VT Data - Overlay District 20170710, South Burlington

Data.gov (United States)

Vermont Center for Geographic Information — Overlay data for the City of South Burlington included in this data:Flood Plain Overlay DistrictTraffic Overlay DistrictInterstate Highway Overlay DistrictScenic...

Advanced overlay analysis through design based metrology

Science.gov (United States)

Ji, Sunkeun; Yoo, Gyun; Jo, Gyoyeon; Kang, Hyunwoo; Park, Minwoo; Kim, Jungchan; Park, Chanha; Yang, Hyunjo; Yim, Donggyu; Maruyama, Kotaro; Park, Byungjun; Yamamoto, Masahiro

2015-03-01

As design rule shrink, overlay has been critical factor for semiconductor manufacturing. However, the overlay error which is determined by a conventional measurement with an overlay mark based on IBO and DBO often does not represent the physical placement error in the cell area. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion caused by etching or CMP also can be a source of the mismatch. In 2014, we have demonstrated that method of overlay measurement in the cell area by using DBM (Design Based Metrology) tool has more accurate overlay value than conventional method by using an overlay mark. We have verified the reproducibility by measuring repeatable patterns in the cell area, and also demonstrated the reliability by comparing with CD-SEM data. We have focused overlay mismatching between overlay mark and cell area until now, further more we have concerned with the cell area having different pattern density and etch loading. There appears a phenomenon which has different overlay values on the cells with diverse patterning environment. In this paper, the overlay error was investigated from cell edge to center. For this experiment, we have verified several critical layers in DRAM by using improved(Better resolution and speed) DBM tool, NGR3520.

Location-Aware Cross-Layer Design Using Overlay Watermarks

Directory of Open Access Journals (Sweden)

Paul Ho

2007-04-01

Full Text Available A new orthogonal frequency division multiplexing (OFDM system embedded with overlay watermarks for location-aware cross-layer design is proposed in this paper. One major advantage of the proposed system is the multiple functionalities the overlay watermark provides, which includes a cross-layer signaling interface, a transceiver identification for position-aware routing, as well as its basic role as a training sequence for channel estimation. Wireless terminals are typically battery powered and have limited wireless communication bandwidth. Therefore, efficient collaborative signal processing algorithms that consume less energy for computation and less bandwidth for communication are needed. Transceiver aware of its location can also improve the routing efficiency by selective flooding or selective forwarding data only in the desired direction, since in most cases the location of a wireless host is unknown. In the proposed OFDM system, location information of a mobile for efficient routing can be easily derived when a unique watermark is associated with each individual transceiver. In addition, cross-layer signaling and other interlayer interactive information can be exchanged with a new data pipe created by modulating the overlay watermarks. We also study the channel estimation and watermark removal techniques at the physical layer for the proposed overlay OFDM. Our channel estimator iteratively estimates the channel impulse response and the combined signal vector from the overlay OFDM signal. Cross-layer design that leads to low-power consumption and more efficient routing is investigated.

A carbon-carbon panel design concept for the inboard limiter of the Compact Ignition Tokamak (CIT)

International Nuclear Information System (INIS)

Mantz, H.C.; Bowers, D.A.; Williams, F.R.; Witten, M.A.

1989-01-01

The inboard limiter of the Compact Ignition Tokamak (CIT) must protect the vacuum vessel from the plasma energy. This limiter region must withstand nominal heat fluxes in excess of 10 MW/m 2 and in addition it must be designed to be remotely maintained. Carbon-carbon composite material was selected over bulk graphite materials for the limiter design because of its ability to meet the thermal and structural requirements. The structural design concept consists of carbon-carbon composite panels attached to the vacuum vessel by a hinged rod/retainer concept. Results of the preliminary design study to define this inboard limiter are presented. The design concept is described along with the analyses of the thermal and structural response during nominal plasma operation and during plasma disruption events. 2 refs., 8 figs

Overlay accuracy with respect to device scaling

Science.gov (United States)

Leray, Philippe; Laidler, David; Cheng, Shaunee

2012-03-01

Overlay metrology performance is usually reported as repeatability, matching between tools or optics aberrations distorting the measurement (Tool induced shift or TIS). Over the last few years, improvement of these metrics by the tool suppliers has been impressive. But, what about accuracy? Using different target types, we have already reported small differences in the mean value as well as fingerprint [1]. These differences make the correctables questionable. Which target is correct and therefore which translation, scaling etc. values should be fed back to the scanner? In this paper we investigate the sources of these differences, using several approaches. First, we measure the response of different targets to offsets programmed in a test vehicle. Second, we check the response of the same overlay targets to overlay errors programmed into the scanner. We compare overlay target designs; what is the contribution of the size of the features that make up the target? We use different overlay measurement techniques; is DBO (Diffraction Based Overlay) more accurate than IBO (Image Based Overlay)? We measure overlay on several stacks; what is the stack contribution to inaccuracy? In conclusion, we offer an explanation for the observed differences and propose a solution to reduce them.

Reaching for the true overlay in advanced nodes

Science.gov (United States)

Koay, Chiew-seng; Hamieh, Bassem; Felix, Nelson; Gaudiello, John

2017-03-01

Traditionally, the total measurement uncertainty (TMU) of overlay metrology focuses on dynamic precision, toolinduced-shift, and matching, while rarely examining inaccuracy. However, some researchers have recently shown that measurement inaccuracy can still be large despite optimized small TMU. Moreover, this inaccuracy can consume a significant portion of the overlay budget in the advanced nodes. In addition to qualifying the overlay error of inline wafers, overlay metrology is also used for improving on-product overlay as it provides corrective feedback to the lithography scanner. The accuracy of the correction terms as a result depends directly upon the measurement accuracy. As such, enhanced overlay accuracy will improve the overlay performance of reworked wafers, or subsequently exposed wafers. We have previously shown that a segmented Blossom target is more prone to asymmetry-induced inaccuracy than a nonsegmented target is [1]. Since target segmentation is inevitable for SADP and SAQP patterning processes, their resulting overlay performance leaves a lot to be desired. In our quest to reach for the true overlay, this paper reports our investigations on accuracy enhancement techniques for image-based targets, such as redundancy and self-calibration, and on the use of simulation-optimized scatterometry-based targets.

Life extension of boilers using weld overlay protection

Energy Technology Data Exchange (ETDEWEB)

Lai, G; Hulsizer, P [Welding Services Inc., Norcross, GA (United States); Brooks, R [Welding Services Inc., Welding Services Europe, Spijkenisse (Netherlands)

1999-12-31

The presentation describes the status of modern weld overlay technology for refurbishment, upgrading and life extension of boilers. The approaches to life extension of boilers include field overlay application, shop-fabricated panels for replacement of the worn, corroded waterwall and shop-fabricated overlay tubing for replacement of individual tubes in superheaters, generating banks and other areas. The characteristics of weld overlay products are briefly described. Also discussed are successful applications of various corrosion-resistant overlays for life extension of boiler tubes in waste-to-energy boilers, coal-fired boilers and chemical recovery boilers. Types of corrosion and selection of weld overlay alloys in these systems are also discussed. (orig.) 14 refs.

Life extension of boilers using weld overlay protection

Energy Technology Data Exchange (ETDEWEB)

Lai, G.; Hulsizer, P. [Welding Services Inc., Norcross, GA (United States); Brooks, R. [Welding Services Inc., Welding Services Europe, Spijkenisse (Netherlands)

1998-12-31

The presentation describes the status of modern weld overlay technology for refurbishment, upgrading and life extension of boilers. The approaches to life extension of boilers include field overlay application, shop-fabricated panels for replacement of the worn, corroded waterwall and shop-fabricated overlay tubing for replacement of individual tubes in superheaters, generating banks and other areas. The characteristics of weld overlay products are briefly described. Also discussed are successful applications of various corrosion-resistant overlays for life extension of boiler tubes in waste-to-energy boilers, coal-fired boilers and chemical recovery boilers. Types of corrosion and selection of weld overlay alloys in these systems are also discussed. (orig.) 14 refs.

Performance of ASML YieldStar μDBO overlay targets for advanced lithography nodes C028 and C014 overlay process control

Science.gov (United States)

Blancquaert, Yoann; Dezauzier, Christophe; Depre, Jerome; Miqyass, Mohamed; Beltman, Jan

2013-04-01

Continued tightening of overlay control budget in semiconductor lithography drives the need for improved metrology capabilities. Aggressive improvements are needed for overlay metrology speed, accuracy and precision. This paper is dealing with the on product metrology results of a scatterometry based platform showing excellent production results on resolution, precision, and tool matching for overlay. We will demonstrate point to point matching between tool generations as well as between target sizes and types. Nowadays, for the advanced process nodes a lot of information is needed (Higher order process correction, Reticle fingerprint, wafer edge effects) to quantify process overlay. For that purpose various overlay sampling schemes are evaluated: ultra- dense, dense and production type. We will show DBO results from multiple target type and shape for on product overlay control for current and future node down to at least 14 nm node. As overlay requirements drive metrology needs, we will evaluate if the new metrology platform meets the overlay requirements.

Enhacement of intrafield overlay using a design based metrology system

Science.gov (United States)

Jo, Gyoyeon; Ji, Sunkeun; Kim, Shinyoung; Kang, Hyunwoo; Park, Minwoo; Kim, Sangwoo; Kim, Jungchan; Park, Chanha; Yang, Hyunjo; Maruyama, Kotaro; Park, Byungjun

2016-03-01

As the scales of the semiconductor devices continue to shrink, accurate measurement and control of the overlay have been emphasized for securing more overlay margin. Conventional overlay analysis methods are based on the optical measurement of the overlay mark. However, the overlay data obtained from these optical methods cannot represent the exact misregistration between two layers at the circuit level. The overlay mismatch may arise from the size or pitch difference between the overlay mark and the real pattern. Pattern distortion, caused by CMP or etching, could be a source of the overlay mismatch as well. Another issue is the overlay variation in the real circuit pattern which varies depending on its location. The optical overlay measurement methods, such as IBO and DBO that use overlay mark on the scribeline, are not capable of defining the exact overlay values of the real circuit. Therefore, the overlay values of the real circuit need to be extracted to integrate the semiconductor device properly. The circuit level overlay measurement using CDSEM is time-consuming in extracting enough data to indicate overall trend of the chip. However DBM tool is able to derive sufficient data to display overlay tendency of the real circuit region with high repeatability. An E-beam based DBM(Design Based Metrology) tool can be an alternative overlay measurement method. In this paper, we are going to certify that the overlay values extracted from optical measurement cannot represent the circuit level overlay values. We will also demonstrate the possibility to correct misregistration between two layers using the overlay data obtained from the DBM system.

Overlay leaves litho: impact of non-litho processes on overlay and compensation

Science.gov (United States)

Ruhm, Matthias; Schulz, Bernd; Cotte, Eric; Seltmann, Rolf; Hertzsch, Tino

2014-10-01

According to the ITRS roadmap [1], the overlay requirement for the 28nm node is 8nm. If we compare this number with the performance given by tool vendors for their most advanced immersion systems (which is emerging. Mask contributions and so-called non-linear wafer distortions are known effects that can impact overlay quite significantly. Furthermore, it is often forgotten that downstream (post-litho) processes can impact the overlay as well. Thus, it can be required to compensate for the effects of subsequent processes already at the lithography operation. Within our paper, we will briefly touch on the wafer distortion topic and discuss the limitations of lithography compensation techniques such as higher order corrections versus solving the root cause of the distortions. The primary focus will be on the impact of the etch processes on the pattern placement error. We will show how individual layers can get affected differently by showing typical wafer signatures. However, in contrast to the above-mentioned wafer distortion topic, lithographic compensation techniques can be highly effective to reduce the placement error significantly towards acceptable levels (see Figure 1). Finally we will discuss the overall overlay budget for a 28nm contact to gate case by taking the impact of the individual process contributors into account.

Effect of neutrals localized at torus inboard side on the impurity transport in edge stochastic magnetic field layer of LHD

International Nuclear Information System (INIS)

Morita, S.; Oishi, T.; Kobayashi, M.; Goto, M.; Kawamura, G.; Zhang, H.M.; Hunag, X.L.; Wang, E.H.

2014-01-01

Two-dimensional (2-D) distribution of impurity line emissions has been measured in Large Helical Device (LHD) based on the 2-D extreme ultraviolet (EUV) spectroscopy for studying the edge impurity transport in stochastic magnetic field layer with three-dimensional (3-D) structure. The impurity behavior in the vicinity of two X-points at inboard and outboard sides of torus becomes separately visible with the 2-D measurement. As a result, it is found that the carbon location changes from inboard to outboard X-points when the plasma axis is shifted from R_a_x=3.6 m to 3.75 m. A 3-D simulation with EMC3-EIRENE code agrees with the result at R_a_x=3.75 m but disagreed with the result at R_a_x=3.60 m. The discrepancy between the measurement and simulation at R_a_x=3.60 m is considerably reduced when the effect of neutral hydrogen localized at the inboard side is taken into account, which can modify the density gradient and friction force along the magnetic field. (author)

Advanced diffraction-based overlay for double patterning

Science.gov (United States)

Li, Jie; Liu, Yongdong; Dasari, Prasad; Hu, Jiangtao; Smith, Nigel; Kritsun, Oleg; Volkman, Catherine

2010-03-01

Diffraction based overlay (DBO) technologies have been developed to address the tighter overlay control challenges as the dimensions of integrated circuit continue to shrink. Several studies published recently have demonstrated that the performance of DBO technologies has the potential to meet the overlay metrology budget for 22nm technology node. However, several hurdles must be cleared before DBO can be used in production. One of the major hurdles is that most DBO technologies require specially designed targets that consist of multiple measurement pads, which consume too much space and increase measurement time. A more advanced spectroscopic ellipsometry (SE) technology-Mueller Matrix SE (MM-SE) is developed to address the challenge. We use a double patterning sample to demonstrate the potential of MM-SE as a DBO candidate. Sample matrix (the matrix that describes the effects of the sample on the incident optical beam) obtained from MM-SE contains up to 16 elements. We show that the Mueller elements from the off-diagonal 2x2 blocks respond to overlay linearly and are zero when overlay errors are absent. This superior property enables empirical DBO (eDBO) using two pads per direction. Furthermore, the rich information in Mueller matrix and its direct response to overlay make it feasible to extract overlay errors from only one pad per direction using modeling approach (mDBO). We here present the Mueller overlay results using both eDBO and mDBO and compare the results with image-based overlay (IBO) and CD-SEM results. We also report the tool induced shifts (TIS) and dynamic repeatability.

Diffraction-based overlay metrology for double patterning technologies

Science.gov (United States)

Dasari, Prasad; Korlahalli, Rahul; Li, Jie; Smith, Nigel; Kritsun, Oleg; Volkman, Cathy

2009-03-01

The extension of optical lithography to 32nm and beyond is made possible by Double Patterning Techniques (DPT) at critical levels of the process flow. The ease of DPT implementation is hindered by increased significance of critical dimension uniformity and overlay errors. Diffraction-based overlay (DBO) has shown to be an effective metrology solution for accurate determination of the overlay errors associated with double patterning [1, 2] processes. In this paper we will report its use in litho-freeze-litho-etch (LFLE) and spacer double patterning technology (SDPT), which are pitch splitting solutions that reduce the significance of overlay errors. Since the control of overlay between various mask/level combinations is critical for fabrication, precise and accurate assessment of errors by advanced metrology techniques such as spectroscopic diffraction based overlay (DBO) and traditional image-based overlay (IBO) using advanced target designs will be reported. A comparison between DBO, IBO and CD-SEM measurements will be reported. . A discussion of TMU requirements for 32nm technology and TMU performance data of LFLE and SDPT targets by different overlay approaches will be presented.

Real cell overlay measurement through design based metrology

Science.gov (United States)

Yoo, Gyun; Kim, Jungchan; Park, Chanha; Lee, Taehyeong; Ji, Sunkeun; Jo, Gyoyeon; Yang, Hyunjo; Yim, Donggyu; Yamamoto, Masahiro; Maruyama, Kotaro; Park, Byungjun

2014-04-01

Until recent device nodes, lithography has been struggling to improve its resolution limit. Even though next generation lithography technology is now facing various difficulties, several innovative resolution enhancement technologies, based on 193nm wavelength, were introduced and implemented to keep the trend of device scaling. Scanner makers keep developing state-of-the-art exposure system which guarantees higher productivity and meets a more aggressive overlay specification. "The scaling reduction of the overlay error has been a simple matter of the capability of exposure tools. However, it is clear that the scanner contributions may no longer be the majority component in total overlay performance. The ability to control correctable overlay components is paramount to achieve the desired performance.(2)" In a manufacturing fab, the overlay error, determined by a conventional overlay measurement: by using an overlay mark based on IBO and DBO, often does not represent the physical placement error in the cell area of a memory device. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion, caused by etching or CMP, also can be a source of the mismatch. Therefore, the requirement of a direct overlay measurement in the cell pattern gradually increases in the manufacturing field, and also in the development level. In order to overcome the mismatch between conventional overlay measurement and the real placement error of layer to layer in the cell area of a memory device, we suggest an alternative overlay measurement method utilizing by design, based metrology tool. A basic concept of this method is shown in figure1. A CD-SEM measurement of the overlay error between layer 1 and 2 could be the ideal method but it takes too long time to extract a lot of data from wafer level. An E-beam based DBM tool provides high speed to cover the whole wafer with high repeatability. It is enabled by using the design as a

A comparison of advanced overlay technologies

Science.gov (United States)

Dasari, Prasad; Smith, Nigel; Goelzer, Gary; Liu, Zhuan; Li, Jie; Tan, Asher; Koh, Chin Hwee

2010-03-01

The extension of optical lithography to 22nm and beyond by Double Patterning Technology is often challenged by CDU and overlay control. With reduced overlay measurement error budgets in the sub-nm range, relying on traditional Total Measurement Uncertainty (TMU) estimates alone is no longer sufficient. In this paper we will report scatterometry overlay measurements data from a set of twelve test wafers, using four different target designs. The TMU of these measurements is under 0.4nm, within the process control requirements for the 22nm node. Comparing the measurement differences between DBO targets (using empirical and model based analysis) and with image-based overlay data indicates the presence of systematic and random measurement errors that exceeds the TMU estimate.

Hybrid overlay metrology for high order correction by using CDSEM

Science.gov (United States)

Leray, Philippe; Halder, Sandip; Lorusso, Gian; Baudemprez, Bart; Inoue, Osamu; Okagawa, Yutaka

2016-03-01

Overlay control has become one of the most critical issues for semiconductor manufacturing. Advanced lithographic scanners use high-order corrections or correction per exposure to reduce the residual overlay. It is not enough in traditional feedback of overlay measurement by using ADI wafer because overlay error depends on other process (etching process and film stress, etc.). It needs high accuracy overlay measurement by using AEI wafer. WIS (Wafer Induced Shift) is the main issue for optical overlay, IBO (Image Based Overlay) and DBO (Diffraction Based Overlay). We design dedicated SEM overlay targets for dual damascene process of N10 by i-ArF multi-patterning. The pattern is same as device-pattern locally. Optical overlay tools select segmented pattern to reduce the WIS. However segmentation has limit, especially the via-pattern, for keeping the sensitivity and accuracy. We evaluate difference between the viapattern and relaxed pitch gratings which are similar to optical overlay target at AEI. CDSEM can estimate asymmetry property of target from image of pattern edge. CDSEM can estimate asymmetry property of target from image of pattern edge. We will compare full map of SEM overlay to full map of optical overlay for high order correction ( correctables and residual fingerprints).

Diffraction-based overlay for spacer patterning and double patterning technology

Science.gov (United States)

Lee, Byoung Hoon; Park, JeongSu; Lee, Jongsu; Park, Sarohan; Lim, ChangMoon; Yim, Dong-Gyu; Park, Sungki; Ryu, Chan-Ho; Morgan, Stephen; van de Schaar, Maurits; Fuchs, Andreas; Bhattacharyya, Kaustuve

2011-03-01

Overlay performance will be increasingly important for Spacer Patterning Technology (SPT) and Double Patterning Technology (DPT) as various Resolution Enhancement Techniques are employed to extend the resolution limits of lithography. Continuous shrinkage of devices makes overlay accuracy one of the most critical issues while overlay performance is completely dependent on exposure tool. Image Based Overlay (IBO) has been used as the mainstream metrology for overlay by the main memory IC companies, but IBO is not suitable for some critical layers due to the poor Tool Induced Shift (TIS) values. Hence new overlay metrology is required to improve the overlay measurement accuracy. Diffraction Based Overlay (DBO) is regarded to be an alternative metrology to IBO for more accurate measurements and reduction of reading errors. Good overlay performances of DBO have been reported in many articles. However applying DBO for SPT and DPT layers poses extra challenges for target design. New vernier designs are considered for different DPT and SPT schemes to meet overlay target in DBO system. In this paper, we optimize the design of the DBO target and the performance of DBO to meet the overlay specification of sub-3x nm devices which are using SPT and DPT processes. We show that the appropriate vernier design yields excellent overlay performance in residual and TIS. The paper also demonstrated the effects of vernier structure on overlay accuracy from SEM analysis.

Effect of constraint condition and internal medium on residual stress under overlay welding for dissimilar metal welding

International Nuclear Information System (INIS)

Song, Tae Kwang; Kim, Yun Jae; Lee, Kyoung Soo; Park, Chi Yong; Kim, Jong Sung; Kim, Jin Weon

2007-01-01

In nuclear power plants, residual stress of dissimilar metal weld propagates cracks in the weld metal which is susceptible to stress corrosion cracking. Overlay welding is a process widely used to mitigate residual stress replacing inside tensile stress by compression stress. However, according to the result of this study the effect of overlay welding on residual stress depends on both internal medium and constraint condition. The purpose of this study is to maximize the positive effect of overlay welding by finite element analyses

High-throughput electrical characterization for robust overlay lithography control

Science.gov (United States)

Devender, Devender; Shen, Xumin; Duggan, Mark; Singh, Sunil; Rullan, Jonathan; Choo, Jae; Mehta, Sohan; Tang, Teck Jung; Reidy, Sean; Holt, Jonathan; Kim, Hyung Woo; Fox, Robert; Sohn, D. K.

2017-03-01

Realizing sensitive, high throughput and robust overlay measurement is a challenge in current 14nm and advanced upcoming nodes with transition to 300mm and upcoming 450mm semiconductor manufacturing, where slight deviation in overlay has significant impact on reliability and yield1). Exponentially increasing number of critical masks in multi-patterning lithoetch, litho-etch (LELE) and subsequent LELELE semiconductor processes require even tighter overlay specification2). Here, we discuss limitations of current image- and diffraction- based overlay measurement techniques to meet these stringent processing requirements due to sensitivity, throughput and low contrast3). We demonstrate a new electrical measurement based technique where resistance is measured for a macro with intentional misalignment between two layers. Overlay is quantified by a parabolic fitting model to resistance where minima and inflection points are extracted to characterize overlay control and process window, respectively. Analyses using transmission electron microscopy show good correlation between actual overlay performance and overlay obtained from fitting. Additionally, excellent correlation of overlay from electrical measurements to existing image- and diffraction- based techniques is found. We also discuss challenges of integrating electrical measurement based approach in semiconductor manufacturing from Back End of Line (BEOL) perspective. Our findings open up a new pathway for accessing simultaneous overlay as well as process window and margins from a robust, high throughput and electrical measurement approach.

New low-viscosity overlay medium for viral plaque assays

Directory of Open Access Journals (Sweden)

Garten Wolfgang

2006-08-01

Full Text Available Abstract Background Plaque assays in cell culture monolayers under solid or semisolid overlay media are commonly used for quantification of viruses and antiviral substances. To overcome the pitfalls of known overlays, we tested suspensions of microcrystalline cellulose Avicel RC/CL™ as overlay media in the plaque and plaque-inhibition assay of influenza viruses. Results Significantly larger plaques were formed under Avicel-containing media, as compared to agar and methylcellulose (MC overlay media. The plaque size increased with decreasing Avicel concentration, but even very diluted Avicel overlays (0.3% ensured formation of localized plaques. Due to their low viscosity, Avicel overlays were easier to use than methylcellulose overlays, especially in the 96-well culture plates. Furthermore, Avicel overlay could be applied without prior removal of the virus inoculum thus facilitating the assay and reducing chances of cross-contamination. Using neuraminidase inhibitor oseltamivir carboxylate, we demonstrated applicability of the Avicel-based plaque reduction assay for testing of antiviral substances. Conclusion Plaque assay under Avicel-containing overlay media is easier, faster and more sensitive than assays under agar- and methylcellulose overlays. The assay can be readily performed in a 96-well plate format and seems particularly suitable for high-throughput virus titrations, serological studies and experiments on viral drug sensitivity. It may also facilitate work with highly pathogenic agents performed under hampered conditions of bio-safety labs.

Colors, colored overlays, and reading skills

OpenAIRE

Uccula, Arcangelo; Enna, Mauro; Mulatti, Claudio

2014-01-01

In this article, we are concerned with the role of colors in reading written texts. It has been argued that colored overlays applied above written texts positively influence both reading fluency and reading speed. These effects would be particularly evident for those individuals affected by the so called Meares-Irlen syndrome, i.e., who experience eyestrain and/or visual distortions – e.g., color, shape, or movement illusions – while reading. This condition would interest the 12–14% of the ge...

SEM based overlay measurement between resist and buried patterns

Science.gov (United States)

Inoue, Osamu; Okagawa, Yutaka; Hasumi, Kazuhisa; Shao, Chuanyu; Leray, Philippe; Lorusso, Gian; Baudemprez, Bart

2016-03-01

With the continuous shrink in pattern size and increased density, overlay control has become one of the most critical issues in semiconductor manufacturing. Recently, SEM based overlay of AEI (After Etch Inspection) wafer has been used for reference and optimization of optical overlay (both Image Based Overlay (IBO) and Diffraction Based Overlay (DBO)). Overlay measurement at AEI stage contributes monitor and forecast the yield after formation by etch and calibrate optical measurement tools. however those overlay value seems difficult directly for feedback to a scanner. Therefore, there is a clear need to have SEM based overlay measurements of ADI (After Develop Inspection) wafers in order to serve as reference for optical overlay and make necessary corrections before wafers go to etch. Furthermore, to make the corrections as accurate as possible, actual device like feature dimensions need to be measured post ADI. This device size measurement is very unique feature of CDSEM , which can be measured with smaller area. This is currently possible only with the CD-SEM. This device size measurement is very unique feature of CD-SEM , which can be measured with smaller area. In this study, we assess SEM based overlay measurement of ADI and AEI wafer by using a sample from an N10 process flow. First, we demonstrate SEM based overlay performance at AEI by using dual damascene process for Via 0 (V0) and metal 1 (M1) layer. We also discuss the overlay measurements between litho-etch-litho stages of a triple patterned M1 layer and double pattern V0. Second, to illustrate the complexities in image acquisition and measurement we will measure overlay between M1B resist and buried M1A-Hard mask trench. Finally, we will show how high accelerating voltage can detect buried pattern information by BSE (Back Scattering Electron). In this paper we discuss the merits of this method versus standard optical metrology based corrections.

Image-based overlay measurement using subsurface ultrasonic resonance force microscopy

Science.gov (United States)

Tamer, M. S.; van der Lans, M. J.; Sadeghian, H.

2018-03-01

Image Based Overlay (IBO) measurement is one of the most common techniques used in Integrated Circuit (IC) manufacturing to extract the overlay error values. The overlay error is measured using dedicated overlay targets which are optimized to increase the accuracy and the resolution, but these features are much larger than the IC feature size. IBO measurements are realized on the dedicated targets instead of product features, because the current overlay metrology solutions, mainly based on optics, cannot provide sufficient resolution on product features. However, considering the fact that the overlay error tolerance is approaching 2 nm, the overlay error measurement on product features becomes a need for the industry. For sub-nanometer resolution metrology, Scanning Probe Microscopy (SPM) is widely used, though at the cost of very low throughput. The semiconductor industry is interested in non-destructive imaging of buried structures under one or more layers for the application of overlay and wafer alignment, specifically through optically opaque media. Recently an SPM technique has been developed for imaging subsurface features which can be potentially considered as a solution for overlay metrology. In this paper we present the use of Subsurface Ultrasonic Resonance Force Microscopy (SSURFM) used for IBO measurement. We used SSURFM for imaging the most commonly used overlay targets on a silicon substrate and photoresist. As a proof of concept we have imaged surface and subsurface structures simultaneously. The surface and subsurface features of the overlay targets are fabricated with programmed overlay errors of +/-40 nm, +/-20 nm, and 0 nm. The top layer thickness changes between 30 nm and 80 nm. Using SSURFM the surface and subsurface features were successfully imaged and the overlay errors were extracted, via a rudimentary image processing algorithm. The measurement results are in agreement with the nominal values of the programmed overlay errors.

Scatterometry or imaging overlay: a comparative study

Science.gov (United States)

Hsu, Simon C. C.; Pai, Yuan Chi; Chen, Charlie; Yu, Chun Chi; Hsing, Henry; Wu, Hsing-Chien; Kuo, Kelly T. L.; Amir, Nuriel

2015-03-01

Most fabrication facilities today use imaging overlay measurement methods, as it has been the industry's reliable workhorse for decades. In the last few years, third-generation Scatterometry Overlay (SCOL™) or Diffraction Based Overlay (DBO-1) technology was developed, along another DBO technology (DBO-2). This development led to the question of where the DBO technology should be implemented for overlay measurements. Scatterometry has been adopted for high volume production in only few cases, always with imaging as a backup, but scatterometry overlay is considered by many as the technology of the future. In this paper we compare imaging overlay and DBO technologies by means of measurements and simulations. We outline issues and sensitivities for both technologies, providing guidelines for the best implementation of each. For several of the presented cases, data from two different DBO technologies are compared as well, the first with Pupil data access (DBO-1) and the other without pupil data access (DBO-2). Key indicators of overlay measurement quality include: layer coverage, accuracy, TMU, process robustness and robustness to process changes. Measurement data from real cases across the industry are compared and the conclusions are also backed by simulations. Accuracy is benchmarked with reference OVL, and self-consistency, showing good results for Imaging and DBO-1 technology. Process sensitivity and metrology robustness are mostly simulated with MTD (Metrology Target Designer) comparing the same process variations for both technologies. The experimental data presented in this study was done on ten advanced node layers and three production node layers, for all phases of the IC fabrication process (FEOL, MEOL and BEOL). The metrology tool used for most of the study is KLA-Tencor's Archer 500LCM system (scatterometry-based and imaging-based measurement technologies on the same tool) another type of tool is used for DBO-2 measurements. Finally, we conclude that

Development of an Overlay Design Procedure for Composite Pavements

Science.gov (United States)

2017-09-01

The composite overlay design procedure currently used by ODOT sometimes produces very large overlay thicknesses that are deemed structurally unnecessary, especially for composite pavements already with thick asphalt overlays. This study was initiated...

BASIC overlay for CAMAC data and command handling

Energy Technology Data Exchange (ETDEWEB)

Ciftcioglu, O [Istanbul Technical Univ. (Turkey). Inst. for Nuclear Energy

1979-11-15

A BASIC overlay has been developed for the BASIC language run in the PDP-11 series of computers. The overlay has particularly been wirtten for a dedicated Camac Crate Controller DC-011 from Ortec. By means of the overlay, any command comprising C, N, A, F information can easily be issued by the host system to communicate with the peripherals connected to the CAMAC system, through the CAMAC interface. The overlay is particularly useful for rather slow control systems and data handling between two different operating systems with incompatible formats for the data files having the CAMAC system as a mutual system component controllable by each of the operating systems individually. The overlay can easily be modified to be used for a Standard controller (type A-1) or any other type of dedicated controller.

Overlay welding of FeCrAl alloys

OpenAIRE

Rashid, Lezan

2016-01-01

In this master thesis different overlay welding methods suitable for boiler application has been investigated. The purpose of this project is to define advantages and disadvantages for each overlay welding methods and suggest some evaluation criteria on some commercial and experimental alloys aimed for overlay welding material. Many components in a boiler are made of low alloy steel and the atmosphere in the furnace region can be very complex; therefore many different types of corrosion can o...

Computational Investigations of Inboard Flow Separation and Mitigation Techniques on Multi-Megawatt Wind Turbines

Science.gov (United States)

Chow, Raymond

The aerodynamic characteristics of the NREL 5-MW rotor have been examined using a Reynolds-averaged Navier-Stokes method, OVERFLOW2. A comprehensive off-body grid independence study has been performed. A strong dependence on the size of the near-body wake grid has been found. Rapid diffusion of the wake appears to generate an overprediction of power and thrust. A large, continuous near-wake grid at minimum of two rotor diameters downstream of the rotor appears to be necessary for accurate predictions of near-body forces. The NREL 5-MW rotor demonstrates significant inboard flow separation up to 30% of span. This separation appears to be highly three-dimensional, with a significant amount of radial flow increasing the size of the separated region outboard. Both integrated aerodynamic coefficients and detailed wake structures for the baseline NREL 5-MW rotor are in excellent agreement with results by Riso at Uinfinity = 8 and 11 m/s. A simple, continuous full-chord fence was applied at the maximum chord location of the blade, within the region of separation. This non-optimized device reduced the boundary-layer cross-flow and resulting separation, and increased rotor power capture by 0.9% and 0.6% at U infinity = 8 and 11 m/s, respectively. Suction side only fences perform similarly in terms of power capture but reduce the increase in rotor thrust. Fence heights from 0.5% to 17.5% of the maximum chord all demonstrate some level of effectiveness, with fences (1-2.5%cmax) showing similar performance gains to taller fences with smaller penalties in thrust. Performance in terms of power capture is not very sensitive to spanwise location when placed within the separation region. Blunt trailing edge modifications to the inboard region of the blade showed a relatively significant effect on rotor power. Over a large range of trailing edge thicknesses from hTE = 10 to 25%c, power was found to increase by 1.4%. Thrust increased proportionally with the thicknesses examined

Performance polymeric concrete with synthetic fiber reinforcement against reflective cracking in rigid pavement overlay

International Nuclear Information System (INIS)

Khan, N.U.; Khan, B.

2012-01-01

Cement concrete pavements are used for heavy traffic loads throughout the world owing to its better and economical performance. Placing of a concrete overlay on the existing pavement is the most prevalent rehabilitating method for such pavements, however, the problem associated with the newly placed overlay is the occurrence of reflective cracking. This paper presents an assessment of the performance of polymeric concrete with synthetic fiber reinforcement against reflective cracking in an overlay system. The performance of polymeric concrete with synthetic fibers as an overlay material is measured in terms of the load-deflection, strain-deflection and load-strain behavior of beams of the polymeric concrete. For this purpose, five types of beams having different number of fiber wires and position are tested for flexure strength. Deflection/strains for each increment of load are recorded. In addition, cubes of plain concrete and of concrete with synthetic fiber needles were tested after 7 and 28 days for compressive strengths. Finite element models in ANSYS software for the beams have also been developed. Beams with greater number of longitudinal fiber wires displayed relatively better performance against deflection whilst beams with synthetic fiber needles showed better performance against strains. Thus, polymeric concrete overlay with fiber reinforcement will serve relatively better against occurrence of reflective cracking. (author)

In-cell overlay metrology by using optical metrology tool

Science.gov (United States)

Lee, Honggoo; Han, Sangjun; Hong, Minhyung; Kim, Seungyoung; Lee, Jieun; Lee, DongYoung; Oh, Eungryong; Choi, Ahlin; Park, Hyowon; Liang, Waley; Choi, DongSub; Kim, Nakyoon; Lee, Jeongpyo; Pandev, Stilian; Jeon, Sanghuck; Robinson, John C.

2018-03-01

Overlay is one of the most critical process control steps of semiconductor manufacturing technology. A typical advanced scheme includes an overlay feedback loop based on after litho optical imaging overlay metrology on scribeline targets. The after litho control loop typically involves high frequency sampling: every lot or nearly every lot. An after etch overlay metrology step is often included, at a lower sampling frequency, in order to characterize and compensate for bias. The after etch metrology step often involves CD-SEM metrology, in this case in-cell and ondevice. This work explores an alternative approach using spectroscopic ellipsometry (SE) metrology and a machine learning analysis technique. Advanced 1x nm DRAM wafers were prepared, including both nominal (POR) wafers with mean overlay offsets, as well as DOE wafers with intentional across wafer overlay modulation. After litho metrology was measured using optical imaging metrology, as well as after etch metrology using both SE and CD-SEM for comparison. We investigate 2 types of machine learning techniques with SE data: model-less and model-based, showing excellent performance for after etch in-cell on-device overlay metrology.

Hybrid overlay metrology with CDSEM in a BEOL patterning scheme

Science.gov (United States)

Leray, Philippe; Jehoul, Christiane; Inoue, Osamu; Okagawa, Yutaka

2015-03-01

Overlay metrology accuracy is a major concern for our industry. Advanced logic process require more tighter overlay control for multipatterning schemes. TIS (Tool Induced Shift) and WIS (Wafer Induced Shift) are the main issues for IBO (Image Based Overlay) and DBO (Diffraction Based Overlay). Methods of compensation have been introduced, some are even very efficient to reduce these measured offsets. Another related question is about the overlay target designs. These targets are never fully representative of the design rules, strong efforts have been achieved, but the device cannot be completely duplicated. Ideally, we would like to measure in the device itself to verify the real overlay value. Top down CDSEM can measure critical dimensions of any structure, it is not dependent of specific target design. It can also measure the overlay errors but only in specific cases like LELE (Litho Etch Litho Etch) after final patterning. In this paper, we will revisit the capability of the CDSEM at final patterning by measuring overlay in dedicated targets as well as inside a logic and an SRAM design. In the dedicated overlay targets, we study the measurement differences between design rules gratings and relaxed pitch gratings. These relaxed pitch which are usually used in IBO or DBO targets. Beyond this "simple" LELE case, we will explore the capability of the CDSEM to measure overlay even if not at final patterning, at litho level. We will assess the hybridization of DBO and CDSEM for reference to optical tools after final patterning. We will show that these reference data can be used to validate the DBO overlay results (correctables and residual fingerprints).

Evaluating diffraction-based overlay

Science.gov (United States)

Li, Jie; Tan, Asher; Jung, JinWoo; Goelzer, Gary; Smith, Nigel; Hu, Jiangtao; Ham, Boo-Hyun; Kwak, Min-Cheol; Kim, Cheol-Hong; Nam, Suk-Woo

2012-03-01

We evaluate diffraction-based overlay (DBO) metrology using two test wafers. The test wafers have different film stacks designed to test the quality of DBO data under a range of film conditions. We present DBO results using traditional empirical approach (eDBO). eDBO relies on linear response of the reflectance with respect to the overlay displacement within a small range. It requires specially designed targets that consist of multiple pads with programmed shifts. It offers convenience of quick recipe setup since there is no need to establish a model. We measure five DBO targets designed with different pitches and programmed shifts. The correlations of five eDBO targets and the correlation of eDBO to image-based overlay are excellent. The targets of 800nm and 600nm pitches have better dynamic precision than targets of 400nm pitch, which agrees with simulated results on signal/noise ratio. 3σ of less than 0.1nm is achieved for both wafers using the best configured targets. We further investigate the linearity assumption of eDBO algorithm. Simulation results indicate that as the pitch of DBO targets gets smaller, the nonlinearity error, i.e., the error in the overlay measurement results caused by deviation from ideal linear response, becomes bigger. We propose a nonlinearity correction (NLC) by including higher order terms in the optical response. The new algorithm with NLC improves measurement consistency for DBO targets of same pitch but different programmed shift, due to improved accuracy. The results from targets with different pitches, however, are improved marginally, indicating the presence of other error sources.

Robotic weld overlay coatings for erosion control

Science.gov (United States)

The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB's.

Ablative overlays for Space Shuttle leading edge ascent heat protection

Science.gov (United States)

Strauss, E. L.

1975-01-01

Ablative overlays were evaluated via a plasma-arc simulation of the ascent pulse on the leading edge of the Space Shuttle Orbiter. Overlay concepts included corkboard, polyisocyanurate foam, low-density Teflon, epoxy, and subliming salts. Their densities ranged from 4.9 to 81 lb per cu ft, and the thicknesses varied from 0.107 to 0.330 in. Swept-leading-edge models were fabricated from 30-lb per cu ft silicone-based ablators. The overlays were bonded to maintain the surface temperature of the base ablator below 500 F during ascent. Foams provided minimum-weight overlays, and subliming salts provided minimum-thickness overlays. Teflon left the most uniform surface after ascent heating.

Tack coat optimization for HMA overlays laboratory testing.

Science.gov (United States)

2008-09-01

Interface bonding between hot-mix asphalt (HMA) overlays and Portland cement concrete (PCC) pavements can be one of the most : significant factors affecting overlay service life. Various factors may affect the bonding condition at the interface, incl...

Accuracy optimization with wavelength tunability in overlay imaging technology

Science.gov (United States)

Lee, Honggoo; Kang, Yoonshik; Han, Sangjoon; Shim, Kyuchan; Hong, Minhyung; Kim, Seungyoung; Lee, Jieun; Lee, Dongyoung; Oh, Eungryong; Choi, Ahlin; Kim, Youngsik; Marciano, Tal; Klein, Dana; Hajaj, Eitan M.; Aharon, Sharon; Ben-Dov, Guy; Lilach, Saltoun; Serero, Dan; Golotsvan, Anna

2018-03-01

As semiconductor manufacturing technology progresses and the dimensions of integrated circuit elements shrink, overlay budget is accordingly being reduced. Overlay budget closely approaches the scale of measurement inaccuracies due to both optical imperfections of the measurement system and the interaction of light with geometrical asymmetries of the measured targets. Measurement inaccuracies can no longer be ignored due to their significant effect on the resulting device yield. In this paper we investigate a new approach for imaging based overlay (IBO) measurements by optimizing accuracy rather than contrast precision, including its effect over the total target performance, using wavelength tunable overlay imaging metrology. We present new accuracy metrics based on theoretical development and present their quality in identifying the measurement accuracy when compared to CD-SEM overlay measurements. The paper presents the theoretical considerations and simulation work, as well as measurement data, for which tunability combined with the new accuracy metrics is shown to improve accuracy performance.

Multi-level Reconfigurable Self-organization in Overlay Services

NARCIS (Netherlands)

Pournaras, E.

2013-01-01

Large-scale decentralized systems organized in overlay networks are complex to manage. Such systems integrate organizational complexity in the application-level resulting in low abstraction and modularity in their services. This thesis introduces a multi-level conceptual architecture for overlay

Strategic intelligence on emerging technologies: Scientometric overlay mapping

NARCIS (Netherlands)

Rotolo, D.; Rafols, I.; Hopkins, M.M.; Leydesdorff, L.

This paper examines the use of scientometric overlay mapping as a tool of “strategic intelligence” to aid the governing of emerging technologies. We develop an integrative synthesis of different overlay mapping techniques and associated perspectives on technological emergence across geographical,

Exploring overlay journals: the RIOJA project

CERN Multimedia

CERN. Geneva

2007-01-01

Researchers in cosmology and astrophysics depend on the arXiv repository for the registration and dissemination of their work, as well as for current awareness, yet they continue to submit papers to journals for review. Could rapid quality certification be overlaid directly onto the arXiv repository? This presentation introduces the RIOJA (Repository Interface to Overlaid Journal Archives) project, on which a group of cosmology researchers from the UK is working with UCL Library Services and Cornell University. The project is creating a tool to support the overlay of journals onto repositories, and will demonstrate a cosmology journal overlaid on top of arXiv. RIOJA will also work with the cosmology community to explore the social and economic aspects of journal overlay in this discipline: what other value, besides the quality stamp, does journal publication typically add? What are the costs of the ideal overlay journal for this community, and how could those costs be recovered? Would researchers real...

Overlay improvements using a real time machine learning algorithm

Science.gov (United States)

Schmitt-Weaver, Emil; Kubis, Michael; Henke, Wolfgang; Slotboom, Daan; Hoogenboom, Tom; Mulkens, Jan; Coogans, Martyn; ten Berge, Peter; Verkleij, Dick; van de Mast, Frank

2014-04-01

While semiconductor manufacturing is moving towards the 14nm node using immersion lithography, the overlay requirements are tightened to below 5nm. Next to improvements in the immersion scanner platform, enhancements in the overlay optimization and process control are needed to enable these low overlay numbers. Whereas conventional overlay control methods address wafer and lot variation autonomously with wafer pre exposure alignment metrology and post exposure overlay metrology, we see a need to reduce these variations by correlating more of the TWINSCAN system's sensor data directly to the post exposure YieldStar metrology in time. In this paper we will present the results of a study on applying a real time control algorithm based on machine learning technology. Machine learning methods use context and TWINSCAN system sensor data paired with post exposure YieldStar metrology to recognize generic behavior and train the control system to anticipate on this generic behavior. Specific for this study, the data concerns immersion scanner context, sensor data and on-wafer measured overlay data. By making the link between the scanner data and the wafer data we are able to establish a real time relationship. The result is an inline controller that accounts for small changes in scanner hardware performance in time while picking up subtle lot to lot and wafer to wafer deviations introduced by wafer processing.

Residual stress reduction in the penetration nozzle weld joint by overlay welding

International Nuclear Information System (INIS)

Jiang, Wenchun; Luo, Yun; Wang, B.Y.; Tu, S.T.; Gong, J.M.

2014-01-01

Highlights: • Residual stress reduction in penetration weld nozzle by overlay welding was studied. • The overlay weld can decrease the residual stress in the weld root. • Long overlay welding is proposed in the actual welding. • Overlay weld to decrease residual stress is more suitable for thin nozzle. - Abstract: Stress corrosion cracking (SCC) in the penetration nozzle weld joint endangers the structural reliability of pressure vessels in nuclear and chemical industries. How to decrease the residual stress is very critical to ensure the structure integrity. In this paper, a new method, which uses overlay welding on the inner surface of nozzle, is proposed to decrease the residual stresses in the penetration joint. Finite element simulation is used to study the change of weld residual stresses before and after overlay welding. It reveals that this method can mainly decrease the residual stress in the weld root. Before overlay welding, large tensile residual stresses are generated in the weld root. After overlay weld, the tensile hoop stress in weld root has been decreased about 45%, and the radial stress has been decreased to compressive stress, which is helpful to decrease the susceptibility to SCC. With the increase of overlay welding length, the residual stress in weld root has been greatly decreased, and thus the long overlay welding is proposed in the actual welding. It also finds that this method is more suitable for thin nozzle rather than thick nozzle

Improving concrete overlay construction.

Science.gov (United States)

2010-03-01

Several road construction projects involving concrete overlays at the state and county levels in Iowa in 2009 were studied for : construction techniques and methods. The projects that were evaluated consisted of sites in four Iowa counties: Osceola, ...

Wafer edge overlay control solution for N7 and beyond

Science.gov (United States)

van Haren, Richard; Calado, Victor; van Dijk, Leon; Hermans, Jan; Kumar, Kaushik; Yamashita, Fumiko

2018-03-01

Historically, the on-product overlay performance close to the wafer edge is lagging with respect to the inner part of the wafer. The reason for this is that wafer processing is less controlled close to the wafer edge as opposed to the rest of the wafer. It is generally accepted that Chemical Vapor Deposition (CVD) of stressed layers that cause wafer warp, wafer table contamination, Chemical Mechanical Polishing (CMP), and Reactive Ion Etch (RIE) may deteriorate the overlay performance and/or registration close to the wafer edge. For the N7 technology node and beyond, it is anticipated that the tight on-product overlay specification is required across the full wafer which includes the edge region. In this work, we highlight one contributor that may negatively impact the on-product overlay performance, namely the etch step. The focus will be mainly on the wafer edge region but the remaining part of the wafer is considered as well. Three use-cases are examined: multiple Litho-Etch steps (LEn), contact hole layer etch, and the copper dual damascene etch. We characterize the etch contribution by considering the overlay measurement after resist development inspect (ADI) and after etch inspect (AEI). We show that the Yieldstar diffraction based overlay (μDBO) measurements can be utilized to characterize the etch contribution to the overlay budget. The effects of target asymmetry as well as overlay shifts are considered and compared with SEM measurements. Based on the results above, we propose a control solution aiming to reduce or even eliminate the delta between ADI and AEI. By doing so, target/mark to device offsets due to etch might be avoided.

Fundamentals of overlay measurement and inspection using scanning electron-microscope

Science.gov (United States)

Kato, T.; Okagawa, Y.; Inoue, O.; Arai, K.; Yamaguchi, S.

2013-04-01

Scanning electron-microscope (SEM) has been successfully applied to CD measurement as promising tools for qualifying and controlling quality of semiconductor devices in in-line manufacturing process since 1985. Furthermore SEM is proposed to be applied to in-die overlay monitor in the local area which is too small to be measured by optical overlay measurement tools any more, when the overlay control limit is going to be stringent and have un-ignorable dependence on device pattern layout, in-die location, and singular locations in wafer edge, etc. In this paper, we proposed new overlay measurement and inspection system to make an effective use of in-line SEM image, in consideration of trade-off between measurement uncertainty and measurement pattern density in each SEM conditions. In parallel, we make it clear that the best hybrid overlay metrology is in considering each tool's technology portfolio.

64nm pitch metal1 double patterning metrology: CD and OVL control by SEMCD, image based overlay and diffraction based overlay

Science.gov (United States)

Ducoté, Julien; Dettoni, Florent; Bouyssou, Régis; Le-Gratiet, Bertrand; Carau, Damien; Dezauzier, Christophe

2015-03-01

Patterning process control of advanced nodes has required major changes over the last few years. Process control needs of critical patterning levels since 28nm technology node is extremely aggressive showing that metrology accuracy/sensitivity must be finely tuned. The introduction of pitch splitting (Litho-Etch-Litho-Etch) at 14FDSOInm node requires the development of specific metrologies to adopt advanced process control (for CD, overlay and focus corrections). The pitch splitting process leads to final line CD uniformities that are a combination of the CD uniformities of the two exposures, while the space CD uniformities are depending on both CD and OVL variability. In this paper, investigations of CD and OVL process control of 64nm minimum pitch at Metal1 level of 14FDSOI technology, within the double patterning process flow (Litho, hard mask etch, line etch) are presented. Various measurements with SEMCD tools (Hitachi), and overlay tools (KT for Image Based Overlay - IBO, and ASML for Diffraction Based Overlay - DBO) are compared. Metrology targets are embedded within a block instanced several times within the field to perform intra-field process variations characterizations. Specific SEMCD targets were designed for independent measurement of both line CD (A and B) and space CD (A to B and B to A) for each exposure within a single measurement during the DP flow. Based on those measurements correlation between overlay determined with SEMCD and with standard overlay tools can be evaluated. Such correlation at different steps through the DP flow is investigated regarding the metrology type. Process correction models are evaluated with respect to the measurement type and the intra-field sampling.

Electronic structure of uranium overlayers on magnesium and aluminium

Science.gov (United States)

Gouder, T.

1997-06-01

We studied U overlayers on polycrystalline Mg and Al by X-ray and ultra-violet photoelectron spectroscopies (XPS and UPS, respectively), and compared the mode of growth and the evolution of the electronic structure as a function of coverage. The goal of this work was to detect localization, or at least correlation effects, in U overlayers and U substrate near surface alloys, which were expected to occur because of the reduced U 5f bandwidth in these systems. On Mg, U deposits as a pure overlayer without any interdiffusion, while on Al spontaneous interdiffusion takes place. The U 4f spectra of {U}/{Mg} show only weak correlation satellites. Nevertheless, the asymmetrical shape of the U 4f peak indicates 5f band narrowing. On Al, strong correlation satellites are observed in addition to plasmon loss features. It seems that U-substrate interactions promote correlation effects, while the reduced coordination in overlayers plays a less important role. UPS valence-band (VB) spectra of the two systems look remarkably similar. They do not show any correlation satellites. With decreasing overlayer thickness the 5f peak narrows, which is attributed to 5f band narrowing at the surface.

High-volume manufacturing device overlay process control

Science.gov (United States)

Lee, Honggoo; Han, Sangjun; Woo, Jaeson; Lee, DongYoung; Song, ChangRock; Heo, Hoyoung; Brinster, Irina; Choi, DongSub; Robinson, John C.

2017-03-01

Overlay control based on DI metrology of optical targets has been the primary basis for run-to-run process control for many years. In previous work we described a scenario where optical overlay metrology is performed on metrology targets on a high frequency basis including every lot (or most lots) at DI. SEM based FI metrology is performed ondevice in-die as-etched on an infrequent basis. Hybrid control schemes of this type have been in use for many process nodes. What is new is the relative size of the NZO as compared to the overlay spec, and the need to find more comprehensive solutions to characterize and control the size and variability of NZO at the 1x nm node: sampling, modeling, temporal frequency and control aspects, as well as trade-offs between SEM throughput and accuracy.

Analysis of an Orthotropic Deck Stiffened with a Cement-Based Overlay

DEFF Research Database (Denmark)

Walter, Rasmus; Olesen, John Forbes; Stang, Henrik

2007-01-01

decks. A solution might be to enhance the stiffness of the traditional orthotropic bridge deck by using a cement-based overlay. In this paper, an orthotropic steel bridge deck stiffened with a cement-based overlay is analyzed. The analysis is based on nonlinear fracture mechanics, and utilizes......Over the past years, with increasing traffic volumes and higher wheel loads, fatigue damage in steel parts of typical orthotropic steel bridge decks has been experienced on heavily trafficked routes. A demand exists to find a durable system to increase the fatigue safety of orthotropic steel bridge...... the finite-element method. The stiffness of the steel deck reinforced with an overlay depends highly on the composite action. The composite action is closely related to cracking of the overlay and interfacial cracking between the overlay and underlying steel plate (debonding). As an example, a real size...

Virtual overlay metrology for fault detection supported with integrated metrology and machine learning

Science.gov (United States)

Lee, Hong-Goo; Schmitt-Weaver, Emil; Kim, Min-Suk; Han, Sang-Jun; Kim, Myoung-Soo; Kwon, Won-Taik; Park, Sung-Ki; Ryan, Kevin; Theeuwes, Thomas; Sun, Kyu-Tae; Lim, Young-Wan; Slotboom, Daan; Kubis, Michael; Staecker, Jens

2015-03-01

While semiconductor manufacturing moves toward the 7nm node for logic and 15nm node for memory, an increased emphasis has been placed on reducing the influence known contributors have toward the on product overlay budget. With a machine learning technique known as function approximation, we use a neural network to gain insight to how known contributors, such as those collected with scanner metrology, influence the on product overlay budget. The result is a sufficiently trained function that can approximate overlay for all wafers exposed with the lithography system. As a real world application, inline metrology can be used to measure overlay for a few wafers while using the trained function to approximate overlay vector maps for the entire lot of wafers. With the approximated overlay vector maps for all wafers coming off the track, a process engineer can redirect wafers or lots with overlay signatures outside the standard population to offline metrology for excursion validation. With this added flexibility, engineers will be given more opportunities to catch wafers that need to be reworked, resulting in improved yield. The quality of the derived corrections from measured overlay metrology feedback can be improved using the approximated overlay to trigger, which wafers should or shouldn't be, measured inline. As a development or integration engineer the approximated overlay can be used to gain insight into lots and wafers used for design of experiments (DOE) troubleshooting. In this paper we will present the results of a case study that follows the machine learning function approximation approach to data analysis, with production overlay measured on an inline metrology system at SK hynix.

Modeling and simulation of adaptive Neuro-fuzzy based intelligent system for predictive stabilization in structured overlay networks

Directory of Open Access Journals (Sweden)

Ramanpreet Kaur

2017-02-01

Full Text Available Intelligent prediction of neighboring node (k well defined neighbors as specified by the dht protocol dynamism is helpful to improve the resilience and can reduce the overhead associated with topology maintenance of structured overlay networks. The dynamic behavior of overlay nodes depends on many factors such as underlying user’s online behavior, geographical position, time of the day, day of the week etc. as reported in many applications. We can exploit these characteristics for efficient maintenance of structured overlay networks by implementing an intelligent predictive framework for setting stabilization parameters appropriately. Considering the fact that human driven behavior usually goes beyond intermittent availability patterns, we use a hybrid Neuro-fuzzy based predictor to enhance the accuracy of the predictions. In this paper, we discuss our predictive stabilization approach, implement Neuro-fuzzy based prediction in MATLAB simulation and apply this predictive stabilization model in a chord based overlay network using OverSim as a simulation tool. The MATLAB simulation results present that the behavior of neighboring nodes is predictable to a large extent as indicated by the very small RMSE. The OverSim based simulation results also observe significant improvements in the performance of chord based overlay network in terms of lookup success ratio, lookup hop count and maintenance overhead as compared to periodic stabilization approach.

Normal-Force and Hinge-Moment Characteristics at Transonic Speeds of Flap-Type Ailerons at Three Spanwise Locations on a 4-Percent-Thick Sweptback-Wing-Body Model and Pressure-Distribution Measurements on an Inboard Aileron

Science.gov (United States)

Runckel, Jack F.; Hieser, Gerald

1961-01-01

An investigation has been conducted at the Langley 16-foot transonic tunnel to determine the loading characteristics of flap-type ailerons located at inboard, midspan, and outboard positions on a 45 deg. sweptback-wing-body combination. Aileron normal-force and hinge-moment data have been obtained at Mach numbers from 0.80 t o 1.03, at angles of attack up to about 27 deg., and at aileron deflections between approximately -15 deg. and 15 deg. Results of the investigation indicate that the loading over the ailerons was established by the wing-flow characteristics, and the loading shapes were irregular in the transonic speed range. The spanwise location of the aileron had little effect on the values of the slope of the curves of hinge-moment coefficient against aileron deflection, but the inboard aileron had the greatest value of the slope of the curves of hinge-moment coefficient against angle of attack and the outboard aileron had the least. Hinge-moment and aileron normal-force data taken with strain-gage instrumentation are compared with data obtained with pressure measurements.

Plastic collapse moment for pipe repaired with weld overlay

International Nuclear Information System (INIS)

Li, Yinsheng; Hasegawa, Kunio; Shibuya, Akira; Deardorff, Arthur

2009-01-01

The Weld Overlay has been used in several countries as an effective method to repair the stress corrosion cracks in nuclear power plant piping. However, the method to evaluate the plastic collapse stress for the pipe repaired with Weld Overlay has not been proposed and the limit load criterion for single uniform material has been used to design its structure by now. In this paper, the equations to evaluate the plastic collapse moment for the pipe repaired with Weld Overlay have been derived considering two layer materials. Moreover, several numerical examples are given to show the validity of Weld Overlay. The equations given in this paper are simple to use like the limit load criterion showed in present standards such as JSME Rules on Fitness-for-Service for Nuclear Power Plants or ASME Boiler and Pressure Vessel Code Section XI, and they can not only be used to evaluate the fracture of the pipe, but also be applied to design the weld structure. (author)

Application of Interfacial Propagation and Kinking Crack Concept to ECC/Concrete Overlay Repair System

Directory of Open Access Journals (Sweden)

Yaw ChiaHwan

2014-01-01

Full Text Available Research on the application of ultraductile engineered cementitious composite (ECC as overlay in the repair of deteriorated concrete structures is performed in this paper. Also, interfacial crack kinking and trapping mechanism experimentally observed in ECC/concrete overlay repair system are described by comparison of toughness and energy release rate. The mechanism involves cycles of extension, kinking, and arrest of interfacial crack into the overlay. Experimental testing of overlay repair system reveals significant improvements in load carrying capacity and ductility over conventional concrete overlay. The commonly observed overlay system failure mode of delamination or spalling is eliminated when ECC is applied. These failure modes are suppressed when ECC is used as an ideal and durable candidate overlay repair material.

Assessment and prediction of drying shrinkage cracking in bonded mortar overlays

Energy Technology Data Exchange (ETDEWEB)

Beushausen, Hans, E-mail: hans.beushausen@uct.ac.za; Chilwesa, Masuzyo

2013-11-15

Restrained drying shrinkage cracking was investigated on composite beams consisting of substrate concrete and bonded mortar overlays, and compared to the performance of the same mortars when subjected to the ring test. Stress development and cracking in the composite specimens were analytically modeled and predicted based on the measurement of relevant time-dependent material properties such as drying shrinkage, elastic modulus, tensile relaxation and tensile strength. Overlay cracking in the composite beams could be very well predicted with the analytical model. The ring test provided a useful qualitative comparison of the cracking performance of the mortars. The duration of curing was found to only have a minor influence on crack development. This was ascribed to the fact that prolonged curing has a beneficial effect on tensile strength at the onset of stress development, but is in the same time not beneficial to the values of tensile relaxation and elastic modulus. -- Highlights: •Parameter study on material characteristics influencing overlay cracking. •Analytical model gives good quantitative indication of overlay cracking. •Ring test presents good qualitative indication of overlay cracking. •Curing duration has little effect on overlay cracking.

Assessment and prediction of drying shrinkage cracking in bonded mortar overlays

International Nuclear Information System (INIS)

Beushausen, Hans; Chilwesa, Masuzyo

2013-01-01

Restrained drying shrinkage cracking was investigated on composite beams consisting of substrate concrete and bonded mortar overlays, and compared to the performance of the same mortars when subjected to the ring test. Stress development and cracking in the composite specimens were analytically modeled and predicted based on the measurement of relevant time-dependent material properties such as drying shrinkage, elastic modulus, tensile relaxation and tensile strength. Overlay cracking in the composite beams could be very well predicted with the analytical model. The ring test provided a useful qualitative comparison of the cracking performance of the mortars. The duration of curing was found to only have a minor influence on crack development. This was ascribed to the fact that prolonged curing has a beneficial effect on tensile strength at the onset of stress development, but is in the same time not beneficial to the values of tensile relaxation and elastic modulus. -- Highlights: •Parameter study on material characteristics influencing overlay cracking. •Analytical model gives good quantitative indication of overlay cracking. •Ring test presents good qualitative indication of overlay cracking. •Curing duration has little effect on overlay cracking

On Adding Structure to Unstructured Overlay Networks

Science.gov (United States)

Leitão, João; Carvalho, Nuno A.; Pereira, José; Oliveira, Rui; Rodrigues, Luís

Unstructured peer-to-peer overlay networks are very resilient to churn and topology changes, while requiring little maintenance cost. Therefore, they are an infrastructure to build highly scalable large-scale services in dynamic networks. Typically, the overlay topology is defined by a peer sampling service that aims at maintaining, in each process, a random partial view of peers in the system. The resulting random unstructured topology is suboptimal when a specific performance metric is considered. On the other hand, structured approaches (for instance, a spanning tree) may optimize a given target performance metric but are highly fragile. In fact, the cost for maintaining structures with strong constraints may easily become prohibitive in highly dynamic networks. This chapter discusses different techniques that aim at combining the advantages of unstructured and structured networks. Namely we focus on two distinct approaches, one based on optimizing the overlay and another based on optimizing the gossip mechanism itself.

Development of new engine bearings with overlay consisting of solid lubricants; Kotai junkatsu overlay tsuki engine yo suberi jikuuke zairyo no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Kanayama, H; Kawakami, S; Gohara, C [Taiho Kogyo Co. Ltd., Aichi (Japan); Fuwa, Y; Michioka, H [Toyota Motor Corp., Aichi (Japan)

1997-10-01

Recently, modern engines have a tendency for higher output and longer periods. As a result , higher bearing performance is required. For this reason, we have developed the new conceptual overlay consisting of solid lubricants and thermosetting plastics. This paper describes the performance of engine bearings with the new overlay. 5 refs., 13 figs., 5 tabs.

Computer vision and soft computing for automatic skull-face overlay in craniofacial superimposition.

Science.gov (United States)

Campomanes-Álvarez, B Rosario; Ibáñez, O; Navarro, F; Alemán, I; Botella, M; Damas, S; Cordón, O

2014-12-01

Craniofacial superimposition can provide evidence to support that some human skeletal remains belong or not to a missing person. It involves the process of overlaying a skull with a number of ante mortem images of an individual and the analysis of their morphological correspondence. Within the craniofacial superimposition process, the skull-face overlay stage just focuses on achieving the best possible overlay of the skull and a single ante mortem image of the suspect. Although craniofacial superimposition has been in use for over a century, skull-face overlay is still applied by means of a trial-and-error approach without an automatic method. Practitioners finish the process once they consider that a good enough overlay has been attained. Hence, skull-face overlay is a very challenging, subjective, error prone, and time consuming part of the whole process. Though the numerical assessment of the method quality has not been achieved yet, computer vision and soft computing arise as powerful tools to automate it, dramatically reducing the time taken by the expert and obtaining an unbiased overlay result. In this manuscript, we justify and analyze the use of these techniques to properly model the skull-face overlay problem. We also present the automatic technical procedure we have developed using these computational methods and show the four overlays obtained in two craniofacial superimposition cases. This automatic procedure can be thus considered as a tool to aid forensic anthropologists to develop the skull-face overlay, automating and avoiding subjectivity of the most tedious task within craniofacial superimposition. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Achieving optimum diffraction based overlay performance

Science.gov (United States)

Leray, Philippe; Laidler, David; Cheng, Shaunee; Coogans, Martyn; Fuchs, Andreas; Ponomarenko, Mariya; van der Schaar, Maurits; Vanoppen, Peter

2010-03-01

Diffraction Based Overlay (DBO) metrology has been shown to have significantly reduced Total Measurement Uncertainty (TMU) compared to Image Based Overlay (IBO), primarily due to having no measurable Tool Induced Shift (TIS). However, the advantages of having no measurable TIS can be outweighed by increased susceptibility to WIS (Wafer Induced Shift) caused by target damage, process non-uniformities and variations. The path to optimum DBO performance lies in having well characterized metrology targets, which are insensitive to process non-uniformities and variations, in combination with optimized recipes which take advantage of advanced DBO designs. In this work we examine the impact of different degrees of process non-uniformity and target damage on DBO measurement gratings and study their impact on overlay measurement accuracy and precision. Multiple wavelength and dual polarization scatterometry are used to characterize the DBO design performance over the range of process variation. In conclusion, we describe the robustness of DBO metrology to target damage and show how to exploit the measurement capability of a multiple wavelength, dual polarization scatterometry tool to ensure the required measurement accuracy for current and future technology nodes.

KML Super Overlay to WMS Translator

Science.gov (United States)

Plesea, Lucian

2007-01-01

This translator is a server-based application that automatically generates KML super overlay configuration files required by Google Earth for map data access via the Open Geospatial Consortium WMS (Web Map Service) standard. The translator uses a set of URL parameters that mirror the WMS parameters as much as possible, and it also can generate a super overlay subdivision of any given area that is only loaded when needed, enabling very large areas of coverage at very high resolutions. It can make almost any dataset available as a WMS service visible and usable in any KML application, without the need to reformat the data.

Longer Lasting Bridge Deck Overlays

Science.gov (United States)

2018-04-01

The objective of this report is to determine the most effective method for bridge deck overlay construction and repair by assessing current practices; examining new products and technologies; and reviewing NCHRP (National Cooperative Highway Research...

Diffraction-based overlay measurement on dedicated mark using rigorous modeling method

Science.gov (United States)

Lu, Hailiang; Wang, Fan; Zhang, Qingyun; Chen, Yonghui; Zhou, Chang

2012-03-01

Diffraction Based Overlay (DBO) is widely evaluated by numerous authors, results show DBO can provide better performance than Imaging Based Overlay (IBO). However, DBO has its own problems. As well known, Modeling based DBO (mDBO) faces challenges of low measurement sensitivity and crosstalk between various structure parameters, which may result in poor accuracy and precision. Meanwhile, main obstacle encountered by empirical DBO (eDBO) is that a few pads must be employed to gain sufficient information on overlay-induced diffraction signature variations, which consumes more wafer space and costs more measuring time. Also, eDBO may suffer from mark profile asymmetry caused by processes. In this paper, we propose an alternative DBO technology that employs a dedicated overlay mark and takes a rigorous modeling approach. This technology needs only two or three pads for each direction, which is economic and time saving. While overlay measurement error induced by mark profile asymmetry being reduced, this technology is expected to be as accurate and precise as scatterometry technologies.

Examination of overlay pipe weldments removed from the Hatch-2 reactor

International Nuclear Information System (INIS)

Park, J.Y.; Kupperman, D.S.; Shack, W.J.

1985-02-01

Laboratory ultrasonic examination (UT), dye penetrant examination (PT), metallography, and sensitization measurements were performed on Type 304 stainless steel overlay pipe weldments from the Hatch-2 BWR to determine the effectiveness of UT through overlays and the effects of the overlays on crack propagation in the weldments. Little correlation was observed between the results of earlier in-service ultrasonic inspection and the results of PT and destructive examination. Considerable difficulty was encountered in correctly detecting the presence of cracks by UT in the laboratory. Blunting of the crack tip by the weld overlay was observed, but there was no evidence of tearing or throughwall extension of the crack beyond the blunted region

Tack coat optimization for HMA overlays : accelerated pavement test report.

Science.gov (United States)

2009-02-01

Interface bonding between hot-mix asphalt (HMA) overlays and Portland cement concrete (PCC) pavements is one : of the most significant factors affecting overlay service life. This study was performed to quantify the effects of HMA type, : tack coat t...

Modern methods of overlay welding for corrosion protection of power generating equipment

International Nuclear Information System (INIS)

Ershov, A.V.; Shul'man, I.E.; Potapov, N.N.

1989-01-01

Methods for overlay welding of inner surfaces of power equipment for corrosion protection are analysed. Various methods of electroslag overlay welding by a band electrode (overlay welding by two-electrode bands by a wide band with magnetic control, by an electrode band with high melting velocity) are marked to be the most perspective for cladding of NPP vessel equipment

VT Data - Overlay District 20170419, Colchester

Data.gov (United States)

Vermont Center for Geographic Information — The following Overlay Districts are included in the data:General Development Four Commercial DistrictGeneral Development Four Openspace DistrictShoreland...

Overlay improvement by exposure map based mask registration optimization

Science.gov (United States)

Shi, Irene; Guo, Eric; Chen, Ming; Lu, Max; Li, Gordon; Li, Rivan; Tian, Eric

2015-03-01

Along with the increased miniaturization of semiconductor electronic devices, the design rules of advanced semiconductor devices shrink dramatically. [1] One of the main challenges of lithography step is the layer-to-layer overlay control. Furthermore, DPT (Double Patterning Technology) has been adapted for the advanced technology node like 28nm and 14nm, corresponding overlay budget becomes even tighter. [2][3] After the in-die mask registration (pattern placement) measurement is introduced, with the model analysis of a KLA SOV (sources of variation) tool, it's observed that registration difference between masks is a significant error source of wafer layer-to-layer overlay at 28nm process. [4][5] Mask registration optimization would highly improve wafer overlay performance accordingly. It was reported that a laser based registration control (RegC) process could be applied after the pattern generation or after pellicle mounting and allowed fine tuning of the mask registration. [6] In this paper we propose a novel method of mask registration correction, which can be applied before mask writing based on mask exposure map, considering the factors of mask chip layout, writing sequence, and pattern density distribution. Our experiment data show if pattern density on the mask keeps at a low level, in-die mask registration residue error in 3sigma could be always under 5nm whatever blank type and related writer POSCOR (position correction) file was applied; it proves random error induced by material or equipment would occupy relatively fixed error budget as an error source of mask registration. On the real production, comparing the mask registration difference through critical production layers, it could be revealed that registration residue error of line space layers with higher pattern density is always much larger than the one of contact hole layers with lower pattern density. Additionally, the mask registration difference between layers with similar pattern density

Overlay Spectrum Sharing using Improper Gaussian Signaling

KAUST Repository

Amin, Osama

2016-11-30

Improper Gaussian signaling (IGS) scheme has been recently shown to provide performance improvements in interference limited networks as opposed to the conventional proper Gaussian signaling (PGS) scheme. In this paper, we implement the IGS scheme in overlay cognitive radio system, where the secondary transmitter broadcasts a mixture of two different signals. The first signal is selected from the PGS scheme to match the primary message transmission. On the other hand, the second signal is chosen to be from the IGS scheme in order to reduce the interference effect on the primary receiver. We then optimally design the overlay cognitive radio to maximize the secondary link achievable rate while satisfying the primary network quality of service requirements. In particular, we consider full and partial channel knowledge scenarios and derive the feasibility conditions of operating the overlay cognitive radio systems. Moreover, we derive the superiority conditions of the IGS schemes over the PGS schemes supported with closed form expressions for the corresponding power distribution and the circularity coefficient and parameters. Simulation results are provided to support our theoretical derivations.

Application of advanced diffraction based optical metrology overlay capabilities for high-volume manufacturing

Science.gov (United States)

Chen, Kai-Hsiung; Huang, Guo-Tsai; Hsieh, Hung-Chih; Ni, Wei-Feng; Chuang, S. M.; Chuang, T. K.; Ke, Chih-Ming; Huang, Jacky; Rao, Shiuan-An; Cumurcu Gysen, Aysegul; d'Alfonso, Maxime; Yueh, Jenny; Izikson, Pavel; Soco, Aileen; Wu, Jon; Nooitgedagt, Tjitte; Ottens, Jeroen; Kim, Yong Ho; Ebert, Martin

2017-03-01

On-product overlay requirements are becoming more challenging with every next technology node due to the continued decrease of the device dimensions and process tolerances. Therefore, current and future technology nodes require demanding metrology capabilities such as target designs that are robust towards process variations and high overlay measurement density (e.g. for higher order process corrections) to enable advanced process control solutions. The impact of advanced control solutions based on YieldStar overlay data is being presented in this paper. Multi patterning techniques are applied for critical layers and leading to additional overlay measurement demands. The use of 1D process steps results in the need of overlay measurements relative to more than one layer. Dealing with the increased number of overlay measurements while keeping the high measurement density and metrology accuracy at the same time presents a challenge for high volume manufacturing (HVM). These challenges are addressed by the capability to measure multi-layer targets with the recently introduced YieldStar metrology tool, YS350. On-product overlay results of such multi-layers and standard targets are presented including measurement stability performance.

VT Data - Overlay District 20070306, Marlboro

Data.gov (United States)

Vermont Center for Geographic Information — Cartographic version of overlay district (surface water buffer), Marlboro, Vermont. Base zoning districts are in a separate shapefile. Data were originally created...

Visualization of Disciplinary Profiles: Enhanced Science Overlay Maps

Directory of Open Access Journals (Sweden)

Stephen Carley

2017-08-01

Full Text Available Purpose: The purpose of this study is to modernize previous work on science overlay maps by updating the underlying citation matrix, generating new clusters of scientific disciplines, enhancing visualizations, and providing more accessible means for analysts to generate their own maps. Design/methodology/approach: We use the combined set of 2015 Journal Citation Reports for the Science Citation Index (n of journals = 8,778 and the Social Sciences Citation Index (n = 3,212 for a total of 11,365 journals. The set of Web of Science Categories in the Science Citation Index and the Social Sciences Citation Index increased from 224 in 2010 to 227 in 2015. Using dedicated software, a matrix of 227 × 227 cells is generated on the basis of whole-number citation counting. We normalize this matrix using the cosine function. We first develop the citing-side, cosine-normalized map using 2015 data and VOSviewer visualization with default parameter values. A routine for making overlays on the basis of the map (“wc15.exe” is available at http://www.leydesdorff.net/wc15/index.htm. Findings: Findings appear in the form of visuals throughout the manuscript. In Figures 1–9 we provide basemaps of science and science overlay maps for a number of companies, universities, and technologies. Research limitations: As Web of Science Categories change and/or are updated so is the need to update the routine we provide. Also, to apply the routine we provide users need access to the Web of Science. Practical implications: Visualization of science overlay maps is now more accurate and true to the 2015 Journal Citation Reports than was the case with the previous version of the routine advanced in our paper. Originality/value: The routine we advance allows users to visualize science overlay maps in VOSviewer using data from more recent Journal Citation Reports.

Axial compression behavior of concrete masonry wallettes strengthened with cement mortar overlays

Directory of Open Access Journals (Sweden)

F. L. De Oliveira

Full Text Available This paper presents the results of a series of axial compression tests on concrete block wallettes coated with cement mortar overlays. Different types of mortars and combinations with steel welded meshes and fibers were tested. The experimental results were discussed based on different theoretical approaches: analytical and Finite Element Method models. The main conclusions are: a the application of mortar overlays increases the wall strength, but not in a uniform manner; b the strengthening efficiency of wallettes loaded in axial compression is not proportional to the overlay mortar strength because it can be affected by the failure mechanisms of the wall; c steel mesh reinforced overlays in combination with high strength mortar show better efficiency, because the steel mesh mitigates the damage effects in the block wall and in the overlays themselves; d simplified theoretical methods of analysis as described in this paper can give satisfactory predictions of masonry wall behavior up to a certain level.

Latex-modified fiber-reinforced concrete bridge deck overlay : construction/interim report.

Science.gov (United States)

1993-06-01

Latex-modified concrete (LMC) is Portland cement concrete (PCC) with an admixture of latex. LMC is considered to be nearly impermeable to chlorides and is extensively used to construct bridge deck overlays. Unfortunately, some of these overlays have ...

A Persistent Structured Hierarchical Overlay Network to Counter Intentional Churn Attack

Directory of Open Access Journals (Sweden)

Ramanpreet Kaur

2016-01-01

Full Text Available The increased use of structured overlay network for a variety of applications has attracted a lot of attention from both research community and attackers. However, the structural constraints, open nature (anybody can join and anybody may leave, and unreliability of its participant nodes significantly affect the performance of these applications and make it vulnerable to a variety of attacks such as eclipse, Sybil, and churn. One attack to compromise the service availability in overlay network is intentional churn (join/leave attack, where a large number of malicious users will join and leave the overlay network so frequently that the entire structure collapses and becomes unavailable. The focus of this paper is to provide a new robust, efficient, and scalable hierarchical overlay architecture that will counter these attacks by providing a structure that can accommodate the fleeting behaviour of nodes without causing much structural inconsistencies. The performance evaluation showed that the proposed architecture has more failure resilience and self-organization as compared to chord based architecture. Experimental results have demonstrated that the effect of failures on an overlay is proportional to the size of failure.

Characterisation of hydrocarbonaceous overlayers important in metal-catalysed selective hydrogenation reactions

Energy Technology Data Exchange (ETDEWEB)

Lennon, David; Warringham, Robbie [School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Guidi, Tatiana [ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Parker, Stewart F., E-mail: stewart.parker@stfc.ac.uk [ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom)

2013-12-12

Highlights: • Inelastic neutron scattering spectroscopy of a commercial dehydrogenation catalyst. • The overlayer present on the catalyst is predominantly aliphatic. • A population of strongly hydrogen bonded hydroxyls is also present. - Abstract: The hydrogenation of alkynes to alkenes over supported metal catalysts is an important industrial process and it has been shown that hydrocarbonaceous overlayers are important in controlling selectivity profiles of metal-catalysed hydrogenation reactions. As a model system, we have selected propyne hydrogenation over a commercial Pd(5%)/Al{sub 2}O{sub 3} catalyst. Inelastic neutron scattering studies show that the C–H stretching mode ranges from 2850 to 3063 cm{sup −1}, indicating the mostly aliphatic nature of the overlayer and this is supported by the quantification of the carbon and hydrogen on the surface. There is also a population of strongly hydrogen-bonded hydroxyls, their presence would indicate that the overlayer probably contains some oxygen functionality. There is little evidence for any olefinic or aromatic species. This is distinctly different from the hydrogen-poor overlayers that are deposited on Ni/Al{sub 2}O{sub 3} catalysts during methane reforming.

New overlay measurement technique with an i-line stepper using embedded standard field image alignment marks for wafer bonding applications

Science.gov (United States)

Kulse, P.; Sasai, K.; Schulz, K.; Wietstruck, M.

2017-06-01

In the last decades the semiconductor technology has been driven by Moore's law leading to high performance CMOS technologies with feature sizes of less than 10 nm [1]. It has been pointed out that not only scaling but also the integration of novel components and technology modules into CMOS/BiCMOS technologies is becoming more attractive to realize smart and miniaturized systems [2]. Driven by new applications in the area of communication, health and automation, new components and technology modules such as BiCMOS embedded RF-MEMS, high-Q passives, Sibased microfluidics and InP-SiGe BiCMOS heterointegration have been demonstrated [3-6]. In contrast to standard VLSI processes fabricated on front side of the silicon wafer, these new technology modules require addition backside processing of the wafer; thus an accurate alignment between the front and backside of the wafer is mandatory. In previous work an advanced back to front side alignment technique and implementation into IHP's 0.25/0.13 μm high performance SiGe:C BiCMOS backside process module has been presented [7]. The developed technique enables a high resolution and accurate lithography on the backside of BiCMOS wafer for additional backside processing. In addition to the aforementioned back side process technologies, new applications like Through-Silicon Vias (TSV) for interposers and advanced substrate technologies for 3D heterogeneous integration demand not only single wafer fabrication but also processing of wafer stacks provided by temporary and permanent wafer bonding [8]. Therefore, the available overlay measurement techniques are not suitable if overlay and alignment marks are realized at the bonding interface of a wafer stack which consists of both a silicon device and a silicon carrier wafer. The former used EVG 40NT automated overlay measurement system, which use two opposite positioned microscopes inspecting simultaneous the wafer back and front side, is not capable measuring embedded overlay

Overlay accuracy on a flexible web with a roll printing process based on a roll-to-roll system.

Science.gov (United States)

Chang, Jaehyuk; Lee, Sunggun; Lee, Ki Beom; Lee, Seungjun; Cho, Young Tae; Seo, Jungwoo; Lee, Sukwon; Jo, Gugrae; Lee, Ki-yong; Kong, Hyang-Shik; Kwon, Sin

2015-05-01

For high-quality flexible devices from printing processes based on Roll-to-Roll (R2R) systems, overlay alignment during the patterning of each functional layer poses a major challenge. The reason is because flexible substrates have a relatively low stiffness compared with rigid substrates, and they are easily deformed during web handling in the R2R system. To achieve a high overlay accuracy for a flexible substrate, it is important not only to develop web handling modules (such as web guiding, tension control, winding, and unwinding) and a precise printing tool but also to control the synchronization of each unit in the total system. A R2R web handling system and reverse offset printing process were developed in this work, and an overlay between the 1st and 2nd layers of ±5μm on a 500 mm-wide film was achieved at a σ level of 2.4 and 2.8 (x and y directions, respectively) in a continuous R2R printing process. This paper presents the components and mechanisms used in reverse offset printing based on a R2R system and the printing results including positioning accuracy and overlay alignment accuracy.

On cooperative and efficient overlay network evolution based on a group selection pattern.

Science.gov (United States)

Nakao, Akihiro; Wang, Yufeng

2010-04-01

In overlay networks, the interplay between network structure and dynamics remains largely unexplored. In this paper, we study dynamic coevolution between individual rational strategies (cooperative or defect) and the overlay network structure, that is, the interaction between peer's local rational behaviors and the emergence of the whole network structure. We propose an evolutionary game theory (EGT)-based overlay topology evolution scheme to drive a given overlay into the small-world structure (high global network efficiency and average clustering coefficient). Our contributions are the following threefold: From the viewpoint of peers' local interactions, we explicitly consider the peer's rational behavior and introduce a link-formation game to characterize the social dilemma of forming links in an overlay network. Furthermore, in the evolutionary link-formation phase, we adopt a simple economic process: Each peer keeps one link to a cooperative neighbor in its neighborhood, which can slightly speed up the convergence of cooperation and increase network efficiency; from the viewpoint of the whole network structure, our simulation results show that the EGT-based scheme can drive an arbitrary overlay network into a fully cooperative and efficient small-world structure. Moreover, we compare our scheme with a search-based economic model of network formation and illustrate that our scheme can achieve the experimental and analytical results in the latter model. In addition, we also graphically illustrate the final overlay network structure; finally, based on the group selection model and evolutionary set theory, we theoretically obtain the approximate threshold of cost and draw the conclusion that the small value of the average degree and the large number of the total peers in an overlay network facilitate the evolution of cooperation.

Overlay control methodology comparison: field-by-field and high-order methods

Science.gov (United States)

Huang, Chun-Yen; Chiu, Chui-Fu; Wu, Wen-Bin; Shih, Chiang-Lin; Huang, Chin-Chou Kevin; Huang, Healthy; Choi, DongSub; Pierson, Bill; Robinson, John C.

2012-03-01

Overlay control in advanced integrated circuit (IC) manufacturing is becoming one of the leading lithographic challenges in the 3x and 2x nm process nodes. Production overlay control can no longer meet the stringent emerging requirements based on linear composite wafer and field models with sampling of 10 to 20 fields and 4 to 5 sites per field, which was the industry standard for many years. Methods that have emerged include overlay metrology in many or all fields, including the high order field model method called high order control (HOC), and field by field control (FxFc) methods also called correction per exposure. The HOC and FxFc methods were initially introduced as relatively infrequent scanner qualification activities meant to supplement linear production schemes. More recently, however, it is clear that production control is also requiring intense sampling, similar high order and FxFc methods. The added control benefits of high order and FxFc overlay methods need to be balanced with the increased metrology requirements, however, without putting material at risk. Of critical importance is the proper control of edge fields, which requires intensive sampling in order to minimize signatures. In this study we compare various methods of overlay control including the performance levels that can be achieved.

Faster diffraction-based overlay measurements with smaller targets using 3D gratings

Science.gov (United States)

Li, Jie; Kritsun, Oleg; Liu, Yongdong; Dasari, Prasad; Volkman, Catherine; Hu, Jiangtao

2012-03-01

Diffraction-based overlay (DBO) technologies have been developed to address the overlay metrology challenges for 22nm technology node and beyond. Most DBO technologies require specially designed targets that consist of multiple measurement pads, which consume too much space and increase measurement time. The traditional empirical approach (eDBO) using normal incidence spectroscopic reflectometry (NISR) relies on linear response of the reflectance with respect to overlay displacement within a small range. It offers convenience of quick recipe setup since there is no need to establish a model. However it requires three or four pads per direction (x or y) which adds burden to throughput and target size. Recent advances in modeling capability and computation power enabled mDBO, which allows overlay measurement with reduced number of pads, thus reducing measurement time and DBO target space. In this paper we evaluate the performance of single pad mDBO measurements using two 3D targets that have different grating shapes: squares in boxes and L-shapes in boxes. Good overlay sensitivities are observed for both targets. The correlation to programmed shifts and image-based overlay (IBO) is excellent. Despite the difference in shapes, the mDBO results are comparable for square and L-shape targets. The impact of process variations on overlay measurements is studied using a focus and exposure matrix (FEM) wafer. Although the FEM wafer has larger process variations, the correlation of mDBO results with IBO measurements is as good as the normal process wafer. We demonstrate the feasibility of single pad DBO measurements with faster throughput and smaller target size, which is particularly important in high volume manufacturing environment.

Driving imaging and overlay performance to the limits with advanced lithography optimization

Science.gov (United States)

Mulkens, Jan; Finders, Jo; van der Laan, Hans; Hinnen, Paul; Kubis, Michael; Beems, Marcel

2012-03-01

Immersion lithography is being extended to 22-nm and even below. Next to generic scanner system improvements, application specific solutions are needed to follow the requirements for CD control and overlay. Starting from the performance budgets, this paper discusses how to improve (in volume manufacturing environment) CDU towards 1-nm and overlay towards 3-nm. The improvements are based on deploying the actuator capabilities of the immersion scanner. The latest generation immersion scanners have extended the correction capabilities for overlay and imaging, offering freeform adjustments of lens, illuminator and wafer grid. In order to determine the needed adjustments the recipe generation per user application is based on a combination wafer metrology data and computational lithography methods. For overlay, focus and CD metrology we use an angle resolved optical scatterometer.

A study of swing-curve physics in diffraction-based overlay

Science.gov (United States)

Bhattacharyya, Kaustuve; den Boef, Arie; Storms, Greet; van Heijst, Joost; Noot, Marc; An, Kevin; Park, Noh-Kyoung; Jeon, Se-Ra; Oh, Nang-Lyeom; McNamara, Elliott; van de Mast, Frank; Oh, SeungHwa; Lee, Seung Yoon; Hwang, Chan; Lee, Kuntack

2016-03-01

With the increase of process complexity in advanced nodes, the requirements of process robustness in overlay metrology continues to tighten. Especially with the introduction of newer materials in the film-stack along with typical stack variations (thickness, optical properties, profile asymmetry etc.), the signal formation physics in diffraction-based overlay (DBO) becomes an important aspect to apply in overlay metrology target and recipe selection. In order to address the signal formation physics, an effort is made towards studying the swing-curve phenomena through wavelength and polarizations on production stacks using simulations as well as experimental technique using DBO. The results provide a wealth of information on target and recipe selection for robustness. Details from simulation and measurements will be reported in this technical publication.

Potential of zero free charge of Pd overlayers on Pt(1 1 1)

International Nuclear Information System (INIS)

El-Aziz, A.M.; Hoyer, R.; Kibler, L.A.; Kolb, D.M.

2006-01-01

Differential capacitance measurements of Pd overlayers on a Pt(1 1 1) electrode in dilute aqueous NaF solutions have been performed as a function of film thickness in order to determine the potential of zero free charge (pzfc). The pzfc of the first, pseudomorphic Pd monolayer on Pt(1 1 1) is -0.21 V versus SCE. By increasing the amount of deposited Pd, a clear shift of the pzfc to more positive values is observed. After deposition of an equivalent of 10 monolayers, the value approaches that of a massive Pd(1 1 1) electrode (-0.12 V versus SCE). The pzfc's for the various Pd coverages are correlated with surface structure information, derived from STM images (R. Hoyer, L.A. Kibler, D.M. Kolb, Electrochim. Acta 49 (2003) 63). Variations in the pzfc are discussed in the context of an electronic modification by the underlying substrate and are compared with corresponding data for Pd overlayers on Au(1 1 1)

Simultaneous overlay and CD measurement for double patterning: scatterometry and RCWA approach

Science.gov (United States)

Li, Jie; Liu, Zhuan; Rabello, Silvio; Dasari, Prasad; Kritsun, Oleg; Volkman, Catherine; Park, Jungchul; Singh, Lovejeet

2009-03-01

As optical lithography advances to 32 nm technology node and beyond, double patterning technology (DPT) has emerged as an attractive solution to circumvent the fundamental optical limitations. DPT poses unique demands on critical dimension (CD) uniformity and overlay control, making the tolerance decrease much faster than the rate at which critical dimension shrinks. This, in turn, makes metrology even more challenging. In the past, multi-pad diffractionbased overlay (DBO) using empirical approach has been shown to be an effective approach to measure overlay error associated with double patterning [1]. In this method, registration errors for double patterning were extracted from specially designed diffraction targets (three or four pads for each direction); CD variation is assumed negligible within each group of adjacent pads and not addressed in the measurement. In another paper, encouraging results were reported with a first attempt at simultaneously extracting overlay and CD parameters using scatterometry [2]. In this work, we apply scatterometry with a rigorous coupled wave analysis (RCWA) approach to characterize two double-patterning processes: litho-etch-litho-etch (LELE) and litho-freeze-litho-etch (LFLE). The advantage of performing rigorous modeling is to reduce the number of pads within each measurement target, thus reducing space requirement and improving throughput, and simultaneously extract CD and overlay information. This method measures overlay errors and CDs by fitting the optical signals with spectra calculated from a model of the targets. Good correlation is obtained between the results from this method and that of several reference techniques, including empirical multi-pad DBO, CD-SEM, and IBO. We also perform total measurement uncertainty (TMU) analysis to evaluate the overall performance. We demonstrate that scatterometry provides a promising solution to meet the challenging overlay metrology requirement in DPT.

VMCast: A VM-Assisted Stability Enhancing Solution for Tree-Based Overlay Multicast.

Directory of Open Access Journals (Sweden)

Weidong Gu

Full Text Available Tree-based overlay multicast is an effective group communication method for media streaming applications. However, a group member's departure causes all of its descendants to be disconnected from the multicast tree for some time, which results in poor performance. The above problem is difficult to be addressed because overlay multicast tree is intrinsically instable. In this paper, we proposed a novel stability enhancing solution, VMCast, for tree-based overlay multicast. This solution uses two types of on-demand cloud virtual machines (VMs, i.e., multicast VMs (MVMs and compensation VMs (CVMs. MVMs are used to disseminate the multicast data, whereas CVMs are used to offer streaming compensation. The used VMs in the same cloud datacenter constitute a VM cluster. Each VM cluster is responsible for a service domain (VMSD, and each group member belongs to a specific VMSD. The data source delivers the multicast data to MVMs through a reliable path, and MVMs further disseminate the data to group members along domain overlay multicast trees. The above approach structurally improves the stability of the overlay multicast tree. We further utilized CVM-based streaming compensation to enhance the stability of the data distribution in the VMSDs. VMCast can be used as an extension to existing tree-based overlay multicast solutions, to provide better services for media streaming applications. We applied VMCast to two application instances (i.e., HMTP and HCcast. The results show that it can obviously enhance the stability of the data distribution.

Effects of Spectral Overlays on Reading Performance of Brazilian Elementary School Children.

Science.gov (United States)

Garcia, Ana Carla Oliveira; Momensohn-Santos, Teresa Maria; Vilhena, Douglas de Araújo

2018-03-20

To investigate the effects of spectral overlays on reading performance of Brazilian elementary school children. Sixty-eight children (aged 9-12 years) enrolled in the 5th and 6th grade were included in the study. The Rate of Reading Test (RRT - Brazilian Portuguese version) was used to evaluate reading speed and the Irlen Reading Perceptual Scale was used to allocate the sample according to reading difficulty/discomfort symptoms and to define the optimal spectral overlays. A total of 13% of the children presented an improvement of at least 15% in reading speed with the use of spectral overlays. Pupils with severe reading difficulties tended to have more improvement in RRT with spectral overlays. Children with severe reading discomfort obtained the highest gains in RRT, with an average of 9.6% improvement with intervention, compared to a decrease of -8.2% in the control group. Participants with severe discomfort had an odds ratio of 3.36 to improve reading speed with intervention compared to the control group. The use of spectral overlays can improve reading performance, particularly in those children with severe visual discomfort. © 2018 S. Karger AG, Basel.

Holistic metrology qualification extension and its application to characterize overlay targets with asymmetric effects

Science.gov (United States)

Dos Santos Ferreira, Olavio; Sadat Gousheh, Reza; Visser, Bart; Lie, Kenrick; Teuwen, Rachel; Izikson, Pavel; Grzela, Grzegorz; Mokaberi, Babak; Zhou, Steve; Smith, Justin; Husain, Danish; Mandoy, Ram S.; Olvera, Raul

2018-03-01

Ever increasing need for tighter on-product overlay (OPO), as well as enhanced accuracy in overlay metrology and methodology, is driving semiconductor industry's technologists to innovate new approaches to OPO measurements. In case of High Volume Manufacturing (HVM) fabs, it is often critical to strive for both accuracy and robustness. Robustness, in particular, can be challenging in metrology since overlay targets can be impacted by proximity of other structures next to the overlay target (asymmetric effects), as well as symmetric stack changes such as photoresist height variations. Both symmetric and asymmetric contributors have impact on robustness. Furthermore, tweaking or optimizing wafer processing parameters for maximum yield may have an adverse effect on physical target integrity. As a result, measuring and monitoring physical changes or process abnormalities/artefacts in terms of new Key Performance Indicators (KPIs) is crucial for the end goal of minimizing true in-die overlay of the integrated circuits (ICs). IC manufacturing fabs often relied on CD-SEM in the past to capture true in-die overlay. Due to destructive and intrusive nature of CD-SEMs on certain materials, it's desirable to characterize asymmetry effects for overlay targets via inline KPIs utilizing YieldStar (YS) metrology tools. These KPIs can also be integrated as part of (μDBO) target evaluation and selection for final recipe flow. In this publication, the Holistic Metrology Qualification (HMQ) flow was extended to account for process induced (asymmetric) effects such as Grating Imbalance (GI) and Bottom Grating Asymmetry (BGA). Local GI typically contributes to the intrafield OPO whereas BGA typically impacts the interfield OPO, predominantly at the wafer edge. Stack height variations highly impact overlay metrology accuracy, in particular in case of multi-layer LithoEtch Litho-Etch (LELE) overlay control scheme. Introducing a GI impact on overlay (in nm) KPI check quantifies the

Effectiveness of polymer bridge deck overlays in highway noise reduction : technical paper.

Science.gov (United States)

2016-04-01

The Kansas Department of Transportation (KDOT) began placing multi-layer polymer bridge deck overlays in 1999 and at the present time have over 200 in service. A few years after placing the overlays, individuals indicated that they noticed how quiet ...

Intermittent-contact scanning capacitance microscopy imaging and modeling for overlay metrology

International Nuclear Information System (INIS)

Mayo, S.; Kopanski, J. J.; Guthrie, W. F.

1998-01-01

Overlay measurements of the relative alignment between sequential layers are one of the most critical issues for integrated circuit (IC) lithography. We have implemented on an AFM platform a new intermittent-contact scanning capacitance microscopy (IC-SCM) mode that is sensitive to the tip proximity to an IC interconnect, thus making it possible to image conductive structures buried under planarized dielectric layers. Such measurements can be used to measure IC metal-to-resist lithography overlay. The AFM conductive cantilever probe oscillating in a vertical plane was driven at frequency ω, below resonance. By measuring the tip-to-sample capacitance, the SCM signal is obtained as the difference in capacitance, ΔC(ω), at the amplitude extremes. Imaging of metallization structures was obtained with a bars-in-bars aluminum structure embedded in a planarized dielectric layer 1 μm thick. We have also modeled, with a two-dimensional (2D) electrostatic field simulator, IC-SCM overlay data of a metallization structure buried under a planarized dielectric having a patterned photoresist layer deposited on it. This structure, which simulates the metal-to-resist overlay between sequential IC levels, allows characterization of the technique sensitivity. The capacitance profile across identical size electrically isolated or grounded metal lines embedded in a dielectric was shown to be different. The floating line shows capacitance enhancement at the line edges, with a minimum at the line center. The grounded line shows a single capacitance maximum located at the line center, with no edge enhancement. For identical line dimensions, the capacitance is significantly larger for grounded lines making them easier to image. A nonlinear regression algorithm was developed to extract line center and overlay parameters with approximately 3 nm resolution at the 95% confidence level, showing the potential of this technique for sub-micrometer critical dimension metrology. Symmetric test

Solidification paths in modified Inconel 625 weld overlay material

DEFF Research Database (Denmark)

Chandrasekaran, Karthik; Tiedje, Niels Skat; Hald, John

2009-01-01

Inconel 625 is commonly used for overlay welding to protect the base metal against high temperature corrosion. The efficiency of corrosion protection depends on effective mixing of the overlay weld with the base metal and the subsequent segregation of alloy elements during solidification....... Metallographic analysis of solidified samples of Inconel 625 with addition of selected elements is compared with thermodynamic modelling of segregation during solidification. The influence of changes in the melt chemistry on the formation of intermetallic phases during solidification is shown. In particular...

Dynamics of a metal overlayer on metallic substrates: High temperature effects

International Nuclear Information System (INIS)

Rahman, T.S.; Black, J.E.; Tian, Zeng Ju

1992-01-01

We have explored the structure and the dynamics of a bimetallic system consisting of a hexagonal (almost) overlayer of Ag on a square lattice (Ni(100) and Cu(100)), as a function of the surface temperature. In each case the structure is ''nearly'' incommensurate giving rise to a low frequency Goldstone mode. Also, the overlayer atoms slosh back and forth over the substrate in a corrugated fashion. The calculated dispersion of the Ag/metal vertical mode, at room temperature, is in excellent agreement with experimental data. At higher temperatures floater atoms appear on top of the overlayer displaying a variety of cluster formations and also exchanges with the substrate atoms leading to surface disordering, interdiffusion and melting

Multi-wavelength approach towards on-product overlay accuracy and robustness

Science.gov (United States)

Bhattacharyya, Kaustuve; Noot, Marc; Chang, Hammer; Liao, Sax; Chang, Ken; Gosali, Benny; Su, Eason; Wang, Cathy; den Boef, Arie; Fouquet, Christophe; Huang, Guo-Tsai; Chen, Kai-Hsiung; Cheng, Kevin; Lin, John

2018-03-01

Success of diffraction-based overlay (DBO) technique1,4,5 in the industry is not just for its good precision and low toolinduced shift, but also for the measurement accuracy2 and robustness that DBO can provide. Significant efforts are put in to capitalize on the potential that DBO has to address measurement accuracy and robustness. Introduction of many measurement wavelength choices (continuous wavelength) in DBO is one of the key new capabilities in this area. Along with the continuous choice of wavelengths, the algorithms (fueled by swing-curve physics) on how to use these wavelengths are of high importance for a robust recipe setup that can avoid the impact from process stack variations (symmetric as well as asymmetric). All these are discussed. Moreover, another aspect of boosting measurement accuracy and robustness is discussed that deploys the capability to combine overlay measurement data from multiple wavelength measurements. The goal is to provide a method to make overlay measurements immune from process stack variations and also to report health KPIs for every measurement. By combining measurements from multiple wavelengths, a final overlay measurement is generated. The results show a significant benefit in accuracy and robustness against process stack variation. These results are supported by both measurement data as well as simulation from many product stacks.

Anomalous positive flatband voltage shifts in metal gate stacks containing rare-earth oxide capping layers

KAUST Repository

Caraveo-Frescas, J. A.; Hedhili, Mohamed N.; Wang, H.; Schwingenschlö gl, Udo; Alshareef, Husam N.

2012-01-01

measure a ∼350 mV negative shift with the Si overlayer present and a ∼110 mV positive shift with the Si overlayer removed. This effect is correlated to a positive change in the average electrostatic potential at the TaN/dielectric interface which

I-line stepper based overlay evaluation method for wafer bonding applications

Science.gov (United States)

Kulse, P.; Sasai, K.; Schulz, K.; Wietstruck, M.

2018-03-01

offsets between all different FIA's into account, after correcting the wafer rotation induced FIA position errors, hence an overlay for the stacked wafers can be determined. The developed approach has been validated by a standard front side resist in resist experiment. After the successful validation of the developed technique, special wafer stacks with FIA alignment marks in the bonding interface are fabricated and exposed. Following overlay calculation shows an overlay of less than 200 nm, which enables very accurate process condition for highly scaled TSV integration and advanced substrate integration into IHP's 0.25/0.13 µm SiGe:C BiCMOS technology. The developed technique also allows using significantly smaller alignment marks (i.e. standard FIA alignment marks). Furthermore, the presented method is used, in case of wafer bow related overlay tool problems, for the overlay evaluation of the last two metal layers from production wafers prepared in IHP's standard 0.25/0.13 µm SiGe:C BiCMOS technology. In conclusion, the exposure and measurement job can be done with the same tool, minimizing the back to front side/interface top layer misalignment which leads to a significant device performance improvement of backside/TSV integrated components and technologies.

A hybrid solution using computational prediction and measured data to accurately determine process corrections with reduced overlay sampling

Science.gov (United States)

Noyes, Ben F.; Mokaberi, Babak; Mandoy, Ram; Pate, Alex; Huijgen, Ralph; McBurney, Mike; Chen, Owen

2017-03-01

Reducing overlay error via an accurate APC feedback system is one of the main challenges in high volume production of the current and future nodes in the semiconductor industry. The overlay feedback system directly affects the number of dies meeting overlay specification and the number of layers requiring dedicated exposure tools through the fabrication flow. Increasing the former number and reducing the latter number is beneficial for the overall efficiency and yield of the fabrication process. An overlay feedback system requires accurate determination of the overlay error, or fingerprint, on exposed wafers in order to determine corrections to be automatically and dynamically applied to the exposure of future wafers. Since current and future nodes require correction per exposure (CPE), the resolution of the overlay fingerprint must be high enough to accommodate CPE in the overlay feedback system, or overlay control module (OCM). Determining a high resolution fingerprint from measured data requires extremely dense overlay sampling that takes a significant amount of measurement time. For static corrections this is acceptable, but in an automated dynamic correction system this method creates extreme bottlenecks for the throughput of said system as new lots have to wait until the previous lot is measured. One solution is using a less dense overlay sampling scheme and employing computationally up-sampled data to a dense fingerprint. That method uses a global fingerprint model over the entire wafer; measured localized overlay errors are therefore not always represented in its up-sampled output. This paper will discuss a hybrid system shown in Fig. 1 that combines a computationally up-sampled fingerprint with the measured data to more accurately capture the actual fingerprint, including local overlay errors. Such a hybrid system is shown to result in reduced modelled residuals while determining the fingerprint, and better on-product overlay performance.

Approaches of multilayer overlay process control for 28nm FD-SOI derivative applications

Science.gov (United States)

Duclaux, Benjamin; De Caunes, Jean; Perrier, Robin; Gatefait, Maxime; Le Gratiet, Bertrand; Chapon, Jean-Damien; Monget, Cédric

2018-03-01

Derivative technology like embedded Non-Volatile Memories (eNVM) is raising new types of challenges on the "more than Moore" path. By its construction: overlay is critical across multiple layers, by its running mode: usage of high voltage are stressing leakages and breakdown, and finally with its targeted market: Automotive, Industry automation, secure transactions… which are all requesting high device reliability (typically below 1ppm level). As a consequence, overlay specifications are tights, not only between one layer and its reference, but also among the critical layers sharing the same reference. This work describes a broad picture of the key points for multilayer overlay process control in the case of a 28nm FD-SOI technology and its derivative flows. First, the alignment trees of the different flow options have been optimized using a realistic process assumptions calculation for indirect overlay. Then, in the case of a complex alignment tree involving heterogeneous scanner toolset, criticality of tool matching between reference layer and critical layers of the flow has been highlighted. Improving the APC control loops of these multilayer dependencies has been studied with simulations of feed-forward as well as implementing new rework algorithm based on multi-measures. Finally, the management of these measurement steps raises some issues for inline support and using calculations or "virtual overlay" could help to gain some tool capability. A first step towards multilayer overlay process control has been taken.

Precise X-ray and video overlay for augmented reality fluoroscopy.

Science.gov (United States)

Chen, Xin; Wang, Lejing; Fallavollita, Pascal; Navab, Nassir

2013-01-01

The camera-augmented mobile C-arm (CamC) augments any mobile C-arm by a video camera and mirror construction and provides a co-registration of X-ray with video images. The accurate overlay between these images is crucial to high-quality surgical outcomes. In this work, we propose a practical solution that improves the overlay accuracy for any C-arm orientation by: (i) improving the existing CamC calibration, (ii) removing distortion effects, and (iii) accounting for the mechanical sagging of the C-arm gantry due to gravity. A planar phantom is constructed and placed at different distances to the image intensifier in order to obtain the optimal homography that co-registers X-ray and video with a minimum error. To alleviate distortion, both X-ray calibration based on equidistant grid model and Zhang's camera calibration method are implemented for distortion correction. Lastly, the virtual detector plane (VDP) method is adapted and integrated to reduce errors due to the mechanical sagging of the C-arm gantry. The overlay errors are 0.38±0.06 mm when not correcting for distortion, 0.27±0.06 mm when applying Zhang's camera calibration, and 0.27±0.05 mm when applying X-ray calibration. Lastly, when taking into account all angular and orbital rotations of the C-arm, as well as correcting for distortion, the overlay errors are 0.53±0.24 mm using VDP and 1.67±1.25 mm excluding VDP. The augmented reality fluoroscope achieves an accurate video and X-ray overlay when applying the optimal homography calculated from distortion correction using X-ray calibration together with the VDP.

Two Dimensional Array Based Overlay Network for Balancing Load of Peer-to-Peer Live Video Streaming

International Nuclear Information System (INIS)

Ibrahimy, Abdullah Faruq Ibn; Rafiqul, Islam Md; Anwar, Farhat; Ibrahimy, Muhammad Ibn

2013-01-01

The live video data is streaming usually in a tree-based overlay network or in a mesh-based overlay network. In case of departure of a peer with additional upload bandwidth, the overlay network becomes very vulnerable to churn. In this paper, a two dimensional array-based overlay network is proposed for streaming the live video stream data. As there is always a peer or a live video streaming server to upload the live video stream data, so the overlay network is very stable and very robust to churn. Peers are placed according to their upload and download bandwidth, which enhances the balance of load and performance. The overlay network utilizes the additional upload bandwidth of peers to minimize chunk delivery delay and to maximize balance of load. The procedure, which is used for distributing the additional upload bandwidth of the peers, distributes the additional upload bandwidth to the heterogeneous strength peers in a fair treat distribution approach and to the homogeneous strength peers in a uniform distribution approach. The proposed overlay network has been simulated by Qualnet from Scalable Network Technologies and results are presented in this paper

Two Dimensional Array Based Overlay Network for Balancing Load of Peer-to-Peer Live Video Streaming

Science.gov (United States)

Faruq Ibn Ibrahimy, Abdullah; Rafiqul, Islam Md; Anwar, Farhat; Ibn Ibrahimy, Muhammad

2013-12-01

The live video data is streaming usually in a tree-based overlay network or in a mesh-based overlay network. In case of departure of a peer with additional upload bandwidth, the overlay network becomes very vulnerable to churn. In this paper, a two dimensional array-based overlay network is proposed for streaming the live video stream data. As there is always a peer or a live video streaming server to upload the live video stream data, so the overlay network is very stable and very robust to churn. Peers are placed according to their upload and download bandwidth, which enhances the balance of load and performance. The overlay network utilizes the additional upload bandwidth of peers to minimize chunk delivery delay and to maximize balance of load. The procedure, which is used for distributing the additional upload bandwidth of the peers, distributes the additional upload bandwidth to the heterogeneous strength peers in a fair treat distribution approach and to the homogeneous strength peers in a uniform distribution approach. The proposed overlay network has been simulated by Qualnet from Scalable Network Technologies and results are presented in this paper.

Overlay field application program, Pennsylvania US-119.

Science.gov (United States)

2010-11-01

The Concrete Overly Filed Application program is administered by FHWA and the National Concrete Pavement Technology Center (CP Tech Center). The overall objective of this program is to increase the awareness and knowledge of concrete overlay applicat...

Implementation and benefits of advanced process control for lithography CD and overlay

Science.gov (United States)

Zavyalova, Lena; Fu, Chong-Cheng; Seligman, Gary S.; Tapp, Perry A.; Pol, Victor

2003-05-01

Due to the rapidly reduced imaging process windows and increasingly stingent device overlay requirements, sub-130 nm lithography processes are more severely impacted than ever by systamic fault. Limits on critical dimensions (CD) and overlay capability further challenge the operational effectiveness of a mix-and-match environment using multiple lithography tools, as such mode additionally consumes the available error budgets. Therefore, a focus on advanced process control (APC) methodologies is key to gaining control in the lithographic modules for critical device levels, which in turn translates to accelerated yield learning, achieving time-to-market lead, and ultimately a higher return on investment. This paper describes the implementation and unique challenges of a closed-loop CD and overlay control solution in high voume manufacturing of leading edge devices. A particular emphasis has been placed on developing a flexible APC application capable of managing a wide range of control aspects such as process and tool drifts, single and multiple lot excursions, referential overlay control, 'special lot' handling, advanced model hierarchy, and automatic model seeding. Specific integration cases, including the multiple-reticle complementary phase shift lithography process, are discussed. A continuous improvement in the overlay and CD Cpk performance as well as the rework rate has been observed through the implementation of this system, and the results are studied.

Reduction of image-based ADI-to-AEI overlay inconsistency with improved algorithm

Science.gov (United States)

Chen, Yen-Liang; Lin, Shu-Hong; Chen, Kai-Hsiung; Ke, Chih-Ming; Gau, Tsai-Sheng

2013-04-01

In image-based overlay (IBO) measurement, the measurement quality of various measurement spectra can be judged by quality indicators and also the ADI-to-AEI similarity to determine the optimum light spectrum. However we found some IBO measured results showing erroneous indication of wafer expansion from the difference between the ADI and the AEI maps, even after their measurement spectra were optimized. To reduce this inconsistency, an improved image calculation algorithm is proposed in this paper. Different gray levels composed of inner- and outer-box contours are extracted to calculate their ADI overlay errors. The symmetry of intensity distribution at the thresholds dictated by a range of gray levels is used to determine the particular gray level that can minimize the ADI-to-AEI overlay inconsistency. After this improvement, the ADI is more similar to AEI with less expansion difference. The same wafer was also checked by the diffraction-based overlay (DBO) tool to verify that there is no physical wafer expansion. When there is actual wafer expansion induced by large internal stress, both the IBO and the DBO measurements indicate similar expansion results. The scanning white-light interference microscope was used to check the variation of wafer warpage during the ADI and AEI stages. It predicts a similar trend with the overlay difference map, confirming the internal stress.

VT Data - Cons/Rec Overlay District 20110301, Winhall

Data.gov (United States)

Vermont Center for Geographic Information — Conservation and Recreatioal Protection overaly districts for the Town of Winhall, Vermont. Other overlay districts (Transfer of Development Rights, and Scenic...

Effects of concrete moisture on polymer overlay bond over new concrete : [technical summary].

Science.gov (United States)

2015-06-01

Epoxy polymer overlays have been used for decades on existing bridge decks to protect : the deck and extend its service life. The polymer overlays ability to seal a bridge deck : is now being specified for new construction. Questions exist about t...

Bandwidth and power allocation for two-way relaying in overlay cognitive radio systems

KAUST Repository

Alsharoa, Ahmad M.; Ghazzai, Hakim; Yaacoub, Elias E.; Alouini, Mohamed-Slim

2014-01-01

In this paper, the problem of both bandwidth and power allocation for two-way multiple relay systems in overlay cognitive radio (CR) setup is investigated. In the CR overlay mode, primary users (PUs) cooperate with cognitive users (CUs) for mutual

Performance of thin bonded epoxy overlays on asphalt and concrete bridge deck surfaces.

Science.gov (United States)

2014-06-01

This study is the evaluation of two thin bonded epoxy overlays: SafeLane (marketed by Cargill), and Flexogrid : (developed by PolyCarb). SafeLane is advertised as an anti-skid/anti-icing overlay that stores deicing chemicals for : release during wint...

Combination of Bayesian Network and Overlay Model in User Modeling

Directory of Open Access Journals (Sweden)

Loc Nguyen

2009-12-01

Full Text Available The core of adaptive system is user model containing personal information such as knowledge, learning styles, goals… which is requisite for learning personalized process. There are many modeling approaches, for example: stereotype, overlay, plan recognition… but they don’t bring out the solid method for reasoning from user model. This paper introduces the statistical method that combines Bayesian network and overlay modeling so that it is able to infer user’s knowledge from evidences collected during user’s learning process.

Overlay Spectrum Sharing using Improper Gaussian Signaling

KAUST Repository

Amin, Osama; Abediseid, Walid; Alouini, Mohamed-Slim

2016-01-01

in overlay cognitive radio system, where the secondary transmitter broadcasts a mixture of two different signals. The first signal is selected from the PGS scheme to match the primary message transmission. On the other hand, the second signal is chosen

Welding overlay analysis of dissimilar metal weld cracking of feedwater nozzle

International Nuclear Information System (INIS)

Tsai, Y.L.; Wang, Li. H.; Fan, T.W.; Ranganath, Sam; Wang, C.K.; Chou, C.P.

2010-01-01

Inspection of the weld between the feedwater nozzle and the safe end at one Taiwan BWR showed axial indications in the Alloy 182 weld. The indication was sufficiently deep that continued operation could not be justified considering the crack growth for one cycle. A weld overlay was decided to implement for restoring the structural margin. This study reviews the cracking cases of feedwater nozzle welds in other nuclear plants, and reports the lesson learned in the engineering project of this weld overlay repair. The overlay design, the FCG calculation and the stress analysis by FEM are presented to confirm that the Code Case structural margins are met. The evaluations of the effect of weld shrinkage on the attached feedwater piping are also included. A number of challenges encountered in the engineering and analysis period are proposed for future study.

Residual stress measurement in 304 stainless steel weld overlay pipes

International Nuclear Information System (INIS)

Yen, H.J.; Lin, M.C.C.; Chen, L.J.

1996-01-01

Welding overlay repair (WOR) is commonly employed to rebuild piping systems suffering from intergranular stress corrosion cracking (IGSCC). To understand the effects of this repair, it is necessary to investigate the distribution of residual stresses in the welding pipe. The overlay welding technique must induce compressive residual stress at the inner surface of the welded pipe to prevent IGSCC. To understand the bulk residual stress distribution, the stress profile as a function of location within wall is examined. In this study the full destructive residual stress measurement technique -- a cutting and sectioning method -- is used to determine the residual stress distribution. The sample is type 304 stainless steel weld overlay pipe with an outside diameter of 267 mm. A pipe segment is cut from the circular pipe; then a thin layer is removed axially from the inner to the outer surfaces until further sectioning is impractical. The total residual stress is calculated by adding the stress relieved by cutting the section away to the stress relieved by axially sectioning. The axial and hoop residual stresses are compressive at the inner surface of the weld overlay pipe. Compressive stress exists not only at the surface but is also distributed over most of the pipe's cross section. On the one hand, the maximum compressive hoop residual stress appears at the pipe's inner surface. The thermal-mechanical induced crack closure from significant compressive residual stress is discussed. This crack closure can thus prevent IGSCC very effectively

OVERLAY DENTURES: A REVIEW AND REPORT OF FOUR CASES

Directory of Open Access Journals (Sweden)

Deeksha SHARMA

2013-12-01

Full Text Available Patients with ectodermal dysplasia or having under‑ gone cleft surgery with anodontia or hypodontia, hypo‑ plastic conical teeth and patients with severely worn dentition are difficult to treat because of the poor remaining tooth structure. These patients often exhibit loss of vertical dimension of occlusion and aesthetic problems and usually need complex prosthetic treatments. Financial constraints or other priorities often restrict one from choosing the most desirable treatment. The overlay removable denture is a covering prosthesis partially supported by natural teeth, tooth roots, or dental implants, providing an efficient alter‑ native of treatment. Clinical reports describe the various applications of overlay dentures.

Opportunistic transmitter selection for selfless overlay cognitive radios

KAUST Repository

Shaqfeh, Mohammad; Zafar, Ammar; Alnuweiri, Hussein M.; Alouini, Mohamed-Slim

2013-01-01

We propose an opportunistic strategy to grant channel access to the primary and secondary transmitters in causal selfless overlay cognitive radios over block-fading channels. The secondary transmitter helps the primary transmitter by relaying

Temperature stable LiNbO3 surface acoustic wave device with diode sputtered amorphous TeO2 over-layer

International Nuclear Information System (INIS)

Dewan, Namrata; Tomar, Monika; Gupta, Vinay; Sreenivas, K.

2005-01-01

Amorphous TeO 2 thin film, sputtered in the O 2 +Ar(25%+75%) gas environment using a metallic tellurium target, has been identified as an attractive negative temperature coefficient of delay (TCD) material that can yield a temperature stable device when combined with a surface acoustic wave (SAW) device based on positive TCD material such as LiNbO 3 . The influence of amorphous TeO 2 over-layer on the SAW propagation characteristics (velocity and temperature coefficient of delay) of the SAW filters (36 and 70 MHz) based on 128 deg. rotated Y-cut X-propagating lithium niobate (128 deg. Y-X LiNbO 3 ) single crystal has been studied. It is found that 0.042 λ thick TeO 2 over-layer on a prefabricated SAW device operating at 36 MHz centre frequency, reduces the TCD of the device from 76 ppm deg. C -1 to almost zero (∼1.4 ppm deg. C -1 ) without deteriorating its efficiency and could be considered as a suitable alternative for temperature stable devices in comparison to conventional SiO 2 over-layer

Advancements of diffraction-based overlay metrology for double patterning

Science.gov (United States)

Li, Jie; Kritsun, Oleg; Liu, Yongdong; Dasari, Prasad; Weher, Ulrich; Volkman, Catherine; Mazur, Martin; Hu, Jiangtao

2011-03-01

As the dimensions of integrated circuit continue to shrink, diffraction based overlay (DBO) technologies have been developed to address the tighter overlay control challenges. Previously data of high accuracy and high precision were reported for litho-etch-litho-etch double patterning (DP) process using normal incidence spectroscopic reflectometry on specially designed targets composed of 1D gratings in x and y directions. Two measurement methods, empirical algorithm (eDBO) using four pads per direction (2x4 target) and modeling based algorithm (mDBO) using two pads per direction (2x2 target) were performed. In this work, we apply DBO techniques to measure overlay errors for a different DP process, litho-freeze-litho-etch process. We explore the possibility of further reducing number of pads in a DBO target using mDBO. For standard targets composed of 1D gratings, we reported results for eDBO 2x4 targets, mDBO 2x2 targets, and mDBO 2x1 target. The results of all three types of targets are comparable in terms of accuracy, dynamic precision, and TIS. TMU (not including tool matching) is less than 0.1nm. In addition, we investigated the possibility of measuring overlay with one single pad that contains 2D gratings. We achieved good correlation to blossom measurements. TMU (not including tool matching) is ~ 0.2nm. To our best knowledge, this is the first time that DBO results are reported on a single pad. eDBO allows quick recipe setup but takes more space and measurement time. Although mDBO needs details of optical properties and modeling, it offers smaller total target size and much faster throughput, which is important in high volume manufacturing environment.

A Measurement Study of the Structured Overlay Network in P2P File-Sharing Systems

Directory of Open Access Journals (Sweden)

Mo Zhou

2007-01-01

Full Text Available The architecture of P2P file-sharing applications has been developing to meet the needs of large scale demands. The structured overlay network, also known as DHT, has been used in these applications to improve the scalability, and robustness of the system, and to make it free from single-point failure. We believe that the measurement study of the overlay network used in the real file-sharing P2P systems can provide guidance for the designing of such systems, and improve the performance of the system. In this paper, we perform the measurement in two different aspects. First, a modified client is designed to provide view to the overlay network from a single-user vision. Second, the instances of crawler programs deployed in many nodes managed to crawl the user information of the overlay network as much as possible. We also find a vulnerability in the overlay network, combined with the character of the DNS service, a more serious DDoS attack can be launched.

Image-based overlay and alignment metrology through optically opaque media with sub-surface probe microscopy

Science.gov (United States)

van Es, Maarten H.; Mohtashami, Abbas; Piras, Daniele; Sadeghian, Hamed

2018-03-01

Nondestructive subsurface nanoimaging through optically opaque media is considered to be extremely challenging and is essential for several semiconductor metrology applications including overlay and alignment and buried void and defect characterization. The current key challenge in overlay and alignment is the measurement of targets that are covered by optically opaque layers. Moreover, with the device dimensions moving to the smaller nodes and the issue of the so-called loading effect causing offsets between between targets and product features, it is increasingly desirable to perform alignment and overlay on product features or so-called on-cell overlay, which requires higher lateral resolution than optical methods can provide. Our recently developed technique known as SubSurface Ultrasonic Resonance Force Microscopy (SSURFM) has shown the capability for high-resolution imaging of structures below a surface based on (visco-)elasticity of the constituent materials and as such is a promising technique to perform overlay and alignment with high resolution in upcoming production nodes. In this paper, we describe the developed SSURFM technique and the experimental results on imaging buried features through various layers and the ability to detect objects with resolution below 10 nm. In summary, the experimental results show that the SSURFM is a potential solution for on-cell overlay and alignment as well as detecting buried defects or voids and generally metrology through optically opaque layers.

Measured residual stresses in overlay pipe weldments removed from service

International Nuclear Information System (INIS)

Shack, W.J.

1985-02-01

Surface and throughwall residual stresses were measured on an elbow-to-pipe weldment that had been removed from the Hatch-2 reactor about a year after the application of a weld overlay. The results were compared with experimental measurements on three mock-up weldments and with finite-element calculations. The comparison shows that there are significant differences in the form and magnitude of the residual stress distributions. However, even after more than a year of service, the residual stresses over most of the inner surface of the actual plant weldment with an overlay were strongly compressive. 3 refs., 7 figs

Cluster-assembled overlayers and high-temperature superconductors

International Nuclear Information System (INIS)

Ohno, T.R.; Yang, Y.; Kroll, G.H.; Krause, K.; Schmidt, L.D.; Weaver, J.H.; Kimachi, Y.; Hidaka, Y.; Pan, S.H.; de Lozanne, A.L.

1991-01-01

X-ray photoemission results for interfaces prepared by cluster assembly with nanometer-size clusters deposited on high-T c superconductors (HTS's) show a reduction in reactivity because atom interactions with the surface are replaced by cluster interactions. Results for conventional atom deposition show the formation of overlayer oxides that are related to oxygen depletion and disruption of the near-surface region of the HTS's. For cluster assembly of Cr and Cu, there is a very thin reacted region on single-crystal Bi 2 Sr 2 CaCu 2 O 8 . Reduced reactivity is observed for Cr cluster deposition on single-crystal YBa 2 Cu 3 O 7 -based interfaces. There is no evidence of chemical modification of the surface for Ge and Au cluster assembly on Bi 2 Sr 2 CaCu 2 O 8 (100). The overlayer grown by Au cluster assembly on Bi 2 Sr 2 CaCu 2 O 8 covers the surface at low temperature but roughening occurs upon warming to 300 K. Scanning-tunneling-microscopy results for the Au(cluster)/Bi 2 Sr 2 CaCu 2 O 8 system warmed to 300 K shows individual clusters that have coalesced into large clusters. These results offer insight into the role of surface energies and cluster interactions in determining the overlayer morphology. Transmission-electron-microscopy results for Cu cluster assembly on silica show isolated irregularly shaped clusters that do not interact at low coverage. Sintering and labyrinth formation is observed at intermediate coverage and, ultimately, a continuous film is achieved at high coverage. Silica surface wetting by Cu clusters demonstrates that dispersive force are important for these small clusters

Using the overlay assay to qualitatively measure bacterial production of and sensitivity to pneumococcal bacteriocins.

Science.gov (United States)

Maricic, Natalie; Dawid, Suzanne

2014-09-30

Streptococcus pneumoniae colonizes the highly diverse polymicrobial community of the nasopharynx where it must compete with resident organisms. We have shown that bacterially produced antimicrobial peptides (bacteriocins) dictate the outcome of these competitive interactions. All fully-sequenced pneumococcal strains harbor a bacteriocin-like peptide (blp) locus. The blp locus encodes for a range of diverse bacteriocins and all of the highly conserved components needed for their regulation, processing, and secretion. The diversity of the bacteriocins found in the bacteriocin immunity region (BIR) of the locus is a major contributor of pneumococcal competition. Along with the bacteriocins, immunity genes are found in the BIR and are needed to protect the producer cell from the effects of its own bacteriocin. The overlay assay is a quick method for examining a large number of strains for competitive interactions mediated by bacteriocins. The overlay assay also allows for the characterization of bacteriocin-specific immunity, and detection of secreted quorum sensing peptides. The assay is performed by pre-inoculating an agar plate with a strain to be tested for bacteriocin production followed by application of a soft agar overlay containing a strain to be tested for bacteriocin sensitivity. A zone of clearance surrounding the stab indicates that the overlay strain is sensitive to the bacteriocins produced by the pre-inoculated strain. If no zone of clearance is observed, either the overlay strain is immune to the bacteriocins being produced or the pre-inoculated strain does not produce bacteriocins. To determine if the blp locus is functional in a given strain, the overlay assay can be adapted to evaluate for peptide pheromone secretion by the pre-inoculated strain. In this case, a series of four lacZ-reporter strains with different pheromone specificity are used in the overlay.

Visualization of disciplinary profiles: Enhanced science overlay maps

NARCIS (Netherlands)

Carley, S.; Porter, A.L.; Rafols, I.; Leydesdorff, L.

Purpose The purpose of this study is to modernize previous work on science overlay maps by updating the underlying citation matrix, generating new clusters of scientific disciplines, enhancing visualizations, and providing more accessible means for analysts to generate their own maps.

Dual-energy CT for detection of endoleaks after endovascular abdominal aneurysm repair: usefulness of colored iodine overlay.

Science.gov (United States)

Ascenti, Giorgio; Mazziotti, Silvio; Lamberto, Salvatore; Bottari, Antonio; Caloggero, Simona; Racchiusa, Sergio; Mileto, Achille; Scribano, Emanuele

2011-06-01

The purpose of our study was to evaluate the value of dual-source dual-energy CT with colored iodine overlay for detection of endoleaks after endovascular abdominal aortic aneurysm repair. We also calculated the potential dose reduction by using a dual-energy CT single-phase protocol. From November 2007 to November 2009, 74 patients underwent CT angiography 2-7 days after endovascular repair during single-energy unenhanced and dual-energy venous phases. By using dual-energy software, the iodine overlay was superimposed on venous phase images with different percentages ranging between 0 (virtual unenhanced images) and 50-75% to show the iodine in an orange color. Two blinded readers evaluated the data for diagnosis of endoleaks during standard unenhanced and venous phase images (session 1, standard of reference) and virtual unenhanced and venous phase images with colored iodine overlay images (session 2). We compared the effective dose radiation of a single-energy biphasic protocol with that of a single-phase dual-energy protocol. The diagnostic accuracy of session 2 was calculated. The mean dual-energy effective dose was 7.27 mSv. By using a dual-energy single-phase protocol, we obtained a mean dose reduction of 28% with respect to a single-energy biphasic protocol. The diagnostic accuracy of session 2 was: 100% sensitivity, 100% specificity, 100% negative predictive value, and 100% positive predictive value. Statistically significant differences in the level of confidence for endoleak detection between the two sessions were found by reviewers for scores 3-5. Dual-energy CT with colored iodine overlay is a useful diagnostic tool in endoleak detection. The use of a dual-energy single-phase study protocol will lower radiation exposure to patients.

Effect of SiO2 Overlayer on WO3 Sensitivity to Ammonia

Directory of Open Access Journals (Sweden)

Vibha Srivastava

2010-06-01

Full Text Available Ammonia gas sensing properties of tungsten trioxide thick film sensor was investigated. The doping of noble catalysts such as Pt, Pd, Au enhanced the gas sensitivity. Platinum doping was found to result in highest sensitivity. Remarkable sensitivity enhancement was realized by coating WO3 thick film sensors with SiO2 overlayer. Sol gel process derived silica overlayer increased ammonia gas sensitivity for doped as well as undoped sensor.

Digitizing geographic data with GRIDOT; a generalized program for drawing overlay grids in various map projections

International Nuclear Information System (INIS)

Edwards, R.G.; Durfee, R.C.

1976-09-01

The GRIDOT computer program draws overlay grids on a Calcomp plotter for use in digitizing information from maps, rectified aerial photographs, and other sources of spatially distributed data related to regional environmental problems. The options of the program facilitate use of the overlays with standard maps and map projections of the continental United States. The overlay grid may be defined as a latitude-longitude grid (geodetic grid), a Universal Transverse Mercator Grid, or one of the standard state-plane coordinate system grids. The map for which the overlay is intended may be in an Albers Equal Area projection, a Lambert Conformal projection, a Polyconic projection, a Transverse Mercator projection, a Universal Transverse Mercator projection, or any of the standard state-plane projections

Visually assessed colour overlay features in shear-wave elastography for breast masses: quantification and diagnostic performance.

Science.gov (United States)

Gweon, Hye Mi; Youk, Ji Hyun; Son, Eun Ju; Kim, Jeong-Ah

2013-03-01

To determine whether colour overlay features can be quantified by the standard deviation (SD) of the elasticity measured in shear-wave elastography (SWE) and to evaluate the diagnostic performance for breast masses. One hundred thirty-three breast lesions in 119 consecutive women who underwent SWE before US-guided core needle biopsy or surgical excision were analysed. SWE colour overlay features were assessed using two different colour overlay pattern classifications. Quantitative SD of the elasticity value was measured with the region of interest including the whole breast lesion. For the four-colour overlay pattern, the area under the ROC curve (Az) was 0.947; with a cutoff point between pattern 2 and 3, sensitivity and specificity were 94.4 % and 81.4 %. According to the homogeneity of the elasticity, the Az was 0.887; with a cutoff point between reasonably homogeneous and heterogeneous, sensitivity and specificity were 86.1 % and 82.5 %. For the SD of the elasticity, the Az was 0.944; with a cutoff point of 12.1, sensitivity and specificity were 88.9 % and 89.7 %. The colour overlay features showed significant correlations with the quantitative SD of the elasticity (P < 0.001). The colour overlay features and the SD of the elasticity in SWE showed excellent diagnostic performance and showed good correlations between them.

On the influence of latency estimation on dynamic group communication using overlays

Science.gov (United States)

Vik, Knut-Helge; Griwodz, Carsten; Halvorsen, Pål

2009-01-01

Distributed interactive applications tend to have stringent latency requirements and some may have high bandwidth demands. Many of them have also very dynamic user groups for which all-to-all communication is needed. In online multiplayer games, for example, such groups are determined through region-of-interest management in the application. We have investigated a variety of group management approaches for overlay networks in earlier work and shown that several useful tree heuristics exist. However, these heuristics require full knowledge of all overlay link latencies. Since this is not scalable, we investigate the effects that latency estimation techqniues have ton the quality of overlay tree constructions. We do this by evaluating one example of our group management approaches in Planetlab and examing how latency estimation techqniues influence their quality. Specifically, we investigate how two well-known latency estimation techniques, Vivaldi and Netvigator, affect the quality of tree building.

Investigation of Iron Aluminide Weld Overlays

Energy Technology Data Exchange (ETDEWEB)

Banovic, S.W.; DuPont, J.B.; Levin, B.F.; Marder, A.R.

1999-08-02

Conventional fossil fired boilers have been retrofitted with low NO(sub)x burners in order for the power plants to comply with new clean air regulations. Due to the operating characteristics of these burners, boiler tube sulfidation corrosion typically has been enhanced resulting in premature tube failure. To protect the existing panels from accelerated attack, weld overlay coatings are typically being applied. By depositing an alloy that offers better corrosion resistance than the underlying tube material, the wastage rates can be reduced. While Ni-based and stainless steel compositions are presently providing protection, they are expensive and susceptible to failure via corrosion-fatigue due to microsegregation upon solidification. Another material system presently under consideration for use as a coating in the oxidation/sulfidation environments is iron-aluminum. These alloys are relatively inexpensive, exhibit little microsegregation, and show excellent corrosion resistance. However, their use is limited due to weldability issues and their lack of corrosion characterization in simulated low NO(sub)x gas compositions. Therefore a program was initiated in 1996 to evaluate the use of iron-aluminum weld overlay coatings for erosion/corrosion protection of boiler tubes in fossil fired boilers with low NO(sub)x burners. Investigated properties included weldability, corrosion behavior, erosion resistance, and erosion-corrosion performance.

Improving Overlay in Nanolithography with a Deformable Mask Holder

National Research Council Canada - National Science Library

Harriott, L. R

2004-01-01

In very fine-line VLSI photolithography, alignment and overlay errors due to distortion in the projected image of a photomask relative to an existing pattern on a silicon wafer are becoming such serious problems...

Utilizing Lab Tests to Predict Asphalt Concrete Overlay Performance

Science.gov (United States)

2017-12-01

A series of five experimental projects and three demonstration projects were constructed to better understand the performance of pavement overlays using various levels of asphalt binder replacement (ABR) from reclaimed asphalt pavement (RAP), recycle...

Effect of Fe content on the friction and abrasion properties of copper base overlay on steel substrate by TIG welding

Institute of Scientific and Technical Information of China (English)

Lü Shixiong; Song Jianling; Liu Lei; Yang Shiqin

2009-01-01

Copper base alloy was overlaid onto 35CrMnSiA steel plate by tungsten inert gas (TIG) welding method. The heat transfer process was simulated, the microstructures of the copper base overlay were analyzed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), and the friction and abrasion properties of the overlay were measured. The results show that the Fe content increases in the overlay with increasing the welding current. And with the increase of Fe content in the overlay, the friction coefficient increases and the wear mechanism changes from oxidation wear to abrasive wear and plough wear, which is related to the size and quantity of Fe grains in the overlay. While with the increase of Fe content in the overlay, the protection of oxidation layer against the oxidation wear on the melted metal decreases.

Influence of curing time, overlay material and thickness on three light-curing composites used for luting indirect composite restorations.

Science.gov (United States)

D'Arcangelo, Camillo; De Angelis, Francesco; Vadini, Mirco; Carluccio, Fabio; Vitalone, Laura Merla; D'Amario, Maurizio

2012-08-01

To assess the microhardness of three resin composites employed in the adhesive luting of indirect composite restorations and examine the influence of the overlay material and thickness as well as the curing time on polymerization rate. Three commercially available resin composites were selected: Enamel Plus HRI (Micerium) (ENA), Saremco ELS (Saremco Dental) (SAR), Esthet-X HD (Dentsply/DeTrey) (EST-X). Post-polymerized cylinders of 6 different thicknesses were produced and used as overlays: 2 mm, 3 mm, 3.5 mm, 4 mm, 5 mm, and 6 mm. Two-mm-thick disks were produced and employed as underlays. A standardized amount of composite paste was placed between the underlay and the overlay surfaces which were maintained at a fixed distance of 0.5 mm. Light curing of the luting composite layer was performed through the overlays for 40, 80, or 120 s. For each specimen, the composite to be cured, the cured overlay, and the underlay were made out of the same batch of resin composite. All specimens were assigned to three experimental groups on the basis of the resin composite used, and to subgroups on the basis of the overlay thickness and the curing time, resulting in 54 experimental subgroups (n = 5). Forty-five additional specimens, 15 for each material under investigation, were produced and subjected to 40, 80, or 120 s of light curing using a microscope glass as an overlay; they were assigned to 9 control subgroups (n = 5). Three Vicker's hardness (VH) indentations were performed on each specimen. Means and standard deviations were calculated. Data were statistically analyzed using 3-way ANOVA. Within the same material, VH values lower than 55% of control were not considered acceptable. The used material, the overlay thickness, and the curing time significantly influenced VH values. In the ENA group, acceptable hardness values were achieved with 3.5-mm or thinner overlays after 120 or 80 s curing time (VH 41.75 and 39.32, respectively), and with 2-mm overlays after 40 s (VH 54

Anomalous positive flatband voltage shifts in metal gate stacks containing rare-earth oxide capping layers

KAUST Repository

Caraveo-Frescas, J. A.

2012-03-09

It is shown that the well-known negative flatband voltage (VFB) shift, induced by rare-earth oxide capping in metal gate stacks, can be completely reversed in the absence of the silicon overlayer. Using TaN metal gates and Gd2O3-doped dielectric, we measure a ∼350 mV negative shift with the Si overlayer present and a ∼110 mV positive shift with the Si overlayer removed. This effect is correlated to a positive change in the average electrostatic potential at the TaN/dielectric interface which originates from an interfacial dipole. The dipole is created by the replacement of interfacial oxygen atoms in the HfO2 lattice with nitrogen atoms from TaN.

Performance Evaluation of Cognitive Interference Channels Using a Spectrum Overlay Strategy

Science.gov (United States)

Knoblock, Eric J.

2018-01-01

The use of cognitive radios (CR) and cooperative communications techniques may assist in interference mitigation via sensing of the environment and dynamically altering communications parameters through the use of various mechanisms - one of which is the overlay technique. This report provides a performance analysis of an interference channel with a cognitive transceiver operating in an overlay configuration to evaluate the gains from using cognition. As shown in this report, a cognitive transceiver can simultaneously share spectrum while enhancing performance of non-cognitive nodes via knowledge of the communications channel as well as knowledge of neighboring users' modulation and coding schemes.

Investigation of Tensile Creep of a Normal Strength Overlay Concrete.

Science.gov (United States)

Drexel, Martin; Theiner, Yvonne; Hofstetter, Günter

2018-06-12

The present contribution deals with the experimental investigation of the time-dependent behavior of a typical overlay concrete subjected to tensile stresses. The latter develop in concrete overlays, which are placed on existing concrete structures as a strengthening measure, due to the shrinkage of the young overlay concrete, which is restrained by the substrate concrete. Since the tensile stresses are reduced by creep, creep in tension is investigated on sealed and unsealed specimens, loaded at different concrete ages. The creep tests as well as the companion shrinkage tests are performed in a climatic chamber at constant temperature and constant relative humidity. Since shrinkage depends on the change of moisture content, the evolution of the mass water content is determined at the center of each specimen by means of an electrolytic resistivity-based system. Together with the experimental results for compressive creep from a previous study, a consistent set of time-dependent material data, determined for the same composition of the concrete mixture and on identical specimens, is now available. It consists of the hygral and mechanical properties, creep and shrinkage strains for both sealed and drying conditions, the respective compliance functions, and the mass water contents in sealed and unsealed, loaded and load-free specimens.

PosQ: Unsupervised Fingerprinting and Visualization of GPS Positioning Quality

DEFF Research Database (Denmark)

Kjærgaard, Mikkel Baun; Weckemann, Kay

. This paper proposes PosQ, a system for unsupervised fingerprinting and visualization of GPS positioning quality. PosQ provides quality maps to position-based applications and visual overlays to users and managers to reveal the positioning quality in a local environment. The system reveals the quality both...

Analysis of mechanical tensile properties of irradiated and annealed RPV weld overlay cladding

Energy Technology Data Exchange (ETDEWEB)

Novak, J [Czech Nuclear Society, Prague (Czech Republic)

1994-12-31

Mechanical tensile properties of irradiated and annealed outer layer of reactor pressure vessel weld overlay cladding, composed of Cr19Ni10Nb alloy, have been experimentally determined by conventional tensile testing and indentation testing. The constitutive properties of weld overlay cladding are then modelled with two homogenization models of the constitutive properties of elastic-plastic matrix-inclusion composites; numerical and experimental results are then compared. 10 refs., 4 figs., 4 tabs.

Analysis of mechanical tensile properties of irradiated and annealed RPV weld overlay cladding

International Nuclear Information System (INIS)

Novak, J.

1993-01-01

Mechanical tensile properties of irradiated and annealed outer layer of reactor pressure vessel weld overlay cladding, composed of Cr19Ni10Nb alloy, have been experimentally determined by conventional tensile testing and indentation testing. The constitutive properties of weld overlay cladding are then modelled with two homogenization models of the constitutive properties of elastic-plastic matrix-inclusion composites; numerical and experimental results are then compared. 10 refs., 4 figs., 4 tabs

Characterizing the Global Impact of P2P Overlays on the AS-Level Underlay

Science.gov (United States)

Rasti, Amir Hassan; Rejaie, Reza; Willinger, Walter

This paper examines the problem of characterizing and assessing the global impact of the load imposed by a Peer-to-Peer (P2P) overlay on the AS-level underlay. In particular, we capture Gnutella snapshots for four consecutive years, obtain the corresponding AS-level topology snapshots of the Internet and infer the AS-paths associated with each overlay connection. Assuming a simple model of overlay traffic, we analyze the observed load imposed by these Gnutella snapshots on the AS-level underlay using metrics that characterize the load seen on individual AS-paths and by the transit ASes, illustrate the churn among the top transit ASes during this 4-year period, and describe the propagation of traffic within the AS-level hierarchy.

On-demand Overlay Networks for Large Scientific Data Transfers

Energy Technology Data Exchange (ETDEWEB)

Ramakrishnan, Lavanya [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Guok, Chin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jackson, Keith [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kissel, Ezra [Univ. of Delaware, Newark, DE (United States); Swany, D. Martin [Univ. of Delaware, Newark, DE (United States); Agarwal, Deborah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2009-10-12

Large scale scientific data transfers are central to scientific processes. Data from large experimental facilities have to be moved to local institutions for analysis or often data needs to be moved between local clusters and large supercomputing centers. In this paper, we propose and evaluate a network overlay architecture to enable highthroughput, on-demand, coordinated data transfers over wide-area networks. Our work leverages Phoebus and On-demand Secure Circuits and AdvanceReservation System (OSCARS) to provide high performance wide-area network connections. OSCARS enables dynamic provisioning of network paths with guaranteed bandwidth and Phoebus enables the coordination and effective utilization of the OSCARS network paths. Our evaluation shows that this approach leads to improved end-to-end data transfer throughput with minimal overheads. The achievedthroughput using our overlay was limited only by the ability of the end hosts to sink the data.

Aircraft Wing for Over-The-Wing Mounting of Engine Nacelle

Science.gov (United States)

Hahn, Andrew S. (Inventor); Kinney, David J. (Inventor)

2011-01-01

An aircraft wing has an inboard section and an outboard section. The inboard section is attached (i) on one side thereof to the aircraft's fuselage, and (ii) on an opposing side thereof to an inboard side of a turbofan engine nacelle in an over-the-wing mounting position. The outboard section's leading edge has a sweep of at least 20 degrees. The inboard section's leading edge has a sweep between -15 and +15 degrees, and extends from the fuselage to an attachment position on the nacelle that is forward of an index position defined as an imaginary intersection between the sweep of the outboard section's leading edge and the inboard side of the nacelle. In an alternate embodiment, the turbofan engine nacelle is replaced with an open rotor engine nacelle.

Hydrogen absorption kinetics of niobium with an ion-plated nickel overlayer

International Nuclear Information System (INIS)

Nakamura, K.

1981-01-01

The hydrogen absorption rate for nickel-ion-plated niobium was measured as a function of hydrogen pressure and temperature. The observed absorption curves of c(mean)/csub(e) against time (c(mean) and csub(e) are the mean and equilibrium hydrogen concentrations respectively) exhibited a marked hydrogen pressure dependence below 628 K but this was less marked above 723 K. The results were analysed on the basis of the proposed model that the rate-determining step is the hydrogen permeation through the nickel overlayer and that the permeation is driven by the hydrogen activity difference between the two interfaces, namely the H 2 -Ni and Ni-Nb interfaces. The marked pressure dependence can be attributed to the fact that the hydrogen activity coefficient in nickel is constant and that in niobium it varies markedly with concentration, i.e. with hydrogen pressure and temperature. It was also found that the change in the nickel overlayer structure caused by the dilatation of bulk niobium during hydrogen absorption enhances the hydrogen absorption rates. The temperature dependence of the hydrogen absorption rate is also discussed in comparison with that for tantalum with a vacuum-deposited nickel overlayer. (Auth.)

C-arm cone beam computed tomography needle path overlay for fluoroscopic guided vertebroplasty.

Science.gov (United States)

Tam, Alda L; Mohamed, Ashraf; Pfister, Marcus; Chinndurai, Ponraj; Rohm, Esther; Hall, Andrew F; Wallace, Michael J

2010-05-01

Retrospective review. To report our early clinical experience using C-arm cone beam computed tomography (C-arm CBCT) with fluoroscopic overlay for needle guidance during vertebroplasty. C-arm CBCT is advanced three-dimensional (3-D) imaging technology that is currently available on state-of-the-art flat panel based angiography systems. The imaging information provided by C-arm CBCT allows for the acquisition and reconstruction of "CT-like" images in flat panel based angiography/interventional suites. As part of the evolution of this technology, enhancements allowing the overlay of cross-sectional imaging information can now be integrated with real time fluoroscopy. We report our early clinical experience with C-arm CBCT with fluoroscopic overlay for needle guidance during vertebroplasty. This is a retrospective review of 10 consecutive oncology patients who underwent vertebroplasty of 13 vertebral levels using C-arm CBCT with fluoroscopic overlay for needle guidance from November 2007 to December 2008. Procedural data including vertebral level, approach (transpedicular vs. extrapedicular), access (bilateral vs. unilateral) and complications were recorded. Technical success with the overlay technology was assessed based on accuracy which consisted of 4 measured parameters: distance from target to needle tip, distance from planned path to needle tip, distance from midline to needle tip, and distance from the anterior 1/3 of the vertebral body to needle tip. Success within each parameter required that the distance between the needle tip and parameter being evaluated be no more than 5 mm on multiplanar CBCT or fluoroscopy. Imaging data for 12 vertebral levels was available for review. All vertebral levels were treated using unilateral access and 9 levels were treated with an extrapedicular approach. Technical success rates were 92% for both distance from planned path and distance from midline to final needle tip, 100% when distance from needle tip to the anterior 1

Forensic Study of Early Failures with Unbonded Concrete Overlays

Science.gov (United States)

2017-11-01

A forensic investigation was conducted to identify failure mechanisms responsible for early failures of unbonded concrete overlays on selected projects in Ohio, including I-70 in Madison County, I-77 in Washington and Noble Counties, and I-90 in Lake...

Evaluation of a novel ultra small target technology supporting on-product overlay measurements

Science.gov (United States)

Smilde, Henk-Jan H.; den Boef, Arie; Kubis, Michael; Jak, Martin; van Schijndel, Mark; Fuchs, Andreas; van der Schaar, Maurits; Meyer, Steffen; Morgan, Stephen; Wu, Jon; Tsai, Vincent; Wang, Cathy; Bhattacharyya, Kaustuve; Chen, Kai-Hsiung; Huang, Guo-Tsai; Ke, Chih-Ming; Huang, Jacky

2012-03-01

Reducing the size of metrology targets is essential for in-die overlay metrology in advanced semiconductor manufacturing. In this paper, μ-diffraction-based overlay (μDBO) measurements with a YieldStar metrology tool are presented for target-sizes down to 10 × 10 μm2. The μDBO technology enables selection of only the diffraction efficiency information from the grating by efficiently separating it from product structure reflections. Therefore, μDBO targets -even when located adjacent to product environment- give excellent correlation with 40 × 160 μm2 reference targets. Although significantly smaller than standard scribe-line targets, they can achieve total-measurement-uncertainty values of below 0.5 nm on a wide range of product layers. This shows that the new μDBO technique allows for accurate metrology on ultra small in-die targets, while retaining the excellent TMU performance of diffraction-based overlay metrology.

Yield impact for wafer shape misregistration-based binning for overlay APC diagnostic enhancement

Science.gov (United States)

Jayez, David; Jock, Kevin; Zhou, Yue; Govindarajulu, Venugopal; Zhang, Zhen; Anis, Fatima; Tijiwa-Birk, Felipe; Agarwal, Shivam

2018-03-01

The importance of traditionally acceptable sources of variation has started to become more critical as semiconductor technologies continue to push into smaller technology nodes. New metrology techniques are needed to pursue the process uniformity requirements needed for controllable lithography. Process control for lithography has the advantage of being able to adjust for cross-wafer variability, but this requires that all processes are close in matching between process tools/chambers for each process. When this is not the case, the cumulative line variability creates identifiable groups of wafers1 . This cumulative shape based effect is described as impacting overlay measurements and alignment by creating misregistration of the overlay marks. It is necessary to understand what requirements might go into developing a high volume manufacturing approach which leverages this grouping methodology, the key inputs and outputs, and what can be extracted from such an approach. It will be shown that this line variability can be quantified into a loss of electrical yield primarily at the edge of the wafer and proposes a methodology for root cause identification and improvement. This paper will cover the concept of wafer shape based grouping as a diagnostic tool for overlay control and containment, the challenges in implementing this in a manufacturing setting, and the limitations of this approach. This will be accomplished by showing that there are identifiable wafer shape based signatures. These shape based wafer signatures will be shown to be correlated to overlay misregistration, primarily at the edge. It will also be shown that by adjusting for this wafer shape signal, improvements can be made to both overlay as well as electrical yield. These improvements show an increase in edge yield, and a reduction in yield variability.

A study and simulation of the impact of high-order aberrations to overlay error distribution

Science.gov (United States)

Sun, G.; Wang, F.; Zhou, C.

2011-03-01

With reduction of design rules, a number of corresponding new technologies, such as i-HOPC, HOWA and DBO have been proposed and applied to eliminate overlay error. When these technologies are in use, any high-order error distribution needs to be clearly distinguished in order to remove the underlying causes. Lens aberrations are normally thought to mainly impact the Matching Machine Overlay (MMO). However, when using Image-Based overlay (IBO) measurement tools, aberrations become the dominant influence on single machine overlay (SMO) and even on stage repeatability performance. In this paper, several measurements of the error distributions of the lens of SMEE SSB600/10 prototype exposure tool are presented. Models that characterize the primary influence from lens magnification, high order distortion, coma aberration and telecentricity are shown. The contribution to stage repeatability (as measured with IBO tools) from the above errors was predicted with simulator and compared to experiments. Finally, the drift of every lens distortion that impact to SMO over several days was monitored and matched with the result of measurements.

He atom-surface scattering: Surface dynamics of insulators, overlayers and crystal growth

International Nuclear Information System (INIS)

Safron, S.A.; Skofronick, J.G.

1994-01-01

This progress report describes work carried out in the study of surface structure and dynamics of ionic insulators, the microscopic interactions controlling epitaxial growth and the formation of overlayers, and energy exchange in multiphonon surface scattering. The approach used is to employ high resolution helium atom scattering to study the geometry and structural features of the surfaces. Experiments have been carried out on the surface dynamics of RbCl and preliminary studies done on CoO and NiO. Epitaxial growth and overlayer dynamics experiments on the systems NaCl/NaCl(001), KBr/NaCl(001), NaCl/KBr(001) and KBr/RbCl(001) have been performed. They have collaborated with two theoretical groups to explore models of overlayer dynamics with which to compare and to interpret their experimental results. They have carried out extensive experiments on the multiphonon scattering of helium atoms from NaCl and, particularly, LiF. Work has begun on self-assembling organic films on gold and silver surfaces (alkyl thiols/Au(111) and Ag(111))

Behaviour of Parallel Coupled Microstrip Band Pass Filter and Simple Microstripline due to Thin-Film Al2O3 Overlay

Directory of Open Access Journals (Sweden)

S. B. Rane

1996-01-01

Full Text Available The X-band behaviour of a seven-section parallel-coupled microstrip band pass filter and microstripline due to thin-film Al2O3 overlay of different thickness is reported in this paper. This Al2O3 film can give a homogeneous overlay structure. There is a substantial increase in the bandwidth due to the overlay, the pass band extending towards higher frequency side. In most of the cases, an increase in the pass band transmittance of a microstripline also increases due to a thin-film Al2O3 overlay, especially for frequencies less than 9.0 GHz. At higher frequencies, random variations are observed. It is felt that thin-film overlays can be used to modify the microstripline circuit properties, thereby avoiding costly and time consuming elaborate design procedures.

Iowa task report : US 18 concrete overlay construction under traffic.

Science.gov (United States)

2012-05-01

The National Concrete Pavement Technology Center, Iowa Department of Transportation, and Federal Highway Administration set out to demonstrate and document the design and construction of portland cement concrete (PCC) overlays on two-lane roadways wh...

Use of Hydrogen Chemisorption and Ethylene Hydrogenation as Predictors for Aqueous Phase Reforming of Lactose over Ni@Pt and Co@Pt Bimetallic Overlayer Catalysts

Energy Technology Data Exchange (ETDEWEB)

Lai, Qinghua; Skoglund, Michael D.; Zhang, Chen; Morris, Allen R.; Holles, Joseph H.

2016-10-20

Overlayer Pt on Ni (Ni@Pt) or Co (Co@Pt) were synthesized and tested for H2 generation from APR of lactose. H2 chemisorption descriptor showed that Ni@Pt and Co@Pt overlayer catalysts had reduced H2 adsorption strength compared to a Pt only catalyst, which agree with computational predictions. The overlayer catalysts also demonstrated lower activity for ethylene hydrogenation than the Pt only catalyst, which likely resulted from decreased H2 binding strength decreasing the surface coverage of H2. XAS results showed that overlayer catalysts exhibited higher white line intensity than the Pt catalyst, which indicates a negative d-band shift for the Pt overlayer, further providing evidence for overlayer formation. Lactose APR studies showed that lactose can be used as feedstock to produce H2 and CO under desirable reaction conditions. The Pt active sites of Ni@Pt and Co@Pt overlayer catalysts showed significantly enhanced H2 production selectivity and activity when compared with that of a Pt only catalyst. The single deposition overlayer with the largest d-band shift showed the highest H2 activity. The results suggest that overlayer formation using directed deposition technique could modify the behavior of the surface metal and ultimately modify the APR activity.

Improvement of CD-SEM mark position measurement accuracy

Science.gov (United States)

Kasa, Kentaro; Fukuhara, Kazuya

2014-04-01

CD-SEM is now attracting attention as a tool that can accurately measure positional error of device patterns. However, the measurement accuracy can get worse due to pattern asymmetry as in the case of image based overlay (IBO) and diffraction based overlay (DBO). For IBO and DBO, a way of correcting the inaccuracy arising from measurement patterns was suggested. For CD-SEM, although a way of correcting CD bias was proposed, it has not been argued how to correct the inaccuracy arising from pattern asymmetry using CD-SEM. In this study we will propose how to quantify and correct the measurement inaccuracy affected by pattern asymmetry.

Effects of layering technique on the shade of resin overlays and the microhardness of dual cure resin cement

Directory of Open Access Journals (Sweden)

Hoon-Sang Chang

2014-06-01

Full Text Available The purpose of this study was to assess the color of layered resin overlays and to test the early microhardness of dual cure resin cement (DCRC light cured through the layered resin overlays. Resin overlays of 1.5 mm thickness were fabricated with the A3 shade of Z350 (Group 1L, the A3B and A3E shades of Supreme XT (Group 2L, and the A3, E3, and T1 shades of Sinfony (Group 3L using one, two, and three layers, respectively (n = 7. Each layer of the resin overlays was set in equal thickness. The color of the resin overlays was measured with a colorimeter and compared with an A3 shade resin denture tooth. DCRC was light cured through the resin overlays, and the early microhardness of the DCRC was measured. The ΔE value between the denture tooth and the resin overlays and the Vickers hardness number (VHN of the DCRC were analyzed with one-way ANOVA and Tukey’s HSD test. The color differences were 8.9 ± 0.5, 5.3 ± 1.0, and 7.3 ± 0.5 and the VHNs were 19.4 ± 1.1, 21.1 ± 0.9, and 29.3 ± 0.6 for Groups 1L, 2L, and 3L, respectively. Therefore, to match the designated tooth color of resin inlays and to increase the early microhardness of DCRC, layered resin inlays are more appropriate than single-dentin-layer resin inlays. However, the translucent layer should be used cautiously because the color difference of resin inlays with a translucent layer was affected more than those without a translucent layer.

Effect of SiO2 passivation overlayers on hillock formation in Al thin films

International Nuclear Information System (INIS)

Kim, Deok-kee

2012-01-01

Hillock formation in Al thin films with varying thicknesses of SiO 2 as a passivation layer was investigated during thermal cycling. Based on the stress measurements and the number of hillocks, 250 nm thick SiO 2 was thick enough to suppress the hillock formation and the suppression of hillock at 250 nm passivation and the lack of suppression at thinner passivation is related to the presence/absence of protection against the diffusive flow of atoms from the surrounding area to the surface due to the biaxial compressive stresses present in the film through the weak spots in the passivation layer. The stress state of Al films measured during annealing (the driving force for hillock formation) did not vary much with SiO 2 thickness. A small number of hillocks formed during the plasma enhanced chemical vapor deposition of SiO 2 overlayers at 300 °C. - Highlights: ► We examined the effect of SiO 2 overlayers on hillock formation in Al thin films. ► Thin overlayers were not effective in suppressing diffusive flow to the surface. ► A thick overlayer suppressed the diffusive flow from the interior to the surface. ► The stress state of Al films did not vary much with SiO 2 passivation thickness. ► High mechanical strength provided a large driving force for the large grain growth.

Reducing overlay sampling for APC-based correction per exposure by replacing measured data with computational prediction

Science.gov (United States)

Noyes, Ben F.; Mokaberi, Babak; Oh, Jong Hun; Kim, Hyun Sik; Sung, Jun Ha; Kea, Marc

2016-03-01

One of the keys to successful mass production of sub-20nm nodes in the semiconductor industry is the development of an overlay correction strategy that can meet specifications, reduce the number of layers that require dedicated chuck overlay, and minimize measurement time. Three important aspects of this strategy are: correction per exposure (CPE), integrated metrology (IM), and the prioritization of automated correction over manual subrecipes. The first and third aspects are accomplished through an APC system that uses measurements from production lots to generate CPE corrections that are dynamically applied to future lots. The drawback of this method is that production overlay sampling must be extremely high in order to provide the system with enough data to generate CPE. That drawback makes IM particularly difficult because of the throughput impact that can be created on expensive bottleneck photolithography process tools. The goal is to realize the cycle time and feedback benefits of IM coupled with the enhanced overlay correction capability of automated CPE without impacting process tool throughput. This paper will discuss the development of a system that sends measured data with reduced sampling via an optimized layout to the exposure tool's computational modelling platform to predict and create "upsampled" overlay data in a customizable output layout that is compatible with the fab user CPE APC system. The result is dynamic CPE without the burden of extensive measurement time, which leads to increased utilization of IM.

Diagnostic performance and color overlay pattern in shear wave elastography (SWE) for palpable breast mass.

Science.gov (United States)

Park, Jiyoon; Woo, Ok Hee; Shin, Hye Seon; Cho, Kyu Ran; Seo, Bo Kyoung; Kang, Eun Young

2015-10-01

The purpose of this study is to evaluate the diagnostic performance of SWE in palpable breast mass and to compare with color overlay pattern in SWE with conventional US and quantitative SWE for assessing palpable breast mass. SWE and conventional breast US were performed in 133 women with 156 palpable breast lesions (81 benign, 75 malignant) between August 2013 to June 2014. Either pathology or periodic imaging surveillance more than 2 years was a reference standard. Existence of previous image was blinded to performing radiologists. US BI-RADS final assessment, qualitative and quantitative SWE measurements were evaluated. Diagnostic performances of grayscale US, SWE and US combined to SWE were calculated and compared. Correlation between pattern classification and quantitative SWE was evaluated. Both color overlay pattern and quantitative SWE improved the specificity of conventional US, from 81.48% to 96.30% (p=0.0005), without improvement in sensitivity. Color overlay pattern was significantly related to all quantitative SWE parameters and malignancy rate (pbreast mass, conventional US combine to SWE improves specificity and reduces the number of biopsies that ultimately yield a benign result. Color overlay pattern classification is more quick and easy and may represent quantitative SWE measurements with similar diagnostic performances. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Description of the signal and background event mixing as implemented in the Marlin processor OverlayTiming

CERN Document Server

Schade, P

2011-01-01

This note documents OverlayTiming, a processor in the Marlin software frame- work. OverlayTiming can model the timing structure of a linear collider bunch train and offers the possibility to merge simulated physics events with beam-beam background events. In addition, a realistic structure of the detector readout can be imitated by defining readout time windows for each subdetector.

EPES information depth for an overlayer/substrate system with a diffuse interface

International Nuclear Information System (INIS)

Zommer, L.

2009-01-01

The information depth (ID) of elastic peak electron spectroscopy (EPES) was considered for an overlayer/substrate system with a diffuse interface. The interface was assumed to have an exponential concentration profile. The paradox previously found by Zommer and Jablonski for the Rh/Al and Al/Rh systems with sharp interfaces also occurs for these systems with diffuse interfaces. We compared IDs for diffuse and sharp interfaces. Deviations between the IDs depend on the interface width, overlayer thickness, and selected system for a given primary energy (here 2000 eV). The deviations for the Rh/Al and Al/Rh systems differ profoundly. These results are of importance when interpreting EPES measurements of layered system

The hilum overlay sign in a child

Directory of Open Access Journals (Sweden)

M J Van Wyk

2010-12-01

Full Text Available A 9-month-old girl presented with a 1-month history of coughing. A chest X-ray (CXR was performed, and the antero-posterior view demonstrated the hilum overlay sign. Furthermore, there was absence of the azygo-oesophageal line and bilateral paraspinal lines. The lateral CXR revealed a posterior mediastinal mass. Subsequently, a computed tomogram of the chest confirmed a posterior mediastinal mass, with calcifications and intraspinal extension consistent with neuroblastoma. Histological analysis confirmed this mass as a neuroblastoma.

Design and performance evaluation of very thin overlays in Texas.

Science.gov (United States)

2009-06-01

Very thin overlays 1-inch thick or less were placed as surface layers on five major highways in Texas. : These mixes were designed in the laboratory to have a balance of good rut resistance as measured by : TxDOTs Hamburg Wheel Tracking test and g...

A comparative study between xerographic, computer-assisted overlay generation and animated-superimposition methods in bite mark analyses.

Science.gov (United States)

Tai, Meng Wei; Chong, Zhen Feng; Asif, Muhammad Khan; Rahmat, Rabiah A; Nambiar, Phrabhakaran

2016-09-01

This study was to compare the suitability and precision of xerographic and computer-assisted methods for bite mark investigations. Eleven subjects were asked to bite on their forearm and the bite marks were photographically recorded. Alginate impressions of the subjects' dentition were taken and their casts were made using dental stone. The overlays generated by xerographic method were obtained by photocopying the subjects' casts and the incisal edge outlines were then transferred on a transparent sheet. The bite mark images were imported into Adobe Photoshop® software and printed to life-size. The bite mark analyses using xerographically generated overlays were done by comparing an overlay to the corresponding printed bite mark images manually. In computer-assisted method, the subjects' casts were scanned into Adobe Photoshop®. The bite mark analyses using computer-assisted overlay generation were done by matching an overlay and the corresponding bite mark images digitally using Adobe Photoshop®. Another comparison method was superimposing the cast images with corresponding bite mark images employing the Adobe Photoshop® CS6 and GIF-Animator©. A score with a range of 0-3 was given during analysis to each precision-determining criterion and the score was increased with better matching. The Kruskal Wallis H test showed significant difference between the three sets of data (H=18.761, p<0.05). In conclusion, bite mark analysis using the computer-assisted animated-superimposition method was the most accurate, followed by the computer-assisted overlay generation and lastly the xerographic method. The superior precision contributed by digital method is discernible despite the human skin being a poor recording medium of bite marks. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

High order field-to-field corrections for imaging and overlay to achieve sub 20-nm lithography requirements

Science.gov (United States)

Mulkens, Jan; Kubis, Michael; Hinnen, Paul; de Graaf, Roelof; van der Laan, Hans; Padiy, Alexander; Menchtchikov, Boris

2013-04-01

Immersion lithography is being extended to the 20-nm and 14-nm node and the lithography performance requirements need to be tightened further to enable this shrink. In this paper we present an integral method to enable high-order fieldto- field corrections for both imaging and overlay, and we show that this method improves the performance with 20% - 50%. The lithography architecture we build for these higher order corrections connects the dynamic scanner actuators with the angle resolved scatterometer via a separate application server. Improvements of CD uniformity are based on enabling the use of freeform intra-field dose actuator and field-to-field control of focus. The feedback control loop uses CD and focus targets placed on the production mask. For the overlay metrology we use small in-die diffraction based overlay targets. Improvements of overlay are based on using the high order intra-field correction actuators on a field-tofield basis. We use this to reduce the machine matching error, extending the heating control and extending the correction capability for process induced errors.

Friction and wear of stainless steel, titanium and aluminium with various surface treatments, ion implantation and overlay hard coatings

International Nuclear Information System (INIS)

Bunshah, R.F.

1979-01-01

This paper deals with the evaluation of the wear properties of 304 stainless steel, commercial grade titanium and commercial grade aluminium without and with different surface treatments, i.e., ion implantation of boron and nitrogen, and overlay coating of superhard materials, titanium carbide and nitride by the Biased Activated Reactive Evaporation (BARE) process. Wear properties were evaluated in adhesive, erosive and abrasive modes of wear. In the case of adhesive wear, ion implantation resulted in an improved wear behaviour in lubricated conditions but had no beneficial effect in dry wear conditions. Overlay coatings on the other hand resulted in improved wear behaviour for both the dry and lubricating conditions. In the case of erosive wear with SiC particles at high velocities, overlay coatings showed higher erosion rates (typical of brittle materials in normal impingement) whereas ion implanted materials behaved similarly as untreated materials; i.e., a lower wear rate than the specimens with overlay coatings. In the case of abrasive wear, it was again observed that the wear rates of overlay coatings is far lower than the wear rates of untreated or ion implanted materials. (author)

Microstructure and Mechanical Properties of Inconel 625 Alloy on Low Carbon Steel by Heat Treatment after Overlay Welding

International Nuclear Information System (INIS)

Kim, Seungpil; Jang, Jaeho; Kim, Jungsoo; Kim, Byung Jun; Sohn, Keun Yong; Nam, Dae-Geun

2016-01-01

Overlay welding technique is one of methods used to improve metal mechanical properties such as strength, toughness and corrosion resistance. Generally, Inconel 625 alloy is used for overlay welding layer on low carbon steels for economic consideration. However, the method produces some problems in the microstructure of the cast structure and some defects, caused by the elevated temperatures of the overlay process. To resolve these problems, heat treatments are required. In this study, Inconel 625 alloy was welded on a low carbon steel by the overlay welding process to investigate the resulting microstructure and mechanical properties. A double heat treatment was performed to improve the mechanical properties of the welding and substrate layers. It was found that Inconel 625 alloy had an austenite microstructure after the first heat treatment, but the low carbon steel had a ferrite-pearlite microstructure after the second heat treatment. After the double heat treatment, the sample showed the optimum hardness because of grain refinement and homogenization of the microstructure.

Distributed fiber optic sensor-enhanced detection and prediction of shrinkage-induced delamination of ultra-high-performance concrete overlay

Science.gov (United States)

Bao, Yi; Valipour, Mahdi; Meng, Weina; Khayat, Kamal H.; Chen, Genda

2017-08-01

This study develops a delamination detection system for smart ultra-high-performance concrete (UHPC) overlays using a fully distributed fiber optic sensor. Three 450 mm (length) × 200 mm (width) × 25 mm (thickness) UHPC overlays were cast over an existing 200 mm thick concrete substrate. The initiation and propagation of delamination due to early-age shrinkage of the UHPC overlay were detected as sudden increases and their extension in spatial distribution of shrinkage-induced strains measured from the sensor based on pulse pre-pump Brillouin optical time domain analysis. The distributed sensor is demonstrated effective in detecting delamination openings from microns to hundreds of microns. A three-dimensional finite element model with experimental material properties is proposed to understand the complete delamination process measured from the distributed sensor. The model is validated using the distributed sensor data. The finite element model with cohesive elements for the overlay-substrate interface can predict the complete delamination process.

Microstructure and Mechanical Properties of Inconel 625 Alloy on Low Carbon Steel by Heat Treatment after Overlay Welding

Energy Technology Data Exchange (ETDEWEB)

Kim, Seungpil; Jang, Jaeho; Kim, Jungsoo; Kim, Byung Jun; Sohn, Keun Yong; Nam, Dae-Geun [Korea Institute of Industrial Technology, Busan (Korea, Republic of)

2016-08-15

Overlay welding technique is one of methods used to improve metal mechanical properties such as strength, toughness and corrosion resistance. Generally, Inconel 625 alloy is used for overlay welding layer on low carbon steels for economic consideration. However, the method produces some problems in the microstructure of the cast structure and some defects, caused by the elevated temperatures of the overlay process. To resolve these problems, heat treatments are required. In this study, Inconel 625 alloy was welded on a low carbon steel by the overlay welding process to investigate the resulting microstructure and mechanical properties. A double heat treatment was performed to improve the mechanical properties of the welding and substrate layers. It was found that Inconel 625 alloy had an austenite microstructure after the first heat treatment, but the low carbon steel had a ferrite-pearlite microstructure after the second heat treatment. After the double heat treatment, the sample showed the optimum hardness because of grain refinement and homogenization of the microstructure.

An Overlay Architecture for Throughput Optimal Multipath Routing

Science.gov (United States)

2017-01-14

maximum throughput. Finally, we propose a threshold-based policy (BP-T) and a heuristic policy (OBP), which dynamically control traffic bifurcations...network stability region is available . Second, given any subset of nodes that are controllable, we also wish to develop an optimal routing policy that...case when tunnels do not overlap. We also develop a heuristic overlay control policy for use on general topologies, and show through simulation that

Integrated scatterometry for tight overlay and CD control to enable 20-nm node wafer manufacturing.

Science.gov (United States)

Benschop, Jos; Engelen, Andre; Cramer, Hugo; Kubis, Michael; Hinnen, Paul; van der Laan, Hans; Bhattacharyya, Kaustuve; Mulkens, Jan

2013-04-01

The overlay, CDU and focus requirements for the 20nm node can only be met using a holistic lithography approach whereby full use is made of high-order, field-by-field, scanner correction capabilities. An essential element in this approach is a fast, precise and accurate in-line metrology sensor, capable to measure on product. The capabilities of the metrology sensor as well as the impact on overlay, CD and focus will be shared in this paper.

Single-Layer Limit of Metallic Indium Overlayers on Si(111).

Science.gov (United States)

Park, Jae Whan; Kang, Myung Ho

2016-09-09

Density-functional calculations are used to identify one-atom-thick metallic In phases grown on the Si(111) surface, which have long been sought in quest of the ultimate two-dimensional (2D) limit of metallic properties. We predict two metastable single-layer In phases, one sqrt[7]×sqrt[3] phase with a coverage of 1.4 monolayer (ML; here 1 ML refers to one In atom per top Si atom) and the other sqrt[7]×sqrt[7] phase with 1.43 ML, which indeed agree with experimental evidences. Both phases reveal quasi-1D arrangements of protruded In atoms, leading to 2D-metallic but anisotropic band structures and Fermi surfaces. This directional feature contrasts with the free-electron-like In-overlayer properties that are known to persist up to the double-layer thickness, implying that the ultimate 2D limit of In overlayers may have been achieved in previous studies of double-layer In phases.

Microeconomics-based resource allocation in overlay networks by using non-strategic behavior modeling

Science.gov (United States)

Analoui, Morteza; Rezvani, Mohammad Hossein

2011-01-01

Behavior modeling has recently been investigated for designing self-organizing mechanisms in the context of communication networks in order to exploit the natural selfishness of the users with the goal of maximizing the overall utility. In strategic behavior modeling, the users of the network are assumed to be game players who seek to maximize their utility with taking into account the decisions that the other players might make. The essential difference between the aforementioned researches and this work is that it incorporates the non-strategic decisions in order to design the mechanism for the overlay network. In this solution concept, the decisions that a peer might make does not affect the actions of the other peers at all. The theory of consumer-firm developed in microeconomics is a model of the non-strategic behavior that we have adopted in our research. Based on it, we have presented distributed algorithms for peers' "joining" and "leaving" operations. We have modeled the overlay network as a competitive economy in which the content provided by an origin server can be viewed as commodity and the origin server and the peers who multicast the content to their downside are considered as the firms. On the other hand, due to the dual role of the peers in the overlay network, they can be considered as the consumers as well. On joining to the overlay economy, each peer is provided with an income and tries to get hold of the service regardless to the behavior of the other peers. We have designed the scalable algorithms in such a way that the existence of equilibrium price (known as Walrasian equilibrium price) is guaranteed.

Lightweight storage and overlay networks for fault tolerance.

Energy Technology Data Exchange (ETDEWEB)

Oldfield, Ron A.

2010-01-01

The next generation of capability-class, massively parallel processing (MPP) systems is expected to have hundreds of thousands to millions of processors, In such environments, it is critical to have fault-tolerance mechanisms, including checkpoint/restart, that scale with the size of applications and the percentage of the system on which the applications execute. For application-driven, periodic checkpoint operations, the state-of-the-art does not provide a scalable solution. For example, on today's massive-scale systems that execute applications which consume most of the memory of the employed compute nodes, checkpoint operations generate I/O that consumes nearly 80% of the total I/O usage. Motivated by this observation, this project aims to improve I/O performance for application-directed checkpoints through the use of lightweight storage architectures and overlay networks. Lightweight storage provide direct access to underlying storage devices. Overlay networks provide caching and processing capabilities in the compute-node fabric. The combination has potential to signifcantly reduce I/O overhead for large-scale applications. This report describes our combined efforts to model and understand overheads for application-directed checkpoints, as well as implementation and performance analysis of a checkpoint service that uses available compute nodes as a network cache for checkpoint operations.

High performance inboard shield design for the compact TIBER-II test reactor: Appendix A-2

International Nuclear Information System (INIS)

El-Guebaly, L.A.; Sviatoslavsky, I.N.

1987-01-01

The compactness of the TIBER-II reactor has placed a premium on the design of a high performance inboard shield to protect the inner legs of the toroidal field (TF) coils. The available space for shield is constrained to 48 cm and the use of tungsten is mandatory to protect the magnet against the 1.53 MW/m 2 neutron wall loading. The primary requirement for the shield is to limit the fast neutron fluence to 10 19 n/cm 2 . In an optimization study, the performance of various candidate materials for protecting the magnet was examined. The optimum shield consists of a 40 cm thick W layer, followed by an 8 cm thick H 2 O/LiNO 3 layer. The mechanical design of the shield calls for tungsten blocks within SS stiffened panels. All the coolant channels are vertical with more of them in the front where there is a high heat load. The coolant pressure is 0.2 MPa and the maximum structural surface temperature is 0 C. The effects of the detailed mechanical design of the shield and the assembly gaps between the shield sectors on the damage in the magnet were analyzed and peaking factors of ∼2 were found at the hot spots. 2 refs., 6 figs., 2 tabs

Surface crystallographic structures of cellulose nanofiber films and overlayers of pentacene

Science.gov (United States)

Nakayama, Yasuo; Mori, Toshiaki; Tsuruta, Ryohei; Yamanaka, Soichiro; Yoshida, Koki; Imai, Kento; Koganezawa, Tomoyuki; Hosokai, Takuya

2018-03-01

Cellulose nanofibers or nanocellulose is a promising recently developed biomass and biodegradable material used for various applications. In order to utilize this material as a substrate in organic electronic devices, thorough understanding of the crystallographic structures of the surfaces of the nanocellulose composites and of their interfaces with organic semiconductor molecules is essential. In this work, surface crystallographic structures of nanocellulose films (NCFs) and overlayers of pentacene were investigated by two-dimensional grazing-incidence X-ray diffraction. The NCFs are found to crystallize on solid surfaces with the crystal lattice preserving the same structure of the known bulk phase, whereas distortion of interchain packing toward the surface normal direction is suggested. The pentacene overlayers on the NCFs are found to form the thin-film phase with an in-plane mean crystallite size of over 10 nm.

Numerical evaluation of weld overlay applied to a pressurized water reactor nozzle mock-up

Energy Technology Data Exchange (ETDEWEB)

Rabello, Emerson G.; Silva, Luiz L.; Gomes, Paulo T.V., E-mail: egr@cdtn.b, E-mail: silvall@cdtn.b, E-mail: gomespt@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Integridade Estrutural

2011-07-01

The primary water stress corrosion cracking (PWSCC) is a major mechanism of failure in the primary circuit of PWR type nuclear power plants. The PWSCC is associated with the presence of corrosive environment, the susceptibility to corrosion cracking of the materials involved and the tensile stresses presence. Residual stresses generated during dissimilar materials welding can contribute to PWSCC. An alternative to the PWSCC mitigation is the application of external weld layers in the regions of greatest susceptibility to corrosion cracking. This process, called Weld Overlay (WOL), has been widely used in regions of dissimilar weld (low alloy steel and stainless steel with nickel alloy addition) of nozzles and pipes on the primary circuit in order to promote internal compressive stresses on the wall of these components. This paper presents the steps required to the numerical stress evaluation (by finite element method) during the dissimilar materials welding as well as application of Weld Overlay process in a nozzle mock-up. Thus, one can evaluate the effectiveness of the application of weld overlay process to internal compressive stress generation on the wall nozzle. (author)

Numerical evaluation of weld overlay applied to a pressurized water reactor nozzle mock-up

International Nuclear Information System (INIS)

Rabello, Emerson G.; Silva, Luiz L.; Gomes, Paulo T.V.

2011-01-01

The primary water stress corrosion cracking (PWSCC) is a major mechanism of failure in the primary circuit of PWR type nuclear power plants. The PWSCC is associated with the presence of corrosive environment, the susceptibility to corrosion cracking of the materials involved and the tensile stresses presence. Residual stresses generated during dissimilar materials welding can contribute to PWSCC. An alternative to the PWSCC mitigation is the application of external weld layers in the regions of greatest susceptibility to corrosion cracking. This process, called Weld Overlay (WOL), has been widely used in regions of dissimilar weld (low alloy steel and stainless steel with nickel alloy addition) of nozzles and pipes on the primary circuit in order to promote internal compressive stresses on the wall of these components. This paper presents the steps required to the numerical stress evaluation (by finite element method) during the dissimilar materials welding as well as application of Weld Overlay process in a nozzle mock-up. Thus, one can evaluate the effectiveness of the application of weld overlay process to internal compressive stress generation on the wall nozzle. (author)

FEM Analysis and Measurement of Residual Stress by Neutron Diffraction on the Dissimilar Overlay Weld Pipe

International Nuclear Information System (INIS)

Kim, Kang Soo; Lee, Ho Jin; Woo, Wan Chuck; Seong, Baek Seok; Byeon, Jin Gwi; Park, Kwang Soo; Jung, In Chul

2010-01-01

Much research has been done to estimate the residual stress on a dissimilar metal weld. There are many methods to estimate the weld residual stress and FEM (Finite Element Method) is generally used due to the advantage of the parametric study. And the X-ray method and a Hole Drilling technique for an experimental method are also usually used. The aim of this paper is to develop the appropriate FEM model to estimate the residual stresses of the dissimilar overlay weld pipe. For this, firstly, the specimen of the dissimilar overlay weld pipe was manufactured. The SA 508 Gr3 nozzle, the SA 182 safe end and SA376 pipe were welded by the Alloy 182. And the overlay weld by the Alloy 52M was performed. The residual stress of this specimen was measured by using the Neutron Diffraction device in the HANARO (High-flux Advanced Neutron Application ReactOr) research reactor, KAERI (Korea Atomic Energy Research Institute). Secondly, FEM Model on the dissimilar overlay weld pipe was made and analyzed by the ABAQUS Code (ABAQUS, 2004). Thermal analysis and stress analysis were performed, and the residual stress was calculated. Thirdly, the results of the FEM analysis were compared with those of the experimental methods

Vision-based overlay of a virtual object into real scene for designing room interior

Science.gov (United States)

Harasaki, Shunsuke; Saito, Hideo

2001-10-01

In this paper, we introduce a geometric registration method for augmented reality (AR) and an application system, interior simulator, in which a virtual (CG) object can be overlaid into a real world space. Interior simulator is developed as an example of an AR application of the proposed method. Using interior simulator, users can visually simulate the location of virtual furniture and articles in the living room so that they can easily design the living room interior without placing real furniture and articles, by viewing from many different locations and orientations in real-time. In our system, two base images of a real world space are captured from two different views for defining a projective coordinate of object 3D space. Then each projective view of a virtual object in the base images are registered interactively. After such coordinate determination, an image sequence of a real world space is captured by hand-held camera with tracking non-metric measured feature points for overlaying a virtual object. Virtual objects can be overlaid onto the image sequence by taking each relationship between the images. With the proposed system, 3D position tracking device, such as magnetic trackers, are not required for the overlay of virtual objects. Experimental results demonstrate that 3D virtual furniture can be overlaid into an image sequence of the scene of a living room nearly at video rate (20 frames per second).

Passivation of surface states of α-Fe2O3(0001) surface by deposition of Ga2O3 overlayers: A density functional theory study.

Science.gov (United States)

Ulman, Kanchan; Nguyen, Manh-Thuong; Seriani, Nicola; Gebauer, Ralph

2016-03-07

There is a big debate in the community regarding the role of surface states of hematite in the photoelectrochemical water splitting. Experimental studies on non-catalytic overlayers passivating the hematite surface states claim a favorable reduction in the overpotential for the water splitting reaction. As a first step towards understanding the effect of these overlayers, we have studied the system Ga2O3 overlayers on hematite (0001) surfaces using first principles computations in the PBE+U framework. Our computations suggest that stoichiometric terminations of Ga2O3 overlayers are energetically more favored than the bare surface, at ambient oxygen chemical potentials. Energetics suggest that the overlayers prefer to grow via a layer-plus-island (Stranski-Krastanov) growth mode with a critical layer thickness of 1-2 layers. Thus, a complete wetting of the hematite surface by an overlayer of gallium oxide is thermodynamically favored. We establish that the effect of deposition of the Ga2O3 overlayers on the bare hematite surface is to passivate the surface states for the stoichiometric termination. For the oxygen terminated surface which is the most stable termination under photoelectrochemical conditions, the effect of deposition of the Ga2O3 overlayer is to passivate the hole-trapping surface state.

Corrosion resistance and microstructure of alloy 625 weld overlay on ASTM A516 grade 70

Energy Technology Data Exchange (ETDEWEB)

Moradi, Mohammad J. [Amirkabir Univ. of Technology, Tehran (Iran, Islamic Republic of). Petroleum Engineering Dept.; Ketabchi, Mostafa [Amirkabir Univ. of Technology, Tehran (Iran, Islamic Republic of). Mining and Metallurgical Engineering Dept.

2016-02-01

Nickel-based alloys are a crucial class of materials because of their excellent corrosion resistance. In the present study, single layer and two layers alloy 625 weld overlays were deposited by GTAW process on A516 grade 70 carbon steel. The dilution in terms of Fe, Ni, Mo and Nb content was calculated in 30 points of weld overlay. Microstructure observations showed that alloy 625 had austenitic structure with two types of Laves and NbC secondary phases. The uniform and pitting corrosion resistance of alloy 625 weld overlay as casted and as forged were evaluated in accordance with ASTM G48-2011 standard at different temperatures to determine the weight loss and critical pitting temperature. For achieving a better comparison, samples from alloy 625 as casted and as forged were tested under the same conditions. The results point out that single layer alloy 625 weld overlay is not suitable for chloride containing environments, two layers alloy 625 weld overlay and alloy 625 as casted have acceptable corrosion resistance and almost the same critical pitting temperature. Alloy 625 as forged has the best corrosion resistance and the highest critical pitting temperature among all test specimens. Also, the corrosion behavior was evaluated in accordance with ASTM G28 standard. The corrosion rate of single layer weld overlay was unacceptable. The average corrosion rate of two layers weld overlay and in casted condition were 35.82 and 33.01 mpy, respectively. [German] Nickellegierungen sind aufgrund ihres exzellenten Korrosionswiderstandes eine bedeutende Werkstoffklasse. In der diesem Beitrag zugrunde liegenden Studie wurden mittels WIG-Schweissens ein- und zweilagige Schweissplattierungen auf den Kohlenstoffstahl A516 (Grade 70) aufgebracht. Die Vermischung in Form des Fe-, Ni-, Mo- und Nb-Gehaltes wurde an 30 Punkten der Schweissplattierungen berechnet. Die mikrostrukturellen Untersuchungen ergaben, dass die Legierung 625 eine austenitische Struktur mit zwei Arten von

Effect of preemptive weld overlay on residual stress mitigation for dissimilar metal weld of nuclear power plant pressurizer

International Nuclear Information System (INIS)

Song, Tae Kwang; Bae, Hong Yeol; Chun, Yun Bae; Oh, Chang Young; Kim, Yun Jae; Lee, Kyoung Soo; Park, Chi Yong

2008-01-01

Weld overlay is one of the residual stress mitigation methods which arrest crack initiation and crack growth. Therefore weld overlay can be applied to the region where cracking is likely to be. An overlay weld used in this manner is termed a Preemptive Weld OverLay(PWOL). In Pressurized Water Reactor(PWR) dissimilar metal weld is susceptible region for Primary Water Stress Corrosion Cracking(PWSCC). In order to examine the effect of PWOL on residual stress mitigation, PWOL was applied to a specific dissimilar metal weld of Kori nuclear power plant by finite element analysis method. As a result, strong compressive residual stress was made in PWSCC susceptible region and PWOL was proved effective preemptive repair method for weldment

Effect of preemptive weld overlay on residual stress mitigation for dissimilar metal weld of nuclear power plant pressurizer

Energy Technology Data Exchange (ETDEWEB)

Song, Tae Kwang; Bae, Hong Yeol; Chun, Yun Bae; Oh, Chang Young; Kim, Yun Jae [Korea University, Seoul (Korea, Republic of); Lee, Kyoung Soo; Park, Chi Yong [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

2008-10-15

Weld overlay is one of the residual stress mitigation methods which arrest crack initiation and crack growth. Therefore weld overlay can be applied to the region where cracking is likely to be. An overlay weld used in this manner is termed a Preemptive Weld OverLay(PWOL). In Pressurized Water Reactor(PWR) dissimilar metal weld is susceptible region for Primary Water Stress Corrosion Cracking(PWSCC). In order to examine the effect of PWOL on residual stress mitigation, PWOL was applied to a specific dissimilar metal weld of Kori nuclear power plant by finite element analysis method. As a result, strong compressive residual stress was made in PWSCC susceptible region and PWOL was proved effective preemptive repair method for weldment.

A Hybrid P2P Overlay Network for Non-strictly Hierarchically Categorized Content

Science.gov (United States)

Wan, Yi; Asaka, Takuya; Takahashi, Tatsuro

In P2P content distribution systems, there are many cases in which the content can be classified into hierarchically organized categories. In this paper, we propose a hybrid overlay network design suitable for such content called Pastry/NSHCC (Pastry for Non-Strictly Hierarchically Categorized Content). The semantic information of classification hierarchies of the content can be utilized regardless of whether they are in a strict tree structure or not. By doing so, the search scope can be restrained to any granularity, and the number of query messages also decreases while maintaining keyword searching availability. Through simulation, we showed that the proposed method provides better performance and lower overhead than unstructured overlays exploiting the same semantic information.

Cracking and debonding of a thin fiber reinforced concrete overlay : research brief.

Science.gov (United States)

2017-03-01

Experimental tests found that the tensile interfacial energy : increased with fiber-reinforcement. Also bond tests indicated : that interfacial fracture occurred through the overlay mixture and : was proportional to the number of fibers which interse...

C-arm Cone Beam Computed Tomographic Needle Path Overlay for Fluoroscopic-Guided Placement of Translumbar Central Venous Catheters

International Nuclear Information System (INIS)

Tam, Alda; Mohamed, Ashraf; Pfister, Marcus; Rohm, Esther; Wallace, Michael J.

2009-01-01

C-arm cone beam computed tomography is an advanced 3D imaging technology that is currently available on state-of-the-art flat-panel-based angiography systems. The overlay of cross-sectional imaging information can now be integrated with real-time fluoroscopy. This overlay technology was used to guide the placement of three percutaneous translumbar inferior vena cava catheters.

Impact of organic overlayers on a-Si:H/c-Si surface potential

KAUST Repository

Seif, Johannes P.

2017-04-11

Bilayers of intrinsic and doped hydrogenated amorphous silicon, deposited on crystalline silicon (c-Si) surfaces, simultaneously provide contact passivation and carrier collection in silicon heterojunction solar cells. Recently, we have shown that the presence of overlaying transparent conductive oxides can significantly affect the c-Si surface potential induced by these amorphous silicon stacks. Specifically, deposition on the hole-collecting bilayers can result in an undesired weakening of contact passivation, thereby lowering the achievable fill factor in a finished device. We test here a variety of organic semiconductors of different doping levels, overlaying hydrogenated amorphous silicon layers and silicon-based hole collectors, to mitigate this effect. We find that these materials enhance the c-Si surface potential, leading to increased implied fill factors. This opens opportunities for improved device performance.

Impact of organic overlayers on a-Si:H/c-Si surface potential

KAUST Repository

Seif, Johannes P.; Niesen, Bjoern; Tomasi, Andrea; Ballif, Christophe; De Wolf, Stefaan

2017-01-01

Bilayers of intrinsic and doped hydrogenated amorphous silicon, deposited on crystalline silicon (c-Si) surfaces, simultaneously provide contact passivation and carrier collection in silicon heterojunction solar cells. Recently, we have shown that the presence of overlaying transparent conductive oxides can significantly affect the c-Si surface potential induced by these amorphous silicon stacks. Specifically, deposition on the hole-collecting bilayers can result in an undesired weakening of contact passivation, thereby lowering the achievable fill factor in a finished device. We test here a variety of organic semiconductors of different doping levels, overlaying hydrogenated amorphous silicon layers and silicon-based hole collectors, to mitigate this effect. We find that these materials enhance the c-Si surface potential, leading to increased implied fill factors. This opens opportunities for improved device performance.

In-die photomask registration and overlay metrology with PROVE using 2D correlation methods

Science.gov (United States)

Seidel, D.; Arnz, M.; Beyer, D.

2011-11-01

According to the ITRS roadmap, semiconductor industry drives the 193nm lithography to its limits, using techniques like double exposure, double patterning, mask-source optimization and inverse lithography. For photomask metrology this translates to full in-die measurement capability for registration and critical dimension together with challenging specifications for repeatability and accuracy. Especially, overlay becomes more and more critical and must be ensured on every die. For this, Carl Zeiss SMS has developed the next generation photomask registration and overlay metrology tool PROVE® which serves the 32nm node and below and which is already well established in the market. PROVE® features highly stable hardware components for the stage and environmental control. To ensure in-die measurement capability, sophisticated image analysis methods based on 2D correlations have been developed. In this paper we demonstrate the in-die capability of PROVE® and present corresponding measurement results for shortterm and long-term measurements as well as the attainable accuracy for feature sizes down to 85nm using different illumination modes and mask types. Standard measurement methods based on threshold criteria are compared with the new 2D correlation methods to demonstrate the performance gain of the latter. In addition, mask-to-mask overlay results of typical box-in-frame structures down to 200nm feature size are presented. It is shown, that from overlay measurements a reproducibility budget can be derived that takes into account stage, image analysis and global effects like mask loading and environmental control. The parts of the budget are quantified from measurement results to identify critical error contributions and to focus on the corresponding improvement strategies.

Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization

International Nuclear Information System (INIS)

Whiteside, Wendy; Christensen, Jason; Zampi, Jeffrey D

2005-01-01

Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI) overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver

Improved Intelligent Underlay-Overlay Combined with Frequency Hopping in GSM

DEFF Research Database (Denmark)

Wigard, Jeroen; Nielsen, Thomas Toftegaard; Mogensen, Preben Elgaard

1997-01-01

IUO (intelligent underlay-overlay) in a combination with random frequency hopping in GSM is analysed. Several improvements to the original IUO concept analysed in Nielsen et al. (1997) are introduced. With the improved IUO concept it is possible to load a network configuration consisting of 4...

Disordering kinetics in surface overlayers

International Nuclear Information System (INIS)

Jesina, A.; Tringides, M.C.

1993-01-01

The disordering kinetics of the O/W(110)-p(2x1)+p(2x2) overlayer, prepared initially in a well-ordered state, are studied with low-energy electron diffraction profile analysis. The decay of the peak intensity, used as a measure of the growing disorder, cannot be fitted to a power law as in the case of ordering processes. The full width at half maximum of the time-dependent structure factor S(q,t) is constant with time, which suggests that the average size remains constant. Diffusion activation energy extracted for the temperature dependence of the disordering is 1.0±0.05 eV, which is different from the value of 0.6 eV measured in ordering processes. The difference can be explained by the adsorbate-adsorbate interactions, which contribute differently to the diffusion barrier, in the two experiments

Evaluation of iron aluminide weld overlays for erosion - corrosion resistant boiler tube coatings in low NO{sub x} boilers

Energy Technology Data Exchange (ETDEWEB)

DuPont, J.N.; Banovic, S.W.; Marder, A.R. [Lehigh Univ., Bethlehem, PA (United States)

1996-08-01

Low NOx burners are being installed in many fossil fired power plants in order to comply with new Clean Air Regulations. Due to the operating characteristics of these burners, boiler tube sulfidation corrosion is often enhanced and premature tube failures can occur. Failures due to oxidation and solid particle erosion are also a concern. A program was initiated in early 1996 to evaluate the use of iron aluminide weld overlays for erosion/corrosion protection of boiler tubes in Low NOx boilers. Composite iron/aluminum wires will be used with the Gas Metal Arc Welding (GMAW) process to prepare overlays on boiler tubes steels with aluminum contents from 8 to 16wt%. The weldability of the composite wires will be evaluated as a function of chemical composition and welding parameters. The effect of overlay composition on corrosion (oxidation and sulfidation) and solid particle erosion will also be evaluated. The laboratory studies will be complemented by field exposures of both iron aluminide weld overlays and co-extruded tubing under actual boiler conditions.

Non-inductive current start-up and plasma equilibrium with an inboard poloidal field null by means of electron cyclotron waves in QUEST

International Nuclear Information System (INIS)

Zushi, H.; Hasegawa, M.; Hanada, K.; Idei, H.; Nakamura, K.; Fujisawa, A.; Nagashima, Y.; Matsuoka, K.; Tashima, S.; Ishiguro, M.; Banerjee, S.; Sharma, S.K.; Liu, H.; Nishino, N.; Isobe, M.; Toi, K.; Okamura, S.; Maekawa, T.; Fukuyama, A.; Ejiri, A.; Yamaguchi, T.; Hiratsuka, J.; Takase, Y.; Kikuchi, Mitsuru; Ueda, Y.; Mitarai, O.

2012-11-01

Non-inductive current start-up via relativistic electron cyclotron resonance interaction is investigated for the high ratio (∼10%) of vertical B v to toroidal B t fields and the concave field lines in the QUEST spherical tokamak. In the start-up scenario with an internal poloidal field null (IPN), the fast current start-up rate of 0.3-0.5 MA/sec and correlation with mildly relativistic electrons accelerated due to multiple ECR interaction are observed. In steady state high β p equilibrium characterized by the inboard null (R s ∼ 0.7×R 0 ) and εβ p of 1.5 is achieved, where ε, β p are the inverse aspect ratio and poloidal beta, respectively. Relaxation oscillations in this equilibrium and confinement of the energetic electrons are discussed. (author)

Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization

Directory of Open Access Journals (Sweden)

Wendy Whiteside

2015-01-01

Full Text Available Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver.

Material development for waste to energy plants. Overlay welding and refractory linings. Final report

Energy Technology Data Exchange (ETDEWEB)

Noergaard Hansson, A.

2011-02-15

Waste is an extremely corrosive fuel. In order to recover a higher percentage of the energy in waste, waste incineration plants have developed from purely heat producing units to heat and power producing units. The change in concept results in higher material temperatures and thereby faster material degradation. As a result material failures have been observed in many waste incineration plants. The purpose of this project was to develop materials with higher resistance to the corrosive elements, in order to reduce the cost of maintenance, increase the availability, and increase the efficiency. The focus is on overlay welding and refractory linings. Inconel 625, alloy 50, alloy 686, and Super 625 offer equivalent corrosion protection at panel walls. 100% overlay performs better than 50% overlay. The corrosion morphology changes with increasing temperature from pitting and general corrosion to pitting and selective corrosion (dendritic core or grain boundaries). The previously observed detrimental effect of Fe on the corrosion resistance was not confirmed. It probably depends on factors such as microstructure of the alloy and local metal temperature. Ni-overlay also reduces the corrosion rates on superheater tubes. However, the superheater environment is less aggressive than the water wall environment. Failure of refractory linings is linked to excess porosity, detrimental reactions between raw materials and other mix constituents, volume growth reactions between base material and salt depositions, and thermal stress induced crack formation. Free water and not decomposition of hydrates causes spalling and cracking during the initial heating of refractory linings. Finite Element analysis confirms the stress levels between steel and refractory with the higher stress level at the top of the panel wall tube. A number of LCC mixes were formulated, adjusted and tested. Mixes with low open porosities ({approx} 10%) and state of the art resistance to KCl were achieved. (LN)

Effect of preemptive weld overlay sequence on residual stress distribution for dissimilar metal weld of Kori nuclear power plant pressurizer

Energy Technology Data Exchange (ETDEWEB)

Bae, Hong Yeol; Song, Tae Kwang; Chun, Yun Bae; Oh, Chang Young; Kim, Yun Jae [Korea Univ., Seoul (Korea, Republic of); Lee, Kyoung Soo; Park, Chi Yong [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

2008-07-01

Weld overlay is one of the residual stress mitigation method which arrest crack. An overlay weld sued in this manner is termed a Preemptive Weld OverLay(PWOL). PWOL was good for distribution of residual stress of Dissimilar Metal Weld(DMW) by previous research. Because range of overlay welding is wide relatively, residual stress distribution on PWR is affected by welding sequence. In order to examine the effect of welding sequence, PWOL was applied to a specific DMW of KORI nuclear power plant by finite element analysis method. As a result, the welding direction that from nozzle to pipe is better good for residual stress distribution on PWR.

Effect of preemptive weld overlay sequence on residual stress distribution for dissimilar metal weld of Kori nuclear power plant pressurizer

International Nuclear Information System (INIS)

Bae, Hong Yeol; Song, Tae Kwang; Chun, Yun Bae; Oh, Chang Young; Kim, Yun Jae; Lee, Kyoung Soo; Park, Chi Yong

2008-01-01

Weld overlay is one of the residual stress mitigation method which arrest crack. An overlay weld sued in this manner is termed a Preemptive Weld OverLay(PWOL). PWOL was good for distribution of residual stress of Dissimilar Metal Weld(DMW) by previous research. Because range of overlay welding is wide relatively, residual stress distribution on PWR is affected by welding sequence. In order to examine the effect of welding sequence, PWOL was applied to a specific DMW of KORI nuclear power plant by finite element analysis method. As a result, the welding direction that from nozzle to pipe is better good for residual stress distribution on PWR

Atomistic simulation study of short pulse laser interactions with a metal target under conditions of spatial confinement by a transparent overlayer

Energy Technology Data Exchange (ETDEWEB)

Karim, Eaman T.; Shugaev, Maxim; Wu, Chengping; Zhigilei, Leonid V., E-mail: lz2n@virginia.edu [Department of Materials Science and Engineering, University of Virginia, 395 McCormick Road, Charlottesville, Virginia 22904-4745 (United States); Lin, Zhibin; Hainsey, Robert F. [Electro Scientific Industries, Inc., 13900 NW Science Park Drive, Portland, Oregon 97229 (United States)

2014-05-14

The distinct characteristics of short pulse laser interactions with a metal target under conditions of spatial confinement by a solid transparent overlayer are investigated in a series of atomistic simulations. The simulations are performed with a computational model combining classical molecular dynamics (MD) technique with a continuum description of the laser excitation, electron-phonon equilibration, and electronic heat transfer based on two-temperature model (TTM). Two methods for incorporation of the description of a transparent overlayer into the TTM-MD model are designed and parameterized for Ag-silica system. The material response to the laser energy deposition is studied for a range of laser fluences that, in the absence of the transparent overlayer, covers the regimes of melting and resolidification, photomechanical spallation, and phase explosion of the overheated surface region. In contrast to the irradiation in vacuum, the spatial confinement by the overlayer facilitates generation of sustained high-temperature and high-pressure conditions near the metal-overlayer interface, suppresses the generation of unloading tensile wave, decreases the maximum depth of melting, and prevents the spallation and explosive disintegration of the surface region of the metal target. At high laser fluences, when the laser excitation brings the surface region of the metal target to supercritical conditions, the confinement prevents the expansion and phase decomposition characteristic for the vacuum conditions leading to a gradual cooling of the hot compressed supercritical fluid down to the liquid phase and eventual solidification. The target modification in this case is limited to the generation of crystal defects and the detachment of the metal target from the overlayer.

Heavy Vehicle Simulator aided evaluation of overlays on pavements with active cracks

CSIR Research Space (South Africa)

Viljoen, AW

1987-07-01

Full Text Available their effects by means of field data from actual pavements. The South African Heavy Simulator was also used to evaluate a variety of conventional and innovative asphaltic overlays on a severely cracked concrete pavement of which the mechanisms and extent...

Opportunistic transmitter selection for selfless overlay cognitive radios

KAUST Repository

Shaqfeh, Mohammad

2013-11-01

We propose an opportunistic strategy to grant channel access to the primary and secondary transmitters in causal selfless overlay cognitive radios over block-fading channels. The secondary transmitter helps the primary transmitter by relaying the primary messages opportunistically, aided by a buffer to store the primary messages temporarily. The optimal channel-aware transmitter- selection strategy is the solution of the maximization of the average secondary rate under the average primary rate requirement and the buffer stability constraints. Numerical results demonstrate the gains of the proposed opportunistic selection strategy. © 2013 IEEE.

Iron aluminide weld overlay coatings for boiler tube protection in coal-fired low NOx boilers

Energy Technology Data Exchange (ETDEWEB)

Banovic, S.W.; DuPont, J.N.; Marder, A.R. [Lehigh Univ., Bethlehem, PA (United States). Energy Research Center

1997-12-01

Iron aluminide weld overlay coatings are currently being considered for enhanced sulfidation resistance in coal-fired low NO{sub x} boilers. The use of these materials is currently limited due to hydrogen cracking susceptibility, which generally increases with an increase in aluminum concentration of the deposit. The overall objective of this program is to attain an optimum aluminum content with good weldability and improved sulfidation resistance with respect to conventional materials presently in use. Research has been initiated using Gas Tungsten Arc Welding (GTAW) in order to achieve this end. Under different sets of GTAW parameters (wire feed speed, current), both single and multiple pass overlays were produced. Characterization of all weldments was conducted using light optical microscopy, scanning electron microscopy, and electron probe microanalysis. Resultant deposits exhibited a wide range of aluminum contents (5--43 wt%). It was found that the GTAW overlays with aluminum contents above {approximately}10 wt% resulted in cracked coatings. Preliminary corrosion experiments of 5 to 10 wt% Al cast alloys in relatively simple H{sub 2}/H{sub 2}S gas mixtures exhibited corrosion rates lower than 304 stainless steel.

Improved antifouling properties and selective biofunctionalization of stainless steel by employing heterobifunctional silane-polyethylene glycol overlayers and avidin-biotin technology

Science.gov (United States)

Hynninen, Ville; Vuori, Leena; Hannula, Markku; Tapio, Kosti; Lahtonen, Kimmo; Isoniemi, Tommi; Lehtonen, Elina; Hirsimäki, Mika; Toppari, J. Jussi; Valden, Mika; Hytönen, Vesa P.

2016-01-01

A straightforward solution-based method to modify the biofunctionality of stainless steel (SS) using heterobifunctional silane-polyethylene glycol (silane-PEG) overlayers is reported. Reduced nonspecific biofouling of both proteins and bacteria onto SS and further selective biofunctionalization of the modified surface were achieved. According to photoelectron spectroscopy analyses, the silane-PEGs formed less than 10 Å thick overlayers with close to 90% surface coverage and reproducible chemical compositions. Consequently, the surfaces also became more hydrophilic, and the observed non-specific biofouling of proteins was reduced by approximately 70%. In addition, the attachment of E. coli was reduced by more than 65%. Moreover, the potential of the overlayer to be further modified was demonstrated by successfully coupling biotinylated alkaline phosphatase (bAP) to a silane-PEG-biotin overlayer via avidin-biotin bridges. The activity of the immobilized enzyme was shown to be well preserved without compromising the achieved antifouling properties. Overall, the simple solution-based approach enables the tailoring of SS to enhance its activity for biomedical and biotechnological applications. PMID:27381834

Improved antifouling properties and selective biofunctionalization of stainless steel by employing heterobifunctional silane-polyethylene glycol overlayers and avidin-biotin technology

Science.gov (United States)

Hynninen, Ville; Vuori, Leena; Hannula, Markku; Tapio, Kosti; Lahtonen, Kimmo; Isoniemi, Tommi; Lehtonen, Elina; Hirsimäki, Mika; Toppari, J. Jussi; Valden, Mika; Hytönen, Vesa P.

2016-07-01

A straightforward solution-based method to modify the biofunctionality of stainless steel (SS) using heterobifunctional silane-polyethylene glycol (silane-PEG) overlayers is reported. Reduced nonspecific biofouling of both proteins and bacteria onto SS and further selective biofunctionalization of the modified surface were achieved. According to photoelectron spectroscopy analyses, the silane-PEGs formed less than 10 Å thick overlayers with close to 90% surface coverage and reproducible chemical compositions. Consequently, the surfaces also became more hydrophilic, and the observed non-specific biofouling of proteins was reduced by approximately 70%. In addition, the attachment of E. coli was reduced by more than 65%. Moreover, the potential of the overlayer to be further modified was demonstrated by successfully coupling biotinylated alkaline phosphatase (bAP) to a silane-PEG-biotin overlayer via avidin-biotin bridges. The activity of the immobilized enzyme was shown to be well preserved without compromising the achieved antifouling properties. Overall, the simple solution-based approach enables the tailoring of SS to enhance its activity for biomedical and biotechnological applications.

Complexity Leadership Theory: A United States Marine Corps Historical Overlay

Science.gov (United States)

2017-05-25

DD-MM-YYYY) 23-04-2017 2. REPORT TYPE Master’s Thesis 3. DATES COVERED (From - To) JUN 2016 – MAY 2017 4. TITLE AND SUBTITLE Complexity...Monograph Title : Complexity Leadership Theory : A United States Marine Corps Historical Overlay Approved by...General Ridgway’s Success in Korea.” Master’s thesis , United States Army Command and General Staff College, 2010. Diana, Gabriel. “Vision, Education

Passivating surface states on water splitting hematite photoanodes with alumina overlayers

KAUST Repository

Le Formal, Florian; Té treault, Nicolas; Cornuz, Maurin; Moehl, Thomas; Grä tzel, Michael; Sivula, Kevin

2011-01-01

Hematite is a promising material for inexpensive solar energy conversion via water splitting but has been limited by the large overpotential (0.5-0.6 V) that must be applied to afford high water oxidation photocurrent. This has conventionally been addressed by coating it with a catalyst to increase the kinetics of the oxygen evolution reaction. However, surface recombination at trapping states is also thought to be an important factor for the overpotential, and herein we investigate a strategy to passivate trapping states using conformal overlayers applied by atomic layer deposition. While TiO2 overlayers show no beneficial effect, we find that an ultra-thin coating of Al2O3 reduces the overpotential required with state-of-the-art nano-structured photo-anodes by as much as 100 mV and increases the photocurrent by a factor of 3.5 (from 0.24 mA cm-2 to 0.85 mA cm-2) at +1.0 V vs. the reversible hydrogen electrode (RHE) under standard illumination conditions. The subsequent addition of Co2+ ions as a catalyst further decreases the overpotential and leads to a record photocurrent density at 0.9 V vs. RHE (0.42 mA cm-2). A detailed investigation into the effect of the Al2O3 overlayer by electrochemical impedance and photoluminescence spectroscopy reveals a significant change in the surface capacitance and radiative recombination, respectively, which distinguishes the observed overpotential reduction from a catalytic effect and confirms the passivation of surface states. Importantly, this work clearly demonstrates that two distinct loss processes are occurring on the surface of high-performance hematite and suggests a viable route to individually address them. © The Royal Society of Chemistry 2011.

Passivating surface states on water splitting hematite photoanodes with alumina overlayers

KAUST Repository

Le Formal, Florian

2011-01-24

Hematite is a promising material for inexpensive solar energy conversion via water splitting but has been limited by the large overpotential (0.5-0.6 V) that must be applied to afford high water oxidation photocurrent. This has conventionally been addressed by coating it with a catalyst to increase the kinetics of the oxygen evolution reaction. However, surface recombination at trapping states is also thought to be an important factor for the overpotential, and herein we investigate a strategy to passivate trapping states using conformal overlayers applied by atomic layer deposition. While TiO2 overlayers show no beneficial effect, we find that an ultra-thin coating of Al2O3 reduces the overpotential required with state-of-the-art nano-structured photo-anodes by as much as 100 mV and increases the photocurrent by a factor of 3.5 (from 0.24 mA cm-2 to 0.85 mA cm-2) at +1.0 V vs. the reversible hydrogen electrode (RHE) under standard illumination conditions. The subsequent addition of Co2+ ions as a catalyst further decreases the overpotential and leads to a record photocurrent density at 0.9 V vs. RHE (0.42 mA cm-2). A detailed investigation into the effect of the Al2O3 overlayer by electrochemical impedance and photoluminescence spectroscopy reveals a significant change in the surface capacitance and radiative recombination, respectively, which distinguishes the observed overpotential reduction from a catalytic effect and confirms the passivation of surface states. Importantly, this work clearly demonstrates that two distinct loss processes are occurring on the surface of high-performance hematite and suggests a viable route to individually address them. © The Royal Society of Chemistry 2011.

Magnetism of CrO overlayers on Fe(001)bcc surface: first principles calculations

Science.gov (United States)

Félix-Medina, Raúl Enrique; Leyva-Lucero, Manuel Andrés; Meza-Aguilar, Salvador; Demangeat, Claude

2018-04-01

Riva et al. [Surf. Sci. 621, 55 (2014)] as well as Calloni et al. [J. Phys.: Condens. Matter 26, 445001 (2014)] have studied the oxydation of Cr films deposited on Fe(001)bcc through low-energy electron diffraction, Auger electron spectroscopy and scanning tunneling microscopy. In the present work we perform a density functional approach within Quantum Expresso code in order to study structural and magnetic properties of CrO overlayers on Fe(001)bcc. The calculations are performed using DFT+U. The investigated systems include O/Cr/Fe(001)bcc, Cr/O/Fe(001)bcc, Cr0.25O0.75/Fe(001)bcc, as well as the O coverage Ox/Cr/Fe(001)bcc (x = 0.25; 0.50). We have found that the ordered CrO overlayer presents an antiferromagnetic coupling between Cr and Fe atoms. The O atoms are located closer to the Fe atoms of the surface than the Cr atoms. The ground state of the systems O/Cr/Fe(001)bcc and Cr/O/Fe(001)bcc corresponds to the O/Cr/Fe(001)bcc system with a magnetic coupling c(2 × 2). The effect of the O monolayer on Cr/Fe(001)bcc changes the ground state from p(1 × 1) ↓ to c(2 × 2) and produces an enhancement of the magnetic moments. The Ox overlayer on Cr/Fe(001)bcc produces an enhancement of the Cr magnetic moments.

Reliability and reproducibility of several methods of arthroscopic assessment of femoral tunnel position during anterior cruciate ligament reconstruction.

Science.gov (United States)

Ilahi, Omer A; Mansfield, David J; Urrea, Luis H; Qadeer, Ali A

2014-10-01

To assess interobserver and intraobserver agreement of estimating anterior cruciate ligament (ACL) femoral tunnel positioning arthroscopically using circular and linear (noncircular) estimation methods and to determine whether overlay template visual aids improve agreement. Standardized intraoperative pictures of femoral tunnel pilot holes (taken with a 30° arthroscope through an anterolateral portal at 90° of knee flexion with horizontal being parallel to the tibial surface) in 27 patients undergoing single-bundle ACL reconstruction were presented to 3 fellowship-trained arthroscopists on 2 separate occasions. On both viewings, each surgeon estimated the femoral tunnel pilot hole location to the nearest half-hour mark using a whole clock face and half clock face, to the nearest 15° using a whole compass and half compass, in the top or bottom half of a linear quadrant, and in the top or bottom half of a linear trisector. Evaluations were performed first without and then with an overlay template of each estimation method. The average difference among reviewers was quite similar for all 4 circular methods with the use of visual aids. Without overlay template visual aids, pair-wise κ statistic values for interobserver agreement ranged from -0.14 to 0.56 for the whole clock face and from 0.16 to 0.42 for the half clock face. With overlay visual guides, interobserver agreement ranged from 0.29 to 0.63 for the whole clock face and from 0.17 to 0.66 for the half clock face. The quadrant method's interobserver agreement ranged from 0.22 to 0.60, and that of the trisection method ranged from 0.17 to 0.57. Neither linear estimation method's reliability uniformly improved with the use of overlay templates. Intraobserver agreement without overlay templates ranged from 0.17 to 0.49 for the whole clock face, 0.11 to 0.47 for the half clock face, 0.01 to 0.66 for the quadrant method, and 0.20 to 0.57 for the trisection method. Use of overlay templates did not uniformly

How a gold substrate can increase the reactivity of a Pt overlayer

DEFF Research Database (Denmark)

Pedersen, Morten Ø.; Helveg, Stig; Ruban, Andrei

1999-01-01

The growth and chemical reactivity of Pt on Au(111) have been studied using scanning tunneling microscopy (STM) and temperature programmed desorption (TPD). Deposition of Pt at coverages from 0.02 ML up to 2.5 ML on Au(111) at room temperature initially leads to the formation of a surface alloy......, in which 3% of the Au atoms are replaced by Pt. Subsequent Pt evaporation leads to island growth with a mixed Pt-Au island composition. The reactivity of the Pt/Au system is studied using CO as a probe molecule. We show that a stronger bonding of CO to the first layer of Pt on Au(111) exists compared...... with the binding of CO on clean Pt. The Au substrate therefore very surprisingly increases the Pt overlayer reactivity. The results can be understood in a simple model, in which the change in the CO binding energy is directly proportional to the shift of the d-band center of the metal overlayer. According...

Integration of the work management of a HVDC overlay grid into the line-frequency control of a three-phase current integrated nework; Integration der Betriebsfuehrung eines HGUe-Overlay-Netzes in die Leitungs-Frequenz-Regelung eines Drehstrom-Verbundnetzes

Energy Technology Data Exchange (ETDEWEB)

Marten, Anne-Katrin

2012-07-01

To reduce emission of carbon dioxide the proportion of renewable energies is rapidly growing in German and European grids in general. Additionally, the bulk of them are generated in only a few spots in European transmission grid, whereas conventional power plants will shut down and the load center distribution will still be decentralized. This results in the need of a new and powerful transmission grid, which is able to transport bulk power over long distances. To overcome this challenge one of the discussed solutions for Europe is an Overlay Network based on HVDC technology connecting spots of bulk renewable energy plants and important load centers. Because of different performance compared to an ac grid, it is necessary for an HVDC Overlay Network to actively sustain system services such as power frequency control to ensure system stability and power quality as well as the ac grid does. A novel method for realizing participation of a HVDC Overlay Network in power frequency control is presented. It hasn't only an advantage for load frequency power flows, but also for contracted balancing power flows which are also feed via the dc grid pro rata. Numerical case studies are made to show some benefits of this method in case of various disturbances. It is shown that a HVDC Overlay Network with the developed operating control releases the ac grid by an adjustable amount of power flows and improves the power frequency control for example in terms of promptness and lower frequency deviations.

NDT with the structural weld overlay program. Recent field experience and lessons learned

International Nuclear Information System (INIS)

Rishel, R.; Lenz, H.; Turley, G.; Newton, B.

2007-01-01

Structural weld overlay (SWOL) has become a predominant mitigation technique within the Alloy 600 program. For the pressurizer nozzles, MRP-139 requires volumetric examination by year end 2007. Many nozzles are un-inspectable due to geometry and material limitations that preclude interrogation of the required examination volume. SWOL therefore is the mitigation technique which overcomes these limitations. SWOL of the pressurizer nozzles has been a challenge for all the vendors. Alloy 52 has proven to be difficult to weld under field conditions. The NDT technique chosen to demonstrate the integrity of the overlay needs to be adapted to the specific repair process and nozzle geometry. The purpose of this paper will be to present Westinghouse's integrated approach for SWOL with the focus on the NDT aspects. Topics will include main repair process steps, NDT qualification, recent field experience and lessons learned. (author)

Evaluating the mechanical performance of Very Thin Asphalt Overlay (VTAO as a sustainable rehabilitation strategy in urban pavements

Directory of Open Access Journals (Sweden)

M. Sol-Sánchez

2017-07-01

Full Text Available Very Thin Asphalt Overlay (VTAO has been introduced as an alternative to traditional thick overlays, seal coats, and micro-surfacings. Nonetheless, there are some challenges that still remain regarding the application of VTAOs (such as mixture type, cohesiveness, wear resistance, cracking and durability, particularly in heavy traffic urban areas. Therefore, this paper presents an extensive comparative evaluation of the mechanical performance, durability and safety issues (cohesiveness, adhesiveness, ageing, cracking, plastic deformation, permeability, macrotexture, skid and wear resistance, and fuel resistance of a VTAO (20 mm thick and a high performance BBTM 11B (35 mm thick, commonly used as an open-graded mixture for pavement overlays. The results demonstrated that VTAO is an appropriate material for urban pavements as it provides good durability and resistance to the propagation of defects. Nonetheless, further studies are required to improve its behavior under distresses related to plastic deformations and safety properties.

Evaluating the mechanical performance of Very Thin Asphalt Overlay (VTAO) as a sustainable rehabilitation strategy in urban pavements

International Nuclear Information System (INIS)

Sol-Sánchez, M.; García-Travé, G.; Ayar, P.; Moreno-Navarro, F.; Rubio-Gámez, M.C.

2017-01-01

Very Thin Asphalt Overlay (VTAO) has been introduced as an alternative to traditional thick overlays, seal coats, and micro-surfacings. Nonetheless, there are some challenges that still remain regarding the application of VTAOs (such as mixture type, cohesiveness, wear resistance, cracking and durability), particularly in heavy traffic urban areas. Therefore, this paper presents an extensive comparative evaluation of the mechanical performance, durability and safety issues (cohesiveness, adhesiveness, ageing, cracking, plastic deformation, permeability, macrotexture, skid and wear resistance, and fuel resistance) of a VTAO (20 mm thick) and a high performance BBTM 11B (35 mm thick), commonly used as an open-graded mixture for pavement overlays. The results demonstrated that VTAO is an appropriate material for urban pavements as it provides good durability and resistance to the propagation of defects. Nonetheless, further studies are required to improve its behavior under distresses related to plastic deformations and safety properties. [es

Science overlay maps: a new tool for research policy and library management

NARCIS (Netherlands)

Rafols, I.; Porter, A.L.; Leydesdorff, L.

2010-01-01

We present a novel approach to visually locate bodies of research within the sciences, both at each moment of time and dynamically. This article describes how this approach fits with other efforts to locally and globally map scientific outputs. We then show how these science overlay maps help

Visual supports for shared reading with young children: the effect of static overlay design.

Science.gov (United States)

Wood Jackson, Carla; Wahlquist, Jordan; Marquis, Cassandra

2011-06-01

This study examined the effects of two types of static overlay design (visual scene display and grid display) on 39 children's use of a speech-generating device during shared storybook reading with an adult. This pilot project included two groups: preschool children with typical communication skills (n = 26) and with complex communication needs (n = 13). All participants engaged in shared reading with two books using each visual layout on a speech-generating device (SGD). The children averaged a greater number of activations when presented with a grid display during introductory exploration and free play. There was a large effect of the static overlay design on the number of silent hits, evidencing more silent hits with visual scene displays. On average, the children demonstrated relatively few spontaneous activations of the speech-generating device while the adult was reading, regardless of overlay design. When responding to questions, children with communication needs appeared to perform better when using visual scene displays, but the effect of display condition on the accuracy of responses to wh-questions was not statistically significant. In response to an open ended question, children with communication disorders demonstrated more frequent activations of the SGD using a grid display than a visual scene. Suggestions for future research as well as potential implications for designing AAC systems for shared reading with young children are discussed.

Formate stability and carbonate hydrogenation on strained Cu overlayers on Pt(111)

DEFF Research Database (Denmark)

Schumacher, Nana Maria Pii; Andersson, Klas Jerker; Nerlov, Jesper

2008-01-01

Formate (HCOO) synthesis, decomposition and the hydrogenation of carbonate (CO3) on Cu overlayers deposited on a Pt(111) single crystal are investigated to examine the reactivity of a Cu surface under tensile strain with defects present. Formate is synthesized from a 0.5 bar mixture of 70% CO2...

Combined Conjunctival Autograft and Overlay Amniotic Membrane Transplantation; a Novel Surgical Treatment for Pterygium

Directory of Open Access Journals (Sweden)

Siamak Zarei Ghanavati

2014-01-01

Full Text Available The authors report the long-term results of combined conjunctival autograft and overlay amniotic membrane transplantation (AMT for treatment of pterygium as a new surgical technique. Nineteen patients including 12 male and 7 female subjects with pterygium (primary, 14 cases; recurrent, 5 cases underwent combined conjunctival autograft and overlay AMT and were followed from 10 to 26 months. Mean age was 44.21±12.49 (range, 29.0-73.0 years. In one patient with grade T3 primary pterygium, the lesion recurred (5.2%, recurrence rate. No intra-and postoperative complication developed. This procedure seems a safe and effective surgical technique for pterygium treatment. Protection of the ocular surface during the early postoperative period reduces the friction-induced inflammation and might be helpful to prevent the recurrence.

Impact of Improper Gaussian Signaling on the Achievable Rate of Overlay Cognitive Radio

KAUST Repository

Amin, Osama

2017-05-12

Improper Gaussian signaling (IGS) has been recently shown to provide performance improvements in underlay cognitive radio systems as opposed to the conventional proper Gaussian signaling (PGS) scheme. For the first time, this paper implements IGS scheme in overlay cognitive radio system, where the secondary transmitter broadcasts a mixture of two different signals. The first signal is selected from the PGS scheme to support the primary message transmission. On the other hand, the second signal is chosen to be from the IGS scheme in order to reduce the interference effect on the primary receiver. We then optimally design the overlay cognitive radio that employs IGS to maximize the secondary link achievable rate while satisfying the minimum rate requirement of the primary network. In particular, we derive closed form expressions for the circularity coefficient used in the IGS scheme and the power distribution parameters. Simulation results are provided to support our theoretical derivations.

Impact of Improper Gaussian Signaling on the Achievable Rate of Overlay Cognitive Radio

KAUST Repository

Amin, Osama; Abediseid, Walid; Alouini, Mohamed-Slim

2017-01-01

Improper Gaussian signaling (IGS) has been recently shown to provide performance improvements in underlay cognitive radio systems as opposed to the conventional proper Gaussian signaling (PGS) scheme. For the first time, this paper implements IGS scheme in overlay cognitive radio system, where the secondary transmitter broadcasts a mixture of two different signals. The first signal is selected from the PGS scheme to support the primary message transmission. On the other hand, the second signal is chosen to be from the IGS scheme in order to reduce the interference effect on the primary receiver. We then optimally design the overlay cognitive radio that employs IGS to maximize the secondary link achievable rate while satisfying the minimum rate requirement of the primary network. In particular, we derive closed form expressions for the circularity coefficient used in the IGS scheme and the power distribution parameters. Simulation results are provided to support our theoretical derivations.

Real-time "x-ray vision" for healthcare simulation: an interactive projective overlay system to enhance intubation training and other procedural training.

Science.gov (United States)

Samosky, Joseph T; Baillargeon, Emma; Bregman, Russell; Brown, Andrew; Chaya, Amy; Enders, Leah; Nelson, Douglas A; Robinson, Evan; Sukits, Alison L; Weaver, Robert A

2011-01-01

We have developed a prototype of a real-time, interactive projective overlay (IPO) system that creates augmented reality display of a medical procedure directly on the surface of a full-body mannequin human simulator. These images approximate the appearance of both anatomic structures and instrument activity occurring within the body. The key innovation of the current work is sensing the position and motion of an actual device (such as an endotracheal tube) inserted into the mannequin and using the sensed position to control projected video images portraying the internal appearance of the same devices and relevant anatomic structures. The images are projected in correct registration onto the surface of the simulated body. As an initial practical prototype to test this technique we have developed a system permitting real-time visualization of the intra-airway position of an endotracheal tube during simulated intubation training.

On-product overlay enhancement using advanced litho-cluster control based on integrated metrology, ultra-small DBO targets and novel corrections

Science.gov (United States)

Bhattacharyya, Kaustuve; Ke, Chih-Ming; Huang, Guo-Tsai; Chen, Kai-Hsiung; Smilde, Henk-Jan H.; Fuchs, Andreas; Jak, Martin; van Schijndel, Mark; Bozkurt, Murat; van der Schaar, Maurits; Meyer, Steffen; Un, Miranda; Morgan, Stephen; Wu, Jon; Tsai, Vincent; Liang, Frida; den Boef, Arie; ten Berge, Peter; Kubis, Michael; Wang, Cathy; Fouquet, Christophe; Terng, L. G.; Hwang, David; Cheng, Kevin; Gau, TS; Ku, Y. C.

2013-04-01

Aggressive on-product overlay requirements in advanced nodes are setting a superior challenge for the semiconductor industry. This forces the industry to look beyond the traditional way-of-working and invest in several new technologies. Integrated metrology2, in-chip overlay control, advanced sampling and process correction-mechanism (using the highest order of correction possible with scanner interface today), are a few of such technologies considered in this publication.

Shadow Segmentation and Augmentation Using á-overlay Models that Account for Penumbra

DEFF Research Database (Denmark)

Nielsen, Michael; Madsen, Claus B.

2006-01-01

that an augmented virtual object can cast an exact shadow. The penumbras (half-shadows) must be taken into account so that we can model the soft shadows.We hope to achieve this by modelling the shadow regions (umbra and penumbra alike) with a transparent overlay. This paper reviews the state-of-the-art shadow...

Ductile film delamination from compliant substrates using hard overlayers.

Science.gov (United States)

Cordill, M J; Marx, V M; Kirchlechner, C

2014-11-28

Flexible electronic devices call for copper and gold metal films to adhere well to polymer substrates. Measuring the interfacial adhesion of these material systems is often challenging, requiring the formulation of different techniques and models. Presented here is a strategy to induce well defined areas of delamination to measure the adhesion of copper films on polyimide substrates. The technique utilizes a stressed overlayer and tensile straining to cause buckle formation. The described method allows one to examine the effects of thin adhesion layers used to improve the adhesion of flexible systems.

The Effects of a Dynamic Spectrum Access Overlay in LTE-Advanced Networks

Energy Technology Data Exchange (ETDEWEB)

Juan D. Deaton; Ryan E. lrwin; Luiz A. DaSilva

2011-05-01

As early as 2014, wireless network operators spectral capacity will be overwhelmed by a data tsunami brought on by new devices and applications. To augment spectral capacity, operators could deploy a Dynamic Spectrum Access (DSA) overlay. In the light of the many planned Long Term Evolution (LTE) network deployments, the affects of a DSA overlay have not been fully considered into the existing LTE standards. Coalescing many different aspects of DSA, this paper develops the Spectrum Accountability (SA) framework. The SA framework defines specific network element functionality, protocol interfaces, and signaling flow diagrams for LTE to support service requests and enforce rights of responsibilities of primary and secondary users, respectively. We also include a network simulation to quantify the benefits of using DSA channels to augment capacity. Based on our simulation we show that, network operators can benefit up to %40 increase in operating capacity when sharing DSA bands to augment spectral capacity. With our framework, this paper could serve as an guide in developing future LTE network standards that include DSA.

MeshTree: A Delay optimised Overlay Multicast Tree Building Protocol

OpenAIRE

Tan, Su-Wei; Waters, A. Gill; Crawford, John

2005-01-01

We study decentralised low delay degree-constrained overlay multicast tree construction for single source real-time applications. This optimisation problem is NP-hard even if computed centrally. We identify two problems in traditional distributed solutions, namely the greedy problem and delay-cost trade-off. By offering solutions to these problems, we propose a new self-organising distributed tree building protocol called MeshTree. The main idea is to embed the delivery tree in a degree-bound...

Texas flexible pavements and overlays : calibration plans for M-E models and related software.

Science.gov (United States)

2013-06-01

This five-year project was initiated to collect materials and pavement performance data on a minimum of 100 highway test sections around the State of Texas, incorporating flexible pavements and overlays. Besides being used to calibrate and validate m...

Disruption, segregation, and passivation for Pd and noble-metal overlayers on YBa2Cu3O/sub 6.9/

International Nuclear Information System (INIS)

Wagener, T.J.; Gao, Y.; Vitomirov, I.M.; Aldao, C.M.; Joyce, J.J.; Capasso, C.; Weaver, J.H.; Capone II, D.W.

1988-01-01

We have investigated interfaces formed when Pd and the noble metals Cu, Ag, and Au are deposited onto polycrystalline samples of YBa 2 Cu 3 O/sub 6.9/ fractured in ultrahigh vacuum. Synchrotron-radiation photoemission results show that Cu and Pd overlayers leach oxygen from the underlying YBa 2 Cu 3 O/sub 6.9/ substrate, disrupt the superconductor, and destroy electronic states near the Fermi level. Interface reactions become kinetically limited at room temperature after the deposition of ∼4 A of Cu or Pd, significantly sooner than for the reactive metals Fe, Al, Ti, and In. The presence of Ba near the surface after the deposition of more than 100 A of Cu and Pd reflects substrate disruption and subsequent surface segregation. In contrast, overlayers of Ag and Au do not disrupt the superconductor substrate, no segregation is observed, but the overlayers are nonuniform and the quality of passivation is in question for coverages <100 A

Satellite Imagery and In-situ Data Overlay Approach for Fishery Zonation

Directory of Open Access Journals (Sweden)

Fardhi Adria

2010-12-01

Full Text Available Remote sensing technology can be used to better understand the earth’s characteristics. SeaWiFS (sea-viewing wide field-of-view sensor is one of remote sensors used to observe global ocean phenomena. Previous studies showed that the distribution of chlorophyll-a in the ocean indicates the presence of fish. However, only a few studies tried to directly relate the chlorophyll-a distribution obtained through interpretation of satellite imagery to in-situ data of fish distribution. This paper investigates the relation between chlorophyll-a distribution and fish-capturing points in Aceh Province sea waters using overlay image analysis. The results are then used to identify the potential fishing ground in Aceh. The profile of chlorophyll-a concentration is derived from SeaWIFS satellite imagery. Fish-capturing points data is obtained from the fisherman communities of Banda Aceh, starting from June to November 2008. The results showed that the chlorophyll-a profile derived from satellite imagery has a positive relationship to fish-capturing point data. The most potential fish-capturing zone in Aceh sea waters is identified at 5-8º north latitude (N and 96-99º east longitude (E.

Automated ultrasonic testing of nuclear reactor welds and overlays in pre-service and in-service inspections

International Nuclear Information System (INIS)

Sladky, J.

1988-01-01

Since 1982, automatic pre-service and in-service checks are being made of welded joints and overlays on pressure vessels of WWER-440 nuclear reactors in Czechoslovakia. This is being done using the SKODA REACTORTEST TRC facility which is used for checking peripheral welded joints on the pressure vessel, neck joints, overlays in other selected areas of the cylindrical section of the pressure vessel, on radius transitions of the pressure vessel and of necks, and on the cylindrical part of necks, and also for checking the base material in selected parts of the pressure vessel and the base material of the neck extension piece. The tests are of two types, namely tests of peripheral welds and overlays of the cylindrical parts of the pressure vessel, and tests of the necks. Different ultrasonic probe holders are used for the tests, with totally different design. Ultrasonic probes which were initially used were of foreign make while at present, those of Czechoslovak make are used. For each pressure vessel a set of ultrasonic probes is used which should suffice for the life of the vessel. Experience gained so far is being used in work on the project of a new device for testing nuclear reactor presure vessels from the inside. (Z.M.)

First-principles study of nitric oxide oxidation on Pt(111) versus Pt overlayer on 3d transition metals

Energy Technology Data Exchange (ETDEWEB)

Arevalo, Ryan Lacdao [Department of Precision Science and Technology and Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Escaño, Mary Clare Sison [Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507 (Japan); Kasai, Hideaki, E-mail: kasai@dyn.ap.eng.osaka-u.ac.jp [Department of Precision Science and Technology and Applied Physics, Center for Atomic and Molecular Technologies, and Center for Continuing Professional Development, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2015-03-15

Catalytic oxidation of NO to NO{sub 2} is a significant research interest for improving the quality of air through exhaust gas purification systems. In this paper, the authors studied this reaction on pure Pt and Pt overlayer on 3d transition metals using kinetic Monte Carlo simulations coupled with density functional theory based first principles calculations. The authors found that on the Pt(111) surface, NO oxidation proceeds via the Eley–Rideal mechanism, with O{sub 2} dissociative adsorption as the rate-determining step. The oxidation path via the Langmuir–Hinshelwood mechanism is very slow and does not significantly contribute to the overall reaction. However, in the Pt overlayer systems, the oxidation of NO on the surface is more thermodynamically and kinetically favorable compared to pure Pt. These findings are attributed to the weaker binding of O and NO on the Pt overlayer systems and the binding configuration of NO{sub 2} that promotes easier N-O bond formation. These results present insights for designing affordable and efficient catalysts for NO oxidation.

First principles analysis of hydrogen chemisorption on Pd-Re alloyed overlayers and alloyed surfaces

DEFF Research Database (Denmark)

Pallassana, Venkataraman; Neurock, Matthew; Hansen, Lars Bruno

2000-01-01

Gradient corrected periodic density functional theory (DFT-GGA) slab calculations were used to examine the chemisorption of atomic hydrogen on various Pd-Re alloyed overlayers and uniformly alloyed surfaces. Adsorption was examined at 33% surface coverage, where atomic hydrogen preferred the thre...

A Secure and Stable Multicast Overlay Network with Load Balancing for Scalable IPTV Services

Directory of Open Access Journals (Sweden)

Tsao-Ta Wei

2012-01-01

Full Text Available The emerging multimedia Internet application IPTV over P2P network preserves significant advantages in scalability. IPTV media content delivered in P2P networks over public Internet still preserves the issues of privacy and intellectual property rights. In this paper, we use SIP protocol to construct a secure application-layer multicast overlay network for IPTV, called SIPTVMON. SIPTVMON can secure all the IPTV media delivery paths against eavesdroppers via elliptic-curve Diffie-Hellman (ECDH key exchange on SIP signaling and AES encryption. Its load-balancing overlay tree is also optimized from peer heterogeneity and churn of peer joining and leaving to minimize both service degradation and latency. The performance results from large-scale simulations and experiments on different optimization criteria demonstrate SIPTVMON's cost effectiveness in quality of privacy protection, stability from user churn, and good perceptual quality of objective PSNR values for scalable IPTV services over Internet.

Comparative evaluation of concrete sealers and multiple layer polymer concrete overlays. Interim report no. 1.

Science.gov (United States)

1987-01-01

The report presents comparisons of initial evaluations of several concrete sealers and multiple layer polymer concrete overlays. The sealers evaluated included a solvent-dlspersed epoxy, a water-dlspersed epoxy, a silane, and a high molecular weight ...

THE FUZZY OVERLAY STUDENT MODEL IN AN INTELLIGENT TUTORING SYSTEM

Directory of Open Access Journals (Sweden)

D. I. Popov

2015-01-01

Full Text Available The article is devoted to the development of the student model for use in an intelligent tutoring system (ITS designed for the evaluation of students’ competencies in different Higher Education Facilities. There are classification and examples of the various student models, the most suitable for the evaluation of competencies is selected and finalized. The dynamic overlay fuzzy student model builded on the domain model based on the concept of didactic units is described in this work. The formulas, chart and diagrams are provided.

Gas Selectivity Control in Co3O4 Sensor via Concurrent Tuning of Gas Reforming and Gas Filtering using Nanoscale Hetero-Overlayer of Catalytic Oxides.

Science.gov (United States)

Jeong, Hyun-Mook; Jeong, Seong-Yong; Kim, Jae-Hyeok; Kim, Bo-Young; Kim, Jun-Sik; Abdel-Hady, Faissal; Wazzan, Abdulaziz A; Al-Turaif, Hamad Ali; Jang, Ho Won; Lee, Jong-Heun

2017-11-29

Co 3 O 4 sensors with a nanoscale TiO 2 or SnO 2 catalytic overlayer were prepared by screen-printing of Co 3 O 4 yolk-shell spheres and subsequent e-beam evaporation of TiO 2 and SnO 2 . The Co 3 O 4 sensors with 5 nm thick TiO 2 and SnO 2 overlayers showed high responses (resistance ratios) to 5 ppm xylene (14.5 and 28.8) and toluene (11.7 and 16.2) at 250 °C with negligible responses to interference gases such as ethanol, HCHO, CO, and benzene. In contrast, the pure Co 3 O 4 sensor did not show remarkable selectivity toward any specific gas. The response and selectivity to methylbenzenes and ethanol could be systematically controlled by selecting the catalytic overlayer material, varying the overlayer thickness, and tuning the sensing temperature. The significant enhancement of the selectivity for xylene and toluene was attributed to the reforming of less reactive methylbenzenes into more reactive and smaller species and oxidative filtering of other interference gases, including ubiquitous ethanol. The concurrent control of the gas reforming and oxidative filtering processes using a nanoscale overlayer of catalytic oxides provides a new, general, and powerful tool for designing highly selective and sensitive oxide semiconductor gas sensors.

Nickel-base alloy overlay weld with improved ultrasonic flaw detection by magnetic stirring welding

International Nuclear Information System (INIS)

Takashi, Hirano; Kenji, Hirano; Masayuki, Watando; Takahiro, Arakawa; Minoru, Maeda

2001-01-01

Ultrasonic flaw detection is more difficult in Nickel-base alloy welds containing dendrites owing to the decrease ultrasonic transmissibility they cause. The present paper discusses application of magnetic stirring welding as a means for reducing dendrite growth with consequent improvement in ultrasonic transmissibility. Single pass and multi-pass welding tests were conducted to determine optimal welding conditions. By PT and macro observation subsequent to welding was carried out, optimal operation conditions were clarified. Overlay welding tests and UT clearly indicated ultrasonic beam transmissibility in overlay welds to be improved and detection capacity to be greater through application of magnetic stirring welding. Optimal operation conditions were determined based on examination of temper bead effects in the heat affected zone of low alloy steel by application of magnetic stirring welding to the butt welded joints between low alloy and stainless steel. Hardness in this zone of low alloy steel after the fourth layer was less than 350 HV. (author)

Accelerated testing for studying pavement design and performance (FY 2000) : effectiveness of fiber reinforced and plain, ultra-thin concrete overlays on Portland Cement Concrete Pavement (PCCP).

Science.gov (United States)

2003-11-01

The objective of the research was to compare the performance of fiber reinforced and plain PCC concrete overlay when used as a thin non-dowelled overlay on top of a rubblized, distressed concrete pavement. The experiment was conducted at the Accelera...

Simple overlay device for determining radial head and neck height

Energy Technology Data Exchange (ETDEWEB)

Moon, Jun-Gyu; Southgate, Richard D.; Fitzsimmons, James S.; O' Driscoll, Shawn W. [Mayo Clinic, Department of Orthopaedic Surgery, Rochester, MN (United States)

2010-09-15

The purpose of this study was to test the hypothesis that a simple overlay device can be used on radiographs to measure radial head and neck height. Thirty anteroposterior elbow radiographs from 30 patients with a clinical diagnosis of lateral epicondylitis were examined to measure radial head and neck height. Three methods using different points along the bicipital tuberosity as a landmark were used. Method 1 used the proximal end of the bicipital tuberosity, method 2 used the most prominent point of the bicipital tuberosity, and method 3 used a simple overlay device (SOD) template that was aligned with anatomic reference points. All measurements were performed three times by three observers to determine interobserver and intraobserver reliability. Intraclass correlation coefficients revealed higher interobserver and intraobserver correlations for the SOD template method than for the other two methods. The 95% limits of agreement between observers were markedly better (-1.8 mm to +1.0 mm) for the SOD template method than for the proximal point method (-3.8 mm to +3.4 mm) or the prominent point method (-5.9 mm to +4.9 mm). We found that the SOD template method was reliable for assessing radial head and neck height. It had less variability than other methods, its 95% limit of agreement being less than 2 mm. This method could be helpful for assessing whether or not the insertion of a radial head prosthesis has resulted in over-lengthening of the radius. (orig.)

Simple overlay device for determining radial head and neck height

International Nuclear Information System (INIS)

Moon, Jun-Gyu; Southgate, Richard D.; Fitzsimmons, James S.; O'Driscoll, Shawn W.

2010-01-01

The purpose of this study was to test the hypothesis that a simple overlay device can be used on radiographs to measure radial head and neck height. Thirty anteroposterior elbow radiographs from 30 patients with a clinical diagnosis of lateral epicondylitis were examined to measure radial head and neck height. Three methods using different points along the bicipital tuberosity as a landmark were used. Method 1 used the proximal end of the bicipital tuberosity, method 2 used the most prominent point of the bicipital tuberosity, and method 3 used a simple overlay device (SOD) template that was aligned with anatomic reference points. All measurements were performed three times by three observers to determine interobserver and intraobserver reliability. Intraclass correlation coefficients revealed higher interobserver and intraobserver correlations for the SOD template method than for the other two methods. The 95% limits of agreement between observers were markedly better (-1.8 mm to +1.0 mm) for the SOD template method than for the proximal point method (-3.8 mm to +3.4 mm) or the prominent point method (-5.9 mm to +4.9 mm). We found that the SOD template method was reliable for assessing radial head and neck height. It had less variability than other methods, its 95% limit of agreement being less than 2 mm. This method could be helpful for assessing whether or not the insertion of a radial head prosthesis has resulted in over-lengthening of the radius. (orig.)

Enabling optical metrology on small 5×5μm2 in-cell targets to support flexible sampling and higher order overlay and CD control for advanced logic devices nodes

Science.gov (United States)

Salerno, Antonio; de la Fuente, Isabel; Hsu, Zack; Tai, Alan; Chang, Hammer; McNamara, Elliott; Cramer, Hugo; Li, Daoping

2018-03-01

In next generation Logic devices, overlay control requirements shrink to sub 2.5nm level on-product overlay. Historically on-product overlay has been defined by the overlay capability of after-develop in-scribe targets. However, due to design and dimension, the after development metrology targets are not completely representative for the final overlay of the device. In addition, they are confined to the scribe-lane area, which limits the sampling possibilities. To address these two issues, metrology on structures matching the device structure and which can be sampled with high density across the device is required. Conventional after-etch CDSEM techniques on logic devices present difficulties in discerning the layers of interest, potential destructive charging effects and finally, they are limited by the long measurement times[1] [2] [3] . All together, limit the sampling densities and making CDSEM less attractive for control applications. Optical metrology can overcome most of these limitations. Such measurement, however, does require repetitive structures. This requirement is not fulfilled by logic devices, as the features vary in pitch and CD over the exposure field. The solution is to use small targets, with a maximum pad size of 5x5um2 , which can easily be placed in the logic cell area. These targets share the process and architecture of the device features of interest, but with a modified design that replicates as close as possible the device layout, allowing for in-device metrology for both CD and Overlay. This solution enables measuring closer to the actual product feature location and, not being limited to scribe-lanes, it opens the possibility of higher-density sampling schemes across the field. In summary, these targets become the facilitator of in-device metrology (IDM), that is, enabling the measurements both in-device Overlay and the CD parameters of interest and can deliver accurate, high-throughput, dense and after-etch measurements for Logic

Interactive overlay maps for US Patent (USPTO) data based on International Patent Classifications (IPC)

NARCIS (Netherlands)

Leydesdorff, L.; Kushnir, D.; Rafols, I.

2014-01-01

We report on the development of an interface to the US Patent and Trademark Office (USPTO) that allows for the mapping of patent portfolios as overlays to basemaps constructed from citation relations among all patents contained in this database during the period 1976-2011. Both the interface and the

Bandwidth auction for SVC streaming in dynamic multi-overlay

Science.gov (United States)

Xiong, Yanting; Zou, Junni; Xiong, Hongkai

2010-07-01

In this paper, we study the optimal bandwidth allocation for scalable video coding (SVC) streaming in multiple overlays. We model the whole bandwidth request and distribution process as a set of decentralized auction games between the competing peers. For the upstream peer, a bandwidth allocation mechanism is introduced to maximize the aggregate revenue. For the downstream peer, a dynamic bidding strategy is proposed. It achieves maximum utility and efficient resource usage by collaborating with a content-aware layer dropping/adding strategy. Also, the convergence of the proposed auction games is theoretically proved. Experimental results show that the auction strategies can adapt to dynamic join of competing peers and video layers.

Leveraging Gaussian process approximations for rapid image overlay production

CSIR Research Space (South Africa)

Burke, Michael

2017-10-01

Full Text Available value, xs = argmax x∗ [ K (x∗, x∗) − K (x∗, x)K (x, x)−1K (x, x∗) ] . (10) Figure 2 illustrates this sampling strategy more clearly. This selec- tion process can be slow, but could be bootstrapped using Latin hypercube sampling [16]. 3 RESULTS Empirical... point - a 240 sample Gaussian process approximation takes roughly the same amount of time to compute as the full blanked overlay. GP 50 GP 100 GP 150 GP 200 GP 250 GP 300 GP 350 GP 400 Full Itti-Koch 0 2 4 6 8 10 Method R at in g Boxplot of storyboard...

DFT study on dry reforming of methane over Ni2Fe overlayer of Ni(1 1 1) surface

Science.gov (United States)

Xu, Li-li; Wen, Hong; Jin, Xin; Bing, Qi-ming; Liu, Jing-yao

2018-06-01

We reported the complete catalytic cycle of dry reforming of methane (DRM) on Ni2Fe overlayer of Ni(1 1 1) surface by periodic density functional theory (DFT) calculations. The pathways for dehydrogenation of CH4 and CO2 activation were located. Our results demonstrate that compared with pure Ni(1 1 1) surface, the introduction Fe into Ni increases the energy barrier of CH dissociation to carbon and hydrogen atoms, thereby suppressing coke deposition on the surface, while it promotes the H-induced CO2 activation pathway to form OH radical, and thus not only the surface oxygen but also OH are responsible for the oxidation of CHx (x = 0,1) on the Ni2Fe overlayer. The most favorable pathway of CH/C oxidation is found to be CH∗ + OH∗ → CHOH∗ → CHO∗ + H∗ → CO∗ + 2H∗, with the rate-limiting energy barrier of 1.12 eV. Furthermore, since Fe is oxidized partially to FeO leading to a partial dealloying under DRM conditions, we also studied the surface-carbon removal and the activity for the reforming of methane on the FeO ribbon supported Ni(1 1 1) (FeO/Ni) interface by DFT+U method. The surface C reacts with lattice oxygen of FeO to produce CO via a Mars-van Krevelen (MvK) mechanism, with a very lower energy barrier of 0.16 eV. The present results show that the introduction of Fe into Ni has a positive effect on the activity toward DRM and has an improved coke resistance.

Equipment stainless steel entire versus steels bimetallics clad or overlay; Utilizacao de equipamentos de processo construidos em aco inoxidavel integral versus acos bimetalicos cladeado ou 'overlay'

Energy Technology Data Exchange (ETDEWEB)

Batista, Itamar da Silva; Lima, Jadival Carneiro de; Leal, Murilo Fonseca; Cardoso, Amauri dos Santos; Jorjan, Roberto [PETROBRAS S.A., Sao Francisco do Conde, BA (Brazil). Refinaria Landulfo Alves Mataripen (RLAM)

2008-07-01

This study does not recommend the use of a pressure vessel made of integral stainless steel, due to the failure mechanisms under stress corrosion assisted by chlorides or polythionic acid. Are presented case studies of literature and analysis of reports of proceedings of RLAM reactors, showing that the materials produced by bimetallic clad overlay or are more appropriate, in terms of integrity, for use in equipment that the internal environment requires austenitic stainless steel specification.

Spatial Analysis for Potential Water Catchment Areas using GIS: Weighted Overlay Technique

Science.gov (United States)

Awanda, Disyacitta; Anugrah Nurul, H.; Musfiroh, Zahrotul; Dinda Dwi, N. P.

2017-12-01

The development of applied GIS is growing rapidly and has been widely applied in various fields. Preparation of a model to obtain information is one of the benefits of GIS. Obtaining information for water resources such as water catchment areas is one part of GIS modelling. Water catchment model can be utilized to see the distribution of potential and ability of a region in water absorbing. The use of overlay techniques with the weighting obtained from the literature from previous research is used to build the model. Model builder parameters are obtained through remote sensing interpretation techniques such as land use, landforms, and soil texture. Secondary data such as rock type maps are also used as water catchment model parameters. The location of this research is in the upstream part of the Opak river basin. The purpose of this research is to get information about potential distribution of water catchment area with overlay technique. The results of this study indicate the potential of water catchment areas with excellent category, good, medium, poor and very poor. These results may indicate that the Upper river basin is either good or in bad condition, so it can be used for better water resources management policy determination.

Structure determination of a multilayer with an island-like overlayer using hard x-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Isomura, N., E-mail: isomura@mosk.tytlabs.co.jp; Kataoka, K.; Horibuchi, K.; Dohmae, K.; Kitazumi, K.; Takahashi, N.; Kimoto, Y. [Toyota Central R& D Laboratories, Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192 (Japan); Oji, H.; Cui, Y.-T.; Son, J.-Y. [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2016-07-27

We use hard X-ray photoelectron spectroscopy (HAXPES) to obtain the surface structure of a multilayer Au/SiO{sub 2}/Si substrate sample with an island-like overlayer. Photoelectron intensities are measured as a function of incident photon energy (PE) and take-off angle (TOA, measured from the sample surface). The Au layer coverage and Au and SiO{sub 2} layer thicknesses are obtained by the PE dependence, and are used for the following TOA analysis. The Au island lateral width in the cross section is obtained by the TOA dependence, including information about surface roughness, in consideration of the island shadowing at small TOAs. In both cases, curve-fitting analysis is conducted. The surface structure, which consists of layer thicknesses, overlayer coverage and island width, is determined nondestructively by a combination of PE and TOA dependent HAXPES measurements.

Self-Adapting Routing Overlay Network for Frequently Changing Application Traffic in Content-Based Publish/Subscribe System

Directory of Open Access Journals (Sweden)

Meng Chi

2014-01-01

Full Text Available In the large-scale distributed simulation area, the topology of the overlay network cannot always rapidly adapt to frequently changing application traffic to reduce the overall traffic cost. In this paper, we propose a self-adapting routing strategy for frequently changing application traffic in content-based publish/subscribe system. The strategy firstly trains the traffic information and then uses this training information to predict the application traffic in the future. Finally, the strategy reconfigures the topology of the overlay network based on this predicting information to reduce the overall traffic cost. A predicting path is also introduced in this paper to reduce the reconfiguration numbers in the process of the reconfigurations. Compared to other strategies, the experimental results show that the strategy proposed in this paper could reduce the overall traffic cost of the publish/subscribe system in less reconfigurations.

Bandwidth and power allocation for two-way relaying in overlay cognitive radio systems

KAUST Repository

Alsharoa, Ahmad M.

2014-12-01

In this paper, the problem of both bandwidth and power allocation for two-way multiple relay systems in overlay cognitive radio (CR) setup is investigated. In the CR overlay mode, primary users (PUs) cooperate with cognitive users (CUs) for mutual benefits. In our framework, we propose that the CUs are allowed to allocate a part of the PUs spectrum to perform their cognitive transmission. In return, acting as an amplify-and-forward two-way relays, they are used to support PUs to achieve their target data rates over the remaining bandwidth. More specifically, CUs acts as relays for the PUs and gain some spectrum as long as they respect a specific power budget and primary quality-of-service constraints. In this context, we first derive closed-form expressions for optimal transmit power allocated to PUs and CUs in order to maximize the cognitive objective. Then, we employ a strong optimization tool based on particle swarm optimization algorithm to find the optimal relay amplification gains and optimal cognitive released bandwidths as well. Our numerical results illustrate the performance of our proposed algorithm for different utility metrics and analyze the impact of some system parameters on the achieved performance.

Influence of bitumen type on cracking resistance of asphalt mixtures used in pavement overlays

Science.gov (United States)

Jaskula, P.; Szydlowski, C.; Stienss, M.

2018-05-01

Cracking is one of the predominant distresses occurring in flexible pavements, especially in old pavements that were rehabilitated with an asphalt overlay. In such cases asphalt mixtures should be designed to ensure high resistance to reflective cracking because new asphalt layers are exposed to existing cracks of the old pavement. The nature of these cracks can be various (transverse, longitudinal as well as crazy cracking). One factor that minimizes this type of distress is the proper mix design process, which should involve selection of specific bitumen binder and mineral mix gradation. However, still there is no universally adopted laboratory test method that would allow to clearly assess resistance of asphalt mixtures to reflective cracking. This paper describes the usage of one of the devices developed to test asphalt mixtures in terms of such distress – Texas Overlay Tester. For this test, samples prepared in laboratory conditions (i.e. compacted with the use of Superpave Gyratory Compactor) as well as obtained in the field (by core drilling) can be used. The results are obtained not only quickly and easily, but also with sufficient repeatability. The described method characterizes both crack initiation and crack propagation properties of asphalt mixtures. In this work one type of mineral mixture was tested with 4 different types of bitumen (one neat bitumen, two ordinary polymer-modified and one polymer-modified with high polymer content). For selected cases extra additives (rubber and loose fibres) were also tested. In total, six asphalt mixtures were tested. A ranking of the used binders was created on the basis of the results in order to conclude which bitumen would ensure the best performance characteristics in terms of reflective cracking. The results have clearly shown that deliberate choice of the binder used in the asphalt mixture for the overlay will significantly improve its reflective cracking resistance or even fatigue resistance.

VUV light induced valence degeneration in Sm over-layer on HOPG

International Nuclear Information System (INIS)

Kutluk, G; Nakatake, M; Arita, M; Namatame, H; Taniguchi, M; Ishitobi, Y; Sumida, H

2013-01-01

Systematic investigation of the influence of vacuum ultraviolet (VUV) irradiation on the valence degeneration in a Sm over-layer on a HOPG substrate was performed using in-situ photoemission spectroscopy (XPS, UPS, and ARPES) for the Sm coverage regime of 0.05-3.6 Å. This investigation confirmed that VUV irradiation-induced degeneration of divalent Sm exerts a more profound effect than Sm contamination during photoemission spectroscopy even under UHV. We found that the charge transfer occurs mainly from divalent Sm to the HOPG surface.

Interactive overlays: a new method for generating global journal maps from Web-of-Science data

NARCIS (Netherlands)

Leydesdorff, L.; Rafols, I.

2012-01-01

Recent advances in methods and techniques enable us to develop interactive overlays to a global map of science based on aggregated citation relations among the 9162 journals contained in the Science Citation Index and Social Science Citation Index 2009. We first discuss the pros and cons of the

Enumeration of phenanthrene-degrading bacteria by an overlayer technique and its use in evaluation of petroleum-contaminated sites

International Nuclear Information System (INIS)

Bogardt, A.H.; Hemmingsen, B.B.

1992-01-01

Bacteria that are capable of degrading polycyclic aromatic hydrocarbons were enumerated by incorporating soil and water dilutions together with fine particles of phenanthrene, a polycyclic aromatic hydrocarbon, into an agarose overlayer and pouring the mixture over a mineral salts underlayer. The phenanthrene-degrading bacteria embedded in the overlayer were recognized by a halo of clearing in the opaque phenanthrene layer. Diesel fuel- or creosote-contaminated soil and water that were undergoing bioremediation contained 6 x 10 6 to 100 x 10 6 phenanthrene-degrading bacteria per g and ca. 5 x 10 5 phenanthrene-degrading bacteria per ml, respectively, whereas samples from untreated polluted sites contained substantially lower numbers. Unpolluted soil and water contained no detectable phenanthrene degraders or only very modest numbers of these organisms

Fluorogenic membrane overlays to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and seawater

Science.gov (United States)

Three assays were developed to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and other foods and in seawater and other environmental samples. Assays involve membrane overlays of overnight colonies on non-selective agar plates to detect ß-glucuronidase and lysyl am...

Posterior open occlusion management by registration of overlay removable partial denture: A clinical report

Science.gov (United States)

Nosouhian, Saeid; Davoudi, Amin; Derhami, Mohammad

2015-01-01

This clinical report describes prosthetic rehabilitation of posterior open bite relationship in a patient with several missing teeth and skeletal Class III malocclusion. Primary diagnostic esthetic evaluations were performed by mounting casts in centric relation and estimating lost vertical dimension of occlusion. Exclusive treatments were designated by applying overlay removable partial denture with external attachment systems for higher retentions. PMID:26929544

The migration law of overlay rock and coal in deeply inclined coal seam with fully mechanized top coal caving.

Science.gov (United States)

Liu, Jian; Chen, Shan-Le; Wang, Hua-Jun; Li, Yu-Cheng; Geng, Xiaowei

2015-07-01

In a mine area, some environment geotechnics problems always occure, induced by mined-out region such as the subsidence and cracks at ground level, deformation and destruction of buildings, landslides destruction of water resources and the ecological environment. In order to research the migration of surrounding rock and coal in steeply inclined super high seams which used fully mechanized top coal caving, a working face of a certain mine was made as an example, analyzed the migration law of the overlay rock and coal under different caving ratio of fully mechanized top coal caving with numerical simulation analysis. The results suggest that the laws of overlay rock deformation caused by deeply inclined coal seam were different from horizontal coal seam. On the inclined direction, with an increase of dip angle and caving ratio, the vertical displacement of overlay rock and coal became greater, the asymmetric phenomenon of vertical displacement became obvious. On the trend direction, active region and transition region in goaf became smaller along with the increase of mining and caving ratio. On the contrary, the stable region area became greater. Therefore, there was an essential difference between the mechanism of surface movement deformation with deeply inclined coal seam and that with horizontal coal seam.

Texas flexible pavements and overlays : year 1 report, test sections, data collection, analyses, and data storage system.

Science.gov (United States)

2012-06-01

This five-year project was initiated to collect materials and pavement performance data on a minimum of 100 highway test sections around the State of Texas, incorporating both flexible pavements and overlays. Besides being used to calibrate and valid...

Overlay cognitive radio systems with adaptive two-way relaying

KAUST Repository

Hyadi, Amal

2013-12-01

In this paper, we propose a spectrum sharing mechanism with a two-phase two-way relaying protocol for an overlay cognitive network. The system comprises two primary users (PUs) and two secondary users (SUs). One of the SUs acts as a relay for the PUs and gains spectrum sharing as long as he respects outage probability constraints of the primary system. Moreover, we consider that the relaying node performs an optimal power allocation scheme that minimizes the outage performance of the secondary receiver. Closed form expressions for the outage probability are derived for the cases of Decode-and-Forward (DF), Amplify-and-Forward (AF), and adaptive relaying. Numerical simulations are presented to illustrate and compare the obtained results. © 2013 IEEE.

Weld overlay cladding with iron aluminides

Energy Technology Data Exchange (ETDEWEB)

Goodwin, G.M. [Oak Ridge National Lab., TN (United States)

1997-12-01

The author has established a range of compositions for these alloys within which hot cracking resistance is very good, and within which cold cracking can be avoided in many instances by careful control of welding conditions, particularly preheat and postweld heat treatment. For example, crack-free butt welds have been produced for the first time in 12-mm thick wrought Fe{sub 3}Al plate. Cold cracking, however, still remains an issue in many cases. The author has developed a commercial source for composite weld filler metals spanning a wide range of achievable aluminum levels, and are pursuing the application of these filler metals in a variety of industrial environments. Welding techniques have been developed for both the gas tungsten arc and gas metal arc processes, and preliminary work has been done to utilize the wire arc process for coating of boiler tubes. Clad specimens have been prepared for environmental testing in-house, and a number of components have been modified and placed in service in operating kraft recovery boilers. In collaboration with a commercial producer of spiral weld overlay tubing, the author is attempting to utilize the new filler metals for this novel application.

Improving Management Performance of P2PSIP for Mobile Sensing in Wireless Overlays

Directory of Open Access Journals (Sweden)

José María Pousada-Carballo

2013-11-01

Full Text Available Future wireless communications are heading towards an all-Internet Protocol (all-IP design, and will rely on the Session Initiation Protocol (SIP to manage services, such as voice over IP (VoIP. The centralized architecture of traditional SIP has numerous disadvantages for mobile ad hoc services that may be possibly overcome by advanced peer-to-peer (P2P technologies initially developed for the Internet. In the context of mobile sensing, P2PSIP protocols facilitate decentralized and fast communications with sensor-enabled terminals. Nevertheless, in order to make P2PSIP protocols feasible in mobile sensing networks, it is necessary to minimize overhead transmissions for signaling purposes, which reduces the battery lifetime. In this paper, we present a solution to improve the management of wireless overlay networks by defining an adaptive algorithm for the calculation of refresh time. The main advantage of the proposed algorithm is that it takes into account new parameters, such as the delay between nodes, and provides satisfactory performance and reliability levels at a much lower management overhead than previous approaches. The proposed solution can be applied to many structured P2P overlays or P2PSIP protocols. We evaluate it with Kademlia-based distributed hash tables (DHT and dSIP.

Improving management performance of P2PSIP for mobile sensing in wireless overlays.

Science.gov (United States)

Sendín-Raña, Pablo; González-Castaño, Francisco Javier; Gómez-Cuba, Felipe; Asorey-Cacheda, Rafael; Pousada-Carballo, José María

2013-11-08

Future wireless communications are heading towards an all-Internet Protocol (all-IP) design, and will rely on the Session Initiation Protocol (SIP) to manage services, such as voice over IP (VoIP). The centralized architecture of traditional SIP has numerous disadvantages for mobile ad hoc services that may be possibly overcome by advanced peer-to-peer (P2P) technologies initially developed for the Internet. In the context of mobile sensing, P2PSIP protocols facilitate decentralized and fast communications with sensor-enabled terminals. Nevertheless, in order to make P2PSIP protocols feasible in mobile sensing networks, it is necessary to minimize overhead transmissions for signaling purposes, which reduces the battery lifetime. In this paper, we present a solution to improve the management of wireless overlay networks by defining an adaptive algorithm for the calculation of refresh time. The main advantage of the proposed algorithm is that it takes into account new parameters, such as the delay between nodes, and provides satisfactory performance and reliability levels at a much lower management overhead than previous approaches. The proposed solution can be applied to many structured P2P overlays or P2PSIP protocols. We evaluate it with Kademlia-based distributed hash tables (DHT) and dSIP.

Hot Corrosion of Inconel 625 Overlay Weld Cladding in Smelting Off-Gas Environment

Science.gov (United States)

Mohammadi Zahrani, E.; Alfantazi, A. M.

2013-10-01

Degradation mechanisms and hot corrosion behavior of weld overlay alloy 625 were studied. Phase structure, morphology, thermal behavior, and chemical composition of deposited salt mixture on the weld overlay were characterized utilizing XRD, SEM/EDX, DTA, and ICP/OES, respectively. Dilution level of Fe in the weldment, dendritic structure, and degradation mechanisms of the weld were investigated. A molten phase formed on the weld layer at the operating temperature range of the boiler, which led to the hot corrosion attack in the water wall and the ultimate failure. Open circuit potential and weight-loss measurements and potentiodynamic polarization were carried out to study the hot corrosion behavior of the weld in the simulated molten salt medium at 873 K, 973 K, and 1073 K (600 °C, 700 °C, and 800 °C). Internal oxidation and sulfidation plus pitting corrosion were identified as the main hot corrosion mechanisms in the weld and boiler tubes. The presence of a significant amount of Fe made the dendritic structure of the weld susceptible to preferential corrosion. Preferentially corroded (Mo, Nb)-depleted dendrite cores acted as potential sites for crack initiation from the surface layer. The penetration of the molten phase into the cracks accelerated the cracks' propagation mainly through the dendrite cores and further crack branching/widening.

Variables affecting viral plaque formation in microculture plaque assays using homologous antibody in a liquid overlay.

Science.gov (United States)

Randhawa, A S; Stanton, G J; Green, J A; Baron, S

1977-05-01

A liquid antibody microculture plaque assay and the variables that govern its effectiveness are described. The assay is based on the principle that low concentrations of homologous antibody can inhibit secondary plaque formation without inhibiting formation of primary plaques. Thus, clear plaques that followed a linear dose response were produced. The assay was found to be more rapid, less cumbersome, and less expensive than assays using agar overlays and larger tissue culture plates. It was reproducible, quantitative, and had about the same sensitivity as the agar overlay technique in measuring infectious coxsackievirus type B-3. It was more sensitive in assaying adenovirus type 3 and Western equine encephalomyelitis, vesicular stomatitis, Semliki forest, Sendai, Sindbis, and Newcastle disease viruses than were liquid, carboxymethylcellulose, and methylcellulose microculture plaque assays. The variables influencing sensitivity and accuracy, as determined by using coxsackievirus type B-3, were: (i) the inoculum volume of virus; (ii) the incubation period of virus; and (iii) the incubation temperature.

Oral rehabilitation of a patient with amelogenesis imperfecta using removable overlay denture: a clinical report.

Science.gov (United States)

Ghodsi, S; Rasaeipour, S; Vojdani, M

2012-03-01

The aim of this study was oral rehabilitation of 17-year old patient with amelogenesis imperfecta using removable overlay denture in order to satisfy her esthetic and functional expectations and enhance her self-image. Amelogenesis imperfecta (AI) is a group of genetic disorders that primarily affect the quality and quantity of amelogenesis in both primary and permanent dentitions. The main clinical characteristics are severe attrition, tooth sensitivity and unesthetic appearance. This clinical report illustrates the oral rehabilitation of a 17-year-old girl with hypoplastic-hypomature type of AI with cobalt-chromium (Co-Cr) overlay removable partial denture (ORPD) that is one of the most economical and biocompatible replacements for noble metal and nickel-chromium (Ni-Cr) alloy. The presented case report suggests that Co-Cr ORPD can be a good temporary or even permanent treatment option for AI patients with limited budget, low esthetic concerns or medical limitations. There are major advantages in cast metal ORPDs; they are simpler, less traumatic and less expensive than fixed prosthetic options. This case report supports their use in patients with amelogenesis imperfecta.

Sputtering of thin benzene and polystyrene overlayers by keV Ga and C60 bombardment

International Nuclear Information System (INIS)

Czerwinski, B.; Delcorte, A.; Garrison, B.J.; Samson, R.; Winograd, N.; Postawa, Z.

2006-01-01

The mechanisms of ion-stimulated desorption of thin organic overlayers deposited on metal substrates by mono- and polyatomic projectiles are examined using molecular dynamics (MD) computer simulations. A monolayer of polystyrene tetramers (PS4) physisorbed on Ag{1 1 1} is irradiated by 15 keV Ga and C 60 projectiles at normal incidence. The results are compared with the data obtained for a benzene overlayer to investigate the differences in sputtering mechanisms of weakly and strongly bound organic molecules. The results indicate that the sputtering yield decreases with the increase of the binding energy and the average kinetic energy of parent molecules is shifted toward higher kinetic energy. Although the total sputtering yield of organic material is larger for 15 keV C 60 , the impact of this projectile leads to a significant fragmentation of ejected species. As a result, the yield of the intact molecules is comparable for C 60 and Ga projectiles. Our data indicate that chemical analysis of the very thin organic films performed by detection of sputtered neutrals will not benefit from the use of C 60 projectiles

Decoupling of Solid 4He Layers under the Superfluid Overlayer

Science.gov (United States)

Ishibashi, Kenji; Hiraide, Jo; Taniguchi, Junko; Suzuki, Masaru

2018-03-01

It has been reported that in a large oscillation amplitude, the mass decoupling of multilayer 4He films adsorbed on graphite results from the depinning of the second solid atomic layer. This decoupling suddenly vanishes below a certain low temperature TD due to the cancellation of mass decoupling by the superfluid counterflow of the the overylayer. We studied the relaxation of the depinned state at various temperatures, after reduction of oscillation amplitude below TD . It was found that above the superfluid transition temperature the mass decoupling revives with a relaxation time of several 100 s. It strongly supports that the depinned state of the second solid atomic layer remains underneath the superfluid overlayer.

Critical temperatures of random iron–cobalt overlayers on the fcc-Cu(001) substrate

Czech Academy of Sciences Publication Activity Database

Mašín, Martin; Bergqvist, L.; Kudrnovský, Josef; Kotrla, Miroslav; Drchal, Václav

2013-01-01

Roč. 26, č. 4 (2013), s. 809-812 ISSN 1557-1939. [International Conference on Superconductivity and Magnetism (ICSM) /3./. Istanbul, 29.04.2012-04.05.2012] R&D Projects: GA ČR GA202/09/0775 Institutional support: RVO:68378271 Keywords : Curie temperature * random overlayer * Heisenberg Hamiltonian * first principles * Monte Carlo simulations Subject RIV: BE - Theoretical Physics Impact factor: 0.930, year: 2013 http://link.springer.com/article/10.1007/s10948-012-2084-1

Clinical Applications of a CT Window Blending Algorithm: RADIO (Relative Attenuation-Dependent Image Overlay).

Science.gov (United States)

Mandell, Jacob C; Khurana, Bharti; Folio, Les R; Hyun, Hyewon; Smith, Stacy E; Dunne, Ruth M; Andriole, Katherine P

2017-06-01

A methodology is described using Adobe Photoshop and Adobe Extendscript to process DICOM images with a Relative Attenuation-Dependent Image Overlay (RADIO) algorithm to visualize the full dynamic range of CT in one view, without requiring a change in window and level settings. The potential clinical uses for such an algorithm are described in a pictorial overview, including applications in emergency radiology, oncologic imaging, and nuclear medicine and molecular imaging.

Characterization of the Interface of an Alloy 625 Overlay on Steels Using Nanoindentation

Science.gov (United States)

Dai, Tao; Lippold, John

2018-06-01

Industry standards require postweld heat treatment (PWHT) to reduce the heat-affected zone hardness of steels such as F22 (2.25Cr-1Mo) and AISI 8630 overlaid (clad) with Alloy 625 weld metal. PWHT results in carbon diffusion and accumulation at the interface between the steel and overlay. The accumulation of carbon in a planar solidification growth zone adjacent to the fusion boundary results in high hardness and the potential for hydrogen-assisted cracking. The planar growth zone (PGZ) is so narrow that normal Vickers hardness testing cannot fully reveal the hardness distribution in this zone. This study focused on the application of nanoindentation to characterize the hardness in the narrow microstructural regions adjacent to the fusion boundary. The development of nanohardness maps revealed that the PGZ is not necessarily the region that exhibits peak hardness after PWHT. The highest hardness values were associated with clusters of M7C3 carbides in specific subregions in the PGZ and also in the partially-mixed zone adjacent to the fusion boundary or in steel "swirl" structures. It was also confirmed in this study that nanohardness has a linear correlation with Vickers hardness values. The results presented here provide new insight into the role of carbon diffusion during PWHT and its effect on interface embrittlement associated with Alloy 625 overlays on steel.

Pavement structure mechanics response of flexible on semi-flexible overlay that based on the old cement concrete pavement damage

Directory of Open Access Journals (Sweden)

Jiang Ruinan

2015-01-01

Full Text Available The old cement pavement damage status directly affect the design of the paving renovation. Based on the state of the old road investigation, combined with the research data at home and abroad, use the control index that average deflection, deflection value and CBR value to determine the reasonable time to overlay. Draw up the typical pavement structure according to the principle of combination of old cement pavement overlay structure design, and calculated that the tensile stress and shear stress in asphalt layer ,semi-flexible layer and the tensile in the old cement pavement adopting BISA3.0 statics finite element analysis model when modulus in the old road was diminishing. Use the computed result to analyses the influence of old road damage condition the influence of pavement structure.

Interactive overlays of journals and the measurement of interdisciplinarity on the basis of aggregated journal-journal citations

NARCIS (Netherlands)

Leydesdorff, L.; Rafols, I.; Chen, C.

2013-01-01

Using the option Analyze Results with the Web of Science, one can directly generate overlays onto global journal maps of science. The maps are based on the 10,000+ journals contained in the Journal Citation Reports (JCR) of the Science and Social Sciences Citation Indices (2011). The disciplinary

The Effects of Letter Spacing and Coloured Overlays on Reading Speed and Accuracy in Adult Dyslexia

Science.gov (United States)

Sjoblom, Amanda M.; Eaton, Elizabeth; Stagg, Steven D.

2016-01-01

Background: Zorzi et al. (2012, Proc. Natl. Acad. Sci. U.S.A., 109, 11455) found evidence that extra-large letter spacing aids children with dyslexia, but the evidence for the coloured overlays is contradictory (e.g., Henderson et al., 2013, "J. Res. Special Educ. Needs," 13, 57; Wilkins, 2002, "Ophthalmic Physiol. Opt.," 22,…

First-principles study of thermodynamical properties of random magnetic overlayers on fcc-Cu(001) substrate

Czech Academy of Sciences Publication Activity Database

Mašín, Martin; Bergqvist, L.; Kudrnovský, Josef; Kotrla, Miroslav; Drchal, Václav

2013-01-01

Roč. 87, č. 7 (2013), "075452-1"-"075452-7" ISSN 1098-0121 R&D Projects: GA ČR GA202/09/0775 Institutional support: RVO:68378271 Keywords : Curie temperature * random overlayer * Heisenberg Hamiltonian * first principles * Monte Carlo simulations * magnon spectra Subject RIV: BE - Theoretical Physics Impact factor: 3.664, year: 2013 http://prb.aps.org/abstract/PRB/v87/i7/e075452

Optimización multiobjetivo para enrutamiento multicast en overlay networks utilizando algoritmos evolutivos Multiobjective Optimization for Multicast Routing in Overlay Networks using Evolutionary Algorithms

Directory of Open Access Journals (Sweden)

Juan Carlos Montoya M.

2008-06-01

Full Text Available Multicast juega un papel muy importante para soportar una nueva generación de aplicaciones. En la actualidad y por diferentes razones, técnicas y no técnicas, multicast IP no ha sido totalmente adoptado en Internet. Durante los últimos a˜nos, un área de investigación activa es la de implementar este tipo de tráfico desde la perspectiva del nivel de aplicación, donde la funcionalidad de multicast no es responsabilidad de los enrutadores sino de los hosts, a lo que se le conoce como Multicast Overlay Network (MON. En este artículo se plantea el enrutamiento en MON como un problema de Optimización Multiobjetivo (MOP donde se optimizan dos funciones: 1 el retardo total extremo a extremo del árbol multicast, y 2 la máxima utilización de los enlaces. La optimización simultánea de estas dos funciones es un problema NP completo y para resolverlo se propone utilizar Algoritmos Evolutivos Multiobjetivos (MOEA, específicamente NSGAIMulticast plays an important role in supporting a new generation of applications. At present and for different reasons, technical and non–technical, multicast IP hasn’t yet been totally adopted for Internet. During recent years, an active area of research is that of implementing this kind of traffic in the application layer where the multicast functionality isn´t a responsibility of the routers but that of the hosts, which we know as Multicast Overlay Networks (MON. In this article, routing in an MON is put forward as a multiobjective optimization problem (MOP where two functions are optimized: 1 the total end to end delay of the multicast tree and 2 the maximum link utilization. The simultaneous optimization of these two functions is an NP–Complete problem and to solve this we suggest using Multiobjective Evolutionary Algorithms (MOEA, specifically NSGA–II.

Journal maps, interactive overlays, and the measurement of interdisciplinarity on the basis of Scopus data (1996-2012)

NARCIS (Netherlands)

Leydesdorff, L.; de Moya-Anegón, F.; Guerrero-Bote, V.P.

2015-01-01

Using Scopus data, we construct a global map of science based on aggregated journal-journal citations from 1996-2012 (N of journals = 20,554). This base map enables users to overlay downloads from Scopus interactively. Using a single year (e.g., 2012), results can be compared with mappings based on

Magnetism of a Co monolayer on Pt(111) capped by overlayers of 5 d elements: A spin-model study

Science.gov (United States)

Simon, E.; Rózsa, L.; Palotás, K.; Szunyogh, L.

2018-04-01

Using first-principles calculations, we study the magnetic properties of a Co monolayer on a Pt(111) surface with a capping monolayer of selected 5 d elements (Re, Os, Ir, Pt, and Au). First we determine the tensorial exchange interactions and magnetic anisotropies characterizing the Co monolayer for all considered systems. We find a close relationship between the magnetic moment of the Co atoms and the nearest-neighbor isotropic exchange interaction, which is attributed to the electronic hybridization between the Co and the capping layers, in the spirit of the Stoner picture of ferromagnetism. The Dzyaloshinskii-Moriya interaction is decreased for all overlayers compared to the uncapped Co/Pt(111) system, while even the sign of the Dzyaloshinskii-Moriya interaction changes in the case of the Ir overlayer. We conclude that the variation of the Dzyaloshinskii-Moriya interaction is well correlated with the change of the magnetic anisotropy energy and of the orbital moment anisotropy. The unique influence of the Ir overlayer on the Dzyaloshinskii-Moriya interaction is traced by scaling the strength of the spin-orbit coupling of the Ir atoms in Ir/Co/Pt(111) and by changing the Ir concentration in the Au1 -xIrx /Co/Pt(111) system. Our spin dynamics simulations indicate that the magnetic ground state of Re/Co/Pt(111) thin film is a spin spiral with a tilted normal vector, while the other systems are ferromagnetic.

Novel WLL Architecture Based on Color Pixel Multiple Access Implemented on a Terrestrial Video Network as the Overlay

DEFF Research Database (Denmark)

Sanyal, Rajarshi; Cianca, Ernestina; Prasad, Ramjee

2013-01-01

Wireless Local Loop deployments are based on the traditional cellular technologies. However there are limitations in terms of intricacy, cost and time to deploy .In this paper, the authors introduce a Wireless Local Loop architecture employing the proposed CPMA technique on existing overlay video...

Microsegregation and Precipitates in Inconel 625 Arc Weld Overlay Coatings on Boiler Pipes / Mikrosegregacja I Wydzielenia W Powłokach Ze Stopu Inconel 625 Napawanych Łukowo Na Rury Kotłowe

Directory of Open Access Journals (Sweden)

Rozmus-Górnikowska M.

2015-12-01

Full Text Available The aim of this work was to investigate the microsegregation and precipitates formed due to segregation in Inconel 625 arc weld overlay coatings on boiler pipes. Examination of microsegregation and precipitates were carried out by means of a scanning electron microscope (SEM equipped with an EDS detector as well as a transmission electron microscope (TEM equipped with a HAADF (STEM and an EDS detectors. The presence of precipitations in the weld overlay was also confirmed with X-ray diffraction analysis (XRD of residue in the form of powder that remained after the electrolytic dissolution of weld overlay matrix.

Successful treatment of direct carotid-cavernous fistula in a patient with Ehlers-Danlos syndrome type IV without arterial puncture: the transvenous triple-overlay embolization (TAILOREd) technique.

Science.gov (United States)

Huynh, Thien J; Morton, Ryan P; Levitt, Michael R; Ghodke, Basavaraj V; Wink, Onno; Hallam, Danial K

2017-08-18

We report successful transvenous treatment of direct carotid-cavernous fistula in a patient with Ehlers-Danlos syndrome type IV using a novel triple-overlay embolization (TAILOREd) technique without the need for arterial puncture, which is known to be highly risky in this patient group. The TAILOREd technique allowed for successful treatment using preoperative MR angiography as a three-dimensional overlay roadmap combined with cone beam CT and live fluoroscopy, precluding the need for an arterial puncture. 2017 BMJ Publishing Group Ltd.

Determination of welding parameters for execution of weld overlayer on PWR nuclear reactor nozzles

International Nuclear Information System (INIS)

Ribeiro, Gabriela M.; Lima, Luciana I.; Quinan, Marco A.; Schvartzman, Monica M.

2009-01-01

In the PWR reactors, nickel based dissimilar welds have been presented susceptibilities the stress corrosion (S C). For the mitigation the problem a deposition of weld layers on the external surface of the nozzle is an alternative, viewing to provoke the compression of the region subjected to S C. This paper presents a preliminary study on the determination of welding parameters to obtain these welding overlayers. Welding depositions were performed on a test piece welded with nickel 182 alloy, simulating the conditions of a nozzle used in a PWR nuclear power plant. The welding process was the GTAW (Gas Tungsten Arc Welding), and a nickel 52 alloy as addition material. The overlayers were performed on the base metals, carbon steel an stainless steel, changing the welding parameters and verifying the the time of each weld filet. After that, the samples were micro structurally characterized. The macro structures and the microstructures obtained through optical microscopy and Vickers microhardness are presented. The preliminary results make evident the good weld quality. However, a small weld parameters influence used in the base material microstructure (carbon steel and stainless steel). The obtained results in this study will be used as reference in the construction of a mock up which will simulate all the conditions of a pressurizer nozzle of PWR reactor

An efficient mechanism for dynamic multicast traffic grooming in overlay IP/MPLS over WDM networks

Science.gov (United States)

Yu, Xiaojun; Xiao, Gaoxi; Cheng, Tee Hiang

2014-08-01

This paper proposes an efficient overlay multicast provisioning (OMP) mechanism for dynamic multicast traffic grooming in overlay IP/MPLS over WDM networks. To facilitate request provisioning, OMP jointly utilizes a data learning (DL) scheme on the IP/MPLS layer for logical link cost estimation, and a lightpath fragmentation (LPF) based method on the WDM layer for improving resource sharing in grooming process. Extensive simulations are carried out to evaluate the performance of OMP mechanism under different traffic loads, with either limited or unlimited port resources. Simulation results demonstrate that OMP significantly outperforms the existing methods. To evaluate the respective influences of the DL scheme and the LPF method on OMP performance, provisioning mechanisms only utilizing either the IP/MPLS layer DL scheme or the WDM layer LPF method are also devised. Comparison results show that both DL and LPF methods help improve OMP blocking performance, and contribution from the DL scheme is more significant when the fixed routing and first-fit wavelength assignment (RWA) strategy is adopted on the WDM layer. Effects of a few other factors, including definition of connection cost to be reported by the WDM layer to the IP/MPLS layer and WDM-layer routing method, on OMP performance are also evaluated.

Temperature coefficient of elastic constants of SiO2 over-layer on LiNbO3 for a temperature stable SAW device

International Nuclear Information System (INIS)

Tomar, Monika; Gupta, Vinay; Sreenivas, K

2003-01-01

The influence of sputtered SiO 2 over-layer on the SAW propagation characteristics of a 128 deg. rotated Y-cut X-propagating lithium niobate SAW filter has been studied. Experimentally measured SAW phase velocity and temperature coefficient of delay (TCD), with varying SiO 2 over-layer thickness, show a significant deviation from the theoretically calculated values using the bulk material parameters of SiO 2 . The observed deviation is attributed to the differences in the material parameters (density, elastic and dielectric constants and their temperature coefficient) of the deposited SiO 2 over-layer. The density and the dielectric constant of the deposited SiO 2 layer were determined separately, and the elastic constants and their temperature coefficients were estimated by fitting the experimental velocity and TCD data, respectively. The deviation in the dielectric constant and the density in comparison to the bulk was insignificant, and the estimated values of the elastic constants (C 11 = 0.75x10 11 N m -2 and C 44 0.225x10 11 N m -2 ) were found to be lower, and the respective temperature coefficients (5.0x10 -4 deg C -1 and 2.0x10 -4 deg C -1 ) were high in comparison to the bulk material parameters

Effects of post weld heat treatment and weld overlay on the residual stress and mechanical properties in dissimilar metal weld

International Nuclear Information System (INIS)

Campos, Wagner R.C.; Ribeiro, Vladimir S.; Vilela, Alisson H.F.; Almeida, Camila R.O.; Rabello, Emerson G.

2017-01-01

The object of this work is a dissimilar metal weld (DMW) pipe joint between carbon steel (A-106 Gr B) and stainless steel (A-312 TP316L) pipes and filler metals of Nickel alloy (82/182), which find wide application in the field of chemical, oil, petroleum industries, fossil fuel and nuclear power plant. A lot of the failures that have occurred in dissimilar metal welded are affected greatly by residual stresses. Residual stress is often a cause of premature failure of critical components under normal operation of welded components. Several methods have been tested and developed for removing the tensile residual stresses. The aim of the methods is to reduce the tensile stress state or to create compressive stresses at a predefined area, such as the inner surface of a welded pipe joint. Post weld heat treatment (PWHT) and weld overlay (WOL) are two of the residual stress mitigation methods which reduce the tensile residual stress, create compressive stresses and arrest crack initiation and crack growth. The technique used to substantially minimized or eliminated this failure development in the root weld is the post weld heat treatments (stress relief heat treatment) or the weld overlay. In this work was studied the effectiveness in reducing internal residual stress in dissimilar metal welded pipe joints subjected to post weld heat treatment and weld overlay, measurement by hole-drilling strain-gage method of stress relaxation. Also held was mechanical characterization of the welded pipe joint itself. (author)

Effects of post weld heat treatment and weld overlay on the residual stress and mechanical properties in dissimilar metal weld

Energy Technology Data Exchange (ETDEWEB)

Campos, Wagner R.C.; Ribeiro, Vladimir S.; Vilela, Alisson H.F.; Almeida, Camila R.O.; Rabello, Emerson G., E-mail: wrcc@cdtn.br, E-mail: camilarezende.cr@gmail.com, E-mail: egr@cdtn.br, E-mail: vladimirsoler@hotmail.com, E-mail: ahfv02@outlook.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

The object of this work is a dissimilar metal weld (DMW) pipe joint between carbon steel (A-106 Gr B) and stainless steel (A-312 TP316L) pipes and filler metals of Nickel alloy (82/182), which find wide application in the field of chemical, oil, petroleum industries, fossil fuel and nuclear power plant. A lot of the failures that have occurred in dissimilar metal welded are affected greatly by residual stresses. Residual stress is often a cause of premature failure of critical components under normal operation of welded components. Several methods have been tested and developed for removing the tensile residual stresses. The aim of the methods is to reduce the tensile stress state or to create compressive stresses at a predefined area, such as the inner surface of a welded pipe joint. Post weld heat treatment (PWHT) and weld overlay (WOL) are two of the residual stress mitigation methods which reduce the tensile residual stress, create compressive stresses and arrest crack initiation and crack growth. The technique used to substantially minimized or eliminated this failure development in the root weld is the post weld heat treatments (stress relief heat treatment) or the weld overlay. In this work was studied the effectiveness in reducing internal residual stress in dissimilar metal welded pipe joints subjected to post weld heat treatment and weld overlay, measurement by hole-drilling strain-gage method of stress relaxation. Also held was mechanical characterization of the welded pipe joint itself. (author)

Digitized video subject positioning and surveillance system for PET

International Nuclear Information System (INIS)

Picard, Y.; Thompson, C.J.

1995-01-01

Head motion is a significant contribution to the degradation of image quality of Positron Emission Tomography (PET) studies. Images from different studies must also be realigned digitally to be correlated when the subject position has changed. These constraints could be eliminated if the subject's head position could be monitored accurately. The authors have developed a video camera-based surveillance system to monitor the head position and motion of subjects undergoing PET studies. The system consists of two CCD (charge-coupled device) cameras placed orthogonally such that both face and profile views of the subject's head are displayed side by side on an RGB video monitor. Digitized images overlay the live images in contrasting colors on the monitor. Such a system can be used to (1) position the subject in the field of view (FOV) by displaying the position of the scanner's slices on the monitor along with the current subject position, (2) monitor head motion and alert the operator of any motion during the study and (3) reposition the subject accurately for subsequent studies by displaying the previous position along with the current position in a contrasting color

Ab initio study of Co and Ni under uniaxial and biaxial loading and in epitaxial overlayers

Czech Academy of Sciences Publication Activity Database

Zelený, Martin; Legut, Dominik; Šob, Mojmír

2008-01-01

Roč. 78, č. 22 (2008), 224105/1-224105/11 ISSN 1098-0121 R&D Projects: GA ČR GD106/05/H008; GA AV ČR IAA1041302; GA MŠk OC 147 Institutional research plan: CEZ:AV0Z20410507 Keywords : ab initio calculations * epitaxial overlayers * uniaxial and biaxial loading Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.322, year: 2008

Reaction of Rb and oxygen overlayers with single-crystalline Bi2Sr2CaCu2O/sub 8+//sub δ/ superconductors

International Nuclear Information System (INIS)

Lindberg, P.A.P.; Shen, Z.; Wells, B.O.; Dessau, D.S.; Mitzi, D.B.; Lindau, I.; Spicer, W.E.; Kapitulnik, A.

1989-01-01

Single crystals of Bi 2 Sr 2 CaCu 2 O/sub 8+//sub δ/ superconductors, in situ cleaved and modified by Rb and oxygen overlayers, have been studied using ultraviolet and x-ray photoemission spectroscopy. The core-level results show that Rb strongly reacts with the Bi and O states, while the Cu and Sr states are left unchanged. This observation strongly indicates that the Bi-O plane forms the surface layer. Subsequent exposure to oxygen results in new oxygen states at the surface as monitored by the O 1s core-level data. For both Rb and oxygen overlayers the valence-band spectra are severely altered. In particular, new valence-band states, presumably of oxygen character, are formed

Alkali-resistant low-temperature atomic-layer-deposited oxides for optical fiber sensor overlays

Science.gov (United States)

Kosiel, K.; Dominik, M.; Ściślewska, I.; Kalisz, M.; Guziewicz, M.; Gołaszewska, K.; Niedziółka-Jonsson, J.; Bock, W. J.; Śmietana, M.

2018-04-01

This paper presents an investigation of properties of selected metallic oxides deposited at a low temperature (100 °C) by atomic layer deposition (ALD) technique, relating to their applicability as thin overlays for optical fiber sensors resistant in alkaline environments. Hafnium oxide (Hf x O y with y/x approx. 2.70), tantalum oxide (Ta x O y with y/x approx. 2.75) and zirconium oxide (Zr x O y with y/x approx. 2.07), which deposition was based, respectively, on tetrakis(ethylmethyl)hafnium, tantalum pentachloride and tetrakis(ethylmethyl)zirconium with deionized water, were tested as thin layers on planar Si (100) and glass substrates. Growth per cycle (GPC) in the ALD processes was 0.133-0.150 nm/cycle. Run-to-run GPC reproducibility of the ALD processes was best for Hf x O y (0.145 ± 0.001 nm/cycle) and the poorest for Ta x O y (0.133 ± 0.003 nm/cycle). Refractive indices n of the layers were 2.00-2.10 (at the wavelength λ = 632 nm), with negligible k value (at λ for 240-930 nm). The oxides examined by x-ray diffractometry proved to be amorphous, with only small addition of crystalline phases for the Zr x O y . The surfaces of the oxides had grainy but smooth topographies with root-mean square roughness ˜0.5 nm (at 10 × 10 μm2 area) according to atomic force microscopy. Ellipsometric measurements, by contrast, suggest rougher surfaces for the Zr x O y layers. The surfaces were also slightly rougher on the glass-based samples than on the Si-based ones. Nanohardness and Young modules were 4.90-8.64 GPa and 83.7-104.4 GPa, respectively. The tests of scratch resistance revealed better tribological properties for the Hf x O y and the Ta x O y than for the Zr x O y . The surfaces were hydrophilic, with wetting angles of 52.5°-62.9°. The planar oxides on Si, being resistive even to concentrated alkali (pH 14), proved to be significantly more alkali-resistive than Al2O3. The Ta x O y overlay was deposited on long-period grating sensor induced in optical

Application of function parametrization for radial plasma position calibration in Aditya-U

International Nuclear Information System (INIS)

Kumar, Sameer; Daniel, Raju

2017-01-01

Calibration experiments to simulate the movement of plasma channel in tokamak ADITYA-U in the horizontal direction (i.e., in-board and out-board movement), are carried out by setting up current carrying conductor inside the vacuum vessel. This conductor is energized with a known current (through a capacitor bank system) and the response at various magnetic pickup coils is recorded. For various radial position of this conductor and for known current, the pickup coil response database is generated. Function parameterization method (FP) is utilized to generate an input-output relation (regression function), in which the input is magnetic pickup coil's signal and the output is the location of conductor. In the real situation, conductor is replaced by the plasma channel and hence, the radial movement of this channel would be directly known from the regression function obtained from FP. Detailed analysis of FP along with the error estimates would be presented in this paper. (author)

Electronic and structural characterizations of unreconstructed {0001} surfaces and the growth of graphene overlayers

International Nuclear Information System (INIS)

Emtsev, Konstantin

2009-01-01

The present work is focused on the characterization of the clean unreconstructed SiC{0001} surfaces and the growth of graphene overlayers thereon. Electronic properties of SiC surfaces and their interfaces with graphene and few layer graphene films were investigated by means of angle resolved photoelectron spectroscopy, X-ray photoelectron spectroscopy and low energy electron diffraction. Structural characterizations of the epitaxial graphene films grown on SiC were carried out by atomic force microscopy and low energy electron microscopy. Supplementary data was obtained by scanning tunneling microscopy. (orig.)

The Effect of pH on Slurry Erosion-Corrosion of Tungsten Carbide Overlays Alloyed with Ru

Science.gov (United States)

Nelwalani, Ndivhuwo B.; van der Merwe, Josias W.

2018-02-01

The aim of the study was to determine the effect of Ru additions to WC-Fe overlays when exposed to low pH slurry erosion conditions. These overlays were applied through Plasma Transferred Arc, and the original bulk Ru powder concentrations varied from 0.5 to 5 wt.%. A slurry jet impingement erosion-corrosion test rig was used to evaluate wear, and electrochemical measurements were performed to characterize the corrosion properties. The slurry mixtures contained silica sand and synthetic mine water. The pH was varied between 3 and 6.5 for the slurry erosion tests and lowered further for the corrosion characterization. Samples were examined optically and with a scanning electron microscope using energy-dispersive x-ray spectroscopy. X-ray diffraction analysis was used to determine the phases present. For the slurry erosion-corrosion results at the pH of 6.5, addition of Ru did not show a decrease in erosion-corrosion rates. However, when the pH was decreased to 3, by the addition of HCl, Ru improved the resistance. From the electrochemistry, it was also clear that Ru additions improved the corrosion resistance, but more than 1 wt.% Ru was required. At very low pH levels, the presence of Ru was not able to prevent corrosion.

RESTORING A DAMAGED 16-YEAR -OLD INSULATING POLYMER CONCRETE DIKE OVERLAY: REPAIR MATERIALS AND TECHNOLOGIES.

Energy Technology Data Exchange (ETDEWEB)

SUGAMA,T.

2007-01-01

The objective of this program was to design and formulate organic polymer-based material systems suitable for repairing and restoring the overlay panels of insulating lightweight polymer concrete (ILPC) from the concrete floor and slope wall of a dike at KeySpan liquefied natural gas (LNG) facility in Greenpoint, Brooklyn, NY, just over sixteen years ago. It also included undertaking a small-scale field demonstration to ensure that the commercial repairing technologies were applicable to the designed and formulated materials.

Accelerated testing for studying pavement design and performance (FY 2004) : thin bonded rigid overlay on PCCP and HMA (CISL experiment no. 13).

Science.gov (United States)

2009-03-01

The thirteenth full-scale Accelerated Pavement Test (APT) experiment at the Civil Infrastructure Laboratory (CISL) : of Kansas State University aimed to determine the response and the failure mode of thin concrete overlays. Four : pavement structures...

ATLAS Simulation using Real Data: Embedding and Overlay

Science.gov (United States)

Haas, Andrew; ATLAS Collaboration

2017-10-01

For some physics processes studied with the ATLAS detector, a more accurate simulation in some respects can be achieved by including real data into simulated events, with substantial potential improvements in the CPU, disk space, and memory usage of the standard simulation configuration, at the cost of significant database and networking challenges. Real proton-proton background events can be overlaid (at the detector digitization output stage) on a simulated hard-scatter process, to account for pileup background (from nearby bunch crossings), cavern background, and detector noise. A similar method is used to account for the large underlying event from heavy ion collisions, rather than directly simulating the full collision. Embedding replaces the muons found in Z→μμ decays in data with simulated taus at the same 4-momenta, thus preserving the underlying event and pileup from the original data event. In all these cases, care must be taken to exactly match detector conditions (beamspot, magnetic fields, alignments, dead sensors, etc.) between the real data event and the simulation. We will discuss the status of these overlay and embedding techniques within ATLAS software and computing.

Secret Forwarding of Events over Distributed Publish/Subscribe Overlay Network.

Science.gov (United States)

Yoon, Young; Kim, Beom Heyn

2016-01-01

Publish/subscribe is a communication paradigm where loosely-coupled clients communicate in an asynchronous fashion. Publish/subscribe supports the flexible development of large-scale, event-driven and ubiquitous systems. Publish/subscribe is prevalent in a number of application domains such as social networking, distributed business processes and real-time mission-critical systems. Many publish/subscribe applications are sensitive to message loss and violation of privacy. To overcome such issues, we propose a novel method of using secret sharing and replication techniques. This is to reliably and confidentially deliver decryption keys along with encrypted publications even under the presence of several Byzantine brokers across publish/subscribe overlay networks. We also propose a framework for dynamically and strategically allocating broker replicas based on flexibly definable criteria for reliability and performance. Moreover, a thorough evaluation is done through a case study on social networks using the real trace of interactions among Facebook users.

Key Management Schemes for Peer-to-Peer Multimedia Streaming Overlay Networks

Science.gov (United States)

Naranjo, J. A. M.; López-Ramos, J. A.; Casado, L. G.

Key distribution for multimedia live streaming peer-to-peer overlay networks is a field still in its childhood stage. A scheme designed for networks of this kind must seek security and efficiency while keeping in mind the following restrictions: limited bandwidth, continuous playing, great audience size and clients churn. This paper introduces two novel schemes that allow a trade-off between security and efficiency by allowing to dynamically vary the number of levels used in the key hierarchy. These changes are motivated by great variations in audience size, and initiated by decision of the Key Server. Additionally, a comparative study of both is presented, focusing on security and audience size. Results show that larger key hierarchies can supply bigger audiences, but offer less security against statistical attacks. The opposite happens for shorter key hierarchies.

Scopus and Web-of-Science 2012 compared in terms of aggregated journal-journal citation relations: Global maps and interactive overlays

NARCIS (Netherlands)

Leydesdorff, L.; de Moya-Anegón, F.; de Nooy, W.; Noyons, E.

2014-01-01

We compare the networks of aggregated journal-journal citation relations as provided by the Journal Citation Reports (JCR) 2012 of the Science and Social Science Citation Indexes (SCI and SSCI) with similar data for 2012 based on Scopus. First, we develop basemaps and overlays for the two sets

Molecular dynamics simulations of sputtering of organic overlayers by slow, large clusters

International Nuclear Information System (INIS)

Rzeznik, L.; Czerwinski, B.; Garrison, B.J.; Winograd, N.; Postawa, Z.

2008-01-01

The ion-stimulated desorption of organic molecules by impact of large and slow clusters is examined using molecular dynamics (MDs) computer simulations. The investigated system, represented by a monolayer of benzene deposited on Ag{1 1 1}, is irradiated with projectiles composed of thousands of noble gas atoms having a kinetic energy of 0.1-20 eV/atom. The sputtering yield of molecular species and the kinetic energy distributions are analyzed and compared to the results obtain for PS4 overlayer. The simulations demonstrate quite clearly that the physics of ejection by large and slow clusters is distinct from the ejection events stimulated by the popular SIMS clusters, like C 60 , Au 3 and SF 5 at tens of keV energies.

Effect of an absorbent overlay on the residual stress field induced by laser shock processing on aluminum samples

International Nuclear Information System (INIS)

Rubio-Gonzalez, C.; Gomez-Rosas, G.; Ocana, J.L.; Molpeceres, C.; Banderas, A.; Porro, J.; Morales, M.

2006-01-01

Laser shock processing (LSP) or laser shock peening is a new technique for strengthening metals. This process induces a compressive residual stress field, which increases fatigue crack initiation life and reduces fatigue crack growth rate. Specimens of 6061-T6 aluminum alloy are used in this investigation. A convergent lens is used to deliver 2.5 J, 8 ns laser pulses by a Q-switch Nd:YAG laser, operating at 10 Hz. The pulses are focused to a diameter of 1.5 mm onto aluminum samples. Density of 2500 pulses/cm 2 with infrared (1064 nm) radiation was used. The effect of an absorbent overlay on the residual stress field using this LSP setup and this energy level is evaluated. Residual stress distribution as a function of depth is assessed by the hole drilling method. It is observed that the overlay makes the compressive residual stress profile move to the surface. This effect is explained on the basis of the vaporization of the coat layer suppressing thermal effects on the metallic substrate. The effect of coating the specimen surface before LSP treatment may have advantages on improving wear and contact fatigue properties of this aluminum alloy

Secret Forwarding of Events over Distributed Publish/Subscribe Overlay Network.

Directory of Open Access Journals (Sweden)

Young Yoon

Full Text Available Publish/subscribe is a communication paradigm where loosely-coupled clients communicate in an asynchronous fashion. Publish/subscribe supports the flexible development of large-scale, event-driven and ubiquitous systems. Publish/subscribe is prevalent in a number of application domains such as social networking, distributed business processes and real-time mission-critical systems. Many publish/subscribe applications are sensitive to message loss and violation of privacy. To overcome such issues, we propose a novel method of using secret sharing and replication techniques. This is to reliably and confidentially deliver decryption keys along with encrypted publications even under the presence of several Byzantine brokers across publish/subscribe overlay networks. We also propose a framework for dynamically and strategically allocating broker replicas based on flexibly definable criteria for reliability and performance. Moreover, a thorough evaluation is done through a case study on social networks using the real trace of interactions among Facebook users.

Field Investigation of Various Weld Overlays in a Waste Incineration Plant

DEFF Research Database (Denmark)

Montgomery, Melanie; Larsen, O. H.

2005-01-01

A test waterwall was fabricated so that alternatives to alloy 625 could be exposed in the first pass of the waste incineration plant Haderslev. The difference between application method was also a parameter, such that manual welding, machine welding and arc spraycoating of alloy 625 were compared...... which was present in every test panel. It was observed that all the weld overlay test sections behaved similar to machined alloy 625 in that there was general corrosion and pitting corrosion. In addition, alloy 622 also exhibited preferential corrosion with respect to its dendrite structure........ In addition to the test waterwall exposure, the chemical environment from the waste incineration was also monitored by analyzing deposits and corrosion products from various locations in the boiler. These were analyzed with respect to morphology and composition using electron microscopy with EDS analysis...

Overlayer structure of subphthalocyanine derivative deposited on Au (111) surface by a spray-jet technique

International Nuclear Information System (INIS)

Suzuki, Hitoshi; Yamada, Toshiki; Miki, Hideki; Mashiko, Shinro

2006-01-01

A new spray-jet technique was used to deposit subphthalocyanine derivative (chloro[tri-tert-butyl subphthalocyaninato]boron (TBSubPc)) on Au (111) surface in an ultra-high vacuum (UHV) chamber. The deposited molecular overlayer was observed with UHV scanning tunneling microscopy (STM) at 77 K. The STM images showed that TBSubPc molecules formed a stripe pattern with regular spacing, indicating that they preferentially adsorbed along the herringbone structure of the Au (111) surface. This behavior was very similar to that of TBSubPc molecules deposited by thermal evaporation

Mechanism of rigid overlaying of carboniferous strata failure in face mining in the case of multiseams deposit

Czech Academy of Sciences Publication Activity Database

Jiránková, E.; Staš, Lubomír; Kajzar, Vlastimil; Doležalová, Hana

2013-01-01

Roč. 10, č. 2 (2013), s. 189-195 ISSN 1214-9705 R&D Projects: GA MŠk ED2.1.00/03.0082; GA MV VG20102014034 Institutional support: RVO:68145535 Keywords : subsidence trough * rock mass * overlaying strata * longwall mining * tensor stress measurement Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 0.667, year: 2013 http://www.irsm.cas.cz/materialy/acta_content/2013_02/acta_170_08_Jirankova_189-195.pdf

Design and implementation of flexible TWDM-PON with PtP WDM overlay based on WSS for next-generation optical access networks

Science.gov (United States)

Wu, Bin; Yin, Hongxi; Qin, Jie; Liu, Chang; Liu, Anliang; Shao, Qi; Xu, Xiaoguang

2016-09-01

Aiming at the increasing demand of the diversification services and flexible bandwidth allocation of the future access networks, a flexible passive optical network (PON) scheme combining time and wavelength division multiplexing (TWDM) with point-to-point wavelength division multiplexing (PtP WDM) overlay is proposed for the next-generation optical access networks in this paper. A novel software-defined optical distribution network (ODN) structure is designed based on wavelength selective switches (WSS), which can implement wavelength and bandwidth dynamical allocations and suits for the bursty traffic. The experimental results reveal that the TWDM-PON can provide 40 Gb/s downstream and 10 Gb/s upstream data transmission, while the PtP WDM-PON can support 10 GHz point-to-point dedicated bandwidth as the overlay complement system. The wavelengths of the TWDM-PON and PtP WDM-PON are allocated dynamically based on WSS, which verifies the feasibility of the proposed structure.

Temperature coefficient of elastic constants of SiO{sub 2} over-layer on LiNbO{sub 3} for a temperature stable SAW device

Energy Technology Data Exchange (ETDEWEB)

Tomar, Monika; Gupta, Vinay; Sreenivas, K [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

2003-08-07

The influence of sputtered SiO{sub 2} over-layer on the SAW propagation characteristics of a 128 deg. rotated Y-cut X-propagating lithium niobate SAW filter has been studied. Experimentally measured SAW phase velocity and temperature coefficient of delay (TCD), with varying SiO{sub 2} over-layer thickness, show a significant deviation from the theoretically calculated values using the bulk material parameters of SiO{sub 2}. The observed deviation is attributed to the differences in the material parameters (density, elastic and dielectric constants and their temperature coefficient) of the deposited SiO{sub 2} over-layer. The density and the dielectric constant of the deposited SiO{sub 2} layer were determined separately, and the elastic constants and their temperature coefficients were estimated by fitting the experimental velocity and TCD data, respectively. The deviation in the dielectric constant and the density in comparison to the bulk was insignificant, and the estimated values of the elastic constants (C{sub 11} = 0.75x10{sup 11} N m{sup -2} and C{sub 44} 0.225x10{sup 11} N m{sup -2}) were found to be lower, and the respective temperature coefficients (5.0x10{sup -4} deg C{sup -1} and 2.0x10{sup -4} deg C{sup -1}) were high in comparison to the bulk material parameters.

Interplanetary Overlay Network Bundle Protocol Implementation

Science.gov (United States)

Burleigh, Scott C.

2011-01-01

The Interplanetary Overlay Network (ION) system's BP package, an implementation of the Delay-Tolerant Networking (DTN) Bundle Protocol (BP) and supporting services, has been specifically designed to be suitable for use on deep-space robotic vehicles. Although the ION BP implementation is unique in its use of zero-copy objects for high performance, and in its use of resource-sensitive rate control, it is fully interoperable with other implementations of the BP specification (Internet RFC 5050). The ION BP implementation is built using the same software infrastructure that underlies the implementation of the CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol (CFDP) built into the flight software of Deep Impact. It is designed to minimize resource consumption, while maximizing operational robustness. For example, no dynamic allocation of system memory is required. Like all the other ION packages, ION's BP implementation is designed to port readily between Linux and Solaris (for easy development and for ground system operations) and VxWorks (for flight systems operations). The exact same source code is exercised in both environments. Initially included in the ION BP implementations are the following: libraries of functions used in constructing bundle forwarders and convergence-layer (CL) input and output adapters; a simple prototype bundle forwarder and associated CL adapters designed to run over an IPbased local area network; administrative tools for managing a simple DTN infrastructure built from these components; a background daemon process that silently destroys bundles whose time-to-live intervals have expired; a library of functions exposed to applications, enabling them to issue and receive data encapsulated in DTN bundles; and some simple applications that can be used for system checkout and benchmarking.

Electronic structure of metal overlayers on rhodium

International Nuclear Information System (INIS)

Feibelman, P.J.; Hamann, D.R.

1983-01-01

We have evaluated work functions, surface core-level shifts, and surface band dispersions for clean, Ag-covered, and Pd-covered Rh(100) surfaces, and for clean and Ag-covered Rh(111). The calculations were performed self-consistently, using the surface-linearized augmented-plane-wave method. As expected from the Pauling electronegativities, Ag adsorption lowers the work function from the clean Rh value, by several tenths of an eV, while Pd has an almost negligible effect. The values calculated for the core-level shifts of various films are shown to correspond to expectations based on surface band narrowing and layerwise charge neutrality. Using the core-level shifts, we predict heat-of-adsorption differences (for Ag on Pd vs Ag on Rh, etc.) that are in quite good agreement with the empirical predictions of Miedema and Dorleijn. Finally, the chemical inactivity of the Ag-covered Rh surface is associated with the fact that, for that system, the outer-layer local density of states is essentially that of Ag, with a characteristically low value at the Fermi energy. On the other hand, the Pd-covered Rh surface should behave much like clean Rh with an extra electron per surface atom. The surface band dispersions for the Pd-covered and clean Rh surfaces are closely similar. This result contrasts sharply with the case of Pd-covered Nb, for which, because of the appreciable electronegativity difference, the Pd overlayer is effectively ''noble.''

A theoretical study of symmetry-breaking organic overlayers on single- and bi-layer graphene

Science.gov (United States)

Morales-Cifuentes, Josue; Einstein, T. L.

2013-03-01

An ``overlayer'' of molecules that breaks the AB symmetry of graphene can produce (modify) a band gap in single- (bi-) layer graphene.[2] Since the triangular shaped trimesic acid (TMA) molecule forms two familiar symmetry breaking configurations, we are motivated to model TMA physisorption on graphene surfaces in conjunction with experiments by Groce et al. at UMD. Using VASP, with ab initio van der Waals density functionals (vdW-DF), we simulate adsorption of TMA onto a graphene surface in several symmetry-breaking arrangements in order to predict/understand the effect of TMA adsorption on experimental observables. Supported by NSF-MRSEC Grant DMR 05-20471.

RelEx: Visualization for Actively Changing Overlay Network Specifications.

Science.gov (United States)

Sedlmair, M; Frank, A; Munzner, T; Butz, A

2012-12-01

We present a network visualization design study focused on supporting automotive engineers who need to specify and optimize traffic patterns for in-car communication networks. The task and data abstractions that we derived support actively making changes to an overlay network, where logical communication specifications must be mapped to an underlying physical network. These abstractions are very different from the dominant use case in visual network analysis, namely identifying clusters and central nodes, that stems from the domain of social network analysis. Our visualization tool RelEx was created and iteratively refined through a full user-centered design process that included a full problem characterization phase before tool design began, paper prototyping, iterative refinement in close collaboration with expert users for formative evaluation, deployment in the field with real analysts using their own data, usability testing with non-expert users, and summative evaluation at the end of the deployment. In the summative post-deployment study, which entailed domain experts using the tool over several weeks in their daily practice, we documented many examples where the use of RelEx simplified or sped up their work compared to previous practices.

Aggregated journal–journal citation relations in scopus and web of science matched and compared in terms of networks, maps, and interactive overlays

NARCIS (Netherlands)

Leydesdorff, L.; de Moya-Anegón, F.; de Nooy, W.

We compare the network of aggregated journal–journal citation relations provided by the Journal Citation Reports (JCR) 2012 of the Science Citation Index (SCI) and Social Sciences Citation Index (SSCI) with similar data based on Scopus 2012. First, global and overlay maps were developed for the 2

Elastic helium scattering studies of ordered overlayers of Ar, Kr, and Xe physisorbed on Ag(111)

International Nuclear Information System (INIS)

Gibson, K.D.; Cerjan, C.; Light, J.C.; Sibener, S.J.

1988-01-01

We describe experiments that measured the angle resolved intensity of He (E/sub i/ = 18 and 66 meV) elastically scattering from the surfaces of rare gas overlayers physisorbed on Ag(111). These studies were done on a layer-by-layer basis for 1, 2, 3, and ∼25 ordered overlayers of Ar, Kr, and Xe. Two types of experiments are described. The first is diffraction, where the scattered He intensity was measured as a function of the detector angle, with the incident polar and azimuthal angles held constant. In the second type of experiment, selective adsorption, we measured the specular intensity as a function of incident angle. The purpose of these experiments was to examine the He--surface potential, to assess the relative contributions that various He--rare gas pair potentials, nonadditive multibody terms, and He--substrate interactions make to the systems studied. The experiments are compared with the results of accurate close-coupling calculations, in order to quantitatively perform these assessments. The comparisons between the selective adsorption data and scattering calculations demonstrate the extreme sensitivity that such measurements have to the He--surface potential. In particular, observable changes in the calculated selective adsorption spectra appear when different He--rare gas potentials are tested, or when various nonadditive terms are included in the potential. The results suggest that further refinements in the He-heavy--rare gas pair potentials may be in order

Gate length scaling trends of drive current enhancement in CMOSFETs with dual stress overlayers and embedded-SiGe

International Nuclear Information System (INIS)

Flachowsky, S.; Wei, A.; Herrmann, T.; Illgen, R.; Horstmann, M.; Richter, R.; Salz, H.; Klix, W.; Stenzel, R.

2008-01-01

Strain engineering in MOSFETs using tensile nitride overlayer (TOL) films, compressive nitride overlayer (COL) films, and embedded-SiGe (eSiGe) is studied by extensive device experiments and numerical simulations. The scaling behavior was analyzed by gate length reduction down to 40 nm and it was found that drive current strongly depends on the device dimensions. The reduction of drain-current enhancement for short-channel devices can be attributed to two competing factors: shorter gate length devices have increased longitudinal and vertical stress components which should result in improved drain-currents. However, there is a larger degradation from external resistance as the gate length decreases, due to a larger voltage dropped across the external resistance. Adding an eSiGe stressor reduces the external resistance in the p-MOSFET, to the extent that the drive current improvement from COL continues to increase even down the shortest gate length studied. This is due to the reduced resistivity of SiGe itself and the SiGe valence band offset relative to Si, leading to a smaller silicide-active contact resistance. It demonstrates the advantage of combining eSiGe and COL, not only for increased stress, but also for parasitic resistance reduction to enable better COL drive current benefit

Modeling the butterfly: the voltammetry of ((sqrt(3)xsqrt(3))R30 and p(2x2) overlayers of (111) electrodes

NARCIS (Netherlands)

Koper, M.T.M.; Lukkien, J.J.

2000-01-01

The voltammetry of the formation of (v3×v3)R30° and p(2×2) overlayers on (111) electrodes is modeled by analytical and Monte Carlo techniques. Both ordered structures are formed by second-order order–disorder phase transitions that lead to sharply-peaked ‘butterfly’ features in the voltammogram. The

Clinical and radiological follow-ups on onlays and overlays from student courses

International Nuclear Information System (INIS)

Amann, W.

1982-01-01

45 patients, whose teeth had been given onlays/overlays in student courses, were followed-up. The following values were measured: plaque index, sulcus bleeding index, clinical depth of the sulcus and the clinical findings for D (decayed) according to the DMF index for the maintained surfaces as well as for the control surfaces; beyond this eye tooth contact in lateral protrusion, lack of contact, approximal contact and approximal spatial orientation were evaluated. Bite wing pictures were taken and evaluated for the comprehension of iatrogenic marginal imperfections, for the control of the dentine in the area of the cervical edge of the filling and for the evaluation of the control surfaces. The maintained approximal surfaces were divided according to the degree of marginal imperfection into four imperfection groups. The data which were collected into a study list were evaluated statistically. (TRV) [de

Cytotoxicity of dental alloys, metals, and ceramics assessed by millipore filter, agar overlay, and MTT tests.

Science.gov (United States)

Sjögren, G; Sletten, G; Dahl, J E

2000-08-01

Biocompatibility of dental materials is dependent on the release of elements from the materials. In addition, the composition, pretreatment, and handling of the materials influence the element release. This study evaluated the cytotoxicity of dental alloys, metals, and ceramics, with specific emphasis on the effects of altering the composition and the pretreatment. By using cells from a mouse fibroblast cell line and the agar overlay test, Millipore filter test, and MTT test, cytotoxicity of various metals, metal alloys, and ceramics for dental restoration were studied. Effects of altering the composition of a high noble gold alloy and of pretreatment of a ceramic-bonding alloy were also studied. In addition, the release of elements into the cell culture medium by the materials studied was measured using an inductively coupled plasma optical emission spectrophotometer. The results of the MTT test were analyzed statistically using ANOVA and Scheffé test at a significance level of P filter tests. For the MTT test, no significant differences were observed between these materials and controls, with the exception of JS C-gold and unalloyed titanium. The modified materials were ranked from "mildly cytotoxic" to "moderately cytotoxic" in the agar overlay and Millipore filter tests and from "noncytotoxic" to "moderately cytotoxic" in the MTT test. Thus, cytotoxicity was related to the alloy composition and treatment. The release of Cu and Zn seemed to be important for the cytotoxic effect. Alterations in the composition and the pretreatment can greatly influence the cytotoxicity, and the results stress the importance of carefully following the manufacturers' instructions when handling dental materials.

Effects of irradiation on the fracture properties of stainless steel weld overlay cladding

International Nuclear Information System (INIS)

Haggag, F.M.; Corwin, W.R.; Nanstad, R.K.

1989-01-01

Stainless steel weld overlay cladding was fabricated using the submerged arc, single-wire, oscillating-electrode, and the three-wire, series-arc methods. Three layers of cladding were applied to a pressure vessel plate to provide adequate thickness for fabrication of test specimens, and irradiations were conducted at temperatures and to fluences relevant to power reactor operation. For the first single-wire method, the first layer was type 309, and the upper two layers were type 308 stainless steel. The type 309 was diluted considerably by excessive melting of the base plate. The three-wire method used various combinations of types 308, 309, and 304 stainless steel weld wires, and produced a highly controlled weld chemistry, microstructure, and fracture properties in all three layers of the weld. 14 refs., 15 figs., 4 tabs

Streaming Multimedia via Overlay Networks using Wi-Fi Peer-to-Peer Connections

DEFF Research Database (Denmark)

Poderys, Justas; Soler, José

2017-01-01

Short range ad-hoc wireless networks can be used to deliver streaming multimedia for information, entertainment and advertisement purposes. To enable short-range communication between various devices, the Wi-Fi Alliance proposed an extension to the IEEE802.11 Wi-Fi standard called Wi-Fi Peer......-to-Peer (P2P). It allows compliant devices to form ad-hoc communication groups without interrupting conventional access point-based Wi-Fi communication. This paper proposes to use Wi-Fi P2P connectivity to distribute streaming multimedia in ah-hoc formed user groups. The exchange of multimedia data...... is performed by forming an overlay network using Peer-to-Peer Streaming Peer Protocol (PPSPP). In order to make PPSPP function over WiFi P2P connections, this paper proposes a number of changes to the protocol. The performance of the proposed system is evaluated using a computer networks emulator...

Dissimilar steel welding and overlay covering with nickel based alloys using SWAM (Shielded Metal Arc Welding) and GTAW (Gas Tungsten Arc Welding) processes in the nuclear industry

Energy Technology Data Exchange (ETDEWEB)

Arce Chilque, Angel Rafael [Centro Tecnico de Engenharia e Inovacao Empresarial Ltda., Belo Horizonte, MG (Brazil); Bracarense, Alexander Queiroz; Lima, Luciana Iglesias Lourenco [Federal University of Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Quinan, Marco Antonio Dutra; Schvartzman, Monica Maria de Abreu Mendonca [Nuclear Technology Development Centre (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Marconi, Guilherme [Federal Center of Technological Education (CEFET-MG), Belo Horizonte, MG (Brazil)

2009-07-01

This work presents the welding of dissimilar ferritic steel type A508 class 3 and austenitic stainless steel type AISI 316 L using Inconel{sup R} 600 (A182 and A82) and overlay covering with Inconel{sup R} 690 (A52) as filler metal. Dissimilar welds with these materials without defects and weldability problems such as hot, cold, reheat cracking and Ductility Dip Crack were obtained. Comparables mechanical properties to those of the base metal were found and signalized the efficiency of the welding procedure and thermal treatment selected and used. This study evidences the importance of meeting compromised properties between heat affected zone of the ferritic steel and the others regions presents in the dissimilar joint, to elaborate the dissimilar metal welding procedure specification and weld overlay. Metallographic studies with optical microscopy and Vickers microhardness were carried out to justified and support the results, showing the efficiency of the technique of elaboration of dissimilar metal welding procedure and overlay. The results are comparables and coherent with the results found by others. Some alternatives of welding procedures are proposed to attain the efficacy. Further studies are proposed like as metallographic studies of the fine microstructure, making use, for example, of scanning electron microscope (SEM adapted with an EDS) to explain looking to increase the resistance to primary water stress corrosion (PWSCC) in nuclear equipment. (author)

U-Pb and Hf isotope analysis of detrital zircons from Mesozoic strata of the Gravina belt, southeast Alaska

Science.gov (United States)

Yokelson, Intan; Gehrels, George E.; Pecha, Mark; Giesler, Dominique; White, Chelsi; McClelland, William C.

2015-10-01

The Gravina belt consists of Upper Jurassic through Lower Cretaceous marine clastic strata and mafic-intermediate volcanic rocks that occur along the western flank of the Coast Mountains in southeast Alaska and coastal British Columbia. This report presents U-Pb ages and Hf isotope determinations of detrital zircons that have been recovered from samples collected from various stratigraphic levels and from along the length of the belt. The results support previous interpretations that strata in the western portion of the Gravina belt accumulated along the inboard margin of the Alexander-Wrangellia terrane and in a back-arc position with respect to the western Coast Mountains batholith. Our results are also consistent with previous suggestions that eastern strata accumulated along the western margin of the inboard Stikine, Yukon-Tanana, and Taku terranes and in a fore-arc position with respect to the eastern Coast Mountains batholith. The history of juxtaposition of western and eastern assemblages is obscured by subsequent plutonism, deformation, and metamorphism within the Coast Mountains orogen, but may have occurred along an Early Cretaceous sinistral transform system. Our results are inconsistent with models in which an east-facing subduction zone existed along the inboard margin of the Alexander-Wrangellia terrane during Late Jurassic-Early Cretaceous time.

TEM Microstructure and Chemical Composition of Transition Zone Between Steel Tube and An Inconel 625 Weld Overlay Coating Produced by CMT Method

Directory of Open Access Journals (Sweden)

Rozmus-Górnikowska M.

2017-06-01

Full Text Available The aim of this work was to investigate the microstructure and chemical composition of the transition zone between 16Mo3 steel and Inconel 625 weld overlay coating produced by the Cold Metal Transfer (CMT method. Investigations were primarily carried out through transmission electron microscopy (TEM on thin foils prepared by FIB (Focus Ion Beam.

Study on microstructural changes in thermally-aged stainless steel weld-overlay cladding of nuclear reactor pressure vessels by atom probe tomography

Energy Technology Data Exchange (ETDEWEB)

Takeuchi, T., E-mail: takeuchi.tomoaki@jaea.go.jp [Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Kameda, J. [National Institute for Materials Science, Sengen, Tsukuba 305-0047 (Japan); Nagai, Y.; Toyama, T. [Oarai Center, Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Nishiyama, Y.; Onizawa, K. [Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)

2011-08-15

Highlights: > Microstructural changes in stainless steel electroslag weld-overlay cladding. > Thermal aging caused progress of spinodal decomposition and precipitation of G phases in the {delta}-ferrite phase. > The degree of the spinodal decomposition had a linear relationship to the hardness. - Abstract: The effect of thermal aging on microstructural changes was investigated in stainless steel weld-overlay cladding composed of 90% austenite and 10% {delta}-ferrite phases using atom probe tomography (APT). In as-received materials subjected to cooling process after post-welding heat treatments (PWHT), a slight fluctuation of the Cr concentration was already observed due to spinodal decomposition in the ferrite phase but not in the austenitic phase. Thermal aging at 400 deg. C for 10,000 h caused not only an increase in the amplitude of spinodal decomposition but also the precipitation of G phases with composition ratios of Ni:Si:Mn = 16:7:6 in the ferrite phase. The chemical compositions of M{sub 23}C{sub 6} type carbides seemed to be formed at the austenite/ferrite interface were analyzed. The analyses of the magnitude of the spinodal decomposition and the hardness implied that the spinodal decomposition was the main cause of the hardening.

Spallation of oxide scales from NiCrAlY overlay coatings

International Nuclear Information System (INIS)

Strawbridge, A.; Evans, H.E.; Ponton, C.B.

1997-01-01

A common method of protecting superalloys from aggressive environments at high temperatures is by plasma spraying MCrAlY (M = Fe, Ni and/or Co) to form an overlay coating. Oxidation resistance is then conferred through the development of an alumina layer. However, the use of such coatings is limited at temperatures above about 1100 C due to rapid failure of the protective oxide scales. In this study, the oxidation behaviour of air-plasma-sprayed NiCrAlY coatings has been investigated at 1200 C in 1 atm air. A protective alumina layer develops during the early stages, but breakaway oxidation occurs after prolonged exposure. The results suggest that the critical temperature drop to initiate failure is inversely proportional to the scale thickness, and an analytical model is put forward to explain this behaviour. Local surface curvature of the coating can lead to delamination within the oxide during cooling and it is shown that the largest individual pore in a spall region is the critical flaw for oxide fracture. (orig.)

Aeroelastic Wing Shaping Using Distributed Propulsion

Science.gov (United States)

Nguyen, Nhan T. (Inventor); Reynolds, Kevin Wayne (Inventor); Ting, Eric B. (Inventor)

2017-01-01

An aircraft has wings configured to twist during flight. Inboard and outboard propulsion devices, such as turbofans or other propulsors, are connected to each wing, and are spaced along the wing span. A flight controller independently controls thrust of the inboard and outboard propulsion devices to significantly change flight dynamics, including changing thrust of outboard propulsion devices to twist the wing, and to differentially apply thrust on each wing to change yaw and other aspects of the aircraft during various stages of a flight mission. One or more generators can be positioned upon the wing to provide power for propulsion devices on the same wing, and on an opposite wing.

Herpin effective media resonant underlayers and resonant overlayer designs for ultra-high NA interference lithography.

Science.gov (United States)

Bourke, Levi; Blaikie, Richard J

2017-12-01

Dielectric waveguide resonant underlayers are employed in ultra-high NA interference photolithography to effectively double the depth of field. Generally a single high refractive index waveguiding layer is employed. Here multilayer Herpin effective medium methods are explored to develop equivalent multilayer waveguiding layers. Herpin equivalent resonant underlayers are shown to be suitable replacements provided at least one layer within the Herpin trilayer supports propagating fields. In addition, a method of increasing the intensity incident upon the photoresist using resonant overlayers is also developed. This method is shown to greatly enhance the intensity within the photoresist making the use of thicker, safer, non-absorbing, low refractive index matching liquids potentially suitable for large-scale applications.

Electronic and structural characterizations of unreconstructed {l_brace}0001{r_brace} surfaces and the growth of graphene overlayers

Energy Technology Data Exchange (ETDEWEB)

Emtsev, Konstantin

2009-06-03

The present work is focused on the characterization of the clean unreconstructed SiC{l_brace}0001{r_brace} surfaces and the growth of graphene overlayers thereon. Electronic properties of SiC surfaces and their interfaces with graphene and few layer graphene films were investigated by means of angle resolved photoelectron spectroscopy, X-ray photoelectron spectroscopy and low energy electron diffraction. Structural characterizations of the epitaxial graphene films grown on SiC were carried out by atomic force microscopy and low energy electron microscopy. Supplementary data was obtained by scanning tunneling microscopy. (orig.)

Evaluation of the AISI 904L Alloy Weld Overlays Obtained by GMAW and Electro-Slag Welding Processes

Science.gov (United States)

Jorge, Jorge C. F.; Meira, O. G.; Madalena, F. C. A.; de Souza, L. F. G.; Araujo, L. S.; Mendes, M. C.

2017-05-01

The use of superaustenitic stainless steels (SASS) as an overlay replacement for nickel-based alloys can be an interesting alternative for the oil and gas industries, due to its lower cost, when compared to superalloys. Usually, the deposition is made with several welding passes by using conventional arc welding processes, such as gas tungsten arc welding (GTAW) or gas metal arc welding (GMAW) processes. In this respect, electro-slag welding (ESW), which promotes high heat inputs and low dilution of the welds, can also be attractive for this application, as it provides a higher productivity, once only one layer is needed for the deposition of the minimum thickness required. The present work evaluates the behavior of an AISI 904L SASS weld overlay deposited on a carbon steel ASTM A516 Grade 70 by ESW and GMAW processes. Both as-welded and heat-treated conditions were evaluated and compared. A multipass welding by GMAW process with three layers and 48 passes was performed on 12.5 × 200 × 250 mm steel plates with average welding energy of 1.0 kJ/mm. For ESW process, only one layer was deposited on 50 × 400 × 400 mm steel plates with average welding energy of 11.7 kJ/mm. After welding, a post-weld heat treatment (PWHT) at 620 °C for 10 h was performed in half of the steel plate, in order to allow the comparison between this condition and the as-welded one. For both processes, the austenitic microstructure of the weld deposits was characterized by optical microscopy and scanning electron microscopy with electron backscatter diffraction. A low proportion of secondary phases were observed in all conditions, and the PWHT did not promote significant changes on the hardness profile. Martensite for GMAW process and bainite for ESW process were the microstructural constituents observed at the coarse grain heat-affected zone, due to the different cooling rates. For ESW process, no evidences of partially diluted zones were found. As a consequence of the microstructural

Augmented Endoscopic Images Overlaying Shape Changes in Bone Cutting Procedures.

Science.gov (United States)

Nakao, Megumi; Endo, Shota; Nakao, Shinichi; Yoshida, Munehito; Matsuda, Tetsuya

2016-01-01

In microendoscopic discectomy for spinal disorders, bone cutting procedures are performed in tight spaces while observing a small portion of the target structures. Although optical tracking systems are able to measure the tip of the surgical tool during surgery, the poor shape information available during surgery makes accurate cutting difficult, even if preoperative computed tomography and magnetic resonance images are used for reference. Shape estimation and visualization of the target structures are essential for accurate cutting. However, time-varying shape changes during cutting procedures are still challenging issues for intraoperative navigation. This paper introduces a concept of endoscopic image augmentation that overlays shape changes to support bone cutting procedures. This framework handles the history of the location of the measured drill tip as a volume label and visualizes the remains to be cut overlaid on the endoscopic image in real time. A cutting experiment was performed with volunteers, and the feasibility of this concept was examined using a clinical navigation system. The efficacy of the cutting aid was evaluated with respect to the shape similarity, total moved distance of a cutting tool, and required cutting time. The results of the experiments showed that cutting performance was significantly improved by the proposed framework.

Landfill Site Selection by Weighted Overlay Technique: Case Study of Al-Kufa, Iraq

Directory of Open Access Journals (Sweden)

Mohammad A. Al-Anbari

2018-03-01

Full Text Available Landfill siting is a hard and complex process. For this reason, it is considered as one of the major problems in waste management. This is due to the fact that a number of factors are involved within the process such as such as inhabitants’ growth, rapid economic growth, living standards improvements, etc. In Iraq, landfill siting does not follow environmental regulations. Al-Kufa city located is located south-western part of Iraq (area of 550 km2 and inhabitants 372,760. Existing landfills are not selected according to the environmental standards. Landfill site that is required was achieved using a multi-criteria decision analysis (MCDA and spatial overlay analysis using a geographic information system (GIS. Many factors were considered in the siting process; including geology, water supplies resources, urban centers, sensitive sites, and wells. AHP (analytic hierarchy process method was used in weighting the criteria used. The result showed that there are six sites most suitable covering an area about (113 km2.

Optical resonance analysis of reflected long period fiber gratings with metal film overlay

Science.gov (United States)

Zhang, Guiju; Cao, Bing; Wang, Chinua; Zhao, Minfu

2008-11-01

We present the experimental results of a novel single-ended reflecting surface plasma resonance (SPR) based long period fiber grating (LPFG) sensor. A long period fiber grating sensing device is properly designed and fabricated with a pulsed CO2 laser writing system. Different nm-thick thin metal films are deposited on the fiber cladding and the fiber end facet for the excitation of surface plasma waves (SPWs) and the reflection of the transmission spectrum of the LPFG with doubled interaction between metal-dielectric interfaces of the fiber to enhance the SPW of the all-fiber SPR-LPFG sensing system. Different thin metal films with different thicknesses are investigated. The effect of the excited SPW transmission along the fiber cladding-metal interface with silver and aluminum films is observed. It is found that different thicknesses of the metal overlay show different resonant behaviors in terms of resonance peak situation, bandwidth and energy loss. Within a certain range, thinner metal film shows narrower bandwidth and deeper peak loss.

Application of support vector machine to three-dimensional shape-based virtual screening using comprehensive three-dimensional molecular shape overlay with known inhibitors.

Science.gov (United States)

Sato, Tomohiro; Yuki, Hitomi; Takaya, Daisuke; Sasaki, Shunta; Tanaka, Akiko; Honma, Teruki

2012-04-23

In this study, machine learning using support vector machine was combined with three-dimensional (3D) molecular shape overlay, to improve the screening efficiency. Since the 3D molecular shape overlay does not use fingerprints or descriptors to compare two compounds, unlike 2D similarity methods, the application of machine learning to a 3D shape-based method has not been extensively investigated. The 3D similarity profile of a compound is defined as the array of 3D shape similarities with multiple known active compounds of the target protein and is used as the explanatory variable of support vector machine. As the measures of 3D shape similarity for our new prediction models, the prediction performances of the 3D shape similarity metrics implemented in ROCS, such as ShapeTanimoto and ScaledColor, were validated, using the known inhibitors of 15 target proteins derived from the ChEMBL database. The learning models based on the 3D similarity profiles stably outperformed the original ROCS when more than 10 known inhibitors were available as the queries. The results demonstrated the advantages of combining machine learning with the 3D similarity profile to process the 3D shape information of plural active compounds.

46 CFR 56.50-95 - Overboard discharges and shell connections.

Science.gov (United States)

2010-10-01

... from a position above the freeboard deck. Where, however, the vertical upward distance from the summer... the inboard valve is always accessible for examination under service conditions. Where that vertical... as required in an emergency. (3) Where scuppers and drains are installed in superstructures or...

Quality metric for accurate overlay control in <20nm nodes

Science.gov (United States)

Klein, Dana; Amit, Eran; Cohen, Guy; Amir, Nuriel; Har-Zvi, Michael; Huang, Chin-Chou Kevin; Karur-Shanmugam, Ramkumar; Pierson, Bill; Kato, Cindy; Kurita, Hiroyuki

2013-04-01

The semiconductor industry is moving toward 20nm nodes and below. As the Overlay (OVL) budget is getting tighter at these advanced nodes, the importance in the accuracy in each nanometer of OVL error is critical. When process owners select OVL targets and methods for their process, they must do it wisely; otherwise the reported OVL could be inaccurate, resulting in yield loss. The same problem can occur when the target sampling map is chosen incorrectly, consisting of asymmetric targets that will cause biased correctable terms and a corrupted wafer. Total measurement uncertainty (TMU) is the main parameter that process owners use when choosing an OVL target per layer. Going towards the 20nm nodes and below, TMU will not be enough for accurate OVL control. KLA-Tencor has introduced a quality score named `Qmerit' for its imaging based OVL (IBO) targets, which is obtained on the-fly for each OVL measurement point in X & Y. This Qmerit score will enable the process owners to select compatible targets which provide accurate OVL values for their process and thereby improve their yield. Together with K-T Analyzer's ability to detect the symmetric targets across the wafer and within the field, the Archer tools will continue to provide an independent, reliable measurement of OVL error into the next advanced nodes, enabling fabs to manufacture devices that meet their tight OVL error budgets.

High efficiency diffractive grating coupler based on transferred silicon nanomembrane overlay on photonic waveguide

Energy Technology Data Exchange (ETDEWEB)

Saha, Tapas Kumar; Zhou Weidong [University of Texas at Arlington, Department of Electrical Engineering, NanoFAB Center, Arlington, TX 76019-0072 (United States)

2009-04-21

We report here the design of a new type of high efficiency grating coupler, based on single crystalline Si nanomembrane overlay and stacking. Such high efficiency diffractive grating couplers are designed for the purpose of coupling light between single mode fibres and nanophotonic waveguides, and for the coupling between multiple photonic interconnect layers for compact three-dimensional vertical integration. Two-dimensional model simulation based on eigenmode expansion shows a diffractive power-up efficiency of 81% and a fibre coupling efficiency of 64%. With nanomembrane stacking, it is feasible to integrate the side-distributed Bragg reflector and bottom reflector, which can lead to the diffractive power-up efficiency and the fibre coupling efficiency of 97% and 73.5%, respectively. For a negatively detuned coupler, the bottom reflector is not needed, and the diffractive power-up efficiency can reach 98% over a large spectral range. The device is extremely tolerant to fabrication errors.

An Investigation of GIS Overlay and PCA Techniques for Urban Environmental Quality Assessment: A Case Study in Toronto, Ontario, Canada

Directory of Open Access Journals (Sweden)

Kamil Faisal

2017-03-01

Full Text Available The United Nations estimates that the global population is going to be double in the coming 40 years, which may cause a negative impact on the environment and human life. Such an impact may instigate increased water demand, overuse of power, anthropogenic noise, etc. Thus, modelling the Urban Environmental Quality (UEQ becomes indispensable for a better city planning and an efficient urban sprawl control. This study aims to investigate the ability of using remote sensing and Geographic Information System (GIS techniques to model the UEQ with a case study in the city of Toronto via deriving different environmental, urban and socio-economic parameters. Remote sensing, GIS and census data were first obtained to derive environmental, urban and socio-economic parameters. Two techniques, GIS overlay and Principal Component Analysis (PCA, were used to integrate all of these environmental, urban and socio-economic parameters. Socio-economic parameters including family income, higher education and land value were used as a reference to assess the outcomes derived from the two integration methods. The outcomes were assessed through evaluating the relationship between the extracted UEQ results and the reference layers. Preliminary findings showed that the GIS overlay represents a better precision and accuracy (71% and 65%, respectively, comparing to the PCA technique. The outcomes of the research can serve as a generic indicator to help the authority for better city planning with consideration of all possible social, environmental and urban requirements or constraints.

Stabilization of the O p2x2 phase on Cu(001) sheltered by wrinkled BN over-layer

Science.gov (United States)

Kim, Yong-Sung; Ma, Chuanxu; Li, An-Ping; Yoon, Mina

The 2 √3x √3R45°phase of oxygen (O) on the Cu(001) surface has been observed in scanning tunneling microscopy (STM) measurements. Although the p2x2 phase of O on the Cu(001) surface has been proposed theoretically to be the most stable in O-lean conditions, it has not been observed in experiments for a long time. Recently, the O p2x2 phase has been found in STM on the Cu(001) surface with an overlying BN monolayer. In this theoretical study, we investigate what the role of BN over-layer is to stabilize the O p2x2 phase on the Cu(001) surface. The BN over-layer is lattice-matched with the Cu(001) surface and the BN mono-layer sheet is periodically wrinkled along the BN arm-chair direction and along the [100] or [010] direction on the Cu(001) surface. The interlayer space between the Cu(001) surface and the bulge of the wrinkled BN sheet is found to play as a preferential shelter for O to be adsorbed, and the boundary of the BN inner wall along the [010] or [100] direction makes the p2x2 phase more favorable against the 45°-tilted 2 √3x √3R45°phase of O on the Cu(001) surface. This was supported by Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility, and the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, maaged by UT-Battelle, LLC, for the U. S. DOE.

Implementation of the production management of a HVDC overlaydistribution system in the load frequency control of a three-phase-current combined systems; Integration der Betriebsfuehrung eines HGUe-Overlay-Netzes in die Leistungs-Frequenz-Regelung eines Drehstrom-Verbundnetzes

Energy Technology Data Exchange (ETDEWEB)

Marten, Anne-Katrin

2012-07-01

To reduce emission of carbon dioxide the proportion of renewable energies is rapidly growing in German and European grids in general. Additionally, the bulk of them are generated in only a few spots in European transmission grid, whereas conventional power plants will shut down and the load center distribution will still be decentralized. This results in the need of a new and powerful transmission grid, which is able to transport bulk power over long distances. To overcome this challenge one of the discussed solutions for Europe is an Overlay Network based on HVDC technology connecting spots of bulk renewable energy plants and important load centers. Because of different performance compared to an ac grid, it is necessary for an HVDC Overlay Network to actively sustain system services such as power frequency control to ensure system stability and power quality as well as the ac grid does. A novel method for realizing participation of a HVDC Overlay Network in power frequency control is presented. It hasn't only an advantage for load frequency power flows, but also for contracted balancing power flows which are also feed via the dc grid pro rata. Numerical case studies are made to show some benefits of this method in case of various disturbances. It is shown that a HVDC Overlay Network with the developed operating control releases the ac grid by an adjustable amount of power flows and improves the power frequency control for example in terms of promptness and lower frequency deviations.

Analysis of the electrodeposition and surface chemistry of CdTe, CdSe, and CdS thin films through substrate-overlayer surface-enhanced Raman spectroscopy.

Science.gov (United States)

Gu, Junsi; Fahrenkrug, Eli; Maldonado, Stephen

2014-09-02

The substrate-overlayer approach has been used to acquire surface enhanced Raman spectra (SERS) during and after electrochemical atomic layer deposition (ECALD) of CdSe, CdTe, and CdS thin films. The collected data suggest that SERS measurements performed with off-resonance (i.e. far from the surface plasmonic wavelength of the underlying SERS substrate) laser excitation do not introduce perturbations to the ECALD processes. Spectra acquired in this way afford rapid insight on the quality of the semiconductor film during the course of an ECALD process. For example, SERS data are used to highlight ECALD conditions that yield crystalline CdSe and CdS films. In contrast, SERS measurements with short wavelength laser excitation show evidence of photoelectrochemical effects that were not germane to the intended ECALD process. Using the semiconductor films prepared by ECALD, the substrate-overlayer SERS approach also affords analysis of semiconductor surface adsorbates. Specifically, Raman spectra of benzenethiol adsorbed onto CdSe, CdTe, and CdS films are detailed. Spectral shifts in the vibronic features of adsorbate bonding suggest subtle differences in substrate-adsorbate interactions, highlighting the sensitivity of this methodology.

Prospective evaluation of MR overlay on real-time fluoroscopy for percutaneous extremity biopsies of bone lesions visible on MRI but not on CT in children in the interventional radiology suite

International Nuclear Information System (INIS)

Shellikeri, Sphoorti; Vatsky, Seth; Srinivasan, Abhay; Krishnamurthy, Ganesh; Zhu, Xiaowei; Keller, Marc S.; Cahill, Anne Marie; Setser, Randolph M.

2018-01-01

Magnetic resonance imaging (MRI) often provides better visualization of bone marrow abnormalities than computed tomography (CT) or fluoroscopy, but bone biopsies are usually performed using conventional CT or, more recently, C-arm CT guidance. Biopsies of bone lesions solely visible on MRI are often challenging to localize and require the operator to review the MRI on a separate console to correlate with MRI anatomical landmarks during the biopsy. The MR overlay technique facilitates such biopsies in the angiographic suite by allowing the pre-procedural 3-D MRI to be overlaid on intraprocedural 2-D fluoroscopy. This study describes our initial experience with the MR overlay technique in the angiography suite during pediatric percutaneous extremity bone biopsies of lesions visible on MRI but not on CT or fluoroscopy and demonstrates its utility in relevant clinical cases. (orig.)

Prospective evaluation of MR overlay on real-time fluoroscopy for percutaneous extremity biopsies of bone lesions visible on MRI but not on CT in children in the interventional radiology suite

Energy Technology Data Exchange (ETDEWEB)

Shellikeri, Sphoorti; Vatsky, Seth; Srinivasan, Abhay; Krishnamurthy, Ganesh; Zhu, Xiaowei; Keller, Marc S.; Cahill, Anne Marie [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Setser, Randolph M. [Siemens Medical Solutions USA, Inc., Hoffman Estates, IL (United States)

2018-02-15

Magnetic resonance imaging (MRI) often provides better visualization of bone marrow abnormalities than computed tomography (CT) or fluoroscopy, but bone biopsies are usually performed using conventional CT or, more recently, C-arm CT guidance. Biopsies of bone lesions solely visible on MRI are often challenging to localize and require the operator to review the MRI on a separate console to correlate with MRI anatomical landmarks during the biopsy. The MR overlay technique facilitates such biopsies in the angiographic suite by allowing the pre-procedural 3-D MRI to be overlaid on intraprocedural 2-D fluoroscopy. This study describes our initial experience with the MR overlay technique in the angiography suite during pediatric percutaneous extremity bone biopsies of lesions visible on MRI but not on CT or fluoroscopy and demonstrates its utility in relevant clinical cases. (orig.)

Use of gum tragacanth overlay, applied at room temperature, in the plaque assay of fish and other animal viruses.

Science.gov (United States)

Dobos, P

1976-01-01

Fish cells derived from rainbow trout gonad or Atlantic salmon are sometimes damaged by the relatively high temperature of agar overlay widely used for plaquing animal viruses. This heat-induced cell damage can be avoided by the use of gum tragacanth, which may be applied at room temperature. When the medium was buffered with tris(hydroxymethyl)aminomethane-hydrochloride and NaHCO3, the plaque assay could be performed without the use of a CO2 incubator. Using this method, a number of animal viruses were plaqued on a variety of cell monolayers at different temperatures under atmospheric ocnditions. Images PMID:818114

Study of overall heat transfer coefficient from upper crust to overlaying water during MCCI

International Nuclear Information System (INIS)

Kondo, Masaya; Nishida, Ayumu; Sugimoto, Jun

2015-01-01

A model of the overall heat transfer between the molten core and the overlying coolant above crust during MCCI in severe accident is proposed and confirmed experimentally and analytically. The model assumes that the heat transferred from molten core to the overlaying water is proportional to the amount of water that reaches the molten core surface. The water flow to the molten core surface is assumes to be prevented by the CCFL in the porous crust. Thus, the steam flow and the non-condensable gas flow interact with the water flow. The present model describes the relationship between the overall heat transfer and the water flow, and furthermore, the CCFL effect on the water flow. The non-condensable gas effect on the overall heat transfer predicted by the present model agrees well with experiments. The effects of porosity and hole diameter on the amount of water, which reaches the molten core surface, has also been confirmed using RELAP5 code. (author)

Processing moldable tasks on the grid: Late job binding with lightweight user-level overlay

CERN Document Server

Moscicki, J T; Sloot, P M A; Lamanna, M

2011-01-01

Independent observations and everyday user experience indicate that performance and reliability of large grid infrastructures may suffer from large and unpredictable variations. In this paper we study the impact of the job queuing time on processing of moldable tasks which are commonly found in large-scale production grids. We use the mean value and variance of makespan as the quality of service indicators. We develop a general task processing model to provide a quantitative comparison between two models: early and late job binding in a user-level overlay applied to the EGEE Grid infrastructure. We find that the late-binding model effectively defines a transformation of the distribution of makespan according to the Central Limit Theorem. As demonstrated by Monte Carlo simulations using real job traces, this transformation allows to substantially reduce the mean value and variance of makespan. For certain classes of applications task granularity may be adjusted such that a speedup of an order of magnitude or m...

Overlay Cognitive Radios With Channel-Aware Adaptive Link Selection and Buffer-Aided Relaying

KAUST Repository

Shaqfeh, Mohammad

2015-08-01

The aim of this work is to maximize the long-term average achievable rate region of a primary and a secondary source-destination pairs operating in an overlay setup over block-fading channels. To achieve this objective, we propose an opportunistic strategy to grant channel access to the primary and secondary sources based on the channel conditions in order to exploit the available multiple-link diversity gains in the system. The secondary source has causal knowledge of the primary messages and it acts as a relay of the primary source in return for getting access to the channel. To maximize the gains of relaying, the relay and destination are equipped with buffers to enable the use of channel-aware adaptive link selection. We propose and optimize different link selection policies and characterize their expected achievable rates. Also, we provide several numerical results to demonstrate the evident mutual benefits of buffer-aided cooperation and adaptive link selection to the primary and the secondary source-destination pairs. © 1972-2012 IEEE.

Overlay Cognitive Radios With Channel-Aware Adaptive Link Selection and Buffer-Aided Relaying

KAUST Repository

Shaqfeh, Mohammad; Zafar, Ammar; Alnuweiri, Hussein; Alouini, Mohamed-Slim

2015-01-01

The aim of this work is to maximize the long-term average achievable rate region of a primary and a secondary source-destination pairs operating in an overlay setup over block-fading channels. To achieve this objective, we propose an opportunistic strategy to grant channel access to the primary and secondary sources based on the channel conditions in order to exploit the available multiple-link diversity gains in the system. The secondary source has causal knowledge of the primary messages and it acts as a relay of the primary source in return for getting access to the channel. To maximize the gains of relaying, the relay and destination are equipped with buffers to enable the use of channel-aware adaptive link selection. We propose and optimize different link selection policies and characterize their expected achievable rates. Also, we provide several numerical results to demonstrate the evident mutual benefits of buffer-aided cooperation and adaptive link selection to the primary and the secondary source-destination pairs. © 1972-2012 IEEE.

Simple method for clonal selection of hepatitis A virus based on recovery of virus from radioimmunofocus overlays

Energy Technology Data Exchange (ETDEWEB)

Lemon, S M; Jansen, R W

1985-06-01

Hepatitis A virus (HAV), has been quantitated in cell culture by autoradiographic detection of foci of viral replication developing beneath an agarose overlay following fixation and 'staining' of the cell sheet with radiolabelled antibody (radioimmunofocus assay). Using a modification of this basic technique, a clonal variant of HM-175 strain HAV was isolated from agarose overlying individual radioimmunofoci. Virus recovered from the agarose was amplified in small volume cultures of BS-C-1 cells and identified in supernatant culture fluids by cDNA-RNA hybridizaton. No virus was recovered from agarose which did not overlie a focus of viral replication. This method offers a simple, yet relatively rapid and certain means of selecting clonal variants of non-plaquing viruses such as hepatitis A virus.

Accelerated Fatigue Resistance of Thick CAD/CAM Composite Resin Overlays Bonded with Light- and Dual-polymerizing Luting Resins.

Science.gov (United States)

Goldberg, Jack; Güth, Jan-Frederik; Magne, Pascal

To evaluate the accelerated fatigue resistance of thick CAD/CAM composite resin overlays luted with three different bonding methods. Forty-five sound human second mandibular molars were organized and distributed into three experimental groups. All teeth were restored with a 5-mm-thick CAD/CAM composite resin overlay. Group A: immediate dentin sealing (IDS) with Optibond FL and luted with light-polymerizing composite (Herculite XRV). Group B: IDS with Optibond FL and luted with dual-polymerizing composite (Nexus 3). Group C: direct luting with Optibond FL and dual-polymerizing composite (Nexus 3). Masticatory forces at a frequency of 5 Hz were simulated using closed-loop servo-hydraulics and forces starting with a load of 200 N for 5000 cycles, followed by steps of 400, 600, 800, 1000, 1200 and 1400 N for a maximum of 30,000 cycles. Each step was applied through a flat steel cylinder at a 45-degree angle under submerged conditions. The fatigue test generated one failure in group A, three failures in group B, and no failures in group C. The survival table analysis for the fatigue test did not demonstrate any significant difference between the groups (p = 0.154). The specimens that survived the fatigue test were set up for the load-to-failure test with a limit of 4600 N. The survival table analysis for the load-to-failure test demonstrates an average failure load of 3495.20 N with survival of four specimens in group A, an average failure load of 4103.60 N with survival of six specimens in group B, and an average failure load of 4075.33 N with survival of nine specimens in group C. Pairwise comparisons revealed no significant differences (p composites in combination with IDS are not contraindicated with thick restorations.

A Graphic Overlay Method for Selection of Osteotomy Site in Chronic Radial Head Dislocation: An Evaluation of 3D-printed Bone Models.

Science.gov (United States)

Kim, Hui Taek; Ahn, Tae Young; Jang, Jae Hoon; Kim, Kang Hee; Lee, Sung Jae; Jung, Duk Young

2017-03-01

Three-dimensional (3D) computed tomography imaging is now being used to generate 3D models for planning orthopaedic surgery, but the process remains time consuming and expensive. For chronic radial head dislocation, we have designed a graphic overlay approach that employs selected 3D computer images and widely available software to simplify the process of osteotomy site selection. We studied 5 patients (2 traumatic and 3 congenital) with unilateral radial head dislocation. These patients were treated with surgery based on traditional radiographs, but they also had full sets of 3D CT imaging done both before and after their surgery: these 3D CT images form the basis for this study. From the 3D CT images, each patient generated 3 sets of 3D-printed bone models: 2 copies of the preoperative condition, and 1 copy of the postoperative condition. One set of the preoperative models was then actually osteotomized and fixed in the manner suggested by our graphic technique. Arcs of rotation of the 3 sets of 3D-printed bone models were then compared. Arcs of rotation of the 3 groups of bone models were significantly different, with the models osteotomized accordingly to our graphic technique having the widest arcs. For chronic radial head dislocation, our graphic overlay approach simplifies the selection of the osteotomy site(s). Three-dimensional-printed bone models suggest that this approach could improve range of motion of the forearm in actual surgical practice. Level IV-therapeutic study.

Enhanced specificity in immunoscreening of expression cDNA clones using radiolabeled antigen overlay

International Nuclear Information System (INIS)

Chao, S.; Chao, L.; Chao, J.

1989-01-01

A highly sensitive and specific method has been developed for immunoscreening clones from an expression cDNA library. The procedures utilize a radiolabeled antigen detection method described originally for the immunoblotting of plasma proteins. Screening of rat alpha 1-antitrypsin clones was used. Comparison between Western blots of alpha 1-antitrypsin using both labeled antigen and protein A detection methods showed that the former yielded lower background and greater sensitivity than the latter. Further, this technique was shown to have a lower detection limit of less than 20 ng through Western blot analysis of varying concentrations of alpha 1-antitrypsin. The procedures are based on the expression of the protein by cDNA clones containing the DNA inserts in the correct reading frame. Following the transfer of phage proteins to nitrocellulose membranes, the bivalent antibodies bind monovalently to both nitrocellulose-bound-antigen in the phage lysates and radiolabeled antigen. The radiolabeled antigen overlay method is superior to the protein A detection method in sensitivity, specificity and reproducibility. This improved method can be applied in general for screening expression cDNA libraries, provided that the specific antiserum and radiolabeled antigen are available

A simple method for clonal selection of hepatitis A virus based on recovery of virus from radioimmunofocus overlays

International Nuclear Information System (INIS)

Lemon, S.M.; Jansen, R.W.

1985-01-01

Hepatitis A virus (HAV), has been quantitated in cell culture by autoradiographic detection of foci of viral replication developing beneath an agarose overlay following fixation and 'staining' of the cell sheet with radiolabelled antibody (radioimmunofocus assay). Using a modification of this basic technique, a clonal variant of HM-175 strain HAV was isolated from agarose overlying individual radioimmunofoci. Virus recovered from the agarose was amplified in small volume cultures of BS-C-1 cells and identified in supernatant culture fluids by cDNA-RNA hybridizaton. No virus was recovered from agarose which did not overlie a focus of viral replication. This method offers a simple, yet relatively rapid and certain means of selecting clonal variants of non-plaquing viruses such as hepatitis A virus. (Auth.)

An Experimental Comparison of CLOS and C++ Implementations of An Object- Oriented Graphical Simulation of Walking Robot Kinematics

Science.gov (United States)

1993-03-25

attachment-angle :accessor leg-attachment-angle) (linkO :initform (make-instance ’linkO) :accessor linkO) ( linki :initform (make-instance ’ linki ...accessor linki ) (link2 :initform (make-instance ’link2) :accessor link2) (link3 :initform (make-instance ’link3) :accessor link3) (motion-complete-flag...inboard-link ( linki leg)) (linkO leg)) (setf (inboard-link (link2 leg)) ( linki leg)) (setf (inboard-link (link3 leg)) (link2 leg)) (rotate-link (linkO

LOFA [loss of flow accident] and LOCA [loss of coolant accident] in the TIBER-II engineering test reactor: Appendix A-4

International Nuclear Information System (INIS)

Sviatoslavsky, I.N.; Attaya, H.M.; Corradini, M.L.; Lomperski, S.

1987-01-01

This paper describes the preliminary analysis of LOFA (loss of flow accident) and LOCA (loss of coolant accident) in the TIBER-II engineering test reactor breeding shield. TIBER-II is a compact reactor with a major radius of 3 m and thus requires a thin, high efficiency shield on the inboard side. The use of tungsten in the inboard shield implies a rather high rate of afterheat upon plasma shutdown, which must be dissipated in a controlled manner to avoid the possibility of radioactivity release or threatening the investment. Because the shield is cooled with an aqueous solution, LOFA does not pose a problem as long as natural convection can be established. LOCA, however, has more serious consequences, particularly on the inboard side. Circulation of air by natural convection is proposed as a means for dissipating the inboard shield decay heat. The safety and environmental implications of such a scheme are evaluated. It is shown that the inboard shield temperature never exceeds 510 0 C following LOCA posing no hazard to reactor personnel and not threatening the investment. 7 refs., 6 figs

Improving overlay control through proper use of multilevel query APC

Science.gov (United States)

Conway, Timothy H.; Carlson, Alan; Crow, David A.

2003-06-01

Many state-of-the-art fabs are operating with increasingly diversified product mixes. For example, at Cypress Semiconductor, it is not unusual to be concurrently running multiple technologies and many devices within each technology. This diverse product mix significantly increases the difficulty of manually controlling overlay process corrections. As a result, automated run-to-run feedforward-feedback control has become a necessary and vital component of manufacturing. However, traditional run-to-run controllers rely on highly correlated historical events to forecast process corrections. For example, the historical process events typically are constrained to match the current event for exposure tool, device, process level and reticle ID. This narrowly defined process stream can result in insufficient data when applied to lowvolume or new-release devices. The run-to-run controller implemented at Cypress utilizes a multi-level query (Level-N) correlation algorithm, where each subsequent level widens the search criteria for available historical data. The paper discusses how best to widen the search criteria and how to determine and apply a known bias to account for tool-to-tool and device-to-device differences. Specific applications include offloading lots from one tool to another when the first tool is down for preventive maintenance, utilizing related devices to determine a default feedback vector for new-release devices, and applying bias values to account for known reticle-to-reticle differences. In this study, we will show how historical data can be leveraged from related devices or tools to overcome the limitations of narrow process streams. In particular, this paper discusses how effectively handling narrow process streams allows Cypress to offload lots from a baseline tool to an alternate tool.

Theoretical simulations of atomic and polyatomic bombardment of an organic overlayer on a metallic substrate

CERN Document Server

Krantzman, K D; Delcorte, A; Garrison, B J

2003-01-01

Our previous molecular dynamics simulations on initial test systems have laid the foundation for understanding some of the effects of polyatomic bombardment. In this paper, we describe simulations of the bombardment of a more realistic model system, an overlayer of sec-butyl-terminated polystyrene tetramers on a Ag left brace 1 1 1 right brace substrate. We have used this model system to study the bombardment with Xe and SF sub 5 projectiles at kinetic energies ranging from 0.50 to 5.0 keV. SF sub 5 sputters more molecules than Xe, but a higher percentage of these are damaged rather than ejected intact when the bombarding energy is greater than 0.50 keV. Therefore, at energies comparable to experimental values, the efficiency, measured as the yield-to-damage ratio, is greater with Xe than SF sub 5. Stable and intact molecules are generally produced by upward moving substrate atoms, while fragments are produced by the upward and lateral motion of reflected projectile atoms and fragments from the target molecul...

Capability for Fine Tuning of the Refractive Index Sensing Properties of Long-Period Gratings by Atomic Layer Deposited Al2O3 Overlays

Directory of Open Access Journals (Sweden)

Mateusz Śmietana

2013-11-01

Full Text Available This work presents an application of thin aluminum oxide (Al2O3 films obtained using atomic layer deposition (ALD for fine tuning the spectral response and refractive-index (RI sensitivity of long-period gratings (LPGs induced in optical fibers. The technique allows for an efficient and well controlled deposition at monolayer level (resolution ~ 0.12 nm of excellent quality nano-films as required for optical sensors. The effect of Al2O3 deposition on the spectral properties of the LPGs is demonstrated experimentally and numerically. We correlated both the increase in Al2O3 thickness and changes in optical properties of the film with the shift of the LPG resonance wavelength and proved that similar films are deposited on fibers and oxidized silicon reference samples in the same process run. Since the thin overlay effectively changes the distribution of the cladding modes and thus also tunes the device’s RI sensitivity, the tuning can be simply realized by varying number of cycles, which is proportional to thickness of the high-refractive-index (n > 1.6 in infrared spectral range Al2O3 film. The advantage of this approach is the precision in determining the film properties resulting in RI sensitivity of the LPGs. To the best of our knowledge, this is the first time that an ultra-precise method for overlay deposition has been applied on LPGs for RI tuning purposes and the results have been compared with numerical simulations based on LP mode approximation.

Evolution of the SrTiO{sub 3} surface electronic state as a function of LaAlO{sub 3} overlayer thickness

Energy Technology Data Exchange (ETDEWEB)

Plumb, N.C.; Kobayashi, M. [Swiss Light Source, Paul Scherrer Insitut, CH-5232 Villigen PSI (Switzerland); Salluzzo, M. [CNR-SPIN, Complesso Universitario Monte S. Angelo, Via Cinthia, I-80126 Napoli (Italy); Razzoli, E.; Matt, C.E.; Strocov, V.N.; Zhou, K.J.; Shi, M. [Swiss Light Source, Paul Scherrer Insitut, CH-5232 Villigen PSI (Switzerland); Mesot, J. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Institut de la Matiere Complexe, EPF Lausanne, CH-1015 Lausanne (Switzerland); Laboratory for Solid State Physics, ETH Zürich, CH-8093 Zürich (Switzerland); Schmitt, T. [Swiss Light Source, Paul Scherrer Insitut, CH-5232 Villigen PSI (Switzerland); Patthey, L. [Swiss Light Source, Paul Scherrer Insitut, CH-5232 Villigen PSI (Switzerland); SwissFEL, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Radović, M., E-mail: milan.radovic@psi.ch [Swiss Light Source, Paul Scherrer Insitut, CH-5232 Villigen PSI (Switzerland); Institut de la Matiere Complexe, EPF Lausanne, CH-1015 Lausanne (Switzerland); SwissFEL, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

2017-08-01

Highlights: • The close similarities in the electronic structures of the metallic bare surface of STO and the buried interfaces (LAO/STO). • The similar spectroscopic responses of these systems to photon irradiation. • The emergence of 2 × 1 structural ordering in sufficiently thick LAO/STO interfaces. - Abstract: The novel electronic properties emerging at interfaces between transition metal oxides, and in particular the discovery of conductivity in heterostructures composed of LaAlO{sub 3} (LAO) and SrTiO{sub 3} (STO) band insulators, have generated new challenges and opportunities in condensed matter physics. Although the interface conductivity is stabilized when LAO matches or exceeds a critical thickness of 4 unit cells (uc), other phenomena such as a universal metallic state found on the bare surface of STO single crystals and persistent photon-triggered conductivity in otherwise insulating STO-based interfaces raise important questions about the role of the LAO overlayer and the possible relations between vacuum/STO and LAO/STO interfaces. Here, using angle-resolved photoemission spectroscopy (ARPES) on in situ prepared samples complemented by resonant inelastic X-ray scattering (RIXS), we study how the metallic STO surface state evolves during the growth of a crystalline LAO overlayer. In all the studied samples, the character of the conduction bands, their carrier densities, the Ti{sup 3+} crystal field, and the response to photon irradiation bear strong similarities. Nevertheless, we report here that studied LAO/STO interfaces exhibit an instability toward an apparent 2 × 1 folding of the Fermi surface at and above a 4 uc thickness threshold, which distinguishes these heterostructures from bare STO and sub-critical-thickness LAO/STO.

TU-FG-BRB-09: Thermoacoustic Range Verification with Perfect Co-Registered Overlay of Bragg Peak onto Ultrasound Image

Energy Technology Data Exchange (ETDEWEB)

Patch, S; Kireeff Covo, M; Jackson, A; Qadadha, Y; Campbell, K; Albright, R; Bloemhard, P; Donoghue, A; Siero, C; Gimpel, T; Small, S; Ninemire, B; Johnson, M; Phair, L [Lawrence Berkeley National Lab, Berkeley, CA (United States)

2016-06-15

Purpose: The potential of particle therapy has not yet been fully realized due to inaccuracies in range verification. The purpose of this work was to correlate the Bragg peak location with target structure, by overlaying thermoacoustic localization of the Bragg peak onto an ultrasound image. Methods: Pulsed delivery of 50 MeV protons was accomplished by a fast chopper installed between the ion source and the inflector of the 88″ cyclotron at Lawrence Berkeley National Lab. 2 Gy were delivered in 2 µs by a beam with peak current of 2 µA. Thermoacoustic emissions were detected by a cardiac array and Verasonics V1 ultrasound system, which also generated a grayscale ultrasound image. 1024 thermoacoustic pulses were averaged before filtering and one-way beamforming focused signal onto the Bragg peak location with perfect co-registration to the ultrasound images. Data was collected in a room temperature water bath and gelatin phantom with a cavity designed to mimic the intestine, in which gas pockets can displace the Bragg peak. Experiments were performed with the cavity both empty and filled with olive oil. Results: In the waterbath overlays of the Bragg peak agreed with Monte Carlo simulations to within 800±170 µm. Agreement within 1.3 ± 0.2 mm was achieved in the gelatin phantom, although relative stopping powers were estimated only to first order from CT scans. Protoacoustic signals were detected after travel from the Bragg peak through 29 mm and 65 mm of phantom material when the cavity was empty and full of olive oil, respectively. Conclusion: Protoacoustic range verification is feasible with a commercial clinical ultrasound array, but at doses exceeding the clinical realm. Further optimization of both transducer array and injection line chopper is required to enable range verification within a 2 Gy dose limit, which would enable online adaptive treatment. This work was supported in part by a UWM Intramural Instrumentation Grant and by the Director, Office

Joint Bandwidth and Power Allocation for MIMO Two-Way Relays-Assisted Overlay Cognitive Radio Systems

KAUST Repository

Alsharoa, Ahmad; Ghazzai, Hakim; Yaacoub, Elias; Alouini, Mohamed-Slim; Kamal, Ahmed

2015-01-01

This paper studies the achievable cognitive sum rate of an overlay cognitive radio (CR) system assisted with multiple antennas two-way relays in which primary users (PUs) cooperate with cognitive users (CUs) for mutual benefits. In this context, the problem of both bandwidth and power allocation is investigated. We propose that the CUs are allowed to allocate a part of the PUs spectrum to perform their cognitive transmission. In return, acting as amplify-and-forward two-way relays, they are exploited to support PUs to reach their target data rates over the remaining bandwidth. Power expressions for optimal transmit power allocated per PU and CU antenna are derived under primary quality-of-service constraint in addition to bandwidth and power budget constraints. More specifically, CUs act as relays for the PUs transmission and gain some spectrum as long as they respect these constraints. After deriving the optimal transmit powers, we employ a strong optimization tool based on swarm intelligence to optimize the full and complex relay amplification gain matrices in addition to the bandwidths released to primary and cognitive transmission. Furthermore, three different utility functions are considered in our optimization problems depending on the level of fairness among CUs.

Joint Bandwidth and Power Allocation for MIMO Two-Way Relays-Assisted Overlay Cognitive Radio Systems

KAUST Repository

Alsharoa, Ahmad

2015-10-08

This paper studies the achievable cognitive sum rate of an overlay cognitive radio (CR) system assisted with multiple antennas two-way relays in which primary users (PUs) cooperate with cognitive users (CUs) for mutual benefits. In this context, the problem of both bandwidth and power allocation is investigated. We propose that the CUs are allowed to allocate a part of the PUs spectrum to perform their cognitive transmission. In return, acting as amplify-and-forward two-way relays, they are exploited to support PUs to reach their target data rates over the remaining bandwidth. Power expressions for optimal transmit power allocated per PU and CU antenna are derived under primary quality-of-service constraint in addition to bandwidth and power budget constraints. More specifically, CUs act as relays for the PUs transmission and gain some spectrum as long as they respect these constraints. After deriving the optimal transmit powers, we employ a strong optimization tool based on swarm intelligence to optimize the full and complex relay amplification gain matrices in addition to the bandwidths released to primary and cognitive transmission. Furthermore, three different utility functions are considered in our optimization problems depending on the level of fairness among CUs.

Effect of structural modulation and thickness of a graphene overlayer on the binding energy of the Rashba-type surface state of Ir(111)

International Nuclear Information System (INIS)

Sánchez-Barriga, J; Marchenko, D; Rader, O; Varykhalov, A; Bihlmayer, G; Wortmann, D

2013-01-01

The Ir(111) surface is known to host a surface state with a giant spin–orbit splitting due to the Rashba effect. This surface state is stable even in air when Ir is protected with an epitaxial graphene overlayer. In the present paper, we reveal an effect allowing one to tune the binding energy of this spin-split surface state up and down and demonstrate the practical application of this effect by two different approaches. The first approach is related to a decoration of the moiré pattern of single-layer graphene on Ir(111) by self-assembled nanoclusters of different compositions. The clusters locally pin graphene to the Ir substrate and enhance the amplitude of its structural corrugation, which, in turn, leads to an increase in the surface state binding energy. The second approach is related to the synthesis of few-layer graphene on Ir(111) by segregation of carbon. Additional graphene layers induce a shift of the Ir surface state towards lower binding energies and bring it almost to the Fermi level. Based on density functional calculations performed for the graphene/Ir(111) system, we show that in both cases the effect causing the binding energy shifts is intimately related to the distance between graphene and the Ir surface, which is subject to change due to deposition of clusters or by increasing the amount of graphene overlayers. In contrast, the observed spin–orbit splitting of the Ir(111) surface state remains remarkably robust and constant in all cases. Our theoretical analysis reveals that such stability can be explained by the localization properties of the Ir surface state that is a deep surface resonance. (paper)

Further contribution to the study of buffer layer on austenitic stainless stell overlays obtained by means of automatic submerged arc welding with electrode-wire

International Nuclear Information System (INIS)

Colla, G.

1988-01-01

The influence of several buffer layer types on a 308 type austenitic stainless steel surface overlay having a 19-21% chromium and 10-12% nikel content have been analysed. Cladding passes have been deposited on carbon steel test samples by using automatic submerged arc welding process with electrode-wire. The experimental tests have involved buffer layers having seven different chemical compositions and the obtained results are reported and discussed in the paper. The achieved experimetal results allow selecting the most suitable buffer layer to be deposited in order to reach the required cladding performance in service

Preliminary radiation criteria and nuclear analysis for ETF

International Nuclear Information System (INIS)

Engholm, B.A.

1980-09-01

Preliminary biological and materials radiation dose criteria for the Engineering Test Facility are described and tabulated. In keeping with the ETF Mission Statement, a key biological dose criterion is a 24-hour shutdown dose rate of 2 mrem/hr on the surface of the outboard bulk shield. Materials dose criteria, which primarily govern the inboard shield design, include 10 9 rads exposure limit to epoxy insulation, 3 x 10 -4 dpa damage to the TF coil copper stabilizer, and a total nuclear heating rate of 5 kW in the inboard TF coils. Nuclear analysis performed during FY 80 was directed primarily at the inboard and outboard bulk shielding, and at radiation streaming in the neutral beam drift ducts. Inboard and outboard shield thicknesses to achieve the biological and materials radiation criteria are 75 cm inboard and 125 cm outboard, the configuration consisting of alternating layers of stainless steel and borated water. The outboard shield also includes a 5 cm layer of lead. NBI duct streaming analyses performed by ORNL and LASL will play a key role in the design of the duct and NBI shielding in FY 81. The NBI aluminum cryopanel nuclear heating rate during the heating cycle is about 1 milliwatt/cm 3 , which is far less than the permissible limit

He atom surface scattering: Surface dynamics of insulators, overlayers and crystal growth

International Nuclear Information System (INIS)

1992-01-01

Investigations have focused primarily on surface structure and dynamics of ionic insulators, epitaxial growth onto alkali halide crystals and multiphoton studies. The surface dynamics of RbCl has been re-examined. We have developed a simple force constant model which provides insight into the dynamics of KBr overlayers on NaCl(001), a system with a large lattice mismatch. The KBr/NaCl(001) results are compared to Na/Cu(001) and NaCl/Ge(001). We have completed epitaxial growth experiments for KBr onto RbCl(001). Slab dynamics calculations using a shell model for this system with very small lattice mismatch are being carried out in collaboration with Professor Manson of Clemson University and with Professor Schroeder in Regensburg, Germany. Extensive experiments on multiphoton scattering of helium atoms onto NaCl and, particularly, LiF have been carried out and the theory has been developed to a rather advanced stage by Professor Manson. This work will permit the extraction of more information from time-of-flight spectra. It is shown that the theoretical model provides a very good description of the multiphoton scattering from organic films. Work has started on self-assembling organic films on gold (alkyl thiols/Au(111)). We have begun to prepare and characterize the gold crystal; one of the group members has spent two weeks at the Oak Ridge National Laboratory learning the proper Au(111) preparation techniques. One of our students has carried out neutron scattering experiments on NiO, measuring both bulk phonon and magnon dispersion curves

Microstructural changes of a thermally aged stainless steel submerged arc weld overlay cladding of nuclear reactor pressure vessels

Science.gov (United States)

Takeuchi, T.; Kameda, J.; Nagai, Y.; Toyama, T.; Matsukawa, Y.; Nishiyama, Y.; Onizawa, K.

2012-06-01

The effect of thermal aging on microstructural changes in stainless steel submerged arc weld-overlay cladding of reactor pressure vessels was investigated using atom probe tomography (APT). In as-received materials subjected to post-welding heat treatments (PWHTs), with a subsequent furnace cooling, a slight fluctuation of the Cr concentration was observed due to spinodal decomposition in the δ-ferrite phase but not in the austenitic phase. Thermal aging at 400 °C for 10,000 h caused not only an increase in the amplitude of spinodal decomposition but also the precipitation of G phases with composition ratios of Ni:Si:Mn = 16:7:6 in the δ-ferrite phase. The degree of the spinodal decomposition in the submerged arc weld sample was similar to that in the electroslag weld one reported previously. We also observed a carbide on the γ-austenite and δ-ferrite interface. There were no Cr depleted zones around the carbide.

Microstructural changes of a thermally aged stainless steel submerged arc weld overlay cladding of nuclear reactor pressure vessels

Energy Technology Data Exchange (ETDEWEB)

Takeuchi, T., E-mail: takeuchi.tomoaki@jaea.go.jp [Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Kameda, J. [National Institute for Materials Science, Sengen, Tsukuba 305-0047 (Japan); Nagai, Y.; Toyama, T.; Matsukawa, Y. [Oarai Center, Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Nishiyama, Y.; Onizawa, K. [Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)

2012-06-15

The effect of thermal aging on microstructural changes in stainless steel submerged arc weld-overlay cladding of reactor pressure vessels was investigated using atom probe tomography (APT). In as-received materials subjected to post-welding heat treatments (PWHTs), with a subsequent furnace cooling, a slight fluctuation of the Cr concentration was observed due to spinodal decomposition in the {delta}-ferrite phase but not in the austenitic phase. Thermal aging at 400 Degree-Sign C for 10,000 h caused not only an increase in the amplitude of spinodal decomposition but also the precipitation of G phases with composition ratios of Ni:Si:Mn = 16:7:6 in the {delta}-ferrite phase. The degree of the spinodal decomposition in the submerged arc weld sample was similar to that in the electroslag weld one reported previously. We also observed a carbide on the {gamma}-austenite and {delta}-ferrite interface. There were no Cr depleted zones around the carbide.

Colonization of overlaying water by bacteria from dry river sediments.

Science.gov (United States)

Fazi, Stefano; Amalfitano, Stefano; Piccini, Claudia; Zoppini, Annamaria; Puddu, Alberto; Pernthaler, Jakob

2008-10-01

We studied the diversity, community composition and activity of the primary microbial colonizers of the water above freshly re-wetted sediments from a temporary river. Dried sediments, collected from Mulargia River (Sardinia, Italy), were covered with sterile freshwater in triplicate microcosms, and changes of the planktonic microbial assemblage were monitored over a 48 h period. During the first 9 h bacterial abundance was low (1.5 x 10(4) cells ml(-1)); it increased to 3.4 x 10(6) cells ml(-1) after 28 h and did not change thereafter. Approximately 20% of bacteria exhibited DNA de novo synthesis already after 9 h of incubation. Changes of the ratios of (3)H-leucine to (3)H-thymidine incorporation rates indicated a shift of growth patterns during the experiment. Extracellular enzyme activity showed a maximum at 48 h with aminopeptidase activity (430.8 +/- 22.6 nmol MCA l(-1) h(-1)) significantly higher than alkaline phosphatase (98.6 +/- 4.3 nmol MUF l(-1) h(-1)). The primary microbial colonizers of the overlaying water - as determined by 16S rRNA gene sequence analysis - were related to at least six different phylogenetic lineages of Bacilli and to Alphaproteobacteria (Brevundimonas spp. and Caulobacter spp.). Large bacterial cells affiliated to one clade of Bacillus sp. were rare in the dried sediments, but constituted the majority of the planktonic microbial assemblage and of cells with detectable DNA-synthesis until 28 h after re-wetting. Their community contribution decreased in parallel with a rise of flagellated and ciliated protists. Estimates based on cell production rates suggested that the rapidly enriched Bacillus sp. suffered disproportionally high loss rates from selective predation, thus favouring the establishment of a more heterogenic assemblage of microbes (consisting of Proteobacteria, Actinobacteria and Cytophaga-Flavobacteria). Our results suggest that the primary microbial colonizers of the water above dried sediments are passively released

Wind turbine rotor blade with in-plane sweep and devices using the same, and methods for making the same

Science.gov (United States)

Wetzel, Kyle Kristopher

2014-06-24

A wind turbine includes a rotor having a hub and at least one blade having a torsionally rigid root, an inboard section, and an outboard section. The inboard section has a forward sweep relative to an elastic axis of the blade and the outboard section has an aft sweep.

78 FR 20844 - Airworthiness Directives; Bombardier, Inc. Airplanes

Science.gov (United States)

2013-04-08

... certain flap actuators require restoration by installing a redesigned flap actuator inboard pinion seal... Engineer, Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft Certification Office (ACO... CL-600-2B19 aeroplane flap actuator inboard pinion seal is prone to leak which can cause internal...

Risk management algorithm for rear-side collision avoidance using a combined steering torque overlay and differential braking

Science.gov (United States)

Lee, Junyung; Yi, Kyongsu; Yoo, Hyunjae; Chong, Hyokjin; Ko, Bongchul

2015-06-01

This paper describes a risk management algorithm for rear-side collision avoidance. The proposed risk management algorithm consists of a supervisor and a coordinator. The supervisor is designed to monitor collision risks between the subject vehicle and approaching vehicle in the adjacent lane. An appropriate criterion of intervention, which satisfies high acceptance to drivers through the consideration of a realistic traffic, has been determined based on the analysis of the kinematics of the vehicles in longitudinal and lateral directions. In order to assist the driver actively and increase driver's safety, a coordinator is designed to combine lateral control using a steering torque overlay by motor-driven power steering and differential braking by vehicle stability control. In order to prevent the collision while limiting actuator's control inputs and vehicle dynamics to safe values for the assurance of the driver's comfort, the Lyapunov theory and linear matrix inequalities based optimisation methods have been used. The proposed risk management algorithm has been evaluated via simulation using CarSim and MATLAB/Simulink.

Automated sub-5 nm image registration in integrated correlative fluorescence and electron microscopy using cathodoluminescence pointers

Science.gov (United States)

Haring, Martijn T.; Liv, Nalan; Zonnevylle, A. Christiaan; Narvaez, Angela C.; Voortman, Lenard M.; Kruit, Pieter; Hoogenboom, Jacob P.

2017-03-01

In the biological sciences, data from fluorescence and electron microscopy is correlated to allow fluorescence biomolecule identification within the cellular ultrastructure and/or ultrastructural analysis following live-cell imaging. High-accuracy (sub-100 nm) image overlay requires the addition of fiducial markers, which makes overlay accuracy dependent on the number of fiducials present in the region of interest. Here, we report an automated method for light-electron image overlay at high accuracy, i.e. below 5 nm. Our method relies on direct visualization of the electron beam position in the fluorescence detection channel using cathodoluminescence pointers. We show that image overlay using cathodoluminescence pointers corrects for image distortions, is independent of user interpretation, and does not require fiducials, allowing image correlation with molecular precision anywhere on a sample.

Aberration analysis for freeform surface terms overlay on general decentered and tilted optical surfaces.

Science.gov (United States)

Yang, Tong; Cheng, Dewen; Wang, Yongtian

2018-03-19

Aberration theory helps designers to better understand the nature of imaging systems. However, the existing aberration theory of freeform surfaces has many limitations. For example, it only works in the special case when the central area of the freeform surface is used. In addition, the light footprint is limited to a circle, which does not match the case of an elliptical footprint for general systems. In this paper, aberrations generated by freeform surface term overlay on general decentered and tilted optical surfaces are analyzed. For the case when the off-axis section of a freeform surface is used, the aberration equation for using stop and nonstop surfaces is discussed, and the aberrations generated by Zernike terms up to Z 17/18 are analyzed in detail. To solve the problem of the elliptical light footprint for tilted freeform surfaces, the scaled pupil vector is used in the aberration analysis. The mechanism of aberration transformation is discovered, and the aberrations generated by different Zernike terms in this case are calculated. Finally we proposed aberration equations for freeform terms on general decentered and tilted freeform surfaces. The research result given in this paper offers an important reference for optical designers and engineers, and it is of great importance in developing analytical methods for general freeform system design, tolerance analysis, and system assembly.

Distributed coordination of heterogeneous agents using a semantic overlay network and a goal-directed graphplan planner.

Directory of Open Access Journals (Sweden)

António Luís Lopes

Full Text Available In this paper, we describe a distributed coordination system that allows agents to seamlessly cooperate in problem solving by partially contributing to a problem solution and delegating the subproblems for which they do not have the required skills or knowledge to appropriate agents. The coordination mechanism relies on a dynamically built semantic overlay network that allows the agents to efficiently locate, even in very large unstructured networks, the necessary skills for a specific problem. Each agent performs partial contributions to the problem solution using a new distributed goal-directed version of the Graphplan algorithm. This new goal-directed version of the original Graphplan algorithm provides an efficient solution to the problem of "distraction", which most forward-chaining algorithms suffer from. We also discuss a set of heuristics to be used in the backward-search process of the planning algorithm in order to distribute this process amongst idle agents in an attempt to find a solution in less time. The evaluation results show that our approach is effective in building a scalable and efficient agent society capable of solving complex distributable problems.

Holistic approach for overlay and edge placement error to meet the 5nm technology node requirements

Science.gov (United States)

Mulkens, Jan; Slachter, Bram; Kubis, Michael; Tel, Wim; Hinnen, Paul; Maslow, Mark; Dillen, Harm; Ma, Eric; Chou, Kevin; Liu, Xuedong; Ren, Weiming; Hu, Xuerang; Wang, Fei; Liu, Kevin

2018-03-01

In this paper, we discuss the metrology methods and error budget that describe the edge placement error (EPE). EPE quantifies the pattern fidelity of a device structure made in a multi-patterning scheme. Here the pattern is the result of a sequence of lithography and etching steps, and consequently the contour of the final pattern contains error sources of the different process steps. EPE is computed by combining optical and ebeam metrology data. We show that high NA optical scatterometer can be used to densely measure in device CD and overlay errors. Large field e-beam system enables massive CD metrology which is used to characterize the local CD error. Local CD distribution needs to be characterized beyond 6 sigma, and requires high throughput e-beam system. We present in this paper the first images of a multi-beam e-beam inspection system. We discuss our holistic patterning optimization approach to understand and minimize the EPE of the final pattern. As a use case, we evaluated a 5-nm logic patterning process based on Self-Aligned-QuadruplePatterning (SAQP) using ArF lithography, combined with line cut exposures using EUV lithography.

Structured P2P overlay of mobile brokers for realizing publish/subscribe communication in VANET.

Science.gov (United States)

Pandey, Tulika; Garg, Deepak; Gore, Manoj Madhava

2014-01-01

Publish/subscribe communication paradigm provides asynchrony and decoupling, making it an elegant alternative for designing applications in distributed and dynamic environment such as vehicular ad hoc networks (VANETs). In this paradigm, the broker is the most important component that decouples other two components, namely, publisher and subscriber. Previous research efforts have either utilized the deployment of distributed brokers on stationary road side info-stations or have assigned the role of broker to any moving vehicle on ad hoc basis. In one approach, lots of preinstalled infrastructures are needed whereas, in another, the quality of service is not guaranteed due to unpredictable moving and stopping patterns of vehicles. In this paper, we present the architecture of distributed mobile brokers which are dynamically reconfigurable in the form of structured P2P overlay and act as rendezvous points for matching publications and subscriptions. We have taken city buses in urban settings to act as mobile brokers whereas other vehicles are considered to be in role of publishers and subscribers. These mobile brokers also assist in locating a vehicle for successful and timely transfer of notifications. We have performed an extensive simulation study to compare our approach with previously proposed approaches. Simulation results establish the applicability of our approach.

Structured P2P Overlay of Mobile Brokers for Realizing Publish/Subscribe Communication in VANET

Directory of Open Access Journals (Sweden)

Tulika Pandey

2014-01-01

Full Text Available Publish/subscribe communication paradigm provides asynchrony and decoupling, making it an elegant alternative for designing applications in distributed and dynamic environment such as vehicular ad hoc networks (VANETs. In this paradigm, the broker is the most important component that decouples other two components, namely, publisher and subscriber. Previous research efforts have either utilized the deployment of distributed brokers on stationary road side info-stations or have assigned the role of broker to any moving vehicle on ad hoc basis. In one approach, lots of preinstalled infrastructures are needed whereas, in another, the quality of service is not guaranteed due to unpredictable moving and stopping patterns of vehicles. In this paper, we present the architecture of distributed mobile brokers which are dynamically reconfigurable in the form of structured P2P overlay and act as rendezvous points for matching publications and subscriptions. We have taken city buses in urban settings to act as mobile brokers whereas other vehicles are considered to be in role of publishers and subscribers. These mobile brokers also assist in locating a vehicle for successful and timely transfer of notifications. We have performed an extensive simulation study to compare our approach with previously proposed approaches. Simulation results establish the applicability of our approach.

77 FR 61542 - Airworthiness Directives; The Boeing Company Airplanes

Science.gov (United States)

2012-10-10

... flange of the inboard track at the rear spar attachment of each outboard flap, and eventual rework of the... inboard track at the rear spar attachment of each outboard flap, and eventual rework of the flap track... required by paragraph (g) of this AD, before further flight, repair or rework the flap track per the...

Radiation safety in sea transport of radioactive material in Japan

International Nuclear Information System (INIS)

Odano, N.; Yanagi, H.

2004-01-01

Radiation safety for sea transport of radioactive material in Japan has been discussed based on records of the exposed dose of sea transport workers and measured data of dose rate equivalents distribution inboard exclusive radioactive material shipping vessels. Recent surveyed records of the exposed doses of workers who engaged in sea transport operation indicate that exposed doses of transport workers are significantly low. Measured distribution of the exposed dose equivalents inboard those vessels indicates that dose rate equivalents inside those vessels are lower than levels regulated by the transport regulations of Japan. These facts clarify that radiation safety of inboard environment and handling of transport casks in sea transport of radioactive material in Japan are assured

Radiation safety in sea transport of radioactive material in Japan

Energy Technology Data Exchange (ETDEWEB)

Odano, N. [National Maritime Research Inst., Tokyo (Japan); Yanagi, H. [Nuclear Fuel Transport Co., Ltd., Tokyo (Japan)

2004-07-01

Radiation safety for sea transport of radioactive material in Japan has been discussed based on records of the exposed dose of sea transport workers and measured data of dose rate equivalents distribution inboard exclusive radioactive material shipping vessels. Recent surveyed records of the exposed doses of workers who engaged in sea transport operation indicate that exposed doses of transport workers are significantly low. Measured distribution of the exposed dose equivalents inboard those vessels indicates that dose rate equivalents inside those vessels are lower than levels regulated by the transport regulations of Japan. These facts clarify that radiation safety of inboard environment and handling of transport casks in sea transport of radioactive material in Japan are assured.

78 FR 73687 - Airworthiness Directives; DASSAULT AVIATION Airplanes

Science.gov (United States)

2013-12-09

... and corrected, could lead to complete fracture of the rib and loss of integrity of the flap structure... inboard end plate (rib) of the inboard flap could lead to complete fracture of the rib and loss of... correct such cracking, which could lead to complete fracture of the rib and loss of integrity of the flap...

TinCan: User-Defined P2P Virtual Network Overlays for Ad-hoc Collaboration

Directory of Open Access Journals (Sweden)

Pierre St Juste

2014-10-01

Full Text Available Virtual private networking (VPN has become an increasingly important component of a collaboration environment because it ensures private, authenticated communication among participants, using existing collaboration tools, where users are distributed across multiple institutions and can be mobile. The majority of current VPN solutions are based on a centralized VPN model, where all IP traffic is tunneled through a VPN gateway. Nonetheless, there are several use case scenarios that require a model where end-to-end VPN links are tunneled upon existing Internet infrastructure in a peer-to-peer (P2P fashion, removing the bottleneck of a centralized VPN gateway. We propose a novel virtual network — TinCan — based on peerto-peer private network tunnels. It reuses existing standards and implementations of services for discovery notification (XMPP, reflection (STUN and relaying (TURN, facilitating configuration. In this approach, trust relationships maintained by centralized (or federated services are automatically mapped to TinCan links. In one use scenario, TinCan allows unstructured P2P overlays connecting trusted end-user devices — while only requiring VPN software on user devices and leveraging online social network (OSN infrastructure already widely deployed. This paper describes the architecture and design of TinCan and presents an experimental evaluation of a prototype supporting Windows, Linux, and Android mobile devices. Results quantify the overhead introduced by the network virtualization layer, and the resource requirements imposed on services needed to bootstrap TinCan links.

Flap Side Edge Liners for Airframe Noise Reduction

Science.gov (United States)

Jones, Michael G. (Inventor); Khorrami, Mehdi R. (Inventor); Choudhari, Meelan M. (Inventor); Howerton, Brian M. (Inventor)

2014-01-01

One or more acoustic liners comprising internal chambers or passageways that absorb energy from a noise source on the aircraft are disclosed. The acoustic liners may be positioned at the ends of flaps of an aircraft wing to provide broadband noise absorption and/or dampen the noise producing unsteady flow features, and to reduce the amount of noise generated due to unsteady flow at the inboard and/or outboard end edges of a flap.

Overlayer growth and electronic properties of the Bi/GaSb(110) interface

Science.gov (United States)

Gavioli, Luca; Betti, Maria Grazia; Casarini, Paolo; Mariani, Carlo

1995-06-01

The overlayer growth and electronic properties of the Bi/GaSb(110) interface and of the two-dimensional ordered (1×1)- and (1×2)-Bi layers have been investigated by complementary spectroscopic techniques (high-resolution electron-energy-loss, photoemission, and Auger spectroscopy). Bismuth forms an epitaxial monolayer, followed by island formation (Stranski-Krastanov growth mode) covering an average surface area of 40% at a nominal coverage of 4 ML. The (1×2)-symmetry stable structural phase, obtained after annealing at ~220 °C, corresponds to an average nominal Bi coverage of about 0.7 ML, suggesting an atomic geometry different from the epitaxial-continued layer structure. The disposal of Bi atoms in the (1×2) structure should build up an ``open'' layer, as the Ga-related surface exciton quenched in the (1×1) epitaxial monolayer is present in the (1×2) stable phase. The two symmetry phases are characterized by strong absorption features at 1 eV [(1×1)-Bi] and 0.54 eV [(1×2)-Bi], related to interband electronic transitions between Bi-induced electronic states. The major Bi-related occupied electronic levels, present in the valence band of the (1×1)- and (1×2)-Bi layer, have been detected by angle-integrated ultraviolet photoemission spectroscopy. Both the (1×1) and (1×2) phases show a metallic nature, with a low density of electronic states at the Fermi level. Schottky barrier heights of 0.20 and 0.14 eV are estimated for the epitaxial (1×1)- and (1×2)-symmetry stage, respectively, by analyzing the space-charge layer conditions through the study of the dopant-induced free-carrier plasmon in the GaSb substrate.

Interaction of epitaxial silicene with overlayers formed by exposure to Al atoms and O2 molecules.

Science.gov (United States)

Friedlein, R; Van Bui, H; Wiggers, F B; Yamada-Takamura, Y; Kovalgin, A Y; de Jong, M P

2014-05-28

As silicene is not chemically inert, the study and exploitation of its electronic properties outside of ultrahigh vacuum environments require the use of insulating capping layers. In order to understand if aluminum oxide might be a suitable encapsulation material, we used high-resolution synchrotron photoelectron spectroscopy to study the interactions of Al atoms and O2 molecules, as well as the combination of both, with epitaxial silicene on thin ZrB2(0001) films grown on Si(111). The deposition of Al atoms onto silicene, up to the coverage of about 0.4 Al per Si atoms, has little effect on the chemical state of the Si atoms. The silicene-terminated surface is also hardly affected by exposure to O2 gas, up to a dose of 4500 L. In contrast, when Al-covered silicene is exposed to the same dose, a large fraction of the Si atoms becomes oxidized. This is attributed to dissociative chemisorption of O2 molecules by Al atoms at the surface, producing reactive atomic oxygen species that cause the oxidation. It is concluded that aluminum oxide overlayers prepared in this fashion are not suitable for encapsulation since they do not prevent but actually enhance the degradation of silicene.

Precise positioning of an intraoral distractor using augmented reality in patients with hemifacial microsomia.

Science.gov (United States)

Qu, Miao; Hou, Yikang; Xu, Yourong; Shen, Congcong; Zhu, Ming; Xie, Le; Wang, Hao; Zhang, Yan; Chai, Gang

2015-01-01

Through three-dimensional real time imaging, augmented reality (AR) can provide an overlay of the anatomical structure, or visual cues for specific landmarks. In this study, an AR Toolkit was used for distraction osteogenesis with hemifacial microsomia to define the mandibular osteotomy line and assist with intraoral distractor placement. 20 patients with hemifacial microsomia were studied and were randomly assigned to experimental and control groups. Pre-operative computed tomography was used in both groups, whereas AR was used in the experimental group. Afterwards, pre- and post-operative computed tomographic scans of both groups were superimposed, and several measurements were made and analysed. Both the conventional method and AR technique achieved proper positioning of the osteotomy planes, although the AR was more accurate. The difference in average vertical distance from the coronoid and condyle process to the pre- and post-operative cutting planes was significant (p 0.05) was observed in the average angle between the two planes. The difference in deviations between the intersection points of the overlaid mandible across two cutting planes was also significant (p Augmented reality tools such as the AR Toolkit may be helpful for precise positioning of intraoral distractors in patients with hemifacial microsomia in craniofacial surgery. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Nucleation and growth of C60 overlayers on the Ag/Pt(111) dislocation network surface

International Nuclear Information System (INIS)

Ait-Mansour, K; Ruffieux, P; Xiao, W; Fasel, R; Groening, P; Groening, O

2007-01-01

We have investigated the room temperature growth of C 60 overlayers on the strainrelief dislocation network formed by two monolayers of Ag on Pt(111) by means of scanning tunneling microscopy. Extended domains of highly ordered dislocation networks with a typical superlattice parameter of 6.8 nm have been prepared, serving as templates for subsequent C 60 depositions. For low C 60 coverages, the molecules decorate the step-edges, where also the first islands nucleate. This indicates that at room temperature the C 60 molecules are sufficiently mobile to cross the dislocation lines and to diffuse to the step-edges. For C 60 coverages of 0.4 monolayer, besides the islands nucleated at the step-edges, C 60 islands also grow in the middle of terraces. The C 60 islands typically extend over several unit cells of the dislocation network and show an unusual orientation of the hexagonally close-packed C 60 lattice as compared to that found on the bare Ag(111) surface. Whereas C 60 grows preferentially in a (2 √3 x 2 √3) R30 0 structure on Ag(111), on the Ag/Pt(111) dislocation network the C 60 lattice adopts an orientation rotated by 30 0 , with the close-packed C 60 rows aligned along the dislocations which themselves are aligned along the Ag(1-10) directions. For higher coverages in the range of 1-2 monolayers, the growth of C 60 continues in a layer-by-layer fashion

Interaction of epitaxial silicene with overlayers formed by exposure to Al atoms and O{sub 2} molecules

Energy Technology Data Exchange (ETDEWEB)

Friedlein, R.; Yamada-Takamura, Y. [Japan Advanced Institute of Science and Technology, School of Materials Science, Nomi, Ishikawa 923-1292 (Japan); Van Bui, H.; Wiggers, F. B.; Kovalgin, A. Y.; Jong, M. P. de, E-mail: M.P.deJong@utwente.nl [MESA Institute for Nanotechnology, University of Twente, 7500 AE Enschede (Netherlands)

2014-05-28

As silicene is not chemically inert, the study and exploitation of its electronic properties outside of ultrahigh vacuum environments require the use of insulating capping layers. In order to understand if aluminum oxide might be a suitable encapsulation material, we used high-resolution synchrotron photoelectron spectroscopy to study the interactions of Al atoms and O{sub 2} molecules, as well as the combination of both, with epitaxial silicene on thin ZrB{sub 2}(0001) films grown on Si(111). The deposition of Al atoms onto silicene, up to the coverage of about 0.4 Al per Si atoms, has little effect on the chemical state of the Si atoms. The silicene-terminated surface is also hardly affected by exposure to O{sub 2} gas, up to a dose of 4500 L. In contrast, when Al-covered silicene is exposed to the same dose, a large fraction of the Si atoms becomes oxidized. This is attributed to dissociative chemisorption of O{sub 2} molecules by Al atoms at the surface, producing reactive atomic oxygen species that cause the oxidation. It is concluded that aluminum oxide overlayers prepared in this fashion are not suitable for encapsulation since they do not prevent but actually enhance the degradation of silicene.

Hybrid Terrestrial-Satellite DVB/IP Infrastructure in Overlay Constellations for Triple-Play Services Access in Rural Areas

Directory of Open Access Journals (Sweden)

E. Pallis

2010-01-01

Full Text Available This paper discusses the convergence of digital broadcasting and Internet technologies, by elaborating on the design, implementation, and performance evaluation of a hybrid terrestrial/satellite networking infrastructure, enabling triple-play services access in rural areas. At local/district level, the paper proposes the exploitation of DVB-T platforms in regenerative configurations for creating terrestrial DVB/IP backhaul between the core backbone (in urban areas and a number of intermediate communication nodes distributed within the DVB-T broadcasting footprint (in rural areas. In this way, triple play services that are available at the core backbone, are transferred via the regenerative DVB-T/IP backhaul to the entire district and can be accessed by rural users via the corresponding intermediate node. On the other hand, at regional/national level, the paper proposes the exploitation of a satellite interactive digital video broadcasting platform (DVB S2/RCS as an overlay network that interconnects the regenerative DVB-T/IP platforms, as well as individual users, and services providers, to each other. Performance of the proposed hybrid terrestrial/satellite networking environment is validated through experimental tests that were conducted under real transmission/reception conditions (for the terrestrial segment and via simulation experiments (for the satellite segment at a prototype network infrastructure.

Study on microstructural changes in thermally-aged stainless steel weld-overlay cladding of nuclear reactor pressure vessels by atom probe tomography

Science.gov (United States)

Takeuchi, T.; Kameda, J.; Nagai, Y.; Toyama, T.; Nishiyama, Y.; Onizawa, K.

2011-08-01

The effect of thermal aging on microstructural changes was investigated in stainless steel weld-overlay cladding composed of 90% austenite and 10% δ-ferrite phases using atom probe tomography (APT). In as-received materials subjected to cooling process after post-welding heat treatments (PWHT), a slight fluctuation of the Cr concentration was already observed due to spinodal decomposition in the ferrite phase but not in the austenitic phase. Thermal aging at 400 °C for 10,000 h caused not only an increase in the amplitude of spinodal decomposition but also the precipitation of G phases with composition ratios of Ni:Si:Mn = 16:7:6 in the ferrite phase. The chemical compositions of M 23C 6 type carbides seemed to be formed at the austenite/ferrite interface were analyzed. The analyses of the magnitude of the spinodal decomposition and the hardness implied that the spinodal decomposition was the main cause of the hardening.

Aspectos metalúrgicos de revestimentos dissimilares com a superliga à base de níquel inconel 625 Metallurgical aspects of dissimilar weld overlays of inconel 625 nickel based superalloys

Directory of Open Access Journals (Sweden)

Cleiton Carvalho Silva

2012-09-01

Full Text Available Prolongar a vida útil e aumentar a confiabilidade de equipamentos e tubulações de plantas de produção e processamento de petróleo é uma busca constante no setor de petróleo e gás. Tais aspectos dependem essencialmente do uso de ligas resistentes à corrosão. Neste contexto, a soldagem de revestimento com superligas à base de níquel tem sido uma alternativa interessante, pois confere aos equipamentos uma alta resistência à corrosão com um custo inferior, se comparado à fabricação de componentes ou tubulações maciças com superligas. Assim, o objetivo do presente trabalho foi investigar o comportamento metalúrgico de revestimento de superliga à base de níquel do tipo Inconel 625 depositados pelo processo TIG com alimentação de arame frio. As soldagens foram realizadas em uma bancada robotizada, empregando uma fonte eletrônica de soldagem com sistema de aquisição de dados para o monitoramento dos sinais de corrente e tensão. A caracterização microestrutural foi realizada através das técnicas de microscopia eletrônica de varredura (MEV e transmissão (MET, espectroscopia de energia dispersiva de raios-X (EDS. Os resultados mostraram que a microestrutura do metal de solda foi constituída por uma matriz γ com fases secundárias ricas em Nb. Foi encontrada a formação de precipitados complexos de carbonetos/nitretos de Ti e Nb.To extend the life and reliability of pipes and equipment in oil & gas production and processing settings is a continuous demand. These aspects are essentially dependent on corrosion resistant alloys used. In this context, the weld overlay with Ni-based superalloys is a great interesting alternative, since improve the corrosion resistance without increase the cost of manufacture when compared to massive equipment. Thus, the objective of this study was to evaluate the metallurgical aspects of Inconel 625 weld overlays deposited by GTAW cold wire feed process. The welds were performed using a

A new divertor plates design concept for the double null NET configuration

International Nuclear Information System (INIS)

Farfaletti-Casali, F.; Renda, V.; Federici, G.; Papa, L.

1986-01-01

A new divertor plate design concept for the Double Null NET configuration (NET-DN) is presented. This concept applies to the plasma configuration of NET and takes advantage by the maintenance scheme of the internal components adopted in NET. According to this maintenance approach, which uses the top loading of the internal segments, 48 inboard removable segments, 3 for each of the 16 reactor sectors, act as simple protective panels, gathering together in only one piece the plates of both the upper and lower divertor regions and the intermediate portion of the inboard first wall. They are cooled by water flowing inside a set of hairpin-shaped, stainless steel tubes, arranged in poloidal direction inside a copper heat sink, and fed by supply lines at the top of the reactor. The surface facing the plasma is covered by a tungsten alloy layer. In such a way, the maintenance of the two divertor regions and of the inboard first wall can be easily achieved by removing the inboard panels from the top of the reactor. The layout of the cooling system and preliminary thermohydraulics and thermomechanical calculations, carried out for assessing the feasibility of the proposed system for the NET reference configuration, are reported in this paper. (author)

A new divertor plates design concept for the double null net configuration

International Nuclear Information System (INIS)

Farfaletti-Casali, F.; Iop, O.; Renda, V.; Federici, G.; Papa, L.

1987-01-01

A new divertor plate design concept for the Double Null NET configuration (NET-DN) is presented in this paper. This concept applies to the plasma configuration of NET and takes advantage by the maintenance scheme of the internal components adopted in NET. According to this maintenance approach, which uses the top loading of the internal segments, 48 inboard removable segments, 3 for each of the 16 reactor sectors, act as simple protective panels, gathering together in only one piece the plates of both the upper and lower divertor regions and the intermediate portion of the inboard first wall. They are cooled by water flowing inside a set of hairpin-shaped, stainless steel tubes, arranged in poloidal direction inside a copper heat sink, and fed by supply lines at the top of the reactor. The surface facing the plasma is covered by a tungsten alloy layer. In such a way, the maintenance of the two divertor regions and of the inboard first wall can be easily achieved by removing the inboard panels from the top of the reactor. The layout of the cooling system and preliminary thermohydraulics and thermomechanical calculations, carried out for assessing the feasibility of the proposed system for the NET reference configuration, are reported in this paper

Groundwater vulnerability assessment: from overlay methods to statistical methods in the Lombardy Plain area

Directory of Open Access Journals (Sweden)

Stefania Stevenazzi

2017-06-01

Full Text Available Groundwater is among the most important freshwater resources. Worldwide, aquifers are experiencing an increasing threat of pollution from urbanization, industrial development, agricultural activities and mining enterprise. Thus, practical actions, strategies and solutions to protect groundwater from these anthropogenic sources are widely required. The most efficient tool, which helps supporting land use planning, while protecting groundwater from contamination, is represented by groundwater vulnerability assessment. Over the years, several methods assessing groundwater vulnerability have been developed: overlay and index methods, statistical and process-based methods. All methods are means to synthesize complex hydrogeological information into a unique document, which is a groundwater vulnerability map, useable by planners, decision and policy makers, geoscientists and the public. Although it is not possible to identify an approach which could be the best one for all situations, the final product should always be scientific defensible, meaningful and reliable. Nevertheless, various methods may produce very different results at any given site. Thus, reasons for similarities and differences need to be deeply investigated. This study demonstrates the reliability and flexibility of a spatial statistical method to assess groundwater vulnerability to contamination at a regional scale. The Lombardy Plain case study is particularly interesting for its long history of groundwater monitoring (quality and quantity, availability of hydrogeological data, and combined presence of various anthropogenic sources of contamination. Recent updates of the regional water protection plan have raised the necessity of realizing more flexible, reliable and accurate groundwater vulnerability maps. A comparison of groundwater vulnerability maps obtained through different approaches and developed in a time span of several years has demonstrated the relevance of the

GOVERNING BOARD OF THE PENSION FUND

CERN Multimedia

2002-01-01

The Governing Board held its hundred-and-tenth and hundred-and-eleventh meetings on 3 September and 2 October respectively. At the first of these meetings, the Governing Board first heard a report presented by B. Strange and F.-X. Douin of JPMorgan Fleming Asset Management on currency overlay. This system has been in operation since 1997 and has fully achieved its objective of allowing the Fund to diversify its investment positions outside Switzerland while reducing portfolio risk. Although the implementation of this currency overlay policy has resulted in substantial disbursements in the first few years, cashflow over the whole period and especially since the weakening of the dollar has been positive. The Governing Board, on the basis of a proposal by the Investment Committee, will have to take a decision on the average level of overlay to be maintained for the Fund's assets. The ordinary meeting held on the afternoon of the same day was mainly devoted to the examination of a number of technical amendments t...

Insight into Rotational Effects on a Wind Turbine Blade Using Navier–Stokes Computations

Directory of Open Access Journals (Sweden)

Iván Herráez

2014-10-01

Full Text Available Rotational effects are known to influence severely the aerodynamic performance of the inboard region of rotor blades. The underlying physical mechanisms are however far from being well understood. The present work addresses this problem using Reynolds averaged Navier–Stokes computations and experimental results of the MEXICO (Model Experiments in Controlled Conditions rotor. Four axisymmetric inflow cases with wind speeds ranging from pre-stall to post-stall conditions are computed and compared with pressure and particle image velocimetry (PIV experimental data, obtaining, in general, consistent results. At low angles of attack, the aerodynamic behavior of all of the studied blade sections resembles the one from the corresponding 2D airfoils. However, at high angles of attack, rotational effects lead to stall delay and/or lift enhancement at inboard positions. Such effects are shown to occur only in the presence of significant radial flows. Interestingly, the way in which rotational effects influence the aerodynamics of the MEXICO blades differs qualitatively in certain aspects from the descriptions found in the literature about this topic. The presented results provide new insights that are useful for the development of advanced and physically-sound correction models.

An investigation on microstructure and mechanical property of thermally aged stainless steel weld overlay cladding

Energy Technology Data Exchange (ETDEWEB)

Cao, X.Y. [National Center for Materials Service Safety, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing (China); Zhu, P. [Suzhou Nuclear Power Research Institute Co. Ltd., 1788 Xihuan Road, 215004 Suzhou (China); Ding, X.F. [National Center for Materials Service Safety, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing (China); Lu, Y.H., E-mail: lu_yonghao@mater.ustb.edu.cn [National Center for Materials Service Safety, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing (China); Shoji, T. [National Center for Materials Service Safety, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing (China); Fracture and Reliability Research Institute, Tohoku University, 6-6-01 Aoba AramakiAobaku, 980-8579 Sendai (Japan)

2017-04-01

Microstructural evolution and mechanical property change of E308L stainless steel weld overlay cladding aged at 400 °C for 400, 1000 and 5000 h were investigated by transmission electron microscope (TEM) and small punch test (SPT). The results indicated that thermal aging had no obvious effect on the volume fraction of ferrite, but can cause microstructural evolution by spinodal decomposotion and G-phase precipitation in the ferrite phase. Spinodal decomposition took place after aging up to 1000 h, while G-phase formed along dislocations, and growed up to 2–11 nm after aging for 5000 h. The total energy for inducing deformation and fracture by the small punch tests decreased with the increase of thermal aging time, and this decline was associated with spinodal decomposition and G-phase precipitation. Plastic deformation of the aged ferrite proceeded via formation of curvilinear slip bands. Nucleation of microcracks occurred at the δ/γ interface along the slip bands. The hardening of the ferrite and high stress concentration on δ/γ phase interface resulted in brittle fracture and phase boundary separation after thermal aging. - Highlights: •Spinodal decomposition took place after long-term therml aging at 400 °C. •Dislocations were the preferable sites for G-phase formation aged at 400 °C for 5000 h. •Spinodal decomposition and G-phase precipitation induced reduction of small punch energy. •Thermal aging led to brittle fracture and phase boundary separation. •Nucleation of microcracks occurred at the δ/γ interface along the slip bands in the aged ferrite phase.

An investigation on microstructure and mechanical property of thermally aged stainless steel weld overlay cladding

International Nuclear Information System (INIS)

Cao, X.Y.; Zhu, P.; Ding, X.F.; Lu, Y.H.; Shoji, T.

2017-01-01

Microstructural evolution and mechanical property change of E308L stainless steel weld overlay cladding aged at 400 °C for 400, 1000 and 5000 h were investigated by transmission electron microscope (TEM) and small punch test (SPT). The results indicated that thermal aging had no obvious effect on the volume fraction of ferrite, but can cause microstructural evolution by spinodal decomposotion and G-phase precipitation in the ferrite phase. Spinodal decomposition took place after aging up to 1000 h, while G-phase formed along dislocations, and growed up to 2–11 nm after aging for 5000 h. The total energy for inducing deformation and fracture by the small punch tests decreased with the increase of thermal aging time, and this decline was associated with spinodal decomposition and G-phase precipitation. Plastic deformation of the aged ferrite proceeded via formation of curvilinear slip bands. Nucleation of microcracks occurred at the δ/γ interface along the slip bands. The hardening of the ferrite and high stress concentration on δ/γ phase interface resulted in brittle fracture and phase boundary separation after thermal aging. - Highlights: •Spinodal decomposition took place after long-term therml aging at 400 °C. •Dislocations were the preferable sites for G-phase formation aged at 400 °C for 5000 h. •Spinodal decomposition and G-phase precipitation induced reduction of small punch energy. •Thermal aging led to brittle fracture and phase boundary separation. •Nucleation of microcracks occurred at the δ/γ interface along the slip bands in the aged ferrite phase.

Determination of thickness of thin turbid painted over-layers using micro-scale spatially offset Raman spectroscopy

Science.gov (United States)

Conti, Claudia; Realini, Marco; Colombo, Chiara; Botteon, Alessandra; Bertasa, Moira; Striova, Jana; Barucci, Marco; Matousek, Pavel

2016-12-01

We present a method for estimating the thickness of thin turbid layers using defocusing micro-spatially offset Raman spectroscopy (micro-SORS). The approach, applicable to highly turbid systems, enables one to predict depths in excess of those accessible with conventional Raman microscopy. The technique can be used, for example, to establish the paint layer thickness on cultural heritage objects, such as panel canvases, mural paintings, painted statues and decorated objects. Other applications include analysis in polymer, biological and biomedical disciplines, catalytic and forensics sciences where highly turbid overlayers are often present and where invasive probing may not be possible or is undesirable. The method comprises two stages: (i) a calibration step for training the method on a well characterized sample set with a known thickness, and (ii) a prediction step where the prediction of layer thickness is carried out non-invasively on samples of unknown thickness of the same chemical and physical make up as the calibration set. An illustrative example of a practical deployment of this method is the analysis of larger areas of paintings. In this case, first, a calibration would be performed on a fragment of painting of a known thickness (e.g. derived from cross-sectional analysis) and subsequently the analysis of thickness across larger areas of painting could then be carried out non-invasively. The performance of the method is compared with that of the more established optical coherence tomography (OCT) technique on identical sample set. This article is part of the themed issue "Raman spectroscopy in art and archaeology".

Current status on detail design and fabrication techniques development of ITER blanket shield block in Korea

International Nuclear Information System (INIS)

Kim, Duck Hoi; Cho, Seungyon; Ahn, Mu-Young; Lee, Eun-Seok; Jung, Ki Jung

2007-01-01

The allocation of components and systems to be delivered to ITER on an in-kind basis, was agreed between the ITER Parties. Among parties, Korea agreed to procure inboard blanket modules 1, 2 and 6, which consists of FW and shield block. Regarding shield block the detail design and Fabrication techniques development have been undertaken in Korea. Especially manufacturing feasibility study on shield block had been performed and some technical issues for the fabrication were selected. Based on these results, fabrication techniques using EB welding are being developed. Meanwhile, the detail design of inboard standard module has been carried out. The optimization of flow driver design to improve the cooling performance was executed. And, thermo-hydraulic analysis on half block of inboard standard module was performed. In this study, current status and some results from Fabrication techniques development on ITER blanket shield block are described. The detail design activity and results on shield block are also introduced herein. (orig.)

Estimation of intrinsic aquifer vulnerability with index-overlay and statistical methods: the case of eastern Kopaida, central Greece

KAUST Repository

Tziritis, E.

2016-03-01

The intrinsic vulnerability of a karstic aquifer system in central Greece was jointly assessed with the use of a statistical approach and PI method, as a function of topography, protective cover effectiveness and the degree to which this cover is bypassed due to flow conditions. The input data for the index-overlay PI method were derived from field works and 71 boreholes of the area; the information was obtained, subsequently its critical factors were compiled which included lithology, fissuring and karstification of bedrock, soil characteristics, hydrology, hydrogeology, topography and vegetation. The aforementioned parameters were processed jointly with the aid of a GIS and yielded the final estimation of intrinsic aquifer vulnerability to contamination. Results were compared with an equivalent spatially distributed probability map obtained through a stochastic approach. The calibration and test phase of the latter relied on morphometric conditions derived by terrain analyses of a digital elevation model as well as on geology and land use from thematic maps. This procedure allowed taking into account the topographic influences with respect to a deep system such as the local karstic aquifer of eastern Kopaida basin. Finally, results were validated with ground truth nitrate values obtained from 41 groundwater samples, highlighted the spatial delineation of susceptible areas to contamination in both cases and provided a robust tool for regional planning actions and water resources management schemes.

Test module in NET for a self-cooled liquid metal blanket concept

International Nuclear Information System (INIS)

Malang, S.; Arheidt, K.; Fischer, U.

1989-01-01

The application of a self-cooled liquid metal blanket concept to the condition of a DEMO-reactor and its testing in NET is described. The neutronics analysis shows that tritium self-sufficiency can be achieved without beryllium multiplier if breeding blankets are arranged at both outboard and inboard side of the torus or, using beryllium as multiplier, with outboard breeding only. First estimates indicate that it should be possible to test all relevant features of the concept in one of the horizontal plug positions of NET. (author). 6 refs.; 7 figs.; 1 tab

Evaluating the mechanical performance of Very Thin Asphalt Overlay (VTAO) as a sustainable rehabilitation strategy in urban pavements; Evaluación del comportamiento mecánico de capas bituminosas ultra delgadas como una adecuada estrategia para la rehabilitación de pavimentos urbanos

Energy Technology Data Exchange (ETDEWEB)

Sol-Sánchez, M.; García-Travé, G.; Ayar, P.; Moreno-Navarro, F.; Rubio-Gámez, M.C.

2017-07-01

Very Thin Asphalt Overlay (VTAO) has been introduced as an alternative to traditional thick overlays, seal coats, and micro-surfacings. Nonetheless, there are some challenges that still remain regarding the application of VTAOs (such as mixture type, cohesiveness, wear resistance, cracking and durability), particularly in heavy traffic urban areas. Therefore, this paper presents an extensive comparative evaluation of the mechanical performance, durability and safety issues (cohesiveness, adhesiveness, ageing, cracking, plastic deformation, permeability, macrotexture, skid and wear resistance, and fuel resistance) of a VTAO (20 mm thick) and a high performance BBTM 11B (35 mm thick), commonly used as an open-graded mixture for pavement overlays. The results demonstrated that VTAO is an appropriate material for urban pavements as it provides good durability and resistance to the propagation of defects. Nonetheless, further studies are required to improve its behavior under distresses related to plastic deformations and safety properties. [Spanish] Las capas bituminosas ultra delgadas para rehabilitación superficial de carreteras son una alternativa a las tradicionales capas asfálticas, riegos bituminosos y micro-aglomerados. No obstante, aún son numerosos los aspectos a estudiar para la generalización de su uso, particularmente en zonas urbanas con elevado tráfico. Así, este artículo recoge un análisis comparativo del comportamiento mecánico, durabilidad y factores de seguridad (evaluando parámetros como cohesividad, adhevisvidad, envejecimiento, fisuración, deformaciones, permeabilidad, macrotextura, y resistencia al deslizamiento, al desgaste y a los combustibles) entre una capa delgada de 20 mm de espesor, y una mezcla discontinua de altas prestaciones (BBTM-11B con 35 mm), comúnmente utilizada en capas de rodadura. Los resultados indican que puede ser una adecuada solución para pavimentos urbanos dada su durabilidad y resistencia a la propagación de

Rational-Emotive Education with Learning Disabled Children

Science.gov (United States)

Knaus, William; McKeever, Cynthia

1977-01-01

Rational-emotive education provides a positive, constructive approach for helping young children with learning problems who have psychogenic overlays to cope with worries and troubles effectively and to accept themselves affirmatively. (Author/SBH)

Vibrations of alkali metal overlayers on metal surfaces

International Nuclear Information System (INIS)

Rusina, G G; Eremeev, S V; Borisova, S D; Echenique, P M; Chulkov, E V; Benedek, G

2008-01-01

We review the current progress in the understanding of vibrations of alkalis adsorbed on metal surfaces. The analysis of alkali vibrations was made on the basis of available theoretical and experimental results. We also include in this discussion our recent calculations of vibrations in K/Pt(111) and Li(Na)/Cu(001) systems. The dependence of alkali adlayer localized modes on atomic mass, adsorption position and coverage as well as the dependence of vertical vibration frequency on the substrate orientation is discussed. The square root of atomic mass dependence of the vertical vibration energy has been confirmed by using computational data for alkalis on the Al(111) and Cu(001) substrates. We have confirmed that in a wide range of submonolayer coverages the stretch mode energy remains nearly constant while the energy of in-plane polarized modes increases with the increase of alkali coverage. It was shown that the spectrum of both stretch and in-plane vibrations can be very sensitive to the adsorption position of alkali atoms and substrate orientation

Augmented reality building operations tool

Science.gov (United States)

Brackney, Larry J.

2014-09-09

A method (700) for providing an augmented reality operations tool to a mobile client (642) positioned in a building (604). The method (700) includes, with a server (660), receiving (720) from the client (642) an augmented reality request for building system equipment (612) managed by an energy management system (EMS) (620). The method (700) includes transmitting (740) a data request for the equipment (612) to the EMS (620) and receiving (750) building management data (634) for the equipment (612). The method (700) includes generating (760) an overlay (656) with an object created based on the building management data (634), which may be sensor data, diagnostic procedures, or the like. The overlay (656) is configured for concurrent display on a display screen (652) of the client (642) with a real-time image of the building equipment (612). The method (700) includes transmitting (770) the overlay (656) to the client (642).

Investigation on synchronization of the offset printing process for fine patterning and precision overlay

International Nuclear Information System (INIS)

Kang, Dongwoo; Lee, Eonseok; Kim, Hyunchang; Choi, Young-Man; Lee, Seunghyun; Kim, Inyoung; Yoon, Dukkyun; Jo, Jeongdai; Kim, Bongmin; Lee, Taik-Min

2014-01-01

Offset printing processes are promising candidates for producing printed electronics due to their capacity for fine patterning and suitability for mass production. To print high-resolution patterns with good overlay using offset printing, the velocities of two contact surfaces, which ink is transferred between, should be synchronized perfectly. However, an exact velocity of the contact surfaces is unknown due to several imperfections, including tolerances, blanket swelling, and velocity ripple, which prevents the system from being operated in the synchronized condition. In this paper, a novel method of measurement based on the sticking model of friction force was proposed to determine the best synchronized condition, i.e., the condition in which the rate of synchronization error is minimized. It was verified by experiment that the friction force can accurately represent the rate of synchronization error. Based on the measurement results of the synchronization error, the allowable margin of synchronization error when printing high-resolution patterns was investigated experimentally using reverse offset printing. There is a region where the patterning performance is unchanged even though the synchronization error is varied, and this may be viewed as indirect evidence that printability performance is secured when there is no slip at the contact interface. To understand what happens at the contact surfaces during ink transfer, the deformation model of the blanket's surface was developed. The model estimates how much deformation on the blanket's surface can be borne by the synchronization error when there is no slip at the contact interface. In addition, the model shows that the synchronization error results in scale variation in the machine direction (MD), which means that the printing registration in the MD can be adjusted actively by controlling the synchronization if there is a sufficient margin of synchronization error to guarantee printability. The effect of

Non-equilibrium surface conditions and microstructural changes following pulsed laser irradiation and ion beam mixing of Ni overlayers on sintered alpha-SiC

International Nuclear Information System (INIS)

More, K.L.; Davis, R.F.

1986-01-01

Pulsed laser irradiation and ion beam mixing of thin Ni overlayers on sintered alpha-SiC have been investigated as potential surface modification techniques for the enhancement of the mechanical properties of the SiC. Each of these surface processing methods are nonequilibrium techniques; materials interactions can be induced at the specimen surface which are not possible with conventional thermal techniques. As a result of the surface modification, the physical properties of the ceramic can be altered under the correct processing conditions. Following laser irradiation using a pulsed ruby or krypton fluoride (KrF) excimer laser, the fracture strength of the SiC was increased by approximately 50 percent and 20 percent, respectively. However, ion-beam mixing of Ni on SiC resulted in no change in fracture strength. Cross-sectional transmission electron microscopy, scanning electron microscopy, secondary ion mass spectroscopy, and Rutherford backscattering techniques, have been used to characterize the extent of mixing between the Ni and SiC as a result of the surface modification and to determine the reason(s) for the observed changes in fracture strength. 19 references

A Comparison of Accuracy of Image- versus Hardware-based Tracking Technologies in 3D Fusion in Aortic Endografting.

Science.gov (United States)

Rolls, A E; Maurel, B; Davis, M; Constantinou, J; Hamilton, G; Mastracci, T M

2016-09-01

Fusion of three-dimensional (3D) computed tomography and intraoperative two-dimensional imaging in endovascular surgery relies on manual rigid co-registration of bony landmarks and tracking of hardware to provide a 3D overlay (hardware-based tracking, HWT). An alternative technique (image-based tracking, IMT) uses image recognition to register and place the fusion mask. We present preliminary experience with an agnostic fusion technology that uses IMT, with the aim of comparing the accuracy of overlay for this technology with HWT. Data were collected prospectively for 12 patients. All devices were deployed using both IMT and HWT fusion assistance concurrently. Postoperative analysis of both systems was performed by three blinded expert observers, from selected time-points during the procedures, using the displacement of fusion rings, the overlay of vascular markings and the true ostia of renal arteries. The Mean overlay error and the deviation from mean error was derived using image analysis software. Comparison of the mean overlay error was made between IMT and HWT. The validity of the point-picking technique was assessed. IMT was successful in all of the first 12 cases, whereas technical learning curve challenges thwarted HWT in four cases. When independent operators assessed the degree of accuracy of the overlay, the median error for IMT was 3.9 mm (IQR 2.89-6.24, max 9.5) versus 8.64 mm (IQR 6.1-16.8, max 24.5) for HWT (p = .001). Variance per observer was 0.69 mm(2) and 95% limit of agreement ±1.63. In this preliminary study, the error of magnitude of displacement from the "true anatomy" during image overlay in IMT was less than for HWT. This confirms that ongoing manual re-registration, as recommended by the manufacturer, should be performed for HWT systems to maintain accuracy. The error in position of the fusion markers for IMT was consistent, thus may be considered predictable. Copyright © 2016 European Society for Vascular Surgery. Published by

Change in equilibrium position of misfit dislocations at the GaN/sapphire interface by Si-ion implantation into sapphire—I. Microstructural characterization

Energy Technology Data Exchange (ETDEWEB)

Lee, Sung Bo, E-mail: bolee@snu.ac.kr; Han, Heung Nam, E-mail: hnhan@snu.ac.kr; Lee, Dong Nyung [Department of Materials Science and Engineering and Research Institute of Advanced Materials (RIAM), Seoul National University, Seoul 151-744 (Korea, Republic of); Ju, Jin-Woo [Korea Photonics Technology Institute, Gwangju 500-779 (Korea, Republic of); Kim, Young-Min; Yoo, Seung Jo; Kim, Jin-Gyu [Korea Basic Science Institute, Daejeon 305-806 (Korea, Republic of)

2015-07-15

Much research has been done to reduce dislocation densities for the growth of GaN on sapphire, but has paid little attention to the elastic behavior at the GaN/sapphire interface. In this study, we have examined effects of the addition of Si to a sapphire substrate on its elastic property and on the growth of GaN deposit. Si atoms are added to a c-plane sapphire substrate by ion implantation. The ion implantation results in scratches on the surface, and concomitantly, inhomogeneous distribution of Si. The scratch regions contain a higher concentration of Si than other regions of the sapphire substrate surface, high-temperature GaN being poorly grown there. However, high-temperature GaN is normally grown in the other regions. The GaN overlayer in the normally-grown regions is observed to have a lower TD density than the deposit on the bare sapphire substrate (with no Si accommodated). As compared with the film on an untreated, bare sapphire, the cathodoluminescence defect density decreases by 60 % for the GaN layer normally deposited on the Si-ion implanted sapphire. As confirmed by a strain mapping technique by transmission electron microscopy (geometric phase analysis), the addition of Si in the normally deposited regions forms a surface layer in the sapphire elastically more compliant than the GaN overlayer. The results suggest that the layer can largely absorb the misfit strain at the interface, which produces the overlayer with a lower defect density. Our results highlight a direct correlation between threading-dislocation density in GaN deposits and the elastic behavior at the GaN/sapphire interface, opening up a new pathway to reduce threading-dislocation density in GaN deposits.

Effects of thermal aging and neutron irradiation on the mechanical properties of three-wire stainless steel weld overlay cladding

International Nuclear Information System (INIS)

Haggag, F.M.; Nanstad, R.K.

1997-05-01

Thermal aging of three-wire series-arc stainless steel weld overlay cladding at 288 degrees C for 1605 h resulted in an appreciable decrease (16%) in the Charpy V-notch (CVN) upper-shelf energy (USE), but the effect on the 41-J transition temperature shift was very small (3 degrees C). The combined effect of aging and neutron irradiation at 288 degrees C to a fluence of 5 x 10 19 neutrons/cm 2 (> 1 MeV) was a 22% reduction in the USE and a 29 degrees C shift in the 41-J transition temperature. The effect of thermal aging on tensile properties was very small. However, the combined effect of irradiation and aging was an increase in the yield strength (6 to 34% at test temperatures from 288 to -125 degrees C) but no apparent change in ultimate tensile strength or total elongation. Neutron irradiation reduced the initiation fracture toughness (J Ic ) much more than did thermal aging alone. Irradiation slightly decreased the tearing modulus, but no reduction was caused by thermal aging alone. Other results from tensile, CVN, and fracture toughness specimens showed that the effects of thermal aging at 288 or 343 degrees C for 20,000 h each were very small and similar to those at 288 degrees C for 1605 h. The effects of long-term thermal exposure time (50,000 h and greater) at 288 degrees C will be investigated as the specimens become available in 1996 and beyond

Reverse depletion method for PWR core reload design

International Nuclear Information System (INIS)

Downar, T.J.; Kim, Y.J.

1985-01-01

Low-leakage fuel management is currently practiced in over half of all pressurized water reactor (PWR) cores. Prospects for even greater use of in-board fresh fuel loading are good as utilities seek to reduce core vessel fluence, mitigate pressurized thermal shock concerns, and extend vessel lifetime. Consequently, large numbers of burnable poison (BP) pins are being used to control the power peaking at the in-board fresh fuel positions. This has presented an additional complexity to the core reload design problem. In addition to determining the best location of each assembly in the core, the designer must concurrently determine the distribution of BP pins in the fresh fuel. A procedure was developed that utilizes the well-known Haling depletion to achieve an end-of-cycle (EOC) core state where the assembly pattern is configured in the absence of all control poison. This effectively separates the assembly assignment and BP distribution problems. Once an acceptable pattern at EOC is configured, the burnable and soluble poison required to control the power and core excess reactivity are solved for as unknown variables while depleting the cycle in reverse from the EOC exposure distribution to the beginning of cycle. The methods developed were implemented in an approved light water reactor licensing code to ensure the validity of the results obtained and provide for the maximum utility to PWR core reload design

Research on fabrication technology for thin film solar cells for practical use. Research on low-cost fabrication technology for large-area modules (Over-layered TCO on tempered glass for solar cell); Usumaku taiyo denchi seizo gijutsu no jitsuyoka kenkyu. Daimenseki module no tei cost seizo gijutsu (kyoka class fukugo tomei doden kiban seizo no gijutsu kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

Tatsuta, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

1994-12-01

This paper reports the study results on the fabrication technology of over-layered TCO on tempered glass in fiscal 1994. (1) On the fabrication technology of heat-resistant over-layered TCO, thermal deformation of TCO substrates was studied by both experiment and numerical computation. The thermal deformation increased with carrier concentration. As the observation result on change in lattice strain of heated TCO films by high-temperature X-ray diffraction, lattice strain was largely affected by thermal expansion. (2) On development of the low-temperature heat treatment method of TCO films, a technological prospect was obtained for fabrication of low-resistance TCO films by heat treatment without strength deterioration of tempered TCO substrates. (3) On development of cost reduction technology, the large-area CVD equipment was devised on the basis of the inline tempering method which tempers substrate glass by air cooling after formation of SnO2 film as fabrication method of tempered TCO. The TCO substrate tempered by air cooling could endure the drop test of 227g and 1.5m. 5 figs., 1 tab.

Facile fabrication of ultrathin Pt overlayers onto nanoporous metal membranes via repeated Cu UPD and in situ redox replacement reaction.

Science.gov (United States)

Liu, Pengpeng; Ge, Xingbo; Wang, Rongyue; Ma, Houyi; Ding, Yi

2009-01-06

Ultrathin Pt films from one to several atomic layers are successfully decorated onto nanoporous gold (NPG) membranes by utilizing under potential deposition (UPD) of Cu onto Au or Pt surfaces, followed by in situ redox replacement reaction (RRR) of UPD Cu by Pt. The thickness of Pt layers can be controlled precisely by repeating the Cu-UPD-RRR cycles. TEM observations coupled with electrochemical testing suggest that the morphology of Pt overlayers changes from an ultrathin epitaxial film in the case of one or two atomic layers to well-dispersed nanoislands in the case of four and more atomic layers. Electron diffraction (ED) patterns confirm that the as-prepared NPG-Pt membranes maintain a single-crystalline structure, even though the thickness of Pt films reaches six atomic layers, indicating the decorated Pt films hold the same crystallographic relationship to the NPG substrate during the entire fabrication process. Due to the regular modulation of Pt utilization, the electrocatalytic activity of NPG-Pt exhibits interesting surface structure dependence in methanol, ethanol, and CO electrooxidation reactions. These novel bimetallic nanocatalysts show excellent electrocatalytic activity and much enhanced poison tolerance as compared to the commercial Pt/C catalysts. The success in the fabrication of NPG-Pt-type materials provides a new path to prepare electrocatalysts with ultralow Pt loading and high Pt utilization, which is of great significance in energy-related applications, such as direct alcohol fuel cells (DAFCs).

Extending the range of low energy electron diffraction (LEED) surface structure determination: Co-adsorbed molecules, incommensurate overlayers and alloy surface order studied by new video and electron counting LEED techniques

Energy Technology Data Exchange (ETDEWEB)

Ogletree, D.F.

1986-11-01

LEED multiple scattering theory is briefly summarized, and aspects of electron scattering with particular significance to experimental measurements such as electron beam coherence, instrument response and phonon scattering are analyzed. Diffuse LEED experiments are discussed. New techniques that enhance the power of LEED are described, including a real-time video image digitizer applied to LEED intensity measurements, along with computer programs to generate I-V curves. The first electron counting LEED detector using a ''wedge and strip'' position sensitive anode and digital electronics is described. This instrument uses picoampere incident beam currents, and its sensitivity is limited only by statistics and counting times. Structural results on new classes of surface systems are presented. The structure of the c(4 x 2) phase of carbon monoxide adsorbed on Pt(111) has been determined, showing that carbon monoxide molecules adsorb in both top and bridge sites, 1.85 +- 0.10 A and 1.55 +- 0.10 A above the metal surface, respectively. The structure of an incommensurate graphite overlayer on Pt(111) is analyzed. The graphite layer is 3.70 +- 0.05 A above the metal surface, with intercalated carbon atoms located 1.25 +- 0.10 A above hollow sites supporting it. The (2..sqrt..3 x 4)-rectangular phase of benzene and carbon monoxide coadsorbed on Pt(111) is analyzed. Benzene molecules adsorb in bridge sites parallel to and 2.10 +- 0.10 A above the surface. The carbon ring is expanded, with an average C-C bond length of 1.72 +- 0.15 A. The carbon monoxide molecules also adsorb in bridge sites. The structure of the (..sqrt..3 x ..sqrt..3) reconstruction on the (111) face of the ..cap alpha..-CuAl alloy has been determined.

Extending the range of low energy electron diffraction (LEED) surface structure determination: Co-adsorbed molecules, incommensurate overlayers and alloy surface order studied by new video and electron counting LEED techniques

International Nuclear Information System (INIS)

Ogletree, D.F.

1986-11-01

LEED multiple scattering theory is briefly summarized, and aspects of electron scattering with particular significance to experimental measurements such as electron beam coherence, instrument response and phonon scattering are analyzed. Diffuse LEED experiments are discussed. New techniques that enhance the power of LEED are described, including a real-time video image digitizer applied to LEED intensity measurements, along with computer programs to generate I-V curves. The first electron counting LEED detector using a ''wedge and strip'' position sensitive anode and digital electronics is described. This instrument uses picoampere incident beam currents, and its sensitivity is limited only by statistics and counting times. Structural results on new classes of surface systems are presented. The structure of the c(4 x 2) phase of carbon monoxide adsorbed on Pt(111) has been determined, showing that carbon monoxide molecules adsorb in both top and bridge sites, 1.85 +- 0.10 A and 1.55 +- 0.10 A above the metal surface, respectively. The structure of an incommensurate graphite overlayer on Pt(111) is analyzed. The graphite layer is 3.70 +- 0.05 A above the metal surface, with intercalated carbon atoms located 1.25 +- 0.10 A above hollow sites supporting it. The (2√3 x 4)-rectangular phase of benzene and carbon monoxide coadsorbed on Pt(111) is analyzed. Benzene molecules adsorb in bridge sites parallel to and 2.10 +- 0.10 A above the surface. The carbon ring is expanded, with an average C-C bond length of 1.72 +- 0.15 A. The carbon monoxide molecules also adsorb in bridge sites. The structure of the (√3 x √3) reconstruction on the (111) face of the α-CuAl alloy has been determined

EGNOS Monitoring Prepared in Space Research Centre P.A.S. for SPMS Project

Science.gov (United States)

Swiatek, Anna; Jaworski, Leszek; Tomasik, Lukasz

2017-12-01

The European Geostationary Overlay Service (EGNOS) augments Global Positioning System (GPS) by providing correction data and integrity information for improving positioning over Europe. EGNOS Service Performance Monitoring Support (SPMS) project has assumed establishment, maintenance and implementation of an EGNOS performance monitoring network. The paper presents preliminary results of analyses prepared in Space Research Centre, Polish Academy of Sciences (Warsaw), as one of partners in SPMS project.

Direct formation of thin films and epitaxial overlayers at low temperatures using a low-energy (10-500 eV) ion beam deposition system

International Nuclear Information System (INIS)

Zuhr, R.A.; Alton, G.D.; Appleton, B.R.; Herbots, N.; Noggle, T.S.; Pennycook, S.J.

1987-01-01

A low-energy ion beam deposition system has been developed at Oak Ridge National Laboratory and has been applied successfully to the growth of epitaxial films at low temperatures for a number of different elements. The deposition system utilizes the ion source and optics of a commercial ion implantation accelerator. The 35 keV mass- and energy-analyzed ion beam from the accelerator is decelerated in a four-element electrostatic lens assembly to energies between 10 and 500 eV for direct deposition onto a target under UHV conditions. Current densities on the order of 10 μA/cm 2 are achieved with good uniformity over a 1.4 cm diameter spot. The completed films are characterized by Rutherford backscattering, ion channeling, cross-section transmission electron microscopy, and x-ray diffraction. The effects of substrate temperature, ion energy, and substrate cleaning have been studied. Epitaxial overlayers which show good minimum yields by ion channeling (3 to 4%) have been produced at temperatures as low as 375 0 C for Si on Si(100) and 250 0 C for Ge on Ge(100) at growth rates that exceed the solid-phase epitaxy rates at these temperatures by more than an order of magnitude

Topographic Information Requirements and Computer-Graphic Display Techniques for Nap-of-the-Earth Flight.

Science.gov (United States)

1979-12-01

of- at Battle Positions sight to target when unmask Concealment of Approach Map j Routes ! I i. 16 ... ’ FUNCTION: IASb SELECT AERIAL OBSERVATION...to select special overlays for temporary display and to remove them for clutter avoidance. In addition to these graphic presentation roles , the

Characterization of anti-listerial lactic acid bacteria isolated from Thai fermented fish products

DEFF Research Database (Denmark)

Østergaard, Anya; Embarek, Peter Karim Ben; Wedell-Neergaard, C.

1998-01-01

Thai fermented fish products were screened for lactic acid bacteria capable of inhibiting Listeria sp. (Listeria innocua). Of 4150 assumed lactic acid bacteria colonies from MRS agar plates that were screened by an agar-overlay method 58 (1.4%) were positive. Forty four of these strains were...

On the stability of copper overlayers on Au(1 1 1) and Au(1 0 0) electrodes under low potential conditions and in the presence on CO and CO2

DEFF Research Database (Denmark)

Schlaup, Christian Georg; Horch, Sebastian; Chorkendorff, Ib

2015-01-01

We have studied the stability of Cu overlayers on Au(1 1 1) and Au(1 0 0) electrodes under low potential conditions and in the presence of CO and CO2 by means of electrochemical STM (EC-STM). For preparation we utilized the well known underpotential deposition (UPD) of copper, which, depending...... on the electrolyte (HClO4 and H2SO4), leads to Cu coverages in the submonolayer to monolayer range. For a Cu submonolayer on Au(1 1 1) we found that independent from the actual gas coadsorbate its closed film-like structure collapses at low potentials due to the desorption of coadsorbed anions. In contrast we found...... for a full Cu monolayer on Au(1 1 1) and Au(1 0 0) the formation of an alloy phase under low potential conditions, which also occurs independent from the presence of gas coadsorbates....

Position detectors, methods of detecting position, and methods of providing positional detectors

Science.gov (United States)

Weinberg, David M.; Harding, L. Dean; Larsen, Eric D.

2002-01-01

Position detectors, welding system position detectors, methods of detecting various positions, and methods of providing position detectors are described. In one embodiment, a welding system positional detector includes a base that is configured to engage and be moved along a curved surface of a welding work piece. At least one position detection apparatus is provided and is connected with the base and configured to measure angular position of the detector relative to a reference vector. In another embodiment, a welding system positional detector includes a weld head and at least one inclinometer mounted on the weld head. The one inclinometer is configured to develop positional data relative to a reference vector and the position of the weld head on a non-planar weldable work piece.

The Low-Noise Potential of Distributed Propulsion on a Catamaran Aircraft

Science.gov (United States)

Posey, Joe W.; Tinetti, A. F.; Dunn, M. H.

2006-01-01

The noise shielding potential of an inboard-wing catamaran aircraft when coupled with distributed propulsion is examined. Here, only low-frequency jet noise from mid-wing-mounted engines is considered. Because low frequencies are the most difficult to shield, these calculations put a lower bound on the potential shielding benefit. In this proof-of-concept study, simple physical models are used to describe the 3-D scattering of jet noise by conceptualized catamaran aircraft. The Fast Scattering Code is used to predict noise levels on and about the aircraft. Shielding results are presented for several catamaran type geometries and simple noise source configurations representative of distributed propulsion radiation. Computational analyses are presented that demonstrate the shielding benefits of distributed propulsion and of increasing the width of the inboard wing. Also, sample calculations using the FSC are presented that demonstrate additional noise reduction on the aircraft fuselage by the use of acoustic liners on the inboard wing trailing edge. A full conceptual aircraft design would have to be analyzed over a complete mission to more accurately quantify community noise levels and aircraft performance, but the present shielding calculations show that a large acoustic benefit could be achieved by combining distributed propulsion and liner technology with a twin-fuselage planform.

Wake Measurement Downstream of a Hybrid Wing Body Model with Blown Flaps

Science.gov (United States)

Lin, John C.; Jones, Gregory S.; Allan, Brian G.; Westra, Bryan W.; Collins, Scott W.; Zeune, Cale H.

2010-01-01

Flow-field measurements were obtained in the wake of a full-span Hybrid Wing Body model with internally blown flaps. The test was performed at the NASA Langley 14 x 22 Foot Subsonic Tunnel at low speeds. Off-body measurements were obtained with a 7-hole probe rake survey system. Three model configurations were investigated. At 0deg angle of attack the surveys were completed with 0deg and 60deg flap deflections. At 10deg angle of attack the wake surveys were completed with a slat and a 60deg flap deflection. The 7-hole probe results further quantified two known swirling regions (downstream of the outboard flap edge and the inboard/outboard flap juncture) for the 60deg flap cases with blowing. Flowfield results and the general trends are very similar for the two blowing cases at nozzle pressure ratios of 1.37 and 1.56. High downwash velocities correlated with the enhanced lift for the 60deg flap cases with blowing. Jet-induced effects are the largest at the most inboard station for all (three) velocity components due in part to the larger inboard slot height. The experimental data are being used to improve computational tools for high-lift wings with integrated powered-lift technologies.

Optimization of Outer Poloidal Field (PF) Coil Configurations for Inductive PF Coil-only Plasma Start-up on Spherical Tori

International Nuclear Information System (INIS)

Wonho Choe; Jayhyun Kim; Masayuki Ono

2004-01-01

The elimination of in-board ohmic heating solenoid is required for the spherical torus (ST) to function as an attractive fusion power plant. An in-board ohmic solenoid, along with the shielding needed for its insulation, increases the size and, hence, the cost of the plant. Here, we investigate using static as well as dynamic codes in ST geometries a solenoid-free start-up concept utilizing a set of out-board poloidal field coils. By using the static code, an optimization of coil positions as well as coil currents was performed to demonstrate that it is indeed possible to create a high quality multi-pole field null region while retaining significant flux (volt-seconds) needed for the subsequent current ramp-up. With the dynamic code that includes the effect of vacuum vessel eddy currents, we then showed that it is possible to maintain a large size field null region for several milliseconds in which sufficient ionization avalanche can develop in the applied toroidal electric field. Under the magnetic geometry typical of a next generation spherical torus experiment, it is shown that the well-known plasma breakdown conditions for conventional ohmic solenoid start-up of E(sub)TB(sub)T/B(sub)P ∼ (0.1-1) kV/m with V(sub)loop ∼ 6 V can be readily met while retaining significant volt-seconds ∼ 4 V-S sufficient to generate multi-MA plasma current in STs

Comparative studies of inner and outer divertor discharges and a fueling study in QUEST

Energy Technology Data Exchange (ETDEWEB)

Mitarai, O., E-mail: omitarai@ktmail.tokai-u.jp [Kumamoto Liberal Arts Education Center, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto 862-8652 (Japan); Nakamura, K.; Hasegawa, M.; Onchi, T.; Idei, H.; Fujisawa, A.; Hanada, K.; Zushi, H.; Higashijima, A.; Nakashima, H.; Kawasaki, S. [Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasugakoen, Kasuga 816-8580 Japan (Japan); Matsuoka, K. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Koike, S.; Takahashi, T. [Division of Electronics and Informatics, Faculty of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Tsutsui, H. [Research Laboratory for Nuclear Reactors, Tokyo Inst. Tech, 2-12-1 Ookayama, Tokyo 152-8550 (Japan)

2016-11-01

Highlights: • Central solenoid has a small flux in QUEST. • Large plasma current is obtained when the position is shifted to the inboard side. • Two types of divertor operation are compared. • Novel merging fueling methods are proposed. • Coaxial helicity injection (CHI) fueling was examined in QUEST divertor configuration. - Abstract: As QUEST has a small central solenoid (CS), a larger Ohmic discharge current has been obtained when the plasma shifts to the inboard side. This tendency restricts a divertor operation to the smaller plasma current regime. As the inner divertor coil has a smaller mutual inductance, it would be expected that its utilization seems to be better for easier plasma current ramp-up for a divertor operation. In this work, we made comparative studies on the plasma current ramp-up for two divertor coils. It is found that while the inner divertor coil with smaller mutual inductance needs a larger coil current, the outer divertor coil with larger mutual inductance needs a smaller coil current for divertor operation. Thus we have found that the plasma current ramp-up characteristics are almost similar for both configurations. We also propose a new fueling method for spherical tokamak (ST) using the coaxial helicity injection (CHI). The main plasma current would be generated at first, and then the CHI plasma current is created between bottom two electrode plates and merged into the main plasma current for fueling.

On the design and role of passive stabilisation within the ST40 spherical tokamak

Science.gov (United States)

Buxton, P. F.; Asunta, O.; Gryaznevich, M. P.; Lockley, D.; McNamara, S.; Medvedev, S.; Ruiz de Villa Valdés, E.; Whitfield, G.; Wood, J. M.

2018-06-01

The position of passive stabilisation has been optimised for the low aspect ratio tokamak ST40. We find that passive stabilisation is most effective when conductors are placed near the plasma’s x-point, and the combined effect of having both inboard and outboard passive stabilisation significantly reduces the vertical instability growth rate. The growth rate can be further decreased by cooling the passive conductors down to 80 K. Two concepts for passive stabilisation are considered, passive plates and passive coils, and the relative advantages and disadvantages of each are discussed. Both concepts involve connecting the upper and lower conductors in an ‘anti-symmetric’ manner, which prevents large currents from being induced.

GIS soil conservation planning: A case study of a pristine Central America watershed

Science.gov (United States)

Steven Shultz

2000-01-01

In the Pacuare River Watershed in Costa Rica, farm size, ownership, and production data were collected and spatially referenced through global positioning surveys and farmer assessments of property boundaries in relation to cadastral maps and air photographs. Using GIs based spatial overlays, this data were integrated with previously collected land use and land...

Fiber Optic Safeguards Sealing System

Science.gov (United States)

1978-01-01

8217 or trade names does not constitute an official indorsement or approval of the use thereof. Destroy this report when it is no longer needed. Do not...an intergrity check of a seal than to photograph the seal’s fingerprints and to match positive/negative overlays. The seal identification time and

Evaluasi Struktural Perkerasan Kaku Menggunakan Metoda AASHTO 1993 dan Metoda AUSTROADS 2011 Studi Kasus : Jalan Cakung-Cilincing

Directory of Open Access Journals (Sweden)

Shinta Rahmalia Irawan

2017-08-01

Full Text Available Cakung-Cilincing Jakarta National Road Section has very rapid traffic load for rigid pavement. The purpose of this study are determining overlay thickness and choosing suitable method for implementation. AASHTO 1993 and AUSTROADS 2011 method are used in this study and using on Falling Weight Deflectometer (FWD data. This study shows that value of Concrete Elasticity Modulus less than 3 million, then this rigid pavement is severely damaged. Based on AASHTO 1993 Method analysis, it needs 11 cm for flexible overlay and 12 cm for rigid overlay on lane 1 with 59% remaining life and lane 2 with 53% remaining life. AUSTROADS 2011 Methods use only FWD data and for overlay thickness determination is use new pavement analysis. Analysis using AUSTROADS 2011 Methods shows that flexible overlay requirement is 24 cm and rigid overlay requirement is 18.50 cm. Comparation between these two methods shows that AASHTO 1993 Method Analysis produce less overlay thickness than AUSTROADS 2011 Methods.

77 FR 4466 - Certifications and Exemptions Under the International Regulations for Preventing Collisions at...

Science.gov (United States)

2012-01-30

... Ave. SE., Suite 3000, Washington Navy Yard, DC 20374-5066, telephone (202) 685-5040. SUPPLEMENTARY... distance distance Forward anchor Anchor lights relationship lights arc of arc of arc of inboard of forward...

33 CFR 174.19 - Contents of a certificate of number.

Science.gov (United States)

2010-07-01

... commercial use. (7) Manufacturer's hull identification number (if any). (8) Make of vessel. (9) Year vessel..., inboard-outdrive, or sail. (14) Whether the fuel is gasoline, diesel, or other. (b) A certificate of...

75 FR 27429 - Certifications and Exemptions Under the International Regulations for Preventing Collisions at...

Science.gov (United States)

2010-05-17

... Patterson Ave., SE., Suite 3000, Washington Navy Yard, DC 20374-5066, telephone number: 202-685-5040... light, light, Anchor lights lights arc arc of arc of inboard of distance height relationship of aft...

Monte Carlo analysis of helium production in the ITER shielding blanket module

International Nuclear Information System (INIS)

Sato, S.

1999-01-01

In order to examine the shielding performances of the inboard blanket module in the international thermonuclear experimental reactor (ITER), shielding calculations have been carried out using a three-dimensional Monte Carlo method. The impact of radiation streaming through the front access holes and gaps between adjacent blanket modules on the helium gas production in the branch pipe weld locations and back plate have been estimated. The three-dimensional model represents an 18 sector of the overall torus region and includes the vacuum vessel, inboard blanket and back plate, plasma region, and outboard reflecting medium. And it includes the 1 m high inboard mid-plane module and the 20 mm wide gaps between adjacent modules. From the calculated results for the reference design, it has been found that the helium production at the plug of the branch pipe is four to five times higher than the design goal of 1 appm for a neutron fluence of 0.9 MW a m -2 at the inboard mid-plane first wall. Also, it has been found that the helium production at the back plate behind the horizontal gap is about three times higher than the design goal. In the reference design, the stainless steel (SS):H 2 O composition in the blanket module is 80:20%. Shielding calculations also have been carried out for the SS:H 2 O composition of 70:30, 60:40, 50:50 and 40:60%. From the evaluated results for their design, it has been found that the dependence of helium production on the SS:H 2 170 mm will reduce helium production to satisfy the design goal and not have a significant impact on weight limitations imposed by remote maintenance handling limitations. Also based on the calculated results, about 200 mm thick shields such as a key structure in the vertical gap are suggested to be installed in the horizontal gap as well to reduce the helium production at the back plate and to satisfy the design goal. (orig.)

Geometric database maintenance using CCTV cameras and overlay graphics

Science.gov (United States)

Oxenberg, Sheldon C.; Landell, B. Patrick; Kan, Edwin

1988-01-01

An interactive graphics system using closed circuit television (CCTV) cameras for remote verification and maintenance of a geometric world model database has been demonstrated in GE's telerobotics testbed. The database provides geometric models and locations of objects viewed by CCTV cameras and manipulated by telerobots. To update the database, an operator uses the interactive graphics system to superimpose a wireframe line drawing of an object with known dimensions on a live video scene containing that object. The methodology used is multipoint positioning to easily superimpose a wireframe graphic on the CCTV image of an object in the work scene. An enhanced version of GE's interactive graphics system will provide the object designation function for the operator control station of the Jet Propulsion Laboratory's telerobot demonstration system.

Interaction between U/UO2 bilayers and hydrogen studied by in-situ X-ray diffraction

Science.gov (United States)

Darnbrough, J. E.; Harker, R. M.; Griffiths, I.; Wermeille, D.; Lander, G. H.; Springell, R.

2018-04-01

This paper reports experiments investigating the reaction of H2 with uranium metal-oxide bilayers. The bilayers consist of ≤ 100 nm of epitaxial α-U (grown on a Nb buffer deposited on sapphire) with a UO2 overlayer of thicknesses of between 20 and 80 nm. The oxides were made either by depositing via reactive magnetron sputtering, or allowing the uranium metal to oxidise in air at room temperature. The bilayers were exposed to hydrogen, with sample temperatures between 80 and 200 C, and monitored via in-situ x-ray diffraction and complimentary experiments conducted using Scanning Transmission Electron Microscopy - Electron Energy Loss Spectroscopy (STEM-EELS). Small partial pressures of H2 caused rapid consumption of the U metal and lead to changes in the intensity and position of the diffraction peaks from both the UO2 overlayers and the U metal. There is an orientational dependence in the rate of U consumption. From changes in the lattice parameter we deduce that hydrogen enters both the oxide and metal layers, contracting the oxide and expanding the metal. The air-grown oxide overlayers appear to hinder the H2-reaction up to a threshold dose, but then on heating from 80 to 140 C the consumption is more rapid than for the as-deposited overlayers. STEM-EELS establishes that the U-hydride layer lies at the oxide-metal interface, and that the initial formation is at defects or grain boundaries, and involves the formation of amorphous and/or nanocrystalline UH3. This explains why no diffraction peaks from UH3 are observed.

77 FR 4468 - Certifications and Exemptions Under the International Regulations for Preventing Collisions at...

Science.gov (United States)

2012-01-30

... Ave. SE., Suite 3000, Washington Navy Yard, DC 20374-5066, telephone (202) 685-5040. SUPPLEMENTARY... lights relationship lights arc of arc of arc of inboard of forward of light, height of aft light to...

Fault tree analysis on BWR core spray system

International Nuclear Information System (INIS)

Watanabe, Norio

1982-06-01

Fault Trees which describe the failure modes for the Core Spray System function in the Browns Ferry Nuclear Plant (BWR 1065MWe) were developed qualitatively and quantitatively. The unavailability for the Core Spray System was estimated to be 1.2 x 10 - 3 /demand. It was found that the miscalibration of four reactor pressure sensors or the failure to open of the two inboard valves (FCV 75-25 and 75-53) could reduce system reliability significantly. It was recommended that the pressure sensors would be calibrated independently. The introduction of the redundant inboard valves could improve the system reliability. Thus this analysis method was verified useful for system analysis. The detailed test and maintenance manual and the informations on the control logic circuits of each active component are necessary for further analysis. (author)

Positive Technologies for Understanding and Promoting Positive Emotions.

Science.gov (United States)

Baños, Rosa María; Carrillo, Alba; Etchemendy, Ernestina; Botella, Cristina

2017-10-26

Information and Communication Technologies (ICTs) have become increasingly present in our lives, and their use has spread considerably. This paper presents a review of the way ICTs can help practitioners and researchers to study, promote, and train positive emotions. It is framed within the field of Positive Technologies: the applied scientific approach to the study of the use of technology to improve the quality of personal experience, with the goal of increasing wellbeing. First, the article presents an introduction to the topic of technologies and positive emotions. Then, it describes how ICTs can aid in monitoring, assessing, promoting, modifying, and training positive emotions. Finally, implications and future directions of the role of Positive Technologies in positive emotions are discussed. The authors conclude that, in the near future, Positive Technologies and the field of positive emotions will interact synergistically, producing an exponential growth in the understanding and promotion of positive emotions.

Tritium analysis of divertor tiles used in JET ITER-like wall campaigns by means of β-ray induced x-ray spectrometry

Science.gov (United States)

Hatano, Y.; Yumizuru, K.; Koivuranta, S.; Likonen, J.; Hara, M.; Matsuyama, M.; Masuzaki, S.; Tokitani, M.; Asakura, N.; Isobe, K.; Hayashi, T.; Baron-Wiechec, A.; Widdowson, A.; contributors, JET

2017-12-01

Energy spectra of β-ray induced x-rays from divertor tiles used in ITER-like wall campaigns of the Joint European Torus were measured to examine tritium (T) penetration into tungsten (W) layers. The penetration depth of T evaluated from the intensity ratio of W(Lα) x-rays to W(Mα) x-rays showed clear correlation with poloidal position; the penetration depth at the upper divertor region reached several micrometers, while that at the lower divertor region was less than 500 nm. The deep penetration at the upper part was ascribed to the implantation of high energy T produced by DD fusion reactions. The poloidal distribution of total x-ray intensity indicated higher T retention in the inboard side than the outboard side of the divertor region.

Are positive emotions just as "positive" across cultures?

Science.gov (United States)

Leu, Janxin; Wang, Jennifer; Koo, Kelly

2011-08-01

Whereas positive emotions and feeling unequivocally good may be at the heart of well-being among Westerners, positive emotions often carry negative associations within many Asian cultures. Based on a review of East-West cultural differences in dialectical emotions, or co-occurring positive and negative feelings, we predicted culture to influence the association between positive emotions and depression, but not the association between negative emotions and depression. As predicted, in a survey of over 600 European-, immigrant Asian-, and Asian American college students, positive emotions were associated with depression symptoms among European Americans and Asian Americans, but not immigrant Asians. Negative emotions were associated with depression symptoms among all three groups. We also found initial evidence that acculturation (i.e., nativity) may influence the role of positive emotions in depression: Asian Americans fell "in between" the two other groups. These findings suggest the importance of studying the role of culture in positive emotions and in positive psychology. The use of interventions based on promoting positive emotions in clinical psychology among Asian clients is briefly discussed. 2011 APA, all rights reserved

The nature of the Pt(111)/α -Fe2O3(0001) interfaces revealed by DFT calculations

Science.gov (United States)

Mahmoud, Agnes; Deleuze, Pierre-Marie; Dupont, Céline

2018-05-01

Density functional theory calculations are performed to give a thorough description of structural, energetic, and electronic properties of Pt(111)/α-Fe2O3(0001) systems by spin-polarized calculations, accounting for the on-site Coulomb interaction. Toward the better understanding of Pt(111)/α-Fe2O3(0001) interfaces, two terminations of α-Fe2O3(0001) surface, namely, the single Fe- and the O3-termination, are considered and coupled with the four possible (top, hcp, fcc, and bridge) sites on Pt(111). The effect of the strain on clean hematite surfaces due to the lattice mismatch between the substrate and the overlayer is included in the analysis. Among the possible adsorption configurations, bridge sites are unstable, while the most favorable configurations are the ones at hollow sites. The stability of the interfaces is not only influenced by the termination of the overlayer but also influenced by the degree of its structural relaxation and the relative position of the first layer of O atoms in hematite with respect to Pt. To elucidate the different nature of the two terminations of the overlayer on Pt, projected density of states and 3D charge density difference plots are also discussed.

Detecting positive quadrant dependence and positive function dependence

NARCIS (Netherlands)

Janic-Wróblewska, A.; Kallenberg, W.C.M.; Ledwina, T.

2004-01-01

There is a lot of interest in positive dependence going beyond linear correlation. In this paper three new rank tests for testing independence against positive dependence are introduced. The first one is directed on positive quadrant dependence, the second and third one concentrate on positive

Detecting positive quadrant dependence and positive function dependence

NARCIS (Netherlands)

Janic-Wróblewska, A.; Kallenberg, W.C.M.; Ledwina, T.

2003-01-01

There is a lot of interest in positive dependence going beyond linear correlation. In this paper three new rank tests for testing independence against positive dependence are introduced. The first one is directed on positive quadrant dependence, the second and third one concentrate on positive

Real-time in situ three-dimensional integral videography and surgical navigation using augmented reality: a pilot study

Science.gov (United States)

Suenaga, Hideyuki; Hoang Tran, Huy; Liao, Hongen; Masamune, Ken; Dohi, Takeyoshi; Hoshi, Kazuto; Mori, Yoshiyuki; Takato, Tsuyoshi

2013-01-01

To evaluate the feasibility and accuracy of a three-dimensional augmented reality system incorporating integral videography for imaging oral and maxillofacial regions, based on preoperative computed tomography data. Three-dimensional surface models of the jawbones, based on the computed tomography data, were used to create the integral videography images of a subject's maxillofacial area. The three-dimensional augmented reality system (integral videography display, computed tomography, a position tracker and a computer) was used to generate a three-dimensional overlay that was projected on the surgical site via a half-silvered mirror. Thereafter, a feasibility study was performed on a volunteer. The accuracy of this system was verified on a solid model while simulating bone resection. Positional registration was attained by identifying and tracking the patient/surgical instrument's position. Thus, integral videography images of jawbones, teeth and the surgical tool were superimposed in the correct position. Stereoscopic images viewed from various angles were accurately displayed. Change in the viewing angle did not negatively affect the surgeon's ability to simultaneously observe the three-dimensional images and the patient, without special glasses. The difference in three-dimensional position of each measuring point on the solid model and augmented reality navigation was almost negligible (augmented reality system was highly accurate and effective for surgical navigation and for overlaying a three-dimensional computed tomography image on a patient's surgical area, enabling the surgeon to understand the positional relationship between the preoperative image and the actual surgical site, with the naked eye. PMID:23703710

Effect of low density H-mode operation on edge and divertor plasma parameters

International Nuclear Information System (INIS)

Maingi, R.; Mioduszewski, P.K.; Cuthbertson, J.W.

1994-07-01

We present a study of the impact of H-mode operation at low density on divertor plasma parameters on the DIII-D tokamak. The line-average density in H-mode was scanned by variation of the particle exhaust rate, using the recently installed divertor cryo-condensation pump. The maximum decrease (50%) in line-average electron density was accompanied by a factor of 2 increase in the edge electron temperature, and 10% and 20% reductions in the measured core and divertor radiated power, respectively. The measured total power to the inboard divertor target increased by a factor of 3, with the major contribution coming from a factor of 5 increase in the peak heat flux very close to the inner strike point. The measured increase in power at the inboard divertor target was approximately equal to the measured decrease in core and divertor radiation

Relationship of condylar position to disc position and morphology

Energy Technology Data Exchange (ETDEWEB)

Incesu, L.; Taskaya-Yilmaz, N. E-mail: nergizy@omu.edu.tr; Oeguetcen-Toller, M.; Uzun, E

2004-09-01

Introduction/objective: The purpose of this study was to assess whether condylar position, as depicted by magnetic resonance imaging, was an indicator of disc morphology and position. Methods and material: One hundred and twenty two TMJs of 61 patients with temporomandibular joint disorder were examined. Condylar position, disc deformity and degree of anterior disc displacement were evaluated by using magnetic resonance imaging. Results and discussion: Posterior condyle position was found to be the main feature of temporomandibular joints with slight and moderate anterior disc displacement. No statistical significance was found between the condylar position, and reducing and nonreducing disc positions. On the other hand, superior disc position was found to be statistically significant for centric condylar position. Conclusion: It was concluded that posterior condyle position could indicate anterior disc displacement whereas there was no relation between the position of condyle and the disc deformity.

Proceedings of the Integrated Ocean Drilling Program Vol. 341: Expedition reports Southern Alaska margin

Digital Repository Service at National Institute of Oceanography (India)

Jaeger, J.M.; Gulick, S.P.S.; LeVay, L.J.; Asahi, H.; Bahlburg, H.; Belanger, C.L.; Berbel, G.B.B.; Childress, L.B.; Cowan, E.A.; Drab, L.; Forwick, M.; Fukumura, A.; Ge, S.; Gupta, S.M.; et. al.

(Fig. F11, F12). Depositional basins inboard of the Khitrov Ridge along the continental slope west of the Bering Trough contain a sedimentary record of glacial–in- terglacial sedimentation overprinted by active tec- tonic deformation (Fig. F13...

Support surfaces for intraoperative prevention of pressure ulcers in patients undergoing surgery: a cost-effectiveness analysis.

Science.gov (United States)

Pham, Ba'; Teague, Laura; Mahoney, James; Goodman, Laurie; Paulden, Mike; Poss, Jeff; Li, Jianli; Sikich, Nancy Joan; Lourenco, Rosemarie; Ieraci, Luciano; Carcone, Steven; Krahn, Murray

2011-07-01

Patients who undergo prolonged surgical procedures are at risk of developing pressure ulcers. Recent systematic reviews suggest that pressure redistribution overlays on operating tables significantly decrease the associated risk. Little is known about the cost effectiveness of using these overlays in a prevention program for surgical patients. Using a Markov cohort model, we evaluated the cost effectiveness of an intraoperative prevention strategy with operating table overlays made of dry, viscoelastic polymer from the perspective of a health care payer over a 1-year period. We simulated patients undergoing scheduled surgical procedures lasting ≥90 min in the supine or lithotomy position. Compared with the current practice of using standard mattresses on operating tables, the intraoperative prevention strategy decreased the estimated intraoperative incidence of pressure ulcers by 0.51%, corresponding to a number-needed-to-treat of 196 patients. The average cost of using the operating table overlay was $1.66 per patient. Compared with current practice, this intraoperative prevention strategy would increase slightly the quality-adjusted life days of patients and by decreasing the incidence of pressure ulcers, this strategy would decrease both hospital and home care costs for treating fewer pressure ulcers originated intraoperatively. The cost savings was $46 per patient, which ranged from $13 to $116 by different surgical populations. Intraoperative prevention was 99% likely to be more cost effective than the current practice. In patients who undergo scheduled surgical procedures lasting ≥90 min, this intraoperative prevention strategy could improve patients' health and save hospital costs. The clinical and economic evidence support the implementation of this prevention strategy in settings where it has yet to become current practice. Copyright © 2011 Mosby, Inc. All rights reserved.

Positive mood broadens visual attention to positive stimuli.

Science.gov (United States)

Wadlinger, Heather A; Isaacowitz, Derek M

2006-03-01

In an attempt to investigate the impact of positive emotions on visual attention within the context of Fredrickson's (1998) broaden-and-build model, eye tracking was used in two studies to measure visual attentional preferences of college students (n=58, n=26) to emotional pictures. Half of each sample experienced induced positive mood immediately before viewing slides of three similarly-valenced images, in varying central-peripheral arrays. Attentional breadth was determined by measuring the percentage viewing time to peripheral images as well as by the number of visual saccades participants made per slide. Consistent with Fredrickson's theory, the first study showed that individuals induced into positive mood fixated more on peripheral stimuli than did control participants; however, this only held true for highly-valenced positive stimuli. Participants under induced positive mood also made more frequent saccades for slides of neutral and positive valence. A second study showed that these effects were not simply due to differences in emotional arousal between stimuli. Selective attentional broadening to positive stimuli may act both to facilitate later building of resources as well as to maintain current positive affective states.

Joint High Speed Sealift (JHSS) Baseline Shaft & Strut (BSS) Model 5653-3: Series 2, Propeller Disk LDV Wake Survey; and Series 3, Stock Propeller Powering and Stern Flap Evaluation Experiments

National Research Council Canada - National Science Library

Cusanelli, Dominic S; Chesnakas, Christopher J

2007-01-01

...) and Stock Propeller Powering and Stern Flap Evaluation tests (Series 3. In order to assist in the design of a propeller for the BSS hull, the nominal wakes in the inboard and outboard starboard propeller planes were measured using LDV...

78 FR 50412 - California State Nonroad Engine Pollution Control Standards; Amendments to Spark Ignition Marine...

Science.gov (United States)

2013-08-19

... Engine Pollution Control Standards; Amendments to Spark Ignition Marine Engine and Boat Regulations... emission standards; enhanced evaporative emission controls for high performance sterndrive/inboard engines... requirement relating to the control of emissions from new nonroad engines which are used in construction...

Neutronics Design of Helical Type DEMO Reactor FFHR-d1

Energy Technology Data Exchange (ETDEWEB)

Tanaka, T.; Sagara, A.; Goto, T.; Yanagi, N.; Masuzaki, S.; Tamura, H.; Miyazawa, J.; Muroga, T., E-mail: teru@nifs.ac.jp [National Institute for Fusion Science, Toki (Japan)

2012-09-15

Full text: Neutronics design study has been performed in a newly started conceptual design activity for a helical type DEMO reactor FFHR-d1. Features of the FFHR-d1 design are enlargement of the basic configurations of reactor components and extrapolation of plasma parameters from those of the helical type plasma experimental machine Large Helical Device (LHD) to achieve the highest feasibility. From the neutronics point of view, a blanket space of FFHR-d1 is severely limited at the inboard of the torus. This is due to the core plasma position shifting to the inboard side under the confinement condition extrapolated from LHD. The first step of the neutronics investigation using the MCNP code has been performed with a simple torus model simulating thin inboard blanket space. A Flibe+Be/Ferritic steel breeding blanket showed preferable performances for both tritium breeding and shielding, and has been adapted as a reference blanket system for FFHR-d1. The investigations indicate that a combination of a 15 cm thick breeding blanket, 55 cm thick WC+B4C shield, i.e., the blanket space of 70 cm, could suppress the fast neutron flux and nuclear heating in the helical coils to the design targets for the neutron wall loading of 1.5 MW/m{sup 2}. Since the outboard side can provide a large space for a 60 cm thick breeding blanket, a fully-covered tritium breeding ratio (TBR) of 1.31 has been obtained in the simple torus model. The neutronics design study has proceeded to the second step using a 3-D helical reactor model. The most important issue in the 3-D neutronics design is a compatibility with the helical divertor design. To achieve a higher TBR and shielding performance, the core plasma has to be covered by the breeding blanket layers as possible. However, the dimensions of the blanket layers are limited by magnetic field lines connecting an edge of the core plasma and divertor pumping ports. After repeating modification of the blanket configuration, the global TBR of 1

Positioning consumption

DEFF Research Database (Denmark)

Halkier, Bente; Keller, Margit

2014-01-01

positionings emerges based on empirical examples of research in parent–children consumption. Positionings are flexible discursive fixations of the relationship between the performances of the practitioner, other practitioners, media discourse and consumption activities. The basic positioning types...... are the practice maintenance and the practice change position, with different sorts of adapting in between. Media discourse can become a resource for a resistant position against social control or for an appropriating position in favour of space for action. Regardless of the current relation to a particular media......This article analyses the ways in which media discourses become a part of contested consumption activities. We apply a positioning perspective with practice theory to focus on how practitioners relate to media discourse as a symbolic resource in their everyday practices. A typology of performance...

Symposium on Command and Control Research (1988) Held in Monterey, California on Jun 7-9, 1988

Science.gov (United States)

1988-09-30

ELa -1cl~ca aya Display: Show-Icon Show-Overlay-icons Erase-icon Eras e.Overlay-icons Highlight: Highlight-Icon Highlight-Overlay-icons Dehighlight...poanrtiso duty hosirs, for the esastesov 5: ’Referencescomptia. Peacetinme diary hos; are trin lsoors a day’,r days ank.Note that thiscanoles os6sio4- to heo

False Position, Double False Position and Cramer's Rule

Science.gov (United States)

Boman, Eugene

2009-01-01

We state and prove the methods of False Position (Regula Falsa) and Double False Position (Regula Duorum Falsorum). The history of both is traced from ancient Egypt and China through the work of Fibonacci, ending with a connection between Double False Position and Cramer's Rule.

The Role of Positive Emotions in Positive Psychology: The Broaden-and-Build Theory of Positive Emotions.

Science.gov (United States)

Fredrickson, Barbara L.

2001-01-01

Describes the broaden-and-build theory of positive emotions, situating it within the field of positive psychology. The theory posits that experiences of positive emotions broaden people's momentary thought-action repertoires, which in turn build their enduring personal resources (physical, intellectual, social, and psychological). Reviews…

Ubiquitous positioning

CERN Document Server

Mannings, Robin

2008-01-01

This groundbreaking resource offers a practical, in-depth understanding of Ubiquitous Positioning - positioning systems that identify the location and position of people, vehicles and objects in time and space in the digitized networked economy. The future and growth of ubiquitous positioning will be fueled by the convergence of many other areas of technology, from mobile telematics, Internet technology, and location systems, to sensing systems, geographic information systems, and the semantic web. This first-of-its-kind volume explores ubiquitous positioning from a convergence perspective, of

A Sleep Position Trainer for positional sleep apnea

DEFF Research Database (Denmark)

Laub, Rasmus R; Tønnesen, Philip; Jennum, Poul J

2017-01-01

We tested the effect of the Sleep Position Trainer, a vibrational device, for positional sleep apnea in an open, randomized controlled trial with 101 patients, where 52 patients were allocated to Sleep Position Trainer and 49 patients to a non-treatment control group for 2 months (Part 1). All...... patients were then followed as a cohort for a period of 6 months with use of the Sleep Position Trainer (Part 2). The participants were assessed with polygraphy at entry, and after 2 and 6 months. The mean apnea-hypopnea index supine was 35 per h (SD, 18) in the Sleep Position Trainer group and 38 per h...... (SD, 15) in the control group at entry. In a per protocol analysis, the mean total apnea-hypopnea index at entry and after 2 months in the Sleep Position Trainer group was 18 per h (SD, 10) and 10 per h (SD, 9; P

Positive Psychology: Positive Emotions and Emotional Intelegence

OpenAIRE

Miloseva, Lence

2008-01-01

The paper focuses on the and emotional intelligence. We try to answer on some questions regarding the role which positive emotions have in our life’s. The broaden-and-build theory (Fredrickson, 1998; 2001) predicts that positive emotions are useful in several ways. They guide present behavior, by broadening one’s attention and cognition, setting the stage for creative, explorative, and innovative pursuits. As well, positive emotions build personal and social resources to help individuals achi...

Preliminary Feasibility Report Stage II, Lorain Small-Boat Harbor, Lorain, Ohio. Revision.

Science.gov (United States)

1982-03-01

frequently trailered, increasing numbers of auxillary powered sailboats and smaller, non- auxillary powered sailboats are creating excess demand for faci...in/outboards, 8 percent inboards, 16 percent sailboats, 8 percent auxillary sailboats, and 40 percent cruisers. The projected fleet mix by size is

75 FR 53846 - Airworthiness Directives; GA 8 Airvan (Pty) Ltd Models GA8 and GA8-TC320 Airplanes

Science.gov (United States)

2010-09-02

... and inboard main ribs around the area of the Horizontal Stabiliser rear pivot attachment. Additionally... City, Missouri 64106; telephone: (816) 329-4059; fax: (816) 329-4090. SUPPLEMENTARY INFORMATION... main ribs around the area of the Horizontal Stabiliser rear pivot attachment. Additionally, failure of...

78 FR 47529 - Airworthiness Directives; Bombardier, Inc. Airplanes

Science.gov (United States)

2013-08-06

... was prompted by a determination that certain flap actuators require restoration by installing a redesigned flap actuator inboard pinion seal. This AD requires revising the maintenance program by..., New York Aircraft Certification Office (ACO), 1600 Stewart Avenue, Suite 410, Westbury, New York 11590...

Nuclear design of a very-low-activation fusion reactor

International Nuclear Information System (INIS)

Cheng, E.T.; Hopkins, G.R.

1983-06-01

An investigation was conducted to study the nuclear design aspects of using very-low-activation materials, such as SiC, MgO, and aluminum for fusion-reactor first wall, blanket, and shield applications. In addition to the advantage of very-low radioactive inventory, it was found that the very-low-activation fusion reactor can also offer an adequate tritium-breeding ratio and substantial amount of blanket nuclear heating as a conventional-material-structured reactor does. The most-stringent design constraint found in a very-low-activation fusion reactor is the limited space available in the inboard region of a tokamak concept for shielding to protect the superconducting toroidal field coil. A reference design was developed which mitigates the constraint by adopting a removable tungsten shield design that retains the inboard dimensions and gives the same shield performance as the reference STARFIRE tokamak reactor design

Spacecraft Radiator Freeze Protection Using a Regenerative Heat Exchanger

Science.gov (United States)

Ungar, Eugene K.; Schunk, Richard G.

2011-01-01

An active thermal control system architecture has been modified to include a regenerative heat exchanger (regenerator) inboard of the radiator. Rather than using a radiator bypass valve a regenerative heat exchanger is placed inboard of the radiators. A regenerator cold side bypass valve is used to set the return temperature. During operation, the regenerator bypass flow is varied, mixing cold radiator return fluid and warm regenerator outlet fluid to maintain the system setpoint. At the lowest heat load for stable operation, the bypass flow is closed off, sending all of the flow through the regenerator. This lowers the radiator inlet temperature well below the system set-point while maintaining full flow through the radiators. By using a regenerator bypass flow control to maintain system setpoint, the required minimum heat load to avoid radiator freezing can be reduced by more than half compared to a radiator bypass system.

Towards integration of PET/MR hybrid imaging into radiation therapy treatment planning

International Nuclear Information System (INIS)

Paulus, Daniel H.; Thorwath, Daniela; Schmidt, Holger; Quick, Harald H.

2014-01-01

Purpose: Multimodality imaging has become an important adjunct of state-of-the-art radiation therapy (RT) treatment planning. Recently, simultaneous PET/MR hybrid imaging has become clinically available and may also contribute to target volume delineation and biological individualization in RT planning. For integration of PET/MR hybrid imaging into RT treatment planning, compatible dedicated RT devices are required for accurate patient positioning. In this study, prototype RT positioning devices intended for PET/MR hybrid imaging are introduced and tested toward PET/MR compatibility and image quality. Methods: A prototype flat RT table overlay and two radiofrequency (RF) coil holders that each fix one flexible body matrix RF coil for RT head/neck imaging have been evaluated within this study. MR image quality with the RT head setup was compared to the actual PET/MR setup with a dedicated head RF coil. PET photon attenuation and CT-based attenuation correction (AC) of the hardware components has been quantitatively evaluated by phantom scans. Clinical application of the new RT setup in PET/MR imaging was evaluated in anin vivo study. Results: The RT table overlay and RF coil holders are fully PET/MR compatible. MR phantom and volunteer imaging with the RT head setup revealed high image quality, comparable to images acquired with the dedicated PET/MR head RF coil, albeit with 25% reduced SNR. Repositioning accuracy of the RF coil holders was below 1 mm. PET photon attenuation of the RT table overlay was calculated to be 3.8% and 13.8% for the RF coil holders. With CT-based AC of the devices, the underestimation error was reduced to 0.6% and 0.8%, respectively. Comparable results were found within the patient study. Conclusions: The newly designed RT devices for hybrid PET/MR imaging are PET and MR compatible. The mechanically rigid design and the reproducible positioning allow for straightforward CT-based AC. The systematic evaluation within this study provides the

Want Positive Behavior? Use Positive Language

Science.gov (United States)

Wood, Chip; Freeman-Loftis, Babs

2012-01-01

Positive adult language is the professional use of words and tone of voice to enable students to learn in an engaged, active way. This includes learning social skills. To guide children toward choosing and maintaining positive behaviors, adults need to carefully choose the words and tone of voice used when speaking to them. Learning to use…

Latest performance of ArF immersion scanner NSR-S630D for high-volume manufacturing for 7nm node

Science.gov (United States)

Funatsu, Takayuki; Uehara, Yusaku; Hikida, Yujiro; Hayakawa, Akira; Ishiyama, Satoshi; Hirayama, Toru; Kono, Hirotaka; Shirata, Yosuke; Shibazaki, Yuichi

2015-03-01

In order to achieve stable operation in cutting-edge semiconductor manufacturing, Nikon has developed NSR-S630D with extremely accurate overlay while maintaining throughput in various conditions resembling a real production environment. In addition, NSR-S630D has been equipped with enhanced capabilities to maintain long-term overlay stability and user interface improvement all due to our newly developed application software platform. In this paper, we describe the most recent S630D performance in various conditions similar to real productions. In a production environment, superior overlay accuracy with high dose conditions and high throughput are often required; therefore, we have performed several experiments with high dose conditions to demonstrate NSR's thermal aberration capabilities in order to achieve world class overlay performance. Furthermore, we will introduce our new software that enables long term overlay performance.

Seleção de parâmetros através do método Taguchi para soldagem de revestimento com ligas de níquel pelo processo MIG/MAG Using the Taguchi method to select welding parameters for weld overlay with nickel alloy through the GMAW process

Directory of Open Access Journals (Sweden)

Antonio Rodolfo Paulino Pessoa

2010-12-01

a bead on plate (BOP technique, flat position, in steel ASTM 516 Gr60 with dimensions of 200 x 50 x 12,7 mm. The results showed that the use of arc oscillation promote weld bead with low values of the ratio R/L and obtain low dilution's values arriving to the order of 5%. The combination of levels of control factors identified as optimal by the Taguchi method obtained values for the variables considered suitable for weld overlay.

Chair time saving method for treatment of an impacted maxillary central incisor with 15-month follow-up

Directory of Open Access Journals (Sweden)

Saeed Noorollahian

2018-01-01

Full Text Available Maxillary permanent incisors have a major role in facial esthetics. Impaction of them has great adverse effect on smile and causes serious concerns in patient and parents. Physical barriers (e.g., overretained primary teeth, supernumerary teeth, and pathologic lesions, space problems, developmental abnormalities, altered eruption sequence, trauma, palatal clefts, and genetics can act as etiologic factors. Currently, the conventional technique to treatment of impacted teeth consists of a combined orthodontic and surgical approach, to guide the impacted teeth in a constant position and surrounded by normal hard and soft tissues. Treatment is challenging because of some limitations such as patient's age, cooperation, anchorage, and mechanotherapy possibilities. Hence, sophisticated treatment planning is crucial. A 9-year-old girl with horizontally impacted maxillary left central incisor treated with surgical exposure and closed orthodontic forced eruption with 2 × 4 partial setup fixed appliances. Force was applied with 0.014 inch nickel–titanium wire as elastic overlay and handmade ligated bracket. To save chair time in each appointment, the overlay was activated by twisting of ligature wire extensions around it. After 16-month treatment, impacted incisor emerged in oral cavity, with accepted alignment and inclination. Handmade ligated bracket with ligature wire extensions is useful for the treatment of impacted teeth. Due to easy activation of overlay in this method, chair time become short in each appointment.

Navicular bone position determined by positional MRI: a reproducibility study

Energy Technology Data Exchange (ETDEWEB)

Hansen, Philip; Nybing, Janus D. [Copenhagen University Hospital Frederiksberg and Bispebjerg, Department of Radiology, Frederiksberg (Denmark); Johannsen, Finn E.; Stallknecht, Sandra E. [Copenhagen University Hospital Bispebjerg, Institute of Sports Medicine Copenhagen, Copenhagen, NV (Denmark); Hangaard, Stine; Hansen, Bjarke B. [Copenhagen University Hospital Frederiksberg, Parker Institute, Department of Rheumatology, Frederiksberg (Denmark); Boesen, Mikael [Copenhagen University Hospital Frederiksberg and Bispebjerg, Department of Radiology, Frederiksberg (Denmark); Copenhagen University Hospital Frederiksberg, Parker Institute, Department of Rheumatology, Frederiksberg (Denmark)

2016-02-15

To examine intraobserver, interobserver and between-day reproducibility of positional MRI for evaluation of navicular bone height (NVH) and medial navicular position (MNP). Positional MRI (pMRI) of the foot was performed on ten healthy participants (0.25 T G-scanner). Scanning was performed in supine and standing position, respectively. Two radiologists evaluated the images in a blinded manner. Reliability and agreement were assessed by calculation of intraclass correlation coefficient (ICC) and 95 % limits of agreement as a percentage of the mean (LOA%). Intraobserver and interobserver reliability was ''substantial'' in both supine and standing position (ICC 0.86-0.98) and showed good agreement (LOA% 4.9-14.7 %). Between-day reliability of navicular height and medial navicular position in standing position remained substantial (ICC 0.85-0.92) with adequate agreement (LOA% 8.3-19.8 %). In supine position between-day reliability was ''moderate'' for NVH (ICC 0.72) and ''slight'' for MNP (ICC 0.39). Agreement remained adequate between-days for MNP in supine position (LOA% 17.7 %), but it was less than adequate for NVH in supine position (LOA% 24.2 %). Navicular height and medial navicular position can be measured by pMRI in a very reproducible manner within and between observers. Increased measurement variation is observed between-days in supine position, which may be due to small positional differences or other unknown biomechanical factors. (orig.)

Navicular bone position determined by positional MRI: a reproducibility study

International Nuclear Information System (INIS)

Hansen, Philip; Nybing, Janus D.; Johannsen, Finn E.; Stallknecht, Sandra E.; Hangaard, Stine; Hansen, Bjarke B.; Boesen, Mikael

2016-01-01

To examine intraobserver, interobserver and between-day reproducibility of positional MRI for evaluation of navicular bone height (NVH) and medial navicular position (MNP). Positional MRI (pMRI) of the foot was performed on ten healthy participants (0.25 T G-scanner). Scanning was performed in supine and standing position, respectively. Two radiologists evaluated the images in a blinded manner. Reliability and agreement were assessed by calculation of intraclass correlation coefficient (ICC) and 95 % limits of agreement as a percentage of the mean (LOA%). Intraobserver and interobserver reliability was ''substantial'' in both supine and standing position (ICC 0.86-0.98) and showed good agreement (LOA% 4.9-14.7 %). Between-day reliability of navicular height and medial navicular position in standing position remained substantial (ICC 0.85-0.92) with adequate agreement (LOA% 8.3-19.8 %). In supine position between-day reliability was ''moderate'' for NVH (ICC 0.72) and ''slight'' for MNP (ICC 0.39). Agreement remained adequate between-days for MNP in supine position (LOA% 17.7 %), but it was less than adequate for NVH in supine position (LOA% 24.2 %). Navicular height and medial navicular position can be measured by pMRI in a very reproducible manner within and between observers. Increased measurement variation is observed between-days in supine position, which may be due to small positional differences or other unknown biomechanical factors. (orig.)

75 FR 23577 - Airworthiness Directives; GA 8 Airvan (Pty) Ltd Models GA8 and GA8-TC320 Airplanes

Science.gov (United States)

2010-05-04

... and inboard main ribs around the area of the Horizontal Stabiliser rear pivot attachment. Additionally... INFORMATION CONTACT: Doug Rudolph, Aerospace Engineer, 901 Locust, Room 301, Kansas City, Missouri 64106... attachment. Additionally, failure of some attach bolts in service may be due to improper assembly. This...

76 FR 28180 - Certifications and Exemptions Under the International Regulations for Preventing Collisions at...

Science.gov (United States)

2011-05-16

... contained incorrect information concerning side lights arc of visibility; rule 21(b). This correcting... Yard, DC 20374-5066, telephone number: 202-685-5040. SUPPLEMENTARY INFORMATION: Pursuant to the... anchor light, relationship of lights arc Side lights Stern light inboard of distance height above aft...

Benign positional vertigo

Science.gov (United States)

Vertigo - positional; Benign paroxysmal positional vertigo; BPPV: dizziness- positional ... Benign positional vertigo is also called benign paroxysmal positional vertigo (BPPV). It is caused by a problem in the inner ear. ...

The Role of Positive Emotions in Positive Psychology: The Broaden-and-Build Theory of Positive Emotions

OpenAIRE

Fredrickson, Barbara L.

2001-01-01

In this article, the author describes a new theoretical perspective on positive emotions and situates this new perspective within the emerging field of positive psychology. The broaden-and-build theory posits that experiences of positive emotions broaden people's momentary thought-action repertoires, which in turn serves to build their enduring personal resources, ranging from physical and intellectual resources to social and psychological resources. Preliminary empirical evidence supporting ...

Positioning performance of a maglev fine positioning system

Energy Technology Data Exchange (ETDEWEB)

Wronosky, J.B.; Smith, T.G.; Jordan, J.D.; Darnold, J.R.

1996-12-01

A wafer positioning system was recently developed by Sandia National Laboratories for an Extreme Ultraviolet Lithography (EUVL) research tool. The system, which utilizes a magnetically levitated fine stage to provide ultra-precise positioning in all six degrees of freedom, incorporates technological improvements resulting from four years of prototype development experience. System enhancements, implemented on a second generation design for an ARPA National Center for Advanced Information Component Manufacturing (NCAICM) project, introduced active structural control for the levitated structure of the system. Magnetic levitation (maglev) is emerging as an important technology for wafer positioning systems in advanced lithography applications. The advantages of maglev stem from the absence of physical contact. The resulting lack of friction enables accurate, fast positioning. Maglev systems are mechanically simple, accomplishing full six degree-of-freedom suspension and control with a minimum of moving parts. Power-efficient designs, which reduce the possibility of thermal distortion of the platen, are achievable. Manufacturing throughput will be improved in future systems with the addition of active structural control of the positioning stages. This paper describes the design, implementation, and functional capability of the maglev fine positioning system. Specifics regarding performance design goals and test results are presented.

Feasibility of Using Ultrasonography to Establish Relationships Among Sacral Base Position, Sacral Sulcus Depth, Body Mass Index, and Sex.

Science.gov (United States)

Lockwood, Michael D; Kondrashova, Tatyana; Johnson, Jane C

2015-11-01

Identifying relationships among anatomical structures is key in diagnosing somatic dysfunction. Ultrasonography can be used to visualize anatomical structures, identify sacroiliac landmarks, and validate anatomical findings and measurements in relation to somatic dysfunction. As part of the osteopathic manipulative medicine course at A.T. Still University-Kirksville College of Osteopathic Medicine, first-year students are trained to use ultrasonography to establish relationships among musculoskeletal structures. To determine the ability of first-year osteopathic medical students to establish sacral base position (SBP) and sacral sulcus depth (SSD) using ultrasonography and to identify the relationship of SBP and SSD to body mass index (BMI) and sex. Students used ultrasonography to obtain the distance between the skin and the sacral base (the SBP) and the distance between the skin and the tip of the posterior superior iliac spine bilaterally. Next, students calculated the SSD (the distance between the tip of the posterior superior iliac spine and the SBP). Data were analyzed with respect to side of the body, BMI, sex, and age. The BMI data were subdivided into normal (18-25 mg/kg) and overweight (25-30 mg/kg) groups. Ultrasound images of 211 students were included in the study. The SBP was not significantly different between the left and right sides (36.5 mm vs 36.5 mm; P=.95) but was significantly different between normal and overweight BMI categories (33.0 mm vs 40.0 mm; Psex may point to more soft tissue overlaying the sacrum in these groups. Further research is needed on the use of ultrasonography to establish criteria for somatic dysfunction.

Formation of titanium nitride layers on titanium metal: Results of XPS and AES investigations

International Nuclear Information System (INIS)

Moers, H.; Pfennig, G.; Klewe-Nebenius, H.; Penzhorn, R.D.; Sirch, M.; Willin, E.

1988-09-01

The reaction of titanium metal with gaseous nitrogen and ammonia at temperatures of 890 0 C leads to the formation of nitridic overlayers on the metallic substrate. The thicknesses of the overlayers increase with increasing reaction time. Under comparable conditions ammonia reacts much slower than nitrogen. XPS and AES depth profile analyses show continuous changes of the in-depth compositions of the overlayers. This can be interpreted in terms of a very irregular thickness of the overlayers, an assumption which is substantiated by local AES analyses and by the observation of a pronounced crystalline structure of the substrate after annealing pretreatment, which can give rise to locally different reaction rates. The depth profile is also influenced by the broad ranges of stability of the titanium nitride phases formed during the reaction. The quantitative analysis of the titanium/nitrogen overlayers by AES is difficult because of the overlap of titanium and nitrogen Auger peaks. In quantitative XPS analysis problems arise due to difficulties in defining Ti 2p peak areas. This work presents practical procedures for the quantitative evaluation by XPS and AES of nitridic overlayers with sufficient accuracy. (orig.) [de

In situ corrosion testing of various nickel alloys at Måbjerg waste incineration plant

DEFF Research Database (Denmark)

Montgomery, Melanie; Hansson, A. N.; Jensen, S. A.

2013-01-01

overlay material currently being used to give improved corrosion resistance. In order to assess the use of alternative nickel alloys, test panels have been manufactured and inserted into Måbjerg waste incineration plant. Inconel 625 as a 50% weld overlay, two layered weld overlay and as a spiral weld......The majority of waste in Denmark is disposed via waste to energy (WTE) incineration plants which are fabricated from carbon steel. However, due to the increasing corrosiveness of waste over the years, more corrosion resistant alloys are required. In Denmark, Inconel 625 (UNSN06625) is the weld...... overlay was exposed. Other nickel materials exposed were weld overlay Alloy 686, Alloy 50 and Sumitomo Super 625 coextruded tube. Exposure has been undertaken from 2003 to 2009 in the first pass and 2005–2009 in the second pass, and sections have been removed and investigated during this period...

Positive Psychology

Science.gov (United States)

Peterson, Christopher

2009-01-01

Positive psychology is a deliberate correction to the focus of psychology on problems. Positive psychology does not deny the difficulties that people may experience but does suggest that sole attention to disorder leads to an incomplete view of the human condition. Positive psychologists concern themselves with four major topics: (1) positive…

75 FR 34953 - Airworthiness Directives; GA 8 Airvan (Pty) Ltd Models GA8 and GA8-TC320 Airplanes

Science.gov (United States)

2010-06-21

... Stabilizer rear pivot attachment. Additionally, failure of some attach bolts in service may be due to..., 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4059; fax: (816) 329-4090... and inboard main ribs around the area of the Horizontal Stabilizer rear pivot attachment. Additionally...

76 FR 24872 - California State Nonroad Engine and Vehicle Pollution Control Standards; Authorization of Tier II...

Science.gov (United States)

2011-05-03

... Pollution Control Standards; Authorization of Tier II Marine Inboard/Sterndrive Spark Ignition Engine... requirement relating to the control of emissions for certain new nonroad engines or vehicles.\\1\\ Section 209(e... control of emissions from either of the following new nonroad engines or nonroad vehicles subject to...

78 FR 28491 - Certifications and Exemptions Under the International Regulations for Preventing Collisions at...

Science.gov (United States)

2013-05-15

... Ave. SE., Suite 3000, Washington Navy Yard, DC 20374-5066, telephone 202-685-5040. SUPPLEMENTARY... lights lights arc Side lights Stern light distance distance light, relationship of Vessel Number of arc of arc of inboard of forward of height above aft light to visibility; visibility; visibility; ship's...

Spiral scan long object reconstruction through PI line reconstruction

International Nuclear Information System (INIS)

Tam, K C; Hu, J; Sourbelle, K

2004-01-01

The response of a point object in a cone beam (CB) spiral scan is analysed. Based on the result, a reconstruction algorithm for long object imaging in spiral scan cone beam CT is developed. A region-of-interest (ROI) of the long object is scanned with a detector smaller than the ROI, and a portion of it can be reconstructed without contamination from overlaying materials. The top and bottom surfaces of the ROI are defined by two sets of PI lines near the two ends of the spiral path. With this novel definition of the top and bottom ROI surfaces and through the use of projective geometry, it is straightforward to partition the cone beam image into regions corresponding to projections of the ROI, the overlaying objects or both. This also simplifies computation at source positions near the spiral ends, and makes it possible to reduce radiation exposure near the spiral ends substantially through simple hardware collimation. Simulation results to validate the algorithm are presented