap used in tin production is between 10 and 25 percent. Unlike many metals, tin recycling is relatively efficient, and the fraction of tin in discarded products that get recycled is greater than 50 percent.Only about 20 percent of the world’s identified tin resources occur as primary hydrothermal hard-rock veins, or lodes. These lodes contain predominantly high-temperature minerals and almost invariably occur in close association with silicic, peraluminous granites. About 80 percent of the world’s identified tin resources occur as unconsolidated secondary or placer deposits in riverbeds and valleys or on the sea floor. The largest concentration of both onshore and offshore placers is in the extensive tin belt of Southeast Asia, which stretches from China in the north, through Thailand, Burma (also referred to as Myanmar), and Malaysia, to the islands of Indonesia in the south. Furthermore, tin placers are almost always found closely allied to the granites from which they originate. Other countries with significant tin resources are Australia, Bolivia, and Brazil.Most hydrothermal tin deposits belong to what can be thought of as a superclass of porphyry-greisen deposits. The hydrothermal tin deposits are all characterized by a close spatial, temporal, and genetic association with highly differentiated, peraluminous porphyritic granite intrusions. The intrusions form pegmatites; disseminated ore; parallel or subparallel, greisen-bordered sheeted veins that either cross-cut the intrusion or are peripheral to it; skarns; and (or) limestone replacements that contain different amounts of cassiterite, molybdenite, and wolframite.The tectonic settings of tin-bearing granites are relatively well understood and of limited variety. Tin and tungsten deposits and their associated igneous rocks are found mainly in continental settings.Historically, prospecting for tin has been carried out by the time-honored methods of panning, drilling, trenching, and assaying. Geophysical and geochemical surveys have been employed to cover large areas more rapidly, isolating areas of possible tin deposits so that drilling can be more effective and less costly. Elemental concentrations and relationships of the lithophile elements, especially barium, lithium, niobium, potassium, rubidium, and zirconium, are the most reliable chemical indicators of ore-forming processes and tin-bearing potential.The average human diet includes an intake of about 10 milligrams per day of tin. Ingestion of tin in significantly greater amounts than 10 milligrams per day may lead to a stomach ache, anemia, and liver and kidney problems. Exposure to some organo-tin compounds can interfere with brain and nervous system function and, in severe cases, can cause death. Extended inhalation of tin oxide—an issue mainly for those people who work in the tin industry—results in a higher potential to develop stannosis, which is a mild disease of the lungs caused by the inhalation of tin-bearing dust. Inorganic tin is poorly absorbed by the body, and no evidence exists for the carcinogenicity of metallic tin and tin compounds in humans.Most placer tin deposits are mined by open pit and (or) dredging methods. Mining of alluvial placers in modern streambeds and riverbeds is likely to increase the amount of sediment delivered downstream. This, combined with potential diversion of rivers and streams, may negatively affect downstream ecosystems. Many of the placer deposits located in Burma, Indonesia, Malaysia, and Thailand are located offshore. Most offshore placer tin deposits are mined by dredging methods, which have the potential to negatively affect benthic, midwater, and pelagic ecosystems.In a congressionally mandated U.S. Department of Defense study of strategic minerals published in 2013, tin has the greatest shortfall amount (insufficient supply to meet demand) at \\$416 million; this amount is more than twice that of antimony ($182 million), which is the strategic mineral with the next largest shortfall amount (U.S. Department of Defense, 2013). The United States imported 75 percent of its tin supply in 2015. During the period 2012–15, these imports were from, in descending order of amount imported, Peru, Indonesia, Malaysia, and Bolivia.A promising advancement concerning research into the origin of tin deposits is the recent development of a reliable method of analyzing tin isotopes in cassiterite. Although the mechanism of transport and deposition of tin is fairly well understood, the means by which tin is incorporated into the parent magma at the points of magma generation and ascent needs further investigation.Tin metallogenic provinces worldwide are well known. Consequently, any undiscovered tin deposits will likely be spatially close to known deposits or extensions of the same.

Hollow tin/chromium whiskers

NASA Astrophysics Data System (ADS)

Cheng, Jing; Vianco, Paul T.; Li, James C. M.

2010-05-01

Tin whiskers have been an engineering challenge for over five decades. The mechanism has not been agreed upon thus far. This experiment aimed to identify a mechanism by applying compressive stresses to a tin film evaporated on silicon substrate with an adhesion layer of chromium in between. A phenomenon was observed in which hollow whiskers grew inside depleted areas. Using focused ion beam, the hollow whiskers were found to contain both tin and chromium. At the bottom of the depleted areas, thin tin/tin oxide film remained over the chromium layer. It indicates that tin transport occurred along the interface between tin and chromium layers.

Peroxide induced tin oxide coating of graphene oxide at room temperature and its application for lithium ion batteries.

PubMed

Sladkevich, S; Gun, J; Prikhodchenko, P V; Gutkin, V; Mikhaylov, A A; Novotortsev, V M; Zhu, J X; Yang, D; Hng, H H; Tay, Y Y; Tsakadze, Z; Lev, O

2012-12-07

We describe a new, simple and low-temperature method for ultra-thin coating of graphene oxide (GO) by peroxostannate, tin oxide or a mixture of tin and tin oxide crystallites by different treatments. The technique is environmentally friendly and does not require complicated infrastructure, an autoclave or a microwave. The supported peroxostannate phase is partially converted after drying to crystalline tin oxide with average, 2.5 nm cassiterite crystals. Mild heat treatment yielded full coverage of the reduced graphene oxide by crystalline tin oxide. Extensive heat treatment in vacuum at >500 °C yielded a mixture of elemental tin and cassiterite tin oxide nanoparticles supported on reduced graphene oxide (rGO). The usefulness of the new approach was demonstrated by the preparation of two types of lithium ion anodes: tin oxide-rGO and a mixture of tin oxide and tin coated rGO composites (SnO(2)-Sn-rGO). The electrodes exhibited stable charge/discharge cyclability and high charging capacity due to the intimate contact between the conductive graphene and the very small tin oxide crystallites. The charging/discharging capacity of the anodes exceeded the theoretical capacity predicted based on tin lithiation. The tin oxide coated rGO exhibited higher charging capacity but somewhat lower stability upon extended charge/discharge cycling compared to SnO(2)-Sn-rGO.

Network-induced oscillatory behavior in material flow networks and irregular business cycles

NASA Astrophysics Data System (ADS)

Helbing, Dirk; Lämmer, Stefen; Witt, Ulrich; Brenner, Thomas

2004-11-01

Network theory is rapidly changing our understanding of complex systems, but the relevance of topological features for the dynamic behavior of metabolic networks, food webs, production systems, information networks, or cascade failures of power grids remains to be explored. Based on a simple model of supply networks, we offer an interpretation of instabilities and oscillations observed in biological, ecological, economic, and engineering systems. We find that most supply networks display damped oscillations, even when their units—and linear chains of these units—behave in a nonoscillatory way. Moreover, networks of damped oscillators tend to produce growing oscillations. This surprising behavior offers, for example, a different interpretation of business cycles and of oscillating or pulsating processes. The network structure of material flows itself turns out to be a source of instability, and cyclical variations are an inherent feature of decentralized adjustments.

Telomere dysfunction and cell survival: Roles for distinct TIN2-containing complexes

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

Kim, Sahn-ho; Davalos, Albert R.; Heo, Seok-Jin

Telomeres are maintained by three DNA binding proteins (TRF1, TRF2 and POT1), and several associated factors. One factor, TIN2, binds TRF1 and TRF2 directly and POT1 indirectly. Along with two other proteins, TPP1 and hRap1, these form a soluble complex that may be the core telomere maintenance complex. It is not clear whether sub-complexes also exist in vivo. We provide evidence for two TIN2 sub-complexes with distinct functions in human cells. We isolated these two TIN2 sub-complexes from nuclear lysates of unperturbed cells and cells expressing TIN2 mutants TIN2-13, TIN2-15C, which cannot bind TRF2 or TRF1, respectively. In cells withmore » wild-type p53 function, TIN2-15C was more potent than TIN2-13 in causing telomere uncapping and eventual growth arrest. In cells lacking p53 function, TIN2-15C was more potent than TIN2-13 in causing telomere dysfunction and cell death. Our findings suggest that distinct TIN2 complexes exist, and that TIN2-15C-sensitive subcomplexes are particularly important for cell survival in the absence of functional p53.« less

Drifting States and Synchronization Induced Chaos in Autonomous Networks of Excitable Neurons.

PubMed

Echeveste, Rodrigo; Gros, Claudius

2016-01-01

The study of balanced networks of excitatory and inhibitory neurons has led to several open questions. On the one hand it is yet unclear whether the asynchronous state observed in the brain is autonomously generated, or if it results from the interplay between external drivings and internal dynamics. It is also not known, which kind of network variabilities will lead to irregular spiking and which to synchronous firing states. Here we show how isolated networks of purely excitatory neurons generically show asynchronous firing whenever a minimal level of structural variability is present together with a refractory period. Our autonomous networks are composed of excitable units, in the form of leaky integrators spiking only in response to driving currents, remaining otherwise quiet. For a non-uniform network, composed exclusively of excitatory neurons, we find a rich repertoire of self-induced dynamical states. We show in particular that asynchronous drifting states may be stabilized in purely excitatory networks whenever a refractory period is present. Other states found are either fully synchronized or mixed, containing both drifting and synchronized components. The individual neurons considered are excitable and hence do not dispose of intrinsic natural firing frequencies. An effective network-wide distribution of natural frequencies is however generated autonomously through self-consistent feedback loops. The asynchronous drifting state is, additionally, amenable to an analytic solution. We find two types of asynchronous activity, with the individual neurons spiking regularly in the pure drifting state, albeit with a continuous distribution of firing frequencies. The activity of the drifting component, however, becomes irregular in the mixed state, due to the periodic driving of the synchronized component. We propose a new tool for the study of chaos in spiking neural networks, which consists of an analysis of the time series of pairs of consecutive interspike intervals. In this space, we show that a strange attractor with a fractal dimension of about 1.8 is formed in the mentioned mixed state.

Drifting States and Synchronization Induced Chaos in Autonomous Networks of Excitable Neurons

PubMed Central

Echeveste, Rodrigo; Gros, Claudius

2016-01-01

The study of balanced networks of excitatory and inhibitory neurons has led to several open questions. On the one hand it is yet unclear whether the asynchronous state observed in the brain is autonomously generated, or if it results from the interplay between external drivings and internal dynamics. It is also not known, which kind of network variabilities will lead to irregular spiking and which to synchronous firing states. Here we show how isolated networks of purely excitatory neurons generically show asynchronous firing whenever a minimal level of structural variability is present together with a refractory period. Our autonomous networks are composed of excitable units, in the form of leaky integrators spiking only in response to driving currents, remaining otherwise quiet. For a non-uniform network, composed exclusively of excitatory neurons, we find a rich repertoire of self-induced dynamical states. We show in particular that asynchronous drifting states may be stabilized in purely excitatory networks whenever a refractory period is present. Other states found are either fully synchronized or mixed, containing both drifting and synchronized components. The individual neurons considered are excitable and hence do not dispose of intrinsic natural firing frequencies. An effective network-wide distribution of natural frequencies is however generated autonomously through self-consistent feedback loops. The asynchronous drifting state is, additionally, amenable to an analytic solution. We find two types of asynchronous activity, with the individual neurons spiking regularly in the pure drifting state, albeit with a continuous distribution of firing frequencies. The activity of the drifting component, however, becomes irregular in the mixed state, due to the periodic driving of the synchronized component. We propose a new tool for the study of chaos in spiking neural networks, which consists of an analysis of the time series of pairs of consecutive interspike intervals. In this space, we show that a strange attractor with a fractal dimension of about 1.8 is formed in the mentioned mixed state. PMID:27708572

Nanocrystal grain growth and device architectures for high-efficiency CdTe ink-based photovoltaics.

PubMed

Crisp, Ryan W; Panthani, Matthew G; Rance, William L; Duenow, Joel N; Parilla, Philip A; Callahan, Rebecca; Dabney, Matthew S; Berry, Joseph J; Talapin, Dmitri V; Luther, Joseph M

2014-09-23

We study the use of cadmium telluride (CdTe) nanocrystal colloids as a solution-processable "ink" for large-grain CdTe absorber layers in solar cells. The resulting grain structure and solar cell performance depend on the initial nanocrystal size, shape, and crystal structure. We find that inks of predominantly wurtzite tetrapod-shaped nanocrystals with arms ∼5.6 nm in diameter exhibit better device performance compared to inks composed of smaller tetrapods, irregular faceted nanocrystals, or spherical zincblende nanocrystals despite the fact that the final sintered film has a zincblende crystal structure. Five different working device architectures were investigated. The indium tin oxide (ITO)/CdTe/zinc oxide structure leads to our best performing device architecture (with efficiency >11%) compared to others including two structures with a cadmium sulfide (CdS) n-type layer typically used in high efficiency sublimation-grown CdTe solar cells. Moreover, devices without CdS have improved response at short wavelengths.

Strategies to Reduce Tin and Other Metals in Electronic Cigarette Aerosol

PubMed Central

Williams, Monique; To, An; Bozhilov, Krassimir; Talbot, Prue

2015-01-01

Background Metals are present in electronic cigarette (EC) fluid and aerosol and may present health risks to users. Objective The objective of this study was to measure the amounts of tin, copper, zinc, silver, nickel and chromium in the aerosol from four brands of EC and to identify the sources of these metals by examining the elemental composition of the atomizer components. Methods Four brands of popular EC were dissected and the cartomizers were examined microscopically. Elemental composition of cartomizer components was determined using integrated energy dispersive X-ray microanalysis, and the concentrations of the tin, copper, zinc silver, nickel, and chromium in the aerosol were determined for each brand using inductively coupled plasma optical emission spectroscopy. Results All filaments were made of nickel and chromium. Thick wires were copper coated with either tin or silver. Wires were joined to each other by tin solder, brazing, or by brass clamps. High concentrations of tin were detected in the aerosol when tin solder joints were friable. Tin coating on copper wires also contributed to tin in the aerosol. Conclusions Tin concentrations in EC aerosols varied both within and between brands. Tin in aerosol was reduced by coating the thick wire with silver rather than tin, placing stable tin solder joints outside the atomizing chamber, joining wires with brass clamps or by brazing rather than soldering wires. These data demonstrate the feasibility of removing tin and other unwanted metals from EC aerosol by altering designs and using materials of suitable quality. PMID:26406602

Cardiac abnormality prediction using HMLP network

NASA Astrophysics Data System (ADS)

Adnan, Ja'afar; Ahmad, K. A.; Mat, Muhamad Hadzren; Rizman, Zairi Ismael; Ahmad, Shahril

2018-02-01

Cardiac abnormality often occurs regardless of gender, age and races but depends on the lifestyle. This problem sometimes does not show any symptoms and usually detected once it already critical which lead to a sudden death to the patient. Basically, cardiac abnormality is the irregular electrical signal that generate by the pacemaker of the heart. This paper attempts to develop a program that can detect cardiac abnormality activity through implementation of Hybrid Multilayer Perceptron (HMLP) network. A certain amount of data of the heartbeat signals from the electrocardiogram (ECG) will be used in this project to train the MLP and HMLP network by using Modified Recursive Prediction Error (MRPE) algorithm and to test the network performance.

Evaluation of statistical methods for quantifying fractal scaling in water-quality time series with irregular sampling

NASA Astrophysics Data System (ADS)

Zhang, Qian; Harman, Ciaran J.; Kirchner, James W.

2018-02-01

River water-quality time series often exhibit fractal scaling, which here refers to autocorrelation that decays as a power law over some range of scales. Fractal scaling presents challenges to the identification of deterministic trends because (1) fractal scaling has the potential to lead to false inference about the statistical significance of trends and (2) the abundance of irregularly spaced data in water-quality monitoring networks complicates efforts to quantify fractal scaling. Traditional methods for estimating fractal scaling - in the form of spectral slope (β) or other equivalent scaling parameters (e.g., Hurst exponent) - are generally inapplicable to irregularly sampled data. Here we consider two types of estimation approaches for irregularly sampled data and evaluate their performance using synthetic time series. These time series were generated such that (1) they exhibit a wide range of prescribed fractal scaling behaviors, ranging from white noise (β = 0) to Brown noise (β = 2) and (2) their sampling gap intervals mimic the sampling irregularity (as quantified by both the skewness and mean of gap-interval lengths) in real water-quality data. The results suggest that none of the existing methods fully account for the effects of sampling irregularity on β estimation. First, the results illustrate the danger of using interpolation for gap filling when examining autocorrelation, as the interpolation methods consistently underestimate or overestimate β under a wide range of prescribed β values and gap distributions. Second, the widely used Lomb-Scargle spectral method also consistently underestimates β. A previously published modified form, using only the lowest 5 % of the frequencies for spectral slope estimation, has very poor precision, although the overall bias is small. Third, a recent wavelet-based method, coupled with an aliasing filter, generally has the smallest bias and root-mean-squared error among all methods for a wide range of prescribed β values and gap distributions. The aliasing method, however, does not itself account for sampling irregularity, and this introduces some bias in the result. Nonetheless, the wavelet method is recommended for estimating β in irregular time series until improved methods are developed. Finally, all methods' performances depend strongly on the sampling irregularity, highlighting that the accuracy and precision of each method are data specific. Accurately quantifying the strength of fractal scaling in irregular water-quality time series remains an unresolved challenge for the hydrologic community and for other disciplines that must grapple with irregular sampling.

METHOD FOR JOINING ALUMINUM TO STAINLESS STEEL

DOEpatents

Lemon, L.C.

1960-05-24

Aluminum may be joined to stainless steel without the use of flux by tinning the aluminum with a tin solder containing 1% silver and 1% lead, tinning the stainless steel with a 50% lead 50% tin solder, and then sweating the tinned surfaces together.

Measuring Ionospheric Irregularities Globally by the Rate of TEC Index and GNSS Networks

NASA Technical Reports Server (NTRS)

Pi, Xiaoqing

2012-01-01

Outline of presentation: Why do we use the rate of TEC index (ROTI) instead of the standard s4 and sigma-phi indices? What are the differences between S4, sigma-phi and ROTI? Examples of ROTI measurements and Development status and plan.

Very long transients, irregular firing, and chaotic dynamics in networks of randomly connected inhibitory integrate-and-fire neurons.

PubMed

Zillmer, Rüdiger; Brunel, Nicolas; Hansel, David

2009-03-01

We present results of an extensive numerical study of the dynamics of networks of integrate-and-fire neurons connected randomly through inhibitory interactions. We first consider delayed interactions with infinitely fast rise and decay. Depending on the parameters, the network displays transients which are short or exponentially long in the network size. At the end of these transients, the dynamics settle on a periodic attractor. If the number of connections per neuron is large ( approximately 1000) , this attractor is a cluster state with a short period. In contrast, if the number of connections per neuron is small ( approximately 100) , the attractor has complex dynamics and very long period. During the long transients the neurons fire in a highly irregular manner. They can be viewed as quasistationary states in which, depending on the coupling strength, the pattern of activity is asynchronous or displays population oscillations. In the first case, the average firing rates and the variability of the single-neuron activity are well described by a mean-field theory valid in the thermodynamic limit. Bifurcations of the long transient dynamics from asynchronous to synchronous activity are also well predicted by this theory. The transient dynamics display features reminiscent of stable chaos. In particular, despite being linearly stable, the trajectories of the transient dynamics are destabilized by finite perturbations as small as O(1/N) . We further show that stable chaos is also observed for postsynaptic currents with finite decay time. However, we report in this type of network that chaotic dynamics characterized by positive Lyapunov exponents can also be observed. We show in fact that chaos occurs when the decay time of the synaptic currents is long compared to the synaptic delay, provided that the network is sufficiently large.

Raman Scattering from Tin

DTIC Science & Technology

2015-09-01

ARL-TR-7448 ● SEP 2015 US Army Research Laboratory Raman Scattering from Tin by Patrick A Folkes, Patrick Taylor, Charles Rong...REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Raman Scattering from Tin 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c... tin as an analytical tool for discerning specific allotropic differences in ultra-thin tin films, and discerning differences between the tin and the

Irregular employment amongst migrants in Spanish cities.

PubMed

Sole, C; Ribas, N; Bergalli, V; Parella, S

1998-04-01

This article presents the irregular employment situation of non-European union immigrants in Spanish cities. Foreign labor is remarkable for its heterogeneity in terms of country of origin, demographic characteristics, and the different ways in which immigrants have entered the job market. Legal immigrants tend to concentrate in five different branches of activity, such as domestic service (mostly women), hotel and restaurant industry, agriculture, building and retail trade. Migrants who work in agriculture suffer the worst labor conditions than all other migrants. However, all migrants experience difficulty in obtaining residency and labor permits. Four integration strategies among Moroccan immigrants in Catalonia are discussed and can be viewed as support networks of the immigrants.

Performance effects of irregular communications patterns on massively parallel multiprocessors

NASA Technical Reports Server (NTRS)

Saltz, Joel; Petiton, Serge; Berryman, Harry; Rifkin, Adam

1991-01-01

A detailed study of the performance effects of irregular communications patterns on the CM-2 was conducted. The communications capabilities of the CM-2 were characterized under a variety of controlled conditions. In the process of carrying out the performance evaluation, extensive use was made of a parameterized synthetic mesh. In addition, timings with unstructured meshes generated for aerodynamic codes and a set of sparse matrices with banded patterns on non-zeroes were performed. This benchmarking suite stresses the communications capabilities of the CM-2 in a range of different ways. Benchmark results demonstrate that it is possible to make effective use of much of the massive concurrency available in the communications network.

Analysis of the acoustic spectral signature of prosthetic heart valves in patients experiencing atrial fibrillation

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

Scott, D.D.; Jones, H.E.

1994-05-06

Prosthetic heart valves have increased the life span of many patients with life threatening heart conditions. These valves have proven extremely reliable adding years to what would have been weeks to a patient`s life. Prosthetic valves, like the heart however, can suffer from this constant work load. A small number of valves have experienced structural fractures of the outlet strut due to fatigue. To study this problem a non-intrusive method to classify valves has been developed. By extracting from an acoustic signal the opening sounds which directly contain information from the outlet strut and then developing features which are suppliedmore » to an adaptive classification scheme (neural network) the condition of the valve can be determined. The opening sound extraction process has proved to be a classification problem itself. Due to the uniqueness of each heart and the occasional irregularity of the acoustic pattern it is often questionable as to the integrity of a given signal (beat), especially one occurring during an irregular beat pattern. A common cause of these irregular patterns is a condition known as atrial fibrillation, a prevalent arrhythmia among patients with prosthetic hear valves. Atrial fibrillation is suspected when the ECG shows no obvious P-waves. The atria do not contract and relax correctly to help contribute to ventricular filling during a normal cardiac cycle. Sometimes this leads to irregular patterns in the acoustic data. This study compares normal beat patterns to irregular patterns of the same heart. By analyzing the spectral content of the beats it can be determined whether or not these irregular patterns can contribute to the classification of a heart valve or if they should be avoided. The results have shown that the opening sounds which occur during irregular beat patterns contain the same spectral information as the opening which occur during a normal beat pattern of the same heart and these beats can be used for classification.« less

From time-series to complex networks: Application to the cerebrovascular flow patterns in atrial fibrillation

NASA Astrophysics Data System (ADS)

Scarsoglio, Stefania; Cazzato, Fabio; Ridolfi, Luca

2017-09-01

A network-based approach is presented to investigate the cerebrovascular flow patterns during atrial fibrillation (AF) with respect to normal sinus rhythm (NSR). AF, the most common cardiac arrhythmia with faster and irregular beating, has been recently and independently associated with the increased risk of dementia. However, the underlying hemodynamic mechanisms relating the two pathologies remain mainly undetermined so far; thus, the contribution of modeling and refined statistical tools is valuable. Pressure and flow rate temporal series in NSR and AF are here evaluated along representative cerebral sites (from carotid arteries to capillary brain circulation), exploiting reliable artificially built signals recently obtained from an in silico approach. The complex network analysis evidences, in a synthetic and original way, a dramatic signal variation towards the distal/capillary cerebral regions during AF, which has no counterpart in NSR conditions. At the large artery level, networks obtained from both AF and NSR hemodynamic signals exhibit elongated and chained features, which are typical of pseudo-periodic series. These aspects are almost completely lost towards the microcirculation during AF, where the networks are topologically more circular and present random-like characteristics. As a consequence, all the physiological phenomena at the microcerebral level ruled by periodicity—such as regular perfusion, mean pressure per beat, and average nutrient supply at the cellular level—can be strongly compromised, since the AF hemodynamic signals assume irregular behaviour and random-like features. Through a powerful approach which is complementary to the classical statistical tools, the present findings further strengthen the potential link between AF hemodynamic and cognitive decline.

42 CFR 425.306 - Participation agreement and exclusivity of ACO participant TINs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... participant TINs. 425.306 Section 425.306 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT... participant TINs. (a) For purposes of the Shared Savings Program, each ACO participant TIN is required to commit to a participation agreement with CMS. (b) Each ACO participant TIN upon which beneficiary...

78 FR 16048 - Proposed Collection; Comment Request for e-Services Registration TIN Matching-Application and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-13

...-Services Registration TIN Matching--Application and Screens for TIN Matching Interactive AGENCY: Internal...(c)(2)(A)). Currently, the IRS is soliciting comments concerning e- Services registration TIN matching--application and screens for TIN matching interactive. DATES: Written comments should be received...

42 CFR 425.306 - Participation agreement and exclusivity of ACO participant TINs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... participant TINs. 425.306 Section 425.306 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT... participant TINs. (a) For purposes of the Shared Savings Program, each ACO participant TIN is required to commit to a participation agreement with CMS. (b) Each ACO participant TIN upon which beneficiary...

75 FR 5854 - Proposed Collection; Comment Request for e-Services Registration TIN Matching-Application and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-04

...-Services Registration TIN Matching--Application and Screens for TIN Matching Interactive AGENCY: Internal...(c)(2)(A)). Currently, the IRS is soliciting comments concerning e- Services Registration TIN Matching--Application and Screens for TIN Matching Interactive. DATES: Written comments should be received...

42 CFR 425.306 - Participation agreement and exclusivity of ACO participant TINs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... participant TINs. 425.306 Section 425.306 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT... participant TINs. (a) For purposes of the Shared Savings Program, each ACO participant TIN is required to commit to a participation agreement with CMS. (b) Each ACO participant TIN upon which beneficiary...

Epigenetic lead, zinc, silver, antimony, tin, and gold veins in Boulder Basin, Blaine and Custer counties, Idaho; potential for economic tin mineralization

USGS Publications Warehouse

Ratchford, Michael E.

2002-01-01

Boulder Basin is in a northwest-trending belt of allochthonous Paleozoic rocks in the Boulder Mountains of central Idaho. Regional Tertiary extension resulted in widespread normal faulting and coeval emplacement of shallow-level intrusions and extrusive rocks of the Challis Volcanic Group. Epigenetic lead-zinc-silver-antimony-tin-gold vein deposits formed during Tertiary extension and are hosted within Paleozoic strata. The major orebodies are in the lower plate of the Boulder Basin thrust fault, in massive quartzite of the Middle Pennsylvanian to Lower Permian Wood River Formation. Anomalous concentrations of tin are present in the base-metal mineral assemblage of the Boulder Basin ore deposits. The tin-bearing veins in Boulder Basin are strikingly similar to Bolivian tin deposits. The deposit model for Bolivian tin deposits identifies buried tin porphyry below the tin-bearing vein system.

Interplay of intrinsic and synaptic conductances in the generation of high-frequency oscillations in interneuronal networks with irregular spiking.

PubMed

Baroni, Fabiano; Burkitt, Anthony N; Grayden, David B

2014-05-01

High-frequency oscillations (above 30 Hz) have been observed in sensory and higher-order brain areas, and are believed to constitute a general hallmark of functional neuronal activation. Fast inhibition in interneuronal networks has been suggested as a general mechanism for the generation of high-frequency oscillations. Certain classes of interneurons exhibit subthreshold oscillations, but the effect of this intrinsic neuronal property on the population rhythm is not completely understood. We study the influence of intrinsic damped subthreshold oscillations in the emergence of collective high-frequency oscillations, and elucidate the dynamical mechanisms that underlie this phenomenon. We simulate neuronal networks composed of either Integrate-and-Fire (IF) or Generalized Integrate-and-Fire (GIF) neurons. The IF model displays purely passive subthreshold dynamics, while the GIF model exhibits subthreshold damped oscillations. Individual neurons receive inhibitory synaptic currents mediated by spiking activity in their neighbors as well as noisy synaptic bombardment, and fire irregularly at a lower rate than population frequency. We identify three factors that affect the influence of single-neuron properties on synchronization mediated by inhibition: i) the firing rate response to the noisy background input, ii) the membrane potential distribution, and iii) the shape of Inhibitory Post-Synaptic Potentials (IPSPs). For hyperpolarizing inhibition, the GIF IPSP profile (factor iii)) exhibits post-inhibitory rebound, which induces a coherent spike-mediated depolarization across cells that greatly facilitates synchronous oscillations. This effect dominates the network dynamics, hence GIF networks display stronger oscillations than IF networks. However, the restorative current in the GIF neuron lowers firing rates and narrows the membrane potential distribution (factors i) and ii), respectively), which tend to decrease synchrony. If inhibition is shunting instead of hyperpolarizing, post-inhibitory rebound is not elicited and factors i) and ii) dominate, yielding lower synchrony in GIF networks than in IF networks.

Interplay of Intrinsic and Synaptic Conductances in the Generation of High-Frequency Oscillations in Interneuronal Networks with Irregular Spiking

PubMed Central

Baroni, Fabiano; Burkitt, Anthony N.; Grayden, David B.

2014-01-01

High-frequency oscillations (above 30 Hz) have been observed in sensory and higher-order brain areas, and are believed to constitute a general hallmark of functional neuronal activation. Fast inhibition in interneuronal networks has been suggested as a general mechanism for the generation of high-frequency oscillations. Certain classes of interneurons exhibit subthreshold oscillations, but the effect of this intrinsic neuronal property on the population rhythm is not completely understood. We study the influence of intrinsic damped subthreshold oscillations in the emergence of collective high-frequency oscillations, and elucidate the dynamical mechanisms that underlie this phenomenon. We simulate neuronal networks composed of either Integrate-and-Fire (IF) or Generalized Integrate-and-Fire (GIF) neurons. The IF model displays purely passive subthreshold dynamics, while the GIF model exhibits subthreshold damped oscillations. Individual neurons receive inhibitory synaptic currents mediated by spiking activity in their neighbors as well as noisy synaptic bombardment, and fire irregularly at a lower rate than population frequency. We identify three factors that affect the influence of single-neuron properties on synchronization mediated by inhibition: i) the firing rate response to the noisy background input, ii) the membrane potential distribution, and iii) the shape of Inhibitory Post-Synaptic Potentials (IPSPs). For hyperpolarizing inhibition, the GIF IPSP profile (factor iii)) exhibits post-inhibitory rebound, which induces a coherent spike-mediated depolarization across cells that greatly facilitates synchronous oscillations. This effect dominates the network dynamics, hence GIF networks display stronger oscillations than IF networks. However, the restorative current in the GIF neuron lowers firing rates and narrows the membrane potential distribution (factors i) and ii), respectively), which tend to decrease synchrony. If inhibition is shunting instead of hyperpolarizing, post-inhibitory rebound is not elicited and factors i) and ii) dominate, yielding lower synchrony in GIF networks than in IF networks. PMID:24784237

26 CFR 1.6050S-0 - Table of contents.

Code of Federal Regulations, 2011 CFR

2011-04-01

... penalties for failures to include a correct TIN. (i) In general. (ii) Acting in a responsible manner. (iii) Manner of soliciting TIN. (4) Failure to furnish TIN. (f) Effective date. § 1.6050S-2TElectronic... include a correct TIN. (i) In general. (ii) Acting in a responsible manner. (iii) Manner of soliciting TIN...

26 CFR 1.6050S-0 - Table of contents.

Code of Federal Regulations, 2014 CFR

2014-04-01

... penalties for failures to include a correct TIN. (i) In general. (ii) Acting in a responsible manner. (iii) Manner of soliciting TIN. (4) Failure to furnish TIN. (f) Effective date. § 1.6050S-2TElectronic... include a correct TIN. (i) In general. (ii) Acting in a responsible manner. (iii) Manner of soliciting TIN...

26 CFR 1.6050S-0 - Table of contents.

Code of Federal Regulations, 2013 CFR

2013-04-01

... penalties for failures to include a correct TIN. (i) In general. (ii) Acting in a responsible manner. (iii) Manner of soliciting TIN. (4) Failure to furnish TIN. (f) Effective date. § 1.6050S-2TElectronic... include a correct TIN. (i) In general. (ii) Acting in a responsible manner. (iii) Manner of soliciting TIN...

78 FR 39644 - Information Reporting for Affordable Insurance Exchanges

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-02

... Exchange-- (i) The name, address, and taxpayer identification number (TIN), or date of birth if a TIN is... advance credit payments (taxpayer), and the name and TIN of the individual's spouse, if applicable; (ii) The name, address, and TIN, or date of birth if a TIN is not available, of an adult enrolling in...

26 CFR 1.6050S-0 - Table of contents.

Code of Federal Regulations, 2010 CFR

2010-04-01

... penalties for failures to include a correct TIN. (i) In general. (ii) Acting in a responsible manner. (iii) Manner of soliciting TIN. (4) Failure to furnish TIN. (f) Effective date. § 1.6050S-2TElectronic... include a correct TIN. (i) In general. (ii) Acting in a responsible manner. (iii) Manner of soliciting TIN...

26 CFR 1.6050S-0 - Table of contents.

Code of Federal Regulations, 2012 CFR

2012-04-01

... penalties for failures to include a correct TIN. (i) In general. (ii) Acting in a responsible manner. (iii) Manner of soliciting TIN. (4) Failure to furnish TIN. (f) Effective date. § 1.6050S-2TElectronic... include a correct TIN. (i) In general. (ii) Acting in a responsible manner. (iii) Manner of soliciting TIN...

LISN: A distributed observatory to image and study ionospheric irregularities

NASA Astrophysics Data System (ADS)

Sheehan, R.; Valladares, C. E.

2013-05-01

During nighttime the low-latitude ionosphere commonly develops plasma irregularities and density structures able to disrupt radio wave signals. This interference produces an adverse impact on satellite communication and navigation signals. For example, EM signals originated from satellites can suffer fading as deep as 20 dB even at UHF frequencies. In addition, civil aviation is increasingly dependent upon Global Navigation Satellite Systems and disruption of the navigation capability from ionospheric irregularities poses a clear threat to passengers and crews. To monitor and specify the conditions of the ionosphere over South America, the Low-latitude Ionospheric Sensor Network (LISN) was established as a permanent array of scientific instruments that operate continuously and transmit their observables to a central server in a real-time basis. Presently, the LISN observatory includes 3 different types of instruments: (1) 47 GPS receivers, (2) 5 flux-gate magnetometers and (3) 2 Vertical Incidence Pulsed Ionospheric Radar (VIPIR) ionosondes. In addition to providing a nowcast of the disturbed state of the ionosphere over South America, LISN permits detailed studies of the initiation and development of plasma irregularities. By using data assimilation and tomography techniques, LISN provides continuous estimates of several important geophysical parameters that are indispensable to a program aimed at forecasting the plasma electrodynamics and the formation of density structures in the low-latitude ionosphere.

The dark side of high-frequency oscillations in the developing brain.

PubMed

Le Van Quyen, Michel; Khalilov, Ilgam; Ben-Ari, Yehezkel

2006-07-01

Adult brain networks generate a wide range of oscillations. Some of these are behaviourally relevant, whereas others occur during seizures and other pathological conditions. This raises the question of how physiological oscillations differ from pathogenic ones. In this review, this issue is discussed from a developmental standpoint. Indeed, both epileptic and physiological high-frequency oscillations (HFOs) appear progressively during maturation, and it is therefore possible to determine how this program corresponds to maturation of the neuronal populations that generate these oscillations. We review here important differences in the development of neuronal populations that might contribute to their different oscillatory properties. In particular, at an early stage, the density of glutamatergic synapses is too low for physiological HFOs but an additional drive can be provided by excitatory GABA, triggering epileptic HFOs and the cascades involved in long-lasting epileptogenic transformations. This review is part of the INMED/TINS special issue "Nature and nurture in brain development and neurological disorders", based on presentations at the annual INMED/TINS symposium (http://inmednet.com/).

Human gamma-frequency oscillations associated with attention and memory.

PubMed

Jensen, Ole; Kaiser, Jochen; Lachaux, Jean-Philippe

2007-07-01

Both theoretical and experimental animal work supports the hypothesis that transient oscillatory synchronization of neuronal assemblies at gamma frequencies (30-100 Hz) is closely associated with sensory processing. Recent data from recordings in animals and humans have suggested that gamma-frequency activity also has an important role in attention and both working and long-term memory. The involvement of gamma-band synchronization in various cognitive paradigms in humans is currently being investigated using intracranial and high-density electro- and magnetoencephalography recordings. Here, we discuss recent findings demonstrating human gamma-frequency activity associated with attention and memory in both sensory and non-sensory areas. Because oscillatory gamma-frequency activity has an important role in neuronal communication and synaptic plasticity, it could provide a key for understanding neuronal processing in both local and distributed cortical networks engaged in complex cognitive functions. This review is part of the INMED/TINS special issue Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com).

Facile synthesis of tin dioxide-based high performance anodes for lithium ion batteries assisted by graphene gel

NASA Astrophysics Data System (ADS)

Wan, Yuanxin; Sha, Ye; Luo, Shaochuan; Deng, Weijia; Wang, Xiaoliang; Xue, Gi; Zhou, Dongshan

2015-11-01

Tin dioxide (SnO2) is an attractive material for anodes in energy storage devices, because it has four times the theoretical capacity of the prevalent anode material (graphite). The main obstacle hampers SnO2 from practical application is the pulverization problem caused by drastic volume change (∼300%) during lithium-ion insertion or extraction, which would lead to the loss of electrical conductivity, unstable solid-electrolyte interphase (SEI) formation and consequently severe capacity fading in the cycling. Here, we anchored the SnO2 nanocrystals into three dimensional graphene gel network to tackle this problem. As a result of the three dimensional (3-D) architecture, the huge volume change during cycling was tolerated by the large free space in this 3-D construction, resulting in a high capacity of 1090 mAh g-1 even after 200 cycles. What's more, at a higher current density 5 A g-1, a reversible capacity of about 491 mAh g-1 was achieved with this electrode.

The prognostic value of tumor-infiltrating neutrophils in gastric adenocarcinoma after resection.

PubMed

Zhao, Jing-jing; Pan, Ke; Wang, Wei; Chen, Ju-gao; Wu, Yan-heng; Lv, Lin; Li, Jian-jun; Chen, Yi-bing; Wang, Dan-dan; Pan, Qiu-zhong; Li, Xiao-dong; Xia, Jian-chuan

2012-01-01

Several pieces of evidence indicate that tumor-infiltrating neutrophils (TINs) are correlated to tumor progression. In the current study, we explore the relationship between TINs and clinicopathological features of gastric adenocarcinoma patients. Furthermore, we investigated the prognostic value of TINs. The study was comprised of two groups, training group (115 patients) and test group (97 patients). Biomarkers (intratumoral CD15+ neutrophils) were assessed by immunohistochemistry. The relationship between clinicopathological features and patient outcome were evaluated using Cox regression and Kaplan-Meier analysis. Immunohistochemical detection showed that the tumor-infiltrating neutrophils (TINs) in the training group ranged from 0.00-115.70 cells/high-power microscopic field (HPF) and the median number was 21.60 cells/HPF. Based on the median number, the patients were divided into high and low TINs groups. Chi-square test analysis revealed that the density of CD15+ TINs was positively associated with lymph node metastasis (p = 0.024), distance metastasis (p = 0.004) and UICC (International Union Against Cancer) staging (p = 0.028). Kaplan-Meier analysis showed that patients with a lower density of TINs had a better prognosis than patients with a higher density of TINs (p = 0.002). Multivariate Cox's analysis showed that the density of CD15+ TINs was an independent prognostic factor for overall survival of gastric adenocarcinoma patients. Using another 97 patients as a test group and basing on the median number of TINs (21.60 cells/HPF) coming from the training group, Kaplan-Meier analysis also showed that patients with a lower density of TINs had a better prognosis than patients with a higher density of TINs (p = 0.032). The results verify that the number of CD15+ TINs can predict the survival of gastric adenocarcinoma surgical patients. The presence of CD15+ TINs is an independent and unfavorable factor in the prognosis of gastric adenocarcinoma patients. Targeting CD15+ TINs may be a potential intervenient therapy in the future.

Thin-Film Nanowire Networks for Transparent Conductor Applications: Simulations of Sheet Resistance and Percolation Thresholds

NASA Astrophysics Data System (ADS)

Winey, Karen I.; Mutiso, Rose M.; Sherrott, Michelle C.; Rathmell, Aaron R.; Wiley, Benjamin J.

2013-03-01

Thin-film metal nanowire networks are being pursued as a viable alternative to the expensive and brittle indium tin oxide (ITO) for transparent conductors. For high performance applications, nanowire networks must exhibit high transmittance at low sheet resistance. Previously, we have used complimentary experimental, simulation and theoretical techniques to explore the effects of filler aspect ratio (L/D), orientation, and size-dispersity on the electrical conductivity of three-dimensional rod-networks in bulk polymer nanocomposites. We adapted our 3D simulation approach and analytical percolation model to study the electrical properties of thin-film rod-networks. By fitting our simulation results to experimental results, we determined the average effective contact resistance between silver nanowires. This contact resistance was then used to quantify how the sheet resistance depends on the aspect ratio of the rods and to show that networks made of nanowires with L/D greater than 100 yield sheet resistances lower than the required 100 Ohm/sq. We also report the critical area fraction of rods required to form a percolated network in thin-film networks and provide an analytical expression for the critical area fraction as a function of L/D.

Evaluation of the suitability of tin slag in cementitious materials: Mechanical properties and Leaching behaviour

NASA Astrophysics Data System (ADS)

Rustandi, Andi; Wafa' Nawawi, Fuad; Pratesa, Yudha; Cahyadi, Agung

2018-01-01

Tin slag, a by-product of tin production has been used in cementitious application. The present investigation focuses on the suitability of tin slag as primary component in cement and as component that substitute some amount of Portland Cement. The tin slags studied were taken from Bangka, Indonesia. The main contents of the tin slag are SiO2, Al2O3, and Fe2O3 according to the XRF investigation. The aim of this article was to study the mechanical behaviour (compressive strength), microstructure and leaching behaviour of tin slag blended cement. This study used air-cooled tin slag that had been passed through 400# sieve to replace Portland Cement with ratio 0, 10, 20, 30, 40 by weight. Cement pastes and tin slag blended cement pastes were prepared by using water/cement ratio (W/C) of 0.40 by weight and hydrated for various curing ages of 3, 7, 14 days The microstructure of the raw tin slag was investigated using Scanning Electron Microscope (SEM). The phase composition of each cement paste was investigated using X-ray Diffraction (XRD). The aim of the leachability test was to investigate the environmental impacts of tin slag blended cement product in the range 4-8 pH by using static pH-dependent leaching test. The result show that the increase of the tin slag content decreasing the mortar compressive strength at early ages. The use of tin slag in cement provide economic benefits for all related industries.

Electronic and Optical Properties of Titanium Nitride Bulk and Surfaces from First Principles Calculations (Postprint)

DTIC Science & Technology

2015-11-18

thickness of the film, or substrate. In this work, we report calculations for titanium nitride ( TiN ), a promising material for plasmonic applications...stoichiometric bulk TiN , as well as of the TiN (100), TiN (110), and TiN (111) outermost surfaces. Density functional theory (DFT) and many-body GW methods...and the band structure for bulk TiN were shown to be consistent with previous work. Calculated dielectric functions, plasma frequencies, reflectivity

77 FR 40596 - Applications for New Awards: Disability and Rehabilitation Research Projects and Centers Program...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-10

...) number and a Taxpayer Identification Number (TIN); b. Register both your DUNS number and TIN with the... number and TIN on your application; and d. Maintain an active CCR registration with current information... a TIN from the Internal Revenue Service. If you are an individual, you can obtain a TIN from the...

The Southeast Asian Tin Belt

NASA Astrophysics Data System (ADS)

Schwartz, M. O.; Rajah, S. S.; Askury, A. K.; Putthapiban, P.; Djaswadi, S.

1995-07-01

The Southeast Asian Tin Belt is a north-south elongate zone 2800 km long and 400 km wide, extending from Burma (Myanmar) and Thailand to Peninsular Malaysia and the Indonesian Tin Islands. Altogether 9.6 million tonnes of tin, equivalent to 54% of the world's tin production is derived from this region. Most of the granitoids in the region can be grouped geographically into elongate provinces or belts, based on petrographic and geochronological features. - The Main Range Granitoid Province in western Peninsular Malaysia, southern Peninsular Thailand and central Thailand is almost entirely made up of biotite granite (184-230 Ma). Tin deposits associated with these granites contributed 55% of the historic tin production of Southeast Asia. - The Northern Granitoid Province in northern Thailand (0.1% of tin production) also has dominant biotite granite (200-269 Ma) but it is distinguished by abundant post-intrusion deformation. - The Eastern Granitoid Province extends from eastern Peninsular Malaysia to eastern Thailand. The Malaysian part is subdivided into the East Coast Belt (220-263 Ma), Boundary Range Belt (197-257 Ma) and Central Belt (79-219 Ma). The granitoids cover a wide compositional range from biotite granite to hornblende-biotite granite/granodiorite and diorite-gabbro. Tin deposits are associated with biotite granite in the East Coast Belt (3% of tin production). The granitoids in the other areas of the Eastern Granitoid Province are barren. - The Western Granitoid Province (22-149 Ma) in northern Peninsular Thailand, western Thailand and Burma has biotite granite and hornblende-biotite granite/granodiorite. Tin deposits are associated with biotite granite, which probably is the dominant phase (14% of tin production). The granitoids of the Indonesian Tin Islands (193-251 Ma) do not permit grouping into geographically distinct units. Main Range-type and Eastern Province-type plutons occur next to each other. Most of the tin deposits are associated with Main Range-type plutons (28% of tin production). Tin-mineralized plutons are characterized by high concentrations of SiO 2, K 2O, Rb, Sn, Th and U, whereas the concentrations of Fe 2O 3, MgO, CaO, Na 2O, Ba and Sr as well as the Fe2O3/FeO ratios are low. Tin-mineralized plutons are also distinguished by high initial 87Sr/86Sr ratios low magnetic susceptibilities.

Distributed Memory Compiler Methods for Irregular Problems - Data Copy Reuse and Runtime Partitioning

DTIC Science & Technology

1991-09-01

addition, support for Saltz was provided by NSF from NSF Grant ASC-8819374. i 1, introduction Over the past fewyers, ,we have devoped -methods needed to... network . In Third Conf. on Hypercube Concurrent Computers and Applications, pages 241-27278, 1988. [17] G. Fox, S. Hiranandani, K. Kennedy, C. Koelbel

Mineral resource of the month: tin

USGS Publications Warehouse

Carlin, James F.

2011-01-01

Tin was one of the earliest-known metals. Because of its hardening effect on copper, tin was used in bronze implements as early as 3500 B.C. Bronze, a copper-tin alloy that can be sharpened and is hard enough to retain a cutting edge, was used during the Bronze Age in construction tools as well as weapons for hunting and war. The geographical separation between tin-producing and tin-consuming nations greatly influenced the patterns of early trade routes. Historians think that as early as 1500 B.C., Phoenicians traveled by sea to the Cornwall district of England to obtain tin. The pure metal was not used unalloyed until about 600 B.C.

Tin recycling in the United States in 1998

USGS Publications Warehouse

Carlin, James F.

2001-01-01

This materials flow study includes a description of tin supply and demand factors for the United States to illustrate the extent of tin recycling and to identify recycling trends. Understanding the flow of materials from source to ultimate disposition can assist in improving the management of the use of natural resources in a manner that is compatible with sound environmental practices. The quantity of tin recycled in 1998 as a percentage of apparent tin supply was estimated to be about 22%, and recycling efficiency was estimated to be 75%. Of the total tin consumed in products for the U.S. market in 1998, an estimated 12% was consumed in products where the tin was not recyclable (dissipative uses).

76 FR 28426 - Applications for New Awards; Assistive Technology Act of 1998, as Amended (AT Act)-National...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-17

... (DUNS) number and a Taxpayer Identification Number (TIN); b. Register both your DUNS number and TIN with... DUNS number and TIN on your application; and d. Maintain an active CCR registration with current... obtain a TIN from the Internal Revenue Service. If you are an individual, you can obtain a TIN from the...

31 CFR 351.43 - Are taxpayer identification numbers (TINs) required for the registration of a definitive Series...

Code of Federal Regulations, 2014 CFR

2014-07-01

... (TINs) required for the registration of a definitive Series EE savings bond? 351.43 Section 351.43 Money... Definitive Series EE Savings Bonds § 351.43 Are taxpayer identification numbers (TINs) required for the... must include the TIN of the owner or first-named coowner. The TIN of the second-named coowner or...

78 FR 42937 - Applications for New Awards; National Institute on Disability and Rehabilitation Research...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-18

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77 FR 11190 - Yokohama Tire Company, Denial of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-24

... (TIN)/partial TIN required by paragraph S5.5.1 on one of the tire sidewalls. YTC indicates that the noncompliant tires do however include the full TIN on the intended outboard sidewall. YTC argues that the TIN and the partial TIN are used to properly identify tires that are involved in a safety campaign. YTC...

26 CFR 31.3406(g)-1 - Exception for payments to certain payees and certain other payments.

Code of Federal Regulations, 2013 CFR

2013-04-01

... payee's TIN and the payee's TIN has been validated through the IRS TIN Matching Program; or (B) The QPCA... not constitute notice by the IRS that the payee's TIN is incorrect for purposes of section 3406(a)(1....) At the time of enrollment, Q obtains Merchant X's taxpayer identification number (TIN). Merchant X is...

31 CFR 351.43 - Are taxpayer identification numbers (TINs) required for the registration of a definitive Series...

Code of Federal Regulations, 2011 CFR

2011-07-01

... (TINs) required for the registration of a definitive Series EE savings bond? 351.43 Section 351.43 Money... Definitive Series EE Savings Bonds § 351.43 Are taxpayer identification numbers (TINs) required for the... must include the TIN of the owner or first-named coowner. The TIN of the second-named coowner or...

31 CFR 351.43 - Are taxpayer identification numbers (TINs) required for the registration of a definitive Series...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (TINs) required for the registration of a definitive Series EE savings bond? 351.43 Section 351.43 Money... Definitive Series EE Savings Bonds § 351.43 Are taxpayer identification numbers (TINs) required for the... must include the TIN of the owner or first-named coowner. The TIN of the second-named coowner or...

78 FR 36755 - Applications for New Awards; National Institute on Disability and Rehabilitation Research...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-19

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78 FR 38958 - Applications for New Awards; National Institute on Disability and Rehabilitation Research...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-28

... Number (TIN); b. Register both your DUNS number and TIN with the System for Award Management (SAM... your DUNS number and TIN on your application; and d. Maintain an active SAM registration with current... obtain a TIN from the Internal Revenue Service. If you are an individual, you can obtain a TIN from the...

31 CFR 351.43 - Are taxpayer identification numbers (TINs) required for the registration of a definitive Series...

Code of Federal Regulations, 2012 CFR

2012-07-01

... (TINs) required for the registration of a definitive Series EE savings bond? 351.43 Section 351.43 Money... Definitive Series EE Savings Bonds § 351.43 Are taxpayer identification numbers (TINs) required for the... must include the TIN of the owner or first-named coowner. The TIN of the second-named coowner or...

31 CFR 351.43 - Are taxpayer identification numbers (TINs) required for the registration of a definitive Series...

Code of Federal Regulations, 2013 CFR

2013-07-01

... (TINs) required for the registration of a definitive Series EE savings bond? 351.43 Section 351.43 Money... Definitive Series EE Savings Bonds § 351.43 Are taxpayer identification numbers (TINs) required for the... must include the TIN of the owner or first-named coowner. The TIN of the second-named coowner or...

Reductive spectrophotometry of divalent tin sensitization on soda lime glass

NASA Astrophysics Data System (ADS)

Bejugam, Vinith; Wei, Xingfei; Roper, D. Keith

2016-07-01

Rapid and facile evaluation of tin (II) sensitization could lead to improved understanding of metal deposition in electroless (EL) plating. This report used a balanced redox reaction between 3,3‧,5,5‧-tetramethylbenzidine dihydrochloride (TMB-HCL) and N-bromosuccinimide (NBS) to evaluate effects of sensitization conditions (i.e., sensitization time, analyte concentration, aqueous immersion, and acid content) on the accumulated mass of surface-associated divalent tin ion. The accumulated mass of tin (II) increased as the sensitization time increased up to 30 s in proportion to aqueous tin (II) chloride concentrations between 2.6 and 26 mM at a trifluoroacetic acid (TFA) content of 68 mM. The average mass peaked at 7.3 nanomoles (nmol) per cm2 after a 5 s aqueous immersion post-sensitization, and then decreased with increasing aqueous immersion post-sensitization. The total average tin (II) + tin (IV) accumulated on soda lime glass measured by inductively coupled plasma optical emission spectrometry (ICP-OES) was 17% higher at 30 s sensitization, suggesting a fraction of the tin (II) present may have oxidized to tin (IV). These results indicated that in situ spectrophotometric evaluation of tin (II) could support development of EL plating for electronics, catalysis, and solar cells.

Networks for image acquisition, processing and display

NASA Technical Reports Server (NTRS)

Ahumada, Albert J., Jr.

1990-01-01

The human visual system comprises layers of networks which sample, process, and code images. Understanding these networks is a valuable means of understanding human vision and of designing autonomous vision systems based on network processing. Ames Research Center has an ongoing program to develop computational models of such networks. The models predict human performance in detection of targets and in discrimination of displayed information. In addition, the models are artificial vision systems sharing properties with biological vision that has been tuned by evolution for high performance. Properties include variable density sampling, noise immunity, multi-resolution coding, and fault-tolerance. The research stresses analysis of noise in visual networks, including sampling, photon, and processing unit noises. Specific accomplishments include: models of sampling array growth with variable density and irregularity comparable to that of the retinal cone mosaic; noise models of networks with signal-dependent and independent noise; models of network connection development for preserving spatial registration and interpolation; multi-resolution encoding models based on hexagonal arrays (HOP transform); and mathematical procedures for simplifying analysis of large networks.

Corrosion Behavior of Carbon Steel in Concrete Material Composed of Tin Slag Waste in Aqueous Chloride Solution

NASA Astrophysics Data System (ADS)

Rustandi, Andi; Cahyadi, Agung; Taruli Siallagan, Sonia; Wafa' Nawawi, Fuad; Pratesa, Yudha

2018-01-01

Tin slag is a byproduct of tin ore smelting process which is rarely utilized. The main purpose of this work is to investigate the use of tin slag for concrete cement material application compared to the industrial Ordinary Portland Cement (OPC). Tin slag composition was characterized by XRD and XRF analysis. The characterization results showed the similar chemical composition of tin slag and OPC. It also revealed the semi crystalline structure of tin slag sample. Several electrochemical tests were performed to evaluate corrosion behavior of tin slag, OPC and various mixed composition of both materials and the addition of CaO. The corrosion behavior of OPC and tin slag were evaluated by using Cyclic Polarization, Electrochemical Impedance Spectroscopy (EIS) and Electrochemical Frequency Modulation (EFM) methods. Aqueous sodium chloride (NaCl) solution with 3.5% w.t concentration which similar to seawater was used as the electrolyte in this work. The steel specimen used as the reinforce bar (rebar) material of the concrete was carbon steel AISI 1045. The rebar was embedded in the concrete cement which composed of OPC and the various composition of tin slag including slag without addition of CaO and slag mixed with addition of 50 % CaO. The electrochemical tests results revealed that tin slag affected its corrosion behavior which becoming more active and increasing the corrosion rate as well as decreasing the electrochemical impedance.

Using GPS TEC measurements to probe ionospheric spatial spectra at mid-latitudes

NASA Astrophysics Data System (ADS)

Lay, E. H.; Parker, P. A.; Light, M. E.; Carrano, C. S.; Debchoudhury, S.; Haaser, R. A.

2017-12-01

The physics of how random ionospheric structure causes signal degradation is well understood as weak forward scattering through an effective diffraction grating created by plasma irregularities in the ionosphere. However, the spatial scale spectrum of those irregularities required for input into scintillation models and models of traveling ionospheric disturbances is poorly characterized, particularly at the kilometer to tens of kilometer scale lengths important for very-high-frequency (VHF) scintillation prediction. Furthermore, the majority of characterization studies have been performed in low-latitude or high-latitude regions where geomagnetic activity dominates the physical processes. At mid-latitudes, tropospheric and geomagnetic phenomena compete in disturbing the ionosphere, and it is not well understood how these multiple sources affect the drivers that influence the spatial spectrum. In this study, we are interested in mid-latitude electron density irregularities on the order of 10s of kilometers that would affect VHF signals. Data from the GPS networks Japan GEONET and the Plate Boundary Observatory (PBO, UNAVCO) in the western United States were analyzed for this study. Japan GEONET is a dense network of GPS receivers (station spacing of tens of km), with fairly evenly spaced positions over all of Japan. The PBO, on the other hand, has several pockets of extremely dense coverage (station spacing within a few km), but is less dense on average. We analyze a day with a large solar storm (2015/03/17, St. Patrick's Day Storm) to allow high scintillation potential at mid-latitudes, a day with low geomagnetic activity and low thunderstorm activity (2016/01/31), and a day with low geomagnetic activity and high thunderstorm activity (2015/08/02). We then perform two-dimensional spatial analyses on the TEC data from these two networks on scale lengths of 20 to 200 km to infer the spatial scale spectra.

Low temperature processed complementary metal oxide semiconductor (CMOS) device by oxidation effect from capping layer.

PubMed

Wang, Zhenwei; Al-Jawhari, Hala A; Nayak, Pradipta K; Caraveo-Frescas, J A; Wei, Nini; Hedhili, M N; Alshareef, H N

2015-04-20

In this report, both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer. The tuning of charge carrier polarity in the tin oxide channel is achieved by selectively depositing a copper oxide capping layer on top of tin oxide, which serves as an oxygen source, providing additional oxygen to form an n-type tin dioxide phase. The oxidation process can be realized by annealing at temperature as low as 190 °C in air, which is significantly lower than the temperature generally required to form tin dioxide. Based on this approach, CMOS inverters based entirely on tin oxide TFTs were fabricated. Our method provides a solution to lower the process temperature for tin dioxide phase, which facilitates the application of this transparent oxide semiconductor in emerging electronic devices field.

Corrosion resistance and mechanical properties of titanium nitride plating on orthodontic wires.

PubMed

Sugisawa, Haruki; Kitaura, Hideki; Ueda, Kyosuke; Kimura, Keisuke; Ishida, Masahiko; Ochi, Yumiko; Kishikawa, Akiko; Ogawa, Saika; Takano-Yamamoto, Teruko

2018-03-30

Titanium nitride (TiN) coating by ion plating has properties such as high hardness, wear resistance, corrosion resistance, and surface lubricity, therefore TiN coating is often used in various dental appliances and materials. In this study, we evaluated the corrosion behaviors and mechanical properties of TiN coated stainless steel (SS) and nickel titanium (Ni-Ti) orthodontic wires prepared by ion plating. TiN coating by ion plating improves the corrosion resistance of orthodontic wires. The corrosion pitting of the TiN coated wire surface become small. The tensile strength and stiffness of SS wire were increased after TiN coating. In contrast, its elastic force, which is a property for Ni-Ti wire, was decreased. In addition, TiN coating provided small friction forces. The low level of friction may increase tooth movement efficiently. Therefore, TiN coated SS wire could be useful for orthodontics treatment.

Low Temperature Processed Complementary Metal Oxide Semiconductor (CMOS) Device by Oxidation Effect from Capping Layer

PubMed Central

Wang, Zhenwei; Al-Jawhari, Hala A.; Nayak, Pradipta K.; Caraveo-Frescas, J. A.; Wei, Nini; Hedhili, M. N.; Alshareef, H. N.

2015-01-01

In this report, both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer. The tuning of charge carrier polarity in the tin oxide channel is achieved by selectively depositing a copper oxide capping layer on top of tin oxide, which serves as an oxygen source, providing additional oxygen to form an n-type tin dioxide phase. The oxidation process can be realized by annealing at temperature as low as 190°C in air, which is significantly lower than the temperature generally required to form tin dioxide. Based on this approach, CMOS inverters based entirely on tin oxide TFTs were fabricated. Our method provides a solution to lower the process temperature for tin dioxide phase, which facilitates the application of this transparent oxide semiconductor in emerging electronic devices field. PMID:25892711

The Prognostic Value of Tumor-Infiltrating Neutrophils in Gastric Adenocarcinoma after Resection

PubMed Central

Wang, Wei; Chen, Ju-gao; Wu, Yan-heng; Lv, Lin; Li, Jian-jun; Chen, Yi-bing; Wang, Dan-dan; Pan, Qiu-zhong; Li, Xiao-dong; Xia, Jian-chuan

2012-01-01

Background Several pieces of evidence indicate that tumor-infiltrating neutrophils (TINs) are correlated to tumor progression. In the current study, we explore the relationship between TINs and clinicopathological features of gastric adenocarcinoma patients. Furthermore, we investigated the prognostic value of TINs. Patients and Methods The study was comprised of two groups, training group (115 patients) and test group (97 patients). Biomarkers (intratumoral CD15+ neutrophils) were assessed by immunohistochemistry. The relationship between clinicopathological features and patient outcome were evaluated using Cox regression and Kaplan-Meier analysis. Results Immunohistochemical detection showed that the tumor-infiltrating neutrophils (TINs) in the training group ranged from 0.00–115.70 cells/high-power microscopic field (HPF) and the median number was 21.60 cells/HPF. Based on the median number, the patients were divided into high and low TINs groups. Chi-square test analysis revealed that the density of CD15+ TINs was positively associated with lymph node metastasis (p = 0.024), distance metastasis (p = 0.004) and UICC (International Union Against Cancer) staging (p = 0.028). Kaplan-Meier analysis showed that patients with a lower density of TINs had a better prognosis than patients with a higher density of TINs (p = 0.002). Multivariate Cox's analysis showed that the density of CD15+ TINs was an independent prognostic factor for overall survival of gastric adenocarcinoma patients. Using another 97 patients as a test group and basing on the median number of TINs (21.60 cells/HPF) coming from the training group, Kaplan-Meier analysis also showed that patients with a lower density of TINs had a better prognosis than patients with a higher density of TINs (p = 0.032). The results verify that the number of CD15+ TINs can predict the survival of gastric adenocarcinoma surgical patients. Conclusions The presence of CD15+ TINs is an independent and unfavorable factor in the prognosis of gastric adenocarcinoma patients. Targeting CD15+ TINs may be a potential intervenient therapy in the future. PMID:22442706

Canopy architectural and physiological characterization of near-isogenic wheat lines differing in the tiller inhibition gene tin.

PubMed

Moeller, Carina; Evers, Jochem B; Rebetzke, Greg

2014-01-01

Tillering is a core constituent of plant architecture, and influences light interception to affect plant and crop performance. Near-isogenic lines (NILs) varying for a tiller inhibition (tin) gene and representing two genetic backgrounds were investigated for tillering dynamics, organ size distribution, leaf area, light interception, red: far-red ratio, and chlorophyll content. Tillering ceased earlier in the tin lines to reduce the frequencies of later primary and secondary tillers compared to the free-tillering NILs, and demonstrated the genetically lower tillering plasticity of tin-containing lines. The distribution of organ sizes along shoots varied between NILs contrasting for tin. Internode elongation commenced at a lower phytomer, and the peduncle was shorter in the tin lines. The flag leaves of tin lines were larger, and the longest leaf blades were observed at higher phytomers in the tin than in free-tillering lines. Total leaf area was reduced in tin lines, and non-tin lines invested more leaf area at mid-canopy height. The tiller economy (ratio of seed-bearing shoots to numbers of shoots produced) was 10% greater in the tin lines (0.73-0.76) compared to the free-tillering sisters (0.62-0.63). At maximum tiller number, the red: far-red ratio (light quality stimulus that is thought to induce the cessation of tillering) at the plant-base was 0.18-0.22 in tin lines and 0.09-0.11 in free-tillering lines at levels of photosynthetic active radiation of 49-53% and 30-33%, respectively. The tin lines intercepted less radiation compared to their free-tillering sisters once genotypic differences in tiller numbers had established, and maintained green leaf area in the lower canopy later into the season. Greater light extinction coefficients (k) in tin lines prior to, but reduced k after, spike emergence indicated that differences in light interception between NILs contrasting in tin cannot be explained by leaf area alone but that geometric and optical canopy properties contributed. The careful characterization of specifically-developed NILs is refining the development of a physiology-based model for tillering to improve understanding of the value of architectural traits for use in cereal improvement.

Tumor-infiltrating neutrophils predict benefit from adjuvant chemotherapy in patients with muscle invasive bladder cancer.

PubMed

Zhou, Lin; Xu, Le; Chen, Lingli; Fu, Qiang; Liu, Zheng; Chang, Yuan; Lin, Zongming; Xu, Jiejie

2017-01-01

Growing evidence shows tumor-infiltrating neutrophils (TINs) involvement in tumorigenesis. The objective of this study is to assess the prognostic effect of TINs and its impact on adjuvant chemotherapy benefits in muscle invasive bladder cancer (MIBC). A total of 142 MIBC patients from Zhongshan Hospital, 119 MIBC patients from FUSCC, and 405 MIBC patients from TCGA cohort were enrolled in the study. TINs were evaluated by immunohistochemical staining of CD66b or the CIBERSORT method. Patients with high TINs had a significantly poorer overall survival ( p = 0.001, p < 0.001, and p = 0.002, respectively) in the three sets. In the multivariate analysis, the presence of high TINs (HR = 2.122, p = 0.007; HR = 3.807, p < 0.001; HR = 2.104, p = 0.001; respectively) was identified as an independent prognostic factor for overall survival in the three sets. More importantly, Low TINs patients had significantly longer overall survival in patients without ACT in the three sets. Gene set enrichment analysis showed that lymphocyte activation ( p < 0.001) and T cell activation ( p = 0.008) were significantly enriched in the low TINs group. In addition, TINs were negatively correlated with CD8 + T cells, suggesting that the status of high-TINs was linked to the status of immunosuppression in MIBC. TINs could be used as independent prognostic factor. Low TINs identified a subgroup of MIBC patients who appeared to benefit from adjuvant chemotherapy. Incorporation of TINs into TNM system could further stratify patients with different prognosis.

Tumor-infiltrating neutrophils predict benefit from adjuvant chemotherapy in patients with muscle invasive bladder cancer

PubMed Central

Zhou, Lin; Xu, Le; Chen, Lingli; Fu, Qiang; Liu, Zheng; Chang, Yuan; Lin, Zongming; Xu, Jiejie

2017-01-01

ABSTRACT Growing evidence shows tumor-infiltrating neutrophils (TINs) involvement in tumorigenesis. The objective of this study is to assess the prognostic effect of TINs and its impact on adjuvant chemotherapy benefits in muscle invasive bladder cancer (MIBC). A total of 142 MIBC patients from Zhongshan Hospital, 119 MIBC patients from FUSCC, and 405 MIBC patients from TCGA cohort were enrolled in the study. TINs were evaluated by immunohistochemical staining of CD66b or the CIBERSORT method. Patients with high TINs had a significantly poorer overall survival (p = 0.001, p < 0.001, and p = 0.002, respectively) in the three sets. In the multivariate analysis, the presence of high TINs (HR = 2.122, p = 0.007; HR = 3.807, p < 0.001; HR = 2.104, p = 0.001; respectively) was identified as an independent prognostic factor for overall survival in the three sets. More importantly, Low TINs patients had significantly longer overall survival in patients without ACT in the three sets. Gene set enrichment analysis showed that lymphocyte activation (p < 0.001) and T cell activation (p = 0.008) were significantly enriched in the low TINs group. In addition, TINs were negatively correlated with CD8+ T cells, suggesting that the status of high-TINs was linked to the status of immunosuppression in MIBC. TINs could be used as independent prognostic factor. Low TINs identified a subgroup of MIBC patients who appeared to benefit from adjuvant chemotherapy. Incorporation of TINs into TNM system could further stratify patients with different prognosis. PMID:28507798

A comparative study of fine polished stainless steel, TiN and TiN/Ag surfaces: adhesion and attachment strength of Listeria monocytogenes as well as anti-listerial effect.

PubMed

Skovager, Anne; Whitehead, Kathryn; Wickens, David; Verran, Joanna; Ingmer, Hanne; Arneborg, Nils

2013-09-01

Magnetron sputtering was used to produce nanocomposite TiN and TiN/Ag coatings on stainless steel surfaces. The surface chemistry (EDX), physicochemical properties (contact angles), topography and roughness parameters (WLP and AFM) of the fine polished stainless steel (FPSS), TiN and TiN/8.6 at.% Ag surfaces were examined. Real-time initial adhesion of two Listeria monocytogenes strains (EGDe and 64) to the three surfaces was determined under flow conditions, and their attachment strength after adhesion was measured using atomic force microscopy (AFM). The anti-listerial properties of the surfaces were determined using LIVE/DEAD staining. Our results demonstrate that FPSS, TiN and TiN/8.6 at.% Ag possessed different surface properties, which may influence both attachment strength and anti-listerial properties. There were no significant (p>0.05) differences in the initial adhesion of the two L. monocytogenes strains to the three different surfaces. Attachment studies showed that the two L. monocytogenes strains did not attach to FPSS under wetted conditions. However, both strains attached to TiN and TiN/8.6 at.% Ag surfaces, although with less strength to TiN/8.6 at.% Ag than to TiN surfaces. The TiN/8.6 at.% Ag surface showed marked anti-listerial properties as compared with FPSS and TiN. Initial adhesion, attachment strength and anti-listerial properties were found to be strain dependent. Copyright © 2013 Elsevier B.V. All rights reserved.

Electrophysiological evidence of sublexical phonological access in character processing by L2 Chinese learners of L1 alphabetic scripts.

PubMed

Yum, Yen Na; Law, Sam-Po; Mo, Kwan Nok; Lau, Dustin; Su, I-Fan; Shum, Mark S K

2016-04-01

While Chinese character reading relies more on addressed phonology relative to alphabetic scripts, skilled Chinese readers also access sublexical phonological units during recognition of phonograms. However, sublexical orthography-to-phonology mapping has not been found among beginning second language (L2) Chinese learners. This study investigated character reading in more advanced Chinese learners whose native writing system is alphabetic. Phonological regularity and consistency were examined in behavioral responses and event-related potentials (ERPs) in lexical decision and delayed naming tasks. Participants were 18 native English speakers who acquired written Chinese after age 5 years and reached grade 4 Chinese reading level. Behaviorally, regular characters were named more accurately than irregular characters, but consistency had no effect. Similar to native Chinese readers, regularity effects emerged early with regular characters eliciting a greater N170 than irregular characters. Regular characters also elicited greater frontal P200 and smaller N400 than irregular characters in phonograms of low consistency. Additionally, regular-consistent characters and irregular-inconsistent characters had more negative amplitudes than irregular-consistent characters in the N400 and LPC time windows. The overall pattern of brain activities revealed distinct regularity and consistency effects in both tasks. Although orthographic neighbors are activated in character processing of L2 Chinese readers, the timing of their impact seems delayed compared with native Chinese readers. The time courses of regularity and consistency effects across ERP components suggest both assimilation and accommodation of the reading network in learning to read a typologically distinct second orthographic system.

Geomorphic Mapping and Paleoterrain Generation for use in Modeling Holocene (8,000 1,500 yr) Agropastoral Landuse and Landscape Interactions in Southeast Spain

NASA Astrophysics Data System (ADS)

Arrowsmith, J. R.; Dimaggio, E. N.; Barton, C. M.; Sarjoughian, H. S.; Fall, P.; Falconer, S. E.; Ullah, I. I.

2006-12-01

Dramatic changes in land use were associated with the rise of agriculture in the mid Holocene. Both the surface properties and the drainage networks were changed. Along with the direct modifications to surface properties (vegetation change, sediment liberation, and compaction) and drainage network alteration (terracing, canals), up and downstream responses in the watersheds communicated these changes throughout the landscape. The magnitude, rate, and feedbacks with the growing human populations are critical questions in our effort to assess human-landscape interactions. Our interdisciplinary team has focused on two field sites around the Mediterranean for model development and testing. We are combining high resolution process- based models of landscape change implemented within the GRASS GIS with agent based models of agropastoral behavior and driven by high resolution climate and vegetation models. In the Spanish field area (Penaguila Valley, 38.41 N 0.23 W), we have produced detailed (1:10,000) geomorphic maps which we combine with high resolution Digital Elevation Models (DEMs) on which we can run the surface process models to assess the portions of the landscape that are most sensitive to the postulated agropastoral landuse changes. To support this modeling we have produced the 1 m DEMs from softcopy photogrammetry. This DEM has greatly improved our overall spatial resolution to permit more accurate terrace correlations and improved quantitative assessment of morphologic processes (e.g. channel erosion, slope stability). In stereo, we have mapped overall landscape morphology that emphasizes areas of active erosion and alluvial terrace surfaces. Alluvial terraces are crucial to this research because they record periods of past stable topography and those of mid Holocene age were settled and farmed. We have correlated mapped terraces across the landscape using elevation and morphological distinctions. Using ArcGIS, we interpolated surfaces across equivalent terraces using triangulated irregular networks (TINs) allowing reconstruction of multiple regional landscapes to establish a chronosequence of absolute landscape change. This mapping and reconstruction will be field checked and numerical age constraints applied. Interestingly, our tentative age assessment of the lowest broad surface indicates that it was occupied about 5 ka, and now has been incised by 20 m. Archeological sites have been cut by the incision. This change from a broad low relief alluvial surface to one cut by narrow channels may have been an important change for the local populations and caused them to change their behaviors, even though it may have been initially triggered by distributed landscape change in the watershed, due to agropastoral activities.

Co-Percolating Graphene-Wrapped Silver Nanowire Network for High Performance, Highly Stable, Transparent Conducting Electrodes

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

Chen, Ruiyi; Das, Suprem R; Jeong, Changwook

Transparent conducting electrodes (TCEs) require high transparency and low sheet resistance for applications in photovoltaics, photodetectors, flat panel displays, touch screen devices, and imagers. Indium tin oxide (ITO), or other transparent conductive oxides, have been used, and provide a baseline sheet resistance (RS) vs. transparency (T) relationship. Several alternative material systems have been investigated. The development of high-performance hybrid structures provides a route towards robust, scalable and low-cost approaches for realizing high-performance TCE.

Crystal structure of tin(IV) chloride octa­hydrate

PubMed Central

Hennings, Erik; Schmidt, Horst; Voigt, Wolfgang

2014-01-01

The title compound, [SnCl4(H2O)2]·6H2O, was crystallized according to the solid–liquid phase diagram at lower temperatures. It is built-up of SnCl4(H2O)2 octa­hedral units (point group symmetry 2) and lattice water mol­ecules. An intricate three-dimensional network of O—H⋯O and O—H⋯Cl hydrogen bonds between the complex molecules and the lattice water molecules is formed in the crystal structure. PMID:25552971

Tin recovery from tin slag using electrolysis method

NASA Astrophysics Data System (ADS)

Jumari, Arif; Purwanto, Agus; Nur, Adrian; Budiman, Annata Wahyu; Lerian, Metty; Paramita, Fransisca A.

2018-02-01

The process in industry, including in mining industry, would surely give negative effect such as waste polluting to the environment. Some of waste could be potentially reutilized to be a commodity with the higher economic value. Tin slag is one of them. The aim of this research was to recover the tin contained in tin slag. Before coming to the electrolysis, tin slag must be treated by dissolution. The grinded tin slag was dissolved into HCl solution to form a slurry. During dissolution, the slurry was agitated and heated, and finally filtered. The filtrate obtained was then electrolyzed. During the process of electrolysis, solid material precipitated on the used cathode. The precipitated solid was then separated and dried. The solid was then analyzed using XRD, XRF and SEM. The XRD analysis showed that the longest time of dissolution and electrolysis the highest the purity obtained in the product. The SEM analysis showed that the longest time of electrolysis the smallest tin particle obtained. Optimum time achieved in this research was 2 hours for the recovering time and 3 hours for the electrolysis time, with 9% tin recovered.

Transcription instability in high-risk neuroblastoma is associated with a global perturbation of chromatin domains.

PubMed

Zanon, Carlo; Tonini, Gian Paolo

2017-11-01

Chromosome instability has a pivotal role among the hallmarks of cancer, but its transcriptional counterpart is rarely considered a relevant factor in cell destabilization. To examine transcription instability (TIN), we first devised a metric we named TIN index and used it to evaluate TIN on a dataset containing more than 500 neuroblastoma samples. We found that metastatic tumors from high-risk (HR) patients are characterized by significantly different TIN index values compared to low/intermediate-risk patients. Our results indicate that the TIN index is a good predictor of neuroblastoma patient's outcome, and a related TIN index gene signature (TIN-signature) is also able to predict the neuroblastoma patient's outcome with high confidence. Interestingly, we find that TIN-signature genes have a strong positional association with superenhancers in neuroblastoma tumors. Finally, we show that TIN is linked to chromatin structural domains and interferes with their integrity in HR neuroblastoma patients. This novel approach to gene expression analysis broadens the perspective of genome instability investigations to include functional aspects. © 2017 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.

Dynamic model of time-dependent complex networks.

PubMed

Hill, Scott A; Braha, Dan

2010-10-01

The characterization of the "most connected" nodes in static or slowly evolving complex networks has helped in understanding and predicting the behavior of social, biological, and technological networked systems, including their robustness against failures, vulnerability to deliberate attacks, and diffusion properties. However, recent empirical research of large dynamic networks (characterized by irregular connections that evolve rapidly) has demonstrated that there is little continuity in degree centrality of nodes over time, even when their degree distributions follow a power law. This unexpected dynamic centrality suggests that the connections in these systems are not driven by preferential attachment or other known mechanisms. We present an approach to explain real-world dynamic networks and qualitatively reproduce these dynamic centrality phenomena. This approach is based on a dynamic preferential attachment mechanism, which exhibits a sharp transition from a base pure random walk scheme.

Mineral of the month: tin

USGS Publications Warehouse

Carlin, James F.

2005-01-01

Tin was one of the first metals discovered by humans and, like most metals, tin is rarely used by itself. Most tin is used as a protective coating or as an alloy with other metals in a diverse range of commercial and defense applications.

Tin whiskers in electronic circuits

NASA Astrophysics Data System (ADS)

Stupian, Gary W.

1992-12-01

Fibrous, conducting 'whiskers' often grow on pure tin plating. These tin whiskers have, for many years, been known to pose a reliability problem in electronic circuitry; therefore, the use of pure tin coatings in any critical electronic application is not recommended. Despite the warnings of the experts, tin plating is still found on electronic and mechanical components and problems with whiskers still arise. This document summarizes what is known about the growth of tin whiskers. A number of factors (e.g., coating thickness, plating conditions) are thought to be important in determining whether whiskers will grow. Although tin whiskers have been investigated from some decades, there is still disagreement on the effects of virtually every coating parameter. There is no disagreement, however, on the essential fact that it is very difficult to predict with certainty whether whiskers will grow on any specific tin-plated component, which of course is the basis of the 'experts' advice not to use pure tin plating. If tin-plated components are found in an electronic system, replacement is the safest policy. Some additional recommendations to minimize risk are presented here that may be of use in situations in which replacement of all suspect components is not the option of choice because of cost or schedule constraints.

Environmental obesogen tributyltin chloride leads to abnormal hypothalamic-pituitary-gonadal axis function by disruption in kisspeptin/leptin signaling in female rats.

PubMed

Sena, Gabriela C; Freitas-Lima, Leandro C; Merlo, Eduardo; Podratz, Priscila L; de Araújo, Julia F P; Brandão, Poliane A A; Carneiro, Maria T W D; Zicker, Marina C; Ferreira, Adaliene V M; Takiya, Christina M; de Lemos Barbosa, Carolina M; Morales, Marcelo M; Santos-Silva, Ana Paula; Miranda-Alves, Leandro; Silva, Ian V; Graceli, Jones B

2017-03-15

Tributyltin chloride (TBT) is a xenobiotic used as a biocide in antifouling paints that has been demonstrated to induce endocrine-disrupting effects, such as obesity and reproductive abnormalities. An integrative metabolic control in the hypothalamus-pituitary-gonadal (HPG) axis was exerted by leptin. However, studies that have investigated the obesogenic TBT effects on the HPG axis are especially rare. We investigated whether metabolic disorders as a result of TBT are correlated with abnormal hypothalamus-pituitary-gonadal (HPG) axis function, as well as kisspeptin (Kiss) action. Female Wistar rats were administered vehicle and TBT (100ng/kg/day) for 15days via gavage. We analyzed their effects on the tin serum and ovary accumulation (as biomarker of TBT exposure), estrous cyclicity, surge LH levels, GnRH expression, Kiss action, fertility, testosterone levels, ovarian apoptosis, uterine inflammation, fibrosis, estrogen negative feedback, body weight gain, insulin, leptin, adiponectin levels, as well as the glucose tolerance (GTT) and insulin sensitivity tests (IST). TBT led to increased serum and ovary tin levels, irregular estrous cyclicity, and decreased surge LH levels, GnRH expression and Kiss responsiveness. A strong negative correlation between the serum and ovary tin levels with lower Kiss responsiveness and GnRH mRNA expression was observed in TBT rats. An increase in the testosterone levels, ovarian and uterine fibrosis, ovarian apoptosis, and uterine inflammation and a decrease in fertility and estrogen negative feedback were demonstrated in the TBT rats. We also identified an increase in the body weight gain and abnormal GTT and IST tests, which were associated with hyperinsulinemia, hyperleptinemia and hypoadiponectinemia, in the TBT rats. TBT disrupted proper functioning of the HPG axis as a result of abnormal Kiss action. The metabolic dysfunctions co-occur with the HPG axis abnormalities. Hyperleptinemia as a result of obesity induced by TBT may be associated with abnormal HPG function. A strong negative correlation between the hyperleptinemia and lower Kiss responsiveness was observed in the TBT rats. These findings provide evidence that TBT leads to toxic effects direct on the HPG axis and/or indirectly by abnormal metabolic regulation of the HPG axis. Copyright © 2017 Elsevier Inc. All rights reserved.

A neural-network-based model for the dynamic simulation of the tire/suspension system while traversing road irregularities.

PubMed

Guarneri, Paolo; Rocca, Gianpiero; Gobbi, Massimiliano

2008-09-01

This paper deals with the simulation of the tire/suspension dynamics by using recurrent neural networks (RNNs). RNNs are derived from the multilayer feedforward neural networks, by adding feedback connections between output and input layers. The optimal network architecture derives from a parametric analysis based on the optimal tradeoff between network accuracy and size. The neural network can be trained with experimental data obtained in the laboratory from simulated road profiles (cleats). The results obtained from the neural network demonstrate good agreement with the experimental results over a wide range of operation conditions. The NN model can be effectively applied as a part of vehicle system model to accurately predict elastic bushings and tire dynamics behavior. Although the neural network model, as a black-box model, does not provide a good insight of the physical behavior of the tire/suspension system, it is a useful tool for assessing vehicle ride and noise, vibration, harshness (NVH) performance due to its good computational efficiency and accuracy.

Hierarchical image feature extraction by an irregular pyramid of polygonal partitions

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

Skurikhin, Alexei N

2008-01-01

We present an algorithmic framework for hierarchical image segmentation and feature extraction. We build a successive fine-to-coarse hierarchy of irregular polygonal partitions of the original image. This multiscale hierarchy forms the basis for object-oriented image analysis. The framework incorporates the Gestalt principles of visual perception, such as proximity and closure, and exploits spectral and textural similarities of polygonal partitions, while iteratively grouping them until dissimilarity criteria are exceeded. Seed polygons are built upon a triangular mesh composed of irregular sized triangles, whose spatial arrangement is adapted to the image content. This is achieved by building the triangular mesh on themore » top of detected spectral discontinuities (such as edges), which form a network of constraints for the Delaunay triangulation. The image is then represented as a spatial network in the form of a graph with vertices corresponding to the polygonal partitions and edges reflecting their relations. The iterative agglomeration of partitions into object-oriented segments is formulated as Minimum Spanning Tree (MST) construction. An important characteristic of the approach is that the agglomeration of polygonal partitions is constrained by the detected edges; thus the shapes of agglomerated partitions are more likely to correspond to the outlines of real-world objects. The constructed partitions and their spatial relations are characterized using spectral, textural and structural features based on proximity graphs. The framework allows searching for object-oriented features of interest across multiple levels of details of the built hierarchy and can be generalized to the multi-criteria MST to account for multiple criteria important for an application.« less

irGPU.proton.Net: Irregular strong charge interaction networks of protonatable groups in protein molecules--a GPU solver using the fast multipole method and statistical thermodynamics.

PubMed

Kantardjiev, Alexander A

2015-04-05

A cluster of strongly interacting ionization groups in protein molecules with irregular ionization behavior is suggestive for specific structure-function relationship. However, their computational treatment is unconventional (e.g., lack of convergence in naive self-consistent iterative algorithm). The stringent evaluation requires evaluation of Boltzmann averaged statistical mechanics sums and electrostatic energy estimation for each microstate. irGPU: Irregular strong interactions in proteins--a GPU solver is novel solution to a versatile problem in protein biophysics--atypical protonation behavior of coupled groups. The computational severity of the problem is alleviated by parallelization (via GPU kernels) which is applied for the electrostatic interaction evaluation (including explicit electrostatics via the fast multipole method) as well as statistical mechanics sums (partition function) estimation. Special attention is given to the ease of the service and encapsulation of theoretical details without sacrificing rigor of computational procedures. irGPU is not just a solution-in-principle but a promising practical application with potential to entice community into deeper understanding of principles governing biomolecule mechanisms. © 2015 Wiley Periodicals, Inc.

A survey of plasma irregularities as seen by the midlatitude Blackstone SuperDARN radar

NASA Astrophysics Data System (ADS)

Ribeiro, A. J.; Ruohoniemi, J. M.; Baker, J. B. H.; Clausen, L. B. N.; Greenwald, R. A.; Lester, M.

2012-02-01

The Super Dual Auroral Radar Network (SuperDARN) is a chain of HF radars that monitor plasma dynamics in the ionosphere. In recent years, SuperDARN has expanded to midlatitudes in order to provide enhanced coverage during geomagnetically active periods. A new type of backscatter from F region plasma irregularities with low Doppler velocity has been frequently observed on the nightside during quiescent conditions. Using three years of data from the Blackstone, VA radar, we have implemented a method for extracting this new type of backscatter from routine observations. We have statistically characterized the occurrence properties of the Sub Auroral Ionospheric Scatter (SAIS) events, including the latitudinal relationships to the equatorward edge of the auroral oval and the ionospheric projection of the plasmapause. We find that the backscatter is confined to local night, occurs on ≈70% of nights, is fixed in geomagnetic latitude, and is equatorward of both the auroral region and the plasmapause boundary. We conclude that SAIS irregularities are observed within a range of latitudes that is conjugate to the inner magnetosphere (plasmasphere).

Friction and wear of tin and tin alloys from minus 100 C to 150 C

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1975-01-01

Sliding friction experiments were conducted with an iron (110) single-crystal pin sliding on single and polycrystalline tin and tin alloys. Specimens were examined at various ambient temperatures from -100 to 150 C. Applied loads varied from 1 to 50 grams, and sliding velocity was constant at 0.7 mm/min. Results indicate that the crystal transformation of tin influences the friction coefficient. Friction was higher for the diamond structure (gray tin) than it was for the body-centered tetragonal structure (white tin). Bismuth arrested the crystal transformation, which resulted in constant friction over the temperature range -100 to 150 C. Both copper and aluminum enhanced the kinetics of transformation, with aluminum producing a nearly twofold change in friction with the crystal transformation.

Nano-soldering of magnetically aligned three-dimensional nanowire networks.

PubMed

Gao, Fan; Gu, Zhiyong

2010-03-19

It is extremely challenging to fabricate 3D integrated nanostructures and hybrid nanoelectronic devices. In this paper, we report a simple and efficient method to simultaneously assemble and solder nanowires into ordered 3D and electrically conductive nanowire networks. Nano-solders such as tin were fabricated onto both ends of multi-segmented nanowires by a template-assisted electrodeposition method. These nanowires were then self-assembled and soldered into large-scale 3D network structures by magnetic field assisted assembly in a liquid medium with a high boiling point. The formation of junctions/interconnects between the nanowires and the scale of the assembly were dependent on the solder reflow temperature and the strength of the magnetic field. The size of the assembled nanowire networks ranged from tens of microns to millimeters. The electrical characteristics of the 3D nanowire networks were measured by regular current-voltage (I-V) measurements using a probe station with micropositioners. Nano-solders, when combined with assembling techniques, can be used to efficiently connect and join nanowires with low contact resistance, which are very well suited for sensor integration as well as nanoelectronic device fabrication.

Regularity and/or Consistency in the Production of the Past Participle?

ERIC Educational Resources Information Center

Colombo, Lucia; Laudanna, Alessandro; De Martino, Maria; Brivio, Cristina

2004-01-01

In the present study we have investigated the acquisition of the past participle of Italian verbs of the second (including mostly irregular verbs) and third (including mostly regular verbs) conjugations in school age children, and with simulations with an artificial neural network. We aimed to verify the extent to which children are sensitive to…

A review of tin oxide-based catalytic systems: Preparation, characterization and catalytic behavior

NASA Technical Reports Server (NTRS)

Hoflund, Gar B.

1987-01-01

This paper reviews the important aspects of the preparation, characterization and catalytic behavior of tin oxide-based catalytic systems including doped tin oxide, mixed oxides which contain tin oxide, Pt supported on tin oxide and Pt/Sn supported on alumina. These systems have a broad range of applications and are continually increasing in importance. However, due to their complex nature, much remains to be understood concerning how they function catalytically.

Contributions of Stress and Oxidation on the Formation of Whiskers in Pb-free Solders

DTIC Science & Technology

2016-01-29

environmental factors influencing formation of tin whiskers on electrodeposited lead free, tin coatings over copper (or copper containing) substrates is the...Oxidation on the Formation of Whiskers in Pb‐free Solders,” WP-1754 15. SUBJECT TERMS Tin Whiskers, Residual Stress, Environmental Degradation 16...showing the surface of a tin film with whisker .................... 2 Figure 2: SEM Micrograph of Tin film on Copper Substrate cross-sectioned by FIB

Error-correcting codes on scale-free networks

NASA Astrophysics Data System (ADS)

Kim, Jung-Hoon; Ko, Young-Jo

2004-06-01

We investigate the potential of scale-free networks as error-correcting codes. We find that irregular low-density parity-check codes with the highest performance known to date have degree distributions well fitted by a power-law function p (k) ˜ k-γ with γ close to 2, which suggests that codes built on scale-free networks with appropriate power exponents can be good error-correcting codes, with a performance possibly approaching the Shannon limit. We demonstrate for an erasure channel that codes with a power-law degree distribution of the form p (k) = C (k+α)-γ , with k⩾2 and suitable selection of the parameters α and γ , indeed have very good error-correction capabilities.

48 CFR 204.7202-3 - TINs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false TINs. 204.7202-3 Section... OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-3 TINs. Requirements for use of TINs are in FAR subpart 4.9. [64 FR 43100, Aug. 9, 1999] ...

40 CFR 421.296 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Tin Subcategory... wastewater pollutants in secondary tin process wastewater introduced into a POTW shall not exceed the following values: (a) Tin smelter SO2 scrubber. PSNS for the Secondary Tin Subcategory Pollutant or...

48 CFR 204.7202-3 - TINs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false TINs. 204.7202-3 Section... OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-3 TINs. Requirements for use of TINs are in FAR subpart 4.9. [64 FR 43100, Aug. 9, 1999] ...

40 CFR 421.296 - Pretreatment standards for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Tin Subcategory... wastewater pollutants in secondary tin process wastewater introduced into a POTW shall not exceed the following values: (a) Tin smelter SO2 scrubber. PSNS for the Secondary Tin Subcategory Pollutant or...

48 CFR 204.7202-3 - TINs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false TINs. 204.7202-3 Section... OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-3 TINs. Requirements for use of TINs are in FAR subpart 4.9. [64 FR 43100, Aug. 9, 1999] ...

40 CFR 421.296 - Pretreatment standards for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Tin Subcategory... wastewater pollutants in secondary tin process wastewater introduced into a POTW shall not exceed the following values: (a) Tin smelter SO2 scrubber. PSNS for the Secondary Tin Subcategory Pollutant or...

40 CFR 421.296 - Pretreatment standards for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Tin Subcategory... wastewater pollutants in secondary tin process wastewater introduced into a POTW shall not exceed the following values: (a) Tin smelter SO2 scrubber. PSNS for the Secondary Tin Subcategory Pollutant or...

40 CFR 421.296 - Pretreatment standards for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Tin Subcategory... wastewater pollutants in secondary tin process wastewater introduced into a POTW shall not exceed the following values: (a) Tin smelter SO2 scrubber. PSNS for the Secondary Tin Subcategory Pollutant or...

48 CFR 204.7202-3 - TINs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false TINs. 204.7202-3 Section... OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-3 TINs. Requirements for use of TINs are in FAR subpart 4.9. [64 FR 43100, Aug. 9, 1999] ...

77 FR 3725 - Proposed Significant New Use Rules on Certain Chemical Substances; Extension of Comment Period

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-25

... chemical substances rutile, tin zinc, calcium-doped (CAS No. 389623-01- 2) and rutile, tin zinc, sodium... substances rutile, tin zinc, calcium- doped (CAS No. 389623-01-2) and rutile, tin zinc, sodium-doped (CAS No...

48 CFR 204.7202-3 - TINs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false TINs. 204.7202-3 Section... OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-3 TINs. Requirements for use of TINs are in FAR subpart 4.9. [64 FR 43100, Aug. 9, 1999] ...

Metallic tin quantum sheets confined in graphene toward high-efficiency carbon dioxide electroreduction

NASA Astrophysics Data System (ADS)

Lei, Fengcai; Liu, Wei; Sun, Yongfu; Xu, Jiaqi; Liu, Katong; Liang, Liang; Yao, Tao; Pan, Bicai; Wei, Shiqiang; Xie, Yi

2016-09-01

Ultrathin metal layers can be highly active carbon dioxide electroreduction catalysts, but may also be prone to oxidation. Here we construct a model of graphene confined ultrathin layers of highly reactive metals, taking the synthetic highly reactive tin quantum sheets confined in graphene as an example. The higher electrochemical active area ensures 9 times larger carbon dioxide adsorption capacity relative to bulk tin, while the highly-conductive graphene favours rate-determining electron transfer from carbon dioxide to its radical anion. The lowered tin-tin coordination numbers, revealed by X-ray absorption fine structure spectroscopy, enable tin quantum sheets confined in graphene to efficiently stabilize the carbon dioxide radical anion, verified by 0.13 volts lowered potential of hydroxyl ion adsorption compared with bulk tin. Hence, the tin quantum sheets confined in graphene show enhanced electrocatalytic activity and stability. This work may provide a promising lead for designing efficient and robust catalysts for electrolytic fuel synthesis.

Platelet composite coatings for tin whisker mitigation

DOE PAGES

Rohwer, Lauren E. S.; Martin, James E.

2015-09-14

In this study, reliable methods for tin whisker mitigation are needed for applications that utilize tin-plated commercial components. Tin can grow whiskers that can lead to electrical shorting, possibly causing critical systems to fail catastrophically. The mechanisms of tin whisker growth are unclear and this makes prediction of the lifetimes of critical components uncertain. The development of robust methods for tin whisker mitigation is currently the best approach to eliminating the risk of shorting. Current mitigation methods are based on unfilled polymer coatings that are not impenetrable to tin whiskers. In this paper we report tin whisker mitigation results formore » several filled polymer coatings. The whisker-penetration resistance of the coatings was evaluated at elevated temperature and high humidity and under temperature cycling conditions. The composite coatings comprised Ni and MgF 2-coated Al/Ni/Al platelets in epoxy resin or silicone rubber. In addition to improved whisker mitigation, these platelet composites have enhanced thermal conductivity and dielectric constant compared with unfilled polymers.« less

Platelet Composite Coatings for Tin Whisker Mitigation

NASA Astrophysics Data System (ADS)

Rohwer, Lauren E. S.; Martin, James E.

2015-11-01

Reliable methods for tin whisker mitigation are needed for applications that utilize tin-plated commercial components. Tin can grow whiskers that can lead to electrical shorting, possibly causing critical systems to fail catastrophically. The mechanisms of tin whisker growth are unclear and this makes prediction of the lifetimes of critical components uncertain. The development of robust methods for tin whisker mitigation is currently the best approach to eliminating the risk of shorting. Current mitigation methods are based on unfilled polymer coatings that are not impenetrable to tin whiskers. In this paper we report tin whisker mitigation results for several filled polymer coatings. The whisker-penetration resistance of the coatings was evaluated at elevated temperature and high humidity and under temperature cycling conditions. The composite coatings comprised Ni and MgF2-coated Al/Ni/Al platelets in epoxy resin or silicone rubber. In addition to improved whisker mitigation, these platelet composites have enhanced thermal conductivity and dielectric constant compared with unfilled polymers.

Irregular synchronous activity in stochastically-coupled networks of integrate-and-fire neurons.

PubMed

Lin, J K; Pawelzik, K; Ernst, U; Sejnowski, T J

1998-08-01

We investigate the spatial and temporal aspects of firing patterns in a network of integrate-and-fire neurons arranged in a one-dimensional ring topology. The coupling is stochastic and shaped like a Mexican hat with local excitation and lateral inhibition. With perfect precision in the couplings, the attractors of activity in the network occur at every position in the ring. Inhomogeneities in the coupling break the translational invariance of localized attractors and lead to synchronization within highly active as well as weakly active clusters. The interspike interval variability is high, consistent with recent observations of spike time distributions in visual cortex. The robustness of our results is demonstrated with more realistic simulations on a network of McGregor neurons which model conductance changes and after-hyperpolarization potassium currents.

Percolation in three-dimensional fracture networks for arbitrary size and shape distributions

NASA Astrophysics Data System (ADS)

Thovert, J.-F.; Mourzenko, V. V.; Adler, P. M.

2017-04-01

The percolation threshold of fracture networks is investigated by extensive direct numerical simulations. The fractures are randomly located and oriented in three-dimensional space. A very wide range of regular, irregular, and random fracture shapes is considered, in monodisperse or polydisperse networks containing fractures with different shapes and/or sizes. The results are rationalized in terms of a dimensionless density. A simple model involving a new shape factor is proposed, which accounts very efficiently for the influence of the fracture shape. It applies with very good accuracy in monodisperse or moderately polydisperse networks, and provides a good first estimation in other situations. A polydispersity index is shown to control the need for a correction, and the corrective term is modelled for the investigated size distributions.

First evidence of anisotropy of GPS phase slips caused by the mid-latitude field-aligned ionospheric irregularities

NASA Astrophysics Data System (ADS)

Afraimovich, E. L.; Ishin, A. B.; Tinin, M. V.; Yasyukevich, Yu. V.; Jin, S. G.

2011-05-01

The mid-latitude field-aligned irregularity (FAI) along the magnetic field line is a common phenomenon in the ionosphere. However, few data reveal the field-aligned ionospheric irregularities. They are insufficient to identify FAIs effects so far, particularly effect on global positioning system (GPS) signals. In this paper, the mid-latitude FAIs by line-of-sight angular scanning relative to the local magnetic field vector are investigated using the denser GPS network observations in Japan. It has been the first found that total GPS L2 phase slips over Japan, during the recovery phase of the 12 Feb 2000 geomagnetic storm were caused by GPS signal scattering on FAIs both for the lines-of-sight aligned to the magnetic field line (the field of aligned scattering, FALS) and across the magnetic field line (the field of across scattering, FACS). The FALS results are also in a good agreement with the data of the magnetic field orientation control of GPS occultation observations of equatorial scintillation during thorough low earth orbit (LEO) satellites measurements, e.g. Challenging Minisatellite Payload (CHAMP) and Satellite de Aplicaciones Cientificas-C (SAC-C). The role of large-angle scattering almost along the normal to the magnetic field line in GPS scintillation is determined by attenuation of the irregularity anisotropy factor as compared with the other factors.

Fractal analysis of scatter imaging signatures to distinguish breast pathologies

NASA Astrophysics Data System (ADS)

Eguizabal, Alma; Laughney, Ashley M.; Krishnaswamy, Venkataramanan; Wells, Wendy A.; Paulsen, Keith D.; Pogue, Brian W.; López-Higuera, José M.; Conde, Olga M.

2013-02-01

Fractal analysis combined with a label-free scattering technique is proposed for describing the pathological architecture of tumors. Clinicians and pathologists are conventionally trained to classify abnormal features such as structural irregularities or high indices of mitosis. The potential of fractal analysis lies in the fact of being a morphometric measure of the irregular structures providing a measure of the object's complexity and self-similarity. As cancer is characterized by disorder and irregularity in tissues, this measure could be related to tumor growth. Fractal analysis has been probed in the understanding of the tumor vasculature network. This work addresses the feasibility of applying fractal analysis to the scattering power map (as a physical modeling) and principal components (as a statistical modeling) provided by a localized reflectance spectroscopic system. Disorder, irregularity and cell size variation in tissue samples is translated into the scattering power and principal components magnitude and its fractal dimension is correlated with the pathologist assessment of the samples. The fractal dimension is computed applying the box-counting technique. Results show that fractal analysis of ex-vivo fresh tissue samples exhibits separated ranges of fractal dimension that could help classifier combining the fractal results with other morphological features. This contrast trend would help in the discrimination of tissues in the intraoperative context and may serve as a useful adjunct to surgeons.

Polynucleotides encoding TRF1 binding proteins

DOEpatents

Campisi, Judith; Kim, Sahn-Ho

2002-01-01

The present invention provides a novel telomere associated protein (Trf1-interacting nuclear protein 2 "Tin2") that hinders the binding of Trf1 to its specific telomere repeat sequence and mediates the formation of a Tin2-Trf1-telomeric DNA complex that limits telomerase access to the telomere. Also included are the corresponding nucleic acids that encode the Tin2 of the present invention, as well as mutants of Tin2. Methods of making, purifying and using Tin2 of the present invention are described. In addition, drug screening assays to identify drugs that mimic and/or complement the effect of Tin2 are presented.

Optical Properties and Plasmonic Performance of Titanium Nitride

PubMed Central

Patsalas, Panos; Kalfagiannis, Nikolaos; Kassavetis, Spyros

2015-01-01

Titanium nitride (TiN) is one of the most well-established engineering materials nowadays. TiN can overcome most of the drawbacks of palsmonic metals due to its high electron conductivity and mobility, high melting point and due to the compatibility of its growth with Complementary Metal Oxide Semiconductor (CMOS) technology. In this work, we review the dielectric function spectra of TiN and we evaluate the plasmonic performance of TiN by calculating (i) the Surface Plasmon Polariton (SPP) dispersion relations and (ii) the Localized Surface Plasmon Resonance (LSPR) band of TiN nanoparticles, and we demonstrate a significant plasmonic performance of TiN.

Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

NASA Technical Reports Server (NTRS)

Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Larry L.; Wright, Maria C.

2009-01-01

To comply with lead-free legislation, many manufacturers have converted from tin-lead to pure tin finishes of electronic components. However, pure tin finishes have a greater propensity to grow tin whiskers than tin-lead finishes. Since tin whiskers present an electrical short circuit hazard in electronic components, simulations have been developed to quantify the risk of said short circuits occurring. Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that had an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage.

Demonstration of high-performance p-type tin oxide thin-film transistors using argon-plasma surface treatments

NASA Astrophysics Data System (ADS)

Bae, Sang-Dae; Kwon, Soo-Hun; Jeong, Hwan-Seok; Kwon, Hyuck-In

2017-07-01

In this work, we investigated the effects of low-temperature argon (Ar)-plasma surface treatments on the physical and chemical structures of p-type tin oxide thin-films and the electrical performance of p-type tin oxide thin-film transistors (TFTs). From the x-ray photoelectron spectroscopy measurement, we found that SnO was the dominant phase in the deposited tin oxide thin-film, and the Ar-plasma treatment partially transformed the tin oxide phase from SnO to SnO2 by oxidation. The resistivity of the tin oxide thin-film increased with the plasma-treatment time because of the reduced hole concentration. In addition, the root-mean-square roughness of the tin oxide thin-film decreased as the plasma-treatment time increased. The p-type oxide TFT with an Ar-plasma-treated tin oxide thin-film exhibited excellent electrical performance with a high current on-off ratio (5.2 × 106) and a low off-current (1.2 × 10-12 A), which demonstrates that the low-temperature Ar-plasma treatment is a simple and effective method for improving the electrical performance of p-type tin oxide TFTs.

40 CFR 421.295 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Tin... existing sources. The mass of wastewater pollutants in secondary tin process wastewater introduced into a POTW must not exceed the following values: (a) Tin smelter SO2 scrubber. PSES for the Secondary Tin...

40 CFR 421.295 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Tin... existing sources. The mass of wastewater pollutants in secondary tin process wastewater introduced into a POTW must not exceed the following values: (a) Tin smelter SO2 scrubber. PSES for the Secondary Tin...

40 CFR 421.295 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Tin... existing sources. The mass of wastewater pollutants in secondary tin process wastewater introduced into a POTW must not exceed the following values: (a) Tin smelter SO2 scrubber. PSES for the Secondary Tin...

40 CFR 421.295 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Tin... existing sources. The mass of wastewater pollutants in secondary tin process wastewater introduced into a POTW must not exceed the following values: (a) Tin smelter SO2 scrubber. PSES for the Secondary Tin...

40 CFR 421.295 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Tin... existing sources. The mass of wastewater pollutants in secondary tin process wastewater introduced into a POTW must not exceed the following values: (a) Tin smelter SO2 scrubber. PSES for the Secondary Tin...

Ionospheric Irregularities Characterization by Ground and Space-based GPS Observations

NASA Astrophysics Data System (ADS)

Zakharenkova, I.; Cherniak, I.; Krankowski, A.

2017-12-01

We present new results on detection and investigation of the topside ionospheric irregularities using GPS measurements from Precise Orbit Determination (POD) GPS antenna onboard Low Earth Orbit satellites. Our investigation is based on the recent ESA's Swarm mission launched on 22 November 2013 and consisted of three identical satellites, two of them fly in a tandem at an orbit altitude of 460 km while the third satellite - at an orbit altitude of 510 km. Each satellite is equipped with a zenith-looking antenna and 8-channel dual-frequency GPS receiver that delivered 1 Hz data for POD purposes, as well as Langmuir Probe instrument for in situ electron density. Additionally, we have analyzed GPS measurements onboard GRACE and TerraSAR-X satellite, which have rather similar to Swarm orbit altitude of 500 km. GPS measurements onboard MetOP-A and MetOP-B satellites (altitude of 840 km) can complement these observations in order to estimate an altitudinal extent of the ionospheric irregularities penetrating to higher altitudes. We demonstrate that space-based GPS observations can be effectively used for monitoring of the topside ionospheric irregularities occurrence in both high-latitude and equatorial regions and may essentially contribute to the multi-instrumental analysis of the ground-based and in situ data. Climatological characteristics of the equatorial ionospheric irregularities occurrence probability are derived from POD GPS measurements for all longitudinal sectors for the years 2013-2016. Several examples of strong geomagnetic storms, including the 2015 St. Patrick's Day storm, were analyzed to demonstrate differences between the climatlogical characteristics in space-based GPS data and storm-induced equatorial irregularities observations (postsunset suppression, night/morning-time occurrence). To support our observations and conclusions, we involve into our analysis in situ plasma density provided by Swarm constellation, GRACE KBR, DMSP satellites, as well as ground-based GNSS and digisonde networks. New International GNSS Service (IGS) product - the Northern Hemisphere GPS-based ROTI (rate of the TEC index) maps - was analyzed to determine similarities and differences in ionospheric irregularities signatures in the ground and space-based GPS observations.

An Investigation of the Electrical Short Circuit Characteristics of Tin Whiskers

NASA Technical Reports Server (NTRS)

Courey, Karim J.

2008-01-01

In this experiment, an empirical model to quantify the probability of occurrence of an electrical short circuit from tin whiskers as a function of voltage was developed. This model can be used to improve existing risk simulation models FIB and TEM images of a tin whisker confirm the rare polycrystalline structure on one of the three whiskers studied. FIB cross-section of the card guides verified that the tin finish was bright tin.

Effect of Tin, Copper and Boron on the Hot Ductility of 20CrMnTi Steel between 650 °C and 1100 °C

NASA Astrophysics Data System (ADS)

Peng, Hong-bing; Chen, Wei-qing; Chen, Lie; Guo, Dong

2015-02-01

The hot ductility of 20CrMnTi steel with x% tin, y% copper and z ppm boron (x = 0, 0.02; y = 0, 0.2; z = 0, 60) was investigated. The results show that tin and copper in 20CrMnTi steel are detrimental to its hot ductility while adding boron can eliminate the adverse effect and enhance hot ductility greatly. Tin is found to segregate to the boundaries tested by EPMA in 20CrMnTi steel containing tin and copper and tin-segregation is suppressed by adding boron, moreover, copper was found not to segregate to boundaries, however, fine copper sulfide was found from carbon extraction replicas using TEM. The adverse effect of tin and copper on the hot ductility was due mainly to tin segregation and fine copper sulfide in the steel. The proeutectoid ferrite film precipitating along the austenite grain boundary causes the ductility trough of the three examined steels. Tin and copper in 20CrMnTi steel can retard the occurrence of dynamic recrystallization (DRX) while boron-addition can compensate for that change. The beneficial effect of boron on 20CrMnTi steel containing tin and copper might be ascribed to the fact that boron segregates to grain boundaries, accelerates onset of DRX, retards austenite/ferrite transformation and promotes intragranular nucleation of ferrite.

Precipitation Behaviors of TiN Inclusion in GCr15 Bearing Steel Billet

NASA Astrophysics Data System (ADS)

Tian, Qianren; Wang, Guocheng; Zhao, Yang; Li, Jing; Wang, Qi

2018-06-01

There are many types of non-metallic TiN-based inclusions observed in GCr15 bearing steel, including single-particle TiN, multi-particle polymerized TiN, and complex inclusions like TiN-MnS, TiN-MgO-MgAl2O4 (TiN-MgO-MA), and TiN-MgAl2O4-MnS (TiN-MA-MnS). Thermodynamic calculations suggest that single-particle TiN precipitates dominate the mushy zone of GCr15 bearing steel. Kinetic calculations regarding TiN growth suggest that the final size of the single-particle TiN ranges between 1 and 6 μm in the initial concentration range of [pct Ti] = 0.0060 to 0.0079 and [pct N] = 0.0049 to 0.0070, at 1620 to 1640 K and a local cooling rate of 0.5 to 10 K/s. The multi-particle polymerized TiN are formed by single TiN particles in three stages: single-particle TiN inclusions approach each other drawn by the cavity bridge force (CBF), local active angles consolidate, and neck region sintering occurs. Based on the thermodynamic calculations of TiN, MnS, and MgO precipitation, the formation behaviors of complex inclusions of TiN-MnS, TiN-MgO-MA, and TiN-MA-MnS were investigated.

Lidar-enhanced geologic mapping, examples from the Medford and Hood River areas, Oregon

NASA Astrophysics Data System (ADS)

Wiley, T. J.; McClaughry, J. D.

2012-12-01

Lidar-based 3-foot digital elevation models (DEMs) and derivatives (slopeshade, hillshade, contours) were used to help map geology across 1700 km2 (650 mi2) near Hood River and Medford, Oregon. Techniques classically applied to interpret coarse DEMs and small-scale topographic maps were adapted to take advantage of lidar's high resolution. Penetration and discrimination of plant cover by the laser system allowed recognition of fine patterns and textures related to underlying geologic units and associated soils. Surficial geologic maps were improved by the ability to examine tiny variations in elevation and slope. Recognition of low-relief features of all sizes was enhanced where pixel elevation ranges of centimeters to meters, established by knowledge of the site or by trial, were displayed using thousands of sequential colors. Features can also be depicted relative to stream level by preparing a DEM that compensates for gradient. Near Medford, lidar-derived contour maps with 1- to 3-foot intervals revealed incised bajada with young, distal lobes defined by concentric contour lines. Bedrock geologic maps were improved by recognizing geologic features associated with surface textures and patterns or topographic anomalies. In sedimentary and volcanic terrain, structure was revealed by outcrops or horizons lying at one stratigraphic level. Creating a triangulated irregular network (TIN) facet from positions of three or more such points gives strike and dip. Each map area benefited from hundreds of these measurements. A more extensive DEM in the plane of the TIN facet can be subtracted from surface elevation (lidar DEM) to make a DEM with elevation zero where the stratigraphic horizon lies at the surface. The distribution of higher and lower stratigraphic horizons can be shown by highlighting areas similarly higher or lower on the same DEM. Poor fit of contacts or faults projected between field traverses suggest the nature and amount of intervening geologic structure. Intrusive bodies were locally delimited by linear mounds where contact metamorphism hardened soft, fractured country rock. Bedrock faults were revealed where fault traces formed topographic anomalies or where topography associated with stratigraphic horizons or bedding-parallel textural fabrics was offset. This was important for identification of young faults and associated earthquake hazards. Previously unknown Holocene faults southwest of Hood River appear as subtle lineaments redirecting modern drainages or offsetting glacial moraines or glaciated bedrock. West of Medford, the presence young faulting was confirmed by elevation data that showed bedrock in the channel of the Rogue River at higher elevations below Gold Ray dam than in boreholes upstream. Such obscure structural features would have gone unrecognized using traditional topographic analysis or field reconnaissance. Fieldwork verified that lidar techniques improved our early geologic models, resolution of geologic features, and mapping of surficial and bedrock geology between traverses.

Low and Mid-Latitude Ionospheric Irregularities Studies Using TEC and Radio Scintillation Data from the CITRIS Radio Beacon Receiver in Low-Earth-Orbit

NASA Astrophysics Data System (ADS)

Siefring, C. L.; Bernhardt, P. A.; Huba, J.; Krall, J.; Roddy, P. A.

2009-12-01

Unique data on ionospheric plasma irregularities from the Naval Research Laboratory (NRL) CITRIS (Scintillation and TEC Receiver in Space) instrument will be presented. CITRIS is a multi-band receiver that recorded TEC (Total Electron Content) and radio scintillations from Low-Earth Orbit (LEO) on STPSat1. The 555+/5 km altitude 35° inclination orbit covers low and mid-latitudes. The measurements require propagation from a transmitter to a receiver through the F-region plasma. CITRIS used both 1) satellite beacons in LEO, such as the NRL CERTO (Coherent Electromagnetic Radio TOmography) beacons and 2) the global network of ground-based DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) beacons. The TEC measurements allow for tracking of ionospheric disturbances and irregularities while the measurements of scintillations can simultaneously characterize their effects. CITRIS was operated in a complementary fashion with the C/NOFS (Communication/Navigations Outages Forecasting System) satellite during most of its first year of operations. C/NOFS carries a three-frequency 150/400/1067 MHz CERTO beacon and is dedicated to the study of Spread-F. In the case of Spread-F, ionospheric irregularities start with large scale size density gradients (100s of km) and cascade through complex processes to short scale sizes (10s of meters). It is typically the 100m-1km scale features that harm communication and navigation systems through scintillations. A multi-sensor approach is needed to completely understand this complex system, such as, the combination of CITRIS remote radio sensing and C/NOFS in-situ data. Several types of irregularities have been studied including Spread-F and the newly discovered dawn-side depletions. Comparisons with the physics based SAMI3 model are being performed to help our understanding of the morphology of the irregularities.

77 FR 32998 - Tin- and Chromium-Coated Steel Sheet From Japan

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-04

... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-860 (Second Review)] Tin- and Chromium... order on tin- and chromium-coated steel sheet from Japan would be likely to lead to continuation or... USITC Publication 4325 (May 2012), entitled Tin- and Chromium-Coated Steel Sheet from Japan...

40 CFR 471.10 - Applicability; description of the lead-tin-bismuth forming subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... METAL POWDERS POINT SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.10 Applicability; description of the lead-tin-bismuth forming subcategory. This subpart applies to discharges of pollutants to...

26 CFR 31.3406(j)-1 - Taxpayer Identification Number (TIN) matching program.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 26 Internal Revenue 15 2013-04-01 2013-04-01 false Taxpayer Identification Number (TIN) matching... Number (TIN) matching program. (a) The matching program. Under section 3406(i), the Commissioner has the authority to establish Taxpayer Identification Number (TIN) matching programs. The Commissioner may...

26 CFR 31.3406(j)-1 - Taxpayer Identification Number (TIN) matching program.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 15 2011-04-01 2011-04-01 false Taxpayer Identification Number (TIN) matching... Number (TIN) matching program. (a) The matching program. Under section 3406(i), the Commissioner has the authority to establish Taxpayer Identification Number (TIN) matching programs. The Commissioner may...

26 CFR 31.3406(j)-1 - Taxpayer Identification Number (TIN) matching program.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 26 Internal Revenue 15 2012-04-01 2012-04-01 false Taxpayer Identification Number (TIN) matching... Number (TIN) matching program. (a) The matching program. Under section 3406(i), the Commissioner has the authority to establish Taxpayer Identification Number (TIN) matching programs. The Commissioner may...

40 CFR 471.10 - Applicability; description of the lead-tin-bismuth forming subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... METAL POWDERS POINT SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.10 Applicability; description of the lead-tin-bismuth forming subcategory. This subpart applies to discharges of pollutants to...

40 CFR 471.10 - Applicability; description of the lead-tin-bismuth forming subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.10 Applicability; description of the lead-tin-bismuth forming subcategory. This subpart applies to discharges of pollutants to waters of the...

40 CFR 471.10 - Applicability; description of the lead-tin-bismuth forming subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... METAL POWDERS POINT SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.10 Applicability; description of the lead-tin-bismuth forming subcategory. This subpart applies to discharges of pollutants to...

40 CFR 471.10 - Applicability; description of the lead-tin-bismuth forming subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.10 Applicability; description of the lead-tin-bismuth forming subcategory. This subpart applies to discharges of pollutants to waters of the...

26 CFR 31.3406(j)-1 - Taxpayer Identification Number (TIN) matching program.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 15 2014-04-01 2014-04-01 false Taxpayer Identification Number (TIN) matching... Number (TIN) matching program. (a) The matching program. Under section 3406(i), the Commissioner has the authority to establish Taxpayer Identification Number (TIN) matching programs. The Commissioner may...

26 CFR 31.3406(j)-1 - Taxpayer Identification Number (TIN) matching program.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Taxpayer Identification Number (TIN) matching... Number (TIN) matching program. (a) The matching program. Under section 3406(i), the Commissioner has the authority to establish Taxpayer Identification Number (TIN) matching programs. The Commissioner may...

An Empirical Model for Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

NASA Technical Reports Server (NTRS)

Courey, Karim; Wright, Clara; Asfour, Shihab; Onar, Arzu; Bayliss, Jon; Ludwig, Larry

2009-01-01

In this experiment, an empirical model to quantify the probability of occurrence of an electrical short circuit from tin whiskers as a function of voltage was developed. This empirical model can be used to improve existing risk simulation models. FIB and TEM images of a tin whisker confirm the rare polycrystalline structure on one of the three whiskers studied. FIB cross-section of the card guides verified that the tin finish was bright tin.

Microwave plasma CVD of NANO structured tin/carbon composites

DOEpatents

Marcinek, Marek [Warszawa, PL; Kostecki, Robert [Lafayette, CA

2012-07-17

A method for forming a graphitic tin-carbon composite at low temperatures is described. The method involves using microwave radiation to produce a neutral gas plasma in a reactor cell. At least one organo tin precursor material in the reactor cell forms a tin-carbon film on a supporting substrate disposed in the cell under influence of the plasma. The three dimensional carbon matrix material with embedded tin nanoparticles can be used as an electrode in lithium-ion batteries.

Preparation of textural lamellar tin deposits via electrodeposition

NASA Astrophysics Data System (ADS)

Wen, Xiaoyu; Pan, Xiaona; Wu, Libin; Li, Ruinan; Wang, Dan; Zhang, Jinqiu; Yang, Peixia

2017-06-01

Lamellar tin deposits were prepared by galvanostatical electroplating from the aqueous acidic-sulfate bath, with gelatin and benzalacetone dissolved in ethanol (ABA+EtOH) as additive, and their morphologies were investigated by scanning electron microscopy. Cathodic polarization curves revealed that the absorbability of ABA+EtOH on the cathode surface was higher than that of gelatin. X-ray diffraction analysis indicated preferred orientations of tin growth led to the formation of lamellar structure and distortion of tin lattice. The growth mechanism of lamellar tin was also discussed.

Modular networks with delayed coupling: Synchronization and frequency control

NASA Astrophysics Data System (ADS)

Maslennikov, Oleg V.; Nekorkin, Vladimir I.

2014-07-01

We study the collective dynamics of modular networks consisting of map-based neurons which generate irregular spike sequences. Three types of intramodule topology are considered: a random Erdös-Rényi network, a small-world Watts-Strogatz network, and a scale-free Barabási-Albert network. The interaction between the neurons of different modules is organized by relatively sparse connections with time delay. For all the types of the network topology considered, we found that with increasing delay two regimes of module synchronization alternate with each other: inphase and antiphase. At the same time, the average rate of collective oscillations decreases within each of the time-delay intervals corresponding to a particular synchronization regime. A dual role of the time delay is thus established: controlling a synchronization mode and degree and controlling an average network frequency. Furthermore, we investigate the influence on the modular synchronization by other parameters: the strength of intermodule coupling and the individual firing rate.

Quantifying climatic controls on river network topology across scales

NASA Astrophysics Data System (ADS)

Ranjbar Moshfeghi, S.; Hooshyar, M.; Wang, D.; Singh, A.

2017-12-01

Branching structure of river networks is an important topologic and geomorphologic feature that depends on several factors (e.g. climate, tectonic). However, mechanisms that cause these drainage patterns in river networks are poorly understood. In this study, we investigate the effects of varying climatic forcing on river network topology and geomorphology. For this, we select 20 catchments across the United States with different long-term climatic conditions quantified by climate aridity index (AI), defined here as the ratio of mean annual potential evaporation (Ep) to precipitation (P), capturing variation in runoff and vegetation cover. The river networks of these catchments are extracted, using a curvature-based method, from high-resolution (1 m) digital elevation models and several metrics such as drainage density, branching angle, and width functions are computed. We also use a multiscale-entropy-based approach to quantify the topologic irregularity and structural richness of these river networks. Our results reveal systematic impacts of climate forcing on the structure of river networks.

NASA GSFC Tin Whisker Homepage http://nepp.nasa.gov/whisker

NASA Technical Reports Server (NTRS)

Shaw, Harry

2000-01-01

The NASA GSFC Tin Whisker Homepage provides general information and GSFC Code 562 experimentation results regarding the well known phenomenon of tin whisker formation from pure tin plated substrates. The objective of this www site is to provide a central repository for information pertaining to this phenomenon and to provide status of the GSFC experiments to understand the behavior of tin whiskers in space environments. The Tin Whisker www site is produced by Code 562. This www site does not provide information pertaining to patented or proprietary information. All of the information contained in this www site is at the level of that produced by industry and university researchers and is published at international conferences.

Effect of thiourea on electrochemical nucleation and electrochemical impedance spectroscopy of electrodeposited tin on a copper substrate in a sulfate bath.

PubMed

Lee, Mi-Ri; Na, Seong-Hun; Park, Hwa-Sun; Suh, Su-Jeong

2014-12-01

The effect of thiourea on the electrochemical nucleation of tin on a copper substrate from a sulfate bath was studied using voltammetry, chronoamperometry, electrochemical impedance spectroscopy, and scanning electron microscopy. Without thiourea, electrodeposition of tin showed very poor surface coverage. However, re-nucleation and growth of tin occurred after the addition of thiourea. In particular, very rapid re-nucleation and growth behavior of tin were observed when up to 6 g/L of thiourea was added. Furthermore, impedance analysis allowed the estimation of the change in the growth behavior of tin when up to 6 g/L of thiourea was added.

Structural studies of supported tin catalysts

NASA Astrophysics Data System (ADS)

Nava, Noel; Viveros, Tomás

1999-11-01

Tin oxide was supported on aluminium oxide, titanium oxide, magnesium oxide and silicon oxide, and the resulting interactions between the components in the prepared samples and after reduction were characterized by Mössbauer spectroscopy. It was observed that in the oxide state, tin is present as SnO2 on alumina, magnesia and silica, but on titania tin occupies Ti sites in the structure. After hydrogen treatment at high temperatures, tin is reduced from Sn(4) to Sn(2) on alumina and titania; it is reduced from Sn(4) to Sn(0) on silica, and is practically not reduced on magnesia. These results reveal the degree of interaction between tin and the different supports studied.

Organic derivatives of tin (II/IV): Investigation of their structure

NASA Astrophysics Data System (ADS)

Szirtes, L.; Megyeri, J.; Kuzmann, E.; Beck, A.

2011-07-01

The structures of tin(II)-oxalate, tin(IV)Na-EDTA and tin(IV)Na 8-inositol hexaphosphate were investigated using XRD analysis. Samples were identified using the Mössbauer study, thermal analysis and FTIR spectrometry. The Mössbauer study determined two different oxidation states of tin atoms, and consequently two different tin surroundings in the end products. The tin oxalate was found to be orthorhombic with space group Pnma, a=9.2066(3) Å, b=9.7590(1) Å, c=13.1848(5) Å, V=1184.62 Å 3 and Z=8. SnNa-EDTA was found to be monoclinic with space group P2 1/c 1, a=10.7544(3) Å, b=10.1455(3) Å, c=16.5130(6) Å, β=98.59(2)°, V=1781.50(4) Å 3 and Z=4. Sn(C 6H 6Na 8O 24P 6) was found to be amorphous.

A charge optimized many-body potential for titanium nitride (TiN).

PubMed

Cheng, Y-T; Liang, T; Martinez, J A; Phillpot, S R; Sinnott, S B

2014-07-02

This work presents a new empirical, variable charge potential for TiN systems in the charge-optimized many-body potential framework. The potential parameters were determined by fitting them to experimental data for the enthalpy of formation, lattice parameters, and elastic constants of rocksalt structured TiN. The potential does a good job of describing the fundamental physical properties (defect formation and surface energies) of TiN relative to the predictions of first-principles calculations. This potential is used in classical molecular dynamics simulations to examine the interface of fcc-Ti(0 0 1)/TiN(0 0 1) and to characterize the adsorption of oxygen atoms and molecules on the TiN(0 0 1) surface. The results indicate that the potential is well suited to model TiN thin films and to explore the chemistry associated with their oxidation.

Effect of doping of tin on optoelectronic properties of indium oxide: DFT study

NASA Astrophysics Data System (ADS)

Tripathi, Madhvendra Nath

2015-06-01

Indium tin oxide is widely used transparent conductor. Experimentally observed that 6% tin doping in indium oxide is suitable for optoelectronic applications and more doping beyond this limit degrades the optoelectronic property. The stoichiometry (In32-xSnxO48+x/2; x=0-6) is taken to understand the change in lattice parameter, electronic structure, and optical property of ITO. It is observed that lattice parameter increases and becomes constant after 6% tin doping that is in good agreement of the experimental observation. The electronic structure calculation shows that the high tin doping in indium oxide adversely affects the dispersive nature of the bottom of conduction band of pure indium oxide and decreases the carrier mobility. Optical calculations show that transmittance goes down upto 60% for the tin concentration more than 6%. The present paper shows that how more than 6% tin doping in indium oxide adversely affects the optoelectronic property of ITO.

A Coral Reef Algorithm Based on Learning Automata for the Coverage Control Problem of Heterogeneous Directional Sensor Networks

PubMed Central

Li, Ming; Miao, Chunyan; Leung, Cyril

2015-01-01

Coverage control is one of the most fundamental issues in directional sensor networks. In this paper, the coverage optimization problem in a directional sensor network is formulated as a multi-objective optimization problem. It takes into account the coverage rate of the network, the number of working sensor nodes and the connectivity of the network. The coverage problem considered in this paper is characterized by the geographical irregularity of the sensed events and heterogeneity of the sensor nodes in terms of sensing radius, field of angle and communication radius. To solve this multi-objective problem, we introduce a learning automata-based coral reef algorithm for adaptive parameter selection and use a novel Tchebycheff decomposition method to decompose the multi-objective problem into a single-objective problem. Simulation results show the consistent superiority of the proposed algorithm over alternative approaches. PMID:26690162

A Coral Reef Algorithm Based on Learning Automata for the Coverage Control Problem of Heterogeneous Directional Sensor Networks.

PubMed

Li, Ming; Miao, Chunyan; Leung, Cyril

2015-12-04

Coverage control is one of the most fundamental issues in directional sensor networks. In this paper, the coverage optimization problem in a directional sensor network is formulated as a multi-objective optimization problem. It takes into account the coverage rate of the network, the number of working sensor nodes and the connectivity of the network. The coverage problem considered in this paper is characterized by the geographical irregularity of the sensed events and heterogeneity of the sensor nodes in terms of sensing radius, field of angle and communication radius. To solve this multi-objective problem, we introduce a learning automata-based coral reef algorithm for adaptive parameter selection and use a novel Tchebycheff decomposition method to decompose the multi-objective problem into a single-objective problem. Simulation results show the consistent superiority of the proposed algorithm over alternative approaches.

77 FR 13156 - Carolina Power & Light Company; Shearon Harris Nuclear Power Plant, Unit 1; Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-05

... percent) and niobium (~1 percent). The elimination of tin has resulted in superior corrosion resistance and reduced irradiation-induced growth relative to both standard zircaloy (1.7 percent tin) and low-tin zircaloy (1.2 percent tin). The addition of niobium increases ductility, which is desirable to...

26 CFR 1.6050H-0 - Table of contents.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., 1989. (i) Failure to file return or to furnish statement. (ii) Failure to furnish TIN. (iii) Failure to...) Failure to furnish TIN. (iii) Failure to include correct information. (f) Requirement to request and to obtain TIN. (1) In general. (2) Manner of requesting TIN. (g) Effective date. (1) In general. (2) Points...

40 CFR 721.10140 - Phosphoric acid, tin (2+) salt (2:3).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phosphoric acid, tin (2+) salt (2:3... Specific Chemical Substances § 721.10140 Phosphoric acid, tin (2+) salt (2:3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphoric acid, tin (2...

78 FR 52802 - Tin T. Win, M.D., Dismissal of Proceeding

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-26

... DEPARTMENT OF JUSTICE Drug Enforcement Administration Tin T. Win, M.D., Dismissal of Proceeding On... Cause and Immediate Suspension of Registration to Tin T. Win, M.D. (hereinafter, Registrant), of Lake... order that the Order to Show Cause and Immediate Suspension of Registration issued to Tin T. Win, M.D...

40 CFR 721.10140 - Phosphoric acid, tin (2+) salt (2:3).

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphoric acid, tin (2+) salt (2:3... Specific Chemical Substances § 721.10140 Phosphoric acid, tin (2+) salt (2:3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphoric acid, tin (2...

40 CFR 721.10140 - Phosphoric acid, tin (2+) salt (2:3).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphoric acid, tin (2+) salt (2:3... Specific Chemical Substances § 721.10140 Phosphoric acid, tin (2+) salt (2:3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphoric acid, tin (2...

77 FR 66449 - Applications for New Awards; National Institute on Disability and Rehabilitation Research...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-05

...) number and a Taxpayer Identification Number (TIN); b. Register both your DUNS number and TIN with the...), the Government's primary registrant database; c. Provide your DUNS number and TIN on your application... you are a corporate entity, agency, institution, or organization, you can obtain a TIN from the...

77 FR 27031 - Applications for New Awards; Centers for Independent Living

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-08

... Number (TIN); b. Register both your DUNS number and TIN with the Central Contractor Registry (CCR), the Government's primary registrant database; c. Provide your DUNS number and TIN on your application; and d..., agency, institution, or organization, you can obtain a TIN from the Internal Revenue Service. If you are...

38 CFR 61.12 - Capital grant application packages-threshold requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... contains the Employer Identification Number or Taxpayer Identification Number (EIN/TIN) that corresponds to... must provide such an IRS determination letter, which includes their EIN/TIN. Applicants that apply under a group EIN/TIN must be identified by the parent EIN/TIN as a member or sub-unit of the parent EIN...

26 CFR 1.6050H-0 - Table of contents.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., 1989. (i) Failure to file return or to furnish statement. (ii) Failure to furnish TIN. (iii) Failure to...) Failure to furnish TIN. (iii) Failure to include correct information. (f) Requirement to request and to obtain TIN. (1) In general. (2) Manner of requesting TIN. (g) Effective date. (1) In general. (2) Points...

38 CFR 61.12 - Capital grant application packages-threshold requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... contains the Employer Identification Number or Taxpayer Identification Number (EIN/TIN) that corresponds to... must provide such an IRS determination letter, which includes their EIN/TIN. Applicants that apply under a group EIN/TIN must be identified by the parent EIN/TIN as a member or sub-unit of the parent EIN...

26 CFR 1.6050H-0 - Table of contents.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., 1989. (i) Failure to file return or to furnish statement. (ii) Failure to furnish TIN. (iii) Failure to...) Failure to furnish TIN. (iii) Failure to include correct information. (f) Requirement to request and to obtain TIN. (1) In general. (2) Manner of requesting TIN. (g) Effective date. (1) In general. (2) Points...

7 CFR 3.44 - Centralized administrative offset.

Code of Federal Regulations, 2012 CFR

2012-01-01

... TINs of debtors who owe debts referred to Treasury under this section shall be compared to the names and TINs on payments to be made by Federal disbursing officials. Federal disbursing officials include... and TIN of a debtor match the name and TIN of a payee and all other requirements for offset have been...

26 CFR 1.6050H-0 - Table of contents.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., 1989. (i) Failure to file return or to furnish statement. (ii) Failure to furnish TIN. (iii) Failure to...) Failure to furnish TIN. (iii) Failure to include correct information. (f) Requirement to request and to obtain TIN. (1) In general. (2) Manner of requesting TIN. (g) Effective date. (1) In general. (2) Points...

40 CFR 721.10230 - Rutile, tin zinc, calcium doped.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Rutile, tin zinc, calcium doped. 721... Substances § 721.10230 Rutile, tin zinc, calcium doped. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as rutile, tin zinc, calcium-doped (PMN P-06...

40 CFR 721.10231 - Rutile, tin zinc, sodium-doped.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Rutile, tin zinc, sodium-doped. 721... Substances § 721.10231 Rutile, tin zinc, sodium-doped. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as rutile, tin zinc, sodium-doped (PMN P-06-37...

77 FR 34938 - Certain Tin Mill Products From Japan: Continuation of Antidumping Duty Order

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-12

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-854] Certain Tin Mill Products... duty order on certain tin mill products from Japan would likely lead to continuation or recurrence of...: Background On August 28, 2000, the Department published the antidumping duty order on certain tin mill...

42 CFR 425.504 - Incorporating reporting requirements related to the Physician Quality Reporting System.

Code of Federal Regulations, 2012 CFR

2012-10-01

... under their ACO participant TIN as a group practice under the Physician Quality Reporting System Group... participant TIN, on behalf of its ACO supplier/provider participants who are eligible professionals, will... Physician Fee Schedule for that TIN. (4) ACO participant TINs and individual ACO providers/suppliers who are...

42 CFR 425.504 - Incorporating reporting requirements related to the Physician Quality Reporting System.

Code of Federal Regulations, 2013 CFR

2013-10-01

... under their ACO participant TIN as a group practice under the Physician Quality Reporting System Group... participant TIN, on behalf of its ACO supplier/provider participants who are eligible professionals, will... Physician Fee Schedule for that TIN. (4) ACO participant TINs and individual ACO providers/suppliers who are...

7 CFR 3.44 - Centralized administrative offset.

Code of Federal Regulations, 2010 CFR

2010-01-01

... TINs of debtors who owe debts referred to Treasury under this section shall be compared to the names and TINs on payments to be made by Federal disbursing officials. Federal disbursing officials include... and TIN of a debtor match the name and TIN of a payee and all other requirements for offset have been...

76 FR 14902 - Certain Tin Mill Products From Japan: Rescission of Antidumping Duty Administrative Review

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-18

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-854] Certain Tin Mill Products... duty order covering certain tin mill products from Japan. The period of review is August 1, 2009... parties to request an administrative review of the antidumping duty order on certain tin mill products...

7 CFR 3.44 - Centralized administrative offset.

Code of Federal Regulations, 2011 CFR

2011-01-01

... TINs of debtors who owe debts referred to Treasury under this section shall be compared to the names and TINs on payments to be made by Federal disbursing officials. Federal disbursing officials include... and TIN of a debtor match the name and TIN of a payee and all other requirements for offset have been...

40 CFR 721.10231 - Rutile, tin zinc, sodium-doped.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Rutile, tin zinc, sodium-doped. 721... Substances § 721.10231 Rutile, tin zinc, sodium-doped. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as rutile, tin zinc, sodium-doped (PMN P-06-37...

77 FR 5767 - Certain Tin Mill Products From Japan: Rescission of Antidumping Duty Administrative Review

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-06

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-854] Certain Tin Mill Products... duty order covering certain tin mill products from Japan. The period of review is August 1, 2010... parties to request an administrative review of the antidumping duty order on certain tin mill products...

40 CFR 721.10140 - Phosphoric acid, tin (2+) salt (2:3).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phosphoric acid, tin (2+) salt (2:3... Specific Chemical Substances § 721.10140 Phosphoric acid, tin (2+) salt (2:3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphoric acid, tin (2...

7 CFR 3.44 - Centralized administrative offset.

Code of Federal Regulations, 2013 CFR

2013-01-01

... TINs of debtors who owe debts referred to Treasury under this section shall be compared to the names and TINs on payments to be made by Federal disbursing officials. Federal disbursing officials include... and TIN of a debtor match the name and TIN of a payee and all other requirements for offset have been...

40 CFR 721.10140 - Phosphoric acid, tin (2+) salt (2:3).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphoric acid, tin (2+) salt (2:3... Specific Chemical Substances § 721.10140 Phosphoric acid, tin (2+) salt (2:3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphoric acid, tin (2...

26 CFR 1.6050H-0 - Table of contents.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., 1989. (i) Failure to file return or to furnish statement. (ii) Failure to furnish TIN. (iii) Failure to...) Failure to furnish TIN. (iii) Failure to include correct information. (f) Requirement to request and to obtain TIN. (1) In general. (2) Manner of requesting TIN. (g) Effective date. (1) In general. (2) Points...

40 CFR 721.10230 - Rutile, tin zinc, calcium doped.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Rutile, tin zinc, calcium doped. 721... Substances § 721.10230 Rutile, tin zinc, calcium doped. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as rutile, tin zinc, calcium-doped (PMN P-06...

76 FR 68512 - Carolina Power & Light Company; H. B. Robinson Steam Electric Plant, Unit 2; Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-04

... (~1 percent). The elimination of tin has resulted in superior corrosion resistance and reduced irradiation-induced growth relative to both standard zircaloy (1.7 percent tin) and low-tin zircaloy (1.2 percent tin). The addition of niobium increases ductility, which is desirable to avoid brittle failures...

7 CFR 3.44 - Centralized administrative offset.

Code of Federal Regulations, 2014 CFR

2014-01-01

... TINs of debtors who owe debts referred to Treasury under this section shall be compared to the names and TINs on payments to be made by Federal disbursing officials. Federal disbursing officials include... and TIN of a debtor match the name and TIN of a payee and all other requirements for offset have been...

Influence of Microstructure on the Electrical Properties of Heteroepitaxial TiN Films

NASA Astrophysics Data System (ADS)

Xiang, Wenfeng; Liu, Yuan; Zhang, Jiaqi

2018-05-01

Heteroepitaxial TiN films were deposited on Si substrates by pulse laser deposition at different substrate temperature. The microstructure and surface morphology of the films were investigated by X-ray diffraction (θ-2θ scan, ω-scan, and ϕ-scan) and atomic force microscopy. The electrical properties of the prepared TiN films were studied using a physical property measurement system. The experimental results showed that the crystallinity and surface morphology of the TiN films were improved gradually with increasing substrate temperature below 700 °C. Specially, single crystal TiN films were prepared when substrate temperature is above 700 °C; However, the quality of TiN films gradually worsened when the substrate temperature was increased further. The electrical properties of the films were directly correlated to their crystalline quality. At the optimal substrate temperature of 700 °C, the TiN films exhibited the lowest resistivity and highest mobility of 25.7 μΩ cm and 36.1 cm2/V s, respectively. In addition, the mechanism concerning the influence of substrate temperature on the microstructure of TiN films is discussed in detail.

From toothpaste to topological insulators and materials for valleytronics: The journeys of fluorinated tin

NASA Astrophysics Data System (ADS)

Barraza-Lopez, Salvador; Rivero, Pablo; Yan, Jia-An; Garcia-Suarez, Victor Manuel; Ferrer, Jaime

2015-03-01

Tin fluoride has a vast literature. This material is stable in bulk form at room temperature and has commercial applications that include fluorinated toothpaste. Bulk tin fluoride has a pair of fluorine atoms bridging two tin atoms. In the recent past the electronic properties of 2D tin with honeycomb structure have been discussed thus generating a wealth of literature that emphasizes its non-topologically-trivial electronic properties due to the combination of a Dirac-like dispersion and a strong spin-orbit coupling given its large atomic mass. Nevertheless the stability of such freestanding structures has been contested recently. As it turns out, the most stable form of fluorinated tin does not possess a graphane-like structure either. In the most stable phase to be discussed here, fluorine atoms tilt away from (graphane-like) positions over/below tin atoms; in an atomistic arrangement similar to the one seen on their parent bulk structure. Electronic properties depend on atomistic coordination, and the most stable form of fluorinated tin does not possess non-trivial topological properties. Nevertheless it represents a new paradigm for valleytronics in 2D.

Organo-tins in sediments and mussels from the Sado estuarine system (Portugal).

PubMed

Quevauviller, P; Lavigne, R; Pinel, R; Astruc, M

1989-01-01

Analyses of methyl- and butyl-tin levels in freshwater, estuarine and marine sediments from the Sado estuarine system, and in mussels (Mytilus galloprovincialis) from its adjacent coast, have been performed in order to detect the contaminated areas. The main inputs of tributyl-tin (TBT), along with degradation products di- and monobutyl-tin (DBT and MBT), were detected in the estuarine zone, due to high discharge from shipyards located in this area. These levels are sometimes very high, ranging from 235 to 12,200 ng g(-1) total butyl-tins in sediments. Such inputs lead to higher bioconcentration values in mussels in the estuarine zone, as well as in a harbour located along the adjacent coast. The bioconcentration of organo-tins in mussel tissues could be enhanced in estuarine turbid waters, due to an ingestion of butyl-tins adsorbed onto fine particles, in comparison with non-turbid coastal waters. Debutylation processes occur in both sediments and mussel tissues; in organisms, these processes may lead to the formation of inorganic tin, which may be methylated differently according to the period of the year.

Carbon/tin oxide composite electrodes for improved lithium-ion batteries

DOE PAGES

Li, Yunchao; Levine, Alan M.; Zhang, Jinshui; ...

2018-05-17

Tin and tin oxide-based electrodes are promising high-capacity anodes for lithium-ion batteries. However, poor capacity retention is the major issue with these materials due to the large volumetric expansion that occurs when lithium is alloyed with tin during lithiation and delithiation process. Here, a method to prepare a low-cost, scalable carbon and tin(II) oxide composite anode is reported. The composite material was prepared by ball milling of carbon recovered from used tire powders with 25 wt% tin(II) oxide to form lithium-ion battery anode. With the impact of energy from the ball milling, tin oxide powders were uniformly distributed inside themore » pores of waste-tire-derived carbon. During lithiation and delithiation, the carbon matrix can effectively absorb the volume expansion caused by tin, thereby minimizing pulverization and capacity fade of the electrodes. In conclusion, the as-synthesized anode yielded a capacity of 690 mAh g –1 after 300 cycles at a current density of 40 mA g –1 with a stable battery performance.« less

Carbon/tin oxide composite electrodes for improved lithium-ion batteries

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

Li, Yunchao; Levine, Alan M.; Zhang, Jinshui

Tin and tin oxide-based electrodes are promising high-capacity anodes for lithium-ion batteries. However, poor capacity retention is the major issue with these materials due to the large volumetric expansion that occurs when lithium is alloyed with tin during lithiation and delithiation process. Here, a method to prepare a low-cost, scalable carbon and tin(II) oxide composite anode is reported. The composite material was prepared by ball milling of carbon recovered from used tire powders with 25 wt% tin(II) oxide to form lithium-ion battery anode. With the impact of energy from the ball milling, tin oxide powders were uniformly distributed inside themore » pores of waste-tire-derived carbon. During lithiation and delithiation, the carbon matrix can effectively absorb the volume expansion caused by tin, thereby minimizing pulverization and capacity fade of the electrodes. In conclusion, the as-synthesized anode yielded a capacity of 690 mAh g –1 after 300 cycles at a current density of 40 mA g –1 with a stable battery performance.« less

Infrared Emissivity of Tin upon Release of a 25 GPa Shock into a LiF Window

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

Turley, W. D., Holtkamp, D. B., Marshall, B. R., Stevens, G. D., Veeser, L. R.

We measured the emissivity of a tin sample at its interface with a lithium-fluoride window upon release of a 25 GPa shock wave from the tin into the window. Measurements were made over four wavelength bands between 1.2 and 5.4 μm. Thermal emission backgrounds from the tin, glue, and lithium fluoride were successfully removed from the reflectance signals. Emissivity changes for the sample, which was initially nearly specular, were small except for the longest wavelength band, where uncertainties were high because of poor signal-to-noise ratio at that wavelength. A thin glue layer, which bonds the sample to the window, wasmore » found to heat from reverberations of the shock wave between the tin and the lithium fluoride. At approximately 3.4 μm the thermal emission from the glue was large compared to the tin, allowing a good estimate of the glue temperature from the thermal radiance. The glue appears to remain slightly colder than the tin, thereby minimizing heat conduction into or out of the tin immediately after the shock passage.« less

A modeling approach on why simple central pattern generators are built of irregular neurons.

PubMed

Reyes, Marcelo Bussotti; Carelli, Pedro Valadão; Sartorelli, José Carlos; Pinto, Reynaldo Daniel

2015-01-01

The crustacean pyloric Central Pattern Generator (CPG) is a nervous circuit that endogenously provides periodic motor patterns. Even after about 40 years of intensive studies, the rhythm genesis is still not rigorously understood in this CPG, mainly because it is made of neurons with irregular intrinsic activity. Using mathematical models we addressed the question of using a network of irregularly behaving elements to generate periodic oscillations, and we show some advantages of using non-periodic neurons with intrinsic behavior in the transition from bursting to tonic spiking (as found in biological pyloric CPGs) as building components. We studied two- and three-neuron model CPGs built either with Hindmarsh-Rose or with conductance-based Hodgkin-Huxley-like model neurons. By changing a model's parameter we could span the neuron's intrinsic dynamical behavior from slow periodic bursting to fast tonic spiking, passing through a transition where irregular bursting was observed. Two-neuron CPG, half center oscillator (HCO), was obtained for each intrinsic behavior of the neurons by coupling them with mutual symmetric synaptic inhibition. Most of these HCOs presented regular antiphasic bursting activity and the changes of the bursting frequencies was studied as a function of the inhibitory synaptic strength. Among all HCOs, those made of intrinsic irregular neurons presented a wider burst frequency range while keeping a reliable regular oscillatory (bursting) behavior. HCOs of periodic neurons tended to be either hard to change their behavior with synaptic strength variations (slow periodic burster neurons) or unable to perform a physiologically meaningful rhythm (fast tonic spiking neurons). Moreover, 3-neuron CPGs with connectivity and output similar to those of the pyloric CPG presented the same results.

Influence of silicon oxide on the performance of TiN bottom electrode in phase change memory

NASA Astrophysics Data System (ADS)

Gao, Dan; Liu, Bo; Xu, Zhen; Wang, Heng; Xia, Yangyang; Wang, Lei; Zhu, Nanfei; Li, Ying; Zhan, Yipeng; Song, Zhitang; Feng, Songlin

2016-10-01

The stability of TiN which is the preferred bottom electrode contact (BEC) of phase change memory (PCM) due to its low thermal conductivity and suitable electrical conductivity, is very essential to the reliability of PCM devices. In this work, in order to investigate the effect of high aspect ratio process (HARP) SiO2 on the performance of TiN, both TiN/SiO2, TiN/SiN thin films and TiN BEC device structures are analyzed. By combining transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS), we found that the TiN would be oxidized after the deposition of HARP SiO2 and there exist a thin ( 4 nm) oxidation interfacial layer between TiN and SiO2. Electrical measurements were performed on the 1R PCM test-key die with 7 nm and 10 nm BEC-only cells. The statistical initial resistances of BEC have wide distribution and it is confirmed that the non-uniform oxidation of TiN BEC affects the astringency of the resistance of TiN BEC. The experimental results help to optimize the process of TiN BEC, and SiN is recommended as a better choice as the linear layer.

Tubulointerstitial nephritis antigen: an extracellular matrix protein that selectively regulates tubulogenesis vs. glomerulogenesis during mammalian renal development.

PubMed

Kanwar, Y S; Kumar, A; Yang, Q; Tian, Y; Wada, J; Kashihara, N; Wallner, E I

1999-09-28

Tubulointerstitial nephritis antigen (TIN-ag) is an extracellular matrix protein and is expressed in the renal tubular basement membranes. Its role in metanephric development was investigated. TIN-ag cDNA, isolated from the newborn mouse library, had an ORF of 1,425 nucleotides, a putative signal sequence, and an ATP/GTP-binding site. The translated sequence had approximately 80% identity with rabbit TIN-ag. Among various tissues, TIN-ag mRNA was primarily expressed in the newborn kidney. In the embryonic metanephros, TIN-ag expression was confined to the distal convolution or pole of the S-shaped body, the segment of the nascent nephron that is the progenitor of renal tubules. Treatment with TIN-ag antisense oligodeoxynucleotide induced dysmorphogenesis of the embryonic metanephroi, malformation of the S-shaped body, and a decrease in the tubular population, whereas the glomeruli were unaffected. Treatment also led to a decrease of TIN-Ag mRNA, de novo synthesis of TIN-ag protein, and its antibody reactivity. The mRNA expression of glomerular epithelial protein 1 (a marker for renal podocytes), anti-heparan-sulfate-proteoglycan antibody reactivity, and wheat germ agglutinin lectin staining of the metanephros were unaffected. The anti-TIN-ag antibody treatment also caused deformation of the S-shaped body and a reduction in the tubular population, whereas the glomeruli were unchanged. The data suggest that the TIN-ag, unlike other basement membrane proteins, selectively regulates tubulogenesis, whereas glomerulogenesis is largely unaffected.

A probabilistic approach for shallow rainfall-triggered landslide modeling at basin scale. A case study in the Luquillo Forest, Puerto Rico

NASA Astrophysics Data System (ADS)

Dialynas, Y. G.; Arnone, E.; Noto, L. V.; Bras, R. L.

2013-12-01

Slope stability depends on geotechnical and hydrological factors that exhibit wide natural spatial variability, yet sufficient measurements of the related parameters are rarely available over entire study areas. The uncertainty associated with the inability to fully characterize hydrologic behavior has an impact on any attempt to model landslide hazards. This work suggests a way to systematically account for this uncertainty in coupled distributed hydrological-stability models for shallow landslide hazard assessment. A probabilistic approach for the prediction of rainfall-triggered landslide occurrence at basin scale was implemented in an existing distributed eco-hydrological and landslide model, tRIBS-VEGGIE -landslide (Triangulated Irregular Network (TIN)-based Real-time Integrated Basin Simulator - VEGetation Generator for Interactive Evolution). More precisely, we upgraded tRIBS-VEGGIE- landslide to assess the likelihood of shallow landslides by accounting for uncertainty related to geotechnical and hydrological factors that directly affect slope stability. Natural variability of geotechnical soil characteristics was considered by randomizing soil cohesion and friction angle. Hydrological uncertainty related to the estimation of matric suction was taken into account by considering soil retention parameters as correlated random variables. The probability of failure is estimated through an assumed theoretical Factor of Safety (FS) distribution, conditioned on soil moisture content. At each cell, the temporally variant FS statistics are approximated by the First Order Second Moment (FOSM) method, as a function of parameters statistical properties. The model was applied on the Rio Mameyes Basin, located in the Luquillo Experimental Forest in Puerto Rico, where previous landslide analyses have been carried out. At each time step, model outputs include the probability of landslide occurrence across the basin, and the most probable depth of failure at each soil column. The use of the proposed probabilistic approach for shallow landslide prediction is able to reveal and quantify landslide risk at slopes assessed as stable by simpler deterministic methods.

Characterization techniques for incorporating backgrounds into DIRSIG

NASA Astrophysics Data System (ADS)

Brown, Scott D.; Schott, John R.

2000-07-01

The appearance of operation hyperspectral imaging spectrometers in both solar and thermal regions has lead to the development of a variety of spectral detection algorithms. The development and testing of these algorithms requires well characterized field collection campaigns that can be time and cost prohibitive. Radiometrically robust synthetic image generation (SIG) environments that can generate appropriate images under a variety of atmospheric conditions and with a variety of sensors offers an excellent supplement to reduce the scope of the expensive field collections. In addition, SIG image products provide the algorithm developer with per-pixel truth, allowing for improved characterization of the algorithm performance. To meet the needs of the algorithm development community, the image modeling community needs to supply synthetic image products that contain all the spatial and spectral variability present in real world scenes, and that provide the large area coverage typically acquired with actual sensors. This places a heavy burden on synthetic scene builders to construct well characterized scenes that span large areas. Several SIG models have demonstrated the ability to accurately model targets (vehicles, buildings, etc.) Using well constructed target geometry (from CAD packages) and robust thermal and radiometry models. However, background objects (vegetation, infrastructure, etc.) dominate the percentage of real world scene pixels and utilizing target building techniques is time and resource prohibitive. This paper discusses new methods that have been integrated into the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model to characterize backgrounds. The new suite of scene construct types allows the user to incorporate both terrain and surface properties to obtain wide area coverage. The terrain can be incorporated using a triangular irregular network (TIN) derived from elevation data or digital elevation model (DEM) data from actual sensors, temperature maps, spectral reflectance cubes (possible derived from actual sensors), and/or material and mixture maps. Descriptions and examples of each new technique are presented as well as hybrid methods to demonstrate target embedding in real world imagery.

The gamma cycle.

PubMed

Fries, Pascal; Nikolić, Danko; Singer, Wolf

2007-07-01

Activated neuronal groups typically engage in rhythmic synchronization in the gamma-frequency range (30-100 Hz). Experimental and modeling studies demonstrate that each gamma cycle is framed by synchronized spiking of inhibitory interneurons. Here, we review evidence suggesting that the resulting rhythmic network inhibition interacts with excitatory input to pyramidal cells such that the more excited cells fire earlier in the gamma cycle. Thus, the amplitude of excitatory drive is recoded into phase values of discharges relative to the gamma cycle. This recoding enables transmission and read out of amplitude information within a single gamma cycle without requiring rate integration. Furthermore, variation of phase relations can be exploited to facilitate or inhibit exchange of information between oscillating cell assemblies. The gamma cycle could thus serve as a fundamental computational mechanism for the implementation of a temporal coding scheme that enables fast processing and flexible routing of activity, supporting fast selection and binding of distributed responses. This review is part of the INMED/TINS special issue Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com).

Manhunting: Counter-Network Organization for Irregular Warfare

DTIC Science & Technology

2009-09-01

received his B.A. in International Relations from the University of Kansas in 1985 and M.S. in Computer Applications Management from Lesley University...collection management , and targeting.b. Operational level processes begin with intelligence on the adversary capabilities with granular focus to mitigate... managers work with analysts, targeting experts, decision makers, planners, and operations personnel, guiding multidisciplinary intelligence collection to

Hydrographic Surveys for Six Water Bodies in Eastern Nebraska, 2005-07

USGS Publications Warehouse

Johnson, Michaela R.; Andersen, Michael J.; Sebree, Sonja K.

2008-01-01

The U.S. Geological Survey, in cooperation with the Nebraska Department of Environmental Quality, completed hydrographic surveys for six water bodies in eastern Nebraska: Maskenthine Wetland, Olive Creek Lake, Standing Bear Lake, Wagon Train Lake and Wetland, Wildwood Lake, and Yankee Hill Lake and sediment basin. The bathymetric data were collected using a boat-mounted survey-grade fathometer that operated at 200 kHz, and a differentially corrected Global Positioning System with antenna mounted directly above the echo-sounder transducer. Shallow-water and terrestrial areas were surveyed using a Real-Time Kinematic Global Positioning System. The bathymetric, shallow-water, and terrestrial data were processed in a geographic information system to generate a triangulated irregular network representation of the bottom of the water body. Bathymetric contours were interpolated from the triangulated irregular network data using a 2-foot contour interval. Bathymetric contours at the conservation pool elevation for Maskenthine Wetland, Yankee Hill Lake, and Yankee Hill sediment pond also were interpolated in addition to the 2-foot contours. The surface area and storage capacity of each lake or wetland were calculated for 1-foot intervals of water surface elevation and are tabulated in the Appendix for all water bodies.

Predicting healthcare trajectories from medical records: A deep learning approach.

PubMed

Pham, Trang; Tran, Truyen; Phung, Dinh; Venkatesh, Svetha

2017-05-01

Personalized predictive medicine necessitates the modeling of patient illness and care processes, which inherently have long-term temporal dependencies. Healthcare observations, stored in electronic medical records are episodic and irregular in time. We introduce DeepCare, an end-to-end deep dynamic neural network that reads medical records, stores previous illness history, infers current illness states and predicts future medical outcomes. At the data level, DeepCare represents care episodes as vectors and models patient health state trajectories by the memory of historical records. Built on Long Short-Term Memory (LSTM), DeepCare introduces methods to handle irregularly timed events by moderating the forgetting and consolidation of memory. DeepCare also explicitly models medical interventions that change the course of illness and shape future medical risk. Moving up to the health state level, historical and present health states are then aggregated through multiscale temporal pooling, before passing through a neural network that estimates future outcomes. We demonstrate the efficacy of DeepCare for disease progression modeling, intervention recommendation, and future risk prediction. On two important cohorts with heavy social and economic burden - diabetes and mental health - the results show improved prediction accuracy. Copyright © 2017 Elsevier Inc. All rights reserved.

76 FR 17391 - Applications for New Awards; United States-Brazil Higher Education Consortia Program

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-29

... Number (TIN); b. Register both your DUNS number and TIN with the Central Contractor Registry (CCR), the Government's primary registrant database; c. Provide your DUNS number and TIN on your application; and d..., agency, institution, or organization, you can obtain a TIN from the Internal Revenue Service. If you are...

19 CFR 159.22 - Net weights and tares.

Code of Federal Regulations, 2013 CFR

2013-04-01

... tins imported from Spain: The following schedule drained weight shall be used as the Customs dutiable... in tins and such drained weight being the allowance made in liquidation for tare for water: Size can Drained weight 3 kilo 13.6 kilograms-case of 6 tins. 794 grams 16.7 kilograms-case of 24 tins. 425 grams 8...

78 FR 22855 - Applications for New Awards; Fulbright-Hays Group Projects Abroad Program-Short-Term Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-17

... (DUNS) number and a Taxpayer Identification Number (TIN); b. Register both your DUNS number and TIN with... (SAM), the Government's primary registrant database; c. Provide your DUNS number and TIN on your... you are a corporate entity, agency, institution, or organization, you can obtain a TIN from the...

76 FR 66855 - United States Savings Bonds, Series EE, HH and I

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-28

.... 351.43 to read as follows: Sec. 351.43 Are Taxpayer Identification Numbers (TINs) required for the... owner's TIN is not known, the TIN of the purchaser must be included in the registration of the bond. 0 6.... 359.28 Are Taxpayer Identification Numbers (TINs) required for the registration of definitive series I...

77 FR 37012 - Applications for New Awards: Disability and Rehabilitation Research Projects and Centers Program...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-20

... Number (TIN); b. Register both your DUNS number and TIN with the Central Contractor Registry (CCR), the Government's primary registrant database; c. Provide your DUNS number and TIN on your application; and d..., agency, institution, or organization, you can obtain a TIN from the Internal Revenue Service. If you are...

77 FR 51782 - Federal Acquisition Regulation; Information Collection; Taxpayer Identification Number Information

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-27

... agency is required to furnish its Tax Identification Number (TIN) to that agency. 31 U.S.C. 3325(d... and submitted to a disbursing official, the TIN of the contractor receiving payment under the voucher... other information, its TIN. The TIN may be used by the Government to collect and report on any...

19 CFR 159.22 - Net weights and tares.

Code of Federal Regulations, 2012 CFR

2012-04-01

... tins imported from Spain: The following schedule drained weight shall be used as the Customs dutiable... in tins and such drained weight being the allowance made in liquidation for tare for water: Size can Drained weight 3 kilo 13.6 kilograms-case of 6 tins. 794 grams 16.7 kilograms-case of 24 tins. 425 grams 8...

78 FR 18343 - Federal Acquisition Regulation; Submission for OMB Review; Taxpayer Identification Number...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

... agency is required to furnish its Tax Identification Number (TIN) to that agency. 31 U.S.C. 3325(d... and submitted to a disbursing official, the TIN of the contractor receiving payment under the voucher... other information, its TIN. The TIN may be used by the Government to collect and report on any...

77 FR 11189 - Yokohama Tire Corporation, Denial of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-24

... full Tire Identification Number (TIN) on one sidewall but omit the partial serial number on the other....'' YTC explained its belief that the Tire Identification Number (TIN) and the partial TIN are used to... TIN is molded on the intended outboard sidewall of these tires and consumers could be directed to have...

21 CFR 184.1845 - Stannous chloride (anhydrous and dihydrated).

Code of Federal Regulations, 2014 CFR

2014-04-01

.... 7772-99-8) is the chloride salt of metallic tin. It is prepared by reacting molten tin with either chlorine or gaseous tin tetrachloride. Dihydrated stannous chloride (SnCl2·2H2O, CAS Reg. No. 10025-69-1) is the chloride salt of metallic tin that contains two molecules of water. It is prepared from...

19 CFR 159.22 - Net weights and tares.

Code of Federal Regulations, 2014 CFR

2014-04-01

... tins imported from Spain: The following schedule drained weight shall be used as the Customs dutiable... in tins and such drained weight being the allowance made in liquidation for tare for water: Size can Drained weight 3 kilo 13.6 kilograms-case of 6 tins. 794 grams 16.7 kilograms-case of 24 tins. 425 grams 8...

75 FR 51524 - Yokohama Tire Corporation, Receipt of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-20

... noncompliance is that the subject tires do not have full or partial Tire Identification Numbers (TIN) on one of their sidewalls. YTC explained that the intended outboard sidewall did have the complete TIN, but the opposite sidewall has no TIN or partial TIN. YTC stated its belief that the noncompliance is...

76 FR 58536 - Tin- and Chromium-Coated Steel Sheet From Japan; Notice of Commission Determination To Conduct a...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-21

... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-860 (Second Review)] Tin- and Chromium... Concerning the Antidumping Duty Order on Tin- and Chromium-Coated Steel Sheet From Japan AGENCY: United.... 1675(c)(5)) to determine whether revocation of the antidumping duty order on tin- and chromium-coated...

19 CFR 159.22 - Net weights and tares.

Code of Federal Regulations, 2010 CFR

2010-04-01

... tins imported from Spain: The following schedule drained weight shall be used as the Customs dutiable... in tins and such drained weight being the allowance made in liquidation for tare for water: Size can Drained weight 3 kilo 13.6 kilograms-case of 6 tins. 794 grams 16.7 kilograms-case of 24 tins. 425 grams 8...

19 CFR 159.22 - Net weights and tares.

Code of Federal Regulations, 2011 CFR

2011-04-01

... tins imported from Spain: The following schedule drained weight shall be used as the Customs dutiable... in tins and such drained weight being the allowance made in liquidation for tare for water: Size can Drained weight 3 kilo 13.6 kilograms-case of 6 tins. 794 grams 16.7 kilograms-case of 24 tins. 425 grams 8...

77 FR 42990 - Significant New Use Rules on Certain Chemical Substances

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-23

... Toxic Substances Control Act (TSCA) for the chemical substances rutile, tin zinc, calcium-doped (CAS No. 389623-01-2) and rutile, tin zinc, sodium-doped (CAS No. 389623-07-8) which were the subject of..., tin zinc, calcium-doped (PMN P-06-36; CAS No. 389623-01-2) and rutile, tin zinc, sodium-doped (PMN P...

Effect of alloying elements on the physicomechanical properties of copper and tin bronze

NASA Astrophysics Data System (ADS)

Ri, Kh.; Komkov, V. G.; Ri, E. Kh.

2014-09-01

The effect of alloying elements (Al, Si, Mn, Zn, Ni, As) on the physicomechanical properties of copper and tin bronze (6 wt % Sn) is studied. These alloying elements are found to increase the hardness and the microhardness of the structural constituents of Cu- X alloys due to hardening the α solid solution and eutectoid, and this effect of alloying elements is most effective in tin bronze. Alloyed copper and tin bronze have a lower thermal conductivity and corrosion resistance as compared to plain copper and tin bronze.

Stannosis in Hearth Tinners

PubMed Central

Cole, C. W. D.; Davies, J. V. S. A.; Kipling, M. D.; Ritchie, G. L.

1964-01-01

There have been no published reports of stannosis in tinners. In this paper its occurrence in hearth tinners is described. In hearth tinning molten tin is poured into heated iron hollow-ware and smoothed over the internal surface with a cork bat. Ammonium chloride powder is used as a flux. It is considered that fumes arising in the process from the reaction of the flux and the tin caused a concentration of tin compounds in the atmosphere, and this was the mechanism by which stannosis was produced. The literature on stannosis and tinning is reviewed. Images PMID:14180484

VO2 /TiN Plasmonic Thermochromic Smart Coatings for Room-Temperature Applications.

PubMed

Hao, Qi; Li, Wan; Xu, Huiyan; Wang, Jiawei; Yin, Yin; Wang, Huaiyu; Ma, Libo; Ma, Fei; Jiang, Xuchuan; Schmidt, Oliver G; Chu, Paul K

2018-03-01

Vanadium dioxide/titanium nitride (VO 2 /TiN) smart coatings are prepared by hybridizing thermochromic VO 2 with plasmonic TiN nanoparticles. The VO 2 /TiN coatings can control infrared (IR) radiation dynamically in accordance with the ambient temperature and illumination intensity. It blocks IR light under strong illumination at 28 °C but is IR transparent under weak irradiation conditions or at a low temperature of 20 °C. The VO 2 /TiN coatings exhibit a good integral visible transmittance of up to 51% and excellent IR switching efficiency of 48% at 2000 nm. These unique advantages make VO 2 /TiN promising as smart energy-saving windows. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molten tin reprocessing of spent nuclear fuel elements

DOEpatents

Heckman, Richard A.

1983-01-01

A method and apparatus for reprocessing spent nuclear fuel is described. Within a containment vessel, a solid plug of tin and nitride precipitates supports a circulating bath of liquid tin therein. Spent nuclear fuel is immersed in the liquid tin under an atmosphere of nitrogen, resulting in the formation of nitride precipitates. The layer of liquid tin and nitride precipitates which interfaces the plug is solidified and integrated with the plug. Part of the plug is melted, removing nitride precipitates from the containment vessel, while a portion of the plug remains solidified to support the liquid tin and nitride precipitates remaining in the containment vessel. The process is practiced numerous times until substantially all of the precipitated nitrides are removed from the containment vessel.

High temperature strain gages

NASA Technical Reports Server (NTRS)

Gregory, Otto J. (Inventor); You, Tao (Inventor)

2011-01-01

A ceramic strain gage based on reactively sputtered indium-tin-oxide (ITO) thin films is used to monitor the structural integrity of components employed in aerospace propulsion systems operating at temperatures in excess of 1500.degree. C. A scanning electron microscopy (SEM) of the thick ITO sensors reveals a partially sintered microstructure comprising a contiguous network of submicron ITO particles with well defined necks and isolated nanoporosity. Densification of the ITO particles was retarded during high temperature exposure with nitrogen thus stabilizing the nanoporosity. ITO strain sensors were prepared by reactive sputtering in various nitrogen/oxygen/argon partial pressures to incorporate more nitrogen into the films. Under these conditions, sintering and densification of the ITO particles containing these nitrogen rich grain boundaries was retarded and a contiguous network of nano-sized ITO particles was established.

catena-Poly[[triphenyl-tin(IV)]-μ-phenyl-phosphinato-κO:O'].

PubMed

Diop, Tidiane; Diop, Libasse; Kociok-Köhn, Gabriele; Molloy, Kieran C; Stoeckli-Evans, Helen

2011-12-01

In the structure of the title coordination polymer, [Sn(C(6)H(5))(3)(C(6)H(6)O(2)P)](n) or [PhP(H)O(2)Sn(IV)(Ph)(3)](n), the Sn(IV) atom is five-coordinate, with the SnC(3)O(2) framework in a trans trigonal-bipyramidal arrangement having the PhP(H)O(2) (-) anions in apical positions. In the crystal, neighbouring polymer chains are linked via C-H⋯π inter-actions, forming a two-dimensional network lying parallel to (001).

An electrical model of vapor-anode, multitube AMTEC cells[Alkali Metal Thermal to Electric Conversion

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

Tournier, J.M.; El-Genk, M.S.

1998-07-01

A two-dimensional electrical model of vapor-anode, multi-tube AMTEC cells was developed, which included four options of current collector configurations. Simulation results of several cells tested at AFRL showed that electrical losses in the current collector networks and the connecting leads were negligible. The polarization/concentration losses in the TiN electrodes were significant, amounting to 25%--50% of the cell theoretical power, while the contact and BASE ionic losses amounted to less than 16% of the cell theoretical power.

Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

NASA Technical Reports Server (NTRS)

Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Larry L.; Wright, Maria C.

2010-01-01

To comply with lead-free legislation, many manufacturers have converted from tin-lead to pure tin finishes of electronic components. However, pure tin finishes have a greater propensity to grow tin whiskers than tin-lead finishes. Since tin whiskers present an electrical short circuit hazard in electronic components, simulations have been developed to quantify the risk of said short circuits occurring. Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that had an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish .

Developing an Empirical Model for Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

NASA Technical Reports Server (NTRS)

Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Larry L.; Wright, Maria C.

2009-01-01

To comply with lead-free legislation, many manufacturers have converted from tin-lead to pure tin finishes of electronic components. However, pure tin finishes have a greater propensity to grow tin whiskers than tin-lead finishes. Since tin whiskers present an electrical short circuit hazard in electronic components, simulations have been developed to quantify the risk of said short circuits occurring. Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that had an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish.

21 CFR 184.1845 - Stannous chloride (anhydrous and dihydrated).

Code of Federal Regulations, 2010 CFR

2010-04-01

.... Anhydrous stannous chloride (SnCl2, CAS Reg. No. 7772-99-8) is the chloride salt of metallic tin. It is prepared by reacting molten tin with either chlorine or gaseous tin tetrachloride. Dihydrated stannous chloride (SnCl2·2H2O, CAS Reg. No. 10025-0969-091) is the chloride salt of metallic tin that contains two...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Tin-coated lead foil capsules for wine bottles... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tin-coated lead foil capsules for wine bottles. 189... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Tin-coated lead foil capsules for wine bottles... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

31 CFR 256.13 - Are agencies required to supply a taxpayer identification number (TIN) when submitting a request...

Code of Federal Regulations, 2011 CFR

2011-07-01

... taxpayer identification number (TIN) when submitting a request for payment? 256.13 Section 256.13 Money and... BILLS Requesting Payments § 256.13 Are agencies required to supply a taxpayer identification number (TIN) when submitting a request for payment? Yes, agencies must include a valid TIN on all requests for...

21 CFR 184.1845 - Stannous chloride (anhydrous and dihydrated).

Code of Federal Regulations, 2013 CFR

2013-04-01

.... Anhydrous stannous chloride (SnCl2, CAS Reg. No. 7772-99-8) is the chloride salt of metallic tin. It is prepared by reacting molten tin with either chlorine or gaseous tin tetrachloride. Dihydrated stannous chloride (SnCl2·2H2O, CAS Reg. No. 10025-69-1) is the chloride salt of metallic tin that contains two...

31 CFR 359.53 - Are taxpayer identification numbers (TINs) required for registration of book-entry Series I...

Code of Federal Regulations, 2012 CFR

2012-07-01

... (TINs) required for registration of book-entry Series I savings bonds? 359.53 Section 359.53 Money and... Savings Bonds § 359.53 Are taxpayer identification numbers (TINs) required for registration of book-entry Series I savings bonds? The TIN of each person named in the registration is required to purchase a book...

31 CFR 351.68 - Are taxpayer identification numbers (TINs) required for registration of book-entry Series EE...

Code of Federal Regulations, 2013 CFR

2013-07-01

... (TINs) required for registration of book-entry Series EE savings bonds? 351.68 Section 351.68 Money and... Savings Bonds § 351.68 Are taxpayer identification numbers (TINs) required for registration of book-entry Series EE savings bonds? The TIN of each person named in the registration is required to purchase a book...

76 FR 60001 - Certain Tin Mill Products From Japan; Final Results of the Second Expedited Sunset Review of the...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-28

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-854] Certain Tin Mill Products... duty order on certain tin mill products from Japan, pursuant to section 751(c) of the Tariff [[Page... on certain tin mill products from Japan pursuant to section 751(c) of the Act. See Initiation of Five...

31 CFR 256.13 - Are agencies required to supply a taxpayer identification number (TIN) when submitting a request...

Code of Federal Regulations, 2010 CFR

2010-07-01

... taxpayer identification number (TIN) when submitting a request for payment? 256.13 Section 256.13 Money and... BILLS Requesting Payments § 256.13 Are agencies required to supply a taxpayer identification number (TIN) when submitting a request for payment? Yes, agencies must include a valid TIN on all requests for...

31 CFR 359.53 - Are taxpayer identification numbers (TINs) required for registration of book-entry Series I...

Code of Federal Regulations, 2011 CFR

2011-07-01

... (TINs) required for registration of book-entry Series I savings bonds? 359.53 Section 359.53 Money and... Savings Bonds § 359.53 Are taxpayer identification numbers (TINs) required for registration of book-entry Series I savings bonds? The TIN of each person named in the registration is required to purchase a book...

21 CFR 184.1845 - Stannous chloride (anhydrous and dihydrated).

Code of Federal Regulations, 2011 CFR

2011-04-01

.... Anhydrous stannous chloride (SnCl2, CAS Reg. No. 7772-99-8) is the chloride salt of metallic tin. It is prepared by reacting molten tin with either chlorine or gaseous tin tetrachloride. Dihydrated stannous chloride (SnCl2·2H2O, CAS Reg. No. 10025-0969-091) is the chloride salt of metallic tin that contains two...

31 CFR 256.13 - Are agencies required to supply a taxpayer identification number (TIN) when submitting a request...

Code of Federal Regulations, 2012 CFR

2012-07-01

... taxpayer identification number (TIN) when submitting a request for payment? 256.13 Section 256.13 Money and... BILLS Requesting Payments § 256.13 Are agencies required to supply a taxpayer identification number (TIN) when submitting a request for payment? Yes, agencies must include a valid TIN on all requests for...

31 CFR 351.68 - Are taxpayer identification numbers (TINs) required for registration of book-entry Series EE...

Code of Federal Regulations, 2014 CFR

2014-07-01

... (TINs) required for registration of book-entry Series EE savings bonds? 351.68 Section 351.68 Money and... EE Savings Bonds § 351.68 Are taxpayer identification numbers (TINs) required for registration of book-entry Series EE savings bonds? The TIN of each person named in the registration is required to...

31 CFR 359.53 - Are taxpayer identification numbers (TINs) required for registration of book-entry Series I...

Code of Federal Regulations, 2014 CFR

2014-07-01

... (TINs) required for registration of book-entry Series I savings bonds? 359.53 Section 359.53 Money and... Savings Bonds § 359.53 Are taxpayer identification numbers (TINs) required for registration of book-entry Series I savings bonds? The TIN of each person named in the registration is required to purchase a book...

31 CFR 256.13 - Are agencies required to supply a taxpayer identification number (TIN) when submitting a request...

Code of Federal Regulations, 2014 CFR

2014-07-01

... taxpayer identification number (TIN) when submitting a request for payment? 256.13 Section 256.13 Money and... BILLS Requesting Payments § 256.13 Are agencies required to supply a taxpayer identification number (TIN) when submitting a request for payment? Yes, agencies must include a valid TIN on all requests for...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Tin-coated lead foil capsules for wine bottles... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

31 CFR 351.68 - Are taxpayer identification numbers (TINs) required for registration of book-entry Series EE...

Code of Federal Regulations, 2011 CFR

2011-07-01

... (TINs) required for registration of book-entry Series EE savings bonds? 351.68 Section 351.68 Money and... Savings Bonds § 351.68 Are taxpayer identification numbers (TINs) required for registration of book-entry Series EE savings bonds? The TIN of each person named in the registration is required to purchase a book...

78 FR 34355 - Applications for New Awards; National Institute on Disability and Rehabilitation Research...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-07

... (TIN); b. Register both your DUNS number and TIN with the Central Contractor Registry (CCR)--and, after...; c. Provide your DUNS number and TIN on your application; and d. Maintain an active CRR or SAM... organization, you can obtain a TIN from the Internal Revenue Service. If you are an individual, you can obtain...

31 CFR 359.53 - Are taxpayer identification numbers (TINs) required for registration of book-entry Series I...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (TINs) required for registration of book-entry Series I savings bonds? 359.53 Section 359.53 Money and... Savings Bonds § 359.53 Are taxpayer identification numbers (TINs) required for registration of book-entry Series I savings bonds? The TIN of each person named in the registration is required to purchase a book...

31 CFR 351.68 - Are taxpayer identification numbers (TINs) required for registration of book-entry Series EE...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (TINs) required for registration of book-entry Series EE savings bonds? 351.68 Section 351.68 Money and... Savings Bonds § 351.68 Are taxpayer identification numbers (TINs) required for registration of book-entry Series EE savings bonds? The TIN of each person named in the registration is required to purchase a book...

31 CFR 359.53 - Are taxpayer identification numbers (TINs) required for registration of book-entry Series I...

Code of Federal Regulations, 2013 CFR

2013-07-01

... (TINs) required for registration of book-entry Series I savings bonds? 359.53 Section 359.53 Money and... Savings Bonds § 359.53 Are taxpayer identification numbers (TINs) required for registration of book-entry Series I savings bonds? The TIN of each person named in the registration is required to purchase a book...

31 CFR 256.13 - Are agencies required to supply a taxpayer identification number (TIN) when submitting a request...

Code of Federal Regulations, 2013 CFR

2013-07-01

... taxpayer identification number (TIN) when submitting a request for payment? 256.13 Section 256.13 Money and... BILLS Requesting Payments § 256.13 Are agencies required to supply a taxpayer identification number (TIN) when submitting a request for payment? Yes, agencies must include a valid TIN on all requests for...

21 CFR 184.1845 - Stannous chloride (anhydrous and dihydrated).

Code of Federal Regulations, 2012 CFR

2012-04-01

.... Anhydrous stannous chloride (SnCl2, CAS Reg. No. 7772-99-8) is the chloride salt of metallic tin. It is prepared by reacting molten tin with either chlorine or gaseous tin tetrachloride. Dihydrated stannous chloride (SnCl2·2H2O, CAS Reg. No. 10025-69-1) is the chloride salt of metallic tin that contains two...

Tin Whisker Testing and Modeling

DTIC Science & Technology

2015-11-01

FINAL REPORT Tin Whisker Testing and Modeling SERDP Project WP-1753 NOVEMBER 2015 Stephan J. Meschter Polina Snugovsky BAE Systems...lead (Pb) is that component manufacturers have primarily switched to tin -rich finishes and solder alloys in commercial-off-the-shelf products...Unfortunately, this creates an increased risk of tin whisker formation that can result in undesirable electrical failures unless military and aerospace

31 CFR 351.68 - Are taxpayer identification numbers (TINs) required for registration of book-entry Series EE...

Code of Federal Regulations, 2012 CFR

2012-07-01

... (TINs) required for registration of book-entry Series EE savings bonds? 351.68 Section 351.68 Money and... Savings Bonds § 351.68 Are taxpayer identification numbers (TINs) required for registration of book-entry Series EE savings bonds? The TIN of each person named in the registration is required to purchase a book...

21 CFR 178.2650 - Organotin stabilizers in vinyl chloride plastics.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-octyl)tin S,S′-bis(isooctylmercaptoacetate) is an octyltin chemical having 15.1 to 16.4 percent by weight of tin (Sn) and having 8.1 to 8.9 percent by weight of mercapto sulfur. It is made from di(n-octyl)tin dichloride or di(n-octyl)tin oxide. The isooctyl radical in the mercaptoacetate is derived from...

Synthesis of tin (II) oxide from tin (II) oxohydroxide

NASA Astrophysics Data System (ADS)

Kuznetsova, Svetlana; Lisitsa, Konstantin

2017-11-01

Sufficiently limited use of tin (II) oxide is associated with the difficulties of its preparation without impurities of tin (IV) oxide. Understanding the cause of the oxidation process will make it possible to develop methods for obtaining SnO without impurities. The influence of ammonium chloride concentration in the suspension on the oxide composition was investigated. The temperature of oxidation (400 °C) on the air and temperature decomposition in the argon (350 °C) of Sn6O4(OH)4 in the solid phase were determined by the thermal analysis method. The decomposition temperature of the oxyhydroxide in the suspension of ammonium chloride does not exceed 100 °C. An increase in the content of ammonium chloride in an aqueous solution leads to an increase i n the solubility of oxohydroxide and leads to an increase in pH. The suspensions of Sn6O4(OH)4 were subjected to heat treatment on a sand bath and under microwave irradiation. Samples of tin oxide were obtained. The quantitative composition of the mixture of tin oxides was determined. The research also highlights emphasizes that the oxidation of tin (II) to tin (IV) is associated with the dissolved oxygen content in the suspension.

Wear of tin coating and Al-Si alloy substrate against carburized steel under mixed lubrication

NASA Astrophysics Data System (ADS)

Wang, Q.; Cheng, H. S.; Fine, M. E.

1994-04-01

Tin coatings on Al-Si alloys are widely used in the automotive industries. The soft tin coating and the harder substrate alloy form a tribological system with the advantages of low friction and reasonably high load-bearing capacity. Wear tests of tin coated Al-Si Z332 alloy in conformal contact against carburized 1016 steel have been carried out under mixed lubrications with SAE 10W30 oil to study the wear mechanisms. Two major wear mechanisms, uniform wear of the tin coating due to micro-plowing and spall pitting related to the substrate are found to contribute to the bearing material loss when the fluid lubrication film is relatively thick (Lambda about 1.6). Under conditions of thinner films (Lambda approximately = 0.8), some local coating debonding occurs. The pitting and local coating debounding are closely related to fracture in the substrate. The bonding between silicon and tin seems to be weaker than between aluminum and tin. During wear, oxidation occurs.

Fabrication of TiN nanorods by electrospinning and their electrochemical properties

NASA Astrophysics Data System (ADS)

Sun, Dongfei; Lang, Junwei; Yan, Xingbin; Hu, Litian; Xue, Qunji

2011-05-01

TiN nanorods were synthesized using electrospinning technique followed by thermolysis in different atmospheres. A dimethyl formamide-ethanol solution of poly-(vinyl pyrrolidone) and Ti (IV)-isopropoxide was used as the electrospinning precursor solution and as-spun nanofibers were calcined at 500 °C in air to generate TiO 2 nanofibers. Subsequently, a conversion from TiO 2 nanofibers to TiN nanorods was employed by the nitridation treatment at 600˜1400 °C in ammonia atmosphere. A typical characteristic of the final products was that the pristine nanofibers were cut into nanorods. The conversion from TiO 2 to TiN was realized when the nitridation temperature was above 800 °C. As-prepared nanorods were composed of TiN nano-crystallites and the average crystallite size gradually increased with the increase of the nitridation temperature. Electrochemical properties of TiN nanorods showed strong dependence on the nitridation temperature. The maximum value of the specific capacitance was obtained from the TiN nanorods prepared at 800 °C.

Effect of doping of tin on optoelectronic properties of indium oxide: DFT study

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

Tripathi, Madhvendra Nath, E-mail: ommadhav27@gmail.com

2015-06-24

Indium tin oxide is widely used transparent conductor. Experimentally observed that 6% tin doping in indium oxide is suitable for optoelectronic applications and more doping beyond this limit degrades the optoelectronic property. The stoichiometry (In{sub 32-x}Sn{sub x}O{sub 48+x/2}; x=0-6) is taken to understand the change in lattice parameter, electronic structure, and optical property of ITO. It is observed that lattice parameter increases and becomes constant after 6% tin doping that is in good agreement of the experimental observation. The electronic structure calculation shows that the high tin doping in indium oxide adversely affects the dispersive nature of the bottom ofmore » conduction band of pure indium oxide and decreases the carrier mobility. Optical calculations show that transmittance goes down upto 60% for the tin concentration more than 6%. The present paper shows that how more than 6% tin doping in indium oxide adversely affects the optoelectronic property of ITO.« less

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

Rohwer, Lauren E. S.; Martin, James E.

In this study, reliable methods for tin whisker mitigation are needed for applications that utilize tin-plated commercial components. Tin can grow whiskers that can lead to electrical shorting, possibly causing critical systems to fail catastrophically. The mechanisms of tin whisker growth are unclear and this makes prediction of the lifetimes of critical components uncertain. The development of robust methods for tin whisker mitigation is currently the best approach to eliminating the risk of shorting. Current mitigation methods are based on unfilled polymer coatings that are not impenetrable to tin whiskers. In this paper we report tin whisker mitigation results formore » several filled polymer coatings. The whisker-penetration resistance of the coatings was evaluated at elevated temperature and high humidity and under temperature cycling conditions. The composite coatings comprised Ni and MgF 2-coated Al/Ni/Al platelets in epoxy resin or silicone rubber. In addition to improved whisker mitigation, these platelet composites have enhanced thermal conductivity and dielectric constant compared with unfilled polymers.« less

Amorphous tin-cadmium oxide films and the production thereof

DOEpatents

Li, Xiaonan; Gessert, Timothy A

2013-10-29

A tin-cadmium oxide film having an amorphous structure and a ratio of tin atoms to cadmium atoms of between 1:1 and 3:1. The tin-cadmium oxide film may have an optical band gap of between 2.7 eV and 3.35 eV. The film may also have a charge carrier concentration of between 1.times.10.sup.20 cm.sup.-3 and 2.times.10.sup.20 cm.sup.-3. The tin cadmium oxide film may also exhibit a Hall mobility of between 40 cm.sup.2V.sup.-1 s.sup.-1 and 60 cm.sup.2V.sup.-1 s.sup.-1. Also disclosed is a method of producing an amorphous tin-cadmium oxide film as described and devices using same.

Nucleation and growth of tin whiskers

NASA Astrophysics Data System (ADS)

Cheng, Jing; Vianco, Paul T.; Zhang, Bei; Li, James C. M.

2011-06-01

Pure tin film of one micron thick was evaporated onto a silicon substrate with chromium and nickel underlayers. The tinned silicon disk was bent by applying a dead load at the center and supported below around the edge to apply biaxial compressive stresses to the tin layer. After 180 C vacuum annealing for 1,2,4,6, and 8 weeks, tin whiskers/hillocks grew. A quantitative method revealed that the overall growth rate decreased with time with a tendency for saturation. A review of the literature showed in general, tin whisker growth has a nucleation period, a growth period and a period of saturation, very similar to recrystallization or phase transformation. In fact we found our data fit Avrami equation very well. This equation shows that the nucleation period was the first week.

Molten tin reprocessing of spent nuclear fuel elements. [Patent application; continuous process

DOEpatents

Heckman, R.A.

1980-12-19

A method and apparatus for reprocessing spent nuclear fuel is described. Within a containment vessel, a solid plug of tin and nitride precipitates supports a circulating bath of liquid tin therein. Spent nuclear fuel is immersed in the liquid tin under an atmosphere of nitrogen, resulting in the formation of nitride precipitates. The layer of liquid tin and nitride precipitates which interfaces the plug is solidified and integrated with the plug. Part of the plug is melted, removing nitride precipitates from the containment vessel, while a portion of the plug remains solidified to support te liquid tin and nitride precipitates remaining in the containment vessel. The process is practiced numerous times until substantially all of the precipitated nitrides are removed from the containment vessel.

Toward link predictability of complex networks

PubMed Central

Lü, Linyuan; Pan, Liming; Zhou, Tao; Zhang, Yi-Cheng; Stanley, H. Eugene

2015-01-01

The organization of real networks usually embodies both regularities and irregularities, and, in principle, the former can be modeled. The extent to which the formation of a network can be explained coincides with our ability to predict missing links. To understand network organization, we should be able to estimate link predictability. We assume that the regularity of a network is reflected in the consistency of structural features before and after a random removal of a small set of links. Based on the perturbation of the adjacency matrix, we propose a universal structural consistency index that is free of prior knowledge of network organization. Extensive experiments on disparate real-world networks demonstrate that (i) structural consistency is a good estimation of link predictability and (ii) a derivative algorithm outperforms state-of-the-art link prediction methods in both accuracy and robustness. This analysis has further applications in evaluating link prediction algorithms and monitoring sudden changes in evolving network mechanisms. It will provide unique fundamental insights into the above-mentioned academic research fields, and will foster the development of advanced information filtering technologies of interest to information technology practitioners. PMID:25659742

Resonance of an unshared electron pair between two atoms connected by a single bond

PubMed Central

Pauling, Linus

1983-01-01

The reported structure of the dimer of a compound of bicovalent tin indicates that the tin-tin bond is of a new type. It can be described as involving resonance between two structures in which there is transfer of an electron pair from one tin atom to the other. The tin atoms are connected by a single covalent bond (each also forms two covalent bonds with carbon atoms), and an unshared electron pair resonates between the fourth sp3 orbitals of the two atoms. Similar structures probably occur in digermene and distannene. PMID:16593329

47 CFR 1.8002 - Obtaining an FRN.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and title, address, and taxpayer identifying number (TIN) must be provided. For individuals, the TIN... deems appropriate for its business operations. Each subsidiary with a different TIN must obtain a...

47 CFR 1.8002 - Obtaining an FRN.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and title, address, and taxpayer identifying number (TIN) must be provided. For individuals, the TIN... deems appropriate for its business operations. Each subsidiary with a different TIN must obtain a...

Conductivity enhancement of silver nanowire networks via simple electrolyte solution treatment and solvent washing.

PubMed

Gu, Jiahui; Wang, Xuelin; Chen, Hongtao; Yang, Shihua; Feng, Huanhuan; Ma, Xing; Ji, Hongjun; Wei, Jun; Li, Mingyu

2018-06-29

As a promising replacement material for indium tin oxide in flexible electronics, silver nanowires (AgNWs) usually need complicated post-treatment to reduce the high contact resistance across the intersections when used as transparent conductive films. In this work, a widely applicable nano-joining method for improving the overall conductivity of AgNW networks with different kinds of electrolyte solutions is presented. By treatment with an electrolyte solution with appropriate ionic strengths, the insulating surfactant layer (polyvinylpyrrolidone, PVP) on the AgNWs could be desorbed, and the AgNW network could be densified. The sheet resistance of the AgNW film on a glass slide is reduced by 60.9% (from 67.5 to 26.4 Ohm sq -1 ) with a transmittance of 92.5%. High-resolution transmission electron microscopy analysis indicates that atomic diffusion occurs at the intersection of two AgNWs. Thus, metallurgical bonding on the nanometer scale is achieved across the junctions of the AgNWs, leading to a significant enhancement in the conductivity of the AgNW network.

Conductivity enhancement of silver nanowire networks via simple electrolyte solution treatment and solvent washing

NASA Astrophysics Data System (ADS)

Gu, Jiahui; Wang, Xuelin; Chen, Hongtao; Yang, Shihua; Feng, Huanhuan; Ma, Xing; Ji, Hongjun; Wei, Jun; Li, Mingyu

2018-06-01

As a promising replacement material for indium tin oxide in flexible electronics, silver nanowires (AgNWs) usually need complicated post-treatment to reduce the high contact resistance across the intersections when used as transparent conductive films. In this work, a widely applicable nano-joining method for improving the overall conductivity of AgNW networks with different kinds of electrolyte solutions is presented. By treatment with an electrolyte solution with appropriate ionic strengths, the insulating surfactant layer (polyvinylpyrrolidone, PVP) on the AgNWs could be desorbed, and the AgNW network could be densified. The sheet resistance of the AgNW film on a glass slide is reduced by 60.9% (from 67.5 to 26.4 Ohm sq‑1) with a transmittance of 92.5%. High-resolution transmission electron microscopy analysis indicates that atomic diffusion occurs at the intersection of two AgNWs. Thus, metallurgical bonding on the nanometer scale is achieved across the junctions of the AgNWs, leading to a significant enhancement in the conductivity of the AgNW network.

Robustness of external/internal correlation models for real-time tumor tracking to breathing motion variations

NASA Astrophysics Data System (ADS)

Seregni, M.; Cerveri, P.; Riboldi, M.; Pella, A.; Baroni, G.

2012-11-01

In radiotherapy, organ motion mitigation by means of dynamic tumor tracking requires continuous information about the internal tumor position, which can be estimated relying on external/internal correlation models as a function of external surface surrogates. In this work, we propose a validation of a time-independent artificial neural networks-based tumor tracking method in the presence of changes in the breathing pattern, evaluating the performance on two datasets. First, simulated breathing motion traces were specifically generated to include gradually increasing respiratory irregularities. Then, seven publically available human liver motion traces were analyzed for the assessment of tracking accuracy, whose sensitivity with respect to the structural parameters of the model was also investigated. Results on simulated data showed that the proposed method was not affected by hysteretic target trajectories and it was able to cope with different respiratory irregularities, such as baseline drift and internal/external phase shift. The analysis of the liver motion traces reported an average RMS error equal to 1.10 mm, with five out of seven cases below 1 mm. In conclusion, this validation study proved that the proposed method is able to deal with respiratory irregularities both in controlled and real conditions.

Dynamic Reorganization of the Cytoskeleton during Apoptosis: The Two Coffins Hypothesis.

PubMed

Povea-Cabello, Suleva; Oropesa-Ávila, Manuel; de la Cruz-Ojeda, Patricia; Villanueva-Paz, Marina; de la Mata, Mario; Suárez-Rivero, Juan Miguel; Álvarez-Córdoba, Mónica; Villalón-García, Irene; Cotán, David; Ybot-González, Patricia; Sánchez-Alcázar, José A

2017-11-11

During apoptosis, cells undergo characteristic morphological changes in which the cytoskeleton plays an active role. The cytoskeleton rearrangements have been mainly attributed to actinomyosin ring contraction, while microtubule and intermediate filaments are depolymerized at early stages of apoptosis. However, recent results have shown that microtubules are reorganized during the execution phase of apoptosis forming an apoptotic microtubule network (AMN). Evidence suggests that AMN is required to maintain plasma membrane integrity and cell morphology during the execution phase of apoptosis. The new "two coffins" hypothesis proposes that both AMN and apoptotic cells can adopt two morphological patterns, round or irregular, which result from different cytoskeleton kinetic reorganization during the execution phase of apoptosis induced by genotoxic agents. In addition, round and irregular-shaped apoptosis showed different biological properties with respect to AMN maintenance, plasma membrane integrity and phagocyte responses. These findings suggest that knowing the type of apoptosis may be important to predict how fast apoptotic cells undergo secondary necrosis and the subsequent immune response. From a pathological point of view, round-shaped apoptosis can be seen as a physiological and controlled type of apoptosis, while irregular-shaped apoptosis can be considered as a pathological type of cell death closer to necrosis.

Dynamic Reorganization of the Cytoskeleton during Apoptosis: The Two Coffins Hypothesis

PubMed Central

Povea-Cabello, Suleva; Oropesa-Ávila, Manuel; de la Cruz-Ojeda, Patricia; Villanueva-Paz, Marina; de la Mata, Mario; Álvarez-Córdoba, Mónica; Villalón-García, Irene; Cotán, David; Ybot-González, Patricia

2017-01-01

During apoptosis, cells undergo characteristic morphological changes in which the cytoskeleton plays an active role. The cytoskeleton rearrangements have been mainly attributed to actinomyosin ring contraction, while microtubule and intermediate filaments are depolymerized at early stages of apoptosis. However, recent results have shown that microtubules are reorganized during the execution phase of apoptosis forming an apoptotic microtubule network (AMN). Evidence suggests that AMN is required to maintain plasma membrane integrity and cell morphology during the execution phase of apoptosis. The new “two coffins” hypothesis proposes that both AMN and apoptotic cells can adopt two morphological patterns, round or irregular, which result from different cytoskeleton kinetic reorganization during the execution phase of apoptosis induced by genotoxic agents. In addition, round and irregular-shaped apoptosis showed different biological properties with respect to AMN maintenance, plasma membrane integrity and phagocyte responses. These findings suggest that knowing the type of apoptosis may be important to predict how fast apoptotic cells undergo secondary necrosis and the subsequent immune response. From a pathological point of view, round-shaped apoptosis can be seen as a physiological and controlled type of apoptosis, while irregular-shaped apoptosis can be considered as a pathological type of cell death closer to necrosis. PMID:29137119

REM sleep respiratory behaviours mental content in narcoleptic lucid dreamers.

PubMed

Oudiette, Delphine; Dodet, Pauline; Ledard, Nahema; Artru, Emilie; Rachidi, Inès; Similowski, Thomas; Arnulf, Isabelle

2018-02-08

Breathing is irregular during rapid eye-movement (REM) sleep, whereas it is stable during non-REM sleep. Why this is so remains a mystery. We propose that irregular breathing has a cortical origin and reflects the mental content of dreams, which often accompany REM sleep. We tested 21 patients with narcolepsy who had the exceptional ability to lucid dream in REM sleep, a condition in which one is conscious of dreaming during the dream and can signal lucidity with an ocular code. Sleep and respiration were monitored during multiple naps. Participants were instructed to modify their dream scenario so that it involved vocalizations or an apnoea, -two behaviours that require a cortical control of ventilation when executed during wakefulness. Most participants (86%) were able to signal lucidity in at least one nap. In 50% of the lucid naps, we found a clear congruence between the dream report (e.g., diving under water) and the observed respiratory behaviour (e.g., central apnoea) and, in several cases, a preparatory breath before the respiratory behaviour. This suggests that the cortico-subcortical networks involved in voluntary respiratory movements are preserved during REM sleep and that breathing irregularities during this stage have a cortical/subcortical origin that reflects dream content.

21 CFR 178.2650 - Organotin stabilizers in vinyl chloride plastics.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) (1), (2), (3), (4), (5), (6), and (7) of this section. (1) Di(n-octyl)tin S,S′-bis(isooctylmercaptoacetate) is an octyltin chemical having 15.1 to 16.4 percent by weight of tin (Sn) and having 8.1 to 8.9 percent by weight of mercapto sulfur. It is made from di(n-octyl)tin dichloride or di(n-octyl)tin oxide...

NASA Goddard Space Flight Center Tin Whisker (and Other Metal Whisker) Homepage

NASA Technical Reports Server (NTRS)

Brusse, Jay; Sampson, Mike; Leidecker, Henning; Kadesch, Jong

2004-01-01

This website provides information about tin whiskers and related research. The independent research performed during the past 50+ years is so vast that it is impractical to cover all aspects of tin whiskers in this one resource. Therefore, the absence of information in this website about a particular aspect of tin whiskers should NOT be construed as evidence of absence.

21 CFR 178.2650 - Organotin stabilizers in vinyl chloride plastics.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) (1), (2), (3), (4), (5), (6), and (7) of this section. (1) Di(n-octyl)tin S,S′-bis(isooctylmercaptoacetate) is an octyltin chemical having 15.1 to 16.4 percent by weight of tin (Sn) and having 8.1 to 8.9 percent by weight of mercapto sulfur. It is made from di(n-octyl)tin dichloride or di(n-octyl)tin oxide...

31 CFR 359.28 - Are taxpayer identification numbers (TINs) required for the registration of definitive Series I...

Code of Federal Regulations, 2013 CFR

2013-07-01

... (TINs) required for the registration of definitive Series I savings bonds? 359.28 Section 359.28 Money... Definitive Series I Savings Bonds § 359.28 Are taxpayer identification numbers (TINs) required for the... include the TIN of the owner or first-named coowner. If the bond was purchased as a gift or award and the...

31 CFR 359.28 - Are taxpayer identification numbers (TINs) required for the registration of definitive Series I...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (TINs) required for the registration of definitive Series I savings bonds? 359.28 Section 359.28 Money... Definitive Series I Savings Bonds § 359.28 Are taxpayer identification numbers (TINs) required for the... include the TIN of the owner or first-named coowner. If the bond is being purchased as a gift or award and...

31 CFR 359.28 - Are taxpayer identification numbers (TINs) required for the registration of definitive Series I...

Code of Federal Regulations, 2012 CFR

2012-07-01

... (TINs) required for the registration of definitive Series I savings bonds? 359.28 Section 359.28 Money... Definitive Series I Savings Bonds § 359.28 Are taxpayer identification numbers (TINs) required for the... include the TIN of the owner or first-named coowner. If the bond was purchased as a gift or award and the...

31 CFR 359.28 - Are taxpayer identification numbers (TINs) required for the registration of definitive Series I...

Code of Federal Regulations, 2011 CFR

2011-07-01

... (TINs) required for the registration of definitive Series I savings bonds? 359.28 Section 359.28 Money... Definitive Series I Savings Bonds § 359.28 Are taxpayer identification numbers (TINs) required for the... include the TIN of the owner or first-named coowner. If the bond is being purchased as a gift or award and...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Tin-coated lead foil capsules for wine bottles... Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one or both sides with a thin layer...

21 CFR 178.2650 - Organotin stabilizers in vinyl chloride plastics.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) (1), (2), (3), (4), (5), (6), and (7) of this section. (1) Di(n-octyl)tin S,S′-bis(isooctylmercaptoacetate) is an octyltin chemical having 15.1 to 16.4 percent by weight of tin (Sn) and having 8.1 to 8.9 percent by weight of mercapto sulfur. It is made from di(n-octyl)tin dichloride or di(n-octyl)tin oxide...

21 CFR 178.2650 - Organotin stabilizers in vinyl chloride plastics.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) (1), (2), (3), (4), (5), (6), and (7) of this section. (1) Di(n-octyl)tin S,S′-bis(isooctylmercaptoacetate) is an octyltin chemical having 15.1 to 16.4 percent by weight of tin (Sn) and having 8.1 to 8.9 percent by weight of mercapto sulfur. It is made from di(n-octyl)tin dichloride or di(n-octyl)tin oxide...

76 FR 75794 - Significant New Use Rules on Certain Chemical Substances; Withdrawal of Two Chemical Substances

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-05

...) for chemical substances which were the subject of premanufacture notices (PMNs), i.e., rutile, tin zinc, calcium-doped (PMN P-06-36; CAS No. 389623-01-2) and rutile, tin zinc, sodium-doped (PMN P-06-37... rutile, tin zinc, calcium-doped (PMN P-06-36; CAS No. 389623-01-2) and rutile, tin zinc, sodium-doped...

31 CFR 359.28 - Are taxpayer identification numbers (TINs) required for the registration of definitive Series I...

Code of Federal Regulations, 2014 CFR

2014-07-01

... (TINs) required for the registration of definitive Series I savings bonds? 359.28 Section 359.28 Money... Definitive Series I Savings Bonds § 359.28 Are taxpayer identification numbers (TINs) required for the... include the TIN of the owner or first-named coowner. If the bond was purchased as a gift or award and the...

Shielding properties of lead-free protective clothing and their impact on radiation doses

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

Schlattl, Helmut; Zankl, Maria; Eder, Heinrich

2007-11-15

The shielding properties of two different lead-free materials--tin and a compound of 80% tin and 20% bismuth--for protective clothing are compared with those of lead for three typical x-ray spectra generated at tube voltages of 60, 75, and 120 kV. Three different quantities were used to compare the shielding capability of the different materials: (1) Air-kerma attenuation factors in narrow-beam geometry, (2) air-kerma attenuation factors in broad-beam geometry, and (3) ratios of organ and effective doses in the human body for a whole-body irradiation with a parallel beam directed frontally at the body. The thicknesses of tin (0.45 mm) andmore » the tin/bismuth compound (0.41 mm) to be compared against lead correspond to a lead equivalence value of 0.35 mm for the 75 kV spectrum. The narrow-beam attenuation factors for 0.45 mm tin are 54% and 32% lower than those for 0.35 mm lead for 60 and 120 kV; those for 0.41 mm tin/bismuth are 12% and 32% lower, respectively. The decrease of the broad-beam air-kerma attenuation factors compared to lead is 74%, 46%, and 41% for tin and 42%, 26%, and 33% for tin/bismuth and the spectra at 60, 75, and 120 kV, respectively. Therefore, it is recommended that the characterization of the shielding potential of a material should be done by measurements in broad-beam geometry. Since the secondary radiation that is mainly responsible for the shielding reduction in broad-beam geometry is of low penetrability, only more superficially located organs receive significantly enhanced doses. The increase for the dose to the glandular breast tissue (female) compared to being shielded by lead is 143%, 37%, and 45% when shielded by tin, and 35%, 15%, and 39% when shielded by tin/bismuth for 60, 75, and 120 kV, respectively. The effective dose rises by 60%, 6%, and 38% for tin, and 14%, 3% and, 35% for tin/bismuth shielding, respectively.« less

Tinned Fruit Consumption and Mortality in Three Prospective Cohorts

PubMed Central

Aasheim, Erlend T.; Sharp, Stephen J.; Appleby, Paul N.; Shipley, Martin J.; Lentjes, Marleen A. H.; Khaw, Kay-Tee; Brunner, Eric; Key, Tim J.; Wareham, Nicholas J.

2015-01-01

Dietary recommendations to promote health include fresh, frozen and tinned fruit, but few studies have examined the health benefits of tinned fruit. We therefore studied the association between tinned fruit consumption and mortality. We followed up participants from three prospective cohorts in the United Kingdom: 22,421 participants from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohort (1993–2012), 52,625 participants from the EPIC-Oxford cohort (1993–2012), and 7440 participants from the Whitehall II cohort (1991–2012), all reporting no history of heart attack, stroke, or cancer when entering these studies. We estimated the association between frequency of tinned fruit consumption and all cause mortality (primary outcome measure) using Cox regression models within each cohort, and pooled hazard ratios across cohorts using random-effects meta-analysis. Tinned fruit consumption was assessed with validated food frequency questionnaires including specific questions about tinned fruit. During 1,305,330 person years of follow-up, 8857 deaths occurred. After adjustment for lifestyle factors and risk markers the pooled hazard ratios (95% confidence interval) of all cause mortality compared with the reference group of tinned fruit consumption less often than one serving per month were: 1.05 (0.99, 1.12) for one to three servings per month, 1.10 (1.03, 1.18) for one serving per week, and 1.13 (1.04, 1.23) for two or more servings per week. Analysis of cause-specific mortality showed that tinned fruit consumption was associated with mortality from cardiovascular causes and from non-cardiovascular, non-cancer causes. In a pooled analysis of three prospective cohorts from the United Kingdom self-reported tinned fruit consumption in the 1990s was weakly but positively associated with mortality during long-term follow-up. These findings raise questions about the evidence underlying dietary recommendations to promote tinned fruit consumption as part of a healthy diet. PMID:25714554

7 CFR 1780.33 - Application requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... time lines. (g) The applicant's Internal Revenue Service Taxpayer Identification Number (TIN). The TIN will be used by the Agency to assign a case number which will be the applicant's or transferee's TIN...

7 CFR 1780.33 - Application requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... time lines. (g) The applicant's Internal Revenue Service Taxpayer Identification Number (TIN). The TIN will be used by the Agency to assign a case number which will be the applicant's or transferee's TIN...

7 CFR 1780.33 - Application requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... time lines. (g) The applicant's Internal Revenue Service Taxpayer Identification Number (TIN). The TIN will be used by the Agency to assign a case number which will be the applicant's or transferee's TIN...

7 CFR 1780.33 - Application requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... time lines. (g) The applicant's Internal Revenue Service Taxpayer Identification Number (TIN). The TIN will be used by the Agency to assign a case number which will be the applicant's or transferee's TIN...

7 CFR 1780.33 - Application requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... time lines. (g) The applicant's Internal Revenue Service Taxpayer Identification Number (TIN). The TIN will be used by the Agency to assign a case number which will be the applicant's or transferee's TIN...

Core Temperature Measurement During Submaximal Exercise: Esophageal, Rectal, and Intestinal Temperatures

NASA Technical Reports Server (NTRS)

Lee, Stuart M. C.; Williams, W. Jon; Schneider, Suzanne M.

2000-01-01

The purpose of this study was to determine if intestinal temperature (Tin) might be in acceptable alternative to esophageal (Tes) and rectal temperature (Trec) to assess thermoregulation during supine exercise. We hypothesized that Tin would have values similar to Tes and a response time similar to Trec, but the rate of temperature change across time would not be different between measurement sites. Seven subjects completed a continuous supine protocol of 20 min of rest, 20 min of cycle exercise at 40% peak oxygen consumption (VO2pk), 20 min of cycle exercise at 65% V02pk, and 20 min of recovery. Tes, Trec, and Tin were recorded each min throughout the test. Temperatures were not different after 20 min of rest, but Trec was less than the Tes and Tin at the end of the 40% and 65% VO2pk stages. After 20 min of recovery, Tes was less than either Trec or Tin, which were not different from each other. Time to threshold for increased temperature from rest was greater for Trec than Tes but not different from Tin. Time to reach peak temperature was greater for Tin and Trec than Tes. Similarly, time to a decrease in temperature after exercise was greater for Trec than Tes, but not different from Tin. The rate of temperature change from threshold to the end of the 40% VO2pk stage was not different between measurement sites. However, the rate of change during recovery was more negative for Tes than Tin and Trec, which were different from each other. Measurement of Tin may he an acceptable alternative to Tes and Trec with an understanding of its limitations.

Dual-band beacon experiment over Southeast Asia for ionospheric irregularity analysis

NASA Astrophysics Data System (ADS)

Watthanasangmechai, K.; Yamamoto, M.; Saito, A.; Saito, S.; Maruyama, T.; Tsugawa, T.; Nishioka, M.

2013-12-01

An experiment of dual-band beacon over Southeast Asia was started in March 2012 in order to capture and analyze ionospheric irregularities in equatorial region. Five GNU Radio Beacon Receivers (GRBRs) were aligned along 100 degree geographic longitude. The distances between the stations reach more than 500 km. The field of view of this observational network covers +/- 20 degree geomagnetic latitude including the geomagnetic equator. To capture ionospheric irregularities, the absolute TEC estimation technique was developed. The two-station method (Leitinger et al., 1975) is generally accepted as a suitable method to estimate TEC offsets of dual-band beacon experiment. However, the distances between the stations directly affect on the robustness of the technique. In Southeast Asia, the observational network is too sparse to attain a benefit of the classic two-station method. Moreover, the least-squares approch used in the two-station method tries too much to adjust the small scales of the TEC distribution which are the local minima. We thus propose a new technique to estimate the TEC offsets with the supporting data from absolute GPS-TEC from local GPS receivers and the ionospheric height from local ionosondes. The key of the proposed technique is to utilize the brute-force technique with weighting function to find the TEC offset set that yields a global minimum of RMSE in whole parameter space. The weight is not necessary when the TEC distribution is smooth, while it significantly improves the TEC estimation during the ESF events. As a result, the latitudinal TEC shows double-hump distribution because of the Equatorial Ionization Anomaly (EIA). In additions, the 100km-scale fluctuations from an Equatorial Spread F (ESF) are captured at night time in equinox seasons. The plausible linkage of the meridional wind with triggering of ESF is under invatigating and will be presented. The proposed method is successful to estimate the latitudinal TEC distribution from dual-band frequency beacon data for the sparse observational network in Southeast Asia which may be useful for other equatorial sectors like Affrican region as well.

Nanostructured antistatic and antireflective thin films made of indium tin oxide and silica over-coat layer

NASA Astrophysics Data System (ADS)

Cho, Young-Sang; Hong, Jeong-Jin; Yang, Seung-Man; Choi, Chul-Jin

2010-08-01

Stable dispersion of colloidal indium tin oxide nanoparticles was prepared by using indium tin oxide nanopowder, organic solvent, and suitable dispersants through attrition process. Various comminution parameters during the attrition step were studied to optimize the process for the stable dispersion of indium tin oxide sol. The transparent and conductive films were fabricated on glass substrate using the indium tin oxide sol by spin coating process. To obtain antireflective function, partially hydrolyzed alkyl silicate was deposited as over-coat layer on the pre-fabricated indium tin oxide film by spin coating technique. This double-layered structure of the nanostructured film was characterized by measuring the surface resistance and reflectance spectrum in the visible wavelength region. The final film structure was enough to satisfy the TCO regulations for EMI shielding purposes.

Monitoring of ionospheric irregularities with multi-GNSS observations: a new ionosphere activity index and product services

NASA Astrophysics Data System (ADS)

Wang, Ningbo; Li, Zishen; Yuan, Yunbin; Yuan, Hong

2017-04-01

Key words: Ionospheric irregularity, Rate of TEC (ROT), Rate of ROT index (RROT), GPS and GLONASS The ionospheric irregularities have a strong impact on many applications of Global Navigation Satellite Systems (GNSS) and other space-based radio systems. The rate of ionospheric total electron content (TEC) change index (ROTI, TECu/min), defined as the standard deviation of rate of TEC change (ROT) within a short time (e.g. 5 minutes), has been developed to describe the ionospheric irregularities and associated scintillations. However, ROT parameter may still contain the trend term of ionospheric TEC in spite of small-scale fluctuations. On the basis of single-differenced ROT (dROT) values, we develop a new ionosphere activity index, rate of ROT change index (RROT, TECu/min), to characterize the irregularity degree of the ionosphere. To illustrate the use of the index, we investigated the consistency between ROTI and RROT indexes, through the analysis of GPS data and S4 observations collected at two high-latitude stations of the northern hemisphere. It is confirmed that the correlation coefficients between RROT and S4 are higher than those between ROTI and S4 for the test period, meaning that the proposed RROT index is applicable to monitor the ionospheric irregularities and associated scintillations. RROT index can be easily calculated from dual-frequency GNSS signals (like GPS L1 and L2 carrier phase measurements). On the basis of GPS and GLONASS data provided by the IGS, ARGN, EPN and USCORS tracking networks (more than 1500 stations per day), absolute ROT (AROT), gradient of TEC index (GOTI), ROTI and RROT maps are generated to reflect the ionospheric irregularity activities. These maps are provided in an IONEX-like format on a global scale with a temporal resolution of 15 minutes and a spatial resolution of 5 and 2.5 degrees in longitude and latitude, respectively, and the maps with high spatial resolution (2x2 degrees) are also generated for European, Australia and North American regions. The product files are produced on a daily basis with a latency of 3 days. Users now can access these products from the ftp archive of the Chinese Academy of Sciences (CAS, ftp://ftp.gipp.org.cn/product/). These maps can be used for ionospheric weather services, ionospheric irregularity modeling and foresting, as well as other GNSS applications. Although they are provided in a post-processing mode at present, it is expected that the near real-time services will be available since the availability of real-time data streams from the IGS.

40 CFR 721.10297 - Tin, C16-18 and C18-unsatd. fatty acids castor-oil fatty acids complexes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Tin, C16-18 and C18-unsatd. fatty... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10297 Tin, C16-18 and C18-unsatd... to reporting. (1) The chemical substance identified as tin, C16-18 and C18-unsatd. fatty acids castor...

40 CFR 721.10297 - Tin, C16-18 and C18-unsatd. fatty acids castor-oil fatty acids complexes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tin, C16-18 and C18-unsatd. fatty... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10297 Tin, C16-18 and C18-unsatd... to reporting. (1) The chemical substance identified as tin, C16-18 and C18-unsatd. fatty acids castor...

40 CFR 721.10297 - Tin, C16-18 and C18-unsatd. fatty acids castor-oil fatty acids complexes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tin, C16-18 and C18-unsatd. fatty... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10297 Tin, C16-18 and C18-unsatd... to reporting. (1) The chemical substance identified as tin, C16-18 and C18-unsatd. fatty acids castor...

Low resistivity contact to iron-pnictide superconductors

DOEpatents

Tanatar, Makariy; Prozorov, Ruslan; Ni, Ni; Bud& #x27; ko, Sergey; Canfield, Paul

2013-05-28

Method of making a low resistivity electrical connection between an electrical conductor and an iron pnictide superconductor involves connecting the electrical conductor and superconductor using a tin or tin-based material therebetween, such as using a tin or tin-based solder. The superconductor can be based on doped AFe.sub.2As.sub.2, where A can be Ca, Sr, Ba, Eu or combinations thereof for purposes of illustration only.

Uptake and Fate of Tri-N-Butyltin Cation in Estuarine Bacteria,

DTIC Science & Technology

1982-04-02

as well as Yamada and co-workers [31] found trialkyltins, especially tripropyl- tin (TPT) and tributyltin ( TBT ), had the highest antiw-,’.?ial...tin-resistant estuarine bacteria was studied. The bacterial isolates accumulated tributyltin to 3.7 to 7.7 mg tin per g dry weight of cells by a non...chromatography-atomic absorption spectrophotometry and tin-selective purge and trap flame photometric gas chromatography for possible tributyltin

Influence of implantation on the electrochemical properties of smooth and porous TiN coatings for stimulation electrodes

NASA Astrophysics Data System (ADS)

Meijs, S.; Sørensen, C.; Sørensen, S.; Rechendorff, K.; Fjorback, M.; Rijkhoff, N. J. M.

2016-04-01

Objective. To determine whether changes in electrochemical properties of porous titanium nitride (TiN) electrodes as a function of time after implantation are different from those of smooth TiN electrodes. Approach. Eight smooth and 8 porous TiN coated electrodes were implanted in 8 rats. Before implantation, voltage transients, cyclic voltammograms and impedance spectra were recorded in phosphate buffered saline (PBS). After implantation, these measurements were done weekly to investigate how smooth and porous electrodes were affected by implantation. Main results. The electrode capacitance of the porous TiN electrodes decreased more than the capacitance of the smooth electrodes due to acute implantation under fast measurement conditions (such as stimulation pulses). This indicates that protein adhesion presents a greater diffusion limitation for counter-ions for the porous than for the smooth electrodes. The changes in electrochemical properties during the implanted period were similar for smooth and porous TiN electrodes, indicating that cell adhesion poses a similar diffusion limitation for smooth and porous electrodes. Significance. This knowledge can be used to optimize the porous structure of the TiN film, so that the effect of protein adhesion on the electrochemical properties is diminished. Alternatively, an additional coating could be applied on the porous TiN that would prevent or minimize protein adhesion.

Silver-tin alloys and amalgams: electrochemical considerations.

PubMed

Mueller, H J

1980-01-01

The corrosion potential and anodic polarization profiles of a representative number of silver-tin alloys and their corresponding amalgams in a physiological solution were determined and compared to their microstructures. For the alloys with tin-content greater than 27%(wt) and for all amalgams, the corrosion process is related to the attack of free tin for the alloys and to the gamma-2 tin for the amalgams. The gamma-2 concentration in the amalgams increases with an increase in tin-content. For alloys with tin-content less than 27%, the corrosion process is even more restricted than for the process observed with pure silver. From a developed theory based upon the potential-time and polarization results, association of the O2 reduction process on a SnO cathodic film to an intermediate specie of H2O2 is made. The rate of H2O2 decomposition on a SnO surface in a four electron process is thought to control the O2 reduction overvoltage. The O2 reduction overvoltage decreases with increases in the silver-content of the amalgam, particularily seen with the 8 and 12% tin compositions. Due to the polarization induced corrosion process, a phase with high silver and high mercury concentrations was observed over the unreacted particles.

Role of point defects and HfO2/TiN interface stoichiometry on effective work function modulation in ultra-scaled complementary metal-oxide-semiconductor devices

NASA Astrophysics Data System (ADS)

Pandey, R. K.; Sathiyanarayanan, Rajesh; Kwon, Unoh; Narayanan, Vijay; Murali, K. V. R. M.

2013-07-01

We investigate the physical properties of a portion of the gate stack of an ultra-scaled complementary metal-oxide-semiconductor (CMOS) device. The effects of point defects, such as oxygen vacancy, oxygen, and aluminum interstitials at the HfO2/TiN interface, on the effective work function of TiN are explored using density functional theory. We compute the diffusion barriers of such point defects in the bulk TiN and across the HfO2/TiN interface. Diffusion of these point defects across the HfO2/TiN interface occurs during the device integration process. This results in variation of the effective work function and hence in the threshold voltage variation in the devices. Further, we simulate the effects of varying the HfO2/TiN interface stoichiometry on the effective work function modulation in these extremely-scaled CMOS devices. Our results show that the interface rich in nitrogen gives higher effective work function, whereas the interface rich in titanium gives lower effective work function, compared to a stoichiometric HfO2/TiN interface. This theoretical prediction is confirmed by the experiment, demonstrating over 700 meV modulation in the effective work function.

Tin-silver-bismuth solders for electronics assembly

DOEpatents

Vianco, Paul T.; Rejent, Jerome A.

1995-01-01

A lead-free solder alloy for electronic assemblies composed of a eutectic alloy of tin and silver with a bismuth addition, x, of 0

Tin-silver-bismuth solders for electronics assembly

DOEpatents

Vianco, P.T.; Rejent, J.A.

1995-08-08

A lead-free solder alloy is disclosed for electronic assemblies composed of a eutectic alloy of tin and silver with a bismuth addition, x, of 0

The oxidation of carbon monoxide using tin oxide based catalysts

NASA Technical Reports Server (NTRS)

Sampson, Christopher F.; Jorgensen, Norman

1990-01-01

The preparation conditions for precious metal/tin oxide catalysts were optimized for maximum carbon monoxide/oxygen recombination efficiency. This was achieved by controlling the tin digestion, the peptization to form the sol, the calcination process and the method of adding the precious metals. Extensive studies of the tin oxide structure were carried out over the temperature range 20 to 500 C in air or hydrogen environments using Raman scattering and X ray diffraction. Adsorbed species on tin oxide, generated in an environment containing carbon monoxide, gave rise to a Raman band at about 1600 cm(exp -1) which was assigned to carbonaceous groups, possible carbonate.

Tribological characterization of TiN coatings prepared by magnetron sputtering

NASA Astrophysics Data System (ADS)

Makwana, Nishant S.; Chauhan, Kamlesh V.; Sonera, Akshay L.; Chauhan, Dharmesh B.; Dave, Divyeshkumar P.; Rawal, Sushant K.

2018-05-01

Titanium nitride (TiN) coating deposited on aluminium and brass pin substrates using RF reactive magnetron sputtering. The structural properties and surface morphology were characterized by X-ray diffraction (XRD), atomic force microscope (AFM) and field emission scanning electron microscope (FE-SEM). There was formation of (101) Ti2N, (110) TiN2 and (102) TiN0.30 peaks at 3.5Pa, 2Pa and 1.25Pa sputtering pressure respectively. The tribological properties of coating were inspected using pin on disc tribometer equipment. It was observed that TiN coated aluminium and brass pins demonstrated improved wear resistance than uncoated aluminium and brass pins.

Bonding in Some Zintl Phases: A Study by Tin-119 Mössbauer Spectroscopy

NASA Astrophysics Data System (ADS)

Asbrand, M.; Berry, F. J.; Eisenmann, B.; Kniep, R.; Smart, L. E.; Thied, R. C.

1995-09-01

The 119Sn Mössbauer parameters for a range of Zintl phase compounds are reported. The compounds containing tetrahedrally coordinated tin of composition M5SnX3 (M = Na, K; X = P, As, Sb) have chemical isomer shifts close to that of grey-tin and can be considered to be covalently bonded species. The layer structures of composition KSnX (X = As, Sb) and double-layer compounds M Sn2X2 (M = Na, Sr; X = As, Sb) have tin in a distorted octahedral environment. The chemical isomer shifts are closer to that of white-tin and can be interpreted in terms of metallic bonding.

99M-Technetium labeled tin colloid radiopharmaceuticals

DOEpatents

Winchell, Harry S.; Barak, Morton; Van Fleet, III, Parmer

1976-07-06

An improved 99m-technetium labeled tin(II) colloid, size-stabilized for reticuloendothelial organ imaging without the use of macromolecular stabilizers and a packaged tin base reagent and an improved method for making it are disclosed.