A CCD portrait of Comet P/Tempel 2

International Nuclear Information System (INIS)

Jewitt, D.; Luu, J.

1989-01-01

The development of activity in Comet P/Tempel 2 is studied from aphelion (R = 4 AU) to perihelion (R = 1.4 AU) using extensive time-series CCD photometry and CCD spectra. The comet undergoes a profound morphological change at R of about 2-2.5 AU, from a bare nucleus at larger distances to an active comet supporting a coma of gas and dust. Cyclic photometric variations with the period T = 8.95 + or - 0.01 hr. are present at all R, and are attributed to the rotation of the nucleus at this period. The nucleus is prolate (axes a:b:c = 1.9:1:1), a property shared with other nuclei studied using CCD photometry. Novel results include a limit on the bulk density of the nucleus, rho above 300 kg/cu m, and a 20-A-resolution CCD spectrum of the nucleus. Spatially and temporally resolved photometry is used to study the effects of nucleus rotation on the coma. The coma does not share the dramatic photometric variations shown by the nucleus. It possesses a steep surface-brightness distribution, which is attributable to progressive destruction of the coma grains with increasing space exposure. 41 refs

A large area cooled-CCD detector for electron microscopy

International Nuclear Information System (INIS)

Faruqi, A.R.; Andrews, H.N.; Raeburn, C.

1994-01-01

Large area cooled-CCDs are an excellent medium for (indirectly) recording electron images and electron diffraction patterns in real time and for use in electron tomography; real-time imaging is extremely useful in making rapid adjustments in the electron microscope. CCDs provide high sensitivity (useful for minimising dosage to radiation-sensitive biological specimen), good resolution, stable performance, excellent dynamic range and linearity and a reasonably fast readout.We have built an electron imaging device based on the EEV 1152 by 814 pixel CCD which is controlled from a unix based SUN Sparcstation operating under X-Windows. The incident 100 kV electrons are converted to visible light in a 0.5 mm thick YAG single crystal which is imaged through a lens on to the CCD.The CCD electronics is designed to be as flexible as possible and allows a wide variation in the readout speed to cater for the relatively fast application where readout noise is less critical and low readout noise applications where the extra few seconds of readout time are not significant. The CCD electronics is built in VME format which is controlled through a S-bus to VME driver. With two parallel channels of readout the whole image can be read out in similar 1 s (using the faster readout speed) with 16 bit precision and the image is displayed under X-Windows in a few seconds. The present readout works at 500 kHz and has a noise of similar 30 e rms per pixel. With a Peltier cooling device we can operate the CCD at similar -40 circle C which reduces the dark current adequately to allow exposures of up to several minutes. Several examples of patterns collected with the system on a Philips CM12 microscope will be presented. ((orig.))

High-resolution CCD imaging alternatives

Science.gov (United States)

Brown, D. L.; Acker, D. E.

1992-08-01

High resolution CCD color cameras have recently stimulated the interest of a large number of potential end-users for a wide range of practical applications. Real-time High Definition Television (HDTV) systems are now being used or considered for use in applications ranging from entertainment program origination through digital image storage to medical and scientific research. HDTV generation of electronic images offers significant cost and time-saving advantages over the use of film in such applications. Further in still image systems electronic image capture is faster and more efficient than conventional image scanners. The CCD still camera can capture 3-dimensional objects into the computing environment directly without having to shoot a picture on film develop it and then scan the image into a computer. 2. EXTENDING CCD TECHNOLOGY BEYOND BROADCAST Most standard production CCD sensor chips are made for broadcast-compatible systems. One popular CCD and the basis for this discussion offers arrays of roughly 750 x 580 picture elements (pixels) or a total array of approximately 435 pixels (see Fig. 1). FOR. A has developed a technique to increase the number of available pixels for a given image compared to that produced by the standard CCD itself. Using an inter-lined CCD with an overall spatial structure several times larger than the photo-sensitive sensor areas each of the CCD sensors is shifted in two dimensions in order to fill in spatial gaps between adjacent sensors.

Assessment of space proton radiation-induced charge transfer inefficiency in the CCD204 for the Euclid space observatory

International Nuclear Information System (INIS)

Gow, J P D; Murray, N J; Holland, A D; Hall, D J; Cropper, M; Burt, D; Hopkinson, G; Duvet, L

2012-01-01

Euclid is a medium class European Space Agency mission candidate for launch in 2019 with a primary goal to study the dark universe using the weak lensing and baryonic acoustic oscillations techniques. Weak lensing depends on accurate shape measurements of distant galaxies. Therefore it is beneficial that the effects of radiation-induced charge transfer inefficiency (CTI) in the Euclid CCDs over the course of the 5 year mission at L2 are understood. This will allow, through experimental analysis and modelling techniques, the effects of radiation induced CTI on shape to be decoupled from those of mass inhomogeneities along the line-of-sight. This paper discusses a selection of work from the study that has been undertaken using the e2v CCD204 as part of the initial proton radiation damage assessment for Euclid. The experimental arrangement and procedure are described followed by the results obtained, thereby allowing recommendations to be made on the CCD operating temperature, to provide an insight into CTI effects using an optical background, to assess the benefits of using charge injection on CTI recovery and the effect of the use of two different methods of serial clocking on serial CTI. This work will form the basis of a comparison with a p-channel CCD204 fabricated using the same mask set as the n-channel equivalent. A custom CCD has been designed, based on this work and discussions between e2v technologies plc. and the Euclid consortium, and designated the CCD273.

CCD-based thermoreflectance microscopy: principles and applications

International Nuclear Information System (INIS)

Farzaneh, M; Maize, K; Shakouri, A; Lueerssen, D; Summers, J A; Hudgings, Janice A; Mayer, P M; Ram, R J; Raad, P E; Pipe, K P

2009-01-01

CCD-based thermoreflectance microscopy has emerged as a high resolution, non-contact imaging technique for thermal profiling and performance and reliability analysis of numerous electronic and optoelectronic devices at the micro-scale. This thermography technique, which is based on measuring the relative change in reflectivity of the device surface as a function of change in temperature, provides high-resolution thermal images that are useful for hot spot detection and failure analysis, mapping of temperature distribution, measurement of thermal transient, optical characterization of photonic devices and measurement of thermal conductivity in thin films. In this paper we review the basic physical principle behind thermoreflectance as a thermography tool, discuss the experimental setup, resolutions achieved, signal processing procedures and calibration techniques, and review the current applications of CCD-based thermoreflectance microscopy in various devices. (topical review)

Enhanced performance CCD output amplifier

Science.gov (United States)

Dunham, Mark E.; Morley, David W.

1996-01-01

A low-noise FET amplifier is connected to amplify output charge from a che coupled device (CCD). The FET has its gate connected to the CCD in common source configuration for receiving the output charge signal from the CCD and output an intermediate signal at a drain of the FET. An intermediate amplifier is connected to the drain of the FET for receiving the intermediate signal and outputting a low-noise signal functionally related to the output charge signal from the CCD. The amplifier is preferably connected as a virtual ground to the FET drain. The inherent shunt capacitance of the FET is selected to be at least equal to the sum of the remaining capacitances.

High-performance visible/UV CCD focal plane technology for spacebased applications

Science.gov (United States)

Burke, B. E.; Mountain, R. W.; Gregory, J. A.; Huang, J. C. M.; Cooper, M. J.; Savoye, E. D.; Kosicki, B. B.

1993-01-01

We describe recent technology developments aimed at large CCD imagers for space based applications in the visible and UV. Some of the principal areas of effort include work on reducing device degradation in the natural space-radiation environment, improvements in quantum efficiency in the visible and UV, and larger-device formats. One of the most serious hazards for space based CCD's operating at low signal levels is the displacement damage resulting from bombardment by energetic protons. Such damage degrades charge-transfer efficiency and increases dark current. We have achieved improved hardness to proton-induced displacement damage by selective ion implants into the CCD channel and by reduced temperature of operation. To attain high quantum efficiency across the visible and UV we have developed a technology for back-illuminated CCD's. With suitable antireflection (AR) coatings such devices have quantum efficiencies near 90 percent in the 500-700-nm band. In the UV band from 200 to 400 nm, where it is difficult to find coatings that are sufficiently transparent and can provide good matching to the high refractive index of silicon, we have been able to substantially increase the quantum efficiency using a thin film of HfO2 as an AR coating. These technology efforts were applied to a 420 x 420-pixel frame-transfer imager, and future work will be extended to a 1024 x 1024-pixel device now under development.

Crystallization of the C-terminal domain of the addiction antidote CcdA in complex with its toxin CcdB

International Nuclear Information System (INIS)

Buts, Lieven; De Jonge, Natalie; Loris, Remy; Wyns, Lode; Dao-Thi, Minh-Hoa

2005-01-01

The CcdA C-terminal domain was crystallized in complex with CcdB in two crystal forms that diffract to beyond 2.0 Å resolution. CcdA and CcdB are the antidote and toxin of the ccd addiction module of Escherichia coli plasmid F. The CcdA C-terminal domain (CcdA C36 ; 36 amino acids) was crystallized in complex with CcdB (dimer of 2 × 101 amino acids) in three different crystal forms, two of which diffract to high resolution. Form II belongs to space group P2 1 2 1 2 1 , with unit-cell parameters a = 37.6, b = 60.5, c = 83.8 Å and diffracts to 1.8 Å resolution. Form III belongs to space group P2 1 , with unit-cell parameters a = 41.0, b = 37.9, c = 69.6 Å, β = 96.9°, and diffracts to 1.9 Å resolution

Water Transport and Removal in PEMFC Gas Flow Channel with Various Water Droplet Locations and Channel Surface Wettability

Directory of Open Access Journals (Sweden)

Yanzhou Qin

2018-04-01

Full Text Available Water transport and removal in the proton exchange membrane fuel cell (PEMFC is critically important to fuel cell performance, stability, and durability. Water emerging locations on the membrane-electrode assembly (MEA surface and the channel surface wettability significantly influence the water transport and removal in PEMFC. In most simulations of water transport and removal in the PEMFC flow channel, liquid water is usually introduced at the center of the MEA surface, which is fortuitous, since water droplet can emerge randomly on the MEA surface in PEMFC. In addition, the commonly used no-slip wall boundary condition greatly confines the water sliding features on hydrophobic MEA/channel surfaces, degrading the simulation accuracy. In this study, water droplet is introduced with various locations along the channel width direction on the MEA surface, and water transport and removal is investigated numerically using an improved model incorporating the sliding flow property by using the shear wall boundary condition. It is found that the water droplet can be driven to the channel sidewall by aerodynamics when the initial water location deviates from the MEA center to a certain amount, forming the water corner flow in the flow channel. The channel surface wettability on the water transport is also studied and is shown to have a significant impact on the water corner flow in the flow channel.

Transmission electron microscope CCD camera

Science.gov (United States)

Downing, Kenneth H.

1999-01-01

In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

CCD research. [design, fabrication, and applications

Science.gov (United States)

Gassaway, J. D.

1976-01-01

The fundamental problems encountered in designing, fabricating, and applying CCD's are reviewed. Investigations are described and results and conclusions are given for the following: (1) the development of design analyses employing computer aided techniques and their application to the design of a grapped structure; (2) the role of CCD's in applications to electronic functions, in particular, signal processing; (3) extending the CCD to silicon films on sapphire (SOS); and (4) all aluminum transfer structure with low noise input-output circuits. Related work on CCD imaging devices is summarized.

Development of X-ray CCD camera system with high readout rate using ASIC

International Nuclear Information System (INIS)

Nakajima, Hiroshi; Matsuura, Daisuke; Anabuki, Naohisa; Miyata, Emi; Tsunemi, Hiroshi; Doty, John P.; Ikeda, Hirokazu; Katayama, Haruyoshi

2009-01-01

We report on the development of an X-ray charge-coupled device (CCD) camera system with high readout rate using application-specific integrated circuit (ASIC) and Camera Link standard. The distinctive ΔΣ type analog-to-digital converter is introduced into the chip to achieve effective noise shaping and to obtain a high resolution with relatively simple circuits. The unit test proved moderately low equivalent input noise of 70μV with a high readout pixel rate of 625 kHz, while the entire chip consumes only 100 mW. The Camera Link standard was applied for the connectivity between the camera system and frame grabbers. In the initial test of the whole system, we adopted a P-channel CCD with a thick depletion layer developed for X-ray CCD camera onboard the next Japanese X-ray astronomical satellite. The characteristic X-rays from 109 Cd were successfully read out resulting in the energy resolution of 379(±7)eV (FWHM) at 22.1 keV, that is, ΔE/E=1.7% with a readout rate of 44 kHz.

Blind Identification of FIR Channels in the Presence of Unknown Noise

Directory of Open Access Journals (Sweden)

Kon Max Wong

2007-01-01

Full Text Available Blind channel identification techniques based on second-order statistics (SOS of the received data have been a topic of active research in recent years. Among the most popular is the subspace method (SS proposed by Moulines et al. (1995. It has good performance when the channel output is corrupted by white noise. However, when the channel noise is correlated and unknown as is often encountered in practice, the performance of the SS method degrades severely. In this paper, we address the problem of estimating FIR channels in the presence of arbitrarily correlated noise whose covariance matrix is unknown. We propose several algorithms according to the different available system resources: (1 when only one receiving antenna is available, by upsampling the output, we develop the maximum a posteriori (MAP algorithm for which a simple criterion is obtained and an efficient implementation algorithm is developed; (2 when two receiving antennae are available, by upsampling both the outputs and utilizing canonical correlation decomposition (CCD to obtain the subspaces, we present two algorithms (CCD-SS and CCD-ML to blindly estimate the channels. Our algorithms perform well in unknown noise environment and outperform existing methods proposed for similar scenarios.

CCD photometry of apparent dwarf galaxies in Fornax

International Nuclear Information System (INIS)

Phillipps, S.; Grimley, P.L.; Disney, M.J.; Cawson, M.G.M.; Kibblewhite, E.J.

1986-01-01

Blue and red CCD surface photometry of two apparent dwarf galaxies in the Fornax cluster region is presented. Luminosity profiles are derived and their form discussed. The fainter galaxy resembles an archetypal diffuse dwarf elliptical but the brighter of the pair is either an unusual red dwarf or a background galaxy in chance juxtaposition. (author)

Channeling regimes in ion surface scattering

NARCIS (Netherlands)

Robin, A; Heiland, W

We report on surface channeling experiments of singly charged ions on single crystal surfaces of Pt(1 1 0) and Pd(1 1 0). Using a time-of-flight system installed in forward direction we analyze the energy distribution of the scattered projectiles. By variation of the primary energy and the angle of

Turbine component having surface cooling channels and method of forming same

Science.gov (United States)

Miranda, Carlos Miguel; Trimmer, Andrew Lee; Kottilingam, Srikanth Chandrudu

2017-09-05

A component for a turbine engine includes a substrate that includes a first surface, and an insert coupled to the substrate proximate the substrate first surface. The component also includes a channel. The channel is defined by a first channel wall formed in the substrate and a second channel wall formed by at least one coating disposed on the substrate first surface. The component further includes an inlet opening defined in flow communication with the channel. The inlet opening is defined by a first inlet wall formed in the substrate and a second inlet wall defined by the insert.

Enzymatic study on AtCCD4 and AtCCD7 and their potential to form acyclic regulatory metabolites

KAUST Repository

Bruno, Mark

2016-09-29

The Arabidopsis carotenoid cleavage dioxygenase 4 (AtCCD4) is a negative regulator of the carotenoid content of seeds and has recently been suggested as a candidate for the generation of retrograde signals that are thought to derive from the cleavage of poly-cis-configured carotene desaturation intermediates. In this work, we investigated the activity of AtCCD4 in vitro and used dynamic modeling to determine its substrate preference. Our results document strict regional specificity for cleavage at the C9–C10 double bond in carotenoids and apocarotenoids, with preference for carotenoid substrates and an obstructing effect on hydroxyl functions, and demonstrate the specificity for all-trans-configured carotenes and xanthophylls. AtCCD4 cleaved substrates with at least one ionone ring and did not convert acyclic carotene desaturation intermediates, independent of their isomeric states. These results do not support a direct involvement of AtCCD4 in generating the supposed regulatory metabolites. In contrast, the strigolactone biosynthetic enzyme AtCCD7 converted 9-cis-configured acyclic carotenes, such as 9-cis-ζ-carotene, 9\\'-cis-neurosporene, and 9-cis-lycopene, yielding 9-cis-configured products and indicating that AtCCD7, rather than AtCCD4, is the candidate for forming acyclic retrograde signals.

Enzymatic study on AtCCD4 and AtCCD7 and their potential to form acyclic regulatory metabolites

KAUST Repository

Bruno, Mark; Koschmieder, Julian; Wuest, Florian; Schaub, Patrick; Fehling-Kaschek, Mirjam; Timmer, Jens; Beyer, Peter; Al-Babili, Salim

2016-01-01

The Arabidopsis carotenoid cleavage dioxygenase 4 (AtCCD4) is a negative regulator of the carotenoid content of seeds and has recently been suggested as a candidate for the generation of retrograde signals that are thought to derive from the cleavage of poly-cis-configured carotene desaturation intermediates. In this work, we investigated the activity of AtCCD4 in vitro and used dynamic modeling to determine its substrate preference. Our results document strict regional specificity for cleavage at the C9–C10 double bond in carotenoids and apocarotenoids, with preference for carotenoid substrates and an obstructing effect on hydroxyl functions, and demonstrate the specificity for all-trans-configured carotenes and xanthophylls. AtCCD4 cleaved substrates with at least one ionone ring and did not convert acyclic carotene desaturation intermediates, independent of their isomeric states. These results do not support a direct involvement of AtCCD4 in generating the supposed regulatory metabolites. In contrast, the strigolactone biosynthetic enzyme AtCCD7 converted 9-cis-configured acyclic carotenes, such as 9-cis-ζ-carotene, 9'-cis-neurosporene, and 9-cis-lycopene, yielding 9-cis-configured products and indicating that AtCCD7, rather than AtCCD4, is the candidate for forming acyclic retrograde signals.

Enzymatic study on AtCCD4 and AtCCD7 and their potential to form acyclic regulatory metabolites

Science.gov (United States)

Bruno, Mark; Koschmieder, Julian; Wuest, Florian; Schaub, Patrick; Fehling-Kaschek, Mirjam; Timmer, Jens; Beyer, Peter; Al-Babili, Salim

2016-01-01

The Arabidopsis carotenoid cleavage dioxygenase 4 (AtCCD4) is a negative regulator of the carotenoid content of seeds and has recently been suggested as a candidate for the generation of retrograde signals that are thought to derive from the cleavage of poly-cis-configured carotene desaturation intermediates. In this work, we investigated the activity of AtCCD4 in vitro and used dynamic modeling to determine its substrate preference. Our results document strict regional specificity for cleavage at the C9–C10 double bond in carotenoids and apocarotenoids, with preference for carotenoid substrates and an obstructing effect on hydroxyl functions, and demonstrate the specificity for all-trans-configured carotenes and xanthophylls. AtCCD4 cleaved substrates with at least one ionone ring and did not convert acyclic carotene desaturation intermediates, independent of their isomeric states. These results do not support a direct involvement of AtCCD4 in generating the supposed regulatory metabolites. In contrast, the strigolactone biosynthetic enzyme AtCCD7 converted 9-cis-configured acyclic carotenes, such as 9-cis-ζ-carotene, 9'-cis-neurosporene, and 9-cis-lycopene, yielding 9-cis-configured products and indicating that AtCCD7, rather than AtCCD4, is the candidate for forming acyclic retrograde signals. PMID:27811075

Determination of optimum "multi-channel surface wave method" field parameters.

Science.gov (United States)

2012-12-01

Multi-channel surface wave methods (especially the multi-channel analyses of surface wave method; MASW) are routinely used to : determine the shear-wave velocity of the subsurface to depths of 100 feet for site classification purposes. Users are awar...

Charge diffusion in CCD X-ray detectors

International Nuclear Information System (INIS)

Pavlov, George G.; Nousek, John A.

1999-01-01

Critical to the detection of X-rays by CCDs, is the detailed process of charge diffusion and drift within the device. We reexamine the prescriptions currently used in the modeling of X-ray CCD detectors to provide analytic expressions for the charge distribution over the CCD pixels which are suitable for use in numerical simulations of CCD response. Our treatment results in models which predict charge distributions which are more centrally peaked and have flatter wings than the Gaussian shapes predicted by previous work and adopted in current CCD modeling codes

In-flight characterization of the HETE soft X-ray CCD cameras

International Nuclear Information System (INIS)

Prigozhin, G.; Villasenor, J.; Vanderspek, R.; Doty, J.; Crew, G.; Ricker, G.; Jernigan, G.

2003-01-01

We have developed a set of software tools that allow to monitor the performance of the flight X-ray CCD cameras as soon as data arrive at MIT. An emission line at 5.9 keV from the on-board Fe-55 radioactive calibration source is clearly visible in the spectra and provides the means to measure the gain and the noise for each observation in each of the 4 CCD chips in operation. Both parameters can change with time, depending on the phase of the moon and the amount of light leaking into the system. Time vs. position scatter plots were found to be an extremely powerful tool in understanding of the device performance. They illustrate the evolution of the light leaks produced by the dark Earth at the beginning and the end of each orbit. With a bright X-ray source in the field of view the shadow of the mask projected on the surface of the CCD clearly shows the motions of the spacecraft

A VXI-based high speed x-ray CCD detector

International Nuclear Information System (INIS)

Huang, Qiang; Hopf, R.; Rodricks, B.

1993-01-01

For time-resolved x-ray scattering, one ideally wants a high speed detector that also is capable of giving position sensitive information. Charge Coupled Devices (CCDS) have been used successfully as x-ray detectors. Unfortunately, they are inherently slow because of the serial readout EEV has developed a CCD that has eight channels of parallel readout, thus increasing the speed eight fold. Using state-of-the-art VXI electronics, we have developed a readout system that could read the entire array in 2.5 ms using a 20-MHz readout clock. For testing and characterization the device was clocked at a significantly slower speed of 30 kHz. The data is preamplified and all eight channels of output are simultaneously digitized to 12 bits and stored in buffer memory. The system is controlled by a 486-based PC through an MXI bus and VXI controller using commercially available software. The system is also capable of real-time image display and manipulation

CCD's at TPC

International Nuclear Information System (INIS)

Zeller, M.E.

1977-01-01

The CCD, Charge Coupled Device, is an analog shift register for which application to the readout of particle detectors has recently been realized. These devices can be used to detect optical information directly, providing an automated readout for streamer or other optical chambers, or as a single input shift register, acting in this instance as a delay line for analog information. A description is given of the latter mode of operation and its utility as a readout method for drift chambers. Most of the information contained herein has been obtained from tests performed in connection with PEP TPC project, PEP-4. That detector will employ approximately 10 4 CCD's making it a reasonable testing ground for ISABELLE size detectors

Purification and crystallization of Vibrio fischeri CcdB and its complexes with fragments of gyrase and CcdA

International Nuclear Information System (INIS)

De Jonge, Natalie; Buts, Lieven; Vangelooven, Joris; Mine, Natacha; Van Melderen, Laurence; Wyns, Lode; Loris, Remy

2007-01-01

A CcdB homologue from V. fischeri was overexpressed in E. coli and purified. The free protein was crystallized, as were its complexes with fragments of E. coli and V. fischeri gyrase and with the F-plasmid CcdA C-terminal domain. The ccd toxin–antitoxin module from the Escherichia coli F plasmid has a homologue on the Vibrio fischeri integron. The homologue of the toxin (CcdB Vfi ) was crystallized in two different crystal forms. The first form belongs to space group I23 or I2 1 3, with unit-cell parameter a = 84.5 Å, and diffracts to 1.5 Å resolution. The second crystal form belongs to space group C2, with unit-cell parameters a = 58.5, b = 43.6, c = 37.5 Å, β = 110.0°, and diffracts to 1.7 Å resolution. The complex of CcdB Vfi with the GyrA14 Vfi fragment of V. fischeri gyrase crystallizes in space group P2 1 2 1 2 1 , with unit-cell parameters a = 53.5, b = 94.6, c = 58.1 Å, and diffracts to 2.2 Å resolution. The corresponding mixed complex with E. coli GyrA14 Ec crystallizes in space group C2, with unit-cell parameters a = 130.1, b = 90.8, c = 58.1 Å, β = 102.6°, and diffracts to 1.95 Å. Finally, a complex between CcdB Vfi and part of the F-plasmid antitoxin CcdA F crystallizes in space group P2 1 2 1 2 1 , with unit-cell parameters a = 46.9, b = 62.6, c = 82.0 Å, and diffracts to 1.9 Å resolution

Follow-up study of children with cerebral coordination disturbance (CCD, Vojta).

Science.gov (United States)

Imamura, S; Sakuma, K; Takahashi, T

1983-01-01

713 children (from newborn to 12-month-old) with delayed motor development were carefully examined and classified into normal, very light cerebral coordination disturbance (CCD, Vojta), light CCD, moderate CCD, severe CCD, suspected cerebral palsy (CP) and other diseases at their first visit, and were followed up carefully. Finally, 89.0% of very light CCD, 71.4% of light CCD, 56.0% of moderate CCD and 30.0% of severe CCD developed into normal. 59.5% of moderate CCD and 45.5% of severe CCD among children who were given Vojta's physiotherapy developed into normal. The classification of cases with delayed motor development into very light, light, moderate and severe CCD based on the extent of abnormality in their postural reflexes is useful and well correlated with their prognosis. Treatment by Vojta's method seems to be efficient and helpful for young children with delayed motor development.

Spectral interference of zirconium on 24 analyte elements using CCD based ICP-AES technique

International Nuclear Information System (INIS)

Adya, V.C.; Sengupta, Arijit; Godbole, S.V.

2014-01-01

In the present studies, the spectral interference of zirconium on different analytical lines of 24 critical analytes using CCD based ICP-AES technique is described. Suitable analytical lines for zirconium were identified along with their detection limits. The sensitivity and the detection limits of analytical channels for different elements in presence of Zr matrix were calculated. Subsequently analytical lines with least interference from Zr and better detection limits were selected for their determinations. (author)

Purification and crystallization of Vibrio fischeri CcdB and its complexes with fragments of gyrase and CcdA

Energy Technology Data Exchange (ETDEWEB)

De Jonge, Natalie, E-mail: ndejonge@vub.ac.be; Buts, Lieven; Vangelooven, Joris [Department of Molecular and Cellular Interactions, VIB, Pleinlaan 2, 1050 Brussels (Belgium); Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium); Mine, Natacha; Van Melderen, Laurence [Laboratoire de Génétique des Procaryotes, Institut de Biologie et de Médecine, Université Libre de Bruxelles, Gosselies (Belgium); Wyns, Lode; Loris, Remy [Department of Molecular and Cellular Interactions, VIB, Pleinlaan 2, 1050 Brussels (Belgium); Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium)

2007-04-01

A CcdB homologue from V. fischeri was overexpressed in E. coli and purified. The free protein was crystallized, as were its complexes with fragments of E. coli and V. fischeri gyrase and with the F-plasmid CcdA C-terminal domain. The ccd toxin–antitoxin module from the Escherichia coli F plasmid has a homologue on the Vibrio fischeri integron. The homologue of the toxin (CcdB{sub Vfi}) was crystallized in two different crystal forms. The first form belongs to space group I23 or I2{sub 1}3, with unit-cell parameter a = 84.5 Å, and diffracts to 1.5 Å resolution. The second crystal form belongs to space group C2, with unit-cell parameters a = 58.5, b = 43.6, c = 37.5 Å, β = 110.0°, and diffracts to 1.7 Å resolution. The complex of CcdB{sub Vfi} with the GyrA14{sub Vfi} fragment of V. fischeri gyrase crystallizes in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 53.5, b = 94.6, c = 58.1 Å, and diffracts to 2.2 Å resolution. The corresponding mixed complex with E. coli GyrA14{sub Ec} crystallizes in space group C2, with unit-cell parameters a = 130.1, b = 90.8, c = 58.1 Å, β = 102.6°, and diffracts to 1.95 Å. Finally, a complex between CcdB{sub Vfi} and part of the F-plasmid antitoxin CcdA{sub F} crystallizes in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 46.9, b = 62.6, c = 82.0 Å, and diffracts to 1.9 Å resolution.

Case study of atmospheric correction on CCD data of HJ-1 satellite based on 6S model

International Nuclear Information System (INIS)

Xue, Xiaoiuan; Meng, Oingyan; Xie, Yong; Sun, Zhangli; Wang, Chang; Zhao, Hang

2014-01-01

In this study, atmospheric radiative transfer model 6S was used to simulate the radioactive transfer process in the surface-atmosphere-sensor. An algorithm based on the look-up table (LUT) founded by 6S model was used to correct (HJ-1) CCD image pixel by pixel. Then, the effect of atmospheric correction on CCD data of HJ-1 satellite was analyzed in terms of the spectral curves and evaluated against the measured reflectance acquired during HJ-1B satellite overpass, finally, the normalized difference vegetation index (NDVI) before and after atmospheric correction were compared. The results showed: (1) Atmospheric correction on CCD data of HJ-1 satellite can reduce the ''increase'' effect of the atmosphere. (2) Apparent reflectance are higher than those of surface reflectance corrected by 6S model in band1∼band3, but they are lower in the near-infrared band; the surface reflectance values corrected agree with the measured reflectance values well. (3)The NDVI increases significantly after atmospheric correction, which indicates the atmospheric correction can highlight the vegetation information

Noise characteristics of neutron images obtained by cooled CCD device

International Nuclear Information System (INIS)

Taniguchi, Ryoichi; Sasaki, Ryoya; Okuda, Shuichi; Okamoto, Ken-Ichi; Ogawa, Yoshihiro; Tsujimoto, Tadashi

2009-01-01

The noise characteristics of a cooled CCD device induced by neutron and gamma ray irradiation have been investigated. In the cooled CCD images, characteristic white spot noises (CCD noise) frequently appeared, which have a shape like a pixel in most cases and their brightness is extremely high compared with that of the image pattern. They could be divided into the two groups, fixed pattern noise (FPN) and random noise. The former always appeared in the same position in the image and the latter appeared at any position. In the background image, nearly all of the CCD noises were found to be the FPN, while many of them were the random noise during the irradiation. The random CCD noises increased with irradiation and decreased soon after the irradiation. In the case of large irradiation, a part of the CCD noise remained as the FPN. These facts suggest that the CCD noise is a phenomenon strongly relating to radiation damage of the CCD device.

Soil bioengineering methods for abandoned mine land surface drainage channels

Energy Technology Data Exchange (ETDEWEB)

Sotir, R.B.; Simms, A.P.; Sweigard, R.J.; Hammer, P.; Graves, D.H.; Adkins, M. [Robbin B. Sotir & Associates, Marietta, GA (USA)

1999-07-01

Research to determine the suitability of soil bioengineering for slope stabilization at abandoned surface mining sites is described. The technology uses live woody plant material as a structural component, in this case live fascine with coir erosion control fabric made from coconut. A large water collection pond draining to nine channels on the slope below was constructed as a test site. The pond has drainage channels for testing at low, intermediate, and steep slope grades. Each group of three channels is composed of one riprap rock channel, one gabion channel, and one soil bioengineering channel. The channels will be tested summer 1999. 11 refs., 5 figs., 2 tabs., 8 photos.

Effect of surface bilayer charges on the magnetic field around ionic channels

Energy Technology Data Exchange (ETDEWEB)

Gomes Soares, Marília Amável [Post-graduation in Computational Sciences, Rio de Janeiro State University (Brazil); Cortez, Celia Martins, E-mail: ccortezs@ime.uerj.br [Post-graduation in Computational Sciences, Rio de Janeiro State University (Brazil); Department of Applied Mathematics, Rio de Janeiro State University (Brazil); Oliveira Cruz, Frederico Alan de [Post-graduation in Computational Sciences, Rio de Janeiro State University (Brazil); Department of Physics, Rural Federal University of Rio de Janeiro (Brazil); Silva, Dilson [Post-graduation in Computational Sciences, Rio de Janeiro State University (Brazil); Department of Applied Mathematics, Rio de Janeiro State University (Brazil)

2017-01-01

In this work, we present a physic-mathematical model for representing the ion transport through membrane channels, in special Na{sup +} and K{sup +}-channels, and discuss the influence of surface bilayer charges on the magnetic field behavior around the ionic current. The model was composed of a set of equations, including: a nonlinear differential Poisson-Boltzmann equation which usually allows to estimate the surface potentials and electric potential profile across membrane; equations for the ionic flux through channel and the ionic current density based on Armstrong's model for Na{sup +} and K{sup +} permeability and other Physics concepts; and a magnetic field expression derived from the classical Ampère equation. Results from computational simulations using the finite element method suggest that the ionic permeability is strongly dependent of surface bilayer charges, the current density through a K{sup +}-channel is very less sensible to temperature changes than the current density through a Na{sup +}- channel, active Na{sup +}-channels do not directly interfere with the K{sup +}-channels around, and vice-versa, since the magnetic perturbation generated by an active channel is of short-range.

The design and development of low- and high-voltage ASICs for space-borne CCD cameras

Science.gov (United States)

Waltham, N.; Morrissey, Q.; Clapp, M.; Bell, S.; Jones, L.; Torbet, M.

2017-12-01

The CCD remains the pre-eminent visible and UV wavelength image sensor in space science, Earth and planetary remote sensing. However, the design of space-qualified CCD readout electronics is a significant challenge with requirements for low-volume, low-mass, low-power, high-reliability and tolerance to space radiation. Space-qualified components are frequently unavailable and up-screened commercial components seldom meet project or international space agency requirements. In this paper, we describe an alternative approach of designing and space-qualifying a series of low- and high-voltage mixed-signal application-specific integrated circuits (ASICs), the ongoing development of two low-voltage ASICs with successful flight heritage, and two new high-voltage designs. A challenging sub-system of any CCD camera is the video processing and digitisation electronics. We describe recent developments to improve performance and tolerance to radiation-induced single event latchup of a CCD video processing ASIC originally developed for NASA's Solar Terrestrial Relations Observatory and Solar Dynamics Observatory. We also describe a programme to develop two high-voltage ASICs to address the challenges presented with generating a CCD's bias voltages and drive clocks. A 0.35 μm, 50 V tolerant, CMOS process has been used to combine standard low-voltage 3.3 V transistors with high-voltage 50 V diffused MOSFET transistors that enable output buffers to drive CCD bias drains, gates and clock electrodes directly. We describe a CCD bias voltage generator ASIC that provides 24 independent and programmable 0-32 V outputs. Each channel incorporates a 10-bit digital-to-analogue converter, provides current drive of up to 20 mA into loads of 10 μF, and includes current-limiting and short-circuit protection. An on-chip telemetry system with a 12-bit analogue-to-digital converter enables the outputs and multiple off-chip camera voltages to be monitored. The ASIC can drive one or more CCDs and

CCD Astrophotography High-Quality Imaging from the Suburbs

CERN Document Server

Stuart, Adam

2006-01-01

This is a reference book for amateur astronomers who have become interested in CCD imaging. Those glorious astronomical images found in astronomy magazines might seem out of reach to newcomers to CCD imaging, but this is not the case. Great pictures are attainable with modest equipment. Adam Stuart’s many beautiful images, reproduced in this book, attest to the quality of – initially – a beginner’s efforts. Chilled-chip astronomical CCD-cameras and software are also wonderful tools for cutting through seemingly impenetrable light-pollution. CCD Astrophotography from the Suburbs describes one man’s successful approach to the problem of getting high-quality astronomical images under some of the most light-polluted conditions. Here is a complete and thoroughly tested program that will help every CCD-beginner to work towards digital imaging of the highest quality. It is equally useful to astronomers who have perfect observing conditions, as to those who have to observe from light-polluted city skies.

Custom CCD for adaptive optics applications

Science.gov (United States)

Downing, Mark; Arsenault, Robin; Baade, Dietrich; Balard, Philippe; Bell, Ray; Burt, David; Denney, Sandy; Feautrier, Philippe; Fusco, Thierry; Gach, Jean-Luc; Diaz Garcia, José Javier; Guillaume, Christian; Hubin, Norbert; Jorden, Paul; Kasper, Markus; Meyer, Manfred; Pool, Peter; Reyes, Javier; Skegg, Michael; Stadler, Eric; Suske, Wolfgang; Wheeler, Patrick

2006-06-01

ESO and JRA2 OPTICON have funded e2v technologies to develop a compact packaged Peltier cooled 24 μm square 240x240 pixels split frame transfer 8-output back-illuminated L3Vision CCD3, L3Vision CCD for Adaptive Optic Wave Front Sensor (AO WFS) applications. The device is designed to achieve sub-electron read noise at frame rates from 25 Hz to 1,500 Hz and dark current lower than 0.01 e-/pixel/frame. The development has many unique features. To obtain high frame rates, multi-output EMCCD gain registers and metal buttressing of row clock lines are used. The baseline device is built in standard silicon. In addition, a split wafer run has enabled two speculative variants to be built; deep depletion silicon devices to improve red response and devices with an electronic shutter to extend use to Rayleigh and Pulsed Laser Guide Star applications. These are all firsts for L3Vision CCDs. The designs of the CCD and Peltier package have passed their reviews and fabrication has begun. This paper will describe the progress to date, the requirements and the design of the CCD and compact Peltier package, technology trade-offs, schedule and proposed test plan. High readout speed, low noise and compactness (requirement to fit in confined spaces) provide special challenges to ESO's AO variant of its NGC, New General detector Controller to drive this CCD. This paper will describe progress made on the design of the controller to meet these special needs.

Effect of nano-scale morphology on micro-channel wall surface and electrical characterization in lead silicate glass micro-channel plate

Science.gov (United States)

Cai, Hua; Li, Fangjun; Xu, Yanglei; Bo, Tiezhu; Zhou, Dongzhan; Lian, Jiao; Li, Qing; Cao, Zhenbo; Xu, Tao; Wang, Caili; Liu, Hui; Li, Guoen; Jia, Jinsheng

2017-10-01

Micro-channel plate (MCP) is a two dimensional arrays of microscopic channel charge particle multiplier. Silicate composition and hydrogen reduction are keys to determine surface morphology of micro-channel wall in MCP. In this paper, lead silicate glass micro-channel plates in two different cesium contents (0at%, 0.5at%) and two different hydrogen reduction temperatures (400°C,450°C) were present. The nano-scale morphology, elements content and chemical states of microporous wall surface treated under different alkaline compositions and reduction conditions was investigated by Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS), respectively. Meanwhile, the electrical characterizations of MCP, including the bulk resistance, electron gain and the density of dark current, were measured in a Vacuum Photoelectron Imaging Test Facility (VPIT).The results indicated that the granular phase occurred on the surface of microporous wall and diffuses in bulk glass is an aggregate of Pb atom derived from the reduction of Pb2+. In micro-channel plate, the electron gain and bulk resistance were mainly correlated to particle size and distribution, the density of dark current (DDC) went up with the increasing root-mean-square roughness (RMS) on the microporous wall surface. Adding cesiums improved the size of Pb atomic aggregation, lowered the relative concentration of [Pb] reduced from Pb2+ and decreased the total roughness of micro-channel wall surface, leading a higher bulk resistance, a lower electron gain and a less dark current. Increasing hydrogen reduction temperature also improved the size of Pb atomic aggregation, but enhanced the relative concentration of [Pb] and enlarged the total roughness of micro-channel wall surface, leading a higher bulk resistance, a lower electron gain and a larger dark current. The reasons for the difference of electrical characteristics were discussed.

THE ACCURACY OF Hβ CCD PHOTOMETRY

Directory of Open Access Journals (Sweden)

C. Kim

1994-12-01

Full Text Available We have undertaken CCD observations of field standard stars with Hβ photometric system to investigate the reliability of Hβ CCD photometry. Flat fielding with dome flat and sky flat for Hβw and Hβn filter was compared with that of B filter in UBV system and, from these, we have not found any difference. It was confirmed that there is a good linear relationship between our Hβ values observed with 2.3m reflector and standard values. However, Hβ values observed with 60cm reflector at Sobaeksan Astronomy Observatory showed very poor relationship. To investigate the accuracy of Hβ CCD photometry for fainter objects, open cluster NGC2437 was observed and reduced with DoPHOT, and the results were compared with those for photoelectric photometry of Stetson (1981.

Correlation and image compression for limited-bandwidth CCD.

Energy Technology Data Exchange (ETDEWEB)

Thompson, Douglas G.

2005-07-01

As radars move to Unmanned Aerial Vehicles with limited-bandwidth data downlinks, the amount of data stored and transmitted with each image becomes more significant. This document gives the results of a study to determine the effect of lossy compression in the image magnitude and phase on Coherent Change Detection (CCD). We examine 44 lossy compression types, plus lossless zlib compression, and test each compression method with over 600 CCD image pairs. We also derive theoretical predictions for the correlation for most of these compression schemes, which compare favorably with the experimental results. We recommend image transmission formats for limited-bandwidth programs having various requirements for CCD, including programs which cannot allow performance degradation and those which have stricter bandwidth requirements at the expense of CCD performance.

Contribution of the Chromosomal ccdAB Operon to Bacterial Drug Tolerance.

Science.gov (United States)

Gupta, Kritika; Tripathi, Arti; Sahu, Alishan; Varadarajan, Raghavan

2017-10-01

One of the first identified and best-studied toxin-antitoxin (TA) systems in Escherichia coli is the F-plasmid-based CcdAB system. This system is involved in plasmid maintenance through postsegregational killing. More recently, ccdAB homologs have been found on the chromosome, including in pathogenic strains of E. coli and other bacteria. However, the functional role of chromosomal ccdAB genes, if any, has remained unclear. We show that both the native ccd operon of the E. coli O157 strain ( ccd O157 ) and the ccd operon from the F plasmid ( ccd F ), when inserted on the E. coli chromosome, lead to protection from cell death under multiple antibiotic stress conditions through formation of persisters, with the O157 operon showing higher protection. While the plasmid-encoded CcdB toxin is a potent gyrase inhibitor and leads to bacterial cell death even under fully repressed conditions, the chromosomally encoded toxin leads to growth inhibition, except at high expression levels, where some cell death is seen. This was further confirmed by transiently activating the chromosomal ccd operon through overexpression of an active-site inactive mutant of F-plasmid-encoded CcdB. Both the ccd F and ccd O157 operons may share common mechanisms for activation under stress conditions, eventually leading to multidrug-tolerant persister cells. This study clearly demonstrates an important role for chromosomal ccd systems in bacterial persistence. IMPORTANCE A large number of free-living and pathogenic bacteria are known to harbor multiple toxin-antitoxin systems, on plasmids as well as on chromosomes. The F-plasmid CcdAB system has been extensively studied and is known to be involved in plasmid maintenance. However, little is known about the function of its chromosomal counterpart, found in several pathogenic E. coli strains. We show that the native chromosomal ccd operon of the E. coli O157 strain is involved in drug tolerance and confers protection from cell death under multiple

Versatile ultrafast pump-probe imaging with high sensitivity CCD camera

OpenAIRE

Pezeril , Thomas; Klieber , Christoph; Temnov , Vasily; Huntzinger , Jean-Roch; Anane , Abdelmadjid

2012-01-01

International audience; A powerful imaging technique based on femtosecond time-resolved measurements with a high dynamic range, commercial CCD camera is presented. Ultrafast phenomena induced by a femtosecond laser pump are visualized through the lock-in type acquisition of images recorded by a femtosecond laser probe. This technique allows time-resolved measurements of laser excited phenomena at multiple probe wavelengths (spectrometer mode) or conventional imaging of the sample surface (ima...

Coevolution of bed surface patchiness and channel morphology: 2. Numerical experiments

Science.gov (United States)

Nelson, Peter A.; McDonald, Richard R.; Nelson, Jonathan M.; Dietrich, William E.

2015-01-01

In gravel bed rivers, bed topography and the bed surface grain size distribution evolve simultaneously, but it is not clear how feedbacks between topography and grain sorting affect channel morphology. In this, the second of a pair of papers examining interactions between bed topography and bed surface sorting in gravel bed rivers, we use a two-dimensional morphodynamic model to perform numerical experiments designed to explore the coevolution of both free and forced bars and bed surface patches. Model runs were carried out on a computational grid simulating a 200 m long, 2.75 m wide, straight, rectangular channel, with an initially flat bed at a slope of 0.0137. Over five numerical experiments, we varied (a) whether an obstruction was present, (b) whether the sediment was a gravel mixture or a single size, and (c) whether the bed surface grain size feeds back on the hydraulic roughness field. Experiments with channel obstructions developed a train of alternate bars that became stationary and were connected to the obstruction. Freely migrating alternate bars formed in the experiments without channel obstructions. Simulations incorporating roughness feedbacks between the bed surface and flow field produced flatter, broader, and longer bars than simulations using constant roughness or uniform sediment. Our findings suggest that patches are not simply a by-product of bed topography, but they interact with the evolving bed and influence morphologic evolution.

High-Voltage Clock Driver for Photon-Counting CCD Characterization

Science.gov (United States)

Baker, Robert

2013-01-01

A document discusses the CCD97 from e2v technologies as it is being evaluated at Goddard Space Flight Center's Detector Characterization Laboratory (DCL) for possible use in ultra-low background noise space astronomy applications, such as Terrestrial Planet Finder Coronagraph (TPF-C). The CCD97 includes a photoncounting mode where the equivalent output noise is less than one electron. Use of this mode requires a clock signal at a voltage level greater than the level achievable by the existing CCD (charge-coupled-device) electronics. A high-voltage waveform generator has been developed in code 660/601 to support the CCD97 evaluation. The unit generates required clock waveforms at voltage levels from -20 to +50 V. It deals with standard and arbitrary waveforms and supports pixel rates from 50 to 500 kHz. The system is designed to interface with existing Leach CCD electronics.

Cooling System for a Frame-Store PN-CCD Detector for Low Background Application

CERN Document Server

Pereira, H; Santos Silva, P; Kuster, M; Lang, P

2012-01-01

The astroparticle physics experiment CERN Axion Solar Telescope (CAST) aims to detect hypothetical axions or axion-like particles produced in the Sun by the Primakoff process. A Large Hadron Collider (LHC) prototype superconducting dipole magnet provides a 9 T transverse magnetic field for the conversion of axions into detectable X-ray photons. These photons are detected with an X-ray telescope and a novel type of frame-store CCD detector built from radio-pure materials, installed in the optics focal plane. A novel type of cooling system has been designed and built based on krypton-filled cryogenic heat pipes, made out of oxygen-free radiopure copper, and a Stirling cryocooler as cold source. The heat pipes provide an efficient thermal coupling between the cryocooler and the CCD which is kept at stable temperatures between 150 and 230 K within an accuracy of 0.1 K. A graded-Z radiation shield, also serving as a gas cold-trap operated at 120 K, is implemented to reduce the surface contamination of the CCD wind...

Caracterização espectral de áreas de gramíneas forrageiras infectadas com a doença "mela-das-sementes da braquiária" por meio de imagens CCD/CBERS-2 Spectral characterization of forage grasses infected with the disease "mela-das-sementes da braquiária" through CCD/CDBERS -2 images

Directory of Open Access Journals (Sweden)

José C. Rosatti

2006-12-01

Full Text Available Imagens CCD/CBERS-2, nas bandas espectrais CCD2, CCD3 e CCD4, dos anos de 2004 e 2005, de Mirante do Paranapanema - SP, foram transformadas em reflectância de superfície usando o modelo 5S de correção atmosférica e normalizadas radiometricamente. O objetivo principal foi caracterizar espectralmente áreas de pastagens de Brachiaria brizantha em fase de florescimento, isentas e infectadas com a doença "mela-das-sementes da braquiária", possibilitando a sua detecção por meio da comparação entre os valores de reflectância de superfície denominada de Fator de Reflectância Bidirecional de Superfície (FRBS. Teve-se, também, o objetivo de avaliar a eficácia das imagens CCD/CBERS-2 para a obtenção de respostas espectrais de pastagens. Os dosséis sadios e doentes da Brachiaria brizantha foram identificados por meio da análise dos valores de reflectância e dos dados observados no Índice de Estresse Hídrico Acumulativo Relativo da Cultura (ACWSI obtidos na área de estudo. Os resultados indicaram que as principais diferenças foram a diminuição da reflectância na banda CCD3 e o aumento da reflectância na banda CCD4 nas áreas doentes. A metodologia empregada com o uso de dados do sensor CCD/CBERS-2, associados ao ACWSI, mostrou-se eficaz para discriminar dosséis infectados com a "mela-das-sementes da braquiária".CCD/CBERS-2 images in the spectral bands of CCD2, CCD3 and CCD4 of the years 2004 and 2005, from Mirante do Paranapanema - SP (Brazil, were transformed into surface reflectance images using the 5S atmospheric correction model and radiometrically normalized. The main objective was to spectrally characterize pastures of Brachiaria brizantha in the flowering phase, exempt and infected with the disease "mela-das-sementes da braquiária" making it possible its detection through the comparison among the SBRF - Surface Bidirectional Reflectance Factor values. At the same time, it was aimed to evaluate the effectiveness of the

Rethinking CCD's Significance in Estimating Late Neogene Whole Ocean Carbonate Budget

Science.gov (United States)

Si, W.; Rosenthal, Y.

2017-12-01

The global averaged calcite compensation depth (CCD) record is conventionally used to reconstruct two correlatable parameters of the carbonate system - the alkalinity budget of the ocean and/or the saturation state of the ocean. Accordingly, the available CCD reconstructions have been interpreted to suggest either relative stable (Pearson and Palmer, 2000) or increased alkalinity of the ocean over the past 15 Ma (Tyrrell and Zeebe, 2004; Pälike et al., 2012). However, CCD alone is insufficient to constrain the carbonate system because the weathering flux of alkalinity into the ocean is not only balanced by CaCO3 dissolution on the seafloor but also by the biologic production in the euphotic zone and, the CCD records cannot be readily interpreted as changes in either process. Here, we present evidence of the co-evolution of surface CaCO3 production and deepsea dissolution through the late Neogene. By examining separately the mass accumulation rates (MAR) of coccoliths, planktonic foraminifera, and quantifying dissolution (using a proxy revised from Broecker et al., 1999) in seventeen deepsea cores from multiple depth-transects, we find that 1) MAR of dissolution-resistant coccoliths was substantially higher in the mid Miocene and declining on a global scale towards the present; 2) unlike coccoliths, MAR of planktonic foraminifera, shows no apparent secular trend through that time; 3) the revised dissolution index, shows significantly improved preservation of planktonic foraminiferal shells over that time, particularly at intermediate water depth and exhibits close association between changes in preservation with key climatic events. Our new records have two immediate implications. First, the substantially weakened pelagic biogenic carbonate production from mid Miocene to present alone could account for the improved preservation of deepsea carbonates without calling for a scenario of increased weathering input. Second, with the constrain of global averaged CCD

Effects of free-surface on design charts for open channels

African Journals Online (AJOL)

2011-12-14

Dec 14, 2011 ... Normal depth is an important parameter for the design of channels and canals. For rectangular, trapezoidal, and circular channel sections it is possible to express normal depth by a trial-and-error procedure or analytically. However, the effects of free-surface on the design charts for determination of the ...

15 CFR 740.19 - Consumer Communications Devices (CCD).

Science.gov (United States)

2010-01-01

... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Consumer Communications Devices (CCD... EXCEPTIONS § 740.19 Consumer Communications Devices (CCD). (a) Authorization. This License Exception... controllers designed for chemical processing) designated EAR99; (4) Graphics accelerators and graphics...

CCD image sensor induced error in PIV applications

Science.gov (United States)

Legrand, M.; Nogueira, J.; Vargas, A. A.; Ventas, R.; Rodríguez-Hidalgo, M. C.

2014-06-01

The readout procedure of charge-coupled device (CCD) cameras is known to generate some image degradation in different scientific imaging fields, especially in astrophysics. In the particular field of particle image velocimetry (PIV), widely extended in the scientific community, the readout procedure of the interline CCD sensor induces a bias in the registered position of particle images. This work proposes simple procedures to predict the magnitude of the associated measurement error. Generally, there are differences in the position bias for the different images of a certain particle at each PIV frame. This leads to a substantial bias error in the PIV velocity measurement (˜0.1 pixels). This is the order of magnitude that other typical PIV errors such as peak-locking may reach. Based on modern CCD technology and architecture, this work offers a description of the readout phenomenon and proposes a modeling for the CCD readout bias error magnitude. This bias, in turn, generates a velocity measurement bias error when there is an illumination difference between two successive PIV exposures. The model predictions match the experiments performed with two 12-bit-depth interline CCD cameras (MegaPlus ES 4.0/E incorporating the Kodak KAI-4000M CCD sensor with 4 megapixels). For different cameras, only two constant values are needed to fit the proposed calibration model and predict the error from the readout procedure. Tests by different researchers using different cameras would allow verification of the model, that can be used to optimize acquisition setups. Simple procedures to obtain these two calibration values are also described.

CCD image sensor induced error in PIV applications

International Nuclear Information System (INIS)

Legrand, M; Nogueira, J; Vargas, A A; Ventas, R; Rodríguez-Hidalgo, M C

2014-01-01

The readout procedure of charge-coupled device (CCD) cameras is known to generate some image degradation in different scientific imaging fields, especially in astrophysics. In the particular field of particle image velocimetry (PIV), widely extended in the scientific community, the readout procedure of the interline CCD sensor induces a bias in the registered position of particle images. This work proposes simple procedures to predict the magnitude of the associated measurement error. Generally, there are differences in the position bias for the different images of a certain particle at each PIV frame. This leads to a substantial bias error in the PIV velocity measurement (∼0.1 pixels). This is the order of magnitude that other typical PIV errors such as peak-locking may reach. Based on modern CCD technology and architecture, this work offers a description of the readout phenomenon and proposes a modeling for the CCD readout bias error magnitude. This bias, in turn, generates a velocity measurement bias error when there is an illumination difference between two successive PIV exposures. The model predictions match the experiments performed with two 12-bit-depth interline CCD cameras (MegaPlus ES 4.0/E incorporating the Kodak KAI-4000M CCD sensor with 4 megapixels). For different cameras, only two constant values are needed to fit the proposed calibration model and predict the error from the readout procedure. Tests by different researchers using different cameras would allow verification of the model, that can be used to optimize acquisition setups. Simple procedures to obtain these two calibration values are also described. (paper)

Improving the resolution in soft X-ray emission spectrometers through photon-counting using an Electron Multiplying CCD

International Nuclear Information System (INIS)

Hall, D J; Soman, M; Tutt, J; Murray, N; Holland, A; Schmitt, T; Raabe, J; Strocov, V N; Schmitt, B

2012-01-01

In 2007, a study of back-illuminated Charge-Coupled Devices (CCDs) for soft X-ray photon detection demonstrated the improvements that could be brought over more traditional micro-channel plate detectors for X-ray spectrometers based on diffraction gratings and position sensitive detectors. Whilst the spatial resolution was reported to be improved dramatically, an intrinsic limit of approximately 25 micrometers was found due to the spreading of the charge cloud generated in the CCD across several pixels. To overcome this resolution limit, it is necessary to move away from the current integrated imaging methods and consider a photon-counting approach, recording the photon interaction locations to the sub-pixel level. To make use of photon-counting techniques it is important that the individual events are separable. To maintain the throughput of the spectrometer for high intensity lines, higher frame rates and therefore higher readout speeds are required. With CCD based systems, the increased noise at high readout speeds can limit the photon-counting performance. The Electron-Multiplying CCD shares a similar architecture with the standard CCD but incorporates a g ain register . This novel addition allows controllable gain to be applied to the signal before the read noise is introduced, therefore allowing individual events to be resolved above the noise even at much higher readout rates. In the past, the EM-CCD has only been available with imaging areas too small to be practical in soft X-ray emission spectrometers. The current drive for large area Electron-Multiplying CCDs is opening this technology to new photon-counting applications, requiring in-depth analysis of the processes and techniques involved. Early results indicate that through the introduction of photon-counting techniques the resolution in such systems can be dramatically improved.

Active Pixel Sensors: Are CCD's Dinosaurs?

Science.gov (United States)

Fossum, Eric R.

1993-01-01

Charge-coupled devices (CCD's) are presently the technology of choice for most imaging applications. In the 23 years since their invention in 1970, they have evolved to a sophisticated level of performance. However, as with all technologies, we can be certain that they will be supplanted someday. In this paper, the Active Pixel Sensor (APS) technology is explored as a possible successor to the CCD. An active pixel is defined as a detector array technology that has at least one active transistor within the pixel unit cell. The APS eliminates the need for nearly perfect charge transfer -- the Achilles' heel of CCDs. This perfect charge transfer makes CCD's radiation 'soft,' difficult to use under low light conditions, difficult to manufacture in large array sizes, difficult to integrate with on-chip electronics, difficult to use at low temperatures, difficult to use at high frame rates, and difficult to manufacture in non-silicon materials that extend wavelength response.

Developing a CCD camera with high spatial resolution for RIXS in the soft X-ray range

Science.gov (United States)

Soman, M. R.; Hall, D. J.; Tutt, J. H.; Murray, N. J.; Holland, A. D.; Schmitt, T.; Raabe, J.; Schmitt, B.

2013-12-01

The Super Advanced X-ray Emission Spectrometer (SAXES) at the Swiss Light Source contains a high resolution Charge-Coupled Device (CCD) camera used for Resonant Inelastic X-ray Scattering (RIXS). Using the current CCD-based camera system, the energy-dispersive spectrometer has an energy resolution (E/ΔE) of approximately 12,000 at 930 eV. A recent study predicted that through an upgrade to the grating and camera system, the energy resolution could be improved by a factor of 2. In order to achieve this goal in the spectral domain, the spatial resolution of the CCD must be improved to better than 5 μm from the current 24 μm spatial resolution (FWHM). The 400 eV-1600 eV energy X-rays detected by this spectrometer primarily interact within the field free region of the CCD, producing electron clouds which will diffuse isotropically until they reach the depleted region and buried channel. This diffusion of the charge leads to events which are split across several pixels. Through the analysis of the charge distribution across the pixels, various centroiding techniques can be used to pinpoint the spatial location of the X-ray interaction to the sub-pixel level, greatly improving the spatial resolution achieved. Using the PolLux soft X-ray microspectroscopy endstation at the Swiss Light Source, a beam of X-rays of energies from 200 eV to 1400 eV can be focused down to a spot size of approximately 20 nm. Scanning this spot across the 16 μm square pixels allows the sub-pixel response to be investigated. Previous work has demonstrated the potential improvement in spatial resolution achievable by centroiding events in a standard CCD. An Electron-Multiplying CCD (EM-CCD) has been used to improve the signal to effective readout noise ratio achieved resulting in a worst-case spatial resolution measurement of 4.5±0.2 μm and 3.9±0.1 μm at 530 eV and 680 eV respectively. A method is described that allows the contribution of the X-ray spot size to be deconvolved from these

Spatial distribution of spin polarization in a channel on the surface of a topological insulator

International Nuclear Information System (INIS)

Zhou Xiaoying; Shao Huaihua; Liu Yiman; Tang Dongsheng; Zhou Guanghui

2012-01-01

We study the spatial distribution of electron spin polarization for a gate-controlled T-shaped channel on the surface of a three-dimensional topological insulator (3D TI). We demonstrate that an energy gap depending on channel geometry parameters is definitely opened due to the spatial confinement. Spin surface locking in momentum space for a uniform wide channel with Hamiltonian linearity in the wavevector is still kept, but it is broken with Hamiltonian nonlinearity in the wavevector, like that for two-dimensional surface states widely studied in the literature. However, the spin surface locking for a T-shaped channel is broken even with Hamiltonian linearity in the wavevector. Interestingly, the magnitude and direction of the in-plane spin polarization are spatially dependent in all regions due to the breaking of translational symmetry of the T-shaped channel system. These interesting findings for an electrically controlled nanostructure based on the 3D TI surface may be testable with the present experimental technique, and may provide further understanding the nature of 3D TI surface states. (paper)

Laser jamming experiment of varifocal colour CCD imaging system%变焦彩色CCD成像系统的激光干扰实验

Institute of Scientific and Technical Information of China (English)

汤伟; 王锐; 王挺峰; 郭劲

2017-01-01

Out-field laser jamming experiment of varifocal colour CCD imaging system irradiated by semiconductor laser was done.Laser jamming effects of colour CCD imaging system with different focal lengths were measured.Laser jamming model was set-up,and theoretical proving and analysis on experimental results were completed.Theorical and experimental results show that laser jamming effect of colour CCD imaging system irradiated by 750 nm laser is obvious,and CCD surface appears obvious light saturation and crosstalk phenomena.In the same initial laser irradiating conduction,laser power truncated by the aperture gradually decreases with increase of focal length f,and light saturation area on the CCD surface gradually increases.When focal length f of colour CCD imaging system is 17 mm,light saturation area on the CCD surface is 0.33 mm×0.29 mm.While focal length f of colour CCD imaging system increases to 120 mm,light saturation area on the CCD surface is 1.8 mm×1.2 mm.Simulation results are coincident with experimental results,and it proves laser jamming model is correct.The conclusions have a reference value for colour CCD in the practical application.%开展了变焦彩色CCD成像系统的激光外场干扰实验,测得了半导体激光(750 nm)对变焦距(17～187 mm)彩色CCD相机的干扰效果;同时利用典型的激光干扰CCD模型,完成了对实验结果的验证与理论分析.理论与实验结果表明:750 nm激光对彩色CCD成像系统的干扰效果明显,CCD靶面出现了明显的光饱和和串扰现象;在激光辐照条件相同情况下,光学系统焦距f越大,被光阑截断的激光就越少,到靶的激光功率密度就越高,CCD靶面的光饱和面积就越大;光学系统焦距f为17mm时,CCD靶面的光饱和面积为0.33 mm×0.29 mm,而当光学系统焦距f增大至120 mm时,CCD靶面的光饱和面积为1.8 mm×1.2 mm.仿真结果与实验结果基本一致,证明了理论模型的正确性.研究结果将对CCD器件的实际应用具有一定的指导意义.

Solution structure and elevator mechanism of the membrane electron transporter CcdA.

Science.gov (United States)

Zhou, Yunpeng; Bushweller, John H

2018-02-01

Membrane oxidoreductase CcdA plays a central role in supplying reducing equivalents from the bacterial cytoplasm to the envelope. It transports electrons across the membrane using a single pair of cysteines by a mechanism that has not yet been elucidated. Here we report an NMR structure of the Thermus thermophilus CcdA (TtCcdA) in an oxidized and outward-facing state. CcdA consists of two inverted structural repeats of three transmembrane helices (2 × 3-TM). We computationally modeled and experimentally validated an inward-facing state, which suggests that CcdA uses an elevator-type movement to shuttle the reactive cysteines across the membrane. CcdA belongs to the LysE superfamily, and thus its structure may be relevant to other LysE clan transporters. Structure comparisons of CcdA, semiSWEET, Pnu, and major facilitator superfamily (MFS) transporters provide insights into membrane transporter architecture and mechanism.

Turbulent oscillating channel flow subjected to a free-surface stress.

NARCIS (Netherlands)

Kramer, W.; Clercx, H.J.H.; Armenio, V.

2010-01-01

The channel flow subjected to a wind stress at the free surface and an oscillating pressure gradient is investigated using large-eddy simulations. The orientation of the surface stress is parallel with the oscillating pressure gradient and a purely pulsating mean flow develops. The Reynolds number

CCD camera eases the control of a soda recovery boiler; CCD-kamera helpottaa soodakattilan valvontaa

Energy Technology Data Exchange (ETDEWEB)

Kinnunen, L.

2001-07-01

Fortum Technology has developed a CCD firebox camera, based on semiconductor technology, enduring hard conditions of soda recovery boiler longer than traditional cameras. The firebox camera air- cooled and the same air is pressed over the main lens so it remains clean despite of the alkaline liquor splashing around in the boiler. The image of the boiler is transferred through the main lens, image transfer lens and a special filter, mounted inside the camera tube, into the CCD camera. The first CCD camera system has been in use since 1999 in Sunila pulp mill in Kotka, owned by Myllykoski Oy and Enso Oyj. The mill has two medium-sized soda recovery boilers. The amount of black liquor, formed daily, is about 2000 tons DS, which is more than enough for the heat generation. Even electric power generation exceeds sometimes the demand, so the surplus power can be sold out. Black liquor is sprayed inside the soda recovery boiler with high pressure. The liquor form droplets in the boiler, the temperature of which is over 1000 deg C. A full-hot pile is formed at the bottom of the boiler after burning. The size and shape of the pile effect on the efficiency and the emissions of the boiler. The camera has operated well.

CCD camera system for use with a streamer chamber

International Nuclear Information System (INIS)

Angius, S.A.; Au, R.; Crawley, G.C.; Djalali, C.; Fox, R.; Maier, M.; Ogilvie, C.A.; Molen, A. van der; Westfall, G.D.; Tickle, R.S.

1988-01-01

A system based on three charge-coupled-device (CCD) cameras is described here. It has been used to acquire images from a streamer chamber and consists of three identical subsystems, one for each camera. Each subsystem contains an optical lens, CCD camera head, camera controller, an interface between the CCD and a microprocessor, and a link to a minicomputer for data recording and on-line analysis. Image analysis techniques have been developed to enhance the quality of the particle tracks. Some steps have been made to automatically identify tracks and reconstruct the event. (orig.)

WFC3 TV2 Testing: UVIS Channel Glint

Science.gov (United States)

Brown, Thomas M.

2007-10-01

The UVIS spare detector (UVIS build 2) was housed in WFC3 during the most recent epoch of thermal vaccum ground testing. We scanned the chip gap with a HeNe laser, to look for scattering from any material in the CCD chip gap or the edges of the CCD chips themselves. Although we found no such scattering issues, we did find a significant glint problem involving reflection from the surface of the CCD to the CCD housing and back down to the CCD. The glint appears as a large streak, ~10,000 pixels in area, containing anywhere from 1% to 30% of the energy within the source itself, depending upon the wavelength and position of the source. Approximately 10% of the detector area leads to glint when a source is placed in that area. Although any one glint comprises a tiny fraction of the detector area, the glint sweeps over a large area as the source is moved, implying that approximately 15% of the detector could be significantly illuminated by glint when observing a crowded field. As a result, the UVIS detectors currently not installed in the instrument have been modified to mask the surfaces responsible for the glint, to avoid this issue on orbit.

A comparison of film and 3 digital imaging systems for natural dental caries detection: CCD, CMOS, PSP and film

Energy Technology Data Exchange (ETDEWEB)

Han, Won Jeong [Dankook University College of Medicine, Seoul (Korea, Republic of)

2004-03-15

To evaluate the diagnostic accuracy of occlusal and proximal caries detection using CCD, CMOS, PSP and film system. 32 occlusal and 30 proximal tooth surfaces were radiographed under standardized conditions using 3 digital systems; CCD (CDX-2000HQ, Biomedysis Co., Seoul, Korea), CMOS (Schick, Schick Inc., Long Island, USA), PSP (Digora FMX, Orion Co./Soredex, Helsinki, Finland) and 1 film system (Kodak Insight, Eastman Kodak, Rochester, USA). 5 observers examined the radiographs for occlusal and proximal caries using a 5-point confidence scale. The presence of caries was validated histologically and radiographically. Diagnostic accuracy was evaluated using ROC curve areas (AZ). Analysis using ROC curves revealed the area under each curve which indicated a diagnostic accuracy. For occlusal caries, Kodak Insight film had an Az of 0.765, CCD one of 0.730, CMOS one of 0.742 and PSP one of 0.735. For proximal caries, Kodak Insight film had an Az of 0.833, CCD one of 0.832, CMOS one of 0.828 and PSP one of 0.868. No statistically significant difference was noted between any of the imaging modalities. CCD, CMOS, PSP and film performed equally well in the detection of occlusal and proximal dental caries. CCD, CMOS and PSP-based digital images provided a level of diagnostic performance comparable to Kodak Insight film.

A comparison of film and 3 digital imaging systems for natural dental caries detection: CCD, CMOS, PSP and film

International Nuclear Information System (INIS)

Han, Won Jeong

2004-01-01

To evaluate the diagnostic accuracy of occlusal and proximal caries detection using CCD, CMOS, PSP and film system. 32 occlusal and 30 proximal tooth surfaces were radiographed under standardized conditions using 3 digital systems; CCD (CDX-2000HQ, Biomedysis Co., Seoul, Korea), CMOS (Schick, Schick Inc., Long Island, USA), PSP (Digora FMX, Orion Co./Soredex, Helsinki, Finland) and 1 film system (Kodak Insight, Eastman Kodak, Rochester, USA). 5 observers examined the radiographs for occlusal and proximal caries using a 5-point confidence scale. The presence of caries was validated histologically and radiographically. Diagnostic accuracy was evaluated using ROC curve areas (AZ). Analysis using ROC curves revealed the area under each curve which indicated a diagnostic accuracy. For occlusal caries, Kodak Insight film had an Az of 0.765, CCD one of 0.730, CMOS one of 0.742 and PSP one of 0.735. For proximal caries, Kodak Insight film had an Az of 0.833, CCD one of 0.832, CMOS one of 0.828 and PSP one of 0.868. No statistically significant difference was noted between any of the imaging modalities. CCD, CMOS, PSP and film performed equally well in the detection of occlusal and proximal dental caries. CCD, CMOS and PSP-based digital images provided a level of diagnostic performance comparable to Kodak Insight film.

Enhancement of Friction against a Rough Surface by a Ridge-Channel Surface Microstructure.

Science.gov (United States)

Bai, Ying; Hui, Chung-Yuen; Levrard, Benjamin; Jagota, Anand

2015-07-14

We report on a study of the sliding friction of elastomeric surfaces patterned with ridges and channels (and unstructured flat controls), against both smooth and roughened spherical indenters. Against the smooth spherical indenter, all of the structured surfaces have highly reduced sliding friction due to the reduction in actual area of contact. Against roughened spherical indenters, however, the sliding force for structured samples can be up to 50% greater than that of an unstructured flat control. The mechanism of enhanced friction against a rough surface is due to a combination of increased actual area of contact, interlocking between roughness and the surface structure, and attendant dynamic instabilities that dissipate energy.

CCD-based X-ray detectors for X-ray diffraction studies

International Nuclear Information System (INIS)

Ito, K.; Amemiya, Y.

1999-01-01

CCD-based X-ray detectors are getting to be used for X-ray diffraction studies especially in the studies where real time (automated) measurements and time-resolved measurements are required. Principles and designs of two typical types of CCD-based detectors are described; one is ths system in which x-ray image intensifiers are coupled to maximize the detective quantum efficiency for time-resolved measurements, and the other is the system in which tapered optical fibers are coupled for the reduction of the image into the CCD, which is optimized for automated measurements for protein crystallography. These CCD-based X-ray detectors have an image distortion and non-uniformity of response to be corrected by software. Correction schemes which we have developed are also described. (author)

Development of a Novel Spectrophotometer for Biochemical Analyzer Based on Volume Holography Transmissive Grating and Linear CCD

International Nuclear Information System (INIS)

Ren Zhong; Liu Guodong; Huang Zhen; Zeng Lvming; Dai Longmin

2011-01-01

The classical surface-embossed plane and concave grating are usually used as the diffraction grating in some spectrophotometers. But the minute cracks are produced on the surface of the gratings' grooves, which leads to generate the stray-light and decrease the efficiency of instrument. Therefore, a novel custom-built spectrophotometer for BCA is developed in this paper. Meanwhile, the volume holography transmissive (VHT) grating is used as the diffraction grating in this spectrophotometer. Additionally, a high resolution CCD and data acquisition (DAQ) card with combined the virtual software platform based on LabVIEW are used to design the spectral acquisition and analysis system. Experimental results show that the spectral range and the diffraction efficiency of the spectrophotometer for BCA are greatly increased. The spectral range of the spectrophotometer for BCA can reach 300-1000 nm, its wavelength resolution can reach 1nm. And, it uses the back-splitting-light technology and multi-channel parallel analysis. Compared with other same types, this spectrophotometer has many advantages, such as, higher efficiency, simpler algorithm, higher accuracy, cheaper cost and fewer stray-light and higher imaging quality, etc. Therefore, this spectrophotometer for BCA based on VHT grating will has the greatly potential values in the fields of the biochemical or medical research.

Image differencing using masked CCD

International Nuclear Information System (INIS)

Rushbrooke, J.G.; Ansorge, R.E.; Webber, C.J. St. J.

1987-01-01

A charge coupled device has some of its ''pixels'' masked by a material which is opaque to the radiation to which the device is to be exposed, each masked region being employed as a storage zone into which the charge pattern from the unmasked pixels can be transferred to enable a subsequent charge pattern to be established on further exposure of the unmasked pixels. The components of the resulting video signal corresponding to the respective charge patterns read-out from the CCD are subtracted to produce a video signal corresponding to the difference between the two images which formed the respective charge patterns. Alternate rows of pixels may be masked, or chequer-board pattern masking may be employed. In an X-ray imaging system the CCD is coupled to image intensifying and converting means. (author)

Tarantula toxins use common surfaces for interacting with Kv and ASIC ion channels.

Science.gov (United States)

Gupta, Kanchan; Zamanian, Maryam; Bae, Chanhyung; Milescu, Mirela; Krepkiy, Dmitriy; Tilley, Drew C; Sack, Jon T; Yarov-Yarovoy, Vladimir; Kim, Jae Il; Swartz, Kenton J

2015-05-07

Tarantula toxins that bind to voltage-sensing domains of voltage-activated ion channels are thought to partition into the membrane and bind to the channel within the bilayer. While no structures of a voltage-sensor toxin bound to a channel have been solved, a structural homolog, psalmotoxin (PcTx1), was recently crystalized in complex with the extracellular domain of an acid sensing ion channel (ASIC). In the present study we use spectroscopic, biophysical and computational approaches to compare membrane interaction properties and channel binding surfaces of PcTx1 with the voltage-sensor toxin guangxitoxin (GxTx-1E). Our results show that both types of tarantula toxins interact with membranes, but that voltage-sensor toxins partition deeper into the bilayer. In addition, our results suggest that tarantula toxins have evolved a similar concave surface for clamping onto α-helices that is effective in aqueous or lipidic physical environments.

Programmable CCD imaging system for synchrotron radiation studies

International Nuclear Information System (INIS)

Rodricks, B.; Brizard, C.

1992-01-01

A real-time imaging system for x-ray detection has been developed. The CAMAC-based system has a Charge Coupled Device (CCD) as its active detection element. The electronics consist of a CAMAC-crate-based dedicated microprocessor coupled to arbitrary waveform generators, programmable timing, and ADC modules. The hardware flexibility achievable through this system enables one to use virtually any commercially available CCD. A dedicated CAMAC-based display driver allows for real-time imaging on a high-resolution color monitor. An optional front end consisting of a fiber-optic taper and a focusing optical lens system coupled to a phosphor screen allows for large area imaging. Further, programming flexibility, in which the detector can be used in different read-out modes, enables it to be exploited for time-resolved experiments. In one mode, sections of the CCD can be read-out with millisecond time-resolution and, in another, the use of the CCD as a storage device is exploited resulting in microsecond time-resolution. Three different CCDs with radically different read-out timings and waveforms have been tested: the TI 4849, a 39Ox584 pixel array; TC 215, a 1024x1O24 pixel array; and the TH 7883, a 576x384 pixel array. The TC 215 and TI 4849 are single-phase CCDs manufactured by Texas Instruments, and the TH 7883 is a four-phase device manufactured by Thomson-CSF. The CCD characterized for uniformity, charge transfer efficiency (CTE), linearity, and sensitivity is the TC215

Characterization of a pnCCD for applications with synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Send, S., E-mail: send@physik.uni-siegen.de [University of Siegen, Department of Physics, Walter-Flex-Straße 3, 57068 Siegen (Germany); Abboud, A. [University of Siegen, Department of Physics, Walter-Flex-Straße 3, 57068 Siegen (Germany); Hartmann, R.; Huth, M. [PNSensor GmbH, Römerstraße 28, 80803 München (Germany); Leitenberger, W. [University of Potsdam, Department of Physics, Karl-Liebknecht-Straße 24/25, 14476 Potsdam (Germany); Pashniak, N. [University of Siegen, Department of Physics, Walter-Flex-Straße 3, 57068 Siegen (Germany); Schmidt, J. [PNSensor GmbH, Römerstraße 28, 80803 München (Germany); Strüder, L. [University of Siegen, Department of Physics, Walter-Flex-Straße 3, 57068 Siegen (Germany); PNSensor GmbH, Römerstraße 28, 80803 München (Germany); Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, 85748 Garching (Germany); Pietsch, U. [University of Siegen, Department of Physics, Walter-Flex-Straße 3, 57068 Siegen (Germany)

2013-05-21

In this work we study the response of a pnCCD by means of X-ray spectroscopy in the energy range between 6 keV and 20 keV and by Laue diffraction techniques. The analyses include measurements of characteristic detector parameters like energy resolution, count rate capability and effects of different gain settings. The limit of a single photon counting operation in white beam X-ray diffraction experiments is discussed with regard to the occurrence of pile-up events, for which the energy information about individual photons is lost. In case of monochromatic illumination the pnCCD can be used as a fast conventional CCD with a charge handling capacity (CHC) of about 300,000 electrons per pixel. If the CHC is exceeded, any surplus charge will spill to neighboring pixels perpendicular to the transfer direction due to electrostatic repulsion. The possibilities of increasing the number of storable electrons are investigated for different voltage settings by exposing a single pixel with X-rays generated by a microfocus X-ray source. The pixel binning mode is tested as an alternative approach that enables a pnCCD operation with significantly shorter readout times. -- Highlights: ► The pnCCD acts as a four-dimensional detector for white X-rays. ► Its performance for applications with synchrotron radiation is investigated. ► The pnCCD can be used for single photon counting and photon integration. ► The operation mode depends on the local frequencies of pile-up events. ► The pnCCD can be optimized for X-ray spectroscopy and X-ray imaging.

Software design of control system of CCD side-scatter lidar

Science.gov (United States)

Kuang, Zhiqiang; Liu, Dong; Deng, Qian; Zhang, Zhanye; Wang, Zhenzhu; Yu, Siqi; Tao, Zongming; Xie, Chenbo; Wang, Yingjian

2018-03-01

Because of the existence of blind zone and transition zone, the application of backscattering lidar in near-ground is limited. The side-scatter lidar equipped with the Charge Coupled Devices (CCD) can separate the transmitting and receiving devices to avoid the impact of the geometric factors which is exited in the backscattering lidar and, detect the more precise near-ground aerosol signals continuously. Theories of CCD side-scatter lidar and the design of control system are introduced. The visible control of laser and CCD and automatic data processing method of the side-scatter lidar are developed by using the software of Visual C #. The results which are compared with the calibration of the atmospheric aerosol lidar data show that signals from the CCD side- scatter lidar are convincible.

A new approach to modelling radiation noise in CCD's

International Nuclear Information System (INIS)

Chugg, A.; Hopkinson, G.

1998-01-01

The energy depositions reported by Monte Carlo electron-photon irradiation transport codes are subject to a random error due to the finite number of particle histories used to generate the results. These statistical variations, normally a nuisance, may also be identified with the real radiation noise effects experienced by CCD pixels in persistent radiation environments. This paper explores the practicability of such radiation noise modelling by applying the ACCEPT code from the ITS suite to the case of a shielded CCD exposed to an electron flux. The results are compared with those obtained in a subsequent electron irradiation of the CCD by a Van de Graaff accelerator

The interaction of DNA gyrase with the bacterial toxin CcdB

DEFF Research Database (Denmark)

Kampranis, S C; Howells, A J; Maxwell, A

1999-01-01

CcdB is a bacterial toxin that targets DNA gyrase. Analysis of the interaction of CcdB with gyrase reveals two distinct complexes. An initial complex (alpha) is formed by direct interaction between GyrA and CcdB; this complex can be detected by affinity column and gel-shift analysis, and has...... of this initial complex with ATP in the presence of GyrB and DNA slowly converts it to a second complex (beta), which has a lower rate of ATP hydrolysis and is unable to catalyse supercoiling. The efficiency of formation of this inactive complex is dependent on the concentrations of ATP and CcdB. We suggest...

Discriminação de variedades de citros em imagens CCD/CBERS-2 Discrimination of citrus varieties using CCD/CBERS-2 satellite imagery

Directory of Open Access Journals (Sweden)

Ieda Del'Arco Sanches

2008-02-01

Full Text Available O presente trabalho teve o objetivo de avaliar as imagens CCD/CBERS-2 quanto à possibilidade de discriminarem variedades de citros. A área de estudo localiza-se em Itirapina (SP e, para este estudo, foram utilizadas imagens CCD de três datas (30/05/2004, 16/08/2004 e 11/09/2004. Um modelo que integra os elementos componentes da cena citrícola sensoriada é proposto com o objetivo de explicar a variabilidade das respostas das parcelas de citros em imagens orbitais do tipo CCD/CBERS-2. Foram feitas classificações pelos algoritmos Isoseg e Maxver e, de acordo com o índice kappa, concluiu-se que é possível obterem-se exatidões qualificadas como muito boas, sendo que as melhores classificações foram conseguidas com imagens da estação seca.This paper was aimed at evaluating the possibility of discriminating citrus varieties in CCD imageries from CBERS-2 satellite ("China-Brazil Earth Resouces Satellite". The study area is located in Itirapina, São Paulo State. For this study, three CCD images from 2004 were acquired (May 30, August 16, and September 11. In order to acquire a better understanding and for explaining the variability of the spectral behavior of the citrus areas in orbital images (like as the CCD/CBERS-2 images a model that integrates the elements of the citrus scene is proposed and discussed. The images were classified by Isoseg and MaxVer classifiers. According to kappa index, it was possible to obtain classifications qualified as 'very good'. The best results were obtained with the images from the dry season.

A computer simulation of the surface channeling of MeV heavy charged particles

International Nuclear Information System (INIS)

Morita, K.

1980-01-01

The surface channeling of 1.5 MeV N + ions incident near the [011] direction on the (100) surface and near the [001] direction on the (110) surface of Ge crystals has been studied using computer simulation. The trajectories of ions incident at angles near the critical angle for axial channeling were traced. The energy spectra, the angular distributions and the reflection-depth distributions of scattered ions were obtained. The calculated energy spectra for both directions are found to be composed of a surface peak and a broad peak, the latter being at the low energy side of the surface peak. The height of the surface peak and the energy position of the broad peak are found to depend on the azimuthal component and the tilt component of the incident angle, respectively. This result is explained to be due to the focusing effect of channeled ions deflected by the atomic rows at the surface. It is shown that the calculated angular distributions of scattered ions form a half-ring pattern and clear dips appear in the scattering intensity curve along the half-ring. The dips are found to be caused by the blocking for scattered ions by the atomic rows arrayed in the major planar directions. (author)

Large-eddy simulation of open channel flow with surface cooling

International Nuclear Information System (INIS)

Walker, R.; Tejada-Martínez, A.E.; Martinat, G.; Grosch, C.E.

2014-01-01

Highlights: • Open channel flow comparable to a shallow tidal ocean flow is simulated using LES. • Unstable stratification is imposed by a constant surface cooling flux. • Full-depth, convection-driven, rotating supercells develop when cooling is applied. • Strengthening of cells occurs corresponding to an increasing of the Rayleigh number. - Abstract: Results are presented from large-eddy simulations of an unstably stratified open channel flow, driven by a uniform pressure gradient and with zero surface shear stress and a no-slip lower boundary. The unstable stratification is applied by a constant cooling flux at the surface and an adiabatic bottom wall, with a constant source term present to ensure the temperature reaches a statistically steady state. The structure of the turbulence and the turbulence statistics are analyzed with respect to the Rayleigh number (Ra τ ) representative of the surface buoyancy relative to shear. The impact of the surface cooling-induced buoyancy on mean and root mean square of velocity and temperature, budgets of turbulent kinetic energy (and components), Reynolds shear stress and vertical turbulent heat flux will be investigated. Additionally, colormaps of velocity fluctuations will aid the visualization of turbulent structures on both vertical and horizontal planes in the flow. Under neutrally stratified conditions the flow is characterized by weak, full-depth, streamwise cells similar to but less coherent than Couette cells in plane Couette flow. Increased Ra τ and thus increased buoyancy effects due to surface cooling lead to full-depth convection cells of significantly greater spanwise size and coherence, thus termed convective supercells. Full-depth convective cell structures of this magnitude are seen for the first time in this open channel domain, and may have important implications for turbulence analysis in a comparable tidally-driven ocean boundary layer. As such, these results motivate further study of the

A self triggered intensified Ccd (Stic)

International Nuclear Information System (INIS)

Charon, Y.; Laniece, P.; Bendali, M.

1990-01-01

We are developing a new device based on the results reported previously of the successfull coincidence detection of β- particles with a high spatial resolution [1]. The novelty of the device consists in triggering an intensified CCD, i.e. a CCD coupled to an image intensifier (II), by an electrical signal collected from the II itself. This is a suitable procedure for detecting with high efficiency and high resolution low light rare events. The trigger pulse is obtained from the secondary electrons produced by multiplication in a double microchannel plate (MCP) and collected on the aluminized layer protecting the phosphor screen in the II. Triggering efficiencies up to 80% has been already achieved

Colony Collapse Disorder (CCD) and bee age impact honey bee pathophysiology.

Science.gov (United States)

vanEngelsdorp, Dennis; Traynor, Kirsten S; Andree, Michael; Lichtenberg, Elinor M; Chen, Yanping; Saegerman, Claude; Cox-Foster, Diana L

2017-01-01

Honey bee (Apis mellifera) colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Understanding the pathways linking pathophysiology with symptoms is an important step in understanding the mechanisms of disease. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD) and compared these with bees collected from apparently healthy colonies. We identified a set of pathological physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse: rectum distension, Malpighian tubule iridescence, fecal matter consistency, rectal enteroliths (hard concretions), and venom sac color. The multiple differences in rectum symptomology in bees from CCD apiaries and colonies suggest effected bees had trouble regulating water. To ensure that pathologies we found associated with CCD were indeed pathologies and not due to normal changes in physical appearances that occur as an adult bee ages (CCD colonies are assumed to be composed mostly of young bees), we documented the changes in bees of different ages taken from healthy colonies. We found that young bees had much greater incidences of white nodules than older cohorts. Prevalent in newly-emerged bees, these white nodules or cellular encapsulations indicate an active immune response. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age (fecal matter consistency, rectal distension size, rectal enteroliths and Malpighian tubule iridescence) and that may serve as biomarkers for colony health. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and factors

Colony Collapse Disorder (CCD and bee age impact honey bee pathophysiology.

Directory of Open Access Journals (Sweden)

Dennis vanEngelsdorp

Full Text Available Honey bee (Apis mellifera colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Understanding the pathways linking pathophysiology with symptoms is an important step in understanding the mechanisms of disease. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD and compared these with bees collected from apparently healthy colonies. We identified a set of pathological physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse: rectum distension, Malpighian tubule iridescence, fecal matter consistency, rectal enteroliths (hard concretions, and venom sac color. The multiple differences in rectum symptomology in bees from CCD apiaries and colonies suggest effected bees had trouble regulating water. To ensure that pathologies we found associated with CCD were indeed pathologies and not due to normal changes in physical appearances that occur as an adult bee ages (CCD colonies are assumed to be composed mostly of young bees, we documented the changes in bees of different ages taken from healthy colonies. We found that young bees had much greater incidences of white nodules than older cohorts. Prevalent in newly-emerged bees, these white nodules or cellular encapsulations indicate an active immune response. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age (fecal matter consistency, rectal distension size, rectal enteroliths and Malpighian tubule iridescence and that may serve as biomarkers for colony health. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and

Amphotericin B channels in phospholipid membrane-coated nanoporous silicon surfaces: implications for photovoltaic driving of ions across membranes.

Science.gov (United States)

Yilma, Solomon; Liu, Nangou; Samoylov, Alexander; Lo, Ting; Brinker, C Jeffrey; Vodyanoy, Vitaly

2007-03-15

The antimycotic agent amphotericin B (AmB) functions by forming complexes with sterols to form ion channels that cause membrane leakage. When AmB and cholesterol mixed at 2:1 ratio were incorporated into phospholipid bilayer membranes formed on the tip of patch pipettes, ion channel current fluctuations with characteristic open and closed states were observed. These channels were also functional in phospholipid membranes formed on nanoporous silicon surfaces. Electrophysiological studies of AmB-cholesterol mixtures that were incorporated into phospholipid membranes formed on the surface of nanoporous (6.5 nm pore diameter) silicon plates revealed large conductance ion channels ( approximately 300 pS) with distinct open and closed states. Currents through the AmB-cholesterol channels on nanoporous silicon surfaces can be driven by voltage applied via conventional electrical circuits or by photovoltaic electrical potential entirely generated when the nanoporous silicon surface is illuminated with a narrow laser beam. Electrical recordings made during laser illumination of AmB-cholesterol containing membrane-coated nanoporous silicon surfaces revealed very large conductance ion channels with distinct open and closed states. Our findings indicate that nanoporous silicon surfaces can serve as mediums for ion-channel-based biosensors. The photovoltaic properties of nanoporous silicon surfaces show great promise for making such biosensors addressable via optical technologies.

pnCCD for photon detection from near-infrared to X-rays

International Nuclear Information System (INIS)

Meidinger, Norbert; Andritschke, Robert; Hartmann, Robert; Herrmann, Sven; Holl, Peter; Lutz, Gerhard; Strueder, Lothar

2006-01-01

A pnCCD is a special type of charge-coupled device developed for spectroscopy and imaging of X-rays with high time resolution and quantum efficiency. Its most famous application is the operation on the XMM-Newton satellite, an X-ray astronomy mission that was launched by the European space agency in 1999. The excellent performance of the focal plane camera has been maintained for more than 6 years in orbit. The energy resolution in particular has shown hardly any degradation since launch. In order to satisfy the requirements of future X-ray astronomy missions as well as those of ground-based experiments, a new type of pnCCD has been developed. This 'frame-store pnCCD' shows an enhanced performance compared to the XMM-Newton type of pnCCD. Now, more options in device design and operation are available to tailor the detector to its respective application. Part of this concept is a programmable analog signal processor, which has been developed for the readout of the CCD signals. The electronic noise of the new detector has a value of only 2 electrons equivalent noise charge (ENC), which is less than half of the figure achieved for the XMM-Newton-type pnCCD. The energy resolution for the Mn-K α line at 5.9 keV is approximately 130 eV FWHM. We have close to 100% quantum efficiency for both low- and high-energy photon detection (e.g. the C-K line at 277 eV, and the Ge-K α line at 10 keV, respectively). Very high frame rates of 1000 images/s have been achieved due to the ultra-fast readout accomplished by the parallel architecture of the pnCCD and the analog signal processor. Excellent spectroscopic performance is shown even at the relatively high operating temperature of -25 deg. C that can be achieved by a Peltier cooler. The applications of the low-noise and fast pnCCD detector are not limited to the detection of X-rays. With an anti-reflective coating deposited on the photon entrance window, we achieve high quantum efficiency also for near-infrared and optical

Study of Internal Channel Surface Roughnesses Manufactured by Selective Laser Melting in Aluminum and Titanium Alloys

Science.gov (United States)

Pakkanen, Jukka; Calignano, Flaviana; Trevisan, Francesco; Lorusso, Massimo; Ambrosio, Elisa Paola; Manfredi, Diego; Fino, Paolo

2016-08-01

Interest in additive manufacturing (AM) has gained considerable impetus over the past decade. One of the driving factors for AM success is the ability to create unique designs with intrinsic characteristics as, e.g., internal channels used for hydraulic components, cooling channels, and heat exchangers. However, a couple of the main problems in internal channels manufactured by AM technologies are the high surface roughness obtained and the distortion of the channel shape. There is still much to understand in these design aspects. In this study, a cylindrical geometry for internal channels to be built with different angles with respect to the building plane in AlSi10Mg and Ti6Al4V alloys by selective laser melting was considered. The internal surfaces of the channels produced in both materials were analyzed by means of a surface roughness tester and by optical and electron microscopy to evaluate the effects of the material and design choices.

Elucidating distinct ion channel populations on the surface of hippocampal neurons via single-particle tracking recurrence analysis

Science.gov (United States)

Sikora, Grzegorz; Wyłomańska, Agnieszka; Gajda, Janusz; Solé, Laura; Akin, Elizabeth J.; Tamkun, Michael M.; Krapf, Diego

2017-12-01

Protein and lipid nanodomains are prevalent on the surface of mammalian cells. In particular, it has been recently recognized that ion channels assemble into surface nanoclusters in the soma of cultured neurons. However, the interactions of these molecules with surface nanodomains display a considerable degree of heterogeneity. Here, we investigate this heterogeneity and develop statistical tools based on the recurrence of individual trajectories to identify subpopulations within ion channels in the neuronal surface. We specifically study the dynamics of the K+ channel Kv1.4 and the Na+ channel Nav1.6 on the surface of cultured hippocampal neurons at the single-molecule level. We find that both these molecules are expressed in two different forms with distinct kinetics with regards to surface interactions, emphasizing the complex proteomic landscape of the neuronal surface. Further, the tools presented in this work provide new methods for the analysis of membrane nanodomains, transient confinement, and identification of populations within single-particle trajectories.

Timing generator of scientific grade CCD camera and its implementation based on FPGA technology

Science.gov (United States)

Si, Guoliang; Li, Yunfei; Guo, Yongfei

2010-10-01

The Timing Generator's functions of Scientific Grade CCD Camera is briefly presented: it generates various kinds of impulse sequence for the TDI-CCD, video processor and imaging data output, acting as the synchronous coordinator for time in the CCD imaging unit. The IL-E2TDI-CCD sensor produced by DALSA Co.Ltd. use in the Scientific Grade CCD Camera. Driving schedules of IL-E2 TDI-CCD sensor has been examined in detail, the timing generator has been designed for Scientific Grade CCD Camera. FPGA is chosen as the hardware design platform, schedule generator is described with VHDL. The designed generator has been successfully fulfilled function simulation with EDA software and fitted into XC2VP20-FF1152 (a kind of FPGA products made by XILINX). The experiments indicate that the new method improves the integrated level of the system. The Scientific Grade CCD camera system's high reliability, stability and low power supply are achieved. At the same time, the period of design and experiment is sharply shorted.

CCD characterization and measurements automation

Czech Academy of Sciences Publication Activity Database

Kotov, I.V.; Frank, J.; Kotov, A.I.; Kubánek, Petr; O´Connor, P.; Prouza, Michael; Radeka, V.; Takacs, P.

2012-01-01

Roč. 695, Dec (2012), 188-192 ISSN 0168-9002 R&D Projects: GA MŠk ME09052 Institutional research plan: CEZ:AV0Z10100502 Keywords : CCD * characterization * test automation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.142, year: 2012

Development of a CCD based system called DIGITRACK for automatic track counting and evaluation

Energy Technology Data Exchange (ETDEWEB)

Molnar, J.; Somogyi, G.; Szilagyi, S.; Sepsy, K. (Magyar Tudomanyos Akademia, Debrecen. Atommag Kutato Intezete)

1984-01-01

We have developed, to the best of our knowledge, the first automatic track analysis system (DIGITRACK) in which the video signals are processed by a new type of video-receiver called charge-coupled device (CCD). The photosensitive semi-conductor device is a 2.5 cm long line imager of type Fairchild CCD 121HC which converts one row of the picture seen through a low magnification microscope into 1728 binary signals by a thresholding logic. The picture elements are analysed by a microcomputer equipped with two INTEL 8080 microprocessors and interfaced to a PDP-11/40 computer. The microcomputer also controls the motion of the stage of microscope. For pattern recognition and analysis a software procedure is developed which is able to differentiate between overlapping tracks and to determine the number, surface opening and x-y coordinates of the tracks occurring in a given detector area. The distribution of track densities and spot areas on the detector surface can be visualized on a graphic display. The DIGITRACK system has been tested for analysis of alpha-tracks registered in CR-39 and LR-115 detectors.

Design and Development of Multi-Purpose CCD Camera System with Thermoelectric Cooling: Hardware

Directory of Open Access Journals (Sweden)

Y.-W. Kang

2007-12-01

Full Text Available We designed and developed a multi-purpose CCD camera system for three kinds of CCDs; KAF-0401E(768×512, KAF-1602E(1536×1024, KAF-3200E(2184×1472 made by KODAK Co.. The system supports fast USB port as well as parallel port for data I/O and control signal. The packing is based on two stage circuit boards for size reduction and contains built-in filter wheel. Basic hardware components include clock pattern circuit, A/D conversion circuit, CCD data flow control circuit, and CCD temperature control unit. The CCD temperature can be controlled with accuracy of approximately 0.4° C in the max. range of temperature, Δ 33° C. This CCD camera system has with readout noise 6 e^{-}, and system gain 5 e^{-}/ADU. A total of 10 CCD camera systems were produced and our tests show that all of them show passable performance.

Study of x-ray CCD image sensor and application

Science.gov (United States)

Wang, Shuyun; Li, Tianze

2008-12-01

In this paper, we expounded the composing, specialty, parameter, its working process, key techniques and methods for charge coupled devices (CCD) twice value treatment. Disposal process for CCD video signal quantification was expatiated; X-ray image intensifier's constitutes, function of constitutes, coupling technique of X-ray image intensifier and CCD were analyzed. We analyzed two effective methods to reduce the harm to human beings when X-ray was used in the medical image. One was to reduce X-ray's radiation and adopt to intensify the image penetrated by X-ray to gain the same effect. The other was to use the image sensor to transfer the images to the safe area for observation. On this base, a new method was presented that CCD image sensor and X-ray image intensifier were combined organically. A practical medical X-ray photo electricity system was designed which can be used in the records and time of the human's penetrating images. The system was mainly made up with the medical X-ray, X-ray image intensifier, CCD vidicon with high resolution, image processor, display and so on. Its characteristics are: change the invisible X-ray into the visible light image; output the vivid images; short image recording time etc. At the same time we analyzed the main aspects which affect the system's resolution. Medical photo electricity system using X-ray image sensor can reduce the X-ray harm to human sharply when it is used in the medical diagnoses. At last we analyzed and looked forward the system's application in medical engineering and the related fields.

Experimental investigations of image quality in X-ray mammography with conventional screen film system (SFS), digital phosphor storage plate in/without magnification technique (CR) and digital CCD-technique (CCD)

International Nuclear Information System (INIS)

Schulz-Wendtland, R.; Aichinger, U.; Boehner, C.; Dobritz, M.; Wenkel, E.; Bautz, W.; Saebel, M.

2001-01-01

Comparison of image quality in X-ray mammography between conventional film screen film system (SFS), digital phosphor storage plate in and without magnification technique (CR) and digital CCD-technique (CCD). Radiograms of an RMI-mammography phantom were acquired using a conventional screen film system, three digital storage plate systems and two digital systems in CCD-technique. Additionally the radiograms of one digital phosphor storage plate system were post-processed regarding contrast and included in the comparison. The detectability of details was best with the digital mammography in CCD-technique. After confirming these promising results in clinical studies, digital mammography should be able to replace conventional screen film technique. (orig.)

Channel surface plasmons in a continuous and flat graphene sheet

Science.gov (United States)

Chaves, A. J.; Peres, N. M. R.; da Costa, D. R.; Farias, G. A.

2018-05-01

We derive an integral equation describing surface-plasmon polaritons in graphene deposited on a substrate with a planar surface and a dielectric protrusion in the opposite surface of the dielectric slab. We show that the problem is mathematically equivalent to the solution of a Fredholm equation, which we solve exactly. In addition, we show that the dispersion relation of the channel surface plasmons is determined by the geometric parameters of the protrusion alone. We also show that such a system supports both even and odd modes. We give the electrostatic potential and the intensity plot of the electrostatic field, which clearly show the transverse localized nature of the surface plasmons in a continuous and flat graphene sheet.

One method for HJ-1-A HSI and CCD data fusion

International Nuclear Information System (INIS)

Xiong, Wencheng; Shao, Yun; Shen, Wenming; Xiao, Rulin; Fu, Zhuo; Shi, Yuanli

2014-01-01

HJ-1-A satellite, developed by China independently, was equipped with two sensors of Hyper Spectral Imager (HSI) and multispectral sensor (CCD). In this paper, we examine the benefits of combining data from CCD data (high-spatial-resolution, low-spectral-resolution image) with HSI data (low -spatial-resolution, high -spectral-resolution image). Due to the same imaging time and similar spectral regime, the CCD and HSI data can be registered with each other well, and the difference between CCD and HSI data mainly is systematic bias. The approach we have been investigating compares the spectral information present in the multispectral image to the spectral content in the hyperspectral image, and derives a set of equations to approximately acquire the systematic bias between the two sensors. The systematic bias is then applied to the interpolated high-spectral CCD image to produce a fused product. This fused image has the spectral resolution of the hyperspectral image (HSI) and the spatial resolution of the multispectral image (CCD). It is capable of full exploitation as a hyperspectral image. We evaluate this technique using the data of Honghe wetland and show both good spectral and visual fidelity. An analysis of SAM classification test case shows good result when compared to original image. All in all, the approach we developed here provides a means for fusing data from HJ-1-A satellite to produce a spatial-resolution-enhanced hyperspectral data cube that can be further analyzed by spectral classification and detection algorithms

High-performance dual-speed CCD camera system for scientific imaging

Science.gov (United States)

Simpson, Raymond W.

1996-03-01

Traditionally, scientific camera systems were partitioned with a `camera head' containing the CCD and its support circuitry and a camera controller, which provided analog to digital conversion, timing, control, computer interfacing, and power. A new, unitized high performance scientific CCD camera with dual speed readout at 1 X 106 or 5 X 106 pixels per second, 12 bit digital gray scale, high performance thermoelectric cooling, and built in composite video output is described. This camera provides all digital, analog, and cooling functions in a single compact unit. The new system incorporates the A/C converter, timing, control and computer interfacing in the camera, with the power supply remaining a separate remote unit. A 100 Mbyte/second serial link transfers data over copper or fiber media to a variety of host computers, including Sun, SGI, SCSI, PCI, EISA, and Apple Macintosh. Having all the digital and analog functions in the camera made it possible to modify this system for the Woods Hole Oceanographic Institution for use on a remote controlled submersible vehicle. The oceanographic version achieves 16 bit dynamic range at 1.5 X 105 pixels/second, can be operated at depths of 3 kilometers, and transfers data to the surface via a real time fiber optic link.

A model for measurement of noise in CCD digital-video cameras

International Nuclear Information System (INIS)

Irie, K; Woodhead, I M; McKinnon, A E; Unsworth, K

2008-01-01

This study presents a comprehensive measurement of CCD digital-video camera noise. Knowledge of noise detail within images or video streams allows for the development of more sophisticated algorithms for separating true image content from the noise generated in an image sensor. The robustness and performance of an image-processing algorithm is fundamentally limited by sensor noise. The individual noise sources present in CCD sensors are well understood, but there has been little literature on the development of a complete noise model for CCD digital-video cameras, incorporating the effects of quantization and demosaicing

Noise analysis for CCD-based ultraviolet and visible spectrophotometry.

Science.gov (United States)

Davenport, John J; Hodgkinson, Jane; Saffell, John R; Tatam, Ralph P

2015-09-20

We present the results of a detailed analysis of the noise behavior of two CCD spectrometers in common use, an AvaSpec-3648 CCD UV spectrometer and an Ocean Optics S2000 Vis spectrometer. Light sources used include a deuterium UV/Vis lamp and UV and visible LEDs. Common noise phenomena include source fluctuation noise, photoresponse nonuniformity, dark current noise, fixed pattern noise, and read noise. These were identified and characterized by varying light source, spectrometer settings, or temperature. A number of noise-limiting techniques are proposed, demonstrating a best-case spectroscopic noise equivalent absorbance of 3.5×10(-4)  AU for the AvaSpec-3648 and 5.6×10(-4)  AU for the Ocean Optics S2000 over a 30 s integration period. These techniques can be used on other CCD spectrometers to optimize performance.

Numerical Simulation of Turbulent Half-corrugated Channel Flow by Hydrophilic and Hydrophobic Surfaces

Directory of Open Access Journals (Sweden)

M. R. Rastan

2018-03-01

Full Text Available In the first part of the present study, a two dimensional half-corrugated channel flow is simulated at Reynolds number of 104, in no-slip condition (hydrophilic surfaces( using various low Reynolds turbulence models as well as standard k-ε model; and an appropriate turbulence model (k-ω 1998 model( is proposed. Then, in order to evaluate the proposed solution method in simulation of flow adjacent to hydrophobic surfaces, turbulent flow is simulated in simple channel and the results are compared with the literature. Finally, two dimensional half-corrugated channel flow at Reynolds number of 104 is simulated again in vicinity of hydrophobic surfaces for varoius slip lengths. The results show that this method is capable of drag reduction in such a way that an increase of 200 μm in slip length leads to a massive drag reduction up to 38%. In addition, to access a significant drag reduction in turbulent flows, the non-dimensionalized slip length should be larger than the minimum.

Investigation of reordered (001) Au surfaces by positive ion channeling spectroscopy, LEED and AES

International Nuclear Information System (INIS)

Appleton, B.R.; Noggle, T.S.; Miller, J.W.; Schow, O.E. III; Zehner, D.M.; Jenkins, L.H.; Barrett, J.H.

1974-01-01

As a consequence of the channeling phenomenon of positive ions in single crystals, the yield of ions Rutherford scattered from an oriented single crystal surface is dependent on the density of surface atoms exposed to the incident ion beam. Thus, the positive ion channeling spectroscopy (PICS) technique should provide a useful tool for studying reordered surfaces. This possibility was explored by examining the surfaces of epitaxially grown thin Au single crystals with the combined techniques of LEED-AES and PICS. The LEED and AES investigations showed that when the (001) surface was sputter cleaned in ultra-high vacuum, the normal (1 x 1) symmetry of the (001) surfaces reordered into a structure which gave a complex (5 x 20) LEED pattern. The yield and energy distributions of 1 MeV He ions scattered from the Au surfaces were used to determine the number of effective monolayers contributing to the normal and reordered surfaces. These combined measurements were used to characterize the nature of the reordered surface. The general applicability of the PICS technique for investigations of surface and near surface regions is discussed

Inversion of membrane surface charge by trivalent cations probed with a cation-selective channel.

Science.gov (United States)

Gurnev, Philip A; Bezrukov, Sergey M

2012-11-13

We demonstrate that the cation-selective channel formed by gramicidin A can be used as a reliable sensor for studying the multivalent ion accumulation at the surfaces of charged lipid membranes and the "charge inversion" phenomenon. In asymmetrically charged membranes with the individual leaflets formed from pure negative and positive lipids bathed by 0.1 M CsCl solutions the channel exhibits current rectification, which is comparable to that of a typical n/p semiconductor diode. We show that even at these highly asymmetrical conditions the channel conductance can be satisfactorily described by the electrodiffusion equation in the constant field approximation but, due to predictable limitations, only when the applied voltages do not exceed 50 mV. Analysis of the changes in the voltage-dependent channel conductance upon addition of trivalent cations allows us to gauge their interactions with the membrane surface. The inversion of the sign of the effective surface charge takes place at the concentrations, which correlate with the cation size. Specifically, these concentrations are close to 0.05 mM for lanthanum, 0.25 mM for hexaamminecobalt, and 4 mM for spermidine.

pH-sensitive diamond field-effect transistors (FETs) with directly aminated channel surface

International Nuclear Information System (INIS)

Song, Kwang-Soup; Nakamura, Yusuke; Sasaki, Yuichi; Degawa, Munenori; Yang, Jung-Hoon; Kawarada, Hiroshi

2006-01-01

We have introduced pH sensors fabricated on diamond thin films through modification of the surface-terminated atom. We directly modified the diamond surface from hydrogen to amine or oxygen with ultraviolet (UV) irradiation under ammonia gas. The quantified amine site based on the spectra obtained by X-ray photoelectron spectroscopy (XPS) is 26% (2.6 x 10 14 cm -2 ) with UV irradiation for 8 h and its coverage is dependent on the UV irradiation time. This directly aminated diamond surface is stable with long-term exposure in air and electrolyte solution. We fabricated diamond solution-gate field-effect transistors (SGFETs) without insulating layers on the channel surface. These diamond SGFETs with amine modified by direct amination are sensitive to pH (45 mV/pH) over a wide range from pH 2 to 12 and their sensitivity is dependent on the density of binding sites corresponding to UV irradiation time on the channel surface

Multi-channel Analysis of Passive Surface Waves (MAPS)

Science.gov (United States)

Xia, J.; Cheng, F. Mr; Xu, Z.; Wang, L.; Shen, C.; Liu, R.; Pan, Y.; Mi, B.; Hu, Y.

2017-12-01

Urbanization is an inevitable trend in modernization of human society. In the end of 2013 the Chinese Central Government launched a national urbanization plan—"Three 100 Million People", which aggressively and steadily pushes forward urbanization. Based on the plan, by 2020, approximately 100 million people from rural areas will permanently settle in towns, dwelling conditions of about 100 million people in towns and villages will be improved, and about 100 million people in the central and western China will permanently settle in towns. China's urbanization process will run at the highest speed in the urbanization history of China. Environmentally friendly, non-destructive and non-invasive geophysical assessment method has played an important role in the urbanization process in China. Because human noise and electromagnetic field due to industrial life, geophysical methods already used in urban environments (gravity, magnetics, electricity, seismic) face great challenges. But humanity activity provides an effective source of passive seismic methods. Claerbout pointed out that wavefileds that are received at one point with excitation at the other point can be reconstructed by calculating the cross-correlation of noise records at two surface points. Based on this idea (cross-correlation of two noise records) and the virtual source method, we proposed Multi-channel Analysis of Passive Surface Waves (MAPS). MAPS mainly uses traffic noise recorded with a linear receiver array. Because Multi-channel Analysis of Surface Waves can produces a shear (S) wave velocity model with high resolution in shallow part of the model, MPAS combines acquisition and processing of active source and passive source data in a same flow, which does not require to distinguish them. MAPS is also of ability of real-time quality control of noise recording that is important for near-surface applications in urban environment. The numerical and real-world examples demonstrated that MAPS can be

Method of relative comparison of the thermohydraulic efficiency of heat exchange intensification in channels of heat-exchange surfaces

International Nuclear Information System (INIS)

Dubrovskij, E.V.; Vasil'ev, V.Ya.

2002-01-01

One introduces a technique to compare relatively thermohydraulic efficiency of heat transfer intensification in channels of heat exchange surfaces of any design types. It is shown that one should compare thermohydraulic efficiency of heat exchange intensification as to the thermal power of heat exchangers and pressure losses in channels with turbulators and in polished channels of heat exchange surfaces on the basis of dimensions of heat exchangers, their heat exchange surfaces and at similar (as to Re numbers) modes of coolant flow [ru

Single-Electron and Single-Photon Sensitivity with a Silicon Skipper CCD

Science.gov (United States)

Tiffenberg, Javier; Sofo-Haro, Miguel; Drlica-Wagner, Alex; Essig, Rouven; Guardincerri, Yann; Holland, Steve; Volansky, Tomer; Yu, Tien-Tien

2017-09-01

We have developed ultralow-noise electronics in combination with repetitive, nondestructive readout of a thick, fully depleted charge-coupled device (CCD) to achieve an unprecedented noise level of 0.068 e- rms /pixel . This is the first time that discrete subelectron readout noise has been achieved reproducible over millions of pixels on a stable, large-area detector. This enables the contemporaneous, discrete, and quantized measurement of charge in pixels, irrespective of whether they contain zero electrons or thousands of electrons. Thus, the resulting CCD detector is an ultra-sensitive calorimeter. It is also capable of counting single photons in the optical and near-infrared regime. Implementing this innovative non-destructive readout system has a negligible impact on CCD design and fabrication, and there are nearly immediate scientific applications. As a particle detector, this CCD will have unprecedented sensitivity to low-mass dark matter particles and coherent neutrino-nucleus scattering, while future astronomical applications may include direct imaging and spectroscopy of exoplanets.

Development of CCD Imaging System Using Thermoelectric Cooling Method

Directory of Open Access Journals (Sweden)

Youngsik Park

2000-06-01

Full Text Available We developed low light CCD imaging system using thermoelectric cooling method collaboration with a company to design a commercial model. It consists of Kodak KAF-0401E (768x512 pixels CCD chip,thermoelectric module manufactured by Thermotek. This TEC system can reach an operative temperature of -25deg. We employed an Uniblitz VS25S shutter and it has capability a minimum exposure time 80ms. The system components are an interface card using a Korea Astronomy Observatory (hereafter KAO ISA bus controller, image acquisition with AD9816 chip, that is 12bit video processor. The performance test with this imaging system showed good operation within the initial specification of our design. It shows a dark current less than 0.4e-/pixel/sec at a temperature of -10deg, a linearity 99.9+/-0.1%, gain 4.24e-adu, and system noise is 25.3e- (rms. For low temperature CCD operation, we designed a TEC, which uses a one-stage peltier module and forced air heat exchanger. This TEC imaging system enables accurate photometry (+/-0.01mag even though the CCD is not at 'conventional' cryogenic temperatures (140K. The system can be a useful instrument for any other imaging applications. Finally, with this system, we obtained several images of astronomical objects for system performance tests.

Research of optical coherence tomography microscope based on CCD detector

Science.gov (United States)

Zhang, Hua; Xu, Zhongbao; Zhang, Shuomo

2008-12-01

The reference wave phase was modulated with a sinusoidal vibrating mirror attached to a Piezoelectric Transducer (PZT), the integration was performed by a CCD, and the charge storage period of the CCD image sensor was one-quarter period of the sinusoidal phase modulation. With the frequency- synchronous detection technique, four images (four frames of interference pattern) were recorded during one period of the phase modulation. In order to obtain the optimum modulation parameter, the values of amplitude and phase of the sinusoidal phase modulation were determined by considering the measurement error caused by the additive noise contained in the detected values. The PZT oscillation was controlled by a closed loop control system based on PID controller. An ideal discrete digital sine function at 50Hz with adjustable amplitude was used to adjust the vibrating of PZT, and a digital phase shift techniques was used to adjust vibrating phase of PZT so that the phase of the modulation could reach their optimum values. The CCD detector was triggered with software at 200Hz. Based on work above a small coherent signal masked by the preponderant incoherent background with a CCD detector was obtained.

Radiation effects in charge coupled devices

International Nuclear Information System (INIS)

Williams, R.A.; Nelson, R.D.

1975-01-01

Charge coupled devices (CCD s) exhibit a number of advantages (low cost, low power, high bit density) in their several applications (serial memories, imagers, digital filters); however, fairly elementary theoretical considerations indicate that they will be very vulnerable to permanent radiation damage, by both neutrons and ionizing radiation, and to transient upset by pulsed ionizing radiation. Although studies of permanent ionizing-radiation damage in CCD's have been reported, little information has been published concerning their overall nuclear radiation vulnerability. This paper presents a fairly comprehensive experimental study of radiation effects in a 256-cell surface-channel, CCD shift-register. A limited amount of similar work is also presented for a 128-cell surface-channel device and a 130 cell peristaltic CCD shift register. The radiation effects phenomena discussed herein, include transient-ionizing-radiation responses, permanent ionizing- radiation damage to transfer efficiency, charge-carrying capacity and input transfer gate bias, and neutron damage to storage time--determined from dark current and charge-up time measurements

Defect testing of large aperture optics based on high resolution CCD camera

International Nuclear Information System (INIS)

Cheng Xiaofeng; Xu Xu; Zhang Lin; He Qun; Yuan Xiaodong; Jiang Xiaodong; Zheng Wanguo

2009-01-01

A fast testing method on inspecting defects of large aperture optics was introduced. With uniform illumination by LED source at grazing incidence, the image of defects on the surface of and inside the large aperture optics could be enlarged due to scattering. The images of defects were got by high resolution CCD camera and microscope, and the approximate mathematical relation between viewing dimension and real dimension of defects was simulated. Thus the approximate real dimension and location of all defects could be calculated through the high resolution pictures. (authors)

Polarized axonal surface expression of neuronal KCNQ potassium channels is regulated by calmodulin interaction with KCNQ2 subunit.

Directory of Open Access Journals (Sweden)

John P Cavaretta

Full Text Available KCNQ potassium channels composed of KCNQ2 and KCNQ3 subunits give rise to the M-current, a slow-activating and non-inactivating voltage-dependent potassium current that limits repetitive firing of action potentials. KCNQ channels are enriched at the surface of axons and axonal initial segments, the sites for action potential generation and modulation. Their enrichment at the axonal surface is impaired by mutations in KCNQ2 carboxy-terminal tail that cause benign familial neonatal convulsion and myokymia, suggesting that their correct surface distribution and density at the axon is crucial for control of neuronal excitability. However, the molecular mechanisms responsible for regulating enrichment of KCNQ channels at the neuronal axon remain elusive. Here, we show that enrichment of KCNQ channels at the axonal surface of dissociated rat hippocampal cultured neurons is regulated by ubiquitous calcium sensor calmodulin. Using immunocytochemistry and the cluster of differentiation 4 (CD4 membrane protein as a trafficking reporter, we demonstrate that fusion of KCNQ2 carboxy-terminal tail is sufficient to target CD4 protein to the axonal surface whereas inhibition of calmodulin binding to KCNQ2 abolishes axonal surface expression of CD4 fusion proteins by retaining them in the endoplasmic reticulum. Disruption of calmodulin binding to KCNQ2 also impairs enrichment of heteromeric KCNQ2/KCNQ3 channels at the axonal surface by blocking their trafficking from the endoplasmic reticulum to the axon. Consistently, hippocampal neuronal excitability is dampened by transient expression of wild-type KCNQ2 but not mutant KCNQ2 deficient in calmodulin binding. Furthermore, coexpression of mutant calmodulin, which can interact with KCNQ2/KCNQ3 channels but not calcium, reduces but does not abolish their enrichment at the axonal surface, suggesting that apo calmodulin but not calcium-bound calmodulin is necessary for their preferential targeting to the axonal

Investigation of radiation damage effects in neutron irradiated CCD

International Nuclear Information System (INIS)

Brau, James E.; Igonkina, Olga; Potter, Chris T.; Sinev, Nikolai B.

2005-01-01

A Charge Coupled Devices (CCD)-based vertex detector is a leading option for vertex detection at the future linear collider. A major issue for this application is the radiation hardness of such devices. Tests of radiation hardness of CCDs used in the SLD vertex detector, VXD3, have been reported earlier. The first measurements of 1998 involved a spare VXD3 CCD that was irradiated with neutrons from a radioactive source (Pu-Be), and from a nuclear reactor. In 2003, we had the opportunity to disassemble the VXD3 detector and study the nature of the radiation damage it incurred during 3 years of operation at SLC. In the preparation for this study, additional experiments with the spare VXD3 CCD were performed. These included measurements of trapping times in neutron irradiated CCDs. Results, reported here, will help us better understand the mechanism of radiation damage effects and develop techniques to minimize performance degradation due to radiation damage

An LOD with improved breakdown voltage in full-frame CCD devices

Science.gov (United States)

Banghart, Edmund K.; Stevens, Eric G.; Doan, Hung Q.; Shepherd, John P.; Meisenzahl, Eric J.

2005-02-01

In full-frame image sensors, lateral overflow drain (LOD) structures are typically formed along the vertical CCD shift registers to provide a means for preventing charge blooming in the imager pixels. In a conventional LOD structure, the n-type LOD implant is made through the thin gate dielectric stack in the device active area and adjacent to the thick field oxidation that isolates the vertical CCD columns of the imager. In this paper, a novel LOD structure is described in which the n-type LOD impurities are placed directly under the field oxidation and are, therefore, electrically isolated from the gate electrodes. By reducing the electrical fields that cause breakdown at the silicon surface, this new structure permits a larger amount of n-type impurities to be implanted for the purpose of increasing the LOD conductivity. As a consequence of the improved conductance, the LOD width can be significantly reduced, enabling the design of higher resolution imaging arrays without sacrificing charge capacity in the pixels. Numerical simulations with MEDICI of the LOD leakage current are presented that identify the breakdown mechanism, while three-dimensional solutions to Poisson's equation are used to determine the charge capacity as a function of pixel dimension.

Insulin and IGF-1 activate Kir4.1/5.1 channels in cortical collecting duct principal cells to control basolateral membrane voltage.

Science.gov (United States)

Zaika, Oleg; Palygin, Oleg; Tomilin, Viktor; Mamenko, Mykola; Staruschenko, Alexander; Pochynyuk, Oleh

2016-02-15

Potassium Kir4.1/5.1 channels are abundantly expressed at the basolateral membrane of principal cells in the cortical collecting duct (CCD), where they are thought to modulate transport rates by controlling transepithelial voltage. Insulin and insulin-like growth factor-1 (IGF-1) stimulate apically localized epithelial sodium channels (ENaC) to augment sodium reabsorption in the CCD. However, little is known about their actions on potassium channels localized at the basolateral membrane. In this study, we implemented patch-clamp analysis in freshly isolated murine CCD to assess the effect of these hormones on Kir4.1/5.1 at both single channel and cellular levels. We demonstrated that K(+)-selective conductance via Kir4.1/5.1 is the major contributor to the macroscopic current recorded from the basolateral side in principal cells. Acute treatment with 10 μM amiloride (ENaC blocker), 100 nM tertiapin-Q (TPNQ; ROMK inhibitor), and 100 μM ouabain (Na(+)-K(+)-ATPase blocker) failed to produce a measurable effect on the macroscopic current. In contrast, Kir4.1 inhibitor nortriptyline (100 μM), but not fluoxetine (100 μM), virtually abolished whole cell K(+)-selective conductance. Insulin (100 nM) markedly increased the open probability of Kir4.1/5.1 and nortriptyline-sensitive whole cell current, leading to significant hyperpolarization of the basolateral membrane. Inhibition of the phosphatidylinositol 3-kinase cascade with LY294002 (20 μM) abolished action of insulin on Kir4.1/5.1. IGF-1 had similar stimulatory actions on Kir4.1/5.1-mediated conductance only when applied at a higher (500 nM) concentration and was ineffective at 100 nM. We concluded that both insulin and, to a lesser extent, IGF-1 activate Kir4.1/5.1 channel activity and open probability to hyperpolarize the basolateral membrane, thereby facilitating Na(+) reabsorption in the CCD. Copyright © 2016 the American Physiological Society.

Air-side performance of a micro-channel heat exchanger in wet surface conditions

Directory of Open Access Journals (Sweden)

Srisomba Raviwat

2017-01-01

Full Text Available The effects of operating conditions on the air-side heat transfer, and pressure drop of a micro-channel heat exchanger under wet surface conditions were studied experimentally. The test section was an aluminum micro-channel heat exchanger, consisting of a multi-louvered fin and multi-port mini-channels. Experiments were conducted to study the effects of inlet relative humidity, air frontal velocity, air inlet temperature, and refrigerant temperature on air-side performance. The experimental data were analyzed using the mean enthalpy difference method. The test run was performed at relative air humidities ranging between 45% and 80%; air inlet temperature ranges of 27, 30, and 33°C; refrigerant-saturated temperatures ranging from 18 to 22°C; and Reynolds numbers between 128 and 166. The results show that the inlet relative humidity, air inlet temperature, and the refrigerant temperature had significant effects on heat transfer performance and air-side pressure drop. The heat transfer coefficient and pressure drop for the micro-channel heat exchanger under wet surface conditions are proposed in terms of the Colburn j factor and Fanning f factor.

Stroboscope Based Synchronization of Full Frame CCD Sensors.

Science.gov (United States)

Shen, Liang; Feng, Xiaobing; Zhang, Yuan; Shi, Min; Zhu, Dengming; Wang, Zhaoqi

2017-04-07

The key obstacle to the use of consumer cameras in computer vision and computer graphics applications is the lack of synchronization hardware. We present a stroboscope based synchronization approach for the charge-coupled device (CCD) consumer cameras. The synchronization is realized by first aligning the frames from different video sequences based on the smear dots of the stroboscope, and then matching the sequences using a hidden Markov model. Compared with current synchronized capture equipment, the proposed approach greatly reduces the cost by using inexpensive CCD cameras and one stroboscope. The results show that our method could reach a high accuracy much better than the frame-level synchronization of traditional software methods.

Evaluation of diagnostic ability of CCD digital radiography in the detection of incipient dental caries

International Nuclear Information System (INIS)

Lee, Wan; Lee, Byung Do

2003-01-01

The purpose of this experiment was to evaluate the diagnostic ability of a CCD-based digital system (CDX-2000HQ) in the detection of incipient dental caries. 93 extracted human teeth with sound proximal surfaces and interproximal artificial cavities were radiographed using 4 imaging methods. Automatically processed No.2 Insight film (Eastman Kodak Co., U.S.A.) was used for conventional radiography, scanned images of conventional radiograms for indirect digital radiography were used. For the direct digital radiography, the CDX-2000HQ CCD system (Biomedisys Co. Korea) was used. The subtraction images were made from two direct digital images by Sunny program in the CDX-2000HQ system. Two radiologists and three endodontists examined the presence of lesions using a five-point confidence scale and compared the diagnostic ability by ROC (Receiver Operating Characteristic) analysis and one way ANOVA test. The mean ROC areas of conventional radiography, indirect digital radiography, direct digital radiography, and digital subtraction radiography were 0.9093, 0.9102, 0.9184, and 0.9056, respectively. The diagnostic ability of direct digital radiography was better than the other imaging modalities, but there were no statistical differences among these imaging modalities (p>0.05). These results indicate that new CCD-based digital systems (CDX-2000HQ) have the potential to serve as an alternative to conventional radiography in the detection of incipient dental caries.

The study of interferometer spectrometer based on DSP and linear CCD

Science.gov (United States)

Kang, Hua; Peng, Yuexiang; Xu, Xinchen; Xing, Xiaoqiao

2010-11-01

In this paper, general theory of Fourier-transform spectrometer and polarization interferometer is presented. A new design is proposed for Fourier-transform spectrometer based on polarization interferometer with Wollaston prisms and linear CCD. Firstly, measured light is changed into linear polarization light by polarization plate. And then the light can be split into ordinary and extraordinary lights by going through one Wollaston prism. At last, after going through another Wollaston prism and analyzer, interfering fringes can be formed on linear CCD behind the analyzer. The linear CCD is driven by CPLD to output amplitude of interfering fringes and synchronous signals of frames and pixels respectively. DSP is used to collect interference pattern signals from CCD and the digital data of interfering fringes are processed by using 2048-point-FFT. Finally, optical spectrum of measured light can be display on LCD connected to DSP with RS232. The spectrometer will possess the features of firmness, portability and the ability of real-time analyzing. The work will provide a convenient and significant foundation for application of more high accuracy of Fourier-transform spectrometer.

Converting structures to optimize the Synchrotron X radiation detection by CCD systems

International Nuclear Information System (INIS)

Zanella, G.; Zannoni, R.

1987-01-01

It is pointed out how the quantum efficiency of X ray detection for CCD detecting system can be improved enlarging their sensivity range by means of heavy element converting structures. So the problem of fabricating CCD with a deep emptying layer is avoided

Design of area array CCD image acquisition and display system based on FPGA

Science.gov (United States)

Li, Lei; Zhang, Ning; Li, Tianting; Pan, Yue; Dai, Yuming

2014-09-01

With the development of science and technology, CCD(Charge-coupled Device) has been widely applied in various fields and plays an important role in the modern sensing system, therefore researching a real-time image acquisition and display plan based on CCD device has great significance. This paper introduces an image data acquisition and display system of area array CCD based on FPGA. Several key technical challenges and problems of the system have also been analyzed and followed solutions put forward .The FPGA works as the core processing unit in the system that controls the integral time sequence .The ICX285AL area array CCD image sensor produced by SONY Corporation has been used in the system. The FPGA works to complete the driver of the area array CCD, then analog front end (AFE) processes the signal of the CCD image, including amplification, filtering, noise elimination, CDS correlation double sampling, etc. AD9945 produced by ADI Corporation to convert analog signal to digital signal. Developed Camera Link high-speed data transmission circuit, and completed the PC-end software design of the image acquisition, and realized the real-time display of images. The result through practical testing indicates that the system in the image acquisition and control is stable and reliable, and the indicators meet the actual project requirements.

A Design and Development of Multi-Purpose CCD Camera System with Thermoelectric Cooling: Software

Directory of Open Access Journals (Sweden)

S. H. Oh

2007-12-01

Full Text Available We present a software which we developed for the multi-purpose CCD camera. This software can be used on the all 3 types of CCD - KAF-0401E (768×512, KAF-1602E (15367times;1024, KAF-3200E (2184×1472 made in KODAK Co.. For the efficient CCD camera control, the software is operated with two independent processes of the CCD control program and the temperature/shutter operation program. This software is designed to fully automatic operation as well as manually operation under LINUX system, and is controled by LINUX user signal procedure. We plan to use this software for all sky survey system and also night sky monitoring and sky observation. As our results, the read-out time of each CCD are about 15sec, 64sec, 134sec for KAF-0401E, KAF-1602E, KAF-3200E., because these time are limited by the data transmission speed of parallel port. For larger format CCD, the data transmission is required more high speed. we are considering this control software to one using USB port for high speed data transmission.

Simulation of an Underwater Acoustic Communication Channel Characterized by Wind-Generated Surface Waves and Bubbles

NARCIS (Netherlands)

Dol, H.S.; Colin, M.E.G.D.; Ainslie, M.A.; Walree, P.A. van; Janmaat, J.

2012-01-01

Sea surface scattering by wind-generated waves and bubbles is regarded to be the main non-platform related cause of the time variability of shallow acoustic communication channels. Simulations for predicting the quality of acoustic communication links in such channels thus require adequate modeling

Design of offline measuring system for radiation damage effects on linear CCD

International Nuclear Information System (INIS)

Zhang Yong; Tang Benqi; Xiao Zhigang; Wang Zujun; Huang Fang; Huang Shaoyan

2004-01-01

The paper discusses the hardware design of offline measuring system for radiation damage effects on linear CCD. Some credible results were achieved by using this system. The test results indicate that the system is available for the study of the radiation damage effects on linear CCD. (authors)

Extrapolation of contrail investigations by LIDAR to larger scale measurements. Analysis and calibration of CCD camera and satellite images

Energy Technology Data Exchange (ETDEWEB)

Sussmann, R.; Homburg, F.; Freudenthaler, V.; Jaeger, H. [Frauenhofer Inst. fuer Atmosphaerische Umweltforschung, Garmisch-Partenkirchen (Germany)

1997-12-31

The CCD image of a persistent contrail and the coincident LIDAR measurement are presented. To extrapolate the LIDAR derived optical thickness to the video field of view an anisotropy correction and calibration has to be performed. Observed bright halo components result from highly regular oriented hexagonal crystals with sizes of 200 {mu}m-2 mm. This explained by measured ambient humidities below the formation threshold of natural cirrus. Optical thickness from LIDAR shows significant discrepancies to the result from coincident NOAA-14 data. Errors result from anisotropy correction and parameterized relations between AVHRR channels and optical properties. (author) 28 refs.

Optimization of polarimetry sensitivity for X-ray CCD

CERN Document Server

Hayashida, K; Tsunemi, H; Hashimoto, Y; Ohtani, M

1999-01-01

X-ray polarimetry with CCD has been performed using a polarized X-ray beam from an electron impact X-ray source. The standard data reduction method employing double-pixel events yields the modulation factor M of 0.14 at 27 keV and 0.24 at 43 keV for the 12 mu m pixel size CCD chip. We develop a new data reduction method, in which multi-pixel events are employed, and which approximates the charge spread as an oval shape. We optimize the reduction parameters, so that we improve the P sub m sub i sub n (minimum detectable polarization degree) by factor of three from the value obtained through the usual double-pixel event method.

Stroboscope Based Synchronization of Full Frame CCD Sensors

Directory of Open Access Journals (Sweden)

Liang Shen

2017-04-01

Full Text Available The key obstacle to the use of consumer cameras in computer vision and computer graphics applications is the lack of synchronization hardware. We present a stroboscope based synchronization approach for the charge-coupled device (CCD consumer cameras. The synchronization is realized by first aligning the frames from different video sequences based on the smear dots of the stroboscope, and then matching the sequences using a hidden Markov model. Compared with current synchronized capture equipment, the proposed approach greatly reduces the cost by using inexpensive CCD cameras and one stroboscope. The results show that our method could reach a high accuracy much better than the frame-level synchronization of traditional software methods.

Numerical Modeling of Surface and Volumetric Cooling using Optimal T- and Y-shaped Flow Channels

Science.gov (United States)

Kosaraju, Srinivas

2017-11-01

The layout of T- and V-shaped flow channel networks on a surface can be optimized for minimum pressure drop and pumping power. The results of the optimization are in the form of geometric parameters such as length and diameter ratios of the stem and branch sections. While these flow channels are optimized for minimum pressure drop, they can also be used for surface and volumetric cooling applications such as heat exchangers, air conditioning and electronics cooling. In this paper, an effort has been made to study the heat transfer characteristics of multiple T- and Y-shaped flow channel configurations using numerical simulations. All configurations are subjected to same input parameters and heat generation constraints. Comparisons are made with similar results published in literature.

Flat Field Anomalies in an X-ray CCD Camera Measured Using a Manson X-ray Source (HTPD 08 paper)

International Nuclear Information System (INIS)

Haugh, M; Schneider, M B

2008-01-01

The Static X-ray Imager (SXI) is a diagnostic used at the National Ignition Facility (NIF) to measure the position of the X-rays produced by lasers hitting a gold foil target. The intensity distribution taken by the SXI camera during a NIF shot is used to determine how accurately NIF can aim laser beams. This is critical to proper NIF operation. Imagers are located at the top and the bottom of the NIF target chamber. The CCD chip is an X-ray sensitive silicon sensor, with a large format array (2k x 2k), 24 (micro)m square pixels, and 15 (micro)m thick. A multi-anode Manson X-ray source, operating up to 10kV and 10W, was used to characterize and calibrate the imagers. The output beam is heavily filtered to narrow the spectral beam width, giving a typical resolution E/ΔE ∼ 10. The X-ray beam intensity was measured using an absolute photodiode that has accuracy better than 1% up to the Si K edge and better than 5% at higher energies. The X-ray beam provides full CCD illumination and is flat, within ±1% maximum to minimum. The spectral efficiency was measured at 10 energy bands ranging from 930 eV to 8470 eV. We observed an energy dependent pixel sensitivity variation that showed continuous change over a large portion of the CCD. The maximum sensitivity variation occurred at 8470 eV. The geometric pattern did not change at lower energies, but the maximum contrast decreased and was not observable below 4 keV. We were also able to observe debris, damage, and surface defects on the CCD chip. The Manson source is a powerful tool for characterizing the imaging errors of an X-ray CCD imager. These errors are quite different from those found in a visible CCD imager

Stellar CCD Photometry: New Approach, Principles and Application

Science.gov (United States)

El-Bassuny Alawy, A.

A new approach is proposed and developed to handle pre-processed CCD frames in order to identify stellar images and derive their relevant parameters. It relies on: 1) Identifying stellar images and assigning approximate positions of their centres using an artificial intelligence technique, (Knowledge Based System), 2) Accurate determination of the centre co-ordinates applying an elementary statistical concept and 3) Estimating the image peak intensity as a stellar magnitude measure employing simple numerical analysis approach. The method has been coded for personal computer users. A CCD frame of the star cluster M67 was adopted as a test case. The results obtained are discussed in comparison with the DAOPHOTII ones and the corresponding published data. Exact coincidence has been found between both results except in very few cases. These exceptions have been discussed in the light of the basis of both methods and the cluster plates. It has been realised that the method suggested represents a very simple, extremely fast, high precision method of stellar CCD photometry. Moreover, it is more capable than DAOPHOTII of handling blended and distorted stellar images. These characteristics show the usefulness of the present method in some astronomical applications, such as auto-focusing and auto-guiding, beside the main purpose, viz. stellar photometry.

Optical CT scanning of PRESAGETM polyurethane samples with a CCD-based readout system

International Nuclear Information System (INIS)

Doran, S J; Krstajic, N; Adamovics, J; Jenneson, P M

2004-01-01

This article demonstrates the resolution capabilities of the CCD scanner under ideal circumstances and describes the first CCD-based optical CT experiments on a new class of dosimeter, known as PRESAGE TM (Heuris Pharma, Skillman, NJ)

Plane development of lateral surfaces for inspection systems

Science.gov (United States)

Francini, F.; Fontani, D.; Jafrancesco, D.; Mercatelli, L.; Sansoni, P.

2006-08-01

The problem of developing the lateral surfaces of a 3D object can arise in item inspection using automated imaging systems. In an industrial environment, these control systems typically work at high rate and they have to assure a reliable inspection of the single item. For compactness requirements it is not convenient to utilise three or four CCD cameras to control all the lateral surfaces of an object. Moreover it is impossible to mount optical components near the object if it is placed on a conveyor belt. The paper presents a system that integrates on a single CCD picture the images of both the frontal surface and the lateral surface of an object. It consists of a freeform lens mounted in front of a CCD camera with a commercial lens. The aim is to have a good magnification of the lateral surface, maintaining a low aberration level for exploiting the pictures in an image processing software. The freeform lens, made in plastics, redirects the light coming from the object to the camera lens. The final result is to obtain on the CCD: - the frontal and lateral surface images, with a selected magnification (even with two different values for the two images); - a gap between these two images, so an automatic method to analyse the images can be easily applied. A simple method to design the freeform lens is illustrated. The procedure also allows to obtain the imaging system modifying a current inspection system reducing the cost.

The quantic distribution of mobile carriers in a surface charge coupled device

International Nuclear Information System (INIS)

Ionescu, M.

1977-01-01

The quantic distribution of the electrons in a surface charge coupled device (CCD), for a MIS structure with a real insulator (finite difference energy between the conduction bands of the insulator and of the semiconductor) is presented. A fundamental limitation of the charge transfer in a surface CCD is obtained. (author)

On-Line High Dose-Rate Gamma Ray Irradiation Test of the CCD/CMOS Cameras

Energy Technology Data Exchange (ETDEWEB)

Cho, Jai Wan; Jeong, Kyung Min [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

In this paper, test results of gamma ray irradiation to CCD/CMOS cameras are described. From the CAMS (containment atmospheric monitoring system) data of Fukushima Dai-ichi nuclear power plant station, we found out that the gamma ray dose-rate when the hydrogen explosion occurred in nuclear reactors 1{approx}3 is about 160 Gy/h. If assumed that the emergency response robot for the management of severe accident of the nuclear power plant has been sent into the reactor area to grasp the inside situation of reactor building and to take precautionary measures against releasing radioactive materials, the CCD/CMOS cameras, which are loaded with the robot, serve as eye of the emergency response robot. In the case of the Japanese Quince robot system, which was sent to carry out investigating the unit 2 reactor building refueling floor situation, 7 CCD/CMOS cameras are used. 2 CCD cameras of Quince robot are used for the forward and backward monitoring of the surroundings during navigation. And 2 CCD (or CMOS) cameras are used for monitoring the status of front-end and back-end motion mechanics such as flippers and crawlers. A CCD camera with wide field of view optics is used for monitoring the status of the communication (VDSL) cable reel. And another 2 CCD cameras are assigned for reading the indication value of the radiation dosimeter and the instrument. In the preceding assumptions, a major problem which arises when dealing with CCD/CMOS cameras in the severe accident situations of the nuclear power plant is the presence of high dose-rate gamma irradiation fields. In the case of the DBA (design basis accident) situations of the nuclear power plant, in order to use a CCD/CMOS camera as an ad-hoc monitoring unit in the vicinity of high radioactivity structures and components of the nuclear reactor area, a robust survivability of this camera in such intense gamma-radiation fields therefore should be verified. The CCD/CMOS cameras of various types were gamma irradiated at a

A Low-Cost and Portable Dual-Channel Fiber Optic Surface Plasmon Resonance System.

Science.gov (United States)

Liu, Qiang; Liu, Yun; Chen, Shimeng; Wang, Fang; Peng, Wei

2017-12-04

A miniaturization and integration dual-channel fiber optic surface plasmon resonance (SPR) system was proposed and demonstrated in this paper. We used a yellow light-emitting diode (LED, peak wavelength 595 nm) and built-in web camera as a light source and detector, respectively. Except for the detection channel, one of the sensors was used as a reference channel to compensate nonspecific binding and physical absorption. We packaged the LED and surface plasmon resonance (SPR) sensors together, which are flexible enough to be applied to mobile devices as a compact and portable system. Experimental results show that the normalized intensity shift and refractive index (RI) of the sample have a good linear relationship in the RI range from 1.328 to 1.348. We used this sensor to monitor the reversible, specific interaction between lectin concanavalin A (Con A) and glycoprotein ribonuclease B (RNase B), which demonstrate its capabilities of specific identification and biochemical samples concentration detection. This sensor system has potential applications in various fields, such as medical diagnosis, public health, food safety, and environment monitoring.

Ultrahigh-speed, high-sensitivity color camera with 300,000-pixel single CCD

Science.gov (United States)

Kitamura, K.; Arai, T.; Yonai, J.; Hayashida, T.; Ohtake, H.; Kurita, T.; Tanioka, K.; Maruyama, H.; Namiki, J.; Yanagi, T.; Yoshida, T.; van Kuijk, H.; Bosiers, Jan T.; Etoh, T. G.

2007-01-01

We have developed an ultrahigh-speed, high-sensitivity portable color camera with a new 300,000-pixel single CCD. The 300,000-pixel CCD, which has four times the number of pixels of our initial model, was developed by seamlessly joining two 150,000-pixel CCDs. A green-red-green-blue (GRGB) Bayer filter is used to realize a color camera with the single-chip CCD. The camera is capable of ultrahigh-speed video recording at up to 1,000,000 frames/sec, and small enough to be handheld. We also developed a technology for dividing the CCD output signal to enable parallel, highspeed readout and recording in external memory; this makes possible long, continuous shots up to 1,000 frames/second. As a result of an experiment, video footage was imaged at an athletics meet. Because of high-speed shooting, even detailed movements of athletes' muscles were captured. This camera can capture clear slow-motion videos, so it enables previously impossible live footage to be imaged for various TV broadcasting programs.

Direct numerical simulation of turbulent channel flow over a liquid-infused micro-grooved surface

Science.gov (United States)

Chang, Jaehee; Jung, Taeyong; Choi, Haecheon; Kim, John

2016-11-01

Recently a superhydrophobic surface has drawn much attention as a passive device to achieve high drag reduction. Despite the high performance promised at ideal conditions, maintaining the interface in real flow conditions is an intractable problem. A non-wetting surface, known as the slippery liquid-infused porous surface (SLIPS) or the lubricant-impregnated surface (LIS), has shown a potential for drag reduction, as the working fluid slips at the interface but cannot penetrate into the lubricant layer. In the present study, we perform direct numerical simulation of turbulent channel flow over a liquid-infused micro-grooved surface to investigate the effects of this surface on the interfacial slip and drag reduction. The flow rate of water is maintained constant corresponding to Reτ 180 in a fully developed turbulent channel flow, and the lubricant layer is shear-driven by the turbulent water flow. The lubricant layer is also simulated with the assumption that the interface is flat (i.e. the surface tension effect is neglected). The solid substrate in which the lubricant is infused is modelled as straight ridges using an immersed boundary method. DNS results show that drag reduction by the liquid-infused surface is highly dependent on the viscosity of the lubricant.

A tilted fiber-optic plate coupled CCD detector for high resolution neutron imaging

Energy Technology Data Exchange (ETDEWEB)

Kim, Jongyul; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Jongyul; Hwy, Limchang; Kim, Taejoo; Lee, Kyehong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Seungwook [Pusan National Univ., Pusan (Korea, Republic of)

2013-05-15

One of these efforts is that a tilted scintillator geometry and lens coupled CCD detector for neutron imaging system were used to improve spatial resolution in one dimension. The increased spatial resolution in one dimension was applied to fuel cell study. However, a lens coupled CCD detector has lower sensitivity than a fiber-optic plate coupled CCD detector due to light loss. In this research, a tilted detector using fiber-optic plate coupled CCD detector was developed to improve resolution and sensitivity. In addition, a tilted detector can prevent an image sensor from direct radiation damage. Neutron imaging has been used for fuel cell study, lithium ion battery study, and many scientific applications. High quality neutron imaging is demanded for more detailed studies of applications, and spatial resolution should be considered to get high quality neutron imaging. Therefore, there were many efforts to improve spatial resolution.

Research on optimization design of conformal cooling channels in hot stamping tool based on response surface methodology and multi-objective optimization

Directory of Open Access Journals (Sweden)

He Bin

2016-01-01

Full Text Available In order to optimize the layout of the conformal cooling channels in hot stamping tools, a response surface methodology and multi-objective optimization technique are proposed. By means of an Optimal Latin Hypercube experimental design method, a design matrix with 17 factors and 50 levels is generated. Three kinds of design variables, the radius Rad of the cooling channel, the distance H from the channel center to tool work surface and the ratio rat of each channel center, are optimized to determine the layout of cooling channels. The average temperature and temperature deviation of work surface are used to evaluate the cooling performance of hot stamping tools. On the basis of the experimental design results, quadratic response surface models are established to describe the relationship between the design variables and the evaluation objectives. The error analysis is performed to ensure the accuracy of response surface models. Then the layout of the conformal cooling channels is optimized in accordance with a multi-objective optimization method to find the Pareto optimal frontier which consists of some optimal combinations of design variables that can lead to an acceptable cooling performance.

Calibration of the CCD photonic measuring system for railway inspection

Science.gov (United States)

Popov, D. V.; Ryabichenko, R. B.; Krivosheina, E. A.

2005-08-01

Increasing of traffic speed is the most important task in Moscow Metro. Requirements for traffic safety grow up simultaneously with the speed increasing. Currently for track inspection in Moscow Metro is used track measurement car has built in 1954. The main drawbacks of this system are absence of automated data processing and low accuracy. Non-contact photonic measurement system (KSIR) is developed for solving this problem. New track inspection car will be built in several months. This car will use two different track inspection systems and car locating subsystem based on track circuit counting. The KSIR consists of four subsystems: rail wear, height and track gauge measurement (BFSM); rail slump measurement (FIP); contact rail measurement (FKR); speed, level and car locating (USI). Currently new subsystem for wheel flange wear (IRK) is developed. The KSIR carry out measurements in real-time mode. The BFSM subsystem contains 4 matrix CCD cameras and 4 infrared stripe illuminators. The FIP subsystem contains 4 line CCD cameras and 4 spot illuminators. The FKR subsystem contains 2 matrix CCD cameras and 2 stripe illuminators. The IRK subsystem contains 2 CCD cameras and 2 stripe illuminators. Each system calibration was carried out for their adjustment. On the first step KSIR obtains data from photonic sensors which is valued in internal measurement units. Due to the calibration on the second step non-contact system converts the data to metric measurement system.

Spatial distribution of electrons on a superfluid helium charge-coupled device

International Nuclear Information System (INIS)

Takita, Maika; Bradbury, F R; Lyon, S A; Gurrieri, T M; Wilkel, K J; Eng, Kevin; Carroll, M S

2012-01-01

Electrons floating on the surface of superfluid helium have been suggested as promising mobile spin qubits. Three micron wide channels fabricated with standard silicon processing are filled with superfluid helium by capillary action. Photoemitted electrons are held by voltages applied to underlying gates. The gates are connected as a 3-phase charge-coupled device (CCD). Starting with approximately one electron per channel, no detectable transfer errors occur while clocking 10 9 pixels. One channel with its associated gates is perpendicular to the other 120, providing a CCD which can transfer electrons between the others. This perpendicular channel has not only shown efficient electron transport but also serves as a way to measure the uniformity of the electron occupancy in the 120 parallel channels.

Four-channel surface coil array for sequential CW-EPR image acquisition

Science.gov (United States)

Enomoto, Ayano; Emoto, Miho; Fujii, Hirotada; Hirata, Hiroshi

2013-09-01

This article describes a four-channel surface coil array to increase the area of visualization for continuous-wave electron paramagnetic resonance (CW-EPR) imaging. A 776-MHz surface coil array was constructed with four independent surface coil resonators and three kinds of switches. Control circuits for switching the resonators were also built to sequentially perform EPR image acquisition for each resonator. The resonance frequencies of the resonators were shifted using PIN diode switches to decouple the inductively coupled coils. To investigate the area of visualization with the surface coil array, three-dimensional EPR imaging was performed using a glass cell phantom filled with a solution of nitroxyl radicals. The area of visualization obtained with the surface coil array was increased approximately 3.5-fold in comparison to that with a single surface coil resonator. Furthermore, to demonstrate the applicability of this surface coil array to animal imaging, three-dimensional EPR imaging was performed in a living mouse with an exogenously injected nitroxyl radical imaging agent.

Comparative Analysis of Chinese HJ-1 CCD, GF-1 WFV and ZY-3 MUX Sensor Data for Leaf Area Index Estimations for Maize

Directory of Open Access Journals (Sweden)

Jing Zhao

2018-01-01

Full Text Available In recent years, China has developed and launched several satellites with high spatial resolutions, such as the resources satellite No. 3 (ZY-3 with a multi-spectral camera (MUX and 5.8 m spatial resolution, the satellite GaoFen No. 1 (GF-1 with a wide field of view (WFV camera and 16 m spatial resolution, and the environment satellite (HJ-1A/B with a charge-coupled device (CCD sensor and 30 m spatial resolution. First, to analyze the potential application of ZY-3 MUX, GF-1 WFV, and HJ-1 CCD to extract the leaf area index (LAI at the regional scale, this study estimated LAI from the relationships between physical model-based spectral vegetation indices (SVIs and LAI values that were generated from look-up tables (LUTs, simulated from the combination of the PROSPECT-5B leaf model and the scattering by arbitrarily inclined leaves with the hot-spot effect (SAILH canopy reflectance model. Second, to assess the surface reflectance quality of these sensors after data preprocessing, the well-processed surface reflectance products of the Landsat-8 operational land imager (OLI sensor with a convincing data quality were used to compare the performances of ZY-3 MUX, GF-1 WFV, and HJ-1 CCD sensors both in theory and reality. Apart from several reflectance fluctuations, the reflectance trends were coincident, and the reflectance values of the red and near-infrared (NIR bands were comparable among these sensors. Finally, to analyze the accuracy of the LAI estimated from ZY-3 MUX, GF-1 WFV, and HJ-1 CCD, the LAI estimations from these sensors were validated based on LAI field measurements in Huailai, Hebei Province, China. The results showed that the performance of the LAI that was inversed from ZY-3 MUX was better than that from GF-1 WFV, and HJ-1 CCD, both of which tended to be systematically underestimated. In addition, the value ranges and accuracies of the LAI inversions both decreased with decreasing spatial resolution.

Subcooled flow boiling heat transfer from microporous surfaces in a small channel

International Nuclear Information System (INIS)

Yan, Sun; Li, Zhang; Hong, Xu; Xiaocheng, Zhong

2011-01-01

The continuously increasing requirement for high heat transfer rate in a compact space can be met by combining the small channel/microchannel and heat transfer enhancement methods during fluid subcooled flow boiling. In this paper, the sintered microporous coating, as an efficient means of enhancing nucleate boiling, was applied to a horizontal, rectangular small channel. Water flow boiling heat transfer characteristics from the small channel with/without the microporous coating were experimentally investigated. The small channel, even without the coating, presented flow boiling heat transfer enhancement at low vapor quality due to size effects of the channel. This enhancement was also verified by under-predictions from macro-scale correlations. In addition to the enhancement from the channel size, all six microporous coatings with various structural parameters were found to further enhance nucleate boiling significantly. Effects of the coating structural parameters, fluid mass flux and inlet subcooling were also investigated to identify the optimum condition for heat transfer enhancement. Under the optimum condition, the microporous coating could produce the heat transfer coefficients 2.7 times the smooth surface value in subcooled flow boiling and 3 times in saturated flow boiling. The combination of the microporous coating and small channel led to excellent heat transfer performance, and therefore was deemed to have promising application prospects in many areas such as air conditioning, chip cooling, refrigeration systems, and many others involving compact heat exchangers. (authors)

Digital Printing Quality Detection and Analysis Technology Based on CCD

Science.gov (United States)

He, Ming; Zheng, Liping

2017-12-01

With the help of CCD digital printing quality detection and analysis technology, it can carry out rapid evaluation and objective detection of printing quality, and can play a certain control effect on printing quality. It can be said CDD digital printing quality testing and analysis of the rational application of technology, its digital printing and printing materials for a variety of printing equipments to improve the quality of a very positive role. In this paper, we do an in-depth study and discussion based on the CCD digital print quality testing and analysis technology.

Experience in CCD Photometry at the Tartu Observatory

Directory of Open Access Journals (Sweden)

Tuvikene T.

2003-12-01

Full Text Available We give overview of the CCD instrumentation and data reduction techniques used at the Tartu Observatory. The first results from photometric observations of the peculiar variable V838 Mon are presented.

Synergistic Malaria Parasite Killing by Two Types of Plasmodial Surface Anion Channel Inhibitors.

Directory of Open Access Journals (Sweden)

Margaret Pain

Full Text Available Malaria parasites increase their host erythrocyte's permeability to a broad range of ions and organic solutes. The plasmodial surface anion channel (PSAC mediates this uptake and is an established drug target. Development of therapies targeting this channel is limited by several problems including interactions between known inhibitors and permeating solutes that lead to incomplete channel block. Here, we designed and executed a high-throughput screen to identify a novel class of PSAC inhibitors that overcome this solute-inhibitor interaction. These new inhibitors differ from existing blockers and have distinct effects on channel-mediated transport, supporting a model of two separate routes for solute permeation though PSAC. Combinations of inhibitors specific for the two routes had strong synergistic action against in vitro parasite propagation, whereas combinations acting on a single route produced only additive effects. The magnitude of synergism depended on external nutrient concentrations, consistent with an essential role of the channel in parasite nutrient acquisition. The identified inhibitors will enable a better understanding of the channel's structure-function and may be starting points for novel combination therapies that produce synergistic parasite killing.

Application of X-ray CCD camera in X-ray spot diagnosis of rod-pinch diode

International Nuclear Information System (INIS)

Song Yan; Zhou Ming; Song Guzhou; Ma Jiming; Duan Baojun; Han Changcai; Yao Zhiming

2015-01-01

The pinhole imaging technique is widely used in the measurement of X-ray spot of rod-pinch diode. The X-ray CCD camera, which was composed of film, fiber optic taper and CCD camera, was employed to replace the imaging system based on scintillator, lens and CCD camera in the diagnosis of X-ray spot. The resolution of the X-ray CCD camera was studied. The resolution is restricted by the film and is 5 lp/mm in the test with Pb resolution chart. The frequency is 1.5 lp/mm when the MTF is 0.5 in the test with edge image. The resolution tests indicate that the X-ray CCD camera can meet the requirement of the diagnosis of X-ray spot whose scale is about 1.5 mm when the pinhole imaging magnification is 0.5. At last, the image of X-ray spot was gained and the restoration was implemented in the diagnosis of X-ray spot of rod-pinch diode. (authors)

N-linked glycans are required on epithelial Na+ channel subunits for maturation and surface expression.

Science.gov (United States)

Kashlan, Ossama B; Kinlough, Carol L; Myerburg, Michael M; Shi, Shujie; Chen, Jingxin; Blobner, Brandon M; Buck, Teresa M; Brodsky, Jeffrey L; Hughey, Rebecca P; Kleyman, Thomas R

2018-03-01

Epithelial Na + channel (ENaC) subunits undergo N-linked glycosylation in the endoplasmic reticulum where they assemble into an αβγ complex. Six, 13, and 5 consensus sites (Asn-X-Ser/Thr) for N-glycosylation reside in the extracellular domains of the mouse α-, β-, and γ-subunits, respectively. Because the importance of ENaC N-linked glycans has not been fully addressed, we examined the effect of preventing N-glycosylation of specific subunits on channel function, expression, maturation, and folding. Heterologous expression in Xenopus oocytes or Fischer rat thyroid cells with αβγ-ENaC lacking N-linked glycans on a single subunit reduced ENaC activity as well as the inhibitory response to extracellular Na + . The lack of N-linked glycans on the β-subunit also precluded channel activation by trypsin. However, channel activation by shear stress was N-linked glycan independent, regardless of which subunit was modified. We also discovered that the lack of N-linked glycans on any one subunit reduced the total and surface levels of cognate subunits. The lack of N-linked glycans on the β-subunit had the largest effect on total levels, with the lack of N-linked glycans on the γ- and α-subunits having intermediate and modest effects, respectively. Finally, channels with wild-type β-subunits were more sensitive to limited trypsin proteolysis than channels lacking N-linked glycans on the β-subunit. Our results indicate that N-linked glycans on each subunit are required for proper folding, maturation, surface expression, and function of the channel.

A GRAPH READER USING A CCD IMAGE SENSOR

African Journals Online (AJOL)

2008-01-18

Jan 18, 2008 ... using a stepper motor controlled by a software program in a ... Keywords: CCD sensor, microcontrollen stepper motor and microcomputer. 1. ... commercial applications (Awcock and ... on-chip amplifier, one pixel at a tirtjie.

C.C.D. readout of a picosecond streak camera with an intensified C.C.D

International Nuclear Information System (INIS)

Lemonier, M.; Richard, J.C.; Cavailler, C.; Mens, A.; Raze, G.

1984-08-01

This paper deals with a digital streak camera readout device. The device consists in a low light level television camera made of a solid state C.C.D. array coupled to an image intensifier associated to a video-digitizer coupled to a micro-computer system. The streak camera images are picked-up as a video signal, digitized and stored. This system allows the fast recording and the automatic processing of the data provided by the streak tube

Effect of surface radiation on natural convection in an asymmetrically heated channel-chimney system

Science.gov (United States)

Nasri, Zied; Derouich, Youssef; Laatar, Ali Hatem; Balti, Jalloul

2018-05-01

In this paper, a more realistic numerical approach that takes into account the effect of surface radiation on the laminar air flow induced by natural convection in a channel-chimney system asymmetrically heated at uniform heat flux is used. The aim is to enrich the results given in Nasri et al. (Int J Therm Sci 90:122-134, 2015) by varying all the geometric parameters of the system and by taking into account the effect of surface radiation on the flows. The numerical results are first validated against experimental and numerical data available in the literature. The computations have allowed the determination of optimal configurations that maximize the mass flow rate and the convective heat transfer and minimize the heated wall temperatures. The analysis of the temperature fields with the streamlines and the pressure fields has helped to explain the effects of surface radiation and of the different thermo-geometrical parameters on the system performances to improve the mass flow rate and the heat transfer with respect to the simple channel. It is shown that the thermal performance of the channel-chimney system in terms of lower heated wall temperatures is little affected by the surface radiation. At the end, simple correlation equations have been proposed for quickly and easily predict the optimal configurations as well as the corresponding enhancement rates of the induced mass flow rate and the convective heat transfer.

A mathematical model for surface roughness of fluidic channels produced by grinding aided electrochemical discharge machining (G-ECDM

Directory of Open Access Journals (Sweden)

Ladeesh V. G.

2017-01-01

Full Text Available Grinding aided electrochemical discharge machining is a hybrid technique, which combines the grinding action of an abrasive tool and thermal effects of electrochemical discharges to remove material from the workpiece for producing complex contours. The present study focuses on developing fluidic channels on borosilicate glass using G-ECDM and attempts to develop a mathematical model for surface roughness of the machined channel. Preliminary experiments are conducted to study the effect of machining parameters on surface roughness. Voltage, duty factor, frequency and tool feed rate are identified as the significant factors for controlling surface roughness of the channels produced by G-ECDM. A mathematical model was developed for surface roughness by considering the grinding action and thermal effects of electrochemical discharges in material removal. Experiments are conducted to validate the model and the results obtained are in good agreement with that predicted by the model.

Control of Ambipolar Transport in SnO Thin-Film Transistors by Back-Channel Surface Passivation for High Performance Complementary-like Inverters.

Science.gov (United States)

Luo, Hao; Liang, Lingyan; Cao, Hongtao; Dai, Mingzhi; Lu, Yicheng; Wang, Mei

2015-08-12

For ultrathin semiconductor channels, the surface and interface nature are vital and often dominate the bulk properties to govern the field-effect behaviors. High-performance thin-film transistors (TFTs) rely on the well-defined interface between the channel and gate dielectric, featuring negligible charge trap states and high-speed carrier transport with minimum carrier scattering characters. The passivation process on the back-channel surface of the bottom-gate TFTs is indispensable for suppressing the surface states and blocking the interactions between the semiconductor channel and the surrounding atmosphere. We report a dielectric layer for passivation of the back-channel surface of 20 nm thick tin monoxide (SnO) TFTs to achieve ambipolar operation and complementary metal oxide semiconductor (CMOS) like logic devices. This chemical passivation reduces the subgap states of the ultrathin channel, which offers an opportunity to facilitate the Fermi level shifting upward upon changing the polarity of the gate voltage. With the advent of n-type inversion along with the pristine p-type conduction, it is now possible to realize ambipolar operation using only one channel layer. The CMOS-like logic inverters based on ambipolar SnO TFTs were also demonstrated. Large inverter voltage gains (>100) in combination with wide noise margins are achieved due to high and balanced electron and hole mobilities. The passivation also improves the long-term stability of the devices. The ability to simultaneously achieve field-effect inversion, electrical stability, and logic function in those devices can open up possibilities for the conventional back-channel surface passivation in the CMOS-like electronics.

Visualization of pre-set vortices in boundary layer flow over wavy surface in rectangular channel

KAUST Repository

Budiman, Alexander Christantho

2014-12-04

Abstract: Smoke-wire flow visualization is used to study the development of pre-set counter-rotating streamwise vortices in boundary layer flow over a wavy surface in a rectangular channel. The formation of the vortices is indicated by the vortical structures on the cross-sectional plane normal to the wavy surface. To obtain uniform spanwise vortex wavelength which will result in uniform vortex size, two types of spanwise disturbances were used: a series of perturbation wires placed prior and normal to the leading edge of the wavy surface, and a jagged pattern in the form of uniform triangles cut at the leading edge. These perturbation wires and jagged pattern induce low-velocity streaks that result in the formation of counter-rotating streamwise vortices that evolve downstream to form the mushroom-like structures on the cross-sectional plane of the flow. The evolution of the most amplified disturbances can be attributed to the formation of these mushroom-like structures. It is also shown that the size of the mushroom-like structures depends on the channel entrance geometry, Reynolds number, and the channel gap.Graphical Abstract: [Figure not available: see fulltext.

Experimental investigation of the effect of variously-shaped ribs on local heat transfer on the outer wall of the turning portion of a U-channel inside solar air heater

Science.gov (United States)

Salameh, Tareq; Alami, Abdul Hai; Sunden, Bengt

2016-03-01

In the present work, an experimental investigation of convective heat transfer and pressure drop was carried out for the turning portion of a U-channel where the outer wall was equipped with ribs. The shape of the ribs was varied. The investigation aims to give guidelines for improving the thermo-hydraulic performance of a solar air heater at the turning portion of a U-channel. Both the U-channel and the ribs were made in acrylic material to allow optical access for measuring the surface temperature by using a high-resolution technique based on narrow band thermochromic liquid crystals (TLC R35C5 W) and a CCD camera placed to face the turning portion of the U-channel. The uncertainties were estimated to 5 and 7 % for the Nusselt number and friction factor, respectively. The pressure drop was approximately the same for all the considered shapes of the ribs while the dimpled rib case gave the highest heat transfer coefficient while the grooved rib presented the highest performance index.

Protein diffraction experiments with Atlas CCD detector

Czech Academy of Sciences Publication Activity Database

Dohnálek, Jan; Kovaľ, Tomáš; Dušek, Michal

2008-01-01

Roč. 64, Suppl. - abstracts (2008), C192 ISSN 0108-7673. [Congress of the International Union of Crystallography (IUCr) /21./. 23.08.2008-31.08.2008, Osaka] Institutional research plan: CEZ:AV0Z10100521 Keywords : x-ray data collection * CCD detectors * protein crystallography applications Subject RIV: BM - Solid Matter Physics ; Magnetism

Discussion on the fusing methods for HR and CCD images of CBERS

International Nuclear Information System (INIS)

Gao Zhangsheng; Zhao Yingjun

2010-01-01

CBERS-02B multi-spectral CCD data are different from HR panchromatic data in resolution, which causes difficulty in image fusion. With the method of Pansharping, HPF, Brovey transform, IHS transform, principal component transform, Gram Schmidt (GS) transform and wavelet transform, the authors have tested the fusion methods for CCD data and HR data of CBERS, and the fusion results are discussed and evaluated qualitatively and quantitatively. (authors)

CCD developed for scientific application by Hamamatsu

CERN Document Server

Miyaguchi, K; Dezaki, J; Yamamoto, K

1999-01-01

We have developed CCDs for scientific applications that feature a low readout noise of less than 5 e-rms and low dark current of 10-25 pA/cm sup 2 at room temperature. CCDs with these characteristics will prove extremely useful in applications such as spectroscopic measurement and dental radiography. In addition, a large-area CCD of 2kx4k pixels and 15 mu m square pixel size has recently been completed for optical use in astronomical observations. Applications to X-ray astronomy require the most challenging device performance in terms of deep depletion, high CTE, and focal plane size, among others. An abuttable X-ray CCD, having 1024x1024 pixels and 24 mu m square pixel size, is to be installed in an international space station (ISS). We are now striving to achieve the lowest usable cooling temperature by means of a built-in TEC with limited power consumption. Details on the development status are described in this report. We would also like to present our future plans for a large active area and deep depleti...

High performance CCD camera system for digitalisation of 2D DIGE gels.

Science.gov (United States)

Strijkstra, Annemieke; Trautwein, Kathleen; Roesler, Stefan; Feenders, Christoph; Danzer, Daniel; Riemenschneider, Udo; Blasius, Bernd; Rabus, Ralf

2016-07-01

An essential step in 2D DIGE-based analysis of differential proteome profiles is the accurate and sensitive digitalisation of 2D DIGE gels. The performance progress of commercially available charge-coupled device (CCD) camera-based systems combined with light emitting diodes (LED) opens up a new possibility for this type of digitalisation. Here, we assessed the performance of a CCD camera system (Intas Advanced 2D Imager) as alternative to a traditionally employed, high-end laser scanner system (Typhoon 9400) for digitalisation of differential protein profiles from three different environmental bacteria. Overall, the performance of the CCD camera system was comparable to the laser scanner, as evident from very similar protein abundance changes (irrespective of spot position and volume), as well as from linear range and limit of detection. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Technical challenges and recent progress in CCD imagers

International Nuclear Information System (INIS)

Bosiers, Jan T.; Peters, Inge M.; Draijer, Cees; Theuwissen, Albert

2006-01-01

This paper gives a review of the performance of charge-coupled device (CCD) imagers for use in consumer, professional and scientific applications. An overview of recent developments and the current state-of-the-art are presented. An extensive list of references is included

CCD [charge-coupled device] sensors in synchrotron x-ray detectors

International Nuclear Information System (INIS)

Strauss, M.G.; Naday, I.; Sherman, I.S.; Kraimer, M.R.; Westbrook, E.M.; Zaluzec, N.J.

1987-01-01

The intense photon flux from advanced synchrotron light sources, such as the 7-GeV synchrotron being designed at Argonne, require integrating-type detectors. Charge-coupled devices (CCDs) are well suited as synchrotron x-ray detectors. When irradiated indirectly via a phosphor followed by reducing optics, diffraction patterns of 100 cm 2 can be imaged on a 2 cm 2 CCD. With a conversion efficiency of ∼1 CCD electron/x-ray photon, a peak saturation capacity of >10 6 x rays can be obtained. A programmable CCD controller operating at a clock frequency of 20 MHz has been developed. The readout rate is 5 x 10 6 pixels/s and the shift rate in the parallel registers is 10 6 lines/s. The test detector was evaluated in two experiments. In protein crystallography diffraction patterns have been obtained from a lysozyme crystal using a conventional rotating anode x-ray generator. Based on these results we expect to obtain at a synchrotron diffraction images at the rate of ∼1 frame/s or a complete 3-dimensional data set from a single crystal in ∼2 min. 16 refs., 16 figs., 2 tabs

Intensified CCD for ultrafast diagnostics

International Nuclear Information System (INIS)

Cheng, J.; Tripp, G.; Coleman, L.

1978-01-01

Many of the present laser fusion diagnostics are recorded on either ultrafast streak cameras or on oscilloscopes. For those experiments in which a large volume of data is accumulated, direct computer processing of the information becomes important. We describe an approach which uses a RCA 52501 back-thinned CCD sensor to obtain direct electron readouts for both the streak camera and the CRT. Performance of the 100 GHz streak camera and the 4 GHz CRT are presented. Design parameters and computer interfacing for both systems are described in detail

Proton radiation damage assessment of a CCD for use in a Ultraviolet and Visible Spectrometer

International Nuclear Information System (INIS)

Gow, J.P.D.; Mason, J.; Leese, M.; Patel, M.; Hathi, B.

2017-01-01

This paper describes the radiation environment and radiation damage analysis performed for the Nadir and Occultation for MArs Discovery (NOMAD) Ultraviolet and Visible Spectrometer (UVIS) channel launched onboard the ExoMars Trace Gas Orbiter (TGO) in 2016. The aim of the instrument is to map the temporal and spatial variation of trace gases such as ozone and dust/cloud aerosols in the atmosphere of Mars. The instrument consists of a set of two miniature telescope viewing optics which allow for selective input onto the optical bench, where an e2v technologies CCD30-11 will be used as the detector. A Geometry Description Markup Language model of the spacecraft and instrument box was created and through the use of ESA's SPace ENVironment Information System (SPENVIS) an estimate of the 10 MeV equivalent proton fluence was made at a number of radiation sensitive regions within NOMAD, including that of the CCD30-11 which is the focus of this paper. The end of life 10 MeV equivalent proton fluence at the charge coupled device was estimated to be 4.7 × 10 9 protons.cm −2 ; three devices were irradiated at different levels up a 10 MeV equivalent fluence of 9.4 × 10 9 protons.cm −2 . The dark current, charge transfer inefficiency, charge storage, and cosmetic quality of the devices was investigated pre- and post-irradiation, determining that the devices will continue to provide excellent science throughout the mission.

Surface dynamics of voltage-gated ion channels

Science.gov (United States)

Heine, Martin; Ciuraszkiewicz, Anna; Voigt, Andreas; Heck, Jennifer; Bikbaev, Arthur

2016-01-01

ABSTRACT Neurons encode information in fast changes of the membrane potential, and thus electrical membrane properties are critically important for the integration and processing of synaptic inputs by a neuron. These electrical properties are largely determined by ion channels embedded in the membrane. The distribution of most ion channels in the membrane is not spatially uniform: they undergo activity-driven changes in the range of minutes to days. Even in the range of milliseconds, the composition and topology of ion channels are not static but engage in highly dynamic processes including stochastic or activity-dependent transient association of the pore-forming and auxiliary subunits, lateral diffusion, as well as clustering of different channels. In this review we briefly discuss the potential impact of mobile sodium, calcium and potassium ion channels and the functional significance of this for individual neurons and neuronal networks. PMID:26891382

Quantitative Determination of Nicotine in a PDMS Microfluidic Channel Using Surface Enhanced Raman Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Jung, Jae Hyun; Choo, Jae Bum [Hanyang University, Ansan (Korea, Republic of); Kim, Duck Joong [Dankook University, Cheonan (Korea, Republic of); Lee, Sang Hoon [Korea University, Seoul (Korea, Republic of)

2006-02-15

Rapid and highly sensitive determination of nicotine in a PDMS microfluidic channel was investigated using surface enhanced Raman spectroscopy (SERS). A three-dimensional PDMS microfluidic channel was fabricated for this purpose. This channel shows a high mixing efficiency because the transverse and vertical dispersions of the fluid occur simultaneously through the upper and lower zig zag-type blocks. A higher efficiency of mixing could also be obtained by splitting each of the confluent streams into two sub-streams that then joined and recombined. The SERS signal was measured after nicotine molecules were effectively adsorbed onto silver nanoparticles by passing through the three-dimensional channel. A quantitative analysis of nicotine was performed based on the measured peak area at 1030 cm{sup -1}. The detection limit was estimated to be below 0.1 ppm. In this work, the SERS detection, in combination with a PDMS microfluidic channel, has been applied to the quantitative analysis of nicotine in aqueous solution. Compared to the other conventional analytical methods, the detection sensitivity was enhanced up to several orders of magnitude.

Measurement of phase function of aerosol at different altitudes by CCD Lidar

Science.gov (United States)

Sun, Peiyu; Yuan, Ke'e.; Yang, Jie; Hu, Shunxing

2018-02-01

The aerosols near the ground are closely related to human health and climate change, the study on which has important significance. As we all know, the aerosol is inhomogeneous at different altitudes, of which the phase function is also different. In order to simplify the retrieval algorithm, it is usually assumed that the aerosol is uniform at different altitudes, which will bring measurement error. In this work, an experimental approach is demonstrated to measure the scattering phase function of atmospheric aerosol particles at different heights by CCD lidar system, which could solve the problem of the traditional CCD lidar system in assumption of phase function. The phase functions obtained by the new experimental approach are used to retrieve the aerosol extinction coefficient profiles. By comparison of the aerosol extinction coefficient retrieved by Mie-scattering aerosol lidar and CCD lidar at night, the reliability of new experimental approach is verified.

Design principles and applications of a cooled CCD camera for electron microscopy.

Science.gov (United States)

Faruqi, A R

1998-01-01

Cooled CCD cameras offer a number of advantages in recording electron microscope images with CCDs rather than film which include: immediate availability of the image in a digital format suitable for further computer processing, high dynamic range, excellent linearity and a high detective quantum efficiency for recording electrons. In one important respect however, film has superior properties: the spatial resolution of CCD detectors tested so far (in terms of point spread function or modulation transfer function) are inferior to film and a great deal of our effort has been spent in designing detectors with improved spatial resolution. Various instrumental contributions to spatial resolution have been analysed and in this paper we discuss the contribution of the phosphor-fibre optics system in this measurement. We have evaluated the performance of a number of detector components and parameters, e.g. different phosphors (and a scintillator), optical coupling with lens or fibre optics with various demagnification factors, to improve the detector performance. The camera described in this paper, which is based on this analysis, uses a tapered fibre optics coupling between the phosphor and the CCD and is installed on a Philips CM12 electron microscope equipped to perform cryo-microscopy. The main use of the camera so far has been in recording electron diffraction patterns from two dimensional crystals of bacteriorhodopsin--from wild type and from different trapped states during the photocycle. As one example of the type of data obtained with the CCD camera a two dimensional Fourier projection map from the trapped O-state is also included. With faster computers, it will soon be possible to undertake this type of work on an on-line basis. Also, with improvements in detector size and resolution, CCD detectors, already ideal for diffraction, will be able to compete with film in the recording of high resolution images.

Pore channel surface modification for enhancing anti-fouling membrane distillation

Science.gov (United States)

Qiu, Haoran; Peng, Yuelian; Ge, Lei; Villacorta Hernandez, Byron; Zhu, Zhonghua

2018-06-01

Membrane surface modification by forming a functional layer is an effective way to improve the anti-fouling properties of membranes; however, the additional layer and the potential blockage of bulk pores may increase the mass transfer resistance and reduce the permeability. In this study, we applied a novel method of preparing anti-fouling membranes for membrane distillation by dispersing graphene oxide (GO) on the channel surface of polyvinylidene fluoride membranes. The surface morphology and properties were characterized by scanning electron microscopy, atomic force microscope, and Fourier transform infrared spectrometry. Compared to the membrane surface modification by nanoparticles (e.g. SiO2), GO was mainly located on the pore surface of the membrane bulk, rather than being formed as an individual layer onto the membrane surface. The performance was evaluated via a direct-contact membrane distillation process with anionic and cationic surfactants as the foulants, separately. Compared to the pristine PVDF membrane, the anti-fouling behavior and distillate flux of the GO-modified membranes were improved, especially when using the anionic surfactant as the foulant. The enhanced anti-fouling performance can be attributed to the oxygen containing functional groups in GO and the healing of the membrane pore defects. This method may provide an effective route to manipulate membrane pore surface properties for anti-fouling separation without increasing mass transfer resistance.

Distribution of small channels on the Martian surface

Science.gov (United States)

Pieri, D.

1976-01-01

The distribution of small channels on Mars has been mapped from Mariner 9 images at the 1:5,000,000 scale. The small channels referred to here are small valleys ranging in width from the resolution limit of the Mariner 9 wide-angle images (about 1 km) to about 10 km. The greatest density of small channels occurs in dark cratered terrain. This dark zone forms a broad subequatorial band around the planet. The observed distribution may be the result of decreased small-channel visibility in bright areas due to obscuration by a high albedo dust or sediment mantle. Crater densities within two small-channel segments show crater size-frequency distributions consistent with those of the oldest of the heavily cratered plains units. Such crater densities coupled with the almost exclusive occurrence of small channels in old cratered terrain and the generally degraded appearance of small channels in the high-resolution images (about 100 m) imply a major episode of small-channel formation early in Martian geologic history.

Suppression of surface-originated gate lag by a dual-channel AlN/GaN high electron mobility transistor architecture

Science.gov (United States)

Deen, David A.; Storm, David F.; Scott Katzer, D.; Bass, R.; Meyer, David J.

2016-08-01

A dual-channel AlN/GaN high electron mobility transistor (HEMT) architecture is demonstrated that leverages ultra-thin epitaxial layers to suppress surface-related gate lag. Two high-density two-dimensional electron gas (2DEG) channels are utilized in an AlN/GaN/AlN/GaN heterostructure wherein the top 2DEG serves as a quasi-equipotential that screens potential fluctuations resulting from distributed surface and interface states. The bottom channel serves as the transistor's modulated channel. Dual-channel AlN/GaN heterostructures were grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. HEMTs fabricated with 300 nm long recessed gates demonstrated a gate lag ratio (GLR) of 0.88 with no degradation in drain current after bias stressed in subthreshold. These structures additionally achieved small signal metrics ft/fmax of 27/46 GHz. These performance results are contrasted with the non-recessed gate dual-channel HEMT with a GLR of 0.74 and 82 mA/mm current collapse with ft/fmax of 48/60 GHz.

Development of online cable eccentricity detection system based on X-ray CCD

International Nuclear Information System (INIS)

Chen Jianzhen; Li Bin; Wei Kaixia; Guo Lanying; Qu Guopu

2008-01-01

An improved technology of online cable eccentricity detection, based on X-ray CCD, greatly improves the measuring precision and the responding speed. The theory of eccentricity measuring based on X-ray CCD, and the structure of an apparatus are described. The apparatus is composed of scanning drive subsystem, X-ray generation components, data acquiring subsystem and high performance computer system. The measuring results are also presented. The features of this cable eccentricity detection technology are compared with the features of other technologies. (authors)

Development of a Portable 3CCD Camera System for Multispectral Imaging of Biological Samples

Science.gov (United States)

Lee, Hoyoung; Park, Soo Hyun; Noh, Sang Ha; Lim, Jongguk; Kim, Moon S.

2014-01-01

Recent studies have suggested the need for imaging devices capable of multispectral imaging beyond the visible region, to allow for quality and safety evaluations of agricultural commodities. Conventional multispectral imaging devices lack flexibility in spectral waveband selectivity for such applications. In this paper, a recently developed portable 3CCD camera with significant improvements over existing imaging devices is presented. A beam-splitter prism assembly for 3CCD was designed to accommodate three interference filters that can be easily changed for application-specific multispectral waveband selection in the 400 to 1000 nm region. We also designed and integrated electronic components on printed circuit boards with firmware programming, enabling parallel processing, synchronization, and independent control of the three CCD sensors, to ensure the transfer of data without significant delay or data loss due to buffering. The system can stream 30 frames (3-waveband images in each frame) per second. The potential utility of the 3CCD camera system was demonstrated in the laboratory for detecting defect spots on apples. PMID:25350510

Heat transport and surface heat transfer with helium in rotating channels

International Nuclear Information System (INIS)

Schnapper, C.

1978-06-01

Heat transport and surface heat transfer with helium in rotating radially arranged channels were experimentally studied with regard to cooling of large turbogenerators with superconducting windings. Measurements with thermosiphon and thermosiphon loops of different channel diameters were performed, and results are presented. The thermodynamic state of the helium in a rotating thermosiphon and the mass flow rate in a thermosiphon loop is characterized by formulas. Heat transport by directed convection in thermosiphon loops is found to be more efficient 12 cm internal convection in thermosiphons. Steady state is reached sooner in thermosiphon loops than in thermosiphons, when heat load suddenly changes. In a very large centrifugal field single-phase heat transfer with natural and forced convection is described by similar formulas which are also applicable 10 thermosiphons in gravitation field or to heat transfer to non-rotating helium. (orig.) [de

A Demosaicking Algorithm with Adaptive Inter-Channel Correlation

Directory of Open Access Journals (Sweden)

Joan Duran

2015-12-01

Full Text Available Most common cameras use a CCD sensor device measuring a single color per pixel. Demosaicking is the interpolation process by which one can infer a full color image from such a matrix of values, thus interpolating the two missing components per pixel. Most demosaicking methods take advantage of inter-channel correlation locally selecting the best interpolation direction. The obtained results look convincing except when local geometry cannot be inferred from neighboring pixels or channel correlation is low. In these cases, these algorithms create interpolation artifacts such as zipper effect or color aliasing. This paper discusses the implementation details of the algorithm proposed in [J. Duran, A. Buades, ``Self-Similarity and Spectral Correlation Adaptive Algorithm for Color Demosaicking'', IEEE Transactions on Image Processing, 23(9, pp. 4031--4040, 2014]. The proposed method involves nonlocal image self-similarity in order to reduce interpolation artifacts when local geometry is ambiguous. It further introduces a clear and intuitive manner of balancing how much channel-correlation must be taken advantage of.

Hand Motion Classification Using a Multi-Channel Surface Electromyography Sensor

Directory of Open Access Journals (Sweden)

Dong Sun

2012-01-01

Full Text Available The human hand has multiple degrees of freedom (DOF for achieving high-dexterity motions. Identifying and replicating human hand motions are necessary to perform precise and delicate operations in many applications, such as haptic applications. Surface electromyography (sEMG sensors are a low-cost method for identifying hand motions, in addition to the conventional methods that use data gloves and vision detection. The identification of multiple hand motions is challenging because the error rate typically increases significantly with the addition of more hand motions. Thus, the current study proposes two new methods for feature extraction to solve the problem above. The first method is the extraction of the energy ratio features in the time-domain, which are robust and invariant to motion forces and speeds for the same gesture. The second method is the extraction of the concordance correlation features that describe the relationship between every two channels of the multi-channel sEMG sensor system. The concordance correlation features of a multi-channel sEMG sensor system were shown to provide a vast amount of useful information for identification. Furthermore, a new cascaded-structure classifier is also proposed, in which 11 types of hand gestures can be identified accurately using the newly defined features. Experimental results show that the success rate for the identification of the 11 gestures is significantly high.

Hand motion classification using a multi-channel surface electromyography sensor.

Science.gov (United States)

Tang, Xueyan; Liu, Yunhui; Lv, Congyi; Sun, Dong

2012-01-01

The human hand has multiple degrees of freedom (DOF) for achieving high-dexterity motions. Identifying and replicating human hand motions are necessary to perform precise and delicate operations in many applications, such as haptic applications. Surface electromyography (sEMG) sensors are a low-cost method for identifying hand motions, in addition to the conventional methods that use data gloves and vision detection. The identification of multiple hand motions is challenging because the error rate typically increases significantly with the addition of more hand motions. Thus, the current study proposes two new methods for feature extraction to solve the problem above. The first method is the extraction of the energy ratio features in the time-domain, which are robust and invariant to motion forces and speeds for the same gesture. The second method is the extraction of the concordance correlation features that describe the relationship between every two channels of the multi-channel sEMG sensor system. The concordance correlation features of a multi-channel sEMG sensor system were shown to provide a vast amount of useful information for identification. Furthermore, a new cascaded-structure classifier is also proposed, in which 11 types of hand gestures can be identified accurately using the newly defined features. Experimental results show that the success rate for the identification of the 11 gestures is significantly high.

The OCA CCD Camera Controller

Science.gov (United States)

1996-01-01

multi CCD arrays for wide field telescopes with an array of 8x8 1K CCDs in use at Las Campanas Observatory in Chile . The same group is also involved...Verify key EPROM -292H VIH . VIH Program security bitl 1 29AH . VPP Program security’ bit 2 *. .298H -Vpp Verify security bits - 9HVIH ViI NOTE: 1...Pulsed from V.. to VIL and returned to VIH . EPROM PROGRAMMING AND VERIFICATION ..t= 21’C to-+27 ’rC:-VCC= 5V ±10%VS3 = OV. SYMBOL I .-- PARAMETER MIN MAX

Effect of Channel Orientation and Rib Pitch-to-Height Ratio on Pressure Drop in a Rotating Square Channel with Ribs on Two Opposite Surfaces

Directory of Open Access Journals (Sweden)

Prabhu S. V.

2005-01-01

Full Text Available The effect of channel orientation and rib pitch-to-height ratio on the pressure drop distribution in a rib-roughened channel is an important issue in turbine blade cooling. The present investigation is a study of the overall pressure drop distribution in a square cross-sectioned channel, with rib turbulators, rotating about an axis normal to the free stream. The ribs are configured in a symmetric arrangement on two opposite surfaces with a rib angle of 90 ∘ to the mainstream flow. The study has been conducted for three Reynolds numbers, namely, 13 000, 17 000, and 22 000 with the rotation number varying from 0– 0.38 . Experiments have been carried out for various rib pitch-to-height ratios ( P/e with a constant rib height-to-hydraulic diameter ratio ( e/D of 0.1 . The test section in which the ribs are placed on the leading and trailing surfaces is considered as the base case ( orientation angle= 0 ∘ , Coriolis force vector normal to the ribbed surfaces. The channel is turned about its axis in steps of 15 ∘ to vary the orientation angle from 0 ∘ to 90 ∘ . The overall pressure drop does not change considerably under conditions of rotation for the base case. However, for the other cases tested, it is observed that the overall pressure drop increases with an increase in the rotation number for a given orientation angle and also increases with an increase in the orientation angle for a given rotation number. This change is attributed to the variation in the separation zone downstream of the ribs due to the presence of the Coriolis force—local pressure drop data is presented which supports this idea. At an orientation angle of 90 ∘ (ribs on the top and bottom surfaces, Coriolis force vector normal to the smooth surfaces, the overall pressure drop is observed to be maximum during rotation. The overall pressure drop for a case with a rib pitch-to-height ratio of 5 on both surfaces is found to be the highest

Micrometer and CCD measurements of double stars (Series 51

Directory of Open Access Journals (Sweden)

Popović G.M.

1998-01-01

Full Text Available 36 micrometric measurements of 20 double or multiple systems carried out with the Zeiss 65/1055 cm Refractor of Belgrade Observatory are communicated. Also 35 CCD measurements of 15 double or multiple systems are included.

Channeling effect in electronic spectra produced by grazing impact of fast protons on insulator surfaces

Energy Technology Data Exchange (ETDEWEB)

Archubi, C D; Gravielle, M S, E-mail: archubi@iafe.uba.a, E-mail: msilvia@iafe.uba.a [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, 1428, Buenos Aires (Argentina)

2009-11-01

Electron emission due to grazing scattering of fast protons from LiF and KCl surfaces is studied under axial incidence conditions. The differential emission probability is calculated within a distorted-wave formalism, taking into account axial channeled trajectories. For different emission angles, electronic spectra for proton incidence along the two principal crystal axes ([100] and [110]) are compared with those corresponding to an impact velocity in a random direction, finding effects associated with the channeling conditions.

STIS-01 CCD Functional

Science.gov (United States)

Valenti, Jeff

2001-07-01

This activity measures the baseline performance and commandability of the CCD subsystem. Only primary amplifier D is used. Bias, Dark, and Flat Field exposures are taken in order to measure read noise, dark current, CTE, and gain. Numerous bias frames are taken to permit construction of "superbias" frames in which the effects of read noise have been rendered negligible. Dark exposures are made outside the SAA. Full frame and binned observations are made, with binning factors of 1x1 and 2x2. Finally, tungsten lamp exposures are taken through narrow slits to confirm the slit positions in the current database. All exposures are internals. This is a reincarnation of SM3A proposal 8502 with some unnecessary tests removed from the program.

Two-dimensional spectrophotometry of planetary nebulae by CCD imaging

International Nuclear Information System (INIS)

Jacoby, G.H.; Africano, J.L.; Quigley, R.J.; Western Washington Univ., Bellingham, WA)

1987-01-01

The spatial distribution of the electron temperature and density and the ionic abundances of O(+), O(2+), N(+), and S(+) have been derived from CCD images of the planetary nebulae NGC 40 and NGC 6826 taken in the important emission lines of forbidden O II, forbidden O III, H-beta, forbidden N II, and forbidden S II. The steps required in the derivation of the absolute fluxes, line, ratios, and ionic abundances are outlined and then discussed in greater detail. The results show that the CCD imaging technique for two-dimensional spectrophotometry can effectively compete with classical spectrophotometry, providing the added benefits of complete spatial coverage at seeing-disk spatial resolution. The multiplexing in the spatial dimension, however, results in a loss of spectral information, since only one emission line is observed at any one time. 37 references

Experimental and numerical study on heat transfer and pressure drop performance of Cross-Wavy primary surface channel

International Nuclear Information System (INIS)

Ma, Ting; Du, Lin-xiu; Sun, Ning; Zeng, Min; Sundén, Bengt; Wang, Qiu-wang

2016-01-01

Highlights: • Naphthalene sublimation experiments were performed for Cross-Wavy channels. • Entrance region has a small effect on unit-averaged heat transfer coefficient of Cross-Wavy channels. • Correlations of Nusselt number and friction factor in Cross-Wavy channel were obtained. • Similar Cross-Wavy channels have similar thermal hydraulic performance. - Abstract: The Cross-Wavy primary surface heat exchanger is one of the most promising candidates for microturbine recuperators. In this paper, naphthalene sublimation experiments are performed for Cross-Wavy channels in a wind tunnel. The experimental results indicate that the entrance region has a small effect on the unit-averaged heat transfer coefficient of whole Cross-Wavy channels. Correlations of Nusselt number and friction factor in the Cross-Wavy channel are obtained. However, only the Cross-Wavy channel with a large equivalent diameter is tested because the actual Cross-Wavy channels are very complicated and small. Therefore, based on the similarity rules, five Cross-Wavy channels with similar structures but different equivalent diameters are further investigated by numerical simulations. The numerical results indicate that the Cross-Wavy channels with similar structures but different equivalent diameters have similar thermal-hydraulic performance in the studied Reynolds number range.

The study of contamination of discharged runoff from surface water disposal channels of Bushehr city in 2012-2013

Directory of Open Access Journals (Sweden)

Vaheid Noroozi-Karbasdehi

2016-09-01

Full Text Available Background: In coastal cities, wastewater discharge into the sea is one of the options for sewage disposal that in case of non-compliance with health standards  in wastewater disposal will be led to the spread of infection and disease. On the other hand, water resources preservation and using them efficiently are the principles of sustainable development of each country. This study was aimed to investigate the contamination of discharged runoff from the surface water disposal channels of Bushehr city in 2012 - 13. Materials and Methods: In this study, Sampling was conducted by composite sampling method from output of the five main surface water disposal channels leading to the Persian Gulf located in the coastal region of Bushehr city during two seasons including wet (winter and dry (summer in 2012- 13. Then, experimental tests of BOD5, total coliform and fecal coliform were done on any of the 96 samples according to the standard method. Results: Analysis of the data showed that the BOD5, total coliform and fecal coliform of effluent runoff of the channels were more than the national standard output of disposal wastewaters into the surface waters, and the highest and lowest amount of BOD5 which obtained were 160 mg/L and 28 mg/L, respectively. Conclusion: considering the fact that discharged runoff from surface water disposal channels link from shoreline to sea in close distance and they often are as natural swimming sites and even fishing sites of Bushehr city, and also according to high level of organic and bacterial load of these channels, it is urgently required to be considered by the authorities.

A fluorescent screen + CCD system for quality assurance of therapeutic scanned ion beams

Energy Technology Data Exchange (ETDEWEB)

Takeshita, E., E-mail: eriuli@nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Furukawa, T., E-mail: t_furu@nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Inaniwa, T., E-mail: taku@nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Sato, S., E-mail: shin_s@nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Himukai, T., E-mail: himukai@nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Shirai, T., E-mail: t_shirai@nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Noda, K., E-mail: noda_k@nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan)

2011-12-15

A fluorescent screen + a charge coupled device (CCD) system were developed to verify the performance of scanned ion beams at the HIMAC. The fluorescent light from the screen is observed by the CCD camera. Two-dimensional fields, produced by the scanning process, i.e., the position and the size of the beam for each scan, represent of the important issues in scanning irradiation. In the developed system, the two-dimensional relative fluence and the flatness of the irradiation field were measured in a straightforward technique from the luminance distribution on the screen. The position and the size of the beams were obtained from centroid computation results of the brightness. By the good sensitivity and spatial resolution of the fluorescent screen + CCD system, the scanned ion beams were verified as the measurements at the HIMAC prototype scanning system.

A fluorescent screen + CCD system for quality assurance of therapeutic scanned ion beams

Science.gov (United States)

Takeshita, E.; Furukawa, T.; Inaniwa, T.; Sato, S.; Himukai, T.; Shirai, T.; Noda, K.

2011-12-01

A fluorescent screen + a charge coupled device (CCD) system were developed to verify the performance of scanned ion beams at the HIMAC. The fluorescent light from the screen is observed by the CCD camera. Two-dimensional fields, produced by the scanning process, i.e., the position and the size of the beam for each scan, represent of the important issues in scanning irradiation. In the developed system, the two-dimensional relative fluence and the flatness of the irradiation field were measured in a straightforward technique from the luminance distribution on the screen. The position and the size of the beams were obtained from centroid computation results of the brightness. By the good sensitivity and spatial resolution of the fluorescent screen + CCD system, the scanned ion beams were verified as the measurements at the HIMAC prototype scanning system.

SlCCD7 controls strigolactone biosynthesis, shoot branching and mycorrhiza-induced apocarotenoid formation in tomato.

NARCIS (Netherlands)

Vogel, J.T.; Walter, M.H.; Giavalisco, P.; Lytovchenko, A.; Kohlen, W.; Charnikhova, T.; Simkin, A.J.; Goulet, C.; Strack, D.; Bouwmeester, H.J.; Fernie, A.R.; Klee, H.J.

2010-01-01

The regulation of shoot branching is an essential determinant of plant architecture, integrating multiple external and internal signals. One of the signaling pathways regulating branching involves the MAX (more axillary branches) genes. Two of the genes within this pathway, MAX3/CCD7 and MAX4/CCD8,

Pool Boiling Characteristics on the Microstructure surfaces with Both Rectangular Cavities and Channels

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Eok; Myung, Byung-Soo [Kyungpook Nat’l Univ., Daegu (Korea, Republic of); Park, Su Cheong; Yu, Dong In [POSTECH, Pohang (Korea, Republic of); Kim, Moo Hwan [Korea Institute of Nuclear Safety (KINS), Daejeon (Korea, Republic of); Ahn, Ho Seon [Incheon Nat’l Univ., Incheon (Korea, Republic of)

2016-06-15

Based on a surface design with rectangular cavities and channels, we investigated the effects of gravity and capillary pressure on pool-boiling Critical Heat Flux (CHF). The microcavity structures could prevent liquid flow by the capillary pressure effect. In addition, the microchannel structures contributed to induce one-dimensional liquid flow on the boiling surface. The relationship between the CHF and capillary flow was clearly established. The driving potentials for the liquid supply into a boiling surface can be generated by the gravitational head and capillary pressure. Through an analysis of pool boiling and visualization data, we reveal that the liquid supplement to maintain the nucleate boiling condition on a boiling surface is closely related to the gravitational pressure head and capillary pressure effect.

OP09O-OP404-9 Wide Field Camera 3 CCD Quantum Efficiency Hysteresis

Science.gov (United States)

Collins, Nick

2009-01-01

The HST/Wide Field Camera (WFC) 3 UV/visible channel CCD detectors have exhibited an unanticipated quantum efficiency hysteresis (QEH) behavior. At the nominal operating temperature of -83C, the QEH feature contrast was typically 0.1-0.2% or less. The behavior was replicated using flight spare detectors. A visible light flat-field (540nm) with a several times full-well signal level can pin the detectors at both optical (600nm) and near-UV (230nm) wavelengths, suppressing the QEH behavior. We are characterizing the timescale for the detectors to become unpinned and developing a protocol for flashing the WFC3 CCDs with the instrument's internal calibration system in flight. The HST/Wide Field Camera 3 UV/visible channel CCD detectors have exhibited an unanticipated quantum efficiency hysteresis (QEH) behavior. The first observed manifestation of QEH was the presence in a small percentage of flat-field images of a bowtie-shaped contrast that spanned the width of each chip. At the nominal operating temperature of -83C, the contrast observed for this feature was typically 0.1-0.2% or less, though at warmer temperatures contrasts up to 5% (at -50C) have been observed. The bowtie morphology was replicated using flight spare detectors in tests at the GSFC Detector Characterization Laboratory by power cycling the detector while cold. Continued investigation revealed that a clearly-related global QE suppression at the approximately 5% level can be produced by cooling the detector in the dark; subsequent flat-field exposures at a constant illumination show asymptotically increasing response. This QE "pinning" can be achieved with a single high signal flat-field or a series of lower signal flats; a visible light (500-580nm) flat-field with a signal level of several hundred thousand electrons per pixel is sufficient for QE pinning at both optical (600nm) and near-UV (230nm) wavelengths. We are characterizing the timescale for the detectors to become unpinned and developing a

Suppression of surface-originated gate lag by a dual-channel AlN/GaN high electron mobility transistor architecture

International Nuclear Information System (INIS)

Deen, David A.; Storm, David F.; Scott Katzer, D.; Bass, R.; Meyer, David J.

2016-01-01

A dual-channel AlN/GaN high electron mobility transistor (HEMT) architecture is demonstrated that leverages ultra-thin epitaxial layers to suppress surface-related gate lag. Two high-density two-dimensional electron gas (2DEG) channels are utilized in an AlN/GaN/AlN/GaN heterostructure wherein the top 2DEG serves as a quasi-equipotential that screens potential fluctuations resulting from distributed surface and interface states. The bottom channel serves as the transistor's modulated channel. Dual-channel AlN/GaN heterostructures were grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. HEMTs fabricated with 300 nm long recessed gates demonstrated a gate lag ratio (GLR) of 0.88 with no degradation in drain current after bias stressed in subthreshold. These structures additionally achieved small signal metrics f_t/f_m_a_x of 27/46 GHz. These performance results are contrasted with the non-recessed gate dual-channel HEMT with a GLR of 0.74 and 82 mA/mm current collapse with f_t/f_m_a_x of 48/60 GHz.

Suppression of surface-originated gate lag by a dual-channel AlN/GaN high electron mobility transistor architecture

Energy Technology Data Exchange (ETDEWEB)

Deen, David A., E-mail: david.deen@alumni.nd.edu; Storm, David F.; Scott Katzer, D.; Bass, R.; Meyer, David J. [Naval Research Laboratory, Electronics Science and Technology Division, Washington, DC 20375 (United States)

2016-08-08

A dual-channel AlN/GaN high electron mobility transistor (HEMT) architecture is demonstrated that leverages ultra-thin epitaxial layers to suppress surface-related gate lag. Two high-density two-dimensional electron gas (2DEG) channels are utilized in an AlN/GaN/AlN/GaN heterostructure wherein the top 2DEG serves as a quasi-equipotential that screens potential fluctuations resulting from distributed surface and interface states. The bottom channel serves as the transistor's modulated channel. Dual-channel AlN/GaN heterostructures were grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. HEMTs fabricated with 300 nm long recessed gates demonstrated a gate lag ratio (GLR) of 0.88 with no degradation in drain current after bias stressed in subthreshold. These structures additionally achieved small signal metrics f{sub t}/f{sub max} of 27/46 GHz. These performance results are contrasted with the non-recessed gate dual-channel HEMT with a GLR of 0.74 and 82 mA/mm current collapse with f{sub t}/f{sub max} of 48/60 GHz.

New low noise CCD cameras for Pi-of-the-Sky project

Science.gov (United States)

Kasprowicz, G.; Czyrkowski, H.; Dabrowski, R.; Dominik, W.; Mankiewicz, L.; Pozniak, K.; Romaniuk, R.; Sitek, P.; Sokolowski, M.; Sulej, R.; Uzycki, J.; Wrochna, G.

2006-10-01

Modern research trends require observation of fainter and fainter astronomical objects on large areas of the sky. This implies usage of systems with high temporal and optical resolution with computer based data acquisition and processing. Therefore Charge Coupled Devices (CCD) became so popular. They offer quick picture conversion with much better quality than film based technologies. This work is theoretical and practical study of the CCD based picture acquisition system. The system was optimized for "Pi of The Sky" project. But it can be adapted to another professional astronomical researches. The work includes issue of picture conversion, signal acquisition, data transfer and mechanical construction of the device.

Binding modes and functional surface of anti-mammalian scorpion α-toxins to sodium channels.

Science.gov (United States)

Chen, Rong; Chung, Shin-Ho

2012-10-02

Scorpion α-toxins bind to the voltage-sensing domains of voltage-gated sodium (Na(V)) channels and interfere with the inactivation mechanisms. The functional surface of α-toxins has been shown to contain an NC-domain consisting of the five-residue turn (positions 8-12) and the C-terminus (positions 56-64) and a core-domain centered on the residue 18. The NC- and core-domains are interconnected by the linker-domain (positions 8-18). Here with atomistic molecular dynamics simulations, we examine the binding modes between two α-toxins, the anti-mammalian AahII and the anti-insect LqhαIT, and the voltage-sensing domain of rat Na(V)1.2, a subtype of Na(V) channels expressed in nerve cells. Both toxins are docked to the extracellular side of the voltage-sensing domain of Na(V)1.2 using molecular dynamics simulations, with the linker-domain assumed to wedge into the binding pocket. Several salt bridges and hydrophobic clusters are observed to form between the NC- and core-domains of the toxins and Na(V)1.2 and stabilize the toxin-channel complexes. The binding modes predicted are consistent with available mutagenesis data and can readily explain the relative affinities of AahII and LqhαIT for Na(V)1.2. The dissociation constants for the two toxin-channel complexes are derived, which compare favorably with experiment. Our models demonstrate that the functional surface of anti-mammalian scorpion α-toxins is centered on the linker-domain, similar to that of β-toxins.

Numerical simulations and analyses of temperature control loop heat pipe for space CCD camera

Science.gov (United States)

Meng, Qingliang; Yang, Tao; Li, Chunlin

2016-10-01

As one of the key units of space CCD camera, the temperature range and stability of CCD components affect the image's indexes. Reasonable thermal design and robust thermal control devices are needed. One kind of temperature control loop heat pipe (TCLHP) is designed, which highly meets the thermal control requirements of CCD components. In order to study the dynamic behaviors of heat and mass transfer of TCLHP, particularly in the orbital flight case, a transient numerical model is developed by using the well-established empirical correlations for flow models within three dimensional thermal modeling. The temperature control principle and details of mathematical model are presented. The model is used to study operating state, flow and heat characteristics based upon the analyses of variations of temperature, pressure and quality under different operating modes and external heat flux variations. The results indicate that TCLHP can satisfy the thermal control requirements of CCD components well, and always ensure good temperature stability and uniformity. By comparison between flight data and simulated results, it is found that the model is to be accurate to within 1°C. The model can be better used for predicting and understanding the transient performance of TCLHP.

The development of high-speed 100 fps CCD camera

International Nuclear Information System (INIS)

Hoffberg, M.; Laird, R.; Lenkzsus, F.; Liu, C.; Rodricks, B.

1997-01-01

This paper describes the development of a high-speed CCD digital camera system. The system has been designed to use CCDs from various manufacturers with minimal modifications. The first camera built on this design utilizes a Thomson 512 x 512 pixel CCD as its sensor, which is read out from two parallel outputs at a speed of 15 MHz/pixel/output. The data undergo correlated double sampling after which it is digitized into 12 bits. The throughput of the system translates into 60 MB/second, which is either stored directly in a PC or transferred to a custom-designed VXI module. The PC data acquisition version of the camera can collect sustained data in real time that is limited to the memory installed in the PC. The VXI version of the camera, also controlled by a PC, stores 512 MB of real-time data before it must be read out to the PC disk storage. The uncooled CCD can be used either with lenses for visible light imaging or with a phosphor screen for X-ray imaging. This camera has been tested with a phosphor screen coupled to a fiber-optic face plate for high-resolution, high-speed X-ray imaging. The camera is controlled through a custom event-driven user-friendly Windows package. The pixel clock speed can be changed from 1 to 15 MHz. The noise was measured to be 1.05 bits at a 13.3 MHz pixel clock. This paper will describe the electronics, software, and characterizations that have been performed using both visible and X-ray photons. (orig.)

Application of the CCD Fabry-Perot Annular Summing Technique to Thermospheric O(1)D.

Science.gov (United States)

Coakley, Monica Marie

1995-01-01

This work will detail the verification of the advantages of the Fabry-Perot charge coupled device (CCD) annular summing technique, the development of the technique for analysis of daysky spectra, and the implications of the resulting spectra for neutral temperature and wind measurements in the daysky thermosphere. The daysky spectral feature of interest is the bright (1 kilo-Rayleigh) thermospheric (OI) emission at 6300 A which had been observed in the nightsky in order to determine winds and temperatures in the vicinity of the altitude of 250 km. In the daysky, the emission line sits on top of a bright Rayleigh scattered continuum background which significantly complicates the observation. With a triple etalon Fabry-Perot spectrometer, the continuum background can be reduced while maintaining high throughput and high resolution. The inclusion of a CCD camera results in significant savings in integration time over the two more standard scanning photomultiplier systems that have made the same wind and temperature measurements in the past. A comparable CCD system can experience an order of magnitude savings in integration time over a PMT system. Laboratory and field tests which address the advantages and limitations of both the Fabry-Perot CCD annular summing technique and the daysky CCD imaging are included in Chap. 2 and Chap. 3. With a sufficiently large throughput associated with the spectrometer and a CCD detector, rapid observations (~4 minute integrations) can be made. Extraction of the line width and line center from the daysky near-continuum background is complicated compared to the nightsky case, but possible. Methods of fitting the line are included in Chap. 4. The daysky O ^1D temperatures are consistent with a lower average emission height than predicted by models. The data and models are discussed in Chap. 5. Although some discrepancies exist between resulting temperatures and models, the observations indicate the potential for other direct measurements

Detection for flatness of large surface based on structured light

Science.gov (United States)

He, Wenyan; Cao, Xuedong; Long, Kuang; Peng, Zhang

2016-09-01

In order to get flatness of a large plane, this paper set up a measurement system, composed by Line Structured Light, imaging system, CCD, etc. Line Structured Light transmits parallel fringes at a proper angle onto the plane which is measured; the imaging system and CCD locate above the plane to catch the fringes. When the plane is perfect, CCD will catch straight fringes; however, the real plane is not perfect; according to the theory of projection, the fringes caught by CCD will be distorted by convex and concave. Extract the center of line fringes to obtain the distortion of the fringe, according to the functional relationship between the distortion of fringes and the height which is measured, then we will get flatness of the entire surface. Data from experiment approached the analysis of theory. In the simulation, the vertical resolution is 0.0075 mm per pixel when measuring a plane of 400mm×400mm, choosing the size of CCD 4096×4096, at the angle 85°. Helped by sub-pixel, the precision will get the level of submicron. There are two obvious advantages: method of surface sampling can increase the efficiency for auto-repairing of machines; considering the center of fringe is required mainly in this system, as a consequence, there is no serious demand for back light.

Flatfielding Errors in Strömvil CCD Photometry

Directory of Open Access Journals (Sweden)

Boyle R. P.

2003-12-01

Full Text Available The importance of determining the error of the flat field in CCD photometry is detailed and our methods of doing this are described. We now have reached a precision of 1-1.5 % in our photometry. Color-magnitude diagrams of the open cluster M67 (ours and Laugalys et al. 2003 are compared.

DNS of Turbulent Flow and Heat Transfer in a Channel with Surface Mounted Cubes

NARCIS (Netherlands)

Verstappen, R.W.C.P.; Velde, R.M. van der; Veldman, A.E.P.

2000-01-01

The turbulent flow and heat transfer in a channel with surface mounted cubical obstacles forms a generic example of a problem that occurs in many engineering applications, for instance in the design of cooling devices. We have performed a numerical simulation of it without using any turbulence

DNS of turbulent flow and heat transfer in a channel with surface mounted cubes

NARCIS (Netherlands)

Verstappen, R.W.C.P.; Velde, R.M. van der; Veldman, A.E.P.

2000-01-01

The turbulent flow and heat transfer in a channel with surface mounted cubical obstacles forms a generic example of a problem that occurs in many engineering applications, for instance in the design of cooling devices. We have performed a numerical simulation of it without using any turbulence

Interannual Variations of Surface Currents and Transports in the Sicily Channel Derived From Coastal Altimetry

Science.gov (United States)

Jebri, Fatma; Zakardjian, Bruno; Birol, Florence; Bouffard, Jérôme; Jullion, Loïc.; Sammari, Cherif

2017-11-01

A 20 year coastal altimetry data set (X-TRACK) is used, for the first time, to gain insight into the long-term interannual variations of the surface circulation in the Sicily Channel. First, a spectral along with a time/space diagram analysis are applied to the monthly means. They reveal a regionally coherent current patterns from track to track with a marked interannual variability that is unequally shared between the Atlantic Tunisian Current and Atlantic Ionian Stream inflows in the Sicily Channel and the Bifurcation Tyrrhenian Current outflow northeast of Sicily. Second, an empirical altimetry-based transport-like technique is proposed to quantify volume budgets inside the closed boxes formed by the crossing of the altimetry tracks and coastlines over the study area. A set of hydrographic measurements is used to validate the method. The inferred altimetry transports give a well-balanced mean eastward Atlantic Waters baroclinic flow of 0.4 Sv and standard deviations of 0.2 Sv on a yearly basis throughout the Sicily Channel and toward the Ionian Sea, which is fairly coherent with those found in the literature. Furthermore, the analysis allows to quantify the intrusions of Atlantic Waters over the Tunisian Shelf (0.12 ± 0.1 Sv) and highlights two main modes of variability of the main surface waters path over the Sicily Channel through the Bifurcation Atlantic Tunisian Current and Atlantic Ionian Stream systems. Some physical mechanisms are finally discussed with regards to changes in the observed currents and transports.

A FORTRAN version implementation of block adjustment of CCD frames and its preliminary application

Science.gov (United States)

Yu, Y.; Tang, Z.-H.; Li, J.-L.; Zhao, M.

2005-09-01

A FORTRAN version implementation of the block adjustment (BA) of overlapping CCD frames is developed and its flowchart is shown. The program is preliminarily applied to obtain the optical positions of four extragalactic radio sources. The results show that because of the increase in the number and sky coverage of reference stars the precision of optical positions with BA is improved compared with the single CCD frame adjustment.

BVR Standardization of the CCD Photometric System of Chungbuk National University Observatory

Directory of Open Access Journals (Sweden)

Jang-Hae Jeong

2009-06-01

Full Text Available BVR observations for 52 standard stars were performed using the 1-m reflecter with 2K CCD System of Chungbuk National University Observatory(CBNUO in 2008. We obtained 1,322 CCD images to establish a correlation between our bvr system and the standard Johnson-Cousins BVR system. We derived the tentative equations of transformation between then as follows; V = v-0.0303(B-V+0.0466 B-V = 1.3475(b-v-0.0251 V-R = 1.0641(v-r-0.0125 Using these equations the magnitudes in V, B-V, and V-R for 197 stars were obtained.

CCD Camera Lens Interface for Real-Time Theodolite Alignment

Science.gov (United States)

Wake, Shane; Scott, V. Stanley, III

2012-01-01

Theodolites are a common instrument in the testing, alignment, and building of various systems ranging from a single optical component to an entire instrument. They provide a precise way to measure horizontal and vertical angles. They can be used to align multiple objects in a desired way at specific angles. They can also be used to reference a specific location or orientation of an object that has moved. Some systems may require a small margin of error in position of components. A theodolite can assist with accurately measuring and/or minimizing that error. The technology is an adapter for a CCD camera with lens to attach to a Leica Wild T3000 Theodolite eyepiece that enables viewing on a connected monitor, and thus can be utilized with multiple theodolites simultaneously. This technology removes a substantial part of human error by relying on the CCD camera and monitors. It also allows image recording of the alignment, and therefore provides a quantitative means to measure such error.

Interactions between β-catenin and the HSlo potassium channel regulates HSlo surface expression.

Directory of Open Access Journals (Sweden)

Shumin Bian

Full Text Available The large conductance calcium-activated potassium channel alpha-subunit (Slo is widely distributed throughout the body and plays an important role in a number of diseases. Prior work has shown that Slo, through its S10 region, interacts with β-catenin, a key component of the cytoskeleton framework and the Wnt signaling pathway. However, the physiological significance of this interaction was not clear.Using a combination of proteomic and cell biology tools we show the existence of additional multiple binding sites in Slo, and explore in detail β-catenin interactions with the S10 region. We demonstrate that deletion of this region reduces Slo surface expression in HEK cells, which indicates that interaction with beta-catenin is important for Slo surface expression. This is confirmed by reduced expression of Slo in HEK cells and chicken (Gallus gallus domesticus leghorn white hair cells treated with siRNA to β-catenin. HSlo reciprocally co-immunoprecipitates with β-catenin, indicating a stable binding between these two proteins, with the S10 deletion mutant having reduced binding with β-catenin. We also observed that mutations of the two putative GSK phosphorylation sites within the S10 region affect both the surface expression of Slo and the channel's voltage and calcium sensitivities. Interestingly, expression of exogenous Slo in HEK cells inhibits β-catenin-dependent canonical Wnt signaling.These studies identify for the first time a central role for β-catenin in mediating Slo surface expression. Additionally we show that Slo overexpression can lead to downregulation of Wnt signaling.

Dai Omega, a large solid angle axial focusing superconducting surface muon channel

International Nuclear Information System (INIS)

Miyadera, H.; Nagamine, K.; Shimomura, K.; Nishiyama, K.; Tanaka, H.; Fukuchi, K.; Makimura, S.; Ishida, K.

2003-01-01

An axial focusing surface muon channel, Dai Omega, was installed at KEK-MSL in the summer of 2001. Large aperture superconducting coils are utilized instead of quadrupole magnets. Dai Omega adopts an axial focusing beam path using symmetric magnetic fields from four coils. Computer simulations were performed on constructing Dai Omega, and the calculated solid angle acceptance of Dai Omega was larger than 1 sr at the optimum momentum. The momentum acceptance of Dai Omega was 6% FWHM. Dai Omega improved the solid angle acceptance by almost 20 times, in comparison with conventional muon channels. Beam tuning tests of Dai Omega have been carried out, and a beam intensity of 10 6 μ + /s was achieved at KEK-NML (500 MeV, 5 μA), which was almost comparable with that of RAL (800 MeV, 200 μA)

Cross calibration of INSAT 3A CCD channel radiances with IRS P6 ...

Indian Academy of Sciences (India)

average sampling distance (∼3 km) of Meteosat. Second Generation ... as snow, agriculture, bare soil, forest, cloud and .... reflecting surfaces are agriculture, bare soil and forest. ..... Parihar J S 2008 A study on land surface radiation bud-.

Análise de mapas de represas publicados na web usando imagens orbitais CCD/CBERS no estado de Minas Gerais Analysis of dams maps published on the web by using orbital CCD/CBERS images in Minas Gerais State, Brazil

Directory of Open Access Journals (Sweden)

Elizabeth Ferreira

2010-02-01

Full Text Available Neste trabalho, bancos de dados públicos e gratuitos disponíveis na World Wide Web (WEB foram utilizados para avaliar as áreas das superfícies dos espelhos d'água das represas de Furnas e do Funil, no Estado de Minas Gerais. O objetivo foi comparar as informações obtidas nos bancos da WEB com os valores das áreas calculadas a partir de imagens do sensor CCD a bordo dos satélites CBERS2 e CBERS2B. A área da represa de Furnas obtida a partir das imagens CCD/CBERS2B, ano 2008, foi de 1.138 km², mas nos bancos de dados consultados esta área estava entre 1.182 e 1.503 km². A represa do Funil, construída em 2003, com superfície de espelho d'água de 29,37 km² e uma ilha com área de 1,93 km² não aparecem nos bancos Atlas, Geominas, IGAM e IBGE. Os resultados mostraram algumas discrepâncias nos bancos de dados publicados na WEB, tais como diferenças em áreas e supressão ou extrapolação de limites do espelho d'água. Concluiu-se que, até o momento, os responsáveis por algumas publicações de bancos de dados no Estado de Minas Gerais não tiveram rigor suficiente com as atualizações. As imagens CCD/CBERS, que também são dados públicos disponíveis na WEB, mostraram ser produtos adequados para verificar, atualizar e melhorar as informações publicadas.In this work some public databases from the World Wide Web (WEB were used to find the area of the Furnas and Funil Dams in Minas Gerais State. The purpose of this work was to compare the WEB public databases values and the real values obtained from the CCD camera images on board CBERS2 and CBERS2B satellites. The Furnas Dam area obtained from CCD/ CBERS2B images, in 2008, was 1.138 km², but in the consulted databases this area ranged from 1.182 to 1.503 km². The dam of the Funil, built in 2003, with a water surface of 29.37 km² and an island with 1.93 km² area, did not appear in Atlas, Geominas, IGAM and IBGE databases. The results revealed some problems in the WEB public

Dynamic imaging with a triggered and intensified CCD camera system in a high-intensity neutron beam

International Nuclear Information System (INIS)

Vontobel, P.; Frei, G.; Brunner, J.; Gildemeister, A.E.; Engelhardt, M.

2005-01-01

When time-dependent processes within metallic structures should be inspected and visualized, neutrons are well suited due to their high penetration through Al, Ag, Ti or even steel. Then it becomes possible to inspect the propagation, distribution and evaporation of organic liquids as lubricants, fuel or water. The principle set-up of a suited real-time system was implemented and tested at the radiography facility NEUTRA of PSI. The highest beam intensity there is 2x10 7 cm -2 s -1 , which enables to observe sequences in a reasonable time and quality. The heart of the detection system is the MCP intensified CCD camera PI-Max with a Peltier cooled chip (1300x1340 pixels). The intensifier was used for both gating and image enhancement, where as the information was accumulated over many single frames on the chip before readout. Although, a 16-bit dynamic range is advertised by the camera manufacturers, it must be less due to the inherent noise level from the intensifier. The obtained result should be seen as the starting point to go ahead to fit the different requirements of car producers in respect to fuel injection, lubricant distribution, mechanical stability and operation control. Similar inspections will be possible for all devices with repetitive operation principle. Here, we report about two measurements dealing with the lubricant distribution in a running motorcycle motor turning at 1200rpm. We were monitoring the periodic stationary movements of piston, valves and camshaft with a micro-channel plate intensified CCD camera system (PI-Max 1300RB, Princeton Instruments) triggered at exactly chosen time points

77 FR 42713 - Notice of Proposed Information Collection RequestsNPEFS 2011-2014: Common Core of Data (CCD...

Science.gov (United States)

2012-07-20

... Core of Data (CCD) National Public Education Financial Survey AGENCY: Institute of Education Sciences, Department of Education. SUMMARY: The National Public Education Financial Survey (NPEFS) is an annual... of Data (CCD) National Public Education Financial Survey. OMB Control Number: 1850-0067. [[Page 42714...

Noise in off-axis type holograms including reconstruction and CCD camera parameters

Energy Technology Data Exchange (ETDEWEB)

Voelkl, Edgar, E-mail: edgar.voelkl@fei.com [FEI Company, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124-5793 (United States)

2010-02-15

Phase and amplitude images as contained in digital holograms are commonly extracted via a process called 'reconstruction'. Expressions for the expected noise in these images have been given in the past by several authors; however, the effect of the actual reconstruction process has not been fully appreciated. By starting with the Quantum Mechanical intensity distribution of the off-axis type interference pattern, then building the digital hologram on an electron-by-electron base while simultaneously reconstructing the phase/amplitude images and evaluating their noise levels, an expression is derived that consistently describes the noise in simulated and experimental phase/amplitude images and contains the reconstruction parameters. Because of the necessity to discretize the intensity distribution function, the digitization effects of an ideal CCD camera had to be included. Subsequently, this allowed a comparison between real and simulated holograms which then led to a comparison between the performance of an 'ideal' CCD camera versus a real device. It was concluded that significant improvement of the phase and amplitude noise may be obtained if CCD cameras were optimized for digitizing intensity distributions at low sampling rates.

A New CCD Camera at the Molėtai Observatory

Directory of Open Access Journals (Sweden)

Zdanavičius J.

2003-12-01

Full Text Available The results of the first testing of a new CCD camera of the Molėtai Observatory are given. The linearity and the flat field corrections of good accuracy are determined by using shifted star field exposures.

Development of network based control and data acquisition systems for diagnostics using CCD detectors. Application to LHD experiments

International Nuclear Information System (INIS)

Kado, Shinichiro; Nakanishi, Hideya; Ida, Katsumi; Kojima, Mamoru

2000-01-01

The needs of CCD detectors as a plasma diagnostic tool have recently been increased. However, many CCD providers have developed their own controlling systems, and it is difficult to customized the usages in order to make them applicable to the network-based data acquisition clusters which consist of various sorts of diagnostics. This paper presents the development of systems in which CCD detectors are controlled and the data are acquired through networks. By making use of the Client/Server (C/S) model in the Windows NT operating system and block transfer method via shared memory relevant to the model, the dependence on the hardware is hidden by the server service, CCD list sequencer. The client program is designed for the LHD (Large Helical Device) discharge operation sequences and the data acquisition system. (author)

Water surface deformation in strong electrical fields and its influence on electrical breakdown in a metal pin-water electrode system

International Nuclear Information System (INIS)

Bruggeman, Peter; Graham, Leigh; Groote, Joris de; Vierendeels, Jan; Leys, Christophe

2007-01-01

Electrical breakdown and water surface deformation in a metal pin-water electrode system with dc applied voltages is studied for small inter-electrode distances (2-12 mm). The radius of curvature of the metal pin is 0.5 cm to exclude corona before breakdown at these small inter-electrode spacings. Calculations of the water surface deformation as a function of the applied voltage and initial inter-electrode spacing are compared with measurements of the water elevation. For distances smaller than 7 mm the calculated stability limit of the water surface corresponds with the experimentally obtained breakdown voltage. It is proved with fast CCD images and calculations of the electrical field distribution that the water surface instability triggers the electrical breakdown in this case. The images show that at breakdown the water surface has a Taylor cone-like shape. At inter-electrode distance of 7 mm and larger the breakdown voltage is well below the water stability limit and the conductive channel at breakdown is formed between the pin electrode and the static water surface. Both cases are discussed and compared

New Design Concept for Universal CCD Controller

Directory of Open Access Journals (Sweden)

Wonyong Han

1994-06-01

Full Text Available Currently, the CCDs are widely used in astronomical observations either in direct imaging use or spectroscopic mode. However according to the recent technical advances, new large format CCDs are rapidly developed which have better performances with higher quantum efficiency and sensitivity. In many cases, some microprocessors have been adopted to deal with necessary digital logic for a CCD imaging system. This could often lack the flexibility of a system for a user to upgrade with new devices, especially of it is a commercial product. A new design concept has been explored which could provide the opportunity to deal with any format of devices from ant manufactures effectively for astronomical purposes. Recently available PLD (Programmable Logic Devices technology makes it possible to develop such digital circuit design, which can be integrated into a single component, instead of using microprocessors. The design concept could dramatically increase the efficiency and flexibility of a CCD imaging system, particularly when new or large format devices are available and to upgrade the performance of a system. Some variable system control parameters can be selected by a user with a wider range of choice. The software can support such functional requirements very conveniently. This approach can be applied not only to astronomical purpose, but also to some related fields, such as remote sensing and industrial applications.

From Surface Down To Bulk X-Ray Channeling

International Nuclear Information System (INIS)

Dabagov, Sultan B.

2003-01-01

The basic point to be considered in this report is that X-ray capillary optics relies on the ability of a tapered and/or bent capillary channel to act as an X-ray waveguide. Recently several coherent phenomena associated with propagation of X-rays in capillary optical elements have been observed. In order to describe coherent phenomena of radiation propagation a quantum-wave theory of X-ray channeling was developed. Simple estimations speak on possibility of X-ray channeling in nano-scale capillaries, but with a significant change in character of channeling. In this connection, discovery of carbon nanotubes opens new opportunities to apply capillary waveguide optics. X-ray propagation in capillary micro- and nanostructures within the frame of wave approach will be discussed

Phase shifting white light interferometry using colour CCD for optical metrology and bio-imaging applications

Science.gov (United States)

Upputuri, Paul Kumar; Pramanik, Manojit

2018-02-01

Phase shifting white light interferometry (PSWLI) has been widely used for optical metrology applications because of their precision, reliability, and versatility. White light interferometry using monochrome CCD makes the measurement process slow for metrology applications. WLI integrated with Red-Green-Blue (RGB) CCD camera is finding imaging applications in the fields optical metrology and bio-imaging. Wavelength dependent refractive index profiles of biological samples were computed from colour white light interferograms. In recent years, whole-filed refractive index profiles of red blood cells (RBCs), onion skin, fish cornea, etc. were measured from RGB interferograms. In this paper, we discuss the bio-imaging applications of colour CCD based white light interferometry. The approach makes the measurement faster, easier, cost-effective, and even dynamic by using single fringe analysis methods, for industrial applications.

The application of μPIV technique in the study of magnetic flows in a micro-channel

International Nuclear Information System (INIS)

Nguyen, N.T.; Wu, Z.G.; Huang, X.Y.; Wen, C.-Y..

2005-01-01

In this preliminary experimental study, micro-scale particle image velocimetry (μPIV) was adopted for the first time to get the quantitative information of magnetic flows in a micro-channel. The μPIV consists of an inverted florescent microscope, a Q-switch Nd:YAG laser and a CCD camera. The florescent liquid with particles of 3 μm diameter was blended homogeneously with the prepared magnetic fluid. A permanent magnet approached and left one end of the micro-channel. The response of the magnetic fluid was recorded with the μPIV simultaneously. The flow features validate the feasibility of using μPIV technique in the study of magnetic flows in a micro-channel. μPIV provides a promising experimental tool for visualization and quantitative measurement of magnetic micro-flows

Predicting the impact of vegetations in open channels with different distributaries' operations on water surface profile using artificial neural networks

International Nuclear Information System (INIS)

Abdeen, Mostafa A. M.

2008-01-01

Most of the open water irrigation channels in Egypt suffer from the infestation of aquatic weeds, especially the submerged ones that cause numerous hydraulic problems for the open channels themselves and their water distributaries such as increasing water losses, obstructing water flow, and reducing channels' water distribution efficiencies. Accurate simulation and prediction of flow behavior in such channels is very essential for water distribution decision makers. Artificial neural networks (ANN) have proven to be very successful in the simulation of several physical phenomena, in general, and in the water research field in particular. Therefore, the current study aims towards introducing the utilization of ANN in simulating the impact of vegetation in main open channel, which supplies water to different distributaries, on the water surface profile in this main channel. Specifically, the study, presented in the current paper utilizes ANN technique for the development of various models to simulate the impact of different submerged weeds' densities, different flow discharges, and different distributaries operation scheduling on the water surface profile in an experimental main open channel that supplies water to different distributaries. In the investigated experiment, the submerged weeds were simulated as branched flexible elements. The investigated experiment was considered as an example for implementing the same methodology and technique in a real open channel system. The results showed that the ANN technique is very successful in simulating the flow behavior of the pre-mentioned open channel experiment with the existence of the submerged weeds. In addition, the developed ANN models were capable of predicting the open channel flow behavior in all the submerged weeds' cases that were considered in the ANN development process

CCD characterization and measurements automation

International Nuclear Information System (INIS)

Kotov, I.V.; Frank, J.; Kotov, A.I.; Kubanek, P.; O'Connor, P.; Prouza, M.; Radeka, V.; Takacs, P.

2012-01-01

Modern mosaic cameras have grown both in size and in number of sensors. The required volume of sensor testing and characterization has grown accordingly. For camera projects as large as the LSST, test automation becomes a necessity. A CCD testing and characterization laboratory was built and is in operation for the LSST project. Characterization of LSST study contract sensors has been performed. The characterization process and its automation are discussed, and results are presented. Our system automatically acquires images, populates a database with metadata information, and runs express analysis. This approach is illustrated on 55 Fe data analysis. 55 Fe data are used to measure gain, charge transfer efficiency and charge diffusion. Examples of express analysis results are presented and discussed.

The Cross-Cultural Dementia Screening (CCD): A new neuropsychological screening instrument for dementia in elderly immigrants.

Science.gov (United States)

Goudsmit, Miriam; Uysal-Bozkir, Özgül; Parlevliet, Juliette L; van Campen, Jos P C M; de Rooij, Sophia E; Schmand, Ben

2017-03-01

Currently, approximately 3.9% of the European population are non-EU citizens, and a large part of these people are from "non-Western" societies, such as Turkey and Morocco. For various reasons, the incidence of dementia in this group is expected to increase. However, cognitive testing is challenging due to language barriers and low education and/or illiteracy. The newly developed Cross-Cultural Dementia Screening (CCD) can be administered without an interpreter. It contains three subtests that assess memory, mental speed, and executive function. We hypothesized the CCD to be a culture-fair test that could discriminate between demented patients and cognitively healthy controls. To test this hypothesis, 54 patients who had probable dementia were recruited via memory clinics. Controls (N = 1625) were recruited via their general practitioners. All patients and controls were aged 55 years and older and of six different self-defined ethnicities (Dutch, Turkish, Moroccan-Arabic, Moroccan-Berber, Surinamese-Creole, and Surinamese-Hindustani). Exclusion criteria included current or previous conditions that affect cognitive functioning. There were performance differences between the ethnic groups, but these disappeared after correcting for age and education differences between the groups, which supports our central hypothesis that the CCD is a culture-fair test. Receiver-operating characteristic (ROC) and logistic regression analyses showed that the CCD has high predictive validity for dementia (sensitivity: 85%; specificity: 89%). The CCD is a sensitive and culture-fair neuropsychological instrument for dementia screening in low-educated immigrant populations.

New design for the UCO/Lick Observatory CCD guide camera

Science.gov (United States)

Wei, Mingzhi; Stover, Richard J.

1996-03-01

A new CCD based field acquisition and telescope guiding camera is being designed and built at UCO/Lick Observatory. Our goal is a camera which is fully computer controllable, compact in size, versatile enough to provide a wide variety of image acquisition modes, and able to operate with a wide variety of CCD detectors. The camera will improve our remote-observing capabilities since it will be easy to control the camera and obtain images over the Observatory computer network. To achieve the desired level of operating flexibility, the design incorporates state-of-the-art technologies such as high density, high speed programmable logic devices and non-volatile static memory. Various types of CCDs can be used in this system without major modification of the hardware or software. Though fully computer controllable, the camera can be operated as a stand-alone unit with most operating parameters set locally. A stand-alone display subsystem is also available. A thermoelectric device is used to cool the CCD to about -45c. Integration times can be varied over a range of 0.1 to 1000 seconds. High speed pixel skipping in both horizontal and vertical directions allows us to quickly access a selected subarea of the detector. Three different read out speeds allow the astronomer to select between high-speed/high-noise and low-speed/low-noise operation. On- chip pixel binning and MPP operation are also selectable options. This system can provide automatic sky level measurement and subtraction to accommodate dynamically changing background levels.

Novel CLCNKB mutations causing Bartter syndrome affect channel surface expression.

Science.gov (United States)

Keck, Mathilde; Andrini, Olga; Lahuna, Olivier; Burgos, Johanna; Cid, L Pablo; Sepúlveda, Francisco V; L'hoste, Sébastien; Blanchard, Anne; Vargas-Poussou, Rosa; Lourdel, Stéphane; Teulon, Jacques

2013-09-01

Mutations in the CLCNKB gene encoding the ClC-Kb Cl(-) channel cause Bartter syndrome, which is a salt-losing renal tubulopathy. Here, we investigate the functional consequences of seven mutations. When expressed in Xenopus laevis oocytes, four mutants carried no current (c.736G>C, p.Gly246Arg; c.1271G>A, p.Gly424Glu; c.1313G>A, p.Arg438His; c.1316T>C, p.Leu439Pro), whereas others displayed a 30%-60% reduction in conductance as compared with wild-type ClC-Kb (c.242T>C, p.Leu81Pro; c.274C>T, p.Arg92Trp; c.1052G>C, p.Arg351Pro). Anion selectivity and sensitivity to external Ca(2+) and H(+), typical of the ClC-Kb channel, were not modified in the partially active mutants. In oocytes, we found that all the mutations reduced surface expression with a profile similar to that observed for currents. In HEK293 cells, the currents in the mutants had similar profiles to those obtained in oocytes, except for p.Leu81Pro, which produced no current. Furthermore, p.Arg92Trp and p.Arg351Pro mutations did not modify the unit-conductance of closely related ClC-K1. Western blot analysis in HEK293 cells showed that ClC-Kb protein abundance was lower for the nonconducting mutants but similar to wild-type for other mutants. Overall, two classes of mutants can be distinguished: nonconducting mutants associated with low total protein expression, and partially conducting mutants with unaltered channel properties and ClC-Kb protein abundance. © 2013 WILEY PERIODICALS, INC.

The development of large-aperture test system of infrared camera and visible CCD camera

Science.gov (United States)

Li, Yingwen; Geng, Anbing; Wang, Bo; Wang, Haitao; Wu, Yanying

2015-10-01

Infrared camera and CCD camera dual-band imaging system is used in many equipment and application widely. If it is tested using the traditional infrared camera test system and visible CCD test system, 2 times of installation and alignment are needed in the test procedure. The large-aperture test system of infrared camera and visible CCD camera uses the common large-aperture reflection collimator, target wheel, frame-grabber, computer which reduces the cost and the time of installation and alignment. Multiple-frame averaging algorithm is used to reduce the influence of random noise. Athermal optical design is adopted to reduce the change of focal length location change of collimator when the environmental temperature is changing, and the image quality of the collimator of large field of view and test accuracy are also improved. Its performance is the same as that of the exotic congener and is much cheaper. It will have a good market.

Comparison of a CCD and an APS for soft X-ray diffraction

International Nuclear Information System (INIS)

Stewart, Graeme; Bates, R; Blue, A; Maneuski, D; Clark, A; Turchetta, R; Dhesi, S S; Marchal, J; Steadman, P; Tartoni, N

2011-01-01

We compare a new CMOS Active Pixel Sensor (APS) to a Princeton Instruments PIXIS-XO: 2048B Charge Coupled Device (CCD) with soft X-rays tested in a synchrotron beam line at the Diamond Light Source (DLS). Despite CCDs being established in the field of scientific imaging, APS are an innovative technology that offers advantages over CCDs. These include faster readout, higher operational temperature, in-pixel electronics for advanced image processing and reduced manufacturing cost. The APS employed was the Vanilla sensor designed by the MI3 collaboration and funded by an RCUK Basic technology grant. This sensor has 520 x 520 square pixels, of size 25 μm on each side. The sensor can operate at a full frame readout of up to 20 Hz. The sensor had been back-thinned, to the epitaxial layer. This was the first time that a back-thinned APS had been demonstrated at a beam line at DLS. In the synchrotron experiment soft X-rays with an energy of approximately 708 eV were used to produce a diffraction pattern from a permalloy sample. The pattern was imaged at a range of integration times with both sensors. The CCD had to be operated at a temperature of -55°C whereas the Vanilla was operated over a temperature range from 20°C to -10°C. We show that the APS detector can operate with frame rates up to two hundred times faster than the CCD, without excessive degradation of image quality. The signal to noise of the APS is shown to be the same as that of the CCD at identical integration times and the response is shown to be linear, with no charge blooming effects. The experiment has allowed a direct comparison of back thinned APS and CCDs in a real soft x-ray synchrotron experiment.

Comparison of a CCD and an APS for soft X-ray diffraction

Science.gov (United States)

Stewart, Graeme; Bates, R.; Blue, A.; Clark, A.; Dhesi, S. S.; Maneuski, D.; Marchal, J.; Steadman, P.; Tartoni, N.; Turchetta, R.

2011-12-01

We compare a new CMOS Active Pixel Sensor (APS) to a Princeton Instruments PIXIS-XO: 2048B Charge Coupled Device (CCD) with soft X-rays tested in a synchrotron beam line at the Diamond Light Source (DLS). Despite CCDs being established in the field of scientific imaging, APS are an innovative technology that offers advantages over CCDs. These include faster readout, higher operational temperature, in-pixel electronics for advanced image processing and reduced manufacturing cost. The APS employed was the Vanilla sensor designed by the MI3 collaboration and funded by an RCUK Basic technology grant. This sensor has 520 x 520 square pixels, of size 25 μm on each side. The sensor can operate at a full frame readout of up to 20 Hz. The sensor had been back-thinned, to the epitaxial layer. This was the first time that a back-thinned APS had been demonstrated at a beam line at DLS. In the synchrotron experiment soft X-rays with an energy of approximately 708 eV were used to produce a diffraction pattern from a permalloy sample. The pattern was imaged at a range of integration times with both sensors. The CCD had to be operated at a temperature of -55°C whereas the Vanilla was operated over a temperature range from 20°C to -10°C. We show that the APS detector can operate with frame rates up to two hundred times faster than the CCD, without excessive degradation of image quality. The signal to noise of the APS is shown to be the same as that of the CCD at identical integration times and the response is shown to be linear, with no charge blooming effects. The experiment has allowed a direct comparison of back thinned APS and CCDs in a real soft x-ray synchrotron experiment.

The possibilities of CCD photometry of optical afterglows of GRBs

Czech Academy of Sciences Publication Activity Database

Šimon, Vojtěch; Polášek, Cyril; Jelínek, M.; Hudec, René; Štrobl, Jan

-, č. 125 (2010), s. 24-28 ISSN 1801-5964. [Conference on Variable Stars Research /41./. Prague, 27.11.2009-29.11.2009] Institutional research plan: CEZ:AV0Z10030501 Keywords : gamma-ray bursts * optical afterglows * CCD photometry Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

Loss of ATP-Sensitive Potassium Channel Surface Expression in Heart Failure Underlies Dysregulation of Action Potential Duration and Myocardial Vulnerability to Injury.

Directory of Open Access Journals (Sweden)

Zhan Gao

Full Text Available The search for new approaches to treatment and prevention of heart failure is a major challenge in medicine. The adenosine triphosphate-sensitive potassium (KATP channel has been long associated with the ability to preserve myocardial function and viability under stress. High surface expression of membrane KATP channels ensures a rapid energy-sparing reduction in action potential duration (APD in response to metabolic challenges, while cellular signaling that reduces surface KATP channel expression blunts APD shortening, thus sacrificing energetic efficiency in exchange for greater cellular calcium entry and increased contractile force. In healthy hearts, calcium/calmodulin-dependent protein kinase II (CaMKII phosphorylates the Kir6.2 KATP channel subunit initiating a cascade responsible for KATP channel endocytosis. Here, activation of CaMKII in a transaortic banding (TAB model of heart failure is coupled with a 35-40% reduction in surface expression of KATP channels compared to hearts from sham-operated mice. Linkage between KATP channel expression and CaMKII is verified in isolated cardiomyocytes in which activation of CaMKII results in downregulation of KATP channel current. Accordingly, shortening of monophasic APD is slowed in response to hypoxia or heart rate acceleration in failing compared to non-failing hearts, a phenomenon previously shown to result in significant increases in oxygen consumption. Even in the absence of coronary artery disease, failing myocardium can be further injured by ischemia due to a mismatch between metabolic supply and demand. Ischemia-reperfusion injury, following ischemic preconditioning, is diminished in hearts with CaMKII inhibition compared to wild-type hearts and this advantage is largely eliminated when myocardial KATP channel expression is absent, supporting that the myocardial protective benefit of CaMKII inhibition in heart failure may be substantially mediated by KATP channels. Recognition of Ca

Preservation of meandering river channels in uniformly aggrading channel belts

NARCIS (Netherlands)

Lageweg, W.I. van de; Schuurman, F.; Cohen, K.M.; Dijk, W.M. van; Shimizu, Y.; Kleinhans, M.G.

2016-01-01

Channel belt deposits from meandering river systems commonly display an internal architecture of stacked depositional features with scoured basal contacts due to channel and bedform migration across a range of scales. Recognition and correct interpretation of these bounding surfaces is essential to

BVRI CCD photometry of the globular cluster NGC 2808

International Nuclear Information System (INIS)

Alcaino, G.; Liller, W.; Alvarado, F.; Wenderoth, E.

1990-01-01

As a part of a continuing program, CCD color-magnitude diagrams are presented for the bright globular cluster NGC 2808 in the four colors comprising BVRI. From a comparison of four different CMDs with theoretical isochrones, an age of 16 + or - 2 Gyr is obtained, assuming a value for Fe/H near -1.3. 28 refs

Denoising Algorithm for CFA Image Sensors Considering Inter-Channel Correlation.

Science.gov (United States)

Lee, Min Seok; Park, Sang Wook; Kang, Moon Gi

2017-05-28

In this paper, a spatio-spectral-temporal filter considering an inter-channel correlation is proposed for the denoising of a color filter array (CFA) sequence acquired by CCD/CMOS image sensors. Owing to the alternating under-sampled grid of the CFA pattern, the inter-channel correlation must be considered in the direct denoising process. The proposed filter is applied in the spatial, spectral, and temporal domain, considering the spatio-tempo-spectral correlation. First, nonlocal means (NLM) spatial filtering with patch-based difference (PBD) refinement is performed by considering both the intra-channel correlation and inter-channel correlation to overcome the spatial resolution degradation occurring with the alternating under-sampled pattern. Second, a motion-compensated temporal filter that employs inter-channel correlated motion estimation and compensation is proposed to remove the noise in the temporal domain. Then, a motion adaptive detection value controls the ratio of the spatial filter and the temporal filter. The denoised CFA sequence can thus be obtained without motion artifacts. Experimental results for both simulated and real CFA sequences are presented with visual and numerical comparisons to several state-of-the-art denoising methods combined with a demosaicing method. Experimental results confirmed that the proposed frameworks outperformed the other techniques in terms of the objective criteria and subjective visual perception in CFA sequences.

Measuring a narrow Bessel beam spot by scanning a charge-coupled device (CCD) pixel

International Nuclear Information System (INIS)

Tiwari, S K; Ram, S P; Jayabalan, J; Mishra, S R

2010-01-01

By scanning a charge-coupled device (CCD) camera transverse to the beam axis and observing the variation in counts on a marked pixel, we demonstrate that we can measure a laser beam spot size smaller than the size of the CCD-pixel. We find this method particularly attractive for measuring the size of central spot of a Bessel beam, for which the established scanning knife-edge method does not work appropriately because of the large contribution of the rings surrounding the central spot to the signal

BECN2 interacts with ATG14 through a metastable coiled-coil to mediate autophagy: BECN2 CCD Structure and Interaction with ATG14

Energy Technology Data Exchange (ETDEWEB)

Su, Minfei; Li, Yue; Wyborny, Shane; Neau, David; Chakravarthy, Srinivas; Levine, Beth; Colbert, Christopher L.; Sinha, Sangita C. (NDSU); (IIT); (Cornell); (UTSMC)

2017-03-12

ATG14 binding to BECN/Beclin homologs is essential for autophagy, a critical catabolic homeostasis pathway. Here, we show that the α-helical, coiled-coil domain (CCD) of BECN2, a recently identified mammalian BECN1 paralog, forms an antiparallel, curved homodimer with seven pairs of nonideal packing interactions, while the BECN2 CCD and ATG14 CCD form a parallel, curved heterodimer stabilized by multiple, conserved polar interactions. Compared to BECN1, the BECN2 CCD forms a weaker homodimer, but binds more tightly to the ATG14 CCD. Mutation of nonideal BECN2 interface residues to more ideal pairs improves homodimer self-association and thermal stability. Unlike BECN1, all BECN2 CCD mutants bind ATG14, although more weakly than wild type. Thus, polar BECN2 CCD interface residues result in a metastable homodimer, facilitating dissociation, but enable better interactions with polar ATG14 residues stabilizing the BECN2:ATG14 heterodimer. These structure-based mechanistic differences in BECN1 and BECN2 homodimerization and heterodimerization likely dictate competitive ATG14 recruitment.

CCD-based vertex detectors

CERN Document Server

Damerell, C J S

2005-01-01

Over the past 20 years, CCD-based vertex detectors have been used to construct some of the most precise 'tracking microscopes' in particle physics. They were initially used by the ACCMOR collaboration for fixed target experiments in CERN, where they enabled the lifetimes of some of the shortest-lived charm particles to be measured precisely. The migration to collider experiments was accomplished in the SLD experiment, where the original 120 Mpixel detector was later upgraded to one with 307 Mpixels. This detector was used in a range of physics studies which exceeded the capability of the LEP detectors, including the most precise limit to date on the Bs mixing parameter. This success, and the high background hit densities that will inevitably be encountered at the future TeV-scale linear collider, have established the need for a silicon pixel-based vertex detector at this machine. The technical options have now been broadened to include a wide range of possible silicon imaging technologies as well as CCDs (mon...

CCD Photometry Using Multiple Comparison Stars

Directory of Open Access Journals (Sweden)

Yonggi Kim

2004-09-01

Full Text Available The accuracy of CCD observations obtained at the Korean 1.8 m telescope has been studied. Seventeen comparison stars in the vicinity of the cataclysmic variable BG CMi have been measured. The ``artificial" star has been used instead of the ``control" star, what made possible to increase accuracy estimates by a factor of 1.3-2.1 times for ``good" and ``cloudy" nights, respectively. The algorithm of iterative determination of accuracy and weights of few comparison stars contributing to the artificial star, has been presented. The accuracy estimates for 13-mag stars are around 0.002 m mag for exposure times of 30 sec.

Measuring high-resolution sky luminance distributions with a CCD camera.

Science.gov (United States)

Tohsing, Korntip; Schrempf, Michael; Riechelmann, Stefan; Schilke, Holger; Seckmeyer, Gunther

2013-03-10

We describe how sky luminance can be derived from a newly developed hemispherical sky imager (HSI) system. The system contains a commercial compact charge coupled device (CCD) camera equipped with a fish-eye lens. The projection of the camera system has been found to be nearly equidistant. The luminance from the high dynamic range images has been calculated and then validated with luminance data measured by a CCD array spectroradiometer. The deviation between both datasets is less than 10% for cloudless and completely overcast skies, and differs by no more than 20% for all sky conditions. The global illuminance derived from the HSI pictures deviates by less than 5% and 20% under cloudless and cloudy skies for solar zenith angles less than 80°, respectively. This system is therefore capable of measuring sky luminance with the high spatial and temporal resolution of more than a million pixels and every 20 s respectively.

Recording of radiation-induced optical density changes in doped agarose gels with a CCD camera

International Nuclear Information System (INIS)

Tarte, B.J.; Jardine, P.A.; Van Doorn, T.

1996-01-01

Full text: Spatially resolved dose measurement with iron-doped agarose gels is continuing to be investigated for applications in radiotherapy dosimetry. It has previously been proposed to use optical methods, rather than MRI, for dose measurement with such gels and this has been investigated using a spectrophotometer (Appleby A and Leghrouz A, Med Phys, 18:309-312, 1991). We have previously studied the use of a pencil beam laser for such optical density measurement of gels and are currently investigating charge-coupled devices (CCD) camera imaging for the same purpose but with the advantages of higher data acquisition rates and potentially greater spatial resolution. The gels used in these studies were poured, irradiated and optically analysed in Perspex casts providing gel sections 1 cm thick and up to 20 cm x 30 cm in dimension. The gels were also infused with a metal indicator dye (xylenol orange) to render the radiation induced oxidation of the iron in the gel sensitive to optical radiation, specifically in the green spectral region. Data acquisition with the CCD camera involved illumination of the irradiated gel section with a diffuse white light source, with the light from the plane of the gel section focussed to the CCD array with a manual zoom lens. The light was also filtered with a green colour glass filter to maximise the contrast between unirradiated and irradiated gels. The CCD camera (EG and G Reticon MC4013) featured a 1024 x 1024 pixel array and was interfaced to a PC via a frame grabber acquisition board with 8 bit resolution. The performance of the gel dosimeter was appraised in mapping of physical and dynamic wedged 6 MV X-ray fields. The results from the CCD camera detection system were compared with both ionisation chamber data and laser based optical density measurements of the gels. Cross beam profiles were extracted from each measurement system at a particular depth (eg. 2.3 cm for the physical wedge field) for direct comparison. A

Effects of irregular two-dimensional and three-dimensional surface roughness in turbulent channel flows

International Nuclear Information System (INIS)

De Marchis, M.; Napoli, E.

2012-01-01

Highlights: ► 3D irregular rough surfaces produce higher effects than those observed over 2D. ► Effective slope is a geometrical parameter representative of the roughness effects. ► 3D rough surfaces enhance the turbulence isotropization. ► 2D and 3D irregular roughness partially support the wall similarity. ► Irregular rough surfaces shear some features with regular rough walls. - Abstract: Wall-resolved Large Eddy Simulation of fully developed turbulent channel flows over two different rough surfaces is performed to investigate on the effects of irregular 2D and 3D roughness on the turbulence. The two geometries are obtained through the superimposition of sinusoidal functions having random amplitudes and different wave lengths. In the 2D configuration the irregular shape in the longitudinal direction is replicated in the transverse one, while in the 3D case the sinusoidal functions are generated both in streamwise and spanwise directions. Both channel walls are roughened in such a way as to obtain surfaces with statistically equivalent roughness height, but different shapes. In order to compare the turbulence properties over the two rough walls and to analyse the differences with a smooth wall, the simulations are performed at the same Reynolds number Re τ = 395. The same mean roughness height h = 0.05δ (δ the half channel height) is used for the rough walls. The roughness function obtained with the 3D roughness is larger than in the 2D case, although the two walls share the same mean height. Thus, the considered irregular 3D roughness is more effective in reducing the flow velocity with respect to the 2D roughness, coherently with the literature results that identified a clear dependence of the roughness function on the effective slope (see ), higher in the generated 3D rough wall. The analysis of higher-order statistics shows that the effects of the roughness, independently on its two- or three-dimensional shape, are mainly confined in the inner

Stroboscope Based Synchronization of Full Frame CCD Sensors

OpenAIRE

Shen, Liang; Feng, Xiaobing; Zhang, Yuan; Shi, Min; Zhu, Dengming; Wang, Zhaoqi

2017-01-01

The key obstacle to the use of consumer cameras in computer vision and computer graphics applications is the lack of synchronization hardware. We present a stroboscope based synchronization approach for the charge-coupled device (CCD) consumer cameras. The synchronization is realized by first aligning the frames from different video sequences based on the smear dots of the stroboscope, and then matching the sequences using a hidden Markov model. Compared with current synchronized capture equi...

STARL -- a Program to Correct CCD Image Defects

Science.gov (United States)

Narbutis, D.; Vanagas, R.; Vansevičius, V.

We present a program tool, STARL, designed for automatic detection and correction of various defects in CCD images. It uses genetic algorithm for deblending and restoring of overlapping saturated stars in crowded stellar fields. Using Subaru Telescope Suprime-Cam images we demonstrate that the program can be implemented in the wide-field survey data processing pipelines for production of high quality color mosaics. The source code and examples are available at the STARL website.

A multiple CCD X-ray detector and its first operation with synchrotron radiation X-ray beam

CERN Document Server

Suzuki, M; Kumasaka, T; Sato, K; Toyokawa, H; Aries, I F; Jerram, P A; Ueki, T

1999-01-01

A 4x4 array structure of 16 identical CCD X-ray detector modules, called the multiple CCD X-ray detector system (MCCDX), was submitted to its first synchrotron radiation experiment at the protein crystallography station of the RIKEN beamline (BL45XU) at the SPring-8 facility. An X-ray diffraction pattern of cholesterol powder was specifically taken in order to investigate the overall system performance.

Construction of a photochemical reactor combining a CCD spectrophotometer and a LED radiation source.

Science.gov (United States)

Gombár, Melinda; Józsa, Éva; Braun, Mihály; Ősz, Katalin

2012-10-01

An inexpensive photoreactor using LED light sources and a fibre-optic CCD spectrophotometer as a detector was built by designing a special cell holder for standard 1.000 cm cuvettes. The use of this device was demonstrated by studying the aqueous photochemical reaction of 2,5-dichloro-1,4-benzoquinone. The developed method combines the highly quantitative data collection of CCD spectrophotometers with the possibility of illuminating the sample independently of the detecting light beam, which is a substantial improvement of the method using diode array spectrophotometers as photoreactors.

CONCENTRATION DEPENDENCE OF STERN LAYER CAPACITANCES AND SURFACE EQUILIBRIUM CONSTANTS IN SILICA-BASED NANOFLUIDIC CHANNELS

DEFF Research Database (Denmark)

Andersen, Mathias Bækbo; Frey, J.; Bruus, Henrik

2010-01-01

Fundamental understanding of the unique physics at the solid-liquid interface in nanofluidic channels is essential for the advancement of basic scientific knowledge and the development of novel applications for pharmaceuticals, environmental health and safety, energy harvesting and biometrics [1......]. The current models used to describe surface phenomena in nanofluidics can differ by orders of magnitude from experimentally measured values [2]. To mitigate the discrepancies, we hypothesize that the Stern-layer capacitance Cs and the surface equilibrium constants pKa, vary with the composition of the solid...

Flat Field Anomalies in an X-Ray CCD Camera Measured Using a Manson X-Ray Source

International Nuclear Information System (INIS)

Michael Haugh

2008-01-01

The Static X-ray Imager (SXI) is a diagnostic used at the National Ignition Facility (NIF) to measure the position of the X-rays produced by lasers hitting a gold foil target. It determines how accurately NIF can point the laser beams and is critical to proper NIF operation. Imagers are located at the top and the bottom of the NIF target chamber. The CCD chip is an X-ray sensitive silicon sensor, with a large format array (2k x 2k), 24 (micro)m square pixels, and 15 (micro)m thick. A multi-anode Manson X-ray source, operating up to 10kV and 2mA, was used to characterize and calibrate the imagers. The output beam is heavily filtered to narrow the spectral beam width, giving a typical resolution E/ΔE ∼ 12. The X-ray beam intensity was measured using an absolute photodiode that has accuracy better than 1% up to the Si K edge and better than 5% at higher energies. The X-ray beam provides full CCD illumination and is flat, within ±1.5% maximum to minimum. The spectral efficiency was measured at 10 energy bands ranging from 930 eV to 8470 eV. The efficiency pattern follows the properties of Si. The maximum quantum efficiency is 0.71. We observed an energy dependent pixel sensitivity variation that showed continuous change over a large portion of the CCD. The maximum sensitivity variation was >8% at 8470 eV. The geometric pattern did not change at lower energies, but the maximum contrast decreased and was less than the measurement uncertainty below 4 keV. We were also able to observe debris on the CCD chip. The debris showed maximum contrast at the lowest energy used, 930 eV, and disappeared by 4 keV. The Manson source is a powerful tool for characterizing the imaging errors of an X-ray CCD imager. These errors are quite different from those found in a visible CCD imager

An X-ray CCD signal generator with true random arrival time

International Nuclear Information System (INIS)

Huo Jia; Xu Yuming; Chen Yong; Cui Weiwei; Li Wei; Zhang Ziliang; Han Dawei; Wang Yusan; Wang Juan

2011-01-01

An FPGA-based true random signal generator with adjustable amplitude and exponential distribution of time interval is presented. Since traditional true random number generators (TRNG) are resource costly and difficult to transplant, we employed a method of random number generation based on jitter and phase noise in ring oscillators formed by gates in an FPGA. In order to improve the random characteristics, a combination of two different pseudo-random processing circuits is used for post processing. The effects of the design parameters, such as sample frequency are discussed. Statistical tests indicate that the generator can well simulate the timing behavior of random signals with Poisson distribution. The X-ray CCD signal generator will be used in debugging the CCD readout system of the Low Energy X-ray Instrument onboard the Hard X-ray Modulation Telescope (HXMT). (authors)

Dynamic Mapping of Rice Growth Parameters Using HJ-1 CCD Time Series Data

Directory of Open Access Journals (Sweden)

Jing Wang

2016-11-01

Full Text Available The high temporal resolution (4-day charge-coupled device (CCD cameras onboard small environment and disaster monitoring and forecasting satellites (HJ-1A/B with 30 m spatial resolution and large swath (700 km have substantially increased the availability of regional clear sky optical remote sensing data. For the application of dynamic mapping of rice growth parameters, leaf area index (LAI and aboveground biomass (AGB were considered as plant growth indicators. The HJ-1 CCD-derived vegetation indices (VIs showed robust relationships with rice growth parameters. Cumulative VIs showed strong performance for the estimation of total dry AGB. The cross-validation coefficient of determination ( R C V 2 was increased by using two machine learning methods, i.e., a back propagation neural network (BPNN and a support vector machine (SVM compared with traditional regression equations of LAI retrieval. The LAI inversion accuracy was further improved by dividing the rice growth period into before and after heading stages. This study demonstrated that continuous rice growth monitoring over time and space at field level can be implemented effectively with HJ-1 CCD 10-day composite data using a combination of proper VIs and regression models.

High Guanidinium Permeability Reveals Dehydration-Dependent Ion Selectivity in the Plasmodial Surface Anion Channel

Directory of Open Access Journals (Sweden)

Abdullah A. B. Bokhari

2014-01-01

Full Text Available Malaria parasites grow within vertebrate erythrocytes and increase host cell permeability to access nutrients from plasma. This increase is mediated by the plasmodial surface anion channel (PSAC, an unusual ion channel linked to the conserved clag gene family. Although PSAC recognizes and transports a broad range of uncharged and charged solutes, it must efficiently exclude the small Na+ ion to maintain infected cell osmotic stability. Here, we examine possible mechanisms for this remarkable solute selectivity. We identify guanidinium as an organic cation with high permeability into human erythrocytes infected with Plasmodium falciparum, but negligible uptake by uninfected cells. Transport characteristics and pharmacology indicate that this uptake is specifically mediated by PSAC. The rank order of organic and inorganic cation permeabilities suggests cation dehydration as the rate-limiting step in transport through the channel. The high guanidinium permeability of infected cells also allows rapid and stringent synchronization of parasite cultures, as required for molecular and cellular studies of this pathogen. These studies provide important insights into how nutrients and ions are transported via PSAC, an established target for antimalarial drug development.

A data-acquisition system for high speed linear CCD

International Nuclear Information System (INIS)

Liu Zhiyan; Chen Xiangcai; Jiang Xiaoshan; Zhang Hongyu; Liang Zhongwang; Xiang Haisheng; Hu Jun

2010-01-01

A data-acquisition system for high speed linear CCD (Charge Coupled device) is mainly introduced. The optical fiber transmission technology is used. The data is sent to PC through USB or PCI interface. The construction of the system, the design of the PCI interface hardware, software design and the design of the control program running on host computer are also introduced. (authors)

Measurements of 42 Wide CPM Pairs with a CCD

Science.gov (United States)

Harshaw, Richard

2015-11-01

This paper addresses the use of a Skyris 618C color CCD camera as a means of obtaining data for analysis in the measurement of wide common proper motion stars. The equipment setup is described and data collection procedure outlined. Results of the measures of 42 CPM stars are presented, showing the Skyris is a reliable device for the measurement of double stars.

Design method of general-purpose driving circuit for CCD based on CPLD

International Nuclear Information System (INIS)

Zhang Yong; Tang Benqi; Xiao Zhigang; Wang Zujun; Huang Shaoyan

2005-01-01

It is very important for studying the radiation damage effects and mechanism systematically about CCD to develop a general-purpose test platform. The paper discusses the design method of general-purpose driving circuit for CCD based on CPLD and the realization approach. A main controller has being designed to read the data file from the outer memory, setup the correlative parameter registers and produce the driving pulses according with parameter request strictly, which is based on MAX7000S by using MAX-PLUS II software. The basic driving circuit module has being finished based on this method. The output waveform of the module is the same figure as the simulation waveform. The result indicates that the design method is feasible. (authors)

Development of Multiple-Element Flame Emission Spectrometer Using CCD Detection

Science.gov (United States)

Seney, Caryn S.; Sinclair, Karen V.; Bright, Robin M.; Momoh, Paul O.; Bozeman, Amelia D.

2005-01-01

The full wavelength coverage of charge coupled device (CCD) detector when coupled with an echelle spectrography, the system allows for simultaneously multiple element spectroscopy to be performed. The multiple-element flame spectrometer was built and characterized through the analysis of environmentally significant elements such as Ca, K, Na, Cu,…

Use of Large Surface MicroChannel Plates for the Tagging of Intermediate Energy Exotic Beams

Energy Technology Data Exchange (ETDEWEB)

Lombardo, I., E-mail: ilombardo@lns.infn.it [Dipartimento di Fisica, Universita di Catania, Catania (Italy); INFN Laboratori Nazionali del Sud, Catania (Italy); Amorini, F. [INFN Laboratori Nazionali del Sud, Catania (Italy); Cardella, G. [INFN, Sezione di Catania, Catania (Italy); Cavallaro, S. [Dipartimento di Fisica, Universita di Catania, Catania (Italy); INFN Laboratori Nazionali del Sud, Catania (Italy); De Filippo, E. [INFN, Sezione di Catania, Catania (Italy); Geraci, E.; Grassi, L. [Dipartimento di Fisica, Universita di Catania, Catania (Italy); INFN, Sezione di Catania, Catania (Italy); La Guidara, E. [INFN, Sezione di Catania, Catania (Italy); Centro Siciliano di Fisica Nucleare e Struttura della Materia, Catania (Italy); Lanzalone, G. [INFN Laboratori Nazionali del Sud, Catania (Italy); Libera Universita Kore, Enna (Italy); Pagano, A.; Papa, M.; Pirrone, S. [INFN, Sezione di Catania, Catania (Italy); Politi, G. [Dipartimento di Fisica, Universita di Catania, Catania (Italy); INFN, Sezione di Catania, Catania (Italy); Porto, F.; Rizzo, F.; Russotto, P. [Dipartimento di Fisica, Universita di Catania, Catania (Italy); INFN Laboratori Nazionali del Sud, Catania (Italy); Verde, G. [INFN, Sezione di Catania, Catania (Italy); Vigilante, M. [INFN, Sezione di Napoli and Dipartimento di Fisica, Universita Federico II di Napoli (Italy)

2011-06-15

We show the properties of the tagging system for exotic beams coupled to the CHIMERA detector. In particular, the characteristics of a newly developed large surface MicroChannel Plate will be discussed. Timing and efficiency of this instrument have been investigated. Preliminary results of tests performed with radioactive beams and alpha sources are presented.

Age, distribution, and significance within a sediment budget, of in-channel depositional surfaces in the Normanby River, Queensland, Australia

Science.gov (United States)

Pietsch, T. J.; Brooks, A. P.; Spencer, J.; Olley, J. M.; Borombovits, D.

2015-06-01

We present the results of investigations into alluvial deposition in the catchment of the Normanby River, which flows into Princess Charlotte Bay (PCB) in the northern part of the Great Barrier Reef Lagoon. Our focus is on the fine fraction (bank attached bars or inset or inner floodplains, these more or less flat-lying surfaces within the macro-channel have hitherto received little attention in sediment budgeting models. We use high resolution LiDAR based mapping combined with optical dating of exposures cut into these in-channel deposits to compare their aggradation rates with those found in other depositional zones in the catchment, namely the floodplain and coastal plain. In total 59 single grain OSL dates were produced across 21 stratigraphic profiles at 14 sites distributed though the 24 226 km2 catchment. In-channel storage in these inset features is a significant component of the contemporary fine sediment budget (i.e. recent decades/last century), annually equivalent to more than 50% of the volume entering the channel network from hillslopes and subsoil sources. Therefore, at the very least, in-channel storage of fine material needs to be incorporated into sediment budgeting exercises. Furthermore, deposition within the channel has occurred in multiple locations coincident in time with accelerated sediment production following European settlement. Generally, this has occurred on a subset of the features we have examined here, namely linear bench features low in the channel. This suggests that accelerated aggradation on in-channel depositional surfaces has been in part a response to accelerated erosion within the catchment. The entire contribution of ~ 370 kilotonnes per annum of fine sediment estimated to have been produced by alluvial gully erosion over the last ~ 100 years can be accounted for by that stored as in-channel alluvium. These features therefore can play an important role in mitigating the impact on the receiving water of accelerated erosion.

Performance of an area variable MOS varicap weighted programmable CCD transversal filter

OpenAIRE

Bhattacharyya, A.B.; Shankarnarayan, L.; Kapur, N.; Wallinga, Hans

1981-01-01

The performance of an electrically programmable CCD transversal filter (PTF) is presented in which tap-weight multiplication is performed by a novel and compact on chip voltage controlled area variable MOS varicap.

Automated galaxy surface photometry

International Nuclear Information System (INIS)

Cawson, M.G.M.; Kibblewhite, E.J.; Disney, M.J.; Phillipps, S.

1987-01-01

Two-dimensional surface photometry of a very large number of galaxies on a deep Schmidt plate has been obtained using the Automatic Plate Measuring System (APM). A method of photometric calibration, suitable for APM measurements, via pixel-by-pixel comparison with CCD frames of a number of the brighter galaxies is described and its advantages are discussed. The same method is used to demonstrate the consistency of measurement of the APM machine when used for surface photometry. (author)

Two Herbig-Haro objects discovered by narrow-band CCD imagery

International Nuclear Information System (INIS)

Ogura, Katsuo

1990-01-01

Two new Herbig-Haro objects, HH 132 and HH 133, have been discovered by CCD imagery behind interference filters on and just off the forbidden S II lines in the red. They are located in Puppis R2 and in Vela R2. Possible locations of their exciting sources are discussed. 12 refs

CCD polarimetry as a probe of regions of recent-star formation

Energy Technology Data Exchange (ETDEWEB)

Draper, P W

1988-01-01

Chapter 1 of this thesis details the incorporation of a Charged-Coupled Device (CCD) detector system with the Durham Imaging Polarimeter. The details include the physical characteristics of the device and the electronics and software associated with the device control and data storage. Chapter 2 of this work describes fully how suitable corrections for this effect can be made, and derives first-order results. The CCD performance is examined in comparison with the detector used previously and hence the veracity of the new results is established. Chapter 3 is a relevant summary of the status of the astronomy of the immediate regions of recent-star formation. Chapter 4 describes multicolor polarimetry of NGC2261/R Mon covering the period 1979 to 1986. The data conclusively prove that the polarization of R Mon must be due to effects close to R Mon (approx.14 astronomical units).

A simple and accurate method for the quality control of the I.I.-DR apparatus using the CCD camera

International Nuclear Information System (INIS)

Igarashi, Hitoshi; Shiraishi, Akihisa; Kuraishi, Masahiko

2000-01-01

With the advancing development of CCD cameras, the I.I.-DR apparatus has been introduced into the x-ray fluoroscopy television system. Consequently, quality control of the system has become a complicated task. We developed a simple, accurate method for quality control of the I.I.-DR apparatus using the CCD camera. Experiments were separately performed for the imager system [laser imager, DDX (dynamic digital x-ray system)] and the imaging system (I.I., ND-filter, IRIS, CCD camera). Quality control of the imager system was done by simply examining both input and output characteristics with a sliding pattern. Quality control of the imaging system was also conducted by estimating AVE (the average volume element), which was obtained using a phantom under the constant conditions. The results indicated that this simplified method is useful as a weekly quality control check of the I.I.-DR apparatus using the CCD camera. (author)

A CCD-based area detector for X-ray crystallography using synchrotron and laboratory sources

International Nuclear Information System (INIS)

Phillips, W.C.; Li Youli; Stanton, M.; Xie Yuanhui; O'Mara, D.; Kalata, K.

1993-01-01

The design and characteristics of a CCD-based area detector suitable for X-ray crystallographic studies using both synchrotron and laboratory sources are described. The active area is 75 mm in diameter, the FWHM of the point response function is 0.20 mm, and for Bragg peaks the dynamic range is 900 and the DQE ∼0.3. The 1320x1035-pixel Kodak CCD is read out into an 8 Mbyte memory system in 0.14 s and digitized to 12 bits. X-ray crystallographic data collected at the NSLS synchrotron from cubic insulin crystals are presented. (orig.)

Validation of simulations of an underwater acoustic communication channel characterized by wind-generated surface waves and bubbles

NARCIS (Netherlands)

Dol, H.S.; Colin, M.E.G.D.; Ainlie, M.A.; Gerdes, F.; Schäfke, A.; Özkan Sertlekc, H.

2013-01-01

This paper shows that it is possible to simulate realistic shallow-water acoustic communication channels using available acoustic propagation models. Key factor is the incorporation of realistic time-dependent sea surface conditions, including both waves and bubbles due to wind.

Secondary Channel Bifurcation Geometry: A Multi-dimensional Problem

Science.gov (United States)

Gaeuman, D.; Stewart, R. L.

2017-12-01

The construction of secondary channels (or side channels) is a popular strategy for increasing aquatic habitat complexity in managed rivers. Such channels, however, frequently experience aggradation that prevents surface water from entering the side channels near their bifurcation points during periods of relatively low discharge. This failure to maintain an uninterrupted surface water connection with the main channel can reduce the habitat value of side channels for fish species that prefer lotic conditions. Various factors have been proposed as potential controls on the fate of side channels, including water surface slope differences between the main and secondary channels, the presence of main channel secondary circulation, transverse bed slopes, and bifurcation angle. A quantitative assessment of more than 50 natural and constructed secondary channels in the Trinity River of northern California indicates that bifurcations can assume a variety of configurations that are formed by different processes and whose longevity is governed by different sets of factors. Moreover, factors such as bifurcation angle and water surface slope vary with discharge level and are continuously distributed in space, such that they must be viewed as a multi-dimensional field rather than a single-valued attribute that can be assigned to a particular bifurcation.

A waveless two-dimensional flow in a channel against an inclined wall with surface tension effect

International Nuclear Information System (INIS)

Merzougui, Abdelkrim; Mekias, Hocine; Guechi, Fairouz

2007-01-01

Surface tension effect on a two-dimensional channel flow against an inclined wall is considered. The flow is assumed to be steady, irrotational, inviscid and incompressible. The effect of surface tension is taken into account and the effect of gravity is neglected. Numerical solutions are obtained via series truncation procedure. The problem is solved numerically for various values of the Weber number α and for various values of the inclination angle β between the horizontal bottom and the inclined wall

A waveless two-dimensional flow in a channel against an inclined wall with surface tension effect

Energy Technology Data Exchange (ETDEWEB)

Merzougui, Abdelkrim [Departement de Mathematiques, Faculte des sciences, Universite Mohamed Boudiaf, M' sila, 28000 (Algeria); Mekias, Hocine [Departement de Mathematiques, Faculte des sciences, Universite Farhat Abbas Setif 19000 (Algeria); Guechi, Fairouz [Departement de Mathematiques, Faculte des sciences, Universite Farhat Abbas Setif 19000 (Algeria)

2007-11-23

Surface tension effect on a two-dimensional channel flow against an inclined wall is considered. The flow is assumed to be steady, irrotational, inviscid and incompressible. The effect of surface tension is taken into account and the effect of gravity is neglected. Numerical solutions are obtained via series truncation procedure. The problem is solved numerically for various values of the Weber number {alpha} and for various values of the inclination angle {beta} between the horizontal bottom and the inclined wall.

Fiber-MZI-based FBG sensor interrogation: comparative study with a CCD spectrometer.

Science.gov (United States)

Das, Bhargab; Chandra, Vikash

2016-10-10

We present an experimental comparative study of the two most commonly used fiber Bragg grating (FBG) sensor interrogation techniques: a charge-coupled device (CCD) spectrometer and a fiber Mach-Zehnder interferometer (F-MZI). Although the interferometric interrogation technique is historically known to offer the highest sensitivity measurements, very little information exists regarding how it compares with the current commercially available spectral-characteristics-based interrogation systems. It is experimentally established here that the performance of a modern-day CCD spectrometer interrogator is very close to a F-MZI interrogator with the capability of measuring Bragg wavelength shifts with sub-picometer-level accuracy. The results presented in this research study can further be used as a guideline for choosing between the two FBG sensor interrogator types for small-amplitude dynamic perturbation measurements down to nano-level strain.

Use of a CCD-based area detection system of a fibre diffractometer

International Nuclear Information System (INIS)

Hanna, S.; Windle, A.H.

1995-01-01

We describe a new X-ray fibre diffractometer, consisting of a commercial X-ray sensitive video camera coupled to a conventional 3 goniometer in place of a more traditional single-point detector. The active element of the video camera is a charge-coupled device (CCD). Diffraction images, obtained at various goniometer settings, are transformed into reciprocal space, and combined to give a complete section through the origin and parallel to the symmetry axis of cylindrically averaged reciprocal space. A greater density of measurements is needed in the vicinity of the reciprocal fibre axis in order to avoid information loss due to the curvature of the Ewald sphere. The pros and cons of using CCD's as X-ray detectors are discussed and sample results from polymer fibers are shown. 17 refs., 5 figs

Charge and spin transport in edge channels of a ν=0 quantum Hall system on the surface of topological insulators.

Science.gov (United States)

Morimoto, Takahiro; Furusaki, Akira; Nagaosa, Naoto

2015-04-10

Three-dimensional topological insulators of finite thickness can show the quantum Hall effect (QHE) at the filling factor ν=0 under an external magnetic field if there is a finite potential difference between the top and bottom surfaces. We calculate energy spectra of surface Weyl fermions in the ν=0 QHE and find that gapped edge states with helical spin structure are formed from Weyl fermions on the side surfaces under certain conditions. These edge channels account for the nonlocal charge transport in the ν=0 QHE which is observed in a recent experiment on (Bi_{1-x}Sb_{x})_{2}Te_{3} films. The edge channels also support spin transport due to the spin-momentum locking. We propose an experimental setup to observe various spintronics functions such as spin transport and spin conversion.

CCD high-speed videography system with new concepts and techniques

Science.gov (United States)

Zheng, Zengrong; Zhao, Wenyi; Wu, Zhiqiang

1997-05-01

A novel CCD high speed videography system with brand-new concepts and techniques is developed by Zhejiang University recently. The system can send a series of short flash pulses to the moving object. All of the parameters, such as flash numbers, flash durations, flash intervals, flash intensities and flash colors, can be controlled according to needs by the computer. A series of moving object images frozen by flash pulses, carried information of moving object, are recorded by a CCD video camera, and result images are sent to a computer to be frozen, recognized and processed with special hardware and software. Obtained parameters can be displayed, output as remote controlling signals or written into CD. The highest videography frequency is 30,000 images per second. The shortest image freezing time is several microseconds. The system has been applied to wide fields of energy, chemistry, medicine, biological engineering, aero- dynamics, explosion, multi-phase flow, mechanics, vibration, athletic training, weapon development and national defense engineering. It can also be used in production streamline to carry out the online, real-time monitoring and controlling.

CCD photometry of Cepheid sequences in four nearby galaxies

International Nuclear Information System (INIS)

Metcalfe, N.; Shanks, T.

1991-01-01

We present Isaac Newton Telescope B and V CCD observations of deep photometric sequences in the vicinity of Cepheid variable stars in three nearby galaxies - M31, M33 and NGC 2403. We have also checked the photometry of the brightest stars in M81 and its dwarf companion, Holmberg IX. We use our data, combined with other recent results, to re-analyse the Cepheid distances to these galaxies. (author)

An Improved Single-Channel Method to Retrieve Land Surface Temperature from the Landsat-8 Thermal Band

Directory of Open Access Journals (Sweden)

Jordi Cristóbal

2018-03-01

Full Text Available Land surface temperature (LST is one of the sources of input data for modeling land surface processes. The Landsat satellite series is the only operational mission with more than 30 years of archived thermal infrared imagery from which we can retrieve LST. Unfortunately, stray light artifacts were observed in Landsat-8 TIRS data, mostly affecting Band 11, currently making the split-window technique impractical for retrieving surface temperature without requiring atmospheric data. In this study, a single-channel methodology to retrieve surface temperature from Landsat TM and ETM+ was improved to retrieve LST from Landsat-8 TIRS Band 10 using near-surface air temperature (Ta and integrated atmospheric column water vapor (w as input data. This improved methodology was parameterized and successfully evaluated with simulated data from a global and robust radiosonde database and validated with in situ data from four flux tower sites under different types of vegetation and snow cover in 44 Landsat-8 scenes. Evaluation results using simulated data showed that the inclusion of Ta together with w within a single-channel scheme improves LST retrieval, yielding lower errors and less bias than models based only on w. The new proposed LST retrieval model, developed with both w and Ta, yielded overall errors on the order of 1 K and a bias of −0.5 K validated against in situ data, providing a better performance than other models parameterized using w and Ta or only w models that yielded higher error and bias.

Measuring neutron fluences and gamma/x-ray fluxes with CCD cameras

International Nuclear Information System (INIS)

Yates, G.J.; Smith, G.W.; Zagarino, P.; Thomas, M.C.

1991-01-01

The capability to measure bursts of neutron fluences and gamma/x-ray fluxes directly with charge coupled device (CCD) cameras while being able to distinguish between the video signals produced by these two types of radiation, even when they occur simultaneously, has been demonstrated. Volume and area measurements of transient radiation-induced pixel charge in English Electric Valve (EEV) Frame Transfer (FT) charge coupled devices (CCDs) from irradiation with pulsed neutrons (14 MeV) and Bremsstrahlung photons (4--12 MeV endpoint) are utilized to calibrate the devices as radiometric imaging sensors capable of distinguishing between the two types of ionizing radiation. Measurements indicate ∼.05 V/rad responsivity with ≥1 rad required for saturation from photon irradiation. Neutron-generated localized charge centers or ''peaks'' binned by area and amplitude as functions of fluence in the 10 5 to 10 7 n/cm 2 range indicate smearing over ∼1 to 10% of CCD array with charge per pixel ranging between noise and saturation levels

Important considerations for radiochromic film dosimetry with flatbed CCD scanners and EBT GAFCHROMIC[reg] film

International Nuclear Information System (INIS)

Lynch, Bart D.; Kozelka, Jakub; Ranade, Manisha K.; Li, Jonathan G.; Simon, William E.; Dempsey, James F.

2006-01-01

In this study, we present three significant artifacts that have the potential to negatively impact the accuracy and precision of film dosimetry measurements made using GAFCHROMIC[reg] EBT radiochromic film when read out with CCD flatbed scanners. Films were scanned using three commonly employed instruments: a Macbeth TD932 spot densitometer, an Epson Expression 1680 CCD array scanner, and a Microtek ScanMaker i900 CCD array scanner. For the two scanners we assessed the variation in optical density (OD) of GAFCHROMIC EBT film with scanning bed position, angular rotation of the film with respect to the scan line direction, and temperature inside the scanner due to repeated scanning. Scanning uniform radiochromic films demonstrated a distinct bowing effect in profiles in the direction of the CCD array with a nonuniformity of up to 17%. Profiles along a direction orthogonal to the CCD array demonstrated a 7% variation. A strong angular dependence was found in measurements made with the flatbed scanners; the effect could not be reproduced with the spot densitometer. An IMRT quality assurance film was scanned twice rotating the film 90 deg. between the scans. For films scanned on the Epson scanner, up to 12% variation was observed in unirradiated EBT films rotated between 0 deg. and 90 deg. , which decreased to approximately 8% for EBT films irradiated to 300 cGy. Variations of up to 80% were observed for films scanned with the Microtek scanner. The scanners were found to significantly increase the film temperature with repeated scanning. Film temperature between 18 and 33 deg. C caused OD changes of approximately 7%. Considering these effects, we recommend adherence to a strict scanning protocol that includes: maintaining the orientation of films scanned on flatbed scanners, limiting scanning to the central portion of the scanner bed, and limiting the number of consecutive scans to minimize changes in OD caused by film heating

CHANNELING OF B-IONS IN SILICON

NARCIS (Netherlands)

VOS, M; MITCHELL, [No Value; SMULDERS, PJM

We present new results on the channeling of B ions in Si crystals. Standard surface barrier detectors have been used to record energy spectra for B ions backscattered from the near surface (approximately 1500 angstrom) of a silicon crystal, under perfect, and near axial and planar channeling

BVRI CCD photometry of Omega Centauri

International Nuclear Information System (INIS)

Alcaino, G.; Liller, W.

1987-01-01

Color-magnitude diagrams (CMDs) of V vs B-V, V vs V-I, and V vs B-I have been constructed based on 179 BVRI CCD frames of two adjoining 4x2.5-arcmin fields in Omega Cen (NGC 5139) obtained with the 1.54-m Danish La Silla telescope. The spread in the main sequences noted in the three CMDs indicates that the wide range in chemical composition among the evolved stars in this cluster persists as well in the unevolved stars. This result suggests that the abundance variations are primordial. A difference in magnitude between the turnoff and the horizontal branch of 3.8 + or - 0.15 is found which is greater than a previous value. 38 references

Drag-reducing performance of obliquely aligned superhydrophobic surface in turbulent channel flow

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Sho; Fukagata, Koji [Department of Mechanical Engineering, Keio University, Hiyoshi 3-14-1, Kohoku-ku, Yokohama 223-8522 (Japan); Mamori, Hiroya, E-mail: fukagata@mech.keio.ac.jp [Department of Mechanical Engineering, Tokyo University of Science, Niijuku 6-3-1, Katsushika-ku, Tokyo 125-8585 (Japan)

2017-04-15

Friction drag reduction effect by superhydrophobic surfaces in a turbulent channel flow is investigated by means of direct numerical simulation. The simulations are performed under a constant pressure gradient at the friction Reynolds number of 180. A special focus is laid upon the influence of the angle of microridge structure to flow direction, while the gas area fraction on the surface is kept at 50% and the groove width is kept constant at 33.75 wall units. Larger drag reduction effect is observed for a smaller angle: the bulk-mean velocity is increased about 15% when the microridge is parallel to the flow. The drag reduction effect is found to deteriorate rapidly with the microridge angle due to a decrease in the slip velocity. The Reynolds stress budgets show that the modification in each physical effect is qualitatively similar but more pronounced when the microridge is aligned with the stream. (paper)

The OmegaCAM 16K x 16K CCD detector system for the ESO VLT Survey Telescope (VST)

Science.gov (United States)

Iwert, Olaf; Baade, D.; Balestra, A.; Baruffolo, A.; Bortolussi, A.; Christen, F.; Cumani, C.; Deiries, S.; Downing, M.; Geimer, C.; Hess, G.; Hess, J.; Kuijken, K.; Lizon, J.; Muschielok, B.; Nicklas, H.; Reiss, R.; Reyes, J.; Silber, A.; Thillerup, J.; Valentijn, E.

2006-06-01

A 16K x 16K, 1 degree x 1 degree field, detector system was developed by ESO for the OmegaCAM instrument for use on the purpose built ESO VLT Survey Telescope (VST). The focal plane consists of an 8 x 4 mosaic of 2K x 4K 15um pixel e2v CCDs and four 2K x 4K CCDs on the periphery for the opto-mechanical control of the telescope. The VST is a single instrument telescope. This placed stringent reliability requirements on the OmegaCAM detector system such as 10 years lifetime and maximum downtime of 1.5 %. Mounting at Cassegrain focus required a highly autonomous self-contained cooling system that could deliver 65 W of cooling power. Interface space for the detector head was severely limited by the way the instrument encloses the CCD cryostat. The detector system features several novel ideas tailored to meet these requirements and described in this paper: Key design drivers of the detector head were the easily separable but precisely aligned connections to the optical field flattener on the top and the cooling system at the bottom. Material selection, surface treatment, specialized coatings and in-situ plasma cleaning were crucial to prevent contamination of the detectors. Inside the cryostat, cryogenic and electrical connections were disentangled to keep the configuration modular, integration friendly and the detectors in a safe condition during all mounting steps. A compact unit for logging up to 125 Pt100 temperature sensors and associated thermal control loops was developed (ESO's new housekeeping unit PULPO 2), together with several new modular Pt100 packaging and mounting concepts. The electrical grouping of CCDs based on process parameters and test results is explained. Three ESO standardized FIERA CCD controllers in different configurations are used. Their synchronization mechanism for read-out is discussed in connection with the CCD grouping scheme, the shutter, and the integrated guiding and image analysis facility with four independent 2K x 4K CCDs. An

CCD photometry of NGC 2419

International Nuclear Information System (INIS)

Christian, C.A.; Heasley, J.N.

1988-01-01

The properties of the globular cluster NGC 2419 are reexamined using CCD photometry deepened to the vicinity of the main-sequence turnoff. A new color-magnitude diagram is derived that extends to V = 24.5 mag. It is concluded that NGC 2419 is an outer-halo analog of the metal-poor globulars closer to the Galactic center. NGC 2419 is probably nearly the same age as M15 and differs only slightly, if at all, in metallicity. NGC 2419 has many similarities with the clusters NGC 5466, M15, and M92. Comparison of the data with the isochrones of VandenBerg and Bell (1985) implies a distance modulus of 20.1 with Delta (B-V) = 0.18 mag. Oxygen-rich models can be fit to the data; such a comparison yields a lower limit to the acceptable distance modulus of the cluster. 26 references

Study of condensation of refrigerants in a micro-channel for development of future compact micro-channel condensers

Science.gov (United States)

Chowdhury, Sourav

2009-12-01

Mini- and micro-channel technology has gained considerable ground in the recent years in industry and is favored due to its several advantages stemming from its high surface to volume ratio and high values of proof pressure it can withstand. Micro-channel technology has paved the way to development of highly compact heat exchangers with low cost and mass penalties. In the present work, the issues related to the sizing of compact micro-channel condensers have been explored. The considered designs encompass both the conventional and MEMS fabrication techniques. In case of MEMS-fabricated micro-channel condenser, wet etching of the micro-channel structures, followed by bonding of two such wafers with silicon nitride layers at the interface was attempted. It was concluded that the silicon nitride bonding requires great care in terms of high degree of surface flatness and absence of roughness and also high degree of surface purity and thus cannot be recommended for mass fabrication. Following this investigation, a carefully prepared experimental setup and test micro-channel with hydraulic diameter 700 mum and aspect ratio 7:1 was fabricated and overall heat transfer and pressure drop aspects of two condensing refrigerants, R134a and R245fa were studied at a variety of test conditions. To the best of author's knowledge, so far no data has been reported in the literature on condensation in such high aspect ratio micro-channels. Most of the published experimental works on condensation of refrigerants are concerning conventional hydraulic diameter channels (> 3mm) and only recently some experimental data has been reported in the sub-millimeter scale channels for which the surface tension and viscosity effects play a dominant role and the effect of gravity is diminished. It is found that both experimental data and empirically-derived correlations tend to under-predict the present data by an average of 25%. The reason for this deviation could be because a high aspect ratio

Independence Between Two Channels of Surface Electromyogram Signal to Measure the Loss of Motor Units

Directory of Open Access Journals (Sweden)

Arjunan Sridhar P.

2015-06-01

Full Text Available This study has investigated the relationship in the connectivity of motor units in surface electromyogram (sEMG of biceps brachii muscle. It is hypothesized that with ageing, there is reduction/loss in number of motor units, leading to reduction in the independence between the channels of the recorded muscle activity. Two channels of sEMG were recorded during three levels of isometric muscle contraction: 50 %, 75 % and 100 % maximal voluntary contraction (MVC. 73 subjects (age range 20-70 participated in the experiments. The independence in channel index (ICI between the two sEMG recording locations was computed using the independent components and Frobenius norm. ANOVA Statistical analysis was performed to test the effect of age (loss of motor units and level of contraction on ICI. The results show that the ICI among the older cohort was significantly lower compared with the younger adults. This research study has shown that the reduction in number of motor units is reflected by the reduction in the ICI of the sEMG signal.

Ultraviolet downconverting phosphor for use with silicon CCD imagers

Science.gov (United States)

Blouke, M. M.; Cowens, M. W.; Hall, J. E.; Westphal, J. A.; Christensen, A. B.

1980-01-01

The properties and application of a UV downconverting phosphor (coronene) to silicon charge coupled devices are discussed. Measurements of the absorption spectrum have been extended to below 1000 A, and preliminary results indicate the existence of useful response to at least 584 A. The average conversion efficiency of coronene was measured to be approximately 20% at 2537 A. Imagery at 3650 A using a backside illuminated 800 x 800 CCD coated with coronene is presented.

Characterization of a 512x512-pixel 8-output full-frame CCD for high-speed imaging

Science.gov (United States)

Graeve, Thorsten; Dereniak, Eustace L.

1993-01-01

The characterization of a 512 by 512 pixel, eight-output full frame CCD manufactured by English Electric Valve under part number CCD13 is discussed. This device is a high- resolution Silicon-based array designed for visible imaging applications at readout periods as low as two milliseconds. The characterization of the device includes mean-variance analysis to determine read noise and dynamic range, as well as charge transfer efficiency, MTF, and quantum efficiency measurements. Dark current and non-uniformity issues on a pixel-to-pixel basis and between individual outputs are also examined. The characterization of the device is restricted by hardware limitations to a one MHz pixel rate, corresponding to a 40 ms readout time. However, subsections of the device have been operated at up to an equivalent 100 frames per second. To maximize the frame rate, the CCD is illuminated by a synchronized strobe flash in between frame readouts. The effects of the strobe illumination on the imagery obtained from the device is discussed.

Three-channel false colour AFM images for improved interpretation of complex surfaces: A study of filamentous cyanobacteria

International Nuclear Information System (INIS)

Kurk, Toby; Adams, David G.; Connell, Simon D.; Thomson, Neil H.

2010-01-01

Imaging signals derived from the atomic force microscope (AFM) are typically presented as separate adjacent images with greyscale or pseudo-colour palettes. We propose that information-rich false-colour composites are a useful means of presenting three-channel AFM image data. This method can aid the interpretation of complex surfaces and facilitate the perception of information that is convoluted across data channels. We illustrate this approach with images of filamentous cyanobacteria imaged in air and under aqueous buffer, using both deflection-modulation (contact) mode and amplitude-modulation (tapping) mode. Topography-dependent contrast in the error and tertiary signals aids the interpretation of the topography signal by contributing additional data, resulting in a more detailed image, and by showing variations in the probe-surface interaction. Moreover, topography-independent contrast and topography-dependent contrast in the tertiary data image (phase or friction) can be distinguished more easily as a consequence of the three dimensional colour-space.

Three-channel false colour AFM images for improved interpretation of complex surfaces: A study of filamentous cyanobacteria

Energy Technology Data Exchange (ETDEWEB)

Kurk, Toby, E-mail: phytak@leeds.ac.uk [School of Physics and Astronomy, University of Leeds, Leeds, West Yorkshire LS2 9JT (United Kingdom); Adams, David G., E-mail: D.G.Adams@leeds.ac.uk [Faculty of Biological Sciences, University of Leeds, Leeds, West Yorkshire LS2 9JT (United Kingdom); Connell, Simon D., E-mail: S.D.A.Connell@leeds.ac.uk [School of Physics and Astronomy, University of Leeds, Leeds, West Yorkshire LS2 9JT (United Kingdom); Thomson, Neil H., E-mail: N.H.Thomson@leeds.ac.uk [School of Physics and Astronomy, University of Leeds, Leeds, West Yorkshire LS2 9JT (United Kingdom); Dental Institute, University of Leeds, Leeds, West Yorkshire LS2 9JT (United Kingdom)

2010-05-15

Imaging signals derived from the atomic force microscope (AFM) are typically presented as separate adjacent images with greyscale or pseudo-colour palettes. We propose that information-rich false-colour composites are a useful means of presenting three-channel AFM image data. This method can aid the interpretation of complex surfaces and facilitate the perception of information that is convoluted across data channels. We illustrate this approach with images of filamentous cyanobacteria imaged in air and under aqueous buffer, using both deflection-modulation (contact) mode and amplitude-modulation (tapping) mode. Topography-dependent contrast in the error and tertiary signals aids the interpretation of the topography signal by contributing additional data, resulting in a more detailed image, and by showing variations in the probe-surface interaction. Moreover, topography-independent contrast and topography-dependent contrast in the tertiary data image (phase or friction) can be distinguished more easily as a consequence of the three dimensional colour-space.

OPTIMASI DENGAN ALGORITMA RSM-CCD PADA EVAPORATOR VAKUM WATERJET DENGAN PENGENDALI SUHU FUZZY PADA PEMBUATAN PERMEN SUSU (RSM-CCD Algorithm for Optimizing Waterjet Vacuum Evaporator Using Fuzzy Temperature Control in The Milk Candy Production

Directory of Open Access Journals (Sweden)

Yusuf Hendrawan

2016-10-01

Full Text Available Milk candy is a product which has to be produced under a high temperature to achieve the caramelization process. The use of vacuum system during a food processing is one of the alternatives to engineer the value of a material’s boiling point. The temperature control system and the mixing speed in machine that produce the milk candy were expected to be able to prevent the formation of off-flavour in the final product. A smart control system based on fuzzy logic was applied in the temperature control within the double jacket vacuum evaporator machine that needs stable temperature in the cooking process. The objective of this research is developing vacuum evaporator for milk candy production using fuzzy temperature control. The result in machine and system planning showed that the process of milk candy production was going on well. The parameter optimization of water content and ash content purposed to acquire the temperature point parameter and mixing speed in milk candy production. The optimization method was response surface methodology (RSM, by using the model of central composite design (CCD. The optimization resulted 90.18oC for the temperature parameter and 512 RPM for the mixing speed, with the prediction about 4.69% of water content and 1.57% of ash content. Keywords: Optimization, vacuum evaporator, fuzzy, milk candy, response surface methodology ABSTRAK Permen susu merupakan salah satu produk yang diolah dengan suhu tinggi untuk mencapai proses karamelisasi. Pengolahan pangan dengan sistem vakum merupakan salah satu alternatif untuk merekayasa nilai titik didih suatu bahan. Sistem pengendalian suhu serta kecepatan pengadukan pada mesin produksi permen susu diharapkan dapat mencegah terbentuknya partikel hitam (off-flavour pada produk akhir. Sistem kontrol cerdas logika fuzzy diaplikasikan dalam pengendalian suhu pada mesin evaporator vakum double jacket yang membutuhkan tingkat stabilitas suhu pemasakan permen susu. Tujuan dari

Soft x-ray imager (SXI) onboard the NeXT satellite

Science.gov (United States)

Tsuru, Takeshi Go; Takagi, Shin-Ichiro; Matsumoto, Hironori; Inui, Tatsuya; Ozawa, Midori; Koyama, Katsuji; Tsunemi, Hiroshi; Hayashida, Kiyoshi; Miyata, Emi; Ozawa, Hideki; Touhiguchi, Masakuni; Matsuura, Daisuke; Dotani, Tadayasu; Ozaki, Masanobu; Murakami, Hiroshi; Kohmura, Takayoshi; Kitamoto, Shunji; Awaki, Hisamitsu

2006-06-01

We give overview and the current status of the development of the Soft X-ray Imager (SXI) onboard the NeXT satellite. SXI is an X-ray CCD camera placed at the focal plane detector of the Soft X-ray Telescopes for Imaging (SXT-I) onboard NeXT. The pixel size and the format of the CCD is 24 x 24μm (IA) and 2048 x 2048 x 2 (IA+FS). Currently, we have been developing two types of CCD as candidates for SXI, in parallel. The one is front illumination type CCD with moderate thickness of the depletion layer (70 ~ 100μm) as a baseline plan. The other one is the goal plan, in which we develop back illumination type CCD with a thick depletion layer (200 ~ 300μm). For the baseline plan, we successfully developed the proto model 'CCD-NeXT1' with the pixel size of 12μm x 12μm and the CCD size of 24mm x 48mm. The depletion layer of the CCD has reached 75 ~ 85μm. The goal plan is realized by introduction of a new type of CCD 'P-channel CCD', which collects holes in stead of electrons in the common 'N-channel CCD'. By processing a test model of P-channel CCD we have confirmed high quantum efficiency above 10 keV with an equivalent depletion layer of 300μm. A back illumination type of P-channel CCD with a depletion layer of 200μm with aluminum coating for optical blocking has been also successfully developed. We have been also developing a thermo-electric cooler (TEC) with the function of the mechanically support of the CCD wafer without standoff insulators, for the purpose of the reduction of thermal input to the CCD through the standoff insulators. We have been considering the sensor housing and the onboard electronics for the CCD clocking, readout and digital processing of the frame date.

CCD linear image sensor ILX511 arrangment for a technical spectrometer

Czech Academy of Sciences Publication Activity Database

Bartoněk, L.; Keprt, Jiří; Vlček, Martin

2003-01-01

Roč. 33, 2-3 (2003), s. 548-553 ISSN 0078-5466 Institutional research plan: CEZ:AV0Z1010921 Keywords : CCD linear sensor ILX511 * enhanced parallel port (EPP able IEEE1284) * A/D converter AD9280 Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.221, year: 2003

The Human Acid-Sensing Ion Channel ASIC1a: Evidence for a Homotetrameric Assembly State at the Cell Surface.

Directory of Open Access Journals (Sweden)

Miguel Xavier van Bemmelen

Full Text Available The chicken acid-sensing ion channel ASIC1 has been crystallized as a homotrimer. We address here the oligomeric state of the functional ASIC1 in situ at the cell surface. The oligomeric states of functional ASIC1a and mutants with additional cysteines introduced in the extracellular pore vestibule were resolved on SDS-PAGE. The functional ASIC1 complexes were stabilized at the cell surface of Xenopus laevis oocytes or CHO cells either using the sulfhydryl crosslinker BMOE, or sodium tetrathionate (NaTT. Under these different crosslinking conditions ASIC1a migrates as four distinct oligomeric states that correspond by mass to multiples of a single ASIC1a subunit. The relative importance of each of the four ASIC1a oligomers was critically dependent on the availability of cysteines in the transmembrane domain for crosslinking, consistent with the presence of ASIC1a homo-oligomers. The expression of ASIC1a monomers, trimeric or tetrameric concatemeric cDNA constructs resulted in functional channels. The resulting ASIC1a complexes are resolved as a predominant tetramer over the other oligomeric forms, after stabilization with BMOE or NaTT and SDS-PAGE/western blot analysis. Our data identify a major ASIC1a homotetramer at the surface membrane of the cell expressing functional ASIC1a channel.

16-Channel surface coil for 13C-hyperpolarized spectroscopic imaging of cardiac metabolism in pig heart

DEFF Research Database (Denmark)

Frijia, Francesca; Santarelli, Maria Filomena; Koellisch, Ulrich

2016-01-01

Magnetic resonance spectroscopy (MRS) of hyperpolarized 13C pyruvate and its metabolites in large animal models is a powerful tool for assessing cardiac metabolism in patho-physiological conditions. In 13C studies, a high signal-to-noise ratio (SNR) is crucial to overcome the intrinsic data quality...... both targets. In this study, a 16-channel receive surface coil was designed for 13C hyperpolarized studies of the pig heart with a clinical 3-T scanner. The coil performance was characterized by phantom experiments and compared with that of a birdcage coil used in transmit/receive mode. Segmental...... of the 16-channel coil is recommended for studies of septal and anterior LV walls....

Computer-aided diagnosis of pneumoconiosis abnormalities extracted from chest radiographs scanned with a CCD scanner

International Nuclear Information System (INIS)

Abe, Koji; Minami, Masahide; Nakamura, Munehiro

2011-01-01

This paper presents a computer-aided diagnosis for pneumoconiosis radiographs obtained with a common charge-coupled devices (CCD) scanner. Since the current computer-aided diagnosis systems of pneumoconiosis are not practical for medical doctors due to high costs of usage for a special scanner, we propose a novel system which measures abnormalities of pneumoconiosis from lung images obtained with a common CCD scanner. Experimental results of discriminations between normal and abnormal cases for 56 right-lung images including 6 standard pneumoconiosis images have shown that the proposed abnormalities are well extracted according to the standards of pneumoconiosis categories. (author)

Atmospheric radiation environment analyses based-on CCD camera at various mountain altitudes and underground sites

Directory of Open Access Journals (Sweden)

Li Cavoli Pierre

2016-01-01

Full Text Available The purpose of this paper is to discriminate secondary atmospheric particles and identify muons by measuring the natural radiative environment in atmospheric and underground locations. A CCD camera has been used as a cosmic ray sensor. The Low Noise Underground Laboratory of Rustrel (LSBB, France gives the access to a unique low-noise scientific environment deep enough to ensure the screening from the neutron and proton radiative components. Analyses of the charge levels in pixels of the CCD camera induced by radiation events and cartographies of the charge events versus the hit pixel are proposed.

High-speed Fourier transform profilometry for reconstructing objects having arbitrary surface colours

International Nuclear Information System (INIS)

Chen, Liang-Chia; Nguyen, Xuan Loc; Zhang, Fu-Hao; Lin, Tzeng-Yow

2010-01-01

In this paper, Fourier transform profilometry (FTP) using a colour fringe selection technique for accurate phase map reconstruction is newly proposed to overcome the limitation of FTP in measuring objects having arbitrary surface colours. The sinusoidal colour fringe pattern is encoded to form a unique colour pattern for projecting onto the object's surface, and its reflected deformed fringe image is taken using a triple-colour CCD camera and rapidly processed by the developed FTP method employing a novel band-pass filter. A new 3D vision system is capable of measuring objects with a high speed of up to 60 frames s −1 . To reconstruct the 3D profile of an object having arbitrary surface colours, an innovative strategy is developed to identify the colour channel of the detected fringe pattern with the best modulation transfer function (MTF) for retrieving accurate phase maps. The experimental results demonstrate that the system has the capability to acquire 3D maps at a high speed while the measurement accuracy of the developed method is substantially better than that of the traditional FTP method. By measuring the standard step heights in a repeatability test, it is confirmed that a maximum measured error can be controlled to less than 2.8% of the overall measuring depth range

The astro-geodetic use of CCD for gravity field refinement

Science.gov (United States)

Gerstbach, G.

1996-07-01

The paper starts with a review of geoid projects, where vertical deflections are more effective than gravimetry. In alpine regions the economy of astrogeoids is at least 10 times higher, but many countries do not make use of this fact - presumably because the measurements are not fully automated up to now. Based upon the experiences of astrometry of high satellites and own tests the author analyses the use of CCD for astro-geodetic measurements. Automation and speeding up will be possible in a few years, the latter depending on the observation scheme. Sensor characteristics, cooling and reading out of the devices should be harmonized. Using line sensors in small prism astrolabes, the CCD accuracy will reach the visual one (±0.2″) within 5-10 years. Astrogeoids can be combined ideally with geological data, because vertical variation of rock densities does not cause systematic effects (contrary to gravimetry). So a geoid of ±5 cm accuracy (achieved in Austria and other alpine countries by 5-10 points per 1000 km 2) can be improved to ±2 cm without additional observations and border effects.

Fine Channel Networks

Science.gov (United States)

1997-01-01

A color image of fine channel networks on Mars; north toward top. The scene shows heavily cratered highlands dissected by dendritic open channel networks that dissect steep slopes of impact crater walls. This image is a composite of Viking high-resolution images in black and white and low-resolution images in color. The image extends from latitude 9 degrees S. to 5 degrees S. and from longitude 312 degrees to 320 degrees; Mercator projection. The dendritic pattern of the fine channels and their location on steep slopes leads to the interpretation that these are runoff channels. The restriction of these types of channels to ancient highland rocks suggests that these channels are old and date from a time on Mars when conditions existed for precipitation to actively erode rocks. After the channels reach a low plain, they appear to end. Termination may have resulted from burial by younger deposits or perhaps the flows percolated into the surface materials and continued underground.

Effect of Equal Channel Angular Pressing on the Surface Roughness of Solid State Recycled Aluminum Alloy 6061 Chips

Directory of Open Access Journals (Sweden)

Adel Taha Abbas

2017-01-01

Full Text Available Solid state recycling through hot extrusion is a promising technique to recycle machining chips without remelting. Furthermore, equal channel angular pressing (ECAP technique coupled with the extruded recycled billet is introduced to enhance the mechanical properties of recycled samples. In this paper, the surface roughness of solid state recycled aluminum alloy 6061 turning chips was investigated. Aluminum chips were cold compacted and hot extruded under an extrusion ratio (ER of 5.2 at an extrusion temperature (ET of 425°C. In order to improve the properties of the extruded samples, they were subjected to ECAP up to three passes at room temperature using an ECAP die with a channel die angle (Φ of 90°. Surface roughness (Ra and Rz of the processed recycled billets machined by turning was investigated. Box-Behnken experimental design was used to investigate the effect of three machining parameters (cutting speed, feed rate, and depth of cut on the surface roughness of the machined specimens for four materials conditions, namely, extruded billet and postextrusion ECAP processed billets to one, two, and three passes. Quadratic models were developed to relate the machining parameters to surface roughness, and a multiobjective optimization scheme was conducted to maximize material removal rate while maintaining the roughness below a preset practical value.

Puesta en marcha de un microdensitómetro automático basado en CCD

Science.gov (United States)

Calderón, J. H.; Bustos Fierro, I. H.

We present the commisioning of a CCD-based microdensitometer intended to perform astrometric measurements of photographic plates. The work done consisted in the installation of a CCD camera, the modification of the motion system, the construction of a new illumination device, the adaptation of the electronics, and the development of software. The instrument is intended to be used for the astrometric measurement mainly of plates of the Astrographic Catalog and Carte du Ciel collections from Córdoba Observatory. In this phase of the project we counted with the collaboration of the Instituto Provincial de Enseñanza Media No 59, 25 de Mayo, Cruz Alta (Province of Córdoba). The origin and importance of such collaboration is commented.

Acid-Sensing Ion Channel 2a (ASIC2a) Promotes Surface Trafficking of ASIC2b via Heteromeric Assembly

OpenAIRE

Kweon, Hae-Jin; Kim, Dong-Il; Bae, Yeonju; Park, Jae-Yong; Suh, Byung-Chang

2016-01-01

Acid-sensing ion channels (ASICs) are proton-activated cation channels that play important roles as typical proton sensors during pathophysiological conditions and normal synaptic activities. Among the ASIC subunits, ASIC2a and ASIC2b are alternative splicing products from the same gene, ACCN1. It has been shown that ASIC2 isoforms have differential subcellular distribution: ASIC2a targets the cell surface by itself, while ASIC2b resides in the ER. However, the underlying mechanism for this d...

Radiation damage of the PCO Pixelfly VGA CCD camera of the BES system on KSTAR tokamak

Energy Technology Data Exchange (ETDEWEB)

Náfrádi, Gábor, E-mail: nafradi@reak.bme.hu [NTI, BME, EURATOM Association, H-1111 Budapest (Hungary); Kovácsik, Ákos, E-mail: kovacsik.akos@reak.bme.hu [NTI, BME, EURATOM Association, H-1111 Budapest (Hungary); Pór, Gábor, E-mail: por@reak.bme.hu [NTI, BME, EURATOM Association, H-1111 Budapest (Hungary); Lampert, Máté, E-mail: lampert.mate@wigner.mta.hu [Wigner RCP, RMI, EURATOM Association, POB 49, 1525 Budapest (Hungary); Un Nam, Yong, E-mail: yunam@nfri.re.kr [NFRI, 169-148 Gwahak-Ro, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of); Zoletnik, Sándor, E-mail: zoletnik.sandor@wigner.mta.hu [Wigner RCP, RMI, EURATOM Association, POB 49, 1525 Budapest (Hungary)

2015-01-11

A PCO Pixelfly VGA CCD camera which is part a of the Beam Emission Spectroscopy (BES) diagnostic system of the Korea Superconducting Tokamak Advanced Research (KSTAR) used for spatial calibrations, suffered from serious radiation damage, white pixel defects have been generated in it. The main goal of this work was to identify the origin of the radiation damage and to give solutions to avoid it. Monte Carlo N-Particle eXtended (MCNPX) model was built using Monte Carlo Modeling Interface Program (MCAM) and calculations were carried out to predict the neutron and gamma-ray fields in the camera position. Besides the MCNPX calculations pure gamma-ray irradiations of the CCD camera were carried out in the Training Reactor of BME. Before, during and after the irradiations numerous frames were taken with the camera with 5 s long exposure times. The evaluation of these frames showed that with the applied high gamma-ray dose (1.7 Gy) and dose rate levels (up to 2 Gy/h) the number of the white pixels did not increase. We have found that the origin of the white pixel generation was the neutron-induced thermal hopping of the electrons which means that in the future only neutron shielding is necessary around the CCD camera. Another solution could be to replace the CCD camera with a more radiation tolerant one for example with a suitable CMOS camera or apply both solutions simultaneously.

CCD Photometry of W UMa Type Binary TY UMa

Directory of Open Access Journals (Sweden)

Young Woon Kang

2001-06-01

Full Text Available We present VRI CCD photometry of W UMa type binary TY UMa. The light curves show that the secondary minimum is deeper than theprimary minimum and the maximum I (0.p25 is 0.m023 brighter than the maximum II (0.p75. The V light curve has beenanalyzed and the photometric solutions have been determined by the method of Wilson & Devinney differential correction. Weadopted the spot model to explain the asymetric light curve.

A CCD fitted to the UV Prime spectrograph: Performance

International Nuclear Information System (INIS)

Boulade, O.

1986-10-01

A CCD camera was fitted to the 3.6 m French-Canadian telescope in Hawai. Performance of the system and observations of elliptic galaxies (stellar content and galactic evolution in a cluster) and quasars (absorption lines in spectra) are reported. In spite of its resolution being only average, the extremely rapid optics of the UV spectrograph gives good signal to noise ratios enabling redshifts and velocity scatter to be calculated with an accuracy better than 30 km/sec [fr

Channel sialic acids limit hERG channel activity during the ventricular action potential.

Science.gov (United States)

Norring, Sarah A; Ednie, Andrew R; Schwetz, Tara A; Du, Dongping; Yang, Hui; Bennett, Eric S

2013-02-01

Activity of human ether-a-go-go-related gene (hERG) 1 voltage-gated K(+) channels is responsible for portions of phase 2 and phase 3 repolarization of the human ventricular action potential. Here, we questioned whether and how physiologically and pathophysiologically relevant changes in surface N-glycosylation modified hERG channel function. Voltage-dependent hERG channel gating and activity were evaluated as expressed in a set of Chinese hamster ovary (CHO) cell lines under conditions of full glycosylation, no sialylation, no complex N-glycans, and following enzymatic deglycosylation of surface N-glycans. For each condition of reduced glycosylation, hERG channel steady-state activation and inactivation relationships were shifted linearly by significant depolarizing ∼9 and ∼18 mV, respectively. The hERG window current increased significantly by 50-150%, and the peak shifted by a depolarizing ∼10 mV. There was no significant change in maximum hERG current density. Deglycosylated channels were significantly more active (20-80%) than glycosylated controls during phases 2 and 3 of action potential clamp protocols. Simulations of hERG current and ventricular action potentials corroborated experimental data and predicted reduced sialylation leads to a 50-70-ms decrease in action potential duration. The data describe a novel mechanism by which hERG channel gating is modulated through physiologically and pathophysiologically relevant changes in N-glycosylation; reduced channel sialylation increases hERG channel activity during the action potential, thereby increasing the rate of action potential repolarization.

Channel erosion in a rapidly urbanizing region of Tijuana, Mexico: Enlargement downstream of channel hardpoints

Science.gov (United States)

Taniguchi, Kristine; Biggs, Trent; Langendoen, Eddy; Castillo, Carlos; Gudiño, Napoleon; Yuan, Yongping; Liden, Douglas

2016-04-01

Urban-induced erosion in Tijuana, Mexico, has led to excessive sediment deposition in the Tijuana Estuary in the United States. Urban areas in developing countries, in contrast to developed countries, are characterized by much lower proportions of vegetation and impervious surfaces due to limited access to urban services such as road paving and landscaping, and larger proportions of exposed soils. In developing countries, traditional watershed scale variables such as impervious surfaces may not be good predictors of channel enlargement. In this research, we surveyed the stream channel network of an erodible tributary of the Tijuana River Watershed, Los Laureles Canyon, at 125 locations, including repeat surveys from 2008. Structure from Motion (SfM) and 3D photo-reconstruction techniques were used to create digital terrain models of stream reaches upstream and downstream of channel hardpoints. Channels are unstable downstream of hardpoints, with incision up to 2 meters and widening up to 12 meters. Coordinated channelization is essential to avoid piece-meal approaches that lead to channel degradation. Watershed impervious area is not a good predictor of channel erosion due to the overriding importance of hardpoints and likely to the high sediment supply from the unpaved roads which prevents channel erosion throughout the stream network.

Researchers develop CCD image sensor with 20ns per row parallel readout time

CERN Multimedia

Bush, S

2004-01-01

"Scientists at the Rutherford Appleton Laboratory (RAL) in Oxfordshire have developed what they claim is the fastest CCD (charge-coupled device) image sensor, with a readout time which is 20ns per row" (1/2 page)

Roentgenographic evaluation of the actual CCD and AT angle. Pt. 2

International Nuclear Information System (INIS)

Brueckl, R.; Grunert, S.; Rosemeyer, B.

1986-01-01

The method developed by Rippstein and Mueller allows a mathematically exact determination of the femoral neck-shaft angle (CCD) and the angle of torsion (AT); already at a deviation of 5-10 0 from the prescribed position of the patient considerable errors (up to more than 15 0 ) may occur. For this reason two alternative methods are cited and described in detail: a) the cinematographic determination of the CCD- and AT-angle according to Schwetlick, and b) the combination of the determination of the AT-angle in exterior rotation according to Rogers and an anteroposterior roentgenogram of the pelvis and hips in interior rotation of the size of the AT-angle. Both methods are also mathematically exact, however, in addition almost independent from minor deviations in the position of the patient. It is advisable to apply one of the cited methods in cases of high AT-angle values (>>30 0 ), in cases where the placing of the patient is difficult and where the determination of the angles would require a major therapeutic measurement. (orig.) [de

An optical test bench for the precision characterization of absolute quantum efficiency for the TESS CCD detectors

International Nuclear Information System (INIS)

Krishnamurthy, A.; Villasenor, J.; Kissel, S.; Ricker, G.; Vanderspek, R.

2017-01-01

The Transiting Exoplanet Survey Satellite (TESS) will search for planets transiting bright stars with Ic ∼< 13. TESS has been selected by NASA for launch in 2018 as an Astrophysics Explorer mission, and is expected to discover a thousand or more planets that are smaller in size than Neptune. TESS will employ four wide-field optical charge-coupled device (CCD) cameras with a band-pass of 650 nm–1050 nm to detect temporary drops in brightness of stars due to planetary transits. The 1050 nm limit is set by the quantum efficiency (QE) of the CCDs. The detector assembly consists of four back-illuminated MIT Lincoln Laboratory CCID-80 devices. Each CCID-80 device consists of 2048×2048 imaging array and 2048×2048 frame store regions. Very precise on-ground calibration and characterization of CCD detectors will significantly assist in the analysis of the science data obtained in space. The characterization of the absolute QE of the CCD detectors is a crucial part of the characterization process because QE affects the performance of the CCD significantly over the redder wavelengths at which TESS will be operating. An optical test bench with significantly high photometric stability has been developed to perform precise QE measurements. The design of the test setup along with key hardware, methodology, and results from the test campaign are presented.

Interatomic potentials from rainbow scattering of keV noble gas atoms under axial surface channeling

International Nuclear Information System (INIS)

Schueller, A.; Wethekam, S.; Mertens, A.; Maass, K.; Winter, H.; Gaertner, K.

2005-01-01

For grazing scattering of keV Ne and Ar atoms from a Ag(1 1 1) and a Cu(1 1 1) surface under axial surface channeling conditions we observe well defined peaks in the angular distributions for scattered projectiles. These peaks can be attributed to 'rainbow-scattering' and are closely related to the geometry of potential energy surfaces which can be approximated by the superposition of continuum potentials along strings of atoms in the surface plane. The dependence of rainbow angles on the scattering geometry provides stringent tests on the scattering potentials. From classical trajectory calculations based on universal (ZBL), adjusted Moliere (O'Connor and Biersack), and individual interatomic potentials we obtain corresponding rainbow angles for comparison with the experimental data. We find good overall agreement with the experiments for a description of trajectories based on adjusted Moliere and individual potentials, whereas the agreement is poorer for potentials with ZBL screening

Modelling of subcritical free-surface flow over an inclined backward-facing step in a water channel

Directory of Open Access Journals (Sweden)

Šulc Jan

2012-04-01

Full Text Available The contribution deals with the experimental and numerical modelling of subcritical turbulent flow in an open channel with an inclined backward-facing step. The step with the inclination angle α = 20° was placed in the water channel of the cross-section 200×200 mm. Experiments were carried out by means of the PIV and LDA measuring techniques. Numerical simulations were executed by means of the commercial software ANSYS CFX 12.0. Numerical results obtained for twoequation models and EARSM turbulence model completed by transport equations for turbulent energy and specific dissipation rate were compared with experimental data. The modelling was concentrated particularly on the development of the flow separation and on the corresponding changes of free surface.

Optimal CCD readout by digital correlated double sampling

Science.gov (United States)

Alessandri, C.; Abusleme, A.; Guzman, D.; Passalacqua, I.; Alvarez-Fontecilla, E.; Guarini, M.

2016-01-01

Digital correlated double sampling (DCDS), a readout technique for charge-coupled devices (CCD), is gaining popularity in astronomical applications. By using an oversampling ADC and a digital filter, a DCDS system can achieve a better performance than traditional analogue readout techniques at the expense of a more complex system analysis. Several attempts to analyse and optimize a DCDS system have been reported, but most of the work presented in the literature has been experimental. Some approximate analytical tools have been presented for independent parameters of the system, but the overall performance and trade-offs have not been yet modelled. Furthermore, there is disagreement among experimental results that cannot be explained by the analytical tools available. In this work, a theoretical analysis of a generic DCDS readout system is presented, including key aspects such as the signal conditioning stage, the ADC resolution, the sampling frequency and the digital filter implementation. By using a time-domain noise model, the effect of the digital filter is properly modelled as a discrete-time process, thus avoiding the imprecision of continuous-time approximations that have been used so far. As a result, an accurate, closed-form expression for the signal-to-noise ratio at the output of the readout system is reached. This expression can be easily optimized in order to meet a set of specifications for a given CCD, thus providing a systematic design methodology for an optimal readout system. Simulated results are presented to validate the theory, obtained with both time- and frequency-domain noise generation models for completeness.

Programmable Clock Waveform Generation for CCD Readout

Energy Technology Data Exchange (ETDEWEB)

Vicente, J. de; Castilla, J.; Martinez, G.; Marin, J.

2006-07-01

Charge transfer efficiency in CCDs is closely related to the clock waveform. In this paper, an experimental framework to explore different FPGA based clock waveform generator designs is described. Two alternative design approaches for controlling the rise/fall edge times and pulse width of the CCD clock signal have been implemented: level-control and time-control. Both approaches provide similar characteristics regarding the edge linearity and noise. Nevertheless, dissimilarities have been found with respect to the area and frequency range of application. Thus, while the time-control approach consumes less area, the level control approach provides a wider range of clock frequencies since it does not suffer capacitor discharge effect. (Author) 8 refs.

As Big and As Good As It Gets: The Large Monolithic Imager for Lowell Observatory's 4.3-m Discovery Channel Telescope

Science.gov (United States)

Massey, Philip; Dunham, E. W.; Bida, T. A.; Collins, P.; Hall, J. C.; Hunter, D. A.; Lauman, S.; Levine, S.; Neugent, K.; Nye, R.; Oliver, R.; Schleicher, D.; Zoonematkermani, S.

2013-01-01

The Large Monolithic Imager (LMI), a camera built at Lowell Observatory, is currently undergoing commissioning on Lowell's new 4.3-m Discovery Channel Telescope (DCT). At the heart of the LMI is the largest charge-coupled device (CCD) that can be built using current fabrication techniques, and the first of its kind to be made by e2v. The active area of the chip is 92.2mmx92.4mm, and has 6144 by 6160 15-micron pixels. Our choice of a single chip over a mosaic of smaller ones was inspired by the success of USNO in deploying a similarly ginormous device made by Semiconductor Technology Associates, Inc. There are some significant advantages that a (very!) large single CCD has over a mosaic of smaller ones. With a mosaic, one has to dither to fill in the gaps between the chips for complete areal coverage. This is not only costly in overhead, but it also poses a limitation in faint surface brightness studies, as the sky brightness is constantly changing during the dithering process. In addition, differences in the wavelength dependence of the DQE can lead to differences in the color terms from chip to chip in mosaics, requiring one to deal with each chip as a separate instrument (see the Local Group Galaxy photometry of Massey et al. 2006, AJ, 131, 2478). The LMI avoids these problems. The Discovery Channel Telescope is being built by Lowell Observatory in partnership with Discovery Communications. First light took place in May 2012. Institutional DCT partners include Boston University (in perpetuity), the University of Maryland, and the University of Toledo. More about the DCT can be found in the adjacent poster by Hall et al. The LMI has been made possible thanks to a National Science Foundation grant (AST-1005313). We are currently doing on-sky evaluation of the camera, as commissioning of the DCT progresses, determining color terms, photometric zero-points, astrometric characteristics, etc. We will present these results, along with technical details and many pretty

MapX: 2D XRF for Planetary Exploration - Image Formation and Optic Characterization

Science.gov (United States)

Sarrazin, P.; Blake, D.; Gailhanou, M.; Marchis, F.; Chalumeau, C.; Webb, S.; Walter, P.; Schyns, E.; Thompson, K.; Bristow, T.

2018-04-01

Map-X is a planetary instrument concept for 2D X-Ray Fluorescence (XRF) spectroscopy. The instrument is placed directly on the surface of an object and held in a fixed position during the measurement. The formation of XRF images on the CCD detector relies on a multichannel optic configured for 1:1 imaging and can be analyzed through the point spread function (PSF) of the optic. The PSF can be directly measured using a micron-sized monochromatic X-ray source in place of the sample. Such PSF measurements were carried out at the Stanford Synchrotron and are compared with ray tracing simulations. It is shown that artifacts are introduced by the periodicity of the PSF at the channel scale and the proximity of the CCD pixel size and the optic channel size. A strategy of sub-channel random moves was used to cancel out these artifacts and provide a clean experimental PSF directly usable for XRF image deconvolution.

Multiband CCD Image Compression for Space Camera with Large Field of View

Directory of Open Access Journals (Sweden)

Jin Li

2014-01-01

Full Text Available Space multiband CCD camera compression encoder requires low-complexity, high-robustness, and high-performance because of its captured images information being very precious and also because it is usually working on the satellite where the resources, such as power, memory, and processing capacity, are limited. However, the traditional compression approaches, such as JPEG2000, 3D transforms, and PCA, have the high-complexity. The Consultative Committee for Space Data Systems-Image Data Compression (CCSDS-IDC algorithm decreases the average PSNR by 2 dB compared with JPEG2000. In this paper, we proposed a low-complexity compression algorithm based on deep coupling algorithm among posttransform in wavelet domain, compressive sensing, and distributed source coding. In our algorithm, we integrate three low-complexity and high-performance approaches in a deeply coupled manner to remove the spatial redundant, spectral redundant, and bit information redundancy. Experimental results on multiband CCD images show that the proposed algorithm significantly outperforms the traditional approaches.

Color balancing in CCD color cameras using analog signal processors made by Kodak

Science.gov (United States)

Kannegundla, Ram

1995-03-01

The green, red, and blue color filters used for CCD sensors generally have different responses. It is often necessary to balance these three colors for displaying a high-quality image on the monitor. The color filter arrays on sensors have different architectures. A CCD with standard G R G B pattern is considered for the present discussion. A simple method of separating the colors using CDS/H that is a part of KASPs (Analog Signal Processors made by Kodak) and using the gain control, which is also a part of KASPs for color balance, is presented. The colors are separated from the video output of sensor by using three KASPs, one each for green, red, and blue colors and by using alternate sample pulses for green and 1 in 4 pulses for red and blue. The separated colors gain is adjusted either automatically or manually and sent to the monitor for direct display in the analog mode or through an A/D converter digitally to the memory. This method of color balancing demands high-quality ASPs. Kodak has designed four different chips with varying levels of power consumption and speed for analog signal processing of video output of CCD sensors. The analog ASICs have been characterized for noise, clock feedthrough, acquisition time, linearity, variable gain, line rate clamp, black muxing, affect of temperature variations on chip performance, and droop. The ASP chips have met their design specifications.

Systems approach to the design of the CCD sensors and camera electronics for the AIA and HMI instruments on solar dynamics observatory

Science.gov (United States)

Waltham, N.; Beardsley, S.; Clapp, M.; Lang, J.; Jerram, P.; Pool, P.; Auker, G.; Morris, D.; Duncan, D.

2017-11-01

Solar Dynamics Observatory (SDO) is imaging the Sun in many wavelengths near simultaneously and with a resolution ten times higher than the average high-definition television. In this paper we describe our innovative systems approach to the design of the CCD cameras for two of SDO's remote sensing instruments, the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI). Both instruments share use of a custom-designed 16 million pixel science-grade CCD and common camera readout electronics. A prime requirement was for the CCD to operate with significantly lower drive voltages than before, motivated by our wish to simplify the design of the camera readout electronics. Here, the challenge lies in the design of circuitry to drive the CCD's highly capacitive electrodes and to digitize its analogue video output signal with low noise and to high precision. The challenge is greatly exacerbated when forced to work with only fully space-qualified, radiation-tolerant components. We describe our systems approach to the design of the AIA and HMI CCD and camera electronics, and the engineering solutions that enabled us to comply with both mission and instrument science requirements.

Charge state distributions from highly charged ions channeled at a metal surface

International Nuclear Information System (INIS)

Folkerts, L.; Meyer, F.W.; Schippers, S.

1994-01-01

The vast majority of the experimental work in the field of multicharged ion-surface interactions, to date, has focused on x-ray and particularly on electron emission. These experiments include measurements of the total electron yield, the emission statistics of the electrons, and, most of all, the electron energy distributions. So far, little attention has been paid to the fate of the multicharged projectile ions after the scattering. To our knowledge, the only measurement of the charge state distribution of the scattered ions is the pioneering experiment of de Zwart et al., who measured the total yield of scattered 1+, 2+, and 3+ ions as a function of the primary charge state q (q = 1--11) for 20 key Ne, Ar, and Kr ions after reflection from a polycrystalline tungsten target. Their main finding is the sudden onset of scattered 3+ ions when inner-shell vacancies are present in the primary particles. This suggests that a certain fraction of the inner-shell vacancies survives the entire collision event, and decays via autoionization on the outgoing path. Since the projectiles scattered in the neutral charge state could not be detected in the experiment of de Zwart et al., they were not able to provide absolute charge state fractions. In our present experiment, we focus on the scattered projectiles, measuring both the final charge state and the total scattering angle with a single 2D position sensitive detector (PSD). This method gives us the number of positive, as well as neutral and negative, scattered ions, thus allowing us to extract absolute charge state fractions. Using a well-prepared single Au(110) crystal and a grazing incidence geometry, we were able to observe surface channeling along the [001] channels

Radial dependence of surface streamer-channel luminosity: experimental evidence of Gaussian radiative profiles in Ar and N2

International Nuclear Information System (INIS)

Šimek, M; Ambrico, P F

2012-01-01

Radial distributions of electronically excited species produced during surface streamer propagation were obtained by applying the Abel inverse transform to projected luminosities of single streamers. The streamers were generated in an argon and nitrogen surface coplanar dielectric barrier discharge at atmospheric pressure and their magnified microscopic images were registered with high time resolution. Selected regions of the projected luminosities were processed by the Abel inverse transform procedure based on the Hankel–Fourier method assuming cylindrical symmetry of the streamer channel. Projected as well as Abel-inverted profiles were fitted by Gaussian functions. It is shown that the projected profiles, in addition to the Abel-inverted ones, can be well approximated by the sum of two coaxial Gaussians with two different half-widths and weights. The sharper Gaussian component with higher weight characterizes the radial dependence of the primary cathode-directed streamer-channel luminosity. The second (broader) Gaussian component probably originates either from the pre-breakdown Townsend phase or from the second wave propagating towards the anode. (paper)

X-ray CCD image sensor with a thick depletion region

International Nuclear Information System (INIS)

Saito, Hirobumi; Watabe, Hiroshi.

1984-01-01

To develop a solid-state image sensor for high energy X-ray above 1 -- 2 keV, basic studies have been made on the CCD (charge coupled device) with a thick depletion region. A method of super-imposing a high DC bias voltage on low voltage signal pulses was newly proposed. The characteristics of both SCCD and BCCD were investigated, and their ability as X-ray sensors was compared. It was found that a depletion region of 60 μm thick was able to be obtained with ordinary doping density of 10 20 /m 3 , and that even thicker over 1 mm depletion region was able to be obtained with doping density of about 10 18 /m 3 , and a high bias voltage above 1 kV was able to be applied. It is suggested that the CCD image sensors for 8 keV or 24 keV X-ray can be realized since the absorption length of these X-ray in Si is about 60 μm and 1 mm, respectively. As for the characteristics other than the depletion thickness, the BCCD is preferable to SCCD for the present purpose because of lower noise and dark current. As for the transfer method, the frame-transfer method is recommended. (Aoki, K.)

A luminescence imaging system based on a CCD camera

DEFF Research Database (Denmark)

Duller, G.A.T.; Bøtter-Jensen, L.; Markey, B.G.

1997-01-01

Stimulated luminescence arising from naturally occurring minerals is likely to be spatially heterogeneous. Standard luminescence detection systems are unable to resolve this variability. Several research groups have attempted to use imaging photon detectors, or image intensifiers linked...... to photographic systems, in order to obtain spatially resolved data. However, the former option is extremely expensive and it is difficult to obtain quantitative data from the latter. This paper describes the use of a CCD camera for imaging both thermoluminescence and optically stimulated luminescence. The system...

Novel driver method to improve ordinary CCD frame rate for high-speed imaging diagnosis

Energy Technology Data Exchange (ETDEWEB)

Luo, Tong-Ding, E-mail: snuohui@126.com; Li, Bin-Kang; Yang, Shao-Hua; Guo, Ming-An; Yan, Ming

2016-06-21

The use of ordinary Charge-coupled-Device (CCD) imagers for the analysis of fast physical phenomenon is restricted because of the low-speed performance resulting from their long output times. Even though the form of Intensified-CCD (ICCD), coupled with a gated image intensifier, has extended their use for high speed imaging, the deficiency remains to be solved that ICDD could record only one image in a single shot. This paper presents a novel driver method designed to significantly improve the ordinary interline CCD burst frame rate for high-speed photography. This method is based on the use of vertical registers as storage, so that a small number of additional frames comprised of reduced-spatial-resolution images obtained via a specific sampling operation can be buffered. Hence, the interval time of the received series of images is related to the exposure and vertical transfer times only and, thus, the burst frame rate can be increased significantly. A prototype camera based on this method is designed as part of this study, exhibiting a burst rate of up to 250,000 frames per second (fps) and a capacity to record three continuous images. This device exhibits a speed enhancement of approximately 16,000 times compared with the conventional speed, with a spatial resolution reduction of only 1/4.

Structure and morphology of surface of silicon crystals to be applied for channeling at relativistic energies

International Nuclear Information System (INIS)

Vomiero, Alberto; Restello, Silvio; Scian, Carlo; Marchi, Enrico Boscolo; Mea, Gianantonio Della; Guidi, Vincenzo; Milan, Emiliano; Baricordi, Stefano; Martinelli, Giuliano; Carnera, Alberto; Sambo, Andrea

2006-01-01

Bent crystals can be successfully applied for extraction/collimation of relativistic particles. A crucial feature to obtain high extraction efficiencies is the treatment of the surfaces being encountered by the beam, since mechanical operations induce considerable lattice imperfections. In order to remove the superficial damaged layer a planar etching can be applied on the surface exposed to the beam. This work presents a systematic study of the morphology and the crystalline perfection of the surface of the samples that have been used in accelerators with high efficiency. Crystals with different surface treatments have been investigated. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were applied on the characterisation of surface morphology. Low energy backscattering channeling of 2-MeV α particles or protons was used as a probe for the crystalline structure. The presence of a superficial damaged layer in the samples just after mechanical treatment was unveiled, while, in contrast, chemical etching leaves a surface with high crystalline perfection that can be related to the record efficiency

Fallow land mapping for better crop monitoring in Huang-Huai-Hai Plain using HJ-1 CCD data

International Nuclear Information System (INIS)

Zhang, Miao; Wu, Bingfang; Meng, Jihua; Dong, Taifeng; You, Xingzhi

2014-01-01

The prediction of grain production is essential for socio-economic development planning, guidance and control of macro cropping structure adjustment. Fallow areas should be identified each growing season which is critical for grain production prediction. This paper focuses on fallow arable land monitoring during summer grain season in the Huang-Huai-Hai Plain using China Environment Satellite HJ-1 CCD data. With the two satellites HJ-1A and HJ-1B, high temporal Normalized Difference Vegetation Index (NDVI) can be obtained. HJ-1 CCD data were acquired from early March to early June in 2010 over the Huang-Huai-Hai Plain. Multi-temporal HJ-1 CCD data were pre-processed and time series of NDVI were derived. An algorithm for separating cropped and fallow areas was developed based on three key periods of NDVI in early-March, mid-April and mid-May, 2010. The influence of fallow arable lands to yield estimation and crop condition monitoring over the Huang-Huai-Hai Plain were also investigated and analyzed. Preliminary results in this paper showed that HJ-1 CCD data are capable for fallow land monitoring. Information of fallow arable lands is an essential part of crop monitoring and it should be incorporated into crop monitoring systems. In the future, the fallow lands over autumn grain season should also be identified and information of fallow arable lands should be generated yearly in order to get more reliable production prediction

First tests with fully depleted PN-CCD's

International Nuclear Information System (INIS)

Strueder, L.; Lutz, G.; Sterzik, M.; Holl, P.; Kemmer, J.; Prechtel, U.; Ziemann, T.; Rehak, P.

1987-01-01

We have fabricated 280 μm thick fully depletable pn CCD's on high resistivity silicon (/rho/ ∼ 2.5 kΩcm). Its operation is based on the semiconductor drift chamber principle proposed by Gatti and Rheak. They are designed as energy and position sensitive radiation detector for (minimum) ionizing particles and X-ray imaging. Two dimensional semiconductor device modeling demonstrates the basic charge transer mechanisms. Prototypes of the detectors have been tested in static and dynamic conditions. A preliminary charge transfer inefficiency was determined to 6 x 10/sup/minus/3/. The charge loss during the transfer is discussed and as a consequence we have developed an improved design for a second fabrication iteration which is now being produced. 4 refs., 15 figs

Brayton Isotope Power System. Phase I. (Ground demonstration system) Configuration Control Document (CCD)

International Nuclear Information System (INIS)

1976-01-01

The configuration control document (CCD) defines the BIPS-GDS configuration. The GDS configuration is similar to a conceptual flight system design, referred to as the BIPS-FS, which is discussed in App. I. The BIPS is being developed by ERDA as a 500 to 2000 W(e), 7-y life, space power system utilizing a closed Brayton cycle gas turbine engine to convert thermal energy (from an isotope heat source) to electrical energy at a net efficiency exceeding 25 percent. The CCD relates to Phase I of an ERDA Program to qualify a dynamic system for launch in the early 1980's. Phase I is a 35-month effort to provide an FS conceptual design and GDS design, fabrication, and test. The baseline is a 7-year life, 450-pound, 4800 W(t), 1300 W(e) system which will use two multihundred watt (MHW) isotope heat sources being developed

Near-infrared Raman spectroscopy using a diode laser and CCD detector for tissue diagnostics

International Nuclear Information System (INIS)

Gustafsson, U.

1993-09-01

This paper surveys the possibility to observe high-quality NIR Raman spectra of both fluorescent and non-fluorescent samples with the use of a diode laser, a fibre optic sample, a single spectrometer and a charge-coupled device (CCD) detector. A shifted excitation difference technique was implemented for removing the broad-band fluorescence emission from Raman spectra of the highly fluorescent samples. Raman spectra of 1.4-dioxane, toluene, rhodamine 6G, and HITCI in the 640 to 1840 cm -1 spectral region and 1.4-dioxane and toluene in the 400 to 3400 cm -1 spectral region have been recorded. The results open the field of sensitive tissue characterisation and the possibility of optical biopsy in vivo by using NIR Raman spectroscopy with fibre optic sampling, a single spectrometer, and a CCD detector

New Cepheid distances to nearby galaxies based on BVRI CCD photometry. III - NGC 300

Energy Technology Data Exchange (ETDEWEB)

Freedman, W.L.; Madore, B.F.; Hawley, S.L.; Horowitz, I.K.; Mould, J.; Navarrete, M.; Sallmen, S. (Carnegie Institution of Washington, Observatories, Pasadena, CA (United States) JPL, Pasadena, CA (United States) Lawrence Livermore National Laboratory, Livermore, CA (United States) California Institute of Technology, Pasadena (United States) Cerro Tololo Inter-American Observatory, La Serena (Chile) California, University, Berkeley (United States))

1992-09-01

A true distance modulus of (m - M) sub 0 = 26.66 +/- 0.10 mag (corresponding to 2.1 +/- 0.1 Mpc) has been determined for the Sculptor Group spiral galaxy NGC 300. New CCD data have been obtained for a sample of known Cepheids in this galaxy from which apparent distance moduli at B, V, R, and I wavelengths are determined. Combining the data available at different wavelenghts, and assuming a true distance modulus to the LMC of 18.5 mag, a true distance modulus is obtained for NGC 300, corrected for the effects of interstellar reddening. The availability of a new distance to NGC 300 brings to five the total number of galaxies with new CCD photometry of Cepheids, useful for calibration of the Hubble constant. 26 refs.

Measurements of 161 Double Stars With a High-Speed CCD: The Winter/Spring 2017 Observing Program at Brilliant Sky Observatory, Part 2

Science.gov (United States)

Harshaw, Richard

2018-04-01

In the winter and spring of 2017, an aggressive observing program of measuring close double stars with speckle interferometry and CCD imaging was undertaken at Brilliant Sky Observatory, my observing site in Cave Creek, Arizona. A total of 596 stars were observed, 8 of which were rejected for various reasons, leaving 588 pairs. Of these, 427 were observed and measured with speckle interferometry, while the remaining 161 were measured with a CCD. This paper reports the results of the observations of the 161 CCD cases. A separate paper in this issue will report the speckle measurements of the 427 other pairs.

BVI CCD photometry of 47 Tucanae

International Nuclear Information System (INIS)

Alcaino, G.; Liller, W.

1987-01-01

CCD BVI main-sequence photometry of 47 Tuc is presented, matched to the recent BVI isochrones of VandenBerg and Bell (1985). The main-sequence turnoffs are found to be at V = 17.60 + or - 0.1, B-V = 0.56 + or - 0.02; V-I = 0.68 + or - 0.02, and B-I = 1.24 + or - 0.02. The magnitude difference between the main-sequence turnoff and the horizontal branch is 3.55 + or - 0.15 for all three color indices. A consistent age for 47 Tuc of 17 Gyr and a consistent distance modulus of (m-M)v = 13.2 are obtained for all three indices, and an absolute magnitude of Mv = 0.85 is determined for the horizontal branch stars. The results also favor the adoption of (Fe/H) near -0.5 as the best abundance value for 47 Tuc. 38 references

Neutral-beam performance analysis using a CCD camera

International Nuclear Information System (INIS)

Hill, D.N.; Allen, S.L.; Pincosy, P.A.

1986-01-01

We have developed an optical diagnostic system suitable for characterizing the performance of energetic neutral beams. An absolutely calibrated CCD video camera is used to view the neutral beam as it passes through a relatively high pressure (10 -5 Torr) region outside the neutralizer: collisional excitation of the fast deuterium atoms produces H/sub proportional to/ emission (lambda = 6561A) that is proportional to the local atomic current density, independent of the species mix of accelerated ions over the energy range 5 to 20 keV. Digital processing of the video signal provides profile and aiming information for beam optimization. 6 refs., 3 figs

Synthesis, characterization, and evaluation of a superficially porous particle with unique, elongated pore channels normal to the surface.

Science.gov (United States)

Wei, Ta-Chen; Mack, Anne; Chen, Wu; Liu, Jia; Dittmann, Monika; Wang, Xiaoli; Barber, William E

2016-04-01

In recent years, superficially porous particles (SPPs) have drawn great interest because of their special particle characteristics and improvement in separation efficiency. Superficially porous particles are currently manufactured by adding silica nanoparticles onto solid cores using either a multistep multilayer process or one-step coacervation process. The pore size is mainly controlled by the size of the silica nanoparticles and the tortuous pore channel geometry is determined by how those nanoparticles randomly aggregate. Such tortuous pore structure is also similar to that of all totally porous particles used in HPLC today. In this article, we report on the development of a next generation superficially porous particle with a unique pore structure that includes a thinner shell thickness and ordered pore channels oriented normal to the particle surface. The method of making the new superficially porous particles is a process called pseudomorphic transformation (PMT), which is a form of micelle templating. Porosity is no longer controlled by randomly aggregated nanoparticles but rather by micelles that have an ordered liquid crystal structure. The new particle possesses many advantages such as a narrower particle size distribution, thinner porous layer with high surface area and, most importantly, highly ordered, non-tortuous pore channels oriented normal to the particle surface. This PMT process has been applied to make 1.8-5.1μm SPPs with pore size controlled around 75Å and surface area around 100m(2)/g. All particles with different sizes show the same unique pore structure with tunable pore size and shell thickness. The impact of the novel pore structure on the performance of these particles is characterized by measuring van Deemter curves and constructing kinetic plots. Reduced plate heights as low as 1.0 have been achieved on conventional LC instruments. This indicates higher efficiency of such particles compared to conventional totally porous and

Opinion rating of comparison photographs of television pictures from CCD cameras under irradiation

International Nuclear Information System (INIS)

Reading, V.M.; Dumbreck, A.A.

1991-01-01

As part of the development of a general method of testing the effects of gamma radiation on CCD television cameras, this is a report of an experimental study on the optimisation of still photographic representation of video pictures recorded before and during camera irradiation. (author)

Surface pH changes suggest a role for H+/OH- channels in salinity response of Chara australis.

Science.gov (United States)

Absolonova, Marketa; Beilby, Mary J; Sommer, Aniela; Hoepflinger, Marion C; Foissner, Ilse

2018-05-01

To understand salt stress, the full impact of salinity on plant cell physiology has to be resolved. Electrical measurements suggest that salinity inhibits the proton pump and opens putative H + /OH - channels all over the cell surface of salt sensitive Chara australis (Beilby and Al Khazaaly 2009; Al Khazaaly and Beilby 2012). The channels open transiently at first, causing a characteristic noise in membrane potential difference (PD), and after longer exposure remain open with a typical current-voltage (I/V) profile, both abolished by the addition of 1 mM ZnCl 2 , the main known blocker of animal H + channels. The cells were imaged with confocal microscopy, using fluorescein isothiocyanate (FITC) coupled to dextran 70 to illuminate the pH changes outside the cell wall in artificial fresh water (AFW) and in saline medium. In the early saline exposure, we observed alkaline patches (bright fluorescent spots) appearing transiently in random spatial distribution. After longer exposure, some of the spots became fixed in space. Saline also abolished or diminished the pH banding pattern observed in the untreated control cells. ZnCl 2 suppressed the alkaline spot formation in saline and the pH banding pattern in AFW. The osmotic component of the saline stress did not produce transient bright spots or affect banding. The displacement of H + from the cell wall charges, the H + /OH - channel conductance/density, and self-organization are discussed. No homologies to animal H + channels were found. Salinity activation of the H + /OH - channels might contribute to saline response in roots of land plants and leaves of aquatic angiosperms.

Magnetic field integral equation analysis of surface plasmon scattering by rectangular dielectric channel discontinuities.

Science.gov (United States)

Chremmos, Ioannis

2010-01-01

The scattering of a surface plasmon polariton (SPP) by a rectangular dielectric channel discontinuity is analyzed through a rigorous magnetic field integral equation method. The scattering phenomenon is formulated by means of the magnetic-type scalar integral equation, which is subsequently treated through an entire-domain Galerkin method of moments (MoM), based on a Fourier-series plane wave expansion of the magnetic field inside the discontinuity. The use of Green's function Fourier transform allows all integrations over the area and along the boundary of the discontinuity to be performed analytically, resulting in a MoM matrix with entries that are expressed as spectral integrals of closed-form expressions. Complex analysis techniques, such as Cauchy's residue theorem and the saddle-point method, are applied to obtain the amplitudes of the transmitted and reflected SPP modes and the radiated field pattern. Through numerical results, we examine the wavelength selectivity of transmission and reflection against the channel dimensions as well as the sensitivity to changes in the refractive index of the discontinuity, which is useful for sensing applications.

The X-ray mirror telescope and the pn-CCD detector of CAST

CERN Document Server

Kuster, M; Englhauser, J; Franz, J; Friedrich, P; Hartmann, R; Kang, D; Kotthaus, R; Lutz, Gerhard; Moralez, J; Serber, W; Strüder, L

2004-01-01

The Cern Axion Solar Telescope - CAST - uses a prototype 9 Tesla LHC superconducting dipole magnet to search for a hypothetical pseudoscalar particle, the axion, which was proposed by theory in the 1980s to solve the strong CP problem and which could be a dark matter candidate. In CAST a strong magnetic field is used to convert the solar axions to detectable photons via inverse Primakoff effect. The resulting X-rays are thermally distributed in the energy range of 1-7 keV and can be observed with conventional X-ray detectors. The most sensitive detector system of CAST is a pn-CCD detector originally developed for XMM-Newton combined with a Wolter I type X-ray mirror system. The combination of a focusing X-ray optics and a state of the art pn-CCD detector which combines high quantum efficiency, good spacial and energy resolution, and low background improves the sensitivity of the CAST experiment such that for the first time the axion photon coupling constant can be probed beyond the best astrophysical constrai...

Correlations of Surface Deformation and 3D Flow Field in a Compliant Wall Turbulent Channel Flow.

Science.gov (United States)

Wang, Jin; Zhang, Cao; Katz, Joseph

2015-11-01

This study focuses on the correlations between surface deformation and flow features, including velocity, vorticity and pressure, in a turbulent channel flow over a flat, compliant Polydimethylsiloxane (PDMS) wall. The channel centerline velocity is 2.5 m/s, and the friction Reynolds number is 2.3x103. Analysis is based on simultaneous measurements of the time resolved 3D velocity and surface deformation using tomographic PIV and Mach-Zehnder Interferometry. The volumetric pressure distribution is calculated plane by plane by spatially integrating the material acceleration using virtual boundary, omni-directional method. Conditional sampling based on local high/low pressure and deformation events reveals the primary flow structures causing the deformation. High pressure peaks appear at the interface between sweep and ejection, whereas the negative deformations peaks (dent) appear upstream, under the sweeps. The persistent phase lag between flow and deformations are presumably caused by internal damping within the PDMS. Some of the low pressure peaks and strong ejections are located under the head of hairpin vortices, and accordingly, are associated with positive deformation (bump). Others bumps and dents are correlated with some spanwise offset large inclined quasi-streamwise vortices that are not necessarily associated with hairpins. Sponsored by ONR.

The golden-mean surface pattern to enhance flow mixing in micro-channel.

Science.gov (United States)

Wang, J F; Liu, Y; Xu, Y S

2009-04-01

Mixing of analytes and reagents in microfluidic devices is often crucial to the effective functioning of lab-on-a-chip. It is possible to affect the mixing in microfluidics by intelligently controlling the thermodynamic and chemical properties of the substrate surface. Numerous studies have shown that the phase behavior of mixtures is significantly affected by surface properties of microfluidics. For example, the phase separation between the fluids can be affected by heterogeneous patterns on the substrate. The patterned substrate can offer an effective means to control fluid behavior and in turn to enhance mixing. The golden mean is a ratio that is present in the growth patterns of many biological systems--the spiral formed by a shell or the curve of a fern, for example. The golden mean or golden section was derived by the ancient Greeks. Like "pi" the golden mean ratio is an irrational number 1.618, or (square root{5} + 1) / 2. It was found that the golden mean was an optimum ratio in natural convection heat transfer problem (Liu and Phan-Thien, Numer Heat Transf 37:613-630, 2000). In this study, we numerically studied the effect of optimum surface pattern on mixing in a micro channel and found that the flow oscillation and chaotic mixing were enhanced apparently when the ratio of hydrophobic and hydrophilic boundary follows the golden mean.

Generic theory for channel sinuosity.

Science.gov (United States)

Lazarus, Eli D; Constantine, José Antonio

2013-05-21

Sinuous patterns traced by fluid flows are a ubiquitous feature of physical landscapes on Earth, Mars, the volcanic floodplains of the Moon and Venus, and other planetary bodies. Typically discussed as a consequence of migration processes in meandering rivers, sinuosity is also expressed in channel types that show little or no indication of meandering. Sinuosity is sometimes described as "inherited" from a preexisting morphology, which still does not explain where the inherited sinuosity came from. For a phenomenon so universal as sinuosity, existing models of channelized flows do not explain the occurrence of sinuosity in the full variety of settings in which it manifests, or how sinuosity may originate. Here we present a generic theory for sinuous flow patterns in landscapes. Using observations from nature and a numerical model of flow routing, we propose that flow resistance (representing landscape roughness attributable to topography or vegetation density) relative to surface slope exerts a fundamental control on channel sinuosity that is effectively independent of internal flow dynamics. Resistance-dominated surfaces produce channels with higher sinuosity than those of slope-dominated surfaces because increased resistance impedes downslope flow. Not limited to rivers, the hypothesis we explore pertains to sinuosity as a geomorphic pattern. The explanation we propose is inclusive enough to account for a wide variety of sinuous channel types in nature, and can serve as an analytical tool for determining the sinuosity a landscape might support.

Role of protein kinase A and class II phosphatidylinositol 3-kinase C2β in the downregulation of KCa3.1 channel synthesis and membrane surface expression by lyso-globotriaosylceramide

Energy Technology Data Exchange (ETDEWEB)

Choi, Ju Yeon; Park, Seonghee, E-mail: sp@ewha.ac.kr

2016-02-19

The intermediate conductance calcium-activated potassium channel (KCa3.1) mediates proliferation of many cell types including fibroblasts, and is a molecular target for intervention in various cell proliferative diseases. Our previous study showed that reduction of KCa3.1 channel expression by lyso-globotriaosylceramide (lyso-Gb3) inhibits differentiation into myofibroblasts and collagen synthesis, which might lead to development of ascending thoracic aortic aneurysm secondary to Fabry disease. However, how lyso-Gb3 downregulates KCa3.1 channel expression is unknown. Therefore, we aimed to investigate the underlying mechanisms of lyso-Gb3-mediated KCa3.1 channel downregulation, focusing on the cAMP signaling pathway. We found that lyso-Gb3 increased the intracellular cAMP concentration by upregulation of adenylyl cyclase 6 and inhibited ERK 1/2 phosphorylation through the protein kinase A (PKA) pathway, leading to the inhibition of KCa3.1 channel synthesis, not the exchange protein directly activated by cAMP (Epac) pathway. Moreover, lyso-Gb3 suppressed expression of class II phosphatidylinositol 3-kinase C2β (PI3KC2β) by PKA activation, which reduces the production of phosphatidylinositol 3-phosphate [PI(3)P], and the reduced membrane surface expression of KCa3.1 channel was recovered by increasing the intracellular levels of PI(3)P. Consequently, our findings that lyso-Gb3 inhibited both KCa3.1 channel synthesis and surface expression by increasing intracellular cAMP, and controlled surface expression through changes in PI3KC2β-mediated PI(3)P production, suggest that modulation of PKA and PI3KC2β activity to control of KCa3.1 channel expression can be an alternative important target to attenuate ascending thoracic aortic aneurysms in Fabry disease. - Highlights: • Lyso-Gb3 causes elevation of intracellular cAMP. • Lyso-Gb3 inhibits the ERK 1/2 phosphorylation through PKA, thereby reducing KCa3.1 channel synthesis. • Lyso-Gb3 reduces PI3KC2�

Measured and calculated K-fluorescence effects on the MTF of an amorphous-selenium based CCD x-ray detector.

Science.gov (United States)

Hunter, David M; Belev, George; Kasap, Safa; Yaffe, Martin J

2012-02-01

Theoretical reasoning suggests that direct conversion digital x-ray detectors based upon photoconductive amorphous-selenium (a-Se) could attain very high values of the MTF (modulation transfer function) at spatial frequencies well beyond 20 cycles mm(-1). One of the fundamental factors affecting resolution loss, particularly at x-ray energies just above the K-edge of selenium (12.66 keV), is the K-fluorescence reabsorption mechanism, wherein energy can be deposited in the detector at locations laterally displaced from the initial x-ray interaction site. This paper compares measured MTF changes above and below the Se K-edge of a CCD based a-Se x-ray detector with theoretical expectations. A prototype 25 μm sampling pitch (Nyquist frequency = 20 cycles mm(-1), 200 μm thick a-Se layer based x-ray detector, utilizing a specialized CCD readout device (200 × 400 area array), was used to make edge images with monochromatic x-rays above and below the K-edge of Se. A vacuum double crystal monochromator, exposed to polychromatic x-rays from a synchrotron, formed the monochromatic x-ray source. The monochromaticity of the x-rays was 99% or better. The presampling MTF was determined using the slanted edge method. The theory modeling the MTF performance of the detector includes the basic x-ray interaction physics in the a-Se layer as well as effects related to the operation of the CCD and charge trapping at a blocking layer present at the CCD/a-Se interface. The MTF performance of the prototype a-Se CCD was reduced from the theoretical value prescribed by the basic Se x-ray interaction physics, principally by the presence of a blocking layer. Nevertheless, the K-fluorescence reduction in the MTF was observed, approximately as predicted by theory. For the CCD prototype detector, at five cycles mm(-1), there was a 14% reduction of the MTF, from a value of 0.7 below the K-edge of Se, to 0.6 just above the K-edge. The MTF of an a-Se x-ray detector has been measured using

Evaluation of the Accuracy of the Dark Frame Subtraction Method in CCD Image Processing

National Research Council Canada - National Science Library

Levesque, Martin P; Lelievre, Mario

2007-01-01

.... This method is frequently used for removing the image background gradient (a thermal artefact) in CCD images. This report demonstrates that this method may not be suitable for the detection of objects with very low signal-to-noise ratio...

Channel Storage change: a new remote sensed surface water measurement

Science.gov (United States)

Coss, S. P.; Durand, M. T.; Yi, Y.; Guo, Q.; Shum, C. K.; Allen, G. H.; Pavelsky, T.

2017-12-01

Here we present river channel storage change (CSC) measurements for 17 major world rivers from 2002-2016. We combined interpolated daily 1 km resolution Global River Radar Altimeter Time Series (GRRATS) river surface elevation data with static widths from the global river Global River Widths from Landsat (GRWL) dataset, to generate preliminary channel storage measurements. CSC is a previously unmeasured component of the terrestrial water balance It is a fundamental Earth science quantity with global bearing on floodplains, ecology, and geochemistry. CSC calculations require only remote sensed data, making them an ideal tool for studying remote regions where hydrological data is not easily accessible. CSC is uniquely suited to determine the role of hydrologic and hydraulic controls in basins with strong seasonal cycles (freeze-up and break-up). The cumulative CSC anomaly can impart spatial details that discharge measurements cannot. With this new measurement, we may be able to determine critical hydrological and hydraulic controls on rapidly changing systems like Arctic rivers. Results for Mississippi River indicate that peak CSC anomaly was the highest in 2011 (12.6 km3) and minimum CSC anomaly was in 2012 (-12.2 km3). Peak CSC has most frequently occurs in May (5 years), but has come as late in the year as July, and as early as January. Results for the Yukon River indicate that peak CSC anomaly was the highest in 2013 (13.9 km3) and minimum CSC anomaly was in 2010 (-14.2 km3). Peak CSC has most frequently come in early to mid-June (4-18), but has occurred in May (19-31) four years in the study period (three of the last 6 years) and once on April 30th.

The role of the potato (Solanum tuberosum) CCD8 gene in stolon and tuber development.

Science.gov (United States)

Pasare, Stefania A; Ducreux, Laurence J M; Morris, Wayne L; Campbell, Raymond; Sharma, Sanjeev K; Roumeliotis, Efstathios; Kohlen, Wouter; van der Krol, Sander; Bramley, Peter M; Roberts, Alison G; Fraser, Paul D; Taylor, Mark A

2013-06-01

· Strigolactones (SLs) are a class of phytohormones controlling shoot branching. In potato (Solanum tuberosum), tubers develop from underground stolons, diageotropic stems which originate from basal stem nodes. As the degree of stolon branching influences the number and size distribution of tubers, it was considered timely to investigate the effects of SL production on potato development and tuber life cycle. · Transgenic potato plants were generated in which the CAROTENOID CLEAVAGE DIOXYGENASE8 (CCD8) gene, key in the SL biosynthetic pathway, was silenced by RNA interference (RNAi). · The resulting CCD8-RNAi potato plants showed significantly more lateral and main branches than control plants, reduced stolon formation, together with a dwarfing phenotype and a lack of flowering in the most severely affected lines. New tubers were formed from sessile buds of the mother tubers. The apical buds of newly formed transgenic tubers grew out as shoots when exposed to light. In addition, we found that CCD8 transcript levels were rapidly downregulated in tuber buds by the application of sprout-inducing treatments. · These results suggest that SLs could have an effect, solely or in combination with other phytohormones, in the morphology of potato plants and also in controlling stolon development and maintaining tuber dormancy. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Development of photoelectric balanced car based on the linear CCD sensor

Directory of Open Access Journals (Sweden)

Wang Feng

2016-01-01

Full Text Available The smart car is designed based on Freescale’s MC9S12XS128 and a linear CCD camera. The linear CCD collects the road information and sends it to MCU through the operational amplifier. The PID control algorithm, the proportional–integral–derivative control algorithm, is adopted synthetically to control the smart car. First, the smart car’s inclination and angular velocity are detect through the accelerometers and gyro sensors, then the PD control algorithm, the proportional–derivative control algorithm, is employed to make the smart car have the ability of two-wheeled self-balancing. Second, the speed of wheel obtained by the encoder is fed back to the MCU by way of pulse signal, then the PI control algorithm, the proportional–integral control algorithm, is employed to make the speed of smart car reach the set point in the shortest possible time and stabilize at the set point. Finally, the PD control algorithm is used to regulate the smart car’s turning angle to make the smart car respond quickly while the smart car is passing the curve path. The smart car can realize the self-balancing control of two wheels and track automatically the black and while lines to march.

An application of CCD read-out technique to neutron distribution measurement using the self-activation method with a CsI scintillator plate

International Nuclear Information System (INIS)

Nohtomi, Akihiro; Kurihara, Ryosuke; Kinoshita, Hiroyuki; Honda, Soichiro; Tokunaga, Masaaki; Uno, Heita; Shinsho, Kiyomitsu; Wakabayashi, Genichiro; Koba, Yusuke; Fukunaga, Junichi; Umezu, Yoshiyuki; Nakamura, Yasuhiko; Ohga, Saiji

2016-01-01

In our previous paper, the self-activation of an NaI scintillator had been successfully utilized for detecting photo-neutrons around a high-energy X-ray radiotherapy machine; individual optical pulses from the self-activated scintillator are read-out by photo sensors such as a photomultiplier tube (PMT). In the present work, preliminary observations have been performed in order to apply a direct CCD read-out technique to the self-activation method with a CsI scintillator plate using a Pu-Be source and a 10-MV linac. In conclusion, it has been revealed that the CCD read-out technique is applicable to neutron measurement around a high-energy X-ray radiotherapy machine with the self-activation of a CsI plate. Such application may provide a possibility of novel method for simple neutron dose-distribution measurement. - Highlights: • Preliminary observations have been performed by a CCD for the CsI self-activation method. • It has been revealed that the CCD read-out technique is applicable to neutron measurement. • Such application may provide a novel method for simple neutron distribution measurement.

An application of CCD read-out technique to neutron distribution measurement using the self-activation method with a CsI scintillator plate

Energy Technology Data Exchange (ETDEWEB)

Nohtomi, Akihiro, E-mail: nohtomi@hs.med.kyushu-u.ac.jp [Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Kurihara, Ryosuke; Kinoshita, Hiroyuki; Honda, Soichiro; Tokunaga, Masaaki; Uno, Heita [Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Shinsho, Kiyomitsu [Graduate School of Human Sciences, Tokyo Metropolitan University, 7-2-10 Higashi-oku, Arakawa-ku, Tokyo 116-8551 (Japan); Wakabayashi, Genichiro [Atomic Energy Research Institute, Kinki University, 3-4-1 Kowakae, Higashiosaka-shi, Osaka 577-8502 (Japan); Koba, Yusuke [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan); Fukunaga, Junichi; Umezu, Yoshiyuki; Nakamura, Yasuhiko [Department of Radiology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Ohga, Saiji [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)

2016-10-01

In our previous paper, the self-activation of an NaI scintillator had been successfully utilized for detecting photo-neutrons around a high-energy X-ray radiotherapy machine; individual optical pulses from the self-activated scintillator are read-out by photo sensors such as a photomultiplier tube (PMT). In the present work, preliminary observations have been performed in order to apply a direct CCD read-out technique to the self-activation method with a CsI scintillator plate using a Pu-Be source and a 10-MV linac. In conclusion, it has been revealed that the CCD read-out technique is applicable to neutron measurement around a high-energy X-ray radiotherapy machine with the self-activation of a CsI plate. Such application may provide a possibility of novel method for simple neutron dose-distribution measurement. - Highlights: • Preliminary observations have been performed by a CCD for the CsI self-activation method. • It has been revealed that the CCD read-out technique is applicable to neutron measurement. • Such application may provide a novel method for simple neutron distribution measurement.

Surface viscosity effects on the motion of self-propelling boat in a channel

Science.gov (United States)

Aliperio, M. G.; Nolan Confesor, Mark

2015-06-01

Self-propelled droplets have been conceived as simple chemical toy models to mimic motile biological samples such as bacteria. The motion of these droplets is believe to be due to the surface tension gradient in the boundary of the droplet. We performed experiments to look at the effect of varying the medium viscosity to the speed of a circular boat that was soaked in Pentanol. We found that the boats undergo oscillatory type of motion inside a channel. Moreover we found the maximum speed of the boat is independent on the viscosity of the medium. On the other a time scale describing the width of the velocity profile of the boat was found to increase with increasing viscosity.

Heat transfer from two-side heated helical channels

International Nuclear Information System (INIS)

Shimonis, V.; Ragaishis, V.; Poshkas, P.

1995-01-01

Experimental results are presented on the heat transfer from two-side heated helical channels to gas (air) flows. The study covered six configurations and wide ranges of geometrical (D/h=5.5 to 84.2) and performance (Re=10 3 to 2*10 5 ) parameters. Under the influence of Re and of the channel curvature, the heat transfer from both the convex and the concave surfaces for two-side heating (q w1 ≅ q w2 ) is augmented by 20-30% over one-side heating. Improved relations to predict the critical values of Reynolds Re cr1 and Re cr2 are suggested. They enable more exact predictions of the heat transfer from convex surface in transient flows for one-side heating. The relation for annular channels is suggested for the turbulent heat transfer from the convex and concave surfaces of two-side heated helical channels. It can be adapted by introducing earlier expresions for one-side heated helical channels. (author). 6 refs., 2 tabs., 3 figs

VXD3: The SLD vertex detector upgrade based on a 307 Mpixel CCD system

International Nuclear Information System (INIS)

1995-07-01

The SLD Collaboration is building a new CCD vertex detector (VXD3) comprising 96 3.2 Mpixel CCDs of 13 cm 2 each for a total of 307 million pixels. This system is an upgrade of the Pioneering CCD vertex detector VXD2 which has operated in SLD since 1992. The CCDs of VXD3 are mounted on beryllium ladders in three cylinders, providing three space point measurements along each track of about 5 microns resolution in all three coordinates. The design and construction of VXD3 builds on three years of successful performance of VXD2. Significant improvements are achieved with VXD3 in impact parameters resolution (about a factor of two) and acceptance (∼20%) through optimized geometry and reduced material. New readout electronics have been developed for this system. This new vertex detector will be installed in late 1995 for the future runs of SLD

Visual tritium imaging of In-Vessel surfaces

International Nuclear Information System (INIS)

Gentile, C. A.; Zweben, S. J.; Skinner, C. H.; Young, K. M.; Langish, S. W.; Nishi, M. F.; Shu, W. M.; Parker, J.; Isobe, K.

2000-01-01

A imaging detector has been developed for the purpose of providing a non-destructive, real time method of determining tritium concentrations on the surface of internal TFTR vacuum vessel components. The detector employs a green phosphor screen (P31, zinc sulfide: copper) with a wave length peak of 530 nm, a charge-coupled device (CCD) camera linked to a computer, and a detection chamber for inserting components recovered from the vacuum vessel. This detector is capable of determining tritium concentrations on the surfaces. The detector provides a method of imaging tritium deposition on the surfaces in a fairly rapid fashion

Visual tritium imaging of in-vessel surfaces

International Nuclear Information System (INIS)

Gentile, C.A.; Zweben, S.J.; Skinner, C.H.; Young, K.M.; Langish, S.W.; Nishi, M.F.; Shu, W.M.; Parker, J.; Isobe, K.

2000-01-01

An imaging detector has been developed for the purpose of providing a non-destructive, real time method of determining tritium concentrations on the surface of internal TFTR vacuum vessel components. The detector employs a green phosphor screen (P31, zinc sulfide: copper) with a wave length peak of 530 nm, a charge-coupled device (CCD) camera linked to a computer, and a detection chamber for inserting components recovered from the vacuum vessel. This detector is capable of determining tritium concentrations on the surfaces. The detector provides a method of imaging tritium deposition on the surfaces in a fairly rapid fashion

New Subarray Readout Patterns for the ACS Wide Field Channel

Science.gov (United States)

Golimowski, D.; Anderson, J.; Arslanian, S.; Chiaberge, M.; Grogin, N.; Lim, Pey Lian; Lupie, O.; McMaster, M.; Reinhart, M.; Schiffer, F.; Serrano, B.; Van Marshall, M.; Welty, A.

2017-04-01

At the start of Cycle 24, the original CCD-readout timing patterns used to generate ACS Wide Field Channel (WFC) subarray images were replaced with new patterns adapted from the four-quadrant readout pattern used to generate full-frame WFC images. The primary motivation for this replacement was a substantial reduction of observatory and staff resources needed to support WFC subarray bias calibration, which became a new and challenging obligation after the installation of the ACS CCD Electronics Box Replacement during Servicing Mission 4. The new readout patterns also improve the overall efficiency of observing with WFC subarrays and enable the processing of subarray images through stages of the ACS data calibration pipeline (calacs) that were previously restricted to full-frame WFC images. The new readout patterns replace the original 512×512, 1024×1024, and 2048×2046-pixel subarrays with subarrays having 2048 columns and 512, 1024, and 2048 rows, respectively. Whereas the original square subarrays were limited to certain WFC quadrants, the new rectangular subarrays are available in all four quadrants. The underlying bias structure of the new subarrays now conforms with those of the corresponding regions of the full-frame image, which allows raw frames in all image formats to be calibrated using one contemporaneous full-frame "superbias" reference image. The original subarrays remain available for scientific use, but calibration of these image formats is no longer supported by STScI.

Fuel cell plates with skewed process channels for uniform distribution of stack compression load

Science.gov (United States)

Granata, Jr., Samuel J.; Woodle, Boyd M.

1989-01-01

An electrochemical fuel cell includes an anode electrode, a cathode electrode, an electrolyte matrix sandwiched between electrodes, and a pair of plates above and below the electrodes. The plate above the electrodes has a lower surface with a first group of process gas flow channels formed thereon and the plate below the electrodes has an upper surface with a second group of process gas flow channels formed thereon. The channels of each group extend generally parallel to one another. The improvement comprises the process gas flow channels on the lower surface of the plate above the anode electrode and the process gas flow channels on the upper surface of the plate below the cathode electrode being skewed in opposite directions such that contact areas of the surfaces of the plates through the electrodes are formed in crisscross arrangements. Also, the plates have at least one groove in areas of the surfaces thereof where the channels are absent for holding process gas and increasing electrochemical activity of the fuel cell. The groove in each plate surface intersects with the process channels therein. Also, the opposite surfaces of a bipolar plate for a fuel cell contain first and second arrangements of process gas flow channels in the respective surfaces which are skewed the same amount in opposite directions relative to the longitudinal centerline of the plate.

Channel follower leakage restrictor

International Nuclear Information System (INIS)

Williamson, H.E.; Smith, B.A.

1977-01-01

An improved means is provided to control coolant leakage between the flow channel and the lower tie plate of a nuclear fuel assembly. The means includes an opening in the lower tie plate and a movable element adjacent thereto. The coolant pressure within the tie plate biases the movable means toward the inner surface of the surrounding flow channel to compensate for any movement of the flow channel away from the lower tie plate to thereby control the leakage of coolant flow from the fuel assemblies to the spaces among the fuel assemblies of the core. 9 figures

Observation of melt surface depressions during electron beam evaporation

International Nuclear Information System (INIS)

Ohba, Hironori; Shibata, Takemasa

2000-08-01

Depths of depressed surface of liquid gadolinium, cerium and copper during electron beam evaporation were measured by triangulation method using a CCD camera. The depression depths estimated from the balance of the vapor pressure and the hydrostatic pressure at the evaporation surface agreed with the measured values. The periodic fluctuation of atomic beam was observed when the depression of 3∼4 mm in depth was formed at the evaporation spot. (author)

Image quality in conventional film screen system, digital phosphor storage plate mammography in magnification technique and digital mammography in CCD-technique

International Nuclear Information System (INIS)

Schulz-Wendtland, R.; Aichinger, U.; Boehner, C.; Dobritz, M.; Bautz, W.; Saebel, M.

2000-01-01

Purpose: Comparison of image quality between conventional film screen system, digital phosphor storage plate mammography in magnification technique and digital mammography in CCD-technique. Materials and Methods: Radiograms of a RMI-mammography phantom were acquired using a conventional film screen system, two digital storage plate systems and two digital systems in CCD-technique. Additionally, the radiograms of one digital phosphor storage plate system were post-processed emphasizing contrast and included in the comparison. Results: The detectability of details was the best with the digital mammography in CCD-technique in comparison with the conventional film screen technique resp. digital phosphor storage plate in magnification technique. Conclusions: Based on these results there is the possibility to replace the conventional film screen system by further studies - this has to be confirmed. (orig.) [de

First-light instrument for the 3.6-m Devasthal Optical Telescope: 4Kx4K CCD Imager

Science.gov (United States)

Pandey, Shashi Bhushan; Yadav, Rama Kant Singh; Nanjappa, Nandish; Yadav, Shobhit; Reddy, Bheemireddy Krishna; Sahu, Sanjit; Srinivasan, Ramaiyengar

2018-04-01

As a part of in-house instrument developmental activity at ARIES, the 4Kx4K CCD Imager is designed and developed as a first-light instrument for the axial port of the 3.6-m Devasthal Optical Telescope (DOT). The f/9 beam of the telescope having a plate-scale of 6.4"/mm is utilized to conduct deeper photom-etry within the central 10' field of view. The pixel size of the blue-enhanced liquid nitrogen cooled STA4150 4Kx4K CCD chip is 15 μm, with options to select gain and speed values to utilize the dynamic range. Using the Imager, it is planned to image the central 6.5'x6.5' field of view of the telescope for various science goals by getting deeper images in several broad-band filters for point sources and objects with low surface brightness. The fully assembled Imager along with automated filter wheels having Bessel UBV RI and SDSS ugriz filters was tested in late 2015 at the axial port of the 3.6-m DOT. This instrument was finally mounted at the axial port of the 3.6-m DOT on 30 March 2016 when the telescope was technically activated jointly by the Prime Ministers of India and Belgium. It is expected to serve as a general purpose multi-band deep imaging instrument for a variety of science goals including studies of cosmic transients, active galaxies, star clusters and optical monitoring of X-ray sources discovered by the newly launched Indian space-mission called ASTROSAT, and follow-up of radio bright objects discovered by the Giant Meterwave Radio Telescope.

Direct and indirect signal detection of 122 keV photons with a novel detector combining a pnCCD and a CsI(Tl) scintillator

Energy Technology Data Exchange (ETDEWEB)

Schlosser, D.M., E-mail: dieter.schlosser@pnsensor.de [PNSensor GmbH, Sckellstraße 3, 81667 München (Germany); Huth, M.; Hartmann, R. [PNSensor GmbH, Sckellstraße 3, 81667 München (Germany); Abboud, A.; Send, S. [Universität Siegen, Walter-Flex-Straße 3, 57072 Siegen (Germany); Conka-Nurdan, T. [Türkisch-Deutsche Universität, Sakinkaya Cad. 86, Beykoz, 34820 Istanbul (Turkey); Shokr, M.; Pietsch, U. [Universität Siegen, Walter-Flex-Straße 3, 57072 Siegen (Germany); Strüder, L. [PNSensor GmbH, Sckellstraße 3, 81667 München (Germany); Universität Siegen, Walter-Flex-Straße 3, 57072 Siegen (Germany)

2016-01-01

By combining a low noise fully depleted pnCCD detector with a CsI(Tl) scintillator, an energy-dispersive area detector can be realized with a high quantum efficiency (QE) in the range from below 1 keV to above 100 keV. In direct detection mode the pnCCD exhibits a relative energy resolution of 1% at 122 keV and spatial resolution of less than 75 µm, the pixel size of the pnCCD. In the indirect detection mode, i.e. conversion of the incoming X-rays in the scintillator, the measured energy resolution was about 9–13% at 122 keV, depending on the depth of interaction in the scintillator, while the position resolution, extracted with the help of simulations, was 30 µm only. We show simulated data for incident photons of 122 keV and compare the various interaction processes and relevant physical parameters to experimental results obtained with a radioactive {sup 57}Co source. - Highlights: • Position and energy resolving pnCCD+CsI(Tl) detector for energies from 1-150 keV • Detection in the pnCCD (122keV): 1% energy and <75µm spatial resolution • Detection in the scintillator (122keV): 9-12% energy and ~30µm spatial resolution.

Macromolecular crystallographic results obtained using a 2048x2048 CCD detector at CHESS

International Nuclear Information System (INIS)

Thiel, D.J.; Ealick, S.E.; Tate, M.W.; Gruner, S.M.; Eikenberry, E.F.

1996-01-01

We present results of macromolecular crystallographic experiments performed at the Cornell High Energy Synchrotron Source (CHESS) with a new CCD-based detector. This detector, installed in January 1995, complements a 1024x1024 CCD detector that has been in continuous operation at CHESS since December 1993. The new detector is based on a 4-port, 2048x2048 pixel CCD that is directly coupled to a Gd 2 O 2 S:Tb phosphor by a 3:1 tapered fiber optic. The active area of the phosphor is a square 82 mm on an edge. The readout time is 7 seconds. In the standard mode of operation, the pixel size at the active area is 41 μm on the edge leading to the capability of resolving approximately 200 orders of diffraction across the detector face. The detector also operates in a 1024x1024 mode in which the pixel size is electronically increased by a factor of 4 in area resulting in smaller data files and faster detector readout but at the expense of spatial resolution. Most of the data that has been collected by this detector has been collected in this mode. Dozens of data sets have been collected by many experimenters using this detector at CHESS during the four month period from its installation until the start of the six-month down period of the storage ring. The capabilities of the detector will be illustrated with results from various crystallographic measurements including experiments in which the recorded diffraction patterns extend in resolution as far as 1 A. The results demonstrate that this detector is capable of collecting data of quality at least equal to that of imaging plates but, in many circumstances, with much greater beamline efficiency. copyright 1996 American Institute of Physics

Improving radiation hardness in space-based Charge-Coupled Devices through the narrowing of the charge transfer channel

Science.gov (United States)

Hall, D. J.; Skottfelt, J.; Soman, M. R.; Bush, N.; Holland, A.

2017-12-01

Charge-Coupled Devices (CCDs) have been the detector of choice for imaging and spectroscopy in space missions for several decades, such as those being used for the Euclid VIS instrument and baselined for the SMILE SXI. Despite the many positive properties of CCDs, such as the high quantum efficiency and low noise, when used in a space environment the detectors suffer damage from the often-harsh radiation environment. High energy particles can create defects in the silicon lattice which act to trap the signal electrons being transferred through the device, reducing the signal measured and effectively increasing the noise. We can reduce the impact of radiation on the devices through four key methods: increased radiation shielding, device design considerations, optimisation of operating conditions, and image correction. Here, we concentrate on device design operations, investigating the impact of narrowing the charge-transfer channel in the device with the aim of minimising the impact of traps during readout. Previous studies for the Euclid VIS instrument considered two devices, the e2v CCD204 and CCD273, the serial register of the former having a 50 μm channel and the latter having a 20 μm channel. The reduction in channel width was previously modelled to give an approximate 1.6× reduction in charge storage volume, verified experimentally to have a reduction in charge transfer inefficiency of 1.7×. The methods used to simulate the reduction approximated the charge cloud to a sharp-edged volume within which the probability of capture by traps was 100%. For high signals and slow readout speeds, this is a reasonable approximation. However, for low signals and higher readout speeds, the approximation falls short. Here we discuss a new method of simulating and calculating charge storage variations with device design changes, considering the absolute probability of capture across the pixel, bringing validity to all signal sizes and readout speeds. Using this method, we

Long-range surface plasmon resonance sensor with liquid micro-channels to maintain the symmetry condition of the refractive index

International Nuclear Information System (INIS)

Kan, Tetsuo; Kojo, Hiroyuki; Iwase, Eiji; Matsumoto, Kiyoshi; Shimoyama, Isao

2010-01-01

We propose a method to maintain the symmetry of the refractive index with respect to an Au film, in which the refractive indices are the same near both surfaces of the Au film, for LRSPR (long-range surface plasmon resonance) sensors. Maintenance of the symmetry is necessary for exciting the LRSPR mode. However, because the buffer layer under the Au film is usually made of a solid dielectric material with a constant refractive index, the quality of the measurement is reduced when the refractive index of the analyte used is dramatically different from that of the buffer layer. To solve this problem, the proposed sensor is equipped with liquid channels under the Au film. The Au film used in this study was supported by a thin (100 nm) polymer film forming parallel, one-dimensional liquid channels with a 29 µm pitch. Because the analyte solution flows in the channels, both surfaces of the Au film face the same analyte. Thus, this configuration automatically satisfies the symmetry condition for analytes with a wide range of refractive indices. We examined the validity of the sensor and compared it to that of a conventional sensor by measuring the LRSPR for five analyte solutions with different refractive indices. LRSPR dips were clearly observed for all of the analytes tested. The dip of the conventional LRSPR sensor became shallow when the refractive index increased, with the final dip depth being 65% of the initial dip depth for a refractive index of 1.358. In contrast, the dip depth of the proposed LRSPR sensor remained constant over the entire measured refractive index range of 1.331 to 1.358. These results indicate that the proposed sensor maintains the symmetry condition and confirm that the proposed method is effective for highly sensitive LRSPR measurements for a wide variety of analyte species

Achromatic Cooling Channel with Li Lenses

Energy Technology Data Exchange (ETDEWEB)

Balbekov, V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2002-04-29

A linear cooling channel with Li lenses, solenoids, and 201 MHz RF cavities is considered. A special lattice design is used to minimize chromatic aberrations by suppression of several betatron resonances. Transverse emittance of muon beam decreases from 2 mm to 0.5 mm at the channel of about 110 m length. Longitudinal heating is modest, therefore transmission of the channel is rather high: 96% without decay and 90% with decay. Minimal beam emittance achievable by similar channel estimated as about 0.25 mm at surface field of Li lenses 10 T.

CHANNEL EVOLUTION IN MODIFIED ALLUVIAL STREAMS.

Science.gov (United States)

Simon, Andrew; Hupp, Cliff R.

1987-01-01

This study (a) assesses the channel changes and network trends of bed level response after modifications between 1959 and 1972 of alluvial channels in western Tennessee and (b) develops a conceptual model of bank slope development to qualitatively assess bank stability and potential channel widening. A six-step, semiquantitative model of channel evolution in disturbed channels was developed by quantifying bed level trends and recognizing qualitative stages of bank slope development. Development of the bank profile is defined in terms of three dynamic and observable surfaces: (a) vertical face (70 to 90 degrees), (b) upper bank (25 to 50 degrees), and (c) slough line (20 to 25 degrees).

Fotometría de imágenes CCD insuficientemente muestreadas

Science.gov (United States)

Ostrov, P. G.

Se enfrenta el problema de la fotometría de imágenes CCD con una escala inadecuada (fwhm menor o igual que el tamaño de un pixel) y psf fuertemente variable con la posición. Se analiza, en particular, la aplicabilidad de una táctica propuesta por Massey, consistente en eliminar las vecinas débiles (utilizando una psf rudimentaria) para luego efectuar una fotometría de apertura sobre las estrellas brillantes. Se determina, mediante experimentos numéricos, la precisión alcanzada mediante esta técnica.

DOUBLE STARS IN THE USNO CCD ASTROGRAPHIC CATALOG

Energy Technology Data Exchange (ETDEWEB)

Hartkopf, William I.; Mason, Brian D.; Finch, Charlie T.; Zacharias, Norbert; Wycoff, Gary L.; Hsu, Danley, E-mail: wih@usno.navy.mil, E-mail: bdm@usno.navy.mil, E-mail: finch@usno.navy.mil, E-mail: nz@usno.navy.mil [US Naval Observatory, Washington, DC 20392 (United States)

2013-10-01

The newly completed Fourth USNO CCD Astrographic Catalog (UCAC4) has proven to be a rich source of double star astrometry and photometry. Following initial comparisons of UCAC4 results against those obtained by speckle interferometry, the UCAC4 catalog was matched against known double stars in the Washington Double Star Catalog in order to provide additional differential astrometry and photometry for these pairs. Matches to 58,131 pairs yielded 61,895 astrometric and 68,935 photometric measurements. Finally, a search for possible new common proper motion (CPM) pairs was made using new UCAC4 proper motion data; this resulted in 4755 new potential CPM doubles (and an additional 27,718 astrometric and photometric measures from UCAC and other sources)

基于线性 CCD 的智能车路径提取与寻迹%Path extraction and tracing of smart car based on linear CCD

Institute of Scientific and Technical Information of China (English)

白晋龙

2016-01-01

Extraction track information and tracing based on linear CCD is a key link in the development of smart car . This paper first introduced the linear CCD with matters should be noted in the use of the process .Then introduced the black and white border extraction algorithm .The effect of dirt or shadow on boundary extraction is eliminated by using corrosion method .Three kinds of track search methods are proposed .The methods are the center line tracing method , single track tracing method and track prediction method .The advantages and disadvantages of the three methods are compared in detail .Finally ,the author makes use of the single track search method to complete the production of intelligent vehicle ,the use of the limited resources of the Carle microcontroller to ensure that the race is not out of the runw ay .%基于线性CCD提取赛道信息和按照赛道信息控制智能车寻迹是光电组智能车制作中的关键环节。本文首先介绍了线性CCD ，以及使用过程中应该注意的事项，然后介绍了黑白边界提取算法，采用腐蚀算法消除了赛道上污垢或阴影对边界提取的影响，提出了3种赛道寻迹方法，分别为中心线寻迹法、单边寻迹法、赛道预估法，详细比较了3种方法的优缺点，单边寻迹法不仅适用于各种赛道情况，而且处理信息少，占用CPU空间小。最后利用单边寻迹法完成智能车制作，使用飞思卡尔单片机有限的资源保证在不冲出跑道的前提下完成了比赛。

Hypotonicity-induced reduction of aquaporin-2 transcription in mpkCCD cells is independent of the tonicity responsive element, vasopressin, and cAMP.

Science.gov (United States)

Kortenoeven, Marleen L A; van den Brand, Michiel; Wetzels, Jack F M; Deen, Peter M T

2011-04-15

The syndrome of inappropriate antidiuretic hormone secretion is characterized by excessive water uptake and hyponatremia. The extent of hyponatremia, however, is less than anticipated, which is ascribed to a defense mechanism, the vasopressin-escape, and is suggested to involve a tonicity-determined down-regulation of the water channel aquaporin-2 (AQP2). The underlying mechanism, however, is poorly understood. To study this, we used the mouse cortical collecting duct (mpkCCD) cell line. MpkCCD cells, transfected with an AQP2-promoter luciferase construct showed a reduced and increased AQP2 abundance and transcription following culture in hypotonic and hypertonic medium, respectively. This depended on tonicity rather than osmolality and occurred independently of the vasopressin analog dDAVP, cAMP levels, or protein kinase A activity. Although prostaglandins and nitric oxide reduced AQP2 abundance, inhibition of their synthesis did not influence tonicity-induced AQP2 transcription. Also, cells in which the cAMP or tonicity-responsive element (CRE/TonE) in the AQP2-promoter were mutated showed a similar response to hypotonicity. Instead, the tonicity-responsive elements were pin-pointed to nucleotides -283 to -252 and -157 to -126 bp. In conclusion, our data indicate that hypotonicity reduces AQP2 abundance and transcription, which occurs independently of vasopressin, cAMP, and the known TonE and CRE in the AQP2-promoter. Increased prostaglandin and nitric oxide, as found in vivo, may contribute to reduced AQP2 in vasopressin-escape, but do not mediate the effect of hypotonicity on AQP2 transcription. Our data suggest that two novel segments (-283 to -252 and -157 to -126 bp) in the AQP2-promoter mediate the hypotonicity-induced AQP2 down-regulation during vasopressin-escape.

[NDVI difference rate recognition model of deciduous broad-leaved forest based on HJ-CCD remote sensing data].

Science.gov (United States)

Wang, Yan; Tian, Qing-Jiu; Huang, Yan; Wei, Hong-Wei

2013-04-01

The present paper takes Chuzhou in Anhui Province as the research area, and deciduous broad-leaved forest as the research object. Then it constructs the recognition model about deciduous broad-leaved forest was constructed using NDVI difference rate between leaf expansion and flowering and fruit-bearing, and the model was applied to HJ-CCD remote sensing image on April 1, 2012 and May 4, 2012. At last, the spatial distribution map of deciduous broad-leaved forest was extracted effectively, and the results of extraction were verified and evaluated. The result shows the validity of NDVI difference rate extraction method proposed in this paper and also verifies the applicability of using HJ-CCD data for vegetation classification and recognition.

Nonlaser-based 3D surface imaging

Energy Technology Data Exchange (ETDEWEB)

Lu, Shin-yee; Johnson, R.K.; Sherwood, R.J. [Lawrence Livermore National Lab., CA (United States)

1994-11-15

3D surface imaging refers to methods that generate a 3D surface representation of objects of a scene under viewing. Laser-based 3D surface imaging systems are commonly used in manufacturing, robotics and biomedical research. Although laser-based systems provide satisfactory solutions for most applications, there are situations where non laser-based approaches are preferred. The issues that make alternative methods sometimes more attractive are: (1) real-time data capturing, (2) eye-safety, (3) portability, and (4) work distance. The focus of this presentation is on generating a 3D surface from multiple 2D projected images using CCD cameras, without a laser light source. Two methods are presented: stereo vision and depth-from-focus. Their applications are described.

Surface enhanced raman spectroscopy on chip

DEFF Research Database (Denmark)

Hübner, Jörg; Anhøj, Thomas Aarøe; Zauner, Dan

2007-01-01

In this paper we report low resolution surface enhanced Raman spectra (SERS) conducted with a chip based spectrometer. The flat field spectrometer presented here is fabricated in SU-8 on silicon, showing a resolution of around 3 nm and a free spectral range of around 100 nm. The output facet...... is projected onto a CCD element and visualized by a computer. To enhance the otherwise rather weak Raman signal, a nanosurface is prepared and a sample solutions is impregnated on this surface. The surface enhanced Raman signal is picked up using a Raman probe and coupled into the spectrometer via an optical...... fiber. The obtained spectra show that chip based spectrometer together with the SERS active surface can be used as Raman sensor....

Sedimentary Facies Mapping Based on Tidal Channel Network and Topographic Features

Science.gov (United States)

Ryu, J. H.; Lee, Y. K.; Kim, K.; Kim, B.

2015-12-01

Tidal flats on the west coast of Korea suffer intensive changes in their surface sedimentary facies as a result of the influence of natural and artificial changes. Spatial relationships between surface sedimentary facies distribution and benthic environments were estimated for the open-type Ganghwa tidal flat and semi closed-type Hwangdo tidal flat, Korea. In this study, we standardized the surface sedimentary facies and tidal channel index of the channel density, distance, thickness and order. To extract tidal channel information, we used remotely sensed data, such as those from the Korea Multi-Purpose Satellite (KOMPSAT)-2, KOMPSAT-3, and aerial photographs. Surface sedimentary facies maps were generated based on field data using an interpolation method.The tidal channels in each sediment facies had relatively constant meandering patterns, but the density and complexity were distinguishable. The second fractal dimension was 1.7-1.8 in the mud flat, about 1.4 in the mixed flat, and about 1.3 in the sand flat. The channel density was 0.03-0.06 m/m2 in the mud flat and less than 0.02 m/m2 in the mixed and sand flat areas of the two test areas. Low values of the tidal channel index, which indicated a simple pattern of tidal channel distribution, were identified at areas having low elevation and coarse-grained sediments. By contrast, high values of the tidal channel index, which indicated a dendritic pattern of tidal channel distribution, were identified at areas having high elevation and fine-grained sediments. Surface sediment classification based on remotely sensed data must circumspectly consider an effective critical grain size, water content, local topography, and intertidal structures.

First observations from a CCD all-sky spectrograph at Barentsburg (Spitsbergen

Directory of Open Access Journals (Sweden)

S. A. Chernouss

2008-05-01

Full Text Available A digital CCD all-sky spectrograph was made by the Polar Geophysical Institute (PGI to support IPY activity in auroral research. The device was tested at the Barentsburg observatory of PGI during the winter season of 2005–2006. The spectrograph is based on a cooled CCD and a transmission grating. The main features of this spectrograph are: a wide field of view (~180°, a wide spectral range (380–740 nm, a spectral resolution of 0.6 nm, a background level of about 100 R at 1-min exposure time. Several thousand spectra of nightglow and aurora were recorded during the observation season. It was possible to register both the strong auroral emissions, as well as weak ones. Spectra of aurora, including nitrogen and oxygen molecular and atomic emissions, as well as OH emissions of the nightglow are shown. A comparison has been conducted of auroral spectra obtained by the film all-sky spectral camera C-180-S at Spitsbergen during IGY, with spectra obtained at Barentsburg during the last winter season. The relationship between the red (630.0 nm and green (557.7 nm auroral emissions shows that the green emission is dominant near the minimum of the solar cycle activity (2005–2006. The opposite situation is observed during 1958–1959, with a maximum solar cycle activity.

Pengembangan Metoda Deteksi Rintangan untuk Traktor tanpa Awak Menggunakan Kamera CCD

Directory of Open Access Journals (Sweden)

Usman Ahmad

2012-04-01

Full Text Available For unmanned tractor guided by global positioning system, ability for eluding obstacles such as trees, big stone, cavity, bund, people, and other objects in the work area is very important in order not to stop the operation.Surrounding detection system using CCD camera makes it possible for unmanned tractor to detect obstacles in front of it realtime. However, with so many different objects that may captured by the camera, it will need a lot of image processing steps that takes a lot of time so it is no longer suitable for realtime detection in application. The proposed research is aimed to develop a simpler obstacle detection method by adding a red laser pointer to the CCD camera used to capture scene in front of the tractor. The red laser light that reflected by an obstacle gives an important information in the image, and the distance of the obstacle could be calculated based on phytagoras theory. The results showed that all obstacles with 1 m distance, 80% obstacles with 2 m distance, and 40% obstacles with 3 m distance could be detected. Obstacles with more than 3 m distances could not be detected due to weak laser light for the distances. The accuracy of distance prediction for all situation is 67.5%, which is still need improvements.

Turbulent flow and heat transfer in channels with combined rough and smooth surfaces

International Nuclear Information System (INIS)

Aytekin, A.

1978-01-01

A two-part experimental investigation is reported on the effects of transverse square rib roughening on fluid flow and heat transfer in channels with uniform and non-uniform boundary conditions. The first part of the experimental programme consisted of providing detailed measurements of mean and basic turbulent characteristics of fully developed flow in two rectangular ducts of aspect ratios 1.63 and 3.0. In each duct only one wall was roughened. In channels having low aspect ratios secondary flows play an important part in momentum transfer, and an interpretation of their effect on the measured Reynolds shear stress distribution has been attempted. In the second part of the experimental programme mean velocity and temperature profiles, friction factors and Stanton numbers were measured in an internally roughened pipe and annuli composed of a rough inner rod and either a smooth or a rough outer pipe. Heating was always applied on the outer surface. In all the geometries the mean velocities near the rough walls were found to be represented by logarithmic straight lines. The gradients of these lines were independent of Reynolds number but differed for various geometries. The mean temperature profiles, measured in the rough pipe and the fully rough annulus, showed that these could also be represented by logarithmic straight lines, but the slopes of these profiles were markedly different from those of the velocity profiles. (author)

Radiochromic film as a radiotherapy surface-dose detector

International Nuclear Information System (INIS)

Butson, M.J.; Metcalfe, P.E.; Wollongong Univ., NSW; Mathur, J.N.

1996-01-01

Radiochromic film is shown to be a useful surface-dose detector for radiotherapy x-ray beams. Central-axis percentage surface-dose results as measured by Gafchromic film for a 6 MVp x-ray beam produced by a Varian 2100C Linac at 100 cm SSD are 16%, 25%, 35%, 41% for 10, 20, 30 and 40 cm square field sizes, respectively. Using a simple, uniform light source and a CCD camera connected to an image analysis system, quantitative 3D surface doses are accurately attainable in real time as either numerical data, a black-and-white image or a colour-enhanced image. (Author)

In-pile behavior of controlled beta-quenched fuel channels

Energy Technology Data Exchange (ETDEWEB)

Moeckel, Andreas; Pflaum, Wolfgang; Cremer, Ingo [AREVA NP GmbH, Erlangen (Germany); Zbib, Ali A. [AREVA NP Inc., Richland, WA (United States)

2011-07-01

Dimensional stability during in-reactor service is the major requirement that is put on fuel channels to provide good moderation and power distribution, and to guarantee unrestricted movement of the control blades during operation. High corrosion resistance and low hydrogen pick-up are required as well. The latter are usually not considered to be life limiting, but may contribute to channel deformation since increased oxide layers due to shadow corrosion on the control blade sides of a channel result in differential oxide thickness and differential volume expansion due to hydride formation. This would be in addition to the well known effects of irradiation induced channel deformation, especially channel growth and bow. In order to meet the trend toward increased fuel assembly discharge burnup levels and the industry wide need for improved dimensional stability of fuel channels, AREVA NP has developed the Controlled Beta-Quenching of fuel channels. The process combines the positive effect of randomization of the crystallographic texture by beta-quenching with the optimization of the microstructure for good corrosion resistance by providing intermetallic phase particles in the optimum size range. The Controlled Beta-Quenching is a continuous heat treatment operation. Its key features are the two-step induction heating to uniformly reach the target temperature, the tight control of the quench rate by cooling the fuel channel from the outer surface using a controlled argon mass flow for quenching, and the protection of the inner surface from oxidation by providing an argon atmosphere. Due to the utilization of argon, the surfaces of the channels remain metal bright after beta-quenching. All in all, the Controlled Beta-Quenching provides an overall 'clean' and environment friendly operation without the need of additional surface conditioning. The first set of beta-quenched fuel channels, exhibiting these optimized material properties, were inserted in the core

Synthesis of Silicalite Membrane with an Aluminum-Containing Surface for Controlled Modification of Zeolitic Pore Entries for Enhanced Gas Separation

Directory of Open Access Journals (Sweden)

Shaowei Yang

2018-02-01

Full Text Available The separation of small molecule gases by membrane technologies can help performance enhancement and process intensification for emerging advanced fossil energy systems with CO2 capture capacity. This paper reports the demonstration of controlled modification of zeolitic channel size for the MFI-type zeolite membranes to enhance the separation of small molecule gases such as O2 and N2. Pure-silica MFI-type zeolite membranes were synthesized on porous α-alumina disc substrates with and without an aluminum-containing thin skin on the outer surface of zeolite membrane. The membranes were subsequently modified by on-stream catalytic cracking deposition (CCD of molecular silica to reduce the effective openings of the zeolitic channels. Such a pore modification caused the transition of gas permeation from the N2-selective gaseous diffusion mechanism in the pristine membrane to the O2-selective activated diffusion mechanism in the modified membrane. The experimental results indicated that the pore modification could be effectively limited within the aluminum-containing surface of the MFI zeolite membrane to minimize the mass transport resistance for O2 permeation while maintaining its selectivity. The implications of pore modification on the size-exclusion-enabled gas selectivity were discussed based on the kinetic molecular theory. In light of the theoretical analysis, experimental investigation was performed to further enhance the membrane separation selectivity by chemical liquid deposition of silica into the undesirable intercrystalline spaces.

The research of digital circuit system for high accuracy CCD of portable Raman spectrometer

Science.gov (United States)

Yin, Yu; Cui, Yongsheng; Zhang, Xiuda; Yan, Huimin

2013-08-01

The Raman spectrum technology is widely used for it can identify various types of molecular structure and material. The portable Raman spectrometer has become a hot direction of the spectrometer development nowadays for its convenience in handheld operation and real-time detection which is superior to traditional Raman spectrometer with heavy weight and bulky size. But there is still a gap for its measurement sensitivity between portable and traditional devices. However, portable Raman Spectrometer with Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy (SHINERS) technology can enhance the Raman signal significantly by several orders of magnitude, giving consideration in both measurement sensitivity and mobility. This paper proposed a design and implementation of driver and digital circuit for high accuracy CCD sensor, which is core part of portable spectrometer. The main target of the whole design is to reduce the dark current generation rate and increase signal sensitivity during the long integration time, and in the weak signal environment. In this case, we use back-thinned CCD image sensor from Hamamatsu Corporation with high sensitivity, low noise and large dynamic range. In order to maximize this CCD sensor's performance and minimize the whole size of the device simultaneously to achieve the project indicators, we delicately designed a peripheral circuit for the CCD sensor. The design is mainly composed with multi-voltage circuit, sequential generation circuit, driving circuit and A/D transition parts. As the most important power supply circuit, the multi-voltage circuits with 12 independent voltages are designed with reference power supply IC and set to specified voltage value by the amplifier making up the low-pass filter, which allows the user to obtain a highly stable and accurate voltage with low noise. What's more, to make our design easy to debug, CPLD is selected to generate sequential signal. The A/D converter chip consists of a correlated

Uncertainty analysis for hot channel

International Nuclear Information System (INIS)

Panka, I.; Kereszturi, A.

2006-01-01

The fulfillment of the safety analysis acceptance criteria is usually evaluated by separate hot channel calculations using the results of neutronic or/and thermo hydraulic system calculations. In case of an ATWS event (inadvertent withdrawal of control assembly), according to the analysis, a number of fuel rods are experiencing DNB for a longer time and must be regarded as failed. Their number must be determined for a further evaluation of the radiological consequences. In the deterministic approach, the global power history must be multiplied by different hot channel factors (kx) taking into account the radial power peaking factors for each fuel pin. If DNB occurs it is necessary to perform a few number of hot channel calculations to determine the limiting kx leading just to DNB and fuel failure (the conservative DNBR limit is 1.33). Knowing the pin power distribution from the core design calculation, the number of failed fuel pins can be calculated. The above procedure can be performed by conservative assumptions (e.g. conservative input parameters in the hot channel calculations), as well. In case of hot channel uncertainty analysis, the relevant input parameters (k x, mass flow, inlet temperature of the coolant, pin average burnup, initial gap size, selection of power history influencing the gap conductance value) of hot channel calculations and the DNBR limit are varied considering the respective uncertainties. An uncertainty analysis methodology was elaborated combining the response surface method with the one sided tolerance limit method of Wilks. The results of deterministic and uncertainty hot channel calculations are compared regarding to the number of failed fuel rods, max. temperature of the clad surface and max. temperature of the fuel (Authors)

Regulation of transport in the connecting tubule and cortical collecting duct

Science.gov (United States)

Staruschenko, Alexander

2012-01-01

The central goal of this overview article is to summarize recent findings in renal epithelial transport, focusing chiefly on the connecting tubule (CNT) and the cortical collecting duct (CCD). Mammalian CCD and CNT are involved in fine tuning of electrolyte and fluid balance through reabsorption and secretion. Specific transporters and channels mediate vectorial movements of water and solutes in these segments. Although only a small percent of the glomerular filtrate reaches the CNT and CCD, these segments are critical for water and electrolyte homeostasis since several hormones, e.g. aldosterone and arginine vasopressin, exert their main effects in these nephron sites. Importantly, hormones regulate the function of the entire nephron and kidney by affecting channels and transporters in the CNT and CCD. Knowledge about the physiological and pathophysiological regulation of transport in the CNT and CCD and particular roles of specific channels/transporters has increased tremendously over the last two decades. Recent studies shed new light on several key questions concerning the regulation of renal transport. Precise distribution patterns of transport proteins in the CCD and CNT will be reviewed, and their physiological roles and mechanisms mediating ion transport in these segments will be also covered. Special emphasis will be given to pathophysiological conditions appearing as a result of abnormalities in renal transport in the CNT and CCD. PMID:23227301

Analysis of total visual and ccd v-broadband observation of comet c/1995 o1 (hale-bopp): 1995-2003

Science.gov (United States)

de Almeida, A. A.; Boczko, R.; Lopes, A. R.; Sanzovo, G. C.

The wealth of available information on total visual magnitudes and broadband-V CCD observations of the exceptionally bright Comet C/1995 O1 (Hale-Bopp) proved to be an excellent opportunity to test the Semi-Empirical Method of Visual Magnitudes (de Almeida, Singh & Huebner, 1997) for very bright comets. The main objective is to extend the method to include total visual magnitude observations obtained with CCD detector and V filter in our analysis of total visual magnitudes and obtain a single light curve. We compare the CCD V-broadband careful observations of Liller (1997) by plotting then together with the total visual magnitude observations from experienced visual observers found in the International Comet Quarterly (ICQ) archive. We find a nice agreement despite of the fact that CCDs and V filter passbands detect systematically more coma than visual observers, since they have different responses to C2, which is the main emission from the coma, and consequently they should be used with larger apperture diameters. A data set of ˜400 CCD selected observations covering about the same 5 years time span of the ˜12,000 ICQ total visual magnitude observations were used in the analysis. A least-squares fit to the values yielded a relation for water production rates vs heliocentric distances for the pre- and post-perihelion phases and are converted into gas production rates (in g/s) released by the nucleus. The dimension of the nucleus as well as its effective active area is determined and compared to other works.

MiCPhot: A prime-focus multicolor CCD photometer on the 85-cm Telescope

International Nuclear Information System (INIS)

Zhou Aiying; Jiang Xiaojun; Wei Jianyan; Zhang Yanping

2009-01-01

We describe a new BV RI multicolor CCD photometric system situated at the prime focus of the 85-cm telescope at the Xinglong Station of NAOC. Atmospheric extinction effects, photometric accuracy and color calibration dependence of the system are investigated. Additional attention was paid to giving observers guidance in estimating throughput, detection limit, signal-to-noise ratio and exposure time. (invited reviews)

A CCD camera probe for a superconducting cyclotron

International Nuclear Information System (INIS)

Marti, F.; Blue, R.; Kuchar, J.; Nolen, J.A.; Sherrill, B.; Yurkon, J.

1991-01-01

The traditional internal beam probes in cyclotrons have consisted of a differential element, a wire or thin strip, and a main probe with several fingers to determine the vertical distribution of the beam. The resolution of these probes is limited, especially in the vertical direction. The authors have developed a probe for their K1200 superconducting cyclotron based on a CCD TV camera that works in a 6 T magnetic field. The camera looks at the beam spot on a scintillating screen. The TV image is processed by a frame grabber that digitizes and displays the image in pseudocolor in real time. This probe has much better resolution than traditional probes. They can see beams with total currents as low as 0.1 pA, with position resolution of about 0.05 mm

Mobility-limiting mechanisms in single and dual channel strained Si/SiGe MOSFETs

International Nuclear Information System (INIS)

Olsen, S.H.; Dobrosz, P.; Escobedo-Cousin, E.; Bull, S.J.; O'Neill, A.G.

2005-01-01

Dual channel strained Si/SiGe CMOS architectures currently receive great attention due to maximum performance benefits being predicted for both n- and p-channel MOSFETs. Epitaxial growth of a compressively strained SiGe layer followed by tensile strained Si can create a high mobility buried hole channel and a high mobility surface electron channel on a single relaxed SiGe virtual substrate. However, dual channel n-MOSFETs fabricated using a high thermal budget exhibit compromised mobility enhancements compared with single channel devices, in which both electron and hole channels form in strained Si. This paper investigates the mobility-limiting mechanisms of dual channel structures. The first evidence of increased interface roughness due to the introduction of compressively strained SiGe below the tensile strained Si channel is presented. Interface corrugations degrade electron mobility in the strained Si. Roughness measurements have been carried out using AFM and TEM. Filtering AFM images allowed roughness at wavelengths pertinent to carrier transport to be studied and the results are in agreement with electrical data. Furthermore, the first comparison of strain measurements in the surface channels of single and dual channel architectures is presented. Raman spectroscopy has been used to study channel strain both before and after processing and indicates that there is no impact of the buried SiGe layer on surface macrostrain. The results provide further evidence that the improved performance of the single channel devices fabricated using a high thermal budget arises from improved surface roughness and reduced Ge diffusion into the Si channel

A USB 2.0 computer interface for the UCO/Lick CCD cameras

Science.gov (United States)

Wei, Mingzhi; Stover, Richard J.

2004-09-01

The new UCO/Lick Observatory CCD camera uses a 200 MHz fiber optic cable to transmit image data and an RS232 serial line for low speed bidirectional command and control. Increasingly RS232 is a legacy interface supported on fewer computers. The fiber optic cable requires either a custom interface board that is plugged into the mainboard of the image acquisition computer to accept the fiber directly or an interface converter that translates the fiber data onto a widely used standard interface. We present here a simple USB 2.0 interface for the UCO/Lick camera. A single USB cable connects to the image acquisition computer and the camera's RS232 serial and fiber optic cables plug into the USB interface. Since most computers now support USB 2.0 the Lick interface makes it possible to use the camera on essentially any modern computer that has the supporting software. No hardware modifications or additions to the computer are needed. The necessary device driver software has been written for the Linux operating system which is now widely used at Lick Observatory. The complete data acquisition software for the Lick CCD camera is running on a variety of PC style computers as well as an HP laptop.

Scan-free grazing emission XRF measurements in the laboratory using a CCD

International Nuclear Information System (INIS)

Szwedowski, Veronika; Baumann, Jonas; Mantouvalou, Ioanna; Bauer, Leona; Malzer, Wolfgang; Kanngiesser, Birgit

2017-01-01

The rapid development of new classes of nanomaterials calls for easy access methods in order to quantify properties essential for their functionality, e.g., interdiffusion of elements at interfaces, or elemental dopant, or depth profiles. Non-destructive methods, like X-ray fluorescence (XRF), are of special interest, for preserving materials and offering the possibility to incorporate the analysis in a production process. In-depth XRF methods for the characterization of nanomaterials are up until now limited to synchrotron radiation facilities. A novel scan-free grazing emission XRF (GEXRF) setup is presented utilizing conventional and low-cost hardware, acting as a transfer of a synchrotron method into the laboratory. A chromium target X-ray tube with a polycapillary lens is used as X-ray source and a conventional CCD as the 2D energy-dispersive detector. To confirm the feasibility of the described setup a nanometer-layered titanium-aluminium sample is measured. An energy-dispersive spectrum is obtained in single-photon-counting-mode from the CCD measurements and first GEXRF profiles generated. A semi-quantitative evaluation of this setup is implemented by comparing the measured results with simulations, allowing conclusions about the investigated samples' elemental, compositional, and structural layer-by-layer characteristics. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Separation followed by direct SERS detection of explosives on a novel black silicon multifunctional nanostructured surface prepared in a microfluidic channel

DEFF Research Database (Denmark)

Talian, Ivan; Hübner, Jörg

2013-01-01

The article describes the multifunctionality of a novel black silicon (BS) nanostructured surface covered with a thin layer of noble metal prepared in the a microfluidic channel. It is focused on the separation properties of the BS substrate with direct detection of the separated analytes utilizing...

Multi-Channel Capacitive Sensor Arrays

Directory of Open Access Journals (Sweden)

Bingnan Wang

2016-01-01

Full Text Available In this paper, multi-channel capacitive sensor arrays based on microstrip band-stop filters are studied. The sensor arrays can be used to detect the proximity of objects at different positions and directions. Each capacitive sensing structure in the array is connected to an inductive element to form resonance at different frequencies. The resonances are designed to be isolated in the frequency spectrum, such that the change in one channel does not affect resonances at other channels. The inductive element associated with each capacitive sensor can be surface-mounted inductors, integrated microstrip inductors or metamaterial-inspired structures. We show that by using metamaterial split-ring structures coupled to a microstrip line, the quality factor of each resonance can be greatly improved compared to conventional surface-mounted or microstrip meander inductors. With such a microstrip-coupled split-ring design, more sensing elements can be integrated in the same frequency spectrum, and the sensitivity can be greatly improved.

A FORTRAN realization of the block adjustment of CCD frames

Science.gov (United States)

Yu, Yong; Tang, Zhenghong; Li, Jinling; Zhao, Ming

A FORTRAN version realization of the block adjustment (BA) of overlapping CCD frames is developed. The flowchart is introduced including (a) data collection, (b) preprocessing, and (c) BA and object positioning. The subroutines and their functions are also demonstrated. The program package is tested by simulated data with/without the application of white noises. It is also preliminarily applied to the reduction of optical positions of four extragalactic radio sources. The results show that because of the increase in the sky coverage and number of reference stars, the precision of deducted positions is improved compared with single plate adjustment.

Wiring assembly and method of forming a channel in a wiring assembly for receiving conductor and providing separate regions of conductor contact with the channel

Energy Technology Data Exchange (ETDEWEB)

Stelzer, Gerald; Meinke, Rainer; Senti, Mark

2018-03-06

A conductor assembly and method for constructing an assembly of the type which, when conducting current, generates a magnetic field or which, in the presence of a changing magnetic field, induces a voltage. In one embodiment the method provides a first insulative layer tubular in shape and including a surface along which a conductor segment may be positioned. A channel formed in the surface of the insulative layer defines a first conductor path and includes a surface of first contour in cross section along a first plane transverse to the conductor path. A segment of conductor having a surface of second contour in cross section is positioned at least partly in the channel and extends along the conductor path. Along the first plane, contact between the conductor surface of second contour and the channel surface of first contour includes at least two separate regions of contact.

On x-ray channelling in microcapillaries and nanocapillaries

CERN Document Server

Bellucci, S

2003-01-01

In this work, x-ray propagation in microsize and nanosize capillaries has been considered in the framework of a simple unified wave theory. It is shown that diminishing of the channel sizes completely changes the mode of beam transportation; that is, we obtain the transformation of surface channelling in microcapillaries to bulk channelling in nanocapillaries (nanotubes).

A new CCD-camera neutron radiography detector at the Atominstitute of the Austrian Universities

International Nuclear Information System (INIS)

Koerner, S.; Boeck, H.; Rauch, H.; Lehmann, E.

1999-01-01

Neutron radiography provides a very efficient tool for non-destructive testing as well as for many applications in fundamental research. A neutron beam penetrating a specimen is attenuated by the sample material and detected by a two dimensional imaging device. The image contains information about materials and structure inside the sample because neutrons are attenuated according to the basic law of radiation attenuation. At the Atominstitute of the Austrian Universities neutron radiographic examinations have been carried out for more than 35 years, mainly with detectors consisting of X-ray films and a Gd- converter enclosed in a vacuum cassette. Presently a neutron tomography set-up is under development. For high quality 3D image reconstruction, about 200 digitized neutron transmission images from different angles of the object are necessary. Therefore the first step was the design of an adequate electronic neutron radiography imaging device. The requirements for a detector suitable for neutron tomography are: exact and reproducible positioning, easy handling, high spatial resolution and dynamic range, high efficiency and a good linearity. The key components of the detector system selected on the basis of the requirements consist of a neutron sensitive scintillator screen, a cooled slow scan CCD camera and a mirror to reflect the light emitted by the scintillator to the CCD camera. The whole assembly is placed in a light tight enclosure. In this paper the strategy of the selection of the individual detector components is described. Comparisons on the influence of the use of different components on the properties of the whole position sensitive imaging device are demonstrated. Finally the new CCD camera neutron radiography detector of the Atominstitute is presented and first results of test measurements performed at the neutron radiography facility NEUTRA at the continuous spallation source SINQ at Paul Scherrer Institute are shown.(author)

Insights into the formation of carlactone from in-depth analysis of the CCD8-catalyzed reactions

KAUST Repository

Bruno, Mark; Vermathen, Martina; Alder, Adrian; Wü st, Florian; Schaub, Patrick; van der Steen, Rob; Beyer, Peter; Ghisla, Sandro; Al-Babili, Salim

2017-01-01

Strigolactones (SLs) are a new class of phytohormones synthesized from carotenoids via carlactone. The complex structure of carlactone is not easily deducible from its precursor, a cis-configured β-carotene cleavage product, and is thus formed via a poorly understood series of reactions and molecular rearrangements, all catalyzed by only one enzyme, the carotenoid cleavage dioxygenase 8 (CCD8). Moreover, the reactions leading to carlactone are expected to form a second, yet unidentified product. In this study, we used (13) C and (18) O-labelling to shed light on the reactions catalyzed by CCD8. The characterization of the resulting carlactone by LC-MS and NMR, and the identification of the assumed, less accessible second product allowed us to formulate a minimal reaction mechanism for carlactone generation. This article is protected by copyright. All rights reserved.

Insights into the formation of carlactone from in-depth analysis of the CCD8-catalyzed reactions

KAUST Repository

Bruno, Mark

2017-02-10

Strigolactones (SLs) are a new class of phytohormones synthesized from carotenoids via carlactone. The complex structure of carlactone is not easily deducible from its precursor, a cis-configured β-carotene cleavage product, and is thus formed via a poorly understood series of reactions and molecular rearrangements, all catalyzed by only one enzyme, the carotenoid cleavage dioxygenase 8 (CCD8). Moreover, the reactions leading to carlactone are expected to form a second, yet unidentified product. In this study, we used (13) C and (18) O-labelling to shed light on the reactions catalyzed by CCD8. The characterization of the resulting carlactone by LC-MS and NMR, and the identification of the assumed, less accessible second product allowed us to formulate a minimal reaction mechanism for carlactone generation. This article is protected by copyright. All rights reserved.

Three-dimensional continuous particle focusing in a microfluidic channel via standing surface acoustic waves (SSAW).

Science.gov (United States)

Shi, Jinjie; Yazdi, Shahrzad; Lin, Sz-Chin Steven; Ding, Xiaoyun; Chiang, I-Kao; Sharp, Kendra; Huang, Tony Jun

2011-07-21

Three-dimensional (3D) continuous microparticle focusing has been achieved in a single-layer polydimethylsiloxane (PDMS) microfluidic channel using a standing surface acoustic wave (SSAW). The SSAW was generated by the interference of two identical surface acoustic waves (SAWs) created by two parallel interdigital transducers (IDTs) on a piezoelectric substrate with a microchannel precisely bonded between them. To understand the working principle of the SSAW-based 3D focusing and investigate the position of the focal point, we computed longitudinal waves, generated by the SAWs and radiated into the fluid media from opposite sides of the microchannel, and the resultant pressure and velocity fields due to the interference and reflection of the longitudinal waves. Simulation results predict the existence of a focusing point which is in good agreement with our experimental observations. Compared with other 3D focusing techniques, this method is non-invasive, robust, energy-efficient, easy to implement, and applicable to nearly all types of microparticles.

Technical aspects and preliminary results of the CCD camera diagnostics on Extrap T2

International Nuclear Information System (INIS)

Cecconello, M.; Brzozowski, J.

1999-01-01

During the last months of Extrap T2 operations an imaging acquisition system, based on charge-coupled devices (CCD) cameras, has been operated. CCD cameras are a standard diagnostic used in many fusion experiments: i) to obtain a direct insight of the plasma behaviour during the pulse, of the evolution of plasma-wall interactions and, eventually, of locked modes, ii) to measure local quantities such as the wall temperature and the impurity influxes, iii) to study the hydrogen recycling behaviour and iv) to estimate the poloidal and toroidal mode numbers. One of the aims of our imaging campaign was to check the utility of such diagnostic for T2. The purpose of this report is to describe the technical aspects involved in the use of such diagnostic and to briefly describe the results obtained. In this view, this report aims to be a guide to the development of a dedicated image acquisition system for Extrap T2, after the planned rebuild, by stressing the problems and limitations encountered during this campaign

Single-Pulse Dual-Energy Mammography Using a Binary Screen Coupled to Dual CCD Cameras

Science.gov (United States)

1999-08-01

Fossum, "Active pixel sensors—Are CCD’s Dinosaurs ?," Proc. SPIE 1900, 2-14 (1993). "S. Mendis, S. E. Kemeny, R. Gee, B. Pain, and E. R. Fossum, "Progress...Clin Oncol 13:1470-1477, 1995 12. Wahl RL, Zasadny K, Helvie M, et al: Metabolic monitoring of breast cancer chemohormonotherapy using posi- tron

Comparison of a CCD and an APS for soft x-ray diffraction

OpenAIRE

Stewart, G.; Bates, R.; Blue, A.; Clark, A.; Dhesi, S.S.; Maneuski, D.; Marchal, J.; Steadman, P.; Tartoni, N.; Turchetta, R.

2011-01-01

We compare a new CMOS Active Pixel Sensor (APS) to a Princeton Instruments PIXIS-XO: 2048B Charge Coupled Device (CCD) with soft X-rays tested in a synchrotron beam line at the Diamond Light Source (DLS). Despite CCDs being established in the field of scientific imaging, APS are an innovative technology that offers advantages over CCDs. These include faster readout, higher operational temperature, in-pixel electronics for advanced image processing and reduced manufacturing cost.\\ud \\ud The AP...

Temperature profiles on the gadolinium surface during electron beam evaporation

Energy Technology Data Exchange (ETDEWEB)

Ohba, Hironori; Shibata, Takemasa [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1995-03-01

The distributions of surface temperature of gadolinium in a water-cooled copper crucible during electron beam evaporation were measured by optical pyrometry. The surface temperatures were obtained from the radiation intensity ratio of the evaporating surface and a reference light source using Planck`s law of radiation. The emitted radiation from the evaporating surface and a reference source was detected by a CCD sensor through a band pass filter of 650 nm. The measured surface temperature generally agreed with those estimated from the deposition rate and the data of the saturated vapor pressure. At high input powers, it was found that the measured value had small difference with the estimated one due to variation of the surface condition. (author).

Temperature profiles on the gadolinium surface during electron beam evaporation

International Nuclear Information System (INIS)

Ohba, Hironori; Shibata, Takemasa

1995-01-01

The distributions of surface temperature of gadolinium in a water-cooled copper crucible during electron beam evaporation were measured by optical pyrometry. The surface temperatures were obtained from the radiation intensity ratio of the evaporating surface and a reference light source using Planck's law of radiation. The emitted radiation from the evaporating surface and a reference source was detected by a CCD sensor through a band pass filter of 650 nm. The measured surface temperature generally agreed with those estimated from the deposition rate and the data of the saturated vapor pressure. At high input powers, it was found that the measured value had small difference with the estimated one due to variation of the surface condition. (author)

Study of surface integrity AISI 4140 as result of hard, dry and high speed machining using CBN

Science.gov (United States)

Ginting, B.; Sembiring, R. W.; Manurung, N.

2017-09-01

The concept of hard, dry and high speed machining can be combined, to produce high productivity, with lower production costs in manufacturing industry. Hard lathe process can be a solution to reduce production time. In lathe hard alloy steels reported problems relating to the integrity of such surface roughness, residual stress, the white layer and the surface integrity. AISI 4140 material is used for high reliable hydraulic system components. This material includes in cold work tool steel. Consideration election is because this material is able to be hardened up to 55 HRC. In this research, the experimental design using CCD model fit with three factors, each factor is composed of two levels, and six central point, experiments were conducted with 1 replications. The experimental design research using CCD model fit.

Applications of a pnCCD detector coupled to columnar structure CsI(Tl) scintillator system in ultra high energy X-ray Laue diffraction

Science.gov (United States)

Shokr, M.; Schlosser, D.; Abboud, A.; Algashi, A.; Tosson, A.; Conka, T.; Hartmann, R.; Klaus, M.; Genzel, C.; Strüder, L.; Pietsch, U.

2017-12-01

Most charge coupled devices (CCDs) are made of silicon (Si) with typical active layer thicknesses of several microns. In case of a pnCCD detector the sensitive Si thickness is 450 μm. However, for silicon based detectors the quantum efficiency for hard X-rays drops significantly for photon energies above 10 keV . This drawback can be overcome by combining a pixelated silicon-based detector system with a columnar scintillator. Here we report on the characterization of a low noise, fully depleted 128×128 pixels pnCCD detector with 75×75 μm2 pixel size coupled to a 700 μm thick columnar CsI(Tl) scintillator in the photon range between 1 keV to 130 keV . The excellent performance of the detection system in the hard X-ray range is demonstrated in a Laue type X-ray diffraction experiment performed at EDDI beamline of the BESSY II synchrotron taken at a set of several GaAs single crystals irradiated by white synchrotron radiation. With the columnar structure of the scintillator, the position resolution of the whole system reaches a value of less than one pixel. Using the presented detector system and considering the functional relation between indirect and direct photon events Laue diffraction peaks with X-ray energies up to 120 keV were efficiently detected. As one of possible applications of the combined CsI-pnCCD system we demonstrate that the accuracy of X-ray structure factors extracted from Laue diffraction peaks can be significantly improved in hard X-ray range using the combined CsI(Tl)-pnCCD system compared to a bare pnCCD.

Multi-spectral CCD camera system for ocean water color and seacoast observation

Science.gov (United States)

Zhu, Min; Chen, Shiping; Wu, Yanlin; Huang, Qiaolin; Jin, Weiqi

2001-10-01

One of the earth observing instruments on HY-1 Satellite which will be launched in 2001, the multi-spectral CCD camera system, is developed by Beijing Institute of Space Mechanics & Electricity (BISME), Chinese Academy of Space Technology (CAST). In 798 km orbit, the system can provide images with 250 m ground resolution and a swath of 500 km. It is mainly used for coast zone dynamic mapping and oceanic watercolor monitoring, which include the pollution of offshore and coast zone, plant cover, watercolor, ice, terrain underwater, suspended sediment, mudflat, soil and vapor gross. The multi- spectral camera system is composed of four monocolor CCD cameras, which are line array-based, 'push-broom' scanning cameras, and responding for four spectral bands. The camera system adapts view field registration; that is, each camera scans the same region at the same moment. Each of them contains optics, focal plane assembly, electrical circuit, installation structure, calibration system, thermal control and so on. The primary features on the camera system are: (1) Offset of the central wavelength is better than 5 nm; (2) Degree of polarization is less than 0.5%; (3) Signal-to-noise ratio is about 1000; (4) Dynamic range is better than 2000:1; (5) Registration precision is better than 0.3 pixel; (6) Quantization value is 12 bit.

BVRI CCD photometry of the metal-poor globular cluster M68 (NGC 4590)

International Nuclear Information System (INIS)

Alcaino, G.; Liller, W.; Alvarado, F.; Wenderoth, E.

1990-01-01

BVRI photometry of the low metallicity globular cluster M68 (NGC 4590) was obtained with a CCD camera and the 2.2-m ESO telescope. The resulting BV color-magnitude diagrams are compared with the observations of McClure et al. (1987). The observations are also compared with theoretical isochrones, yielding a cluster age of 13 Gyr with a likely external uncertainty of 2 or 3 Gyr. 25 refs

Use of 198 Au, with surface labelling, in the study of solid transport by bed load in large natural channels

International Nuclear Information System (INIS)

Nakahira, S.

1987-01-01

The present study aims to present a method of measuring the bed load transport using a radioisotope technique in large natural channels. This study describes the basic principles of radioisotope application in this field, emphasizing the use of 198 Au for surface labelling of a natural sediment. Moreover, it presents the theoretical aspects, critical analysis, recommendations and comments on the methodology proposed. (author)

Superconducting muon channel at J-PARC

International Nuclear Information System (INIS)

Shimomura, K.; Koda, A.; Strasser, P.; Kawamura, N.; Fujimori, H.; Makimura, S.; Higemoto, W.; Nakahara, K.; Ishida, K.; Nishiyama, K.; Nagamine, K.; Miyake, Y.

2009-01-01

The Muon Science Laboratory at the Materials and Life Science Facility is now under construction in Japan Proton Accelerator Research Complex (J-PARC), where four types of muon channels are planned to be installed. A conventional superconducting muon channel will be installed at the first stage, which can extract surface (positive) muons and decay positive/negative muons up to 120 MeV/c, and the expected muon yield is a few 10 6 /s at 60 MeV/c (for both positive and negative). This channel will be used for various kinds of experiments like muon catalyzed fusion, μSR and nondestructive elements analysis. The present status of the superconducting muon channel is briefly reported.

Acoustic Imaging of a Turbidity Current Flowing along a Channel

Science.gov (United States)

Hughes Clarke, J. E.; Hiroji, A.; Cahill, L.; Fedele, J. J.

2017-12-01

As part of a 3 month sequence of repetitive surveys and ADCP monitoring, more than 30 turbidity currents have been identified modifying a lobe channel in 130 to 190m of water on the Squamish prodelta. For a 6 day period, daily surveys at low tide tried to capture the change resulting from a single flow. On the 8thof June three flows occurred within a half hour. Along channel multibeam images of the seabed and water column were obtained from a moving vessel immediately before, during and after the passage of the third flow. In this manner the spatial extent of the in-channel and overbank flow could be constrained. By following the flow, the spatial pattern of scattering from the flow upper surface could be examined over a 2 km length of the channel. Along channel bands of high scattering appear related to enhanced release of gas along the channel flanks. Notably, no signature of the underlying across-channel bedform modulations were evident, suggesting that the upper surface of the flow does not feel the influence of the channel floor. Overbank spillage of the flow could be detected by perturbation of a plankton scattering layer just above the seabed. Additionally, evidence of enhanced overbank deposition due to flow stripping on the outer corner of a bend was identified from backscatter changes. The specific seabed alteration due to this flow could be identified and compared with the cumulative change over three months in the channel and adjacent channel-lobe transition zone. As the flow passed under the ADCP, it had a peak velocity of over 2 m/s, a thickness of 4-5m and duration of 35 minutes. Based on the timing of the flow head when in view of the surface vessel, it was decelerating as it exited the mouth of the channel.

Automated CCD camera characterization. 1998 summer research program for high school juniors at the University of Rochester's Laboratory for Laser Energetics. Student research reports

International Nuclear Information System (INIS)

Silbermann, J.

1999-03-01

The OMEGA system uses CCD cameras for a broad range of applications. Over 100 video rate CCD cameras are used for such purposes as targeting, aligning, and monitoring areas such as the target chamber, laser bay, and viewing gallery. There are approximately 14 scientific grade CCD cameras on the system which are used to obtain precise photometric results from the laser beam as well as target diagnostics. It is very important that these scientific grade CCDs are properly characterized so that the results received from them can be evaluated appropriately. Currently characterization is a tedious process done by hand. The operator must manually operate the camera and light source simultaneously. Because more exposures means more accurate information on the camera, the characterization tests can become very length affairs. Sometimes it takes an entire day to complete just a single plot. Characterization requires the testing of many aspects of the camera's operation. Such aspects include the following: variance vs. mean signal level--this should be proportional due to Poisson statistics of the incident photon flux; linearity--the ability of the CCD to produce signals proportional to the light it received; signal-to-noise ratio--the relative magnitude of the signal vs. the uncertainty in that signal; dark current--the amount of noise due to thermal generation of electrons (cooling lowers this noise contribution significantly). These tests, as well as many others, must be conducted in order to properly understand a CCD camera. The goal of this project was to construct an apparatus that could characterize a camera automatically

On the Efficiency of the Multi-Channel Analysis of Surface Wave Method for Shallow and Semi-Deep Loose Soil Layers

Directory of Open Access Journals (Sweden)

Kasgin Khaheshi Banab

2010-01-01

Full Text Available The multi-channel analysis of surface waves (MASWs method was used to obtain the shear wave velocity variations through near surface (depth 2,300 m/s is very large. The MASW velocity results compared with those of other geophysical approaches, such as seismic reflection/refraction methods and borehole data, where available, mostly confirming the capability of the MASW method to distinguish the high shear wave velocity contrast in the study area. We have found that, of the inversion procedures of MASW data, the random search inversion technique provides better results than the analytical generalized inversion method.

Multiple flow profiles for two-phase flow in single microfluidic channels through site-selective channel coating.

Science.gov (United States)

Logtenberg, Hella; Lopez-Martinez, Maria J; Feringa, Ben L; Browne, Wesley R; Verpoorte, Elisabeth

2011-06-21

An approach to control two-phase flow systems in a poly(dimethylsiloxane) (PDMS) microfluidic device using spatially selective surface modification is demonstrated. Side-by-side flows of ethanol : water solutions containing different polymers are used to selectively modify both sides of a channel by laminar flow patterning. Introduction of air pockets during modification allows for control over the length of the channel section that is modified. This approach makes it possible to achieve slug flow and side-by-side flow of water : 1-octanol simultaneously within the same PDMS channel, without the need of additional structural elements. A key finding is that conditioning of the PDMS channels with 1-octanol before polymer deposition is crucial to achieving stable side-by-side flows.

The effects of processing parameters on the properties of micro-scale porous surface for a micro-channel reactor

International Nuclear Information System (INIS)

Feng, Yanbing; Mei, Deqing; Qian, Miao; Yi, Zoudongyi; Chen, Zichen

2017-01-01

To improve the performance of hydrogen production via a microchannel reactor with a porous surface, the process of layered powder sintering and dissolution method is optimized, and the effects of processing parameters on the morphological and mechanical properties of the porous surface structure are studied. Based on the preliminary experiments, three key parameters in the process are the size of the NaCl particle, the compaction pressure, and the sintering temperature. Besides, the porous surface structures are evaluated by the specific surface area and compression strength to optimize the influencing variables. Results show that the specific surface area of porous surface structure is determined mainly by the size of NaCl particle, while the pressure and temperature have little influence unexpectedly within the range of experimental condition. With the increase of temperature and pressure, the compression strength will be enhanced, but the increase of the size of NaCl particles will cause the decrease of compression strength. The optimum compaction pressure, sintering temperature, and size of the NaCl particle are obtained respectively. Finally, the optimum parameters have been used to manufacture the micro-channel catalyst support with a porous surface, and its hydrogen production can be maximumly enhanced by 90% compared with the surface fabricated with NaCl particles of 125–150 µ m. (paper)

Fog-Harvesting Properties of Dryopteris marginata: Role of Interscalar Microchannels in Water-Channeling

Directory of Open Access Journals (Sweden)

Vipul Sharma

2018-04-01

Full Text Available Several flora and fauna species found in arid areas have adapted themselves to collect water by developing unique structures and to intake the collected moisture. Apart from the capture of the moisture and fog on the surface, water transport and collection both play an important part in fog-harvesting systems as it prevents the loss of captured water through evaporation and makes the surface available for the capture of water again. Here, we report the remarkable fog collection and water-channeling properties of Dryopteris marginata. The surface of D. marginata has developed an integrated system of multiscale channels so that the water spreads quickly and is transported via these channels very efficiently. These integrated multiscale channels have also been replicated using a facile soft lithography technique to prepare biomimetic surfaces and it has been proved that it is the surface architecture that plays a role in the water transport rather than the material’s properties (waxes present on the surface of the leaves. Based on our studies, we infer that the microlevel hierarchy of the structures make the surface hydrophilic and the multiscale channels allow the efficient passage and transport of water. The understanding of the efficient and well-directed water transport and collection in D. marginata is expected to provide valuable insights to design efficient surfaces for fog-harvesting applications.

Fluid and solute transport in a network of channels

International Nuclear Information System (INIS)

Moreno, L.; Neretnieks, I.

1991-09-01

A three-dimensional channel network model is presented. The fluid flow and solute transport are assumed to take place through a network of connected channels. The channels are generated assuming that the conductances are lognormally distributed. The flow is calculated resolving the pressure distribution and the sole transport is calculated by using a particle tracking technique. The model includes diffusion into the rock matrix and sorption within the matrix in addition to advection along the channel network. Different approaches are used to describe the channel volume and its relation to the conductivity. To quantify the diffusion into the rock matrix the size of the flow wetted surface (contact surface between the channel and the rock) is needed in addition to the diffusion properties and the sorption capacity of the rock. Two different geometries were simulated: regional parallel flow and convergent flow toward a tunnel. In the generation of the channel network, it is found that its connectivity is reduced when the standard deviation in conductances is increased. For large standard deviations, the water conducting channels are found to be few. Standard deviations for the distribution of the effluent channel flowrates were calculated. Comparisons were made with experimental data from drifts and tunnels as well as boreholes as a means to validate the model. (au) (31 refs.)

Making channeling visible: keV noble gas ion trails on Pt(111)

Energy Technology Data Exchange (ETDEWEB)

Redinger, A; Standop, S; Michely, T [II Physikalisches Institut, Universitaet zu Koeln, D-50937 Koeln (Germany); Rosandi, Y; Urbassek, H M, E-mail: urbassek@rhrk.uni-kl.de [Fachbereich Physik und Forschungszentrum OPTIMAS, Universitaet Kaiserslautern, Erwin-Schroedinger-Strasse, D-67663 Kaiserslautern (Germany)

2011-01-15

The impact of argon and xenon noble gas ions on Pt(111) in grazing incidence geometry are studied through direct comparison of scanning tunneling microscopy images and molecular dynamics simulations. The energy range investigated is 1-15 keV and the angles of incidence with respect to the surface normal are between 78.5{sup 0} and 88{sup 0}. The focus of the paper is on events where ions gently enter the crystal at steps and are guided in channels between the top most layers of the crystal. The trajectories of the subsurface channeled ions are visible as trails of surface damage. The mechanism of trail formation is analyzed using simulations and analytical theory. Significant differences between Xe{sup +} and Ar{sup +} projectiles in damage, in the onset energy of subsurface channeling as well as in ion energy dependence of trail length and appearance are traced back to the projectile and ion energy dependence of the stopping force. The asymmetry of damage production with respect to the ion trajectory direction is explained through the details of the channel shape and subchannel structure as calculated from the continuum approximation of the channel potential. Measured and simulated channel switching in directions normal and parallel to the surface as well as an increase of ions entering into channels from the perfect surface with increasing angles of incidence are discussed.

A Binary Offset Effect in CCD Readout and Its Impact on Astronomical Data

Science.gov (United States)

Boone, K.; Aldering, G.; Copin, Y.; Dixon, S.; Domagalski, R. S.; Gangler, E.; Pecontal, E.; Perlmutter, S.

2018-06-01

We have discovered an anomalous behavior of CCD readout electronics that affects their use in many astronomical applications. An offset in the digitization of the CCD output voltage that depends on the binary encoding of one pixel is added to pixels that are read out one, two, and/or three pixels later. One result of this effect is the introduction of a differential offset in the background when comparing regions with and without flux from science targets. Conventional data reduction methods do not correct for this offset. We find this effect in 16 of 22 instruments investigated, covering a variety of telescopes and many different front-end electronics systems. The affected instruments include LRIS and DEIMOS on the Keck telescopes, WFC3 UVIS and STIS on HST, MegaCam on CFHT, SNIFS on the UH88 telescope, GMOS on the Gemini telescopes, HSC on Subaru, and FORS on VLT. The amplitude of the introduced offset is up to 4.5 ADU per pixel, and it is not directly proportional to the measured ADU level. We have developed a model that can be used to detect this “binary offset effect” in data, and correct for it. Understanding how data are affected and applying a correction for the effect is essential for precise astronomical measurements.

Sculpting ion channel functional expression with engineered ubiquitin ligases

Science.gov (United States)

Kanner, Scott A; Morgenstern, Travis

2017-01-01

The functional repertoire of surface ion channels is sustained by dynamic processes of trafficking, sorting, and degradation. Dysregulation of these processes underlies diverse ion channelopathies including cardiac arrhythmias and cystic fibrosis. Ubiquitination powerfully regulates multiple steps in the channel lifecycle, yet basic mechanistic understanding is confounded by promiscuity among E3 ligase/substrate interactions and ubiquitin code complexity. Here we targeted the catalytic domain of E3 ligase, CHIP, to YFP-tagged KCNQ1 ± KCNE1 subunits with a GFP-nanobody to selectively manipulate this channel complex in heterologous cells and adult rat cardiomyocytes. Engineered CHIP enhanced KCNQ1 ubiquitination, eliminated KCNQ1 surface-density, and abolished reconstituted K+ currents without affecting protein expression. A chemo-genetic variation enabling chemical control of ubiquitination revealed KCNQ1 surface-density declined with a ~ 3.5 hr t1/2 by impaired forward trafficking. The results illustrate utility of engineered E3 ligases to elucidate mechanisms underlying ubiquitin regulation of membrane proteins, and to achieve effective post-translational functional knockdown of ion channels. PMID:29256394

Channeling in helium ion microscopy: Mapping of crystal orientation

Directory of Open Access Journals (Sweden)

Vasilisa Veligura

2012-07-01

Full Text Available Background: The unique surface sensitivity and the high resolution that can be achieved with helium ion microscopy make it a competitive technique for modern materials characterization. As in other techniques that make use of a charged particle beam, channeling through the crystal structure of the bulk of the material can occur.Results: Here, we demonstrate how this bulk phenomenon affects secondary electron images that predominantly contain surface information. In addition, we will show how it can be used to obtain crystallographic information. We will discuss the origin of channeling contrast in secondary electron images, illustrate this with experiments, and develop a simple geometric model to predict channeling maxima.Conclusion: Channeling plays an important role in helium ion microscopy and has to be taken into account when trying to achieve maximum image quality in backscattered helium images as well as secondary electron images. Secondary electron images can be used to extract crystallographic information from bulk samples as well as from thin surface layers, in a straightforward manner.

Surface displacement imaging by interferometry with a light emitting diode

International Nuclear Information System (INIS)

Dilhaire, Stefan; Grauby, Stephane; Jorez, Sebastien; Lopez, Luis David Patino; Rampnoux, Jean-Michel; Claeys, Wilfrid

2002-01-01

We present an imaging technique to measure static surface displacements of electronic components. A device is supplied by a transient current that creates a variation of temperature, thus a surface displacement. To measure the latter, a setup that is based on a Michelson interferometer is used. To avoid the phenomenon of speckle and the drawbacks inherent to it, we use a light emitting diode as the light source for the interferometer. The detector is a visible CCD camera that analyzes the optical signal containing the information of surface displacement of the device. Combining images, we extract the amplitude of the surface displacement. Out-of-plane surface-displacement images of a thermoelectric device are presented

Quantitative shearography: error reduction by using more than three measurement channels

International Nuclear Information System (INIS)

Charrett, Tom O. H.; Francis, Daniel; Tatam, Ralph P.

2011-01-01

Shearography is a noncontact optical technique used to measure surface displacement derivatives. Full surface strain characterization can be achieved using shearography configurations employing at least three measurement channels. Each measurement channel is sensitive to a single displacement gradient component defined by its sensitivity vector. A matrix transformation is then required to convert the measured components to the orthogonal displacement gradients required for quantitative strain measurement. This transformation, conventionally performed using three measurement channels, amplifies any errors present in the measurement. This paper investigates the use of additional measurement channels using the results of a computer model and an experimental shearography system. Results are presented showing that the addition of a fourth channel can reduce the errors in the computed orthogonal components by up to 33% and that, by using 10 channels, reductions of around 45% should be possible.

BV photographic and CCD photometry of IC 4651

International Nuclear Information System (INIS)

Anthony-Twarog, B.J.; Mukherjee, K.; Twarog, B.A.; Caldwell, N.

1988-01-01

A BV photometric survey in IC 4651 based on photographic and CCD material calibrated with photoelectric photometry from Eggen (1971) and Anthony-Twarog and Twarog (1987) has been completed. The color-magnitude diagram is consistent with an age of 2.4 + or - 0.3 x 10 to the 9th yr derived by comparison with the isochrones of VandenBerg (1985) if the apparent distance modulus and reddening derived from uvby photometry in Anthony-Twarog and Twarog (1987) are employed. While evidence is found of a hook in the upper main sequence, no evidence is found of a significantly bifurcated main sequence for this cluster, although it is similar in age to NGC 752 and NGC 3680, where this phenomenon has been noted. Finally, the survey has not resolved the apparent deficit of main-sequence stars fainter than V = 14.5 noted in Anthony-Twarog and Twarog (1987). 16 references

Toward prethreshold gate-based quantum simulation of chemical dynamics: using potential energy surfaces to simulate few-channel molecular collisions

Science.gov (United States)

Sornborger, Andrew T.; Stancil, Phillip; Geller, Michael R.

2018-05-01

One of the most promising applications of an error-corrected universal quantum computer is the efficient simulation of complex quantum systems such as large molecular systems. In this application, one is interested in both the electronic structure such as the ground state energy and dynamical properties such as the scattering cross section and chemical reaction rates. However, most theoretical work and experimental demonstrations have focused on the quantum computation of energies and energy surfaces. In this work, we attempt to make the prethreshold (not error-corrected) quantum simulation of dynamical properties practical as well. We show that the use of precomputed potential energy surfaces and couplings enables the gate-based simulation of few-channel but otherwise realistic molecular collisions. Our approach is based on the widely used Born-Oppenheimer approximation for the structure problem coupled with a semiclassical method for the dynamics. In the latter the electrons are treated quantum mechanically but the nuclei are classical, which restricts the collisions to high energy or temperature (typically above ≈ 10 eV). By using operator splitting techniques optimized for the resulting time-dependent Hamiltonian simulation problem, we give several physically realistic collision examples, with 3-8 channels and circuit depths < 1000.

The Channel Network model and field applications

International Nuclear Information System (INIS)

Khademi, B.; Moreno, L.; Neretnieks, I.

1999-01-01

The Channel Network model describes the fluid flow and solute transport in fractured media. The model is based on field observations, which indicate that flow and transport take place in a three-dimensional network of connected channels. The channels are generated in the model from observed stochastic distributions and solute transport is modeled taking into account advection and rock interactions, such as matrix diffusion and sorption within the rock. The most important site-specific data for the Channel Network model are the conductance distribution of the channels and the flow-wetted surface. The latter is the surface area of the rock in contact with the flowing water. These parameters may be estimated from hydraulic measurements. For the Aespoe site, several borehole data sets are available, where a packer distance of 3 meters was used. Numerical experiments were performed in order to study the uncertainties in the determination of the flow-wetted surface and conductance distribution. Synthetic data were generated along a borehole and hydraulic tests with different packer distances were simulated. The model has previously been used to study the Long-term Pumping and Tracer Test (LPT2) carried out in the Aespoe Hard Rock Laboratory (HRL) in Sweden, where the distance travelled by the tracers was of the order hundreds of meters. Recently, the model has been used to simulate the tracer tests performed in the TRUE experiment at HRL, with travel distance of the order of tens of meters. Several tracer tests with non-sorbing and sorbing species have been performed

Spectral re-distribution and surface loss effects in Swift XRT (XMM-Newton EPIC) MOS CCDs

CERN Document Server

Short, A D; Turner, M J L

2002-01-01

In the course of testing and selecting the EPIC MOS CCDs for the XMM-Newton observatory, the developed a Monte-Carlo model of the CCD response. Among other things, this model was used to investigate surface loss effects evident at low energies. By fitting laboratory data, these losses were characterised as a simple function of X-ray interaction depth and this result enabled the spectral re-distribution itself to be modelled as a simple analytical function. Subsequently, this analytical function has been used to generate the response matrix for the EPIC MOS instruments and will now be employed to model the spectral re-distribution for the Swift XRT CCD.

Continuous Estimates of Surface Density and Annual Snow Accumulation with Multi-Channel Snow/Firn Penetrating Radar in the Percolation Zone, Western Greenland Ice Sheet

Science.gov (United States)

Meehan, T.; Marshall, H. P.; Bradford, J.; Hawley, R. L.; Osterberg, E. C.; McCarthy, F.; Lewis, G.; Graeter, K.

2017-12-01

A priority of ice sheet surface mass balance (SMB) prediction is ascertaining the surface density and annual snow accumulation. These forcing data can be supplied into firn compaction models and used to tune Regional Climate Models (RCM). RCMs do not accurately capture subtle changes in the snow accumulation gradient. Additionally, leading RCMs disagree among each other and with accumulation studies in regions of the Greenland Ice Sheet (GrIS) over large distances and temporal scales. RCMs tend to yield inconsistencies over GrIS because of sparse and outdated validation data in the reanalysis pool. Greenland Traverse for Accumulation and Climate Studies (GreenTrACS) implemented multi-channel 500 MHz Radar in multi-offset configuration throughout two traverse campaigns totaling greater than 3500 km along the western percolation zone of GrIS. The multi-channel radar has the capability of continuously estimating snow depth, average density, and annual snow accumulation, expressed at 95% confidence (+-) 0.15 m, (+-) 17 kgm-3, (+-) 0.04 m w.e. respectively, by examination of the primary reflection return from the previous year's summer surface.

Charged and Neutral Particles Channeling Phenomena Channeling 2008

Science.gov (United States)

Dabagov, Sultan B.; Palumbo, Luigi

2010-04-01

regime by a buried oxide layer / V. Guidi, A. Mazzolari and V. V. Tikhomirov -- A positron source using channeling in crystals for linear colliders / X. Artru ... [et al.] -- Parametric channeling and collapse of charged particles beams in crystals / M. Vysotskyy and V. Vysotskii.The formation and usage of coherent correlated charged particles states in the physics of channeling in crystals / S. V. Adamenko, V. I. Vysotskii and M. V. Vysotskyy -- Surface channeling of magnetic-charged particles on multilayer surface / S. V. Adamenko and V. I. Vysotskii -- Coherent creation of anti-hydrogen atoms in a crystal by relativistic antiproton / Yu. P. Kunashenko -- Thermal equilibrium of light ions in heavy crystals / E. Tsyganov -- Photon emission of electrons in a crystalline undulator / H. Backe ... [et al.] -- Channeling radiation from relativistic electrons in a crystal target as complementary x-ray and gamma ray source at synchrotron light facilities / K. B. Korotchenko, Yu. L. Pivovarov and T. A. Tukhfatullin -- Diffracted channeling radiation and other compound radiation processes / H. Nitta -- Collective scattering on the atom planes under the condition of full transition / A. R. Mkrtchyan ... [et al.] -- The proposal of the experiment on the research of the diffracted channeling radiation / D. A. Baklanov ... [et al.] -- Positron channeling at the DaOne BTF Facility: the cup experiment / L. Quintieri ... [et al.] -- Radiation spectra of 200 MeV electrons in diamond and silicon crystals at axial and planar orientations / K. Fissum ... [et al.] -- Channeling experiments with electrons at the Mainz Microtron Mami / W. Lauth ... [et al.] -- Dechanneling of positrons by dislocations: effects of anharmonic interactions / J. George and A. P. Pathak -- Diffracted channeling radiation from axially channeled relativistic electrons / K. B. Korotchenko ... [et al.] -- Intensive quasi-monochromatic, directed x-ray radiation of planar channeled positron bunch / L. Gevorgian

Smear correction of highly variable, frame-transfer CCD images with application to polarimetry.

Science.gov (United States)

Iglesias, Francisco A; Feller, Alex; Nagaraju, Krishnappa

2015-07-01

Image smear, produced by the shutterless operation of frame-transfer CCD detectors, can be detrimental for many imaging applications. Existing algorithms used to numerically remove smear do not contemplate cases where intensity levels change considerably between consecutive frame exposures. In this report, we reformulate the smearing model to include specific variations of the sensor illumination. The corresponding desmearing expression and its noise properties are also presented and demonstrated in the context of fast imaging polarimetry.

The use of a CCD imaging system for X-ray film intensity measurement

International Nuclear Information System (INIS)

Grigg, M.W.; Barnea, Z.

1994-01-01

The use of a simple CCD-based imaging system for digitizing and x-ray film image is demonstrated. A method of extending the region of linear response of the film based upon an analytic representation of the observed response to a series of increasing exposures is described. The validity of the procedure is illustrated through an example of the absolute intensity measurement of a reflection of cadmium sulphide. 3 refs., 7 figs

Jets from young stars - CCD imaging, long-slit spectroscopy, and interpretation of existing data

International Nuclear Information System (INIS)

Mundt, R.; Brugel, E.W.; Buehrke, T.

1987-01-01

High-velocity jets and collimated outflows are now recognized as phenomena commonly associated with young stars. New CCD imaging of five objects, and in particular spatially resolved spectroscopy of eight highly-collimated flows, are discussed. Through the CCD imaging, three new jets have been discovered. It is shown that several previously known Herbig-Haro objects have extended bow-shock-like structures. In most of the latter cases, a jet is pointing from the star toward the bow-shock apex. The concave side of the bow-shock structure is in all cases oriented toward the outflow source. Using a data base of about 20 known jets, a detailed list of observational criteria describing these phenomena is compiled. A physical description and interpretation is presented which discusses the origin of knots in these jets and other structures, the relationship between jets and Herbig-Haro objects, the dissipation of energy along the jet due to internal shocks, the physical parameters, the relationship of optical jets to molecular outflows, and time scales for outflow activity. A short discussion of the driving sources for these jets is also included. 116 references

Boundary vapor contentsin an annular channel

International Nuclear Information System (INIS)

Remizov, O.V.; Shurkin, N.G.; Podgornyj, K.K.; Gal'chenko, Eh.F.; Bukhteev, I.S.

1978-01-01

The work is aimed at the experimental investigation of the worsening of the heat transfer in an annular channel. The experiments have been carried out on the annular channel 32x28x3000 mm with the even distribution of the heat flux along the length at pressures of 6.9-19.6 MPa, flow rate of 350-1000 kg/m 2 s, and specific heat fluxes from 0.18 up to 0.6 MW/m 2 . Heating is external, oneside. Water monodistillate of the following composition has been used as a coolant: pH 9; dry residue - 0.8-1.2 mg/kg, oxygen -10-15 mg/kg. It is found out that the change character of the temperature field of the heating surface of the annular channel at the regime with the worsen of heat emission depends on the ratio of regime parameters. At pressures of 6.9-13.7 MPa and flow rate of 350-500 kg/m 2 s the channel wall temperature rises monotoneously, never reaching its maximum. With pressure rise > 13.7 MPa and mass velocity > 500 kg/m 2 s the temperature of the heat emitting surface reaches its maximum, and then slowly falls. At pressures of 6.9-11.8 MPa the boundary vapor content value within the whole range of mass velocities does not depend on the specific heat flux q. At pressures higher than 13.7 MPa and mass velocities of 350-1000 kg/m 2 s the boundary vapor content depends on q. The heating of the external or internal surface of the annular channel affects the value of the boundary vapor content within the whole range of regime parameters' change under investigation

32x32 HgCdTe/CCD infrared camera for the 2-5 micron range

International Nuclear Information System (INIS)

Monin, J.L.; Vauglin, I.; Sibille, F.

1988-01-01

The paper presents a complete infrared camera system, based on a high electron capacity detector (HgCdTe/CCD), that has been used under high background conditions to generate astronomical images. The performance of the system and some results are presented, and the use of such a detector in astronomy is discussed. 8 references

Medición de posiciones astrométricas con CCD en la zona de Rup 21

Science.gov (United States)

Bustos Fierro, I. H.; Calderón, J. H.

It is shown the utilization of the block adjustment method for the measurement of astrometric positions from a mosaic of sixteen CCD images with partial overlap, which were taken with the Telescope Jorge Sahade of CASLEO. The observations cover an area of 25' x 25' around the open cluster Rup21. The source of reference positions was ACT Reference Catalog. The internal error of the measured positions is analyzed, and the external error is estimated from the comparison with the catalog USNO-A. In this comparison it is found that the direct CCD images taken with focal reducer could be distorted by severe field curvature. The effect of the distortion presumably introduced by the optics is eliminated with the suitable corrections of the stellar positions measured on every frame, but a new systematic effect on scales of the entire field is observed, which could be due to the distribution of the reference stars.

On the capacity of multiaccess fading channels with full channel state information at low power regime

KAUST Repository

Rezki, Zouheir

2013-06-01

We study the throughput capacity region of the Gaussian multiaccess (MAC) fading channel with perfect channel state information (CSI) at the receiver (CSI-R) and at the transmitters (CSI-T), at low power regime. We show that it has a multidimensional rectangle structure and thus is simply characterized by single user capacity points. More specifically, we show that at low power regime, the boundary surface of the capacity region shrinks to a single point corresponding to the sum rate maximizer and that the coordinates of this point coincide with single user capacity bounds. Inspired from this result, we propose an on-off scheme, compute its achievable rate, and provide a necessary condition on the fading channels under which this scheme achieves single user capacity bounds of the MAC channel at asymptotically low power regime. We argue that this necessary condition characterizes a class of fading that encompasses all known wireless channels, where the capacity region of the MAC channel has a simple expression in terms of users\\' average power constraints only. © 2013 IEEE.

Simultaneous estimation of vitamin K1 and heparin with low limit of detection using cascaded channels fiber optic surface plasmon resonance.

Science.gov (United States)

Tabassum, Rana; Gupta, Banshi D

2016-12-15

We report an approach for the simultaneous estimation of vitamin K1 (VK1) and heparin via cascaded channel multianalyte sensing probe employing fiber optic surface plasmon resonance technique. Cladding from two well separated portions of the fiber is removed and are respectively coated with thin films of silver (channel-1) and copper (channel-2). The nanohybrid of multiwalled carbon nanotube in chitosan is fabricated over silver layer for the sensing of VK1 whereas core shell nanostructure of polybrene@ZnO is coated over copper layer for the sensing of heparin. Spectral interrogation method is used for the characterization of the sensor. Analyte selectivity of both the channels is performed by carrying out experiments using independent solutions of VK1 and heparin. Experiments performed on the solution of the mixture of VK1 and heparin show red shifts in both the channels on changing the concentration of both the analytes in the mixture. The operating range of both VK1 and heparin is from 0 to 10(-3)g/l. The limit of detection of the sensor is 2.66×10(-4)µg/l and 2.88×10(-4)µg/l for VK1 and heparin respectively which are lower than the reported ones. The additional advantages of the present sensor are low cost, possibility of online monitoring and remote sensing. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of Channel Infill Processes in Relation to Forcing Data

Science.gov (United States)

2016-05-01

provides the water that drives flow in surface waters through surface runoff and groundwater recharge for spring-fed channels and influences sediment...transport both in runoff entering the channel and increasing river discharge quantities during major precipitation events. At the other extreme...often more exposed either due to decreased land cover or the receding water levels and therefore more prone to erosion by wind or rain . Additionally

Channeling effect for low energy ion implantation in Si

International Nuclear Information System (INIS)

Cho, K.; Allen, W.R.; Finstad, T.G.; Chu, W.K.; Liu, J.; Wortman, J.J.

1985-01-01

Ion implantation is one of the most important processes in semiconductor device fabrication. Due to the crystalline nature of Si, channeling of implanted ions occurs during this process. Modern devices become smaller and shallower and therefore require ion implantation at lower energies. The effect of channeling on ion implantation becomes a significant problem for low energy ion implantation. The critical angle for axial and planar channeling increases with decreasing energy. This corresponds to an increased probability for channeling with lowering of ion energy. The industry approach to avoid the channeling problem is to employ a tilt angle of 7 0 between the ion implantation direction and the surface normal. We approach the problem by mapping major crystalline axes and planes near the [100] surface normal. Our analysis indicates that a 7 0 tilt is not an optimum selection in channeling reduction. Tilt angles in the range 5 0 to 6 0 combined with 7 0 +- 0.5 0 rotation from the (100) plane are better selections for the reduction of the channeling effect. The range of suitable angles is a function of the implantation energy. Implantations of boron along well specified crystallographic directions have been carried out by careful alignment and the resulting boron profiles measured by SIMS. (orig.)

Freeform Deposition Method for Coolant Channel Closeout

Science.gov (United States)

Gradl, Paul R. (Inventor); Reynolds, David Christopher (Inventor); Walker, Bryant H. (Inventor)

2017-01-01

A method is provided for fabricating a coolant channel closeout jacket on a structure having coolant channels formed in an outer surface thereof. A line of tangency relative to the outer surface is defined for each point on the outer surface. Linear rows of a metal feedstock are directed towards and deposited on the outer surface of the structure as a beam of weld energy is directed to the metal feedstock so-deposited. A first angle between the metal feedstock so-directed and the line of tangency is maintained in a range of 20-90.degree.. The beam is directed towards a portion of the linear rows such that less than 30% of the cross-sectional area of the beam impinges on a currently-deposited one of the linear rows. A second angle between the beam and the line of tangency is maintained in a range of 5-65 degrees.

Infrared detectors, focal plane arrays, and imaging sensors; Proceedings of the Meeting, Orlando, FL, Mar. 30, 31, 1989

Science.gov (United States)

Dereniak, Eustace L.; Sampson, Robert T.

1989-10-01

The present conference on advancements in IR detectors, Schottky-barrier focal plane arrays, CCD image analysis, and HgCdTe materials gives attention to a 256 x 256 PtSi array for IR astronomy, proposals for a second-generation meteosat's advanced optical payload, cryogenic bipolar technology for on-focal-plane signal processing, a parallel cellular processing system for fast generation of perspective plots, and ultrahigh-speed CCD image sensors for scanning applications. Also discussed are MBE GaAs rib waveguide experiments at 10.6 microns, an interferometric thermal detector, the development status of superconducting IR detector research, the absorption coefficients of n-type Hg(1-x)Cd(x)Te samples, and the influence of the surface channel on crosstalk in HgCdTe photovoltaic arrays.

Deep CCD survey - galaxy luminosity and color evolution

International Nuclear Information System (INIS)

Tyson, J.A.

1988-01-01

Imaging and photometric observations of a statistically complete sample of galaxies in 12 high-latitude fields, obtained in the BJ (360-520 nm), R (580-720 nm) and I (780-1100 nm) bands using CCD detectors on the 4-m telescopes at CTIO and KPNO, are reported. The data are presented in extensive graphs and sample images and analyzed in detail with reference to theoretical models of galactic origin and evolution. The galaxy number-count slopes, d(log N)/dm, are found to be sub-Euclidean, varying from 0.34 in the I band to 0.45 in the BJ band, where the corrected counts appear to saturate at about 27 mag. The predictions of no-evolution models are shown to underpredict the counts at 25 mag (BJ) by a factor of 5-15 and the extragalactic background light from all galaxies (6.8 x 10 to the -6th erg/sq cm sec sr micron at 450 nm) by a factor greater than 2. 114 references

Substrate channel in nitrogenase revealed by a molecular dynamics approach.

Science.gov (United States)

Smith, Dayle; Danyal, Karamatullah; Raugei, Simone; Seefeldt, Lance C

2014-04-15

Mo-dependent nitrogenase catalyzes the biological reduction of N2 to two NH3 molecules at FeMo-cofactor buried deep inside the MoFe protein. Access of substrates, such as N2, to the active site is likely restricted by the surrounding protein, requiring substrate channels that lead from the surface to the active site. Earlier studies on crystallographic structures of the MoFe protein have suggested three putative substrate channels. Here, we have utilized submicrosecond atomistic molecular dynamics simulations to allow the nitrogenase MoFe protein to explore its conformational space in an aqueous solution at physiological ionic strength, revealing a putative substrate channel. The viability of this observed channel was tested by examining the free energy of passage of N2 from the surface through the channel to FeMo-cofactor, resulting in the discovery of a very low energy barrier. These studies point to a viable substrate channel in nitrogenase that appears during thermal motions of the protein in an aqueous environment and that approaches a face of FeMo-cofactor earlier implicated in substrate binding.

Bywalled plasma formation in vacuum prolonged channels

International Nuclear Information System (INIS)

Korenev, S.A.; Rubin, N.B.

1982-01-01

To produce homogeneous along the channel length plasma the application of incomplete rate-in surface dielectric discharge for generating the bywalled plasma in prolonged cylindrical channels at a pressure of the residual gas of P approximately 10 -5 Torr is proposed. Experimental set-up consisted of a pulse voltage generator and a plasma channel. The plasma channel was a coaxial system of three tubes inserted into each other. The first outer tube is made of a stainless steel, the second - of a dielectric material, the third - of smallsized stainless steel greed. It is demonstrated that the plasma being formed in the process is sufficiently homogeneous by concentration of the components, by the channel length and azimuth. The length of the experimental channel under investigation was 1.6 m, its diameter amounted 0.05 m. The maximum concentration of electron component was 10 17 m -3

Development and field example of multi channel surface wave data acquisition and processing system (SWS-1); Multi channel hyomenha data shutoku shori system (SWS-1) no kaihatsu to jikkenrei

Energy Technology Data Exchange (ETDEWEB)

Liu, Y [Huashui Institute of Geophysical Exploration, (China); Wang, Z [Bureauof Engineering MGMR, (China); Zhang, Z [STG Corp., (China); Tanaka, Y

1996-05-01

A report is given here about the use of a newly-developed multi-channel surface wave data acquisition and processing system different from the conventional surface wave exploration device. This system enables the on-site pickup of a dispersion curve out of the multi-component surface wave data and, in the analysis of underground structure, performs the forward modeling and inversion. The system, furthermore, acquires and analyzes the data obtained from reflection earthquake exploration and constant microtremor observation. During a survey conducted along the highway from Port Ren-un to Xuzhou, China, estimation of the basement boundary was made by use of dynamite, and what was obtained agreed with the result of boring though with an error of 3m. In addition, this system could probe levels deeper than 100m using the instantaneous Rayleigh wave exploration method. This system and the conventional surface exploration device were compared in a soft ground in Fukui Prefecture, the former using a 10kg hammer and the latter using a 350kg exciter, when it was verified that the results produced by both techniques excellently agree with the geologic columnar section and changes in the N-value. 4 refs., 4 figs.

Miniature CCD X-Ray Imaging Camera Technology Final Report CRADA No. TC-773-94

Energy Technology Data Exchange (ETDEWEB)

Conder, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mummolo, F. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-10-19

The goal of the project was to develop a compact, large active area, high spatial resolution, high dynamic range, charge-coupled device (CCD) camera to replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating X-rays. The camera head and controller needed to be capable of operation within a vacuum environment and small enough to be fielded within the small vacuum target chambers at LLNL.

Visualization of an air-water interface on superhydrophobic surfaces in turbulent channel flows

Science.gov (United States)

Kim, Hyunseok; Park, Hyungmin

2017-11-01

In the present study, three-dimensional deformation of air-water interface on superhydrophobic surfaces in turbulent channel flows at the Reynolds numbers of Re = 3000 and 10000 is measured with RICM (Reflection Interference Contrast Microscopy) technique. Two different types of roughness feature of circular hole and rectangular grate are considered, whose depth is 20 μm and diameter (or width) is varied between 20-200 μm. Since the air-water interface is always at de-pinned state at the considered condition, air-water interface shape and its sagging velocity is maintained to be almost constant as time goes one. In comparison with the previous results under the laminar flow, due to turbulent characteristics of the flow, sagging velocity is much faster. Based on the measured sagging profiles, a modified model to describe the air-water interface dynamics under turbulent flows is suggested. Supported by City of Seoul through Seoul Urban Data Science Laboratory Project (Grant No 0660-20170004) administered by SNU Big Data Institute.

Local Multi-Channel RF Surface Coil versus Body RF Coil Transmission for Cardiac Magnetic Resonance at 3 Tesla: Which Configuration Is Winning the Game?

Directory of Open Access Journals (Sweden)

Oliver Weinberger

Full Text Available The purpose of this study was to demonstrate the feasibility and efficiency of cardiac MR at 3 Tesla using local four-channel RF coil transmission and benchmark it against large volume body RF coil excitation.Electromagnetic field simulations are conducted to detail RF power deposition, transmission field uniformity and efficiency for local and body RF coil transmission. For both excitation regimes transmission field maps are acquired in a human torso phantom. For each transmission regime flip angle distributions and blood-myocardium contrast are examined in a volunteer study of 12 subjects. The feasibility of the local transceiver RF coil array for cardiac chamber quantification at 3 Tesla is demonstrated.Our simulations and experiments demonstrate that cardiac MR at 3 Tesla using four-channel surface RF coil transmission is competitive versus current clinical CMR practice of large volume body RF coil transmission. The efficiency advantage of the 4TX/4RX setup facilitates shorter repetition times governed by local SAR limits versus body RF coil transmission at whole-body SAR limit. No statistically significant difference was found for cardiac chamber quantification derived with body RF coil versus four-channel surface RF coil transmission. Our simulation also show that the body RF coil exceeds local SAR limits by a factor of ~2 when driven at maximum applicable input power to reach the whole-body SAR limit.Pursuing local surface RF coil arrays for transmission in cardiac MR is a conceptually appealing alternative to body RF coil transmission, especially for patients with implants.

Local Multi-Channel RF Surface Coil versus Body RF Coil Transmission for Cardiac Magnetic Resonance at 3 Tesla: Which Configuration Is Winning the Game?

Science.gov (United States)

Winter, Lukas; Dieringer, Matthias A.; Els, Antje; Oezerdem, Celal; Rieger, Jan; Kuehne, Andre; Cassara, Antonino M.; Pfeiffer, Harald; Wetterling, Friedrich; Niendorf, Thoralf

2016-01-01

Introduction The purpose of this study was to demonstrate the feasibility and efficiency of cardiac MR at 3 Tesla using local four-channel RF coil transmission and benchmark it against large volume body RF coil excitation. Methods Electromagnetic field simulations are conducted to detail RF power deposition, transmission field uniformity and efficiency for local and body RF coil transmission. For both excitation regimes transmission field maps are acquired in a human torso phantom. For each transmission regime flip angle distributions and blood-myocardium contrast are examined in a volunteer study of 12 subjects. The feasibility of the local transceiver RF coil array for cardiac chamber quantification at 3 Tesla is demonstrated. Results Our simulations and experiments demonstrate that cardiac MR at 3 Tesla using four-channel surface RF coil transmission is competitive versus current clinical CMR practice of large volume body RF coil transmission. The efficiency advantage of the 4TX/4RX setup facilitates shorter repetition times governed by local SAR limits versus body RF coil transmission at whole-body SAR limit. No statistically significant difference was found for cardiac chamber quantification derived with body RF coil versus four-channel surface RF coil transmission. Our simulation also show that the body RF coil exceeds local SAR limits by a factor of ~2 when driven at maximum applicable input power to reach the whole-body SAR limit. Conclusion Pursuing local surface RF coil arrays for transmission in cardiac MR is a conceptually appealing alternative to body RF coil transmission, especially for patients with implants. PMID:27598923

Local Multi-Channel RF Surface Coil versus Body RF Coil Transmission for Cardiac Magnetic Resonance at 3 Tesla: Which Configuration Is Winning the Game?

Science.gov (United States)

Weinberger, Oliver; Winter, Lukas; Dieringer, Matthias A; Els, Antje; Oezerdem, Celal; Rieger, Jan; Kuehne, Andre; Cassara, Antonino M; Pfeiffer, Harald; Wetterling, Friedrich; Niendorf, Thoralf

2016-01-01

The purpose of this study was to demonstrate the feasibility and efficiency of cardiac MR at 3 Tesla using local four-channel RF coil transmission and benchmark it against large volume body RF coil excitation. Electromagnetic field simulations are conducted to detail RF power deposition, transmission field uniformity and efficiency for local and body RF coil transmission. For both excitation regimes transmission field maps are acquired in a human torso phantom. For each transmission regime flip angle distributions and blood-myocardium contrast are examined in a volunteer study of 12 subjects. The feasibility of the local transceiver RF coil array for cardiac chamber quantification at 3 Tesla is demonstrated. Our simulations and experiments demonstrate that cardiac MR at 3 Tesla using four-channel surface RF coil transmission is competitive versus current clinical CMR practice of large volume body RF coil transmission. The efficiency advantage of the 4TX/4RX setup facilitates shorter repetition times governed by local SAR limits versus body RF coil transmission at whole-body SAR limit. No statistically significant difference was found for cardiac chamber quantification derived with body RF coil versus four-channel surface RF coil transmission. Our simulation also show that the body RF coil exceeds local SAR limits by a factor of ~2 when driven at maximum applicable input power to reach the whole-body SAR limit. Pursuing local surface RF coil arrays for transmission in cardiac MR is a conceptually appealing alternative to body RF coil transmission, especially for patients with implants.

Chromatic Modulator for High Resolution CCD or APS Devices

Science.gov (United States)

Hartley, Frank T. (Inventor); Hull, Anthony B. (Inventor)

2003-01-01

A system for providing high-resolution color separation in electronic imaging. Comb drives controllably oscillate a red-green-blue (RGB) color strip filter system (or otherwise) over an electronic imaging system such as a charge-coupled device (CCD) or active pixel sensor (APS). The color filter is modulated over the imaging array at a rate three or more times the frame rate of the imaging array. In so doing, the underlying active imaging elements are then able to detect separate color-separated images, which are then combined to provide a color-accurate frame which is then recorded as the representation of the recorded image. High pixel resolution is maintained. Registration is obtained between the color strip filter and the underlying imaging array through the use of electrostatic comb drives in conjunction with a spring suspension system.

BVI CCD photometry of the globular cluster M4

International Nuclear Information System (INIS)

Alcaino, G.; Liller, W.; Alvarado, F.

1988-01-01

CCD BV1 main-sequence (MS) photometry of M4, the globular cluster closest to the sun, is presented. The photometry is matched to the BVI isochrones of VandenBerg and Bell (1985). The MS turnoffs are found to be at V = 16.90 + or - 0.05, B-V = 0.81 + or - 0.02, V-I = 0.96 + or - 0.02, and B - I = 1.77 + or - 0.02. The magnitude difference between the MS turnoff and the horizontal branch is Delta M(V) = 3.52 + or - 0.1 for all three color indices. Using Y = 0.2, (Fe/H) = - 1.27, and alpha = 1.65, with a distance modulus of (m-M)V = 12.7 and E(B-V) = 0.41, a consistent age for M4 is deduced in all three color indices of 17 + or - 1.5 Gyr. 34 references

Achieving more efficient operation of the nozzle vane and rotor blade rows of gas turbines through using nonaxisymmetric end wall surfaces of interblade channels

Science.gov (United States)

Inozemtsev, A. A.; Samokhvalov, N. Yu.; Tikhonov, A. S.

2012-09-01

Results from a numerical study of three versions of the end-wall generatrix of the interblade channel used in the second-stage nozzle vanes of a prospective engine's turbine are presented. Recommendations for designing nonaxisymmetric end-wall surfaces are suggested based on the obtained data.

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from CEFAS ENDEAVOUR in the Bristol Channel, English Channel and others from 2012-09-13 to 2012-09-25 (NCEI Accession 0157385)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157385 includes Surface underway, chemical, meteorological and physical data collected from CEFAS ENDEAVOUR in the Bristol Channel, English Channel,...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from CEFAS ENDEAVOUR in the Bristol Channel, English Channel and others from 2013-09-10 to 2013-10-02 (NCEI Accession 0157366)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157366 includes Surface underway, chemical, meteorological and physical data collected from CEFAS ENDEAVOUR in the Bristol Channel, English Channel,...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from CEFAS ENDEAVOUR in the Bristol Channel, English Channel and others from 2013-05-08 to 2013-05-28 (NCEI Accession 0157373)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157373 includes Surface underway, chemical, meteorological and physical data collected from CEFAS ENDEAVOUR in the Bristol Channel, English Channel,...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from CEFAS ENDEAVOUR in the Bristol Channel, English Channel and others from 2013-04-19 to 2013-05-08 (NCEI Accession 0157305)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157305 includes Surface underway, chemical, meteorological and physical data collected from CEFAS ENDEAVOUR in the Bristol Channel, English Channel,...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from CEFAS ENDEAVOUR in the Bristol Channel, English Channel and others from 2012-09-27 to 2012-10-04 (NCEI Accession 0157267)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157267 includes Surface underway, chemical, meteorological and physical data collected from CEFAS ENDEAVOUR in the Bristol Channel, English Channel,...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from CEFAS ENDEAVOUR in the Bristol Channel, English Channel and others from 2013-02-03 to 2013-02-13 (NCEI Accession 0157382)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157382 includes Surface underway, chemical, meteorological and physical data collected from CEFAS ENDEAVOUR in the Bristol Channel, English Channel,...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from CEFAS ENDEAVOUR in the Bristol Channel, English Channel and others from 2012-10-23 to 2012-11-09 (NCEI Accession 0157241)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157241 includes Surface underway, chemical, meteorological and physical data collected from CEFAS ENDEAVOUR in the Bristol Channel, English Channel,...

X-ray diagnostic study on the optimization of digital radiography in dentistry. Optimal exposure conditions for X-ray CCD sensor

International Nuclear Information System (INIS)

Hakata, Toshifumi

2002-01-01

The purpose of this research is to reduce the patient dose by optimization of irradiation conditions of an X-ray CCD sensor in intra-oral digital radiography. The X-ray diagnosis was divided into two, high quality-of-image diagnosis and low quality-of-image diagnosis, and it optimized by using the exposure of necessary minimum for each. The image quality of CCD was evaluated using the signal-to-noise ratio (SNR) in order to estimate the influence of irradiation conditions. The dose based on CCD maker setting value was set up so that the highest quality of image might be obtained mostly. In low quality-of-image diagnosis, even if it reduced the dose to 13.2% of standard irradiation, SNR was 40% and interpretation was possible. In high quality-of-image diagnosis, even if it reduces the dose to 49% of standard irradiation, SNR remained 80% and there were few differences of the image with a standard. A study of the digital X-ray examination taken at the dental clinic showed high quality-of-image diagnosis was 69% and low quality-of-image one was 31%. When this optimization was performed, it was presumed that reduction of about 62% of the dose is possible. (author)

Universal description of channel plasmons in two-dimensional materials

DEFF Research Database (Denmark)

Gonçalves, P. A. D.; Bozhevolnyi, Sergey I.; Mortensen, N. Asger

2017-01-01

Channeling surface plasmon-polaritons to control their propagation direction is of the utmost importance for future optoelectronic devices. Here, we develop an effective-index method to describe and characterize the properties of 2D material's channel plasmon-polaritons (CPPs) guided along a V-sh...

The thin-walled abnormity measurement technology research based on CCD

International Nuclear Information System (INIS)

Wang Bin

2014-01-01

The character of the thin-walled irregular parts is: the measured parameters for spatial structure size, need to design special measurement positioning fixture to complete detection, the wall thickness is very thin, and the processing is composite, its size is small and shape is complex, it is difficulty to collect image edge by using the optical measurement method. In this paper, a special measurement method of CCD that based on the image measurement technique was advanced, this kind of parts was measured quickly, accurately and automaticly through design the high precision positioning fixture and image acquisition method. At the same time, the comprehensive evaluation standard was given to assess the measurement accuracy method, and the reliability of measurement method was ensured. (author)

Electromagnetic Compatibility Assessment of CCD Detector Acquisition Chains not Synchronized

Science.gov (United States)

Nicoletto, M.; Boschetti, D.; Ciancetta, E.; Maiorano, E.; Stagnaro, L.

2016-05-01

Euclid is a space observatory managed by the European Space Agency; it is the second medium class mission (see Figure 1) in the frame of Cosmic Vision 2015-2025 program.In the frame of this project, the electromagnetic interference between two different and not synchronized Charge Coupled Device (CCD) (see Figure 2) acquisition chains has been evaluated. The key parameter used for this assessment is the electromagnetic noise induced on each other. Taking into account the specificity of the issue, radiation coupling at relative low frequency and in near field conditions, classical approach based on simulations and testing on qualification model cannot be directly applied. Based on that, it has been decided to investigate the issue by test in an incremental way.

Numerical simulation of hydrogen-air reacting flows in rectangular channels with catalytic surface reactions

Science.gov (United States)

Amano, Ryoichi S.; Abou-Ellail, Mohsen M.; Elhaw, Samer; Saeed Ibrahim, Mohamed

2013-09-01

In this work a prediction was numerically modeled for a catalytically stabilized thermal combustion of a lean homogeneous mixture of air and hydrogen. The mixture flows in a narrow rectangular channel lined with a thin coating of platinum catalyst. The solution using an in-house code is based on the steady state partial differential continuity, momentum and energy conservation equations for the mixture and species involved in the reactions. A marching technique is used along the streamwise direction to solve the 2-D plane-symmetric laminar flow of the gas. Two chemical kinetic reaction mechanisms were included; one for the gas phase reactions consisting of 17 elementary reactions; of which 7 are forward-backward reactions while the other mechanism is for the surface reactions—which are the prime mover of the combustion under a lean mixture condition—consisting of 16 elementary reactions. The results were compared with a former congruent experimental work where temperature was measured using thermocouples, while using PLIF laser for measuring water and hydrogen mole fractions. The comparison showed good agreement. More results for the velocities, mole fractions of other species were carried out across the transverse and along the streamwise directions providing a complete picture of overall mechanism—gas and surface—and on the production, consumptions and travel of the different species. The variations of the average OH mole fraction with the streamwise direction showed a sudden increase in the region where the ignition occurred. Also the rate of reactions of the entire surface species were calculated along the streamwise direction and a surface water production flux equation was derived by calculating the law of mass action's constants from the concentrations of hydrogen, oxygen and the rate of formation of water near the surface.

Warpage optimisation on the moulded part with straight-drilled and conformal cooling channels using response surface methodology (RSM) and glowworm swarm optimisation (GSO)

Science.gov (United States)

Hazwan, M. H. M.; Shayfull, Z.; Sharif, S.; Nasir, S. M.; Zainal, N.

2017-09-01

In injection moulding process, quality and productivity are notably important and must be controlled for each product type produced. Quality is measured as the extent of warpage of moulded parts while productivity is measured as a duration of moulding cycle time. To control the quality, many researchers have introduced various of optimisation approaches which have been proven enhanced the quality of the moulded part produced. In order to improve the productivity of injection moulding process, some of researches have proposed the application of conformal cooling channels which have been proven reduced the duration of moulding cycle time. Therefore, this paper presents an application of alternative optimisation approach which is Response Surface Methodology (RSM) with Glowworm Swarm Optimisation (GSO) on the moulded part with straight-drilled and conformal cooling channels mould. This study examined the warpage condition of the moulded parts before and after optimisation work applied for both cooling channels. A front panel housing have been selected as a specimen and the performance of proposed optimisation approach have been analysed on the conventional straight-drilled cooling channels compared to the Milled Groove Square Shape (MGSS) conformal cooling channels by simulation analysis using Autodesk Moldflow Insight (AMI) 2013. Based on the results, melt temperature is the most significant factor contribute to the warpage condition and warpage have optimised by 39.1% after optimisation for straight-drilled cooling channels and cooling time is the most significant factor contribute to the warpage condition and warpage have optimised by 38.7% after optimisation for MGSS conformal cooling channels. In addition, the finding shows that the application of optimisation work on the conformal cooling channels offers the better quality and productivity of the moulded part produced.