Ocular aberrations with ray tracing and Shack-Hartmann wave-front sensors: Does polarization play a role?

Science.gov (United States)

Marcos, Susana; Diaz-Santana, Luis; Llorente, Lourdes; Dainty, Chris

2002-06-01

Ocular aberrations were measured in 71 eyes by using two reflectometric aberrometers, employing laser ray tracing (LRT) (60 eyes) and a Shack-Hartmann wave-front sensor (S-H) (11 eyes). In both techniques a point source is imaged on the retina (through different pupil positions in the LRT or a single position in the S-H). The aberrations are estimated by measuring the deviations of the retinal spot from the reference as the pupil is sampled (in LRT) or the deviations of a wave front as it emerges from the eye by means of a lenslet array (in the S-H). In this paper we studied the effect of different polarization configurations in the aberration measurements, including linearly polarized light and circularly polarized light in the illuminating channel and sampling light in the crossed or parallel orientations. In addition, completely depolarized light in the imaging channel was obtained from retinal lipofuscin autofluorescence. The intensity distribution of the retinal spots as a function of entry (for LRT) or exit pupil (for S-H) depends on the polarization configuration. These intensity patterns show bright corners and a dark area at the pupil center for crossed polarization, an approximately Gaussian distribution for parallel polarization and a homogeneous distribution for the autofluorescence case. However, the measured aberrations are independent of the polarization states. These results indicate that the differences in retardation across the pupil imposed by corneal birefringence do not produce significant phase delays compared with those produced by aberrations, at least within the accuracy of these techniques. In addition, differences in the recorded aerial images due to changes in polarization do not affect the aberration measurements in these reflectometric aberrometers.

Optimal Shack-Hartmann Wavefront Sensing For Low-Light-Levels

National Research Council Canada - National Science Library

Solomon, Christopher

1997-01-01

.... He will analyze the sensitivity gains achievable in shack-hartmann wavefront sensors using bayesian estimators and compare the results with those achieved using a standard least squares approach...

Least-squares wave-front reconstruction of Shack-Hartmann sensors and shearing interferometers using multigrid techniques

International Nuclear Information System (INIS)

Baker, K.L.

2005-01-01

This article details a multigrid algorithm that is suitable for least-squares wave-front reconstruction of Shack-Hartmann and shearing interferometer wave-front sensors. The algorithm detailed in this article is shown to scale with the number of subapertures in the same fashion as fast Fourier transform techniques, making it suitable for use in applications requiring a large number of subapertures and high Strehl ratio systems such as for high spatial frequency characterization of high-density plasmas, optics metrology, and multiconjugate and extreme adaptive optics systems

Nonlinear differential equations for the wavefront surface at arbitrary Hartmann-plane distances.

Science.gov (United States)

Téllez-Quiñones, Alejandro; Malacara-Doblado, Daniel; Flores-Hernández, Ricardo; Gutiérrez-Hernández, David A; León-Rodríguez, Miguel

2016-03-20

In the Hartmann test, a wave aberration function W is estimated from the information of the spot diagram drawn in an observation plane. The distance from a reference plane to the observation plane, the Hartmann-plane distance, is typically chosen as z=f, where f is the radius of a reference sphere. The function W and the transversal aberrations {X,Y} calculated at the plane z=f are related by two well-known linear differential equations. Here, we propose two nonlinear differential equations to denote a more general relation between W and the transversal aberrations {U,V} calculated at any arbitrary Hartmann-plane distance z=r. We also show how to directly estimate the wavefront surface w from the information of {U,V}. The use of arbitrary r values could improve the reliability of the measurements of W, or w, when finding difficulties in adequate ray identification at z=f.

Comparison of performance of some common Hartmann-Shack centroid estimation methods

Science.gov (United States)

Thatiparthi, C.; Ommani, A.; Burman, R.; Thapa, D.; Hutchings, N.; Lakshminarayanan, V.

2016-03-01

The accuracy of the estimation of optical aberrations by measuring the distorted wave front using a Hartmann-Shack wave front sensor (HSWS) is mainly dependent upon the measurement accuracy of the centroid of the focal spot. The most commonly used methods for centroid estimation such as the brightest spot centroid; first moment centroid; weighted center of gravity and intensity weighted center of gravity, are generally applied on the entire individual sub-apertures of the lens let array. However, these processes of centroid estimation are sensitive to the influence of reflections, scattered light, and noise; especially in the case where the signal spot area is smaller compared to the whole sub-aperture area. In this paper, we give a comparison of performance of the commonly used centroiding methods on estimation of optical aberrations, with and without the use of some pre-processing steps (thresholding, Gaussian smoothing and adaptive windowing). As an example we use the aberrations of the human eye model. This is done using the raw data collected from a custom made ophthalmic aberrometer and a model eye to emulate myopic and hyper-metropic defocus values up to 2 Diopters. We show that the use of any simple centroiding algorithm is sufficient in the case of ophthalmic applications for estimating aberrations within the typical clinically acceptable limits of a quarter Diopter margins, when certain pre-processing steps to reduce the impact of external factors are used.

Novel Detecting Methods of Shack-Hartmann Wavefront Sensor at Low Light Levels

International Nuclear Information System (INIS)

Zhang, A; Rao, C H; Zhang, Y D; Jiang, W H

2006-01-01

A study of novel detecting methods of Shack-Hartmann wavefront sensor at low light levels has been made. Three methods of images processing before slope estimating are presented: Linear Enhancing (LE), Exponential Enhancing (EE) and Fourier Spectrum Filtering (FSF). The idea of LE method is to time the image intensity with a special coefficient before slope estimation. The image points are powered by a selected exponent in EE method. The FSF method is based on the spectrum difference between signal and noise. Most of noise spectrum is filtered and the noise is restrained. The simulated and experimental results show that the LE method does not work effectively, and the other two methods can improve the slope estimation when the Signal-to-noise ratio is higher than 3.0. When the Signal-to-noise ratio is less than 3.0, especially when it is less than 1.0, the FSF is the only method that can overcome the readout noise of the CCD detector

The size effect of searching window for measuring wavefront of laser beam

International Nuclear Information System (INIS)

Park, Seung Kyu; Baik, Sung Hoon; Lim, Chang Hwan; Kim, Jung Cheol; Yi, Seung Jun; Ra, Sung Woong

2003-01-01

We investigated the size effect of the searching window for measuring of a laser beam using a Shack-Hartmann sensor. The shapes of spot images on an acquired wavefront image by using a Shack-Hartmann sensor are usually imbalanced. Also, the distributed intensity pattern of each spot image is varied according to successively acquired wavefront image. We studied on the optimized size of searching window to get wavefront with high measurement resolution. We experimented on the various size effect of searching window on an acquired wavefront image to get fine wavefront information using a Shack-Hartmann sensor. As the experimental results, we proposed the optimum size of searching window to measure improved wavefront.

A video Hartmann wavefront diagnostic that incorporates a monolithic microlens array

International Nuclear Information System (INIS)

Toeppen, J.S.; Bliss, E.S.; Long, T.W.; Salmon, J.T.

1991-07-01

we have developed a video Hartmann wavefront sensor that incorporates a monolithic array of microlenses as the focusing elements. The sensor uses a monolithic array of photofabricated lenslets. Combined with a video processor, this system reveals local gradients of the wavefront at a video frame rate of 30 Hz. Higher bandwidth is easily attainable with a camera and video processor that have faster frame rates. When used with a temporal filter, the reconstructed wavefront error is less than 1/10th wave

Multi-image acquisition-based distance sensor using agile laser spot beam.

Science.gov (United States)

Riza, Nabeel A; Amin, M Junaid

2014-09-01

We present a novel laser-based distance measurement technique that uses multiple-image-based spatial processing to enable distance measurements. Compared with the first-generation distance sensor using spatial processing, the modified sensor is no longer hindered by the classic Rayleigh axial resolution limit for the propagating laser beam at its minimum beam waist location. The proposed high-resolution distance sensor design uses an electronically controlled variable focus lens (ECVFL) in combination with an optical imaging device, such as a charged-coupled device (CCD), to produce and capture different laser spot size images on a target with these beam spot sizes different from the minimal spot size possible at this target distance. By exploiting the unique relationship of the target located spot sizes with the varying ECVFL focal length for each target distance, the proposed distance sensor can compute the target distance with a distance measurement resolution better than the axial resolution via the Rayleigh resolution criterion. Using a 30 mW 633 nm He-Ne laser coupled with an electromagnetically actuated liquid ECVFL, along with a 20 cm focal length bias lens, and using five spot images captured per target position by a CCD-based Nikon camera, a proof-of-concept proposed distance sensor is successfully implemented in the laboratory over target ranges from 10 to 100 cm with a demonstrated sub-cm axial resolution, which is better than the axial Rayleigh resolution limit at these target distances. Applications for the proposed potentially cost-effective distance sensor are diverse and include industrial inspection and measurement and 3D object shape mapping and imaging.

Deposition of sol-gel sensor spots by nanoimprint lithography and hemi-wicking

DEFF Research Database (Denmark)

Mikkelsen, Morten Bo Lindholm; Marie, Rodolphe; Hansen, Jan H.

2011-01-01

We present a method for homogeneous deposition of sol-gel sensor materials, which enable fabrication of sensor spots for optical pH and oxygen measurements inside plastic containers. A periodic pattern of posts is imprinted into a polycarbonate substrate and, using the principle of hemi-wicking, ......We present a method for homogeneous deposition of sol-gel sensor materials, which enable fabrication of sensor spots for optical pH and oxygen measurements inside plastic containers. A periodic pattern of posts is imprinted into a polycarbonate substrate and, using the principle of hemi...

Correlation Wave-Front Sensing Algorithms for Shack-Hartmann-Based Adaptive Optics using a Point Source

International Nuclear Information System (INIS)

Poynee, L A

2003-01-01

Shack-Hartmann based Adaptive Optics system with a point-source reference normally use a wave-front sensing algorithm that estimates the centroid (center of mass) of the point-source image 'spot' to determine the wave-front slope. The centroiding algorithm suffers for several weaknesses. For a small number of pixels, the algorithm gain is dependent on spot size. The use of many pixels on the detector leads to significant propagation of read noise. Finally, background light or spot halo aberrations can skew results. In this paper an alternative algorithm that suffers from none of these problems is proposed: correlation of the spot with a ideal reference spot. The correlation method is derived and a theoretical analysis evaluates its performance in comparison with centroiding. Both simulation and data from real AO systems are used to illustrate the results. The correlation algorithm is more robust than centroiding, but requires more computation

Detecting Blind Spot By Using Ultrasonic Sensor

Directory of Open Access Journals (Sweden)

T. S. Ajay

2015-08-01

Full Text Available Safety remains a top concern for automobile industries and new-car shoppers. Detection of Blind Spots is a major concern for safety issues. So automobiles have been constantly updating their products with new technologies to detect blind spots so that they can add more safety to the vehicle and also reduce the road accidents. Almost 1.5 million people die in road accidents each year. Blind spot of an automobile is the region of the vehicle which cannot be observed properly while looking either through side or rear mirror view. To meet the above requirements this paper describes detecting blind spot by using ultrasonic sensor and controlling the direction of car by automatic steering. The technology embedded in the system is capable of automatically steer the vehicle away from an obstacle if the system determines that a collision is impending or if the vehicle is in the vicinity of our car.

Objective measurement of intraocular forward light scatter using Hartmann-Shack spot patterns from clinical aberrometers. Model-eye and human-eye study.

Science.gov (United States)

Cerviño, Alejandro; Bansal, Dheeraj; Hosking, Sarah L; Montés-Micó, Robert

2008-07-01

To apply software-based image-analysis tools to objectively determine intraocular scatter determined from clinically derived Hartmann-Shack patterns. Aston Academy of Life Sciences, Aston University, Birmingham, United Kingdom, and Department of Optics, University of Valencia, Valencia, Spain. Purpose-designed image-analysis software was used to quantify scatter from centroid patterns obtained using a clinical Hartmann-Shack analyzer (WASCA, Zeiss/Meditec). Three scatter values, as the maximum standard deviation within a lenslet for all lenslets in the pattern, were obtained in 6 model eyes and 10 human eyes. In the model-eye sample, patterns were obtained in 4 sessions: 2 without realigning between measurements, 1 with realignment, and 1 with an angular shift of 6 degrees from the instrument axis. Three measurements were made in the human eyes with the C-Quant straylight meter (Oculus) to obtain psychometric and objective measures of retinal straylight. Analysis of variance, intraclass correlation coefficients, coefficient of repeatability (CoR), and correlations were used to determine intrasession and intersession repeatability and the relationship between measures. No significant differences were found between the sessions in the model eye (P=.234). The mean CoR was less than 10% in all model- and human-eye sessions. After incomplete patterns were removed, good correlation was achieved between psychometric and objective scatter measurements despite the small sample size (n=6; r=-0.831; P=.040). The methodology was repeatable in model and human eyes, strong against realignment and misalignment, and sensitive. Clinical application would benefit from effective use of the sensor's dynamic range.

Reversal of Hartmann's procedure following acute diverticulitis: is timing everything?

LENUS (Irish Health Repository)

Fleming, Fergal J

2012-02-01

BACKGROUND: Patients who undergo a Hartmann\\'s procedure may not be offered a reversal due to concerns over the morbidity of the second procedure. The aims of this study were to examine the morbidity post reversal of Hartmann\\'s procedure. METHODS: Patients who underwent a Hartmann\\'s procedure for acute diverticulitis (Hinchey 3 or 4) between 1995 and 2006 were studied. Clinical factors including patient comorbidities were analysed to elucidate what preoperative factors were associated with complications following reversal of Hartmann\\'s procedure. RESULTS: One hundred and ten patients were included. Median age was 70 years and 56% of the cohort were male (n = 61). The mortality and morbidity rate for the acute presentation was 7.3% (n = 8) and 34% (n = 37) respectively. Seventy six patients (69%) underwent a reversal at a median of 7 months (range 3-22 months) post-Hartmann\\'s procedure. The complication rate in the reversal group was 25% (n = 18). A history of current smoking (p = 0.004), increasing time to reversal (p = 0.04) and low preoperative albumin (p = 0.003) were all associated with complications following reversal. CONCLUSIONS: Reversal of Hartmann\\'s procedure can be offered to appropriately selected patients though with a significant (25%) morbidity rate. The identification of potential modifiable factors such as current smoking, prolonged time to reversal and low preoperative albumin may allow optimisation of such patients preoperatively.

Hartmann-Shack wave front measurements for real time determination of laser beam propagation parameters

International Nuclear Information System (INIS)

Schaefer, B.; Luebbecke, M.; Mann, K.

2006-01-01

The suitability of the Hartmann-Shack technique for the determination of the propagation parameters of a laser beam is faced against the well known caustic approach according to the ISO 11146 standard. A He-Ne laser (543 nm) was chosen as test beam, both in its fundamental mode as well as after intentional distortion, introducing a moderate amount of spherical aberration. Results are given for the most important beam parameters M 2 , divergence, and beam widths, indicating an agreement of better than 10% and for adapted beam diameter <5%. Furthermore, the theoretical background, pros and cons, as well as some features of the software implementation for the Hartmann-Shack sensor are briefly reviewed

Transition to turbulence in the Hartmann boundary layer

Energy Technology Data Exchange (ETDEWEB)

Thess, A.; Krasnov, D.; Boeck, T.; Zienicke, E. [Dept. of Mechanical Engineering, Ilmenau Univ. of Tech. (Germany); Zikanov, O. [Dept. of Mechanical Engineering, Univ. of Michigan, Dearborn, MI (United States); Moresco, P. [School of Physics and Astronomy, The Univ. of Manchester (United Kingdom); Alboussiere, T. [Lab. de Geophysique Interne et Tectonophysique, Observatoire des Science de l' Univers de Grenoble, Univ. Joseph Fourier, Grenoble (France)

2007-07-01

The Hartmann boundary layer is a paradigm of magnetohydrodynamic (MHD) flows. Hartmann boundary layers develop when a liquid metal flows under the influence of a steady magnetic field. The present paper is an overview of recent successful attempts to understand the mechanisms by which the Hartmann layer undergoes a transition from laminar to turbulent flow. (orig.)

Multi-optical-axis measurement of freeform progressive addition lenses using a Hartmann-Shack wavefront sensor

Science.gov (United States)

Xiang, Huazhong; Guo, Hang; Fu, Dongxiang; Zheng, Gang; Zhuang, Songlin; Chen, JiaBi; Wang, Cheng; Wu, Jie

2018-05-01

To precisely measure the whole-surface characterization of freeform progressive addition lenses (PALs), considering the multi-optical-axis conditions is becoming particularly important. Spherical power and astigmatism (cylinder) measurements for freeform PALs, using a Hartmann-Shack wavefront sensor (HSWFS) are proposed herein. Conversion formulas for the optical performance results were provided as HSWFS Zernike polynomial expansions. For each selected zone, the studied PALs were placed and tilted to simulate the multi-optical-axis conditions. The results of two tested PALs were analyzed using MATLAB programs and represented as contour plots of the spherical equivalent and cylinder of the whole-surface. The proposed experimental setup can provide a high accuracy as well as a possibility of choosing 12 lines and positions of 193 measurement zones on the entire surface. This approach to PAL analysis is potentially an efficient and useful method to objectively evaluate the optical performances, in which the full lens surface is defined and expressed as the contour plots of power in different regions (i.e., the distance region, progressive region, and near region) of the lens for regions of interest.

Integrated fiber optic sensors for hot spot detection and temperature field reconstruction in satellites

International Nuclear Information System (INIS)

Rapp, S; Baier, H

2010-01-01

Large satellites are often equipped with more than 1000 temperature sensors during the test campaign. Hundreds of them are still used for monitoring during launch and operation in space. This means an additional mass and especially high effort in assembly, integration and verification on a system level. So the use of fiber Bragg grating temperature sensors is investigated as they offer several advantages. They are lightweight, small in size and electromagnetically immune, which fits well in space applications. Their multiplexing capability offers the possibility to build extensive sensor networks including dozens of sensors of different types, such as strain sensors, accelerometers and temperature sensors. The latter allow the detection of hot spots and the reconstruction of temperature fields via proper algorithms, which is shown in this paper. A temperature sensor transducer was developed, which can be integrated into satellite sandwich panels with negligible mechanical influence. Mechanical and thermal vacuum tests were performed to verify the space compatibility of the developed sensor system. Proper reconstruction algorithms were developed to estimate the temperature field and detect thermal hot spots on the panel surface. A representative hardware demonstrator has been built and tested, which shows the capability of using an integrated fiber Bragg grating temperature sensor network for temperature field reconstruction and hot spot detection in satellite structures

Quantitative comparison of different-shaped wavefront sensors and preliminary results for defocus aberrations on a mechanical eye Comparações quantitativas entre o sensor Hartmann-Shack e o sensor de Castro e resultados preliminares para um olho mecânico

Directory of Open Access Journals (Sweden)

Luis Alberto Carvalho

2006-04-01

Full Text Available PURPOSE: There is a general acceptance among the scientific community of Cartesian symmetry wavefront sensors (such as the Hartmann-Shack (HS sensor as a standard in the field of optics and vision science. In this study it is shown that sensors of different symmetries and/or configurations should also be tested and analyzed in order to quantify and compare their effectiveness when applied to visual optics. Three types of wave-aberration sensors were developed and tested here. Each sensor has a very different configuration and/or symmetry (dodecagonal (DOD, cylindrical (CYL and conventional Hartmann-Shack (HS. METHODS: All sensors were designed and developed in the Physics Department of the Universidade de São Paulo - São Carlos. Each sensor was mounted on a laboratory optical bench used in a previous study. A commercial mechanical eye was used as control. This mechanical eye has a rotating mechanism that allows the retinal plane to be positioned at different axial distances. Ten different defocus aberrations were generated: 5 cases of myopia from -1D to -5D and 5 cases of hyperopia, from +1D to +5D, in steps of 1D following the scale printed on the mechanical eye. For each wavefront sensor a specific image-processing and fitting algorithm was implemented. For all three cases, the wavefront information was fit using the first 36 VSIA standard Zernike polynomials. Results for the mechanical eye were also compared to the absolute Zernike surface generated from coefficients associated with the theoretical sphere-cylinder aberration value. RESULTS: Precision was analyzed using two different methods: first, a theoretical approach was used by generating synthetic Zernike coefficients from the known sphere-cylinder aberrations, simply by applying sphere-cylinder equations in the backward direction. Then comparisons were made of these coefficients with the ones obtained in practice. Results for DOD, HS and CYL sensors were, respectively, as follows

For an aesthetics of communication: Interview with Frank Hartmann Por uma estética da comunicação: entrevista com Frank Hartmann

Directory of Open Access Journals (Sweden)

Lucia Leao

2011-07-01

Full Text Available In August 18, 2010, Frank Hartmann was present at the Post Graduate Program in Communication and Semiotics of PUC-SP, where he lectured on the following theme: “Towards an aesthetics of communication”. Frank Hartmann is full professor at the Bauhaus University, Weimar in Germany and external faculty member at the Dept. of Communication, University of Vienna, Austria. He is the author, among others, of: Medien und Kommunikation (2008; Mediologie - Ansatz einer der Medientheorie Kulturwissenschaften (2003, and Medienphilosophie (2000. More information on his website: http://www.medienphilosophie.net/f_hartmann.htmlFrank Hartmann esteve no dia 18 de agosto de 2010 no Programa de Pós-Graduação em Comunicação e Semiótica da PUC-SP, onde proferiu a palestra “Towards an aesthetics of communication”. Hartmann é professor titular da Universidade Bauhaus, em Weimar, na Alemanha e professor convidado do Departamento de Comunicação da Universidade de Viena, na Áustria. É autor, entre outros, de: Medien und Kommunikation (2008; Mediologie – Ansätze einer Medientheorie der Kulturwissenschaften (2003; e Medienphilosophie (2000. Mais informações em seu site: http://www.medienphilosophie.net/f_hartmann.html

Morbidity and Mortality of Hartmann's Procedure for Sigmoid ...

African Journals Online (AJOL)

Background: The restoration of intestinal continuity following Hartmann's procedure is associated with high morbidity and mortality rates and low restoration rate. Objective: To determine the causes of complications and deaths associated with Hartmann's procedure and the secondary restoration of digestive continuity for ...

Comparison of sorting algorithms to increase the range of Hartmann-Shack aberrometry.

Science.gov (United States)

Bedggood, Phillip; Metha, Andrew

2010-01-01

Recently many software-based approaches have been suggested for improving the range and accuracy of Hartmann-Shack aberrometry. We compare the performance of four representative algorithms, with a focus on aberrometry for the human eye. Algorithms vary in complexity from the simplistic traditional approach to iterative spline extrapolation based on prior spot measurements. Range is assessed for a variety of aberration types in isolation using computer modeling, and also for complex wavefront shapes using a real adaptive optics system. The effects of common sources of error for ocular wavefront sensing are explored. The results show that the simplest possible iterative algorithm produces comparable range and robustness compared to the more complicated algorithms, while keeping processing time minimal to afford real-time analysis.

Corneal topographer based on the Hartmann test.

Science.gov (United States)

Mejía, Yobani; Galeano, Janneth C

2009-04-01

The purpose of this article is to show the performance of a topographer based on the Hartmann test for convex surfaces of F/# approximately 1. This topographer, called "Hartmann Test topographer (HT topographer)," is a prototype developed in the Physics Department of the Universidad Nacional de Colombia. From the Hartmann pattern generated by the surface under test, and by the Fourier analysis and the optical aberration theory we obtain the sagitta (elevation map) of the surface. Then, taking the first and the second derivatives of the sagitta in the radial direction we obtain the meridional curvature map. The method is illustrated with an example. To check the performance of the HT topographer a toric surface, a revolution aspherical surface, and two human corneas were measured. Our results are compared with those obtained with a Placido ring topographer (Tomey TMS-4 videokeratoscope), and we show that our curvature maps are similar to those obtained with the Placido ring topographer. The HT topographer is able to reconstruct the corneal topography potentially eradicating the skew ray problem, therefore, corneal defects can be visualized more. The results are presented by elevation and meridional curvature maps.

Laparoscopic reversal of Hartmann's procedure

DEFF Research Database (Denmark)

Svenningsen, Peter Olsen; Bulut, Orhan; Jess, Per

2010-01-01

of Hartmann's procedure as safely as in open surgery and with a faster recovery, shorter hospital stay and less blood loss despite a longer knife time. It therefore seems reasonable to offer patients a laparoscopic procedure at departments which are skilled in laparoscopic surgery and use it for standard...

Assessing the utility of the spot 6 sensor in detecting and mapping ...

African Journals Online (AJOL)

Lantana camara is a significant weed in South Africa which is causing severe impacts on agriculture by reducing grazing areas. This study assessed the potential of the SPOT 6 multispectral sensor and two broadband vegetation indices (NDVI and SR) for detecting and mapping Lantana camara in a community grazing ...

Effect of Hartmann layer resolution for MHD flow in a straight ...

Indian Academy of Sciences (India)

851–861. c Indian Academy of Sciences. Effect of Hartmann layer resolution for MHD flow in a straight, conducting duct at high Hartmann numbers. SHARANYA SUBRAMANIAN1,∗, P K SWAIN2,. A V DESHPANDE1 and P SATYAMURTHY2. 1Mechanical Engineering Department, Veermata Jijabai Technological Institute,.

Characterisation and deployment of an immobilised pH sensor spot towards surface ocean pH measurements.

Science.gov (United States)

Clarke, Jennifer S; Achterberg, Eric P; Rérolle, Victoire M C; Abi Kaed Bey, Samer; Floquet, Cedric F A; Mowlem, Matthew C

2015-10-15

The oceans are a major sink for anthropogenic atmospheric carbon dioxide, and the uptake causes changes to the marine carbonate system and has wide ranging effects on flora and fauna. It is crucial to develop analytical systems that allow us to follow the increase in oceanic pCO2 and corresponding reduction in pH. Miniaturised sensor systems using immobilised fluorescence indicator spots are attractive for this purpose because of their simple design and low power requirements. The technology is increasingly used for oceanic dissolved oxygen measurements. We present a detailed method on the use of immobilised fluorescence indicator spots to determine pH in ocean waters across the pH range 7.6-8.2. We characterised temperature (-0.046 pH/°C from 5 to 25 °C) and salinity dependences (-0.01 pH/psu over 5-35), and performed a preliminary investigation into the influence of chlorophyll on the pH measurement. The apparent pKa of the sensor spots was 6.93 at 20 °C. A drift of 0.00014 R (ca. 0.0004 pH, at 25 °C, salinity 35) was observed over a 3 day period in a laboratory based drift experiment. We achieved a precision of 0.0074 pH units, and observed a drift of 0.06 pH units during a test deployment of 5 week duration in the Southern Ocean as an underway surface ocean sensor, which was corrected for using certified reference materials. The temperature and salinity dependences were accounted for with the algorithm, R=0.00034-0.17·pH+0.15·S(2)+0.0067·T-0.0084·S·1.075. This study provides a first step towards a pH optode system suitable for autonomous deployment. The use of a short duration low power illumination (LED current 0.2 mA, 5 μs illumination time) improved the lifetime and precision of the spot. Further improvements to the pH indicator spot operations include regular application of certified reference materials for drift correction and cross-calibration against a spectrophotometric pH system. Desirable future developments should involve novel

Fabrication of an infrared Shack-Hartmann sensor by combining high-speed single-point diamond milling and precision compression molding processes.

Science.gov (United States)

Zhang, Lin; Zhou, Wenchen; Naples, Neil J; Yi, Allen Y

2018-05-01

A novel fabrication method by combining high-speed single-point diamond milling and precision compression molding processes for fabrication of discontinuous freeform microlens arrays was proposed. Compared with slow tool servo diamond broaching, high-speed single-point diamond milling was selected for its flexibility in the fabrication of true 3D optical surfaces with discontinuous features. The advantage of single-point diamond milling is that the surface features can be constructed sequentially by spacing the axes of a virtual spindle at arbitrary positions based on the combination of rotational and translational motions of both the high-speed spindle and linear slides. By employing this method, each micro-lenslet was regarded as a microstructure cell by passing the axis of the virtual spindle through the vertex of each cell. An optimization arithmetic based on minimum-area fabrication was introduced to the machining process to further increase the machining efficiency. After the mold insert was machined, it was employed to replicate the microlens array onto chalcogenide glass. In the ensuing optical measurement, the self-built Shack-Hartmann wavefront sensor was proven to be accurate in detecting an infrared wavefront by both experiments and numerical simulation. The combined results showed that precision compression molding of chalcogenide glasses could be an economic and precision optical fabrication technology for high-volume production of infrared optics.

Design and Fabricate the Remote Monitor on the Scenic Spot Based on Integrated Sensor System

Directory of Open Access Journals (Sweden)

Xiaohui Wang

2014-10-01

Full Text Available Based on the embedded Linux system, established the integrated sensing system to monitor the scenic spot and transmit the collected data to the users. The platform based on the ARM11 development board as the hardware of the system. Used the sensors to collect the different data and pictures and then they were transmitted by the wired and wireless mode. Set up the small Web server by the Boa (small Web server and realized the integrated Web technology and CGI (Common Gateway Interface program. According to the difference information of the scenic spot, the mobile platform collected the needed data and transmitted it to the control platform by the ZigBee wireless module and displayed in the embedded platform. The administrator can realize monitoring all the spots of the scenic and control the terminal equipments in the whole day.

Is Diversion with Ileostomy Non-inferior to Hartmann Resection for Left-sided Colorectal Anastomotic Leak?

Science.gov (United States)

Stafford, Caitlin; Francone, Todd D; Marcello, Peter W; Roberts, Patricia L; Ricciardi, Rocco

2018-03-01

Treatment of left-sided colorectal anastomotic leaks often requires fecal stream diversion for prevention of further septic complications. To manage anastomotic leak, it is unclear if diverting ileostomy provides similar outcomes to Hartmann resection with colostomy. We identified all patients who developed anastomotic leak following left-sided colorectal resections from 1/2012 through 12/2014 using the American College of Surgeons National Surgical Quality Improvement Program. Then, we examined the risk of mortality and abdominal reoperation in patients treated with diverting ileostomy as compared to Hartmann resection. There were 1745 patients who experienced an anastomotic leak in a cohort of 63,748 patients (3.7%). Two hundred thirty-five patients had a reoperation for anastomotic leak involving the formation of a diverting ileostomy (n = 77) or Hartmann resection (n = 158). There was no difference in mortality or abdominal reoperation in patients treated with diverting ileostomy (3.9, 7.8%) versus Hartmann resection (3.8, 6.3%) (p = 0.8). There was no difference in the outcomes of mortality or need for second abdominal reoperation in patients treated with diverting ileostomy as compared to Hartmann resection for left-sided colorectal anastomotic leak. Thus, select patients with left-sided colorectal anastomotic leaks may be safely managed with diverting ileostomy.

Exact solutions of continuous states for Hartmann potential

International Nuclear Information System (INIS)

Chen Changyuan; Lu Falin; Sun Dongsheng

2004-01-01

In this Letter, we obtain the exact solutions of continuous states for the Hartmann potential. The normalized wave functions of continuous states on the 'k/2π scale' and the calculation formula of phase shifts are presented. Analytical properties of the scattering amplitude are discussed

Optical design of a novel instrument that uses the Hartmann-Shack sensor and Zernike polynomials to measure and simulate customized refraction correction surgery outcomes and patient satisfaction

Science.gov (United States)

Yasuoka, Fatima M. M.; Matos, Luciana; Cremasco, Antonio; Numajiri, Mirian; Marcato, Rafael; Oliveira, Otavio G.; Sabino, Luis G.; Castro N., Jarbas C.; Bagnato, Vanderlei S.; Carvalho, Luis A. V.

2016-03-01

An optical system that conjugates the patient's pupil to the plane of a Hartmann-Shack (HS) wavefront sensor has been simulated using optical design software. And an optical bench prototype is mounted using mechanical eye device, beam splitter, illumination system, lenses, mirrors, mirrored prism, movable mirror, wavefront sensor and camera CCD. The mechanical eye device is used to simulate aberrations of the eye. From this device the rays are emitted and travelled by the beam splitter to the optical system. Some rays fall on the camera CCD and others pass in the optical system and finally reach the sensor. The eye models based on typical in vivo eye aberrations is constructed using the optical design software Zemax. The computer-aided outcomes of each HS images for each case are acquired, and these images are processed using customized techniques. The simulated and real images for low order aberrations are compared using centroid coordinates to assure that the optical system is constructed precisely in order to match the simulated system. Afterwards a simulated version of retinal images is constructed to show how these typical eyes would perceive an optotype positioned 20 ft away. Certain personalized corrections are allowed by eye doctors based on different Zernike polynomial values and the optical images are rendered to the new parameters. Optical images of how that eye would see with or without corrections of certain aberrations are generated in order to allow which aberrations can be corrected and in which degree. The patient can then "personalize" the correction to their own satisfaction. This new approach to wavefront sensing is a promising change in paradigm towards the betterment of the patient-physician relationship.

SPOT Program

Science.gov (United States)

Smith, Jason T.; Welsh, Sam J.; Farinetti, Antonio L.; Wegner, Tim; Blakeslee, James; Deboeck, Toni F.; Dyer, Daniel; Corley, Bryan M.; Ollivierre, Jarmaine; Kramer, Leonard;

Peak-locking centroid bias in Shack-Hartmann wavefront sensing

Science.gov (United States)

Anugu, Narsireddy; Garcia, Paulo J. V.; Correia, Carlos M.

2018-05-01

Shack-Hartmann wavefront sensing relies on accurate spot centre measurement. Several algorithms were developed with this aim, mostly focused on precision, i.e. minimizing random errors. In the solar and extended scene community, the importance of the accuracy (bias error due to peak-locking, quantization, or sampling) of the centroid determination was identified and solutions proposed. But these solutions only allow partial bias corrections. To date, no systematic study of the bias error was conducted. This article bridges the gap by quantifying the bias error for different correlation peak-finding algorithms and types of sub-aperture images and by proposing a practical solution to minimize its effects. Four classes of sub-aperture images (point source, elongated laser guide star, crowded field, and solar extended scene) together with five types of peak-finding algorithms (1D parabola, the centre of gravity, Gaussian, 2D quadratic polynomial, and pyramid) are considered, in a variety of signal-to-noise conditions. The best performing peak-finding algorithm depends on the sub-aperture image type, but none is satisfactory to both bias and random errors. A practical solution is proposed that relies on the antisymmetric response of the bias to the sub-pixel position of the true centre. The solution decreases the bias by a factor of ˜7 to values of ≲ 0.02 pix. The computational cost is typically twice of current cross-correlation algorithms.

Geometrical error calibration in reflective surface testing based on reverse Hartmann test

Science.gov (United States)

Gong, Zhidong; Wang, Daodang; Xu, Ping; Wang, Chao; Liang, Rongguang; Kong, Ming; Zhao, Jun; Mo, Linhai; Mo, Shuhui

2017-08-01

In the fringe-illumination deflectometry based on reverse-Hartmann-test configuration, ray tracing of the modeled testing system is performed to reconstruct the test surface error. Careful calibration of system geometry is required to achieve high testing accuracy. To realize the high-precision surface testing with reverse Hartmann test, a computer-aided geometrical error calibration method is proposed. The aberrations corresponding to various geometrical errors are studied. With the aberration weights for various geometrical errors, the computer-aided optimization of system geometry with iterative ray tracing is carried out to calibration the geometrical error, and the accuracy in the order of subnanometer is achieved.

Shack-Hartmann Electron Densitometer (SHED): An Optical System for Diagnosing Free Electron Density in Laser-Produced Plasmas

Science.gov (United States)

2016-11-01

Free Electron Density in Laser-Produced Plasmas by Anthony R Valenzuela Approved for public release; distribution is...AND SUBTITLE Shack-Hartmann Electron Densitometer (SHED): An Optical System for Diagnosing Free Electron Density in Laser-Produced Plasmas 5a...SUPPLEMENTARY NOTES 14. ABSTRACT The Shack-Hartmann Electron Densitometer is a novel method to diagnose ultrashort pulse laser–produced plasmas

Numerical Evaluation of Parameter Correlation in the Hartmann-Tran Line Profile

Science.gov (United States)

Adkins, Erin M.; Reed, Zachary; Hodges, Joseph T.

2017-06-01

The partially correlated quadratic, speed-dependent hard-collision profile (pCqSDHCP), for simplicity referred to as the Hartmann-Tran profile (HTP), has been recommended as a generalized lineshape for high resolution spectroscopy. The HTP parameterizes complex collisional effects such as Dicke narrowing, speed dependent narrowing, and correlations between velocity-changing and dephasing collisions, while also simplifying to simpler profiles that are widely used, such as the Voigt profile. As advanced lineshape profiles are adopted by more researchers, it is important to understand the limitations that data quality has on the ability to retrieve physically meaningful parameters using sophisticated lineshapes that are fit to spectra of finite signal-to-noise ratio. In this work, spectra were simulated using the HITRAN Application Programming Interface (HAPI) across a full range of line parameters. Simulated spectra were evaluated to quantify the precision with which fitted lineshape parameters can be determined at a given signal-to-noise ratio, focusing on the numerical correlation between the retrieved Dicke narrowing frequency and the velocity-changing and dephasing collisions correlation parameter. Tran, H., N. Ngo, and J.-M. Hartmann, Journal of Quantitative Spectroscopy and Radiative Transfer 2013. 129: p. 89-100. Tennyson, et al., Pure Appl. Chem. 2014, 86: p. 1931-1943. Kochanov, R.V., et al., Journal of Quantitative Spectroscopy and Radiative Transfer 2016. 177: p. 15-30. Tran, H., N. Ngo, and J.-M. Hartmann, Journal of Quantitative Spectroscopy and Radiative Transfer 2013. 129: p. 199-203.

Life Cycle Management at Brødrene Hartmann A/S - strategy,- organisation and implementation

DEFF Research Database (Denmark)

Pedersen, Claus Stig; Alting, Leo; Mortensen, Anna Lise

1997-01-01

decisionmaking is under development.The implementation of life cycle management in Hartmann is organised with respect to the divisional areas: strategic management, product development, purchase, production, sale and distribution. The implementation of life cycle managment is assisted by tools to support...... decision making. The tools are developed in coorporation with the Department of Manufacturing Engineering at the Technical University of Denmark.This paper presents- The Hartmann environmental strategy, based on the life cycle concept- Experiences and results from developing a life cycle orientated...... organisation- Experiences and results from developing and implementing tools for life cycle management...

Ekman-Hartmann layer in a magnetohydrodynamic Taylor-Couette flow.

Science.gov (United States)

Szklarski, Jacek; Rüdiger, Günther

2007-12-01

We study magnetic effects induced by rigidly rotating plates enclosing a cylindrical magnetohydrodynamic (MHD) Taylor-Couette flow at the finite aspect ratio HD=10 . The fluid confined between the cylinders is assumed to be liquid metal characterized by small magnetic Prandtl number, the cylinders are perfectly conducting, an axial magnetic field is imposed with Hartmann number Ha approximately 10 , and the rotation rates correspond to Reynolds numbers of order 10(2)-10(3). We show that the end plates introduce, besides the well-known Ekman circulation, similar magnetic effects which arise for infinite, rotating plates, horizontally unbounded by any walls. In particular, there exists the Hartmann current, which penetrates the fluid, turns in the radial direction, and together with the applied magnetic field gives rise to a force. Consequently, the flow can be compared with a Taylor-Dean flow driven by an azimuthal pressure gradient. We analyze the stability of such flows and show that the currents induced by the plates can give rise to instability for the considered parameters. When designing a MHD Taylor-Couette experiment, special care must be taken concerning the vertical magnetic boundaries so that they do not significantly alter the rotational profile.

The best body spot to detect the vital capacity from the respiratory movement data obtained by the wearable strain sensor.

Science.gov (United States)

Liu, Haijuan; Guo, Shaopeng; Liu, Huilin; Zhang, Hao; Chen, Sujie; Kuramoto-Ahuja, Tsugumi; Sato, Tamae; Kaneko, Junichiro; Onoda, Ko; Maruyama, Hitoshi

2018-04-01

[Purpose] The purpose of this study is to find the best body spots on the chest and abdomen wall to obtain the correlated indicators to the vital capacity. [Subjects and Methods] Thirty healthy male staff of the center served as the participants were advised to conduct a breathing movement using spirometer and a wearable strain sensor (WSS) respectively, which was the measured at four spots on chest and abdomen wall from maximal end of inspiration to maximal end of expiration. The Pearson's correlation analysis was conducted to find the correlation of the data obtained respectively by the WSS and spirometer. [Results] The correlation of the mobility data at the four body spots to the vital capacity data were calculated for each level by means of Pearson's correlation coefficient, which showed that the values at each body spot were positive significant correlations and the highest value was at the 10th rib. [Conclusion] There was a correlation between the mobility data of the chest and abdomen obtained by the WSS and the vital capacity data obtained by the spirometer, for which, the 10th rib is the best body spot to detect the positive significant correlation.

The impact of surgeon volume on colostomy reversal outcomes after Hartmann's procedure for diverticulitis.

Science.gov (United States)

Aquina, Christopher T; Probst, Christian P; Becerra, Adan Z; Hensley, Bradley J; Iannuzzi, James C; Noyes, Katia; Monson, John R T; Fleming, Fergal J

2016-11-01

Colostomy reversal after Hartmann's procedure for diverticulitis is a morbid procedure, and studies investigating factors associated with outcomes are lacking. This study identifies patient, surgeon, and hospital-level factors associated with perioperative outcomes after stoma reversal. The Statewide Planning and Research Cooperative System was queried for urgent/emergency Hartmann's procedures for diverticulitis between 2000-2012 in New York State and subsequent colostomy reversal within 1 year of the procedure. Surgeon and hospital volume were categorized into tertiles based on the annual number of colorectal resections performed each year. Bivariate and mixed-effects analyses were used to assess the association between patient, surgeon, and hospital-level factors and perioperative outcomes after colostomy reversal, including a laparoscopic approach; duration of stay; intensive care unit admission; complications; mortality; and 30-day, unscheduled readmission. Among 10,487 patients who underwent Hartmann's procedure and survived to discharge, 63% had the colostomy reversed within 1 year. After controlling for patient, surgeon, and hospital-level factors, high-volume surgeons (≥40 colorectal resections/yr) were independently associated with higher odds of a laparoscopic approach (unadjusted rates: 14% vs 7.6%; adjusted odds ratio = 1.84, 95% confidence interval = 1.12, 3.00), shorter duration of stay (median: 6 versus 7 days; adjusted incidence rate ratio = 0.87, 95% confidence interval = 0.81, 0.95), and lower odds of 90-day mortality (unadjusted rates: 0.4% vs 1.0%; adjusted odds ratio = 0.30, 95% confidence interval = 0.10, 0.88) compared with low-volume surgeons (1-15 colorectal resections/yr). High-volume surgeons are associated with better perioperative outcomes and lower health care utilization after Hartmann's reversal for diverticulitis. These findings support referral to high-volume surgeons for colostomy reversal. Copyright © 2016

Design process for NIF laser alignment and beam diagnostics

Energy Technology Data Exchange (ETDEWEB)

Grey, A., LLNL

1998-06-09

In a controller for an adaptive optic system designed to correct phase aberrations in a high power laser, the wavefront sensor is a discrete Hartmann-Shack design. It uses an army of lenslets (like a fly` s eye) to focus the laser into 77 spots on a CCD camera. Average local tilt of the wavefront across each lenslet changes the position of its focal spot. The system requires 0.1 pixel accuracy in determining the focal spot location. We determine a small area around each spot` s previous location. Within this area, we calculate the centroid of the light intensity in x and y. This calculation fails if the spot regions overlap. Especially during initial acquisition of a highly distorted beam, distinguishing overlapping spots is difficult. However, low resolution analysis of the overlapping spots allows the system to estimate their positions. With this estimate, it can use the deformable mirror to correct the beam enough so we can detect the spots using conventional image processing.

Generalized peritonitis due to perforated diverticulitis: Hartmann's procedure or primary anastomosis?

Science.gov (United States)

Trenti, Loris; Biondo, Sebastiano; Golda, Thomas; Monica, Millan; Kreisler, Esther; Fraccalvieri, Domenico; Frago, Ricardo; Jaurrieta, Eduardo

2011-03-01

Hartmann's procedure (HP) still remains the most frequently performed procedure for diffuse peritonitis due to perforated diverticulitis. The aims of this study were to assess the feasibility and safety of resection with primary anastomosis (RPA) in patients with purulent or fecal diverticular peritonitis and review morbidity and mortality after single stage procedure and Hartmann in our experience. From January 1995 through December 2008, patients operated for generalized diverticular peritonitis were studied. Patients were classified into two main groups: RPA and HP. A total of 87 patients underwent emergency surgery for diverticulitis complicated with purulent or diffuse fecal peritonitis. Sixty (69%) had undergone HP while RPA was performed in 27 patients (31%). At the multivariate analysis, RPA was associated with less post-operative complications (P clinical anastomotic leakage and needed re-operation. RPA can be safely performed without adding morbidity and mortality in cases of diffuse diverticular peritonitis. HP should be reserved only for hemodynamically unstable or high-risk patients. Specialization in colorectal surgery improves mortality and raises the percentage of one-stage procedures.

Hartmann test of the COMPASS RICH-1 optical telescopes

CERN Document Server

Polak, J; Alekseev, M; Angerer, H; Apollonio, M; Birsa, R; Bordalo, P; Bradamante, F; Bressan, A; Busso, L; Chiosso, V M; Ciliberti, P; Colantoni, M L; Costa, S; Dibiase, N; Dafni, T; Dalla Torre, S; Diaz, V; Duic, V; Delagnes, E; Deschamps, H; Eyrich, W; Faso, D; Ferrero, A; Finger, M; Finger, M Jr; Fischer, H; Gerassimov, S; Giorgi, M; Gobbo, B; Hagemann, R; von Harrach, D; Heinsius, F H; Joosten, R; Ketzer, B; Königsmann, K; Kolosov, V N; Konorov, I; Kramer, D; Kunne, F; Levorato, S; Maggiora, A; Magnon, A; Mann, A; Martin, A; Rebourgeard, P; Mutter, A; Nähle, O; Neyret, D; Nerling, F; Pagano, P; Paul, S; Panebianco, S; Panzieri, D; Pesaro, G; Pizzolotto, C; Menon, G; Rocco, E; Robinet, F; Schiavon, P; Schill, C; Schoenmeier, P; Silva, L; Slunecka, M; Steiger, L; Sozzi, F; Sulc, M; Svec, M; Tessarotto, F; Teufel, A; Wollny, H

2008-01-01

The central region of COMPASS RICH-1 has been equipped with a new photon detection system based on MultiAnode PhotoMultiplier Tubes (MAPMT). The Cherenkov photons are focused by an array of 576 fused silica telescopes onto 576 MAPMTs. The quality and positioning of all optical components have been tested by Hartmann method. The validation procedures are described. The quality of the optical concentrators was checked and alignment corrections were made. The upgraded detector showed excellent performances during 2006 data taking.

[Stefan Hartmann. Revaler Handwerker im Spiegel fer Ratsprotokolle von 1722 bis 1755] / Paul Kaegbein

Index Scriptorium Estoniae

Kaegbein, Paul

2007-01-01

Arvustus: Stefan Hartmann. Revaler Handwerker im Spiegel fer Ratsprotokolle von 1722 bis 1755. In : Ostseeprovinzen, baltische Staaten und das Nationale. Münster : LIT, 2005. lk. 89-112. Kanuti gildi koondunud ametite organisatsioonist ja struktuurist

Hot spot in GdBa2Cu3O7-δ-based composite ceramics rods and their applications for oxygen sensors

International Nuclear Information System (INIS)

Okamoto, T; Takata, M

2011-01-01

A hot spot, which is a local area glowing orange, appears in a LnBa 2 Cu 3 O 7-δ (Ln: rare earth element) ceramic rod when a voltage exceeding a certain value is applied to the rod at room temperature. After the appearance of the hot spot, the current changes according to the oxygen partial pressure in ambient atmosphere, which acts as an oxygen sensor without the need for any heating system. The GdBa 2 Cu 3 O 7-δ rod tended to be melted and broken by a sustained presence of the hot spot in a high oxygen partial pressure Po 2 (∼100 kPa). The composite rod containing high melting point materials, such as BaAl 2 O 4 , BaZrO 3 and Gd 2 BaCuO 5 , showed a remarkable high durability in O 2 atmosphere. In a low Po 2 ( 2 Cu3O 7-δ rod decreases to almost zero and the hot spot disappeared, resulting in an insensitive rod to oxygen. The composite rod containing CuO detected oxygen even in Po 2 < 0.002 kPa.

Adaptive optics retinal imaging with automatic detection of the pupil and its boundary in real time using Shack-Hartmann images.

Science.gov (United States)

de Castro, Alberto; Sawides, Lucie; Qi, Xiaofeng; Burns, Stephen A

2017-08-20

Retinal imaging with an adaptive optics (AO) system usually requires that the eye be centered and stable relative to the exit pupil of the system. Aberrations are then typically corrected inside a fixed circular pupil. This approach can be restrictive when imaging some subjects, since the pupil may not be round and maintaining a stable head position can be difficult. In this paper, we present an automatic algorithm that relaxes these constraints. An image quality metric is computed for each spot of the Shack-Hartmann image to detect the pupil and its boundary, and the control algorithm is applied only to regions within the subject's pupil. Images on a model eye as well as for five subjects were obtained to show that a system exit pupil larger than the subject's eye pupil could be used for AO retinal imaging without a reduction in image quality. This algorithm automates the task of selecting pupil size. It also may relax constraints on centering the subject's pupil and on the shape of the pupil.

Machine learning enhanced optical distance sensor

Science.gov (United States)

Amin, M. Junaid; Riza, N. A.

2018-01-01

Presented for the first time is a machine learning enhanced optical distance sensor. The distance sensor is based on our previously demonstrated distance measurement technique that uses an Electronically Controlled Variable Focus Lens (ECVFL) with a laser source to illuminate a target plane with a controlled optical beam spot. This spot with varying spot sizes is viewed by an off-axis camera and the spot size data is processed to compute the distance. In particular, proposed and demonstrated in this paper is the use of a regularized polynomial regression based supervised machine learning algorithm to enhance the accuracy of the operational sensor. The algorithm uses the acquired features and corresponding labels that are the actual target distance values to train a machine learning model. The optimized training model is trained over a 1000 mm (or 1 m) experimental target distance range. Using the machine learning algorithm produces a training set and testing set distance measurement errors of learning. Applications for the proposed sensor include industrial scenario distance sensing where target material specific training models can be generated to realize low <1% measurement error distance measurements.

Colostomia tipo hartmann em ratos: alterações morfológicas e dosagem de hidroxiprolina

Directory of Open Access Journals (Sweden)

João Carlos Simões

Full Text Available A colostomia tem sido um procedimento cirúrgico freqüentemente empregado nas doenças colônicas, lesões traumáticas e neoplásicas. Este trabalho experimental, em ratos, visou estudar as progressivas mudanças morfológicas no cólon proximal e distal , após uma laparotomia e colostomia terminal, tipo Hartmann, que foram estudadas histologicamente e através da dosagem tecidual de hidroxiprolina. Utilizaram-se 40 ratos, machos, raça Wistar, com peso médio de 200 gramas, alocados em dois grupos (grupo I ou experimento e grupo II ou controle, subdivididos em quatro subgrupos: A,B,C e D com 10 animais em cada subgrupo. Os animais do grupo I (subgrupos A e B foram submetidos à colostomia tipo Hartmann, no cólon distal, a 7,5cm do canal anal. Nos ratos do grupo II foi praticada apenas uma laparotomia mediana. Os animais dos subgrupo A e C foram sacrificados no 30º dia de P.O., enquanto que os animais dos subgrupos B e D o sacrifício foi no 60º dia de P.O. A análise histológica dos segmentos colônicos permitiu observar infiltrado inflamatório agudo e crônico na lâmina própria, achatamento pronunciado das criptas, diminuição do número de criptas e da celularidade epitelial, redução das células caliciformes e da mucossecreção, adelgaçamento da muscular da mucosa, mais intensos no coto colônico distal dos animais submetidos à colostomia terminal tipo Hartmann (subgrupos A e B. Os segmentos proximais apresentavam estas alterações, porém mais discretas. A dosagem de hidroxiprolina nos tecidos colônicos não revelou alterações estatisticamente significativas quanto ao conteúdo de colágeno ou do peso desidratado. Estes achados permitem demonstrar alterações morfológicas inflamatórias e hipotróficas mais pronunciadas no cólon distal de ratos submetidos à colostomia tipo Hartmann.

Field-programmable gate array based controller for multi spot light-addressable potentiometric sensors with integrated signal correction mode

Energy Technology Data Exchange (ETDEWEB)

Werner, Carl Frederik; Schusser, Sebastian; Spelthahn, Heiko [Aachen University of Applied Sciences, Juelich Campus, Institute of Nano- and Biotechnologies, Heinrich-Mussmann-Strasse 1, 52428 Juelich (Germany); Institute of Bio- and Nanosystems (IBN-2), Research Centre Juelich GmbH, 52425 Juelich (Germany); Wagner, Torsten; Yoshinobu, Tatsuo [Tohoku University, Department of Electronic Engineering, 6-6-05 Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Schoening, Michael J., E-mail: schoening@fh-aachen.de [Aachen University of Applied Sciences, Juelich Campus, Institute of Nano- and Biotechnologies, Heinrich-Mussmann-Strasse 1, 52428 Juelich (Germany); Institute of Bio- and Nanosystems (IBN-2), Research Centre Juelich GmbH, 52425 Juelich (Germany)

2011-11-01

Highlights: > Flexible up-scalable design of a light-addressable potentiometric sensor set-up. > Utilisation of a field-programmable gate array to address LAPS measurement spots. > Measurements in amplitude-mode and phase-mode for different pH solutions. > Amplitude, phase and frequency behaviour of LAPS for single and multiple light stimulus. > Signal calibration method by brightness control to compensated systematic errors. - Abstract: A light-addressable potentiometric sensor (LAPS) can measure the concentration of one or several analytes at the sensor surface simultaneously in a spatially resolved manner. A modulated light pointer stimulates the semiconductor structure at the area of interest and a responding photocurrent can be read out. By simultaneous stimulation of several areas with light pointers of different modulation frequencies, the read out can be performed at the same time. With the new proposed controller electronic based on a field-programmable gate array (FPGA), it is possible to control the modulation frequencies, phase shifts, and light brightness of multiple light pointers independently and simultaneously. Thus, it is possible to investigate the frequency response of the sensor, and to examine the analyte concentration by the determination of the surface potential with the help of current/voltage curves and phase/voltage curves. Additionally, the ability to individually change the light intensities of each light pointer is used to perform signal correction.

Alignment and qualification of the Gaia telescope using a Shack-Hartmann sensor

Science.gov (United States)

Dovillaire, G.; Pierot, D.

2017-09-01

Since almost 20 years, Imagine Optic develops, manufactures and offers to its worldwide customers reliable and accurate wavefront sensors and adaptive optics solutions. Long term collaboration between Imagine Optic and Airbus Defence and Space has been initiated on the Herschel program. More recently, a similar technology has been used to align and qualify the GAIA telescope.

Health economic analysis of laparoscopic lavage versus Hartmann's procedure for diverticulitis in the randomized DILALA trial

DEFF Research Database (Denmark)

Gehrman, J.; Angenete, E; Björholt, I.

2016-01-01

Background: Open surgery with resection and colostomy (Hartmann's procedure) has been the standard treatment for perforated diverticulitis with purulent peritonitis. In recent years laparoscopic lavage has emerged as an alternative, with potential benefits for patients with purulent peritonitis...

Comparison of Available Technologies for Fire Spots Detection via Linear Heat Detector

Directory of Open Access Journals (Sweden)

Miksa František

2016-12-01

Full Text Available It is very demanding to detect fire spots under difficult conditions with high occurrence of interfering external factors such as large distances, airflow difficultly, high dustiness, high humidity, etc. Spot fire sensors do not meet the requirements due to the aforementioned conditions as well as large distances. Therefore, the detection of a fire spot via linear heat sensing cables is utilized.

The SPOT-HRV instrument - An overview of design and performance

Science.gov (United States)

Midan, J. P.

1983-10-01

The SPOT spacecraft's High Visible Resolution (HVR) earth resources sensor performance requirements, system and subsystem design features, and technology development considerations, are discussed. Attention is given to such problem areas involving extensive design tradeoff analyses and testing as those uncovered by mechanical design and thermal distortion studies and SNR analysis and calibration considerations. The SPOT spacecraft will be placed in orbit in 1985.

Ontologie della resistenza: note sul concetto di materia in N. Hartmann e G. Lukács

Directory of Open Access Journals (Sweden)

D’Anna, Giuseppe

2010-01-01

Full Text Available The essay discusses the topic of matter in N. Hartmann and G. Lukács. It shows how both of them use their own concepts of matter in order to counter correlativistic philosophies – such as Phenomenology, Neo-Kantianism, Existentialism, Pragmatism, Positivism, Empirio-Criticism or Conventionalism – which reduce the real world to the laws of thought, to those of the absolute consciousness or to scientific laws, therefore eliminating the resistance of the reality and the meaning of praxis and dialectic in front of the givenness of the world. While Hartmann uses the concept of matter in order to revive the idea of a reality going beyond the laws of thought, Lukács uses Hartmann’s ontology in order to counter the philosophies that, by excluding the exceedance of reality and matter, provide theories which appear to him functional to the capitalist society.

Autonomia apesar da dependência: a construção de uma Antropologia Dimensional no diálogo entre Frankl e Hartmann

Directory of Open Access Journals (Sweden)

Daniel Rubens Santiago da Silva

2016-12-01

Full Text Available O artigo se trata de um estudo teórico onde são apresentados alguns pontos da Ontologia Dimensional de Nicolai Hartmann e a relação destes com a Antropologia Ontológico-Dimensional de Viktor Frankl. Além dos pontos em que se percebe uma clara influência de Hartmann no pensamento frankliano, procurou-se chegar a elementos do pensamento do primeiro para além daquilo que serve de fundamento à Logoterapia. Quanto à influência de Hartmann, concluiu-se pela centralidade de sua Ontologia Dimensional no esquema frankliano, atestada pelas concessões ao condicionamento “psicofísico” e pela crítica ao pandeterminismo e ao reducionismo. O resultado é a fórmula: “autonomia apesar da dependência”. Quanto aos elementos que estão para além daquilo que serve de fundamento à Logoterapia, perceberam-se possibilidades fecundas de diálogo, como por ocasião da discussão em torno da vida espiritual “a-temporal” e do “espírito objetivo”.

Hartmann wavefront sensing of the corrective optics for the Hubble Space Telescope

Science.gov (United States)

Davila, Pam S.; Eichhorn, William L.; Wilson, Mark E.

1994-06-01

aberration content of the corrected images. Also, from only this test it was difficult to measure important pupil parameters, such as pupil intensity profiles and pupil sizes and location. To measure the COSTAR wavefront accurately and to determine pupil parameters, another very important test was performed on the COSTAR optics. A Hartmann test of the optical system consisting of the RAS and COSTAR was conducted by the Goddard Independent Verification Team (IVT). In this paper, we first describe the unique Hartmann sensor that was developed by the IVT. Then we briefly describe the RAS and COSTAR optical systems and the test setup. Finally, we present the results of the test and compare our results with results obtained from optical analysis and from image tests with the BIA.

Thermoelectric infrared imaging sensors for automotive applications

Science.gov (United States)

Hirota, Masaki; Nakajima, Yasushi; Saito, Masanori; Satou, Fuminori; Uchiyama, Makoto

2004-07-01

This paper describes three low-cost thermoelectric infrared imaging sensors having a 1,536, 2,304, and 10,800 element thermoelectric focal plane array (FPA) respectively and two experimental automotive application systems. The FPAs are basically fabricated with a conventional IC process and micromachining technologies and have a low cost potential. Among these sensors, the sensor having 2,304 elements provide high responsivity of 5,500 V/W and a very small size with adopting a vacuum-sealed package integrated with a wide-angle ZnS lens. One experimental system incorporated in the Nissan ASV-2 is a blind spot pedestrian warning system that employs four infrared imaging sensors. This system helps alert the driver to the presence of a pedestrian in a blind spot by detecting the infrared radiation emitted from the person"s body. The system can also prevent the vehicle from moving in the direction of the pedestrian. The other is a rearview camera system with an infrared detection function. This system consists of a visible camera and infrared sensors, and it helps alert the driver to the presence of a pedestrian in a rear blind spot. Various issues that will need to be addressed in order to expand the automotive applications of IR imaging sensors in the future are also summarized. This performance is suitable for consumer electronics as well as automotive applications.

Image system analysis of human eye wave-front aberration on the basis of HSS

Science.gov (United States)

Xu, Ancheng

2017-07-01

Hartmann-Shack sensor (HSS) has been used in objective measurement of human eye wave-front aberration, but the research on the effects of sampling point size on the accuracy of the result has not been reported. In this paper, point spread function (PSF) of the whole system mathematical model was obtained via measuring the optical imaging system structure of human eye wave-front aberration measurement. The impact of Airy spot size on the accuracy of system was analyzed. Statistics study show that the geometry of Airy spot size of the ideal light source sent from eye retina formed on the surface of HSS is far smaller than the size of the HSS sample point image used in the experiment. Therefore, the effect of Airy spot on the precision of the system can be ignored. This study theoretically and experimentally justifies the reliability and accuracy of human eye wave-front aberration measurement based on HSS.

Multi-Aperture CMOS Sun Sensor for Microsatellite Attitude Determination

Directory of Open Access Journals (Sweden)

Michele Grassi

2009-06-01

Full Text Available This paper describes the high precision digital sun sensor under development at the University of Naples. The sensor determines the sun line orientation in the sensor frame from the measurement of the sun position on the focal plane. It exploits CMOS technology and an original optical head design with multiple apertures. This allows simultaneous multiple acquisitions of the sun as spots on the focal plane. The sensor can be operated either with a fixed or a variable number of sun spots, depending on the required field of view and sun-line measurement precision. Multiple acquisitions are averaged by using techniques which minimize the computational load to extract the sun line orientation with high precision. Accuracy and computational efficiency are also improved thanks to an original design of the calibration function relying on neural networks. Extensive test campaigns are carried out using a laboratory test facility reproducing sun spectrum, apparent size and distance, and variable illumination directions. Test results validate the sensor concept, confirming the precision improvement achievable with multiple apertures, and sensor operation with a variable number of sun spots. Specifically, the sensor provides accuracy and precision in the order of 1 arcmin and 1 arcsec, respectively.

Oral histories in meteoritics and planetary science—XXIV: William K. Hartmann

Science.gov (United States)

Sears, Derek W. G.

2014-06-01

In this interview, William Hartmann (Bill, Fig. 1) describes how he was inspired as a teenager by a map of the Moon in an encyclopedia and by the paintings by Chesley Bonestell. Through the amateur journal "Strolling Astronomer," he shared his interests with other teenagers who became lifelong colleagues. At college, he participated in Project Moonwatch, observing early artificial satellites. In graduate school, under Gerard Kuiper, Bill discovered Mare Orientale and other large concentric lunar basin structures. In the 1960s and 1970s, he used crater densities to study surface ages and erosive/depositional effects, predicted the approximately 3.6 Gyr ages of the lunar maria before the Apollo samples, discovered the intense pre-mare lunar bombardment, deduced the youthful Martian volcanism as part of the Mariner 9 team, and proposed (with Don Davis) the giant impact model for lunar origin. In 1972, he helped found (what is now) the Planetary Science Institute. From the late 1970s to early 1990s, Bill worked mostly with Dale Cruikshank and Dave Tholen at Mauna Kea Observatory, helping to break down the Victorian paradigm that separated comets and asteroids, and determining the approximately 4% albedo of comet nuclei. Most recently, Bill has worked with the imaging teams for several additional Mars missions. He has written three college textbooks and, since the 1970s, after painting illustrations for his textbooks, has devoted part of his time to painting, having had several exhibitions. He has also published two novels. Bill Hartmann won the 2010 Barringer Award for impact studies and the first Carl Sagan Award for outreach in 1997.

Videosensor for the detection of unsafe driving behavior in the proximity of black spots.

Science.gov (United States)

Fuentes, Andres; Fuentes, Ricardo; Cabello, Enrique; Conde, Cristina; Martin, Isaac

2014-10-24

This paper discusses the overall design and implementation of a video sensor for the detection of risky behaviors of car drivers near previously identified and georeferenced black spots. The main goal is to provide the driver with a visual audio alert that informs of the proximity of an area of high incidence of highway accidents only if their driving behavior could result in a risky situation. It proposes a video sensor for detecting and supervising driver behavior, its main objective being manual distractions, so hand driver supervision is performed. A GPS signal is also considered, the GPS information is compared with a database of global positioning Black Spots to determine the relative proximity of a risky area. The outputs of the video sensor and GPS sensor are combined to evaluate a possible risky behavior. The results are promising in terms of risk analysis in order to be validated for use in the context of the automotive industry as future work.

Videosensor for the Detection of Unsafe Driving Behavior in the Proximity of Black Spots

Directory of Open Access Journals (Sweden)

Andres Fuentes

2014-10-01

Full Text Available This paper discusses the overall design and implementation of a video sensor for the detection of risky behaviors of car drivers near previously identified and georeferenced black spots. The main goal is to provide the driver with a visual audio alert that informs of the proximity of an area of high incidence of highway accidents only if their driving behavior could result in a risky situation. It proposes a video sensor for detecting and supervising driver behavior, its main objective being manual distractions, so hand driver supervision is performed. A GPS signal is also considered, the GPS information is compared with a database of global positioning Black Spots to determine the relative proximity of a risky area. The outputs of the video sensor and GPS sensor are combined to evaluate a possible risky behavior. The results are promising in terms of risk analysis in order to be validated for use in the context of the automotive industry as future work.

Analysis of the unmodulated diffraction beam of the phase-only liquid crystal spatial light modulator and a method for reducing its influence

International Nuclear Information System (INIS)

Qi, Yue; Li, Dayu; Hu, Lifa; Xuan, Li; Xia, Mingliang

2012-01-01

As a wavefront corrector, the phase-only liquid crystal spatial light modulator has been widely using in adaptive optics systems. However, the unmodulated diffracted beam of the modulator will affect the light spot centroid detection accuracy of a Shack–Hartmann wavefront sensor and decrease the image quality after correction. In this paper, we have diminished the effect by introducing a modified weight algorithm in our closed-loop adaptive optics system. The Strehl ratio of the image is higher than 0.8 after correction, even when the wavefront aberration is larger than 3 μm. The correction precision and image quality are both improved significantly. (paper)

Séries temporais de NDVI do sensor SPOT Vegetation e algoritmo SAM aplicados ao mapeamento de cana‑de‑açúcar

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Luiz Eduardo Vicente

2012-09-01

Full Text Available O objetivo deste trabalho foi avaliar o mapeamento de área de cana‑de‑açúcar por meio de série temporal, de seis anos de dados do índice de vegetação por diferença normalizada (NDVI, oriundos do sensor Vegetation, a bordo do satélite "système pour l'observation de la Terre" (SPOT. Três classes de cobertura do solo (cana‑de‑açúcar, pasto e floresta, do Estado de São Paulo, foram selecionadas como assinaturas espectro‑temporais de referência, que serviram como membros extremos ("endmembers" para classificação com o algoritmo "spectral angle mapper" (SAM. A partir desta classificação, o mapeamento da área de cana‑de‑açúcar foi realizado com uso de limiares na imagem-regra do SAM, gerados a partir dos valores dos espectros de referência. Os resultados mostram que o algoritmo SAM pode ser aplicado a séries de dados multitemporais de resolução moderada, o que permite eficiente mapeamento de alvo agrícola em escala mesorregional. Dados oficiais de áreas de cana‑de‑açúcar, para as microrregiões paulistas, apresentam boa correlação (r² = 0,8 com os dados obtidos pelo método avaliado. A aplicação do algoritmo SAM mostrou ser útil em análises temporais. As séries temporais de NDVI do sensor SPOT Vegetation podem ser utilizadas para mapeamento da área de cana‑de‑açúcar em baixa resolução.

Dynamically variable spot size laser system

Science.gov (United States)

Gradl, Paul R. (Inventor); Hurst, John F. (Inventor); Middleton, James R. (Inventor)

2012-01-01

A Dynamically Variable Spot Size (DVSS) laser system for bonding metal components includes an elongated housing containing a light entry aperture coupled to a laser beam transmission cable and a light exit aperture. A plurality of lenses contained within the housing focus a laser beam from the light entry aperture through the light exit aperture. The lenses may be dynamically adjusted to vary the spot size of the laser. A plurality of interoperable safety devices, including a manually depressible interlock switch, an internal proximity sensor, a remotely operated potentiometer, a remotely activated toggle and a power supply interlock, prevent activation of the laser and DVSS laser system if each safety device does not provide a closed circuit. The remotely operated potentiometer also provides continuous variability in laser energy output.

Range-Measuring Video Sensors

Science.gov (United States)

Howard, Richard T.; Briscoe, Jeri M.; Corder, Eric L.; Broderick, David

2006-01-01

Optoelectronic sensors of a proposed type would perform the functions of both electronic cameras and triangulation- type laser range finders. That is to say, these sensors would both (1) generate ordinary video or snapshot digital images and (2) measure the distances to selected spots in the images. These sensors would be well suited to use on robots that are required to measure distances to targets in their work spaces. In addition, these sensors could be used for all the purposes for which electronic cameras have been used heretofore. The simplest sensor of this type, illustrated schematically in the upper part of the figure, would include a laser, an electronic camera (either video or snapshot), a frame-grabber/image-capturing circuit, an image-data-storage memory circuit, and an image-data processor. There would be no moving parts. The laser would be positioned at a lateral distance d to one side of the camera and would be aimed parallel to the optical axis of the camera. When the range of a target in the field of view of the camera was required, the laser would be turned on and an image of the target would be stored and preprocessed to locate the angle (a) between the optical axis and the line of sight to the centroid of the laser spot.

Reconstrução de trânsito intestinal após confecção de colostomia à Hartmann

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Rodrigo Gomes da Silva

Full Text Available OBJETIVO: O objetivo desse estudo foi avaliar as taxas de morbidade e de mortalidade da tentativa de reversão do procedimento de Hartmann. MÉTODOS: Foram estudados retrospectivamente 29 pacientes submetidos à operação para reconstrução do trânsito intestinal após procedimento de Hartmann no Hospital das Clínicas da Universidade Federal de Minas Gerais no período de janeiro de 1998 a dezembro de 2006. Foram avaliados dados pré-operatório, intra-operatórios e pós-operatórios. RESULTADOS: A média de idade dos pacientes submetidos à operação para reconstrução de trânsito intestinal após realização de colostomia a Hartmann foi de 52,6 anos, sendo 16 pacientes do sexo masculino (55,2%. O tempo médio da permanência da colostomia foi de 17,6 meses (variando de 1 a 84 meses. O tempo operatório médio foi de 300 minutos (variando de 180 a 720 minutos. O sucesso na reconstrução do trânsito intestinal foi alcançado em 27 pacientes (93%. Dois pacientes apresentaram fístula anastomótica (7% e seis tiveram infecção de parede (22%. Ocorreu um óbito (3,4% em paciente com fístula anastomótica e sepse abdominal. Dentre os fatores relacionados ao insucesso na reconstrução da colostomia a Hartmann observou-se associação estatisticamente significativa com a tentativa prévia de reconstrução (p = 0,007, a utilização prévia de quimioterapia (p = 0,037 e o longo tempo de permanência da colostomia (p = 0,025 CONCLUSÃO: O intervalo entre a confecção e a tentativa de reversão não deve ser muito longo e os pacientes devem ser alertados que, numa pequena porcentagem dos casos, a reconstrução do trânsito intestinal pode ser impossível devido às condições locais do reto excluído.

More about tunnelling times and superluminal tunnelling (Hartmann effect)

International Nuclear Information System (INIS)

Olkhovsky, V.S.; Recami, E.; Raciti, F.; Zaichenko, A.

1995-05-01

Aims of the present paper are: i) presenting and analysing the results of various numerical calculations on the penetration and return times Pen >, Ret >, during tunnelling inside a rectangular potential barrier, for various penetration depths x f ; ii) putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D τT and D τR for the time durations of transmission and reflection processes; iii)mentioning, moreover, that our definition T > for the average transmission time results to constitute an improvement of the ordinary dwell- time formula; iv) commenting, at last, on the basis of the new numerical results, upon some recent criticism by C.R. Leavens. The paper stresses that numerical evaluations confirm that the approach implied, and implies, the existence of the Hartmann effect: an effect that in these days (due to the theoretical connections between tunnelling and evanescent-wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna - indirect, but quite interesting, experimental verification

Performance analysis of coherent free space optical communications with sequential pyramid wavefront sensor

Science.gov (United States)

Liu, Wei; Yao, Kainan; Chen, Lu; Huang, Danian; Cao, Jingtai; Gu, Haijun

2018-03-01

Based-on the previous study on the theory of the sequential pyramid wavefront sensor (SPWFS), in this paper, the SPWFS is first applied to the coherent free space optical communications (FSOC) with more flexible spatial resolution and higher sensitivity than the Shack-Hartmann wavefront sensor, and with higher uniformity of intensity distribution and much simpler than the pyramid wavefront sensor. Then, the mixing efficiency (ME) and the bit error rate (BER) of the coherent FSOC are analyzed during the aberrations correction through numerical simulation with binary phase shift keying (BPSK) modulation. Finally, an experimental AO system based-on SPWFS is setup, and the experimental data is used to analyze the ME and BER of homodyne detection with BPSK modulation. The results show that the AO system based-on SPWFS can increase ME and decrease BER effectively. The conclusions of this paper provide a new method of wavefront sensing for designing the AO system for a coherent FSOC system.

Capillarity-based preparation system for optical colorimetric sensor arrays.

Science.gov (United States)

Luo, Xiao-Gang; Yi, Xin; Bu, Xiang-Nan; Hou, Chang-Jun; Huo, Dan-Qun; Yang, Mei; Fa, Huan-Bao; Lei, Jin-Can

2017-03-01

In recent years, optical colorimetric sensor arrays have demonstrated beneficial features, including rapid response, high selectivity, and high specificity; as a result, it has been extensively applied in food inspection and chemical studies, among other fields. There are instruments in the current market available for the preparation of an optical colorimetric sensor array, but it lacks the corresponding research of the preparation mechanism. Therefore, in connection with the main features of this kind of sensor array such as consistency, based on the preparation method of contact spotting, combined with a capillary fluid model, Washburn equation, Laplace equation, etc., this paper develops a diffusion model of an optical colorimetric sensor array during its preparation and sets up an optical colorimetric sensor array preparation system based on this diffusion model. Finally, this paper compares and evaluates the sensor arrays prepared by the system and prepared manually in three aspects such as the quality of array point, response of array, and response result, and the results show that the performance index of the sensor array prepared by a system under this diffusion model is better than that of the sensor array of manual spotting, which meets the needs of the experiment.

An Optical Wavefront Sensor Based on a Double Layer Microlens Array

Directory of Open Access Journals (Sweden)

Hsiang-Chun Wei

2011-10-01

Full Text Available In order to determine light aberrations, Shack-Hartmann optical wavefront sensors make use of microlens arrays (MLA to divide the incident light into small parts and focus them onto image planes. In this paper, we present the design and fabrication of long focal length MLA with various shapes and arrangements based on a double layer structure for optical wavefront sensing applications. A longer focal length MLA could provide high sensitivity in determining the average slope across each microlens under a given wavefront, and spatial resolution of a wavefront sensor is increased by numbers of microlenses across a detector. In order to extend focal length, we used polydimethysiloxane (PDMS above MLA on a glass substrate. Because of small refractive index difference between PDMS and MLA interface (UV-resin, the incident light is less refracted and focused in further distance. Other specific focal lengths could also be realized by modifying the refractive index difference without changing the MLA size. Thus, the wavefront sensor could be improved with better sensitivity and higher spatial resolution.

Method for laser spot welding monitoring

Science.gov (United States)

Manassero, Giorgio

1994-09-01

As more powerful solid state laser sources appear on the market, new applications become technically possible and important from the economical point of view. For every process a preliminary optimization phase is necessary. The main parameters, used for a welding application by a high power Nd-YAG laser, are: pulse energy, pulse width, repetition rate and process duration or speed. In this paper an experimental methodology, for the development of an electrooptical laser spot welding monitoring system, is presented. The electromagnetic emission from the molten pool was observed and measured with appropriate sensors. The statistical method `Parameter Design' was used to obtain an accurate analysis of the process parameter that influence process results. A laser station with a solid state laser coupled to an optical fiber (1 mm in diameter) was utilized for the welding tests. The main material used for the experimental plan was zinc coated steel sheet 0.8 mm thick. This material and the related spot welding technique are extensively used in the automotive industry, therefore, the introduction of laser technology in production line will improve the quality of the final product. A correlation, between sensor signals and `through or not through' welds, was assessed. The investigation has furthermore shown the necessity, for the modern laser production systems, to use multisensor heads for process monitoring or control with more advanced signal elaboration procedures.

Optimization of scanning strategy of digital Shack-Hartmann wavefront sensing.

Science.gov (United States)

Guo, Wenjiang; Zhao, Liping; Li, Xiang; Chen, I-Ming

2012-01-01

In the traditional Shack-Hartmann wavefront sensing (SHWS) system, a lenslet array with a bigger configuration is desired to achieve a higher lateral resolution. However, practical implementation limits the configuration and this parameter is contradicted with the measurement range. We have proposed a digital scanning technique by making use of the high flexibility of a spatial light modulator to sample the reflected wavefront [X. Li, L. P. Zhao, Z. P. Fang, and C. S. Tan, "Improve lateral resolution in wavefront sensing with digital scanning technique," in Asia-Pacific Conference of Transducers and Micro-Nano Technology (2006)]. The lenslet array pattern is programmed to laterally scan the whole aperture. In this paper, the methodology to optimize the scanning step for the purpose of form measurement is proposed. The correctness and effectiveness are demonstrated in numerical simulation and experimental investigation. © 2012 Optical Society of America

Deforestation and Secondary Growth in Rondonia, Brazil from SIR-C SAR and Landsat.SPOT data

Science.gov (United States)

Rignot, Eric; Salas, William A.; Skole, David L.

1996-01-01

Covers problems with existing data collected with high-resolution optical sensors. They say active microwave sensors could complement other sensors in getting through things like cloud cover. They analyzed SIR-C data in combination with Landsat TM data, a 9-year time series of SPOT XS data, and a preliminary field survey. They report findings and draw conclusions, including that SARs operating at long radar wavelengths, with both like and cross-polarizations, are needed for tropical deforestation studies.

MHD from a Microscopic Concept and Onset of Turbulence in Hartmann Flow

International Nuclear Information System (INIS)

Jirkovsky, L.; Bo-ot, L. Ma.; Chiang, C. M.

2010-01-01

We derive higher order magneto-hydrodynamic (MHD) equations from a microscopic picture using projection and perturbation formalism. In an application to Hartmann flow we find velocity profiles flattening towards the center at the onset of turbulence in hydrodynamic limit. Comparison with the system under the effect of a uniform magnetic field yields difference in the onset of turbulence consistent with observations, showing that the presence of magnetic field inhibits onset of instability or turbulence. The laminar-turbulent transition is demonstrated in a phase transition plot of the development in time of the relative average velocities vs. Reynolds number showing a sharp increase of the relative average velocity at the transition point as determined by the critical Reynolds number. (physics of gases, plasmas, and electric discharges)

Liver spots

Science.gov (United States)

... skin changes - liver spots; Senile or solar lentigines; Skin spots - aging; Age spots ... Liver spots are changes in skin color that occur in older skin. The coloring may be due to aging, exposure to the sun ...

SpotADAPT

DEFF Research Database (Denmark)

Kaulakiene, Dalia; Thomsen, Christian; Pedersen, Torben Bach

2015-01-01

by Amazon Web Services (AWS). The users aiming for the spot market are presented with many instance types placed in multiple datacenters in the world, and thus it is difficult to choose the optimal deployment. In this paper, we propose the framework SpotADAPT (Spot-Aware (re-)Deployment of Analytical...... of typical analytical workloads and real spot price traces. SpotADAPT's suggested deployments are comparable to the theoretically optimal ones, and in particular, it shows good cost benefits for the budget optimization -- on average SpotADAPT is at most 0.3% more expensive than the theoretically optimal...

Numerical simulations of MHD flow transition in ducts with conducting Hartmann walls. Limtech project A3 D4 (TUI)

Energy Technology Data Exchange (ETDEWEB)

Krasnov, D.; Boeck, T. [Technische Univ. Ilmenau (Germany). Inst. of Thermodynamics and Fluid Mechanics; Braiden, L.; Molokov, S. [Conventry Univ. (United Kingdom). Dept. of Mathematics and Physics; Buehler, L. [Karlsruher Institut fuer Technologie (Germany). Inst. fuer Kern- und Energietechnik, Programm Kernfusion

2016-07-01

Pressure-driven magnetohydrodynamic duct flows in a transverse, wall-parallel and uniform field have been studied by direct numerical. The conducting Hartmann walls give rise to a laminar velocity distribution with strong jets at the side walls, which are susceptible to flow instability. The onset of time-dependent flow as well as fully developed turbulent flow have been explored in a wide range of parameters.

Sensor device for X-ray beam to evaluate the radiation focal spot

International Nuclear Information System (INIS)

Santos, Lara H.E. dos; Schiabel, Homero; Silva, Aderbal A.B. da; Marques, Paulo M.A.; Campos, Marcelo; Slaets, Annie F.F.

1996-01-01

A new electronic device to determine the position of the central ray of the radiation beam is proposed. The device aims to provide a perfect alignment of test objects used for evaluating focal spots with this reference axis

Hartmann characterization of the PEEM-3 aberration-corrected X-ray photoemission electron microscope.

Science.gov (United States)

Scholl, A; Marcus, M A; Doran, A; Nasiatka, J R; Young, A T; MacDowell, A A; Streubel, R; Kent, N; Feng, J; Wan, W; Padmore, H A

2018-05-01

Aberration correction by an electron mirror dramatically improves the spatial resolution and transmission of photoemission electron microscopes. We will review the performance of the recently installed aberration corrector of the X-ray Photoemission Electron Microscope PEEM-3 and show a large improvement in the efficiency of the electron optics. Hartmann testing is introduced as a quantitative method to measure the geometrical aberrations of a cathode lens electron microscope. We find that aberration correction leads to an order of magnitude reduction of the spherical aberrations, suggesting that a spatial resolution of below 100 nm is possible at 100% transmission of the optics when using x-rays. We demonstrate this improved performance by imaging test patterns employing element and magnetic contrast. Published by Elsevier B.V.

Dependence of the compensation error on the error of a sensor and corrector in an adaptive optics phase-conjugating system

International Nuclear Information System (INIS)

Kiyko, V V; Kislov, V I; Ofitserov, E N

2015-01-01

In the framework of a statistical model of an adaptive optics system (AOS) of phase conjugation, three algorithms based on an integrated mathematical approach are considered, each of them intended for minimisation of one of the following characteristics: the sensor error (in the case of an ideal corrector), the corrector error (in the case of ideal measurements) and the compensation error (with regard to discreteness and measurement noises and to incompleteness of a system of response functions of the corrector actuators). Functional and statistical relationships between the algorithms are studied and a relation is derived to ensure calculation of the mean-square compensation error as a function of the errors of the sensor and corrector with an accuracy better than 10%. Because in adjusting the AOS parameters, it is reasonable to proceed from the equality of the sensor and corrector errors, in the case the Hartmann sensor is used as a wavefront sensor, the required number of actuators in the absence of the noise component in the sensor error turns out 1.5 – 2.5 times less than the number of counts, and that difference grows with increasing measurement noise. (adaptive optics)

Dependence of the compensation error on the error of a sensor and corrector in an adaptive optics phase-conjugating system

Energy Technology Data Exchange (ETDEWEB)

Kiyko, V V; Kislov, V I; Ofitserov, E N [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2015-08-31

In the framework of a statistical model of an adaptive optics system (AOS) of phase conjugation, three algorithms based on an integrated mathematical approach are considered, each of them intended for minimisation of one of the following characteristics: the sensor error (in the case of an ideal corrector), the corrector error (in the case of ideal measurements) and the compensation error (with regard to discreteness and measurement noises and to incompleteness of a system of response functions of the corrector actuators). Functional and statistical relationships between the algorithms are studied and a relation is derived to ensure calculation of the mean-square compensation error as a function of the errors of the sensor and corrector with an accuracy better than 10%. Because in adjusting the AOS parameters, it is reasonable to proceed from the equality of the sensor and corrector errors, in the case the Hartmann sensor is used as a wavefront sensor, the required number of actuators in the absence of the noise component in the sensor error turns out 1.5 – 2.5 times less than the number of counts, and that difference grows with increasing measurement noise. (adaptive optics)

Optically sensitive Medipix2 detector for adaptive optics wavefront sensing

CERN Document Server

Vallerga, John; Tremsina, Anton; Siegmund, Oswald; Mikulec, Bettina; Clark, Allan G; CERN. Geneva

2005-01-01

A new hybrid optical detector is described that has many of the attributes desired for the next generation adaptive optics (AO) wavefront sensors. The detector consists of a proximity focused microchannel plate (MCP) read out by multi-pixel application specific integrated circuit (ASIC) chips developed at CERN ("Medipix2") with individual pixels that amplify, discriminate and count input events. The detector has 256 x 256 pixels, zero readout noise (photon counting), can be read out at 1 kHz frame rates and is abutable on 3 sides. The Medipix2 readout chips can be electronically shuttered down to a temporal window of a few microseconds with an accuracy of 10 ns. When used in a Shack-Hartmann style wavefront sensor, a detector with 4 Medipix chips should be able to centroid approximately 5000 spots using 7 x 7 pixel sub-apertures resulting in very linear, off-null error correction terms. The quantum efficiency depends on the optical photocathode chosen for the bandpass of interest.

Optically sensitive Medipix2 detector for adaptive optics wavefront sensing

International Nuclear Information System (INIS)

Vallerga, John; McPhate, Jason; Tremsin, Anton; Siegmund, Oswald; Mikulec, Bettina; Clark, Allan

2005-01-01

A new hybrid optical detector is described that has many of the attributes desired for the next generation adaptive optics (AO) wavefront sensors. The detector consists of a proximity focused microchannel plate (MCP) read out by multi-pixel application specific integrated circuit (ASIC) chips developed at CERN ('Medipix2') with individual pixels that amplify, discriminate and count input events. The detector has 256x256 pixels, zero readout noise (photon counting), can be read out at 1 kHz frame rates and is abutable on 3 sides. The Medipix2 readout chips can be electronically shuttered down to a temporal window of a few microseconds with an accuracy of 10 ns. When used in a Shack-Hartmann style wavefront sensor, a detector with 4 Medipix chips should be able to centroid approximately 5000 spots using 7x7 pixel sub-apertures resulting in very linear, off-null error correction terms. The quantum efficiency depends on the optical photocathode chosen for the bandpass of interest

Nuclear Magnetic Resonance Trackbed Moisture Sensor System

Science.gov (United States)

2018-02-01

In this initial phase, conducted from March 2015 through December 2016, Vista Clara and its subcontractor Zetica Rail successfully developed and tested a man-portable, non-invasive spot-check nuclear magnetic resonance (NMR) moisture sensor that dire...

Distinct Rayleigh scattering from hot spot mutant p53 proteins reveals cancer cells.

Science.gov (United States)

Jun, Ho Joon; Nguyen, Anh H; Kim, Yeul Hong; Park, Kyong Hwa; Kim, Doyoun; Kim, Kyeong Kyu; Sim, Sang Jun

2014-07-23

The scattering of light redirects and resonances when an electromagnetic wave interacts with electrons orbits in the hot spot core protein and oscillated electron of the gold nanoparticles (AuNP). This report demonstrates convincingly that resonant Rayleigh scattering generated from hot spot mutant p53 proteins is correspondence to cancer cells. Hot spot mutants have unique local electron density changes that affect specificity of DNA binding affinity compared with wild types. Rayleigh scattering changes introduced by hot-spot mutations were monitored by localized surface plasmon resonance (LSPR) shift changes. The LSPR λmax shift for hot-spot mutants ranged from 1.7 to 4.2 nm for mouse samples and from 0.64 nm to 2.66 nm for human samples, compared to 9.6 nm and 15 nm for wild type and mouse and human proteins, respectively with a detection sensitivity of p53 concentration at 17.9 nM. It is interesting that hot-spot mutants, which affect only interaction with DNA, launches affinitive changes as considerable as wild types. These changes propose that hot-spot mutants p53 proteins can be easily detected by local electron density alterations that disturbs the specificity of DNA binding of p53 core domain on the surface of the DNA probed-nanoplasmonic sensor. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Integrated Health Monitoring Method for Structural Fatigue Life Evaluation Using Limited Sensor Data

Directory of Open Access Journals (Sweden)

Jingjing He

2016-11-01

Full Text Available A general framework for structural fatigue life evaluation under fatigue cyclic loading using limited sensor data is proposed in this paper. First, limited sensor data are measured from various sensors which are preset on the complex structure. Then the strain data at remote spots are used to obtain the strain responses at critical spots by the strain/stress reconstruction method based on empirical mode decomposition (REMD method. All the computations in this paper are directly performed in the time domain. After the local stress responses at critical spots are determined, fatigue life evaluation can be performed for structural health management and risk assessment. Fatigue life evaluation using the reconstructed stresses from remote strain gauge measurement data is also demonstrated with detailed error analysis. Following this, the proposed methodology is demonstrated using a three-dimensional frame structure and a simplified airfoil structure. Finally, several conclusions and future work are drawn based on the proposed study.

Bier spots

Directory of Open Access Journals (Sweden)

Ahu Yorulmaz,

2015-10-01

Full Text Available Also called as physiologic anemic macules, Bier spots are small, hypopigmented irregularly shaped macules against a background of diffuse erythema, which creates an appearance of speckled vascular mottling of the skin. Bier spots most commonly appear on distal portions of the limbs though there are case reports describing diffuse involvement, which also affect trunk and mucous membranes of the patient. Although the exact pathophysiological mechanisms underlying Bier spots still need to be elucidated, Bier spots have been suggested to be a vascular anomaly caused by vasoconstriction of small vessels. In addition, several diseases have been proposed to be associated with Bier spots, including scleroderma renal crisis, cryoglobulinemia, Peutz-Jeghers syndrome, alopecia areata and hypoplasia of the aorta, although it has not been shown whether these associations are casual or coincidental. The clinical presentation of Bier spots is quite typical. These tiny whitish macules easily become prominent when the affected limb is placed in a dependent position and fade away when the limb is raised. Here we report a case of Bier spots in a 32-year-old male patient with characteristical clinical manifestations.

Hot-Spot Fatigue and Impact Damage Detection on a Helicopter Tailboom

Science.gov (United States)

2011-09-01

other 14 PZT disks were used as sensors. Among the 28 PZT disks, 16 PZT disks were placed in the two fatigue hot-spot areas to detect cracks initiated...more efficient and effective airframe maintenance, fatigue cracking and impact damage detection technologies were developed and demonstrated on a...SHM system in successfully monitoring fatigue cracks initiated from cyclical loading conditions; detecting, locating and quantifying ballistic

Long fiber Bragg grating sensor interrogation using discrete-time microwave photonic filtering techniques.

Science.gov (United States)

Ricchiuti, Amelia Lavinia; Barrera, David; Sales, Salvador; Thevenaz, Luc; Capmany, José

2013-11-18

A novel technique for interrogating photonic sensors based on long fiber Bragg gratings (FBGs) is presented and experimentally demonstrated, dedicated to detect the presence and the precise location of several spot events. The principle of operation is based on a technique used to analyze microwave photonics (MWP) filters. The long FBGs are used as quasi-distributed sensors. Several hot-spots can be detected along the FBG with a spatial accuracy under 0.5 mm using a modulator and a photo-detector (PD) with a modest bandwidth of less than 1 GHz. The proposed interrogation system is intrinsically robust against environmental changes.

SU-E-T-510: Interplay Between Spots Sizes, Spot / Line Spacing and Motion in Spot Scanning Proton Therapy

International Nuclear Information System (INIS)

Lee, TK

2015-01-01

Purpose In proton beam configuration for spot scanning proton therapy (SSPT), one can define the spacing between spots and lines of scanning as a ratio of given spot size. If the spacing increases, the number of spots decreases which can potentially decrease scan time, and so can whole treatment time, and vice versa. However, if the spacing is too large, the uniformity of scanned field decreases. Also, the field uniformity can be affected by motion during SSPT beam delivery. In the present study, the interplay between spot/ line spacing and motion is investigated. Methods We used four Gaussian-shape spot sizes with 0.5cm, 1.0cm, 1.5cm, and 2.0cm FWHM, three spot/line spacing that creates uniform field profile which are 1/3*FWHM, σ/3*FWHM and 2/3*FWHM, and three random motion amplitudes within, +/−0.3mm, +/−0.5mm, and +/−1.0mm. We planned with 2Gy uniform single layer of 10×10cm2 and 20×20cm2 fields. Then, mean dose within 80% area of given field size, contrubuting MU per each spot assuming 1cGy/MU calibration for all spot sizes, number of spots and uniformity were calculated. Results The plans with spot/line spacing equal to or smaller than 2/3*FWHM without motion create ∼100% uniformity. However, it was found that the uniformity decreases with increased spacing, and it is more pronounced with smaller spot sizes, but is not affected by scanned field sizes. Conclusion It was found that the motion during proton beam delivery can alter the dose uniformity and the amount of alteration changes with spot size which changes with energy and spot/line spacing. Currently, robust evaluation in TPS (e.g. Eclipse system) performs range uncertainty evaluation using isocenter shift and CT calibration error. Based on presented study, it is recommended to add interplay effect evaluation to robust evaluation process. For future study, the additional interplay between the energy layers and motion is expected to present volumetric effect

Using AVIRIS for in-flight calibration of the spectral shifts of SPOT-HRV and of AVHRR?

Science.gov (United States)

Willart-Soufflet, Veronique; Santer, Richard

1993-01-01

The response of a satellite sensor varies during its lifetime; internal calibration devices can be used to follow the sensor degradation or in-flight calibrations are conducted from estimates of the radiance at satellite level for well predictable situations. Changes in gain are evaluated assuming that the spectral response of the sensor is stable with time; i.e., that the filter response as well as the optics or the electronics are not modified since the prelaunch determinations. Nevertheless, there is some evidence that the SPOT interferometer filters are affected by outgassing effects during the launch. Tests in vacuum chambers indicated a narrowing of the filters with a shift of the upper side towards the blue of about 10 nm which is more over consistant with the loss of gain observed during the launch. Also, during the lifetime of SPOT, the relationship between the loss of sensitivity and the filter bandwidth may correspond to this effect. On the other hand, the inconsistancy of the NOAA7 calibration between two methods (desert and ocean) having a different spectral sensitivity may indicate a spectral problem with a shift of the central wavelength of -20 nm. The basic idea here is to take advantage of the good spectral definition of AVIRIS to monitor these potential spectral degradations with an experimental opportunity provided by a field campaign held in La Crau (S.E. of France) in June 1991 which associated ground-based measurements and AVIRIS, SPOT2, NOAA-11 overpasses over both the calibration site of La Crau and an agricultural area.

Process for manufacturing shell membrane force and deflection sensor

Science.gov (United States)

Park, Yong-Lae (Inventor); Moslehi, Behzad (Inventor); Black, Richard James (Inventor); Cutkosky, Mark R. (Inventor); Chau, Kelvin K. (Inventor)

2012-01-01

A sensor for force is formed from an elastomeric cylinder having a region with apertures. The apertures have passageways formed between them, and an optical fiber is introduced into these passageways, where the optical fiber has a grating for measurement of tension positioned in the passageways between apertures. Optionally, a temperature measurement sensor is placed in or around the elastomer for temperature correction, and if required, a copper film may be deposited in the elastomer for reduced sensitivity to spot temperature variations in the elastomer near the sensors.

Transitional–turbulent spots and turbulent–turbulent spots in boundary layers

Science.gov (United States)

Wu, Xiaohua; Moin, Parviz; Wallace, James M.; Skarda, Jinhie; Lozano-Durán, Adrián; Hickey, Jean-Pierre

2017-01-01

Two observations drawn from a thoroughly validated direct numerical simulation of the canonical spatially developing, zero-pressure gradient, smooth, flat-plate boundary layer are presented here. The first is that, for bypass transition in the narrow sense defined herein, we found that the transitional–turbulent spot inception mechanism is analogous to the secondary instability of boundary-layer natural transition, namely a spanwise vortex filament becomes a Λ vortex and then, a hairpin packet. Long streak meandering does occur but usually when a streak is infected by a nearby existing transitional–turbulent spot. Streak waviness and breakdown are, therefore, not the mechanisms for the inception of transitional–turbulent spots found here. Rather, they only facilitate the growth and spreading of existing transitional–turbulent spots. The second observation is the discovery, in the inner layer of the developed turbulent boundary layer, of what we call turbulent–turbulent spots. These turbulent–turbulent spots are dense concentrations of small-scale vortices with high swirling strength originating from hairpin packets. Although structurally quite similar to the transitional–turbulent spots, these turbulent–turbulent spots are generated locally in the fully turbulent environment, and they are persistent with a systematic variation of detection threshold level. They exert indentation, segmentation, and termination on the viscous sublayer streaks, and they coincide with local concentrations of high levels of Reynolds shear stress, enstrophy, and temperature fluctuations. The sublayer streaks seem to be passive and are often simply the rims of the indentation pockets arising from the turbulent–turbulent spots. PMID:28630304

Transitional-turbulent spots and turbulent-turbulent spots in boundary layers.

Science.gov (United States)

Wu, Xiaohua; Moin, Parviz; Wallace, James M; Skarda, Jinhie; Lozano-Durán, Adrián; Hickey, Jean-Pierre

2017-07-03

Two observations drawn from a thoroughly validated direct numerical simulation of the canonical spatially developing, zero-pressure gradient, smooth, flat-plate boundary layer are presented here. The first is that, for bypass transition in the narrow sense defined herein, we found that the transitional-turbulent spot inception mechanism is analogous to the secondary instability of boundary-layer natural transition, namely a spanwise vortex filament becomes a [Formula: see text] vortex and then, a hairpin packet. Long streak meandering does occur but usually when a streak is infected by a nearby existing transitional-turbulent spot. Streak waviness and breakdown are, therefore, not the mechanisms for the inception of transitional-turbulent spots found here. Rather, they only facilitate the growth and spreading of existing transitional-turbulent spots. The second observation is the discovery, in the inner layer of the developed turbulent boundary layer, of what we call turbulent-turbulent spots. These turbulent-turbulent spots are dense concentrations of small-scale vortices with high swirling strength originating from hairpin packets. Although structurally quite similar to the transitional-turbulent spots, these turbulent-turbulent spots are generated locally in the fully turbulent environment, and they are persistent with a systematic variation of detection threshold level. They exert indentation, segmentation, and termination on the viscous sublayer streaks, and they coincide with local concentrations of high levels of Reynolds shear stress, enstrophy, and temperature fluctuations. The sublayer streaks seem to be passive and are often simply the rims of the indentation pockets arising from the turbulent-turbulent spots.

Spotted inflation

International Nuclear Information System (INIS)

Matsuda, Tomohiro

2010-01-01

We describe new scenarios for generating curvature perturbations when inflaton (curvaton) has significant interactions. We consider a ''spot'', which arises from interactions associated with an enhanced symmetric point (ESP) on the trajectory. Our first example uses the spot to induce a gap in the field equation. We observe that the gap in the field equation may cause generation of curvature perturbation if it does not appear simultaneous in space. The mechanism is similar to the scenario of inhomogeneous phase transition. Then we observe that the spot interactions may initiate warm inflation in the cold Universe. Creation of cosmological perturbation is discussed in relation to the inflaton dynamics and the modulation associated with the spot interactions

Spot Weight Adaptation for Moving Target in Spot Scanning Proton Therapy.

Science.gov (United States)

Morel, Paul; Wu, Xiaodong; Blin, Guillaume; Vialette, Stéphane; Flynn, Ryan; Hyer, Daniel; Wang, Dongxu

2015-01-01

This study describes a real-time spot weight adaptation method in spot-scanning proton therapy for moving target or moving patient, so that the resultant dose distribution closely matches the planned dose distribution. The method proposed in this study adapts the weight (MU) of the delivering pencil beam to that of the target spot; it will actually hit during patient/target motion. The target spot that a certain delivering pencil beam may hit relies on patient monitoring and/or motion modeling using four-dimensional (4D) CT. After the adapted delivery, the required total weight [Monitor Unit (MU)] for this target spot is then subtracted from the planned value. With continuous patient motion and continuous spot scanning, the planned doses to all target spots will eventually be all fulfilled. In a proof-of-principle test, a lung case was presented with realistic temporal and motion parameters; the resultant dose distribution using spot weight adaptation was compared to that without using this method. The impact of the real-time patient/target position tracking or prediction was also investigated. For moderate motion (i.e., mean amplitude 0.5 cm), D95% to the planning target volume (PTV) was only 81.5% of the prescription (RX) dose; with spot weight adaptation PTV D95% achieves 97.7% RX. For large motion amplitude (i.e., 1.5 cm), without spot weight adaptation PTV D95% is only 42.9% of RX; with spot weight adaptation, PTV D95% achieves 97.7% RX. Larger errors in patient/target position tracking or prediction led to worse final target coverage; an error of 3 mm or smaller in patient/target position tracking is preferred. The proposed spot weight adaptation method was able to deliver the planned dose distribution and maintain target coverage when patient motion was involved. The successful implementation of this method would rely on accurate monitoring or prediction of patient/target motion.

Spot Weight Adaptation for Moving Target in Spot Scanning Proton Therapy

Directory of Open Access Journals (Sweden)

Paul eMorel

2015-05-01

Full Text Available Purpose: This study describes a real-time spot weight adaptation method in spot-scanning proton therapy for moving target or moving patient, so that the resultant dose distribution closely matches the planned dose distribution. Materials and Methods: The method proposed in this study adapts the weight (MU of the delivering pencil beam to that of the target spot it will actually hit during patient/target motion. The target spot a certain delivering pencil beam may hit relies on patient monitoring and/or motion modeling using four-dimensional (4D CT. After the adapted delivery, the required total weight (MU for this target spot is then subtracted from the planned value. With continuous patient motion and continuous spot scanning, the planned doses to all target spots will eventually be all fulfilled. In a proof-of-principle test, a lung case was presented with realistic temporal and motion parameters; the resultant dose distribution using spot weight adaptation was compared to that without using this method. The impact of the real-time patient/target position tracking or prediction was also investigated.Results: For moderate motion (i.e., mean amplitude 0.5 cm, D95% to the planning target volume (PTV was only 81.5% of the prescription (RX dose; with spot weight adaptation PTV D95% achieves 97.7%RX. For large motion amplitude (i.e., 1.5 cm, without spot weight adaptation PTV D95% is only 42.9% of RX; with spot weight adaptation, PTV D95% achieves 97.7%RX. Larger errors in patient/target position tracking or prediction led to worse final target coverage; an error of 3mm or smaller in patient/target position tracking is preferred. Conclusion: The proposed spot weight adaptation method was able to deliver the planned dose distribution and maintain target coverage when patient motion was involved. The successful implementation of this method would rely on accurate monitoring or prediction of patient/target motion.

Experiment of Laser Pointing Stability on Different Surfaces to validate Micrometric Positioning Sensor

CERN Document Server

AUTHOR|(SzGeCERN)721924; Mainaud Durand, Helene; Piedigrossi, Didier; Sandomierski, Jacek; Sosin, Mateusz; Geiger, Alain; Guillaume, Sebastien

2014-01-01

CLIC requires 10 μm precision and accuracy over 200m for the pre-alignment of beam related components. A solution based on laser beam as straight line reference is being studied at CERN. It involves camera/shutter assemblies as micrometric positioning sensors. To validate the sensors, it is necessary to determine an appropriate material for the shutter in terms of laser pointing stability. Experiments are carried out with paper, metal and ceramic surfaces. This paper presents the standard deviations of the laser spot coordinates obtained on the different surfaces, as well as the measurement error. Our experiments validate the choice of paper and ceramic for the shutter of the micrometric positioning sensor. It also provides an estimate of the achievable precision and accuracy of the determination of the laser spot centre with respect to the shutter coordinate system defined by reference targets.

Study on the effect of sink moving trajectory on wireless sensor networks

Science.gov (United States)

Zhong, Peijun; Ruan, Feng

2018-03-01

Wireless sensor networks are developing very fast in recent years, due to their wide potential applications. However there exists the so-called hot spot problem, namely the nodes close to static sink node tend to die earlier than other nodes since they have heavier burden to forward. The introduction of mobile sink node can effectively alleviate this problem since sink node can move along certain trajectories, causing hot spot nodes more evenly distributed. In this paper, we make extensive experimental simulations for circular sensor network, with one mobile sink moving along different radius circumference. The whole network is divided into several clusters and there is one cluster head (CH) inside each cluster. The ordinary sensors communicate with CH and CHs construct a chain until the sink node. Simulation results show that the best network performance appears when sink moves along 0.25 R in terms of network lifetime.

Bier spots

OpenAIRE

Ahu Yorulmaz,; Seray Kulcu Cakmak; Esra Ar?; Ferda Artuz

2015-01-01

Also called as physiologic anemic macules, Bier spots are small, hypopigmented irregularly shaped macules against a background of diffuse erythema, which creates an appearance of speckled vascular mottling of the skin. Bier spots most commonly appear on distal portions of the limbs though there are case reports describing diffuse involvement, which also affect trunk and mucous membranes of the patient. Although the exact pathophysiological mechanisms underlying Bier spots still need to be elu...

Spot weld arrangement effects on the fatigue behavior of multi-spot welded joints

International Nuclear Information System (INIS)

Hassanifard, Soran; Zehsaz, Mohammad; Esmaeili, Firooz

2011-01-01

In the present study, the effects of spot weld arrangements in multi-spot welded joints on the fatigue behavior of the joints are studied. Three different four-spot welded joints are considered: one-row four-spot parallel to the loading direction, one-row four-spot perpendicular to the loading direction and two-row four-spot weld specimens. The experimental fatigue test results reveal that the differences between the fatigue lives of three spot welded types in the low cycle regime are more considerable than those in the high cycle regime. However, all kinds of spot weld specimens have similar fatigue strength when approaching a million cycles. A non-linear finite element analysis is performed to obtain the relative stress gradients, effective distances and notch strength reduction factors based on the volumetric approach. The work here shows that the volumetric approach does a very good job in predicting the fatigue life of the multi-spot welded joints

Colovaginal anastomosis: an unusual complication of stapler use in restorative procedure after Hartmann operation

Directory of Open Access Journals (Sweden)

Liao Guoqing

2005-11-01

Full Text Available Abstract Background Rectovaginal fistula is uncommon after lower anterior resection for rectal cancer. The most leading cause of this complication is involvement of the posterior wall of the vagina into the staple line when firing the circular stapler. Case presentation A 50-year-old women underwent resection for obstructed carcinoma of the sigmoid colon with Hartmann procedure. Four months later she underwent restorative surgery with circular stapler. Following which she developed rectovaginal fistula. A transvaginal repair was performed but stool passing from vagina not per rectum. Laporotomy revealed colovaginal anastomosis, which was corrected accordingly. Patient had an uneventful recovery. Conclusion Inadvertent formation of colovaginal anastomosis associated with a rectovaginal fistula is a rare complication caused by the operator's error. The present case again highlights the importance of ensuring that the posterior wall of vagina is away from the staple line.

Particle detection and classification using commercial off the shelf CMOS image sensors

Energy Technology Data Exchange (ETDEWEB)

Pérez, Martín [Instituto Balseiro, Av. Bustillo 9500, Bariloche, 8400 (Argentina); Comisión Nacional de Energía Atómica (CNEA), Centro Atómico Bariloche, Av. Bustillo 9500, Bariloche 8400 (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, Av. Bustillo 9500, 8400 Bariloche (Argentina); Lipovetzky, Jose, E-mail: lipo@cab.cnea.gov.ar [Instituto Balseiro, Av. Bustillo 9500, Bariloche, 8400 (Argentina); Comisión Nacional de Energía Atómica (CNEA), Centro Atómico Bariloche, Av. Bustillo 9500, Bariloche 8400 (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, Av. Bustillo 9500, 8400 Bariloche (Argentina); Sofo Haro, Miguel; Sidelnik, Iván; Blostein, Juan Jerónimo; Alcalde Bessia, Fabricio; Berisso, Mariano Gómez [Instituto Balseiro, Av. Bustillo 9500, Bariloche, 8400 (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, Av. Bustillo 9500, 8400 Bariloche (Argentina)

2016-08-11

In this paper we analyse the response of two different Commercial Off The shelf CMOS image sensors as particle detectors. Sensors were irradiated using X-ray photons, gamma photons, beta particles and alpha particles from diverse sources. The amount of charge produced by different particles, and the size of the spot registered on the sensor are compared, and analysed by an algorithm to classify them. For a known incident energy spectrum, the employed sensors provide a dose resolution lower than microGray, showing their potentials in radioprotection, area monitoring, or medical applications.

Energy is not Coffee. An assessment of blind spots on energy spot-markets

International Nuclear Information System (INIS)

Jepma, C.J.; Spijker, E.; Van der Gaast, W.; De Jong, F.; Overmars, P.

2006-01-01

This study was to be the first in a series of studies on the title subject. It specifically focuses on the differences and similarities with a number of other spot-markets and aims to frame the energy spot markets and their potential development into a broader perspective. Main conclusion is that energy spot-markets differ from several other physical and non-physical spot-markets in many ways. This implies that 'perfect' energy spot-markets may inherently be (much) less perfect than other spot-markets that have approximated the stage of theoretical perfection

An improved triangulation laser rangefinder using a custom CMOS HDR linear image sensor

Science.gov (United States)

Liscombe, Michael

3-D triangulation laser rangefinders are used in many modern applications, from terrain mapping to biometric identification. Although a wide variety of designs have been proposed, laser speckle noise still provides a fundamental limitation on range accuracy. These works propose a new triangulation laser rangefinder designed specifically to mitigate the effects of laser speckle noise. The proposed rangefinder uses a precision linear translator to laterally reposition the imaging system (e.g., image sensor and imaging lens). For a given spatial location of the laser spot, capturing N spatially uncorrelated laser spot profiles is shown to improve range accuracy by a factor of N . This technique has many advantages over past speckle-reduction technologies, such as a fixed system cost and form factor, and the ability to virtually eliminate laser speckle noise. These advantages are made possible through spatial diversity and come at the cost of increased acquisition time. The rangefinder makes use of the ICFYKWG1 linear image sensor, a custom CMOS sensor developed at the Vision Sensor Laboratory (York University). Tests are performed on the image sensor's innovative high dynamic range technology to determine its effects on range accuracy. As expected, experimental results have shown that the sensor provides a trade-off between dynamic range and range accuracy.

Comparison of SAR and optical sensor data for monitoring of rice plant around Hiroshima

Science.gov (United States)

Oguro, Y.; Suga, Y.; Takeuchi, S.; Ogawa, M.; Konishi, T.; Tsuchiya, K.

2001-01-01

Through the research on the application of the multi-temporal data acquired with Landsat-5 TM, SPOT-2 HRV, SPOT-4 HRVIR and RADARSAT-1 SAR to monitoring of rice field following features are clarified. Vegetation indices NDVI (Normalized Difference Vegetation Index) and EVI (Extended Vegetation Index) derived from different optical sensors TM, HVR, HRVIR indicate nearly same characteristics suggesting validity of calibration of respective sensors. It was found that by combined use of multi-temporal vegetation indices NDVI and EVI together with SAR (Synthetic Aperture Radar) data it was found that rice planted area can be estimated with the error less than 2%.

Dynamics of the near response under natural viewing conditions with an open-view sensor

Science.gov (United States)

Chirre, Emmanuel; Prieto, Pedro; Artal, Pablo

2015-01-01

We have studied the temporal dynamics of the near response (accommodation, convergence and pupil constriction) in healthy subjects when accommodation was performed under natural binocular and monocular viewing conditions. A binocular open-view multi-sensor based on an invisible infrared Hartmann-Shack sensor was used for non-invasive measurements of both eyes simultaneously in real time at 25Hz. Response times for each process under different conditions were measured. The accommodative responses for binocular vision were faster than for monocular conditions. When one eye was blocked, accommodation and convergence were triggered simultaneously and synchronized, despite the fact that no retinal disparity was available. We found that upon the onset of the near target, the unblocked eye rapidly changes its line of sight to fix it on the stimulus while the blocked eye moves in the same direction, producing the equivalent to a saccade, but then converges to the (blocked) target in synchrony with accommodation. This open-view instrument could be further used for additional experiments with other tasks and conditions. PMID:26504666

Java-based mobile agent platforms for wireless sensor networks

NARCIS (Netherlands)

Aiello, F.; Carbone, A.; Fortino, G.; Galzarano, S.; Ganzha, M.; Paprzycki, M.

2010-01-01

This paper proposes an overview and comparison of mobile agent platforms for the development of wireless sensor network applications. In particular, the architecture, programming model and basic performance of two Java-based agent platforms, Mobile Agent Platform for Sun SPOT (MAPS) and Agent

Quality assurance tests of the CBM silicon tracking system sensors with an infrared laser

Energy Technology Data Exchange (ETDEWEB)

Teklishyn, Maksym [FAIR GmbH, Darmstadt (Germany); KINR, Kyiv (Ukraine); Collaboration: CBM-Collaboration

2016-07-01

Double-sided 300 μm thick silicon microstrip sensors are planned to be used in the Silicon Tracking System (STS) of the future CBM experiment. Different tools, including an infrared laser, are used to induce charge in the sensor medium to study the sensor response. We use present installation to develop a procedure for the sensor quality assurance during mass production. The precise positioning of the laser spot allows to make a clear judgment about the sensor interstrip gap response which provides information about the charge distribution inside the sensor medium. Results are compared with the model estimations.

Practical polarization maintaining optical fibre temperature sensor for harsh environment application

Science.gov (United States)

Yang, Yuanhong; Xia, Haiyun; Jin, Wei

2007-10-01

A reflection spot temperature sensor was proposed based on the polarization mode interference in polarization maintaining optical fibre (PMF) and the phenomenon that the propagation constant difference of the two orthogonal polarization modes in stressing structures PMF is sensitive to temperature and the sensing equation was obtained. In this temperature sensor, a broadband source was used to suppress the drift due to polarization coupling in lead-in/lead-out PMF. A characteristic and performance investigation proved this sensor to be practical, flexible and precise. Experimental results fitted the theory model very well and the noise-limited minimum detectable temperature variation is less than 0.01 °C. The electric arc processing was investigated and the differential propagation constant modifying the PMF probe is performed. For the demand of field hot-spot monitoring of huge power transformers, a remote multi-channel temperature sensor prototype has been made and tested. Specially coated Panda PMF that can stand high temperatures up to 250 °C was fabricated and used as probe fibres. The sensor probes were sealed within thin quartz tubes that have high voltage insulation and can work in a hot oil and vapour environment. Test results show that the accuracy of the system is better than ±0.5 °C within 0 °C to 200 °C.

Distribución espacial de anomalías del NDVI derivado del sensor VEGETATION SPOT 4/5 ysu relación con las coberturas vegetales, usos de la tierra y características geomorfológicas en la provincia de Santiago del Estero, Argentina / Spatial distribution of anomalies of NDVI derived from sensor VEGETATION SPOT 4/5 and its relation with vegetation cover, uses of ground and geomorphology in Santiago del Estero, Argentina

Directory of Open Access Journals (Sweden)

Jose Luis Tiedermann

2010-12-01

Full Text Available Se determinaron las anomalías negativas (AN y positivas (AP del NDVI derivado del sensor VEGETATION SPOT 4/5, en la provincia de Santiago del Estero, Argentina. El periodo analizado (1998-2008 tuvo fuertes variaciones en los patrones de precipitación, por efecto del ENSO, por cuanto las anomalías del NDVI fueron evaluadas, mediante tabulación cruzada, en función de dos periodos: húmedo (PH y seco (PS. Las AN, se relacionaron, durante todo el periodo, con vegetación halófila en áreas deprimidas salobres, con vegetación hidrófila en ambientes acuáticos y con suelo rocoso. Durante el PS, las AN se relacionaron con áreas deforestadas con fines agrícolas. Las AP, se relacionaron, durante todo el periodo, con el bosque Chaqueño denso y bosque Chaqueño Serrano denso. La mayor estabilidad y productividad de biomasa verde de los bosques, estaría relacionada, a su mayor biodiversidad, estratificación, al predominio de especies leñosas perennes de raíces profundas y a las estratégicas adaptaciones, morfológicas y fisiológicas, para el uso eficiente del agua. Las regiones geomorfológicas no se relacionan entre si entre periodos.AbstractThe negative (AN and positive (AP anomalies of the NDVI derived from sensor VEGETATION SPOT 4/5 were determined in the province of Santiago del Estero, Argentina. The analyzed period (1998-2008 presented strong variations in rainfall patterns, as a result of the ENSO, inasmuch as the anomalies of the NDVI were evaluated, by means of crossed tabulation, based on two periods: humid (PH and dry (PS. The AN, were related with halophytic species of depressed areas, with vegetation aquatic hydrophilic and rocky ground. During the dry period, the AN were related to deforested areas with agricultural aims. The AP, were related, throughout the period with the forest dense Chaco Semiarid and forest dense Chaco Serrano. The greater stability and productivity of green biomass of forest, would be related, greater

Matching between the light spots and lenslets of an artificial compound eye system

Science.gov (United States)

He, Jianzheng; Jian, Huijie; Zhu, Qitao; Ma, Mengchao; Wang, Keyi

2017-10-01

As the visual organ of many arthropods, the compound eye has attracted a lot of attention with the advantage of wide field-of-view, multi-channel imaging ability and high agility. Extended from this concept, a new kind of artificial compound eye device is developed. There are 141 lenslets which share one image sensor distributed evenly on a curved surface, thus it is difficult to distinguish the lenslets which the light spot belongs to during calibration and positioning process. Therefore, the matching algorithm is proposed based on the device structure and the principle of calibration and positioning. Region partition of lenslet array is performed at first. Each lenslet and its adjacent lenslets are defined as cluster eyes and constructed into an index table. In the calibration process, a polar coordinate system is established, and the matching can be accomplished by comparing the rotary table position in the polar coordinate system and the central light spot angle in the image. In the positioning process, the spot is paired to the correct region according to the spots distribution firstly, and the final results is determined by the dispersion of the distance from the target point to the incident ray in the region traversal matching. Finally, the experiment results show that the presented algorithms provide a feasible and efficient way to match the spot to the lenslet, and perfectly meet the needs in the practical application of the compound eye system.

Hartmann tests to measure the spherical and cylindrical curvatures and the axis orientation of astigmatic lenses or optical surfaces.

Science.gov (United States)

Hernández-Gómez, Geovanni; Malacara-Hernández, Zacarías; Malacara-Hernández, Daniel

2014-02-20

The measurement of astigmatic lenses, optical surfaces or wavefronts are a highly studied problem and many different instruments have been commercially fabricated to perform this task. Many of them use a Hartmann arrangement to obtain the result. In this paper, we analyze with detail the algorithms that can be used to make the necessary calculations and propose several alternatives with different advantages and disadvantages. Different mathematical algorithms that are involved in the calculation process have been given whereas any description of the instrument itself is not proposed, but only the different mathematical algorithms that are involved in the calculation process.

Controlled deposition of sol–gel sensor material using hemiwicking

DEFF Research Database (Denmark)

Mikkelsen, Morten Bo Lindholm; Marie, Rodolphe; Hansen, Jan H

2011-01-01

the volume between the surface structures and form a liquid film with a thickness determined by the height of the micropillars. After evaporation of solvents, a uniform layer of sensor material resides on the surface. This fabrication method enables easy and reproducible deposits of isolated spots...

Rocky Mountain spotted fever

Science.gov (United States)

... spotted fever on the foot Rocky Mountain spotted fever, petechial rash Antibodies Deer and dog tick References McElligott SC, Kihiczak GG, Schwartz RA. Rocky Mountain spotted fever and other rickettsial infections. In: Lebwohl MG, Heymann ...

Anisotropic multi-spot DBR porous silicon chip for the detection of human immunoglobin G.

Science.gov (United States)

Cho, Bomin; Um, Sungyong; Sohn, Honglae

2014-07-01

Asymmetric porous silicon multilayer (APSM)-based optical biosensor was developed to specify human Immunoglobin G (Ig G). APSM chip was generated by an electrochemical etching of silicon wafer using an asymmetric electrode configuration in aqueous ethanolic HF solution and constituted with nine arrayed porous silicon multilayer. APSM prepared from anisotropic etching conditions displayed a sharp reflection resonance in the reflectivity spectrum. Each spot displayed single reflection resonance at different wavelengths as a function of the lateral distance from the Pt counter electrode. The sensor system was consisted of the 3 x 3 spot array of APSM modified with protein A. The system was probed with an aqueous human Ig G. Molecular binding and specificity was monitored as a shift in wavelength of reflection resonance.

The Spotting Distribution of Wildfires

Directory of Open Access Journals (Sweden)

Jonathan Martin

2016-06-01

Full Text Available In wildfire science, spotting refers to non-local creation of new fires, due to downwind ignition of brands launched from a primary fire. Spotting is often mentioned as being one of the most difficult problems for wildfire management, because of its unpredictable nature. Since spotting is a stochastic process, it makes sense to talk about a probability distribution for spotting, which we call the spotting distribution. Given a location ahead of the fire front, we would like to know how likely is it to observe a spot fire at that location in the next few minutes. The aim of this paper is to introduce a detailed procedure to find the spotting distribution. Most prior modelling has focused on the maximum spotting distance, or on physical subprocesses. We will use mathematical modelling, which is based on detailed physical processes, to derive a spotting distribution. We discuss the use and measurement of this spotting distribution in fire spread, fire management and fire breaching. The appendix of this paper contains a comprehensive review of the relevant underlying physical sub-processes of fire plumes, launching fire brands, wind transport, falling and terminal velocity, combustion during transport, and ignition upon landing.

Relationship between hot spot residues and ligand binding hot spots in protein-protein interfaces.

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Zerbe, Brandon S; Hall, David R; Vajda, Sandor; Whitty, Adrian; Kozakov, Dima

2012-08-27

In the context of protein-protein interactions, the term "hot spot" refers to a residue or cluster of residues that makes a major contribution to the binding free energy, as determined by alanine scanning mutagenesis. In contrast, in pharmaceutical research, a hot spot is a site on a target protein that has high propensity for ligand binding and hence is potentially important for drug discovery. Here we examine the relationship between these two hot spot concepts by comparing alanine scanning data for a set of 15 proteins with results from mapping the protein surfaces for sites that can bind fragment-sized small molecules. We find the two types of hot spots are largely complementary; the residues protruding into hot spot regions identified by computational mapping or experimental fragment screening are almost always themselves hot spot residues as defined by alanine scanning experiments. Conversely, a residue that is found by alanine scanning to contribute little to binding rarely interacts with hot spot regions on the partner protein identified by fragment mapping. In spite of the strong correlation between the two hot spot concepts, they fundamentally differ, however. In particular, while identification of a hot spot by alanine scanning establishes the potential to generate substantial interaction energy with a binding partner, there are additional topological requirements to be a hot spot for small molecule binding. Hence, only a minority of hot spots identified by alanine scanning represent sites that are potentially useful for small inhibitor binding, and it is this subset that is identified by experimental or computational fragment screening.

The influence of image sensor irradiation damage on the tracking and pointing accuracy of optical communication system

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Li, Xiaoliang; Luo, Lei; Li, Pengwei; Yu, Qingkui

2018-03-01

The image sensor in satellite optical communication system may generate noise due to space irradiation damage, leading to deviation for the determination of the light spot centroid. Based on the irradiation test data of CMOS devices, simulated defect spots in different sizes have been used for calculating the centroid deviation value by grey-level centroid algorithm. The impact on tracking & pointing accuracy of the system has been analyzed. The results show that both the amount and the position of irradiation-induced defect pixels contribute to spot centroid deviation. And the larger spot has less deviation. At last, considering the space radiation damage, suggestions are made for the constraints of spot size selection.

Hartmann's Procedure or Primary Anastomosis for Generalized Peritonitis due to Perforated Diverticulitis: A Prospective Multicenter Randomized Trial (DIVERTI).

Science.gov (United States)

Bridoux, Valerie; Regimbeau, Jean Marc; Ouaissi, Mehdi; Mathonnet, Muriel; Mauvais, Francois; Houivet, Estelle; Schwarz, Lilian; Mege, Diane; Sielezneff, Igor; Sabbagh, Charles; Tuech, Jean-Jacques

2017-12-01

About 25% of patients with acute diverticulitis require emergency intervention. Currently, most patients with diverticular peritonitis undergo a Hartmann's procedure. Our objective was to assess whether primary anastomosis (PA) with a diverting stoma results in lower mortality rates than Hartmann's procedure (HP) in patients with diverticular peritonitis. We conducted a multicenter randomized controlled trial conducted between June 2008 and May 2012: the DIVERTI (Primary vs Secondary Anastomosis for Hinchey Stage III-IV Diverticulitis) trial. Follow-up duration was up to 18 months. A random sample of 102 eligible participants with purulent or fecal diverticular peritonitis from tertiary care referral centers and associated centers in France were equally randomized to either a PA arm or to an HP arm. Data were analyzed on an intention-to-treat basis. The primary end point was mortality rate at 18 months. Secondary outcomes were postoperative complications, operative time, length of hospital stay, rate of definitive stoma, and morbidity. All 102 patients enrolled were comparable for age (p = 0.4453), sex (p = 0.2347), Hinchey stage III vs IV (p = 0.2347), and Mannheim Peritonitis Index (p = 0.0606). Overall mortality did not differ significantly between HP (7.7%) and PA (4%) (p = 0.4233). Morbidity for both resection and stoma reversal operations were comparable (39% in the HP arm vs 44% in the PA arm; p = 0.4233). At 18 months, 96% of PA patients and 65% of HP patients had a stoma reversal (p = 0.0001). Although mortality was similar in both arms, the rate of stoma reversal was significantly higher in the PA arm. This trial provides additional evidence in favor of PA with diverting ileostomy over HP in patients with diverticular peritonitis. ClinicalTrials.gov Identifier: NCT 00692393. Copyright © 2017. Published by Elsevier Inc.

Models of spots and flares

International Nuclear Information System (INIS)

Mullan, D.J.

1983-01-01

Laboratory experiments in recent years have shown that there are many more ways to drive a plasma out of equilibrium than to preserve equilibrium. In that sense, it is perhaps easier to understand why flares should occur in a stellar atmosphere than why a long-lived feature such as a dark spot should persist. The author summarizes work on the equilibrium structure of cool spots in the sun and stars. Since spots involve complex interactions between convective flows and magnetic fields, he needs to refer to observations for help in identifying the dominant processes which should enter into the modelling. His summary therefore begins by discussing certain relevant properties of spots in the solar atmosphere. The next sections deal with the magnetic fields in spots, the stability of spots, spot cooling and missing flux. The author concludes that spots should be viewed not simply as cool areas, but rather as engines which do the work of converting the energy of convective flows into flare-compatible form. (Auth.)

Fabrication of bimetallic microfluidic surface-enhanced Raman scattering sensors on paper by screen printing.

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Qu, Lu-Lu; Song, Qi-Xia; Li, Yuan-Ting; Peng, Mao-Pan; Li, Da-Wei; Chen, Li-Xia; Fossey, John S; Long, Yi-Tao

2013-08-20

Au-Ag bimetallic microfluidic, dumbbell-shaped, surface enhanced Raman scattering (SERS) sensors were fabricated on cellulose paper by screen printing. These printed sensors rely on a sample droplet injection zone, and a SERS detection zone at either end of the dumbbell motif, fabricated by printing silver nanoparticles (Ag NPs) and gold nanoparticles (Au NPs) successively with microscale precision. The microfluidic channel was patterned using an insulating ink to connect these two zones and form a hydrophobic circuit. Owing to capillary action of paper in the millimeter-sized channels, the sensor could enable self-filtering of fluids to remove suspended particles within wastewater without pumping. This sensor also allows sensitive SERS detection, due to advantageous combination of the strong surface enhancement of Ag NPs and excellent chemical stability of Au NPs. The SERS performance of the sensors was investigated by employing the probe rhodamine 6G, a limit of detection (LOD) of 1.1×10(-13)M and an enhancement factor of 8.6×10(6) could be achieved. Moreover, the dumbbell-shaped bimetallic sensors exhibited good stability with SERS performance being maintained over 14 weeks in air, and high reproducibility with less than 15% variation in spot-to-spot SERS intensity. Using these dumbbell-shaped bimetallic sensors, substituted aromatic pollutants in wastewater samples could be quantitatively analyzed, which demonstrated their excellent capability for rapid trace pollutant detection in wastewater samples in the field without pre-separation. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of spot size and spot spacing on lateral penumbra reduction when using a dynamic collimation system for spot scanning proton therapy

International Nuclear Information System (INIS)

Hyer, Daniel E; Hill, Patrick M; Wang, Dongxu; Smith, Blake R; Flynn, Ryan T

2014-01-01

The purpose of this work was to investigate the reduction in lateral dose penumbra that can be achieved when using a dynamic collimation system (DCS) for spot scanning proton therapy as a function of two beam parameters: spot size and spot spacing. This is an important investigation as both values impact the achievable dose distribution and a wide range of values currently exist depending on delivery hardware. Treatment plans were created both with and without the DCS for in-air spot sizes (σ air ) of 3, 5, 7, and 9 mm as well as spot spacing intervals of 2, 4, 6 and 8 mm. Compared to un-collimated treatment plans, the plans created with the DCS yielded a reduction in the mean dose to normal tissue surrounding the target of 26.2–40.6% for spot sizes of 3–9 mm, respectively. Increasing the spot spacing resulted in a decrease in the time penalty associated with using the DCS that was approximately proportional to the reduction in the number of rows in the raster delivery pattern. We conclude that dose distributions achievable when using the DCS are comparable to those only attainable with much smaller initial spot sizes, suggesting that the goal of improving high dose conformity may be achieved by either utilizing a DCS or by improving beam line optics. (note)

An energy efficient multiple mobile sinks based routing algorithm for wireless sensor networks

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Zhong, Peijun; Ruan, Feng

2018-03-01

With the fast development of wireless sensor networks (WSNs), more and more energy efficient routing algorithms have been proposed. However, one of the research challenges is how to alleviate the hot spot problem since nodes close to static sink (or base station) tend to die earlier than other sensors. The introduction of mobile sink node can effectively alleviate this problem since sink node can move along certain trajectories, causing hot spot nodes more evenly distributed. In this paper, we mainly study the energy efficient routing method with multiple mobile sinks support. We divide the whole network into several clusters and study the influence of mobile sink number on network lifetime. Simulation results show that the best network performance appears when mobile sink number is about 3 under our simulation environment.

On the origin of delta spots

International Nuclear Information System (INIS)

Tang, F.

1983-01-01

Mount Wilson sunspot drawings from 1966 through 1980 were used in conjunction with Hα filtergrams from Big Bear Solar Observatory to examine the origin of delta spots, spots with bipolar umbrae within one penumbra. Of the six cases we studied, five were formed by the union of non-paired spots. They are either shoved into one another by two neighboring growing bipoles or by a new spot born piggy-back style on an existing spot of opposite polarity. Proper motions of the growing spots take on curvilinear paths around one another to avoid a collision. This is the shear motion observed in delta spots (Tanaka, 1979). In the remaining case, the delta spot was formed by spots that emerged as a pair. Our findings indicate no intrinsic differences in the formation or the behavior between delta spots of normal magnetic configuration. (orig.)

Adaptive optics retinal imaging in the living mouse eye

Science.gov (United States)

Geng, Ying; Dubra, Alfredo; Yin, Lu; Merigan, William H.; Sharma, Robin; Libby, Richard T.; Williams, David R.

2012-01-01

Correction of the eye’s monochromatic aberrations using adaptive optics (AO) can improve the resolution of in vivo mouse retinal images [Biss et al., Opt. Lett. 32(6), 659 (2007) and Alt et al., Proc. SPIE 7550, 755019 (2010)], but previous attempts have been limited by poor spot quality in the Shack-Hartmann wavefront sensor (SHWS). Recent advances in mouse eye wavefront sensing using an adjustable focus beacon with an annular beam profile have improved the wavefront sensor spot quality [Geng et al., Biomed. Opt. Express 2(4), 717 (2011)], and we have incorporated them into a fluorescence adaptive optics scanning laser ophthalmoscope (AOSLO). The performance of the instrument was tested on the living mouse eye, and images of multiple retinal structures, including the photoreceptor mosaic, nerve fiber bundles, fine capillaries and fluorescently labeled ganglion cells were obtained. The in vivo transverse and axial resolutions of the fluorescence channel of the AOSLO were estimated from the full width half maximum (FWHM) of the line and point spread functions (LSF and PSF), and were found to be better than 0.79 μm ± 0.03 μm (STD)(45% wider than the diffraction limit) and 10.8 μm ± 0.7 μm (STD)(two times the diffraction limit), respectively. The axial positional accuracy was estimated to be 0.36 μm. This resolution and positional accuracy has allowed us to classify many ganglion cell types, such as bistratified ganglion cells, in vivo. PMID:22574260

Material influence on hot spot distribution in the nanoparticle heterodimer on film

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Chen, Fang; Huang, Yingzhou; Wei, Hua; Wang, Shuxia; Zeng, Xiping; Cao, Wenbin; Wen, Weijia

2018-04-01

The metal nanoparticle aggregated on film, as an effective plasma enhancement pathway, has been widely used in various surface plasmon-related fields. In this study, the hot spots on the metal nanoparticle dimer composed of different materials (Agsbnd Au, Agsbnd Pd, and Agsbnd Cu) on metal (Au) film were investigated with finite element method. Based on the results, the hot spot distribution affected by the material can be confirmed by the electric field distribution of the metal nanoparticle dimer on the film. The aggregation effects of Au and Ag nanoparticles in Ausbnd Ag dimer system are not significant. However, for the Pdsbnd Ag dimer system, the hot spot aggregation effect is slightly larger than that of the Pd nanoparticle under the Ag nanoparticle. Besides, the non-uniform hot spots would bring about the light focusing phenomenon that the light intensity under Ag nanoparticle is almost 100 times greater than that under Cu nanoparticle in Agsbnd Cu dimer system. These results were further confirmed by the surface charge distribution, and analyzed based on the plasmonic hybridization theory. The data about the nanoparticle dimer on the dielectric (Si) film demonstrate the importance of induced image charges on the film surface in such a light focusing phenomenon. Our findings can enhance the understanding of the surface plasmon coupling in different materials, which may have great application prospects in surface plasmon-related fields, such as SERS, plasmonic enhanced solar cell, and plasmonic sensoring, etc.

Spot market for uranium

International Nuclear Information System (INIS)

Colhoun, C.

1982-01-01

The spot market is always quoted for the price of uranium because little information is available about long-term contracts. A review of the development of spot market prices shows the same price curve swings that occur with all raw materials. Future long-term contracts will probably be lower to reflect spot market prices, which are currently in the real-value range of $30-$35. An upswing in the price of uranium could come in the next few months as utilities begin making purchases and trading from stockpiles. The US, unlike Europe and Japan, has already reached a supply and demand point where the spot market share is increasing. Forecasters cannot project the market price, they can only predict the presence of an oscillating spot or a secondary market. 5 figures

Development of a position sensor based on a four quadrant structured optic fiber bundle

International Nuclear Information System (INIS)

Boukellal, Younes; Ducourtieux, Sebastien

2015-01-01

This article reports on the development of a new kind of 2D displacement sensor based on an optic fiber bundle whose fiber arrangement has been customized to provide an input sensitive surface with four quadrants. The fibers of each quadrant are regrouped to form four output arms. The aim is to reach behavior similar to that of a quad cell photodiode when illuminated by a laser spot. In this paper, we present the motivations for developing such a sensor and its design. Prior to the fabrication of a first prototype, the optic fiber bundle has been modelled and compared to a quad cell photodiode. It has an active surface which is 10 mm in diameter and which comprises 40 000 fibers of 50 µm core diameter. For this experimental test, a specific electronic conditioning circuit has been developed to process the signals. From both modelled and experimental results, fiber optic bundle and quad cell photodiode behavior has proved to be very similar, provided that the number of fibers is sufficient to achieve a statistical effect on the detected displacement, i.e. the laser spot diameter is rightly chosen as a function of the fiber diameter. For the use of the bundle as position sensor, a laser spot size of 5 mm has been fixed to achieve a good compromise between sensitivity and displacement range. With this spot size, sensitivity and displacement range have been experimentally evaluated to 2 mV µm −1 and 3.8 mm respectively with a corresponding displacement resolution of 5 nm in the best case. (paper)

Roth spots in pernicious anaemia.

Science.gov (United States)

Macauley, Mavin; Nag, Satyajit

2011-04-19

Roth spots are white-centred retinal haemorrhages, previously thought to be pathognomonic for subacute bacterial endocarditis. A number of other conditions can be associated with Roth spots. In this case, the authors describe the association of Roth spots and pernicious anaemia. This association has been rarely described in the medical literature. Correct diagnosis and treatment with intramuscular vitamin B(12) injections resulted in complete resolution of the anaemia and Roth spots. The authors hope to alert clinicians to think of various differentials of Roth spots, and initiate prompt investigation and management.

Comparison of outcomes between overlapping-spot and single-spot photodynamic therapy for circumscribed choroidal hemangioma

Directory of Open Access Journals (Sweden)

Zhao-An Su

2014-02-01

Full Text Available AIM:To compare the efficacy and safety of photodynamic therapy (PDT with overlapping multiple spots and single spot for treating circumscribed choroidal hemangioma.METHODS:Twenty-two patients (22 eyes with symptomatic circumscribed choroidal hemangioma received PDT treatment. Fourteen patients received overlapping spots (two to three spots PDT, whereas eight patients received single-spot PDT. Laser was used at 50J/cm2 for 83s in the overlapping-spot group and 50J/cm2 for 166s in the single-spot group. Clinical examination, funduscopy, fluorescein angiography, and ultrasonography were performed at baseline and after treatment.RESULTS:The mean follow-up time was 28.5±8.0 months in the overlapping-spot group and 27.0±5.0 months in the single-spot group. Nine patients (64.2% had their vision improved over two lines on the Snellen chart, and five patients showed stable visual acuity in the overlapping-spot group. The mean thickness of tumor decreased from 2.7±0.8mm to 1.2±0.9mm, and the mean greatest tumor linear dimension decreased from 7.4±1.5mm to 4.5±3.5mm after treatment. In the single-spot group, two patients (25% had their vision improved over two lines on the Snellen chart, and six patients had unchanged stable vision. The mean tumor thickness in this group decreased from 2.5±0.7mm to 1.4±1.0mm, and the mean greatest tumor linear dimension decreased from 7.2±1.3mm to 4.7±3.6mm. No significant differences in visual improvement and tumor regression were found between the two groups.CONCLUSION: Overlapping-spot PDT under appropriate treatment parameters and strategies is as effective and safe as single-spot PDT for treating symptomatic circumscribed choroidal hemangioma. Improved or stabilized visual acuity was achieved as a result of tumor regression.

Development of a low-cost sun sensor for nanosatellites

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Antonello, Andrea; Olivieri, Lorenzo; Francesconi, Alessandro

2018-03-01

Sun sensors represent a common and reliable technology for attitude determination, employed in many space missions thanks to their limited size and weight. Typically, two-axis digital Sun sensors employ an array of active pixels arranged behind a small aperture; the position of the sunlight's spot allows to determine the direction of the Sun. With the advent of smaller vehicles such as CubeSats and Nanosats, there is the need to further reduce the size and weight of such devices: as a trade-off, this usually results in the curtail of the performances. Nowadays, state of the art Sun sensors for CubeSats have resolutions of about 0.5°, with fields of view in the ±45° to ±90° range, with off-the-self prices of several thousands of dollars. In this work we introduce a novel low-cost miniaturized Sun sensor, based on a commercial CMOS camera detector; its main feature is the reduced size with respect to state-of-the-art sensors developed from the same technology, making it employable on CubeSats. The sensor consists of a precisely machined pinhole with a 10 μm circular aperture, placed at a distance of 7 mm from the CMOS. The standoff distance and casing design allow for a maximum resolution of less than 0.03°, outperforming most of the products currently available for nano and pico platforms; furthermore, the nature of the technology allows for reduced size and lightweight characteristics. The design, development and laboratory tests of the sensor are here introduced, starting with the definition of the physical model, the geometrical layout and its theoretical resolution; a more accurate model was then developed in order to account for the geometrical deviations and deformations of the pinhole-projected light-spot, as well as to account for the background noise and disturbances to the electronics. Finally, the laboratory setup is presented along with the test campaigns: the results obtained are compared with the simulations, allowing for the validation of the

A Generic Algorithm to Estimate LAI, FAPAR and FCOVER Variables from SPOT4_HRVIR and Landsat Sensors: Evaluation of the Consistency and Comparison with Ground Measurements

Directory of Open Access Journals (Sweden)

Wenjuan Li

2015-11-01

Full Text Available The leaf area index (LAI and the fraction of photosynthetically active radiation absorbed by green vegetation (FAPAR are essential climatic variables in surface process models. FCOVER is also important to separate vegetation and soil for energy balance processes. Currently, several LAI, FAPAR and FCOVER satellite products are derived moderate to coarse spatial resolution. The launch of Sentinel-2 in 2015 will provide data at decametric resolution with a high revisit frequency to allow quantifying the canopy functioning at the local to regional scales. The aim of this study is thus to evaluate the performances of a neural network based algorithm to derive LAI, FAPAR and FCOVER products at decametric spatial resolution and high temporal sampling. The algorithm is generic, i.e., it is applied without any knowledge of the landcover. A time series of high spatial resolution SPOT4_HRVIR (16 scenes and Landsat 8 (18 scenes images acquired in 2013 over the France southwestern site were used to generate the LAI, FAPAR and FCOVER products. For each sensor and each biophysical variable, a neural network was first trained over PROSPECT+SAIL radiative transfer model simulations of top of canopy reflectance data for green, red, near-infra red and short wave infra-red bands. Our results show a good spatial and temporal consistency between the variables derived from both sensors: almost half the pixels show an absolute difference between SPOT and LANDSAT estimates of lower that 0.5 unit for LAI, and 0.05 unit for FAPAR and FCOVER. Finally, downward-looking digital hemispherical cameras were completed over the main land cover types to validate the accuracy of the products. Results show that the derived products are strongly correlated with the field measurements (R2 > 0.79, corresponding to a RMSE = 0.49 for LAI, RMSE = 0.10 (RMSE = 0.12 for black-sky (white sky FAPAR and RMSE = 0.15 for FCOVER. It is concluded that the proposed generic algorithm provides a good

Subnanomolar Sensitivity of Filter Paper-Based SERS Sensor for Pesticide Detection by Hydrophobicity Change of Paper Surface.

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Lee, Minwoo; Oh, Kyudeok; Choi, Han-Kyu; Lee, Sung Gun; Youn, Hye Jung; Lee, Hak Lae; Jeong, Dae Hong

2018-01-26

As a cost-effective approach for detecting trace amounts of pesticides, filter paper-based SERS sensors have been the subject of intensive research. One of the hurdles to overcome is the difficulty of retaining nanoparticles on the surface of the paper because of the hydrophilic nature of the cellulose fibers in paper. This reduces the sensitivity and reproducibility of paper-based SERS sensors due to the low density of nanoparticles and short retention time of analytes on the paper surface. In this study, filter paper was treated with alkyl ketene dimer (AKD) to modify its property from hydrophilic to hydrophobic. AKD treatment increased the contact angle of the aqueous silver nanoparticle (AgNP) dispersion, which consequently increased the density of AgNPs. The retention time of the analyte was also increased by preventing its rapid absorption into the filter paper. The SERS signal was strongly enhanced by the increased number of SERS hot spots owing to the increased density of AgNPs on a small contact area of the filter surface. The reproducibility and sensitivity of the SERS signal were optimized by controlling the distribution of AgNPs on the surface of the filter paper by adjusting the concentration of the AgNP solution. Using this SERS sensor with a hydrophobicity-modified filter paper, the spot-to-spot variation of the SERS intensity of 25 spots of 4-aminothiophenol was 6.19%, and the limits of detection of thiram and ferbam as test pesticides were measured to be 0.46 nM and 0.49 nM, respectively. These proof-of-concept results indicate that this paper-based SERS sensor can serve for highly sensitive pesticide detection with low cost and easy fabrication.

The AOLI Non-Linear Curvature Wavefront Sensor: High sensitivity reconstruction for low-order AO

Science.gov (United States)

Crass, Jonathan; King, David; Mackay, Craig

2013-12-01

Many adaptive optics (AO) systems in use today require bright reference objects to determine the effects of atmospheric distortions on incoming wavefronts. This requirement is because Shack Hartmann wavefront sensors (SHWFS) distribute incoming light from reference objects into a large number of sub-apertures. Bright natural reference objects occur infrequently across the sky leading to the use of laser guide stars which add complexity to wavefront measurement systems. The non-linear curvature wavefront sensor as described by Guyon et al. has been shown to offer a significant increase in sensitivity when compared to a SHWFS. This facilitates much greater sky coverage using natural guide stars alone. This paper describes the current status of the non-linear curvature wavefront sensor being developed as part of an adaptive optics system for the Adaptive Optics Lucky Imager (AOLI) project. The sensor comprises two photon-counting EMCCD detectors from E2V Technologies, recording intensity at four near-pupil planes. These images are used with a reconstruction algorithm to determine the phase correction to be applied by an ALPAO 241-element deformable mirror. The overall system is intended to provide low-order correction for a Lucky Imaging based multi CCD imaging camera. We present the current optical design of the instrument including methods to minimise inherent optical effects, principally chromaticity. Wavefront reconstruction methods are discussed and strategies for their optimisation to run at the required real-time speeds are introduced. Finally, we discuss laboratory work with a demonstrator setup of the system.

The EO-1 hyperion and advanced land imager sensors for use in tundra classification studies within the Upper Kuparuk River Basin, Alaska

Science.gov (United States)

Hall-Brown, Mary

The heterogeneity of Arctic vegetation can make land cover classification vey difficult when using medium to small resolution imagery (Schneider et al., 2009; Muller et al., 1999). Using high radiometric and spatial resolution imagery, such as the SPOT 5 and IKONOS satellites, have helped arctic land cover classification accuracies rise into the 80 and 90 percentiles (Allard, 2003; Stine et al., 2010; Muller et al., 1999). However, those increases usually come at a high price. High resolution imagery is very expensive and can often add tens of thousands of dollars onto the cost of the research. The EO-1 satellite launched in 2002 carries two sensors that have high specral and/or high spatial resolutions and can be an acceptable compromise between the resolution versus cost issues. The Hyperion is a hyperspectral sensor with the capability of collecting 242 spectral bands of information. The Advanced Land Imager (ALI) is an advanced multispectral sensor whose spatial resolution can be sharpened to 10 meters. This dissertation compares the accuracies of arctic land cover classifications produced by the Hyperion and ALI sensors to the classification accuracies produced by the Systeme Pour l' Observation de le Terre (SPOT), the Landsat Thematic Mapper (TM) and the Landsat Enhanced Thematic Mapper Plus (ETM+) sensors. Hyperion and ALI images from August 2004 were collected over the Upper Kuparuk River Basin, Alaska. Image processing included the stepwise discriminant analysis of pixels that were positively classified from coinciding ground control points, geometric and radiometric correction, and principle component analysis. Finally, stratified random sampling was used to perform accuracy assessments on satellite derived land cover classifications. Accuracy was estimated from an error matrix (confusion matrix) that provided the overall, producer's and user's accuracies. This research found that while the Hyperion sensor produced classfication accuracies that were

SpotCaliper: fast wavelet-based spot detection with accurate size estimation.

Science.gov (United States)

Püspöki, Zsuzsanna; Sage, Daniel; Ward, John Paul; Unser, Michael

2016-04-15

SpotCaliper is a novel wavelet-based image-analysis software providing a fast automatic detection scheme for circular patterns (spots), combined with the precise estimation of their size. It is implemented as an ImageJ plugin with a friendly user interface. The user is allowed to edit the results by modifying the measurements (in a semi-automated way), extract data for further analysis. The fine tuning of the detections includes the possibility of adjusting or removing the original detections, as well as adding further spots. The main advantage of the software is its ability to capture the size of spots in a fast and accurate way. http://bigwww.epfl.ch/algorithms/spotcaliper/ zsuzsanna.puspoki@epfl.ch Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A fast high-precision six-degree-of-freedom relative position sensor

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Hughes, Gary B.; Macasaet, Van P.; Griswold, Janelle; Sison, Claudia A.; Lubin, Philip; Meinhold, Peter; Suen, Jonathan; Brashears, Travis; Zhang, Qicheng; Madajian, Jonathan

2016-03-01

Lasers are commonly used in high-precision measurement and profiling systems. Some laser measurement systems are based on interferometry principles, and others are based on active triangulation, depending on requirements of the application. This paper describes an active triangulation laser measurement system for a specific application wherein the relative position of two fixed, rigid mechanical components is to be measured dynamically with high precision in six degrees of freedom (DOF). Potential applications include optical systems with feedback to control for mechanical vibration, such as target acquisition devices with multiple focal planes. The method uses an array of several laser emitters mounted on one component. The lasers are directed at a reflective surface on the second component. The reflective surface consists of a piecewise-planar pattern such as a pyramid, or more generally a curved reflective surface such as a hyperbolic paraboloid. The reflected spots are sensed at 2-dimensional photodiode arrays on the emitter component. Changes in the relative position of the emitter component and reflective surface will shift the location of the reflected spots within photodiode arrays. Relative motion in any degree of freedom produces independent shifts in the reflected spot locations, allowing full six-DOF relative position determination between the two component positions. Response time of the sensor is limited by the read-out rate of the photodiode arrays. Algorithms are given for position determination with limits on uncertainty and sensitivity, based on laser and spot-sensor characteristics, and assuming regular surfaces. Additional uncertainty analysis is achievable for surface irregularities based on calibration data.

Force and deflection sensor with shell membrane and optical gratings and method of manufacture

Science.gov (United States)

Park, Yong-Lae (Inventor); Moslehi, Behzad (Inventor); Black, Richard James (Inventor); Cutkosky, Mark R. (Inventor); Chau, Kelvin K (Inventor)

2011-01-01

A sensor for force is formed from an elastomeric cylinder having a region with apertures. The apertures have passageways formed between them, and an optical fiber is introduced into these passageways, where the optical fiber has a grating for measurement of tension positioned in the passageways between apertures. Optionally, a temperature measurement sensor is placed in or around the elastomer for temperature correction, and if required, a copper film may be deposited in the elastomer for reduced sensitivity to spot temperature variations in the elastomer near the sensors.

Roth spots in pernicious anaemia

OpenAIRE

Macauley, Mavin; Nag, Satyajit

2011-01-01

Roth spots are white-centred retinal haemorrhages, previously thought to be pathognomonic for subacute bacterial endocarditis. A number of other conditions can be associated with Roth spots. In this case, the authors describe the association of Roth spots and pernicious anaemia. This association has been rarely described in the medical literature. Correct diagnosis and treatment with intramuscular vitamin B12 injections resulted in complete resolution of the anaemia and Roth spots. The author...

Ionospheric hot spot at high latitudes

International Nuclear Information System (INIS)

Schunk, R.W.; Sojka, J.J.

1982-01-01

A hot spot (or spots) can occur in the high-latitude ionosphere depending on the plasma convection pattern. The hot spot corresponds to a small magnetic local time-magnetic latitude region of elevated ion temperatures located near the dusk and/or dawn meridians. For asymmetric convection electric field patterns, with enhanced flow in either the dusk or dawn sector of the polar cap, a single hot spot should occur in association with the strong convection cell. However, on geomagnetically disturbed days, two strong convection cells can occur, and hence, two hot spots should exist. The hot spot should be detectable when the electric field in the strong convection cell exceeds about 40 mV m -1 . For electric fields of the order of 100 mV m -1 in the convection cell, the ion temperature in the hot spot is greatest at low altitudes, reaching 4000 0 K at 160 km, and decreases with altitude in the F-region. An ionospheric hot spot (or spots) can be expected at all seasons and for a wide range of solar cycle conditions

Variable-spot ion beam figuring

International Nuclear Information System (INIS)

Wu, Lixiang; Qiu, Keqiang; Fu, Shaojun

2016-01-01

This paper introduces a new scheme of ion beam figuring (IBF), or rather variable-spot IBF, which is conducted at a constant scanning velocity with variable-spot ion beam collimated by a variable diaphragm. It aims at improving the reachability and adaptation of the figuring process within the limits of machine dynamics by varying the ion beam spot size instead of the scanning velocity. In contrast to the dwell time algorithm in the conventional IBF, the variable-spot IBF adopts a new algorithm, which consists of the scan path programming and the trajectory optimization using pattern search. In this algorithm, instead of the dwell time, a new concept, integral etching time, is proposed to interpret the process of variable-spot IBF. We conducted simulations to verify its feasibility and practicality. The simulation results indicate the variable-spot IBF is a promising alternative to the conventional approach.

[Study on Hexagonal Super-Lattice Pattern with Light Spot and Dim Spot in Dielectric Barrier Discharge by Optical Emission Spectra].

Science.gov (United States)

Liu, Ying; Dong, Li-fang; Niu, Xue-jiao; Zhang, Chao

2016-02-01

The hexagonal super-lattice pattern composed of the light spot and the dim spot is firstly observed and investigated in the discharge of gas mixture of air and argon by using the dielectric barrier discharge device with double water electrodes. It is found that the dim spot is located at the center of its surrounding three light spots by observing the discharge image. Obviously, the brightness of the light spot and the dim spot are different, which indicates that the plasma states of the light spot and the dim spot may be different. The optical emission spectrum method is used to further study the several plasma parameters of the light spot and the dim spot in different argon content. The emission spectra of the N₂ second positive band (C³IIu --> B³IIg) are measured, from which the molecule vibration temperatures of the light spot and the dim spot are calculated. Based on the relative intensity ratio of the line at 391.4 nm and the N₂ line at 394.1 nm, the average electron energies of the light spot and the dim spot are investigated. The broadening of spectral line 696.57 nm (2P₂-1S₅) is used to study the electron densities of the light spot and the dim spot. The experiment shows that the molecule vibration temperature, average electron energy and the electron density of the dim spot are higher than those of the light spot in the same argon content. The molecule vibration temperature and electron density of the light spot and dim spot increase with the argon content increasing from 70% to 95%, while average electron energies of the light spot and dim spot decrease gradually. The short-exposure image recorded by a high speed video camera shows that the dim spot results from the surface discharges (SDs). The surface discharge induced by the volume discharge (VD) has the decisive effect on the formation of the dim spot. The experiment above plays an important role in studying the formation mechanism of the hexagonal super-lattice pattern with light spot and

Numerical optimisation in spot detector design

NARCIS (Netherlands)

van der Heijden, Ferdinand; Apperloo, W.; Spreeuwers, Lieuwe Jan

1997-01-01

Spots are image details resulting from objects, the projections of which are so small that the inner structure of these objects cannot be resolved from their image. Spot detectors are image operators aiming at the detection and localisation of spots in the image. Most spot detectors can be tuned

ANALYSIS OF SPECTRAL CHARACTERISTICS AMONG DIFFERENT SENSORS BY USE OF SIMULATED RS IMAGES

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

This research, by use of RS image-simulating method, simulated apparent reflectance images at sensor level and ground-reflectance images of SPOT-HRV,CBERS-CCD,Landsat-TM and NOAA14-AVHRR' s corresponding bands. These images were used to analyze sensor's differences caused by spectral sensitivity and atmospheric impacts. The differences were analyzed on Normalized Difference Vegetation Index(NDVI). The results showed that the differences of sensors' spectral characteristics cause changes of their NDVI and reflectance. When multiple sensors' data are applied to digital analysis, the error should be taken into account. Atmospheric effect makes NDVI smaller, and atn~pheric correction has the tendency of increasing NDVI values. The reflectance and their NDVIs of different sensors can be used to analyze the differences among sensor' s features. The spectral analysis method based on RS simulated images can provide a new way to design the spectral characteristics of new sensors.

9 CFR 149.4 - Spot audit.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Spot audit. 149.4 Section 149.4... LIVESTOCK IMPROVEMENT VOLUNTARY TRICHINAE CERTIFICATION PROGRAM § 149.4 Spot audit. (a) In addition to regularly scheduled site audits, certified production sites will be subject to spot audits. (1) Random spot...

Handheld multi-channel LAPS device as a transducer platform for possible biological and chemical multi-sensor applications

International Nuclear Information System (INIS)

Wagner, Torsten; Molina, Roberto; Yoshinobu, Tatsuo; Kloock, Joachim P.; Biselli, Manfred; Canzoneri, Michelangelo; Schnitzler, Thomas; Schoening, Michael J.

2007-01-01

The light-addressable potentiometric sensor is a promising technology platform for multi-sensor applications and lab-on-chip devices. However, many prior LAPS developments suffer from their lack in terms of non-portability, insufficient robustness, complicate handling, etc. Hence, portable and robust LAPS-based measurement devices have been investigated by the authors recently. In this work, a 'chip card'-based light-addressable potentiometric sensor system is presented. The utilisation of ordinary 'chip cards' allows an easy handling of different sensor chips for a wide range of possible applications. The integration of the electronic and the mechanical set-up into a single reader unit results in a compact design with the benefits of portability and low required space. In addition, the presented work includes a new multi-frequency measurement procedure, based on an FFT algorithm, which enables the simultaneous real-time measurement of up to 16 sensor spots. The comparison between the former batch-LAPS and the new FFT-based LAPS set-up will be presented. The immobilisation of biological cells (CHO: Chinese hamster ovary) demonstrates the possibility to record their metabolic activity with 16 measurement spots on the same chip. Furthermore, a Cd 2+ -selective chalcogenide-glass layer together with a pH-sensitive Ta 2 O 5 layer validates the use of the LAPS for chemical multi-sensor applications

The AOLI low-order non-linear curvature wavefront sensor: laboratory and on-sky results

Science.gov (United States)

Crass, Jonathan; King, David; MacKay, Craig

2014-08-01

Many adaptive optics (AO) systems in use today require the use of bright reference objects to determine the effects of atmospheric distortions. Typically these systems use Shack-Hartmann Wavefront sensors (SHWFS) to distribute incoming light from a reference object between a large number of sub-apertures. Guyon et al. evaluated the sensitivity of several different wavefront sensing techniques and proposed the non-linear Curvature Wavefront Sensor (nlCWFS) offering improved sensitivity across a range of orders of distortion. On large ground-based telescopes this can provide nearly 100% sky coverage using natural guide stars. We present work being undertaken on the nlCWFS development for the Adaptive Optics Lucky Imager (AOLI) project. The wavefront sensor is being developed as part of a low-order adaptive optics system for use in a dedicated instrument providing an AO corrected beam to a Lucky Imaging based science detector. The nlCWFS provides a total of four reference images on two photon-counting EMCCDs for use in the wavefront reconstruction process. We present results from both laboratory work using a calibration system and the first on-sky data obtained with the nlCWFS at the 4.2 metre William Herschel Telescope, La Palma. In addition, we describe the updated optical design of the wavefront sensor, strategies for minimising intrinsic effects and methods to maximise sensitivity using photon-counting detectors. We discuss on-going work to develop the high speed reconstruction algorithm required for the nlCWFS technique. This includes strategies to implement the technique on graphics processing units (GPUs) and to minimise computing overheads to obtain a prior for a rapid convergence of the wavefront reconstruction. Finally we evaluate the sensitivity of the wavefront sensor based upon both data and low-photon count strategies.

Sensors for advanced driver assistance systems; Sensoren fuer Fahrerassistenzsysteme

Energy Technology Data Exchange (ETDEWEB)

Ritschel, W.; Wixforth, T. [Hella KGaA Hueck und Co., Lippstadt (Germany)

2004-07-01

Essential safety applications and those aimed at driver convenience (blind spot surveillance, stop and go, pre-crash, parking assistant) can be effected in vehicles with the aid of radar sensors. The radar sensors used can be differentiated in terms of the bandwidth required (narrow band or ultra-wide band) and in terms of the modulation of the transmission signal (pulse modulation or CW). Ultra-wide band systems at the moment are not eligible for admission and do not conform with the present regulations in the European Union. The sensors currently being developed at hella for production use are characterized by the fact that they cover the primary applications in motor vehicles. In these cases the transmission signals radiated lie within the valid limits currently approved within the European Union. (orig.)

Spot formation of radiation particles by electrochemical etching

International Nuclear Information System (INIS)

Nozaki, Tetsuya

1999-01-01

An electrochemical etching (ECE) spot formation from the top of chemical etching (CE) spot was confirmed by a series of experiments. One of polycarbonate (Iupilon) could not make the spot, because ECE spot had grown up before the microscope confirming the CE spot. Clear CEC spots by α-ray and neutron were found on Harzlas and Baryotrak, both improvements of CR-39. Under the same etching conditions, the growth of ECE spot on Harzlas was more rapid than Baryotrak, but both spots were almost the same. All CE spot by α-ray produced the CEC spots, but a part of CE circle spot by neutron formed them. (S.Y.)

Managing emerging threats to spotted owls

Science.gov (United States)

Ho Yi Wan; Joseph L. Ganey; Christina D. Vojta; Samuel A. Cushman

2018-01-01

The 3 spotted owl (Strix occidentalis) subspecies in North America (i.e., northern spotted owl [S. o. caurina], California spotted owl [S. o. occidentalis], Mexican spotted owl [S. o. lucida]) have all experienced population declines over the past century due to habitat loss and fragmentation from logging. Now, the emerging influences of climate change, high-severity...

Computational Prediction of Hot Spot Residues

Science.gov (United States)

Morrow, John Kenneth; Zhang, Shuxing

2013-01-01

Most biological processes involve multiple proteins interacting with each other. It has been recently discovered that certain residues in these protein-protein interactions, which are called hot spots, contribute more significantly to binding affinity than others. Hot spot residues have unique and diverse energetic properties that make them challenging yet important targets in the modulation of protein-protein complexes. Design of therapeutic agents that interact with hot spot residues has proven to be a valid methodology in disrupting unwanted protein-protein interactions. Using biological methods to determine which residues are hot spots can be costly and time consuming. Recent advances in computational approaches to predict hot spots have incorporated a myriad of features, and have shown increasing predictive successes. Here we review the state of knowledge around protein-protein interactions, hot spots, and give an overview of multiple in silico prediction techniques of hot spot residues. PMID:22316154

Poisson Spot with Magnetic Levitation

Science.gov (United States)

Hoover, Matthew; Everhart, Michael; D'Arruda, Jose

2010-01-01

In this paper we describe a unique method for obtaining the famous Poisson spot without adding obstacles to the light path, which could interfere with the effect. A Poisson spot is the interference effect from parallel rays of light diffracting around a solid spherical object, creating a bright spot in the center of the shadow.

Time Resolved X-Ray Spot Size Diagnostic

CERN Document Server

Richardson, Roger; Falabella, Steven; Guethlein, Gary; Raymond, Brett; Weir, John

2005-01-01

A diagnostic was developed for the determination of temporal history of an X-ray spot. A pair of thin (0.5 mm) slits image the x-ray spot to a fast scintillator which is coupled to a fast detector, thus sampling a slice of the X-Ray spot. Two other scintillator/detectors are used to determine the position of the spot and total forward dose. The slit signal is normalized to the dose and the resulting signal is analyzed to get the spot size. The position information is used to compensate for small changes due to spot motion and misalignment. The time resolution of the diagnostic is about 1 ns and measures spots from 0.5 mm to over 3 mm. The theory and equations used to calculate spot size and position are presented, as well as data. The calculations assume a symmetric, Gaussian spot. The spot data is generated by the ETA II accelerator, a 2kA, 5.5 MeV, 60ns electron beam focused on a Tantalum target. The spot generated is typically about 1 mm FWHM. Comparisons are made to an X-ray pinhole camera which images th...

Statistical hot spot analysis of reactor cores

International Nuclear Information System (INIS)

Schaefer, H.

1974-05-01

This report is an introduction into statistical hot spot analysis. After the definition of the term 'hot spot' a statistical analysis is outlined. The mathematical method is presented, especially the formula concerning the probability of no hot spots in a reactor core is evaluated. A discussion with the boundary conditions of a statistical hot spot analysis is given (technological limits, nominal situation, uncertainties). The application of the hot spot analysis to the linear power of pellets and the temperature rise in cooling channels is demonstrated with respect to the test zone of KNK II. Basic values, such as probability of no hot spots, hot spot potential, expected hot spot diagram and cumulative distribution function of hot spots, are discussed. It is shown, that the risk of hot channels can be dispersed equally over all subassemblies by an adequate choice of the nominal temperature distribution in the core

Proximity Operations and Docking Sensor Development

Science.gov (United States)

Howard, Richard T.; Bryan, Thomas C.; Brewster, Linda L.; Lee, James E.

2009-01-01

The Next Generation Advanced Video Guidance Sensor (NGAVGS) has been under development for the last three years as a long-range proximity operations and docking sensor for use in an Automated Rendezvous and Docking (AR&D) system. The first autonomous rendezvous and docking in the history of the U.S. Space Program was successfully accomplished by Orbital Express, using the Advanced Video Guidance Sensor (AVGS) as the primary docking sensor. That flight proved that the United States now has a mature and flight proven sensor technology for supporting Crew Exploration Vehicles (CEV) and Commercial Orbital Transport Systems (COTS) Automated Rendezvous and Docking (AR&D). NASA video sensors have worked well in the past: the AVGS used on the Demonstration of Autonomous Rendezvous Technology (DART) mission operated successfully in spot mode out to 2 km, and the first generation rendezvous and docking sensor, the Video Guidance Sensor (VGS), was developed and successfully flown on Space Shuttle flights in 1997 and 1998. 12 Parts obsolescence issues prevent the construction of more AVGS units, and the next generation sensor was updated to allow it to support the CEV and COTS programs. The flight proven AR&D sensor has been redesigned to update parts and add additional capabilities for CEV and COTS with the development of the Next Generation AVGS at the Marshall Space Flight Center. The obsolete imager and processor are being replaced with new radiation tolerant parts. In addition, new capabilities include greater sensor range, auto ranging capability, and real-time video output. This paper presents some sensor hardware trades, use of highly integrated laser components, and addresses the needs of future vehicles that may rendezvous and dock with the International Space Station (ISS) and other Constellation vehicles. It also discusses approaches for upgrading AVGS to address parts obsolescence, and concepts for minimizing the sensor footprint, weight, and power requirements

Hot Spot Removal System: System description

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-09-01

Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System`s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section.

Hot Spot Removal System: System description

International Nuclear Information System (INIS)

1997-09-01

Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System''s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section

Rocky Mountain Spotted Fever

Science.gov (United States)

... with facebook share with twitter share with linkedin Rocky Mountain Spotted Fever Credit: CDC A male cayenne tick, Amblyomma cajennense, ... and New Mexico. Why Is the Study of Rocky Mountain Spotted Fever a Priority for NIAID? Tickborne diseases are becoming ...

Differential computation method used to calibrate the angle-centroid relationship in coaxial reverse Hartmann test

Science.gov (United States)

Li, Xinji; Hui, Mei; Zhao, Zhu; Liu, Ming; Dong, Liquan; Kong, Lingqin; Zhao, Yuejin

2018-05-01

A differential computation method is presented to improve the precision of calibration for coaxial reverse Hartmann test (RHT). In the calibration, the accuracy of the distance measurement greatly influences the surface shape test, as demonstrated in the mathematical analyses. However, high-precision absolute distance measurement is difficult in the calibration. Thus, a differential computation method that only requires the relative distance was developed. In the proposed method, a liquid crystal display screen successively displayed two regular dot matrix patterns with different dot spacing. In a special case, images on the detector exhibited similar centroid distributions during the reflector translation. Thus, the critical value of the relative displacement distance and the centroid distributions of the dots on the detector were utilized to establish the relationship between the rays at certain angles and the detector coordinates. Experiments revealed the approximately linear behavior of the centroid variation with the relative displacement distance. With the differential computation method, we increased the precision of traditional calibration 10-5 rad root mean square. The precision of the RHT was increased by approximately 100 nm.

Comparativa de sensores espaciales de diferente resolución espectral en la exploración minera

OpenAIRE

Lora López, Jose Carlos

2016-01-01

El reconocimiento de minerales en la superficie terrestre se lleva a cabo desde hace años con imágenes captadas desde satélites artificiales (LANDSAT, SPOT, EO-1, TERRA, etc.). La resolución espectral de los sensores a bordo de dichos satélites es muy variada, y aunque los sensores hiperespectrales aerotransportados son ideales, por sus elevadas resolución espacial y espectral, la información captada por estos tiene un coste económico mucho mayor que la procedente de otros sensores espacia...

Brightness checkerboard lattice method for the calibration of the coaxial reverse Hartmann test

Science.gov (United States)

Li, Xinji; Hui, Mei; Li, Ning; Hu, Shinan; Liu, Ming; Kong, Lingqin; Dong, Liquan; Zhao, Yuejin

2018-01-01

The coaxial reverse Hartmann test (RHT) is widely used in the measurement of large aspheric surfaces as an auxiliary method for interference measurement, because of its large dynamic range, highly flexible test with low frequency of surface errors, and low cost. And the accuracy of the coaxial RHT depends on the calibration. However, the calibration process remains inefficient, and the signal-to-noise ratio limits the accuracy of the calibration. In this paper, brightness checkerboard lattices were used to replace the traditional dot matrix. The brightness checkerboard method can reduce the number of dot matrix projections in the calibration process, thus improving efficiency. An LCD screen displayed a brightness checkerboard lattice, in which the brighter checkerboard and the darker checkerboard alternately arranged. Based on the image on the detector, the relationship between the rays at certain angles and the photosensitive positions of the detector coordinates can be obtained. And a differential de-noising method can effectively reduce the impact of noise on the measurement results. Simulation and experimentation proved the feasibility of the method. Theoretical analysis and experimental results show that the efficiency of the brightness checkerboard lattices is about four times that of the traditional dot matrix, and the signal-to-noise ratio of the calibration is significantly improved.

Laser Pyrometer For Spot Temperature Measurements

Science.gov (United States)

Elleman, D. D.; Allen, J. L.; Lee, M. C.

1988-01-01

Laser pyrometer makes temperature map by scanning measuring spot across target. Scanning laser pyrometer passively measures radiation emitted by scanned spot on target and calibrated by similar passive measurement on blackbody of known temperature. Laser beam turned on for active measurements of reflectances of target spot and reflectance standard. From measurements, temperature of target spot inferred. Pyrometer useful for non-contact measurement of temperature distributions in processing of materials.

Discovery of a Sweet Spot on the Foot with a Smart Wearable Soccer Boot Sensor That Maximizes the Chances of Scoring a Curved Kick in Soccer.

Science.gov (United States)

Fuss, Franz Konstantin; Düking, Peter; Weizman, Yehuda

2018-01-01

This paper provides the evidence of a sweet spot on the boot/foot as well as the method for detecting it with a wearable pressure sensitive device. This study confirmed the hypothesized existence of sweet and dead spots on a soccer boot or foot when kicking a ball. For a stationary curved kick, kicking the ball at the sweet spot maximized the probability of scoring a goal (58-86%), whereas having the impact point at the dead zone minimized the probability (11-22%). The sweet spot was found based on hypothesized favorable parameter ranges (center of pressure in x/y-directions and/or peak impact force) and the dead zone based on hypothesized unfavorable parameter ranges. The sweet spot was rather concentrated, independent of which parameter combination was used (two- or three-parameter combination), whereas the dead zone, located 21 mm from the sweet spot, was more widespread.

Resistance Spot Welding of dissimilar Steels

Directory of Open Access Journals (Sweden)

Ladislav Kolařík

2012-01-01

Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

Automated translating beam profiler for in situ laser beam spot-size and focal position measurements

Science.gov (United States)

Keaveney, James

2018-03-01

We present a simple and convenient, high-resolution solution for automated laser-beam profiling with axial translation. The device is based on a Raspberry Pi computer, Pi Noir CMOS camera, stepper motor, and commercial translation stage. We also provide software to run the device. The CMOS sensor is sensitive over a large wavelength range between 300 and 1100 nm and can be translated over 25 mm along the beam axis. The sensor head can be reversed without changing its axial position, allowing for a quantitative estimate of beam overlap with counter-propagating laser beams. Although not limited to this application, the intended use for this device is the automated measurement of the focal position and spot-size of a Gaussian laser beam. We present example data of one such measurement to illustrate device performance.

On the relationships between electron spot size, focal spot size, and virtual source position in Monte Carlo simulations

International Nuclear Information System (INIS)

Sterpin, E.; Chen, Y.; Lu, W.; Mackie, T. R.; Olivera, G. H.; Vynckier, S.

2011-01-01

Purpose: Every year, new radiotherapy techniques including stereotactic radiosurgery using linear accelerators give rise to new applications of Monte Carlo (MC) modeling. Accurate modeling requires knowing the size of the electron spot, one of the few parameters to tune in MC models. The resolution of integrated megavoltage imaging systems, such as the tomotherapy system, strongly depends on the photon spot size which is closely related to the electron spot. The aim of this article is to clarify the relationship between the electron spot size and the photon spot size (i.e., the focal spot size) for typical incident electron beam energies and target thicknesses. Methods: Three electron energies (3, 5.5, and 18 MeV), four electron spot sizes (FWHM=0, 0.5, 1, and 1.5 mm), and two tungsten target thicknesses (0.15 and 1 cm) were considered. The formation of the photon beam within the target was analyzed through electron energy deposition with depth, as well as photon production at several phase-space planes placed perpendicular to the beam axis, where only photons recorded for the first time were accounted for. Photon production was considered for ''newborn'' photons intersecting a 45x45 cm 2 plane at the isocenter (85 cm from source). Finally, virtual source position and ''effective'' focal spot size were computed by backprojecting all the photons from the bottom of the target intersecting a 45x45 cm 2 plane. The virtual source position and focal spot size were estimated at the plane position where the latter is minimal. Results: In the relevant case of considering only photons intersecting the 45x45 cm 2 plane, the results unambiguously showed that the effective photon spot is created within the first 0.25 mm of the target and that electron and focal spots may be assumed to be equal within 3-4%. Conclusions: In a good approximation photon spot size equals electron spot size for high energy X-ray treatments delivered by linear accelerators.

Solar 'hot spots' are still hot

Science.gov (United States)

Bai, Taeil

1990-01-01

Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22.

Arc cathode spots

International Nuclear Information System (INIS)

Schrade, H.O.

1989-01-01

Arc spots are usually highly unstable and jump statistically over the cathode surface. In a magnetic field parallel to the surface, preferably they move in the retrograde direction; i.e., opposite to the Lorentzian rule. If the field is inclined with respect to the surface, the spots drift away at a certain angle with respect to the proper retrograde direction (Robson drift motion). These well-known phenomena are explained by one stability theory

7 CFR 28.413 - Middling Light Spotted Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Middling Light Spotted Color. 28.413 Section 28.413... Spotted Color. Middling Light Spotted Color is color which in spot or color, or both, is between Middling Color and Middling Spotted Color. ...

Solar hot spots are still hot

International Nuclear Information System (INIS)

Bai, T.

1990-01-01

Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22. 14 refs

7 CFR 28.423 - Middling Spotted Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Middling Spotted Color. 28.423 Section 28.423... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Spotted Cotton § 28.423 Middling Spotted Color. Middling Spotted Color is color which is within the range represented by a set of samples in the custody of...

Determination of the paraxial focal length using Zernike polynomials over different apertures

Science.gov (United States)

Binkele, Tobias; Hilbig, David; Henning, Thomas; Fleischmann, Friedrich

2017-02-01

The paraxial focal length is still the most important parameter in the design of a lens. As presented at the SPIE Optics + Photonics 2016, the measured focal length is a function of the aperture. The paraxial focal length can be found when the aperture approaches zero. In this work, we investigate the dependency of the Zernike polynomials on the aperture size with respect to 3D space. By this, conventional wavefront measurement systems that apply Zernike polynomial fitting (e.g. Shack-Hartmann-Sensor) can be used to determine the paraxial focal length, too. Since the Zernike polynomials are orthogonal over a unit circle, the aperture used in the measurement has to be normalized. By shrinking the aperture and keeping up with the normalization, the Zernike coefficients change. The relation between these changes and the paraxial focal length are investigated. The dependency of the focal length on the aperture size is derived analytically and evaluated by simulation and measurement of a strong focusing lens. The measurements are performed using experimental ray tracing and a Shack-Hartmann-Sensor. Using experimental ray tracing for the measurements, the aperture can be chosen easily. Regarding the measurements with the Shack-Hartmann- Sensor, the aperture size is fixed. Thus, the Zernike polynomials have to be adapted to use different aperture sizes by the proposed method. By doing this, the paraxial focal length can be determined from the measurements in both cases.

Vehicle tracking for an evasive manoeuvres assistant using low-cost ultrasonic sensors.

Science.gov (United States)

Jiménez, Felipe; Naranjo, José E; Gómez, Oscar; Anaya, José J

2014-11-28

Many driver assistance systems require knowledge of the vehicle environment. As these systems are increasing in complexity and performance, this knowledge of the environment needs to be more complete and reliable, so sensor fusion combining long, medium and short range sensors is now being used. This paper analyzes the feasibility of using ultrasonic sensors for low cost vehicle-positioning and tracking in the lane adjacent to the host vehicle in order to identify free areas around the vehicle and provide information to an automatic avoidance collision system that can perform autonomous braking and lane change manoeuvres. A laser scanner is used for the early detection of obstacles in the direction of travel while two ultrasonic sensors monitor the blind spot of the host vehicle. The results of tests on a test track demonstrate the ability of these sensors to accurately determine the kinematic variables of the obstacles encountered, despite a clear limitation in range.

An edge-TCT setup for the investigation of radiation damaged silicon sensors

Energy Technology Data Exchange (ETDEWEB)

Feindt, Finn; Scharf, Christian; Garutti, Erika; Klanner, Robert [Institute for Experimental Physics, Hamburg University, Luruper Chaussee 149, D-22761 Hamburg (Germany)

2016-07-01

The aim of this work is to measure the electric field, drift velocity and charge collection of electrons and holes in radiation-damaged silicon strip sensors. For this purpose the edge Transient Current Technique (TCT) is employed. In contrast to conventional TCT, this method requires light from a sub-ns pulsed, infrared laser to be focused to a μm-size spot and scanned across the polished edge of a strip sensor. Thus electron-hole pairs are generated at a known depth in the sensor. Electrons and holes drift in the electric field and induce transient currents on the sensor electrodes. The current wave forms are analyzed as a function of the applied voltage and the position of the laser focus in order to determine the electric field, the drift velocities and the charge collection. In this talk the setup and the procedure for polishing the sensor edge are described, and first results, regarding the measurement of the laser light focus are presented.

Vehicle Tracking for an Evasive Manoeuvres Assistant Using Low-Cost Ultrasonic Sensors

Directory of Open Access Journals (Sweden)

Felipe Jiménez

2014-11-01

Full Text Available Many driver assistance systems require knowledge of the vehicle environment. As these systems are increasing in complexity and performance, this knowledge of the environment needs to be more complete and reliable, so sensor fusion combining long, medium and short range sensors is now being used. This paper analyzes the feasibility of using ultrasonic sensors for low cost vehicle-positioning and tracking in the lane adjacent to the host vehicle in order to identify free areas around the vehicle and provide information to an automatic avoidance collision system that can perform autonomous braking and lane change manoeuvres. A laser scanner is used for the early detection of obstacles in the direction of travel while two ultrasonic sensors monitor the blind spot of the host vehicle. The results of tests on a test track demonstrate the ability of these sensors to accurately determine the kinematic variables of the obstacles encountered, despite a clear limitation in range.

Improved simulation method of automotive spot weld failure with an account of the mechanical properties of spot welds

Science.gov (United States)

Wu, H.; Meng, X. M.; Fang, R.; Huang, Y. F.; Zhan, S.

2017-12-01

In this paper, the microstructure and mechanical properties of spot weld were studied, the hardness of nugget and heat affected zone (HAZ) were also tested by metallographic microscope and microhardness tester. The strength of the spot weld with the different parts' area has been characterized. According to the experiments result, CAE model of spot weld with HAZ structure was established, and simulation results of different lap-shear CAE models were analyzed. The results show that the spot weld model which contained the HAZ has good performance and more suitable for engineering application in spot weld simulation.

TV spots' impact.

Science.gov (United States)

El-bakly, S

1994-09-01

The Information, Education and Communication (IEC) Center of the State Information Service was established in 1979 for the purpose of providing information to the people on the population issue. The Ministry of Information has accorded the State Information Service free TV and radio air time for family planning dramas and spots. In the early years information campaigns were organized to make people aware of the population problem by slogans, songs, and cartoons. Around 1984 misconceptions about family planning and contraceptives were attacked through a number of TV and radio spots. A few years later 21 spots on specific contraceptive methods were broadcast which were aired for three years over 3000 times. They were extremely successful. The impact of these TV spots was one of the major reasons why the contraceptive prevalence rate increased from 30% in 1984 to 38% in 1988 and 47% in 1992. Spots were also broadcast about the social implications of large families. The TV soap opera "And The Nile Flows On", with the family planning message interwoven into it, was very well received by the target audience. A program entitled "Wedding of the Month" features couples who know family planning well. The most successful radio program is a 15-20 minute long quiz show for residents of the villages where the Select Villages Project is being implemented. The State Information Service has 60 local information centers in the 26 governorates of Egypt that make plans for the family planning campaign. In 1992 the Minya Initiative, a family planning project was implemented in the Minya Governorate. As a result, the contraceptive prevalence rate rose from 22% to 30% over 18 months. A new project, the Select Village Project, was developed in 1993 that replicates the Minya Initiative on the village level in other governorates. This new project that was implemented in sixteen governorates.

Black-spot poison ivy.

Science.gov (United States)

Schram, Sarah E; Willey, Andrea; Lee, Peter K; Bohjanen, Kimberly A; Warshaw, Erin M

2008-01-01

In black-spot poison ivy dermatitis, a black lacquerlike substance forms on the skin when poison ivy resin is exposed to air. Although the Toxicodendron group of plants is estimated to be the most common cause of allergic contact dermatitis in the United States, black-spot poison ivy dermatitis is relatively rare.

A True-Color Sensor and Suitable Evaluation Algorithm for Plant Recognition.

Science.gov (United States)

Schmittmann, Oliver; Schulze Lammers, Peter

2017-08-08

Plant-specific herbicide application requires sensor systems for plant recognition and differentiation. A literature review reveals a lack of sensor systems capable of recognizing small weeds in early stages of development (in the two- or four-leaf stage) and crop plants, of making spraying decisions in real time and, in addition, are that are inexpensive and ready for practical use in sprayers. The system described in this work is based on free cascadable and programmable true-color sensors for real-time recognition and identification of individual weed and crop plants. The application of this type of sensor is suitable for municipal areas and farmland with and without crops to perform the site-specific application of herbicides. Initially, databases with reflection properties of plants, natural and artificial backgrounds were created. Crop and weed plants should be recognized by the use of mathematical algorithms and decision models based on these data. They include the characteristic color spectrum, as well as the reflectance characteristics of unvegetated areas and areas with organic material. The CIE-Lab color-space was chosen for color matching because it contains information not only about coloration (a- and b-channel), but also about luminance (L-channel), thus increasing accuracy. Four different decision making algorithms based on different parameters are explained: (i) color similarity (ΔE); (ii) color similarity split in ΔL, Δa and Δb; (iii) a virtual channel 'd' and (iv) statistical distribution of the differences of reflection backgrounds and plants. Afterwards, the detection success of the recognition system is described. Furthermore, the minimum weed/plant coverage of the measuring spot was calculated by a mathematical model. Plants with a size of 1-5% of the spot can be recognized, and weeds in the two-leaf stage can be identified with a measuring spot size of 5 cm. By choosing a decision model previously, the detection quality can be increased

Computational prediction of protein hot spot residues.

Science.gov (United States)

Morrow, John Kenneth; Zhang, Shuxing

2012-01-01

Most biological processes involve multiple proteins interacting with each other. It has been recently discovered that certain residues in these protein-protein interactions, which are called hot spots, contribute more significantly to binding affinity than others. Hot spot residues have unique and diverse energetic properties that make them challenging yet important targets in the modulation of protein-protein complexes. Design of therapeutic agents that interact with hot spot residues has proven to be a valid methodology in disrupting unwanted protein-protein interactions. Using biological methods to determine which residues are hot spots can be costly and time consuming. Recent advances in computational approaches to predict hot spots have incorporated a myriad of features, and have shown increasing predictive successes. Here we review the state of knowledge around protein-protein interactions, hot spots, and give an overview of multiple in silico prediction techniques of hot spot residues.

Evaluating the capability of Landsat 8 OLI and SPOT 6 for discriminating invasive alien species in the African Savanna landscape

Science.gov (United States)

Kganyago, Mahlatse; Odindi, John; Adjorlolo, Clement; Mhangara, Paidamoyo

2018-05-01

Globally, there is paucity of accurate information on the spatial distribution and patch sizes of Invasive Alien Plants (IAPs) species. Such information is needed to aid optimisation of control mechanisms to prevent further spread of IAPs and minimize their impacts. Recent studies have shown the capability of very high spatial (management. In this study medium and high resolution datasets from Landsat Operational Land Imager (OLI) and SPOT 6 sensors respectively, were evaluated for mapping the distribution and patch sizes of IAP, Parthenium hysterophorus in the savannah landscapes of KwaZulu-Natal, South Africa. Support Vector Machines (SVM) classifier was used for classification of both datasets. Results indicated that SPOT 6 had a higher overall accuracy (86%) than OLI (83%) in mapping P. hysterophorus. The study found larger distributions and patch sizes in OLI than in SPOT 6 as a result of possible P. hysterophorus expansion due to temporal differences between images and coarser pixels were insufficient to delineate gaps inside larger patches. On the other hand, SPOT 6 showed better capabilities of delineating gaps and boundaries of patches, hence had better estimates of distribution and patch sizes. Overall, the study showed that OLI may be suitable for mapping well-established patches for the purpose of large scale monitoring, while SPOT 6 can be used for mapping small patches and prioritising them for eradication to prevent further spread at a landscape scale.

7 CFR 1421.11 - Spot checks.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Spot checks. 1421.11 Section 1421.11 Agriculture... ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 General § 1421.11 Spot checks. (a) CCC... CCC access to the farm and storage facility as necessary to conduct collateral inspections, or “spot...

21 CFR 886.1435 - Maxwell spot.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Maxwell spot. 886.1435 Section 886.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1435 Maxwell spot. (a) Identification. A Maxwell spot is an AC...

Roll Attitude Determination of Spin Projectile Based on GPS and Magnetoresistive Sensor

Directory of Open Access Journals (Sweden)

Dandan Yuan

2017-01-01

Full Text Available Improvement in attack accuracy of the spin projectiles is a very significant objective, which increases the overall combat efficiency of projectiles. The accurate determination of the projectile roll attitude is the recent objective of the efficient guidance and control. The roll measurement system for the spin projectile is commonly based on the magnetoresistive sensor. It is well known that the magnetoresistive sensor produces a sinusoidally oscillating signal whose frequency slowly decays with time, besides the possibility of blind spot. On the other hand, absolute sensors such as GPS have fixed errors even though the update rates are generally low. To earn the benefit while eliminating weaknesses from both types of sensors, a mathematical model using filtering technique can be designed to integrate the magnetoresistive sensor and GPS measurements. In this paper, a mathematical model is developed to integrate the magnetoresistive sensor and GPS measurements in order to get an accurate prediction of projectile roll attitude in a real flight time. The proposed model is verified using numerical simulations, which illustrated that the accuracy of the roll attitude measurement is improved.

Wavefront correction system based on an equilateral triangular arrangement of actuators

International Nuclear Information System (INIS)

Salmon, J.T.; Bergum, J.W.; Kartz, M.W.; Presta, R.W.; Swift, C.D.

1993-02-01

Atomic Vapor Laser Isotope Separation (AVLIS) requires the copropagation of multiple beams at different wavelengths and at average powers exceeding 1 kW. Although mirror coatings are used that absorb less than one part in 10 5 , the beams still suffer from thermally induced phase distortions, both in the dye amplifiers and in transmissive optics, such as beam combiners and vacuum windows. These aberrations are 2nd-order and 3rd-order and can reach 5 waves peak-to-valley (p-v), which causes the beam to distort and break up when propagated over large distances. The magnitude of the aberrations scales with power, with time constants on the order of 30 seconds. Previous adaptive systems that have been developed corrected these thermally induced phase distortions of both 2nd-order and 3rd-order; however, these systems had limited spatial resolution and in some cases marginal stability. The authors have developed a new adaptive optics system where both the actuators of the deformable mirror and the lenslets of the Hartmann sensor are arranged with centers at the vertices of equilateral triangles. The wavefront sensor is a video Hartmann sensor that also uses an equilateral array of lenslets. The controller hardware uses a VME bus. The design minimizes the generation of reflected wavefronts higher than first order across each lenslet for large excursions of actuators from positions where the mirror is flat and, thus maximizes the precision of the slopes measured by the Hartmann sensor. The design is also immune to the waffle mode that is present in the reconstructors of adaptive optics systems where actuators are arranged in a square array

Research on the compensation of laser launch optics to improve the performance of the LGS spot.

Science.gov (United States)

Liu, Jie; Wang, Jianli; Wang, Yuning; Tian, Donghe; Zheng, Quan; Lin, Xudong; Wang, Liang; Yang, Qingyun

2018-02-01

To improve the beam quality of the uplink laser, a 37 channel piezo-ceramic deformable mirror was inserted into the laser launch optics to compensate the static aberrations. An interferometer was used as the calibration light source as well as the wavefront sensor to perform closed-loop correction for the moment. About 0.38λ root mean square (rms) aberrations, including the deformable mirror's initial figure error, were compensated, and the residual error was less than 0.07λ rms. Field observations with a 2 m optical telescope demonstrated that the peak intensity value of the laser guide star (LGS) spot increased from 5650 to 7658, and the full width at half-maximum (FWHM) size reduced from 4.07 arcseconds to 3.52 arcseconds. With the compensation, an improved guide star spot can be obtained, which is crucial for the adaptive optics systems of ground-based large telescopes.

Newborn screening blood spot analysis in the UK: influence of spot size, punch location and haematocrit.

Science.gov (United States)

Lawson, A J; Bernstone, L; Hall, S K

2016-03-01

In dried blood spot analysis, punch location and variations in applied sample volume and haematocrit can produce different measured concentrations of analytes. We investigated the magnitude of these effects in newborn screening in the UK. Heparinized blood spiked with thyroid stimulating hormone (TSH), phenylalanine, tyrosine, leucine, methionine, octanoyl carnitine (C8), and immunoreactive trypsinogen (IRT) was spotted onto filter paper: (i) at a constant haematocrit of 50% at various volumes, and (ii) at a range of haematocrits using a constant volume. Subpunches (3.2 mm) of the dried blood spots were then analysed. Compared with a central punch from a 50 µL blood spot with 50% haematocrit, 10 µL spots can have significantly lower measured concentrations of all analytes, with decreases of 15% or more observed for leucine, methionine, phenylalanine, and tyrosine. Punching at the edge of a spot can increase measured concentrations up to 35%. Higher haematocrit decreased measured TSH and C8 yet increased amino acids and IRT by 15% compared with 50% haematocrit. Lower haematocrits had the opposite effect, but only with higher concentrations of some analytes. Differences in blood spot size, haematocrit and punch location substantially affect measured concentrations for analytes used in the UK newborn screening programme, and this could affect false positive and negative rates. To minimize analytical bias, these variables should be controlled or adjusted for where possible. © The Author(s) 2015.

Wavefront error sensing for LDR

Science.gov (United States)

Tubbs, Eldred F.; Glavich, T. A.

1988-01-01

Wavefront sensing is a significant aspect of the LDR control problem and requires attention at an early stage of the control system definition and design. A combination of a Hartmann test for wavefront slope measurement and an interference test for piston errors of the segments was examined and is presented as a point of departure for further discussion. The assumption is made that the wavefront sensor will be used for initial alignment and periodic alignment checks but that it will not be used during scientific observations. The Hartmann test and the interferometric test are briefly examined.

High-precision methods and devices for in situ measurements of thermally induced aberrations in optical elements

International Nuclear Information System (INIS)

Zelenogorsky, Victor V.; Solovyov, Alexander A.; Kozhevatov, Ilya E.; Kamenetsky, Eugene E.; Rudenchik, Eugene A.; Palashov, Oleg V.; Silin, Dmitry E.; Khazanov, Efim A.

2006-01-01

An optical system that comprises two devices for remote measurements, a broadband optical interferometer and a scanning Hartmann sensor, is described. The results of simultaneous measurements with both devices and the results of numerical modeling of sample surface heating are presented

Thermal lensing measurement from the coefficient of defocus aberration

CSIR Research Space (South Africa)

Bell, Teboho

2016-03-01

Full Text Available We measured the thermally induced lens from the coefficient of defocus aberration using a Shack-Hartmann wavefront sensor (SHWFS). As a calibration technique, we infer the focal length of standard lenses probed by a collimated Gaussian beam...

Advances in spot curing technology

International Nuclear Information System (INIS)

Burga, R.

1999-01-01

A brief review of spot curing technology was presented. The process which a spot of energy of a specific wavelength bandwidth and irradiance is used to cause a coating, encapsulant or adhesive to change from a liquid to a solid state

High-QE fast-readout wavefront sensor with analog phase reconstruction

Science.gov (United States)

Baker, Jeffrey T.; Loos, Gary C.; Restaino, Sergio R.; Percheron, Isabelle; Finkner, Lyle G.

1998-09-01

The contradiction inherent in high temporal bandwidth adaptive optics wavefront sensing at low-light-levels (LLL) has driven many researchers to consider the use of high bandwidth high quantum efficiency (QE) CCD cameras with the lowest possible readout noise levels. Unfortunately, the performance of these relatively expensive and low production volume devices in the photon counting regime is inevitably limited by readout noise, no matter how arbitrarily close to zero that specification may be reduced. Our alternative approach is to optically couple a new and relatively inexpensive Ultra Blue Gen III image intensifier to an also relatively inexpensive high bandwidth CCD camera with only moderate QE and high rad noise. The result is a high bandwidth broad spectral response image intensifier with a gain of 55,000 at 560 nm. Use of an appropriately selected lenslet array together with coupling optics generates 16 X 16 Shack-Hartmann type subapertures on the image intensifier photocathode, which is imaged onto the fast CCD camera. An integral A/D converter in the camera sends the image data pixel by pixel to a computer data acquisition system for analysis, storage and display. Timing signals are used to decode which pixel is being rad out and the wavefront is calculated in an analog fashion using a least square fit to both x and y tilt data for all wavefront sensor subapertures. Finally, we present system level performance comparisons of these new concept wavefront sensors versus the more standard low noise CCD camera based designs in the low-light-level limit.

The fractal nature of vacuum arc cathode spots

International Nuclear Information System (INIS)

Anders, Andre

2005-01-01

Cathode spot phenomena show many features of fractals, for example self-similar patterns in the emitted light and arc erosion traces. Although there have been hints on the fractal nature of cathode spots in the literature, the fractal approach to spot interpretation is underutilized. In this work, a brief review of spot properties is given, touching the differences between spot type 1 (on cathodes surfaces with dielectric layers) and spot type 2 (on metallic, clean surfaces) as well as the known spot fragment or cell structure. The basic properties of self-similarity, power laws, random colored noise, and fractals are introduced. Several points of evidence for the fractal nature of spots are provided. Specifically power laws are identified as signature of fractal properties, such as spectral power of noisy arc parameters (ion current, arc voltage, etc) obtained by fast Fourier transform. It is shown that fractal properties can be observed down to the cutoff by measurement resolution or occurrence of elementary steps in physical processes. Random walk models of cathode spot motion are well established: they go asymptotically to Brownian motion for infinitesimal step width. The power spectrum of the arc voltage noise falls as 1/f 2 , where f is frequency, supporting a fractal spot model associated with Brownian motion

Prototype of a laser guide star wavefront sensor for the Extremely Large Telescope

Science.gov (United States)

Patti, M.; Lombini, M.; Schreiber, L.; Bregoli, G.; Arcidiacono, C.; Cosentino, G.; Diolaiti, E.; Foppiani, I.

2018-06-01

The new class of large telescopes, like the future Extremely Large Telescope (ELT), are designed to work with a laser guide star (LGS) tuned to a resonance of atmospheric sodium atoms. This wavefront sensing technique presents complex issues when applied to big telescopes for many reasons, mainly linked to the finite distance of the LGS, the launching angle, tip-tilt indetermination and focus anisoplanatism. The implementation of a laboratory prototype for the LGS wavefront sensor (WFS) at the beginning of the phase study of MAORY (Multi-conjugate Adaptive Optics Relay) for ELT first light has been indispensable in investigating specific mitigation strategies for the LGS WFS issues. This paper presents the test results of the LGS WFS prototype under different working conditions. The accuracy within which the LGS images are generated on the Shack-Hartmann WFS has been cross-checked with the MAORY simulation code. The experiments show the effect of noise on centroiding precision, the impact of LGS image truncation on wavefront sensing accuracy as well as the temporal evolution of the sodium density profile and LGS image under-sampling.

Laser Spot Detection Based on Reaction Diffusion

OpenAIRE

Alejandro Vázquez-Otero; Danila Khikhlukha; J. M. Solano-Altamirano; Raquel Dormido; Natividad Duro

2016-01-01

Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD) system as the main computational framework for robustly finding laser spot centers. The method presente...

7 CFR 28.415 - Low Middling Light Spotted Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Low Middling Light Spotted Color. 28.415 Section 28... Spotted Color. Low Middling Light Spotted Color is color which in spot or color, or both, is between Low Middling Color and Low Middling Spotted Color. ...

PyTranSpot: A tool for multiband light curve modeling of planetary transits and stellar spots

Science.gov (United States)

Juvan, Ines G.; Lendl, M.; Cubillos, P. E.; Fossati, L.; Tregloan-Reed, J.; Lammer, H.; Guenther, E. W.; Hanslmeier, A.

2018-02-01

Several studies have shown that stellar activity features, such as occulted and non-occulted starspots, can affect the measurement of transit parameters biasing studies of transit timing variations and transmission spectra. We present PyTranSpot, which we designed to model multiband transit light curves showing starspot anomalies, inferring both transit and spot parameters. The code follows a pixellation approach to model the star with its corresponding limb darkening, spots, and transiting planet on a two dimensional Cartesian coordinate grid. We combine PyTranSpot with a Markov chain Monte Carlo framework to study and derive exoplanet transmission spectra, which provides statistically robust values for the physical properties and uncertainties of a transiting star-planet system. We validate PyTranSpot's performance by analyzing eleven synthetic light curves of four different star-planet systems and 20 transit light curves of the well-studied WASP-41b system. We also investigate the impact of starspots on transit parameters and derive wavelength dependent transit depth values for WASP-41b covering a range of 6200-9200 Å, indicating a flat transmission spectrum.

Rocky Mountain spotted fever in Argentina.

Science.gov (United States)

Paddock, Christopher D; Fernandez, Susana; Echenique, Gustavo A; Sumner, John W; Reeves, Will K; Zaki, Sherif R; Remondegui, Carlos E

2008-04-01

We describe the first molecular confirmation of Rickettsia rickettsii, the cause of Rocky Mountain spotted fever (RMSF), from a tick vector, Amblyomma cajennense, and from a cluster of fatal spotted fever cases in Argentina. Questing A. cajennense ticks were collected at or near sites of presumed or confirmed cases of spotted fever rickettsiosis in Jujuy Province and evaluated by polymerase chain reaction assays for spotted fever group rickettsiae. DNA of R. rickettsii was amplified from a pool of A. cajennense ticks and from tissues of one of four patients who died during 2003-2004 after illnesses characterized by high fever, severe headache, myalgias, and petechial rash. The diagnosis of spotted fever rickettsiosis was confirmed in the other patients by indirect immunofluorescence antibody and immunohistochemical staining techniques. These findings show the existence of RMSF in Argentina and emphasize the need for clinicians throughout the Americas to consider RMSF in patients with febrile rash illnesses.

Crack imaging by pulsed laser spot thermography

International Nuclear Information System (INIS)

Li, T; Almond, D P; Rees, D A S; Weekes, B

2010-01-01

A surface crack close to a spot heated by a laser beam impedes lateral heat flow and produces alterations to the shape of the thermal image of the spot that can be monitored by thermography. A full 3D simulation has been developed to simulate heat flow from a laser heated spot in the proximity of a crack. The modelling provided an understanding of the ways that different parameters affect the thermal images of laser heated spots. It also assisted in the development of an efficient image processing strategy for extracting the scanned cracks. Experimental results show that scanning pulsed laser spot thermography has considerable potential as a remote, non-contact crack imaging technique.

Spot Welding of Honeycomb Structures

Science.gov (United States)

Cohal, V.

2017-08-01

Honeycomb structures are used to prepare meals water jet cutting machines for textile. These honeycomb structures are made of stainless steel sheet thickness of 0.1-0.2 mm. Corrugated sheet metal strips are between two gears with special tooth profile. Hexagonal cells for obtaining these strips are welded points between them. Spot welding device is three electrodes in the upper part, which carries three welding points across the width of the strip of corrugated sheet metal. Spot welding device filled with press and advance mechanisms. The paper presents the values of the regime for spot welding.

7 CFR 28.412 - Strict Middling Light Spotted Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Strict Middling Light Spotted Color. 28.412 Section 28... Light Spotted Color. Strict Middling Light Spotted Color is color which in spot or color, or both, is between Strict Middling Color and Strict Middling Spotted Color. ...

7 CFR 28.411 - Good Middling Light Spotted Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Good Middling Light Spotted Color. 28.411 Section 28... Light Spotted Color. Good Middling Light Spotted Color is color which in spot or color, or both, is between Good Middling Color and Good Middling Spotted Color. ...

An optode sensor array for long term in situ Oxygen measurements in soil and sediment

DEFF Research Database (Denmark)

Rickelt, Lars F; Jensen, Louise Askær; Walpersdorf, Eva Christine

2013-01-01

Long-term measurements of molecular oxygen (O2) dynamics in wetlands are highly relevant for understanding the eff ects of water level changes on net greenhouse gas budgets in these ecosystems. However, such measurements have been limited due to a lack of suitable measuring equipment. We construc......Long-term measurements of molecular oxygen (O2) dynamics in wetlands are highly relevant for understanding the eff ects of water level changes on net greenhouse gas budgets in these ecosystems. However, such measurements have been limited due to a lack of suitable measuring equipment. We...... constructed an O2 optode sensor array for long-term in situ measurements in soil and sediment. Th e new device consists of a 1.3-m-long, cylindrical, spear-shaped rod equipped with 10 sensor spots along the shaft . Each spot contains a thermocouple fi xed with a robust fi beroptic O2 optode made...... characteristics of the sensor array system are presented along with a novel approach for temperature compensation of O2 optodes. During in situ application over several months in a peat bog, we used the new device to document pronounced variations in O2 distribution aft er marked shift s in water level. Th e...

Effect of ambient humidity on the rate at which blood spots dry and the size of the spot produced.

Science.gov (United States)

Denniff, Philip; Woodford, Lynsey; Spooner, Neil

2013-08-01

For shipping and storage, dried blood spot (DBS) samples must be sufficiently dry to protect the integrity of the sample. When the blood is spotted the humidity has the potential to affect the size of the spot created and the speed at which it dries. The area of DBS produced on three types of substrates were not affected by the humidity under which they were generated. DBS samples reached a steady moisture content 150 min after spotting and 90 min for humidities less than 60% relative humidity. All packaging materials examined provided some degree of protection from external extreme conditions. However, none of the packaging examined provided a total moisture barrier to extreme environmental conditions. Humidity was shown not to affect the spot area and DBS samples were ready for shipping and storage 2 h after spotting. The packing solutions examined all provided good protection from external high humidity conditions.

Demography of Northern Spotted Owls in southwestern Oregon

Science.gov (United States)

Zabel, Cynthia J.; Salmons, Susan E.; Forsman, Eric D.; DeStefano, Stephen; Raphael, Martin G.; Gutierrez, R.J.

1996-01-01

Northern Spotted Owls (Strix occidentalis caurina) are associated with lower elevation, commercially valuable, late-successional coniferous forests in the Pacific Northwest. Meta-analyses of demographic parameters indicate that Northern Spotted Owl populations are declining throughout their range (Anderson and Burnham 1992, Burnham et al. this volume). Recent research has attempted to determine whether management activities have affected the viability of Spotted Owl populations, and results have led to development of conservation plans for the species (Dawson et al. 1987, Thomas et al. 1990, Murphy and Noon 1992, USDI 1992, Thomas et al. 1993b).In the Recovery Plan for the Northern Spotted Owl (USDI 1992b) threats to the species were identified as small population sizes, declining populations, limited amounts of habitat, continued loss and fragmentation of habitat, geographically isolated populations, and predation and competition from other avian species. Weather and fire are natural processes that also may affect reproductive success of Spotted Owls. Weather may be a factor in the high annual variability in fecundity of Spotted Owls, as has been suggested for other predatory bird species (Newton, 1979, 1986). However, these factors have not been addressed in previous studies of Spotted Owls.Our objectives were to estimate survival, fecundity, and annual rates of population change (l) for resident, territorial female Spotted Owls at two study areas in the coastal mountains of southwestern Oregon. We tested if the amount of rainfall was correlated with reproduction of Spotted Owls. While surveying for Spotted Owls, we documented the increased presence of Barred Owls (Strix varia), a potential competitor of Spotted Owls.

Unblinding the dark matter blind spots

International Nuclear Information System (INIS)

Han, Tao; Kling, Felix

2017-01-01

The dark matter (DM) blind spots in the Minimal Supersymmetric Standard Model (MSSM) refer to the parameter regions where the couplings of the DM particles to the Z-boson or the Higgs boson are almost zero, leading to vanishingly small signals for the DM direct detections. In this paper, we carry out comprehensive analyses for the DM searches under the blind-spot scenarios in MSSM. Guided by the requirement of acceptable DM relic abundance, we explore the complementary coverage for the theory parameters at the LHC, the projection for the future underground DM direct searches, and the indirect searches from the relic DM annihilation into photons and neutrinos. We find that (i) the spin-independent (SI) blind spots may be rescued by the spin-dependent (SD) direct detection in the future underground experiments, and possibly by the indirect DM detections from IceCube and SuperK neutrino experiments; (ii) the detection of gamma rays from Fermi-LAT may not reach the desirable sensitivity for searching for the DM blind-spot regions; (iii) the SUSY searches at the LHC will substantially extend the discovery region for the blind-spot parameters. As a result, the dark matter blind spots thus may be unblinded with the collective efforts in future DM searches.

Characterization of silicon microstrip sensors with a pulsed infrared laser system for the CBM experiment at FAIR

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Pradeep [Goethe Univ., Frankfurt (Germany); GSI (Germany); Eschke, Juergen [GSI (Germany); FAIR (Germany); Collaboration: CBM-Collaboration

2014-07-01

The Silicon Tracking System (STS) for the Compressed Baryonic Matter (CBM) experiment at FAIR will comprise more than 1200 double-sided silicon microstrip sensors. For the quality assurance of the prototype sensors a laser test system has been built up. The aim of the sensor scans with the pulsed infrared laser system is to determine the charge sharing between strips and to measure the uniformity of the sensor response over the whole active area. The laser system measures the sensor response in an automatized procedure at several thousand positions across the sensor with focused infrared laser light (σ∼15 μm, λ=1060 nm). The duration (5 ns) and power (few mW) of the laser pulses are selected such, that the absorption of the laser light in the 300 μm thick silicon sensors produces a number of about 24k electrons, which is similar to the charge created by minimum ionizing particles in these sensors. Results from the characterization of monolithic active pixel sensors, to understand the spot-size of the laser, and laser scans for different sensors are presented.

On the Design of Smart Parking Networks in the Smart Cities: An Optimal Sensor Placement Model

Science.gov (United States)

Bagula, Antoine; Castelli, Lorenzo; Zennaro, Marco

2015-01-01

Smart parking is a typical IoT application that can benefit from advances in sensor, actuator and RFID technologies to provide many services to its users and parking owners of a smart city. This paper considers a smart parking infrastructure where sensors are laid down on the parking spots to detect car presence and RFID readers are embedded into parking gates to identify cars and help in the billing of the smart parking. Both types of devices are endowed with wired and wireless communication capabilities for reporting to a gateway where the situation recognition is performed. The sensor devices are tasked to play one of the three roles: (1) slave sensor nodes located on the parking spot to detect car presence/absence; (2) master nodes located at one of the edges of a parking lot to detect presence and collect the sensor readings from the slave nodes; and (3) repeater sensor nodes, also called “anchor” nodes, located strategically at specific locations in the parking lot to increase the coverage and connectivity of the wireless sensor network. While slave and master nodes are placed based on geographic constraints, the optimal placement of the relay/anchor sensor nodes in smart parking is an important parameter upon which the cost and efficiency of the parking system depends. We formulate the optimal placement of sensors in smart parking as an integer linear programming multi-objective problem optimizing the sensor network engineering efficiency in terms of coverage and lifetime maximization, as well as its economic gain in terms of the number of sensors deployed for a specific coverage and lifetime. We propose an exact solution to the node placement problem using single-step and two-step solutions implemented in the Mosel language based on the Xpress-MPsuite of libraries. Experimental results reveal the relative efficiency of the single-step compared to the two-step model on different performance parameters. These results are consolidated by simulation results

On the Design of Smart Parking Networks in the Smart Cities: An Optimal Sensor Placement Model

Directory of Open Access Journals (Sweden)

Antoine Bagula

2015-06-01

Full Text Available Smart parking is a typical IoT application that can benefit from advances in sensor, actuator and RFID technologies to provide many services to its users and parking owners of a smart city. This paper considers a smart parking infrastructure where sensors are laid down on the parking spots to detect car presence and RFID readers are embedded into parking gates to identify cars and help in the billing of the smart parking. Both types of devices are endowed with wired and wireless communication capabilities for reporting to a gateway where the situation recognition is performed. The sensor devices are tasked to play one of the three roles: (1 slave sensor nodes located on the parking spot to detect car presence/absence; (2 master nodes located at one of the edges of a parking lot to detect presence and collect the sensor readings from the slave nodes; and (3 repeater sensor nodes, also called “anchor” nodes, located strategically at specific locations in the parking lot to increase the coverage and connectivity of the wireless sensor network. While slave and master nodes are placed based on geographic constraints, the optimal placement of the relay/anchor sensor nodes in smart parking is an important parameter upon which the cost and efficiency of the parking system depends. We formulate the optimal placement of sensors in smart parking as an integer linear programming multi-objective problem optimizing the sensor network engineering efficiency in terms of coverage and lifetime maximization, as well as its economic gain in terms of the number of sensors deployed for a specific coverage and lifetime. We propose an exact solution to the node placement problem using single-step and two-step solutions implemented in the Mosel language based on the Xpress-MPsuite of libraries. Experimental results reveal the relative efficiency of the single-step compared to the two-step model on different performance parameters. These results are consolidated by

On the Design of Smart Parking Networks in the Smart Cities: An Optimal Sensor Placement Model.

Science.gov (United States)

Bagula, Antoine; Castelli, Lorenzo; Zennaro, Marco

2015-06-30

Smart parking is a typical IoT application that can benefit from advances in sensor, actuator and RFID technologies to provide many services to its users and parking owners of a smart city. This paper considers a smart parking infrastructure where sensors are laid down on the parking spots to detect car presence and RFID readers are embedded into parking gates to identify cars and help in the billing of the smart parking. Both types of devices are endowed with wired and wireless communication capabilities for reporting to a gateway where the situation recognition is performed. The sensor devices are tasked to play one of the three roles: (1) slave sensor nodes located on the parking spot to detect car presence/absence; (2) master nodes located at one of the edges of a parking lot to detect presence and collect the sensor readings from the slave nodes; and (3) repeater sensor nodes, also called "anchor" nodes, located strategically at specific locations in the parking lot to increase the coverage and connectivity of the wireless sensor network. While slave and master nodes are placed based on geographic constraints, the optimal placement of the relay/anchor sensor nodes in smart parking is an important parameter upon which the cost and efficiency of the parking system depends. We formulate the optimal placement of sensors in smart parking as an integer linear programming multi-objective problem optimizing the sensor network engineering efficiency in terms of coverage and lifetime maximization, as well as its economic gain in terms of the number of sensors deployed for a specific coverage and lifetime. We propose an exact solution to the node placement problem using single-step and two-step solutions implemented in the Mosel language based on the Xpress-MPsuite of libraries. Experimental results reveal the relative efficiency of the single-step compared to the two-step model on different performance parameters. These results are consolidated by simulation results

Evaluation of actual vs expected photodynamic therapy spot size.

Science.gov (United States)

Ranchod, Tushar M; Brucker, Alexander J; Liu, Chengcheng; Cukras, Catherine A; Hopkins, Tim B; Ying, Gui-Shuang

2009-05-01

To determine the accuracy of the photodynamic therapy (PDT) laser spot size on the retina as generated by 2 Food and Drug Administration (FDA)-approved lasers. Prospective observational case series. Fundus photographs were taken of 1 eye of each of 10 subjects with the WinStation 4000 fundus photography system (OIS; Ophthalmic Imaging Systems, Sacramento, California, USA); disc size was calculated using OIS software. Slit-lamp photographs were taken of the PDT laser spot focused on the retina adjacent to the optic disc, using various spot sizes in combination with 3 different contact lenses and 2 different lasers. Spot size at the retina was determined by measuring the ratio of disc diameter to spot diameter in Adobe Photoshop (San Jose, California, USA) and applying this ratio to the OIS disc measurements. Spot size at the retina averaged 87% of expected spot size for the Coherent Opal laser (Coherent Inc, Santa Clara, California, USA) and 104% of expected spot size for the Zeiss Visulas laser (Carl Zeiss Meditec Inc, Dublin, California, USA)(P = .002). Multivariate analysis demonstrated that percentage of expected spot size decreased with larger spot diameter (P = .01 for Coherent laser; P = .02 for Zeiss laser). PDT spot size at the retina appears to be consistently smaller than expected for the Coherent laser while the spot size was consistently within 10% of expected size for the Zeiss laser. The deviation from expected size increased with larger spot size using the Coherent laser.

Laser Spot Detection Based on Reaction Diffusion.

Science.gov (United States)

Vázquez-Otero, Alejandro; Khikhlukha, Danila; Solano-Altamirano, J M; Dormido, Raquel; Duro, Natividad

2016-03-01

Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD) system as the main computational framework for robustly finding laser spot centers. The method presented is compared with a conventional approach for locating laser spots, and the experimental results indicate that RD-based computation generates reliable and precise solutions. These results confirm the flexibility of the new computational paradigm based on RD systems for addressing problems that can be reduced to a set of geometric operations.

Adaptive Square-Shaped Trajectory-Based Service Location Protocol in Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Hwa-Jung Lim

2010-04-01

Full Text Available In this paper we propose an adaptive square-shaped trajectory (ASST-based service location method to ensure load scalability in wireless sensor networks. This first establishes a square-shaped trajectory over the nodes that surround a target point computed by the hash function and any user can access it, using the hash. Both the width and the size of the trajectory are dynamically adjustable, depending on the number of queries made to the service information on the trajectory. The number of sensor nodes on the trajectory varies in proportion to the changing trajectory shape, allowing high loads to be distributed around the hot spot area.

Insights from ecological niche modeling on the taxonomic distinction and niche differentiation between the black-spotted and red-spotted tokay geckoes (Gekko gecko)

OpenAIRE

Zhang, Yueyun; Chen, Chongtao; Li, Li; Zhao, Chengjian; Chen, Weicai; Huang, Yong

2014-01-01

The black-spotted tokay and the red-spotted tokay are morphologically distinct and have largely allopatric distributions. The black-spotted tokay is characterized by a small body size and dark skin with sundry spots, while the red-spotted tokay has a relatively large body size and red spots. Based on morphological, karyotypic, genetic, and distribution differences, recent studies suggested their species status; however, their classifications remain controversial, and additional data such as e...

Small laser spot versus standard laser spot photodynamic therapy for idiopathic choroidal neovascularization: a randomized controlled study.

Science.gov (United States)

Li, Xiao-xin; Tao, Yong

2012-12-01

Idiopathic choroidal neovascularization (ICNV) affects young patients and thus may have a significant impact on vision and life quality over a patient's lifespan. This study was designed to compare the visual outcome and retinal pigment epithelium (RPE) damage after photodynamic therapy (PDT) with small laser spot and PDT with standard laser spot for idiopathic choroidal neovascularization (ICNV). This was a randomized controlled study. Fifty-two patients with ICNV were enrolled and randomly divided into a study group (small laser spot PDT, n = 27) and a control group (standard laser spot PDT, n = 25). Best corrected visual acuity (BCVA), optic coherence tomography (OCT) and fluorescein angiography (FA) findings were the main measurements. The patients were followed up 1 week, 1, 3, 6, 9 months and 1 year after PDT. BCVA improvement was statistically significantly higher in the study group than the control group at 6-month ((25.53 ± 15.01) letters vs. (14.71 ± 11.66) letters, P = 0.025) and 9-month follow-ups ((27.53 ± 17.78) letters vs. (15.59 ± 12.21) letters, P = 0.039). At 3- and 6-month follow-ups, the quadrants of RPE damage between the two groups varied significantly (P laser spot PDT group than in the standard laser spot PDT group for ICNV.

A comparative study of x-ray emission from laser spots in laser-heated hohlraums relative to spots on simple disk targets

International Nuclear Information System (INIS)

Ze, F.; Langer, S.H.; Kauffman, R.L.; Kilkenny, J.D.; Landen, O.; Ress, D.; Rosen, M.D.; Suter, L.J.; Wallace, R.J.; Wiedwald, J.D.

1997-01-01

In this paper we report the results of experiments that compare the x-ray emission from a laser spot in a radiation-filled hohlraum to that from a similar laser spot on a simple disk target. The studies were done using the Nova laser facility [J. D. Lindl, Phys. Plasmas 2, 3933 (1995)] in its 0.35 μm wavelength, 1 ns square pulse configuration. Focal spot intensities were 2 endash 3.5x10 15 W/cm 2 . X-ray images measured x-ray conversion in a hohlraum and from an isolated disk simultaneously. A laser spot inside a hohlraum emitted more x rays, after subtracting the background emission from the hohlraum walls, than a spot on a disk. Numerical models suggest the enhanced spot emission inside the hohlraum is due to an increase in lateral transport relative to the disk. Filamentation in the hohlraum will also increase the spot size. The models agree fairly well with the results on spot spreading but do not explain the overall increase in conversion efficiency. copyright 1997 American Institute of Physics

PENGARUH KURS SPOT DAN KURS FORWARD DALAM MEMPREDIKSI FUTURE SPOT PADA PASAR VALAS KAWASAN ASIA TENGGARA

Directory of Open Access Journals (Sweden)

I Gusti Ayu Kade Diana Yanthi

2013-10-01

Full Text Available The importance of the activity in foreign exchange occur as the result of the development of international trading and increased international money and capital movement. The vast development of international economic  caused  economic relationship  among  countries  will  be  linked  to  each other  and  subsequently improve trading activities in their goods, money and capital flows. The variables used in this study are spot, forward  and future  spot. Based  on  the result  of Regression  Estimation  applied in  hypothesis on foreign currencies exchange which done simultaneously are proven able to predict future spot. The investor and international economic  actor could use spot  exchange rate and forward  exchange rate as a  short terms predictor for the next trimester in 2011.

Consistency of land surface reflectance data: presentation of a new tool and case study with Formosat-2, SPOT-4 and Landsat-5/7/8 data

Science.gov (United States)

Claverie, M.; Vermote, E.; Franch, B.; Huc, M.; Hagolle, O.; Masek, J.

2013-12-01

Maintaining consistent dataset of Surface Reflectance (SR) data derived from the large panel of in-orbit sensors is an important challenge to ensure long term analysis of earth observation data. Continuous validation of such SR products through comparison with a reference dataset is thus an important challenge. Validating with in situ or airborne SR data is not easy since the sensors rarely match completely the same spectral, spatial and directional characteristics of the satellite measurement. Inter-comparison between satellites sensors data appears as a valuable tool to maintain a long term consistency of the data. However, satellite data are acquired at various times of the day (i.e., variation of the atmosphere content) and within a relative large range of geometry (view and sun angles). Also, even if band-to-band spectral characteristics of optical sensors are closed, they rarely have identical spectral responses. As the results, direct comparisons without consideration of these differences are poorly suitable. In this study, we suggest a new systematic method to assess land optical SR data from high to medium resolution sensors. We used MODIS SR products (MO/YD09CMG) which benefit from a long term calibration/validation process, to assess SR from 3 sensors data: Formosat-2 (280 scenes 24x24km - 5 sites), SPOT-4 (62 scenes 120x60km - 1 site) and Landsat-5/7 (104 180x180km scenes - 50 sites). The main issue concerns the difference in term of geometry acquisition between MODIS and compared sensors data. We used the VJB model (Vermote et al. 2009, TGRS) to correct MODIS SR from BRDF effects and to simulate SR at the corresponding geometry (view and sun angles) of each pixel of the compared sensor data. The comparison is done at the CMG spatial resolution (0.05°) which ensures a constant field-of-view and negligible geometrical errors. Figure 1 displays the summary of the NIR results through APU graphs where metrics A, P and U stands for Accuracy, Precision and

Estimating rice grain protein contents with SPOT/HRV data acquired at maturing stage

International Nuclear Information System (INIS)

Asaka, D.; Shiga, H.

2003-01-01

Rice grain protein contents that play an important role in the eating quality of rice can be estimated from leaf color in maturing stage. In order to investigate the distribution of paddy rice grain protein of a wide area, we employed SPOT/HRV data from August to September for successive 4 years, selecting the Naganuma town, Hokkaido as the study area. The relationship between each spectral bands and ground survey data were examined. The result showed that the grain protein contents could be estimated using the normalized difference vegetation index (NDVI) with the absolute root mean square error less than 0.4% under the condition that the time lag between the satellite observation date and the maturing stage was within 20 days. In this period, we would have enough chance to get clear observation data every year under the weather conditions in the study area using the SPOT/HRV sensors that has pointing ability. For major rice varieties cultivated in Hokkaido, the same relationship between NDVI and protein contents was observed. Thus, we conclude that the method proposed in this study is operational in rice production

Laser Spot Detection Based on Reaction Diffusion

Directory of Open Access Journals (Sweden)

Alejandro Vázquez-Otero

2016-03-01

Full Text Available Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD system as the main computational framework for robustly finding laser spot centers. The method presented is compared with a conventional approach for locating laser spots, and the experimental results indicate that RD-based computation generates reliable and precise solutions. These results confirm the flexibility of the new computational paradigm based on RD systems for addressing problems that can be reduced to a set of geometric operations.

Rocky Mountain spotted fever, Colombia.

Science.gov (United States)

Hidalgo, Marylin; Orejuela, Leonora; Fuya, Patricia; Carrillo, Pilar; Hernandez, Jorge; Parra, Edgar; Keng, Colette; Small, Melissa; Olano, Juan P; Bouyer, Donald; Castaneda, Elizabeth; Walker, David; Valbuena, Gustavo

2007-07-01

We investigated 2 fatal cases of Rocky Mountain spotted fever that occurred in 2003 and 2004 near the same locality in Colombia where the disease was first reported in the 1930s. A retrospective serosurvey of febrile patients showed that > 21% of the serum samples had antibodies aaainst spotted fever group rickettsiae.

Age Spots

Science.gov (United States)

... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Age Spots Treatment Options Learn more about treatment ...

Splitting of turbulent spot in transitional pipe flow

Science.gov (United States)

Wu, Xiaohua; Moin, Parviz; Adrian, Ronald J.

2017-11-01

Recent study (Wu et al., PNAS, 1509451112, 2015) demonstrated the feasibility and accuracy of direct computation of the Osborne Reynolds' pipe transition problem without the unphysical, axially periodic boundary condition. Here we use this approach to study the splitting of turbulent spot in transitional pipe flow, a feature first discovered by E.R. Lindgren (Arkiv Fysik 15, 1959). It has been widely believed that spot splitting is a mysterious stochastic process that has general implications on the lifetime and sustainability of wall turbulence. We address the following two questions: (1) What is the dynamics of turbulent spot splitting in pipe transition? Specifically, we look into any possible connection between the instantaneous strain rate field and the spot splitting. (2) How does the passive scalar field behave during the process of pipe spot splitting. In this study, the turbulent spot is introduced at the inlet plane through a sixty degree wide numerical wedge within which fully-developed turbulent profiles are assigned over a short time interval; and the simulation Reynolds numbers are 2400 for a 500 radii long pipe, and 2300 for a 1000 radii long pipe, respectively. Numerical dye is tagged on the imposed turbulent spot at the inlet. Splitting of the imposed turbulent spot is detected very easily. Preliminary analysis of the DNS results seems to suggest that turbulent spot slitting can be easily understood based on instantaneous strain rate field, and such spot splitting may not be relevant in external flows such as the flat-plate boundary layer.

Laser based spot weld characterization

Science.gov (United States)

Jonietz, Florian; Myrach, Philipp; Rethmeier, Michael; Suwala, Hubert; Ziegler, Mathias

2016-02-01

Spot welding is one of the most important joining technologies, especially in the automotive industry. Hitherto, the quality of spot welded joints is tested mainly by random destructive tests. A nondestructive testing technique offers the benefit of cost reduction of the testing procedure and optimization of the fabrication process, because every joint could be examined. This would lead to a reduced number of spot welded joints, as redundancies could be avoided. In the procedure described here, the spot welded joint between two zinc-coated steel sheets (HX340LAD+Z100MB or HC340LA+ZE 50/50) is heated optically on one side. Laser radiation and flash light are used as heat sources. The melted zone, the so called "weld nugget" provides the mechanical stability of the connection, but also constitutes a thermal bridge between the sheets. Due to the better thermal contact, the spot welded joint reveals a thermal behavior different from the surrounding material, where the heat transfer between the two sheets is much lower. The difference in the transient thermal behavior is measured with time resolved thermography. Hence, the size of the thermal contact between the two sheets is determined, which is directly correlated to the size of the weld nugget, indicating the quality of the spot weld. The method performs well in transmission with laser radiation and flash light. With laser radiation, it works even in reflection geometry, thus offering the possibility of testing with just one-sided accessibility. By using heating with collimated laser radiation, not only contact-free, but also remote testing is feasible. A further convenience compared to similar thermographic approaches is the applicability on bare steel sheets without any optical coating for emissivity correction. For this purpose, a proper way of emissivity correction was established.

Advanced spot quality analysis in two-colour microarray experiments

Directory of Open Access Journals (Sweden)

Vetter Guillaume

2008-09-01

Full Text Available Abstract Background Image analysis of microarrays and, in particular, spot quantification and spot quality control, is one of the most important steps in statistical analysis of microarray data. Recent methods of spot quality control are still in early age of development, often leading to underestimation of true positive microarray features and, consequently, to loss of important biological information. Therefore, improving and standardizing the statistical approaches of spot quality control are essential to facilitate the overall analysis of microarray data and subsequent extraction of biological information. Findings We evaluated the performance of two image analysis packages MAIA and GenePix (GP using two complementary experimental approaches with a focus on the statistical analysis of spot quality factors. First, we developed control microarrays with a priori known fluorescence ratios to verify the accuracy and precision of the ratio estimation of signal intensities. Next, we developed advanced semi-automatic protocols of spot quality evaluation in MAIA and GP and compared their performance with available facilities of spot quantitative filtering in GP. We evaluated these algorithms for standardised spot quality analysis in a whole-genome microarray experiment assessing well-characterised transcriptional modifications induced by the transcription regulator SNAI1. Using a set of RT-PCR or qRT-PCR validated microarray data, we found that the semi-automatic protocol of spot quality control we developed with MAIA allowed recovering approximately 13% more spots and 38% more differentially expressed genes (at FDR = 5% than GP with default spot filtering conditions. Conclusion Careful control of spot quality characteristics with advanced spot quality evaluation can significantly increase the amount of confident and accurate data resulting in more meaningful biological conclusions.

Detecting hot spots at hazardous-waste sites

International Nuclear Information System (INIS)

Zirschky, J.; Gilbert, R.O.

1984-01-01

Evaluating the need for remedial cleanup at a waste site involves both finding the average contaminant concentration and identifying highly contaminated areas, or hot spots. A nomographic procedure to determine the sample configuration needed to locate a hot spot is presented. The technique can be used to develop a waste-site sampling plant - to determine either the grid spacing required to detect a hot spot at a given level of confidence, or the probability of finding a hot spot of a certain size, given a particular grid spacing. The method and computer program (ELIPGRID) were developed for locating geologic deposits, but the basic procedure can also be used to detect hot spots at chemical- or nuclear-waste disposal sites. Nomographs based on the original program are presented for three sampling-grid configurations - square, rectangular and triangular

Judging a salmon by its spots: environmental variation is the primary determinant of spot patterns in Salmo salar.

Science.gov (United States)

Jørgensen, Katarina M; Solberg, Monica F; Besnier, Francois; Thorsen, Anders; Fjelldal, Per Gunnar; Skaala, Øystein; Malde, Ketil; Glover, Kevin A

2018-04-12

In fish, morphological colour changes occur from variations in pigment concentrations and in the morphology, density, and distribution of chromatophores in the skin. However, the underlying mechanisms remain unresolved in most species. Here, we describe the first investigation into the genetic and environmental basis of spot pattern development in one of the world's most studied fishes, the Atlantic salmon. We reared 920 salmon from 64 families of domesticated, F1-hybrid and wild origin in two contrasting environments (Hatchery; tanks for the freshwater stage and sea cages for the marine stage, and River; a natural river for the freshwater stage and tanks for the marine stage). Fish were measured, photographed and spot patterns evaluated. In the Hatchery experiment, significant but modest differences in spot density were observed among domesticated, F1-hybrid (1.4-fold spottier than domesticated) and wild salmon (1.7-fold spottier than domesticated). A heritability of 6% was calculated for spot density, and a significant QTL on linkage group SSA014 was detected. In the River experiment, significant but modest differences in spot density were also observed among domesticated, F1-hybrid (1.2-fold spottier than domesticated) and wild salmon (1.8-fold spottier than domesticated). Domesticated salmon were sevenfold spottier in the Hatchery vs. River experiment. While different wild populations were used for the two experiments, on average, these were 6.2-fold spottier in the Hatchery vs. River experiment. Fish in the Hatchery experiment displayed scattered to random spot patterns while fish in the River experiment displayed clustered spot patterns. These data demonstrate that while genetics plays an underlying role, environmental variation represents the primary determinant of spot pattern development in Atlantic salmon.

Impact of spot charge inaccuracies in IMPT treatments.

Science.gov (United States)

Kraan, Aafke C; Depauw, Nicolas; Clasie, Ben; Giunta, Marina; Madden, Tom; Kooy, Hanne M

2017-08-01

Spot charge is one parameter of pencil-beam scanning dose delivery system whose accuracy is typically high but whose required value has not been investigated. In this work we quantify the dose impact of spot charge inaccuracies on the dose distribution in patients. Knowing the effect of charge errors is relevant for conventional proton machines, as well as for new generation proton machines, where ensuring accurate charge may be challenging. Through perturbation of spot charge in treatment plans for seven patients and a phantom, we evaluated the dose impact of absolute (up to 5× 10 6 protons) and relative (up to 30%) charge errors. We investigated the dependence on beam width by studying scenarios with small, medium and large beam sizes. Treatment plan statistics included the Γ passing rate, dose-volume-histograms and dose differences. The allowable absolute charge error for small spot plans was about 2× 10 6 protons. Larger limits would be allowed if larger spots were used. For relative errors, the maximum allowable error size for small, medium and large spots was about 13%, 8% and 6% for small, medium and large spots, respectively. Dose distributions turned out to be surprisingly robust against random spot charge perturbation. Our study suggests that ensuring spot charge errors as small as 1-2% as is commonly aimed at in conventional proton therapy machines, is clinically not strictly needed. © 2017 American Association of Physicists in Medicine.

Spot: A Programming Language for Verified Flight Software

Science.gov (United States)

Bocchino, Robert L., Jr.; Gamble, Edward; Gostelow, Kim P.; Some, Raphael R.

2014-01-01

The C programming language is widely used for programming space flight software and other safety-critical real time systems. C, however, is far from ideal for this purpose: as is well known, it is both low-level and unsafe. This paper describes Spot, a language derived from C for programming space flight systems. Spot aims to maintain compatibility with existing C code while improving the language and supporting verification with the SPIN model checker. The major features of Spot include actor-based concurrency, distributed state with message passing and transactional updates, and annotations for testing and verification. Spot also supports domain-specific annotations for managing spacecraft state, e.g., communicating telemetry information to the ground. We describe the motivation and design rationale for Spot, give an overview of the design, provide examples of Spot's capabilities, and discuss the current status of the implementation.

Hot spot formation on different tokamak wall materials

International Nuclear Information System (INIS)

Nedospasov, A.V.; Bezlyudny, I.V.

1998-01-01

The thermal contraction phenomenon and generation of 'hot spots' due to thermoemission were described. The paper consider non-linear stages of heat contraction on the graphite, beryllium, tungsten and vanadium wall. It is shown that on the beryllium surface hot spot can't appear due to strong cooling by sublimation. For other materials the conditions of hot spot appearance due to local superheating of the wall have been calculated and their parameters were found: critical surface temperature, size of spots and their temperature profiles, heat fluxes from plasma to the spots. It have been calculated fluxes of sublimating materials from spots to the plasma. It is noticed that nominal temperature of the grafite divertor plate, accepted in ITER's project to being equal 1500 C, is lower then critical temperature of the development heat contraction due to thermoemission. (orig.)

Enhanced processing of SPOT multispectral satellite imagery for environmental monitoring and modelling

Energy Technology Data Exchange (ETDEWEB)

Clark, B.

2010-07-01

The Taita Hills in southeastern Kenya form the northernmost part of Africa's Eastern Arc Mountains, which have been identified by Conservation International as one of the top ten biodiversity hotspots on Earth. As with many areas of the developing world, over recent decades the Taita Hills have experienced significant population growth leading to associated major changes in land use and land cover (LULC), as well as escalating land degradation, particularly soil erosion. Multi-temporal medium resolution multispectral optical satellite data, such as imagery from the SPOT HRV, HRVIR, and HRG sensors, provides a valuable source of information for environmental monitoring and modelling at a landscape level at local and regional scales. However, utilization of multi-temporal SPOT data in quantitative remote sensing studies requires the removal of atmospheric effects and the derivation of surface reflectance factor (rho{sub s}). Furthermore, for areas of rugged terrain, such as the Taita Hills, topographic correction is necessary to derive comparable (rho{sub s}) throughout a SPOT scene. Reliable monitoring of LULC change over time and modelling of land degradation and human population distribution and abundance are of crucial importance to sustainable development, natural resource management, biodiversity conservation, and understanding and mitigating climate change and its impacts. The main purpose of this thesis was to develop and validate enhanced processing of SPOT satellite imagery for use in environmental monitoring and modelling at a landscape level, in regions of the developing world with limited ancillary data availability. The Taita Hills formed the application study site, whilst the Helsinki metropolitan region was used as a control site for validation and assessment of the applied atmospheric correction techniques, where multiangular (rho{sub s}) field measurements were taken and where horizontal visibility meteorological data concurrent with image

Volume higher; spot price ranges widen

International Nuclear Information System (INIS)

Anon.

1994-01-01

This article is the October 1994 uranium market summary. During this reporting period, volume on the spot concentrates market doubled. Twelve deals took place: three in the spot concentrates market, one in the medium and long-term market, four in the conversion market, and four in the enrichment market. The restricted price range widened due to higher prices at the top end of the range, while the unrestricted price range widened because of lower prices at the bottom end. Spot conversion prices were higher, and enrichment prices were unchanged

Space-time modeling of electricity spot prices

DEFF Research Database (Denmark)

Abate, Girum Dagnachew; Haldrup, Niels

In this paper we derive a space-time model for electricity spot prices. A general spatial Durbin model that incorporates the temporal as well as spatial lags of spot prices is presented. Joint modeling of space-time effects is necessarily important when prices and loads are determined in a network...... in the spot price dynamics. Estimation of the spatial Durbin model show that the spatial lag variable is as important as the temporal lag variable in describing the spot price dynamics. We use the partial derivatives impact approach to decompose the price impacts into direct and indirect effects and we show...... that price effects transmit to neighboring markets and decline with distance. In order to examine the evolution of the spatial correlation over time, a time varying parameters spot price spatial Durbin model is estimated using recursive estimation. It is found that the spatial correlation within the Nord...

Smart sensor-based geospatial architecture for dike monitoring

Science.gov (United States)

Herle, S.; Becker, R.; Blankenbach, J.

2016-04-01

Artificial hydraulic structures like dams or dikes used for water level regulations or flood prevention are continuously under the influence of the weather and variable river regimes. Thus, ongoing monitoring and simulation is crucial in order to determine the inner condition. Potentially life-threatening situations, in extreme case a failure, must be counteracted by all available means. Nowadays flood warning systems rely exclusively on water level forecast without considering the state of the structure itself. Area-covering continuous knowledge of the inner state including time dependent changes increases the capability of recognizing and locating vulnerable spots for early treatment. In case of a predicted breach, advance warning time for alerting affected citizens can be extended. Our approach is composed of smart sensors integrated in a service-oriented geospatial architecture to monitor and simulate artificial hydraulic structures continuously. The sensors observe the inner state of the construction like the soil moisture or the stress and deformation over time but also various external influences like water levels or wind speed. They are interconnected in distributed network architecture by a so-called sensor bus system based on lightweight protocols like Message Queue Telemetry Transport for Sensor Networks (MQTT-SN). These sensor data streams are transferred into an OGC Sensor Web Enablement (SWE) data structure providing high-level geo web services to end users. Bundled with 3rd party geo web services (WMS etc.) powerful processing and simulation tools can be invoked using the Web Processing Service (WPS) standard. Results will be visualized in a geoportal allowing user access to all information.

Poisson's spot and Gouy phase

Science.gov (United States)

da Paz, I. G.; Soldati, Rodolfo; Cabral, L. A.; de Oliveira, J. G. G.; Sampaio, Marcos

2016-12-01

Recently there have been experimental results on Poisson spot matter-wave interferometry followed by theoretical models describing the relative importance of the wave and particle behaviors for the phenomenon. We propose an analytical theoretical model for Poisson's spot with matter waves based on the Babinet principle, in which we use the results for free propagation and single-slit diffraction. We take into account effects of loss of coherence and finite detection area using the propagator for a quantum particle interacting with an environment. We observe that the matter-wave Gouy phase plays a role in the existence of the central peak and thus corroborates the predominantly wavelike character of the Poisson's spot. Our model shows remarkable agreement with the experimental data for deuterium (D2) molecules.

7 CFR 28.421 - Good Middling Spotted Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Good Middling Spotted Color. 28.421 Section 28.421 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Color. Good Middling Spotted Color is color which is better than Strict Middling Spotted Color. ...

Spatiotemporal chaos of self-replicating spots in reaction-diffusion systems.

Science.gov (United States)

Wang, Hongli; Ouyang, Qi

2007-11-23

The statistical properties of self-replicating spots in the reaction-diffusion Gray-Scott model are analyzed. In the chaotic regime of the system, the spots that dominate the spatiotemporal chaos grow and divide in two or decay into the background randomly and continuously. The rates at which the spots are created and decay are observed to be linearly dependent on the number of spots in the system. We derive a probabilistic description of the spot dynamics based on the statistical independence of spots and thus propose a characterization of the spatiotemporal chaos dominated by replicating spots.

High-resolution UV-visible spectroscopy of lunar red spots

Science.gov (United States)

Bruno, B. C.; Lucey, P. G.; Hawke, B. R.

1991-01-01

A spectral reflectance study of selected lunar 'red spots', highland areas characterized by an absorption in the ultraviolet relative to the visible was conducted. Some red spots were suggested to be the sites of ancient highland volcanism. High-resolution spectral data of eight red spots on the western portion of the moon over the wavelength region 0.39-0.82 micron were obtained. Much spectral variation among these red spots in the magnitude as well as the wavelength position of the ultraviolet absorption were found. Spectral structure at visible and near-infrared wavelength were also identified. These spectral differences indicate that red spots do not have a single mineralogical composition, which in turn suggests that red spots may have multiple origins. Additional imaging spectroscopic observations were taken of the Herigonius red spot, a morphologically complex region northeast of Mare Humorum. These data reveal significant spectral differences among the various morphological units within the Herigonius red spot. Although some of these are likely due to the effects of the maturation process, others appear to reflect differences in mineral abundances and composition.

The Next Generation Advanced Video Guidance Sensor: Flight Heritage and Current Development

Science.gov (United States)

Howard, Richard T.; Bryan, Thomas C.

2009-01-01

The Next Generation Advanced Video Guidance Sensor (NGAVGS) is the latest in a line of sensors that have flown four times in the last 10 years. The NGAVGS has been under development for the last two years as a long-range proximity operations and docking sensor for use in an Automated Rendezvous and Docking (AR&D) system. The first autonomous rendezvous and docking in the history of the U.S. Space Program was successfully accomplished by Orbital Express, using the Advanced Video Guidance Sensor (AVGS) as the primary docking sensor. That flight proved that the United States now has a mature and flight proven sensor technology for supporting Crew Exploration Vehicles (CEV) and Commercial Orbital Transport Systems (COTS) Automated Rendezvous and Docking (AR&D). NASA video sensors have worked well in the past: the AVGS used on the Demonstration of Autonomous Rendezvous Technology (DART) mission operated successfully in "spot mode" out to 2 km, and the first generation rendezvous and docking sensor, the Video Guidance Sensor (VGS), was developed and successfully flown on Space Shuttle flights in 1997 and 1998. This paper presents the flight heritage and results of the sensor technology, some hardware trades for the current sensor, and discusses the needs of future vehicles that may rendezvous and dock with the International Space Station (ISS) and other Constellation vehicles. It also discusses approaches for upgrading AVGS to address parts obsolescence, and concepts for minimizing the sensor footprint, weight, and power requirements. In addition, the testing of the various NGAVGS development units will be discussed along with the use of the NGAVGS as a proximity operations and docking sensor.

Tuning temperature and size of hot spots and hot-spot arrays.

Science.gov (United States)

Saïdi, Elika; Babinet, Nicolas; Lalouat, Loïc; Lesueur, Jérôme; Aigouy, Lionel; Volz, Sébastian; Labéguerie-Egéa, Jessica; Mortier, Michel

2011-01-17

By using scanning thermal microscopy, it is shown that nanoscale constrictions in metallic microwires deposited on an oxidized silicon substrate can be tuned in terms of temperature and confinement size. High-resolution temperature maps indeed show that submicrometer hot spots and hot-spot arrays are obtained when the SiO(2) layer thickness decreases below 100 nm. When the SiO(2) thickness becomes larger, heat is less confined in the vicinity of the constrictions and laterally spreads all along the microwire. These results are in good agreement with numerical simulations, which provide dependences between silica-layer thickness and nanodot shape and temperature. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The spot market and the spot price: applicability and limitations

International Nuclear Information System (INIS)

White, G. Jr.

1987-01-01

The subject of spot prices and their relationship to long-term contracting is addressed. The author is associated with Nuexco, which originally was called the Nuclear Exchange Corporation. They use the term Exchange Value which originated in the idea that Nuexco operated an exchange 'bank' - those with too much uranium could 'bank it', those with short-term needs could borrow from the 'bank'. If the borrower repaid slightly more or less the difference was settled using the 'exchange value'. This became used for longer-term transactions and now settling the monthly value is an important part of Nuexco's activities. The exact nature of the Exchange Value is defined. Now more and more buyers are insisting on spot market related pricing even where this is not meaningfully related to uranium production costs. (U.K.)

Edge-TCT for the investigation of radiation damaged silicon strip sensors

Energy Technology Data Exchange (ETDEWEB)

Feindt, Finn

2017-02-15

The edge Transient Current Technique (TCT) is a method for the investigation of silicon sensors. This method requires infrared light from a sub-ns pulsed laser to be focused to a μm-size spot and scanned across the polished cut edge of a sensor. Electron-hole pairs are generated along the light beam in the sensor. These charge carriers drift in the electric field and induce transient currents on the sensor electrodes. The current transients are analyzed as a function of the applied voltage, temperature, absorbed dose and position of the laser-light focus, in order to determine the the drift velocities, electric field and the charge collection in the strip sensor. In the scope of this work, a new edge-TCT setup is commissioned, a procedure for the polishing of the cut edge is implemented and a method to position the focus of the laser light with respect to the sensor is developed. First edge-TCT measurements are performed on non-irradiated, 285 μm thick n-type strip sensors, and the pulse shape and charge collection is studied under different conditions. Furthermore, the prompt current of the transients is extracted, which is the first step towards the determination of the electric field. A new method to measure the attenuation of light in silicon is tested on a non-irradiated sensor and on sensors irradiated with up to a 1 MeV neutron equivalent fluence of 1.14 x 10{sup 15} cm{sup -2}, using laser light with a wavelength of 1052 nm.

Edge-TCT for the investigation of radiation damaged silicon strip sensors

International Nuclear Information System (INIS)

Feindt, Finn

2017-02-01

The edge Transient Current Technique (TCT) is a method for the investigation of silicon sensors. This method requires infrared light from a sub-ns pulsed laser to be focused to a μm-size spot and scanned across the polished cut edge of a sensor. Electron-hole pairs are generated along the light beam in the sensor. These charge carriers drift in the electric field and induce transient currents on the sensor electrodes. The current transients are analyzed as a function of the applied voltage, temperature, absorbed dose and position of the laser-light focus, in order to determine the the drift velocities, electric field and the charge collection in the strip sensor. In the scope of this work, a new edge-TCT setup is commissioned, a procedure for the polishing of the cut edge is implemented and a method to position the focus of the laser light with respect to the sensor is developed. First edge-TCT measurements are performed on non-irradiated, 285 μm thick n-type strip sensors, and the pulse shape and charge collection is studied under different conditions. Furthermore, the prompt current of the transients is extracted, which is the first step towards the determination of the electric field. A new method to measure the attenuation of light in silicon is tested on a non-irradiated sensor and on sensors irradiated with up to a 1 MeV neutron equivalent fluence of 1.14 x 10"1"5 cm"-"2, using laser light with a wavelength of 1052 nm.

Is this Red Spot the Blue Spot (locus ceruleum)?

Energy Technology Data Exchange (ETDEWEB)

Choe, Won Sick; Lee, Yu Kyung; Lee, Min Kyung; Hwang, Kyung Hoon [Gachon University Gil Hospital, Incheon (Korea, Republic of)

2010-06-15

The authors report brain images of 18F-FDG-PET in a case of schizophrenia. The images showed strikingly increased bilateral uptake in the locus ceruleum. The locus ceruleum is called the blue spot and known to be a center of the norepinephrinergic system.

Is this Red Spot the Blue Spot (locus ceruleum)?

International Nuclear Information System (INIS)

Choe, Won Sick; Lee, Yu Kyung; Lee, Min Kyung; Hwang, Kyung Hoon

2010-01-01

The authors report brain images of 18F-FDG-PET in a case of schizophrenia. The images showed strikingly increased bilateral uptake in the locus ceruleum. The locus ceruleum is called the blue spot and known to be a center of the norepinephrinergic system.

Integrative Multi-Spectral Sensor Device for Far-Infrared and Visible Light Fusion

Science.gov (United States)

Qiao, Tiezhu; Chen, Lulu; Pang, Yusong; Yan, Gaowei

2018-06-01

Infrared and visible light image fusion technology is a hot spot in the research of multi-sensor fusion technology in recent years. Existing infrared and visible light fusion technologies need to register before fusion because of using two cameras. However, the application effect of the registration technology has yet to be improved. Hence, a novel integrative multi-spectral sensor device is proposed for infrared and visible light fusion, and by using the beam splitter prism, the coaxial light incident from the same lens is projected to the infrared charge coupled device (CCD) and visible light CCD, respectively. In this paper, the imaging mechanism of the proposed sensor device is studied with the process of the signals acquisition and fusion. The simulation experiment, which involves the entire process of the optic system, signal acquisition, and signal fusion, is constructed based on imaging effect model. Additionally, the quality evaluation index is adopted to analyze the simulation result. The experimental results demonstrate that the proposed sensor device is effective and feasible.

Non-destructive inspection technology using a magnetic transmission sensor; Jiki toka sensor wo mochiita hihakai kensa gijutsu

Energy Technology Data Exchange (ETDEWEB)

Obama, H.

1996-06-01

A newly developed magnetic sensor for non-destructive inspection has acquired the U.S. patent. The starting point of the invention was an inspection of aluminum broth bags in cup-noodle containers with aluminum leaf cover, which was asked from a food maker. A method was developed, in which the microwave is transmitted through containers below their covers and the reflected wave is detected. Then, development of an inspection apparatus for spot welding parts used for automobiles was requested. Since welding is carried out using large current for the spot welding, magnetic characteristics change greatly, which is a remarkable phenomenon appearing especially for magnetic substances. This was found out to be the same phenomenon as the hardening of swords consisting of high temperature heating, pressurizing, and quenching. This substance with two changes can be considered as another material different from the base metal. Coils fitted to impressions were made, and their test pieces were measured. The correlation coefficient over 0.9 was obtained between measured values and results of tensile strength tests. This apparatus can be applied to the non-destructive inspection of internal defects of castings. 2 figs.

Spot Pricing When Lagrange Multipliers Are Not Unique

DEFF Research Database (Denmark)

Feng, Donghan; Xu, Zhao; Zhong, Jin

2012-01-01

Classical spot pricing theory is based on multipliers of the primal problem of an optimal market dispatch, i.e., the solution of the dual problem. However, the dual problem of market dispatch may yield multiple solutions. In these circumstances, spot pricing or any standard pricing practice based...... on a strict extension of the principles of spot pricing and surplus allocation, we propose a new pricing methodology that can yield unique, impartial, and robust solution. The new method has been analyzed and compared with other pricing approaches in accordance with spot pricing theory. Case studies support...

Jumping-droplet electronics hot-spot cooling

Science.gov (United States)

Oh, Junho; Birbarah, Patrick; Foulkes, Thomas; Yin, Sabrina L.; Rentauskas, Michelle; Neely, Jason; Pilawa-Podgurski, Robert C. N.; Miljkovic, Nenad

2017-03-01

Demand for enhanced cooling technologies within various commercial and consumer applications has increased in recent decades due to electronic devices becoming more energy dense. This study demonstrates jumping-droplet based electric-field-enhanced (EFE) condensation as a potential method to achieve active hot spot cooling in electronic devices. To test the viability of EFE condensation, we developed an experimental setup to remove heat via droplet evaporation from single and multiple high power gallium nitride (GaN) transistors acting as local hot spots (4.6 mm × 2.6 mm). An externally powered circuit was developed to direct jumping droplets from a copper oxide (CuO) nanostructured superhydrophobic surface to the transistor hot spots by applying electric fields between the condensing surface and the transistor. Heat transfer measurements were performed in ambient air (22-25 °C air temperature, 20%-45% relative humidity) to determine the effect of gap spacing (2-4 mm), electric field (50-250 V/cm) and applied heat flux (demonstrated to 13 W/cm2). EFE condensation was shown to enhance the heat transfer from the local hot spot by ≈200% compared to cooling without jumping and by 20% compared to non-EFE jumping. Dynamic switching of the electric field for a two-GaN system reveals the potential for active cooling of mobile hot spots. The opportunity for further cooling enhancement by the removal of non-condensable gases promises hot spot heat dissipation rates approaching 120 W/cm2. This work provides a framework for the development of active jumping droplet based vapor chambers and heat pipes capable of spatial and temporal thermal dissipation control.

Jumping-droplet electronics hot-spot cooling

International Nuclear Information System (INIS)

Oh, Junho; Birbarah, Patrick; Foulkes, Thomas; Yin, Sabrina L.; Rentauskas, Michelle

2017-01-01

Demand for enhanced cooling technologies within various commercial and consumer applications has increased in recent decades due to electronic devices becoming more energy dense. This study demonstrates jumping-droplet based electric-field-enhanced (EFE) condensation as a potential method to achieve active hot spot cooling in electronic devices. To test the viability of EFE condensation, we developed an experimental setup to remove heat via droplet evaporation from single and multiple high power gallium nitride (GaN) transistors acting as local hot spots (4.6 mm x 2.6 mm). An externally powered circuit was developed to direct jumping droplets from a copper oxide (CuO) nanostructured superhydrophobic surface to the transistor hot spots by applying electric fields between the condensing surface and the transistor. Heat transfer measurements were performed in ambient air (22-25°C air temperature, 20-45% relative humidity) to determine the effect of gap spacing (2-4 mm), electric field (50-250 V/cm), and heat flux (demonstrated to 13 W/cm"2). EFE condensation was shown to enhance the heat transfer from the local hot spot by ≈ 200% compared to cooling without jumping and by 20% compared to non-EFE jumping. Dynamic switching of the electric field for a two-GaN system reveals the potential for active cooling of mobile hot spots. The opportunity for further cooling enhancement by the removal of non-condensable gases promises hot spot heat dissipation rates approaching 120 W/cm"2. Finally, this work provides a framework for the development of active jumping droplet based vapor chambers and heat pipes capable of spatial and temporal thermal dissipation control.

Intraday price dynamics in spot and derivatives markets

Science.gov (United States)

Kim, Jun Sik; Ryu, Doojin

2014-01-01

This study examines intraday relationships among the spot index, index futures, and the implied volatility index based on the VAR(1)-asymmetric BEKK-MGARCH model. Analysis of a high-frequency dataset from the Korean financial market confirms that there is a strong intraday market linkage between the spot index, KOSPI200 futures, and VKOSPI and that asymmetric volatility behaviour is clearly present in the Korean market. The empirical results indicate that the futures return shock affects the spot market more severely than the spot return shock affects the futures market, though there is a bi-directional causal relationship between the spot and futures markets. Our results, based on a high-quality intraday dataset, satisfy both the positive risk-return relationship and asymmetric volatility effect, which are not reconciled in the frameworks of previous studies.

Modeling deflagration waves out of hot spots

Science.gov (United States)

Partom, Yehuda

2017-01-01

It is widely accepted that shock initiation and detonation of heterogeneous explosives comes about by a two-step process known as ignition and growth. In the first step a shock sweeping through an explosive cell (control volume) creates hot spots that become ignition sites. In the second step, deflagration waves (or burn waves) propagate out of those hot spots and transform the reactant in the cell into reaction products. The macroscopic (or average) reaction rate of the reactant in the cell depends on the speed of those deflagration waves and on the average distance between neighboring hot spots. Here we simulate the propagation of deflagration waves out of hot spots on the mesoscale in axial symmetry using a 2D hydrocode, to which we add heat conduction and bulk reaction. The propagation speed of the deflagration waves may depend on both pressure and temperature. It depends on pressure for quasistatic loading near ambient temperature, and on temperature at high temperatures resulting from shock loading. From the simulation we obtain deflagration fronts emanating out of the hot spots. For 8 to 13 GPa shocks, the emanating fronts propagate as deflagration waves to consume the explosive between hot spots. For higher shock levels deflagration waves may interact with the sweeping shock to become detonation waves on the mesoscale. From the simulation results we extract average deflagration wave speeds.

Model for calculation of spot prices and uncertainties integration; Modelo de calculo de precos spot e integracao de incertezas

Energy Technology Data Exchange (ETDEWEB)

Saraiva, J. Tome [Instituto de Engenharia de Sistemas e Computadores (INESC), Porto (Portugal). E-mail: jsaraiva@inescn.pt

1999-07-01

This paper presents a model for systematic and structured impact evaluation of the uncertainties existent in the load powers, on the spot prices on the various bars of a electric power system. The application developed allows the specification of load power as inaccurate trapezoidal numbers and adopts the DC model for the representation of system exploration conditions. Considering the influence of the loss power on the formulation of a spot prices spatial distribution, the model allows the inclusion of transmission network loss estimation. The results correspond to appurtenance functions of spot prices in each barm, consisting of a discrete set of ordered pais which integrates the spot price values and the appurtenance or compatibility level, in accordance with Fuzzy Sets.

Mononucleosis spot test

Science.gov (United States)

Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...

SPOTTED STAR LIGHT CURVES WITH ENHANCED PRECISION

International Nuclear Information System (INIS)

Wilson, R. E.

2012-01-01

The nearly continuous timewise coverage of recent photometric surveys is free of the large gaps that compromise attempts to follow starspot growth and decay as well as motions, thereby giving incentive to improve computational precision for modeled spots. Due to the wide variety of star systems in the surveys, such improvement should apply to light/velocity curve models that accurately include all the main phenomena of close binaries and rotating single stars. The vector fractional area (VFA) algorithm that is introduced here represents surface elements by small sets of position vectors so as to allow accurate computation of circle-triangle overlap by spherical geometry. When computed by VFA, spots introduce essentially no noticeable scatter in light curves at the level of one part in 10,000. VFA has been put into the Wilson-Devinney light/velocity curve program and all logic and mathematics are given so as to facilitate entry into other such programs. Advantages of precise spot computation include improved statistics of spot motions and aging, reduced computation time (intrinsic precision relaxes needs for grid fineness), noise-free illustration of spot effects in figures, and help in guarding against false positives in exoplanet searches, where spots could approximately mimic transiting planets in unusual circumstances. A simple spot growth and decay template quantifies time profiles, and specifics of its utilization in differential corrections solutions are given. Computational strategies are discussed, the overall process is tested in simulations via solutions of synthetic light curve data, and essential simulation results are described. An efficient time smearing facility by Gaussian quadrature can deal with Kepler mission data that are in 30 minute time bins.

X-ray spot film device

International Nuclear Information System (INIS)

1981-01-01

Improvements are described in an X-ray spot film device which is used in conjunction with an X-ray table to make a selected number of radiographic exposures on a single film and to perform fluoroscopic examinations. To date, the spot film devices consist of two X-ray field defining masks, one of which is moved manually. The present device is more convenient to use and speeds up the procedure. (U.K.)

Hot spot manifestation in eclipsing dwarf nova HT Cassiopeiae

OpenAIRE

Bakowska, K.; Olech, A.

2014-01-01

We report the detection of the hot spot in light curves of the eclipsing dwarf nova HT Cassiopeiae during its superoutburst in 2010 November. Analysis of eight reconstructed light curves of the hot spot eclipses showed directly that the brightness of the hot spot was changing significantly during the superoutburst. Thereby, detected hot spot manifestation in HT Cas is the newest observational evidence for the EMT model for dwarf novae.

Integrating sustainable hunting in biodiversity protection in Central Africa: hot spots, weak spots, and strong spots.

Directory of Open Access Journals (Sweden)

John E Fa

Full Text Available Wild animals are a primary source of protein (bushmeat for people living in or near tropical forests. Ideally, the effect of bushmeat harvests should be monitored closely by making regular estimates of offtake rate and size of stock available for exploitation. However, in practice, this is possible in very few situations because it requires both of these aspects to be readily measurable, and even in the best case, entails very considerable time and effort. As alternative, in this study, we use high-resolution, environmental favorability models for terrestrial mammals (N = 165 in Central Africa to map areas of high species richness (hot spots and hunting susceptibility. Favorability models distinguish localities with environmental conditions that favor the species' existence from those with detrimental characteristics for its presence. We develop an index for assessing Potential Hunting Sustainability (PHS of each species based on their ecological characteristics (population density, habitat breadth, rarity and vulnerability, weighted according to restrictive and permissive assumptions of how species' characteristics are combined. Species are classified into five main hunting sustainability classes using fuzzy logic. Using the accumulated favorability values of all species, and their PHS values, we finally identify weak spots, defined as high diversity regions of especial hunting vulnerability for wildlife, as well as strong spots, defined as high diversity areas of high hunting sustainability potential. Our study uses relatively simple models that employ easily obtainable data of a species' ecological characteristics to assess the impacts of hunting in tropical regions. It provides information for management by charting the geography of where species are more or less likely to be at risk of extinction from hunting.

7 CFR 27.94 - Spot markets for contract settlement purposes.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Spot markets for contract settlement purposes. 27.94... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Spot Markets § 27.94 Spot markets for contract settlement purposes. The following are designated as spot markets for...

The rise and fall of a human recombination hot spot.

Science.gov (United States)

Jeffreys, Alec J; Neumann, Rita

2009-05-01

Human meiotic crossovers mainly cluster into narrow hot spots that profoundly influence patterns of haplotype diversity and that may also affect genome instability and sequence evolution. Hot spots also seem to be ephemeral, but processes of hot-spot activation and their subsequent evolutionary dynamics remain unknown. We now analyze the life cycle of a recombination hot spot. Sperm typing revealed a polymorphic hot spot that was activated in cis by a single base change, providing evidence for a primary sequence determinant necessary, though not sufficient, to activate recombination. This activating mutation occurred roughly 70,000 y ago and has persisted to the present, most likely fortuitously through genetic drift despite its systematic elimination by biased gene conversion. Nonetheless, this self-destructive conversion will eventually lead to hot-spot extinction. These findings define a subclass of highly transient hot spots and highlight the importance of understanding hot-spot turnover and how it influences haplotype diversity.

Multi-sensor fusion with interacting multiple model filter for improved aircraft position accuracy.

Science.gov (United States)

Cho, Taehwan; Lee, Changho; Choi, Sangbang

2013-03-27

The International Civil Aviation Organization (ICAO) has decided to adopt Communications, Navigation, and Surveillance/Air Traffic Management (CNS/ATM) as the 21st century standard for navigation. Accordingly, ICAO members have provided an impetus to develop related technology and build sufficient infrastructure. For aviation surveillance with CNS/ATM, Ground-Based Augmentation System (GBAS), Automatic Dependent Surveillance-Broadcast (ADS-B), multilateration (MLAT) and wide-area multilateration (WAM) systems are being established. These sensors can track aircraft positions more accurately than existing radar and can compensate for the blind spots in aircraft surveillance. In this paper, we applied a novel sensor fusion method with Interacting Multiple Model (IMM) filter to GBAS, ADS-B, MLAT, and WAM data in order to improve the reliability of the aircraft position. Results of performance analysis show that the position accuracy is improved by the proposed sensor fusion method with the IMM filter.

Motion Interplay as a Function of Patient Parameters and Spot Size in Spot Scanning Proton Therapy for Lung Cancer

Science.gov (United States)

Grassberger, Clemens; Dowdell, Stephen; Lomax, Antony; Sharp, Greg; Shackleford, James; Choi, Noah; Willers, Henning; Paganetti, Harald

2013-01-01

Purpose Quantify the impact of respiratory motion on the treatment of lung tumors with spot scanning proton therapy. Methods and Materials 4D Monte Carlo simulations were used to assess the interplay effect, which results from relative motion of the tumor and the proton beam, on the dose distribution in the patient. Ten patients with varying tumor sizes (2.6-82.3cc) and motion amplitudes (3-30mm) were included in the study. We investigated the impact of the spot size, which varies between proton facilities, and studied single fractions and conventionally fractionated treatments. The following metrics were used in the analysis: minimum/maximum/mean dose, target dose homogeneity and 2-year local control rate (2y-LC). Results Respiratory motion reduces the target dose homogeneity, with the largest effects observed for the highest motion amplitudes. Smaller spot sizes (σ≈3mm) are inherently more sensitive to motion, decreasing target dose homogeneity on average by a factor ~2.8 compared to a larger spot size (σ≈13mm). Using a smaller spot size to treat a tumor with 30mm motion amplitude reduces the minimum dose to 44.7% of the prescribed dose, decreasing modeled 2y-LC from 87.0% to 2.7%, assuming a single fraction. Conventional fractionation partly mitigates this reduction, yielding a 2y-LC of 71.6%. For the large spot size, conventional fractionation increases target dose homogeneity and prevents a deterioration of 2y-LC for all patients. No correlation with tumor volume is observed. The effect on the normal lung dose distribution is minimal: observed changes in mean lung dose and lung V20 are interplay using a large spot size and conventional fractionation. For treatments employing smaller spot sizes and/or in the delivery of single fractions, interplay effects can lead to significant deterioration of the dose distribution and lower 2y-LC. PMID:23462423

Motion Interplay as a Function of Patient Parameters and Spot Size in Spot Scanning Proton Therapy for Lung Cancer

International Nuclear Information System (INIS)

Grassberger, Clemens; Dowdell, Stephen; Lomax, Antony; Sharp, Greg; Shackleford, James; Choi, Noah; Willers, Henning; Paganetti, Harald

2013-01-01

Purpose: To quantify the impact of respiratory motion on the treatment of lung tumors with spot scanning proton therapy. Methods and Materials: Four-dimensional Monte Carlo simulations were used to assess the interplay effect, which results from relative motion of the tumor and the proton beam, on the dose distribution in the patient. Ten patients with varying tumor sizes (2.6-82.3 cc) and motion amplitudes (3-30 mm) were included in the study. We investigated the impact of the spot size, which varies between proton facilities, and studied single fractions and conventionally fractionated treatments. The following metrics were used in the analysis: minimum/maximum/mean dose, target dose homogeneity, and 2-year local control rate (2y-LC). Results: Respiratory motion reduces the target dose homogeneity, with the largest effects observed for the highest motion amplitudes. Smaller spot sizes (σ ≈ 3 mm) are inherently more sensitive to motion, decreasing target dose homogeneity on average by a factor 2.8 compared with a larger spot size (σ ≈ 13 mm). Using a smaller spot size to treat a tumor with 30-mm motion amplitude reduces the minimum dose to 44.7% of the prescribed dose, decreasing modeled 2y-LC from 87.0% to 2.7%, assuming a single fraction. Conventional fractionation partly mitigates this reduction, yielding a 2y-LC of 71.6%. For the large spot size, conventional fractionation increases target dose homogeneity and prevents a deterioration of 2y-LC for all patients. No correlation with tumor volume is observed. The effect on the normal lung dose distribution is minimal: observed changes in mean lung dose and lung V 20 are <0.6 Gy(RBE) and <1.7%, respectively. Conclusions: For the patients in this study, 2y-LC could be preserved in the presence of interplay using a large spot size and conventional fractionation. For treatments using smaller spot sizes and/or in the delivery of single fractions, interplay effects can lead to significant deterioration of the

Complete mitochondrial genome of the red-spotted tokay gecko (Gekko gecko, Reptilia: Gekkonidae): comparison of red- and black-spotted tokay geckos.

Science.gov (United States)

Qin, Xin-Min; Qian, Fang; Zeng, De-Long; Liu, Xiao-Can; Li, Hui-Min

2011-10-01

Here, we sequenced the complete mitochondrial genome of the red-spotted tokay gecko (Squamata: Gekkonidae). The genome is 16,590 bp in size. Its gene arrangement pattern was identical with that of black-spotted tokay gecko. We compared the mitochondrial genome of red-spotted tokay gecko with that of the black-spotted tokay gecko. Nucleotide sequence of the two whole mitochondrial genomes was 97.99% similar, and the relatively high similarity seems to indicate that they may be separated at the subspecies level. The information of mitochondrial genome comparison of the two morphological types of tokay gecko is discussed in detail.

Rocky Mountain spotted fever in children.

Science.gov (United States)

Woods, Charles R

2013-04-01

Rocky Mountain spotted fever is typically undifferentiated from many other infections in the first few days of illness. Treatment should not be delayed pending confirmation of infection when Rocky Mountain spotted fever is suspected. Doxycycline is the drug of choice even for infants and children less than 8 years old. Copyright © 2013 Elsevier Inc. All rights reserved.

Spot på samtalen:

DEFF Research Database (Denmark)

Danneris, Sophie; Jensen, Tanja Dall; Caswell, Dorte

Spot på samtalen sætter fokus på det, der konkret foregår i samtaler mellem borgere og de beskæftigelsesfaglige medarbejdere i jobcentrene. Da de udsatte grupper i mange tilfælde er langt fra arbejdsmarkedet, er interessen rettet mod, hvilke forhold i kontakten med beskæftigelsessystemet, der...... har betydning hvilke indsatser ledige modtager, men også hvordan de modtager dem. Her rettes blikket mod den centrale del af den beskæftigelsespolitiske indsats som samtalerne udgør. I Spot på samtalen er blikket rettet mod de dynamikker, mønstre og mekanismer, der kommer i spil i samtalerne i...

Rocky Mountain Spotted Fever: Statistics and Epidemiology

Science.gov (United States)

... Search Form Controls Cancel Submit Search the CDC Rocky Mountain Spotted Fever (RMSF) Note: Javascript is disabled or is not ... message, please visit this page: About CDC.gov . Rocky Mountain Spotted Fever (RMSF) Transmission Signs and Symptoms Diagnosis and Testing ...

Motion-Dependent Filling-In of Spatiotemporal Information at the Blind Spot.

Science.gov (United States)

Maus, Gerrit W; Whitney, David

2016-01-01

We usually do not notice the blind spot, a receptor-free region on the retina. Stimuli extending through the blind spot appear filled in. However, if an object does not reach through but ends in the blind spot, it is perceived as "cut off" at the boundary. Here we show that even when there is no corresponding stimulation at opposing edges of the blind spot, well known motion-induced position shifts also extend into the blind spot and elicit a dynamic filling-in process that allows spatial structure to be extrapolated into the blind spot. We presented observers with sinusoidal gratings that drifted into or out of the blind spot, or flickered in counterphase. Gratings moving into the blind spot were perceived to be longer than those moving out of the blind spot or flickering, revealing motion-dependent filling-in. Further, observers could perceive more of a grating's spatial structure inside the blind spot than would be predicted from simple filling-in of luminance information from the blind spot edge. This is evidence for a dynamic filling-in process that uses spatiotemporal information from the motion system to extrapolate visual percepts into the scotoma of the blind spot. Our findings also provide further support for the notion that an explicit spatial shift of topographic representations contributes to motion-induced position illusions.

Wave Front Sensor for Solar Concentrator Control

Science.gov (United States)

2009-10-01

terrestrial-based and space-based. Both types of concentrator can be either imaging or nonimaging and they can be rigid or inflatable. Other...and T is the temperature of the absorber and propellant. In (5), Iin is input intensity with effects of the optical path through the concentrator acting...Hartmann in 1900 and was used for checking optical telescopes for aberrations. It was an array of holes in a plate placed in front of the mirror of

7 CFR 27.96 - Quotations in bona fide spot markets.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Quotations in bona fide spot markets. 27.96 Section 27... Differences § 27.96 Quotations in bona fide spot markets. The price or value and differences between the price... determined by the sale of spot cotton in such spot market. Quotations shall be determined and maintained in...

OPERA, an automatic PSF reconstruction software for Shack-Hartmann AO systems: application to Altair

Science.gov (United States)

Jolissaint, Laurent; Veran, Jean-Pierre; Marino, Jose

2004-10-01

When doing high angular resolution imaging with adaptive optics (AO), it is of crucial importance to have an accurate knowledge of the point spread function associated with each observation. Applications are numerous: image contrast enhancement by deconvolution, improved photometry and astrometry, as well as real time AO performance evaluation. In this paper, we present our work on automatic PSF reconstruction based on control loop data, acquired simultaneously with the observation. This problem has already been solved for curvature AO systems. To adapt this method to another type of WFS, a specific analytical noise propagation model must be established. For the Shack-Hartmann WFS, we are able to derive a very accurate estimate of the noise on each slope measurement, based on the covariances of the WFS CCD pixel values in the corresponding sub-aperture. These covariances can be either derived off-line from telemetry data, or calculated by the AO computer during the acquisition. We present improved methods to determine 1) r0 from the DM drive commands, which includes an estimation of the outer scale L0 2) the contribution of the high spatial frequency component of the turbulent phase, which is not corrected by the AO system and is scaled by r0. This new method has been implemented in an IDL-based software called OPERA (Performance of Adaptive Optics). We have tested OPERA on Altair, the recently commissioned Gemini-North AO system, and present our preliminary results. We also summarize the AO data required to run OPERA on any other AO system.

X-ray metrology of an array of active edge pixel sensors for use at synchrotron light sources

Science.gov (United States)

Plackett, R.; Arndt, K.; Bortoletto, D.; Horswell, I.; Lockwood, G.; Shipsey, I.; Tartoni, N.; Williams, S.

2018-01-01

We report on the production and testing of an array of active edge silicon sensors as a prototype of a large array. Four Medipix3RX.1 chips were bump bonded to four single chip sized Advacam active edge n-on-n sensors. These detectors were then mounted into a 2 by 2 array and tested on B16 at Diamond Light Source with an x-ray beam spot of 2um. The results from these tests, compared with optical metrology demonstrate that this type of sensor is sensitive to the physical edge of the silicon, with only a modest loss of efficiency in the final two rows of pixels. We present the efficiency maps recorded with the microfocus beam and a sample powder diffraction measurement. These results give confidence that this sensor technology can be used effectively in larger arrays of detectors at synchrotron light sources.

Plasma spot welding of ferritic stainless steels

International Nuclear Information System (INIS)

Lesnjak, A.; Tusek, J.

2002-01-01

Plasma spot wedding of ferritic stainless steels studied. The study was focused on welding parameters, plasma and shieldings and the optimum welding equipment. Plasma-spot welded overlap joints on a 0.8 mm thick ferritic stainless steel sheet were subjected to a visual examination and mechanical testing in terms of tension-shear strength. Several macro specimens were prepared Plasma spot welding is suitable to use the same gas as shielding gas and as plasma gas , i. e. a 98% Ar/2% H 2 gas mixture. Tension-shear strength of plasma-spot welded joint was compared to that of resistance sport welded joints. It was found that the resistance welded joints withstand a somewhat stronger load than the plasma welded joints due to a large weld sport diameter of the former. Strength of both types of welded joints is approximately the same. (Author) 32 refs

7 CFR 28.426 - Strict Good Ordinary Spotted Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Strict Good Ordinary Spotted Color. 28.426 Section 28.426 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Spotted Color. Strict Good Ordinary Spotted Color is color which is within the range represented by a set...

7 CFR 28.424 - Strict Low Middling Spotted Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Strict Low Middling Spotted Color. 28.424 Section 28.424 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Spotted Color. Strict Low Middling Spotted Color is color which is within the range represented by a set...

Effects of spot parameters in pencil beam scanning treatment planning.

Science.gov (United States)

Kraan, Aafke Christine; Depauw, Nicolas; Clasie, Ben; Giunta, Marina; Madden, Tom; Kooy, Hanne M

2018-01-01

Spot size σ (in air at isocenter), interspot spacing d, and spot charge q influence dose delivery efficiency and plan quality in Intensity Modulated Proton Therapy (IMPT) treatment planning. The choice and range of parameters varies among different manufacturers. The goal of this work is to demonstrate the influence of the spot parameters on dose quality and delivery in IMPT treatment plans, to show their interdependence, and to make practitioners aware of the spot parameter values for a certain facility. Our study could help as a guideline to make the trade-off between treatment quality and time in existing PBS centers and in future systems. We created plans for seven patients and a phantom, with different tumor sites and volumes, and compared the effect of small-, medium-, and large-spot widths (σ = 2.5, 5, and 10 mm) and interspot distances (1σ, 1.5σ, and 1.75σ) on dose, spot charge, and treatment time. Moreover, we quantified how postplanning charge threshold cuts affect plan quality and the total number of spots to deliver, for different spot widths and interspot distances. We show the effect of a minimum charge (or MU) cutoff value for a given proton delivery system. Spot size had a strong influence on dose: larger spots resulted in more protons delivered outside the target region. We observed dose differences of 2-13 Gy (RBE) between 2.5 mm and 10 mm spots, where the amount of extra dose was due to dose penumbra around the target region. Interspot distance had little influence on dose quality for our patient group. Both parameters strongly influence spot charge in the plans and thus the possible impact of postplanning charge threshold cuts. If such charge thresholds are not included in the treatment planning system (TPS), it is important that the practitioner validates that a given combination of lower charge threshold, interspot spacing, and spot size does not result in a plan degradation. Low average spot charge occurs for small spots, small interspot

TSH IRMA of dried blood spots

International Nuclear Information System (INIS)

Tojinda, N.; Pattanachak, C.; Chongchirasiri, S.; Pattanachak, S.; Putrasreni, N.; Pleehachinda, R.; Suwanik, R.

1990-01-01

TSH determination is most useful for screening of neonatal hypothyroid in the population in iodine deficient areas. The NETRIA IRMA method for serum TSH was applied for blood-spot TSH. Cord blood on SS No. 903 filter paper was left dry overnight. The spot of 6 mm diameter, one/tube, was mixed with an assay buffer, diluted labelled m-anti-TSH, and diluted anti-TSH-solid phase. The mixture was rotated for 22-24 hours. After washing twice with wash buffer, it was counted for 1 minute. The standard curve with 0, 5, 10, 25, 50, 100, and 150 mIU/L whole blood was obtained with the maximum binding of 25%. The precision profile was satisfactory with %CV of 0 C) or 4 0 C or -20 0 C. The correlation between serum and blood-spot TSH values (n=120) showed r of 0.9541 and y=1.6123 (BS-TSH) +1.382. The mean of normal cord blood spot TSH (n=142) was 5.27 mIU/L. The technique was found to be precise, sensitive and easy to perform. Mass screening with this developed method is underway

A novel word spotting method based on recurrent neural networks.

Science.gov (United States)

Frinken, Volkmar; Fischer, Andreas; Manmatha, R; Bunke, Horst

2012-02-01

Keyword spotting refers to the process of retrieving all instances of a given keyword from a document. In the present paper, a novel keyword spotting method for handwritten documents is described. It is derived from a neural network-based system for unconstrained handwriting recognition. As such it performs template-free spotting, i.e., it is not necessary for a keyword to appear in the training set. The keyword spotting is done using a modification of the CTC Token Passing algorithm in conjunction with a recurrent neural network. We demonstrate that the proposed systems outperform not only a classical dynamic time warping-based approach but also a modern keyword spotting system, based on hidden Markov models. Furthermore, we analyze the performance of the underlying neural networks when using them in a recognition task followed by keyword spotting on the produced transcription. We point out the advantages of keyword spotting when compared to classic text line recognition.

An Energy Efficient Stable Election-Based Routing Algorithm for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Weiwei Yuan

2013-10-01

Full Text Available Sensor nodes usually have limited energy supply and they are impractical to recharge. How to balance traffic load in sensors in order to increase network lifetime is a very challenging research issue. Many clustering algorithms have been proposed recently for wireless sensor networks (WSNs. However, sensor networks with one fixed sink node often suffer from a hot spots problem since nodes near sinks have more traffic burden to forward during a multi-hop transmission process. The use of mobile sinks has been shown to be an effective technique to enhance network performance features such as latency, energy efficiency, network lifetime, etc. In this paper, a modified Stable Election Protocol (SEP, which employs a mobile sink, has been proposed for WSNs with non-uniform node distribution. The decision of selecting cluster heads by the sink is based on the minimization of the associated additional energy and residual energy at each node. Besides, the cluster head selects the shortest path to reach the sink between the direct approach and the indirect approach with the use of the nearest cluster head. Simulation results demonstrate that our algorithm has better performance than traditional routing algorithms, such as LEACH and SEP.

Normalization of NDVI from Different Sensor System using MODIS Products as Reference

International Nuclear Information System (INIS)

Wenxia, Gan; Liangpei, Zhang; Wei, Gong; Huanfeng, Shen

2014-01-01

Medium Resolution NDVI(Normalized Difference Vegetation Index) from different sensor systems such as Landsat, SPOT, ASTER, CBERS and HJ-1A/1B satellites provide detailed spatial information for studies of ecosystems, vegetation biophysics, and land cover. Limitation of sensor designs, cloud contamination, and sensor failure highlighted the need to normalize and integrate NDVI from multiple sensor system in order to create a consistent, long-term NDVI data set. In this paper, we used a reference-based method for NDVI normalization. And present an application of this approach which covert Landsat ETM+ NDVI calculated by digital number (NDVI DN ) to NDVI calculated by surface reflectance (NDVI SR ) using MODIS products as reference, and different cluster was treated differently. Result shows that this approach can produce NDVI with highly agreement to NDVI calculated by surface reflectance from physical approaches based on 6S (Second Simulation of the satellite Signal in the Solar Spectrum). Although some variability exists, the cluster specified reference based approach shows considerable potential for NDVI normalization. Therefore, NDVI products in MODIS era from different sources can be combined for time-series analysis, biophysical parameter retrievals, and other downstream analysis

Characterization of silicon micro-strip sensors with a pulsed infra-red laser system for the CBM experiment at FAIR

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Pradeep [Goethe University, Frankfurt am Main (Germany); GSI Helmholtz Center for Heavy Ion Research GmbH, Darmstadt (Germany); Eschke, Juergen [GSI Helmholtz Center for Heavy Ion Research GmbH, Darmstadt (Germany); Facility for Anti-proton and Ion Research, GmbH, Darmstadt (Germany); Collaboration: CBM-Collaboration

2015-07-01

The Silicon Tracking System (STS) of the CBM experiment at FAIR is composed of 8 tracking stations comprising of 1292 double-sided silicon micro-strip sensors. A Laser Test System (LTS) has been developed for the quality assurance of prototype sensors. The aim is to scan sensors with a pulsed infra-red laser driven by step motor to determine the charge sharing in-between strips and to measure qualitative uniformity of the sensor response over the whole active area. Several prototype sensors with strip pitch of 50 and 58 μm have been tested, as well as a prototype module with realistic mechanical arrangement of sensor and read-out cables. The LTS is designed to measure sensor response in an automatized procedure across the sensor with focused laser beam (spot-size ∼ 12 μm, wavelength = 1060 nm). The pulse with duration (∼ 10 ns) and power (∼ 5 mW) of the laser pulses is selected such, that the absorption of the laser light in the 300 μm thick silicon sensors produces a number of about 24000 electrons, which is similar to the charge created by minimum ionizing particles (MIP) in these sensors. Results from laser scans of prototype sensors and detector module are reported.

Particle-wave discrimination in Poisson spot experiments

International Nuclear Information System (INIS)

Reisinger, T; Bracco, G; Holst, B

2011-01-01

Matter-wave interferometry has been used extensively over the last few years to demonstrate the quantum-mechanical wave nature of increasingly larger and more massive particles. We have recently suggested the use of the historical Poisson spot setup to test the diffraction properties of larger objects. In this paper, we present the results of a classical particle van der Waals (vdW) force model for a Poisson spot experimental setup and compare these to Fresnel diffraction calculations with a vdW phase term. We include the effect of disc-edge roughness in both models. Calculations are performed with D 2 and with C 70 using realistic parameters. We find that the sensitivity of the on-axis interference/focus spot to disc-edge roughness is very different in the two cases. We conclude that by measuring the intensity on the optical axis as a function of disc-edge roughness, it can be determined whether the objects behave as de Broglie waves or classical particles. The scaling of the Poisson spot experiment to larger molecular masses is, however, not as favorable as in the case of near-field light-grating-based interferometers. Instead, we discuss the possibility of studying the Casimir-Polder potential using the Poisson spot setup.

Molecular and histological characterization of age spots

Science.gov (United States)

Choi, Wonseon; Yin, Lanlan; Smuda, Christoph; Batzer, Jan; Hearing, Vincent J.; Kolbe, Ludger

2016-01-01

Age spots, also called solar lentigines and lentigo senilis, are light brown to black pigmented lesions of various sizes that typically develop in chronically sun-exposed skin. It is well known that age spots are strongly related to chronic sun exposure and are associated with photodamage and an increased risk for skin cancer, however, the mechanism(s) underlying their development remain poorly understood. We used immunohistochemical analysis and microarray analysis to investigate the processes involved in their formation, focusing on specific markers associated with the functions and proliferation of melanocytes and keratinocytes. A total of 193 genes were differentially expressed in age spots but melanocyte pigment genes were not among them. The increased expression of keratins 5 and 10, markers of basal and suprabasal keratinocytes, respectively, in age spots suggests that the increased proliferation of basal keratinocytes combined with the decreased turnover of suprabasal keratinocytes leads to the exaggerated formation of rete ridges in lesional epidermis which in turn disrupts the normal processing of melanin upwards from the basal layer. Based on our results, we propose a model for the development of age spots that explains the accumulation of melanin and the development of extensive rete ridges in those hyperpigmented lesions. PMID:27621222

Plutonium spot of mixed oxide fuel, 2

International Nuclear Information System (INIS)

Suzuki, Yukio; Maruishi, Yoshihiro; Satoh, Masaichi; Aoki, Toshimasa; Muto, Tadashi

1974-01-01

In a fast reactor, the specification for the homogeneity of plutonium in plutonium-uranium mixed-oxide fuel is mainly dependent on the nuclear characteristics, whereas in a thermal reactor, on thermal characteristics. This homogeneity is measured by autoradiography as the plutonium spot size of the specimens which are arbitrarily chosen fuel pellets from a lot. Although this is a kind of random sampling, it is difficult to apply this method to conventional digital standards including JIS standards. So a special sampling inspection method was studied. First, it is assumed that the shape of plutonium spots is spherical, the size distribution is logarithmic normal, and the standard deviation is constant. Then, if standard deviation and mean spot size are given, the logarithmic normal distribution is decided unitarily, and further if the total weight of plutonium spots for a lot of pellets is known, the number of the spots (No) which does not conform to the specification can be obtained. Then, the fraction defective is defined as No devided by the number of pellets per lot. As to the lot with such fraction defective, the acceptance coefficient of the lot was obtained through calculation, in which the number of sampling, acceptable diameter limit observed and acceptable conditions were used as parameters. (Tai, I.)

Cellular localization of the Escherichia coli SpoT protein.

OpenAIRE

Gentry, D R; Cashel, M

1995-01-01

The SpoT protein of Escherichia coli serves as a source of degradation as well as an apparent source of synthesis of (p)ppGpp. Since the subcellular localization of SpoT might be a clue to its function, we have used SpoT-specific antisera to analyze cell extracts fractionated on sucrose gradients. We find that the SpoT protein is not bound to ribosomes or to either inner or outer membrane fractions. Although the SpoT protein is found in large aggregates, its localization is probably cytosolic.

Wireless Sensor Network Deployment for Monitoring Wildlife Passages

Science.gov (United States)

Garcia-Sanchez, Antonio-Javier; Garcia-Sanchez, Felipe; Losilla, Fernando; Kulakowski, Pawel; Garcia-Haro, Joan; Rodríguez, Alejandro; López-Bao, José-Vicente; Palomares, Francisco

2010-01-01

Wireless Sensor Networks (WSNs) are being deployed in very diverse application scenarios, including rural and forest environments. In these particular contexts, specimen protection and conservation is a challenge, especially in natural reserves, dangerous locations or hot spots of these reserves (i.e., roads, railways, and other civil infrastructures). This paper proposes and studies a WSN based system for generic target (animal) tracking in the surrounding area of wildlife passages built to establish safe ways for animals to cross transportation infrastructures. In addition, it allows target identification through the use of video sensors connected to strategically deployed nodes. This deployment is designed on the basis of the IEEE 802.15.4 standard, but it increases the lifetime of the nodes through an appropriate scheduling. The system has been evaluated for the particular scenario of wildlife monitoring in passages across roads. For this purpose, different schemes have been simulated in order to find the most appropriate network operational parameters. Moreover, a novel prototype, provided with motion detector sensors, has also been developed and its design feasibility demonstrated. Original software modules providing new functionalities have been implemented and included in this prototype. Finally, main performance evaluation results of the whole system are presented and discussed in depth. PMID:22163601

Wireless Sensor Network Deployment for Monitoring Wildlife Passages

Directory of Open Access Journals (Sweden)

José-Vicente López-Bao

2010-08-01

Full Text Available Wireless Sensor Networks (WSNs are being deployed in very diverse application scenarios, including rural and forest environments. In these particular contexts, specimen protection and conservation is a challenge, especially in natural reserves, dangerous locations or hot spots of these reserves (i.e., roads, railways, and other civil infrastructures. This paper proposes and studies a WSN based system for generic target (animal tracking in the surrounding area of wildlife passages built to establish safe ways for animals to cross transportation infrastructures. In addition, it allows target identification through the use of video sensors connected to strategically deployed nodes. This deployment is designed on the basis of the IEEE 802.15.4 standard, but it increases the lifetime of the nodes through an appropriate scheduling. The system has been evaluated for the particular scenario of wildlife monitoring in passages across roads. For this purpose, different schemes have been simulated in order to find the most appropriate network operational parameters. Moreover, a novel prototype, provided with motion detector sensors, has also been developed and its design feasibility demonstrated. Original software modules providing new functionalities have been implemented and included in this prototype. Finally, main performance evaluation results of the whole system are presented and discussed in depth.

New 40Ar/39Ar age progression for the Louisville hot spot trail and implications for inter-hot spot motion

Science.gov (United States)

Koppers, Anthony A. P.; Gowen, Molly D.; Colwell, Lauren E.; Gee, Jeffrey S.; Lonsdale, Peter F.; Mahoney, John J.; Duncan, Robert A.

2011-12-01

In this study we present 42 new 40Ar/39Ar incremental heating age determinations that contribute to an updated age progression for the Louisville seamount trail. Louisville is the South Pacific counterpart to the Hawaiian-Emperor seamount trail, both trails representing intraplate volcanism over the same time interval (˜80 Ma to present) and being examples of primary hot spot lineaments. Our data provide evidence for an age-progressive trend from 71 to 21 Ma. Assuming fixed hot spots, this makes possible a direct comparison to the Hawaiian-Emperor age progression and the most recent absolute plate motion (APM) model (WK08G) of Wessel and Kroenke (2008). We observe that for the Louisville seamount trail the measured ages are systematically older relative to both the WK08G model predictions and Hawaiian seamount ages, with offsets ranging up to 6 Myr. Taking into account the uncertainty about the duration of eruption and magmatic succession at individual Louisville volcanoes, these age offsets should be considered minimum estimates, as our sampling probably tended to recover the youngest lava flows. These large deviations point to either a contribution of inter-hot spot motion between the Louisville and Hawaiian hot spots or to a more easterly location of the Louisville hot spot than the one inferred in the WK08G model. Both scenarios are investigated in this paper, whereby the more eastern hot spot location (52.0°S, 134.5°W versus 52.4°S, 137.2°W) reduces the average age offset, but still results in a relatively large maximum offset of 3.7 Myr. When comparing the new ages to the APM models (S04P, S04G) by Steinberger et al. (2004) that attempt to compensate for the motion of hot spots in the Pacific (Hawaii) or globally (Hawaii, Louisville, Reunion and Walvis), the measured and predicted ages are more in agreement, showing only a maximum offset of 2.3 Myr with respect to the S04G model. At face value these more advanced APM models, which consider both plate and

Wave front sensing for next generation earth observation telescope

Science.gov (United States)

Delvit, J.-M.; Thiebaut, C.; Latry, C.; Blanchet, G.

2017-09-01

High resolution observations systems are highly dependent on optics quality and are usually designed to be nearly diffraction limited. Such a performance allows to set a Nyquist frequency closer to the cut off frequency, or equivalently to minimize the pupil diameter for a given ground sampling distance target. Up to now, defocus is the only aberration that is allowed to evolve slowly and that may be inflight corrected, using an open loop correction based upon ground estimation and refocusing command upload. For instance, Pleiades satellites defocus is assessed from star acquisitions and refocusing is done with a thermal actuation of the M2 mirror. Next generation systems under study at CNES should include active optics in order to allow evolving aberrations not only limited to defocus, due for instance to in orbit thermal variable conditions. Active optics relies on aberration estimations through an onboard Wave Front Sensor (WFS). One option is using a Shack Hartmann. The Shack-Hartmann wave-front sensor could be used on extended scenes (unknown landscapes). A wave-front computation algorithm should then be implemented on-board the satellite to provide the control loop wave-front error measure. In the worst case scenario, this measure should be computed before each image acquisition. A robust and fast shift estimation algorithm between Shack-Hartmann images is then needed to fulfill this last requirement. A fast gradient-based algorithm using optical flows with a Lucas-Kanade method has been studied and implemented on an electronic device developed by CNES. Measurement accuracy depends on the Wave Front Error (WFE), the landscape frequency content, the number of searched aberrations, the a priori knowledge of high order aberrations and the characteristics of the sensor. CNES has realized a full scale sensitivity analysis on the whole parameter set with our internally developed algorithm.

Magnetohydrodynamic flow in a rectangular duct under a uniform transverse magnetic field at high Hartmann number

International Nuclear Information System (INIS)

Temperley, D.J.

1976-01-01

In this paper we consider fully developed, laminar, unidirectional flow of uniformly conducting, incompressible fluid through a rectangular duct of uniform cross-section. An externally applied magnetic field acts parallel to one pair of opposite walls and induced velocity and magnetic fields are generated in a direction parallel to the axis of the duct. The governing equations and boundary conditions for the latter fields are introduced and study is then concentrated on the special case of a duct having all walls non-conducting. For values of the Hartmann number M>>1, classical asymptotic analysis reveals the leading terms in the expansions of the induced fields in all key regions, with the exception of certain boundary layers near the corners of the duct. The order of magnitude of the affect of the latter layers on the flow-rate is discussed and closed-form solutions are obtained for the induced fields near the corners of the duct. Attempts were made to formulate a concise Principle of Minimum Singularity to enable the correct choice of eigen functions for the various field components in the boundary layers on the walls parallel to the applied field. It was found, however, that these components are best found by taking the outer expansion of the closed-form solution in those boundary-layers near the corners of the duct where classical asymptotic analysis is not applicable. (author)

Sensors and OBIA synergy for operational monitoring of surface water

Science.gov (United States)

Masson, Eric; Thenard, Lucas

2010-05-01

This contribution will focus on combining Object Based Image Analysis (i.e. OBIA with e-Cognition 8) and recent sensors (i.e. Spot 5 XS, Pan and ALOS Prism, Avnir2, Palsar) to address the technical feasibility for an operational monitoring of surface water. Three cases of river meandering (India), flood mapping (Nepal) and dam's seasonal water level monitoring (Morocco) using recent sensors will present various application of surface water monitoring. The operational aspect will be demonstrated either by sensor properties (i.e. spatial resolution and bandwidth), data acquisition properties (i.e. multi sensor, return period and near real-time acquisition) but also with OBIA algorithms (i.e. fusion of multi sensors / multi resolution data and batch processes). In the first case of river meandering (India) we will address multi sensor and multi date satellite acquisition to monitor the river bed mobility within a floodplain using an ALOS dataset. It will demonstrate the possibility of an operational monitoring system that helps the geomorphologist in the analysis of fluvial dynamic and sediment budget for high energy rivers. In the second case of flood mapping (Nepal) we will address near real time Palsar data acquisition at high spatial resolution to monitor and to map a flood extension. This ALOS sensor takes benefit both from SAR and L band properties (i.e. atmospheric transparency, day/night acquisition, low sensibility to surface wind). It's a real achievement compared to optical imagery or even other high resolution SAR properties (i.e. acquisition swath, bandwidth and data price). These advantages meet the operational needs set by crisis management of hydrological disasters but also for the implementation of flood risk management plans. The last case of dam surface water monitoring (Morocco) will address an important issue of water resource management in countries affected by water scarcity. In such countries water users have to cope with over exploitation

Technical Note: Spot characteristic stability for proton pencil beam scanning.

Science.gov (United States)

Chen, Chin-Cheng; Chang, Chang; Moyers, Michael F; Gao, Mingcheng; Mah, Dennis

2016-02-01

The spot characteristics for proton pencil beam scanning (PBS) were measured and analyzed over a 16 month period, which included one major site configuration update and six cyclotron interventions. The results provide a reference to establish the quality assurance (QA) frequency and tolerance for proton pencil beam scanning. A simple treatment plan was generated to produce an asymmetric 9-spot pattern distributed throughout a field of 16 × 18 cm for each of 18 proton energies (100.0-226.0 MeV). The delivered fluence distribution in air was measured using a phosphor screen based CCD camera at three planes perpendicular to the beam line axis (x-ray imaging isocenter and up/down stream 15.0 cm). The measured fluence distributions for each energy were analyzed using in-house programs which calculated the spot sizes and positional deviations of the Gaussian shaped spots. Compared to the spot characteristic data installed into the treatment planning system, the 16-month averaged deviations of the measured spot sizes at the isocenter plane were 2.30% and 1.38% in the IEC gantry x and y directions, respectively. The maximum deviation was 12.87% while the minimum deviation was 0.003%, both at the upstream plane. After the collinearity of the proton and x-ray imaging system isocenters was optimized, the positional deviations of the spots were all within 1.5 mm for all three planes. During the site configuration update, spot positions were found to deviate by 6 mm until the tuning parameters file was properly restored. For this beam delivery system, it is recommended to perform a spot size and position check at least monthly and any time after a database update or cyclotron intervention occurs. A spot size deviation tolerance of spot positions were <2 mm at any plane up/down stream 15 cm from the isocenter.

[Effect of resin infiltration treatment on the colour of white spot lesions].

Science.gov (United States)

Zhao, Xiaoyi; Gao, Xuejun

2014-06-01

This study aimed to evaluate the effect of resin infiltration and fluoride solution on masking different demineralized white spot lesions by assessing color change. Artificial white spot lesions were produced on 60 human molars. Each sample had at least two enamel surfaces opened (named A and B). The samples were randomly divided into groups 1, 2, and 3 according to their time of demineralization (24, 48, and 72 h). After demineralization, the A spot of each sample was treated by resin infiltration. The B spot was treated with 0.1% fluoride solution daily for 30 days. After the remineralization of the B spot, resin infiltration was used again on the B spot of each sample. Color assessment was performed by a spectrophotometer in five distinct stages: baseline, after the production of artificial caries, after resin infiltration of A spots, after 30 days of fluoride solution treatment of B spots, and after resin infiltration of remineralized B spots. Before demineralization, the L* values of spots A and B in all groups were not significantly different (P > 0.05), whereas the L* values of spots A and B were significantly increased after demineralization. The L* values of A spots recovered significantly after treatment by resin infiltration (P 0.05) after fluoride treatment compared with that after demineralization. After resin infiltration on B spots, the L* values recovered but could not reach the baseline nor the level of A spots treated by resin infiltration only. Resin infiltration is a more effective treatment for masking white spot lesions than traditional fluoride treatment. The effect of masking white spot lesions has certain relationships with the degree of demineralization and activity of the lesion.

El spot electoral negativo

Directory of Open Access Journals (Sweden)

Palma Peña-Jiménez

2011-01-01

Full Text Available l spot político tiene durante la campaña un objetivo final inequívoco: la consecución del voto favorable. Se dirige al cuerpo electoral a través de la televisión y de Internet, y presenta, en muchos casos, un planteamiento negativo, albergando mensajes destinados a la crítica frontal contra el adversario, más que a la exposición de propuestas propias. Este artículo se centra en el análisis del spot electoral negativo, en aquellas producciones audiovisuales construidas sin más causa que la reprobación del contrincante. Se trata de vídeos que, lejos de emplearse en difundir las potencialidades de la organización y las virtudes de su candidato –además de su programa electoral–, consumen su tiempo en descalificar al oponente mediante la transmisión de mensajes, muchas veces, ad hominem. Repasamos el planteamiento negativo del spot electoral desde su primera manifestación, que en España data de 1996, año de emisión del conocido como vídeo del dóberman, sin olvidar otros ejemplos que completan el objeto de estudio.

Fundus autofluorescence and optical coherence tomography of congenital grouped albinotic spots.

Science.gov (United States)

Kim, David Y; Hwang, John C; Moore, Anthony T; Bird, Alan C; Tsang, Stephen H

2010-09-01

The purpose of this study was to describe the findings of fundus autofluores-cence (FAF) and optical coherence tomography in a series of patients with congenital grouped albinotic spots. Three eyes of three patients with congenital grouped albinotic spots were evaluated with FAF and optical coherence tomography imaging to evaluate the nature of the albinotic spots. In all three eyes with congenital grouped albinotic spots, FAF imaging showed autofluorescent spots corresponding to the albinotic spots seen on stereo biomicroscopy. One eye also had additional spots detected on FAF imaging that were not visible on stereo biomicroscopy or color fundus photographs. Fundus autofluorescence imaging of the spots showed decreased general autofluorescence and decreased peripheral autofluorescence surrounding central areas of retained or increased autofluorescence. Optical coherence tomography showed a disruption in signal from the hyperreflective layer corresponding to the inner and outer segment junction and increased signal backscattering from the choroid in the area of the spots. Fluorescein angiography showed early and stable hyperfluorescence of the spots without leakage. In this case series, FAF showed decreased autofluorescence of the spots consistent with focal retinal pigment epithelium atrophy or abnormal material blocking normal autofluorescence and areas of increased autofluorescence suggesting retinal pigment epithelium dysfunction. The findings of optical coherence tomography and fluorescein angiography suggest photoreceptor and retinal pigment epithelium layer abnormalities. Fundus autofluorescence and optical coherence tomography are useful noninvasive diagnostic adjuncts that can aid in the diagnosis of congenital grouped albinotic spots, help determine extent of disease, and contribute to our understanding of its pathophysiology.

Addition of Adapted Optics towards obtaining a quantitative detection of diabetic retinopathy

Science.gov (United States)

Yust, Brian; Obregon, Isidro; Tsin, Andrew; Sardar, Dhiraj

2009-04-01

An adaptive optics system was assembled for correcting the aberrated wavefront of light reflected from the retina. The adaptive optics setup includes a superluminous diode light source, Hartmann-Shack wavefront sensor, deformable mirror, and imaging CCD camera. Aberrations found in the reflected wavefront are caused by changes in the index of refraction along the light path as the beam travels through the cornea, lens, and vitreous humour. The Hartmann-Shack sensor allows for detection of aberrations in the wavefront, which may then be corrected with the deformable mirror. It has been shown that there is a change in the polarization of light reflected from neovascularizations in the retina due to certain diseases, such as diabetic retinopathy. The adaptive optics system was assembled towards the goal of obtaining a quantitative measure of onset and progression of this ailment, as one does not currently exist. The study was done to show that the addition of adaptive optics results in a more accurate detection of neovascularization in the retina by measuring the expected changes in polarization of the corrected wavefront of reflected light.

Damage tolerance reliability analysis of automotive spot-welded joints

International Nuclear Information System (INIS)

Mahadevan, Sankaran; Ni Kan

2003-01-01

This paper develops a damage tolerance reliability analysis methodology for automotive spot-welded joints under multi-axial and variable amplitude loading history. The total fatigue life of a spot weld is divided into two parts, crack initiation and crack propagation. The multi-axial loading history is obtained from transient response finite element analysis of a vehicle model. A three-dimensional finite element model of a simplified joint with four spot welds is developed for static stress/strain analysis. A probabilistic Miner's rule is combined with a randomized strain-life curve family and the stress/strain analysis result to develop a strain-based probabilistic fatigue crack initiation life prediction for spot welds. Afterwards, the fatigue crack inside the base material sheet is modeled as a surface crack. Then a probabilistic crack growth model is combined with the stress analysis result to develop a probabilistic fatigue crack growth life prediction for spot welds. Both methods are implemented with MSC/NASTRAN and MSC/FATIGUE software, and are useful for reliability assessment of automotive spot-welded joints against fatigue and fracture

Duodenal White Spots Mimicking Intestinal Candidiasis: Report of Case

Directory of Open Access Journals (Sweden)

Ozgur Turk

2015-12-01

Full Text Available Duodenal white spots are mentioned in these nonspecific lesions until recently. Although there is not enough studies about duedonal white spots yet; these lesions described in a separate syndrome. Here now we reported a case that we diagnosed multiple Duodenal white spots mimicking intestinal candidiasis. Clinical manifestation and endoscopic appearance of lesions gave rise to thought intestinal candidiasis histopathological examination revealed us several duodenitis. There was no evidence of fungal infection in PAS staining. Early after endoscopy patient took treatment of Lansoprozole at the 30 mg dose and bismuth salicylate. Patients compliant declined and control endoscopy exposed white duodenal spots cleared away three months later. Duodenal white spots are becoming to be designated as a separate disease even a syndrome. Etiology of duodenal white spots must be determined carefully during endoscopy. Sometimes it is difficult to make the correct diagnosis by appearance of lesion; in such cases histopathological examination can be useful both differential diagnosis of disease and determination of etiological factor. [J Contemp Med 2015; 5(4.000: 249-252

Finite Element and Experimental Study of Shunting in Resistance Spot Welding

DEFF Research Database (Denmark)

Seyyedian Choobi, M.; Nielsen, C. V.; Bay, N.

2015-01-01

This research is focused on one of the problems frequently encountered in spot welding in industry. In many applications several spot welds are made close to each other. The spots made after the first spot may become smaller in size due to shunt effect. A numerical and experimental study has been...... conducted to investigate the effect of shunting on nugget size in spot welding of HSLA steel sheets. Different cases with different spacing between weld spots have been examined. The nugget sizes have been measured by metallographic examination and have been compared with 3D finite element simulations...

Does contrast between eggshell ground and spot coloration affect egg rejection?

Science.gov (United States)

Dainson, Miri; Hauber, Mark E; López, Analía V; Grim, Tomáš; Hanley, Daniel

2017-08-01

Obligate avian brood parasitic species impose the costs of incubating foreign eggs and raising young upon their unrelated hosts. The most common host defence is the rejection of parasitic eggs from the nest. Both egg colours and spot patterns influence egg rejection decisions in many host species, yet no studies have explicitly examined the role of variation in spot coloration. We studied the American robin Turdus migratorius, a blue-green unspotted egg-laying host of the brown-headed cowbird Molothrus ater, a brood parasite that lays non-mimetic spotted eggs. We examined host responses to model eggs with variable spot coloration against a constant robin-mimetic ground colour to identify patterns of rejection associated with perceived contrast between spot and ground colours. By using avian visual modelling, we found that robins were more likely to reject eggs whose spots had greater chromatic (hue) but not achromatic (brightness) contrast. Therefore, egg rejection decision rules in the American robin may depend on the colour contrast between parasite eggshell spot and host ground coloration. Our study also suggests that egg recognition in relation to spot coloration, like ground colour recognition, is tuned to the natural variation of avian eggshell spot colours but not to unnatural spot colours.

Semantic markup of sensor capabilities: how simple it too simple?

Science.gov (United States)

Rueda-Velasquez, C. A.; Janowicz, K.; Fredericks, J.

2016-12-01

Semantics plays a key role for the publication, retrieval, integration, and reuse of observational data across the geosciences. In most cases, one can safely assume that the providers of such data, e.g., individual scientists, understand the observation context in which their data are collected,e.g., the used observation procedure, the sampling strategy, the feature of interest being studied, and so forth. However, can we expect that the same is true for the technical details of the used sensors and especially the nuanced changes that can impact observations in often unpredictable ways? Should the burden of annotating the sensor capabilities, firmware, operation ranges, and so forth be really part of a scientist's responsibility? Ideally, semantic annotations should be provided by the parties that understand these details and have a vested interest in maintaining these data. With manufactures providing semantically-enabled metadata for their sensors and instruments, observations could more easily be annotated and thereby enriched using this information. Unfortunately, today's sensor ontologies and tool chains developed for the Semantic Web community require expertise beyond the knowledge and interest of most manufacturers. Consequently, knowledge engineers need to better understand the sweet spot between simple ontologies/vocabularies and sufficient expressivity as well as the tools required to enable manufacturers to share data about their sensors. Here, we report on the current results of EarthCube's X-Domes project that aims to address the questions outlined above.

Evaluation of a new fiber-grating vision sensor for assessing pulmonary functions in healthy and COPD subjects

International Nuclear Information System (INIS)

Tsujimura, S; Tsuduki, K; Shirahata, T; Yoshida, S; Chubachi, S; Miyazaki, M; Nakamura, M; Takahashi, S; Nakajima, T; Minematsu, N; Tateno, H; Asano, K; Nakamura, H; Sato, I; Aoki, H

2011-01-01

Spirometry is practically the only tool to evaluate pulmonary functions. Other automatic systems comparable to spirometry are expected. A fiber-grating (FG) vision sensor is a non-contact respiratory monitoring system to detect changes in volumes by measuring the movement of laser spots on the body surface. We examined the contributions of the FG sensor to evaluating pulmonary functions. The FG sensor showed a linear correlation with spirometry in tidal volumes (TV) obtained from five controls (R = 0.98, P < 0.0001). We also showed agreement of TV between the two devices using Bland–Altman analysis. TV measured by the FG sensor were reproducible and applicable to distinct subjects. To detect airway obstruction, we performed forced expiration in controls (n = 16) and chronic obstructive pulmonary disease (COPD) patients (n = 18) with the FG sensor and spirometry. Forced expiratory volume in 1 s (FEV 1 ) and FEV 1 /forced vital capacity in COPD patients were lower than those in controls by the FG sensor. In addition, prolonged expiration in natural breathing by the FG sensor was related to airflow limitation by spirometry. The FG sensor was helpful to measure volume changes and to evaluate pulmonary functions in controls and patients with COPD. Its upcoming clinical applications are promising for simplicity and feasibility

Fast spot-based multiscale simulations of granular drainage

Energy Technology Data Exchange (ETDEWEB)

Rycroft, Chris H.; Wong, Yee Lok; Bazant, Martin Z.

2009-05-22

We develop a multiscale simulation method for dense granular drainage, based on the recently proposed spot model, where the particle packing flows by local collective displacements in response to diffusing"spots'" of interstitial free volume. By comparing with discrete-element method (DEM) simulations of 55,000 spheres in a rectangular silo, we show that the spot simulation is able to approximately capture many features of drainage, such as packing statistics, particle mixing, and flow profiles. The spot simulation runs two to three orders of magnitude faster than DEM, making it an appropriate method for real-time control or optimization. We demonstrateextensions for modeling particle heaping and avalanching at the free surface, and for simulating the boundary layers of slower flow near walls. We show that the spot simulations are robust and flexible, by demonstrating that they can be used in both event-driven and fixed timestep approaches, and showing that the elastic relaxation step used in the model can be applied much less frequently and still create good results.

Thermally-Driven Mantle Plumes Reconcile Hot-spot Observations

Science.gov (United States)

Davies, D.; Davies, J.

2008-12-01

Hot-spots are anomalous regions of magmatism that cannot be directly associated with plate tectonic processes (e.g. Morgan, 1972). They are widely regarded as the surface expression of upwelling mantle plumes. Hot-spots exhibit variable life-spans, magmatic productivity and fixity (e.g. Ito and van Keken, 2007). This suggests that a wide-range of upwelling structures coexist within Earth's mantle, a view supported by geochemical and seismic evidence, but, thus far, not reproduced by numerical models. Here, results from a new, global, 3-D spherical, mantle convection model are presented, which better reconcile hot-spot observations, the key modification from previous models being increased convective vigor. Model upwellings show broad-ranging dynamics; some drift slowly, while others are more mobile, displaying variable life-spans, intensities and migration velocities. Such behavior is consistent with hot-spot observations, indicating that the mantle must be simulated at the correct vigor and in the appropriate geometry to reproduce Earth-like dynamics. Thermally-driven mantle plumes can explain the principal features of hot-spot volcanism on Earth.

Measurement of PuO2 spot in the mixed-oxide fuels

International Nuclear Information System (INIS)

Yokosuka, Yoshifumi; Kaneda, Kenichiro; Ishikawa, Eiji; Nakajima, Katsuaki; Kashima, Sadamitsu

1974-01-01

The homogeneity of mixed-oxide fuel is evaluated with the maximum diameter of PuO 2 spots. PuO 2 spot distribution is influenced by fuel production process and raw materials used. Analytical measurement of the PuO 2 spot distribution was carried out. α-autoradiograph was taken with nitrocellulose film as a detector. The film was exposed for 15 and 30 minutes to the sample pellets, and etched in 10% NaOH for 2 minutes at 60 0 C. Measurement of PuO 2 spots was performed manually with a projector. PuO 2 spot distribution was measured. There is no difference of spot distribution owing to the location in a pellet. However some discrepancy exists in spot number and maximum diameter between surface and inner part. This phenomenon is explained by considering that the diffusion on surface is more effective than in inner part in sintering process. Three pellets were taken out from a lot at random, and α-autoradiograph was taken longitudinally with a pellet and transversely with the others. PuO 2 spot number counted from three autoradiographs was about 150/cm 2 , and the standard deviation was about 1.5. No difference was observed among them. Concerning the influence of mixing method on PuO 2 spot formation, three methods were examined; ball mill mixing (with and without lining) and Kneader mixing. Kneader mixing gave the worst results in maximum spot diameter and spot distribution range. (Tai, I.)

Hot spots on Tc-99m MAA perfusion lung scan

International Nuclear Information System (INIS)

Lim, Seok Tae; Sohn, Myung Hee

2001-01-01

A 61 year-old woman underwent perfusion and inhalation lung scan for the evaluation of pulmonary thromboembolism. Tc-99m MAA perfusion lung scan showed multiple round hot spots in both lung fields. Tc-99m DTPA aerosol inhalation lung scan and chest radiography taken at the same time showed normal findings. A repeated perfusion lung scan taken 24 hours later demonstrated no abnormalities. Hot spots on perfusion lung scan can be caused by microsphere clumping due to faulty injection technique by radioactive embolization from upper extremity thrombophlebitis after injection. Focal hot spots can signify zones of atelectasis, where the hot spots probably represent a failure of hypoxic vasoconstriction. Artifactual hot spots due to microsphere clumping usually appear to be round and in peripheral location, and the lesions due to a loss of hypoxic vasoconstriction usually appear to be hot uptakes having linear borders. Although these artifactual hot spots have been well-known, we rarely encounter them. This report presents a case with artifactual hot spots due to microsphere clumping on Tc-99m MAA perfusion lung scan

Sugarbeet leaf spot disease (Cercospora beticola Sacc.)dagger.

Science.gov (United States)

Weiland, John; Koch, Georg

2004-05-01

SUMMARY Leaf spot disease caused by Cercospora beticola Sacc. is the most destructive foliar pathogen of sugarbeet worldwide. In addition to reducing yield and quality of sugarbeet, the control of leaf spot disease by extensive fungicide application incurs added costs to producers and repeatedly has selected for fungicide-tolerant C. beticola strains. The genetics and biochemistry of virulence have been examined less for C. beticola as compared with the related fungi C. nicotianae, C. kikuchii and C. zeae-maydis, fungi to which the physiology of C. beticola is often compared. C. beticola populations generally are not characterized as having race structure, although a case of race-specific resistance in sugarbeet to C. beticola has been reported. Resistance currently implemented in the field is quantitatively inherited and exhibits low to medium heritability. Cercospora beticola Sacc.; Kingdom Fungi, Subdivision Deuteromycetes, Class Hyphomycetes, Order Hyphales, Genus Cercospora. Circular, brown to red delimited spots with ashen-grey centre, 0.5-6 mm diameter; dark brown to black stromata against grey background; pale brown unbranched sparingly septate conidiophores, hyaline acicular conidia, multiseptate, from 2.5 to 4 microm wide and 50-200 microm long. Propagative on Beta vulgaris and most species of Beta. Reported on members of the Chenopodiaceae and on Amaranthus. Disease symptoms: Infected leaves and petioles of B. vulgaris exhibit numerous circular leaf spots that coalesce in severe cases causing complete leaf collapse. Dark specks within a grey spot centre are characteristic for the disease. Older leaves exhibit a greater number of lesions with larger spot diameter. During the latter stage of severe epiphytotics, new leaf growth can be seen emerging from the plant surrounded by prostrate, collapsed leaves. Fungicides in the benzimidazole and triazole class as well as organotin derivatives and strobilurins have successfully been used to control Cercospora

Justifications shape ethical blind spots.

Science.gov (United States)

Pittarello, Andrea; Leib, Margarita; Gordon-Hecker, Tom; Shalvi, Shaul

2015-06-01

To some extent, unethical behavior results from people's limited attention to ethical considerations, which results in an ethical blind spot. Here, we focus on the role of ambiguity in shaping people's ethical blind spots, which in turn lead to their ethical failures. We suggest that in ambiguous settings, individuals' attention shifts toward tempting information, which determines the magnitude of their lies. Employing a novel ambiguous-dice paradigm, we asked participants to report the outcome of the die roll appearing closest to the location of a previously presented fixation cross on a computer screen; this outcome would determine their pay. We varied the value of the die second closest to the fixation cross to be either higher (i.e., tempting) or lower (i.e., not tempting) than the die closest to the fixation cross. Results of two experiments revealed that in ambiguous settings, people's incorrect responses were self-serving. Tracking participants' eye movements demonstrated that people's ethical blind spots are shaped by increased attention toward tempting information. © The Author(s) 2015.

The sweet spots in human communication.

Science.gov (United States)

Salem, Philip

2011-07-01

In baseball, the sweet spot is a special place on a bat where the batter can hit the ball with the most power. It is the place where the performances of the batter and pitcher collide with maximum effect. It is the place where the dynamic tension between opponents leads to transformation. The dynamic tension in all living systems is between similarity and difference. Chaos and complexity scholars recognized this tension as amounts of information. When the amounts of information were high, but not too high, the system moved to the edge of chaos, to the complexity regime, to strange attractors, or to chaos, depending on the model. The sweet spot is that range of relative variety, just the proper mix of similarity and difference, leading to transformation. This essay contains a model of human communication as an emergent social process with its own sweet spots. The essay also includes a description of current literature highlighting tensions between similarity and difference, and there is an exploration of the potential to move from one basin of attraction to another. The primary constraints on finding communication sweet spots are paradigmatic - adopting a process orientation, discovering the proper parameters, bracketing sequences to define initial conditions, and understanding the strengths and weaknesses of various modeling techniques.

Coupling effects of refractive index discontinuity, spot size and spot location on the deflection sensitivity of optical-lever based atomic force microscopy

International Nuclear Information System (INIS)

Liu Yu; Yang Jun

2008-01-01

Atomic force microscopy (AFM) plays an essential role in nanotechnology and nanoscience. The recent advances of AFM in bionanotechnology include phase imaging of living cells and detection of biomolecular interactions in liquid biological environments. Deflection sensitivity is a key factor in both imaging and force measurement, which is significantly affected by the coupling effects of the refractive index discontinuity between air, the glass window and the liquid medium, and the laser spot size and spot location. The effects of both the spot size and the spot location on the sensitivity are amplified by the refractive index discontinuity. The coupling effects may govern a transition of the deflection sensitivity from enhancement to degradation. It is also found that there is a critical value for the laser spot size, above which the deflection sensitivity is mainly determined by the refractive index of the liquid. Experimental results, in agreement with theoretical predication, elucidate the coupling effects

Sowing rates for reforestation by the seed-spotting method

Science.gov (United States)

Gilbert H. Schubert; Harry A. Fowells

1964-01-01

Presents guides to determine the number of seeds to sow per spot and the number of spots required per acre to obtain acceptable stocking. Based on theoretical probabilities, these guides were found to be reasonably close to actual field results When the probability-of-success was at least 55 percent. To compensate for lower actual stocking, increase the number of spots...

Simulation of eye-tracker latency, spot size, and ablation pulse depth on the correction of higher order wavefront aberrations with scanning spot laser systems.

Science.gov (United States)

Bueeler, Michael; Mrochen, Michael

2005-01-01

The aim of this theoretical work was to investigate the robustness of scanning spot laser treatments with different laser spot diameters and peak ablation depths in case of incomplete compensation of eye movements due to eye-tracker latency. Scanning spot corrections of 3rd to 5th Zernike order wavefront errors were numerically simulated. Measured eye-movement data were used to calculate the positioning error of each laser shot assuming eye-tracker latencies of 0, 5, 30, and 100 ms, and for the case of no eye tracking. The single spot ablation depth ranged from 0.25 to 1.0 microm and the spot diameter from 250 to 1000 microm. The quality of the ablation was rated by the postoperative surface variance and the Strehl intensity ratio, which was calculated after a low-pass filter was applied to simulate epithelial surface smoothing. Treatments performed with nearly ideal eye tracking (latency approximately 0) provide the best results with a small laser spot (0.25 mm) and a small ablation depth (250 microm). However, combinations of a large spot diameter (1000 microm) and a small ablation depth per pulse (0.25 microm) yield the better results for latencies above a certain threshold to be determined specifically. Treatments performed with tracker latencies in the order of 100 ms yield similar results as treatments done completely without eye-movement compensation. CONCWSIONS: Reduction of spot diameter was shown to make the correction more susceptible to eye movement induced error. A smaller spot size is only beneficial when eye movement is neutralized with a tracking system with a latency <5 ms.

White-centred retinal haemorrhages (Roth spots).

OpenAIRE

Ling, R.; James, B.

1998-01-01

Roth spots (white-centred retinal haemorrhages) were classically described as septic emboli lodged in the retina of patients with subacute bacterial endocarditis. Indeed many have considered Roth spots pathognomonic for this condition. More recent histological evidence suggests, however, that they are not foci of bacterial abscess. Instead, they are nonspecific and may be found in many other diseases. A review of the histology and the pathogenesis of these white-centred haemorrhages will be p...

Technical Note: Spot characteristic stability for proton pencil beam scanning

Energy Technology Data Exchange (ETDEWEB)

Chen, Chin-Cheng, E-mail: chen.ccc@gmail.com; Chang, Chang; Mah, Dennis [ProCure Treatment Center, Somerset, New Jersey 08873 (United States); Moyers, Michael F. [ProCure Treatment Center, Somerset, New Jersey 08873 and Shanghai Proton and Heavy Ion Center, Shanghai 201321 (China); Gao, Mingcheng [CDH Proton Center, Warrenville, Illinois 60555 (United States)

2016-02-15

Purpose: The spot characteristics for proton pencil beam scanning (PBS) were measured and analyzed over a 16 month period, which included one major site configuration update and six cyclotron interventions. The results provide a reference to establish the quality assurance (QA) frequency and tolerance for proton pencil beam scanning. Methods: A simple treatment plan was generated to produce an asymmetric 9-spot pattern distributed throughout a field of 16 × 18 cm for each of 18 proton energies (100.0–226.0 MeV). The delivered fluence distribution in air was measured using a phosphor screen based CCD camera at three planes perpendicular to the beam line axis (x-ray imaging isocenter and up/down stream 15.0 cm). The measured fluence distributions for each energy were analyzed using in-house programs which calculated the spot sizes and positional deviations of the Gaussian shaped spots. Results: Compared to the spot characteristic data installed into the treatment planning system, the 16-month averaged deviations of the measured spot sizes at the isocenter plane were 2.30% and 1.38% in the IEC gantry x and y directions, respectively. The maximum deviation was 12.87% while the minimum deviation was 0.003%, both at the upstream plane. After the collinearity of the proton and x-ray imaging system isocenters was optimized, the positional deviations of the spots were all within 1.5 mm for all three planes. During the site configuration update, spot positions were found to deviate by 6 mm until the tuning parameters file was properly restored. Conclusions: For this beam delivery system, it is recommended to perform a spot size and position check at least monthly and any time after a database update or cyclotron intervention occurs. A spot size deviation tolerance of <15% can be easily met with this delivery system. Deviations of spot positions were <2 mm at any plane up/down stream 15 cm from the isocenter.

Technical Note: Spot characteristic stability for proton pencil beam scanning

International Nuclear Information System (INIS)

Chen, Chin-Cheng; Chang, Chang; Mah, Dennis; Moyers, Michael F.; Gao, Mingcheng

2016-01-01

Purpose: The spot characteristics for proton pencil beam scanning (PBS) were measured and analyzed over a 16 month period, which included one major site configuration update and six cyclotron interventions. The results provide a reference to establish the quality assurance (QA) frequency and tolerance for proton pencil beam scanning. Methods: A simple treatment plan was generated to produce an asymmetric 9-spot pattern distributed throughout a field of 16 × 18 cm for each of 18 proton energies (100.0–226.0 MeV). The delivered fluence distribution in air was measured using a phosphor screen based CCD camera at three planes perpendicular to the beam line axis (x-ray imaging isocenter and up/down stream 15.0 cm). The measured fluence distributions for each energy were analyzed using in-house programs which calculated the spot sizes and positional deviations of the Gaussian shaped spots. Results: Compared to the spot characteristic data installed into the treatment planning system, the 16-month averaged deviations of the measured spot sizes at the isocenter plane were 2.30% and 1.38% in the IEC gantry x and y directions, respectively. The maximum deviation was 12.87% while the minimum deviation was 0.003%, both at the upstream plane. After the collinearity of the proton and x-ray imaging system isocenters was optimized, the positional deviations of the spots were all within 1.5 mm for all three planes. During the site configuration update, spot positions were found to deviate by 6 mm until the tuning parameters file was properly restored. Conclusions: For this beam delivery system, it is recommended to perform a spot size and position check at least monthly and any time after a database update or cyclotron intervention occurs. A spot size deviation tolerance of <15% can be easily met with this delivery system. Deviations of spot positions were <2 mm at any plane up/down stream 15 cm from the isocenter

SPOT: How good for geology? A comparison with LANDSAT MSS

Science.gov (United States)

Sesoeren, A.

1986-12-01

Geological interpretation possibilities of SPOT MSS and LANDSAT MSS positive prints enlarged to the same scale were compared, using as a test area part of the Jebel Amour (Algeria). The SPOT imagery offers many advantages, filling the gap between remote sensing from space and aerial photography. The best results by visual interpretation are obtained in combining SPOT for the required details with LANDSAT for the synoptic veiw. Further improvements are expected from the use of SPOT stereo-pairs.

Meteorology of Jupiter's Equatorial Hot Spots and Plumes from Cassini

Science.gov (United States)

Choi, David Sanghun; Showman, Adam P.; Vasavada, Ashwin R.; Simon-Miller, Amy A.

2013-01-01

We present an updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the Imaging Science Subsystem (ISS) onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial hot spots and their interactions with adjacent latitudes. Hot spots are relatively cloud-free regions that emit strongly at 5 lm; improved knowledge of these features is crucial for fully understanding Galileo probe measurements taken during its descent through one. Hot spots are quasistable, rectangular dark areas on visible-wavelength images, with defined eastern edges that sharply contrast with surrounding clouds, but diffuse western edges serving as nebulous boundaries with adjacent equatorial plumes. Hot spots exhibit significant variations in size and shape over timescales of days and weeks. Some of these changes correspond with passing vortex systems from adjacent latitudes interacting with hot spots. Strong anticyclonic gyres present to the south and southeast of the dark areas appear to circulate into hot spots. Impressive, bright white plumes occupy spaces in between hot spots. Compact cirrus-like 'scooter' clouds flow rapidly through the plumes before disappearing within the dark areas. These clouds travel at 150-200 m/s, much faster than the 100 m/s hot spot and plume drift speed. This raises the possibility that the scooter clouds may be more illustrative of the actual jet stream speed at these latitudes. Most previously published zonal wind profiles represent the drift speed of the hot spots at their latitude from pattern matching of the entire longitudinal image strip. If a downward branch of an equatorially-trapped Rossby wave controls the overall appearance of hot spots, however, the westward phase velocity of the wave leads to underestimates of the true jet stream speed.

Edge pixel response studies of edgeless silicon sensor technology for pixellated imaging detectors

Science.gov (United States)

Maneuski, D.; Bates, R.; Blue, A.; Buttar, C.; Doonan, K.; Eklund, L.; Gimenez, E. N.; Hynds, D.; Kachkanov, S.; Kalliopuska, J.; McMullen, T.; O'Shea, V.; Tartoni, N.; Plackett, R.; Vahanen, S.; Wraight, K.

2015-03-01

Silicon sensor technologies with reduced dead area at the sensor's perimeter are under development at a number of institutes. Several fabrication methods for sensors which are sensitive close to the physical edge of the device are under investigation utilising techniques such as active-edges, passivated edges and current-terminating rings. Such technologies offer the goal of a seamlessly tiled detection surface with minimum dead space between the individual modules. In order to quantify the performance of different geometries and different bulk and implant types, characterisation of several sensors fabricated using active-edge technology were performed at the B16 beam line of the Diamond Light Source. The sensors were fabricated by VTT and bump-bonded to Timepix ROICs. They were 100 and 200 μ m thick sensors, with the last pixel-to-edge distance of either 50 or 100 μ m. The sensors were fabricated as either n-on-n or n-on-p type devices. Using 15 keV monochromatic X-rays with a beam spot of 2.5 μ m, the performance at the outer edge and corners pixels of the sensors was evaluated at three bias voltages. The results indicate a significant change in the charge collection properties between the edge and 5th (up to 275 μ m) from edge pixel for the 200 μ m thick n-on-n sensor. The edge pixel performance of the 100 μ m thick n-on-p sensors is affected only for the last two pixels (up to 110 μ m) subject to biasing conditions. Imaging characteristics of all sensor types investigated are stable over time and the non-uniformities can be minimised by flat-field corrections. The results from the synchrotron tests combined with lab measurements are presented along with an explanation of the observed effects.

KFC Server: interactive forecasting of protein interaction hot spots.

Science.gov (United States)

Darnell, Steven J; LeGault, Laura; Mitchell, Julie C

2008-07-01

The KFC Server is a web-based implementation of the KFC (Knowledge-based FADE and Contacts) model-a machine learning approach for the prediction of binding hot spots, or the subset of residues that account for most of a protein interface's; binding free energy. The server facilitates the automated analysis of a user submitted protein-protein or protein-DNA interface and the visualization of its hot spot predictions. For each residue in the interface, the KFC Server characterizes its local structural environment, compares that environment to the environments of experimentally determined hot spots and predicts if the interface residue is a hot spot. After the computational analysis, the user can visualize the results using an interactive job viewer able to quickly highlight predicted hot spots and surrounding structural features within the protein structure. The KFC Server is accessible at http://kfc.mitchell-lab.org.

Intelligent error correction method applied on an active pixel sensor based star tracker

Science.gov (United States)

Schmidt, Uwe

2005-10-01

Star trackers are opto-electronic sensors used on-board of satellites for the autonomous inertial attitude determination. During the last years star trackers became more and more important in the field of the attitude and orbit control system (AOCS) sensors. High performance star trackers are based up today on charge coupled device (CCD) optical camera heads. The active pixel sensor (APS) technology, introduced in the early 90-ties, allows now the beneficial replacement of CCD detectors by APS detectors with respect to performance, reliability, power, mass and cost. The company's heritage in star tracker design started in the early 80-ties with the launch of the worldwide first fully autonomous star tracker system ASTRO1 to the Russian MIR space station. Jena-Optronik recently developed an active pixel sensor based autonomous star tracker "ASTRO APS" as successor of the CCD based star tracker product series ASTRO1, ASTRO5, ASTRO10 and ASTRO15. Key features of the APS detector technology are, a true xy-address random access, the multiple windowing read out and the on-chip signal processing including the analogue to digital conversion. These features can be used for robust star tracking at high slew rates and under worse conditions like stray light and solar flare induced single event upsets. A special algorithm have been developed to manage the typical APS detector error contributors like fixed pattern noise (FPN), dark signal non-uniformity (DSNU) and white spots. The algorithm works fully autonomous and adapts to e.g. increasing DSNU and up-coming white spots automatically without ground maintenance or re-calibration. In contrast to conventional correction methods the described algorithm does not need calibration data memory like full image sized calibration data sets. The application of the presented algorithm managing the typical APS detector error contributors is a key element for the design of star trackers for long term satellite applications like

Reliability of copper based alloys for electric resistance spot welding

International Nuclear Information System (INIS)

Jovanovicj, M.; Mihajlovicj, A.; Sherbedzhija, B.

1977-01-01

Durability of copper based alloys (B-5 and B-6) for electric resistance spot-welding was examined. The total amount of Be, Ni and Zr was up to 2 and 1 wt.% respectively. Good durability and satisfactory quality of welded spots were obtained in previous laboratory experiments carried out on the fixed spot-welding machine of an industrial type (only B-5 alloy was examined). Electrodes made of both B-5 and B-6 alloy were tested on spot-welding grips and fixed spot-welding machines in Tvornica automobila Sarajevo (TAS). The obtained results suggest that the durability of electrodes made of B-5 and B-6 alloys is more than twice better than of that used in TAS

Acute infectious purpura fulminans due to probable spotted fever

Directory of Open Access Journals (Sweden)

A Kundavaram

2014-01-01

Full Text Available Purpura fulminans (PF is associated with several infections, most notably with meningococcus, staphylococcus, and streptococcus infections. However, there are few reports of association of this entity with spotted fever from India. We report the case of a 55-year-old man who presented with fever, headache, and myalgia. On the seventh day of fever he developed nonblanching purple hemorrhagic purpura on the trunk and most prominently on the extremities consistent with purpura fulminans. Immunofluorescent assay confirmed the diagnosis of spotted fever. PF though common with rocky mountain spotted fever (RMSF is rarely seen in association with Indian tick typhus, the usual cause of spotted fever in India.

Wood ant nests as hot spots of carbon dioxide production and cold spots of methane oxidation in temperate forests

Czech Academy of Sciences Publication Activity Database

Jílková, Veronika; Picek, T.; Cajthaml, Tomáš; Frouz, Jan

2016-01-01

Roč. 18, April (2016), EGU2016-4634 ISSN 1607-7962. [European Geosciences Union General Assembly 2016. 17.04.2016-22.04.2016, Vienna] Institutional support: RVO:60077344 ; RVO:61388971 Keywords : wood ant nests * hot spots of carbon dioxide production * cold spots of methane oxidation * temperate forests Subject RIV: DF - Soil Science

Influence of cross-breeding of native breed sows of Zlotnicka spotted ...

African Journals Online (AJOL)

The aim of this study was the estimation of the cross-breeding influence of Zlotnicka spotted sows with boars of polish large white and Duroc breeds on carcass traits of fatteners. 50 pigs were divided into four groups: Zlotnicka spotted (ZS), Zlotnicka spotted x polish large white (ZS x PLW), Zlotnicka spotted x Duroc (ZS x D) ...

Transition Heat Transfer Modeling Based on the Characteristics of Turbulent Spots

Science.gov (United States)

Simon, Fred; Boyle, Robert

1998-01-01

While turbulence models are being developed which show promise for simulating the transition region on a turbine blade or vane, it is believed that the best approach with the greatest potential for practical use is the use of models which incorporate the physics of turbulent spots present in the transition region. This type of modeling results in the prediction of transition region intermittency which when incorporated in turbulence models give a good to excellent prediction of the transition region heat transfer. Some models are presented which show how turbulent spot characteristics and behavior can be employed to predict the effect of pressure gradient and Mach number on the transition region. The models predict the spot formation rate which is needed, in addition to the transition onset location, in the Narasimha concentrated breakdown intermittency equation. A simplified approach is taken for modeling turbulent spot growth and interaction in the transition region which utilizes the turbulent spot variables governing transition length and spot generation rate. The models are expressed in terms of spot spreading angle, dimensionless spot velocity, dimensionless spot area, disturbance frequency and Mach number. The models are used in conjunction with a computer code to predict the effects of pressure gradient and Mach number on the transition region and compared with VKI experimental turbine data.

Impact of low-dose electron irradiation on n+p silicon strip sensors

CERN Document Server

Adam, W.; Dragicevic, M.; Friedl, M.; Fruehwirth, R.; Hoch, M.; Hrubec, J.; Krammer, M.; Treberspurg, W.; Waltenberger, W.; Alderweireldt, S.; Beaumont, W.; Janssen, X.; Luyckx, S.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Barria, P.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Dobur, D.; Favart, L.; Grebenyuk, A.; Lenzi, Th.; Leonard, A.; Maerschalk, Th.; Mohammadi, A.; Pernie, L.; Randle-Conde, A.; Reis, T.; Seva, T.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Zenoni, F.; Abu Zeid, S.; Blekman, F.; De Bruyn, I.; D'Hondt, J.; Daci, N.; Deroover, K.; Heracleous, N.; Keaveney, J.; Lowette, S.; Moreels, L.; Olbrechts, A.; Python, Q.; Tavernier, S.; Van Mulders, P.; Van Onsem, G.; Van Parijs, I.; Strom, D.A.; Basegmez, S.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; De Callatay, B.; Delaere, C.; Pree, T.Du; Forthomme, L.; Giammanco, A.; Hollar, J.; Jez, P.; Michotte, D.; Nuttens, C.; Perrini, L.; Pagano, D.; Quertenmont, L.; Selvaggi, M.; Marono, M.Vidal; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G.H.; Harkonen, J.; Lampen, T.; Luukka, P.R.; Maenpaa, T.; Peltola, T.; Tuominen, E.; Tuovinen, E.; Eerola, P.; Tuuva, T.; Beaulieu, G.; Boudoul, G.; Combaret, C.; Contardo, D.; Gallbit, G.; Lumb, N.; Mathez, H.; Mirabito, L.; Perries, S.; Sabes, D.; Vander Donckt, M.; Verdier, P.; Viret, S.; Zoccarato, Y.; Agram, J.L.; Conte, E.; Fontaine, J.Ch.; Andrea, J.; Bloch, D.; Bonnin, C.; Brom, J.M.; Chabert, E.; Charles, L.; Goetzmann, Ch.; Gross, L.; Hosselet, J.; Mathieu, C.; Richer, M.; Skovpen, K.; Autermann, C.; Edelhoff, M.; Esser, H.; Feld, L.; Karpinski, W.; Klein, K.; Lipinski, M.; Ostapchuk, A.; Pierschel, G.; Preuten, M.; Raupach, F.; Sammet, J.; Schael, S.; Schwering, G.; Wittmer, B.; Wlochal, M.; Zhukov, V.; Pistone, C.; Fluegge, G.; Kuensken, A.; Geisler, M.; Pooth, O.; Stahl, A.; Bartosik, N.; Behr, J.; Burgmeier, A.; Calligaris, L.; Dolinska, G.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Fluke, G.; Garcia, J.Garay; Gizhko, A.; Hansen, K.; Harb, A.; Hauk, J.; Kalogeropoulos, A.; Kleinwort, C.; Korol, I.; Lange, W.; Lohmann, W.; Mankel, R.; Maser, H.; Mittag, G.; Muhl, C.; Mussgiller, A.; Nayak, A.; Ntomari, E.; Perrey, H.; Pitzl, D.; Schroeder, M.; Seitz, C.; Spannagel, S.; Zuber, A.; Biskop, H.; Blobel, V.; Buhmann, P.; Centis-Vignali, M.; Draeger, A.R.; Erfle, J.; Garutti, E.; Haller, J.; Henkel, Ch.; Hoffmann, M.; Junkes, A.; Klanner, R.; Lapsien, T.; Mattig, S.; Matysek, M.; Perieanu, A.; Poehlsen, J.; Poehlsen, T.; Scharf, Ch.; Schleper, P.; Schmidt, A.; Schuwalow, S.; Schwandt, J.; Sola, V.; Steinbruck, G.; Vormwald, B.; Wellhausen, J.; Barvich, T.; Barth, Ch.; Boegelspacher, F.; De Boer, W.; Butz, E.; Casele, M.; Colombo, F.; Dierlamm, A.; Eber, R.; Freund, B.; Hartmann, F.; Hauth, Th.; Heindl, S.; Hoffmann, K.H.; Husemann, U.; Kornmeyer, A.; Mallows, S.; Muller, Th.; Nuernberg, A.; Printz, M.; Simonis, H.J.; Steck, P.; Weber, M.; Weiler, Th.; Bhardwaj, A.; Kumar, A.; Ranjan, K.; Bakhshiansohl, H.; Behnamian, H.; Khakzad, M.; Naseri, M.; Cariola, P.; De Robertis, G.; Fiore, L.; Franco, M.; Loddo, F.; Sala, G.; Silvestris, L.; Creanza, D.; De Palma, M.; Maggi, G.; My, S.; Selvaggi, G.; Albergo, S.; Cappello, G.; Chiorboli, M.; Costa, S.; Giordano, F.; Di Mattia, A.; Potenza, R.; Saizu, M.A.; Tricomi, A.; Tuve, C.; Barbagli, G.; Brianzi, M.; Ciaranfi, R.; Civinini, C.; Gallo, E.; Meschini, M.; Paoletti, S.; Sguazzoni, G.; Ciulli, V.; D'Alessandro, R.; Gonzi, S.; Gori, V.; Focardi, E.; Lenzi, P.; Scarlini, E.; Tropiano, A.; Viliani, L.; Ferro, F.; Robutti, E.; Lo Vetere, M.; Gennai, S.; Malvezzi, S.; Menasce, D.; Moroni, L.; Pedrini, D.; Dinardo, M.; Fiorendi, S.; Manzoni, R.A.; Azzi, P.; Bacchetta, N.; Bisello, D.; Dall'Osso, M.; Dorigo, T.; Giubilato, P.; Pozzobon, N.; Tosi, M.; Zucchetta, A.; De Canio, F.; Gaioni, L.; Manghisoni, M.; Nodari, B.; Re, V.; Traversi, G.; Comotti, D.; Ratti, L.; Bilei, G.M.; Bissi, L.; Checcucci, B.; Magalotti, D.; Menichelli, M.; Saha, A.; Servoli, L.; Storchi, L.; Biasini, M.; Conti, E.; Ciangottini, D.; Fano, L.; Lariccia, P.; Mantovani, G.; Passeri, D.; Placidi, P.; Salvatore, M.; Santocchia, A.; Solestizi, L.A.; Spiezia, A.; Demaria, N.; Rivetti, A.; Bellan, R.; Casasso, S.; Costa, M.; Covarelli, R.; Migliore, E.; Monteil, E.; Musich, M.; Pacher, L.; Ravera, F.; Romero, A.; Solano, A.; Trapani, P.; Jaramillo Echeverria, R.; Fernandez, M.; Gomez, G.; Moya, D.; F. Gonzalez Sanchez, J.; Munoz Sanchez, F.J.; Vila, I.; Virto, A.L.; Abbaneo, D.; Ahmed, I.; Albert, E.; Auzinger, G.; Berruti, G.; Bianchi, G.; Blanchot, G.; Breuker, H.; Ceresa, D.; Christiansen, J.; Cichy, K.; Daguin, J.; D'Alfonso, M.; D'Auria, A.; Detraz, S.; De Visscher, S.; Deyrail, D.; Faccio, F.; Felici, D.; Frank, N.; Gill, K.; Giordano, D.; Harris, P.; Honma, A.; Kaplon, J.; Kornmayer, A.; Kortelainen, M.; Kottelat, L.; Kovacs, M.; Mannelli, M.; Marchioro, A.; Marconi, S.; Martina, S.; Mersi, S.; Michelis, S.; Moll, M.; Onnela, A.; Pakulski, T.; Pavis, S.; Peisert, A.; Pernot, J.F.; Petagna, P.; Petrucciani, G.; Postema, H.; Rose, P.; Rzonca, M.; Stoye, M.; Tropea, P.; Troska, J.; Tsirou, A.; Vasey, F.; Vichoudis, P.; Verlaat, B.; Zwalinski, L.; Bachmair, F.; Becker, R.; Bani, L.; di Calafiori, D.; Casal, B.; Djambazov, L.; Donega, M.; Dunser, M.; Eller, P.; Grab, C.; Hits, D.; Horisberger, U.; Hoss, J.; Kasieczka, G.; Lustermann, W.; Mangano, B.; Marionneau, M.; Martinez Ruiz del Arbol, P.; Masciovecchio, M.; Perrozzi, L.; Roeser, U.; Rossini, M.; Starodumov, A.; Takahashi, M.; Wallny, R.; Amsler, C.; Bosiger, K.; Caminada, L.; Canelli, F.; Chiochia, V.; De Cosa, A.; Galloni, C.; Hreus, T.; Kilminster, B.; Lange, C.; Maier, R.; Ngadiuba, J.; Pinna, D.; Robmann, P.; Taroni, S.; Yang, Y.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Kaestli, H.C.; Kotlinski, D.; Langenegger, U.; Meier, B.; Rohe, T.; Streuli, S.; Chen, P.H.; Dietz, C.; Grundler, U.; Hou, W.S.; Lu, R.S.; Moya, M.; Wilken, R.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Jacob, J.; El Nasr-Storey, S.Seif; Cole, J.; Hobson, P.; Leggat, D.; Reid, I.D.; Teodorescu, L.; Bainbridge, R.; Dauncey, P.; Fulcher, J.; Hall, G.; Magnan, A.M.; Pesaresi, M.; Raymond, D.M.; Uchida, K.; Coughlan, J.A.; Harder, K.; Ilic, J.; Tomalin, I.R.; Garabedian, A.; Heintz, U.; Narain, M.; Nelson, J.; Sagir, S.; Speer, T.; Swanson, J.; Tersegno, D.; Watson-Daniels, J.; Chertok, M.; Conway, J.; Conway, R.; Flores, C.; Lander, R.; Pellett, D.; Ricci-Tam, F.; Squires, M.; Thomson, J.; Yohay, R.; Burt, K.; Ellison, J.; Hanson, G.; Malberti, M.; Olmedo, M.; Cerati, G.; Sharma, V.; Vartak, A.; Yagil, A.; Della Porta, G.Zevi; Dutta, V.; Gouskos, L.; Incandela, J.; Kyre, S.; McColl, N.; Mullin, S.; White, D.; Cumalat, J.P.; Ford, W.T.; Gaz, A.; Krohn, M.; Stenson, K.; Wagner, S.R.; Baldin, B.; Bolla, G.; Burkett, K.; Butler, J.; Cheung, H.; Chramowicz, J.; Christian, D.; Cooper, W.E.; Deptuch, G.; Derylo, G.; Gingu, C.; Gruenendahl, S.; Hasegawa, S.; Hoff, J.; Howell, J.; Hrycyk, M.; Jindariani, S.; Johnson, M.; Jung, A.; Joshi, U.; Kahlid, F.; Lei, C.M.; Lipton, R.; Liu, T.; Los, S.; Matulik, M.; Merkel, P.; Nahn, S.; Prosser, A.; Rivera, R.; Shenai, A.; Spiegel, L.; Tran, N.; Uplegger, L.; Voirin, E.; Yin, H.; Adams, M.R.; Berry, D.R.; Evdokimov, A.; Evdokimov, O.; Gerber, C.E.; Hofman, D.J.; Kapustka, B.K.; O'Brien, C.; Sandoval Gonzalez, D.I.; Trauger, H.; Turner, P.; Parashar, N.; Stupak, J., III; Bortoletto, D.; Bubna, M.; Hinton, N.; Jones, M.; Miller, D.H.; Shi, X.; Tan, P.; Baringer, P.; Bean, A.; Benelli, G.; Gray, J.; Majumder, D.; Noonan, D.; Sanders, S.; Stringer, R.; Ivanov, A.; Makouski, M.; Skhirtladze, N.; Taylor, R.; Anderson, I.; Fehling, D.; Gritsan, A.; Maksimovic, P.; Martin, C.; Nash, K.; Osherson, M.; Swartz, M.; Xiao, M.; Acosta, J.G.; Cremaldi, L.M.; Oliveros, S.; Perera, L.; Summers, D.; Bloom, K.; Bose, S.; Claes, D.R.; Dominguez, A.; Fangmeier, C.; Gonzalez Suarez, R.; Meier, F.; Monroy, J.; Hahn, K.; Sevova, S.; Sung, K.; Trovato, M.; Bartz, E.; Duggan, D.; Halkiadakis, E.; Lath, A.; Park, M.; Schnetzer, S.; Stone, R.; Walker, M.; Malik, S.; Mendez, H.; Ramirez Vargas, J.E.; Alyari, M.; Dolen, J.; George, J.; Godshalk, A.; Iashvili, I.; Kaisen, J.; Kharchilava, A.; Kumar, A.; Rappoccio, S.; Alexander, J.; Chaves, J.; Chu, J.; Dittmer, S.; Kaufman, G.; Mirman, N.; Ryd, A.; Salvati, E.; Skinnari, L.; Thom, J.; Thompson, J.; Tucker, J.; Winstrom, L.; Akgun, B.; Ecklund, K.M.; Nussbaum, T.; Zabel, J.; Betchart, B.; Demina, R.; Hindrichs, O.; Petrillo, G.; Eusebi, R.; Osipenkov, I.; Perloff, A.; Ulmer, K.A.; Delannoy, A.G.; D'Angelo, P.; Johns, W.

2015-01-01

The response of n+p silicon strip sensors to electrons from a Sr-90 source was measured using a multi-channel read-out system with 25 ns sampling time. The measurements were performed over a period of several weeks, during which the operating conditions were varied. The sensors were fabricated by Hamamatsu Photonics K.K. on 200 micrometer thick float-zone and magnetic-Czochralski silicon. Their pitch was 80 micrometer, and both p-stop and p-spray isolation of the n+ strips were studied. The electrons from the Sr-90 source were collimated to a spot with a full-width-at-half-maximum of 2 mm at the sensor surface, and the dose rate in the SiO2 at the maximum was about 50 Gy/d. After only a few hours of making measurements, significant changes in charge collection and charge sharing were observed. Annealing studies, with temperatures up to 80{\\deg}C and annealing times of 18 hours, showed that the changes can only be partially annealed. The observations can be qualitatively explained by the increase of the positi...

Laser Spot Center Detection and Comparison Test

Science.gov (United States)

Zhu, Jun; Xu, Zhengjie; Fu, Deli; Hu, Cong

2018-04-01

High efficiency and precision of the pot center detection are the foundations of avionics instrument navigation and optics measurement basis for many applications. It has noticeable impact on overall system performance. Among them, laser spot detection is very important in the optical measurement technology. In order to improve the low accuracy of the spot center position, the algorithm is improved on the basis of the circle fitting. The pretreatment is used by circle fitting, and the improved adaptive denoising filter for TV repair technology can effectively improves the accuracy of the spot center position. At the same time, the pretreatment and de-noising can effectively reduce the influence of Gaussian white noise, which enhances the anti-jamming capability.

Resistance in winter barley against Ramularia leaf spot

DEFF Research Database (Denmark)

Hjortshøj, Rasmus Lund

Ramularia leaf spot is an emerging disease in barley caused by R. collo-cygni. At present little is known about the resistance mechanisms carried out by the host plant to avoid disease development. Nor is the lifecycle of the fungus or its populations structure fully understood. To gain insight....... fulvum-tomato and S. tritici-wheat in order to find modelsystems to enhance interpretation of results from R. collo-cygni-barley interaction. Results from the mapping showed that resistance to Ramularia leaf spot is controlled by a number of QTL’s, some of which co-locate with other physiological traits....... The populations further segregated for physiological leaf spots, a phenomenon related to the leaf damage imposed by Rubellin, although, resistance to physiological leafspots appeared to come from the Ramularia leaf spot susceptible parent. The toxin assay further supported this result as the genotypes susceptible...

Change Detection with GRASS GIS – Comparison of images taken by different sensors

Directory of Open Access Journals (Sweden)

Michael Fuchs

2009-04-01

Full Text Available Images of American military reconnaissance satellites of the Sixties (CORONA in combination with modern sensors (SPOT, QuickBird were used for detection of changes in land use. The pilot area was located about 40 km northwest of Yemen’s capital Sana’a and covered approximately 100 km2 . To produce comparable layers from images of distinctly different sources, the moving window technique was applied, using the diversity parameter. The resulting difference layers reveal plausible and interpretable change patterns, particularly in areas where urban sprawl occurs.The comparison of CORONA images with images taken by modern sensors proved to be an additional tool to visualize and quantify major changes in land use. The results should serve as additional basic data eg. in regional planning.The computation sequence was executed in GRASS GIS.

Timing of Occurrence Is the Most Important Characteristic of Spot Sign.

Science.gov (United States)

Wang, Binli; Yan, Shenqiang; Xu, Mengjun; Zhang, Sheng; Liu, Keqin; Hu, Haitao; Selim, Magdy; Lou, Min

2016-05-01

Most previous studies have used single-phase computed tomographic angiography to detect the spot sign, a marker for hematoma expansion (HE) in spontaneous intracerebral hemorrhage. We investigated whether defining the spot sign based on timing on perfusion computed tomography (CTP) would improve its specificity for predicting HE. We prospectively enrolled supratentorial spontaneous intracerebral hemorrhage patients who underwent CTP within 6 hours of onset. Logistic regression was performed to assess the risk factors for HE and poor outcome. Predictive performance of individual CTP spot sign characteristics were examined with receiver operating characteristic analysis. Sixty-two men and 21 women with spontaneous intracerebral hemorrhage were included in this analysis. Spot sign was detected in 46% (38/83) of patients. Receiver operating characteristic analysis indicated that the timing of spot sign occurrence on CTP had the greatest area under receiver operating characteristic curve for HE (0.794; 95% confidence interval, 0.630-0.958; P=0.007); the cutoff time was 23.13 seconds. On multivariable analysis, the presence of early-occurring spot sign (ie, spot sign before 23.13 seconds) was an independent predictor not only of HE (odds ratio=28.835; 95% confidence interval, 6.960-119.458; Pspot sign maintained a higher specificity for HE compared with spot sign (91% versus 74%). Redefining the spot sign based on timing of contrast leakage on CTP to determine early-occurring spot sign improves the specificity for predicting HE and 3-month mortality. The use of early-occurring spot sign could improve the selection of ICH patients for potential hemostatic therapy. © 2016 American Heart Association, Inc.

[Rocky Mountain spotted fever in Brazil].

Science.gov (United States)

del Sá DelFiol, Fernando; Junqueira, Fábio Miranda; da Rocha, Maria Carolina Pereira; de Toledo, Maria Inês; Filho, Silvio Barberato

2010-06-01

Although the number of confirmed cases of spotted fever has been declining in Brazil since 2005, the mortality rate (20% to 30%) is still high in comparison to other countries. This high mortality rate is closely related to the difficulty in making the diagnosis and starting the correct treatment. Only two groups of antibiotics have proven clinical effectiveness against spotted fever: chloramphenicol and tetracyclines. Until recently, the use of tetracyclines was restricted to adults because of the associated bone and tooth changes in children. Recently, however, the American Academy of Pediatrics and various researchers have recommended the use of doxycycline in children. In more severe cases, chloramphenicol injections are often preferred in Brazil because of the lack of experience with injectable tetracycline. Since early diagnosis and the adequate drug treatment are key to a good prognosis, health care professionals must be better prepared to recognize and treat spotted fever.

Mapping Geological Structures In Wadi Ghoweibaarea, Northwest Gulf Of Suez, Egypt, Using Aster-Spot Data Fusion And Aster DEM

International Nuclear Information System (INIS)

Abdeen, M.M.; Hassan, S.M.; EL-Kazzaz, Y.A.H.A.; Attia, G.M.; Yehia, M.A.

2009-01-01

Practical and economical constraints prompt the need of obtaining lithological and structural information for development of desert areas with reduced field effort. The fusion of multi-sensor satellite data is an effective mean of exploiting the complimentary nature of different data types. This technique allows fusion of spectral-spectral information of multi-source data with high accuracy. In the present study, fusion of SPOT and ASTER data was applied to test the potentiality of this technique in mapping geological formations and structural lineaments in Wadi Ghoweiba area, to the west of the northwestern tip of the Gulf of Suez, Egypt. ASTER data is characterized by a wide range of spectral bands (14 bands), while SPOT panchromatic data is characterized by high (10 meters) spatial resolution. Based on spectral characteristic analysis (SCA) of the 3 VNIR and the 6 SWIR bands of ASTER data, two false-color band-ratio images (1/3, 2/5, and 4/ 9) and (1/5, 8/9, and 4/6) in R, G, B were produced for better lithological discrimination. SPOT panchromatic image data was fused with ASTER band ratio images data using principal component (PC) and color normalization or Brovey transformation techniques. The fused images proved to be excellent for lithological discrimination. ASTER data includes bands 3N (Nadir) and 3B (Backward) that are acquired in the spectral range of near infrared region (from 0.78 to 0.86 microns) allowing extraction of digital elevation model (DEM). Three-dimensional perspective views were generated by draping SPOT-ASTER ratio fused images over ASTER DEM. This technique was used to enhance morphologically-defined structures. The fused images and the 3D perspective views were interpreted to produce a photo geological-structural map that was verified using the available geological maps and subsequent field check. The produced photo geological map indicates that fusion of SPOT and ASTER ratio image's data is a reliable technique for geological mapping

First Beam Test of Nanometer Spot Size Monitor Using Laser Interferometry

CERN Document Server

Walz, D

2003-01-01

The nanometer spot size monitor based on the laser interferometry (Laser-Compton Spot Size Monitor) has been tested in FFTB beam line at SLAC. A low emittance beam of 46 GeV electrons, provided by the two-mile linear accelerator, was focused into nanometer spot in the FFTB line, and its transverse dimensions were precisely measured by the spot size monitor.

First Beam Test of Nanometer Spot Size Monitor Using Laser Interferometry

International Nuclear Information System (INIS)

Walz, Dieter R

2003-01-01

The nanometer spot size monitor based on the laser interferometry (Laser-Compton Spot Size Monitor) has been tested in FFTB beam line at SLAC. A low emittance beam of 46 GeV electrons, provided by the two-mile linear accelerator, was focused into nanometer spot in the FFTB line, and its transverse dimensions were precisely measured by the spot size monitor

Performance of laser distance sensors for Atlas Micromegas production

Energy Technology Data Exchange (ETDEWEB)

Mueller, Ralph; Biebel, Otmar; Bortfeldt, Jonathan; Flierl, Bernhard; Hertenberger, Ralf; Loesel, Philipp; Pree, Elias [LMU Muenchen (Germany); Zibell, Andre [JMU Wuerzburg (Germany)

2015-07-01

During the second long LHC shutdown, 2018/19, the precision tracking detectors of the ATLAS muon spectrometer in the inner end caps will be replaced using Micromegas, a planar gas-detector technology. Modules of 2 m{sup 2} area are built in quadruplets from five precisely planar sandwich panels that define the anodes and the cathodes of the four active detector planes. Single plane spatial resolutions below 100 μ m are achievable when the deviation from planarity of the strip-anodes does not exceed 80 μ m RMS over the whole active area and the parallelism of the readout strips is within 30 μ m. In order to measure the dimensional accuracy of each panel, laser distance sensors to be combined with a coordinate measurement system have been investigated. One of them turned out to be capable to measure the planarity of the panels. It has a resolution of 0.3 μ m and a beam spot diameter of ∼50 μ m, which is well below 100 μ m the size of the smallest structures. For monitoring purposes during the construction process a less accurate but cheaper sensor turned out to be sufficient. We report on the performance of the sensors and their applicability to our tasks.

Effects of small, intense laser spots on thin films

International Nuclear Information System (INIS)

Estabrook, K.

1986-01-01

Two-dimensional hydrodynamic simulations show that small diameter laser spots burn through flat foils considerably faster than larger spots. The physical mechanisms are (1) more nearly spherical divergence from the smaller spots which allows the debris to rapidly convect radially away from the small volume of laser heated plasma and (2) a variation on thermal self-focusing in which light is refracted into this volume, increasing the local heating rate

Computed tomography angiography spot sign predicts intraprocedural aneurysm rupture in subarachnoid hemorrhage.

Science.gov (United States)

Burkhardt, Jan-Karl; Neidert, Marian Christoph; Stienen, Martin Nikolaus; Schöni, Daniel; Fung, Christian; Roethlisberger, Michel; Corniola, Marco Vincenzo; Bervini, David; Maduri, Rodolfo; Valsecchi, Daniele; Tok, Sina; Schatlo, Bawarjan; Bijlenga, Philippe; Schaller, Karl; Bozinov, Oliver; Regli, Luca

2017-07-01

To analyze whether the computed tomography angiography (CTA) spot sign predicts the intraprocedural rupture rate and outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). From a prospective nationwide multicenter registry database, 1023 patients with aneurysmal subarachnoid hemorrhage (aSAH) were analyzed retrospectively. Descriptive statistics and logistic regression analysis were used to compare spot sign-positive and -negative patients with aneurysmal intracerebral hemorrhage (aICH) for baseline characteristics, aneurysmal and ICH imaging characteristics, treatment and admission status as well as outcome at discharge and 1-year follow-up (1YFU) using the modified Rankin Scale (mRS). A total of 218 out of 1023 aSAH patients (21%) presented with aICH including 23/218 (11%) patients with spot sign. Baseline characteristics were comparable between spot sign-positive and -negative patients. There was a higher clip-to-coil ratio in patients with than without aICH (both spot sign positive and negative). Median aICH volume was significantly higher in the spot sign-positive group (50 ml, 13-223 ml) than in the spot sign-negative group (18 ml, 1-416; p spot sign-positive aICH thus were three times as likely as those with spot sign-negative aICH to show an intraoperative aneurysm rupture [odds ratio (OR) 3.04, 95% confidence interval (CI) 1.04-8.92, p = 0.046]. Spot sign-positive aICH patients showed a significantly worse mRS at discharge (p = 0.039) than patients with spot sign-negative aICH (median mRS 5 vs. 4). Logistic regression analysis showed that the spot sign was an aICH volume-dependent predictor for outcome. Both spot sign-positive and -negative aICH patients showed comparable rates of hospital death, death at 1YFU and mRS at 1YFU. In this multicenter data analysis, patients with spot sign-positive aICH showed higher aICH volumes and a higher rate of intraprocedural aneurysm rupture, but comparable long-term outcome to spot sign

Methodology and software to detect viral integration site hot-spots

Science.gov (United States)

2011-01-01

Background Modern gene therapy methods have limited control over where a therapeutic viral vector inserts into the host genome. Vector integration can activate local gene expression, which can cause cancer if the vector inserts near an oncogene. Viral integration hot-spots or 'common insertion sites' (CIS) are scrutinized to evaluate and predict patient safety. CIS are typically defined by a minimum density of insertions (such as 2-4 within a 30-100 kb region), which unfortunately depends on the total number of observed VIS. This is problematic for comparing hot-spot distributions across data sets and patients, where the VIS numbers may vary. Results We develop two new methods for defining hot-spots that are relatively independent of data set size. Both methods operate on distributions of VIS across consecutive 1 Mb 'bins' of the genome. The first method 'z-threshold' tallies the number of VIS per bin, converts these counts to z-scores, and applies a threshold to define high density bins. The second method 'BCP' applies a Bayesian change-point model to the z-scores to define hot-spots. The novel hot-spot methods are compared with a conventional CIS method using simulated data sets and data sets from five published human studies, including the X-linked ALD (adrenoleukodystrophy), CGD (chronic granulomatous disease) and SCID-X1 (X-linked severe combined immunodeficiency) trials. The BCP analysis of the human X-linked ALD data for two patients separately (774 and 1627 VIS) and combined (2401 VIS) resulted in 5-6 hot-spots covering 0.17-0.251% of the genome and containing 5.56-7.74% of the total VIS. In comparison, the CIS analysis resulted in 12-110 hot-spots covering 0.018-0.246% of the genome and containing 5.81-22.7% of the VIS, corresponding to a greater number of hot-spots as the data set size increased. Our hot-spot methods enable one to evaluate the extent of VIS clustering, and formally compare data sets in terms of hot-spot overlap. Finally, we show that the

Does the G-spot exist? A review of the current literature.

Science.gov (United States)

Puppo, Vincenzo; Gruenwald, Ilan

2012-12-01

In 1950, Gräfenberg described a distinct erotogenic zone on the anterior wall of the vagina, which was referred to as the Gräfenberg spot (G-spot) by Addiego, Whipple (a nurse) et al. in 1981. As a result, the G-spot has become a central topic of popular speculation and a basis of a huge business surrounding it. In our opinion, these sexologists have made a hotchpotch of Gräfenberg's thoughts and ideas that were set forth and expounded in his 1950 article: the intraurethral glands are not the corpus spongiosum of the female urethra, and Gräfenberg did not report an orgasm of the intraurethral glands. G-spot amplification is a cosmetic surgery procedure for temporarily increasing the size and sensitivity of the G-spot in which a dermal filler or a collagen-like material is injected into the bladder-vaginal septum. All published scientific data point to the fact that the G-spot does not exist, and the supposed G-spot should not be identified with Gräfenberg's name. Moreover, G-spot amplification is not medically indicated and is an unnecessary and inefficacious medical procedure.

A measurement concept for hot-spot BRDFs from space

Energy Technology Data Exchange (ETDEWEB)

Gerstl, S.A.W.

1996-09-01

Several concepts for canopy hot-spot measurements from space have been investigated. The most promising involves active illumination and bistatic detection that would allow hot-spot angular distribution (BRDF) measurements from space in a search-light mode. The concept includes a pointable illumination source, such as a laser operating at an atmospheric window wavelength, coupled with a number of high spatial-resolution detectors that are clustered around the illumination source in space, receiving photons nearly coaxial with the reto-reflection direction. Microwave control and command among the satellite cluster would allow orienting the direction of the laser beam as well as the focusing detectors simultaneously so that the coupled system can function like a search light with almost unlimited pointing capabilities. The concept is called the Hot-Spot Search-Light (HSSL) satellite. A nominal satellite altitude of 600 km will allow hot-spot BRDF measurements out to about 18 degrees phase angle. The distributed are taking radiometric measurements of the intensity wings of the hot-spot angular distribution without the need for complex imaging detectors. The system can be operated at night for increased signal-to-noise ratio. This way the hot-spot angular signatures can be quantified and parameterized in sufficient detail to extract the biophysical information content of plant architectures.

A measurement concept for hot-spot BRDFs from space

Science.gov (United States)

Gerstl, S.A.W.

1996-01-01

Several concepts for canopy hot-spot measurements from space have been investigated. The most promising involves active illumination and bistatic detection that would allow hot-spot angular distribution (BRDF) measurements from space in a search-light mode. The concept includes a pointable illumination source, such as a laser operating at an atmospheric window wavelength, coupled with a number of high spatial-resolution detectors that are clustered around the illumination source in space, receiving photons nearly coaxial with the reto-reflection direction. Microwave control and command among the satellite cluster would allow orienting the direction of the laser beam as well as the focusing detectors simultaneously so that the coupled system can function like a search light with almost unlimited pointing capabilities. The concept is called the Hot-Spot Search-Light (HSSL) satellite. A nominal satellite altitude of 600 km will allow hot-spot BRDF measurements out to about 18 degrees phase angle. The distributed are taking radiometric measurements of the intensity wings of the hot-spot angular distribution without the need for complex imaging detectors. The system can be operated at night for increased signal-to-noise ratio. This way the hot-spot angular signatures can be quantified and parameterized in sufficient detail to extract the biophysical information content of plant architectures.

Insights from ecological niche modeling on the taxonomic distinction and niche differentiation between the black-spotted and red-spotted tokay geckoes (Gekko gecko).

Science.gov (United States)

Zhang, Yueyun; Chen, Chongtao; Li, Li; Zhao, Chengjian; Chen, Weicai; Huang, Yong

2014-09-01

The black-spotted tokay and the red-spotted tokay are morphologically distinct and have largely allopatric distributions. The black-spotted tokay is characterized by a small body size and dark skin with sundry spots, while the red-spotted tokay has a relatively large body size and red spots. Based on morphological, karyotypic, genetic, and distribution differences, recent studies suggested their species status; however, their classifications remain controversial, and additional data such as ecological niches are necessary to establish firm hypotheses regarding their taxonomic status. We reconstructed their ecological niches models using climatic and geographic data. We then performed niche similarity tests (niche identity and background tests) and point-based analyses to explore whether ecological differentiation has occurred, and whether such differences are sufficient to explain the maintenance of their separate segments of environmental ranges. We found that both niche models of the black- and the red-spotted tokay had a good fit and a robust performance, as indicated by the high area under the curve (AUC) values ("black" = 0.982, SD = ± 0.002, "red" = 0.966 ± 0.02). Significant ecological differentiation across the entire geographic range was found, indicating that the involvement of ecological differentiation is important for species differentiation. Divergence along the environmental axes is highly associated with climatic conditions, with isothermality being important for the "black" form, while temperature seasonality, precipitation of warmest quarter, and annual temperature range together being important for the "red" form. These factors are likely important factors in niche differentiation between the two forms, which result in morphological replacement. Overall, beside morphological and genetic differentiation information, our results contribute to additional insights into taxonomic distinction and niche differentiation between the black- and the red-spotted

White-centred retinal haemorrhages (Roth spots).

Science.gov (United States)

Ling, R; James, B

1998-10-01

Roth spots (white-centred retinal haemorrhages) were classically described as septic emboli lodged in the retina of patients with subacute bacterial endocarditis. Indeed many have considered Roth spots pathognomonic for this condition. More recent histological evidence suggests, however, that they are not foci of bacterial abscess. Instead, they are nonspecific and may be found in many other diseases. A review of the histology and the pathogenesis of these white-centred haemorrhages will be provided, along with the work-up of the differential diagnosis.

Long-term Spot-Coverage Variations of 13 BY Dra G-K Dwarfs

Science.gov (United States)

Alekseev, I. Yu.; Kozhevnikova, A. V.

2018-06-01

The results of spot-coverage modeling for 13 active G-K dwarf stars based on many-year photometric observations are presented. The results of UBV RI observations of eight stars performed at the Crimean Astrophysical Observatory were used together with data from the literature in this analysis. The spot-coverage parameters for 13 selected BY Dra active red dwarfs have been redetermined to improve the zonal spot-coverage model for the stellar photospheres, which currently allows for the presence of two active longitudes. Time variations of the spot-activity characteristics of these systems were analyzed with the aim of searching for possible cyclic variations. All the stars, with the exception of OU Gem and BE Cet, show fairly strong correlations between variations in the spot latitudes and spot areas, with absolute values of the correlation coefficients, R(, S), ranging from 0.38 to 0.92. For five stars, an anti-correlation between the mean latitude and area of the spots was found ( R(, S) from-0.24 to-0.73). This behavior may reflect the drift of spots toward the equator in the course of their development. Eight stars feature positive correlations, i.e. the spots drift towards the pole as their areas increase. Nine stars demonstrate activity cycles, which are reflected in photometric variations as well as variations of the spot areas and mean latitudes. The periods of the latitude drift of the spots are found for five stars; the magnitudes of the spot-latitude drift rates are lower than the corresponding value for sunspots by a factor of 1.5-3.

PREDICTING RELEVANT EMPTY SPOTS IN SOCIAL INTERACTION

Institute of Scientific and Technical Information of China (English)

Yoshiharu MAENO; Yukio OHSAWA

2008-01-01

An empty spot refers to an empty hard-to-fill space which can be found in the records of the social interaction, and is the clue to the persons in the underlying social network who do not appear in the records. This contribution addresses a problem to predict relevant empty spots in social interaction. Homogeneous and inhomogeneous networks are studied as a model underlying the social interaction. A heuristic predictor function method is presented as a new method to address the problem. Simulation experiment is demonstrated over a homogeneous network. A test data set in the form of market baskets is generated from the simulated communication. Precision to predict the empty spots is calculated to demonstrate the performance of the presented method.

How much extra spot gas is there?

International Nuclear Information System (INIS)

Bros, Th.

2007-01-01

With the increase of European gas demand and the sharp decrease of local supply, security of supply is becoming an ever greater issue. However, liberalization tilts the traditional equilibrium based on long term 'take or pay' contracts between big suppliers and national distribution companies. Today, buying gas on the spot market is becoming more and more important to balance supply portfolio with a fast moving market share. But the way gas spot markets are operating is not well documented. It is very difficult to assess its impact on the European security of supply. Therefore, the aim of this article is to evaluate the amount of 'spot' liquefied natural gas (LNG) that could be found in case of a major supply disruption in pipe gas delivered to Europe

Spot på interaktive teknologier

DEFF Research Database (Denmark)

Brooks, Anthony Lewis

2014-01-01

Spot på interaktive teknologier Af Anthony Lewis Brooks, PhD Associate Professor, Aalborg University & Director SensoramaLab Den verdensomspændende paraplyorganisation for it-foreninger IFIP har netop afholdt sin årlige ”International Conference on Entertainment Computing”. Se her, hvad tre af top...... fra hele verden for at sætte fokus på, hvordan de nyeste teknologier inden for digital underholdning, kan bruges i forskellige sammenhænge. Bag begivenheden står IFIP, som DANSK IT er repræsenteret i. I år var der blandt andet spot på wearables og andre interaktive teknologier. Leila Alem fra den...

78 FR 9330 - Revision of Regulations Defining Bona Fide Cotton Spot Markets

Science.gov (United States)

2013-02-08

... Cotton Spot Markets AGENCY: Agricultural Marketing Service, USDA. ACTION: Proposed rule. SUMMARY: The... bona fide cotton spot markets in order to assure consistency with the revised Cotton Research and Promotion Act. Updated bona fide spot market definitions will allow for published spot quotes to consider...

Management of white spots: resin infiltration technique and microabrasion

Directory of Open Access Journals (Sweden)

Jeong-Hye Son

2011-01-01

Full Text Available This case report compared the effectiveness of resin infiltration technique (Icon, DMG with microabrasion (Opalustre, Ultradent Products, Inc. in management of white spot lesions. It demonstrates that although neither microabrasion nor resin infiltration technique can remove white spot lesions completely, resin infiltration technique seems to be more effective than microabrasion. Therefore resin infiltration technique can be chosen preferentially for management of white spot lesions and caution should be taken for case selection.

Fabrication and characterization of a metal-packaged regenerated fiber Bragg grating strain sensor for structural integrity monitoring of high-temperature components

International Nuclear Information System (INIS)

Tu, Yun; Tu, Shan-Tung

2014-01-01

Assessment of the structural integrity of components operating at high temperatures requires the development of novel sensors to measure strain. A metal-packaged regenerated fiber Bragg grating (RFBG) sensor is developed for measurement of strain using titanium–silver magnetron sputtering and nickel electroplating. The strain response of the sensor mounted onto a flat tensile specimen by spot welding is evaluated by uniaxial tensile tests at constant temperatures ranging from room temperature to 400 °C. Similar tests are performed on a bare RFBG sensor for comparison. The metal-packaged RFBG strain sensor exhibits higher strain sensitivity than that of the bare RFBG sensor, as well as good linearity, stability and repeatability of strain measurements. A three-dimensional finite element model of the sensor is established to predict the strain sensitivity based on the sensing principle of the fiber Bragg grating. Comparisons of the experimental results with the numerical predictions for the strain sensitivity show a satisfactory agreement. These results demonstrate that the metal-packaged RFBG strain sensors can be successfully fabricated by combining magnetron sputtering with electroplating, and provide great promise for structural integrity monitoring of high-temperature components. (paper)

Design of a cost-effective laser spot tracker

Science.gov (United States)

Artan, Göktuǧ Gencehan; Sari, Hüseyin

2017-05-01

One of the most important aspects of guided systems is detection. The most convenient detection in the sense of precision can be achieved with a laser spot tracker. This study deals with a military grade, high performance and cost-effective laser spot tracker for a guided system. The aim is to develop a high field of view system that will detect a laser spot from a distance of 3 kilometers in which the target is designated from 3 kilometers with a laser. The study basically consists of the system design, modeling, producing and the conducting performance tests of the whole system.

Robust adaptive optics systems for vision science

Science.gov (United States)

Burns, S. A.; de Castro, A.; Sawides, L.; Luo, T.; Sapoznik, K.

2018-02-01

Adaptive Optics (AO) is of growing importance for understanding the impact of retinal and systemic diseases on the retina. While AO retinal imaging in healthy eyes is now routine, AO imaging in older eyes and eyes with optical changes to the anterior eye can be difficult and requires a control and an imaging system that is resilient when there is scattering and occlusion from the cornea and lens, as well as in the presence of irregular and small pupils. Our AO retinal imaging system combines evaluation of local image quality of the pupil, with spatially programmable detection. The wavefront control system uses a woofer tweeter approach, combining an electromagnetic mirror and a MEMS mirror and a single Shack Hartmann sensor. The SH sensor samples an 8 mm exit pupil and the subject is aligned to a region within this larger system pupil using a chin and forehead rest. A spot quality metric is calculated in real time for each lenslet. Individual lenslets that do not meet the quality metric are eliminated from the processing. Mirror shapes are smoothed outside the region of wavefront control when pupils are small. The system allows imaging even with smaller irregular pupils, however because the depth of field increases under these conditions, sectioning performance decreases. A retinal conjugate micromirror array selectively directs mid-range scatter to additional detectors. This improves detection of retinal capillaries even when the confocal image has poorer image quality that includes both photoreceptors and blood vessels.

Design and research of intelligent mobile robot environment detection system based on multi-sensor technology

International Nuclear Information System (INIS)

Chen Yu; Wen Xinling

2007-01-01

The intelligent mobile robot environment detection system is researched based on SCM MC68HC908GP3 as core of control system. The four groups of detection systems constituted by ultrasonic sensors and infrared sensors gather information of forward, behind, left and right different directions, solve the problem of blind spot, and make up each other shortage. The distance measurement precision is improved rapidly and the detection precision is less than ±1% through using the way of the pulse shooting, the signal chooses circuit, and the temperature compensation. The system design method and the hardware circuit are introduced in detail. Simultaneity, the system adopts the single chip control technology, it makes the system possess favorable expansibility and gains the practicability in engineering field. (authors)

Characterization of silicon micro-strip sensors with a pulsed infra-red laser system for the CBM experiment at FAIR

International Nuclear Information System (INIS)

Ghosh, P.

2015-01-01

The Compressed Baryonic Matter (CBM) experiment at FAIR is composed of 8 tracking stations consisting of 1292 double sided silicon micro-strip sensors. For the quality assurance of produced prototype sensors a laser test system (LTS) has been developed. The aim of the LTS is to scan sensors with a pulsed infra-red laser driven by step motor to determine the charge sharing in-between strips and to measure qualitative uniformity of the sensor response over the whole active area. The prototype sensors which are tested with the LTS so far have 256 strips with a pitch of 50 μm on each side. They are read-out using a self-triggering prototype read-out electronic ASIC called n-XYTER. The LTS is designed to measure sensor response in an automatized procedure at several thousand positions across the sensor with focused infra-red laser light (spot size ≈ 12 μm , wavelength = 1060 nm). The pulse with duration (≈ 10 ns) and power (≈ 5 mW) of the laser pulses is selected such, that the absorption of the laser light in the 300 μm thick silicon sensors produces a number of about 24000 electrons, which is similar to the charge created by minimum ionizing particles (MIP) in these sensors. Laser scans different prototype sensors is reported

Electricity spot price dynamics: Beyond financial models

International Nuclear Information System (INIS)

Guthrie, Graeme; Videbeck, Steen

2007-01-01

We reveal properties of electricity spot prices that cannot be captured by the statistical models, commonly used to model financial asset prices, that are increasingly used to model electricity prices. Using more than eight years of half-hourly spot price data from the New Zealand Electricity Market, we find that the half-hourly trading periods fall naturally into five groups corresponding to the overnight off-peak, the morning peak, daytime off-peak, evening peak, and evening off-peak. The prices in different trading periods within each group are highly correlated with each other, yet the correlations between prices in different groups are lower. Models, adopted from the modeling of security prices, that are currently applied to electricity spot prices are incapable of capturing this behavior. We use a periodic autoregression to model prices instead, showing that shocks in the peak periods are larger and less persistent than those in off-peak periods, and that they often reappear in the following peak period. In contrast, shocks in the off-peak periods are smaller, more persistent, and die out (perhaps temporarily) during the peak periods. Current approaches to modeling spot prices cannot capture this behavior either. (author)

Dried blood spots as a source of anti-malarial antibodies for epidemiological studies

Science.gov (United States)

Corran, Patrick H; Cook, Jackie; Lynch, Caroline; Leendertse, Heleen; Manjurano, Alphaxard; Griffin, Jamie; Cox, Jonathan; Abeku, Tarekegn; Bousema, Teun; Ghani, Azra C; Drakeley, Chris; Riley, Eleanor

2008-01-01

Background Blood spots collected onto filter paper are an established and convenient source of antibodies for serological diagnosis and epidemiological surveys. Although recommendations for the storage and analysis of small molecule analytes in blood spots exist, there are no published systematic studies of the stability of antibodies under different storage conditions. Methods Blood spots, on filter paper or glass fibre mats and containing malaria-endemic plasma, were desiccated and stored at various temperatures for different times. Eluates of these spots were assayed for antibodies against two Plasmodium falciparum antigens, MSP-119 and MSP2, and calculated titres used to fit an exponential (first order kinetic) decay model. The first order rate constants (k) for each spot storage temperature were used to fit an Arrhenius equation, in order to estimate the thermal and temporal stability of antibodies in dried blood spots. The utility of blood spots for serological assays was confirmed by comparing antibodies eluted from blood spots with the equivalent plasma values in a series of samples from North Eastern Tanzania and by using blood spot-derived antibodies to estimate malaria transmission intensity in this site and for two localities in Uganda. Results Antibodies in spots on filter paper and glass fibre paper had similar stabilities but blood was more easily absorbed onto filter papers than glass fibre, spots were more regular and spot size was more closely correlated with blood volume for filter paper spots. Desiccated spots could be stored at or below 4°C for extended periods, but were stable for only very limited periods at ambient temperature. When desiccated, recoveries of antibodies that are predominantly of IgG1 or IgG3 subclasses were similar. Recoveries of antibodies from paired samples of serum and of blood spots from Tanzania which had been suitably stored showed similar recoveries of antibodies, but spots which had been stored for extended periods

Spot market activity remains weak as prices continue to fall

International Nuclear Information System (INIS)

Anon.

1996-01-01

A summary of financial data for the uranium spot market in November 1996 is provided. Price ranges for the restricted and unrestricted markets, conversion, and separative work are listed, and total market volume and new contracts are noted. Transactions made are briefly described. Deals made and pending in the spot concentrates, medium and long-term, conversion, and markets are listed for U.S. and non-U.S. buyers. Spot market activity increased in November with just over 1.0 million lbs of U3O8 equivalent being transacted compared to October's total of 530,000 lbs of U3O8 equivalent. The restricted uranium spot market price range slipped from $15.50-$15.70/lb U3O8 last month to $14.85/lb - $15.25/lb U3O8 this month. The unrestricted uranium spot market price range also slipped to $14.85/lb - $15.00/lb this month from $15.00/lb - $15.45/lb in October. Spot prices for conversion and separative work units remained at their October levels

Recurrent star-spot activity and differential rotation in KIC 11560447

Science.gov (United States)

Özavcı, I.; Şenavcı, H. V.; Işık, E.; Hussain, G. A. J.; O'Neal, D.; Yılmaz, M.; Selam, S. O.

2018-03-01

We present a detailed analysis of surface inhomogeneities on the K1-type subgiant component of the rapidly rotating eclipsing binary KIC 11560447, using high-precision Kepler light curves spanning nearly 4 yr, which corresponds to about 2800 orbital revolutions. We determine the system parameters precisely, using high-resolution spectra from the 2.1-m Otto Struve Telescope at the McDonald Observatory. We apply the maximum entropy method to reconstruct the relative longitudinal spot occupancy. Our numerical tests show that the procedure can recover large-scale random distributions of individually unresolved spots, and it can track the phase migration of up to three major spot clusters. By determining the drift rates of various spotted regions in orbital longitude, we suggest a way to constrain surface differential rotation and we show that the results are consistent with periodograms. The K1IV star exhibits two mildly preferred longitudes of emergence, indications of solar-like differential rotation, and a 0.5-1.3-yr recurrence period in star-spot emergence, accompanied by a secular increase in the axisymmetric component of spot occupancy.

Hot spot-based design of small-molecule inhibitors for protein-protein interactions.

Science.gov (United States)

Guo, Wenxing; Wisniewski, John A; Ji, Haitao

2014-06-01

Protein-protein interactions (PPIs) are important targets for the development of chemical probes and therapeutic agents. From the initial discovery of the existence of hot spots at PPI interfaces, it has been proposed that hot spots might provide the key for developing small-molecule PPI inhibitors. However, there has been no review on the ways in which the knowledge of hot spots can be used to achieve inhibitor design, nor critical examination of successful examples. This Digest discusses the characteristics of hot spots and the identification of druggable hot spot pockets. An analysis of four examples of hot spot-based design reveals the importance of this strategy in discovering potent and selective PPI inhibitors. A general procedure for hot spot-based design of PPI inhibitors is outlined. Copyright © 2014 Elsevier Ltd. All rights reserved.

Retrieving handwriting by combining word spotting and manifold ranking

Science.gov (United States)

Peña Saldarriaga, Sebastián; Morin, Emmanuel; Viard-Gaudin, Christian

2012-01-01

Online handwritten data, produced with Tablet PCs or digital pens, consists in a sequence of points (x, y). As the amount of data available in this form increases, algorithms for retrieval of online data are needed. Word spotting is a common approach used for the retrieval of handwriting. However, from an information retrieval (IR) perspective, word spotting is a primitive keyword based matching and retrieval strategy. We propose a framework for handwriting retrieval where an arbitrary word spotting method is used, and then a manifold ranking algorithm is applied on the initial retrieval scores. Experimental results on a database of more than 2,000 handwritten newswires show that our method can improve the performances of a state-of-the-art word spotting system by more than 10%.

Locating the Great Red Spot: Yesterday, Today, and Tomorrow

Science.gov (United States)

Lesniak, Michael V.; Stapleton, J. C.

2014-01-01

The Great Red Spot, a persistent storm in Jupiter's atmosphere, is the most prominent feature of that planet's disk as viewed from Earth. Combined with the fact that Jupiter is a gas giant planet and has no visible surface with discernible landmarks, this means that following the passage of the Great Red Spot is the primary method of observing the planet's rotation. Therefore, it is paramount for any program which generates synthetic images of the planet to accurately place the feature. The U.S. Naval Observatory's "Apparent Disk of a Solar System Object" online web service (http://aa.usno.navy.mil/data/docs/diskmap.php) is such a program. The Great Red Spot's planetary latitude is locked between two of Jupiter's striated atmospheric layers at 22 °S. However, its planetary longitude is not constant; over time it migrates east and west along the atmospheric layer boundary it is trapped within. Observing and recording its longitude is made difficult because Jupiter's atmosphere is subject to differential rotation and the Great Red Spot slowly migrates with respect to the surrounding atmospheric layers. Furthermore, the Great Red Spot does not move at a uniform rate. Currently its relative motion is approximately 0°.051 per day. Since its first recorded observation in 1831, the Great Red Spot has made almost three complete laps around the planet at the 22nd parallel. "Apparent Disk of a Solar System Object" operates over any requested date between 1700 and 2100 A.D. Therefore, our treatment of the Great Red Spot needs to take into account both historical positions and future predicted motion. Based on researching past observations of the spot's position on the disk, we find that its behavior prior to 2009 is best represented by a 10-part piecewise function. Each component of the piecewise function is a 2nd order polynomial. Observations from 2009-present are better fit with a linear function; this function is used for future years by extrapolation. Using these fits

Dissecting black spot resistance in polyploid hybrid roses

Science.gov (United States)

Devastating foliar diseases, such as black spot caused by Diplocarpon rosae, pose constant threats to the ornamental quality of outdoor grown roses. Black spot is primarily managed though the use of fungicides, however, there is a high demand for resistant roses which require low chemical inputs. To...

Blind spot detection & passive lane change assist systems

NARCIS (Netherlands)

Surovtcev, I.

2015-01-01

The project goal was design and implementation of proof-of-concept for two systems that aim to tackle the blind spot problem of for the commercial vehicles: Blind Spot Detection and Passive Lane Change Assist functions. The system implementation was done using Rapid Control Prototype (RCP) hardware.

Laser Beam Caustic Measurement with Focal Spot Analyser

DEFF Research Database (Denmark)

Olsen, Flemming Ove; Gong, Hui; Bagger, Claus

2005-01-01

In industrial applications of high power CO2-lasers the caustic characteristics of the laser beam have great effects on the performance of the lasers. A welldefined high intense focused spot is essential for reliable production results. This paper presents a focal spot analyser that is developed...

Volume dips; spot price ranges narrow

International Nuclear Information System (INIS)

Anon.

1994-01-01

This article is the September 1994 uranium market summary. Volume in the spot concentrates market fell below 1 million lbs U3O8. In total, twelve deals took place compared to 28 deals in August. Of the twelve deals, three took place in the spot concentrates market, two took place in the medium and long-term market, three in the conversion market, and four in the enrichment market. Restricted prices weakened, but unrestricted prices firmed slightly. The enrichment price range narrowed a bit

Spot Ignition of Natural Fuels by Hot Metal Particles

OpenAIRE

Urban, James Linwood

2017-01-01

The spot ignition of combustible material by hot metal particles is an important pathway by which wildland and urban spot fires and smolders are started. Upon impact with a fuel, such as dry grass, duff, or saw dust, these particles can initiate spot fires by direct flaming or smoldering which can transition to a flame. These particles can be produced by processes such as welding, powerline interactions, fragments from bullet impacts, abrasive cutting, and pyrotechnics. There is little publi...

Stress hot spots in viscoplastic deformation of polycrystals

International Nuclear Information System (INIS)

Rollett, A D; Li, J; Rohrer, G S; Lebensohn, R A; Groeber, M; Choi, Y

2010-01-01

The viscoplastic deformation of polycrystals under uniaxial loading is investigated to determine the relationship between hot spots in stress and their location in relation to the microstructure. A 3D full-field formulation based on fast Fourier transforms for the prediction of the viscoplastic deformation of poly-crystals is used with rate-sensitive crystal plasticity. Two measured polycrystalline structures are used to instantiate the simulations, as well as a fully periodic synthetic polycrystal adapted from a simulation of grain growth. Application of (Euclidean) distance maps shows that hot spots in stress tend to occur close to grain boundaries. It is also found that low stress regions lie close to boundaries. The radial distribution function of the hot spots indicates clustering. Despite the lack of texture in the polycrystals, the hot spots are strongly concentrated in (1 1 0) orientations, which can account for the observed clustering. All three microstructures yield similar results despite significant differences in topology

Management of post-orthodontic white spot lesions

DEFF Research Database (Denmark)

Sonesson, Mikael; Bergstrand, Fredrik; Gizani, Sotiria

2016-01-01

BACKGROUND/OBJECTIVES: The management of post-orthodontic white spot lesions is based on remineralization strategies or a minimal-invasive camouflage of the lesions. AIM: The aim of this systematic review was to identify and assess the quality of evidence for the various clinical technologies......-orthodontic white spot lesions. Further well-performed controlled clinical trials with long-term follow-up are needed to establish best clinical practice....

Spot table - RPD | LSDB Archive [Life Science Database Archive metadata

Lifescience Database Archive (English)

Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data ...d_spot.zip File URL: ftp://ftp.biosciencedbc.jp/archive/rpd/LATEST/rpd_spot.zip F... cDNA. (multiple entries) About This Database Database Description Download License Update History of This Database Site Policy | Contact Us Spot table - RPD | LSDB Archive ...

Investigation of shinning Spot Defect on Hot-Dip Galvanized Steel Sheets

International Nuclear Information System (INIS)

Yonggang, Liu; Lei, Cui

2014-01-01

Shinning spot defects on galvanized steel sheets were studied by optical microscope, scanning electron microscope(SEM), Energy Dispersive Spectrometer (EDS) and Laser-Induced Breakdown Spectroscopy Original Position Statistic Distribution Analysis (LIBSOPA) in this study. The research shows that the coating thickness of shinning spot defects which caused by the substrate defect is much lower than normal area, and when skin passed, the shinning spot defect area can not touch with skin pass roll which result in the surface of shinning spot is flat while normal area is rough. The different coating morphologies have different effects on the reflection of light, which cause the shinning spot defects more brighter than normal area

Single-shot and single-spot measurement of laser ablation threshold for carbon nanotubes

OpenAIRE

Lednev, Vasily N.; Pershin, Sergey M.; Obraztsova, Elena D.; Kudryashov, Sergey I.; Bunkin, Alexey F.

2013-01-01

A simple and convenient procedure for single-shot, single-spot ablation threshold measurement has been developed. It is based on the employment of cylindrical lens to obtain elliptical Gaussian laser spot. The ablated spot chords which are parallel to the minor axis were measured across the spot major axis which is proportional to the fluence cross-section thus providing wide range dependence of damaged spot size versus fluence in one spot measurement. For both conventional and new-developed ...

Verification of the anatomy and newly discovered histology of the G-spot complex.

Science.gov (United States)

Ostrzenski, A; Krajewski, P; Ganjei-Azar, P; Wasiutynski, A J; Scheinberg, M N; Tarka, S; Fudalej, M

2014-10-01

To expand the anatomical investigations of the G-spot and to assess the G-spot's characteristic histological and immunohistochemical features. An observational study. International multicentre. Eight consecutive fresh human female cadavers. Anterior vaginal wall dissections were executed and G-spot microdissections were performed. All specimens were stained with haematoxylin and eosin (H&E). The tissues of two women were selected at random for immunohistochemical staining. The primary outcome measure was to document the anatomy of the G-spot. The secondary outcome measures were to identify the histology of the G-spot and to determine whether histological samples stained with H&E are sufficient to identify the G-spot. The anatomical existence of the G-spot was identified in all women and was in a diagonal plane. In seven (87.5%) and one (12.5%) of the women the G-spot complex was found on the left or right side, respectively. The G-spot was intimately fused with vessels, creating a complex. A large tangled vein-like vascular structure resembled an arteriovenous malformation and there were a few smaller feeding arteries. A band-like structure protruded from the tail of the G-spot. The size of the G-spot varied. Histologically, the G-spot was determined as a neurovascular complex structure. The neural component contained abundant peripheral nerve bundles and a nerve ganglion. The vascular component comprised large vein-like vessels and smaller feeding arteries. Circular and longitudinal muscles covered the G-complex. The anatomy of the G-spot complex was confirmed. The histology of the G-spot presents as neurovascular tissues with a nerve ganglion. H&E staining is sufficient for the identification of the G-spot complex. © 2014 Royal College of Obstetricians and Gynaecologists.

Spots on AG Virginis - paradigm or panacea?

International Nuclear Information System (INIS)

Bell, S.A.; Rainger, P.P.; Hilditch, R.W.

1990-01-01

New photometric and spectroscopic observations of the eclipsing binary AG Vir are presented. Medium-resolution spectroscopy has allowed the measurement of velocities for the secondary component for the first time. The V light curve shows many of the features seen in previous studies of this system. A full analysis of the spectroscopic and photometric data has been made which suggests that the system is either in a marginal state of contact or a deep-contact configuration depending on the type of spot model invoked. AG Vir constitutes an excellent example of the expected manifestations of spot activity on a light curve. It also demonstrates the ease with which the spot phenomenon can be invoked to explain the appearance of a light curve and to provide conflicting results. (author)

A method for short term electricity spot price forecasting

International Nuclear Information System (INIS)

Koreneff, G.; Seppaelae, A.; Lehtonen, M.; Kekkonen, V.; Laitinen, E.; Haekli, J.; Antila, E.

1998-01-01

In Finland, the electricity market was de-regulated in November 1995. For the electricity purchase of power companies this has caused big changes, since the old tariff based contracts of bulk power supply have been replaced by negotiated bilateral short term contracts and by power purchase from the spot market. In the spot market, in turn, there are at the present two strong actors: The electricity exchange of Finland and the Nordic power pool which is run by the Swedish and Norwegian companies. Today, the power companies in Finland have short term trade with both of the electricity exchanges. The aim of this chapter is to present methods for spot price forecasting in the electricity exchange. The main focus is given to the Finnish circumstances. In the beginning of the presentation, the practices of the electricity exchange of Finland are described, and a brief presentation is given on the different contracts, or electricity products, available in the spot market. For comparison, the practices of the Nordic electricity exchange are also outlined. A time series technique for spot price forecasting is presented. The structure of the model is presented, and its validity is tested using real case data obtained from the Finnish power market. The spot price forecasting model is a part of a computer system for distribution energy management (DEM) in a de-regulated power market

A method for short term electricity spot price forecasting

Energy Technology Data Exchange (ETDEWEB)

Koreneff, G; Seppaelae, A; Lehtonen, M; Kekkonen, V [VTT Energy, Espoo (Finland); Laitinen, E; Haekli, J [Vaasa Univ. (Finland); Antila, E [ABB Transmit Oy (Finland)

1998-08-01

In Finland, the electricity market was de-regulated in November 1995. For the electricity purchase of power companies this has caused big changes, since the old tariff based contracts of bulk power supply have been replaced by negotiated bilateral short term contracts and by power purchase from the spot market. In the spot market, in turn, there are at the present two strong actors: The electricity exchange of Finland and the Nordic power pool which is run by the Swedish and Norwegian companies. Today, the power companies in Finland have short term trade with both of the electricity exchanges. The aim of this chapter is to present methods for spot price forecasting in the electricity exchange. The main focus is given to the Finnish circumstances. In the beginning of the presentation, the practices of the electricity exchange of Finland are described, and a brief presentation is given on the different contracts, or electricity products, available in the spot market. For comparison, the practices of the Nordic electricity exchange are also outlined. A time series technique for spot price forecasting is presented. The structure of the model is presented, and its validity is tested using real case data obtained from the Finnish power market. The spot price forecasting model is a part of a computer system for distribution energy management (DEM) in a de-regulated power market

7 CFR 28.422 - Strict Middling Spotted Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Strict Middling Spotted Color. 28.422 Section 28.422 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Color. Strict Middling Spotted Color is color which is within the range represented by a set of samples...

7 CFR 28.425 - Low Middling Spotted Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Low Middling Spotted Color. 28.425 Section 28.425 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Color. Low Middling Spotted Color is color which is within the range represented by a set of samples in...

Triggered tremor sweet spots in Alaska

Science.gov (United States)

Gomberg, Joan; Prejean, Stephanie

2013-01-01

To better understand what controls fault slip along plate boundaries, we have exploited the abundance of seismic and geodetic data available from the richly varied tectonic environments composing Alaska. A search for tremor triggered by 11 large earthquakes throughout all of seismically monitored Alaska reveals two tremor “sweet spots”—regions where large-amplitude seismic waves repeatedly triggered tremor between 2006 and 2012. The two sweet spots locate in very different tectonic environments—one just trenchward and between the Aleutian islands of Unalaska and Akutan and the other in central mainland Alaska. The Unalaska/Akutan spot corroborates previous evidence that the region is ripe for tremor, perhaps because it is located where plate-interface frictional properties transition between stick-slip and stably sliding in both the dip direction and laterally. The mainland sweet spot coincides with a region of complex and uncertain plate interactions, and where no slow slip events or major crustal faults have been noted previously. Analyses showed that larger triggering wave amplitudes, and perhaps lower frequencies (tremor. However, neither the maximum amplitude in the time domain or in a particular frequency band, nor the geometric relationship of the wavefield to the tremor source faults alone ensures a high probability of triggering. Triggered tremor at the two sweet spots also does not occur during slow slip events visually detectable in GPS data, although slow slip below the detection threshold may have facilitated tremor triggering.

Effect of the small accessary laser spots on the harmonic emission stimulated by self-focusing of a 10-micrometer scale laser spot

International Nuclear Information System (INIS)

Lin Zunqi; Zhang Huihuang; He Xingfa

1992-01-01

A novel group of experiments has shown that single 10-micrometer-radius-scale laser spot is not able to produce the 90 deg side emitted three half harmonic efficiently in a preformed laser plasmas. However, with the help of one or two accessory laser spots with the size similar to the main one, the side emitted three half can easily built up when some position and angle conditions for the accessory spots are fulfilled. The origin of these phenomena have been analyzed in terms of the two plasmon decay theory and dynamic self-focusing model

ESA uncovers Geminga's `hot spot'

Science.gov (United States)

2004-07-01

16 July 2004 Astronomers using ESA’s X-ray observatory XMM-Newton have detected a small, bright ‘hot spot’ on the surface of the neutron star called Geminga, 500 light-years away. The hot spot is the size of a football field and is caused by the same mechanism producing Geminga’s X-ray tails. This discovery identifies the missing link between the X-ray and gamma-ray emission from Geminga. hi-res Size hi-res: 1284 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot This figure shows the effects of charged particles accelerated in the magnetosphere of Geminga. Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of particles kicked out by Geminga’s strong magnetic field, trail the neutron star as it moves about in space. Panel (b) shows how electrically charged particles interact with Geminga’s magnetic field. For example, if electrons (blue) are kicked out by the star, positrons (in red) hit the star’s magnetic poles like in an ‘own goal’. Panel (c) illustrates the size of Geminga’s magnetic field (blue) compared to that of the star itself at the centre (purple). The magnetic field is tilted with respect to Geminga’s rotation axis (red). Panel (d) shows the magnetic poles of Geminga, where charged particles hit the surface of the star, creating a two-million degrees hot spot, a region much hotter than the surroundings. As the star spins on its rotation axis, the hot spot comes into view and then disappears, causing the periodic colour change seen by XMM-Newton. An animated version of the entire sequence can be found at: Click here for animated GIF [low resolution, animated GIF, 5536 KB] Click here for AVI [high resolution, AVI with DIVX compression, 19128 KB] hi-res Size hi-res: 371 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot, panel (a) Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of

spots de campaña

Directory of Open Access Journals (Sweden)

Julio Juárez Gámiz

2007-01-01

publicidad política en televisión. Ilustrado por los spots televisivos, el debate se ha centrado en el alto costo que representa para los contribuyentes, a través de los partidos políticos, la producción y transmisión de estos mensajes. El presente trabajo consiste en un análisis de contenido de una muestra de spots transmitidos por las tres principales fuerzas electorales en México durante la campaña presidencial de 2006. El objetivo es identificar, de manera sistemática, características particulares en el formato y contenido de estos mensajes a la luz de su función persuasiva e informativa.

Estimation method for volumes of hot spots created by heavy ions

International Nuclear Information System (INIS)

Kanno, Ikuo; Kanazawa, Satoshi; Kajii, Yuji

1999-01-01

As a ratio of volumes of hot spots to cones, which have the same lengths and bottom radii with the ones of hot spots, a simple and convenient method for estimating the volumes of hot spots is described. This calculation method is useful for the study of damage producing mechanism in hot spots, and is also convenient for the estimation of the electron-hole densities in plasma columns created by heavy ions in semiconductor detectors. (author)

A highly accurate wireless digital sun sensor based on profile detecting and detector multiplexing technologies

Science.gov (United States)

Wei, Minsong; Xing, Fei; You, Zheng

2017-01-01

The advancing growth of micro- and nano-satellites requires miniaturized sun sensors which could be conveniently applied in the attitude determination subsystem. In this work, a profile detecting technology based high accurate wireless digital sun sensor was proposed, which could transform a two-dimensional image into two-linear profile output so that it can realize a high update rate under a very low power consumption. A multiple spots recovery approach with an asymmetric mask pattern design principle was introduced to fit the multiplexing image detector method for accuracy improvement of the sun sensor within a large Field of View (FOV). A FOV determination principle based on the concept of FOV region was also proposed to facilitate both sub-FOV analysis and the whole FOV determination. A RF MCU, together with solar cells, was utilized to achieve the wireless and self-powered functionality. The prototype of the sun sensor is approximately 10 times lower in size and weight compared with the conventional digital sun sensor (DSS). Test results indicated that the accuracy of the prototype was 0.01° within a cone FOV of 100°. Such an autonomous DSS could be equipped flexibly on a micro- or nano-satellite, especially for highly accurate remote sensing applications.

Analysis and validation of laser spot weld-induced distortion

Energy Technology Data Exchange (ETDEWEB)

Knorovsky, G.A.; Kanouff, M.P.; Maccallum, D.O.; Fuerschbach, P.W.

1999-12-09

Laser spot welding is an ideal process for joining small parts with tight tolerances on weld size, location, and distortion, particularly those with near-by heat sensitive features. It is also key to understanding the overlapping laser spot seam welding process. Rather than attempting to simulate the laser beam-to-part coupling (particularly if a keyhole occurs), it was measured by calorimetry. This data was then used to calculate the thermal and structural response of a laser spot welded SS304 disk using the finite element method. Five combinations of process parameter values were studied. Calculations were compared to experimental data for temperature and distortion profiles measured by thermocouples and surface profiling. Results are discussed in terms of experimental and modeling factors. The authors then suggest appropriate parameters for laser spot welding.

HotRegion: a database of predicted hot spot clusters.

Science.gov (United States)

Cukuroglu, Engin; Gursoy, Attila; Keskin, Ozlem

2012-01-01

Hot spots are energetically important residues at protein interfaces and they are not randomly distributed across the interface but rather clustered. These clustered hot spots form hot regions. Hot regions are important for the stability of protein complexes, as well as providing specificity to binding sites. We propose a database called HotRegion, which provides the hot region information of the interfaces by using predicted hot spot residues, and structural properties of these interface residues such as pair potentials of interface residues, accessible surface area (ASA) and relative ASA values of interface residues of both monomer and complex forms of proteins. Also, the 3D visualization of the interface and interactions among hot spot residues are provided. HotRegion is accessible at http://prism.ccbb.ku.edu.tr/hotregion.

Assessment of White Spot Lesions and In-Vivo Evaluation of the Effect of CPP-ACP on White Spot Lesions in Permanent Molars of Children.

Science.gov (United States)

Munjal, Deepti; Garg, Shalini; Dhindsa, Abhishek; Sidhu, Gagandeep Kaur; Sethi, Harsimran Singh

2016-05-01

As hindrance of remineralisation process occurs during orthodontic therapy resulting in decalcification of enamel because number of plaque retention sites increases due to banding and bonding of appliances to teeth. The present analytic study was undertaken to assess the occurrence of white spot lesions in permanent molars of children with and without orthodontic therapy and to evaluate the effect of Casein PhosphoPeptide-Amorphous Calcium Phosphate (CPP-ACP) on white spot lesions in post-orthodontic patients in a given period of time. The study comprised of examination of 679 first permanent molars which were examined to assess the occurrence of smooth surface white spot lesions in children of 8 to 16 years age group. Group I comprised subjects without any orthodontic treatment and Group II comprised of subjects who had undergone orthodontic therapy. The sample size was calculated using the epi-info6 computer package. Treatment group included 20 post-orthodontic patients examined with at least one white spot lesion within the enamel who received remineralizing cream (GC Tooth Mousse, Recaldent, GC Corporation.) i.e., CPP-ACP cream two times a day for 12 consecutive weeks. Computerized image analysis method was taken to evaluate white spot lesions. These frequency and percentages were compared with chi-square test. For comparison of numeric data, paired t-test was used. Of the total 278 (49.6%) first permanent molars showed occurrence of smooth surface white spot lesions out of 560 in Group I and 107 (89.9%) first permanent molars showed presence of white spot lesions out of 119 debanded first permanent molars of children examined in Group II. CPP-ACP therapy group showed reduction in severity of codes which was found to be highly significant after 12 weeks and eight weeks on gingival-third, p-value (spot lesions on teeth undergoing fixed orthodontic therapy according to the present study.

Association of poly-purine/poly-pyrimidine sequences with meiotic recombination hot spots

Directory of Open Access Journals (Sweden)

Pitt Joel PW

2006-07-01

Full Text Available Abstract Background Meiotic recombination events have been found to concentrate in 1–2.5 kilo base regions, but these recombination hot spots do not share a consensus sequence and why they occur at specific sites is not fully understood. Some previous evidence suggests that poly-purine/poly-pyrimidine (poly-pu/py tracts (PPTs, a class of sequence with distinctive biochemical properties, could be involved in recombination, but no general association of PPTs with meiotic recombination hot spots has previously been reported. Results We used computational methods to investigate in detail the relationship between PPTs and hot spots. We show statistical associations of PPT frequency with hot spots of meiotic recombination initiating lesions, double-strand breaks, in the genome of the yeast S. cerevisiae and with experimentally well characterized human meiotic recombination hot spots. Supporting a possible role of poly-pu/py-rich sequences in hot spot recombination, we also found that all three single nucleotide polymorphisms previously shown to be associated with human hot spot activity changes occur within sequence contexts of 14 bp or longer that are 85% or more poly-pu/py and at least 70% G/C. These polymorphisms are all close to the hot spot mid points. Comparing the sequences of experimentally characterized human hot spots with the orthologous regions of the chimpanzee genome previously shown not to contain hot spots, we found that in all five cases in which comparisons for the hot spot central regions are possible with publicly available sequence data, there are differences near the human hot spot mid points within sequences 14 bp or longer consisting of more than 80% poly-pu/py and at least 50% G/C. Conclusion Our results, along with previous evidence for the unique biochemical properties and recombination-stimulating potential of poly-pu/py-rich sequences, suggest that the possible functional involvement of this type of sequence in meiotic

Efecto de la fluido terapia endovenosa en los electrolitos y gases arteriales de pacientes ancianos hospitalizados. Estudio comparativo: Solución Hartmann y solución salina hipotónica.

Directory of Open Access Journals (Sweden)

Germán Javier MALAGA RODRIGUEZ

2006-10-01

Full Text Available Objetivos: Comparar el efecto de una solución de dextrosa hipotónica y de una solución isotónica (Hartmann en los niveles séricos de electrolitos y el equilibrio ácido base en pacientes ancianos hospitalizados. Materiales y métodos: Se evaluaron prospectivamente a 18 pacientes mayores de 60 años hospitalizados en el departamento de Medicina del Hospital Nacional Cayetano Heredia que recibieron fluidos endovenosos al menos por 48 horas. El primer grupo (G1 recibió una solución de dextrosa al 5%, 71 mmol/L de ClNa y 27 mmol/L de cloruro de potasio. El segundo grupo (G2 recibió solución Hartmann, más una solución glucosada de 100 cc al 50% simultáneamente. Se controlaron los valores de los electrolitos y los gases sanguíneos a las 0, 24 y 48 horas de iniciada la observación. Resultados: Ambos grupos presentaron condiciones comparables al ingreso. A las 48 horas los valores del sodio para el G1 fueron 134,5±4,4 mEq/L y para el G2 140±2,4 mEq/L (p<0,01, el pH del G1 fue 7,32±0,07 y el del G2 fue 7,4±0,03 (p<0,01, y el bicarbonato fue 16,6±2,2 mEq/L para el G1 y 22,3±1,6 mEq/L para el G2 (p<0,001. La diferencia entre los valores a las 0 (delta y 48 horas fueron: sodio -6,1±3,78(G1, 0,9±2,25(G2 en mEq/L, (p<0,001; potasio 0,01±0,43(G1, -0,61±0,56(G2 en mEq/L, (p<0,05; pH -0,09±0,07(G1, -0,01±0,04(G2, (p<0,01; bicarbonato -6,34±1,21(G1, -0,27±1,43(G2 en mEq/L, (p<0,001; pCO2 -6,25±5,33 (G1, 1,4±4,52(G2 en mmHg, (p<0,01. Conclusiones: Los pacientes ancianos hospitalizados que recibieron solución de dextrosa hipotónica, tuvieron niveles significativamente menores de sodio, pH, bicarbonato y pCO2 después de 48 horas comparados con quienes recibieron solución de Hartmann. No se observaron diferencias en los niveles de cloruro, pO2 y anion gap.(Rev Med Hered 2006;17:189-195.

"Center punch" and "whole spot" bioanalysis of apixaban in human dried blood spot samples by UHPLC-MS/MS.

Science.gov (United States)

Zheng, Naiyu; Yuan, Long; Ji, Qin C; Mangus, Heidi; Song, Yan; Frost, Charles; Zeng, Jianing; Aubry, Anne-Françoise; Arnold, Mark E

2015-04-15

Apixaban (Eliquis™) was developed by Bristol-Myers Squibb (BMS) and Pfizer to use as an antithrombotic/anticoagulant agent and has been recently approved for the prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. A clinical study of apixaban, sponsored by BMS and Pfizer, included a pilot exploratory portion to evaluate the potential for future drug concentration monitoring using dried blood spot (DBS) sample collection. For DBS sample collection, a fixed blood volume was dispensed onto a DBS card by either regular volumetric pipette (venous blood collection) or capillary dispenser (finger prick blood collection). A 96-well semi-automated liquid-liquid extraction sample preparation procedure was developed to provide clean extracts for UHPLC-MS/MS quantitation. Assays using both partial-spot center punch and whole spot punch were developed and validated. The linear dynamic ranges for all the analyses were from 0.5 to 500 ng/mL. The coefficient of determination (r(2)) values was >0.9944 for all the validation runs. For the center punch approach, the intra-assay precision (%CV) was within 4.4% and inter-assay precision was within 2.6%. The assay accuracy, expressed as %Dev., was within ± 5.4% of the nominal concentrations. One accuracy and precision run was performed using the whole spot approach, the intra-assay precision (%CV) was within 7.1% and the accuracy was within ± 8.0% of the nominal concentrations. In contrast to the center punch approach, the whole spot approach eliminated the effect of hematocrit and high lipids on the analysis of apixaban in human DBS when an accurate sample blood volume was collected on DBS cards. Copyright © 2015 Elsevier B.V. All rights reserved.

Performance of an app measuring spot quality in dried blood spot sampling

NARCIS (Netherlands)

Veenhof, Herman

2016-01-01

Introduction: The Dried Blood Spot sampling (DBS) method gives patients and health care workers the opportunity for remote sampling using a drop of blood from a fingerprick on a sampling card which can be send to the laboratory by mail. Laboratory analysts frequently reject DBS samples because of

Image-guided brachytherapy for cervical cancer: analysis of D2 cc hot spot in three-dimensional and anatomic factors affecting D2 cc hot spot in organs at risk.

Science.gov (United States)

Kim, Robert Y; Dragovic, Alek F; Whitley, Alexander C; Shen, Sui

2014-01-01

To analyze the D2 cc hot spot in three-dimensional CT and anatomic factors affecting the D2 cc hot spot in organs at risk (OARs). Thirty-one patients underwent pelvic CT scan after insertion of the applicator. High-dose-rate treatment planning was performed with standard loading patterns. The D2 cc structures in OARs were generated in three dimensional if the total equivalent dose in 2 Gy exceeded our defined dose limits (hot spot). The location of D2 cc hot spot was defined as the center of the largest D2 cc fragment. The relationship between the hot spot and the applicator position was reported in Digital Imaging and Communication in Medicine coordinates. The location of sigmoid, small bowel, and bladder D2 cc hot spots was around the endocervix: The mean location of sigmoid hot spot for lateral view was 1.6 cm posteriorly and 2.3 cm superiorly (Y, 1.6 and Z, 2.3), small bowel was 1.6 cm anteriorly and 2.7 cm superiorly (Y, -1.6 and Z, 2.7). The mean location of bladder hot spot was 1.6 cm anteriorly and 1.6 cm superiorly (Y, -1.6 and Z, 1.6). These hot spots were near the plane of Point A (X, 2.0 or -2.0; Y, 0; and Z, 2.0). The mean location of rectal hot spot was 1.6 cm posteriorly and 1.9 cm inferiorly (Y, 1.6 and Z, -1.9). D2 cc hot spot was affected by uterine wall thickness, uterine tandem position, fibroids, bladder fullness, bowel gas, and vaginal packing. Because of the location of the D2 cc hot spots, larger tumors present a challenge for adequate tumor coverage with a conventional brachytherapy applicator without an interstitial implant. Additionally, anatomic factors were identified which affect the D2 cc hot spot in OARs. Copyright © 2014 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Angle dependent focal spot size of a conical X-ray target

International Nuclear Information System (INIS)

Saeed Raza, Hamid; Jin Kim, Hyun; Nam Kim, Hyun; Oh Cho, Sung

2015-01-01

Misaligned phantoms may severely affect the focal spot calculations. A method is proposed to determine the geometry of the X-ray target and the position of the image radiograph around the X-ray target to get a relatively smaller focal spot size. Results reveal that the focal spot size is not always isotropic around the target but it decreases as the point of observation shifts radially away from the center line of the conical X-ray target. This research will help in producing high quality X-ray images in multi-directions by properly aligning the phantoms and the radiograph tallies. - Highlights: • Misaligned phantoms may severely affect the focal spot calculations. • The aim of this research is to analyze systematically the angle dependent behavior of the focal spot size around a conical shaped X-ray target. • A general purpose Monte Carlo (MCNP5) computer code is used to achieve a relatively small focal spot size. • Angular distribution of the X-ray focal spot size mainly depends on the angular orientation of the phantom and its aligned FIR tally. • This research will help in producing high quality X-ray images in multi-directions

Risks versus savings in the international spot market

International Nuclear Information System (INIS)

Karalus, J.L.

1988-01-01

This paper describes the international spot market, some of its risks and difficulties, and examples of the ways potential savings can be realized. Fuel cycle goods and services available in the international spot market include uranium as U 3 O 8 , natural UF 6 , enriched UF 6 , conversion services, and enriching services

MICROSTRUCTURE AND FATIGUE PROPERTIES OF DISSIMILAR SPOT WELDED JOINTS OF AISI 304 AND AISI 1008

Directory of Open Access Journals (Sweden)

Nachimani Charde

2013-06-01

Full Text Available Carbon steel and stainless steel composites are being more frequently used for applications requiring a corrosion resistant and attractive exterior surface and a high strength structural substrate. Spot welding is a potentially useful and efficient jointing process for the production of components consisting of these two materials. The spot welding characteristics of weld joints between these two materials are discussed in this paper. The experiment was conducted on dissimilar weld joints using carbon steel and 304L (2B austenitic stainless steel by varying the welding currents and electrode pressing forces. Throughout the welding process; the electrical signals from the strain sensor, current transducer and terminal voltage clippers are measured in order to understand each and every millisecond of the welding process. In doing so, the dynamic resistances, heat distributions and forging forces are computed for various currents and force levels within the good welds’ regions. The other process controlling parameters, particularly the electrode tip and weld time, remained constant throughout the experiment. The weld growth was noted for the welding current increment, but in the electrode force increment it causes an adverse reaction to weld growth. Moreover, the effect of heat imbalance was clearly noted during the welding process due to the different electrical and chemical properties. The welded specimens finally underwent tensile, hardness and metallurgical testing to characterise the weld growth.

Vocal complexity and sociality in spotted paca (Cuniculus paca).

Science.gov (United States)

Lima, Stella G C; Sousa-Lima, Renata S; Tokumaru, Rosana S; Nogueira-Filho, Sérgio L G; Nogueira, Selene S C

2018-01-01

The evolution of sociality is related to many ecological factors that act on animals as selective forces, thus driving the formation of groups. Group size will depend on the payoffs of group living. The Social Complexity Hypothesis for Communication (SCHC) predicts that increases in group size will be related to increases in the complexity of the communication among individuals. This hypothesis, which was confirmed in some mammal societies, may be useful to trace sociality in the spotted paca (Cuniculus paca), a Neotropical caviomorph rodent reported as solitary. There are, however, sightings of groups in the wild, and farmers easily form groups of spotted paca in captivity. Thus, we aimed to describe the acoustic repertoire of captive spotted paca to test the SCHC and to obtain insights about the sociability of this species. Moreover, we aimed to verify the relationship between group size and acoustic repertoire size of caviomorph rodents, to better understand the evolution of sociality in this taxon. We predicted that spotted paca should display a complex acoustic repertoire, given their social behavior in captivity and group sightings in the wild. We also predicted that in caviomorph species the group size would increase with acoustic repertoire, supporting the SCHC. We performed a Linear Discriminant Analysis (LDA) based on acoustic parameters of the vocalizations recorded. In addition, we applied an independent contrasts approach to investigate sociality in spotted paca following the social complexity hypothesis, independent of phylogeny. Our analysis showed that the spotted paca's acoustic repertoire contains seven vocal types and one mechanical signal. The broad acoustic repertoire of the spotted paca might have evolved given the species' ability to live in groups. The relationship between group size and the size of the acoustic repertoires of caviomorph species was confirmed, providing additional support for the SCHC in yet another group of diverse mammals

Zonal wavefront sensing using a grating array printed on a polyester film

Energy Technology Data Exchange (ETDEWEB)

Pathak, Biswajit; Boruah, Bosanta R., E-mail: brboruah@iitg.ernet.in [Department of Physics, Indian Institute of Technology Guwahati, Guwahati, Assam 781039 (India); Kumar, Suraj [Department of Applied Sciences, Gauhati University, Guwahati, Assam 781014 (India)

2015-12-15

In this paper, we describe the development of a zonal wavefront sensor that comprises an array of binary diffraction gratings realized on a transparent sheet (i.e., polyester film) followed by a focusing lens and a camera. The sensor works in a manner similar to that of a Shack-Hartmann wavefront sensor. The fabrication of the array of gratings is immune to certain issues associated with the fabrication of the lenslet array which is commonly used in zonal wavefront sensing. Besides the sensing method offers several important advantages such as flexible dynamic range, easy configurability, and option to enhance the sensing frame rate. Here, we have demonstrated the working of the proposed sensor using a proof-of-principle experimental arrangement.

Zonal wavefront sensing using a grating array printed on a polyester film

Science.gov (United States)

Pathak, Biswajit; Kumar, Suraj; Boruah, Bosanta R.

2015-12-01

In this paper, we describe the development of a zonal wavefront sensor that comprises an array of binary diffraction gratings realized on a transparent sheet (i.e., polyester film) followed by a focusing lens and a camera. The sensor works in a manner similar to that of a Shack-Hartmann wavefront sensor. The fabrication of the array of gratings is immune to certain issues associated with the fabrication of the lenslet array which is commonly used in zonal wavefront sensing. Besides the sensing method offers several important advantages such as flexible dynamic range, easy configurability, and option to enhance the sensing frame rate. Here, we have demonstrated the working of the proposed sensor using a proof-of-principle experimental arrangement.

Inhibition of turbulence in inertial-confinement-fusion hot spots by viscous dissipation.

Science.gov (United States)

Weber, C R; Clark, D S; Cook, A W; Busby, L E; Robey, H F

2014-05-01

Achieving ignition in inertial confinement fusion (ICF) requires the formation of a high-temperature (>10 keV) central hot spot. Turbulence has been suggested as a mechanism for degrading the hot-spot conditions by altering transport properties, introducing colder, mixed material, or reducing the conversion of radially directed kinetic energy to hot-spot heating. We show, however, that the hot spot is very viscous, and the assumption of turbulent conditions in the hot spot is incorrect. This work presents the first high-resolution, three-dimensional simulations of National Ignition Facility (NIF) implosion experiments using detailed knowledge of implosion dynamics and instability seeds and including an accurate model of physical viscosity. We find that when viscous effects are neglected, the hot spot can exhibit a turbulent kinetic energy cascade. Viscous effects, however, are significant and strongly damp small-scale velocity structures, with a hot-spot Reynolds number in the range of only 10-100.

Crude oil spot market pricing: Pearsonian analysis of crude oil spot market prices

International Nuclear Information System (INIS)

Akinnusi, Ayo

1994-01-01

This paper presents a brief overview of crude oil pricing before describing a study of sets of 1991 spot market prices, and examining Pearson's model. Empirical distribution characteristics for 14 crude oils are tabulated, and skewness-kurtosis relationship and implication are considered. (UK)

Morphological changes in ultrafast laser ablation plumes with varying spot size.

Science.gov (United States)

Harilal, S S; Diwakar, P K; Polek, M P; Phillips, M C

2015-06-15

We investigated the role of spot size on plume morphology during ultrafast laser ablation of metal targets. Our results show that the spatial features of fs LA plumes are strongly dependent on the focal spot size. Two-dimensional self-emission images showed that the shape of the ultrafast laser ablation plumes changes from spherical to cylindrical with an increasing spot size from 100 to 600 μm. The changes in plume morphology and internal structures are related to ion emission dynamics from the plasma, where broader angular ion distribution and faster ions are noticed for the smallest spot size used. The present results clearly show that the morphological changes in the plume with spot size are independent of laser pulse width.

Modelling energy spot prices by Lévy semistationary processes

DEFF Research Database (Denmark)

Barndorff-Nielsen, Ole; Benth, Fred Espen; Veraart, Almut

This paper introduces a new modelling framework for energy spot prices based on Lévy semistationary processes. Lévy semistationary processes are special cases of the general class of ambit processes. We provide a detailed analysis of the probabilistic properties of such models and we show how...... they are able to capture many of the stylised facts observed in energy markets. Furthermore, we derive forward prices based on our spot price model. As it turns out, many of the classical spot models can be embedded into our novel modelling framework....

Spotted fever rickettsiosis in Coronel Fabriciano, Minas Gerais State

Directory of Open Access Journals (Sweden)

Galvão Márcio Antônio Moreira

2003-01-01

Full Text Available We report cases of spotted fever rickettsiosis in Coronel Fabriciano Municipality of Minas Gerais State, Brazil. The cases occurred in May and June of 2000. During this period there were two deaths among children from an area named Pedreira in a periurban area of this municipality. In a boy who died with clinical manifestations of Brazilian spotted fever, a necropsy revealed the presence of a spotted fever group Rickettsia. The serological results confirm the difficulty in the differential diagnosis of patients with symptoms of rickettsial diseases.

Resistance spot weldability of 11Cr–ferritic/martensitic steel sheets

International Nuclear Information System (INIS)

Uwaba, Tomoyuki; Yano, Yasuhide; Ito, Masahiro

2012-01-01

Resistance spot welding of 11Cr–0.4Mo–2W, V, Nb ferritic/martensitic steel sheets with different thicknesses was examined to develop a manufacturing technology for a fast reactor fuel subassembly with an inner duct structure. In the spot welding, welding current, electrode force, welding time and holding time were varied as welding parameters to investigate the appropriate welding conditions. Welding conditions under which spot weld joints did not have either crack or void defects in the nugget could be found when the electrode force was increased to 9.8 kN. It was also found that the electrode cap with a longer tip end length was effective for preventing weld defect formations. Strength of the spot welded joint was characterized from micro hardness and shear tension tests. In addition, the ductile-to-brittle transition temperature of the spot welded joint was measured by Charpy impact tests with specimens that had notches in the welded zone.

Ultrasonic Real-Time Quality Monitoring Of Aluminum Spot Weld Process

Science.gov (United States)

Perez Regalado, Waldo Josue

The real-time ultrasonic spot weld monitoring system, introduced by our research group, has been designed for the unsupervised quality characterization of the spot welding process. It comprises the ultrasonic transducer (probe) built into one of the welding electrodes and an electronics hardware unit which gathers information from the transducer, performs real-time weld quality characterization and communicates with the robot programmable logic controller (PLC). The system has been fully developed for the inspection of spot welds manufactured in steel alloys, and has been mainly applied in the automotive industry. In recent years, a variety of materials have been introduced to the automotive industry. These include high strength steels, magnesium alloys, and aluminum alloys. Aluminum alloys have been of particular interest due to their high strength-to-weight ratio. Resistance spot welding requirements for aluminum vary greatly from those of steel. Additionally, the oxide film formed on the aluminum surface increases the heat generation between the copper electrodes and the aluminum plates leading to accelerated electrode deterioration. Preliminary studies showed that the real-time quality inspection system was not able to monitor spot welds manufactured with aluminum. The extensive experimental research, finite element modelling of the aluminum welding process and finite difference modeling of the acoustic wave propagation through the aluminum spot welds presented in this dissertation, revealed that the thermodynamics and hence the acoustic wave propagation through an aluminum and a steel spot weld differ significantly. For this reason, the hardware requirements and the algorithms developed to determine the welds quality from the ultrasonic data used on steel, no longer apply on aluminum spot welds. After updating the system and designing the required algorithms, parameters such as liquid nugget penetration and nugget diameter were available in the ultrasonic data

Charge-Spot Model for Electrostatic Forces in Simulation of Fine Particulates

Science.gov (United States)

Walton, Otis R.; Johnson, Scott M.

2010-01-01

The charge-spot technique for modeling the static electric forces acting between charged fine particles entails treating electric charges on individual particles as small sets of discrete point charges, located near their surfaces. This is in contrast to existing models, which assume a single charge per particle. The charge-spot technique more accurately describes the forces, torques, and moments that act on triboelectrically charged particles, especially image-charge forces acting near conducting surfaces. The discrete element method (DEM) simulation uses a truncation range to limit the number of near-neighbor charge spots via a shifted and truncated potential Coulomb interaction. The model can be readily adapted to account for induced dipoles in uncharged particles (and thus dielectrophoretic forces) by allowing two charge spots of opposite signs to be created in response to an external electric field. To account for virtual overlap during contacts, the model can be set to automatically scale down the effective charge in proportion to the amount of virtual overlap of the charge spots. This can be accomplished by mimicking the behavior of two real overlapping spherical charge clouds, or with other approximate forms. The charge-spot method much more closely resembles real non-uniform surface charge distributions that result from tribocharging than simpler approaches, which just assign a single total charge to a particle. With the charge-spot model, a single particle may have a zero net charge, but still have both positive and negative charge spots, which could produce substantial forces on the particle when it is close to other charges, when it is in an external electric field, or when near a conducting surface. Since the charge-spot model can contain any number of charges per particle, can be used with only one or two charge spots per particle for simulating charging from solar wind bombardment, or with several charge spots for simulating triboelectric charging

Demographic response of northern spotted owls to barred owl removal

Science.gov (United States)

Diller, V. Lowell; Hamm, Keith A; Early, Desiree A; Lamphear, David W; Dugger, Katie M.; Yackulic, Charles B.; Schwarz, Carl J.; Carlson, Peter C.; McDonald, Trent L.

2016-01-01

Federally listed as threatened in 1990 primarily because of habitat loss, the northern spotted owl (Strix occidentalis caurina) has continued to decline despite conservation efforts resulting in forested habitat being reserved throughout its range. Recently, there is growing evidence the congeneric invasive barred owl (Strix varia) may be responsible for the continued decline primarily by excluding spotted owls from their preferred habitat. We used a long-term demographic study for spotted owls in coastal northern California as the basis for a pilot barred owl removal experiment. Our demography study used capture–recapture, reproductive output, and territory occupancy data collected from 1990 to 2013 to evaluate trends in vital rates and populations. We used a classic before-after-control-impact (BACI) experimental design to investigate the demographic response of northern spotted owls to the lethal removal of barred owls. According to the best 2-species dynamic occupancy model, there was no evidence of differences in barred or northern spotted owl occupancy prior to the initiation of the treatment (barred owl removal). After treatment, barred owl occupancy was lower in the treated relative to the untreated areas and spotted owl occupancy was higher relative to the untreated areas. Barred owl removal decreased spotted owl territory extinction rates but did not affect territory colonization rates. As a result, spotted owl occupancy increased in the treated area and continued to decline in the untreated areas. Prior to and after barred owl removal, there was no evidence that average fecundity differed on the 2 study areas. However, the greater number of occupied spotted owl sites on the treated areas resulted in greater productivity in the treated areas based on empirical counts of fledged young. Prior to removal, survival was declining at a rate of approximately 0.2% per year for treated and untreated areas. Following treatment, estimated survival was 0.859 for

Managing Rocky Mountain spotted fever.

Science.gov (United States)

Minniear, Timothy D; Buckingham, Steven C

2009-11-01

Rocky Mountain spotted fever is caused by the tick-borne bacterium Rickettsia rickettsii. Symptoms range from moderate illness to severe illness, including cardiovascular compromise, coma and death. The disease is prevalent in most of the USA, especially during warmer months. The trademark presentation is fever and rash with a history of tick bite, although tick exposure is unappreciated in over a third of cases. Other signature symptoms include headache and abdominal pain. The antibiotic therapy of choice for R. rickettsii infection is doxycycline. Preventive measures for Rocky Mountain spotted fever and other tick-borne diseases include: wearing long-sleeved, light colored clothing; checking for tick attachment and removing attached ticks promptly; applying topical insect repellent; and treating clothing with permethrin.

Food habits of Mexican Spotted Owls in Arizona

Science.gov (United States)

Joseph L. Ganey

1992-01-01

The Spotted Owl (Strix occidentalis) is most common in mature and old-growth coniferous forests throughout much of its range (Forsman et al. 1984, Laymon 1988, Ganey and Balda 1989a, Thomas et al. 1990). Proximate factors underlying habitat selection in Spotted Owls are understood poorly. Abundance and availability of food, however, may be a key...

Predictive Value of CTA Spot Sign on Hematoma Expansion in Intracerebral Hemorrhage Patients

Directory of Open Access Journals (Sweden)

Wen-Jie Peng

2017-01-01

Full Text Available Hematoma expansion (HE occurs in approximately one-third of patients with intracerebral hemorrhage and leads to high rates of mortality and morbidity. Currently, contrast extravasation within hematoma, termed the spot sign on computed tomography angiography (CTA, has been identified as a strong independent predictor of early hematoma expansion. Past studies indicate that the spot sign is a dynamic entity and is indicative of active hemorrhage. Furthermore, to enhance the spot sign’s accuracy of predicting HE, spot parameters observed on CTA or dynamic CTA were used for its quantification. In addition, spot signs detected on multiphase CTA and dynamic CTA are shown to have higher sensitivity and specificity when compared with simple standardized spot sign detection in recent studies. Based on the spot sign, novel methods such as leakage sign and rate of contrast extravasation were explored to redefine HE prediction in combination with clinical characteristics and spot sign on CTA to assist clinical judgment. The spot sign is an accepted independent predictor of active hemorrhage and is used in both secondary intracerebral hemorrhage and the process of surgical assessment for hemorrhagic risk in patients with ischemic stroke. Spot sign predicts patients at high risk for hematoma expansion.

Hot-spot mix in ignition-scale inertial confinement fusion targets.

Science.gov (United States)

Regan, S P; Epstein, R; Hammel, B A; Suter, L J; Scott, H A; Barrios, M A; Bradley, D K; Callahan, D A; Cerjan, C; Collins, G W; Dixit, S N; Döppner, T; Edwards, M J; Farley, D R; Fournier, K B; Glenn, S; Glenzer, S H; Golovkin, I E; Haan, S W; Hamza, A; Hicks, D G; Izumi, N; Jones, O S; Kilkenny, J D; Kline, J L; Kyrala, G A; Landen, O L; Ma, T; MacFarlane, J J; MacKinnon, A J; Mancini, R C; McCrory, R L; Meezan, N B; Meyerhofer, D D; Nikroo, A; Park, H-S; Ralph, J; Remington, B A; Sangster, T C; Smalyuk, V A; Springer, P T; Town, R P J

2013-07-26

Mixing of plastic ablator material, doped with Cu and Ge dopants, deep into the hot spot of ignition-scale inertial confinement fusion implosions by hydrodynamic instabilities is diagnosed with x-ray spectroscopy on the National Ignition Facility. The amount of hot-spot mix mass is determined from the absolute brightness of the emergent Cu and Ge K-shell emission. The Cu and Ge dopants placed at different radial locations in the plastic ablator show the ablation-front hydrodynamic instability is primarily responsible for hot-spot mix. Low neutron yields and hot-spot mix mass between 34(-13,+50)  ng and 4000(-2970,+17 160)  ng are observed.

Hot spots in Ar and Ne gas puff Z-pinch

International Nuclear Information System (INIS)

Krejci, A.; Krousky, E.; Renner, O.

1989-02-01

The hot spots in Ar and Ne pinch plasma were investigated. Two pinhole cameras with entrance diameter 13 to 250 μm and flat crystal spectrographs with Si and KAP crystals were used for spatially and spectrally resolved soft X-ray diagnostics. The diameters of Ar (25 to 30 μm) and Ne (40 μm) hot spots were found. From X-ray spectrum of Ar spots the following plasma parameters were determined: T e =1.0 to 1.1 keV and n e =(1.8 to 4.0)x10 27 m -3 . The validity of the Bennett equilibrium for unstable hot spots is discussed. (author). 1 fig., 11 refs

Mutant of Japanese pear resistant to Black Spot Disease

International Nuclear Information System (INIS)

Sanada, T.; Nishida, T.; Ikeda, F.

1987-01-01

Full text: Nijisseike is one of the leading cultivars of Japanese pear (Pyrus serotinea Rehd.), but susceptible to black spot disease. Farmers try to prevent this disease by wrapping the fruit with a paper bag and by repeated spraying of fungicides. The disease is caused by a Japanese pear pathotype of Alternaria alternata (Fr.) Keissler. Susceptibility is controlled by a single dominant gene. In 1962, grafted trees of this cultivar were planted at a distance between 53 and 93 m from the 60 Co source in the gamma-field (daily dose 15-4 rad). One branch on a tree planted at 53 m was detected as resistant in 1981. Under field conditions, black spots were observed on many fruits and leaves of the original trees by natural infection in early July, however, they were not observed on the mutant. To examine the resistance of the mutant, artificial inoculations were made using spores of the pathogen and the host specific toxin produced by germinating spores. When some drops of the spore suspension are placed on leaves, the formation of black spots depends upon the leaf age. In a resistant cv. as Chojuro, black spot symptoms are formed only when inoculated on young leaves. An intermediate reaction was observed in the mutant, whereas the original Nijisseiki showed severe symptoms. When inoculation was made on matured fruit skins, no black spot was formed on the mutant just like on the resistant cv. Chojuro, while many small black spots were formed and grew into large spots overlapping each other on the susceptible cv. Nijisseiki. In case of the crude toxin inoculation (4-0.04 ppm) of cv. Nijisseiki black spots were formed on the surface of the susceptible fruit skin, and necrotic lesions at the cut end of detached small pieces of leaves, although reaction on fruit skins was weaker compared with inoculation by spores. However, no symptoms were observed from the toxin application on the mutant and the resistant cv. Chojuro. That the resistance of the mutant is classified as

Quantitation of pregabalin in dried blood spots and dried plasma spots by validated LC-MS/MS methods.

Science.gov (United States)

Kostić, Nađa; Dotsikas, Yannis; Jović, Nebojša; Stevanović, Galina; Malenović, Anđelija; Medenica, Mirjana

2015-05-10

In this paper, novel LC-MS/MS methods for the determination of antiepileptic drug pregabalin in dried matrix spots (DMS) are presented. This attractive technique of sample collection in micro amount was utilized in the form of dried blood spots (DBS) and dried plasma spots (DPS). Following a pre-column derivatization procedure, using n-propyl chloroformate in the presence of n-propanol, and consecutive liquid-liquid extraction, derivatized pregabalin and its internal standard, 4-aminocyclohexanecarboxylic acid, were detected in positive ion mode by applying two SRM transitions per analyte. A YMC-Pack Octyl column (50mm×4.0mm, 3μm particle size) maintained at 30°C, was utilized with running mobile phase composed of acetonitrile: 0.15% formic acid (85:15, v/v). Flow rate was 550μL/min and total run time 2min. Established methods were fully validated over the concentration range of 0.200-20.0μg/mL for DBS and 0.400-40.0μg/mL for DPS, respectively, while specificity, accuracy, precision, recovery, matrix-effect, stability, dilution integrity and spot homogeneity were found within acceptance criteria. Validated methods were applied for the determination of pregabalin levels in dried blood and plasma samples obtained from patients with epilepsy, after per os administration of commercial capsules. Comparison of drug level in blood and plasma, as well as correction steps undertaken in order to overcome hematocrit issue, when analyzing DBS, are also given. Copyright © 2015 Elsevier B.V. All rights reserved.

Significant Change Spotting for Periodic Human Motion Segmentation of Cleaning Tasks Using Wearable Sensors

Directory of Open Access Journals (Sweden)

Kai-Chun Liu

2017-01-01

Full Text Available The proportion of the aging population is rapidly increasing around the world, which will cause stress on society and healthcare systems. In recent years, advances in technology have created new opportunities for automatic activities of daily living (ADL monitoring to improve the quality of life and provide adequate medical service for the elderly. Such automatic ADL monitoring requires reliable ADL information on a fine-grained level, especially for the status of interaction between body gestures and the environment in the real-world. In this work, we propose a significant change spotting mechanism for periodic human motion segmentation during cleaning task performance. A novel approach is proposed based on the search for a significant change of gestures, which can manage critical technical issues in activity recognition, such as continuous data segmentation, individual variance, and category ambiguity. Three typical machine learning classification algorithms are utilized for the identification of the significant change candidate, including a Support Vector Machine (SVM, k-Nearest Neighbors (kNN, and Naive Bayesian (NB algorithm. Overall, the proposed approach achieves 96.41% in the F1-score by using the SVM classifier. The results show that the proposed approach can fulfill the requirement of fine-grained human motion segmentation for automatic ADL monitoring.

Impact of low-dose electron irradiation on n{sup +}p silicon strip sensors

Energy Technology Data Exchange (ETDEWEB)

NONE

2015-12-11

The response of n{sup +}p silicon strip sensors to electrons from a {sup 90}Sr source was measured using a multi-channel read-out system with 25 ns sampling time. The measurements were performed over a period of several weeks, during which the operating conditions were varied. The sensors were fabricated by Hamamatsu Photonics on 200 μm thick float-zone and magnetic-Czochralski silicon. Their pitch was 80 μm, and both p-stop and p-spray isolation of the n{sup +} strips were studied. The electrons from the {sup 90}Sr source were collimated to a spot with a full-width-at-half-maximum of 2 mm at the sensor surface, and the dose rate in the SiO{sub 2} at the maximum was about 50 Gy(SiO{sub 2})/d. After only a few hours of making measurements, significant changes in charge collection and charge sharing were observed. Annealing studies, with temperatures up to 80 °C and annealing times of 18 h showed that the changes can only be partially annealed. The observations can be qualitatively explained by the increase of the positive oxide-charge density due to the ionization of the SiO{sub 2} by the radiation from the β source. TCAD simulations of the electric field in the sensor for different oxide-charge densities and different boundary conditions at the sensor surface support this explanation. The relevance of the measurements for the design of n{sup +}p strip sensors is discussed.

SOAP 2.0: Spot Oscillation And Planet 2.0

Science.gov (United States)

Dumusque, Xavier; Boisse, I.; Santos, N. C.

2015-04-01

SOAP (Spot Oscillation And Planet) 2.0 simulates the effects of dark spots and bright plages on the surface of a rotating star, computing their expected radial velocity and photometric signatures. It includes the convective blueshift and its inhibition in active regions.

Damage threshold from large retinal spot size repetitive-pulse laser exposures.

Science.gov (United States)

Lund, Brian J; Lund, David J; Edsall, Peter R

2014-10-01

The retinal damage thresholds for large spot size, multiple-pulse exposures to a Q-switched, frequency doubled Nd:YAG laser (532 nm wavelength, 7 ns pulses) have been measured for 100 μm and 500 μm retinal irradiance diameters. The ED50, expressed as energy per pulse, varies only weakly with the number of pulses, n, for these extended spot sizes. The previously reported threshold for a multiple-pulse exposure for a 900 μm retinal spot size also shows the same weak dependence on the number of pulses. The multiple-pulse ED50 for an extended spot-size exposure does not follow the n dependence exhibited by small spot size exposures produced by a collimated beam. Curves derived by using probability-summation models provide a better fit to the data.

A keyword spotting model using perceptually significant energy features

Science.gov (United States)

Umakanthan, Padmalochini

The task of a keyword recognition system is to detect the presence of certain words in a conversation based on the linguistic information present in human speech. Such keyword spotting systems have applications in homeland security, telephone surveillance and human-computer interfacing. General procedure of a keyword spotting system involves feature generation and matching. In this work, new set of features that are based on the psycho-acoustic masking nature of human speech are proposed. After developing these features a time aligned pattern matching process was implemented to locate the words in a set of unknown words. A word boundary detection technique based on frame classification using the nonlinear characteristics of speech is also addressed in this work. Validation of this keyword spotting model was done using widely acclaimed Cepstral features. The experimental results indicate the viability of using these perceptually significant features as an augmented feature set in keyword spotting.

Hot spot(s) of the lung in technetium-99m albumin colloid liver-spleen scintigraphy: case report

International Nuclear Information System (INIS)

Shih, W.J.; Brandenburg, S.; Coupal, J.J.; Sullivan, J.D.; Beeler, J.A.; Magoun, S.; Ryo, U.Y.

1988-01-01

The authors replaced /sup 99m/Tc albumin colloid for /sup 99m/Tc sulfur colloid as a radiopharmaceutical for liver-spleen imaging and found two instances of hot spot(s) in the lung. The preparation procedure of albumin colloid is easier and more convenient as compared to that of sulfur colloid. Whereas replacement of /sup 99m/Tc sulfur colloid by /sup 99m/Tc albumin colloid is inevitable, it should be emphasized that one should avoid blood withdrawal in the syringe containing albumin colloid to prevent formation of clot(s) during the venous puncture for /sup 99m/Tc albumin colloid

21 CFR 892.1620 - Cine or spot fluorographic x-ray camera.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cine or spot fluorographic x-ray camera. 892.1620... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1620 Cine or spot fluorographic x-ray camera. (a) Identification. A cine or spot fluorographic x-ray camera is a device intended to photograph...

A simple assay of paracetamol based on dried blood spot suitable ...

African Journals Online (AJOL)

Dried blood spots in Guthrie cards are a reliable means of blood sampling suitable for pharmacoki-netic analysis in children. The aim of this study was to develop a simple and reliable bioanalytical method to measure the concentration of paracetamol in dried blood spots. Paracetamol was ex-tracted from dry blood spots by ...

A spot-matching method using cumulative frequency matrix in 2D gel images

Science.gov (United States)

Han, Chan-Myeong; Park, Joon-Ho; Chang, Chu-Seok; Ryoo, Myung-Chun

2014-01-01

A new method for spot matching in two-dimensional gel electrophoresis images using a cumulative frequency matrix is proposed. The method improves on the weak points of the previous method called ‘spot matching by topological patterns of neighbour spots’. It accumulates the frequencies of neighbour spot pairs produced through the entire matching process and determines spot pairs one by one in order of higher frequency. Spot matching by frequencies of neighbour spot pairs shows a fairly better performance. However, it can give researchers a hint for whether the matching results can be trustworthy or not, which can save researchers a lot of effort for verification of the results. PMID:26019609

Tractor-mounted, GPS-based spot fumigation system manages Prunus replant disease

Directory of Open Access Journals (Sweden)

V. Udompetaikul

2013-10-01

Full Text Available Our research goal was to use recent advances in global positioning system (GPS and computer technology to apply just the right amount of fumigant where it is most needed (i.e., in a small target treatment zone in and around each tree replanting site to control Prunus replant disease (PRD. We developed and confirmed the function of (1 GPS-based software that can be used on cleared orchard land to flexibly plan and map all of an orchard's future tree sites and associated spot fumigation treatment zones and 2 a tractor-based GPS-controlled spot fumigation system to quickly and safely treat the targeted tree site treatment zones. In trials in two almond orchards and one peach orchard, our evaluations of the composite mapping and application system, which examined spatial accuracy of the spot treatments, delivery rate accuracy of the spot treatments, and tree growth responses to the spot treatments, all indicated that GPS spot fumigation has excellent potential to greatly reduce fumigant usage while adequately managing the PRD complex.

Beam reducery - optika pro diagnostiku širokých laserových svazků

Czech Academy of Sciences Publication Activity Database

Stanke, Ladislav; Palatka, Miroslav

2017-01-01

Roč. 62, Jan (2017), s. 141-147 ISSN 0447-6441 R&D Projects: GA MŠk EF15_008/0000162 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : telescope design * laser beam diagnostics * Shack-Hartmann sensor Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics)

Quantitation of 5-Methyltetrahydrofolic Acid in Dried Blood Spots and Dried Plasma Spots by Stable Isotope Dilution Assays.

Directory of Open Access Journals (Sweden)

Markus Kopp

Full Text Available Because of minimal data available on folate analysis in dried matrix spots (DMSs, we combined the advantages of stable isotope dilution assays followed by LC-MS/MS analysis with DMS sampling to develop a reliable method for the quantitation of plasma 5-methyltetrahydrofolic acid in dried blood spots (DBSs and dried plasma spots (DPSs as well as for the quantitation of whole blood 5-methyltetrahydrofolic acid in DBSs. We focused on two diagnostically conclusive parameters exhibited by the plasma and whole blood 5-methyltetrahydrofolic acid levels that reflect both temporary and long-term folate status. The method is performed using the [2H4]-labeled isotopologue of the vitamin as the internal standard, and three steps are required for the extraction procedure. Elution of the punched out matrix spots was performed using stabilization buffer including Triton X-100 in a standardized ultrasonication treatment followed by enzymatic digestion (whole blood only and solid-phase extraction with SAX cartridges. This method is sensitive enough to quantify 27 nmol/L whole blood 5-methyltetrahydrofolic acid in DBSs and 6.3 and 4.4 nmol/L plasma 5-methyltetrahydrofolic acid in DBSs and DPSs, respectively. The unprecedented accurate quantification of plasma 5-methyltetrahydrofolic acid in DBSs was achieved by thermal treatment prior to ultrasonication, inhibiting plasma conjugase activity. Mass screenings are more feasible and easier to facilitate for this method in terms of sample collection and storage compared with conventional clinical sampling for the assessment of folate status.

Design of the smart scenic spot service platform

Science.gov (United States)

Yin, Min; Wang, Shi-tai

2015-12-01

With the deepening of the smart city construction, the model "smart+" is rapidly developing. Guilin, the international tourism metropolis fast constructing need smart tourism technology support. This paper studied the smart scenic spot service object and its requirements. And then constructed the smart service platform of the scenic spot application of 3S technology (Geographic Information System (GIS), Remote Sensing (RS) and Global Navigation Satellite System (GNSS)) and the Internet of things, cloud computing. Based on Guilin Seven-star Park scenic area as an object, this paper designed the Seven-star smart scenic spot service platform framework. The application of this platform will improve the tourists' visiting experience, make the tourism management more scientifically and standardly, increase tourism enterprises operating earnings.

Plasmonic nanocarrier grid-enhanced Raman sensor for studies of anticancer drug delivery.

Science.gov (United States)

Kurzątkowska, Katarzyna; Santiago, Ty; Hepel, Maria

2017-05-15

Targeted drug delivery systems using nanoparticle nanocarriers offer remarkable promise for cancer therapy by discriminating against devastating cytotoxicity of chemotherapeutic drugs to healthy cells. To aid in the development of new drug nanocarriers, we propose a novel plasmonic nanocarrier grid-enhanced Raman sensor which can be applied for studies and testing of drug loading onto the nanocarriers, attachment of targeting ligands, dynamics of drug release, assessment of nanocarrier stability in biological environment, and general capabilities of the nanocarrier. The plasmonic nanogrid sensor offers strong Raman enhancement due to the overlapping plasmonic fields emanating from the nearest-neighbor gold nanoparticle nanocarriers and creating the enhancement "hot spots". The sensor has been tested for immobilization of an anticancer drug gemcitabine (2',2'-difluoro-2'-deoxycytidine, GEM) which is used in treatment of pancreatic tumors. The drawbacks of currently applied treatment include high systemic toxicity, rapid drug decay, and low efficacy (ca. 20%). Therefore, the development of a targeted GEM delivery system is highly desired. We have demonstrated that the proposed nanocarrier SERS sensor can be utilized to investigate attachment of targeting ligands to nanocarriers (attachment of folic acid ligand recognized by folate receptors of cancer cells is described). Further testing of the nanocarrier SERS sensor involved drug release induced by lowering pH and increasing GSH levels, both occurring in cancer cells. The proposed sensor can be utilized for a variety of drugs and targeting ligands, including those which are Raman inactive, since the linkers can act as the Raman markers, as illustrated with mercaptobenzoic acid and para-aminothiophenol. Copyright © 2017 Elsevier B.V. All rights reserved.

A feature-based approach to modeling protein-protein interaction hot spots.

Science.gov (United States)

Cho, Kyu-il; Kim, Dongsup; Lee, Doheon

2009-05-01

Identifying features that effectively represent the energetic contribution of an individual interface residue to the interactions between proteins remains problematic. Here, we present several new features and show that they are more effective than conventional features. By combining the proposed features with conventional features, we develop a predictive model for interaction hot spots. Initially, 54 multifaceted features, composed of different levels of information including structure, sequence and molecular interaction information, are quantified. Then, to identify the best subset of features for predicting hot spots, feature selection is performed using a decision tree. Based on the selected features, a predictive model for hot spots is created using support vector machine (SVM) and tested on an independent test set. Our model shows better overall predictive accuracy than previous methods such as the alanine scanning methods Robetta and FOLDEF, and the knowledge-based method KFC. Subsequent analysis yields several findings about hot spots. As expected, hot spots have a larger relative surface area burial and are more hydrophobic than other residues. Unexpectedly, however, residue conservation displays a rather complicated tendency depending on the types of protein complexes, indicating that this feature is not good for identifying hot spots. Of the selected features, the weighted atomic packing density, relative surface area burial and weighted hydrophobicity are the top 3, with the weighted atomic packing density proving to be the most effective feature for predicting hot spots. Notably, we find that hot spots are closely related to pi-related interactions, especially pi . . . pi interactions.

A feature-based approach to modeling protein–protein interaction hot spots

Science.gov (United States)

Cho, Kyu-il; Kim, Dongsup; Lee, Doheon

2009-01-01

Identifying features that effectively represent the energetic contribution of an individual interface residue to the interactions between proteins remains problematic. Here, we present several new features and show that they are more effective than conventional features. By combining the proposed features with conventional features, we develop a predictive model for interaction hot spots. Initially, 54 multifaceted features, composed of different levels of information including structure, sequence and molecular interaction information, are quantified. Then, to identify the best subset of features for predicting hot spots, feature selection is performed using a decision tree. Based on the selected features, a predictive model for hot spots is created using support vector machine (SVM) and tested on an independent test set. Our model shows better overall predictive accuracy than previous methods such as the alanine scanning methods Robetta and FOLDEF, and the knowledge-based method KFC. Subsequent analysis yields several findings about hot spots. As expected, hot spots have a larger relative surface area burial and are more hydrophobic than other residues. Unexpectedly, however, residue conservation displays a rather complicated tendency depending on the types of protein complexes, indicating that this feature is not good for identifying hot spots. Of the selected features, the weighted atomic packing density, relative surface area burial and weighted hydrophobicity are the top 3, with the weighted atomic packing density proving to be the most effective feature for predicting hot spots. Notably, we find that hot spots are closely related to π–related interactions, especially π · · · π interactions. PMID:19273533

Experimental Study of Tensile Test in Resistance Spot Welding Process

Directory of Open Access Journals (Sweden)

Lebbal Habib

Full Text Available Abstract Resistance spot welding (RSW is a widely used joining process for fabricating sheet metal assemblies in automobile industry .In comparison with other welding processes the RSW is faster and easier for automation. This process involves electrical, thermal and mechanical interactions. Resistance spot welding primarily takes place by localized melting spot at the interface of the sheets followed by its quick solidification under sequential control of pressure water-cooled electrode and flow of required electric current for certain duration. In this work the tensile tests were studied, the results obtained show that the type material, the overlap length, the angle of the rolling direction and the thickness of the sheet have an influence in resistance spot welding process.

Collaboration spotting for dental science.

Science.gov (United States)

Leonardi, E; Agocs, A; Fragkiskos, S; Kasfikis, N; Le Goff, J M; Cristalli, M P; Luzzi, V; Polimeni, A

2014-10-06

The goal of the Collaboration Spotting project is to create an automatic system to collect information about publications and patents related to a given technology, to identify the key players involved, and to highlight collaborations and related technologies. The collected information can be visualized in a web browser as interactive graphical maps showing in an intuitive way the players and their collaborations (Sociogram) and the relations among the technologies (Technogram). We propose to use the system to study technologies related to Dental Science. In order to create a Sociogram, we create a logical filter based on a set of keywords related to the technology under study. This filter is used to extract a list of publications from the Web of Science™ database. The list is validated by an expert in the technology and sent to CERN where it is inserted in the Collaboration Spotting database. Here, an automatic software system uses the data to generate the final maps. We studied a set of recent technologies related to bone regeneration procedures of oro--maxillo--facial critical size defects, namely the use of Porous HydroxyApatite (HA) as a bone substitute alone (bone graft) or as a tridimensional support (scaffold) for insemination and differentiation ex--vivo of Mesenchymal Stem Cells. We produced the Sociograms for these technologies and the resulting maps are now accessible on--line. The Collaboration Spotting system allows the automatic creation of interactive maps to show the current and historical state of research on a specific technology. These maps are an ideal tool both for researchers who want to assess the state--of--the--art in a given technology, and for research organizations who want to evaluate their contribution to the technological development in a given field. We demonstrated that the system can be used for Dental Science and produced the maps for an initial set of technologies in this field. We now plan to enlarge the set of mapped

Collaboration Spotting for oral medicine.

Science.gov (United States)

Leonardi, E; Agocs, A; Fragkiskos, S; Kasfikis, N; Le Goff, J M; Cristalli, M P; Luzzi, V; Polimeni, A

2014-09-01

The goal of the Collaboration Spotting project is to create an automatic system to collect information about publications and patents related to a given technology, to identify the key players involved, and to highlight collaborations and related technologies. The collected information can be visualized in a web browser as interactive graphical maps showing in an intuitive way the players and their collaborations (Sociogram) and the relations among the technologies (Technogram). We propose to use the system to study technologies related to oral medicine. In order to create a sociogram, we create a logical filter based on a set of keywords related to the technology under study. This filter is used to extract a list of publications from the Web of Science™ database. The list is validated by an expert in the technology and sent to CERN where it is inserted in the Collaboration Spotting database. Here, an automatic software system uses the data to generate the final maps. We studied a set of recent technologies related to bone regeneration procedures of oro-maxillo-facial critical size defects, namely the use of porous hydroxyapatite (HA) as a bone substitute alone (bone graft) or as a tridimensional support (scaffold) for insemination and differentiation ex vivo of mesenchymal stem cells. We produced the sociograms for these technologies and the resulting maps are now accessible on-line. The Collaboration Spotting system allows the automatic creation of interactive maps to show the current and historical state of research on a specific technology. These maps are an ideal tool both for researchers who want to assess the state-of-the-art in a given technology, and for research organizations who want to evaluate their contribution to the technological development in a given field. We demonstrated that the system can be used in oral medicine as is produced the maps for an initial set of technologies in this field. We now plan to enlarge the set of mapped technologies in

Improved laser-based triangulation sensor with enhanced range and resolution through adaptive optics-based active beam control.

Science.gov (United States)

Reza, Syed Azer; Khwaja, Tariq Shamim; Mazhar, Mohsin Ali; Niazi, Haris Khan; Nawab, Rahma

2017-07-20

Various existing target ranging techniques are limited in terms of the dynamic range of operation and measurement resolution. These limitations arise as a result of a particular measurement methodology, the finite processing capability of the hardware components deployed within the sensor module, and the medium through which the target is viewed. Generally, improving the sensor range adversely affects its resolution and vice versa. Often, a distance sensor is designed for an optimal range/resolution setting depending on its intended application. Optical triangulation is broadly classified as a spatial-signal-processing-based ranging technique and measures target distance from the location of the reflected spot on a position sensitive detector (PSD). In most triangulation sensors that use lasers as a light source, beam divergence-which severely affects sensor measurement range-is often ignored in calculations. In this paper, we first discuss in detail the limitations to ranging imposed by beam divergence, which, in effect, sets the sensor dynamic range. Next, we show how the resolution of laser-based triangulation sensors is limited by the interpixel pitch of a finite-sized PSD. In this paper, through the use of tunable focus lenses (TFLs), we propose a novel design of a triangulation-based optical rangefinder that improves both the sensor resolution and its dynamic range through adaptive electronic control of beam propagation parameters. We present the theory and operation of the proposed sensor and clearly demonstrate a range and resolution improvement with the use of TFLs. Experimental results in support of our claims are shown to be in strong agreement with theory.

Experimental Study of Ignition by Hot Spot in Internal Combustion Engines

Science.gov (United States)

Serruys, Max

1938-01-01

In order to carry out the contemplated study, it was first necessary to provide hot spots in the combustion chamber, which could be measured and whose temperature could be changed. It seemed difficult to realize both conditions working solely on the temperature of the cooling water in a way so as to produce hot spots on the cylinder wall capable of provoking autoignition. Moreover, in the majority of practical cases, autoignition is produced by the spark plug, one of the least cooled parts in the engine. The first procedure therefore did not resemble that which most generally occurs in actual engine operation. All of these considerations caused us to reproduce similar hot spots at the spark plugs. The hot spots produced were of two kinds and designated with the name of thermo-electric spark plug and of metallic hot spot.

Spot On! Engelske plakater fra mellemkrigsårene - genstandstekster

DEFF Research Database (Denmark)

Christensen, Line Hjorth

2015-01-01

genstandstekster til udstillingen Spot On! Engelske plakater fra mellemkrigsårene. alle tekster oversat til engelsk, men postes her i den danske udgave......genstandstekster til udstillingen Spot On! Engelske plakater fra mellemkrigsårene. alle tekster oversat til engelsk, men postes her i den danske udgave...

EDF experience with {open_quotes}hot spot{close_quotes} management

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