NASA Astrophysics Data System (ADS)
Greene, S. E.; Ridgwell, A. J.; Schmidt, D. N.; Kirtland Turner, S.; Paelike, H.; Thomas, E.
2014-12-01
The carbonate compensation depth (CCD) is the depth below which negligible calcium carbonate is preserved in marine sediments. The long-term position of the CCD is often considered to be a powerful constraint on palaeoclimate and atmospheric CO2 concentration due to the requirement that carbonate burial balance riverine weathering over long timescales. The requirement that weathering and burial be in balance is clear, but it is less certain that burial compensates for changes in weathering via shoaling or deepening of the CCD. Because most carbonate burial occurs well above the CCD , changes in weathering fluxes may be primarily accommodated by increasing or decreasing carbonate burial at shallower depths, i.e., at or near the lysocline, the depth range over which carbonate dissolution markedly increases. Indeed, recent earth system modelling studies have suggested that the position of the CCD is relatively insensitive to changes in atmospheric pCO2. Additionally, studies have questioned the nature and strength of the relationship between the CCD, carbonate saturation state in the water column, and lysocline. To test the relationship between palaeoclimate and the location of the CCD, we reconstructed the global, long-term CCD behaviour across major Cenozoic climate transitions: the late Paleocene - early Eocene long-term warming trend (study interval ~58 to 49 Ma) and the late Eocene - early Oligocene cooling and glaciation (study interval ~38 to 27 Ma). We use Earth system modelling (GENIE) to explore the links between atmospheric pCO2 and the CCD, isolating and teasing apart the roles of total dissolved inorganic carbon, temperature, circulation, and productivity in determining the CCD.
Paleoenvironments of the Jurassic and Cretaceous Oceans: Selected Highlights
NASA Astrophysics Data System (ADS)
Ogg, J. G.
2007-12-01
There are many themes contributing to the sedimentation history of the Mesozoic oceans. This overview briefly examines the roles of the carbonate compensation depth (CCD) and the associated levels of atmospheric carbon dioxide, of the evolution of marine calcareous microplankton, of major transgressive and regressive trends, and of super-plume eruptions. Initiation of Atlantic seafloor spreading in the Middle Jurassic coincided with an elevated carbonate compensation depth (CCD) in the Pacific-Tethys mega-ocean. Organic-rich sediments that would become the oil wealth of regions from Saudi Arabia to the North Sea were deposited during a continued rise in CCD during the Oxfordian-early Kimmeridgian, which suggests a possible increase in carbon dioxide release by oceanic volcanic activity. Deep-sea deposits in near-equatorial settings are dominated by siliceous shales or cherts, which reflect the productivity of siliceous microfossils in the tropical surface waters. The end-Jurassic explosion in productivity by calcareous microplankton contributed to the lowering of the CCD and onset of the chalk ("creta") deposits that characterize the Tithonian and lower Cretaceous in all ocean basins. During the mid-Cretaceous, the eruption of enormous Pacific igneous provinces (Ontong Java Plateau and coeval edifices) increased carbon dioxide levels. The resulting rise in CCD terminated chalk deposition in the deep sea. The excess carbon was progressively removed in widespread black-shale deposits in the Atlantic basins and other regions - another major episode of oil source rock. A major long-term transgression during middle and late Cretaceous was accompanied by extensive chalk deposition on continental shelves and seaways while the oceanic CCD remained elevated. Pacific guyots document major oscillations (sequences) of global sea level superimposed on this broad highstand. The Cretaceous closed with a progressive sea-level regression and lowering of the CCD that again enabled widespread carbonate deposition in the deep sea.
Intermittent carbonate sedimentation in the equatoral Indian Ocean: fluctuations of the Eocene CCD?
NASA Astrophysics Data System (ADS)
Mitchison, F.; Kachovich, S.; Backman, J.; Pike, J.
2017-12-01
IODP Expedition 362 recently drilled from the sea floor to oceanic basement in the eastern equatorial Indian Ocean at Site U1480G (3°N, 91°E, water depth 4148 m). Beneath the thick ( 1250 m) predominantly siliciclastic Nicobar Fan succession, a condensed ( 10 m) middle Eocene pelagic interval displayed striking decimetre-scale banding, alternating between calcareous oozes and darker clays. We investigate whether deposition of the calcareous sediments was associated with periodic global carbonate accumulation events previously documented in the Equatorial Pacific and Atlantic Oceans, linked to oscillations of the carbonate compensation depth (CCD). We present high-resolution geochemical records (carbonate, organic carbon, bulk carbonate stable isotopes) and scanning electron microscope micro-element maps through several of the calcareous to clay transitions, as well as microfossil assemblages and new biostratigraphic constraints for the interval. Our data will reveal whether the banded sediments represent fluctuations of the CCD, and whether the CCD was likely responding to global (e.g. changes in pCO2) or local (e.g. local changes in calcareous plankton productivity) processes.
NASA Astrophysics Data System (ADS)
Lindsey, M. M.; Schellenberg, S. A.
2006-12-01
Carbonate saturation profiles are complex and dynamic products of processes operating on spatiotemporal scales from the "short-term local" (e.g. carbonate export production, carbonate ion concentration) to the "long- term global" (e.g. carbonate-silicate weathering, shelf:basin carbonate partitioning). Thus, a refined history of carbonate saturation may provide insight on global carbon-cycle dynamics. An established, if crude, proxy for reconstructing carbonate saturation is the wt% carbonate content of pelagic sediments, where <20 wt% is ascribed to deposition below the carbonate compensation depth (CCD). A number of now classic works (e.g. Berger and Roth, 1975; van Andel, 1977) established first-order and presumably global Cenozoic CCD fluctuations. The Walvis Ridge depth-transect of ODP Leg 208 represents an excellent opportunity to refine our understanding of the South Atlantic Cenozoic CCD. Wt% carbonate determinations (n = 299) through the Early Eocene to Late Miocene section at Site 1267 are significantly correlated with associated natural gamma ray values (r2 = 0.92). This relationship was used to produce a cm-scale synthetic wt% carbonate record ordinated in the time-domain via the ship-board age-model and in the paleodepth-domain via Sclater and Parsons (1977) crustal age-depth relationship. The Site 1267 record shows good general agreement with previous low-resolution (>10^{5-6} yr) CCD reconstructions and correlates relatively well with estimates of eustatic sea level fluctuations. Ongoing research expands this general approach to shallower and deeper ODP Leg 208 sites to provide greater constraints on the history of the South Atlantic CCD. These data, combined with other proxies (e.g. planktonic foraminifer fragmentation, stable isotopes) and placed within evolving Leg 208 age-models, will provide valuable constraints on cyclic and secular fluctuations in the South Atlantic carbonate saturation profile and their relation to various components of the earth system (e.g. pCO2, sea level, tectonics).
Influence of camera parameters on the quality of mobile 3D capture
NASA Astrophysics Data System (ADS)
Georgiev, Mihail; Boev, Atanas; Gotchev, Atanas; Hannuksela, Miska
2010-01-01
We investigate the effect of camera de-calibration on the quality of depth estimation. Dense depth map is a format particularly suitable for mobile 3D capture (scalable and screen independent). However, in real-world scenario cameras might move (vibrations, temp. bend) form their designated positions. For experiments, we create a test framework, described in the paper. We investigate how mechanical changes will affect different (4) stereo-matching algorithms. We also assess how different geometric corrections (none, motion compensation-like, full rectification) will affect the estimation quality (how much offset can be still compensated with "crop" over a larger CCD). Finally, we show how estimated camera pose change (E) relates with stereo-matching, which can be used for "rectification quality" measure.
,
1990-01-01
Site 766 is located at the base of the steep western margin of the Exmouth Plateau. The oldest sediment penetrated at Site 766, in Section 123-766A-49R-4 at 66 cm (466.7 mbsf), is uppermost Valanginian sandstone and siltstone, alternating with inclined basaltic intrusions (see "Igneous Rock Lithostratigraphy" section, this chapter). The uppermost sediment/basalt interface occurs in Section 123-766A-48R-6 at 129 cm (460.6 mbsf) At least 300 m (approximately 65%) of the sediments penetrated accumulated during the Lower Cretaceous, compared with less than 150 m thereafter. At Site 765, on the Argo Abyssal Plain, the Lower Cretaceous also is slightly more than 300 m thick. However, approximately 65% of the total sediment column at this site accumulated after the Lower Cretaceous, primarily during the Neogene. The sedimentation history, based on the age and present depth of basement(?) and time-depth relationship for oceanic crust, suggests that Site 766 began at a depth of about 800 m. However, the presence of shallow marine components in the oldest lithologic unit, if not redeposited, suggests that initial depths were shallower. Site 766 appears to have remained above or near the carbonate compensation depth (CCD) throughout its history, whereas Site 765 may have started near the CCD, but remained below it throughout most of its history.
Effects of Dynamic Topography on the Cenozoic Carbonate Compensation Depth
NASA Astrophysics Data System (ADS)
Campbell, Siobhan M.; Moucha, Robert; Derry, Louis A.; Raymo, Maureen E.
2018-04-01
Reconstructions of the carbonate compensation depth (CCD) in the past have been used to inform hypotheses about the nature of weathering, tectonics, climate change, and the major ion content of the world's oceans over the Cenozoic. These reconstructions are sensitive to uncertainties in the input data, in particular, the paleodepth estimates of sediment cores. Here we propose that a significant, previously unconsidered contributor to uncertainties in paleodepth estimates is from dynamic topography produced by radial stresses exerted on the Earth's surface by the convecting mantle; these stresses can warp the ocean floor by hundreds of meters over broad regions and also vary significantly over millions of years. We present new reconstructions of the equatorial Pacific and Indian Ocean CCDs over the last 30 and 23 Myr, respectively, which demonstrate an overall deepening trend since the Miocene, and illustrate the possible effect of long-term changes in dynamic topography on these reconstructions.
NASA Astrophysics Data System (ADS)
Slotnick, B. S.; Lauretano, V.; Backman, J.; Dickens, G. R.; Sluijs, A.; Lourens, L.
2015-03-01
Major variations in global carbon cycling occurred between 62 and 48 Ma, and these very likely related to changes in the total carbon inventory of the ocean-atmosphere system. Based on carbon cycle theory, variations in the mass of the ocean carbon should be reflected in contemporaneous global ocean carbonate accumulation on the seafloor and, thereby, the depth of the calcite compensation depth (CCD). To better constrain the cause and magnitude of these changes, the community needs early Paleogene carbon isotope and carbonate accumulation records from widely separated deep-sea sediment sections, especially including the Indian Ocean. Several CCD reconstructions for this time interval have been generated using scientific drill sites in the Atlantic and Pacific oceans; however, corresponding information from the Indian Ocean has been extremely limited. To assess the depth of the CCD and the potential for renewed scientific drilling of Paleogene sequences in the Indian Ocean, we examine lithologic, nannofossil, carbon isotope, and carbonate content records for late Paleocene - early Eocene sediments recovered at three sites spanning Ninetyeast Ridge: Deep Sea Drilling Project (DSDP) Sites 213 (deep, east), 214 (shallow, central), and 215 (deep, west). The disturbed, discontinuous sediment sections are not ideal, because they were recovered in single holes using rotary coring methods, but remain the best Paleogene sediments available from the central Indian Ocean. The δ13C records at Sites 213 and 215 are similar to those generated at several locations in the Atlantic and Pacific, including the prominent high in δ13C across the Paleocene carbon isotope maximum (PCIM) at Site 215, and the prominent low in δ13C across the early Eocene Climatic Optimum (EECO) at both Site 213 and Site 215. The Paleocene-Eocene thermal maximum (PETM) and the K/X event are found at Site 213 but not at Site 215, presumably because of coring gaps. Carbonate content at both Sites 213 and 215 drops to <5% shortly after the first occurrence of Discoaster lodoensis and the early Eocene rise in δ13C (~52 Ma). This reflects a rapid shoaling of the CCD, and likely a major decrease in the net flux of 13C-depleted carbon to the ocean. Our results support ideas that major changes in net fluxes of organic carbon to and from the exogenic carbon cycle occurred during the early Paleogene. Moreover, we conclude that excellent early Paleogene carbonate accumulation records might be recovered from the central Indian Ocean with future scientific drilling.
Rethinking CCD's Significance in Estimating Late Neogene Whole Ocean Carbonate Budget
NASA Astrophysics Data System (ADS)
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 records, the net accumulation of pelagic carbonate has declined over the course of late Neogene. Hence, the weathering alkalinity input should have decreased since 15 Ma, as oppose to the weathering hypothesis (Raymo et al., 1988).
The timing of events surrounding the Eocene-Oligocene boundary - Results from ODP Leg 199
NASA Astrophysics Data System (ADS)
Pälike, H.; Wilson, P. A.; Coxall, H.; Backman, J.
2003-04-01
The Eocene/Oligocene (E/O) boundary represents an extreme and rapid climatic transition from the ``greenhouse'' world of the Cretaceous and early Paleogene into the late Paleogene-Neogene ``ice-house''. It is marked by a large and global deepening in the calcite compensation depth (CCD), as well as pronounced changes in the isotopic composition of carbon and oxygen in seawater, recorded in biogenic calcium carbonate. A good understanding is still lacking as to why climatic, palaeoceanographic and marine biological productivity changes occurred within a few tens of thousands of years, and what change in boundary conditions triggered a non-linear response of the climate system. Detailed palaeoceanographic records surrounding the E/O have been rare because of the lack of well-dated, expanded deep-sea sedimentary sections containing well-preserved calcareous microfossils. Ocean Drilling Program Leg 199 recently recovered an extensive set of high-quality sediment cores across the E/O that span a latitudinal and depth transect in the central Pacific Ocean. We present new high-resolution records of bulk %CaCO3, δ18O and δ13C for a set of sites that form a depth transect, clearly delineating the relative depth with respect to the CCD during the transition. Our data show that a two-stepped deepening of the CCD coincides with a remarkably similar and simultaneous evolution of bulk δ18O values. We can demonstrate the imprint of climatic cycles around the E/O boundary, and very high-quality bio- and paleomagnetic datum points allow us to link these to Earth's orbital variations. Shipboard measurements of sediment properties and down-hole log measurements also display an imprint of climatic cycles, and allow us to obtain an astronomically calibrated time scale across the E/O. Our results put tighter constraints on the timing of the evolution of the CCD, mass accumulation rates, and biological productivity across the E/O, which display a distinct two-step shift in the most expanded section at the shallowest end of the transect (Site 1218). The initial deepening of the CCD occurred in less than 50 thousand years, and we observe a change in the nature and amplitude of climatic cycles that are recorded in sediments from Leg 199 across the E/O.
Mesozoic Alpine facies deposition as a result of past latitudinal plate motion.
Muttoni, Giovanni; Erba, Elisabetta; Kent, Dennis V; Bachtadse, Valerian
2005-03-03
The fragmentation of Pangaea as a consequence of the opening of the Atlantic Ocean is documented in the Alpine-Mediterranean region by the onset of widespread pelagic sedimentation. Shallow-water sediments were replaced by mainly pelagic limestones in the Early Jurassic period, radiolarian cherts in the Middle-Late Jurassic period, and again pelagic limestones in the Late Jurassic-Cretaceous period. During initial extension, basin subsidence below the carbonate compensation depth (CCD) is thought to have triggered the transition from Early Jurassic limestones to Middle-Late Jurassic radiolarites. It has been proposed that the transition from radiolarites to limestones in the Late Jurassic period was due to an increase in calcareous nannoplankton abundance when the CCD was depressed below the ocean floor. But in modern oceans, sediments below the CCD are not necessarily radiolaritic. Here we present palaeomagnetic samples from the Jurassic-Cretaceous pelagic succession exposed in the Lombardian basin, Italy. On the basis of an analysis of our palaeolatitudinal data in a broader palaeogeographic context, we propose an alternative explanation for the above facies tripartition. We suggest that the Lombardian basin drifted initially towards, and subsequently away from, a near-equatorial upwelling zone of high biosiliceous productivity. Our tectonic model for the genesis of radiolarites adds an essential horizontal plate motion component to explanations involving only vertical variations of CCD relative to the ocean floor. It may explain the deposition of radiolarites throughout the Mediterranean and Middle Eastern region during the Jurassic period.
Yasuhara, Moriaki; Cronin, T. M.; Martinez, Arbizu P.
2008-01-01
We report the distribution of ostracods from ???5000 m depth from the Southeast and Equatorial Atlantic Ocean recovered from the uppermost 10 cm of minimally disturbed sediments taken by multiple-corer during the R/V Meteor DIVA2 expedition M63.2. Five cores yielded the following major deep-sea genera: Krithe, Henryhowella, Poseidonamicus, Legitimocythere, Pseudobosquetina, and Pennyella. All genera are widely distributed in abyssal depths in the world's oceans and common in Cenozoic deep-sea sediments. The total number of ostracod specimens is higher and ostracod shell preservation is better near the sediment-water interface, especially at the 0-1 cm core depths. Core slices from ???5 to 10 cm were barren or yielded a few poorly preserved specimens. The DIVA2 cores show that deep-sea ostracod species inhabit corrosive bottom water near the carbonate compensation depth (CCD) even though their calcareous valves are rarely preserved as fossils in sediment cores due to postmortem dissolution. Their occurrence at great water depths may partially explain the well-known global distributions of major deep-sea taxa in the world's oceans, although further expeditions using minimal-disturbance sampling devices are needed to fill geographic gaps. ?? 2008 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Darnell, K.; Flemings, P. B.; DiCarlo, D. A.
2016-12-01
In June 2016, seawater samples at sediment-seawater interface and sediment samples were collected by the he Jiaolong, China's manned submersible, at four sampling sites located in the Yap Trench. Seawater samples from different depths of the trench were also collected by CTD. Chemical parameters, including pH, alkanility, concentrations of dissolved inorganic carbon, dissolved and total organic carbon, methane, dimethylsulfoniopropionate, nutrients, carbohydrates, and amino acids were analyzed in the seawater samples. Concentrations of total organic carbon, six constant elements and nine trace elements were determined in the sediment samples. All the vertical profiles of the chemical parameters in the seawater have unique characteristics. Our resluts also showed that the carbonate compensation depth (CCD) was between 4500 m and 5000 m in the trench. The hadal sediment at 6500 m depth under the CCD line was siliceous ooze favored for the burial of orgaic carbon, attributed to accumulation of surface sediment by gravity flow. The abyssal sediment at the 4500 m depth was calcareous ooze. Various microfossils, such as discoasters and diatoms, were identified in different sediment layers of the sediment samples.Based on the ratios of Fe/Al and Ti/Al, and the correlation between different elements, the sediment in the Yap Trench were derived from biogenic, terrestrial, volcanic and autogenic sources. The ratios of Ni/Co and V/Cr showed that the deposition environment of the trench should be oxidative, arributed to inflow of the Antractic bottom oxygen-rich seawater.The high concentraiont of Ca in the sediment from the station 371-Yap-S02 below 4 cm depth indicated that there was no large-scale volcanic eruption in the research area and the volcanic materials in the sediment might orginated from the Mariana Volcanic Arc, and the Carolyn Ridge has been slowly sinking on the east side of the trench due to plate subduction. This study is the first systematic study of chemical characteristics in the seawater and sediment of the Yap Trench.
Chemical Characteristics of Seawater and Sediment in the Yap Trench
NASA Astrophysics Data System (ADS)
Ding, H.; Sun, C.; Yang, G.
2017-12-01
In June 2016, seawater samples at sediment-seawater interface and sediment samples were collected by the he Jiaolong, China's manned submersible, at four sampling sites located in the Yap Trench. Seawater samples from different depths of the trench were also collected by CTD. Chemical parameters, including pH, alkanility, concentrations of dissolved inorganic carbon, dissolved and total organic carbon, methane, dimethylsulfoniopropionate, nutrients, carbohydrates, and amino acids were analyzed in the seawater samples. Concentrations of total organic carbon, six constant elements and nine trace elements were determined in the sediment samples. All the vertical profiles of the chemical parameters in the seawater have unique characteristics. Our resluts also showed that the carbonate compensation depth (CCD) was between 4500 m and 5000 m in the trench. The hadal sediment at 6500 m depth under the CCD line was siliceous ooze favored for the burial of orgaic carbon, attributed to accumulation of surface sediment by gravity flow. The abyssal sediment at the 4500 m depth was calcareous ooze. Various microfossils, such as discoasters and diatoms, were identified in different sediment layers of the sediment samples.Based on the ratios of Fe/Al and Ti/Al, and the correlation between different elements, the sediment in the Yap Trench were derived from biogenic, terrestrial, volcanic and autogenic sources. The ratios of Ni/Co and V/Cr showed that the deposition environment of the trench should be oxidative, arributed to inflow of the Antractic bottom oxygen-rich seawater.The high concentraiont of Ca in the sediment from the station 371-Yap-S02 below 4 cm depth indicated that there was no large-scale volcanic eruption in the research area and the volcanic materials in the sediment might orginated from the Mariana Volcanic Arc, and the Carolyn Ridge has been slowly sinking on the east side of the trench due to plate subduction. This study is the first systematic study of chemical characteristics in the seawater and sediment of the Yap Trench.
Koottathape, Natthavoot; Takahashi, Hidekazu; Finger, Wernerj; Kanehira, Masafumi; Iwasaki, Naohiko; Aoyagi, Yujin
2012-06-01
Although attritive and abrasive wear of recent composite resins has been substantially reduced, in vitro wear testing with reasonably simulating devices and quantitative determination of resulting wear is still needed. Three-dimensional scanning methods are frequently used for this purpose. The aim of this trial was to compare maximum depth of wear and volume loss of composite samples, evaluated with a contact profilometer and a non-contact CCD camera imaging system, respectively. Twenty-three random composite specimens with wear traces produced in a ball-on-disc sliding device, using poppy seed slurry and PMMA suspension as third-body media, were evaluated with the contact profilometer (TalyScan 150, Taylor Hobson LTD, Leicester, UK) and with the digital CCD microscope (VHX1000, KEYENCE, Osaka, Japan). The target parameters were maximum depth of the wear and volume loss.Results - The individual time of measurement needed with the non-contact CCD method was almost three hours less than that with the contact method. Both, maximum depth of wear and volume loss data, recorded with the two methods were linearly correlated (r(2) > 0.97; p < 0.01). The contact scanning method and the non-contact CCD method are equally suitable for determination of maximum depth of wear and volume loss of abraded composite resins.
Flat-panel detector, CCD cameras, and electron-beam-tube-based video for use in portal imaging
NASA Astrophysics Data System (ADS)
Roehrig, Hans; Tang, Chuankun; Cheng, Chee-Way; Dallas, William J.
1998-07-01
This paper provides a comparison of some imaging parameters of four portal imaging systems at 6 MV: a flat panel detector, two CCD cameras and an electron beam tube based video camera. Measurements were made of signal and noise and consequently of signal-to-noise per pixel as a function of the exposure. All systems have a linear response with respect to exposure, and with the exception of the electron beam tube based video camera, the noise is proportional to the square-root of the exposure, indicating photon-noise limitation. The flat-panel detector has a signal-to-noise ratio, which is higher than that observed with both CCD-Cameras or with the electron beam tube based video camera. This is expected because most portal imaging systems using optical coupling with a lens exhibit severe quantum-sinks. The measurements of signal-and noise were complemented by images of a Las Vegas-type aluminum contrast detail phantom, located at the ISO-Center. These images were generated at an exposure of 1 MU. The flat-panel detector permits detection of Aluminum holes of 1.2 mm diameter and 1.6 mm depth, indicating the best signal-to-noise ratio. The CCD-cameras rank second and third in signal-to- noise ratio, permitting detection of Aluminum-holes of 1.2 mm diameter and 2.2 mm depth (CCD_1) and of 1.2 mm diameter and 3.2 mm depth (CCD_2) respectively, while the electron beam tube based video camera permits detection of only a hole of 1.2 mm diameter and 4.6 mm depth. Rank Order Filtering was applied to the raw images from the CCD-based systems in order to remove the direct hits. These are camera responses to scattered x-ray photons which interact directly with the CCD of the CCD-Camera and generate 'Salt and Pepper type noise,' which interferes severely with attempts to determine accurate estimates of the image noise. The paper also presents data on the metal-phosphor's photon gain (the number of light-photons per interacting x-ray photon).
Seawater calcium isotope ratios across the Eocene-Oligocene transition
Griffith, E.M.; Paytan, A.; Eisenhauer, A.; Bullen, T.D.; Thomas, E.
2011-01-01
During the Eocene-Oligocene transition (EOT, ca. 34 Ma), Earth's climate cooled significantly from a greenhouse to an icehouse climate, while the calcite (CaCO3) compensation depth (CCD) in the Pacific Ocean increased rapidly. Fluctuations in the CCD could result from various processes that create an imbalance between calcium (Ca) sources to, and sinks from, the ocean (e.g., weathering and CaCO3 deposition), with different effects on the isotopic composition of dissolved Ca in the oceans due to differences in the Ca isotopic composition of various inputs and outputs. We used Ca isotope ratios (??44/40Ca) of coeval pelagic marine barite and bulk carbonate to evaluate changes in the marine Ca cycle across the EOT. We show that the permanent deepening of the CCD was not accompanied by a pronounced change in seawater ??44/40Ca, whereas time intervals in the Neogene with smaller carbonate depositional changes are characterized by seawater ??44/40Ca shifts. This suggests that the response of seawater ??44/40Ca to changes in weathering fluxes and to imbalances in the oceanic alkalinity budget depends on the chemical composition of seawater. A minor and transient fluctuation in the Ca isotope ratio of bulk carbonate may reflect a change in isotopic fractionation associated with CaCO3 precipitation from seawater due to a combination of factors, including changes in temperature and/or in the assemblages of calcifying organisms. ?? 2011 Geological Society of America.
CCD-camera-based diffuse optical tomography to study ischemic stroke in preclinical rat models
NASA Astrophysics Data System (ADS)
Lin, Zi-Jing; Niu, Haijing; Liu, Yueming; Su, Jianzhong; Liu, Hanli
2011-02-01
Stroke, due to ischemia or hemorrhage, is the neurological deficit of cerebrovasculature and is the third leading cause of death in the United States. More than 80 percent of stroke patients are ischemic stroke due to blockage of artery in the brain by thrombosis or arterial embolism. Hence, development of an imaging technique to image or monitor the cerebral ischemia and effect of anti-stoke therapy is more than necessary. Near infrared (NIR) optical tomographic technique has a great potential to be utilized as a non-invasive image tool (due to its low cost and portability) to image the embedded abnormal tissue, such as a dysfunctional area caused by ischemia. Moreover, NIR tomographic techniques have been successively demonstrated in the studies of cerebro-vascular hemodynamics and brain injury. As compared to a fiberbased diffuse optical tomographic system, a CCD-camera-based system is more suitable for pre-clinical animal studies due to its simpler setup and lower cost. In this study, we have utilized the CCD-camera-based technique to image the embedded inclusions based on tissue-phantom experimental data. Then, we are able to obtain good reconstructed images by two recently developed algorithms: (1) depth compensation algorithm (DCA) and (2) globally convergent method (GCM). In this study, we will demonstrate the volumetric tomographic reconstructed results taken from tissuephantom; the latter has a great potential to determine and monitor the effect of anti-stroke therapies.
ERIC Educational Resources Information Center
Johnson, Frank; Cornman, Stephen Q.
2008-01-01
The Common Core of Data (CCD) is an annual collection of public elementary and secondary education data administered by the National Center for Education Statistics (NCES) and its collection agent, the U.S. Census Bureau. Data for CCD surveys are provided by state education agencies (SEAs). This report presents summary data from the Pilot Teacher…
NASA Astrophysics Data System (ADS)
Schellenberg, S. A.; Nielsen, J. L.
2004-12-01
Ocean Drilling Program Leg 208 Science Party (D. Kroon, J. C. Zachos, P. Blum, J. Bowles, P. Gaillot, T. Hasegawa, E. C. Hawthorne, D. A. Hodell, D. C. Kelly, J. Jung, S. M. Keller, Y. Lee, D. C. Leuschner, Z. Liu, K. C. Lohmann, L. Lourens, S. Monechi, M. Nicolo, I. Raffi, C. Riesselman, U. Röhl, D. Schmidt, A. Sluijs, D. Thomas, E. Thomas, H. Vallius) Carbonate saturation profiles are complex and dynamic products of processes operating on temporospatial scales from the "short-term local" (e.g. carbonate export production) to the "long-term global" (e.g. carbonate-silicate weathering, shelf:basin carbonate partitioning). Established, if admittedly crude, proxies for reconstructing carbonate saturation from sediments include wt% carbonate, where values of 0-20% are typically attributed to deposition below the carbonate compensation depth (CCD), and planktonic foraminifer fragmentation, where enhanced fragmentation is typically attributed to deposition below the lysocline. Ocean Drilling Program Leg 208 successfully drilled a six-site Walvis Ridge depth-transect spanning modern water depths from 2,717 to 4,755 m. Exceptional core recovery, well-constrained biomagnetostratigraphy, and standard crustal subsidence corrections provide a working age-depth framework for contouring ship-board wt% carbonate determinations and identifying the following first-order features of the regional CCD: (1) >3.5 km position from 60-48 Ma punctuated by a major transient shoaling to <2 km during the Paleocene-Eocene Thermal Maximum at ˜55 Ma; (2) shoaling to ˜2.75 km from 48 to 44 Ma; (3) subsequent deepening to >4.25 km from 37 to 28 Ma; (4) marked high amplitude fluctuations from 28 to 20 Ma followed by deepening to >4.75 km; (5) transient shoaling to ˜4 km around 15 Ma followed by deepening to >4.75 km by ˜12 Ma. These first-order features are broadly congruent with classic Atlantic CCD reconstructions by van Andel (1975) and Berger and Roth (1975). A wealth of higher frequency variation in carbonate saturation is clearly preserved within the Leg 208 depth-transect. Ongoing shore-based analyses aim to transform cm-scale variations in core physical properties (i.e. magnetic susceptibility, color reflectance) into synthetic records of wt% carbonate. These data, combined with other proxies (e.g., planktonic foraminifer fragmentation, stable isotopes) and placed within the evolving post-cruise biomagnetostratigraphic and cyclostratigraphic age-model, will provide valuable constraints on cyclic and secular fluctuations in the South Atlantic carbonate saturation profile and their relation to other major components of the earth system (e.g. pCO2, eustacy).
NASA Astrophysics Data System (ADS)
Kanamatsu, Toshiya; Usami, Kazuko; McHugh, Cecilia M. G.; Ikehara, Ken
2017-08-01
Using high-resolution paleomagnetic data, we examined the potential for obtaining precise ages from sediment core samples recovered from deep-sea basins close to rupture zones of the 2011 and earlier earthquakes off Tohoku, Japan. Obtaining detailed stratigraphic ages from deep-sea sediments below the calcium compensation depth (CCD) is difficult, but we found that the samples contain excellent paleomagnetic secular variation records to constrain age models. Variations in paleomagnetic directions obtained from the sediments reveal systematic changes in the cores. A stacked paleomagnetic profile closely matches the Lake Biwa data sets in southwest Japan for the past 7000 years, one can establish age models based on secular variations of the geomagnetic field on sediments recovered uniquely below the CCD. Comparison of paleomagnetic directions near a tephra and a paleomagnetic direction of contemporaneous pyroclastic flow deposits acquired by different magnetization processes shows precise depositional ages reflecting the magnetization delay of the marine sediment record.
Three-dimensional charge coupled device
Conder, Alan D.; Young, Bruce K. F.
1999-01-01
A monolithic three dimensional charged coupled device (3D-CCD) which utilizes the entire bulk of the semiconductor for charge generation, storage, and transfer. The 3D-CCD provides a vast improvement of current CCD architectures that use only the surface of the semiconductor substrate. The 3D-CCD is capable of developing a strong E-field throughout the depth of the semiconductor by using deep (buried) parallel (bulk) electrodes in the substrate material. Using backside illumination, the 3D-CCD architecture enables a single device to image photon energies from the visible, to the ultra-violet and soft x-ray, and out to higher energy x-rays of 30 keV and beyond. The buried or bulk electrodes are electrically connected to the surface electrodes, and an E-field parallel to the surface is established with the pixel in which the bulk electrodes are located. This E-field attracts charge to the bulk electrodes independent of depth and confines it within the pixel in which it is generated. Charge diffusion is greatly reduced because the E-field is strong due to the proximity of the bulk electrodes.
Process for fabricating a charge coupled device
Conder, Alan D.; Young, Bruce K. F.
2002-01-01
A monolithic three dimensional charged coupled device (3D-CCD) which utilizes the entire bulk of the semiconductor for charge generation, storage, and transfer. The 3D-CCD provides a vast improvement of current CCD architectures that use only the surface of the semiconductor substrate. The 3D-CCD is capable of developing a strong E-field throughout the depth of the semiconductor by using deep (buried) parallel (bulk) electrodes in the substrate material. Using backside illumination, the 3D-CCD architecture enables a single device to image photon energies from the visible, to the ultra-violet and soft x-ray, and out to higher energy x-rays of 30 keV and beyond. The buried or bulk electrodes are electrically connected to the surface electrodes, and an E-field parallel to the surface is established with the pixel in which the bulk electrodes are located. This E-field attracts charge to the bulk electrodes independent of depth and confines it within the pixel in which it is generated. Charge diffusion is greatly reduced because the E-field is strong due to the proximity of the bulk electrodes.
NASA Astrophysics Data System (ADS)
Bralower, T. J.; Kump, L. R.; Robinson, M. M.; Self-Trail, J. M.; Zachos, J. C.
2016-12-01
Continental-shelf sediments of the US Atlantic margin experienced a brief episode of carbonate dissolution during the onset of the Paleocene-Eocene Thermal Maximum (PETM). Dissolution is represented by reduced percentages of carbonate, and calcareous microfossil distribution and preservation trends, in cores from Maryland and New Jersey. The base and the top of the dissolution zone are abrupt compared to the gradual nature of the onset of the carbon isotope excursion (CIE). The thickness of the dissolution zone varies from 9 cm in the Bass River core (outer paleoshelf) to 1.6 m in the CamDor core (middle paleoshelf). The decrease in %CaCO3 suggests dissolution locally removed 83 to 100% of the initial biogenic carbonate. Shelf-wide dissolution during the onset of the PETM may be a regional event, associated, for example, with eutrophication. Samples from across the paleoshelf contain abundant fine-grained framboidal pyrite, which suggests photic-zone euxinia occurred before, during, and after the dissolution event. Dissolution may also be associated with oxidation of this pyrite during later exposure to oxidizing groundwaters, although the restricted duration of the dissolution interval argues against this. Alternatively, the dissolution event may have global significance related to surface ocean-water acidification or shoaling of the calcite compensation depth (CCD) to shelf depths. The event began near the onset of the CIE on the shelf, whereas dissolution in deep-sea sections began later. Earlier shelf dissolution is consistent with surface ocean acidification while later deep-sea dissolution is thought to be associated with shoaling of the CCD. In our presentation, we weigh evidence for each of these possibilities and test them using the global dataset.
Design and realization of adaptive optical principle system without wavefront sensing
NASA Astrophysics Data System (ADS)
Wang, Xiaobin; Niu, Chaojun; Guo, Yaxing; Han, Xiang'e.
2018-02-01
In this paper, we focus on the performance improvement of the free space optical communication system and carry out the research on wavefront-sensorless adaptive optics. We use a phase only liquid crystal spatial light modulator (SLM) as the wavefront corrector. The optical intensity distribution of the distorted wavefront is detected by a CCD. We develop a wavefront controller based on ARM and a software based on the Linux operating system. The wavefront controller can control the CCD camera and the wavefront corrector. There being two SLMs in the experimental system, one simulates atmospheric turbulence and the other is used to compensate the wavefront distortion. The experimental results show that the performance quality metric (the total gray value of 25 pixels) increases from 3037 to 4863 after 200 iterations. Besides, it is demonstrated that our wavefront-sensorless adaptive optics system based on SPGD algorithm has a good performance in compensating wavefront distortion.
NASA Astrophysics Data System (ADS)
Deng, Chao; Ren, Wei; Mao, Yao; Ren, Ge
2017-08-01
A plug-in module acceleration feedback control (Plug-In AFC) strategy based on the disturbance observer (DOB) principle is proposed for charge-coupled device (CCD)-based fast steering mirror (FSM) stabilization systems. In classical FSM tracking systems, dual-loop control (DLC), including velocity feedback and position feedback, is usually utilized to enhance the closed-loop performance. Due to the mechanical resonance of the system and CCD time delay, the closed-loop bandwidth is severely restricted. To solve this problem, cascade acceleration feedback control (AFC), which is a kind of high-precision robust control method, is introduced to strengthen the disturbance rejection property. However, in practical applications, it is difficult to realize an integral algorithm in an acceleration controller to compensate for the quadratic differential contained in the FSM acceleration model, resulting in a challenging controller design and a limited improvement. To optimize the acceleration feedback framework in the FSM system, different from the cascade AFC, the accelerometers are used to construct DOB to compensate for the platform vibrations directly. The acceleration nested loop can be plugged into the velocity loop without changing the system stability, and the controller design is quite simple. A series of comparative experimental results demonstrate that the disturbance rejection property of the CCD-based FSM can be effectively improved by the proposed approach.
Portal imaging with flat-panel detector and CCD camera
NASA Astrophysics Data System (ADS)
Roehrig, Hans; Tang, Chuankun; Cheng, Chee-Wai; Dallas, William J.
1997-07-01
This paper provides a comparison of imaging parameters of two portal imaging systems at 6 MV: a flat panel detector and a CCD-camera based portal imaging system. Measurements were made of the signal and noise and consequently of signal-to-noise per pixel as a function of the exposure. Both systems have a linear response with respect to exposure, and the noise is proportional to the square-root of the exposure, indicating photon-noise limitation. The flat-panel detector has a signal- to-noise ratio, which is higher than that observed wit the CCD-camera based portal imaging system. This is expected because most portal imaging systems using optical coupling with a lens exhibit severe quantum-sinks. The paper also presents data on the screen's photon gain (the number of light-photons per interacting x-ray photon), as well as on the magnitude of the Swank-noise, (which describes fluctuation in the screen's photon gain). Images of a Las Vegas-type aluminum contrast detail phantom, located at the ISO-Center, were generated at an exposure of 1 MU. The CCD-camera based system permits detection of aluminum-holes of 0.01194 cm diameter and 0.228 mm depth while the flat-panel detector permits detection of aluminum holes of 0.01194 cm diameter and 0.1626 mm depth, indicating a better signal-to-noise ratio. Rank order filtering was applied to the raw images from the CCD-based system in order to remove the direct hits. These are camera responses to scattered x-ray photons which interact directly with the CCD of the CCD-camera and generate 'salt and pepper type noise,' which interferes severely with attempts to determine accurate estimates of the image noise.
NASA Technical Reports Server (NTRS)
1999-01-01
Analytical Spectral Devices was able to commercialize the "engine" of SeaSpec. The Dual CCD developed for SeaSpec is used in our FieldSpecO Dual UV/VNIR/CCD. This product is very popular for coastal research. It allows for a small suitcase sized spectrometer to be placed in a boat and the attached fiber optic cable can be lowered 30 feet below the surface allowing researchers to perform the same studies as SeaSpec just not at the deep-water depths. Most of the people who inquire about SeaSpec end up purchasing a FieldSpec Dual CCD.SeaSpec was designed to withstand harsh marine environments and depths up to 200 m. While it meets these requirements it is the only instrument of its kind and we consider it a prototype. The first version was released in April 1997. It was tested, we made modification and returned the product in March 1998.
Eliminating "Hotspots" in Digital Image Processing
NASA Technical Reports Server (NTRS)
Salomon, P. M.
1984-01-01
Signals from defective picture elements rejected. Image processing program for use with charge-coupled device (CCD) or other mosaic imager augmented with algorithm that compensates for common type of electronic defect. Algorithm prevents false interpretation of "hotspots". Used for robotics, image enhancement, image analysis and digital television.
Fercher, A; Hitzenberger, C; Sticker, M; Zawadzki, R; Karamata, B; Lasser, T
2001-12-03
Dispersive samples introduce a wavelength dependent phase distortion to the probe beam. This leads to a noticeable loss of depth resolution in high resolution OCT using broadband light sources. The standard technique to avoid this consequence is to balance the dispersion of the sample byarrangingadispersive materialinthereference arm. However, the impact of dispersion is depth dependent. A corresponding depth dependent dispersion balancing technique is diffcult to implement. Here we present a numerical dispersion compensation technique for Partial Coherence Interferometry (PCI) and Optical Coherence Tomography (OCT) based on numerical correlation of the depth scan signal with a depth variant kernel. It can be used a posteriori and provides depth dependent dispersion compensation. Examples of dispersion compensated depth scan signals obtained from microscope cover glasses are presented.
Yao, Tao; Yin, Shi-Min; Xiangli, Bin; Lü, Qun-Bo
2010-06-01
Based on in-depth analysis of the relative radiation scaling theorem and acquired scaling data of pixel response nonuniformity correction of CCD (charge-coupled device) in spaceborne visible interferential imaging spectrometer, a pixel response nonuniformity correction method of CCD adapted to visible and infrared interferential imaging spectrometer system was studied out, and it availably resolved the engineering technical problem of nonuniformity correction in detector arrays for interferential imaging spectrometer system. The quantitative impact of CCD nonuniformity on interferogram correction and recovery spectrum accuracy was given simultaneously. Furthermore, an improved method with calibration and nonuniformity correction done after the instrument is successfully assembled was proposed. The method can save time and manpower. It can correct nonuniformity caused by other reasons in spectrometer system besides CCD itself's nonuniformity, can acquire recalibration data when working environment is changed, and can also more effectively improve the nonuniformity calibration accuracy of interferential imaging
Linear CCD attitude measurement system based on the identification of the auxiliary array CCD
NASA Astrophysics Data System (ADS)
Hu, Yinghui; Yuan, Feng; Li, Kai; Wang, Yan
2015-10-01
Object to the high precision flying target attitude measurement issues of a large space and large field of view, comparing existing measurement methods, the idea is proposed of using two array CCD to assist in identifying the three linear CCD with multi-cooperative target attitude measurement system, and to address the existing nonlinear system errors and calibration parameters and more problems with nine linear CCD spectroscopic test system of too complicated constraints among camera position caused by excessive. The mathematical model of binocular vision and three linear CCD test system are established, co-spot composition triangle utilize three red LED position light, three points' coordinates are given in advance by Cooperate Measuring Machine, the red LED in the composition of the three sides of a triangle adds three blue LED light points as an auxiliary, so that array CCD is easier to identify three red LED light points, and linear CCD camera is installed of a red filter to filter out the blue LED light points while reducing stray light. Using array CCD to measure the spot, identifying and calculating the spatial coordinates solutions of red LED light points, while utilizing linear CCD to measure three red LED spot for solving linear CCD test system, which can be drawn from 27 solution. Measured with array CCD coordinates auxiliary linear CCD has achieved spot identification, and has solved the difficult problems of multi-objective linear CCD identification. Unique combination of linear CCD imaging features, linear CCD special cylindrical lens system is developed using telecentric optical design, the energy center of the spot position in the depth range of convergence in the direction is perpendicular to the optical axis of the small changes ensuring highprecision image quality, and the entire test system improves spatial object attitude measurement speed and precision.
Nano-JASMINE: cosmic radiation degradation of CCD performance and centroid detection
NASA Astrophysics Data System (ADS)
Kobayashi, Yukiyasu; Shimura, Yuki; Niwa, Yoshito; Yano, Taihei; Gouda, Naoteru; Yamada, Yoshiyuki
2012-09-01
Nano-JASMINE (NJ) is a very small astrometry satellite project led by the National Astronomical Observatory of Japan. The satellite is ready for launch, and the launch is currently scheduled for late 2013 or early 2014. The satellite is equipped with a fully depleted CCD and is expected to perform astrometry observations for stars brighter than 9 mag in the zw-band (0.6 µm-1.0 µm). Distances of stars located within 100 pc of the Sun can be determined by using annual parallax measurements. The targeted accuracy for the position determination of stars brighter than 7.5 mag is 3 mas, which is equivalent to measuring the positions of stars with an accuracy of less than one five-hundredth of the CCD pixel size. The position measurements of stars are performed by centroiding the stellar images taken by the CCD that operates in the time and delay integration mode. The degradation of charge transfer performance due to cosmic radiation damage in orbit is proved experimentally. A method is then required to compensate for the effects of performance degradation. One of the most effective ways of achieving this is to simulate observed stellar outputs, including the effect of CCD degradation, and then formulate our centroiding algorithm and evaluate the accuracies of the measurements. We report here the planned procedure to simulate the outputs of the NJ observations. We also developed a CCD performance-measuring system and present preliminary results obtained using the system.
Concordia CCD - A Geoscope station in continental Antarctica
NASA Astrophysics Data System (ADS)
Maggi, A.; Lévêque, J.; Thoré, J.; Bes de Berc, M.; Bernard, A.; Danesi, S.; Morelli, A.; Delladio, A.; Sorrentino, D.; Stutzmann, E.; Geoscope Team
2010-12-01
Concordia (Dome C, Antarctica) has had a permanent seismic station since 2005. It is run by EOST and INGV in collaboration with the French and Italian polar institutes (IPEV and PNRA). It is installed in an ice-vault, at 12m depth, distant 1km from the permanent scientific base at Concordia. The temperature in the vault is a constant -55°C. The data quality at the station has improved continuously since its installation. In 2007, the station was declared at ISC as an open station with station code CCD (ConCorDia), with data available upon request. It is only the second permanent station in the Antarctic continent, after South Pole. In 2010, CCD was included in the Geoscope network. Data from CCD starting in 2007 are now freely available from the Geoscope Data Center and IRIS. We present an analysis of the data quality at CCD, and describe the technical difficulties of operating an observatory-quality seismic station in the extreme environmental conditons present in continental Antarctica.
Lee, Juncheol; Song, Yeongtak; Oh, Jaehoon; Chee, Youngjoon; Ahn, Chiwon; Shin, Hyungoo; Kang, Hyunggoo; Lim, Tae Ho
2018-02-12
According to the guidelines, rescuers should provide chest compressions (CC) ∼1.5 inches (40 mm) for infants. Feedback devices could help rescuers perform CC with adequate rates (CCR) and depths (CCD). However, there is no CC feedback device for infant cardiopulmonary resuscitation (CPR). We suggest a smartwatch-based CC feedback application for infant CPR. We created a smartwatch-based CC feedback application. This application provides feedback on CCD and CCR by colour and text for infant CPR. To evaluate the application, 30 participants were divided randomly into two groups on the basis of whether CC was performed with or without the assistance of the smartwatch application. Both groups performed continuous CC-only CPR for 2 min on an infant mannequin placed on a firm table. We collected CC parameters from the mannequin, including the proportion of correct depth, CCR, CCD and the proportion of correct decompression depth. Demographics between the two groups were not significantly different. The median (interquartile range) proportion of correct depth was 99 (97-100) with feedback compared with 83 (58-97) without feedback (P=0.002). The CCR and proportion of correct decompression depth were not significantly different between the two groups (P=0.482 and 0.089). The CCD of the feedback group was significantly deeper than that of the control group [feedback vs. 41.2 (39.8-41.7) mm vs. 38.6 (36.1-39.6) mm; P=0.004]. Rescuers who receive feedback of CC parameters from a smartwatch could perform adequate CC during infant CPR.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/.
NASA Astrophysics Data System (ADS)
Muralidhara, .; Vasa, Nilesh J.; Singaperumal, M.
2010-02-01
A micro-electro-discharge machine (Micro EDM) was developed incorporating a piezoactuated direct drive tool feed mechanism for micromachining of Silicon using a copper tool. Tool and workpiece materials are removed during Micro EDM process which demand for a tool wear compensation technique to reach the specified depth of machining on the workpiece. An in-situ axial tool wear and machining depth measurement system is developed to investigate axial wear ratio variations with machining depth. Stepwise micromachining experiments on silicon wafer were performed to investigate the variations in the silicon removal and tool wear depths with increase in tool feed. Based on these experimental data, a tool wear compensation method is proposed to reach the desired depth of micromachining on silicon using copper tool. Micromachining experiments are performed with the proposed tool wear compensation method and a maximum workpiece machining depth variation of 6% was observed.
NASA Astrophysics Data System (ADS)
Janesick, James R.; Elliott, Tom S.; Winzenread, Rusty; Pinter, Jeff H.; Dyck, Rudolph H.
1995-04-01
Seven new CCDs are presented. The devices will be used in a variety of applications ranging from generating color cinema movies to adaptive optics camera systems to compensate for atmospheric turbulence at major astronomical observatories. This paper highlights areas of design, fabrication, and operation techniques to achieve state-of-the-art performance. We discuss current limitations of CCD technology for several key parameters.
Experimental study on synchronization of three coupled mechanical metronomes
NASA Astrophysics Data System (ADS)
Hu, Qiang; Liu, Weiqing; Yang, Hujiang; Xiao, Jinghua; Qian, Xiaolan
2013-03-01
In this paper, a CCD acquisition system is set up to explore the dynamics of three coupled mechanical metronomes in order to compensate for the defects of visual observation. The facility is efficient to observe rich dynamics in an experiment, such as phase synchronization, partial phase synchronization and quasi-periodical oscillation, by accurately recording the trajectory of three coupled metronomes. The parameters, e.g., pendulum length and rolling friction are deemed to significantly influence the dynamics of three coupled mechanical metronomes judging from the experimental phenomena. The experimental results are confirmed by the numerical simulation based on the model with different intrinsic frequencies between three metronomes. The metronome and CCD acquisition systems are excellent demonstration apparatuses for a class and an undergraduate physics laboratory.
Dumoulin, Julie A.; Bown, Paul R.; Stewart, Sondra K.; Kennett, Diana; Mazzullo, Elsa K.
1992-01-01
Sediments from the Argo Abyssal Plain (AAP), northwest of Australia, are the oldest known from the Indian Ocean and were recovered from ODP Site 765 and DSDP Site 261. New biostratigraphic and sedimentologic data from these sites, as well as reinterpretations of earlier findings, indicate that basal sediments at both localities are of Late Jurassic age and delineate a history of starved sedimentation punctuated by periodic influx of calcareous pelagic turbidites.Biostratigraphy and correlation of Upper Jurassic-Lower Cretaceous sediments is based largely on calcareous nannofossils. Both sites yielded variably preserved nannofossil successions ranging from Tithonian to Hauterivian at Site 765 and Kimmeridgian to Hauterivian at Site 261. The nannofloras are comparable to those present in the European and Atlantic Boreal and Tethyan areas, but display important differences that reflect biogeographic differentiation. The Argo region is thought to have occupied a position at the southern limit of the Tethyan nannofloral realm, thus yielding both Tethyan and Austral biogeographic features.Sedimentary successions at the two sites are grossly similar, and differences largely reflect Site 765 's greater proximity to the continental margin. Jurassic sediments were deposited at rates of about 2 m/m.y. near the carbonate compensation depth (CCD) and contain winnowed concentrations of inoceramid prisms and nannofossils, redeposited layers rich in calcispheres and calcisphere debris, manganese nodules, and volcanic detritus. Lower Cretaceous and all younger sediments accumulated below the CCD at rates that were highest (about 20 m/m.y.) during mid-Cretaceous and Neogene time. Background sediment in this interval is noncalcareous claystone; turbidites dominate the sequence and are thicker and coarser grained at Site 765.AAP turbidites consist mostly of calcareous and siliceous biogenic components and volcanogenic smectite clay; they were derived from relatively deep parts of the continental margin that lay below the photic zone, but above the CCD. The Jurassic-Lower Cretaceous section is about the same thickness across the AAP; turbidites in this interval appear to have had multiple sources along the Australian margin. The Upper Cretaceous-Cenozoic section, however, is three times thicker at Site 765 than at Site 261; turbidites in this interval were derived predominantly from the south.Patterns of sedimentation across the AAP have been influenced by shifts in sea level, the CCD, and configuration of the continental margin. Major pulses of calcareous turbidite deposition occurred during Valanginian, Aptian, and Neogene time—all periods of eustatic lowstands and depressed CCD levels. Sediment redeposited on the AAP has come largely from the Australian outer shelf, continental slope, or rise, rather than the continent itself. Most terrigenous detritus was trapped in epicontinental basins that have flanked northwestern Australia since the early Mesozoic.
Mastoris, Mihalis; Li, Gang; Welander, Ulf; McDavid, W D
2004-03-01
To determine Line Spread Functions (LSFs) and Modulation Transfer Functions (MTFs) for a digital system for panoramic radiography: the Dimax I (Planmeca Oy, Helsinki, Finland) based on Charge-Coupled Device (CCD) technology. A test object was specially designed having a gold foil positioned vertically. Images of the gold foil created edge functions that were used to determine LSFs and MTFs. The design of the test object made it possible to move the gold foil forward and backward relative to the central plane of the image layer by means of a micrometer screw. The experiment was carried out for different object depths in 5 different regions: the anterior, the canine, the premolar, the molar, and the TMJ regions. LSFs and MTFs were calculated using specially designed software. The results are presented graphically. LSFs and MTFs for the central plane were essentially the same for all regions. The MTFs for different object depths in the 5 investigated regions exhibited typical characteristics of MTFs for panoramic radiography with the exception for the functions for the molar region. The present findings indicate that the resolution of the Dimax I CCD system is comparable to that of film-based panoramic radiography.
Chavarria, Alvaro E.; Tiffenberg, Javier; Aguilar-Arevalo, Alexis; ...
2015-03-24
We introduce the fully-depleted charge-coupled device (CCD) as a particle detector. We demonstrate its low energy threshold operation, capable of detecting ionizing energy depositions in a single pixel down to 50 eV ee. We present results of energy calibrations from 0.3 keV ee to 60 ke Vee, showing that the CCD is a fully active detector with uniform energy response throughout the silicon target, good resolution (Fano ~0.16), and remarkable linear response to electron energy depositions. We show the capability of the CCD to localize the depth of particle interactions within the silicon target. We discuss the mode of operationmore » and unique imaging capabilities of the CCD, and how they may be exploited to characterize and suppress backgrounds. We present the first results from the deployment of 250 μm thick CCDs in SNOLAB, a prototype for the upcoming DAMIC100. DAMIC100 will have a target mass of 0.1 kg and should be able to directly test the CDMS-Si signal within a year of operation.« less
Lacroix, Fréderic; Archambault, Louis; Gingras, Luc; Guillot, Mathieu; Beddar, A Sam; Beaulieu, Luc
2008-08-01
A clinical prototype of a scintillating fiber dosimeter array for quality assurance applications is presented. The array consists of a linear array of 29 plastic scintillation detectors embedded in a water-equivalent plastic sheet coupled to optical fibers used to guide optical photons to a charge coupled device (CCD) camera. The CCD is packaged in a light-tight, radiation-shielded housing designed for convenient transport. A custom designed connector is used to ensure reproducible mechanical positioning of the optical fibers relative to the CCD. Profile and depth dose characterization measurements are presented and show that the prototype provides excellent dose measurement reproducibility (+/-0.8%) in-field and good accuracy (+/-1.6% maximum deviation) relative to the dose measured with an IC10 ionization chamber.
NASA Astrophysics Data System (ADS)
Dittert, Nicolas; Henrich, Rüdiger
2000-04-01
Ultrastructure dissolution susceptibility of the planktic foraminifer Globigerina bulloides, carbonate ion content of the water column, calcium carbonate content of the sediment surface, and carbonate/carbon weight percentage ratio derived from sediment surface samples were investigated in order to reconstruct the position of the calcite saturation horizon, the sedimentary calcite lysocline, and the calcium carbonate compensation depth (CCD) in the modern South Atlantic Ocean. Carbonate ion data from the water column refer to the GEOSECS locations 48, 103, and 109 and calcium carbonate data come from 19 GeoB sediment surface samples of 4 transects into the Brazil, the Guinea, and the Cape Basins. We present a new (paleo-) oceanographic tool, namely the Globigerina bulloides dissolution index (BDX). Further, we give evidence (a) for progressive G. bulloides ultrastructural breakdown with increasing carbonate dissolution even above the lysocline; (b) for a sharp BDX increase at the sedimentary lysocline; and (c) for the total absence of this species at the CCD. BDX puts us in the position to distinguish the upper open ocean and the upwelling influenced continental margin above from the deep ocean below the sedimentary lysocline. Carbonate ion data from water column samples, calcite weight percentage data from surface sediment samples, and carbonate/carbon weight percentage ratio appear to be good proxies to confirm BDX. As shown by BDX both the calcite saturation horizon (in the water column) and the sedimentary lysocline (at the sediment-water interface) mark the boundary between the carbonate ion undersaturated and highly corrosive Antarctic Bottom Water and the carbonate ion saturated North Atlantic Deep Water (NADW) of the modern South Atlantic.
NASA Astrophysics Data System (ADS)
Chiyonobu, Shun; Yamamoto, Yuzuru; Saito, Saneatsu
2017-07-01
The geological structure and calcareous nannofossil biostratigraphy of the Middle to Late Miocene trench-slope succession in the southern Boso Peninsula, central Japan, were examined to obtain chronological constraints on the accretion and formation of the trench-slope architecture. As a result, trench-slope cover sediments (Kinone and Amatsu Formations) are clearly distinguishable from the Early Miocene Hota accretionary complex (Hota Group). The Hota accretionary complex was deposited below the carbonate compensation depth (CCD) and was affected by intense shearing, forming an east-west trending and south-verging fold and thrust belt. In contrast, the trench-slope cover sediments basically have a homoclinal dip, except at the northern rim where they are bounded by fault contact. They contain many species of calcareous nannofossils and foraminifers, which are indicative of their depositional environment above the CCD, and they show shallowing-upward sedimentary structures. Biostratigraphy revealed that the depositional age of the trench-slope sediments is ca. 15-5.5 Ma, suggesting that there is an approximately 2 myr hiatus beween the Miura Group and the underlying accretionary prism. Based on these results, the age of accretion of the Hota Group is inferred to be between ca. 17-15 Ma, and the group is covered by trench-slope sediments overlain on it after ca. 15 Ma. The timing of accretion and the age of the trench-slope basin tend to be younger southward of the Boso Peninsula. The accretionary system of the Boso Peninsula apparently developed in two stages, in the Middle Miocene and in the Late Miocene to Pliocene.
Characterization of a fully depleted CCD on high-resistivity silicon
NASA Astrophysics Data System (ADS)
Stover, Richard J.; Wei, Mingzhi; Lee, Y.; Gilmore, David K.; Holland, S. E.; Groom, D. E.; Moses, William W.; Perlmutter, Saul; Goldhaber, G.; Pennypacker, C.; Wang, N. W.; Palaio, N.
1997-04-01
Most scientific CCD imagers are fabricated on 30-50 (Omega) - cm epitaxial silicon. When illuminated form the front side of the device they generally have low quantum efficiency in the blue region of the visible spectrum because of strong absorption in the polycrystalline silicon gates as well as poor quantum efficiency in the far red and near infrared region of the spectrum because of the shallow depletion depth of the low-resistivity silicon. To enhance the blue response of scientific CCDs they are often thinned and illuminated from the back side. While blue response is greatly enhanced by this process, it is expensive and it introduces additional problems for the red end of the spectrum. A typical thinned CCD is 15 to 25 micrometers thick, and at wavelengths beyond about 800 nm the absorption depth becomes comparable to the thickness of the device, leading to interference fringes from reflected light. Because these interference fringes are of high order, the spatial pattern of the fringes is extremely sensitive to small changes in the optical illumination of the detector. Calibration and removal of the effects of the fringes is one of the primary limitations on the performance of astronomical images taken at wavelengths of 800 nm or more. In this paper we present results from the characterization of a CCD which promises to address many of the problems of typical thinned CCDs. The CCD reported on here was fabricated at Lawrence Berkeley National Laboratory (LBNL) on a 10-12 K$OMega-cm n-type silicon substrate.THe CCD is a 200 by 200 15-micrometers square pixel array, and due to the very high resistivity of the starting material, the entire 300 micrometers substrate is depleted. Full depletion works because of the gettering technology developed at LBNL which keeps leakage current down. Both front-side illuminated and backside illuminated devices have been tested. We have measured quantum efficiency, read-noise, full-well, charge-transfer efficiency, and leakage current. We have also observed the effects of clocking waveform shapes on spurious charge generation. While these new CCDs promise to be a major advance in CD technology, they too have limitations such as charge spreading and cosmic-ray effects. These limitations have been characterized and are presented. Examples of astronomical observations obtained with the backside CCD on the 1-meter reflector at Lick Observatory are presented.
NASA Astrophysics Data System (ADS)
Pea, Laura; Fioroni, Chiara; Villa, Giuliana; Persico, Davide; Bohaty, Steve
2010-05-01
The Eocene-Oligocene transition represents the biggest biotic turnover in the Cenozoic, involving both terrestrial and marine realms. In this study we present the results obtained by a quantitative analysis of late Eocene-early Oligocene (35.5- 33.1 Ma) calcareous nannofossil assemblages from ODP Site 1090 Hole B (Leg 177). This Hole is located on the southern flank of the Agulhas Ridge on the Subantarctic sector of the Atlantic Ocean (42°54'S), and lies along the boundary between the North Atlantic Deep Water and the Circumpolar Deep Water. Thanks to its position above the Carbonate Compensation Depth (3702 m), the nannofossil assemblage preservation is from poor to good in most of the section, even thought some intervals are barren. A well-preserved magnetostratigraphic signal along all of the section and nannofossil biostratigraphy provided the time framework essential for interpreting the assemblage variations. Within a high resolution biostratigraphic framework and through the comparison with bulk oxygen and carbon isotope datasets we attempt to reconstruct sea surface water temperature and trophic conditions, aimed to a late Eocene - early Oligocene paleoceanographic reconstruction for the South Atlantic. A marked change in the nannofossil assemblages is associated with the Oi-1 event: a nonlinear increase of cool-water taxa gives evidence as the evolution of this climatic event is more complex than previously estimated by calcareous nannofossils in the Southern Ocean (Villa et al., 2008). In fact cool-water taxa variation trend likely reflects the two distinct shifts (Step 1 and Step) recognised by Coxall et al. (2005) within the oxygen isotope shift .Step 1 falls in the uppermost part of magnetochron C13r, while the end of step 2 correlates with the base of Chron C13n (Channell et al., 2005). Furthermore, changes in nannofossil abundance and preservation suggest CCD depth fluctuations, showing a deepening near the Eocene/Oligocene boundary, as previously suggested (Coxall et al., 2005). Site 1090 is located at 3702 m water depth, currently lays above the CCD (Gersonde et al., 1999), but it was probably close or below it during the Eocene until its deepening at the Oi-1 event; this might explain the presence of numerous barren samples along the section and a major dissolution event occurring just before Step 1. References Channell, J.E.T., Galeotti, S., Martin, E.E., Billups, K., Scher, H., Stoner, J.S., 2002. Eocene to Miocene magnetostratigraphy, biostratigraphy, and chemostratigraphy at ODP Site 1090 (sub-Antarctic South Atlantic). Geological Society of America Bulletin, 115, 607-623. Coxall H.,, Wilson P.A., Palike H., Lear C.H., Backman J.(2005). Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean. Nature, 433 6 January 2005. Gersonde, R., Hodell, D.A., Blum, P., et al., 1999b. Proc. ODP Init. Rep. 177 [Online]. Available from World Wide Web: http://www-odp.tamu.edu/publications/177_IR/177toc.htm. Villa G., Fioroni C., Pea L., Bohaty S.M., Persico D., 2008. Middle Eocene - Late Oligocene climate variability: Calcareous Nannofossil response at Kerguelen Plateau, Site 748. Mar. Micropaleont., 69, 173-192.
A CT-based software tool for evaluating compensator quality in passively scattered proton therapy
NASA Astrophysics Data System (ADS)
Li, Heng; Zhang, Lifei; Dong, Lei; Sahoo, Narayan; Gillin, Michael T.; Zhu, X. Ronald
2010-11-01
We have developed a quantitative computed tomography (CT)-based quality assurance (QA) tool for evaluating the accuracy of manufactured compensators used in passively scattered proton therapy. The thickness of a manufactured compensator was measured from its CT images and compared with the planned thickness defined by the treatment planning system. The difference between the measured and planned thicknesses was calculated with use of the Euclidean distance transformation and the kd-tree search method. Compensator accuracy was evaluated by examining several parameters including mean distance, maximum distance, global thickness error and central axis shifts. Two rectangular phantoms were used to validate the performance of the QA tool. Nine patients and 20 compensators were included in this study. We found that mean distances, global thickness errors and central axis shifts were all within 1 mm for all compensators studied, with maximum distances ranging from 1.1 to 3.8 mm. Although all compensators passed manual verification at selected points, about 5% of the pixels still had maximum distances of >2 mm, most of which correlated with large depth gradients. The correlation between the mean depth gradient of the compensator and the percentage of pixels with mean distance <1 mm is -0.93 with p < 0.001, which suggests that the mean depth gradient is a good indicator of compensator complexity. These results demonstrate that the CT-based compensator QA tool can be used to quantitatively evaluate manufactured compensators.
CCD image sensor induced error in PIV applications
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
Harper, D. T.; Penman, D. E.; Hoenisch, B.; Zachos, J. C.
2014-12-01
Boron isotopes (δ11B) and boron/calcium ratios (B/Ca) in tests of planktic foraminifera are controlled by equilibrium reactions between boron and carbon species in seawater, and thus represent important proxies of past marine carbonate chemistry. Indeed, the recent application of these boron-based proxies to fossil shells of planktic foraminifera from cores spanning the Paleocene-Eocene Thermal Maximum (PETM; 56Ma, an abrupt global warming and ocean acidification event) reveal a decline of ~0.3 in the pH of the mixed-layer [1], an anomaly that is well within the range of estimates based on the observed shoaling of the carbonate compensation depth (CCD) [2, and references therein]. The PETM occurred superimposed on a long-term warming trend that initiated in the Late Paleocene and continued into the Early Eocene (LPEE; 53-59Ma). The magnitude of warming [3] and deepening of the CCD [4] indicate that the LPEE was driven by a rise in pCO2 nearly equivalent to that of the PETM [5]. Here we extend the PETM record of boron-based proxies at IODP Site 1209 across the LPEE, in conjunction with stable carbon and oxygen isotopes in planktic foraminifera, in order to better constrain the long-term changes in pH and carbonate chemistry that accompanied the suggested rise in atmospheric CO2. The 20kyr resolution B/Ca record shows a long-term decline of ~25% during the LPEE, as well as subtle 400kyr cycles associated with eccentricity that mirror those observed in δ13C, and thus might reflect on changes in pH. The lower resolution δ11B record exhibits little change during the Late Paleocene before decreasing step-wise to lower values following the PETM, indicating that either pH in the upper ocean did not change significantly prior to the PETM, despite warming and inferred pCO2 increase, or changes in δ11Bseawater compensated for pH driven changes. As verification of these observations at Site 1209, complementary B/Ca and δ11B records are being generated for Atlantic IODP Sites 1262 and 1263. [1] Penman et al. 2014. Paleoceanography. [2] Palike et al. 2012. Nature. [3] Zachos et al. 2001. Science. [4] Leon-Rodriguez and Dickens 2010. Palaeogeogrphy, Palaeoclimatology, and Palaeoecology. [5] Komar, Zeebe and Dickens 2013. Paleoceanography.
Quantitative measurement of marginal disintegration of ceramic inlays.
Hayashi, Mikako; Tsubakimoto, Yuko; Takeshige, Fumio; Ebisu, Shigeyuki
2004-01-01
The objectives of this study include establishing a method for quantitative measurement of marginal change in ceramic inlays and clarifying their marginal disintegration in vivo. An accurate CCD optical laser scanner system was used for morphological measurement of the marginal change of ceramic inlays. The accuracy of the CCD measurement was assessed by comparing it with microscopic measurement. Replicas of 15 premolars restored with Class II ceramic inlays at the time of placement and eight years after restoration were used for morphological measurement by means of the CCD laser scanner system. Occlusal surfaces of the restored teeth were scanned and cross-sections of marginal areas were computed with software. Marginal change was defined as the area enclosed by two profiles obtained by superimposing two cross-sections of the same location at two different times and expressing the maximum depth and mean area of the area enclosed. The accuracy of this method of measurement was 4.3 +/- 3.2 microm in distance and 2.0 +/- 0.6% in area. Quantitative marginal changes for the eight-year period were 10 x 10 microm in depth and 50 x 10(3) microm2 in area at the functional cusp area and 7 x 10 microm in depth and 28 x 10(3) microm2 in area at the non-functional cusp area. Marginal disintegration at the functional cusp area was significantly greater than at the non-functional cusp area (Wilcoxon signed-ranks test, p < 0.05). This study constitutes a quantitative measurement of in vivo deterioration in marginal adaptation of ceramic inlays and indicates that occlusal force may accelerate marginal disintegration.
Feasibility study of proton-based quality assurance of proton range compensator
NASA Astrophysics Data System (ADS)
Park, S.; Jeong, C.; Min, B. J.; Kwak, J.; Lee, J.; Cho, S.; Shin, D.; Lim, Y. K.; Park, S. Y.; Lee, S. B.
2013-06-01
All patient specific range compensators (RCs) are customized for achieving distal dose conformity of target volume in passively scattered proton therapy. Compensators are milled precisely using a computerized machine. In proton therapy, precision of the compensator is critical and quality assurance (QA) is required to protect normal tissues and organs from radiation damage. This study aims to evaluate the precision of proton-based quality assurance of range compensator. First, the geometry information of two compensators was extracted from the DICOM Radiotherapy (RT) plan. Next, RCs were irradiated on the EBT film individually by proton beam which is modulated to have a photon-like percent depth dose (PDD). Step phantoms were also irradiated on the EBT film to generate calibration curve which indicates relationship between optical density of irradiated film and perpendicular depth of compensator. Comparisons were made using the mean absolute difference (MAD) between coordinate information from DICOM RT and converted depth information from the EBT film. MAD over the whole region was 1.7, and 2.0 mm. However, MAD over the relatively flat regions on each compensator selected for comparison was within 1 mm. These results shows that proton-based quality assurance of range compensator is feasible and it is expected to achieve MAD over the whole region less than 1 mm with further correction about scattering effect of proton imaging.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tabibian, Art A., E-mail: art.tabibian@gmail.com; Powers, Adam; Dolormente, Keith
In proton therapy, passive scattered proton plans use compensators to conform the dose to the distal surface of the planning volume. These devices are custom made from acrylic or wax for each treatment field using either a plunge-drilled or smooth-milled compensator design. The purpose of this study was to investigate if there is a clinical benefit of generating passive scattered proton radiation treatment plans with the smooth compensator design. We generated 4 plans with different techniques using the smooth compensators. We chose 5 sites and 5 patients for each site for the range of dosimetric effects to show adequate sample.more » The plans were compared and evaluated using multicriteria (MCA) plan quality metrics for plan assessment and comparison using the Quality Reports [EMR] technology by Canis Lupus LLC. The average absolute difference for dosimetric metrics from the plunged-depth plan ranged from −4.7 to +3.0 and the average absolute performance results ranged from −6.6% to +3%. The manually edited smooth compensator plan yielded the best dosimetric metric, +3.0, and performance, + 3.0% compared to the plunged-depth plan. It was also superior to the other smooth compensator plans. Our results indicate that there are multiple approaches to achieve plans with smooth compensators similar to the plunged-depth plans. The smooth compensators with manual compensator edits yielded equal or better target coverage and normal tissue (NT) doses compared with the other smooth compensator techniques. Further studies are under investigation to evaluate the robustness of the smooth compensator design.« less
NASA Technical Reports Server (NTRS)
Powell, J. D.; Schneider, J. B.
1986-01-01
The use of charge-coupled-devices, or CCD's, has been documented by a number of sources as an effective means of providing a measurement of spacecraft attitude with respect to the stars. A method exists of defocussing and interpolation of the resulting shape of a star image over a small subsection of a large CCD array. This yields an increase in the accuracy of the device by better than an order of magnitude over the case when the star image is focussed upon a single CCD pixel. This research examines the effect that image motion has upon the overall precision of this star sensor when applied to an orbiting infrared observatory. While CCD's collect energy within the visible spectrum of light, the targets of scientific interest may well have no appreciable visible emissions. Image motion has the effect of smearing the image of the star in the direction of motion during a particular sampling interval. The presence of image motion is incorporated into a Kalman filter for the system, and it is shown that the addition of a gyro command term is adequate to compensate for the effect of image motion in the measurement. The updated gyro model is included in this analysis, but has natural frequencies faster than the projected star tracker sample rate for dim stars. The system state equations are reduced by modelling gyro drift as a white noise process. There exists a tradeoff in selected star tracker sample time between the CCD, which has improved noise characteristics as sample time increases, and the gyro, which will potentially drift further between long attitude updates. A sample time which minimizes pointing estimation error exists for the random drift gyro model as well as for a random walk gyro model.
Online detecting system of roller wear based on laser-linear array CCD technology
NASA Astrophysics Data System (ADS)
Guo, Yuan
2010-10-01
Roller is an important metallurgy tool in the rolling mill. And the surface of a roller affects the quantity of the rolling product directly. After using a period of time, roller must be repaired or replaced. Examining the profile of a working roller between the intervals of rolling is called online detecting for roller wear. The study of online detecting roller wear is very important for selecting the grinding time in reason, reducing the exchanging times of rollers, improving the quality of the product and realizing online grinding rollers. By applying the laser-linear array CCD detective technology, a method for online non-touch detecting roller wear was brought forward. The principle, composition and the operation process of the linear array CCD detecting system were expatiated. And an error compensation algorithm is exactly calculated to offset the shift of the roller axis in this measurement system. So the stability and the accuracy were improved remarkably. The experiment proves that the accuracy of the detecting system reaches to the demand of practical production process. It can provide a new method of high speed and high accuracy online detecting for roller wear.
NASA Astrophysics Data System (ADS)
Chen, Chun-Jen; Wu, Wen-Hong; Huang, Kuo-Cheng
2009-08-01
A multi-function lens test instrument is report in this paper. This system can evaluate the image resolution, image quality, depth of field, image distortion and light intensity distribution of the tested lens by changing the tested patterns. This system consists of a tested lens, a CCD camera, a linear motorized stage, a system fixture, an observer LCD monitor, and a notebook for pattern providing. The LCD monitor displays a serious of specified tested patterns sent by the notebook. Then each displayed pattern goes through the tested lens and images in the CCD camera sensor. Consequently, the system can evaluate the performance of the tested lens by analyzing the image of CCD camera with special designed software. The major advantage of this system is that it can complete whole test quickly without interruption due to part replacement, because the tested patterns are statically displayed on monitor and controlled by the notebook.
Kim, Yeomyung
2017-01-01
Objective We developed a new chest compression depth (CCD) measuring technology using radar and impulse-radio ultra-wideband (IR-UWB) sensor. This study was performed to determine its accuracy on a soft surface. Methods Four trials, trial 1: chest compressions on the floor using an accelerometer device; trial 2: chest compressions on the floor using an IR-UWB sensor; trial 3: chest compressions on a foam mattress using an accelerometer device; trial 4: chest compressions on a foam mattress using an IR-UWB sensor, were performed in a random order. In all the trials, a cardiopulmonary resuscitation provider delivered 50 uninterrupted chest compressions to a manikin. Results The CCD measured by the manikin and the device were as follows: 57.42 ± 2.23 and 53.92 ± 2.92 mm, respectively in trial 1 (p < 0.001); 56.29 ± 1.96 and 54.16 ± 3.90 mm, respectively in trial 2 (p < 0.001); 55.61 ± 1.57 and 103.48 ± 10.48 mm, respectively in trial 3 (p < 0.001); 57.14 ± 3.99 and 55.51 ± 3.39 mm, respectively in trial 4 (p = 0.012). The gaps between the CCD measured by the manikin and the devices (accelerometer device vs. IR-UWB sensor) on the floor were not different (3.50 ± 2.08 mm vs. 3.15 ± 2.27 mm, respectively, p = 0.136). However, the gaps were significantly different on the foam mattress (48.53 ± 5.65 mm vs. 4.10 ± 2.47 mm, p < 0.001). Conclusion The IR-UWB sensor could measure the CCD accurately both on the floor and on the foam mattress. PMID:28854262
Yu, Byung Gyu; Oh, Je Hyeok; Kim, Yeomyung; Kim, Tae Wook
2017-01-01
We developed a new chest compression depth (CCD) measuring technology using radar and impulse-radio ultra-wideband (IR-UWB) sensor. This study was performed to determine its accuracy on a soft surface. Four trials, trial 1: chest compressions on the floor using an accelerometer device; trial 2: chest compressions on the floor using an IR-UWB sensor; trial 3: chest compressions on a foam mattress using an accelerometer device; trial 4: chest compressions on a foam mattress using an IR-UWB sensor, were performed in a random order. In all the trials, a cardiopulmonary resuscitation provider delivered 50 uninterrupted chest compressions to a manikin. The CCD measured by the manikin and the device were as follows: 57.42 ± 2.23 and 53.92 ± 2.92 mm, respectively in trial 1 (p < 0.001); 56.29 ± 1.96 and 54.16 ± 3.90 mm, respectively in trial 2 (p < 0.001); 55.61 ± 1.57 and 103.48 ± 10.48 mm, respectively in trial 3 (p < 0.001); 57.14 ± 3.99 and 55.51 ± 3.39 mm, respectively in trial 4 (p = 0.012). The gaps between the CCD measured by the manikin and the devices (accelerometer device vs. IR-UWB sensor) on the floor were not different (3.50 ± 2.08 mm vs. 3.15 ± 2.27 mm, respectively, p = 0.136). However, the gaps were significantly different on the foam mattress (48.53 ± 5.65 mm vs. 4.10 ± 2.47 mm, p < 0.001). The IR-UWB sensor could measure the CCD accurately both on the floor and on the foam mattress.
Earth elevation map production and high resolution sensing camera imaging analysis
NASA Astrophysics Data System (ADS)
Yang, Xiubin; Jin, Guang; Jiang, Li; Dai, Lu; Xu, Kai
2010-11-01
The Earth's digital elevation which impacts space camera imaging has prepared and imaging has analysed. Based on matching error that TDI CCD integral series request of the speed of image motion, statistical experimental methods-Monte Carlo method is used to calculate the distribution histogram of Earth's elevation in image motion compensated model which includes satellite attitude changes, orbital angular rate changes, latitude, longitude and the orbital inclination changes. And then, elevation information of the earth's surface from SRTM is read. Earth elevation map which produced for aerospace electronic cameras is compressed and spliced. It can get elevation data from flash according to the shooting point of latitude and longitude. If elevation data between two data, the ways of searching data uses linear interpolation. Linear interpolation can better meet the rugged mountains and hills changing requests. At last, the deviant framework and camera controller are used to test the character of deviant angle errors, TDI CCD camera simulation system with the material point corresponding to imaging point model is used to analyze the imaging's MTF and mutual correlation similarity measure, simulation system use adding cumulation which TDI CCD imaging exceeded the corresponding pixel horizontal and vertical offset to simulate camera imaging when stability of satellite attitude changes. This process is practicality. It can effectively control the camera memory space, and meet a very good precision TDI CCD camera in the request matches the speed of image motion and imaging.
Heat dissipation schemes in QCLs monitored by CCD thermoreflectance (Conference Presentation)
NASA Astrophysics Data System (ADS)
Pierscinski, Kamil; Pierścińska, Dorota; Morawiec, Magdalena; Gutowski, Piotr; Karbownik, Piotr; Serebrennikova, Olga; Bugajski, Maciej
2017-02-01
In this paper we present the development of the instrumentation for accurate evaluation of the thermal characteristics of quantum cascade lasers based on CCD thermoreflectance (CCD TR). This method allows rapid thermal characterization of QCLs, as the registration of high-resolution map of the whole device facet lasts only several seconds. The capabilities of the CCD TR are used to study temperature dissipation schemes in different designs of QCLs. We report on the investigation of thermal performance of QCLs developed at the Institute of Electron Technology, with an emphasis on the influence of different material system, processing technology and device designs. We investigate and compare AlInAs/InGaAs/InP QCLs (lattice matched and strain compensated) of different architectures, i.e., double trench and buried heterostructure (BH) in terms of thermal management. Experimental results are in very good agreement with numerical predictions of heat dissipation in various device constructions. Numerical model is based on FEM model solved by commercial software package. The model assumes anisotropic thermal conductivity in the AR layers as well as the temperature dependence of thermal conductivities of all materials in the project. We have observed experimentally improvement of thermal properties of devices based on InP materials, especially for buried heterostructure type. The use of buried heterostructure enhanced the lateral heat dissipation from the active region of QCLs. The BH structure and epilayer-down bonding help dissipate the heat generated from active core of the QCL.
NASA Astrophysics Data System (ADS)
Wei, Hui; Gong, Guanghong; Li, Ni
2017-10-01
Computer-generated hologram (CGH) is a promising 3D display technology while it is challenged by heavy computation load and vast memory requirement. To solve these problems, a depth compensating CGH calculation method based on symmetry and similarity of zone plates is proposed and implemented on graphics processing unit (GPU). An improved LUT method is put forward to compute the distances between object points and hologram pixels in the XY direction. The concept of depth compensating factor is defined and used for calculating the holograms of points with different depth positions instead of layer-based methods. The proposed method is suitable for arbitrary sampling objects with lower memory usage and higher computational efficiency compared to other CGH methods. The effectiveness of the proposed method is validated by numerical and optical experiments.
Western Aphrodite Terra, tectonics, geology, and line-of-sight gravity
NASA Technical Reports Server (NTRS)
Hays, John E.; Morgan, Paul
1992-01-01
Aphrodite Terra is the largest area of high-standing topography on Venus, and isostatic considerations strongly suggest that this high topography is supported at least in part by thickened crust. Previous studies of line-of-sight gravity data from the Pioneer Venus Orbiter indicate rapidly changing apparent depths of compensation across Aphrodite Terra. Magellan imaging data provide the first detailed images of this region, and we are mapping the region along Pioneer Venus orbit 440 to investigate whether the changing apparent depths of compensation correlate with changes in surficial tectonics. Preliminary mapping of geological features on Magellan images along the path of Pioneer Venus orbit 440 do not indicate a first-order correlation among surface features and changes in the apparent depth of compensation of line-of-sight gravity data. The apparent depth of compensation appears to be most variable in regions dominated by tessera, but not all areas of tessera have distinct gravity signatures. There is a weak correlation among areas in which impact craters are relatively common and areas in which the observed and predicted gravity anomalies are poorly correlated.
Optical registration of spaceborne low light remote sensing camera
NASA Astrophysics Data System (ADS)
Li, Chong-yang; Hao, Yan-hui; Xu, Peng-mei; Wang, Dong-jie; Ma, Li-na; Zhao, Ying-long
2018-02-01
For the high precision requirement of spaceborne low light remote sensing camera optical registration, optical registration of dual channel for CCD and EMCCD is achieved by the high magnification optical registration system. System integration optical registration and accuracy of optical registration scheme for spaceborne low light remote sensing camera with short focal depth and wide field of view is proposed in this paper. It also includes analysis of parallel misalignment of CCD and accuracy of optical registration. Actual registration results show that imaging clearly, MTF and accuracy of optical registration meet requirements, it provide important guarantee to get high quality image data in orbit.
PN-CCD camera for XMM: performance of high time resolution/bright source operating modes
NASA Astrophysics Data System (ADS)
Kendziorra, Eckhard; Bihler, Edgar; Grubmiller, Willy; Kretschmar, Baerbel; Kuster, Markus; Pflueger, Bernhard; Staubert, Ruediger; Braeuninger, Heinrich W.; Briel, Ulrich G.; Meidinger, Norbert; Pfeffermann, Elmar; Reppin, Claus; Stoetter, Diana; Strueder, Lothar; Holl, Peter; Kemmer, Josef; Soltau, Heike; von Zanthier, Christoph
1997-10-01
The pn-CCD camera is developed as one of the focal plane instruments for the European photon imaging camera (EPIC) on board the x-ray multi mirror (XMM) mission to be launched in 1999. The detector consists of four quadrants of three pn-CCDs each, which are integrated on one silicon wafer. Each CCD has 200 by 64 pixels (150 micrometer by 150 micrometers) with 280 micrometers depletion depth. One CCD of a quadrant is read out at a time, while the four quadrants can be processed independently of each other. In standard imaging mode the CCDs are read out sequentially every 70 ms. Observations of point sources brighter than 1 mCrab will be effected by photon pile- up. However, special operating modes can be used to observe bright sources up to 150 mCrab in timing mode with 30 microseconds time resolution and very bright sources up to several crab in burst mode with 7 microseconds time resolution. We have tested one quadrant of the EPIC pn-CCD camera at line energies from 0.52 keV to 17.4 keV at the long beam test facility Panter in the focus of the qualification mirror module for XMM. In order to test the time resolution of the system, a mechanical chopper was used to periodically modulate the beam intensity. Pulse periods down to 0.7 ms were generated. This paper describes the performance of the pn-CCD detector in timing and burst readout modes with special emphasis on energy and time resolution.
Laser focus compensating sensing and imaging device
Vann, Charles S.
1993-01-01
A laser focus compensating sensing and imaging device permits the focus of a single focal point of different frequency laser beams emanating from the same source point. In particular it allows the focusing of laser beam originating from the same laser device but having differing intensities so that a low intensity beam will not convert to a higher frequency when passing through a conversion crystal associated with the laser generating device. The laser focus compensating sensing and imaging device uses a cassegrain system to fold the lower frequency, low intensity beam back upon itself so that it will focus at the same focal point as a high intensity beam. An angular tilt compensating lens is mounted about the secondary mirror of the cassegrain system to assist in alignment. In addition cameras or CCD's are mounted with the primary mirror to sense the focused image. A convex lens is positioned co-axial with the cassegrain system on the side of the primary mirror distal of the secondary for use in aligning a target with the laser beam. A first alternate embodiment includes a cassegrain system using a series of shutters and an internally mounted dichroic mirror. A second alternate embodiment uses two laser focus compensating sensing and imaging devices for aligning a moving tool with a work piece.
Laser focus compensating sensing and imaging device
Vann, C.S.
1993-08-31
A laser focus compensating sensing and imaging device permits the focus of a single focal point of different frequency laser beams emanating from the same source point. In particular it allows the focusing of laser beam originating from the same laser device but having differing intensities so that a low intensity beam will not convert to a higher frequency when passing through a conversion crystal associated with the laser generating device. The laser focus compensating sensing and imaging device uses a Cassegrain system to fold the lower frequency, low intensity beam back upon itself so that it will focus at the same focal point as a high intensity beam. An angular tilt compensating lens is mounted about the secondary mirror of the Cassegrain system to assist in alignment. In addition cameras or CCD's are mounted with the primary mirror to sense the focused image. A convex lens is positioned co-axial with the Cassegrain system on the side of the primary mirror distal of the secondary for use in aligning a target with the laser beam. A first alternate embodiment includes a Cassegrain system using a series of shutters and an internally mounted dichroic mirror. A second alternate embodiment uses two laser focus compensating sensing and imaging devices for aligning a moving tool with a work piece.
NASA Astrophysics Data System (ADS)
Schedler, Johannes
As astrophotographers we are living in a golden age. In recent years CCD technology and the quality of amateur telescopes have reached a level of perfection, giving amateurs the chance to produce images rivaling those taken from mountaintops by large professional systems as recently as two decades ago. However hardware and good imaging location is only a part of the game. A high level of skill with image processing can offer amateurs an edge and provide a chance to compensate for the limited aperture of our telescopes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Saotome, N; Furukawa, T; Mizushima, K
2016-06-15
Purpose: To investigate the time structure of the range, we have verified the rang shift due to the betatron tune shift with several synchrotron parameters. Methods: A cylindrical plastic scintillator block and a CCD camera were installed on the black box. Using image processing, the range was determined the 80 percent of distal dose of the depth light distribution. The root mean square error of the range measurement using the scintillator and CCD system is about 0.2 mm. Range measurement was performed at interval of 170 msec. The chromaticity of the synchrotron was changed in the range of plus ormore » minus 1% from reference chromaticity in this study. All of the particle inside the synchrotron ring were extracted with the output beam intensity 1.8×10{sup 8} and 5.0×10{sub 7} particle per sec. Results: The time strictures of the range were changed by changing of the chromaticity. The reproducibility of the measurement was sufficient to observe the time structures of the range. The range shift was depending on the number of the residual particle inside the synchrotron ring. Conclusion: In slow beam extraction for scanned carbon-ion therapy, the range shift is undesirable because it causes the dose uncertainty in the target. We introduced the time-resolved range measurement using scintillator and CCD system. The scintillator and CCD system have enabled to verify the range shift with sufficient spatial resolution and reproducibility.« less
Isostatic GOCE Moho model for Iran
NASA Astrophysics Data System (ADS)
Eshagh, Mehdi; Ebadi, Sahar; Tenzer, Robert
2017-05-01
One of the major issues associated with a regional Moho recovery from the gravity or gravity-gradient data is the optimal choice of the mean compensation depth (i.e., the mean Moho depth) for a certain area of study, typically for orogens characterised by large Moho depth variations. In case of selecting a small value of the mean compensation depth, the pattern of deep Moho structure might not be reproduced realistically. Moreover, the definition of the mean compensation depth in existing isostatic models affects only low-degrees of the Moho spectrum. To overcome this problem, in this study we reformulate the Sjöberg and Jeffrey's methods of solving the Vening-Meinesz isostatic problem so that the mean compensation depth contributes to the whole Moho spectrum. Both solutions are then defined for the vertical gravity gradient, allowing estimating the Moho depth from the GOCE satellite gravity-gradiometry data. Moreover, gravimetric solutions provide realistic results only when a priori information on the crust and upper mantle structure is known (usually from seismic surveys) with a relatively good accuracy. To investigate this aspect, we formulate our gravimetric solutions for a variable Moho density contrast to account for variable density of the uppermost mantle below the Moho interface, while taking into consideration also density variations within the sediments and consolidated crust down to the Moho interface. The developed theoretical models are applied to estimate the Moho depth from GOCE data at the regional study area of the Iranian tectonic block, including also parts of surrounding tectonic features. Our results indicate that the regional Moho depth differences between Sjöberg and Jeffrey's solutions, reaching up to about 3 km, are caused by a smoothing effect of Sjöberg's method. The validation of our results further shows a relatively good agreement with regional seismic studies over most of the continental crust, but large discrepancies are detected under the Oman Sea and the Makran subduction zone. We explain these discrepancies by a low quality of seismic data offshore.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, M; Suh, T; Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul
2015-06-15
Purpose: To develop and validate an innovative method of using depth sensing cameras and 3D printing techniques for Total Body Irradiation (TBI) treatment planning and compensator fabrication. Methods: A tablet with motion tracking cameras and integrated depth sensing was used to scan a RANDOTM phantom arranged in a TBI treatment booth to detect and store the 3D surface in a point cloud (PC) format. The accuracy of the detected surface was evaluated by comparison to extracted measurements from CT scan images. The thickness, source to surface distance and off-axis distance of the phantom at different body section was measured formore » TBI treatment planning. A 2D map containing a detailed compensator design was calculated to achieve uniform dose distribution throughout the phantom. The compensator was fabricated using a 3D printer, silicone molding and tungsten powder. In vivo dosimetry measurements were performed using optically stimulated luminescent detectors (OSLDs). Results: The whole scan of the anthropomorphic phantom took approximately 30 seconds. The mean error for thickness measurements at each section of phantom compare to CT was 0.44 ± 0.268 cm. These errors resulted in approximately 2% dose error calculation and 0.4 mm tungsten thickness deviation for the compensator design. The accuracy of 3D compensator printing was within 0.2 mm. In vivo measurements for an end-to-end test showed the overall dose difference was within 3%. Conclusion: Motion cameras and depth sensing techniques proved to be an accurate and efficient tool for TBI patient measurement and treatment planning. 3D printing technique improved the efficiency and accuracy of the compensator production and ensured a more accurate treatment delivery.« less
Lee, Min-Young; Han, Bin; Jenkins, Cesare; Xing, Lei; Suh, Tae-Suk
2016-01-01
Purpose: The purpose of total body irradiation (TBI) techniques is to deliver a uniform radiation dose to the entire volume of a patient’s body. Due to variations in the thickness of the patient, it is difficult to produce such a uniform dose distribution throughout the body. In many techniques, a compensator is used to adjust the dose delivered to various sections of the patient. The current study aims to develop and validate an innovative method of using depth-sensing cameras and 3D printing techniques for TBI treatment planning and compensator fabrication. Methods: A tablet with an integrated depth-sensing camera and motion tracking sensors was used to scan a RANDO™ phantom positioned in a TBI treatment booth to detect and store the 3D surface in a point cloud format. The accuracy of the detected surface was evaluated by comparing extracted body thickness measurements with corresponding measurements from computed tomography (CT) scan images. The thickness, source to surface distance, and off-axis distance of the phantom at different body section were measured for TBI treatment planning. A detailed compensator design was calculated to achieve a uniform dose distribution throughout the phantom. The compensator was fabricated using a 3D printer, silicone molding, and a mixture of wax and tungsten powder. In vivo dosimetry measurements were performed using optically stimulated luminescent detectors. Results: The scan of the phantom took approximately 30 s. The mean error for thickness measurements at each section of phantom relative to CT was 0.48 ± 0.27 cm. The average fabrication error for the 3D-printed compensator was 0.16 ± 0.15 mm. In vivo measurements for an end-to-end test showed that overall dose differences were within 5%. Conclusions: A technique for planning and fabricating a compensator for TBI treatment using a depth camera equipped tablet and a 3D printer was demonstrated to be sufficiently accurate to be considered for further investigation. PMID:27806603
NASA Astrophysics Data System (ADS)
Dicus, C. M.; Snyder, G. T.; Dickens, G. R.
2004-12-01
Site 1230 of the Ocean Drilling Program targeted the chemistry and microbiology of an active deep-water gas hydrate system in the Peru Trench. The site is noteworthy because, at nearly 6000 m water depth, it lies well below the carbonate compensation depth and the sediments comprise mostly terrigenous clays and biogenic silica. Shipboard work at this site delineated a prominent sulfate-methane transition (SMT) at 8-10 m below seafloor (mbsf) as well as some carbonate horizons. In this study, we present calcium and strontium data for pore waters and sediments at this site, including across the SMT. Concentration profiles show that dissolved Ca2+ diffuses downward from the seafloor toward the SMT, where a sharp inflection indicates consumption of Ca2+ into an authigenic phase. Dissolved Sr2+, on the other hand, diffuses upward from depth toward the SMT. Again, however, a prominent inflection suggests removal of Sr2+ to sediment. The inferences from pore water profiles are borne out by sediment chemistry. Large peaks in the calcium and strontium content of sediment mark the SMT. The calcium and strontium fronts reach ˜2700 and ˜5 mmol/kg, respectively, at 9 mbsf, which are much greater than average background values of ˜10 and ˜1 mmol/kg. These authigenic fronts are primarily composed of carbonate minerals, as determined by acetic acid extractions and x-ray diffraction. Because the calcium and strontium fronts coincide with both the SMT and changes in dissolved chemistry, it is proposed that the carbonates are currently forming as follows: methane rising from the underlying gas hydrate system reacts with dissolved sulfate through anaerobic oxidation of methane which releases HCO3- and alkalinity and causes carbonate precipitation. The overall process has been observed elsewhere; the Peru Trench is interesting, however, because the process leads to carbonate in sediments otherwise devoid of carbonate.
Design of automatic leveling and centering system of theodolite
NASA Astrophysics Data System (ADS)
Liu, Chun-tong; He, Zhen-Xin; Huang, Xian-xiang; Zhan, Ying
2012-09-01
To realize the theodolite automation and improve the azimuth Angle measurement instrument, the theodolite automatic leveling and centering system with the function of leveling error compensation is designed, which includes the system solution, key components selection, the mechanical structure of leveling and centering, and system software solution. The redesigned leveling feet are driven by the DC servo motor; and the electronic control center device is installed. Using high precision of tilt sensors as horizontal skew detection sensors ensures the effectiveness of the leveling error compensation. Aiming round mark center is located using digital image processing through surface array CCD; and leveling measurement precision can reach the pixel level, which makes the theodolite accurate centering possible. Finally, experiments are conducted using the automatic leveling and centering system of the theodolite. The results show the leveling and centering system can realize automatic operation with high centering accuracy of 0.04mm.The measurement precision of the orientation angle after leveling error compensation is improved, compared with that of in the traditional method. Automatic leveling and centering system of theodolite can satisfy the requirements of the measuring precision and its automation.
Adaptive optics system for the IRSOL solar observatory
NASA Astrophysics Data System (ADS)
Ramelli, Renzo; Bucher, Roberto; Rossini, Leopoldo; Bianda, Michele; Balemi, Silvano
2010-07-01
We present a low cost adaptive optics system developed for the solar observatory at Istituto Ricerche Solari Locarno (IRSOL), Switzerland. The Shack-Hartmann Wavefront Sensor is based on a Dalsa CCD camera with 256 pixels × 256 pixels working at 1kHz. The wavefront compensation is obtained by a deformable mirror with 37 actuators and a Tip-Tilt mirror. A real time control software has been developed on a RTAI-Linux PC. Scicos/Scilab based software has been realized for an online analysis of the system behavior. The software is completely open source.
Manipulating Digital Holograms to Modify Phase of Reconstructed Wavefronts
NASA Astrophysics Data System (ADS)
Ferraro, Pietro; Paturzo, Melania; Memmolo, Pasquale; Finizio, Andrea
2010-04-01
We show that through an adaptive deformation of digital holograms it is possible to manage the depth of focus in the numerical reconstruction. Deformation is applied to the original hologram with the aim to put simultaneously in-focus, and in one reconstructed image plane, different objects lying at different distance from the hologram plane (i.e. CCD sensor), but in the same field of view. In the same way it is possible to extend the depth of field for 3D object having a tilted object whole in-focus.
Research on automatic Hartmann test of membrane mirror
NASA Astrophysics Data System (ADS)
Zhong, Xing; Jin, Guang; Liu, Chunyu; Zhang, Peng
2010-10-01
Electrostatic membrane mirror is ultra-lightweight and easy to acquire a large diameter comparing with traditional optical elements, so its development and usage is the trend of future large mirrors. In order to research the control method of the static stretching membrane mirror, the surface configuration must be tested. However, membrane mirror's shape is always changed by variable voltages on the electrodes, and the optical properties of membrane materials using in our experiment are poor, so it is difficult to test membrane mirror by interferometer and null compensator method. To solve this problem, an automatic optical test procedure for membrane mirror is designed based on Hartmann screen method. The optical path includes point light source, CCD camera, splitter and diffuse transmittance screen. The spots' positions on the diffuse transmittance screen are pictured by CCD camera connected with computer, and image segmentation and centroid solving is auto processed. The CCD camera's lens distortion is measured, and fixing coefficients are given to eliminate the spots' positions recording error caused by lens distortion. To process the low sampling Hartmann test results, Zernike polynomial fitting method is applied to smooth the wave front. So low frequency error of the membrane mirror can be measured then. Errors affecting the test accuracy are also analyzed in this paper. The method proposed in this paper provides a reference for surface shape detection in membrane mirror research.
The Brunhes/Matuyama polarity transition recorded as Be-10 flux changes in deep-sea sediments
NASA Astrophysics Data System (ADS)
Suganuma, Y.; Yokoyama, Y.; Yamazaki, T.
2008-12-01
Fluxes of meteoric cosmogenic radionuclide, Be-10, is thought to be varied due to changes of incoming comic-ray flux modulated by geomagnetic field intensity variation. Enhanced production rate of the nuclides during a geomagnetic polarity transition period is expected as a result of the low dipole field strength. We therefore measured Be-10 concentrations in deep-sea sediments including the Brunhes/Matuyama geomagnetic polarity transition to reconstruct the detailed structures of the geomagnetic field behavior. A piston core, MD982187 was taken from the West Caroline Basin, the western equatorial Pacific Ocean, during the IMAGES IV campaign. The water depth of the site of MD982187 core is about 4600 m, which is close to the carbonate compensation depth (CCD) in this area at present (Berger et al., 1976). Measurement of Be-10 was conducted using the accelerator mass spectrometry (AMS) of the University of Tokyo, Japan. The result shows significant increase of Be-10 concentration during the polarity transition, indicating that the geomagnetic field intensity was low during this interval. In detail, well-defined double highs of Be-10 concentration are recognized. These highs are thought to correspond to the B/M polarity boundary and the "precursor" event, 15 kyr before the M/B boundary (e.g., Hartl and Tauxe, 1996; Singer et al., 2005), respectively. This feature is very similar to the relative paleointensity record of MR982187 core by Yamazaki and Oda (2005) and other published relative paleointensity records of the Brunhes/Matuyama geomagnetic polarity transition, indicating that Be-10 concentration of the deep-sea sedimentary sequence well records the variation of the geomagnetic field intensity. However, ca. 18 cm of clear depth offset between the Be-10 concentration and the relative paleointensity record was observed from the same sedimentary sequence of MR982187 core. This indicates that the relative paleointensity record of MR982187 core is offset by ca. 18 cm below the actual level of the polarity transition, which is thought to be the paleomagnetic lock-in depth effect.
Rolling Shutter Effect aberration compensation in Digital Holographic Microscopy
NASA Astrophysics Data System (ADS)
Monaldi, Andrea C.; Romero, Gladis G.; Cabrera, Carlos M.; Blanc, Adriana V.; Alanís, Elvio E.
2016-05-01
Due to the sequential-readout nature of most CMOS sensors, each row of the sensor array is exposed at a different time, resulting in the so-called rolling shutter effect that induces geometric distortion to the image if the video camera or the object moves during image acquisition. Particularly in digital holograms recording, while the sensor captures progressively each row of the hologram, interferometric fringes can oscillate due to external vibrations and/or noises even when the object under study remains motionless. The sensor records each hologram row in different instants of these disturbances. As a final effect, phase information is corrupted, distorting the reconstructed holograms quality. We present a fast and simple method for compensating this effect based on image processing tools. The method is exemplified by holograms of microscopic biological static objects. Results encourage incorporating CMOS sensors over CCD in Digital Holographic Microscopy due to a better resolution and less expensive benefits.
NASA Astrophysics Data System (ADS)
Wu, L.; San Segundo Bello, D.; Coppejans, P.; Craninckx, J.; Wambacq, P.; Borremans, J.
2017-02-01
This paper presents a 20 Mfps 32 × 84 pixels CMOS burst-mode imager featuring high frame depth with a passive in-pixel amplifier. Compared to the CCD alternatives, CMOS burst-mode imagers are attractive for their low power consumption and integration of circuitry such as ADCs. Due to storage capacitor size and its noise limitations, CMOS burst-mode imagers usually suffer from a lower frame depth than CCD implementations. In order to capture fast transitions over a longer time span, an in-pixel CDS technique has been adopted to reduce the required memory cells for each frame by half. Moreover, integrated with in-pixel CDS, an in-pixel NMOS-only passive amplifier alleviates the kTC noise requirements of the memory bank allowing the usage of smaller capacitors. Specifically, a dense 108-cell MOS memory bank (10fF/cell) has been implemented inside a 30μm pitch pixel, with an area of 25 × 30μm2 occupied by the memory bank. There is an improvement of about 4x in terms of frame depth per pixel area by applying in-pixel CDS and amplification. With the amplifier's gain of 3.3, an FD input-referred RMS noise of 1mV is achieved at 20 Mfps operation. While the amplification is done without burning DC current, including the pixel source follower biasing, the full pixel consumes 10μA at 3.3V supply voltage at full speed. The chip has been fabricated in imec's 130nm CMOS CIS technology.
De, Abhijit; Gambhir, Sanjiv Sam
2005-12-01
This study demonstrates a significant advancement of imaging of a distance-dependent physical process, known as the bioluminescent resonance energy transfer (BRET2) signal in living subjects, by using a cooled charge-coupled device (CCD) camera. A CCD camera-based spectral imaging strategy enables simultaneous visualization and quantitation of BRET signal from live cells and cells implanted in living mice. We used the BRET2 system, which utilizes Renilla luciferase (hRluc) protein and its substrate DeepBlueC (DBC) as an energy donor and a mutant green fluorescent protein (GFP2) as the acceptor. To accomplish this objective in this proof-of-principle study, the donor and acceptor proteins were fused to FKBP12 and FRB, respectively, which are known to interact only in the presence of the small molecule mediator rapamycin. Mammalian cells expressing these fusion constructs were imaged using a cooled-CCD camera either directly from culture dishes or by implanting them into mice. By comparing the emission photon yields in the presence and absence of rapamycin, the specific BRET signal was determined. The CCD imaging approach of BRET signal is particularly appealing due to its capacity to seamlessly bridge the gap between in vitro and in vivo studies. This work validates BRET as a powerful tool for interrogating and observing protein-protein interactions directly at limited depths in living mice.
Active depth-guiding handheld micro-forceps for membranectomy based on CP-SSOCT
NASA Astrophysics Data System (ADS)
Cheon, Gyeong Woo; Lee, Phillip; Gonenc, Berk; Gehlbach, Peter L.; Kang, Jin U.
2016-03-01
In this study, we demonstrate a handheld motion-compensated micro-forceps system using common-path swept source optical coherence tomography with highly accurate depth-targeting and depth-locking for Epiretinal Membrane Peeling. Two motors and a touch sensor were used to separate the two independent motions: motion compensation and tool-tip manipulation. A smart motion monitoring and guiding algorithm was devised for precise and intuitive freehand control. Ex-vivo bovine eye experiments were performed to evaluate accuracy in a bovine retina retinal membrane peeling model. The evaluation demonstrates system capabilities of 40 um accuracy when peeling the epithelial layer of bovine retina.
Lee, Sangyoon; Hu, Xinda; Hua, Hong
2016-05-01
Many error sources have been explored in regards to the depth perception problem in augmented reality environments using optical see-through head-mounted displays (OST-HMDs). Nonetheless, two error sources are commonly neglected: the ray-shift phenomenon and the change in interpupillary distance (IPD). The first source of error arises from the difference in refraction for virtual and see-through optical paths caused by an optical combiner, which is required of OST-HMDs. The second occurs from the change in the viewer's IPD due to eye convergence. In this paper, we analyze the effects of these two error sources on near-field depth perception and propose methods to compensate for these two types of errors. Furthermore, we investigate their effectiveness through an experiment comparing the conditions with and without our error compensation methods applied. In our experiment, participants estimated the egocentric depth of a virtual and a physical object located at seven different near-field distances (40∼200 cm) using a perceptual matching task. Although the experimental results showed different patterns depending on the target distance, the results demonstrated that the near-field depth perception error can be effectively reduced to a very small level (at most 1 percent error) by compensating for the two mentioned error sources.
NASA Astrophysics Data System (ADS)
Brubaker, Timothy R.; Ishikawa, Kenji; Takeda, Keigo; Oh, Jun-Seok; Kondo, Hiroki; Hashizume, Hiroshi; Tanaka, Hiromasa; Knecht, Sean D.; Bilén, Sven G.; Hori, Masaru
2017-12-01
The liquid-phase chemical kinetics of a cell culture basal medium during treatment by an argon-fed, non-equilibrium atmospheric-pressure plasma source were investigated using real-time ultraviolet absorption spectroscopy and colorimetric assays. Depth- and time-resolved NO2- and NO3- concentrations were strongly inhomogeneous and primarily driven by convection during and after plasma-liquid interactions. H2O2 concentrations determined from deconvolved optical depth spectra were found to compensate for the optical depth spectra of excluded reactive species and changes in dissolved gas content. Plasma-activated media remained weakly basic due to NaHCO3 buffering, preventing the H+-catalyzed decomposition of NO2- seen in acidic plasma-activated water. An initial increase in pH may indicate CO2 sparging. Furthermore, the pH-dependency of UV optical depth spectra illustrated the need for pH compensation in the fitting of optical depth data.
GSC 4232.2850, a new eclipsing binary with elliptical orbit
NASA Astrophysics Data System (ADS)
Goranskij, V.; Shugarov, S.; Kroll, P.; Golovin, A.
2005-04-01
GSC 4232.2830 (20h 01m 28s.407, +61? 10' 17".18, 2000.0, v=12m.1) was suspected to be an eclipsing binary by VPG in the routine overview of photographical plates taken with 40-cm astrograph of SAI Crimean station. To define orbital elements of the binary, we searched for observations in Sonneberg Observatory plate collection, NSVS database (Wozniak et al., 2004), and carried out visual monitoring with a small telescope equipped with an electronic image tube, an analogue of a night vision device. Later, when we had found a preliminary solution, we carried out accurate CCD photometry to improve the orbital elements. We should note, that the depths of eclipses in the NSVS database do not exceed 0m.2, what contradicts to other observations. We suppose that NSVS measurements concern to integral light of two stars, a variable star, and a nearby brighter star, GSC 4232.2395, due to low resolution of this survey, 72". Using all the available observations we found the single orbital solution with an elliptical orbit and the period of 11,6 day. The center of the secondary minimum occurs at the orbital phase 0.69835 or 8.1 day after the primary minimum. The improved ephemeris derived using accurate CCD observations is following: HJD Min I = 2453278,3185(2) + 11.628188 (5) x E. O-C analysis does not show orbital period variations during the time interval of observations, or any evidence of apsidal motion. The observations show that both eclipses have about equal depth 0m.60, but essentially different duration, 0p.028 (7 h.8) for Min I, and 0 p.0175 (4 h.9) for Min II. The eclipses are partial. CCD photometry gives mean colors U-B = -0 m.06, B-V = 0 m.57, and V-R = 0 m.50 without notable color variations in the eclipse phases. Old Sonneberg photographic observations indicate that the eclipses were shallower in the middle of the past century than in the present time! Such contradictions may suggest that the depth of eclipses varied, as in the well-known system SSLac (Mossakovskaja, 1993; Milone et al, 2000; Torres and Stefanic, 2001). The eclipse depth variations should be verified with more precise observations taken during the longer time interval.
Research on Hartmann test for progressive addition lenses
NASA Astrophysics Data System (ADS)
Qin, Lin-ling; Yu, Jing-chi
2009-05-01
Recently, in the world some growing-up measurements for Progressive addition lenses and relevant equipments have been developed. They are single point measurement, moiré deflectometry, Ronchi test techniques. Hartmann test for Progressive addition lenses is proposed in the article. The measurement principle of Hartmann test for ophthalmic lenses and the power compensation of off-axis rays are introduced. The experimental setup used to test lenses is put forward. For experimental test, a spatial filter is used for selecting a clean Gaussian beam; a collimating lens with focal distance f =300 mm is used to produce collimated beam. The Hartmann plate with a square array of holes separated at 2 mm is selected. The selection of laser and CCD camera is critical to the accuracy of experiment and the image processing algorithm. The spot patterns from CCD are obtained from the experimental tests. The power distribution map for lenses can be obtained by image processing in theory. The results indicate that Hartmann test for Progressive addition lenses is convenient and feasible; also its structure is simple.
NGS2: a focal plane array upgrade for the GeMS multiple tip-tilt wavefront sensor
NASA Astrophysics Data System (ADS)
Rigaut, François; Price, Ian; d'Orgeville, Céline; Bennet, Francis; Herrald, Nick; Paulin, Nicolas; Uhlendorf, Kristina; Garrel, Vincent; Sivo, Gaetano; Montes, Vanessa; Trujillo, Chad
2016-07-01
NGS2 is an upgrade for the multi-natural guide star tip-tilt & plate scale wavefront sensor for GeMS (Gemini Multi-Conjugate Adaptive Optics system). It uses a single Nüvü HNü-512 Electron-Multiplied CCD array that spans the entire GeMS wavefront sensor focal plane. Multiple small regions-of-interest are used to enable frame rates up to 800Hz. This set up will improve the optical throughput with respect to the current wavefront sensor, as well as streamline acquisition and allow for distortion compensation.
True 3D digital holographic tomography for virtual reality applications
NASA Astrophysics Data System (ADS)
Downham, A.; Abeywickrema, U.; Banerjee, P. P.
2017-09-01
Previously, a single CCD camera has been used to record holograms of an object while the object is rotated about a single axis to reconstruct a pseudo-3D image, which does not show detailed depth information from all perspectives. To generate a true 3D image, the object has to be rotated through multiple angles and along multiple axes. In this work, to reconstruct a true 3D image including depth information, a die is rotated along two orthogonal axes, and holograms are recorded using a Mach-Zehnder setup, which are subsequently numerically reconstructed. This allows for the generation of multiple images containing phase (i.e., depth) information. These images, when combined, create a true 3D image with depth information which can be exported to a Microsoft® HoloLens for true 3D virtual reality.
Roy, Nathalie; Roy, Gilles; Bissonnette, Luc R; Simard, Jean-Robert
2004-05-01
We measure with a gated intensified CCD camera the cross-polarized backscattered light from a linearly polarized laser beam penetrating a cloud made of spherical particles. In accordance with previously published results we observe a clear azimuthal pattern in the recorded images. We show that the pattern is symmetrical, that it originates from second-order scattering, and that higher-order scattering causes blurring that increases with optical depth. We also find that the contrast in the symmetrical features can be related to measurement of the optical depth. Moreover, when the blurring contributions are identified and subtracted, the resulting pattern provides a pure second-order scattering measurement that can be used for retrieval of droplet size.
NASA Astrophysics Data System (ADS)
Geethalekshmi Sreeush, Mohanan; Valsala, Vinu; Pentakota, Sreenivas; Venkata Siva Rama Prasad, Koneru; Murtugudde, Raghu
2018-04-01
Biological modelling approach adopted by the Ocean Carbon-Cycle Model Intercomparison Project (OCMIP-II) provided amazingly simple but surprisingly accurate rendition of the annual mean carbon cycle for the global ocean. Nonetheless, OCMIP models are known to have seasonal biases which are typically attributed to their bulk parameterisation of compensation depth. Utilising the criteria of surface Chl a-based attenuation of solar radiation and the minimum solar radiation required for production, we have proposed a new parameterisation for a spatially and temporally varying compensation depth which captures the seasonality in the production zone reasonably well. This new parameterisation is shown to improve the seasonality of CO2 fluxes, surface ocean pCO2, biological export and new production in the major upwelling zones of the Indian Ocean. The seasonally varying compensation depth enriches the nutrient concentration in the upper ocean yielding more faithful biological exports which in turn leads to accurate seasonality in the carbon cycle. The export production strengthens by ˜ 70 % over the western Arabian Sea during the monsoon period and achieves a good balance between export and new production in the model. This underscores the importance of having a seasonal balance in the model export and new productions for a better representation of the seasonality of the carbon cycle over upwelling regions. The study also implies that both the biological and solubility pumps play an important role in the Indian Ocean upwelling zones.
Bottenberg, Peter; Jacquet, Wolfgang; Stachniss, Vitus; Wellnitz, Johann; Schulte, Andreas G
2011-04-01
To determine the ability of digital sensors (CMOS and CCD sensors) and D and F-speed films to detect cavitated and non-cavitated enamel caries lesions at different exposure conditions compared to a gold standard. 100 extracted human molars and premolars were selected and mounted in a block between two neighboring teeth. Sensors or films were exposed with voltages of 60 or 70 kVp at varying times. Three observers assessed each approximal site independently. Lesion depth was rated according to an anatomical five-point scale (0 = no lesion to 4 = lesion reaching inner half of dentin). Serial sections of resin-embedded teeth were prepared. Gold-standard scores were established by consensus based on histological sectioning. A carious lesion was present at scores of 1 and higher. Statistical evaluation (sensitivity, specificity and receiver-operating curves) was based on caries-free surfaces and those presenting enamel caries (n=116). The ROC curves had "area under the curve" values (Az) from 0.50 (F-speed, 70 kVp, 0.20 seconds) to 0.58 (CCD 60 kVp, 0.08 seconds). The detection percentage of cavitated lesions was generally higher (0-52%, depending on technique and observer) than that of non-cavitated lesions (3-32%). The CMOS sensor showed Az values comparable to the CCD sensors but required higher exposure times. There was no significant difference between 60 and 70 kVp.
Characterization and Design of Digital Pointing Subsystem for Optical Communication Demonstrator
NASA Technical Reports Server (NTRS)
Racho, C.; Portillo, A.
1998-01-01
The Optical Communications Demonstrator (OCD) is a laboratory-based lasercom demonstration terminal designed to validate several key technologies, including beacon acquisition, high bandwidth tracking, precision bearn pointing, and point-ahead compensation functions. It has been under active development over the past few years. The instrument uses a CCD array detector for both spatial acquisition and high-bandwidth tracking, and a fiber coupled laser transmitter. The array detector tracking concept provides wide field-of-view acquisition and permits effective platform jitter compensation and point-ahead control using only one steering mirror. This paper describes the detailed design and characterization of the digital control loop system which includes the Fast Steering Mirror (FSM), the CCD image tracker, and the associated electronics. The objective is to improve the overall system performance using laboratory measured data. The. design of the digital control loop is based on a linear time invariant open loop model. The closed loop performance is predicted using the theoretical model. With the digital filter programmed into the OCD control software, data is collected to verify the predictions. This paper presents the results of the, system modeling and performance analysis. It has been shown that measurement data closely matches theoretical predictions. An important part of the laser communication experiment is the ability of FSM to track the laser beacon within the. required tolerances. The pointing must be maintained to an accuracy that is much smaller than the transmit signal beamwidth. For an earth orbit distance, the system must be able to track the receiving station to within a few microradians. The failure. to do so will result in a severely degraded system performance.
Fixed, object-specific intensity compensation for cone beam optical CT radiation dosimetry
NASA Astrophysics Data System (ADS)
Dekker, Kurtis H.; Hazarika, Rubin; Silveira, Matheus A.; Jordan, Kevin J.
2018-03-01
Optical cone beam computed tomography (CT) scanning of radiochromic gel dosimeters, using a CCD camera and a low stray light convergent source, provides fast, truly 3D radiation dosimetry with high accuracy. However, a key limiting factor in radiochromic gel dosimetry at large (⩾10 cm diameter) volumes is the initial attenuation of the dosimeters. It is not unusual to observe a 5–10× difference in signal intensity through the dosimeter center versus through the surrounding medium in pre-irradiation images. Thus, all dosimetric information in a typical experiment is measured within the lower 10%–20% of the camera sensor’s range, and re-use of gels is often not possible due to a lack of transmission. To counteract this, in this note we describe a simple method to create source compensators by printing on transparent films. This technique, which is easily implemented and inexpensive, is an optical analogue to the bowtie filter in x-ray CT. We present transmission images and solution phantom reconstructions to demonstrate that (1) placing compensators beyond the focal zone of the imaging lens prevents high spatial frequency features of the printed films from generating reconstruction artifacts, and (2) object-specific compensation considerably reduces the range of intensities measured in projection images. This will improve the measurable dose range in optical CT dosimetry, and will enable imaging of larger gel volumes (∼15 cm diameter). Additionally, it should enable re-use of dosimeters by printing a new compensator for a second experiment.
Kessler, Terrance J [Mendon, NY; Bunkenburg, Joachim [Victor, NY; Huang, Hu [Pittsford, NY
2007-02-13
A plurality of gratings (G1, G2) are arranged together with a wavefront sensor, actuators, and feedback system to align the gratings in such a manner, that they operate like a single, large, monolithic grating. Sub-wavelength-scale movements in the mechanical mounting, due to environmental influences, are monitored by an interferometer (28), and compensated by precision actuators (16, 18, 20) that maintain the coherently additive mode. The actuators define the grating plane, and are positioned in response to the wavefronts from the gratings and a reference flat, thus producing the interferogram that contains the alignment information. Movement of the actuators is also in response to a diffraction-limited spot on the CCD (36) to which light diffracted from the gratings is focused. The actuator geometry is implemented to take advantage of the compensating nature of the degrees of freedom between gratings, reducing the number of necessary control variables.
Choi, Min; Kim, Hyoung-Ryoul; Lee, Jinwoo; Lee, Hye-Eun; Byun, Junsu; Won, Jong Uk
2014-01-01
The most common occupational disease that is compensated by Industrial Accident Compensation Insurance (IACI) in Korea is musculoskeletal disease (MSD). Although complaints about the workers' compensation system have been raised by injured workers with MSD, studies that examine workers' experiences with the Korean system are rare. This paper is a qualitative study designed to examine injured workers' experiences with the workers' compensation system in Korea. The aim of this study is to explore the drawbacks of the workers' compensation system and to suggest ways to improve this system. All workers from an automobile parts factory in Anseong, GyeongGi province who were compensated for MSD by IACI from January 2003 to August 2013 were invited to participate. Among these 153 workers, 142 workers completed the study. Semi-structured open-ended interviews and questionnaires were administered by occupational physicians. The responses of 131 workers were analyzed after excluding 11 workers, 7 of whom provided incomplete answers and 4 of whom were compensated by accidental injury. Based on their age, disease, department of employment, and compensation time, 16 of these 131 workers were invited to participate in an individual in-depth interview. In-depth interviews were conducted by one of 3 occupational physicians until the interview contents were saturated. Injured workers with MSD reported that the workers' compensation system was intimidating. These workers suffered more emotional distress than physical illness due to the workers' compensation system. Injured workers reported that they were treated inadequately and remained isolated for most of the recuperation period. The compensation period was terminated without ample guidance or a plan for an appropriate rehabilitation process. Interventions to alleviate the negative experiences of injured workers, including quality control of the medical care institutions and provisions for mental and psychological care for injured workers, are needed to help injured workers return to work earlier and more healthy.
Nanometric depth resolution from multi-focal images in microscopy.
Dalgarno, Heather I C; Dalgarno, Paul A; Dada, Adetunmise C; Towers, Catherine E; Gibson, Gavin J; Parton, Richard M; Davis, Ilan; Warburton, Richard J; Greenaway, Alan H
2011-07-06
We describe a method for tracking the position of small features in three dimensions from images recorded on a standard microscope with an inexpensive attachment between the microscope and the camera. The depth-measurement accuracy of this method is tested experimentally on a wide-field, inverted microscope and is shown to give approximately 8 nm depth resolution, over a specimen depth of approximately 6 µm, when using a 12-bit charge-coupled device (CCD) camera and very bright but unresolved particles. To assess low-flux limitations a theoretical model is used to derive an analytical expression for the minimum variance bound. The approximations used in the analytical treatment are tested using numerical simulations. It is concluded that approximately 14 nm depth resolution is achievable with flux levels available when tracking fluorescent sources in three dimensions in live-cell biology and that the method is suitable for three-dimensional photo-activated localization microscopy resolution. Sub-nanometre resolution could be achieved with photon-counting techniques at high flux levels.
Nanometric depth resolution from multi-focal images in microscopy
Dalgarno, Heather I. C.; Dalgarno, Paul A.; Dada, Adetunmise C.; Towers, Catherine E.; Gibson, Gavin J.; Parton, Richard M.; Davis, Ilan; Warburton, Richard J.; Greenaway, Alan H.
2011-01-01
We describe a method for tracking the position of small features in three dimensions from images recorded on a standard microscope with an inexpensive attachment between the microscope and the camera. The depth-measurement accuracy of this method is tested experimentally on a wide-field, inverted microscope and is shown to give approximately 8 nm depth resolution, over a specimen depth of approximately 6 µm, when using a 12-bit charge-coupled device (CCD) camera and very bright but unresolved particles. To assess low-flux limitations a theoretical model is used to derive an analytical expression for the minimum variance bound. The approximations used in the analytical treatment are tested using numerical simulations. It is concluded that approximately 14 nm depth resolution is achievable with flux levels available when tracking fluorescent sources in three dimensions in live-cell biology and that the method is suitable for three-dimensional photo-activated localization microscopy resolution. Sub-nanometre resolution could be achieved with photon-counting techniques at high flux levels. PMID:21247948
Active Wireline Heave Compensation for Ocean Drilling
NASA Astrophysics Data System (ADS)
Goldberg, D.; Liu, T.; Swain, K.; Furman, C.; Iturrino, G. J.
2014-12-01
The up-and-down heave motion of a ship causes a similar motion on any instruments tethered on wireline cable below it. If the amplitude of this motion is greater than a few tens of cm, significant discrepancy in the depth below the ship is introduced, causing uncertainty in the acquired data. Large and irregular cabled motions also increase the risk of damaging tethered instruments, particularly those with relatively delicate sensors. In 2005, Schlumberger and Deep Down, Inc built an active wireline heave compensator (AHC) system for use onboard the JOIDES Resolution to compensate for heave motion on wireline logging tools deployed in scientific drill holes. The goals for the new AHC system were to (1) design a reliable heave compensation system; and (2) devise a robust and quantitative methodology for routine assessment of compensation efficiency (CE) during wireline operations. Software programs were developed to monitor CE and the dynamics of logging tools in real-time, including system performance under variable parameters such as water depth, sea state, cable length, logging speed and direction. We present the CE results from the AHC system on the JOIDES Resolution during a 5-year period of recent IODP operations and compare the results to those from previous compensation systems deployed during ODP and IODP. Based on new data under heave conditions of ±0.2-2.0 m and water depths of 300-4,800 m in open holes, the system reduces 65-80% of downhole tool displacement under stationary conditions and 50-60% during normal logging operations. Moreover, down/up tool motion at low speeds (300-600 m/h) reduces the system's CE values by 15-20%, and logging down at higher speeds (1,000-1,200 m/h) reduces CE values by 55-65%. Furthermore, the system yields slightly lower CE values of 40-50% without tension feedback of the downhole cable while logging. These results indicate that the new system's compensation efficiency is comparable to or better than previous systems, with additional advantages that include upgradable compensation control software and the capability for continued assessment under varying environmental conditions. Future integration of downhole cable dynamics as an input feedback could further improve CE during logging operations.
Comparisons of global topographic/isostatic models to the Earth's observed gravity field
NASA Technical Reports Server (NTRS)
Rummel, Reiner; Rapp, Richard H.; Suenkel, Hans; Tscherning, C. Christian
1988-01-01
The Earth's gravitational potential, as described by a spherical harmonic expansion to degree 180, was compared to the potential implied by the topography and its isostatic compensation using five different hypothesis. Initially, series expressions for the Airy/Heiskanen topographic isostatic model were developed to the third order in terms of (h/R), where h is equivalent rock topography and R is a mean Earth radius. Using actual topographic developments for the Earth, it was found that the second and third terms of the expansion contributed 30 and 3 percents, of the first of the expansion. With these new equations it is possible to compute depths (D) of compensation, by degree, using 3 different criteria. The results show that the average depth implied by criterion I is 60 km while it is about 33 km for criteria 2 and 3 with smaller compensation depths at the higher degrees. Another model examined was related to the Vening-Meinesz regional hypothesis implemented in the spectral domain. Finally, oceanic and continental response functions were derived for the global data sets and comparisons made to locally determined values.
Pi of the Sky full system and the new telescope
NASA Astrophysics Data System (ADS)
Mankiewicz, L.; Batsch, T.; Castro-Tirado, A.; Czyrkowski, H.; Cwiek, A.; Cwiok, M.; Dabrowski, R.; Jelínek, M.; Kasprowicz, G.; Majcher, A.; Majczyna, A.; Malek, K.; Nawrocki, K.; Obara, L.; Opiela, R.; Piotrowski, L. W.; Siudek, M.; Sokolowski, M.; Wawrzaszek, R.; Wrochna, G.; Zaremba, M.; Żarnecki, A. F.
2014-12-01
The Pi of the Sky is a system of wide field of view robotic telescopes, which search for short timescale astrophysical phenomena, especially for prompt optical GRB emission. The system was designed for autonomous operation, monitoring a large fraction of the sky to a depth of 12(m}-13({m)) and with time resolution of the order of 1 - 10 seconds. The system design and observation strategy were successfully tested with a prototype detector operational at Las Campanas Observatory, Chile from 2004-2009 and moved to San Pedro de Atacama Observatory in March 2011. In October 2010 the first unit of the final Pi of the Sky detector system, with 4 CCD cameras, was successfully installed at the INTA El Arenosillo Test Centre in Spain. In July 2013 three more units (12 CCD cameras) were commissioned and installed, together with the first one, on a new platform in INTA, extending sky coverage to about 6000 square degrees.
Reverse engineering of the homogeneous-entity product profiles based on CCD
NASA Astrophysics Data System (ADS)
Gan, Yong; Zhong, Jingru; Sun, Ning; Sun, Aoran
2011-08-01
This measurement system uses delaminated measurement principle, measures the three perpendicular direction values of the entities. When the measured entity is immerged in the liquid layer by layer, every layer's image are collected by CCD and digitally processed. It introduces the basic measuring principle and the working process of the measure method. According to Archimedes law, the related buoyancy and volume that soaked in different layer's depth are measured by electron balance and the mathematics models are established. Through calculating every layer's weight and centre of gravity by computer based on the method of Artificial Intelligence, we can reckon 3D coordinate values of every minute entity cell in different layers and its 3D contour picture is constructed. The experimental results show that for all the homogeneous entity insoluble in water, it can measure them. The measurement velocity is fast and non-destructive test, it can measure the entity with internal hole.
High-performance dual-speed CCD camera system for scientific imaging
NASA Astrophysics Data System (ADS)
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.
NASA Technical Reports Server (NTRS)
Bowin, C.
1982-01-01
A negative free-air gravity anomaly which occurs in the central part of the Philippine Sea was examined to determine the distribution and nature of possible regional mass excesses or deficiencies. Geoid anomalies from GEOS-3 observation were positive. A negative residual geoid anomaly consistent with the area of negative free-air gravity anomalies were found. Theoretical gravity-topography and geoid-topography admittance functions indicated that high density mantle at about 60 km dept could account for the magnitudes of the gravity and residual geoid anomaly and the 1 km residual water depth anomaly in the Philippine Sea. The negative residual depth anomaly may be compensated for by excess density in the uppermost mantle, but the residual geoid and regional free-air gravity anomalies and a slow surface wave velocity structure might result from low-density warm upper mantle material lying beneath the zone of high-density uppermost mantle. From a horizontal disk approximation, the depth of the low-density warm mantle was estimated to be on the order of 200 km.
Tertiary carbonate-dissolution cycles on the Sierra Leone Rise, eastern equatorial Atlantic Ocean
Dean, W.E.; Gardner, J.V.; Cepek, P.
1981-01-01
Most of the Tertiary section on Sierra Leone Rise off northwest Africa consists of chalk, marl, and limestone that show cyclic alterations of clay-rich and clay-poor beds about 20-60 cm thick. On the basis of biostratigraphic accumulation rates, the cycles in Oligocene and Miocene chalk have periods which average about 44,000 years, and those in Eocene siliceous limestone have periods of 4000-27,000 years. Several sections were sampled in detail to further define the cycles in terms of content of CaCO3, clay minerals, and relative abundances of calcareous nannofossils. Extending information gained by analyses of Pleistocene cores from the continental margin of northwest Africa to the Tertiary cycles on Sierra Leone Rise, both dilution by noncarbonate material and dissolution of CaCO3 could have contributed to the observed relative variations in clay and CaCO3. However, dissolution of CaCO3 as the main cause of the carbonate-clay cycles on the Sierra Leone Rise, rather than dilution by clay, is suggested by the large amount of change (several thousand percent) in terrigenous influx required to produce the observed variations in amount of clay and by the marked increase in abundance of dissolution-resistant discoasters relative to more easily dissolved coccoliths in low-carbonate parts of cycles. The main cause of dissolution of CaCO3 was shoaling of the carbonate compensation depth (CCD) during the early Neogene and climatically induced fluctuations in the thickness of Antarctic Bottom Water. ?? 1981.
Venus - Ishtar gravity anomaly
NASA Technical Reports Server (NTRS)
Sjogren, W. L.; Bills, B. G.; Mottinger, N. A.
1984-01-01
The gravity anomaly associated with Ishtar Terra on Venus is characterized, comparing line-of-sight acceleration profiles derived by differentiating Pioneer Venus Orbiter Doppler residual profiles with an Airy-compensated topographic model. The results are presented in graphs and maps, confirming the preliminary findings of Phillips et al. (1979). The isostatic compensation depth is found to be 150 + or - 30 km.
Jiao, Leizi; Dong, Daming; Zhao, Xiande; Han, Pengcheng
2016-12-01
In the study, we proposed an animal surface temperature measurement method based on Kinect sensor and infrared thermal imager to facilitate the screening of animals with febrile diseases. Due to random motion and small surface temperature variation of animals, the influence of the angle of view on temperature measurement is significant. The method proposed in the present study could compensate the temperature measurement error caused by the angle of view. Firstly, we analyzed the relationship between measured temperature and angle of view and established the mathematical model for compensating the influence of the angle of view with the correlation coefficient above 0.99. Secondly, the fusion method of depth and infrared thermal images was established for synchronous image capture with Kinect sensor and infrared thermal imager and the angle of view of each pixel was calculated. According to experimental results, without compensation treatment, the temperature image measured in the angle of view of 74° to 76° showed the difference of more than 2°C compared with that measured in the angle of view of 0°. However, after compensation treatment, the temperature difference range was only 0.03-1.2°C. This method is applicable for real-time compensation of errors caused by the angle of view during the temperature measurement process with the infrared thermal imager. Copyright © 2016 Elsevier Ltd. All rights reserved.
Optical head tracking for functional magnetic resonance imaging using structured light.
Zaremba, Andrei A; MacFarlane, Duncan L; Tseng, Wei-Che; Stark, Andrew J; Briggs, Richard W; Gopinath, Kaundinya S; Cheshkov, Sergey; White, Keith D
2008-07-01
An accurate motion-tracking technique is needed to compensate for subject motion during functional magnetic resonance imaging (fMRI) procedures. Here, a novel approach to motion metrology is discussed. A structured light pattern specifically coded for digital signal processing is positioned onto a fiduciary of the patient. As the patient undergoes spatial transformations in 6 DoF (degrees of freedom), a high-resolution CCD camera captures successive images for analysis on a computing platform. A high-speed image processing algorithm is used to calculate spatial transformations in a time frame commensurate with patient movements (10-100 ms) and with a precision of at least 0.5 microm for translations and 0.1 deg for rotations.
NASA Astrophysics Data System (ADS)
Zhou, Yi; Tang, Yan; Deng, Qinyuan; Liu, Junbo; Wang, Jian; Zhao, Lixin
2017-08-01
Dimensional metrology for micro structure plays an important role in addressing quality issues and observing the performance of micro-fabricated products. In white light interferometry, the proposed method is expected to measure three-dimensional topography through modulation depth in spatial frequency domain. A normalized modulation depth is first obtained in the xy plane (image plane) for each CCD image individually. After that, the modulation depth of each pixel is analyzed along the scanning direction (z-axis) to reshape the topography of micro samples. Owing to the characteristics of modulation depth in broadband light interferometry, the method could effectively suppress the negative influences caused by light fluctuations and external irradiance disturbance. Both theory and experiments are elaborated in detail to verify that the modulation depth-based method can greatly level up the stability and sensitivity with satisfied precision in the measurement system. This technique can achieve an improved robustness in a complex measurement environment with the potential to be applied in online topography measurement such as chemistry and medical domains.
Hot spot heat transfer - Its application to Venus and implications to Venus and earth
NASA Technical Reports Server (NTRS)
Morgan, P.; Phillips, R. J.
1983-01-01
Using a model that gives a relationship between surface elevation, lithospheric thickness, and heat flux, the hot spot heat loss mechanism is tested for Venus. The mechanism is found to readily explain the predicted heat loss of the planet with a modest number of hot spots (of the order of 35). Lithospheric thickness variations can explain approximately 93 percent of the mapped topography of Venus. Above a radius of 6053 km, additional compensation is required, and this can be effected by incorporating a variable thickness crust into the model. If it is assumed that the crust is generated on the crests of the hot spots, probably by processes associated with volcanism, the model is consistent with nearly 99 percent of the mapped topography of Venus. In addition, the model is basically consistent with available gravity data and interpretations that suggest compensated topography and great depths of compensation (100-1000 km) for the midlatitudes of the planet. It is thought that the approximately 1 percent of the topography not explained by hot spot crustal generation is compensated at a shallower depth primarily by variations in crustal thickness that are not directly related to hot spot volcanism.
Tanner, Dwight Q.; Bragg, Heather M.
2002-03-06
At times in July and August 2001, the total-dissolved-gas probe at Warrendale could not be positioned below the minimum compensation depth because the river was too shallow at that location. Consequently, degassing at probe depth may have occurred, and total dissolved gas may have been larger in locations with greater depths.
High-uniformity centimeter-wide Si etching method for MEMS devices with large opening elements
NASA Astrophysics Data System (ADS)
Okamoto, Yuki; Tohyama, Yukiya; Inagaki, Shunsuke; Takiguchi, Mikio; Ono, Tomoki; Lebrasseur, Eric; Mita, Yoshio
2018-04-01
We propose a compensated mesh pattern filling method to achieve highly uniform wafer depth etching (over hundreds of microns) with a large-area opening (over centimeter). The mesh opening diameter is gradually changed between the center and the edge of a large etching area. Using such a design, the etching depth distribution depending on sidewall distance (known as the local loading effect) inversely compensates for the over-centimeter-scale etching depth distribution, known as the global or within-die(chip)-scale loading effect. Only a single DRIE with test structure patterns provides a micro-electromechanical systems (MEMS) designer with the etched depth dependence on the mesh opening size as well as on the distance from the chip edge, and the designer only has to set the opening size so as to obtain a uniform etching depth over the entire chip. This method is useful when process optimization cannot be performed, such as in the cases of using standard conditions for a foundry service and of short turn-around-time prototyping. To demonstrate, a large MEMS mirror that needed over 1 cm2 of backside etching was successfully fabricated using as-is-provided DRIE conditions.
Comparison of nine methods to estimate ear-canal stimulus levels
Souza, Natalie N.; Dhar, Sumitrajit; Neely, Stephen T.; Siegel, Jonathan H.
2014-01-01
The reliability of nine measures of the stimulus level in the human ear canal was compared by measuring the sensitivity of behavioral hearing thresholds to changes in the depth of insertion of an otoacoustic emission probe. Four measures were the ear-canal pressure, the eardrum pressure estimated from it and the pressure measured in an ear simulator with and without compensation for insertion depth. The remaining five quantities were derived from the ear-canal pressure and the Thévenin-equivalent source characteristics of the probe: Forward pressure, initial forward pressure, the pressure transmitted into the middle ear, eardrum sound pressure estimated by summing the magnitudes of the forward and reverse pressure (integrated pressure) and absorbed power. Two sets of behavioral thresholds were measured in 26 subjects from 0.125 to 20 kHz, with the probe inserted at relatively deep and shallow positions in the ear canal. The greatest dependence on insertion depth was for transmitted pressure and absorbed power. The measures with the least dependence on insertion depth throughout the frequency range (best performance) included the depth-compensated simulator, eardrum, forward, and integrated pressures. Among these, forward pressure is advantageous because it quantifies stimulus phase. PMID:25324079
Skydan, Oleksandr A; Lilley, Francis; Lalor, Michael J; Burton, David R
2003-09-10
We present an investigation into the phase errors that occur in fringe pattern analysis that are caused by quantization effects. When acquisition devices with a limited value of camera bit depth are used, there are a limited number of quantization levels available to record the signal. This may adversely affect the recorded signal and adds a potential source of instrumental error to the measurement system. Quantization effects also determine the accuracy that may be achieved by acquisition devices in a measurement system. We used the Fourier fringe analysis measurement technique. However, the principles can be applied equally well for other phase measuring techniques to yield a phase error distribution that is caused by the camera bit depth.
Radiation-tolerant imaging device
Colella, N.J.; Kimbrough, J.R.
1996-11-19
A barrier at a uniform depth for an entire wafer is used to produce imaging devices less susceptible to noise pulses produced by the passage of ionizing radiation. The barrier prevents charge created in the bulk silicon of a CCD detector or a semiconductor logic or memory device from entering the collection volume of each pixel in the imaging device. The charge barrier is a physical barrier, a potential barrier, or a combination of both. The physical barrier is formed by an SiO{sub 2} insulator. The potential barrier is formed by increasing the concentration of majority carriers (holes) to combine with the electron`s generated by the ionizing radiation. A manufacturer of CCD imaging devices can produce radiation-tolerant devices by merely changing the wafer type fed into his process stream from a standard wafer to one possessing a barrier beneath its surface, thus introducing a very small added cost to his production cost. An effective barrier type is an SiO{sub 2} layer. 7 figs.
The faint intergalactic-medium red-shifted emission balloon: future UV observations with EMCCDs
NASA Astrophysics Data System (ADS)
Kyne, Gillian; Hamden, Erika T.; Lingner, Nicole; Morrissey, Patrick; Nikzad, Shouleh; Martin, D. Christopher
2016-08-01
We present the latest developments in our joint NASA/CNES suborbital project. This project is a balloon-borne UV multi-object spectrograph, which has been designed to detect faint emission from the circumgalactic medium (CGM) around low redshift galaxies. One major change from FIREBall-1 has been the use of a delta-doped Electron Multiplying CCD (EMCCD). EMCCDs can be used in photon-counting (PC) mode to achieve extremely low readout noise (¡ 1e-). Our testing initially focused on reducing clock-induced-charge (CIC) through wave shaping and well depth optimisation with the CCD Controller for Counting Photons (CCCP) from Nüvü. This optimisation also includes methods for reducing dark current, via cooling and substrate voltage adjustment. We present result of laboratory noise measurements including dark current. Furthermore, we will briefly present some initial results from our first set of on-sky observations using a delta-doped EMCCD on the 200 inch telescope at Palomar using the Palomar Cosmic Web Imager (PCWI).
Radiation-tolerant imaging device
Colella, Nicholas J.; Kimbrough, Joseph R.
1996-01-01
A barrier at a uniform depth for an entire wafer is used to produce imaging devices less susceptible to noise pulses produced by the passage of ionizing radiation. The barrier prevents charge created in the bulk silicon of a CCD detector or a semiconductor logic or memory device from entering the collection volume of each pixel in the imaging device. The charge barrier is a physical barrier, a potential barrier, or a combination of both. The physical barrier is formed by an SiO.sub.2 insulator. The potential barrier is formed by increasing the concentration of majority carriers (holes) to combine with the electron's generated by the ionizing radiation. A manufacturer of CCD imaging devices can produce radiation-tolerant devices by merely changing the wafer type fed into his process stream from a standard wafer to one possessing a barrier beneath its surface, thus introducing a very small added cost to his production cost. An effective barrier type is an SiO.sub.2 layer.
Protein model discrimination using mutational sensitivity derived from deep sequencing.
Adkar, Bharat V; Tripathi, Arti; Sahoo, Anusmita; Bajaj, Kanika; Goswami, Devrishi; Chakrabarti, Purbani; Swarnkar, Mohit K; Gokhale, Rajesh S; Varadarajan, Raghavan
2012-02-08
A major bottleneck in protein structure prediction is the selection of correct models from a pool of decoys. Relative activities of ∼1,200 individual single-site mutants in a saturation library of the bacterial toxin CcdB were estimated by determining their relative populations using deep sequencing. This phenotypic information was used to define an empirical score for each residue (RankScore), which correlated with the residue depth, and identify active-site residues. Using these correlations, ∼98% of correct models of CcdB (RMSD ≤ 4Å) were identified from a large set of decoys. The model-discrimination methodology was further validated on eleven different monomeric proteins using simulated RankScore values. The methodology is also a rapid, accurate way to obtain relative activities of each mutant in a large pool and derive sequence-structure-function relationships without protein isolation or characterization. It can be applied to any system in which mutational effects can be monitored by a phenotypic readout. Copyright © 2012 Elsevier Ltd. All rights reserved.
Efficient dense blur map estimation for automatic 2D-to-3D conversion
NASA Astrophysics Data System (ADS)
Vosters, L. P. J.; de Haan, G.
2012-03-01
Focus is an important depth cue for 2D-to-3D conversion of low depth-of-field images and video. However, focus can be only reliably estimated on edges. Therefore, Bea et al. [1] first proposed an optimization based approach to propagate focus to non-edge image portions, for single image focus editing. While their approach produces accurate dense blur maps, the computational complexity and memory requirements for solving the resulting sparse linear system with standard multigrid or (multilevel) preconditioning techniques, are infeasible within the stringent requirements of the consumer electronics and broadcast industry. In this paper we propose fast, efficient, low latency, line scanning based focus propagation, which mitigates the need for complex multigrid or (multilevel) preconditioning techniques. In addition we propose facial blur compensation to compensate for false shading edges that cause incorrect blur estimates in people's faces. In general shading leads to incorrect focus estimates, which may lead to unnatural 3D and visual discomfort. Since visual attention mostly tends to faces, our solution solves the most distracting errors. A subjective assessment by paired comparison on a set of challenging low-depth-of-field images shows that the proposed approach achieves equal 3D image quality as optimization based approaches, and that facial blur compensation results in a significant improvement.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rana, Suresh; Zeidan, Omar; Ramirez, Eric
2013-09-15
Purpose: The main purposes of this study were to (1) investigate the dependency of lateral penumbra (80%–20% distance) of uniform scanning proton beams on various factors such as air gap, proton range, modulation width, compensator thickness, and depth, and (2) compare the lateral penumbra calculated by a treatment planning system (TPS) with measurements.Methods: First, lateral penumbra was measured using solid–water phantom and radiographic films for (a) air gap, ranged from 0 to 35 cm, (b) proton range, ranged from 8 to 30 cm, (c) modulation, ranged from 2 to 10 cm, (d) compensator thickness, ranged from 0 to 20 cm,more » and (e) depth, ranged from 7 to 15 cm. Second, dose calculations were computed in a virtual water phantom using the XiO TPS with pencil beam algorithm for identical beam conditions and geometrical configurations that were used for the measurements. The calculated lateral penumbra was then compared with the measured one for both the horizontal and vertical scanning magnets of our uniform scanning proton beam delivery system.Results: The results in the current study showed that the lateral penumbra of horizontal scanning magnet was larger (up to 1.4 mm for measurement and up to 1.0 mm for TPS) compared to that of vertical scanning magnet. Both the TPS and measurements showed an almost linear increase in lateral penumbra with increasing air gap as it produced the greatest effect on lateral penumbra. Lateral penumbra was dependent on the depth and proton range. Specifically, the width of lateral penumbra was found to be always lower at shallower depth than at deeper depth within the spread out Bragg peak (SOBP) region. The lateral penumbra results were less sensitive to the variation in the thickness of compensator, whereas lateral penumbra was independent of modulation. Overall, the comparison between the results of TPS with that of measurements indicates a good agreement for lateral penumbra, with TPS predicting higher values compared to measurements.Conclusions: Lateral penumbra of uniform scanning proton beams depends on air gap, proton range, compensator thickness, and depth, whereas lateral penumbra is not dependent on modulation. The XiO TPS typically overpredicted lateral penumbra compared to measurements, within 1 mm for most cases, but the difference could be up to 2.5 mm at a deep depth and large air gap.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, S; Alaei, P
2015-06-15
Purpose: To implement full/half bowtie filter models in a commercial treatment planning system (TPS) to calculate kilovoltage (kV) x-ray imaging dose of Varian On-Board Imager (OBI) cone beam CT (CBCT) system. Methods: Full/half bowtie filters of Varian OBI were created as compensator models in Pinnacle TPS (version 9.6) using Matlab software (version 2011a). The profiles of both bowtie filters were acquired from the manufacturer, imported into the Matlab system and hard coded in binary file format. A Pinnacle script was written to import each bowtie filter data into a Pinnacle treatment plan as a compensator. A kV x-ray beam modelmore » without including the compensator model was commissioned per each bowtie filter setting based on percent depth dose and lateral profile data acquired from Monte Carlo simulations. To validate the bowtie filter models, a rectangular water phantom was generated in the planning system and an anterior/posterior beam with each bowtie filter was created. Using the Pinnacle script, each bowtie filter compensator was added to the treatment plan. Lateral profile at the depth of 3cm and percent depth dose were measured using an ion chamber and compared with the data extracted from the treatment plans. Results: The kV x-ray beams for both full and half bowtie filter have been modeled in a commercial TPS. The difference of lateral and depth dose profiles between dose calculations and ion chamber measurements were within 6%. Conclusion: Both full/half bowtie filter models provide reasonable results in kV x-ray dose calculations in the water phantom. This study demonstrates the possibility of using a model-based treatment planning system to calculate the kV imaging dose for both full and half bowtie filter modes. Further study is to be performed to evaluate the models in clinical situations.« less
Follow-up study of children with cerebral coordination disturbance (CCD, Vojta).
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.
Glacial magnetite dissolution in abyssal NW Pacific sediments - evidence for carbon trapping?
NASA Astrophysics Data System (ADS)
Korff, Lucia; von Dobeneck, Tilo; Frederichs, Thomas; Kasten, Sabine; Kuhn, Gerhard; Gersonde, Rainer; Diekmann, Bernhard
2016-04-01
The abyssal North Pacific Ocean's large volume, depth, and terminal position on the deep oceanic conveyor make it a candidate site for deep carbon trapping as postulated by climate theory to explain the massive glacial drawdown of atmospheric CO2. As the major basins of the North Pacific have depths of 5500-6500m, far below the modern and glacial Calcite Compensation Depths (CCD), these abyssal sediments are carbonate-free and therefore not suitable for carbonate-based paleoceanographic proxy reconstructions. Instead, paleo-, rock and environmental magnetic methods are generally well applicable to hololytic abyssal muds and clays. In 2009, the international paleoceanographic research cruise SO 202 INOPEX ('Innovative North Pacific Experiment') of the German RV SONNE collected two ocean-spanning EW sediment core transects of the North Pacific and Bering Sea recovering a total of 50 piston and gravity cores from 45 sites. Out of seven here considered abyssal Northwest Pacific piston cores collected at water depths of 5100 to 5700m with mostly coherent shipboard susceptibility logs, the 20.23m long SO202-39-3, retrieved from 5102 m water depth east of northern Shatsky Rise (38°00.70'N, 164°26.78'E), was rated as the stratigraphically most promising record of the entire core transect and selected for detailed paleo- and environmental magnetic, geochemical and sedimentological investigations. This core was dated by correlating its RPI and Ba/Ti records to well-dated reference records and obviously provides a continuous sequence of the past 940 kyrs. The most striking orck magnetic features are coherent magnetite-depleted zones corresponding to glacial periods. In the interglacial sections, detrital, volcanic and even submicron bacterial magnetite fractions are excellently preserved. These alternating magnetite preservation states seem to reflect dramatic oxygenation changes in the deep North Pacific Ocean and hint at large-scale benthic glacial carbon trapping followed by subsequent interglacial carbon burn-down and CO2 release. Abyssal Northwest Pacific sediments may have served as glacial carbon reservoir in particular since the onset of systematic 100 kyr ice age cycles at the end of the Mid-Pleistocene transition (MPT). Stagnant glacial Antarctic Bottom Water, which expanded primarily into abyssal South Atlantic basins during the MPT interim phase, thereafter seemed to flow preferentially into the deeper and larger abyssal Indo-Pacific basins, where it may have enabled more efficient carbon-trapping. More intensive scavenging of the Northwest Pacific surface ocean by enhanced glacial Asian dust flux is suggested by parallel TOC and quartz contents, enhancing glacial carbon accumulation despite potentially lower export production. The magnetic records also identify numerous partly consistent tephra layers, which can be matched between most records of the core transect.
Earth's isostatic gravity anomaly field: Contributions to National Geodetic Satellite Program
NASA Technical Reports Server (NTRS)
Khan, M. A.
1973-01-01
On the assumption that the compensation for the topographic load is achieved in the manner of Airy-Heiskenenan hypothesis at a compensation depth of 30 kilometers, the spherical harmonic coefficients of the isostatic reduction potential U are computed. The degree power spectra of these coefficients are compared with the power spectra of the isostatic reduction coefficients given by Uotila. Results are presented in tabular form.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Plessis, F.C.P. du; Willemse, C.A.
In this paper the radiological properties of a compensator material consisting of wax and gypsum is presented. Effective attenuation coefficients (EACs) have been determined from transmission measurements with an ion chamber in a Perspex phantom. Measurements were made at 80 and 100 cm source-to-skin distance (SSD) for beam energies of 6, 8, and 15 MV, for field sizes ranging from narrow beam geometries up to 40x40 cm{sup 2}, and at measurement depths of maximum dose build-up, 5 and 10 cm. A parametrization equation could be constructed to predict the EAC values within 4% uncertainty as a function of field sizemore » and depth of measurement. The EAC dependence on off-axis position was also quantified at each beam energy and SSD. It was found that the compensator material reduced the required thickness for compensation by 26% at 8 MV when compared to pure paraffin wax for a 10x10 cm{sup 2} field. Relative surface ionization (RSI) measurements have been made to quantify the effect of scattered electrons from the wax-gypsum compensator. Results indicated that for 80 cm SSD the RSI would exceed 50% for fields larger than 15x15 cm{sup 2}. At 100 cm SSD the RSI values were below 50% for all field sizes used.« less
SU-F-T-533: Study of Dosimetric Properties of Cadmium Free Alloy Used in Compensator Based IMRT
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tyagi, A; Kaushik, S; Guru Jambheshwar University of Science & Technology, Hisar, Haryana
Purpose: To study the dosimetric properties of cadmium free alloy which is used in compensator based IMRT. Methods: A mixture of 30% of lead,52% of bismuth and 18% of tin was used to prepare alloy. We prepared slabs of different thicknesses ranging from 0.71 cm to 6.14 cm. Density of alloy was measured by Archimedes’ principle using SI-234 Denver instrument and water as buoyant liquid. Transmission, linear attenuation coefficient (µ), tissue phantom ration (TPR), beam hardening, surface dose (Ds), percentage depth dose (PDD) and effect of scatter were measured and analyze for different field size and different thickness of compensatormore » for 6 MV photon beam. Measurements were carried out at 100 cm SSD and 160 cm SSD. Results: Density of alloy was found to be 9.5456 gm/cm3. Melting point of alloy is 90–95 °C. For a field size of 10×10 cm2 µ was 0.4253 cm-1 at 100 cm SSD. Calculated TPR was found to be within 3 % of measured TPR. Ds was found to be decreasing with increasing thickness of compensator. 1cm, 1.98 cm and 4.16 cm thick compensator slab decreased surface dose by 4.2%, 6.1% and 9.5% respectively for a field size of 10×10cm2 at 100 cm SSD. As field size increases Ds increases for a given compensator thickness. This is due to increase in amount of scattered dose from wider collimator opening. For smaller field size, PDDs are increased from 3.0% to 5.5% of open beam PDDs as compensator thickness increases from 1 cm to 6.14 cm at a depth of 10 cm in water. For larger field size variation in PDDs is not significant. Conclusion: High degree of modulation can be achieved from this compensator material, which is essential in compensator based IMRT. Dosimetric properties analyzed in this study establish this alloy as a reliable, cost effective, reusable compensator material.« less
Dosimetric studies of cadmium free alloy used in compensator based intensity modulated radiotherapy
NASA Astrophysics Data System (ADS)
Kaushik, Sandeep; Punia, Rajesh; Tyagi, Atul; Singh, Mann P.
2017-10-01
Aim of this study was to investigate dosimetric properties of cadmium free alloy which is used in compensator based intensity modulated radiotherapy (cIMRT). A mixture of lead, bismuth and tin was used to prepare the alloy whose melting point is 90-95 °C. Slabs of different thicknesses ranging from 0.71 cm to 6.14 cm were prepared. Density of alloy was measured by Archimedes' principle using water. For six megavolt (6 MV) photon beam energy transmission, linear effective attenuation coefficient (μeff), tissue phantom ratio (TPR1020), beam hardening, surface dose (Ds), percentage depth dose (PDD) and effect of scatter has been measured and analyzed for different field sizes and different thickness of compensator. Effect of extended source to detector distance (SDD) on transmissions and μeff was measured. The density of alloy was found to be 9.5456 g/cm3. At SDD of 100 cm, μeff was observed 0.4253 cm-1 for a field size of 10×10 cm 2. Calculated TPR1020 was found to be within 3% of experimental TPR1020 . It was found to be increasing with increasing thickness of compensator. Ds was found to decrease with thickness of compensator and increase with wider collimator opening due to increased scattered dose. Compensator slabs of 1 cm, 1.98 cm and 4.16 cm decreased surface dose by 4.2%, 6.1% and 9.5% respectively for a field size of 10×10 cm2 at 100 cm SDD. For small field size of 3×3 cm2 and 5×5 cm2 PDDs are increased from 3.0% to 5.5% of open beam PDDs as compensator thickness increased from 1 cm to 6.14 cm at a depth of 10 cm in water while variation in PDD is insignificant in for larger field sizes 10×10 cm2 to 20×20 cm2. A high degree of intensity modulation is essential in cIMRT and it can be achieved with this compensator material. Dosimetric properties analyzed in this study establish this alloy as a reliable, reusable, optimally dense and cost effective compensator material.
Improving depth estimation from a plenoptic camera by patterned illumination
NASA Astrophysics Data System (ADS)
Marshall, Richard J.; Meah, Chris J.; Turola, Massimo; Claridge, Ela; Robinson, Alex; Bongs, Kai; Gruppetta, Steve; Styles, Iain B.
2015-05-01
Plenoptic (light-field) imaging is a technique that allows a simple CCD-based imaging device to acquire both spatially and angularly resolved information about the "light-field" from a scene. It requires a microlens array to be placed between the objective lens and the sensor of the imaging device1 and the images under each microlens (which typically span many pixels) can be computationally post-processed to shift perspective, digital refocus, extend the depth of field, manipulate the aperture synthetically and generate a depth map from a single image. Some of these capabilities are rigid functions that do not depend upon the scene and work by manipulating and combining a well-defined set of pixels in the raw image. However, depth mapping requires specific features in the scene to be identified and registered between consecutive microimages. This process requires that the image has sufficient features for the registration, and in the absence of such features the algorithms become less reliable and incorrect depths are generated. The aim of this study is to investigate the generation of depth-maps from light-field images of scenes with insufficient features for accurate registration, using projected patterns to impose a texture on the scene that provides sufficient landmarks for the registration methods.
Perry, R.W.; Adams, N.S.; Rondorf, D.W.
2001-01-01
We investigated the effect of two different sizes of surgically implanted transmitters on the buoyancy compensation of juvenile chinook salmon Oncorhynchus tshawytscha. We determined buoyancy by measuring the density of fish with a filled air bladder in graded salinity baths. In addition, we examined the effect of pressure changes on buoyancy by measuring the pressure reduction (PR) at which fish became neutrally buoyant. We found no significant difference between the density of control and tagged groups, indicating that fish were able to compensate for the transmitter by filling their air bladders. However, both groups of tagged fish had significantly lower PR than control fish. Regression analysis of fish density on PR indicated that density of the tagged groups changed at a higher rate than that of the controls. As a result, tagged fish attained neutral buoyancy with less pressure reduction even though the tagged and control groups exhibited similar densities. This relation was confirmed by using Boyle's law to simulate buoyancy changes with change in depth. Although fish compensated for the transmitter, changes in depth affected the buoyancy of tagged fish more than that of untagged fish. Reduced buoyancy at depth may affect the behavior and physiology of tagged juvenile salmonids, and researchers should be aware of this potential bias in telemetry data. In addition, there was little difference in PR or the slope of the density - PR regression lines between tagged groups. This was caused by the small difference in excess mass (i.e., weight in water) of the two transmitters. Thus, although two transmitters may not weigh the same, their effects on buoyancy may be similar depending on the excess mass.
NASA Astrophysics Data System (ADS)
Zigone, D.; Danecek, P.; Bès de Berc, M.; Maggi, A.; Thore, J. Y.; Leveque, J. J.; Vallee, M.; Bernard, A.; Sayadi, J.; Morelli, A.; Delladio, A.; Chappellaz, J. A.; Alemany, O.; Possenti, P.; Stutzmann, E.; Bonaime, S.; Pesqueira, F.; Pardo, C.; Vincent, D.
2017-12-01
Concordia (75°S 123°E) is a scientific base operated by French polar institute IPEV (Institut Paul-Emile Victor) and Italian Antarctic Program PNRA (Programma Nazionale di Ricerche in Antartide), and is located at Dome C, on the ice sheet of the East Antarctica plateau. It hosts a seismological observatory (CCD), which is jointly operated by EOST (Strasbourg) and INGV (Roma). The highly strategic location and remoteness is the key strength of our program, which has provided observatory quality data since 2000. The station has been integrated into the GEOSCOPE network in 2008 and the data are now available in real time through GEOSCOPE and IRIS. The observatory is located at distance of 1km from the base. The current installation is placed at a depth of 12m in an artificial vault constructed from two shipping containers and buried in the snow. The vault is thermally very stable, but the relatively close proximity to the base causes increased diurnal noise ( 40 dB) at frequencies above 1Hz, especially during the summer season. The uppermost 100 m thick firn (snow) layer forms a waveguide, where anthropic noise from the base is trapped and easily picked up by the seismometers (T240 and STS2). Another limitation comes from the hydrostatic pressure of the snow which is continuously deforming the metallic structures: we record container cracking events on the seismograms, and we see visual evidence of structural deformations inside the tunnel and the vault. We propose an evolution of the CCD station towards a post-hole installation. Placing a sensor at a depth of approximately 130 meters, will reduce noise from thermal effects, from tilting and from anthropogenic activity, because it would be located below the firn layer waveguide and the ice pinch-out depth. In order to operate the borehole station for several years, we intend to keep the hole open and the sensor accessible, while ensuring good coupling between the sensor and the surrounding hard ice. To achieve these goals and to avoid any hydrostatic movement, we shall install a PEHD casing in the upper section of the borehole located in the firn layer. After installing the instrument in the hard ice, we shall then fill the hole with silicone oil whose density is similar to that of ice. The drilling is scheduled to start in January 2018. Updates on the project will be presented at the meeting.
NASA Astrophysics Data System (ADS)
Kleiber, Michael; Winkelholz, Carsten
2008-02-01
The aim of the presented research was to quantify the distortion of depth perception when using stereoscopic displays. The visualization parameters of the used virtual reality system such as perspective, haploscopic separation and width of stereoscopic separation were varied. The experiment was designed to measure distortion in depth perception according to allocentric frames of reference. The results of the experiments indicate that some of the parameters have an antithetic effect which allows to compensate the distortion of depth perception for a range of depths. In contrast to earlier research which reported underestimation of depth perception we found that depth was overestimated when using true projection parameters according to the position of the eyes of the user and display geometry.
Adding polarimetric imaging to depth map using improved light field camera 2.0 structure
NASA Astrophysics Data System (ADS)
Zhang, Xuanzhe; Yang, Yi; Du, Shaojun; Cao, Yu
2017-06-01
Polarization imaging plays an important role in various fields, especially for skylight navigation and target identification, whose imaging system is always required to be designed with high resolution, broad band, and single-lens structure. This paper describe such a imaging system based on light field 2.0 camera structure, which can calculate the polarization state and depth distance from reference plane for every objet point within a single shot. This structure, including a modified main lens, a multi-quadrants Polaroid, a honeycomb-liked micro lens array, and a high resolution CCD, is equal to an "eyes array", with 3 or more polarization imaging "glasses" in front of each "eye". Therefore, depth can be calculated by matching the relative offset of corresponding patch on neighboring "eyes", while polarization state by its relative intensity difference, and their resolution will be approximately equal to each other. An application on navigation under clear sky shows that this method has a high accuracy and strong robustness.
A four-lens based plenoptic camera for depth measurements
NASA Astrophysics Data System (ADS)
Riou, Cécile; Deng, Zhiyuan; Colicchio, Bruno; Lauffenburger, Jean-Philippe; Kohler, Sophie; Haeberlé, Olivier; Cudel, Christophe
2015-04-01
In previous works, we have extended the principles of "variable homography", defined by Zhang and Greenspan, for measuring height of emergent fibers on glass and non-woven fabrics. This method has been defined for working with fabric samples progressing on a conveyor belt. Triggered acquisition of two successive images was needed to perform the 3D measurement. In this work, we have retained advantages of homography variable for measurements along Z axis, but we have reduced acquisitions number to a single one, by developing an acquisition device characterized by 4 lenses placed in front of a single image sensor. The idea is then to obtain four projected sub-images on a single CCD sensor. The device becomes a plenoptic or light field camera, capturing multiple views on the same image sensor. We have adapted the variable homography formulation for this device and we propose a new formulation to calculate a depth with plenoptic cameras. With these results, we have transformed our plenoptic camera in a depth camera and first results given are very promising.
Resolution Enhancement In Ultrasonic Imaging By A Time-Varying Filter
NASA Astrophysics Data System (ADS)
Ching, N. H.; Rosenfeld, D.; Braun, M.
1987-09-01
The study reported here investigates the use of a time-varying filter to compensate for the spreading of ultrasonic pulses due to the frequency dependence of attenuation by tissues. The effect of this pulse spreading is to degrade progressively the axial resolution with increasing depth. The form of compensation required to correct for this effect is impossible to realize exactly. A novel time-varying filter utilizing a bank of bandpass filters is proposed as a realizable approximation of the required compensation. The performance of this filter is evaluated by means of a computer simulation. The limits of its application are discussed. Apart from improving the axial resolution, and hence the accuracy of axial measurements, the compensating filter could be used in implementing tissue characterization algorithms based on attenuation data.
Vail, III, William B.
1993-01-01
Methods of operation of an apparatus having at least two pairs of voltage measurement electrodes vertically disposed in a cased well to measure the resistivity of adjacent geological formations from inside the cased well. During stationary measurements with the apparatus at a fixed vertical depth within the cased well, the invention herein discloses methods of operation which include a measurement step and subsequent first and second compensation steps respectively resulting in improved accuracy of measurement. First and second order errors of measurement are identified, and the measurement step and two compensation steps provide methods to substantially eliminate their influence on the results. A multiple frequency apparatus adapted to movement within the well is described which simultaneously provide the measurement and two compensation steps.
The design of L1-norm visco-acoustic wavefield extrapolators
NASA Astrophysics Data System (ADS)
Salam, Syed Abdul; Mousa, Wail A.
2018-04-01
Explicit depth frequency-space (f - x) prestack imaging is an attractive mechanism for seismic imaging. To date, the main focus of this method was data migration assuming an acoustic medium, but until now very little work assumed visco-acoustic media. Real seismic data usually suffer from attenuation and dispersion effects. To compensate for attenuation in a visco-acoustic medium, new operators are required. We propose using the L1-norm minimization technique to design visco-acoustic f - x extrapolators. To show the accuracy and compensation of the operators, prestack depth migration is performed on the challenging Marmousi model for both acoustic and visco-acoustic datasets. The final migrated images show that the proposed L1-norm extrapolation results in practically stable and improved resolution of the images.
Lee, Sang Yoon; Hong, Jun Young; Oh, Je Hyeok; Son, Sun-Han
2017-03-21
The two-finger technique (TFT) using the index-middle fingers of the right hand (TFT-R23) was recently confirmed to produce deeper chest compression depth (CCD) compared with the TFT using any other fingers. This study was carried out to confirm whether the TFT-R23 would be as effective as the two-thumb technique (TTT). In addition, individual finger strengths were measured to identify the reasons why the TTT and TFT-R23 produced deeper CCD than any other methods. This prospective randomized cross-over trial compared TTT with TFT-R23. A total of 37 doctors conducted 2 min single-rescuer cardiopulmonary resuscitation using TTT and TFT-R23 in a random order using a 3-month-old sized infant manikin laid on the floor. The chest compression to ventilation ratio was set to 15 : 2. In addition, finger strengths were measured using a pinch meter. The actual CCD of the TTT was significantly deeper than that of the TFT-R23 (41.3±1.3 vs. 39.8±1.5 mm, P<0.001). Although the hands-off time of the TTT was significantly longer than that of the TFT-R23 (55.6±5.7 vs. 53.6±5.8 s, P=0.002), the mean difference was only 2.0±3.7 s (95% confidence interval: 0.755-3.245). The finger strength of the TTT was significantly higher than that of TFT-R23 (23.8±10.1 vs. 13.7±5.1 kg, P<0.001). The TTT produced deeper CCD compared with that of the TFT-R23 because the finger strength of the TTT was significantly higher than that of the TFT-R23.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Buts, Lieven; De Jonge, Natalie; Loris, Remy, E-mail: reloris@vub.ac.be
2005-10-01
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{sub 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{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 37.6, b = 60.5, c = 83.8 Å and diffracts to 1.8more » Å resolution. Form III belongs to space group P2{sub 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.« less
NASA Astrophysics Data System (ADS)
Boroomand, Ameneh; Tan, Bingyao; Wong, Alexander; Bizheva, Kostadinka
2015-03-01
The axial resolution of Spectral Domain Optical Coherence Tomography (SD-OCT) images degrades with scanning depth due to the limited number of pixels and the pixel size of the camera, any aberrations in the spectrometer optics and wavelength dependent scattering and absorption in the imaged object [1]. Here we propose a novel algorithm which compensates for the blurring effect of these factors of the depth-dependent axial Point Spread Function (PSF) in SDOCT images. The proposed method is based on a Maximum A Posteriori (MAP) reconstruction framework which takes advantage of a Stochastic Fully Connected Conditional Random Field (SFCRF) model. The aim is to compensate for the depth-dependent axial blur in SD-OCT images and simultaneously suppress the speckle noise which is inherent to all OCT images. Applying the proposed depth-dependent axial resolution enhancement technique to an OCT image of cucumber considerably improved the axial resolution of the image especially at higher imaging depths and allowed for better visualization of cellular membrane and nuclei. Comparing the result of our proposed method with the conventional Lucy-Richardson deconvolution algorithm clearly demonstrates the efficiency of our proposed technique in better visualization and preservation of fine details and structures in the imaged sample, as well as better speckle noise suppression. This illustrates the potential usefulness of our proposed technique as a suitable replacement for the hardware approaches which are often very costly and complicated.
Soft x-ray imager (SXI) onboard the NeXT satellite
NASA Astrophysics Data System (ADS)
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.
Brown, Sarah; Hinsley, Samantha; Ballesteros, Mónica; Bourne, Sue; McGarry, Paul; Sherratt, Debbie; Flanagan, Louise; Gregory, Walter; Cavenagh, Jamie; Owen, Roger; Williams, Cathy; Kaiser, Martin; Low, Eric; Yong, Kwee
2016-01-01
Multiple myeloma is a plasma cell tumour with an annual incidence in the UK of approximately 40-50 per million i.e. about 4500 new cases per annum. The triple combination cyclophosphamide, bortezomib (Velcade®) and dexamethasone (CVD) is an effective regimen at relapse and has emerged in recent years as the standard therapy at first relapse in the UK. Carfilzomib has good activity as a single agent in the relapsed setting, and it is expected that efficacy will be improved when used in combination with dexamethasone and cyclophosphamide. MUK Five is a phase II open label, randomised, controlled, parallel group, multi-centre trial that will compare the activity of carfilzomib, cyclophosphamide and dexamethasone (CCD) with that of CVD, given over an equivalent treatment period (24 weeks), in participants with multiple myeloma at first relapse, or refractory to no more than 1 line of treatment. In addition, the study also aims to assess the utility of a maintenance schedule of carfilzomib in these participants. The primary objective of the trial is to assess whether CCD provides non-inferior activity in terms of ≥ VGPR rates at 24 weeks, and whether the addition of maintenance treatment with carfilzomib to CCD provides superior activity in terms of progression-free survival, as compared to CCD with no maintenance. Secondary objectives include comparing toxicity profiles, further summarizing and comparing the activity of the different treatment arms and analysis of the effect of each treatment arm on minimal residual disease status. The development of carfilzomib offers the opportunity to further explore the anti-tumour efficacy of proteasome inhibition and, based on the available evidence, it is important and timely to obtain data on the activity, toxicity and tolerability of this drug. In contrast to ongoing phase III trials, this phase II trial has a unique subset of participants diagnosed with multiple myeloma at first relapse or refractory to no more than 1 line of treatment and will also evaluate the utility of maintenance with carfilzomib for up to 18 months and investigate minimal residual disease status to provide information on depth of response and the prognostic impact thereof. The trial is registered under ISRCTN17354232, December 2012.
NASA Astrophysics Data System (ADS)
Chi, S.; Kim, K.; Lee, H.; Ju, S.; Yoo, C.
2007-12-01
Recently the market price of valuable metals are rapidly increased due to the high demand and limited resources. Therefore, manganese (Mn)-nodules (Polymetallic nodules) in the Clarion-Clipperton fracture zone have stimulated economic interest. Nickel, copper, cobalt and manganese are the economically most interesting metals of Mn-nodules. In order to mine Mn-nodules from sea floor, understanding the geotechnical properties of surface sediment are very important for two major reasons. First, geotechnical data are required to design and build the stable and environmentally acceptable mining vehicles. Second, deep-sea mining activity could significantly effect on the surface layer of deep sea floor. For example, surface sediments will be redistributed through the resuspension and redeposition. Reliable sedimentological and soil mechanical baseline data of the undisturbed benthic environment are essential to assess and evaluate these environmental impacts by mining activity using physical and numerical modeling. The 225 times deployments of the multiple corer guaranteed undisturbed sediment samples in which geotechnical parameters were measured including sediment grain size, density, water content, shear strength. The sea floor sediments in this study area are generally characterized into three different types as follow. The seabed of the middle part (8-12° N) of this study area is mainly covered with biogenic siliceous sediment compared with pelagic red clays in the northern part (16-17° N). However, the southern part (5-6° N) is dominant with calcareous sediments because its water depth is shallower than the carbonate compensation depth (CCD). This result suggests that middle area, covered with siliceous sediment, is more feasible for commercial mining than northern area, covered with pelagic red clay, with the consideration of the nodule miner maneuverability and the environmental impact. Especially, middle part with the highest nodule abundance and valuable metal contents is mainly (more than 90% of area) covered with consolidated sediments, which are expected to be appropriate for effective miner movement. Furthermore, middle part with coarse siliceous sediments could be less environmentally disturbed by the mining activity. It makes middle part more plausible site than other sites in this study area for the commercial mining.
Adaptive compensation of aberrations in ultrafast 3D microscopy using a deformable mirror
NASA Astrophysics Data System (ADS)
Sherman, Leah R.; Albert, O.; Schmidt, Christoph F.; Vdovin, Gleb V.; Mourou, Gerard A.; Norris, Theodore B.
2000-05-01
3D imaging using a multiphoton scanning confocal microscope is ultimately limited by aberrations of the system. We describe a system to adaptively compensate the aberrations with a deformable mirror. We have increased the transverse scanning range of the microscope by three with compensation of off-axis aberrations.We have also significantly increased the longitudinal scanning depth with compensation of spherical aberrations from the penetration into the sample. Our correction is based on a genetic algorithm that uses second harmonic or two-photon fluorescence signal excited by femtosecond pulses from the sample as the enhancement parameter. This allows us to globally optimize the wavefront without a wavefront measurement. To improve the speed of the optimization we use Zernike polynomials as the basis for correction. Corrections can be stored in a database for look-up with future samples.
2013-01-01
Background In plants, carotenoids serve as the precursors to C13-norisoprenoids, a group of apocarotenoid compounds with diverse biological functions. Enzymatic cleavage of carotenoids catalysed by members of the carotenoid cleavage dioxygenase (CCD) family has been shown to produce a number of industrially important volatile flavour and aroma apocarotenoids including β-ionone, geranylacetone, pseudoionone, α-ionone and 3-hydroxy-β-ionone in a range of plant species. Apocarotenoids contribute to the floral and fruity attributes of many wine cultivars and are thereby, at least partly, responsible for the “varietal character”. Despite their importance in grapes and wine; carotenoid cleavage activity has only been described for VvCCD1 and the mechanism(s) and regulation of carotenoid catabolism remains largely unknown. Results Three grapevine-derived CCD-encoding genes have been isolated and shown to be functional with unique substrate cleavage capacities. Our results demonstrate that the VvCCD4a and VvCCD4b catalyse the cleavage of both linear and cyclic carotenoid substrates. The expression of VvCCD1, VvCCD4a and VvCCD4b was detected in leaf, flower and throughout berry development. VvCCD1 expression was constitutive, whereas VvCCD4a expression was predominant in leaves and VvCCD4b in berries. A transgenic population with a 12-fold range of VvCCD1 expression exhibited a lack of correlation between VvCCD1 expression and carotenoid substrates and/or apocarotenoid products in leaves, providing proof that the in planta function(s) of VvCCD1 in photosynthetically active tissue is distinct from the in vitro activities demonstrated. The isolation and functional characterisation of VvCCD4a and VvCCD4b identify two additional CCDs that are functional in grapevine. Conclusions Taken together, our results indicate that the three CCDs are under various levels of control that include gene expression (spatial and temporal), substrate specificity and compartmentalisation that act individually and/or co-ordinately to maintain carotenoid and volatile apocarotenoid levels in plants. Altering the expression of VvCCD1 in a transgenic grapevine population illustrated the divergence between the in vitro enzyme activity and the in planta activity of this enzyme, thereby contributing to the efforts to understand how enzymatic degradation of carotenoids involved in photosynthesis occurs. The identification and functional characterisation of VvCCD4a and VvCCD4b suggest that these enzymes are primarily responsible for catalysing the cleavage of plastidial carotenoids. PMID:24106789
Panoramic 3D Reconstruction by Fusing Color Intensity and Laser Range Data
NASA Astrophysics Data System (ADS)
Jiang, Wei; Lu, Jian
Technology for capturing panoramic (360 degrees) three-dimensional information in a real environment have many applications in fields: virtual and complex reality, security, robot navigation, and so forth. In this study, we examine an acquisition device constructed of a regular CCD camera and a 2D laser range scanner, along with a technique for panoramic 3D reconstruction using a data fusion algorithm based on an energy minimization framework. The acquisition device can capture two types of data of a panoramic scene without occlusion between two sensors: a dense spatio-temporal volume from a camera and distance information from a laser scanner. We resample the dense spatio-temporal volume for generating a dense multi-perspective panorama that has equal spatial resolution to that of the original images acquired using a regular camera, and also estimate a dense panoramic depth-map corresponding to the generated reference panorama by extracting trajectories from the dense spatio-temporal volume with a selecting camera. Moreover, for determining distance information robustly, we propose a data fusion algorithm that is embedded into an energy minimization framework that incorporates active depth measurements using a 2D laser range scanner and passive geometry reconstruction from an image sequence obtained using the CCD camera. Thereby, measurement precision and robustness can be improved beyond those available by conventional methods using either passive geometry reconstruction (stereo vision) or a laser range scanner. Experimental results using both synthetic and actual images show that our approach can produce high-quality panoramas and perform accurate 3D reconstruction in a panoramic environment.
Isostatic Compensation of the Lunar Highlands
NASA Astrophysics Data System (ADS)
Sori, Michael M.; James, Peter B.; Johnson, Brandon C.; Soderblom, Jason M.; Solomon, Sean C.; Wieczorek, Mark A.; Zuber, Maria T.
2018-02-01
The lunar highlands are isostatically compensated at large horizontal scales, but the specific compensation mechanism has been difficult to identify. With topographic data from the Lunar Orbiter Laser Altimeter and gravity data from the Gravity Recovery and Interior Laboratory, we investigate support of highland topography. Poor correlation between crustal density and elevation shows that Pratt compensation is not important in the highlands. Using spectrally weighted admittance, we compared observed values of geoid-to-topography ratio (GTR) with those predicted by isostatic models. Observed GTRs are 25.8+7.5-5.7 m/km for the nearside highlands and 39.3+5.7-6.2 m/km for the farside highlands. These values are not consistent with flexural compensation of long-wavelength topography or Airy isostasy defined under an assumption of equal mass in crustal columns. Instead, the observed GTR values are consistent with models of Airy compensation in which isostasy is defined under a requirement of equal pressures at equipotential surfaces at depth. The gravity and topography data thus reveal that long-wavelength topography on the Moon is most likely compensated by variations in crustal thickness, implying that highland topography formed early in lunar history before the development of a thick elastic lithosphere.
Calcareous sponges from abyssal and bathyal depths in the Weddell Sea, Antarctica
NASA Astrophysics Data System (ADS)
Rapp, Hans Tore; Janussen, Dorte; Tendal, Ole S.
2011-03-01
Calcareous sponges have traditionally been regarded as shallow-water organisms, a persistent myth created by Hentschel (1925), partly supported by the problematic question of calcareous skeletal secretion under high partial CO 2-pressure below the CCD in the abyss. Up to now, only few species world-wide of the sponge class Calcarea have been described from depths below 2000 m. By far, the largest number of records of Antarctic Calcarea is known from shelf areas between 50 and 400 m depth. They have only been sporadically recorded on the lower shelf and the upper slope from depths between 570 and 850 m. From abyssal depths in the Antarctic there are no previous records of calcareous sponges. It was therefore a big surprise when the first true deep-sea Calcarea from the Antarctic were collected at depths between 1120 and 4400 m during the ANDEEP I, II and III expeditions ( Janussen et al., 2006). To date, five calcareous sponge species have been found, including three species new to science. The three new species belong to the genera Ascaltis, Clathrina and Leucetta. Although calcareous sponges are rare in the Antarctic deep sea, they seem to constitute a constant component of the fauna. Antarctic Calcarea shows all the characteristics of need for revision and further collection and investigation. Still, many new species are likely to be discovered in the Antarctic deep-sea.
NASA Astrophysics Data System (ADS)
Okokpujie, Imhade Princess; Ikumapayi, Omolayo M.; Okonkwo, Ugochukwu C.; Salawu, Enesi Y.; Afolalu, Sunday A.; Dirisu, Joseph O.; Nwoke, Obinna N.; Ajayi, Oluseyi O.
2017-12-01
In recent machining operation, tool life is one of the most demanding tasks in production process, especially in the automotive industry. The aim of this paper is to study tool wear on HSS in end milling of aluminium 6061 alloy. The experiments were carried out to investigate tool wear with the machined parameters and to developed mathematical model using response surface methodology. The various machining parameters selected for the experiment are spindle speed (N), feed rate (f), axial depth of cut (a) and radial depth of cut (r). The experiment was designed using central composite design (CCD) in which 31 samples were run on SIEG 3/10/0010 CNC end milling machine. After each experiment the cutting tool was measured using scanning electron microscope (SEM). The obtained optimum machining parameter combination are spindle speed of 2500 rpm, feed rate of 200 mm/min, axial depth of cut of 20 mm, and radial depth of cut 1.0mm was found out to achieved the minimum tool wear as 0.213 mm. The mathematical model developed predicted the tool wear with 99.7% which is within the acceptable accuracy range for tool wear prediction.
Motion compensation and noise tolerance in phase-shifting digital in-line holography.
Stenner, Michael D; Neifeld, Mark A
2006-05-15
We present a technique for phase-shifting digital in-line holography which compensates for lateral object motion. By collecting two frames of interference between object and reference fields with identical reference phase, one can estimate the lateral motion that occurred between frames using the cross-correlation. We also describe a very general linear framework for phase-shifting holographic reconstruction which minimizes additive white Gaussian noise (AWGN) for an arbitrary set of reference field amplitudes and phases. We analyze the technique's sensitivity to noise (AWGN, quantization, and shot), errors in the reference fields, errors in motion estimation, resolution, and depth of field. We also present experimental motion-compensated images achieving the expected resolution.
Paguirigan, Medel Salvador
2012-01-01
The sale of solid organs is illegal in many countries, but the reality is that it happens. This study investigated and identified the structure of sacrificing something important among compensated kidney donors in the Philippines by conducting in-depth, face-to-face dialogues from 13 participants in the town of Baseco, Manila, Philippines. The structure of sacrificing something important among compensated kidney donors emerges from the extrinsic intent of adversity and the intrinsic intent of altruism, which is instrumental to the struggle of making a difficult decision, emerging in the act with reciprocation, and although resulting in the consequences of health deterioration and loss, resilience makes bouncing back possible.
NASA Astrophysics Data System (ADS)
Raffi, I.; Ciummelli, M.; Backman, J.; Iodp Expedition 320/321 Shipboard Scientific Party
2010-12-01
A continuous Cenozoic sediment record of the paleoequatorial Pacific ocean was recovered during IODP Expedition 320/321 (March-June 2009). The Pacific Equatorial Age Transect (PEAT) includes eight sites (U1331 to U1338), cored above the paleo-position of the equator at successive crustal ages on the Pacific plate, with records from the sediment surface to basement, with basalt aged between 53 to 18 Ma. The present study is focused on IODP Site 1338 that collected a 3-18 Ma segment of the PEAT equatorial megasplice. Although the target equatorial interval of Site 1338 was the middle and late Miocene, ~415 m of a complete sedimentary succession from Pleistocene to lower Miocene was recovered. Sediments are nannofossil ooze and chalk with varying concentrations (often relatively high abundances) of biosiliceous components, and show decimeter to meter lithological cycles that possibly reflect changes in production, dissolution, photic zone paleoecology. Ongoing analysis on nannofossil assemblages and selected taxa are providing distribution and abundance data that, combined with geochemical proxies, will unravel the biotic response to different climatic and oceanographic conditions. Biometric analysis and quantitative abundance analysis are used for providing a clear taxonomy of an important Neogene component of the nannofossil assemblages, the genus Discoaster, and for delineating in detail the evolutionary trends within the taxon. Moreover, we will try to relate the evolutionary signal observed in Discoaster lineage to the environmental evolution, namely to significant events such as the carbonate crash (Vincent and Berger, 1985; Lyle, et al., in prep.), the fluctuation and shallowing of the Calcite Compensation Depth (CCD) (Lyle, 2003), and deposition of diatom enriched intervals (Kemp and Baldauf, 1993).
A real-time monitoring system for night glare protection
NASA Astrophysics Data System (ADS)
Ma, Jun; Ni, Xuxiang
2010-11-01
When capturing a dark scene with a high bright object, the monitoring camera will be saturated in some regions and the details will be lost in and near these saturated regions because of the glare vision. This work aims at developing a real-time night monitoring system. The system can decrease the influence of the glare vision and gain more details from the ordinary camera when exposing a high-contrast scene like a car with its headlight on during night. The system is made up of spatial light modulator (The liquid crystal on silicon: LCoS), image sensor (CCD), imaging lens and DSP. LCoS, a reflective liquid crystal, can modular the intensity of reflective light at every pixel as a digital device. Through modulation function of LCoS, CCD is exposed with sub-region. With the control of DSP, the light intensity is decreased to minimum in the glare regions, and the light intensity is negative feedback modulated based on PID theory in other regions. So that more details of the object will be imaging on CCD and the glare protection of monitoring system is achieved. In experiments, the feedback is controlled by the embedded system based on TI DM642. Experiments shows: this feedback modulation method not only reduces the glare vision to improve image quality, but also enhances the dynamic range of image. The high-quality and high dynamic range image is real-time captured at 30hz. The modulation depth of LCoS determines how strong the glare can be removed.
NASA Technical Reports Server (NTRS)
Matus, Carlos V.
1989-01-01
Alignment viewed through microscope. Alignment jig positions shadow mask on charge-coupled device (CCD) so metal film deposited on it precisely. Allows CCD package to be inserted and removed without disturbing alignment of mask. Holds CCD packages securely and isolates it electrostatically while providing electrical contact to each of its pins. When alignment jig assembled with CCD, used to move mask under micrometer control.
Rubio, Angela; Rambla, José Luís; Santaella, Marcella; Gómez, M. Dolores; Orzaez, Diego; Granell, Antonio; Gómez-Gómez, Lourdes
2008-01-01
Saffron, the processed stigma of Crocus sativus, is characterized by the presence of several apocarotenoids that contribute to the color, flavor, and aroma of the spice. However, little is known about the synthesis of aroma compounds during the development of the C. sativus stigma. The developing stigma is nearly odorless, but before and at anthesis, the aromatic compound β-ionone becomes the principal norisoprenoid volatile in the stigma. In this study, four carotenoid cleavage dioxygenase (CCD) genes, CsCCD1a, CsCCD1b, CsCCD4a, and CsCCD4b, were isolated from C. sativus. Expression analysis showed that CsCCD1a was constitutively expressed, CsCCD1b was unique to the stigma tissue, but only CsCCD4a and -b had expression patterns consistent with the highest levels of β-carotene and emission of β-ionone derived during the stigma development. The CsCCD4 enzymes were localized in plastids and more specifically were present in the plastoglobules. The enzymatic activities of CsCCD1a, CsCCD1b, and CsCCD4 enzymes were determined by Escherichia coli expression, and subsequent analysis of the volatile products was generated by GC/MS. The four CCDs fell in two phylogenetically divergent dioxygenase classes, but all could cleave β-carotene at the 9,10(9′,10′) positions to yield β-ionone. The data obtained suggest that all four C. sativus CCD enzymes may contribute in different ways to the production of β-ionone. In addition, the location and precise timing of β-ionone synthesis, together with its known activity as a fragrance and insect attractant, suggest that this volatile may have a role in Crocus pollination. PMID:18611853
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-24
... probes would be recorded by collaborating fishermen, along with information on location, depth fished... probes to gain information about fish distribution. Compensation fishing for this research would occur...
Using a delta-doped CCD to determine the energy of a low-energy particle
NASA Technical Reports Server (NTRS)
Nikzad, Shouleh (Inventor); Croley, Donald R. (Inventor); Murphy, Gerald B. (Inventor)
2001-01-01
The back surface of a thinned charged-coupled device (CCD) is treated to eliminate the backside potential well that appears in a conventional thinned CCD during backside illumination. The backside of the CCD includes a delta layer of high-concentration dopant confined to less than one monolayer of the crystal semiconductor. The thinned, delta-doped CCD is used to determine the energy of a very low-energy particle that penetrates less than 1.0 nm into the CCD, such as a proton having energy less than 10 keV.
Delta-doped CCD's as low-energy particle detectors and imagers
NASA Technical Reports Server (NTRS)
Nikzad, Shouleh (Inventor); Hoenk, Michael E. (Inventor); Hecht, Michael H. (Inventor)
2002-01-01
The back surface of a thinned charged-coupled device (CCD) is treated to eliminate the backside potential well that appears in a conventional thinned CCD during backside illumination. The backside of the CCD includes a delta layer of high-concentration dopant confined to less than one monolayer of the crystal semiconductor. The thinned, delta-doped CCD is used to detect very low-energy particles that penetrate less than 1.0 nm into the CCD, including electrons having energies less than 1000 eV and protons having energies less than 10 keV.
Smith, Andrew B.; Maxwell, Anthony
2006-01-01
DNA gyrase is the only topoisomerase able to introduce negative supercoils into DNA. Absent in humans, gyrase is a successful target for antibacterial drugs. However, increasing drug resistance is a serious problem and new agents are urgently needed. The naturally-produced Escherichia coli toxin CcdB has been shown to target gyrase by what is predicted to be a novel mechanism. CcdB has been previously shown to stabilize the gyrase ‘cleavage complex’, but it has not been shown to inhibit the catalytic reactions of gyrase. We present data showing that CcdB does indeed inhibit the catalytic reactions of gyrase by stabilization of the cleavage complex and that the GyrA C-terminal DNA-wrapping domain and the GyrB N-terminal ATPase domain are dispensable for CcdB's action. We further investigate the role of specific GyrA residues in the action of CcdB by site-directed mutagenesis; these data corroborate a model for CcdB action based on a recent crystal structure of a CcdB–GyrA fragment complex. From this work, we are now able to present a model for CcdB action that explains all previous observations relating to CcdB–gyrase interaction. CcdB action requires a conformation of gyrase that is only revealed when DNA strand passage is taking place. PMID:16963775
Smith, Andrew B; Maxwell, Anthony
2006-01-01
DNA gyrase is the only topoisomerase able to introduce negative supercoils into DNA. Absent in humans, gyrase is a successful target for antibacterial drugs. However, increasing drug resistance is a serious problem and new agents are urgently needed. The naturally-produced Escherichia coli toxin CcdB has been shown to target gyrase by what is predicted to be a novel mechanism. CcdB has been previously shown to stabilize the gyrase 'cleavage complex', but it has not been shown to inhibit the catalytic reactions of gyrase. We present data showing that CcdB does indeed inhibit the catalytic reactions of gyrase by stabilization of the cleavage complex and that the GyrA C-terminal DNA-wrapping domain and the GyrB N-terminal ATPase domain are dispensable for CcdB's action. We further investigate the role of specific GyrA residues in the action of CcdB by site-directed mutagenesis; these data corroborate a model for CcdB action based on a recent crystal structure of a CcdB-GyrA fragment complex. From this work, we are now able to present a model for CcdB action that explains all previous observations relating to CcdB-gyrase interaction. CcdB action requires a conformation of gyrase that is only revealed when DNA strand passage is taking place.
Drummond, Revel S M; Martínez-Sánchez, N Marcela; Janssen, Bart J; Templeton, Kerry R; Simons, Joanne L; Quinn, Brian D; Karunairetnam, Sakuntala; Snowden, Kimberley C
2009-12-01
One of the key factors that defines plant form is the regulation of when and where branches develop. The diversity of form observed in nature results, in part, from variation in the regulation of branching between species. Two CAROTENOID CLEAVAGE DIOXYGENASE (CCD) genes, CCD7 and CCD8, are required for the production of a branch-suppressing plant hormone. Here, we report that the decreased apical dominance3 (dad3) mutant of petunia (Petunia hybrida) results from the mutation of the PhCCD7 gene and has a less severe branching phenotype than mutation of PhCCD8 (dad1). An analysis of the expression of this gene in wild-type, mutant, and grafted petunia suggests that in petunia, CCD7 and CCD8 are coordinately regulated. In contrast to observations in Arabidopsis (Arabidopsis thaliana), ccd7ccd8 double mutants in petunia show an additive phenotype. An analysis using dad3 or dad1 mutant scions grafted to wild-type rootstocks showed that when these plants produce adventitious mutant roots, branching is increased above that seen in plants where the mutant roots are removed. The results presented here indicate that mutation of either CCD7 or CCD8 in petunia results in both the loss of an inhibitor of branching and an increase in a promoter of branching.
Drummond, Revel S.M.; Martínez-Sánchez, N. Marcela; Janssen, Bart J.; Templeton, Kerry R.; Simons, Joanne L.; Quinn, Brian D.; Karunairetnam, Sakuntala; Snowden, Kimberley C.
2009-01-01
One of the key factors that defines plant form is the regulation of when and where branches develop. The diversity of form observed in nature results, in part, from variation in the regulation of branching between species. Two CAROTENOID CLEAVAGE DIOXYGENASE (CCD) genes, CCD7 and CCD8, are required for the production of a branch-suppressing plant hormone. Here, we report that the decreased apical dominance3 (dad3) mutant of petunia (Petunia hybrida) results from the mutation of the PhCCD7 gene and has a less severe branching phenotype than mutation of PhCCD8 (dad1). An analysis of the expression of this gene in wild-type, mutant, and grafted petunia suggests that in petunia, CCD7 and CCD8 are coordinately regulated. In contrast to observations in Arabidopsis (Arabidopsis thaliana), ccd7ccd8 double mutants in petunia show an additive phenotype. An analysis using dad3 or dad1 mutant scions grafted to wild-type rootstocks showed that when these plants produce adventitious mutant roots, branching is increased above that seen in plants where the mutant roots are removed. The results presented here indicate that mutation of either CCD7 or CCD8 in petunia results in both the loss of an inhibitor of branching and an increase in a promoter of branching. PMID:19846541
A spherical aberration-free microscopy system for live brain imaging.
Ue, Yoshihiro; Monai, Hiromu; Higuchi, Kaori; Nishiwaki, Daisuke; Tajima, Tetsuya; Okazaki, Kenya; Hama, Hiroshi; Hirase, Hajime; Miyawaki, Atsushi
2018-06-02
The high-resolution in vivo imaging of mouse brain for quantitative analysis of fine structures, such as dendritic spines, requires objectives with high numerical apertures (NAs) and long working distances (WDs). However, this imaging approach is often hampered by spherical aberration (SA) that results from the mismatch of refractive indices in the optical path and becomes more severe with increasing depth of target from the brain surface. Whereas a revolving objective correction collar has been designed to compensate SA, its adjustment requires manual operation and is inevitably accompanied by considerable focal shift, making it difficult to acquire the best image of a given fluorescent object. To solve the problems, we have created an objective-attached device and formulated a fast iterative algorithm for the realization of an automatic SA compensation system. The device coordinates the collar rotation and the Z-position of an objective, enabling correction collar adjustment while stably focusing on a target. The algorithm provides the best adjustment on the basis of the calculated contrast of acquired images. Together, they enable the system to compensate SA at a given depth. As proof of concept, we applied the SA compensation system to in vivo two-photon imaging with a 25 × water-immersion objective (NA, 1.05; WD, 2 mm). It effectively reduced SA regardless of location, allowing quantitative and reproducible analysis of fine structures of YFP-labeled neurons in the mouse cerebral cortical layers. Interestingly, although the cortical structure was optically heterogeneous along the z-axis, the refractive index of each layer could be assessed on the basis of the compensation degree. It was also possible to make fully corrected three-dimensional reconstructions of YFP-labeled neurons in live brain samples. Our SA compensation system, called Deep-C, is expected to bring out the best in all correction-collar-equipped objectives for imaging deep regions of heterogeneous tissues. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.
Asteroseismology with FRESIP: A meter class space telescope
NASA Technical Reports Server (NTRS)
Milford, Peter
1994-01-01
The requirements for asteroseismology and searching for occulting inner planets are similar. The FRESIP mission will be suited to making asteroseismology measurements. Recommendation: Use 30-60 second integrations from one or more CCD's in the FRESIP mosaic, sampled continuously for the entire mission to measure stellar non-radial oscillations with amplitudes of parts per million and frequencies of 0.1 to 10 MHz. These measurements lead to determination of stellar interior helium abundances, rotation rates, depth of convection zones and measuring stellar cycle frequency changes for a variety of stellar types, enabling major advances in stellar structure and evolutionary theories.
Brehler, Randolf; von Schaewen, Antje
2011-01-01
Background A longstanding debate in allergy is whether or not specific immunoglobulin-E antibodies (sIgE), recognizing cross-reactive carbohydrate determinants (CCD), are able to elicit clinical symptoms. In pollen and food allergy, ≥20% of patients display in-vitro CCD reactivity based on presence of α1,3-fucose and/or β1,2-xylose residues on N-glycans of plant (xylose/fucose) and insect (fucose) glycoproteins. Because the allergenicity of tomato glycoallergen Lyc e 2 was ascribed to N-glycan chains alone, this study aimed at evaluating clinical relevance of CCD-reduced foodstuff in patients with carbohydrate-specific IgE (CCD-sIgE). Methodology/Principal Findings Tomato and/or potato plants with stable reduction of Lyc e 2 (tomato) or CCD formation in general were obtained via RNA interference, and gene-silencing was confirmed by immunoblot analyses. Two different CCD-positive patient groups were compared: one with tomato and/or potato food allergy and another with hymenoptera-venom allergy (the latter to distinguish between CCD- and peptide-specific reactions in the food-allergic group). Non-allergic and CCD-negative food-allergic patients served as controls for immunoblot, basophil activation, and ImmunoCAP analyses. Basophil activation tests (BAT) revealed that Lyc e 2 is no key player among other tomato (glyco)allergens. CCD-positive patients showed decreased (re)activity with CCD-reduced foodstuff, most obvious in the hymenoptera venom-allergic but less in the food-allergic group, suggesting that in-vivo reactivity is primarily based on peptide- and not CCD-sIgE. Peptide epitopes remained unaffected in CCD-reduced plants, because CCD-negative patient sera showed reactivity similar to wild-type. In-house-made ImmunoCAPs, applied to investigate feasibility in routine diagnosis, confirmed BAT results at the sIgE level. Conclusions/Significance CCD-positive hymenoptera venom-allergic patients (control group) showed basophil activation despite no allergic symptoms towards tomato and potato. Therefore, this proof-of-principle study demonstrates feasibility of CCD-reduced foodstuff to minimize ‘false-positive results’ in routine serum tests. Despite confirming low clinical relevance of CCD antibodies, we identified one patient with ambiguous in-vitro results, indicating need for further component-resolved diagnosis. PMID:21423762
Timing generator of scientific grade CCD camera and its implementation based on FPGA technology
NASA Astrophysics Data System (ADS)
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.
z'-BAND GROUND-BASED DETECTION OF THE SECONDARY ECLIPSE OF WASP-19b
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burton, J. R.; Watson, C. A.; Pollacco, D.
2012-08-01
We present the ground-based detection of the secondary eclipse of the transiting exoplanet WASP-19b. The observations were made in the Sloan z' band using the ULTRACAM triple-beam CCD camera mounted on the New Technology Telescope. The measurement shows a 0.088% {+-} 0.019% eclipse depth, matching previous predictions based on H- and K-band measurements. We discuss in detail our approach to the removal of errors arising due to systematics in the data set, in addition to fitting a model transit to our data. This fit returns an eclipse center, T{sub 0}, of 2455578.7676 HJD, consistent with a circular orbit. Our measurementmore » of the secondary eclipse depth is also compared to model atmospheres of WASP-19b and is found to be consistent with previous measurements at longer wavelengths for the model atmospheres we investigated.« less
NASA Astrophysics Data System (ADS)
Palevsky, Hilary I.; Doney, Scott C.
2018-05-01
Estimated rates and efficiency of ocean carbon export flux are sensitive to differences in the depth horizons used to define export, which often vary across methodological approaches. We evaluate sinking particulate organic carbon (POC) flux rates and efficiency (e-ratios) in a global earth system model, using a range of commonly used depth horizons: the seasonal mixed layer depth, the particle compensation depth, the base of the euphotic zone, a fixed depth horizon of 100 m, and the maximum annual mixed layer depth. Within this single dynamically consistent model framework, global POC flux rates vary by 30% and global e-ratios by 21% across different depth horizon choices. Zonal variability in POC flux and e-ratio also depends on the export depth horizon due to pronounced influence of deep winter mixing in subpolar regions. Efforts to reconcile conflicting estimates of export need to account for these systematic discrepancies created by differing depth horizon choices.
NASA Astrophysics Data System (ADS)
Abdullayev, B. I.; Gulmaliyev, N. I.; Majidova, S. O.; Mikayilov, Kh. M.; Rustamov, B. N.
2009-12-01
Basic technical characteristics of CCD matrix U-47 made by the Apogee Alta Instruments Inc. are provided. Short description and features of various noises introduced by optical system and CCD camera are presented. The technique of getting calibration frames: bias, dark, flat field and main stages of processing of results CCD photometry are described.
Western Ishtar Terra and Lakshmi Planum, Venus - Models of formation and evolution
NASA Astrophysics Data System (ADS)
Roberts, Kari M.; Head, James W.
1990-08-01
Regional geologic mapping and gravity data reveal a variety of characteristics that must be accounted for in models for the formation and evolution of Western Ishtar Terra and Lakshmi Planum, including: (1) high elevation, (2) plateau-shaped profile, (3) abnormally steep bounding slopes, (4) foredeeps, (5) polygonal outline, (6) adjacent orogenic belts, (7) volcanic plains, (8) plains emplaced synchronously with orogenic belts, (9) paterae, (10) variable topography of Lakshmi, (11) tessera-like material underlying Lakshmi, and (12) a large apparent depth of compensation. A tessera/peripheral deformation model, in which a preexisting block of tessera is the locus of convergence of adjacent thinner crust and lithosphere, underthrusting, mountain building, subsurface melting, and plateau uplift, is interpreted to account for most of the characteristics. The aparent depth of compensation is not simply explained by this model and appears to require a second, deeper mantle anomaly component, such as broad mantle upwelling or a hot spot.
Comparative analysis of data quality and applications in vegetation of HJ-1A CCD images
NASA Astrophysics Data System (ADS)
Wei, Hongwei; Tian, Qingjiu; Huang, Yan; Wang, Yan
2014-05-01
To study the data quality and to find the differences in vegetation monitoring applications, the same region at Chuzhou Lai 'an, the data of HJ-1A CCD1 on the April 1st, 2012 and the data of HJ-1A CCD2 on the March 31, 2012 have being comparative analysis by the method of objective quality (image)assessment which selecting over five spectral image evaluation parameters: radiation precision (mean, variance, inclination, steepness), information entropy, signal-to-noise ratio, sharpness, contrast, and normalized differential vegetation index. The results show that there is little differences between the HJ-1A CCD1 and CCD2 by objective evaluation of data quality except radiation precision conform to their design theory, so the conclusion is that the difference of them without considering on the usual unless continuation;and Combination of field observation data Lai'an spectral data and GPS data (each point),selecting the normalized difference vegetation index as CCD1, CCD2 in vegetation monitoring application on the evaluation of the differences, and the specific process is based on GPS data is divided into nine small plots of spectral data ,and image data of nine one-to-one correspondence plots, and their normalized difference vegetation index values were calculated ,and measured spectra data resampling HJ-1A CCD1, CCD2 spectral response function calculated NDVI, and the results show that there is little differences between the HJ-1A CCD1 and CCD2 by objective evaluation of data quality, and, the differences of wheat `s reflection and normalized vegetation index is mainly due to calibration coefficients of CCD1 and CCD2, the differences of the solar elevation angle when obtaining the image and atmospheric conditions, so it has to consider the performance indicators as well as access conditions of CCD1 and CCD2, and to be take the normalization techniques for processing for the comparison analysis in the use of HJ-1A CCD Data to surface dynamic changes; Finally, in order to study the response of the spectral response function proposed spectral response function of impact factor, and in view of the spectral response function measured spectral data resampling only HJ-1A CCD spectral response function, calculated according to the formula of the equivalent reflectivity quantitative spectral response function, and spectral normalization of proposed theoretical Technical Support. The Objective evaluation of its application of HJ-1A CCD1, and CCD2 data quality differences research has important implications for broader application to further promote China-made remote sensing satellite data, future research also needs calibration coefficient, the solar elevation angle atmospheric conditions and its image scanning angle be taken into account, and to make the corresponding normalized its impact quantitative research has important significance for the timing changes in the application of the ecological environment in China.
Denoising Algorithm for CFA Image Sensors Considering Inter-Channel Correlation.
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.
Upper mantle heterogeneity: Comparisons of regions south of Australia with Philippine Basin
NASA Technical Reports Server (NTRS)
1982-01-01
The nature of mass anomalies that occur beneath the regions of negative residual depth anomalies were identified. Residual geoid anomalies with negative residual depth anomalies are identified in the Philippine Basin (negative) and in the region south of Australia (positive and negative). In the latter region the geoid anomalies are eastward and the depth anomaly is northeast. It is suggested that the negative depth anomaly and the compensating mass excess in the uppermost mantle developed in the Eocene as the lithosphere of the west Philippine basin formed. Heating of the deeper upper mantle which causes slow surface wave velocities and negative gravity and geoid anomalies may be a younger phenomenon which is still in progress.
CCD TV focal plane guider development and comparison to SIRTF applications
NASA Technical Reports Server (NTRS)
Rank, David M.
1989-01-01
It is expected that the SIRTF payload will use a CCD TV focal plane fine guidance sensor to provide acquisition of sources and tracking stability of the telescope. Work has been done to develop CCD TV cameras and guiders at Lick Observatory for several years and have produced state of the art CCD TV systems for internal use. NASA decided to provide additional support so that the limits of this technology could be established and a comparison between SIRTF requirements and practical systems could be put on a more quantitative basis. The results of work carried out at Lick Observatory which was designed to characterize present CCD autoguiding technology and relate it to SIRTF applications is presented. Two different design types of CCD cameras were constructed using virtual phase and burred channel CCD sensors. A simple autoguider was built and used on the KAO, Mt. Lemon and Mt. Hamilton telescopes. A video image processing system was also constructed in order to characterize the performance of the auto guider and CCD cameras.
NASA Astrophysics Data System (ADS)
Volkamer, Rainer; Coburn, Sean; Dix, Barbara; Sinreich, Roman
2009-08-01
Multi AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) instruments, as solar straylight satellites, require an accurate characterization and elimination of Fraunhofer lines from solar straylight spectra to measure the atmospheric column abundance of reactive gases that destroy toxic and heat trapping ozone and form climate cooling aerosols, like glyoxal (CHOCHO), iodine oxide (IO), or bromine oxide (BrO). The currently achievable noise levels with state-of-the-art DOAS instruments are limited to δ'DL ~ 10-4 (noise equivalent differential optical density, δ') further noise reductions are typically not straightforward, and the reason for this barrier is not well understood. Here we demonstrate that the nonlinearity of state-of-the-art CCD detectors poses a limitation to accurately characterize Fraunhofer lines; the incomplete elimination of Fraunhofer lines is found to cause residual structures of δ' ~ 10-4, and only partially accounted by fitting of an "offset" spectrum. We have developed a novel software tool, the CU Data Acquisition Code that overcomes this barrier by actively controlling the CCD saturation level, and demonstrates that δ'DL on the order of 10-5 are possible without apparent limitations from the presence of Fraunhofer lines. The software also implements active control of the elevation angle (angle with respect to the horizon) by means of a Motion Compensation System for use with mobile MAX-DOAS deployments from ships and aircraft. Finally, a novel approach to convert slant column densities into line-of-sight averaged concentrations is discussed.
The soft x ray telescope for Solar-A
NASA Technical Reports Server (NTRS)
Brown, W. A.; Acton, L. W.; Bruner, M. E.; Lemen, J. R.; Strong, K. T.
1989-01-01
The Solar-A satellite being prepared by the Institute for Sapce and Astronautical Sciences (ISAS) in Japan is dedicated to high energy observations of solar flares. The Soft X Ray Telescope (SXT) is being prepared to provide filtered images in the 2 to 60 A interval. The flight model is now undergoing tests in the 1000 foot tunnel at MSFC. Launch will be in September 1991. Earlier resolution and efficiency tests on the grazing incidence mirror have established its performance in soft x rays. The one-piece, two mirror grazing incidence telescope is supported in a strain free mount separated from the focal plane assembly by a carbon-epoxy metering tube whose windings and filler are chosen to minimize thermal and hygroscopic effects. The CCD detector images both the x ray and the concentric visible light aspect telescope. Optical filters provide images at 4308 and 4700 A. The SXT will be capable of producing over 8000 of the smallest partial frame images per day, or fewer but larger images, up to 1024 x 1024 pixel images. Image sequence with two or more of the five x ray analysis filters, with automatic exposure compensation to optimize the charge collection by the CCD detector, will be used to provide plasma diagnostics. Calculations using a differential emission measure code were used to optimize filter selection over the range of emission measure variations and to avoid redundancy, but the filters were chosen primarily to give ratios that are monotonic in plasma temperature.
SU-E-T-357: Electronic Compensation Technique to Deliver Total Body Dose
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lakeman, T; Wang, I; Podgorsak, M
Purpose: Total body irradiation (TBI) uses large parallel-opposed radiation fields to suppress the patient’s immune system and eradicate the residual cancer cells in preparation of recipient for bone marrow transplant. The manual placement of lead compensators has conventionally been used to compensate for the varying thickness through the entire body in large-field TBI. The goal of this study is to pursue utilizing the modern electronic compensation technique to more accurately and efficiently deliver dose to patients in need of TBI. Methods: Treatment plans utilizing electronic compensation to deliver a total body dose were created retrospectively for patients for whom CTmore » data had been previously acquired. Each treatment plan includes two, specifically weighted, pair of opposed fields. One pair of open, large fields (collimator=45°), to encompass the patient’s entire anatomy, and one pair of smaller fields (collimator=0°) focused only on the thicker midsection of the patient. The optimal fluence for each one of the smaller fields was calculated at a patient specific penetration depth. Irregular surface compensators provide a more uniform dose distribution within the smaller opposed fields. Results: Dose-volume histograms (DVH) were calculated for the evaluating the electronic compensation technique. In one case, the maximum body doses calculated from the DVH were reduced from the non-compensated 195.8% to 165.3% in the electronically compensated plans, indicating a more uniform dose with the region of electronic compensation. The mean body doses calculated from the DVH were also reduced from the non-compensated 120.6% to 112.7% in the electronically compensated plans, indicating a more accurate delivery of the prescription dose. All calculated monitor units were well within clinically acceptable limits. Conclusion: Electronic compensation technique for TBI will not substantially increase the beam on time while it can significantly reduce the compensator setup time and the potential risk of errors in manually placing lead compensators.« less
A metagenomic survey of microbes in honey bee colony collapse disorder.
Cox-Foster, Diana L; Conlan, Sean; Holmes, Edward C; Palacios, Gustavo; Evans, Jay D; Moran, Nancy A; Quan, Phenix-Lan; Briese, Thomas; Hornig, Mady; Geiser, David M; Martinson, Vince; vanEngelsdorp, Dennis; Kalkstein, Abby L; Drysdale, Andrew; Hui, Jeffrey; Zhai, Junhui; Cui, Liwang; Hutchison, Stephen K; Simons, Jan Fredrik; Egholm, Michael; Pettis, Jeffery S; Lipkin, W Ian
2007-10-12
In colony collapse disorder (CCD), honey bee colonies inexplicably lose their workers. CCD has resulted in a loss of 50 to 90% of colonies in beekeeping operations across the United States. The observation that irradiated combs from affected colonies can be repopulated with naive bees suggests that infection may contribute to CCD. We used an unbiased metagenomic approach to survey microflora in CCD hives, normal hives, and imported royal jelly. Candidate pathogens were screened for significance of association with CCD by the examination of samples collected from several sites over a period of 3 years. One organism, Israeli acute paralysis virus of bees, was strongly correlated with CCD.
Color management in textile application
NASA Astrophysics Data System (ADS)
De Lucia, Maurizio; Vannucci, Massimiliano; Buonopane, Massimo; Fabroni, Cosimo; Fabrini, Francesco
2002-03-01
The aim of this research was to study a system of acquisition and processing of images capable of confronting colored wool with a reference specimen, in order to define the conformity using objective parameters. The first step of the research was to comprise and to analyze in depth the problem: there has been numerous implications of technical, physical, cultural, biological and also psychological character, that come down from the attempt of giving a quantitative appraisal to the color. In the scene of the national and international scientific and technological research, little has been made as regards measurement of color through digital processing of the images through linear CCD. The reason is fundamentally of technological nature: only during the last years we found the presence on the market of low cost equipment capable of acquiring and processing images with adequate performances and qualities. The job described has permitted to create a first prototype of system for the color measuring with use of CCD linear devices. -Hardware identification to carry out a series of tests and experiments in laboratory. -Verification of such device in a textile facility. -Statistics analysis of the collected data and of the employed models.
Design of a Day/Night Star Camera System
NASA Technical Reports Server (NTRS)
Alexander, Cheryl; Swift, Wesley; Ghosh, Kajal; Ramsey, Brian
1999-01-01
This paper describes the design of a camera system capable of acquiring stars during both the day and night cycles of a high altitude balloon flight (35-42 km). The camera system will be filtered to operate in the R band (590-810 nm). Simulations have been run using MODTRAN atmospheric code to determine the worse case sky brightness at 35 km. With a daytime sky brightness of 2(exp -05) W/sq cm/str/um in the R band, the sensitivity of the camera system will allow acquisition of at least 1-2 stars/sq degree at star magnitude limits of 8.25-9.00. The system will have an F2.8, 64.3 mm diameter lens and a 1340X1037 CCD array digitized to 12 bits. The CCD array is comprised of 6.8 X 6.8 micron pixels with a well depth of 45,000 electrons and a quantum efficiency of 0.525 at 700 nm. The camera's field of view will be 6.33 sq degree and provide attitude knowledge to 8 arcsec or better. A test flight of the system is scheduled for fall 1999.
Silicide Schottky Barrier For Back-Surface-Illuminated CCD
NASA Technical Reports Server (NTRS)
Hecht, Michael H.
1990-01-01
Quantum efficiency of back-surface-illuminated charge-coupled device (CCD) increased by coating back surface with thin layer of PtSi or IrSi on thin layer of SiO2. In its interaction with positively-doped bulk Si of CCD, silicide/oxide layer forms Schottky barrier that repels electrons, promoting accumulation of photogenerated charge carriers in front-side CCD potential wells. Physical principle responsible for improvement explained in "Metal Film Increases CCD Output" (NPO-16815).
Gain-Compensating Circuit For NDE and Ultrasonics
NASA Technical Reports Server (NTRS)
Kushnick, Peter W.
1987-01-01
High-frequency gain-compensating circuit designed for general use in nondestructive evaluation and ultrasonic measurements. Controls gain of ultrasonic receiver as function of time to aid in measuring attenuation of samples with high losses; for example, human skin and graphite/epoxy composites. Features high signal-to-noise ratio, large signal bandwidth and large dynamic range. Control bandwidth of 5 MHz ensures accuracy of control signal. Currently being used for retrieval of more information from ultrasonic signals sent through composite materials that have high losses, and to measure skin-burn depth in humans.
NASA Technical Reports Server (NTRS)
Garmire, Gordon P.; Nousek, John; Burrows, David; Ricker, George; Bautz, Mark; Doty, John; Collins, Stewart; Janesick, James
1988-01-01
The search for the optimum CCD to be used at the focal surface of the Advanced X-ray Astrophysics Facility (AXAF) is described. The physics of the interaction of X-rays in silicon through the photoelectric effect is reviewed. CCD technology at the beginning of the AXAF definition phase is summarized, and the results of the CCD enhancement program are discussed. Other sources of optimum CCDs are examined, and CCD enhancements made at MIT Lincoln Laboratory are addressed.
CCD research. [design, fabrication, and applications
NASA Technical Reports Server (NTRS)
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.
Tectonic contrasts between Venus and the earth
NASA Technical Reports Server (NTRS)
Kaula, W. M.
1984-01-01
The long-wave features of the gravity field of Venus differ from those of the earth's field not only in their strong positive correlation with topography, but also in their gentler spectral slope. These properties are inconsistent with generation of the gravity field by plate tectonics or by processes at great depths; they are consistent with generation by a mantle convective system supporting the broad features in topography with an effective compensation depth of about 450 km.
NASA Astrophysics Data System (ADS)
Petit, Carole; Le Pourhiet, Laetitia; Scalabrino, Bruno; Corsini, Michel; Bonnin, Mickaël; Romagny, Adrien
2015-07-01
We analyse Bouguer anomaly data and previously published Moho depths estimated from receiver functions in order to determine the amount of isostatic compensation or uncompensation of the Rif topography in northern Morocco. We use Moho depth variations extracted from receiver function analyses to predict synthetic Bouguer anomalies that are then compared to observed Bouguer anomaly. We find that Moho depth variations due to isostatic compensation of topographic and/or intracrustal loads do not match Moho depth estimates obtained from receiver function analyses. The isostatic misfit map evidences excess crustal root as large as 10 km in the western part of the study area, whereas a `missing' crustal root of ˜5 km appears east of 4.3°E. This excess root/missing topography correlates with the presence of a dense mantle lid, the noticeable southwestward drift of the Western Rif area, and with a current surface uplift. We propose that a delaminated mantle lid progressively detaching westward or southwestward from the overlying crust is responsible for viscous flow of the ductile lower crust beneath the Rif area. This gives rise to isostatic uplift and westward drift due to viscous coupling at the upper/lower crust boundary. At the same time, the presence of this dense sinking mantle lid causes a negative dynamic topography, which explains why the observed topography is too low compared to the crustal thickness.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Craft, D; Kry, S; Salehpour, M
Purpose: Patient-specific tissue equivalent compensators can be used for post-mastectomy radiation therapy (PMRT) to achieve homogenous dose distributions with single-field treatments. However, current fabrication methods are time consuming and expensive. 3D-printing technology could overcome these limitations. The purposes of this study were to [1] evaluate materials for 3D-printed compensators [2] design and print a compensator to achieve a uniform thickness to a clinical target volume (CTV), and [3] demonstrate that a single-field electron compensator plan is a clinically feasible treatment option for PMRT. Methods: Blocks were printed with three materials; print accuracy, density, Hounsfield units (HU), and percent depth dosesmore » (PDD) were evaluated. For a CT scan of an anthropomorphic phantom, we used a ray-tracing method to design a compensator that achieved uniform thickness from compensator surface to CTV. The compensator was printed with flexible tissue equivalent material whose physical and radiological properties were most similar to soft tissue. A single-field electron compensator plan was designed and compared with two standard-of-care techniques. The compensator plan was validated with thermoluminescent dosimeter (TLD) measurements. Results: We identified an appropriate material for 3D-printed compensators that had high print accuracy (99.6%) and was similar to soft tissue; density was 1.04, HU was - 45 ± 43, and PDD curves agreed with clinical curves within 3 mm. We designed and printed a compensator that conformed well to the phantom surface and created a uniform thickness to the CTV. In-house fabrication was simple and inexpensive (<$75). Compared with the two standard plans, the compensator plan resulted in overall more homogeneous dose distributions and performed similarly in terms of lung/heart doses and 90% isodose coverage of the CTV. TLD measurements agreed well with planned doses (within 5 %). Conclusions: We have demonstrated that 3D-printed compensators make single-field electron therapy a clinically feasible treatment option for PMRT.« less
SU-F-T-372: Surface and Peripheral Dose in Compensator-Based FFF Beam IMRT
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, D; Feygelman, V; Moros, E
2016-06-15
Purpose: Flattening filter free (FFF) beams produce higher dose rates. Combined with compensator IMRT techniques, the dose delivery for each beam can be much shorter compared to the flattened beam MLC-based or compensator-based IMRT. This ‘snap shot’ IMRT delivery is beneficial to patients for tumor motion management. Due to softer energy, surface doses in FFF beam treatment are usually higher than those from flattened beams. Because of less scattering due to no flattening filter, peripheral doses are usually lower in FFF beam treatment. However, in compensator-based IMRT using FFF beams, the compensator is in the beam pathway. Does it introducemore » beam hardening effects and scattering such that the surface dose is lower and peripheral dose is higher compared to FFF beam MLC-based IMRT? Methods: This study applied Monte Carlo techniques to investigate the surface and peripheral doses in compensator-based IMRT using FFF beams and compared it to the MLC-based IMRT using FFF beams and flattened beams. Besides various thicknesses of copper slabs to simulate various thicknesses of compensators, a simple cone-shaped compensator was simulated to mimic a clinical application. The dose distribution in water phantom by the cone-shaped compensator was then simulated by multiple MLC defined FFF and flattened beams with various openings. After normalized to Dmax, the surface and peripheral dose was compared between the FFF beam compensator-based IMRT and FFF/flattened beam MLC-based IMRT. Results: The surface dose at the central 0.5mm depth was close between the compensator and 6FFF MLC dose distributions, and about 8% (of Dmax) higher than the flattened 6MV MLC dose. At 8cm off axis at dmax, the peripheral dose between the 6FFF and flattened 6MV MLC demonstrated similar doses, while the compensator dose was about 1% higher. Conclusion: Compensator does not reduce the surface doses but slightly increases the peripheral doses due to scatter inside compensator.« less
Saotome, Naoya; Furukawa, Takuji; Hara, Yousuke; Mizushima, Kota; Tansho, Ryohei; Saraya, Yuichi; Shirai, Toshiyuki; Noda, Koji
2016-04-01
Three-dimensional irradiation with a scanned carbon-ion beam has been performed from 2011 at the authors' facility. The authors have developed the rotating-gantry equipped with the scanning irradiation system. The number of combinations of beam properties to measure for the commissioning is more than 7200, i.e., 201 energy steps, 3 intensities, and 12 gantry angles. To compress the commissioning time, quick and simple range verification system is required. In this work, the authors develop a quick range verification system using scintillator and charge-coupled device (CCD) camera and estimate the accuracy of the range verification. A cylindrical plastic scintillator block and a CCD camera were installed on the black box. The optical spatial resolution of the system is 0.2 mm/pixel. The camera control system was connected and communicates with the measurement system that is part of the scanning system. The range was determined by image processing. Reference range for each energy beam was determined by a difference of Gaussian (DOG) method and the 80% of distal dose of the depth-dose distribution that were measured by a large parallel-plate ionization chamber. The authors compared a threshold method and a DOG method. The authors found that the edge detection method (i.e., the DOG method) is best for the range detection. The accuracy of range detection using this system is within 0.2 mm, and the reproducibility of the same energy measurement is within 0.1 mm without setup error. The results of this study demonstrate that the authors' range check system is capable of quick and easy range verification with sufficient accuracy.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Saotome, Naoya, E-mail: naosao@nirs.go.jp; Furukawa, Takuji; Hara, Yousuke
Purpose: Three-dimensional irradiation with a scanned carbon-ion beam has been performed from 2011 at the authors’ facility. The authors have developed the rotating-gantry equipped with the scanning irradiation system. The number of combinations of beam properties to measure for the commissioning is more than 7200, i.e., 201 energy steps, 3 intensities, and 12 gantry angles. To compress the commissioning time, quick and simple range verification system is required. In this work, the authors develop a quick range verification system using scintillator and charge-coupled device (CCD) camera and estimate the accuracy of the range verification. Methods: A cylindrical plastic scintillator blockmore » and a CCD camera were installed on the black box. The optical spatial resolution of the system is 0.2 mm/pixel. The camera control system was connected and communicates with the measurement system that is part of the scanning system. The range was determined by image processing. Reference range for each energy beam was determined by a difference of Gaussian (DOG) method and the 80% of distal dose of the depth-dose distribution that were measured by a large parallel-plate ionization chamber. The authors compared a threshold method and a DOG method. Results: The authors found that the edge detection method (i.e., the DOG method) is best for the range detection. The accuracy of range detection using this system is within 0.2 mm, and the reproducibility of the same energy measurement is within 0.1 mm without setup error. Conclusions: The results of this study demonstrate that the authors’ range check system is capable of quick and easy range verification with sufficient accuracy.« less
Molecular Determinants of Mutant Phenotypes, Inferred from Saturation Mutagenesis Data.
Tripathi, Arti; Gupta, Kritika; Khare, Shruti; Jain, Pankaj C; Patel, Siddharth; Kumar, Prasanth; Pulianmackal, Ajai J; Aghera, Nilesh; Varadarajan, Raghavan
2016-11-01
Understanding how mutations affect protein activity and organismal fitness is a major challenge. We used saturation mutagenesis combined with deep sequencing to determine mutational sensitivity scores for 1,664 single-site mutants of the 101 residue Escherichia coli cytotoxin, CcdB at seven different expression levels. Active-site residues could be distinguished from buried ones, based on their differential tolerance to aliphatic and charged amino acid substitutions. At nonactive-site positions, the average mutational tolerance correlated better with depth from the protein surface than with accessibility. Remarkably, similar results were observed for two other small proteins, PDZ domain (PSD95 pdz3 ) and IgG-binding domain of protein G (GB1). Mutational sensitivity data obtained with CcdB were used to derive a procedure for predicting functional effects of mutations. Results compared favorably with those of two widely used computational predictors. In vitro characterization of 80 single, nonactive-site mutants of CcdB showed that activity in vivo correlates moderately with thermal stability and solubility. The inability to refold reversibly, as well as a decreased folding rate in vitro, is associated with decreased activity in vivo. Upon probing the effect of modulating expression of various proteases and chaperones on mutant phenotypes, most deleterious mutants showed an increased in vivo activity and solubility only upon over-expression of either Trigger factor or SecB ATP-independent chaperones. Collectively, these data suggest that folding kinetics rather than protein stability is the primary determinant of activity in vivo This study enhances our understanding of how mutations affect phenotype, as well as the ability to predict fitness effects of point mutations. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Design and Development of Multi-Purpose CCD Camera System with Thermoelectric Cooling: Hardware
NASA Astrophysics Data System (ADS)
Kang, Y.-W.; Byun, Y. I.; Rhee, J. H.; Oh, S. H.; Kim, D. K.
2007-12-01
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.
NASA Astrophysics Data System (ADS)
Wen, Lin; Li, Yu-dong; Guo, Qi; Wang, Chao-min
2018-02-01
Total ionizing dose effect is a major threat to space applications of CCD, which leads to the decrease of CCD saturation output voltage and the increase of dark signal. This paper investigated CCD and its readout circuit for experimental samples of different channel width to length ratio of MOSFET, and readout circuit amplifier, and CCD. The irradiation source was 60Co- gamma ray. through testing the parameters degradation of MOSFET and amplifier degradation, the generation and annealing law of irradiation induced defects in MOS single tube are analyzed. Combined with the radiation effect of amplifier and CCD, The correlation of radiation damage of the MOSFET and the readout circuit amplifier and CCD parameter degradation is established. Finally, this paper reveals the physical mechanism of ionizing radiation damage of the readout circuit. The research results provide a scientific basis for the selection of anti-radiation technology and structure optimization of domestic CCD.
Analysis of the in vivo confocal Raman spectral variability in human skin
NASA Astrophysics Data System (ADS)
Mogilevych, Borys; dos Santos, Laurita; Rangel, Joao L.; Grancianinov, Karen J. S.; Sousa, Mariane P.; Martin, Airton A.
2015-06-01
Biochemical composition of the skin changes in each layer and, therefore, the skin spectral profile vary with the depth. In this work, in vivo Confocal Raman spectroscopy studies were performed at different skin regions and depth profile (from the surface down to 10 μm) of the stratum corneum, to verify the variability and reproducibility of the intra- and interindividual Raman data. The Raman spectra were collected from seven healthy female study participants using a confocal Raman system from Rivers Diagnostic, with 785 nm excitation line and a CCD detector. Measurements were performed in the volar forearm region, at three different points at different depth, with the step of 2 μm. For each depth point, three spectra were acquired. Data analysis included the descriptive statistics (mean, standard deviation and residual) and Pearson's correlation coefficient calculation. Our results show that inter-individual variability is higher than intraindividual variability, and variability inside the SC is higher than on the skin surface. In all these cases we obtained r values, higher than 0.94, which correspond to high correlation between Raman spectra. It reinforces the possibility of the data reproducibility and direct comparison of in vivo results obtained with different study participants of the same age group and phototype.
Depth Perception of Surgeons in Minimally Invasive Surgery.
Bogdanova, Rositsa; Boulanger, Pierre; Zheng, Bin
2016-10-01
Minimally invasive surgery (MIS) poses visual challenges to the surgeons. In MIS, binocular disparity is not freely available for surgeons, who are required to mentally rebuild the 3-dimensional (3D) patient anatomy from a limited number of monoscopic visual cues. The insufficient depth cues from the MIS environment could cause surgeons to misjudge spatial depth, which could lead to performance errors thus jeopardizing patient safety. In this article, we will first discuss the natural human depth perception by exploring the main depth cues available for surgeons in open procedures. Subsequently, we will reveal what depth cues are lost in MIS and how surgeons compensate for the incomplete depth presentation. Next, we will further expand our knowledge by exploring some of the available solutions for improving depth presentation to surgeons. Here we will review the innovative approaches (multiple 2D camera assembly, shadow introduction) and devices (3D monitors, head-mounted devices, and auto-stereoscopic monitors) for 3D image presentation from the past few years. © The Author(s) 2016.
2014-01-01
Background In saffron (Crocus sativus), new corms develop at the base of every shoot developed from the maternal corm, a globular underground storage stem. Since the degree of bud sprouts influences the number and size of new corms, and strigolactones (SLs) suppress growth of pre-formed axillary bud, it was considered appropriate to investigate SL involvement in physiology and molecular biology in saffron. We focused on two of the genes within the SL pathway, CCD7 and CCD8, encoding carotenoid cleavage enzymes required for the production of SLs. Results The CsCCD7 and CsCCD8 genes are the first ones isolated and characterized from a non-grass monocotyledonous plant. CsCCD7 and CsCCD8 expression showed some overlapping, although they were not identical. CsCCD8 was highly expressed in quiescent axillary buds and decapitation dramatically reduced its expression levels, suggesting its involvement in the suppression of axillary bud outgrowth. Furthermore, in vitro experiments showed also the involvement of auxin, cytokinin and jasmonic acid on the sprouting of axillary buds from corms in which the apical bud was removed. In addition, CsCCD8 expression, but not CsCCD7, was higher in the newly developed vascular tissue of axillary buds compared to the vascular tissue of the apical bud. Conclusions We showed that production and transport of auxin in saffron corms could act synergistically with SLs to arrest the outgrowth of the axillary buds, similar to the control of above-ground shoot branching. In addition, jasmonic acid seems to play a prominent role in bud dormancy in saffron. While cytokinins from roots promote bud outgrowth. In addition the expression results of CsCCD8 suggest that SLs could positively regulate procambial activity and the development of new vascular tissues connecting leaves with the mother corm. PMID:24947472
Triton stellar occultation candidates: 1995-1999
NASA Technical Reports Server (NTRS)
Mcdonald, S. W.; Elliot, J. L.
1995-01-01
We have completed a search for candidates for stellar occultations by Triton over the years 1995-1999. CCd strip scan images provided star positions in the relevant sky area to a depth of about 17.5 R magnitude. Over this time period, we find that Triton passes within 1.0 arcsec of 75 stars. Appulses with geocentric minimum separations of less than 0.35 arcsec will result in stellar occultations, but further astrometry and photometry is necessary to refine individual predictions for identification of actual occultations. Finder charts are included to aid in further studies and prediction refinement. The two most promising potential occultations, Tr176 and Tr180, occur in 1997.
NASA Technical Reports Server (NTRS)
Chie, C. M.; Su, Y. T.; Lindsey, W. C.; Koukos, J.
1984-01-01
The autonomous and integrated aspects of the operation of the AIRS (Autonomous Integrated Receive System) are discussed from a system operation point of view. The advantages of AIRS compared to the existing SSA receive chain equipment are highlighted. The three modes of AIRS operation are addressed in detail. The configurations of the AIRS are defined as a function of the operating modes and the user signal characteristics. Each AIRS configuration selection is made up of three components: the hardware, the software algorithms and the parameters used by these algorithms. A comparison between AIRS and the wide dynamics demodulation (WDD) is provided. The organization of the AIRS analytical/simulation software is described. The modeling and analysis is for simulating the performance of the PN subsystem is documented. The frequence acquisition technique using a frequency-locked loop is also documented. Doppler compensation implementation is described. The technological aspects of employing CCD's for PN acquisition are addressed.
Attitude determination for high-accuracy submicroradian jitter pointing on space-based platforms
NASA Astrophysics Data System (ADS)
Gupta, Avanindra A.; van Houten, Charles N.; Germann, Lawrence M.
1990-10-01
A description of the requirement definition process is given for a new wideband attitude determination subsystem (ADS) for image motion compensation (IMC) systems. The subsystem consists of either lateral accelerometers functioning in differential pairs or gas-bearing gyros for high-frequency sensors using CCD-based star trackers for low-frequency sensors. To minimize error the sensor signals are combined so that the mixing filter does not allow phase distortion. The two ADS models are introduced in an IMC simulation to predict measurement error, correction capability, and residual image jitter for a variety of system parameters. The IMC three-axis testbed is utilized to simulate an incoming beam in inertial space. Results demonstrate that both mechanical and electronic IMC meet the requirements of image stabilization for space-based observation at submicroradian-jitter levels. Currently available technology may be employed to implement IMC systems.
Redesigning reservoir compensation releases for ecological beenfit
NASA Astrophysics Data System (ADS)
Maynard, Carly
2010-05-01
River regulation is commonplace in England and much of the UK. Regulation for the purposes of public water supply causes flows downstream of a reservoir to be attenuated and the flow regime of the channel to be altered. The impact of channel impoundment on a small, upland UK river, has been assessed and methods for mitigation of ecological impacts explored. The method utilised a unique macroinvertebrate data set for pre- and post-impoundment periods to quantify the impact of Derwent Reservoir and the steady, continuous compensation release into the River Derwent, Northumberland. Impacts on the hydrological regime were also investigated and links drawn between changes in flow regime and changes in macroinvertebrate richness and diversity as a result of impoundment. In response to the claim that the impoundment has caused a change in flow regime and had deleterious effects on fish and macroinvertebrates, a compensation redesign tool (CRAB: Compensation Release Assessment at the Broad scale) was employed to design new compensation release regimes from the reservoir which account for the seasonal flow requirements of a number of key fish species. The impact of impoundment on the current flow regime was modelled and the impacts of predicted new regimes were predicted, using a 1D hydrodynamic model (HEC-RAS), as part of a modelling process known as CRAM (Compensation Release Assessment at the Meso-scale). Depth and velocity were the foci of the analysis as they are the two habitat requirements most well documented for the fish species in question, they could be modelled using HEC-RAS and they can act as surrogates for other habitat parameters such as temperature and substrate. The suitability of the depth and velocity combinations predicted using the HEC-RAS model were assessed using fuzzy-rule based modelling, which allowed the habitat quality of a given parameter combination to be quantified. Based on the results of the investigation it was concluded that there has been a change in flow regime and in ecological community structure since impoundment. The flow regime of the River Derwent has become less flashy with fewer extreme events, while macroinvertebrate richness and diversity have increased. The new flow regimes that were designed by CRAB, based on the depth and velocity requirements of brown trout, grayling and Atlantic salmon were predicted through CRAM to have minimal benefits for the fish populations of the River Derwent and it was concluded that no changes to flow regime should be made based solely on the assessment of habitat for fish. Impacts for the macroinvertebrate communities must also be considered as well as the impacts on other aspects of fish habitat including temperature, substrate and cover. A more detailed, micro-scale investigation into the effects of changing flow regime would be required to warrant a change in compensation release regime from Derwent Reservoir.
Temperature Versus Salinity Gradients Below the Ocean Mixed Layer
2012-05-03
where salinity controls the depth of the mixed layer are understood to have “barrier” layers [Lukas and Lindstrom , 1991], where the depth of vertically...the horizontal. For example, Rudnick and Martin [2002] have shown that the ocean mixed layer at sub-mesoscales is horizontally well density compensated...Res., 102, 23,063–23,078, doi:10.1029/97JC01443. Barron, C. N., A. B. Kara, P. J. Martin , R. C. Rhodes, and L. F. Smedstad (2006), Formulation
A case study of a team-based, quality-focused compensation model for primary care providers.
Greene, Jessica; Hibbard, Judith H; Overton, Valerie
2014-06-01
In 2011, Fairview Health Services began replacing their fee-for-service compensation model for primary care providers (PCPs), which included an annual pay-for-performance bonus, with a team-based model designed to improve quality of care, patient experience, and (eventually) cost containment. In-depth interviews and an online survey of PCPs early after implementation of the new model suggest that it quickly changed the way many PCPs practiced. Most PCPs reported a shift in orientation toward quality of care, working more collaboratively with their colleagues and focusing on their full panel of patients. The majority reported that their quality of care had improved because of the model and that their colleagues' quality had to. The comprehensive change did, however, result in lower fee-for-service billing and reductions in PCP satisfaction. While Fairview's compensation model is still a work in progress, their early experiences can provide lessons for other delivery systems seeking to reform PCP compensation.
Han, Yuanji; Wu, Miao; Cao, Liya; Yuan, Wangjun; Dong, Meifang; Wang, Xiaohui; Chen, Weicai; Shang, Fude
2016-07-01
The sweet osmanthus carotenoid cleavage dioxygenase 4 (OfCCD4) cleaves carotenoids such as β-carotene and zeaxanthin to yield β-ionone. OfCCD4 is a member of the CCD gene family, and its promoter contains a W-box palindrome with two reversely oriented TGAC repeats, which are the proposed binding sites of WRKY transcription factors. We isolated three WRKY cDNAs from the petal of Osmanthus fragrans. One of them, OfWRKY3, encodes a protein containing two WRKY domains and two zinc finger motifs. OfWRKY3 and OfCCD4 had nearly identical expression profile in petals of 'Dangui' and 'Yingui' at different flowering stages and showed similar expression patterns in petals treated by salicylic acid, jasmonic acid and abscisic acid. Activation of OfCCD4pro:GUS by OfWRKY3 was detected in coinfiltrated tobacco leaves and very weak GUS activity was detected in control tissues, indicating that OfWRKY3 can interact with the OfCCD4 promoter. Yeast one-hybrid and electrophoretic mobility shift assay showed that OfWRKY3 was able to bind to the W-box palindrome motif present in the OfCCD4 promoter. These results suggest that OfWRKY3 is a positive regulator of the OfCCD4 gene, and might partly account for the biosynthesis of β-ionone in sweet osmanthus.
High-resolution CCD imaging alternatives
NASA Astrophysics Data System (ADS)
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.
Spectral analysis using the CCD Chirp Z-transform
NASA Technical Reports Server (NTRS)
Eversole, W. L.; Mayer, D. J.; Bosshart, P. W.; Dewit, M.; Howes, C. R.; Buss, D. D.
1978-01-01
The charge coupled device (CCD) Chirp Z transformation (CZT) spectral analysis techniques were reviewed and results on state-of-the-art CCD CZT technology are presented. The CZT algorithm was examined and the advantages of CCD implementation are discussed. The sliding CZT which is useful in many spectral analysis applications is described, and the performance limitations of the CZT are studied.
Documentation to the 2015-16 Common Core of Data (CCD) Universe Files. NCES 2017-074
ERIC Educational Resources Information Center
Glander, Mark
2017-01-01
The Common Core of Data (CCD) is a national statistical program that collects and compiles administrative data from SEAs covering the universe of all public elementary and secondary schools and school districts in the United States. The first CCD collection was for SY 1986-87. The predecessor to CCD was the Elementary and Secondary General…
NASA Astrophysics Data System (ADS)
Mori, Koji; Nishioka, Yusuke; Ohura, Satoshi; Koura, Yoshiaki; Yamauchi, Makoto; Nakajima, Hiroshi; Ueda, Shutaro; Kan, Hiroaki; Anabuki, Naohisa; Nagino, Ryo; Hayashida, Kiyoshi; Tsunemi, Hiroshi; Kohmura, Takayoshi; Ikeda, Shoma; Murakami, Hiroshi; Ozaki, Masanobu; Dotani, Tadayasu; Maeda, Yukie; Sagara, Kenshi
2013-12-01
We report on a proton radiation damage experiment on P-channel CCD newly developed for an X-ray CCD camera onboard the ASTRO-H satellite. The device was exposed up to 109 protons cm-2 at 6.7 MeV. The charge transfer inefficiency (CTI) was measured as a function of radiation dose. In comparison with the CTI currently measured in the CCD camera onboard the Suzaku satellite for 6 years, we confirmed that the new type of P-channel CCD is radiation tolerant enough for space use. We also confirmed that a charge-injection technique and lowering the operating temperature efficiently work to reduce the CTI for our device. A comparison with other P-channel CCD experiments is also discussed. We performed a proton radiation damage experiment on a new P-channel CCD. The device was exposed up to 109 protons cm-2 at 6.7 MeV. We confirmed that it is radiation tolerant enough for space use. We confirmed that a charge-injection technique reduces the CTI. We confirmed that lowering the operating temperature also reduces the CTI.
View generation for 3D-TV using image reconstruction from irregularly spaced samples
NASA Astrophysics Data System (ADS)
Vázquez, Carlos
2007-02-01
Three-dimensional television (3D-TV) will become the next big step in the development of advanced TV systems. One of the major challenges for the deployment of 3D-TV systems is the diversity of display technologies and the high cost of capturing multi-view content. Depth image-based rendering (DIBR) has been identified as a key technology for the generation of new views for stereoscopic and multi-view displays from a small number of views captured and transmitted. We propose a disparity compensation method for DIBR that does not require spatial interpolation of the disparity map. We use a forward-mapping disparity compensation with real precision. The proposed method deals with the irregularly sampled image resulting from this disparity compensation process by applying a re-sampling algorithm based on a bi-cubic spline function space that produces smooth images. The fact that no approximation is made on the position of the samples implies that geometrical distortions in the final images due to approximations in sample positions are minimized. We also paid attention to the occlusion problem. Our algorithm detects the occluded regions in the newly generated images and uses simple depth-aware inpainting techniques to fill the gaps created by newly exposed areas. We tested the proposed method in the context of generation of views needed for viewing on SynthaGram TM auto-stereoscopic displays. We used as input either a 2D image plus a depth map or a stereoscopic pair with the associated disparity map. Our results show that this technique provides high quality images to be viewed on different display technologies such as stereoscopic viewing with shutter glasses (two views) and lenticular auto-stereoscopic displays (nine views).
Choroidal and scleral mechanisms of compensation for spectacle lenses in chicks.
Wildsoet, C; Wallman, J
1995-05-01
It is known that when hyperopic or myopic defocus is imposed on chick eyes by spectacle lenses, they rapidly compensate, becoming myopic or hyperopic respectively, by altering the depth of their vitreous chamber. Changes in two components--ocular length and choroidal thickness--underlie this rapid compensation. With monocular lens treatment, hyperopic defocus imposed by negative lenses resulted in substantially increased ocular elongation and a slight thinning of the choroid, both changes resulting in myopia; myopic defocus imposed by positive lenses resulted a dramatic increase in choroidal thickness, which pushed the retina forward toward the image plane, and a slight decrease in ocular elongation, both changes resulting in hyperopia. The refractive error after 5 days of lens wear correlated well with vitreous chamber depth, which reflected the changes in both choroidal thickness and ocular length. The degree of compensation for lenses was not affected by whether the fellow eye was covered or open. Both form-deprivation myopia and lens-induced myopia declined with age in parallel, but wearing a -15 D lens produced more myopia than did form deprivation. The spectacle lenses affected the refractive error not only of the lens-wearing eye, but also, to a much lesser degree, of the untreated fellow eye. At lens removal refractive errors were opposite in sign to the lense worn, and the subsequent changes in choroidal thickness and ocular length were also opposite to those that occurred when the lenses were in place. In this situation as well, effects of the spectacle lenses on the fellow eyes were observed. Eyes with no functional afferent connection to the brain because of either prior optic nerve section or intraocular tetrodotoxin injections showed compensatory changes to imposed defocus, but these were limited to compensation for imposed myopic defocus, at least for the eyes with optic nerve section. In addition, optic nerve section, but not tetrodotoxin treatment, moved the set-point of the visual compensatory mechanism toward hyperopia. Optic nerve section prevents myopia in response to negative lenses but not to diffusers, suggesting that compensation for hyperopia requires the central nervous system.
NASA Technical Reports Server (NTRS)
Hewes, C. R.; Bosshart, P. W.; Eversole, W. L.; Dewit, M.; Buss, D. D.
1976-01-01
Two CCD techniques were discussed for performing an N-point sampled data correlation between an input signal and an electronically programmable reference function. The design and experimental performance of an implementation of the direct time correlator utilizing two analog CCDs and MOS multipliers on a single IC were evaluated. The performance of a CCD implementation of the chirp z transform was described, and the design of a new CCD integrated circuit for performing correlation by multiplication in the frequency domain was presented. This chip provides a discrete Fourier transform (DFT) or inverse DFT, multipliers, and complete support circuitry for the CCD CZT. The two correlation techniques are compared.
Lobato-Márquez, Damián; Molina-García, Laura; Moreno-Córdoba, Inma; García-Del Portillo, Francisco; Díaz-Orejas, Ramón
2016-01-01
Certain Salmonella enterica serovars belonging to subspecies I carry low-copy-number virulence plasmids of variable size (50-90 kb). All of these plasmids share the spv operon, which is important for systemic infection. Virulence plasmids are present at low copy numbers. Few copies reduce metabolic burden but suppose a risk of plasmid loss during bacterial division. This drawback is counterbalanced by maintenance modules that ensure plasmid stability, including partition systems and toxin-antitoxin (TA) loci. The low-copy number virulence pSLT plasmid of Salmonella enterica serovar Typhimurium encodes three auxiliary maintenance systems: one partition system ( parAB ) and two TA systems ( ccdAB ST and vapBC2 ST ). The TA module ccdAB ST has previously been shown to contribute to pSLT plasmid stability and vapBC2 ST to bacterial virulence. Here we describe a novel assay to measure plasmid stability based on the selection of plasmid-free cells following elimination of plasmid-containing cells by ParE toxin, a DNA gyrase inhibitor. Using this new maintenance assay we confirmed a crucial role of parAB in pSLT maintenance. We also showed that vapBC2 ST , in addition to contribute to bacterial virulence, is important for plasmid stability. We have previously shown that ccdAB ST encodes an inactive CcdB ST toxin. Using our new stability assay we monitored the contribution to plasmid stability of a ccdAB ST variant containing a single mutation (R99W) that restores the toxicity of CcdB ST . The "activation" of CcdB ST (R99W) did not increase pSLT stability by ccdAB ST . In contrast, ccdAB ST behaves as a canonical type II TA system in terms of transcriptional regulation. Of interest, ccdAB ST was shown to control the expression of a polycistronic operon in the pSLT plasmid. Collectively, these results show that the contribution of the CcdB ST toxin to pSLT plasmid stability may depend on its role as a co-repressor in coordination with CcdA ST antitoxin more than on its toxic activity.
Wavelength scanning digital interference holography for high-resolution ophthalmic imaging
NASA Astrophysics Data System (ADS)
Potcoava, Mariana C.; Kim, M. K.; Kay, Christine N.
2009-02-01
An improved digital interference holography (DIH) technique suitable for fundus images is proposed. This technique incorporates a dispersion compensation algorithm to compensate for the unknown axial length of the eye. Using this instrument we acquired successfully tomographic fundus images in human eye with narrow axial resolution less than 5μm. The optic nerve head together with the surrounding retinal vasculature were constructed. We were able to quantify a depth of 84μm between the retinal fiber and the retinal pigmented epithelium layers. DIH provides high resolution 3D information which could potentially aid in guiding glaucoma diagnosis and treatment.
Gravity anomalies, compensation mechanisms, and the geodynamics of western Ishtar Terra, Venus
NASA Technical Reports Server (NTRS)
Grimm, Robert E.; Phillips, Roger J.
1991-01-01
Pioneer Venus line-of-sight orbital accelerations were utilized to calculate the geoid and vertical gravity anomalies for western Ishtar Terra on various planes of altitude z sub 0. The apparent depth of isostatic compensation at z sub 0 = 1400 km is 180 + or - 20 km based on the usual method of minimum variance in the isostatic anomaly. An attempt is made here to explain this observation, as well as the regional elevation, peripheral mountain belts, and inferred age of western Ishtar Terra, in terms of one or three broad geodynamic models.
A GAS PRESSURE DISCHARGE TUBE FOR SEVERAL DIFFERENT LIQUID GAS CONTAINERS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Thunborg, S.
1963-04-01
A discharge tube was developed to fit several different liquefied-gas containers. A rubber stopper was used to adjust to variations between neck openings. A method of compensating for variations in the depths of the containers was also incorporated. (M.C.G.)
NASA Astrophysics Data System (ADS)
Lee, John H.; Fernandez, Patricia; Madden, Tim; Molitsky, Michael; Weizeorick, John
2007-11-01
This paper will describe two ongoing detector projects being developed by the Beamline Technical Support Group at the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The first project is the design and construction of two detectors: a single-CCD system and a two-by-two Mosaic CCD camera for Small-Angle X-ray Scattering (SAXS). Both of these systems utilize the Kodak KAF-4320E CCD coupled to fiber optic tapers, custom mechanical hardware, electronics, and software developed at ANL. The second project is a Fast-CCD (FCCD) detector being developed in a collaboration between ANL and Lawrence Berkeley National Laboratory (LBNL). This detector will use ANL-designed readout electronics and a custom LBNL-designed CCD, with 480×480 pixels and 96 outputs, giving very fast readout.
The In-flight Spectroscopic Performance of the Swift XRT CCD Camera During 2006-2007
NASA Technical Reports Server (NTRS)
Godet, O.; Beardmore, A.P.; Abbey, A.F.; Osborne, J.P.; Page, K.L.; Evans, P.; Starling, R.; Wells, A.A.; Angelini, L.; Burrows, D.N.;
2007-01-01
The Swift X-ray Telescope focal plane camera is a front-illuminated MOS CCD, providing a spectral response kernel of 135 eV FWHM at 5.9 keV as measured before launch. We describe the CCD calibration program based on celestial and on-board calibration sources, relevant in-flight experiences, and developments in the CCD response model. We illustrate how the revised response model describes the calibration sources well. Comparison of observed spectra with models folded through the instrument response produces negative residuals around and below the Oxygen edge. We discuss several possible causes for such residuals. Traps created by proton damage on the CCD increase the charge transfer inefficiency (CTI) over time. We describe the evolution of the CTI since the launch and its effect on the CCD spectral resolution and the gain.
Pathogen webs in collapsing honey bee colonies.
Cornman, R Scott; Tarpy, David R; Chen, Yanping; Jeffreys, Lacey; Lopez, Dawn; Pettis, Jeffery S; vanEngelsdorp, Dennis; Evans, Jay D
2012-01-01
Recent losses in honey bee colonies are unusual in their severity, geographical distribution, and, in some cases, failure to present recognized characteristics of known disease. Domesticated honey bees face numerous pests and pathogens, tempting hypotheses that colony collapses arise from exposure to new or resurgent pathogens. Here we explore the incidence and abundance of currently known honey bee pathogens in colonies suffering from Colony Collapse Disorder (CCD), otherwise weak colonies, and strong colonies from across the United States. Although pathogen identities differed between the eastern and western United States, there was a greater incidence and abundance of pathogens in CCD colonies. Pathogen loads were highly covariant in CCD but not control hives, suggesting that CCD colonies rapidly become susceptible to a diverse set of pathogens, or that co-infections can act synergistically to produce the rapid depletion of workers that characterizes the disorder. We also tested workers from a CCD-free apiary to confirm that significant positive correlations among pathogen loads can develop at the level of individual bees and not merely as a secondary effect of CCD. This observation and other recent data highlight pathogen interactions as important components of bee disease. Finally, we used deep RNA sequencing to further characterize microbial diversity in CCD and non-CCD hives. We identified novel strains of the recently described Lake Sinai viruses (LSV) and found evidence of a shift in gut bacterial composition that may be a biomarker of CCD. The results are discussed with respect to host-parasite interactions and other environmental stressors of honey bees.
Modeling the impact of preflushing on CTE in proton irradiated CCD-based detectors
NASA Astrophysics Data System (ADS)
Philbrick, R. H.
2002-04-01
A software model is described that performs a "real world" simulation of the operation of several types of charge-coupled device (CCD)-based detectors in order to accurately predict the impact that high-energy proton radiation has on image distortion and modulation transfer function (MTF). The model was written primarily to predict the effectiveness of vertical preflushing on the custom full frame CCD-based detectors intended for use on the proposed Kepler Discovery mission, but it is capable of simulating many other types of CCD detectors and operating modes as well. The model keeps track of the occupancy of all phosphorous-silicon (P-V), divacancy (V-V) and oxygen-silicon (O-V) defect centers under every CCD electrode over the entire detector area. The integrated image is read out by simulating every electrode-to-electrode charge transfer in both the vertical and horizontal CCD registers. A signal level dependency on the capture and emission of signal is included and the current state of each electrode (e.g., barrier or storage) is considered when distributing integrated and emitted signal. Options for performing preflushing, preflashing, and including mini-channels are available on both the vertical and horizontal CCD registers. In addition, dark signal generation and image transfer smear can be selectively enabled or disabled. A comparison of the charge transfer efficiency (CTE) data measured on the Hubble space telescope imaging spectrometer (STIS) CCD with the CTE extracted from model simulations of the STIS CCD show good agreement.
Characterization of Electrically Active Defects in Si Using CCD Image Sensors
1978-02-01
63 35 Dislocation Segments in CCD Imager . . . . . . . . . . . . . 64 36 422 Reflection Topograph of Dislocation Loop ir... Loops . . . . . 3 39 422 Reflection Topograph of Scratch on CCD Imager, . . . 69 40 Dark Current Display of a CCD Imager with 32 ms integration Time...made of each slice using the elon -asoorbio aold developer described in Appendix D. The inagers were then thinned using the procedure at Appendix taor
Mosaic CCD method: A new technique for observing dynamics of cometary magnetospheres
NASA Technical Reports Server (NTRS)
Saito, T.; Takeuchi, H.; Kozuba, Y.; Okamura, S.; Konno, I.; Hamabe, M.; Aoki, T.; Minami, S.; Isobe, S.
1992-01-01
On April 29, 1990, the plasma tail of Comet Austin was observed with a CCD camera on the 105-cm Schmidt telescope at the Kiso Observatory of the University of Tokyo. The area of the CCD used in this observation is only about 1 sq cm. When this CCD is used on the 105-cm Schmidt telescope at the Kiso Observatory, the area corresponds to a narrow square view of 12 ft x 12 ft. By comparison with the photograph of Comet Austin taken by Numazawa (personal communication) on the same night, we see that only a small part of the plasma tail can be photographed at one time with the CCD. However, by shifting the view on the CCD after each exposure, we succeeded in imaging the entire length of the cometary magnetosphere of 1.6 x 10(exp 6) km. This new technique is called 'the mosaic CCD method'. In order to study the dynamics of cometary plasma tails, seven frames of the comet from the head to the tail region were twice imaged with the mosaic CCD method and two sets of images were obtained. Six microstructures, including arcade structures, were identified in both the images. Sketches of the plasma tail including microstructures are included.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gelb, B.D.; Desnick, R.J.; Shevell, M.
1995-08-28
Cleidocranial dysplasia (CCD) is a generalized skeletal dysplasia with autosomal dominant inheritance. Recently, the CCD disease locus was localized to 23 and 17 cM regions of chromosome band 6p21 by linkage studies of seven affected families. Of note, the 23 cM region contained a microdeletion detected in one family at D6S459, an interval that was excluded in the 17 cM overlapping region. Here, linkage of CCD to 6p21 was independently confirmed with a maximal two-point LOD score of Z=5.12 with marker D6S452 at {theta}=0.00. Recombinant events in two affected individuals defined a CCD region of 7 cM from D6S465 tomore » D6S282, which overlapped with the CCD region containing the microdeletion but did not overlap with the 17 cM critical region from D6S282 to D6S291. These results suggest the refined localization of the CCD region to 6 cM spanning markers D6S438 to D6S282, thereby reviving the possibility that the CCD gene lies within the microdeletion at D6S459. 13 refs., 2 figs., 1 tab.« less
NASA Astrophysics Data System (ADS)
Wang, X.; Holmes, C. S.
2015-08-01
When grinding helical components, errors occur at the beginning and end of the contact path between the component and grinding wheel. This is due to the forces on the component changing as the grinding wheel comes into and out-of full contact with the component. In addition, shaft bending may add depth changes which vary along the length. This may result in an interrupted contact line and increased noise from the rotors. Using on-board scanning, software has been developed to calculate a compensated grinding path, which includes the adjustments of head angle, work rotation and infeed. This grinding path compensates not only lead errors, but also reduces the profile errors as well. The program has been tested in rotor production and the results are shown.
NASA Astrophysics Data System (ADS)
Watanabe, Shigeo; Takahashi, Teruo; Bennett, Keith
2017-02-01
The"scientific" CMOS (sCMOS) camera architecture fundamentally differs from CCD and EMCCD cameras. In digital CCD and EMCCD cameras, conversion from charge to the digital output is generally through a single electronic chain, and the read noise and the conversion factor from photoelectrons to digital outputs are highly uniform for all pixels, although quantum efficiency may spatially vary. In CMOS cameras, the charge to voltage conversion is separate for each pixel and each column has independent amplifiers and analog-to-digital converters, in addition to possible pixel-to-pixel variation in quantum efficiency. The "raw" output from the CMOS image sensor includes pixel-to-pixel variability in the read noise, electronic gain, offset and dark current. Scientific camera manufacturers digitally compensate the raw signal from the CMOS image sensors to provide usable images. Statistical noise in images, unless properly modeled, can introduce errors in methods such as fluctuation correlation spectroscopy or computational imaging, for example, localization microscopy using maximum likelihood estimation. We measured the distributions and spatial maps of individual pixel offset, dark current, read noise, linearity, photoresponse non-uniformity and variance distributions of individual pixels for standard, off-the-shelf Hamamatsu ORCA-Flash4.0 V3 sCMOS cameras using highly uniform and controlled illumination conditions, from dark conditions to multiple low light levels between 20 to 1,000 photons / pixel per frame to higher light conditions. We further show that using pixel variance for flat field correction leads to errors in cameras with good factory calibration.
NASA Astrophysics Data System (ADS)
Dong, Jianing; Zhang, Yinchao; Chen, Siying; Chen, He; Guo, Pan
2017-02-01
In order to improve the remote target detection ability of infrared (IR) images effectively, an infrared telephoto objective for 3μm 5μm and 8μm 12μm dual wave-band is designed for 640 pixel×512 pixel infrared CCD detector. The effects of the surrounding environmental temperature are analyzed and the refractive diffractive hybrid thermal compensation is discussed. The focal length of the system is 200mm, the relative aperture is 1:2.2 and the field of view is 7°. The infrared dual band telephoto system with small volume and compact structure is designed in a large range of temperature. The system is composed of four lenses with only three materials of zinc sulfide, zinc selenide and germanium to compensate for the temperature. The image quality of the system is evaluated by ZEMAX optical design software. The results show that the modulation transfer function (MTF) for each field of view at cut-off frequency of 17 lp/mm are respectively greater than 0.6 and 0.4 which approaches the diffraction limit. The telephoto objective has favorable performance at the working temperature of -40°C +60°C. The relative aperture, field of view, and focal length are same for both spectral regions. The system meets the requirements of technical specification.
CCD radiation damage in ESA Cosmic Visions missions: assessment and mitigation
NASA Astrophysics Data System (ADS)
Lumb, David H.
2009-08-01
Charge Coupled Device (CCD) imagers have been widely used in space-borne astronomical instruments. A frequent concern has been the radiation damage effects on the CCD charge transfer properties. We review some methods for assessing the Charge Transfer Inefficiency (CTI) in CCDs. Techniques to minimise degradation using background charge injection and p-channel CCD architectures are discussed. A critical review of the claims for p-channel architectures is presented. The performance advantage for p-channel CCD performance is shown to be lower than claimed previously. Finally we present some projections for the performance in the context of some future ESA missions.
Targeting excited states in all-trans polyenes with electron-pair states.
Boguslawski, Katharina
2016-12-21
Wavefunctions restricted to electron pair states are promising models for strongly correlated systems. Specifically, the pair Coupled Cluster Doubles (pCCD) ansatz allows us to accurately describe bond dissociation processes and heavy-element containing compounds with multiple quasi-degenerate single-particle states. Here, we extend the pCCD method to model excited states using the equation of motion (EOM) formalism. As the cluster operator of pCCD is restricted to electron-pair excitations, EOM-pCCD allows us to target excited electron-pair states only. To model singly excited states within EOM-pCCD, we modify the configuration interaction ansatz of EOM-pCCD to contain also single excitations. Our proposed model represents a simple and cost-effective alternative to conventional EOM-CC methods to study singly excited electronic states. The performance of the excited state models is assessed against the lowest-lying excited states of the uranyl cation and the two lowest-lying excited states of all-trans polyenes. Our numerical results suggest that EOM-pCCD including single excitations is a good starting point to target singly excited states.
A Design and Development of Multi-Purpose CCD Camera System with Thermoelectric Cooling: Software
NASA Astrophysics Data System (ADS)
Oh, S. H.; Kang, Y. W.; Byun, Y. I.
2007-12-01
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.
Robust gaze-steering of an active vision system against errors in the estimated parameters
NASA Astrophysics Data System (ADS)
Han, Youngmo
2015-01-01
Gaze-steering is often used to broaden the viewing range of an active vision system. Gaze-steering procedures are usually based on estimated parameters such as image position, image velocity, depth and camera calibration parameters. However, there may be uncertainties in these estimated parameters because of measurement noise and estimation errors. In this case, robust gaze-steering cannot be guaranteed. To compensate for such problems, this paper proposes a gaze-steering method based on a linear matrix inequality (LMI). In this method, we first propose a proportional derivative (PD) control scheme on the unit sphere that does not use depth parameters. This proposed PD control scheme can avoid uncertainties in the estimated depth and camera calibration parameters, as well as inconveniences in their estimation process, including the use of auxiliary feature points and highly non-linear computation. Furthermore, the control gain of the proposed PD control scheme on the unit sphere is designed using LMI such that the designed control is robust in the presence of uncertainties in the other estimated parameters, such as image position and velocity. Simulation results demonstrate that the proposed method provides a better compensation for uncertainties in the estimated parameters than the contemporary linear method and steers the gaze of the camera more steadily over time than the contemporary non-linear method.
Bioluminescence as an ecological factor during high Arctic polar night
NASA Astrophysics Data System (ADS)
Cronin, Heather A.; Cohen, Jonathan H.; Berge, Jørgen; Johnsen, Geir; Moline, Mark A.
2016-11-01
Bioluminescence commonly influences pelagic trophic interactions at mesopelagic depths. Here we characterize a vertical gradient in structure of a generally low species diversity bioluminescent community at shallower epipelagic depths during the polar night period in a high Arctic fjord with in situ bathyphotometric sampling. Bioluminescence potential of the community increased with depth to a peak at 80 m. Community composition changed over this range, with an ecotone at 20-40 m where a dinoflagellate-dominated community transitioned to dominance by the copepod Metridia longa. Coincident at this depth was bioluminescence exceeding atmospheric light in the ambient pelagic photon budget, which we term the bioluminescence compensation depth. Collectively, we show a winter bioluminescent community in the high Arctic with vertical structure linked to attenuation of atmospheric light, which has the potential to influence pelagic ecology during the light-limited polar night.
Resolution power in digital in-line holography
NASA Astrophysics Data System (ADS)
Garcia-Sucerquia, J.; Xu, W.; Jericho, S. K.; Jericho, M. H.; Klages, P.; Kreuzer, H. J.
2006-01-01
Digital in-line holographic microscopy (DIHM) can achieve wavelength resolution both laterally and in depth with the simple optical setup consisting of a laser illuminating a wavelength-sized pinhole and a CCD camera for recording the hologram. The reconstruction is done numerically on the basis of the Kirchhoff-Helmholtz transform which yields a three-dimensional image of the objects throughout the sample volume. Resolution in DIHM depends on several controllable factors or parameters: (1) pinhole size controlling spatial coherence, (2) numerical aperture given by the size and positioning of the recording CCD chip, (3) pixel density and dynamic range controlling fringe resolution and noise level in the hologram and (4) wavelength. We present a detailed study of the individual and combined effects of these factors by doing an analytical analysis coupled with numerical simulations of holograms and their reconstruction. The result of this analysis is a set of criteria, also in the form of graphs, which can be used for the optimum design of the DIHM setup. We will also present a series of experimental results that test and confirm our theoretical analysis. The ultimate resolution to date is the imaging of the motion of submicron spheres and bacteria, a few microns apart, with speeds of hundreds of microns per second.
DECam SAM 0.9-m CCD Goodman SOI Optical Spectrographs CHIRON COSMOS Goodman Filters Telescopes Blanco 4 4.4.4 Gain 4.5: CCD scales at various foci APPENDIX I: Filters for CCD Imaging II: Gain and Readout
High-frame rate multiport CCD imager and camera
NASA Astrophysics Data System (ADS)
Levine, Peter A.; Patterson, David R.; Esposito, Benjamin J.; Tower, John R.; Lawler, William B.
1993-01-01
A high frame rate visible CCD camera capable of operation up to 200 frames per second is described. The camera produces a 256 X 256 pixel image by using one quadrant of a 512 X 512 16-port, back illuminated CCD imager. Four contiguous outputs are digitally reformatted into a correct, 256 X 256 image. This paper details the architecture and timing used for the CCD drive circuits, analog processing, and the digital reformatter.
Transmission electron microscope CCD camera
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.
Lack of evidence for an association between Iridovirus and colony collapse disorder.
Tokarz, Rafal; Firth, Cadhla; Street, Craig; Cox-Foster, Diana L; Lipkin, W Ian
2011-01-01
Colony collapse disorder (CCD) is characterized by the unexplained losses of large numbers of adult worker bees (Apis mellifera) from apparently healthy colonies. Although infections, toxins, and other stressors have been associated with the onset of CCD, the pathogenesis of this disorder remains obscure. Recently, a proteomics study implicated a double-stranded DNA virus, invertebrate iridescent virus (Family Iridoviridae) along with a microsporidium (Nosema sp.) as the cause of CCD. We tested the validity of this relationship using two independent methods: (i) we surveyed healthy and CCD colonies from the United States and Israel for the presence of members of the Iridovirus genus and (ii) we reanalyzed metagenomics data previously generated from RNA pools of CCD colonies for the presence of Iridovirus-like sequences. Neither analysis revealed any evidence to suggest the presence of an Iridovirus in healthy or CCD colonies.
Lack of Evidence for an Association between Iridovirus and Colony Collapse Disorder
Street, Craig; Cox-Foster, Diana L.; Lipkin, W. Ian
2011-01-01
Colony collapse disorder (CCD) is characterized by the unexplained losses of large numbers of adult worker bees (Apis mellifera) from apparently healthy colonies. Although infections, toxins, and other stressors have been associated with the onset of CCD, the pathogenesis of this disorder remains obscure. Recently, a proteomics study implicated a double-stranded DNA virus, invertebrate iridescent virus (Family Iridoviridae) along with a microsporidium (Nosema sp.) as the cause of CCD. We tested the validity of this relationship using two independent methods: (i) we surveyed healthy and CCD colonies from the United States and Israel for the presence of members of the Iridovirus genus and (ii) we reanalyzed metagenomics data previously generated from RNA pools of CCD colonies for the presence of Iridovirus-like sequences. Neither analysis revealed any evidence to suggest the presence of an Iridovirus in healthy or CCD colonies. PMID:21738798
Fully depleted back illuminated CCD
Holland, Stephen Edward
2001-01-01
A backside illuminated charge coupled device (CCD) is formed of a relatively thick high resistivity photon sensitive silicon substrate, with frontside electronic circuitry, and an optically transparent backside ohmic contact for applying a backside voltage which is at least sufficient to substantially fully deplete the substrate. A greater bias voltage which overdepletes the substrate may also be applied. One way of applying the bias voltage to the substrate is by physically connecting the voltage source to the ohmic contact. An alternate way of applying the bias voltage to the substrate is to physically connect the voltage source to the frontside of the substrate, at a point outside the depletion region. Thus both frontside and backside contacts can be used for backside biasing to fully deplete the substrate. Also, high resistivity gaps around the CCD channels and electrically floating channel stop regions can be provided in the CCD array around the CCD channels. The CCD array forms an imaging sensor useful in astronomy.
High-Voltage Clock Driver for Photon-Counting CCD Characterization
NASA Technical Reports Server (NTRS)
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.
Signal processing applications of massively parallel charge domain computing devices
NASA Technical Reports Server (NTRS)
Fijany, Amir (Inventor); Barhen, Jacob (Inventor); Toomarian, Nikzad (Inventor)
1999-01-01
The present invention is embodied in a charge coupled device (CCD)/charge injection device (CID) architecture capable of performing a Fourier transform by simultaneous matrix vector multiplication (MVM) operations in respective plural CCD/CID arrays in parallel in O(1) steps. For example, in one embodiment, a first CCD/CID array stores charge packets representing a first matrix operator based upon permutations of a Hartley transform and computes the Fourier transform of an incoming vector. A second CCD/CID array stores charge packets representing a second matrix operator based upon different permutations of a Hartley transform and computes the Fourier transform of an incoming vector. The incoming vector is applied to the inputs of the two CCD/CID arrays simultaneously, and the real and imaginary parts of the Fourier transform are produced simultaneously in the time required to perform a single MVM operation in a CCD/CID array.
Spectral analysis of the gravity and topography of Mars
NASA Technical Reports Server (NTRS)
Bills, Bruce G.; Frey, Herbert V.; Kiefer, Walter S.; Nerem, R. Steven; Zuber, Maria T.
1993-01-01
New spherical harmonic models of the gravity and topography of Mars place important constraints on the structure and dynamics of the interior. The gravity and topography models are significantly phase coherent for harmonic degrees n less than 30 (wavelengths greater than 700 km). Loss of coherence below that wavelength is presumably due to inadequacies of the models, rather than a change in behavior of the planet. The gravity/topography admittance reveals two very different spectral domains: for n greater than 4, a simple Airy compensation model, with mean depth of 100 km, faithfully represents the observed pattern; for degrees 2 and 3, the effective compensation depths are 1400 and 550 km, respectively, strongly arguing for dynamic compensation at those wavelengths. The gravity model has been derived from a reanalysis of the tracking data for Mariner 9 and the Viking Orbiters, The topography model was derived by harmonic analysis of the USGS digital elevation model of Mars. Before comparing gravity and topography for internal structure inferences, we must ensure that both are consistently referenced to a hydrostatic datum. For the gravity, this involves removal of hydrostatic components of the even degree zonal coefficients. For the topography, it involves adding the degree 4 equipotential reference surface, to get spherically referenced values, and then subtracting the full degree 50 equipotential. Variance spectra and phase coherence of orthometric heights and gravity anomalies are addressed.
Robust incremental compensation of the light attenuation with depth in 3D fluorescence microscopy.
Kervrann, C; Legland, D; Pardini, L
2004-06-01
Summary Fluorescent signal intensities from confocal laser scanning microscopes (CLSM) suffer from several distortions inherent to the method. Namely, layers which lie deeper within the specimen are relatively dark due to absorption and scattering of both excitation and fluorescent light, photobleaching and/or other factors. Because of these effects, a quantitative analysis of images is not always possible without correction. Under certain assumptions, the decay of intensities can be estimated and used for a partial depth intensity correction. In this paper we propose an original robust incremental method for compensating the attenuation of intensity signals. Most previous correction methods are more or less empirical and based on fitting a decreasing parametric function to the section mean intensity curve computed by summing all pixel values in each section. The fitted curve is then used for the calculation of correction factors for each section and a new compensated sections series is computed. However, these methods do not perfectly correct the images. Hence, the algorithm we propose for the automatic correction of intensities relies on robust estimation, which automatically ignores pixels where measurements deviate from the decay model. It is based on techniques adopted from the computer vision literature for image motion estimation. The resulting algorithm is used to correct volumes acquired in CLSM. An implementation of such a restoration filter is discussed and examples of successful restorations are given.
Bueeler, Michael; Mrochen, Michael
2005-01-01
The aim of this theoretical work was to investigate the robustness of scanning spot laser treatments with different laser spot diameters and peak ablation depths in case of incomplete compensation of eye movements due to eye-tracker latency. Scanning spot corrections of 3rd to 5th Zernike order wavefront errors were numerically simulated. Measured eye-movement data were used to calculate the positioning error of each laser shot assuming eye-tracker latencies of 0, 5, 30, and 100 ms, and for the case of no eye tracking. The single spot ablation depth ranged from 0.25 to 1.0 microm and the spot diameter from 250 to 1000 microm. The quality of the ablation was rated by the postoperative surface variance and the Strehl intensity ratio, which was calculated after a low-pass filter was applied to simulate epithelial surface smoothing. Treatments performed with nearly ideal eye tracking (latency approximately 0) provide the best results with a small laser spot (0.25 mm) and a small ablation depth (250 microm). However, combinations of a large spot diameter (1000 microm) and a small ablation depth per pulse (0.25 microm) yield the better results for latencies above a certain threshold to be determined specifically. Treatments performed with tracker latencies in the order of 100 ms yield similar results as treatments done completely without eye-movement compensation. CONCWSIONS: Reduction of spot diameter was shown to make the correction more susceptible to eye movement induced error. A smaller spot size is only beneficial when eye movement is neutralized with a tracking system with a latency <5 ms.
Pathogen Webs in Collapsing Honey Bee Colonies
Cornman, R. Scott; Tarpy, David R.; Chen, Yanping; Jeffreys, Lacey; Lopez, Dawn; Pettis, Jeffery S.; vanEngelsdorp, Dennis; Evans, Jay D.
2012-01-01
Recent losses in honey bee colonies are unusual in their severity, geographical distribution, and, in some cases, failure to present recognized characteristics of known disease. Domesticated honey bees face numerous pests and pathogens, tempting hypotheses that colony collapses arise from exposure to new or resurgent pathogens. Here we explore the incidence and abundance of currently known honey bee pathogens in colonies suffering from Colony Collapse Disorder (CCD), otherwise weak colonies, and strong colonies from across the United States. Although pathogen identities differed between the eastern and western United States, there was a greater incidence and abundance of pathogens in CCD colonies. Pathogen loads were highly covariant in CCD but not control hives, suggesting that CCD colonies rapidly become susceptible to a diverse set of pathogens, or that co-infections can act synergistically to produce the rapid depletion of workers that characterizes the disorder. We also tested workers from a CCD-free apiary to confirm that significant positive correlations among pathogen loads can develop at the level of individual bees and not merely as a secondary effect of CCD. This observation and other recent data highlight pathogen interactions as important components of bee disease. Finally, we used deep RNA sequencing to further characterize microbial diversity in CCD and non-CCD hives. We identified novel strains of the recently described Lake Sinai viruses (LSV) and found evidence of a shift in gut bacterial composition that may be a biomarker of CCD. The results are discussed with respect to host-parasite interactions and other environmental stressors of honey bees. PMID:22927991
NASA Technical Reports Server (NTRS)
Janesick, J. R.; Elliott, T.; Collins, S.; Marsh, H.; Blouke, M. M.
1984-01-01
Since the first introduction of charge-coupled devices (CCDs) in 1970, CCDs have been considered for applications related to memories, logic circuits, and the detection of visible radiation. It is pointed out, however, that the mass market orientation of CCD development has left largely untapped the enormous potential of these devices for advanced scientific instrumentation. The present paper has, therefore, the objective to introduce the CCD characteristics to the scientific community, taking into account prospects for further improvement. Attention is given to evaluation criteria, a summary of current CCDs, CCD performance characteristics, absolute calibration tools, quantum efficiency, aspects of charge collection, charge transfer efficiency, read noise, and predictions regarding the characteristics of the next generation of silicon scientific CCD imagers.
Enhanced performance CCD output amplifier
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.
Advances in CCD detector technology for x-ray diffraction applications
NASA Astrophysics Data System (ADS)
Thorson, Timothy A.; Durst, Roger D.; Frankel, Dan; Bordwell, Rex L.; Camara, Jose R.; Leon-Guerrero, Edward; Onishi, Steven K.; Pang, Francis; Vu, Paul; Westbrook, Edwin M.
2004-01-01
Phosphor-coupled CCDs are established as one of the most successful technologies for x-ray diffraction. This application demands that the CCD simultaneously achieve both the highest possible sensitivity and high readout speeds. Recently, wafer-scale, back illuminated devices have become available which offer significantly higher quantum efficiency than conventional devices (the Fairchild Imaging CCD 486 BI). However, since back thinning significantly changes the electrical properties of the CCD the high speed operation of wafer-scale, back-illuminated devices is not well understood. Here we describe the operating characteristics (including noise, linearity, full well capacity and CTE) of the back-illuminated CCD 486 at readout speeds up to 4 MHz.
Scientific CCD technology at JPL
NASA Technical Reports Server (NTRS)
Janesick, J.; Collins, S. A.; Fossum, E. R.
1991-01-01
Charge-coupled devices (CCD's) were recognized for their potential as an imaging technology almost immediately following their conception in 1970. Twenty years later, they are firmly established as the technology of choice for visible imaging. While consumer applications of CCD's, especially the emerging home video camera market, dominated manufacturing activity, the scientific market for CCD imagers has become significant. Activity of the Jet Propulsion Laboratory and its industrial partners in the area of CCD imagers for space scientific instruments is described. Requirements for scientific imagers are significantly different from those needed for home video cameras, and are described. An imager for an instrument on the CRAF/Cassini mission is described in detail to highlight achieved levels of performance.
Colony Collapse Disorder: A Descriptive Study
vanEngelsdorp, Dennis; Evans, Jay D.; Saegerman, Claude; Mullin, Chris; Haubruge, Eric; Nguyen, Bach Kim; Frazier, Maryann; Frazier, Jim; Cox-Foster, Diana; Chen, Yanping; Underwood, Robyn; Tarpy, David R.; Pettis, Jeffery S.
2009-01-01
Background Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L.) colonies in the United States. In the absence of a known cause, this syndrome was named Colony Collapse Disorder (CCD) because the main trait was a rapid loss of adult worker bees. We initiated a descriptive epizootiological study in order to better characterize CCD and compare risk factor exposure between populations afflicted by and not afflicted by CCD. Methods and Principal Findings Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels), no single measure emerged as a most-likely cause of CCD. Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor) were higher in control colonies than CCD-affected colonies. Conclusions/Significance This is the first comprehensive survey of CCD-affected bee populations that suggests CCD involves an interaction between pathogens and other stress factors. We present evidence that this condition is contagious or the result of exposure to a common risk factor. Potentially important areas for future hypothesis-driven research, including the possible legacy effect of mite parasitism and the role of honey bee resistance to pesticides, are highlighted. PMID:19649264
Colony collapse disorder: a descriptive study.
Vanengelsdorp, Dennis; Evans, Jay D; Saegerman, Claude; Mullin, Chris; Haubruge, Eric; Nguyen, Bach Kim; Frazier, Maryann; Frazier, Jim; Cox-Foster, Diana; Chen, Yanping; Underwood, Robyn; Tarpy, David R; Pettis, Jeffery S
2009-08-03
Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L.) colonies in the United States. In the absence of a known cause, this syndrome was named Colony Collapse Disorder (CCD) because the main trait was a rapid loss of adult worker bees. We initiated a descriptive epizootiological study in order to better characterize CCD and compare risk factor exposure between populations afflicted by and not afflicted by CCD. Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels), no single measure emerged as a most-likely cause of CCD. Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor) were higher in control colonies than CCD-affected colonies. This is the first comprehensive survey of CCD-affected bee populations that suggests CCD involves an interaction between pathogens and other stress factors. We present evidence that this condition is contagious or the result of exposure to a common risk factor. Potentially important areas for future hypothesis-driven research, including the possible legacy effect of mite parasitism and the role of honey bee resistance to pesticides, are highlighted.
Cryostat and CCD for MEGARA at GTC
NASA Astrophysics Data System (ADS)
Castillo-Domínguez, E.; Ferrusca, D.; Tulloch, S.; Velázquez, M.; Carrasco, E.; Gallego, J.; Gil de Paz, A.; Sánchez, F. M.; Vílchez Medina, J. M.
2012-09-01
MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is the new integral field unit (IFU) and multi-object spectrograph (MOS) instrument for the GTC. The spectrograph subsystems include the pseudo-slit, the shutter, the collimator with a focusing mechanism, pupil elements on a volume phase holographic grating (VPH) wheel and the camera joined to the cryostat through the last lens, with a CCD detector inside. In this paper we describe the full preliminary design of the cryostat which will harbor the CCD detector for the spectrograph. The selected cryogenic device is an LN2 open-cycle cryostat which has been designed by the "Astronomical Instrumentation Lab for Millimeter Wavelengths" at INAOE. A complete description of the cryostat main body and CCD head is presented as well as all the vacuum and temperature sub-systems to operate it. The CCD is surrounded by a radiation shield to improve its performance and is placed in a custom made mechanical mounting which will allow physical adjustments for alignment with the spectrograph camera. The 4k x 4k pixel CCD231 is our selection for the cryogenically cooled detector of MEGARA. The characteristics of this CCD, the internal cryostat cabling and CCD controller hardware are discussed. Finally, static structural finite element modeling and thermal analysis results are shown to validate the cryostat model.
Enceladus's ice shell thickness and ocean depth from gravity, topography, and libration measurements
NASA Astrophysics Data System (ADS)
Trinh, A.; Rivoldini, A.; Beuthe, M.; Rekier, J.; Baland, R. M.; Van Hoolst, T.
2017-12-01
One of Cassini's major achievements is the discovery of a global ocean a few kilometres beneath Enceladus's south polar terrain. Here we infer the thickness of Enceladus's ice shell and ocean from Cassini's observations using our latest models of isostatic compensation, shell libration, and ocean dynamics.
Robotic CCD microscope for enhanced crystal recognition
Segelke, Brent W.; Toppani, Dominique
2007-11-06
A robotic CCD microscope and procedures to automate crystal recognition. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of smaller crystals compared to other methods available today.
Optical CT scanning of PRESAGETM polyurethane samples with a CCD-based readout system
NASA Astrophysics Data System (ADS)
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 PRESAGETM (Heuris Pharma, Skillman, NJ).
Digital holographic diagnostics of near-injector region
NASA Astrophysics Data System (ADS)
Lee, Jaiho
Study of primary breakup of liquid jets is important because it is motivated by the application to gas turbine fuel injectors, diesel fuel injectors, industrial cleaning and washing machine, medical spray, and inkjet printers, among others. When it comes to good injectors, a liquid jet has to be disintegrated into a fine spray near injector region during primary breakup. However the dense spray region near the injectors is optically obscure for Phase Doppler Interferometer like Phase Doppler Particle Analyzers (PDPA). Holography can provide three dimensional image of the dense spray and eliminate the problem of the small depth of focus associated with shadowgraphs. Traditional film-based holographic technique has long been used for three dimensional measurements in particle fields, but it is time consuming, expensive, chemically hazardous. With the development of the CCD sensor, holograms were recorded and reconstructed digitally. Digital microscopic holography (DMH) is similar to digital inline holography (DIH) except that no lens is used to collimate the object beam. The laser beams are expanded with an objective lens and a spatial filter. This eliminates two lenses from the typical optical path used for in-line holography, which results in a much cleaner hologram recording. The DMH was used for drop size and velocity measurements of the breakup of aerated liquid jets because it is unaffected by the non-spherical droplets that are encountered very close to the injector exit, which would cause problems for techniques such as Phase Doppler Particle Analyzer, otherwise. Large field of view was obtained by patching several high resolution holograms. Droplet velocities in three dimensions were measured by tracking their displacements in the streamwise and cross-stream direction and by tracking the change in the plane of focus in the spanwise direction. The uncertainty in spanwise droplet location and velocity measurements using single view DMH was large at least 33%. This large uncertainty in the spanwise direction, however, can be reduced to 2% by employing double view DMH. Double view DMH successfully tracked the three dimensional bending trajectories of polymer jets during electrospinning. The uncertainty in the spatial growth measurements of the bending instability was reduced using orthogonal double view DMH. Moreover, a commercial grade CCD was successfully used for single- and double-pulsed DMH of micro liquid jet breakup. Using a commercial grade CCD for the DMH, the cost of CCD sensor needed for recording holograms can be reduced.
Aziz, Danish Abdul; Kahlid, Misha; Memon, Fozia; Sadiq, Kamran
2017-01-01
To determine clinical features and relevant laboratory investigations of patient with celiac disease (CD) and comparing classical celiac disease (CCD) with Non-diarrheal celiac disease (NDCD). This is a five years retrospective study conducted at The Aga Khan University Hospital Karachi, Pakistan from January 2010 to December 2015, enrolling children from one year to 15 years of either gender diagnosed as celiac disease in accordance with revised ESPGHAN criteria. Biopsy samples with grade 2 or more on Modified Marsh Classification were considered as consistent with celiac disease. Celiac patients were categorized into Classical celiac disease (with Chronic Diarrhea) and non-diarrheal celiac disease (Atypical celiac) and their clinical features and relevant laboratory investigations were documented. Total 66 patients were selected with celiac disease according to inclusion criteria, 39 (59.09%) patients were labeled as CCD and 27 (40.91%) patients were labeled as NDCD. Marsh grading 3a and above were more marked in CCD as compared to NDCD. Mean titer for Tissue transglutaminase antibodies (TTG) were higher in CCD group in comparison to NDCD group. In CCD, the most common clinical presentations were abdominal distension whereas in NDCD, the most remarkable features were recurrent abdominal pain (62.9%). Frequency of failure to thrive is significantly high in CCD (82.05%) but patients merely with short stature were more common in NDCD (33.3%). Refractory anemia was present in 66.6% patients in NDCD group and 41.1% patients in CCD group. 74.3% patients in CCD group were vitamin D deficient whereas 85% patient had vitamin D deficiency in NDCD group (p= 0.03). NDCD is not uncommon in our population. Recurrent abdominal pain, failure to thrive or patients only with short stature and refractory anemia are prominent features in NCDC group whereas abdominal distension, failure to thrive and recurrent abdominal pain were noticeable features in CCD. High grade histopathology and raised antibodies titer is hallmark of CCD. Vitamin D deficiency is almost equally present in both groups.
CCD filter and transform techniques for interference excision
NASA Technical Reports Server (NTRS)
Borsuk, G. M.; Dewitt, R. N.
1976-01-01
The theoretical and some experimental results of a study aimed at applying CCD filter and transform techniques to the problem of interference excision within communications channels were presented. Adaptive noise (interference) suppression was achieved by the modification of received signals such that they were orthogonal to the recently measured noise field. CCD techniques were examined to develop real-time noise excision processing. They were recursive filters, circulating filter banks, transversal filter banks, an optical implementation of the chirp Z transform, and a CCD analog FFT.
VizieR Online Data Catalog: BVR light curves of UZ Leo (Lee+, 2018)
NASA Astrophysics Data System (ADS)
Lee, J. W.; Park, J.-H.
2018-04-01
We performed new CCD photometry of UZ Leo during two observing seasons between 2012 February and 2013 April, using a PIXIS: 2048B CCD and a BVR filter set attached to the 61 cm reflector at Sobaeksan Optical Astronomy Observatory (SOAO) in Korea. The CCD chip has 2048x2048pixels and a pixel size of 13.5um, so the field of view of a CCD frame is 17.6'x17.6'. (1 data file).
Observed flow compensation associated with the MOC at 26.5 degrees N in the Atlantic.
Kanzow, Torsten; Cunningham, Stuart A; Rayner, Darren; Hirschi, Joël J-M; Johns, William E; Baringer, Molly O; Bryden, Harry L; Beal, Lisa M; Meinen, Christopher S; Marotzke, Jochem
2007-08-17
The Atlantic meridional overturning circulation (MOC), which provides one-quarter of the global meridional heat transport, is composed of a number of separate flow components. How changes in the strength of each of those components may affect that of the others has been unclear because of a lack of adequate data. We continuously observed the MOC at 26.5 degrees N for 1 year using end-point measurements of density, bottom pressure, and ocean currents; cable measurements across the Straits of Florida; and wind stress. The different transport components largely compensate for each other, thus confirming the validity of our monitoring approach. The MOC varied over the period of observation by +/-5.7 x 10(6) cubic meters per second, with density-inferred and wind-driven transports contributing equally to it. We find evidence for depth-independent compensation for the wind-driven surface flow.
Colony Collapse Disorder (CCD) and bee age impact honey bee pathophysiology
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 impacting bee health. PMID:28715431
Colony Collapse Disorder (CCD) and bee age impact honey bee pathophysiology.
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 impacting bee health.
Extended depth of field imaging for high speed object analysis
NASA Technical Reports Server (NTRS)
Frost, Keith (Inventor); Ortyn, William (Inventor); Basiji, David (Inventor); Bauer, Richard (Inventor); Liang, Luchuan (Inventor); Hall, Brian (Inventor); Perry, David (Inventor)
2011-01-01
A high speed, high-resolution flow imaging system is modified to achieve extended depth of field imaging. An optical distortion element is introduced into the flow imaging system. Light from an object, such as a cell, is distorted by the distortion element, such that a point spread function (PSF) of the imaging system is invariant across an extended depth of field. The distorted light is spectrally dispersed, and the dispersed light is used to simultaneously generate a plurality of images. The images are detected, and image processing is used to enhance the detected images by compensating for the distortion, to achieve extended depth of field images of the object. The post image processing preferably involves de-convolution, and requires knowledge of the PSF of the imaging system, as modified by the optical distortion element.
Quantitative operando visualization of the energy band depth profile in solar cells.
Chen, Qi; Mao, Lin; Li, Yaowen; Kong, Tao; Wu, Na; Ma, Changqi; Bai, Sai; Jin, Yizheng; Wu, Dan; Lu, Wei; Wang, Bing; Chen, Liwei
2015-07-13
The energy band alignment in solar cell devices is critically important because it largely governs elementary photovoltaic processes, such as the generation, separation, transport, recombination and collection of charge carriers. Despite the expenditure of considerable effort, the measurement of energy band depth profiles across multiple layers has been extremely challenging, especially for operando devices. Here we present direct visualization of the surface potential depth profile over the cross-sections of operando organic photovoltaic devices using scanning Kelvin probe microscopy. The convolution effect due to finite tip size and cantilever beam crosstalk has previously prohibited quantitative interpretation of scanning Kelvin probe microscopy-measured surface potential depth profiles. We develop a bias voltage-compensation method to address this critical problem and obtain quantitatively accurate measurements of the open-circuit voltage, built-in potential and electrode potential difference.
Quantitative operando visualization of the energy band depth profile in solar cells
Chen, Qi; Mao, Lin; Li, Yaowen; Kong, Tao; Wu, Na; Ma, Changqi; Bai, Sai; Jin, Yizheng; Wu, Dan; Lu, Wei; Wang, Bing; Chen, Liwei
2015-01-01
The energy band alignment in solar cell devices is critically important because it largely governs elementary photovoltaic processes, such as the generation, separation, transport, recombination and collection of charge carriers. Despite the expenditure of considerable effort, the measurement of energy band depth profiles across multiple layers has been extremely challenging, especially for operando devices. Here we present direct visualization of the surface potential depth profile over the cross-sections of operando organic photovoltaic devices using scanning Kelvin probe microscopy. The convolution effect due to finite tip size and cantilever beam crosstalk has previously prohibited quantitative interpretation of scanning Kelvin probe microscopy-measured surface potential depth profiles. We develop a bias voltage-compensation method to address this critical problem and obtain quantitatively accurate measurements of the open-circuit voltage, built-in potential and electrode potential difference. PMID:26166580
NASA Astrophysics Data System (ADS)
Garza, Alejandro J.; Sousa Alencar, Ana G.; Scuseria, Gustavo E.
2015-12-01
Singlet-paired coupled cluster doubles (CCD0) is a simplification of CCD that relinquishes a fraction of dynamic correlation in order to be able to describe static correlation. Combinations of CCD0 with density functionals that recover specifically the dynamic correlation missing in the former have also been developed recently. Here, we assess the accuracy of CCD0 and CCD0+DFT (and variants of these using Brueckner orbitals) as compared to well-established quantum chemical methods for describing ground-state properties of singlet actinide molecules. The f0 actinyl series (UO22+, NpO23+, PuO24+), the isoelectronic NUN, and thorium (ThO, ThO2+) and nobelium (NoO, NoO2) oxides are studied.
A programmable CCD driver circuit for multiphase CCD operation
NASA Technical Reports Server (NTRS)
Ewin, Audrey J.; Reed, Kenneth V.
1989-01-01
A programmable CCD (charge-coupled device) driver circuit was designed to drive CCDs in multiphased modes. The purpose of the drive electronics is to operate developmental CCD imaging arrays for NASA's tiltable moderate resolution imaging spectrometer (MODIS-T). Five objectives for the driver were considered during its design: (1) the circuit drives CCD electrode voltages between 0 V and +30 V to produce reasonable potential wells, (2) the driving sequence is started with one input signal, (3) the driving sequence is started with one input signal, (4) the circuit allows programming of frame sequences required by arrays of any size, (5) it produces interfacing signals for the CCD and the DTF (detector test facility). Simulation of the driver verified its function with the master clock running up to 10 MHz. This suggests a maximum rate of 400,000 pixels/s. Timing and packaging parameters were verified. The design uses 54 TTL (transistor-transistor logic) chips. Two versions of hardware were fabricated: wirewrap and printed circuit board. Both were verified functionally with a logic analyzer.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Su, Minfei; Li, Yue; Wyborny, Shane
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 CCDmore » 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.« less
Smith, Andrew B; López-Villarejo, Juan; Diago-Navarro, Elizabeth; Mitchenall, Lesley A; Barendregt, Arjan; Heck, Albert J; Lemonnier, Marc; Maxwell, Anthony; Díaz-Orejas, Ramón
2012-01-01
Bacterial toxin-antitoxin (TA) systems encode two proteins, a potent inhibitor of cell proliferation (toxin) and its specific antidote (antitoxin). Structural data has revealed striking similarities between the two model TA toxins CcdB, a DNA gyrase inhibitor encoded by the ccd system of plasmid F, and Kid, a site-specific endoribonuclease encoded by the parD system of plasmid R1. While a common structural fold seemed at odds with the two clearly different modes of action of these toxins, the possibility of functional crosstalk between the parD and ccd systems, which would further point to their common evolutionary origin, has not been documented. Here, we show that the cleavage of RNA and the inhibition of protein synthesis by the Kid toxin, two activities that are specifically counteracted by its cognate Kis antitoxin, are altered, but not inhibited, by the CcdA antitoxin. In addition, Kis was able to inhibit the stimulation of DNA gyrase-mediated cleavage of DNA by CcdB, albeit less efficiently than CcdA. We further show that physical interactions between the toxins and antitoxins of the different systems do occur and define the stoichiometry of the complexes formed. We found that CcdB did not degrade RNA nor did Kid have any reproducible effect on the tested DNA gyrase activities, suggesting that these toxins evolved to reach different, rather than common, cellular targets.
Changes in transcript abundance relating to colony collapse disorder in honey bees (Apis mellifera).
Johnson, Reed M; Evans, Jay D; Robinson, Gene E; Berenbaum, May R
2009-09-01
Colony collapse disorder (CCD) is a mysterious disappearance of honey bees that has beset beekeepers in the United States since late 2006. Pathogens and other environmental stresses, including pesticides, have been linked to CCD, but a causal relationship has not yet been demonstrated. Because the gut acts as a primary interface between the honey bee and its environment as a site of entry for pathogens and toxins, we used whole-genome microarrays to compare gene expression between guts of bees from CCD colonies originating on both the east and west coasts of the United States and guts of bees from healthy colonies sampled before the emergence of CCD. Considerable variation in gene expression was associated with the geographical origin of bees, but a consensus list of 65 transcripts was identified as potential markers for CCD status. Overall, elevated expression of pesticide response genes was not observed. Genes involved in immune response showed no clear trend in expression pattern despite the increased prevalence of viruses and other pathogens in CCD colonies. Microarray analysis revealed unusual ribosomal RNA fragments that were conspicuously more abundant in the guts of CCD bees. The presence of these fragments may be a possible consequence of picorna-like viral infection, including deformed wing virus and Israeli acute paralysis virus, and may be related to arrested translation. Ribosomal fragment abundance and presence of multiple viruses may prove to be useful diagnostic markers for colonies afflicted with CCD.
Changes in transcript abundance relating to colony collapse disorder in honey bees (Apis mellifera)
Johnson, Reed M.; Evans, Jay D.; Robinson, Gene E.; Berenbaum, May R.
2009-01-01
Colony collapse disorder (CCD) is a mysterious disappearance of honey bees that has beset beekeepers in the United States since late 2006. Pathogens and other environmental stresses, including pesticides, have been linked to CCD, but a causal relationship has not yet been demonstrated. Because the gut acts as a primary interface between the honey bee and its environment as a site of entry for pathogens and toxins, we used whole-genome microarrays to compare gene expression between guts of bees from CCD colonies originating on both the east and west coasts of the United States and guts of bees from healthy colonies sampled before the emergence of CCD. Considerable variation in gene expression was associated with the geographical origin of bees, but a consensus list of 65 transcripts was identified as potential markers for CCD status. Overall, elevated expression of pesticide response genes was not observed. Genes involved in immune response showed no clear trend in expression pattern despite the increased prevalence of viruses and other pathogens in CCD colonies. Microarray analysis revealed unusual ribosomal RNA fragments that were conspicuously more abundant in the guts of CCD bees. The presence of these fragments may be a possible consequence of picorna-like viral infection, including deformed wing virus and Israeli acute paralysis virus, and may be related to arrested translation. Ribosomal fragment abundance and presence of multiple viruses may prove to be useful diagnostic markers for colonies afflicted with CCD. PMID:19706391
Hewetson, Ronelle; Cornwell, Petrea; Shum, David
2017-07-01
Rehabilitation positively influences return to activities and social roles in people with aphasia. The cognitive-communication disorder (CCD) found following a right hemisphere stroke has been less extensively researched with rehabilitation access and outcomes yet to be determined. To document rehabilitation access and outcomes for people with CCD post-stroke; and compare outcomes based on presence (viz CCD; aphasia) or absence of communication impairment. A retrospective chart audit was completed for patients with first onset unilateral stroke, with a hospital length of stay (LOS) of at least two days and a communication assessment by a speech pathologist. Data extracted included presence and severity of communication impairment, access to and LOS in a rehabilitation unit, and functional outcome measures recorded at rehabilitation discharge. The majority of the 115 patients who met inclusion criteria were living independently (n = 112, 97.4%) at the time of stroke. CCD (66%) was diagnosed with similar frequency to aphasia (68%). The presence of communication impairment did not result in significant differences in rehabilitation LOS and discharge destination when compared to hemispheric strokes without communication impairment. Severity of CCD was an independent predictor of functional gain by rehabilitation discharge. People with CCD require comparable access to rehabilitation as people with aphasia, and severity of CCD should be considered in determining rehabilitation LOS. A large number of people are discharged with ongoing CCD which warrants exploration of potential participation restrictions created by the communication impairment.
Mitchenall, Lesley A.; Barendregt, Arjan; Heck, Albert J.; Lemonnier, Marc; Maxwell, Anthony; Díaz-Orejas, Ramón
2012-01-01
Bacterial toxin-antitoxin (TA) systems encode two proteins, a potent inhibitor of cell proliferation (toxin) and its specific antidote (antitoxin). Structural data has revealed striking similarities between the two model TA toxins CcdB, a DNA gyrase inhibitor encoded by the ccd system of plasmid F, and Kid, a site-specific endoribonuclease encoded by the parD system of plasmid R1. While a common structural fold seemed at odds with the two clearly different modes of action of these toxins, the possibility of functional crosstalk between the parD and ccd systems, which would further point to their common evolutionary origin, has not been documented. Here, we show that the cleavage of RNA and the inhibition of protein synthesis by the Kid toxin, two activities that are specifically counteracted by its cognate Kis antitoxin, are altered, but not inhibited, by the CcdA antitoxin. In addition, Kis was able to inhibit the stimulation of DNA gyrase-mediated cleavage of DNA by CcdB, albeit less efficiently than CcdA. We further show that physical interactions between the toxins and antitoxins of the different systems do occur and define the stoichiometry of the complexes formed. We found that CcdB did not degrade RNA nor did Kid have any reproducible effect on the tested DNA gyrase activities, suggesting that these toxins evolved to reach different, rather than common, cellular targets. PMID:23029540
Evens, Emily; Lanham, Michele; Murray, Kate; Rao, Samwel; Agot, Kawango; Omanga, Eunice; Thirumurthy, Harsha
2016-08-15
Interventions to increase demand for medical male circumcision are urgently needed in eastern and southern Africa. Following promising evidence that providing economic compensation can increase male circumcision uptake in Kenya, there is a need to understand the role of this intervention in individuals' decision-making regarding circumcision and explore perceptions of the intervention and concerns such as coercion. As part of a randomized controlled trial in Kenya that found compensation in the form of food vouchers worth US $8.75-US $15.00 to be effective in increasing male circumcision uptake, we conducted qualitative in-depth interviews with 45 circumcised and uncircumcised male participants and 19 female partners to explore how compensation provision influenced the decision to get circumcised. Interview transcripts were coded and an inductive thematic analysis was conducted to identify patterns in decision-making. Interviews revealed that compensation promoted circumcision uptake by addressing a major barrier to male circumcision uptake: lost wages during and after the circumcision procedure. Participants who did not get circumcised perceived the compensation amounts to be insufficient for offsetting their costs associated with getting circumcised or reported having nonfinancial barriers that were not addressed by the intervention, such as fear of pain. Participants also reported that they did not feel compelled to get circumcised for financial gain. Female partners of circumcised participants felt that the intervention helped to motivate their partners to get circumcised. The results suggest that the provision of economic compensation is an acceptable intervention that can address an important barrier to male circumcision uptake. Providing compensation to circumcision clients in the form of food vouchers warrants further consideration in voluntary medical male circumcision demand creation efforts.
Compensating for Tissue Changes in an Ultrasonic Power Link for Implanted Medical Devices.
Vihvelin, Hugo; Leadbetter, Jeff; Bance, Manohar; Brown, Jeremy A; Adamson, Robert B A
2016-04-01
Ultrasonic power transfer using piezoelectric devices is a promising wireless power transfer technology for biomedical implants. However, for sub-dermal implants where the separation between the transmitter and receiver is on the order of several acoustic wavelengths, the ultrasonic power transfer efficiency (PTE) is highly sensitive to the distance between the transmitter and receiver. This sensitivity can cause large swings in efficiency and presents a serious limitation on battery life and overall performance. A practical ultrasonic transcutaneous energy transfer (UTET) system design must accommodate different implant depths and unpredictable acoustic changes caused by tissue growth, hydration, ambient temperature, and movement. This paper describes a method used to compensate for acoustic separation distance by varying the transmit (Tx) frequency in a UTET system. In a benchtop UTET system we experimentally show that without compensation, power transfer efficiency can range from 9% to 25% as a 5 mm porcine tissue sample is manipulated to simulate in situ implant conditions. Using an active frequency compensation method, we show that the power transfer efficiency can be kept uniformly high, ranging from 20% to 27%. The frequency compensation strategy we propose is low-power, non-invasive, and uses only transmit-side measurements, making it suitable for active implanted medical device applications.
NASA Astrophysics Data System (ADS)
Petronotis, K. E.; Robertson, A.; Kutterolf, S.; Avery, A.; Baxter, A.; Schindlbeck, J. C.; Wang, K. L.; Acton, G.
2016-12-01
International Ocean Discovery Program (IODP) Expedition 352 recovered early Oligocene to recent sediments above Eocene igneous basement at 4 sites in the Izu-Bonin Forearc. The sites were selected to investigate the forearc region since subduction initiation in the Eocene, with Sites U1439 and U1442 being cored into the upper trench slope and Sites U1440 and U1441 into the lower trench slope. Postcruise studies of biostratigraphy, sediment chemistry, tephra composition and chronology and magnetic properties, along with observations from prior coring help constrain the regional geological development. Volcanic activity in the area, as inferred from its influence on sediment composition, has varied between long periods of activity and quiescence. Combined whole-rock sediment chemistry and tephra compositions suggest that during the Oligocene to earliest Miocene ( 30-22 Ma) tuffaceous input of predominantly dacitic composition was mainly derived from the intra-oceanic Izu-Bonin Arc. The early Miocene interval ( 22-15 Ma) lacks tuffaceous input, as supported by rock magnetic data. During this period, the forearc subsided beneath the carbonate compensation depth (CCD), as evidenced by radiolarian-bearing mud and metal-rich silty clay. This was followed by input of tephra with bimodal felsic and mafic compositions from the Izu-Bonin Arc from 15 to 5 Ma. Middle Miocene to Quaternary time was characterized by increased carbonate preservation, coupled with abundant, predominantly felsic tephra input, which is chemically indicative of a Japan continental arc source (Honshu), with additional chemically distinctive input from the Izu-Bonin Arc. Extending back to 32 Ma, tephra layers can be correlated between the upper-slope sites, extrapolated to the less well-dated lower-slope sites, and further correlated with onland Japanese tephra (Kutterolf et al., 2016; Goldschmidt Conference). Overall, the new results provide an improved understanding of the regional tectonic evolution.
Lower Cretaceous smarl turbidites of the Argo Abyssal Plain, Indian Ocean
Dumoulin, Julie A.; Stewart, Sondra K.; Kennett, Diana; Mazzullo, Elsa K.
1992-01-01
Sediments recovered during Ocean Drilling Program (ODP) Leg 123 from the Argo Abyssal Plain (AAP) consist largely of turbidites derived from the adjacent Australian continental margin. The oldest abundant turbidites are Valanginian-Aptian in age and have a mixed (smarl) composition; they contain subequal amounts of calcareous and siliceous biogenic components, as well as clay and lesser quartz. Most are thin-bedded, fine sand to mud-sized, and best described by Stow and Piper's model (1984) for fine-grained biogenic turbidites. Thicker (to 3 m), coarser-grained (medium-to-coarse sand-sized) turbidites fit Bouma's model (1962) for sandy turbidites; these generally are base-cut-out (BCDE, BDE) sequences, with B-division parallel lamination as the dominant structure. Parallel laminae most commonly concentrate quartz and/or calcispheres vs. lithic clasts or clay, but distinctive millimeter to centimeter-thick, radiolarian-rich laminae occur in both fine and coarse-grained Valanginian-Hauterivian turbidites.AAP turbidites were derived from relatively deep parts of the continental margin (outer shelf, slope, or rise) that lay below the photic zone, but above the calcite compensation depth (CCD). Biogenic components are largely pelagic (calcispheres, foraminifers, radiolarians, nannofossils); lesser benthic foraminifers are characteristic of deep-water (abyssal to bathyal) environments. Abundant nonbiogenic components are mostly clay and clay clasts; smectite is the dominant clay species, and indicates a volcanogenic provenance, most likely the Triassic-Jurassic volcanic suite exposed along the northern Exmouth Plateau.Lower Cretaceous smarl turbidites were generated during eustatic lowstands and may have reached the abyssal plain via Swan Canyon, a submarine canyon thought to have formed during the Late Jurassic. In contrast to younger AAP turbidites, however, Lower Cretaceous turbidites are relatively fine-grained and do not contain notably older reworked fossils. Early in its history, the northwest Australian margin provided mainly contemporaneous slope sediment to the AAP; marginal basins adjacent to the continent trapped most terrigenous detritus, and pronounced canyon incisement did not occur until Late Cretaceous and, especially, Cenozoic time.
CCD Detects Two Images In Quick Succession
NASA Technical Reports Server (NTRS)
Janesick, James R.; Collins, Andy
1996-01-01
Prototype special-purpose charge-coupled device (CCD) designed to detect two 1,024 x 1,024-pixel images in rapid succession. Readout performed slowly to minimize noise. CCD operated in synchronism with pulsed laser, stroboscope, or other pulsed source of light to form pairs of images of rapidly moving objects.
Maori, E; Paldi, N; Shafir, S; Kalev, H; Tsur, E; Glick, E; Sela, I
2009-02-01
Colony Collapse Disorder (CCD) has been associated with Israeli acute paralysis virus (IAPV). CCD poses a serious threat to apiculture and agriculture as a whole, due to the consequent inability to provide the necessary amount of bees for pollination of critical crops. Here we report on RNAi-silencing of IAPV infection by feeding bees with double-stranded RNA, as an efficient and feasible way of controlling this viral disease. The association of CCD with IAPV is discussed, as well as the potential of controlling CCD.
SCP -- A Simple CCD Processing Package
NASA Astrophysics Data System (ADS)
Lewis, J. R.
This note describes a small set of programs, written at RGO, which deal with basic CCD frame processing (e.g. bias subtraction, flat fielding, trimming etc.). The need to process large numbers of CCD frames from devices such as FOS or ISIS in order to extract spectra has prompted the writing of routines which will do the basic hack-work with a minimal amount of interaction from the user. Although they were written with spectral data in mind, there are no ``spectrum-specific'' features in the software which means they can be applied to any CCD data.
Software design of control system of CCD side-scatter lidar
NASA Astrophysics Data System (ADS)
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.
Regulation of transport in the connecting tubule and cortical collecting duct
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
Design of area array CCD image acquisition and display system based on FPGA
NASA Astrophysics Data System (ADS)
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.
Silicon sample holder for molecular beam epitaxy on pre-fabricated integrated circuits
NASA Technical Reports Server (NTRS)
Hoenk, Michael E. (Inventor); Grunthaner, Paula J. (Inventor); Grunthaner, Frank J. (Inventor)
1994-01-01
The sample holder of the invention is formed of the same semiconductor crystal as the integrated circuit on which the molecular beam expitaxial process is to be performed. In the preferred embodiment, the sample holder comprises three stacked micro-machined silicon wafers: a silicon base wafer having a square micro-machined center opening corresponding in size and shape to the active area of a CCD imager chip, a silicon center wafer micro-machined as an annulus having radially inwardly pointing fingers whose ends abut the edges of and center the CCD imager chip within the annulus, and a silicon top wafer micro-machined as an annulus having cantilevered membranes which extend over the top of the CCD imager chip. The micro-machined silicon wafers are stacked in the order given above with the CCD imager chip centered in the center wafer and sandwiched between the base and top wafers. The thickness of the center wafer is about 20% less than the thickness of the CCD imager chip. Preferably, four titanium wires, each grasping the edges of the top and base wafers, compress all three wafers together, flexing the cantilever fingers of the top wafer to accommodate the thickness of the CCD imager chip, acting as a spring holding the CCD imager chip in place.
Ilg, Andrea; Yu, Qiuju; Schaub, Patrick; Beyer, Peter; Al-Babili, Salim
2010-08-01
Carotenoids are converted by carotenoid cleavage dioxygenases that catalyze oxidative cleavage reactions leading to apocarotenoids. However, apocarotenoids can also be further truncated by some members of this enzyme family. The plant carotenoid cleavage dioxygenase 1 (CCD1) subfamily is known to degrade both carotenoids and apocarotenoids in vitro, leading to different volatile compounds. In this study, we investigated the impact of the rice CCD1 (OsCCD1) on the pigmentation of Golden Rice 2 (GR2), a genetically modified rice variety accumulating carotenoids in the endosperm. For this purpose, the corresponding cDNA was introduced into the rice genome under the control of an endosperm-specific promoter in sense and anti-sense orientations. Despite high expression levels of OsCCD1 in sense plants, pigment analysis revealed carotenoid levels and patterns comparable to those of GR2, pleading against carotenoids as substrates in rice endosperm. In support, similar carotenoid contents were determined in anti-sense plants. To check whether OsCCD1 overexpressed in GR2 endosperm is active, in vitro assays were performed with apocarotenoid substrates. HPLC analysis confirmed the cleavage activity of introduced OsCCD1. Our data indicate that apocarotenoids rather than carotenoids are the substrates of OsCCD1 in planta.
The deep structure of Venusian plateau highlands
NASA Technical Reports Server (NTRS)
Grimm, Robert E.
1994-01-01
Magellan gravity data confirm that several of the large, tectonically deformed, plateau-like highlands on venus are shallowly compensated, most likely by crustal thickness variations. Apparent depths of isostatic compensation, computed in the spatial domain, range from 30 to 50 km for Alpha, Tellus, Ovda, and Thetis Regiones. Using a two-layer model for isostatic compensation, Alpha, Tellus, and Ovda are best represented as nearly completely compensated in crust that is regionally 20-40 km thick around these highlands, with little contribution from deeper mantle sources. In contrast to these three areas, a stronger regional gravity high associated with Thetis requires a significant upper mantle component to compensation. This is evident in the spectral admittance as a pronounced deep, long-wavelength anomaly. In the two-layer isostatic model, a broad, deeply compensated upland underlies a shallowly compensated central block of Thetis. If this deep component is interpreted as a thermal anomaly, the loci of maximum upwelling agree well with sites of recent extension. The plateau highlands are thus physiographically and isostatically equivalent to terrestrial continents, though probably not compositionally. They also share the record of a long tectonic history. The large regional gravity anomaly of Thetis indicates that active mantle proceses continue even beneath some areas (tessera) thought to be a relic of a former geological regime. The excellent agreement of modeled crustal thicknesses around Alpha, Tellus, and Ovda Regiones suggests that 20-40 km is a representative global value for the plains. Such a crust is thicker than previously estimated and about twice as thick as the expected thickness of crust produced at venusian spreading centers
Method to control artifacts of microstructural fabrication
Shul, Randy J.; Willison, Christi G.; Schubert, W. Kent; Manginell, Ronald P.; Mitchell, Mary-Anne; Galambos, Paul C.
2006-09-12
New methods for fabrication of silicon microstructures have been developed. In these methods, an etching delay layer is deposited and patterned so as to provide differential control on the depth of features being etched into a substrate material. Compensation for etching-related structural artifacts can be accomplished by proper use of such an etching delay layer.
Que Gacho Es Ser Macho: It's a Drag to Be a Macho Man.
ERIC Educational Resources Information Center
Mirande, Alfredo
1986-01-01
Focuses on variations in perceptions and conceptions of machismo within Mexican and Latino culture. Studies how Latino fathers living in United States perceive machismo, utilizing data from in-depth interviews. Identifies two models of masculinity, one as compensation for powerlessness, the other grounded in ethics, honor, and courage. (TES)
NASA Astrophysics Data System (ADS)
Gorshkov, A. M.; Kudryashova, L. K.; Lee-Van-Khe, O. S.
2016-09-01
The article presents the results of studying petrophysical rock properties of the Bazhenov Formation of the South-Eastern part of Kaymysovsky Vault with the Gas Research Institute (GRI) method. The authors have constructed dependence charts for bulk and grain density, open porosity and matrix permeability vs. depth. The results of studying petrophysical properties with the GRI method and core description have allowed dividing the entire section into three intervals each of which characterized by different conditions of Bazhenov Formation rock formation. The authors have determined a correlation between the compensated neutron log and the rock density vs. depth chart on the basis of complex well logging and petrophysical section analysis. They have determined a promising interval for producing hydrocarbons from the Bazhenov Formation in the well under study. Besides, they have determined the typical behavior of compensated neutron logs and SP logs on well logs for this interval. These studies will allow re-interpreting available well logs in order to determine the most promising interval to be involved in Bazhenov Formation development in Tomsk Region.
Influence of the Hyporheic Zone on Supersaturated Gas Exposure to Incubating Chum Salmon
DOE Office of Scientific and Technical Information (OSTI.GOV)
Arntzen, Evan V.; Geist, David R.; Murray, Katherine J.
2009-12-01
Supersaturated total dissolved gas (TDG) is elevated seasonally in the lower Columbia River, with surface water concentrations approaching 120% saturation of TDG. Chum salmon (Oncorhynchus keta) embryos incubating in nearby spawning areas could be affected if depth-compensated TDG concentrations within the hyporheic zone exceed 103% TDG. The objective of this study was to determine if TDG of the hyporheic zone in two chum salmon spawning areas -- one in a side channel near Ives Island, Washington, and another on the mainstem Columbia River near Multnomah Falls, Oregon -- was affected by the elevated TDG of the surface water. Depth-compensated hyporheicmore » TDG did not exceed 103% at the Multnomah Falls site. However, in the Ives Island area, chum salmon redds were exposed to TDG greater than 103% for more than 600 hours. In response to river depth fluctuations, TDG varied significantly in the Ives Island area, suggesting increased interaction between the hyporheic zone and surface water at that site. We conclude from this study that the interaction between surface water and the hyporheic zone affects the concentration of TDG within the hyporheic zone directly via physical mixing as well as indirectly by altering water chemistry and thus dissolved gas solubility. These interactions are important considerations when estimating TDG exposure within egg pocket environments, facilitating improved exposure estimates, and enabling managers to optimize recovery strategies.« less
Pressure as a limit to bloater (Coregonus hoyi) vertical migration
TeWinkel, Leslie M.; Fleischer, Guy W.
1998-01-01
Observations of bloater vertical migration showed a limit to the vertical depth changes that bloater experience. In this paper, we conducted an analysis of maximum differences in pressure encountered by bloater during vertical migration. Throughout the bottom depths studied, bloater experienced maximum reductions in swim bladder volume equal to approximately 50-60% of the volume in midwater. The analysis indicated that the limit in vertical depth change may be related to a maximum level of positive or negative buoyancy for which bloater can compensate using alternative mechanisms such as hydrodynamic lift. Bloater may be limited in the extent of migration by either their depth of neutral buoyancy or the distance above the depth of neutral buoyancy at which they can still maintain their position in the water column. Although a migration limit for the bloater population was evident, individual distances of migration varied at each site. These variations in migration distances may indicate differences in depths of neutral buoyancy within the population. However, in spite of these variations, the strong correlation between shallowest depths of migration and swim bladder volume reduction across depths provides evidence that hydrostatic pressure limits the extent of daily vertical movement in bloater.
Guan, Phillip
2016-01-01
Depth constancy is the ability to perceive a fixed depth interval in the world as constant despite changes in viewing distance and the spatial scale of depth variation. It is well known that the spatial frequency of depth variation has a large effect on threshold. In the first experiment, we determined that the visual system compensates for this differential sensitivity when the change in disparity is suprathreshold, thereby attaining constancy similar to contrast constancy in the luminance domain. In a second experiment, we examined the ability to perceive constant depth when the spatial frequency and viewing distance both changed. To attain constancy in this situation, the visual system has to estimate distance. We investigated this ability when vergence, accommodation and vertical disparity are all presented accurately and therefore provided veridical information about viewing distance. We found that constancy is nearly complete across changes in viewing distance. Depth constancy is most complete when the scale of the depth relief is constant in the world rather than when it is constant in angular units at the retina. These results bear on the efficacy of algorithms for creating stereo content. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269596
Fabrication of Robust, Flat, Thinned, UV-Imaging CCDs
NASA Technical Reports Server (NTRS)
Grunthaner, Paula; Elliott, Stythe; Jones, Todd; Nikzad, Shouleh
2004-01-01
An improved process that includes a high-temperature bonding subprocess has been developed to enable the fabrication of robust, flat, silicon-based charge-coupled devices (CCDs) for imaging in ultraviolet (UV) light and/or for detecting low-energy charged particles. The CCDs in question are devices on which CCD circuitry has already been formed and have been thinned for backsurface illumination. These CCDs may be delta doped, and aspects of this type of CCD have been described in several prior articles in NASA Tech Briefs. Unlike prior low-temperature bonding subprocesses based on the use of epoxies or waxes, the high-temperature bonding subprocess is compatible with the deltadoping process as well as with other CCD-fabrication processes. The present improved process and its bonding, thinning, and delta-doping subprocesses, are characterized as postfabrication processes because they are undertaken after the fabrication of CCD circuitry on the front side of a full-thickness silicon substrate. In a typical case, it is necessary to reduce the thickness of the CCD to between 10 and 20 m in order to take advantage of back-side illumination and in order to perform delta doping and/or other back-side treatment to enhance the quantum efficiency. In the prior approach to the fabrication of back-side-illuminated CCDs, the thinning subprocess turned each CCD into a free-standing membrane that was fragile and tended to become wrinkled. In the present improved process, prior to thinning and delta doping, a CCD is bonded on its front side to a silicon substrate that has been prefabricated to include cutouts to accommodate subsequent electrical connections to bonding pads on the CCD circuitry. The substrate provides structural support to increase ruggedness and maintain flatness. At the beginning of this process, the back side of a CCD as fabricated on a full-thickness substrate is polished. Silicon nitride is deposited on the back side, opposite the bonding pads on the front side, in order to define a relatively thick frame. The portion of the CCD not covered by the frame is the portion to be thinned by etching.
NASA Astrophysics Data System (ADS)
Garcia-Sucerquia, J.; Xu, W.; Jericho, S. K.; Jericho, M. H.; Tamblyn, I.; Kreuzer, H. J.
2006-01-01
In recent years, in-line holography as originally proposed by Gabor, supplemented with numerical reconstruction, has been perfected to the point at which wavelength resolution both laterally and in depth is routinely achieved with light by using digital in-line holographic microscopy (DIHM). The advantages of DIHM are: (1) simplicity of the hardware (laser- pinhole-CCD camera), (2) magnification is obtained in the numerical reconstruction, (3) maximum information of the 3-D structure with a depth of field of millimeters, (4) changes in the specimen and the simultaneous motion of many species, can be followed in 4-D at the camera frame rate. We present results obtained with DIHM in biological and microfluidic applications. By taking advantage of the large depth of field and the plane-to-plane reconstruction capability of DIHM, we can produce 3D representations of the paths followed by micron-sized objects such as suspensions of microspheres and biological samples (cells, algae, protozoa, bacteria). Examples from biology include a study of the motion of bacteria in a diatom and the track of algae and paramecium. In microfluidic applications we observe micro-channel flow, motion of bubbles in water and evolution in electrolysis. The paper finishes with new results from an underwater version of DIHM.
NASA Astrophysics Data System (ADS)
Li, Xiaoqin; Li, Baian; Chen, Naisong; Huang, Xuxiong; Hua, Xuemin; Leng, Xiangjun
2017-12-01
To compare the flesh quality of large yellow croaker cultured with three different modes, enclosure culture (EC), cage culture with feeding trash fish (CCF) and cage culture with feeding formula diet (CCD), thirty six fish individuals of EC (484.6 ± 79.8 g), CCF (432.7 ± 87.9 g) and CCD (416.9 ± 49.5 g) were sampled to measure body color, flesh water holding capacity, flesh proximate composition, amino acids and fatty acids composition, and collagen and inosinic acid contents. The analysis showed that there was no significant difference in the yellowness of skin and the contents of crude protein and inosinic acid between CCD and EC (P >0.05), and the two modes showed higher values than CCF ( P < 0.05). Most of the amino acids (AA) in flesh were higher in EC than in CCF ( P < 0.05), but CCD showed no difference in AA composition from the other two modes ( P > 0.05). EC and CCD had higher contents of collagen, free AA and lower drip loss than CC ( P < 0.05). In polyunsaturated fatty acids, EC showed significantly higher levels of C20:5n-3 and C22:6n-3 than CCF and CCD ( P < 0.05), but CCD had significantly higher C18:2n-6 than CCF and EC ( P < 0.05). In conclusion, the flesh quality of CCD fish is similar to EC fish, and these two modes have better flesh quality than CCF.
Chevrot, G; Schurhammer, R; Wipff, G
2007-04-28
We report a molecular dynamics study of chlorinated cobalt bis(dicarbollide) anions [(B(9)C(2)H(8)Cl(3))(2)Co](-)"CCD(-)" in octanol and at the octanol-water interface, with the main aim to understand why these hydrophobic species act as strong synergists in assisted liquid-liquid cation extraction. Neat octanol is quite heterogeneous and is found to display dual solvation properties, allowing to well solubilize CCD(-), Cs(+) salts in the form of diluted pairs or oligomers, without displaying aggregation. At the aqueous interface, octanol behaves as an amphiphile, forming either monolayers or bilayers, depending on the initial state and confinement conditions. In biphasic octanol-water systems, CCD(-) anions are found to mainly partition to the organic phase, thus attracting Cs(+) or even more hydrophilic counterions like Eu(3+) into that phase. The remaining CCD(-) anions adsorb at the interface, but are less surface active than at the chloroform interface. Finally, we compare the interfacial behavior of the Eu(BTP)(3)(3+) complex in the absence and in the presence of CCD(-) anions and extractant molecules. It is found that when the CCD(-)'s are concentrated enough, the complex is extracted to the octanol phase. Otherwise, it is trapped at the interface, attracted by water. These results are compared to those obtained with chloroform as organic phase and discussed in the context of synergistic effect of CCD(-) in liquid-liquid extraction, pointing to the importance of dual solvation properties of octanol and of the hydrophobic character of CCD(-) for synergistic extraction of cations.
A Low-Cost "Stationary Eye" in the Sky
NASA Astrophysics Data System (ADS)
Koch, R.; Lande, K.; Mitchell, R.; Wildenhain, P.; Hoang, N.; Langford, J.
1997-12-01
We are developing a stationary, near the top of the atmosphere, astronomical observing system. The platform is a high altitude robotic aircraft (THESEUS) flying in anti-sense to Earth's rotation at a latitude where the plane's speed closely matches the local ground spin velocity. Thus, either an extended day or night viewing program of a given object can be achieved. Our intention here concentrates on astronomical targets. The system consists of the following components. (1) A low cost robotic aircraft that can fly at an altitude of about 25 km. for 30 to 40 hours with differential GPS navigation. Real time control of the aircraft and the observing instruments is either by on-board computer or from the ground via low altitude, commercial satellite communications systems (Iridium, Teledesic, etc.). (2) A siderostat-fed telescope of small f-ratio is attached to the aircraft via critically damped mechanical isolators. An electronic camera at the prime focus looks at a chosen astronomical target. (3) Image smear due to aircraft engine vibration will be eliminated by a combination of critically damped mechanical isolators and electronic CCD pixel jogging. Very precise piezo- electric driven transverse translation of the CCD camera will be used to compensate for wind induced drift of the image on the focal plane. Bright field stars will be used to drive the stabilizing system. (4) Data are stored on high capacity ruggedized hard drives similar to that used by the Mars Lander. The Aurora THESEUS aircraft, whose design is based upon earlier models, is under development. The image stabilizing system components have been identified. An off-the-shelf data-storage device has been chosen. A first prototype telescope has been built and tested. Other optical configurations are possible and collaborators will be welcomed.
Study of physical and sound absorbing property of epoxy blended coir dust biocomposite
NASA Astrophysics Data System (ADS)
Nath, G.; Mishra, S. P.
2016-09-01
Reinforcement biocomposite has gained more attention recently due to its low cost, abundantly availability, low density, specific properties, easy method of separation, enhanced energy recovery, CO2 neutrality, biodegradability and recyclable in nature. As a waste product of coconut fruit, the coconut coir dust (CCD) obtained from the coconut husk. The biocomposite material prepared from the CCD modified with the proper blended solution with the help of ultrasonic technique. The study of adiabatic compressibility of acetone / water (70/30) worth its blending property for bleaching of CCD. The biocomposite material of CCD was prepared with epoxy resin. The different physical properties such as sound absorption coefficient, thermal conductivity and electrical conductivity were measured. The morphological study of biocomposite and measurement of sound absorption coefficient shows good evidence of sound absorbing characteristics of biocomposite of CCD. The sound absorption property of composite material shows a significant result where as the thermal conductivity and electrical conductivity executes a weak result. Thus biocomposite of CCD can acts as a good sound absorber and band conductor of heat and electric current.
Driving techniques for high frame rate CCD camera
NASA Astrophysics Data System (ADS)
Guo, Weiqiang; Jin, Longxu; Xiong, Jingwu
2008-03-01
This paper describes a high-frame rate CCD camera capable of operating at 100 frames/s. This camera utilizes Kodak KAI-0340, an interline transfer CCD with 640(vertical)×480(horizontal) pixels. Two output ports are used to read out CCD data and pixel rates approaching 30 MHz. Because of its reduced effective opacity of vertical charge transfer registers, interline transfer CCD can cause undesired image artifacts, such as random white spots and smear generated in the registers. To increase frame rate, a kind of speed-up structure has been incorporated inside KAI-0340, then it is vulnerable to a vertical stripe effect. The phenomena which mentioned above may severely impair the image quality. To solve these problems, some electronic methods of eliminating these artifacts are adopted. Special clocking mode can dump the unwanted charge quickly, then the fast readout of the images, cleared of smear, follows immediately. Amplifier is used to sense and correct delay mismatch between the dual phase vertical clock pulses, the transition edges become close to coincident, so vertical stripes disappear. Results obtained with the CCD camera are shown.
An Optical Fibre Depth (Pressure) Sensor for Remote Operated Vehicles in Underwater Applications
Duraibabu, Dinesh Babu; Poeggel, Sven; Omerdic, Edin; Capocci, Romano; Lewis, Elfed; Newe, Thomas; Leen, Gabriel; Toal, Daniel; Dooly, Gerard
2017-01-01
A miniature sensor for accurate measurement of pressure (depth) with temperature compensation in the ocean environment is described. The sensor is based on an optical fibre Extrinsic Fabry-Perot interferometer (EFPI) combined with a Fibre Bragg Grating (FBG). The EFPI provides pressure measurements while the Fibre Bragg Grating (FBG) provides temperature measurements. The sensor is mechanically robust, corrosion-resistant and suitable for use in underwater applications. The combined pressure and temperature sensor system was mounted on-board a mini remotely operated underwater vehicle (ROV) in order to monitor the pressure changes at various depths. The reflected optical spectrum from the sensor was monitored online and a pressure or temperature change caused a corresponding observable shift in the received optical spectrum. The sensor exhibited excellent stability when measured over a 2 h period underwater and its performance is compared with a commercially available reference sensor also mounted on the ROV. The measurements illustrates that the EFPI/FBG sensor is more accurate for depth measurements (depth of ~0.020 m). PMID:28218727
Accurate object tracking system by integrating texture and depth cues
NASA Astrophysics Data System (ADS)
Chen, Ju-Chin; Lin, Yu-Hang
2016-03-01
A robust object tracking system that is invariant to object appearance variations and background clutter is proposed. Multiple instance learning with a boosting algorithm is applied to select discriminant texture information between the object and background data. Additionally, depth information, which is important to distinguish the object from a complicated background, is integrated. We propose two depth-based models that can compensate texture information to cope with both appearance variants and background clutter. Moreover, in order to reduce the risk of drifting problem increased for the textureless depth templates, an update mechanism is proposed to select more precise tracking results to avoid incorrect model updates. In the experiments, the robustness of the proposed system is evaluated and quantitative results are provided for performance analysis. Experimental results show that the proposed system can provide the best success rate and has more accurate tracking results than other well-known algorithms.
A 128K-bit CCD buffer memory system
NASA Technical Reports Server (NTRS)
Siemens, K. H.; Wallace, R. W.; Robinson, C. R.
1976-01-01
A prototype system was implemented to demonstrate that CCD's can be applied advantageously to the problem of low power digital storage and particularly to the problem of interfacing widely varying data rates. 8K-bit CCD shift register memories were used to construct a feasibility model 128K-bit buffer memory system. Peak power dissipation during a data transfer is less than 7 W., while idle power is approximately 5.4 W. The system features automatic data input synchronization with the recirculating CCD memory block start address. Descriptions are provided of both the buffer memory system and a custom tester that was used to exercise the memory. The testing procedures and testing results are discussed. Suggestions are provided for further development with regards to the utilization of advanced versions of CCD memory devices to both simplified and expanded memory system applications.
Lucas, J E; Richter, L M; Daelmans, B
2018-01-01
An estimated 43% of children younger than 5 years of age are at elevated risk of failing to achieve their human potential. In response, the World Health Organization and UNICEF developed Care for Child Development (CCD), based on the science of child development, to improve sensitive and responsive caregiving and promote the psychosocial development of young children. In 2015, the World Health Organization and UNICEF identified sites where CCD has been implemented and sustained. The sites were surveyed, and responses were followed up by phone interviews. Project reports provided information on additional sites, and a review of published studies was undertaken to document the effectiveness of CCD for improving child and family outcomes, as well as its feasibility for implementation in resource-constrained communities. The inventory found that CCD had been integrated into existing services in diverse sectors in 19 countries and 23 sites, including child survival, health, nutrition, infant day care, early education, family and child protection and services for children with disabilities. Published and unpublished evaluations have found that CCD interventions can improve child development, growth and health, as well as responsive caregiving. It has also been reported to reduce maternal depression, a known risk factor for poor pregnancy outcomes and poor child health, growth and development. Although CCD has expanded beyond initial implementation sites, only three countries reported having national policy support for integrating CCD into health or other services. Strong interest exists in many countries to move beyond child survival to protect and support optimal child development. The United Nations Sustainable Development Goals depend on children realizing their potential to build healthy and emotionally, cognitively and socially competent future generations. More studies are needed to guide the integration of the CCD approach under different conditions. Nevertheless, the time is right to provide for the scale-up of CCD as part of services for families and children. © 2017 The Authors. Child: Care, Health and Development Published by John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Zeng, Yi; Han, Xue-bing; Yang, Dong-shang; Gui, Li-jia; Zhao, Xiao-xiang; Si, Fu-qi
2016-03-01
A space-borne differential optical absorption spectrometer is a high precision aerospace optical remote sensor. It obtains the hyper-spectral,high spatial resolution radiation information by using the spectrometer with CCD(Charge Coupled Device)array detectors. Since a few CCDs are used as the key detector, the performance of the entire instrument is greatly affected by working condition of CCDs. The temperature of CCD modules has a great impact on the instrument measurement accuracy. It requires strict temperature control. The selection of the thermal conductive filler sticking CCD to the radiator is important in the CCD thermal design. Besides,due tothe complex and compact structure, it needs to take into account the anti-pollution of the optical system. Therefore, it puts forward high requirements on the selection of the conductive filler. In this paper, according to the structure characteristics of the CCD modules and the distribution of heat consumption, the thermal analysis tool I-DEAS/TMG is utilized to compute and simulate the temperature level of the CCD modules, while filling in thermal grease and thermal pad respectively. The temperature distribution of CCD heat dissipation in typical operating conditions is obtained. In addition, the heat balance test was carried out under the condition of two kinds of thermal conductive fillers. The thermal control of CCD was tested under various conditions, and the results were compared with the results of thermal analysis. The results show that there are some differences in thermal performance between the two kinds of thermal conductive fillers. Although they both can meet the thermal performance requirements of the instrument, either would be chosen taking account of other conditions and requirements such as anti-pollution and insulation. The content and results of this paper will be a good reference for the thermal design of the CCD in the aerospace optical payload.
Image processing of metal surface with structured light
NASA Astrophysics Data System (ADS)
Luo, Cong; Feng, Chang; Wang, Congzheng
2014-09-01
In structured light vision measurement system, the ideal image of structured light strip, in addition to black background , contains only the gray information of the position of the stripe. However, the actual image contains image noise, complex background and so on, which does not belong to the stripe, and it will cause interference to useful information. To extract the stripe center of mental surface accurately, a new processing method was presented. Through adaptive median filtering, the noise can be preliminary removed, and the noise which introduced by CCD camera and measured environment can be further removed with difference image method. To highlight fine details and enhance the blurred regions between the stripe and noise, the sharping algorithm is used which combine the best features of Laplacian operator and Sobel operator. Morphological opening operation and closing operation are used to compensate the loss of information.Experimental results show that this method is effective in the image processing, not only to restrain the information but also heighten contrast. It is beneficial for the following processing.
A machine vision system for micro-EDM based on linux
NASA Astrophysics Data System (ADS)
Guo, Rui; Zhao, Wansheng; Li, Gang; Li, Zhiyong; Zhang, Yong
2006-11-01
Due to the high precision and good surface quality that it can give, Electrical Discharge Machining (EDM) is potentially an important process for the fabrication of micro-tools and micro-components. However, a number of issues remain unsolved before micro-EDM becomes a reliable process with repeatable results. To deal with the difficulties in micro electrodes on-line fabrication and tool wear compensation, a micro-EDM machine vision system is developed with a Charge Coupled Device (CCD) camera, with an optical resolution of 1.61μm and an overall magnification of 113~729. Based on the Linux operating system, an image capturing program is developed with the V4L2 API, and an image processing program is exploited by using OpenCV. The contour of micro electrodes can be extracted by means of the Canny edge detector. Through the system calibration, the micro electrodes diameter can be measured on-line. Experiments have been carried out to prove its performance, and the reasons of measurement error are also analyzed.
Precision Spectrophotometric Calibration System for Dark Energy Instruments
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schubnell, Michael S.
2015-06-30
For this research we build a precision calibration system and carried out measurements to demonstrate the precision that can be achieved with a high precision spectrometric calibration system. It was shown that the system is capable of providing a complete spectrophotometric calibration at the sub-pixel level. The calibration system uses a fast, high precision monochromator that can quickly and efficiently scan over an instrument’s entire spectral range with a spectral line width of less than 0.01 nm corresponding to a fraction of a pixel on the CCD. The system was extensively evaluated in the laboratory. Our research showed that amore » complete spectrophotometric calibration standard for spectroscopic survey instruments such as DESI is possible. The monochromator precision and repeatability to a small fraction of the DESI spectrograph LSF was demonstrated with re-initialization on every scan and thermal drift compensation by locking to multiple external line sources. A projector system that mimics telescope aperture for point source at infinity was demonstrated.« less
Dai, Meiling; Yang, Fujun; He, Xiaoyuan
2012-04-20
A simple but effective fringe projection profilometry is proposed to measure 3D shape by using one snapshot color sinusoidal fringe pattern. One color fringe pattern encoded with a sinusoidal fringe (as red component) and one uniform intensity pattern (as blue component) is projected by a digital video projector, and the deformed fringe pattern is recorded by a color CCD camera. The captured color fringe pattern is separated into its RGB components and division operation is applied to red and blue channels to reduce the variable reflection intensity. Shape information of the tested object is decoded by applying an arcsine algorithm on the normalized fringe pattern with subpixel resolution. In the case of fringe discontinuities caused by height steps, or spatially isolated surfaces, the separated blue component is binarized and used for correcting the phase demodulation. A simple and robust method is also introduced to compensate for nonlinear intensity response of the digital video projector. The experimental results demonstrate the validity of the proposed method.
Toolkit for testing scientific CCD cameras
NASA Astrophysics Data System (ADS)
Uzycki, Janusz; Mankiewicz, Lech; Molak, Marcin; Wrochna, Grzegorz
2006-03-01
The CCD Toolkit (1) is a software tool for testing CCD cameras which allows to measure important characteristics of a camera like readout noise, total gain, dark current, 'hot' pixels, useful area, etc. The application makes a statistical analysis of images saved in files with FITS format, commonly used in astronomy. A graphical interface is based on the ROOT package, which offers high functionality and flexibility. The program was developed in a way to ensure future compatibility with different operating systems: Windows and Linux. The CCD Toolkit was created for the "Pie of the Sky" project collaboration (2).
Low temperature multi-alkali photocathode processing technique for sealed intensified CCD tubes
NASA Technical Reports Server (NTRS)
Doliber, D. L.; Dozier, E. E.; Wenzel, H.; Beaver, E. A.; Hier, R. G.
1989-01-01
A low temperature photocathode process has been used to fabricate an intensified CCD visual photocathode image tube, by incorporating a thinned, backside-illumined CCD as the target anode of a digicon tube of Hubble Space Telescope (HST) design. The CCD digicon tube employs the HST's sodium bialkali photocathode and MgF2 substrate, thereby allowing a direct photocathode quantum efficiency comparison between photocathodes produced by the presently employed low temperature process and those of the conventional high temperature process. Attention is given to the processing chamber used, as well as the details of gas desorption and photocathode processing.
NASA Astrophysics Data System (ADS)
Liberini, Mariacira; Esposito, Sara; Reshad, Kambitz; Previtali, Barbara; Viola, Marco; Squillace, Antonino
2016-10-01
Every manufacturing process leaves on the surface of the piece a typical "technology signature". In particular, the laser welding leaves a feature at the edge of the weld bead called "undercut". In this work an experimental campaign has been conducted on Ti6Al4V butt joints. In particular a Central Composite Design (CCD) with the central point repeated three times has been investigated. In the CCD there are two factors (power and speed of the fiber laser) and five levels for each factor. This paper deals with the investigation about the correlation between the severity of the undercut and the process parameters of the laser welding. In particular, through the confocal microscopy, the original geometry of the joint was accurately acquired and rebuilt in order to make a FEM model and simulate the mechanical behavior using Ansys14.5. Moreover, response surfaces and level curves were carried out to understand and predict the depth and the width of the undercut starting from the power and the speed of the laser. At last a mathematic and geometry regression was performed in order to find a unique conical curve that interpolates all the different undercuts and that varies its parameters according to the process parameters. It is established that the process with higher speed minimizes and optimizes the undercut in the joints.
Cone beam x-ray luminescence computed tomography reconstruction with a priori anatomical information
NASA Astrophysics Data System (ADS)
Lo, Pei-An; Lin, Meng-Lung; Jin, Shih-Chun; Chen, Jyh-Cheng; Lin, Syue-Liang; Chang, C. Allen; Chiang, Huihua Kenny
2014-09-01
X-ray luminescence computed tomography (XLCT) is a novel molecular imaging modality that reconstructs the optical distribution of x-ray-excited phosphor particles with prior informational of anatomical CT image. The prior information improves the accuracy of image reconstruction. The system can also present anatomical CT image. The optical system based on a high sensitive charge coupled device (CCD) is perpendicular with a CT system. In the XLCT system, the xray was adopted to excite the phosphor of the sample and CCD camera was utilized to acquire luminescence emitted from the sample in 360 degrees projection free-space. In this study, the fluorescence diffuse optical tomography (FDOT)-like algorithm was used for image reconstruction, the structural prior information was incorporated in the reconstruction by adding a penalty term to the minimization function. The phosphor used in this study is Gd2O2S:Tb. For the simulation and experiments, the data was collected from 16 projections. The cylinder phantom was 40 mm in diameter and contains 8 mm diameter inclusion; the phosphor in the in vivo study was 5 mm in diameter at a depth of 3 mm. Both the errors were no more than 5%. Based on the results from these simulation and experimental studies, the novel XLCT method has demonstrated the feasibility for in vivo animal model studies.
Regulation of transport in the connecting tubule and cortical collecting duct.
Staruschenko, Alexander
2012-04-01
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, for example, 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 also be covered. Special emphasis will be given to pathophysiological conditions appearing as a result of abnormalities in renal transport in the CNT and CCD. © 2012 American Physiological Society. Compr Physiol 2:1491-1539, 2012.
Cervical spine dysfunction signs and symptoms in individuals with temporomandibular disorder.
Weber, Priscila; Corrêa, Eliane Castilhos Rodrigues; Ferreira, Fabiana dos Santos; Soares, Juliana Corrêa; Bolzan, Geovana de Paula; Silva, Ana Maria Toniolo da
2012-01-01
To study the frequency of cervical spine dysfunction (CCD) signs and symptoms in subjects with and without temporomandibular disorder (TMD) and to assess the craniocervical posture influence on TMD and CCD coexistence. Participants were 71 women (19 to 35 years), assessed about TMD presence; 34 constituted the TMD group (G1) and 37 comprised the group without TMD (G2). The CCD was evaluated through the Craniocervical Dysfunction Index and the Cervical Mobility Index. Subjects were also questioned about cervical pain. Craniocervical posture was assessed by cephalometric analysis. There was no difference in the craniocervical posture between groups. G2 presented more mild CCD frequency and less moderate and severe CCD frequency (p=0.01). G1 presented higher percentage of pain during movements (p=0.03) and pain during cervical muscles palpation (p=0.01) compared to G2. Most of the TMD patients (88.24%) related cervical pain with significant difference when compared to G2 (p=0.00). Craniocervical posture assessment showed no difference between groups, suggesting that postural alterations could be more related to the CCD. Presence of TMD resulted in higher frequency of cervical pain symptom. Thus the coexistence of CCD and TMD signs and symptoms appear to be more related to the common innervations of the trigeminocervical complex and hyperalgesia of the TMD patients than to craniocervical posture deviations.
Analysis of stratification of Cr with depth in the atmospheres of normal and CP stars.
NASA Astrophysics Data System (ADS)
Savanov, I. S.
We present the results of analysis of stratification of Cr with depth in the atmospheres of normal, Am, HgMn and Ap stars. On the base of high resolution CCD-spectrograms obtained with spectrograph of 2.6-meter Shajn reflector using synthetic spectrum technique analysis of eight Cr II lines (30 multiplet) located in the wings of Hb Hydrogen line. For all investigated Am stars as well as for HgMn components of 46 Dra we suspect the similar small increase of Cr abundance in the upper atmosphere. For the hot spotted Ap stars α2 CVn and 17 Com we do not find evidence for the inhomogeneity distribution of Chromium while for the group of cool Ap stars (β CrB, HR 7575, 10 Aql and γ Equ) the increase of Cr abundance with depth was found. Detailed modelling of Cr II line profiles was performed in order to obtain vertical distributions of this element in the atmospheres of several Ap and Am stars. Our results for cool Ap stars were compared with vertical Cr distribution calculated by J.Babel using the diffusion theory and magnetically confined wind for Ap star 53 Cam (e.g. Astronomy and Astrophysics, v.258, p.449-463, 1992). It was shown that our observational material cannot be interpreted using hypothesis of depth-dependent microturbulent velocity. While the investigation of β CrB we demonstrate that obtained results insignificantly depend upon the uncertainties of the parameters of models of atmospheres.
Why do veins appear blue? A new look at an old question
NASA Astrophysics Data System (ADS)
Kienle, Alwin; Hibst, Raimund; Steiner, Rudolf; Lilge, Lothar; Vitkin, I. Alex; Wilson, Brian C.; Patterson, Michael S.
1996-03-01
We investigate why vessels that contain blood, which has a red or a dark red color, may look bluish in human tissue. A CCD camera was used to make images of diffusely reflected light at different wavelengths. Measurements of reflectance that are due to model blood vessels in scattering media and of human skin containing a prominent vein are presented. Monte Carlo simulations were used to calculate the spatially resolved diffuse reflectance for both situations. We show that the color of blood vessels is scattering and absorption characteristics of skin at different wavelengths, (ii) the oxygenation state of blood, which affects its absorption properties, (iii) the diameter and the depth of the vessels, and (iv) the visual perception process.
Distribution and geologic history of materials excavated by the lunar crater Bullialdus
NASA Technical Reports Server (NTRS)
Tompkins, Stefanie; Pieters, Carle M.; Mustard, John F.
1993-01-01
The crater Bullialdus is a 61 km, Eratosthenian-age impact crater located on the western edge of Mare Nubium. Previous analysis of the spatial distribution of materials in the area using nine telescopic near-infrared spectra suggested a possible three-layer structure prior to the impact event: two shallow gabbroic layers and one deeper noritic layer (from a potential depth of 5.5 km). The initial interpretation of this stratigraphy was that Bullialdus may have tapped a layered mafic pluton, such as have been invoked to explain the existence of Mg-suite rocks. High-spatial resolution CCD images of Bullialdus were analyzed to better map the spatial distribution of the observed lithologies, and to assess the plausibility of the pluton interpretation.
Instructional Staff Salary and Benefits Spending: 1991-2011. Data Point. NCES 2016-156
ERIC Educational Resources Information Center
Malkus, Nat; Hoyer, Kathleen Mulvaney
2016-01-01
This report uses expenditure data from the Common Core of Data (CCD) "National Public Education Financial Survey (NPEFS)" for fiscal years 1991 to 2011 and instructional staff data from the CCD "State Nonfiscal Survey of Public Elementary/Secondary Education" for school years 1990-91 to 2010-11. The CCD annually collects fiscal…
NASA Astrophysics Data System (ADS)
Adesta, Erry Yulian T.; Riza, Muhammad; Avicena
2018-03-01
Tool wear prediction plays a significant role in machining industry for proper planning and control machining parameters and optimization of cutting conditions. This paper aims to investigate the effect of tool path strategies that are contour-in and zigzag tool path strategies applied on tool wear during pocket milling process. The experiments were carried out on CNC vertical machining centre by involving PVD coated carbide inserts. Cutting speed, feed rate and depth of cut were set to vary. In an experiment with three factors at three levels, Response Surface Method (RSM) design of experiment with a standard called Central Composite Design (CCD) was employed. Results obtained indicate that tool wear increases significantly at higher range of feed per tooth compared to cutting speed and depth of cut. This result of this experimental work is then proven statistically by developing empirical model. The prediction model for the response variable of tool wear for contour-in strategy developed in this research shows a good agreement with experimental work.
Verbal Memory Compensation: Application to Left and Right Temporal Lobe Epileptic Patients
ERIC Educational Resources Information Center
Bresson, Christel; Lespinet-Najib, Veronique; Rougier, Alain; Claverie, Bernard; N'Kaoua, Bernard
2007-01-01
This study investigates the compensatory impact of cognitive aids on left and right temporal lobe epileptic patients suffering from verbal memory disorders, who were candidates for surgery. Cognitive aids are defined in the levels-of-processing framework and deal with the depth of encoding, the elaboration of information, and the use of retrieval…
The Darfur Swell, Africa: Gravity constraints on its isostatic compensation
NASA Astrophysics Data System (ADS)
Crough, S. Thomas
The free-air gravity anomaly observed over the Darfur Swell is explainable by local isostatic balance with a root approximately 50 km deep on average. This root depth is similar to that inferred beneath other African domes and beneath oceanic midplate swells, suggesting that the Darfur Swell is a hotspot uplift created by lithospheric reheating.
Quantifying how the combination of blur and disparity affects the perceived depth
NASA Astrophysics Data System (ADS)
Wang, Junle; Barkowsky, Marcus; Ricordel, Vincent; Le Callet, Patrick
2011-03-01
The influence of a monocular depth cue, blur, on the apparent depth of stereoscopic scenes will be studied in this paper. When 3D images are shown on a planar stereoscopic display, binocular disparity becomes a pre-eminent depth cue. But it induces simultaneously the conflict between accommodation and vergence, which is often considered as a main reason for visual discomfort. If we limit this visual discomfort by decreasing the disparity, the apparent depth also decreases. We propose to decrease the (binocular) disparity of 3D presentations, and to reinforce (monocular) cues to compensate the loss of perceived depth and keep an unaltered apparent depth. We conducted a subjective experiment using a twoalternative forced choice task. Observers were required to identify the larger perceived depth in a pair of 3D images with/without blur. By fitting the result to a psychometric function, we obtained points of subjective equality in terms of disparity. We found that when blur is added to the background of the image, the viewer can perceive larger depth comparing to the images without any blur in the background. The increase of perceived depth can be considered as a function of the relative distance between the foreground and background, while it is insensitive to the distance between the viewer and the depth plane at which the blur is added.
Familial cleidocranial dysplasia misdiagnosed as rickets over three generations.
Franceschi, Roberto; Maines, Evelina; Fedrizzi, Michela; Piemontese, Maria Rosaria; De Bonis, Patrizia; Agarwal, Nivedita; Bellizzi, Maria; Di Palma, Annunziata
2015-10-01
Cleidocranial dysplasia (CCD) is a rare autosomal dominant skeletal dysplasia characterized by hypoplastic clavicles, late closure of the fontanels, dental problems and other skeletal features. CCD is caused by mutations, deletions or duplications in runt-related transcription factor 2 (RUNX2), which encodes for a protein essential for osteoblast differentiation and chondrocyte maturation. We describe three familial cases of CCD, misdiagnosed as rickets over three generations. No mutations were detected on standard DNA sequencing of RUNX2, but a novel deletion was identified on quantitative polymerase chain reaction (qPCR) and multiple ligation-dependent probe amplification (MLPA). The present cases indicate that CCD could be misdiagnosed as rickets, leading to inappropriate treatment, and confirm that mutations in RUNX2 are not able to be identified on standard DNA sequencing in all CCD patients, but can be identified on qPCR and MLPA. © 2015 Japan Pediatric Society.
A CCD experimental platform for large telescope in Antarctica based on FPGA
NASA Astrophysics Data System (ADS)
Zhu, Yuhua; Qi, Yongjun
2014-07-01
The CCD , as a detector , is one of the important components of astronomical telescopes. For a large telescope in Antarctica, a set of CCD detector system with large size, high sensitivity and low noise is indispensable. Because of the extremely low temperatures and unattended, system maintenance and software and hardware upgrade become hard problems. This paper introduces a general CCD controller experiment platform, using Field programmable gate array FPGA, which is, in fact, a large-scale field reconfigurable array. Taking the advantage of convenience to modify the system, construction of driving circuit, digital signal processing module, network communication interface, control algorithm validation, and remote reconfigurable module may realize. With the concept of integrated hardware and software, the paper discusses the key technology of building scientific CCD system suitable for the special work environment in Antarctica, focusing on the method of remote reconfiguration for controller via network and then offering a feasible hardware and software solution.
Atac, M.; McKay, T.A.
1998-04-21
An imaging system is provided for direct detection of x-rays from an irradiated biological tissue. The imaging system includes an energy source for emitting x-rays toward the biological tissue and a charge coupled device (CCD) located immediately adjacent the biological tissue and arranged transverse to the direction of irradiation along which the x-rays travel. The CCD directly receives and detects the x-rays after passing through the biological tissue. The CCD is divided into a matrix of cells, each of which individually stores a count of x-rays directly detected by the cell. The imaging system further includes a pattern generator electrically coupled to the CCD for reading a count from each cell. A display device is provided for displaying an image representative of the count read by the pattern generator from the cells of the CCD. 13 figs.
Atac, Muzaffer; McKay, Timothy A.
1998-01-01
An imaging system is provided for direct detection of x-rays from an irradiated biological tissue. The imaging system includes an energy source for emitting x-rays toward the biological tissue and a charge coupled device (CCD) located immediately adjacent the biological tissue and arranged transverse to the direction of irradiation along which the x-rays travel. The CCD directly receives and detects the x-rays after passing through the biological tissue. The CCD is divided into a matrix of cells, each of which individually stores a count of x-rays directly detected by the cell. The imaging system further includes a pattern generator electrically coupled to the CCD for reading a count from each cell. A display device is provided for displaying an image representative of the count read by the pattern generator from the cells of the CCD.
Extended depth of focus intraocular lens: Chromatic performance
Millán, Maria S.; Vega, Fidel
2017-01-01
We describe a first-and-second-diffractive-order intraocular lens ((1st,2nd)DIOL) within the class of hybrid refractive-diffractive designs for intraocular lenses (IOLs) and analyse its properties of focus extension and compensation of longitudinal chromatic aberration (LCA), particularly for lenses with low addition. Power, energy efficiency and their wavelength dependence are extended from monofocal IOL and conventional bifocal zeroth-and-first-diffractive-order IOL ((0th,1st)DIOL) to (1st,2nd)DIOL of low addition. Compensation of LCA is experimentally assessed in optical bench through the through-focus energy efficiency of three Tecnis IOLs with red, green and blue illuminations: ZA9003 (monofocal), ZKB00 (bifocal (0th,1st)DIOL with + 2.75 D add) and Symfony ZXR00. We prove Tecnis Symfony ZXR00 IOL can be considered an example of (1st,2nd)DIOL design of low addition, with LCA compensation in both the distance and intermediate foci, whereas the bifocal (0th,1st)DIOL does not compensate in the distance focus. However, the energy efficiency of (1st,2nd)DIOL for wavelengths other than the design wavelength is markedly more asymmetric. PMID:28966865
Isostatic compensation of equatorial highlands on Venus
NASA Technical Reports Server (NTRS)
Kucinskas, Algis B.; Turcotte, Donald L.
1994-01-01
Spherical harmonic models for Venus' global topography and gravity incorporating Magellan data are used to test isostatic compensation models in five 30 deg x 30 deg regions representative of the main classes of equatorial highlands. The power spectral density for the harmonic models obeys a power-law scaling with spectral slope Beta approximately 2 (Brown noise) for the topography and Beta approximately 3 (Kaula's law) for the geoid, similar to what is observed for Earth. The Venus topography spectrum has lower amplitudes than Earth's which reflects the dominant lowland topography on Venus. Observed degree geoid to topography ratios (GTRs) on Venus are significantly smaller than degree GTRs for uncompensated topography, indicative of substantial compensation. Assuming a global Airy compensation, most of the topography is compensated at depths greater than 100 km, suggesting a thick lithosphere on Venus. For each region considered we obtain a regional degree of compensation C from a linear regression of Bouguer anomaly versus Bouguer gravity data. Geoid anomaly (N) versus topography variation (h) data for each sample were compared, in the least-squares sense, to theoretical correlations for Pratt, Airy, and thermal thinning isostasy models yielding regional GTR, zero-elevation crustal thickness (H), and zero elevation thermal lithosphere thickness (y(sub L(sub 0)), respectively. We find the regional compensation to be substantial (C approximately 52-80%), and the h, N data correlations in the chosen areas can be explained by isostasy models applicable on the Earth and involving variations in crustal thickness (Airy) and/or lithospheric (thermal thinning) thickness. However, a thick crust and lithosphere (y(sub L(sub 0)) approximately 300 km) must be assumed for Venus.
Isolation Mounting for Charge-Coupled Devices
NASA Technical Reports Server (NTRS)
Goss, W. C.; Salomon, P. M.
1985-01-01
CCD's suspended by wires under tension. Remote thermoelectric cooling of charge coupled device allows vibration isolating mounting of CCD assembly alone, without having to suspend entire mass and bulk of thermoelectric module. Mounting hardware simple and light. Developed for charge-coupled devices (CCD's) in infrared telescope support adaptable to sensors in variety of environments, e.g., sensors in nuclear reactors, engine exhausts and plasma chambers.
Test of CCD Precision Limits for Differential Photometry
NASA Technical Reports Server (NTRS)
Borucki, W. J.; Dunham, E. W.; Wei, M. Z.; Robinson, L. B.; Ford, C. H.; Granados, A. F.
1995-01-01
Results of tests to demonstrate the very high differential-photometric stability of CCD light sensors are presented. The measurements reported here demonstrate that in a controlled laboratory environment, a front-illuminated CCD can provide differential-photometric measurements with reproducible precision approaching one part in 105. Practical limitations to the precision of differential-photometric measurements with CCDs and implications for spaceborne applications are discussed.
Common Core of Data (CCD): School Years 1996-1997 through 2000-2001. [CD-ROM].
ERIC Educational Resources Information Center
National Center for Education Statistics (ED), Washington, DC.
The Common Core of Data (CCD) is NCES's primary database on elementary and secondary public education in the United States. CCD is a comprehensive, annual, national statistical database of all elementary and secondary schools and school districts, which contains data that are comparable across all states. The 50 states and the District of Columbia…
NASA Astrophysics Data System (ADS)
Mugrauer, M.
2016-03-01
The Cassegrain-Teleskop-Kamera (CTK-II) and the Refraktor-Teleskop-Kamera (RTK) are two CCD-imagers which are operated at the 25 cm Cassegrain and 20 cm refractor auxiliary telescopes of the University Observatory Jena. This article describes the main characteristics of these instruments. The properties of the CCD-detectors, the astrometry, the image quality, and the detection limits of both CCD-cameras, as well as some results of ongoing observing projects, carried out with these instruments, are presented. Based on observations obtained with telescopes of the University Observatory Jena, which is operated by the Astrophysical Institute of the Friedrich-Schiller-University.
CCD charge collection efficiency and the photon transfer technique
NASA Technical Reports Server (NTRS)
Janesick, J.; Klaasen, K.; Elliott, T.
1985-01-01
The charge-coupled device (CCD) has shown unprecendented performance as a photon detector in the areas of spectral response, charge transfer, and readout noise. Recent experience indicates, however, that the full potential for the CCD's charge collection efficiency (CCE) lies well beyond that which is realized in currently available devices. A definition of CCE performance is presented and a standard test tool (the photon transfer technique) for measuring and optimizing this important CCD parameter is introduced. CCE characteristics for different types of CCDs are compared; the primary limitations in achieving high CCE performance are discussed, and the prospects for future improvement are outlined.
Howard, Richard; Finn, Peter; Jose, Paul; Gallagher, Jennifer
2011-12-16
This study tested the hypothesis that adolescent-onset alcohol abuse (AOAA) would both mediate and moderate the effect of childhood conduct disorder on antisocial behaviour in late adolescence and early adulthood. A sample comprising 504 young men and women strategically recruited from the community were grouped using the criteria of the Diagnostic and Statistical Manual (DSM-IV, American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: APA), as follows: neither childhood conduct disorder (CCD) nor alcohol abuse/dependence; CCD but no alcohol abuse or dependence; alcohol abuse/dependence but no CCD; both CCD and alcohol abuse/dependence. The outcome measure was the sum of positive responses to 55 interview items capturing a variety of antisocial behaviours engaged in since age 15. Severity of lifetime alcohol-related and CCD problems served as predictor variables in regression analysis. Antisocial behaviour problems were greatest in individuals with a history of co-occurring conduct disorder (CD) and alcohol abuse/dependence. While CCD was strongly predictive of adult antisocial behaviour, this effect was both mediated and moderated (exacerbated) by AOAA.
NASA Astrophysics Data System (ADS)
Garza, Alejandro J.; Bulik, Ireneusz W.; Alencar, Ana G. Sousa; Sun, Jianwei; Perdew, John P.; Scuseria, Gustavo E.
2016-04-01
Contrary to standard coupled cluster doubles (CCD) and Brueckner doubles (BD), singlet-paired analogues of CCD and BD (denoted here as CCD0 and BD0) do not break down when static correlation is present, but neglect substantial amounts of dynamic correlation. In fact, CCD0 and BD0 do not account for any contributions from multielectron excitations involving only same-spin electrons at all. We exploit this feature to add - without introducing double counting, self-interaction, or increase in cost - the missing correlation to these methods via meta-GGA (generalised gradient approximation) density functionals (Tao-Perdew-Staroverov-Scuseria and strongly constrained and appropriately normed). Furthermore, we improve upon these CCD0+DFT blends by invoking range separation: the short- and long-range correlations absent in CCD0/BD0 are evaluated with density functional theory and the direct random phase approximation, respectively. This corrects the description of long-range van der Waals forces. Comprehensive benchmarking shows that the combinations presented here are very accurate for weakly correlated systems, while also providing a reasonable description of strongly correlated problems without resorting to symmetry breaking.
NASA Astrophysics Data System (ADS)
von Zanthier, Christoph; Holl, Peter; Kemmer, Josef; Lechner, Peter; Maier, B.; Soltau, Heike; Stoetter, R.; Braeuninger, Heinrich W.; Dennerl, Konrad; Haberl, Frank; Hartmann, R.; Hartner, Gisela D.; Hippmann, H.; Kastelic, E.; Kink, W.; Krause, N.; Meidinger, Norbert; Metzner, G.; Pfeffermann, Elmar; Popp, M.; Reppin, Claus; Stoetter, Diana; Strueder, Lothar; Truemper, Joachim; Weber, U.; Carathanassis, D.; Engelhard, S.; Gebhart, Th.; Hauff, D.; Lutz, G.; Richter, R. H.; Seitz, H.; Solc, P.; Bihler, Edgar; Boettcher, H.; Kendziorra, Eckhard; Kraemer, J.; Pflueger, Bernhard; Staubert, Ruediger
1998-04-01
The concept and performance of the fully depleted pn- junction CCD system, developed for the European XMM- and the German ABRIXAS-satellite missions for soft x-ray imaging and spectroscopy in the 0.1 keV to 15 keV photon range, is presented. The 58 mm X 60 mm large pn-CCD array uses pn- junctions for registers and for the backside instead of MOS registers. This concept naturally allows to fully deplete the detector volume to make it an efficient detector to photons with energies up to 15 keV. For high detection efficiency in the soft x-ray region down to 100 eV, an ultrathin pn-CCD backside deadlayer has been realized. Each pn-CCD-channel is equipped with an on-chip JFET amplifier which, in combination with the CAMEX-amplifier and multiplexing chip, facilitates parallel readout with a pixel read rate of 3 MHz and an electronic noise floor of ENC < e-. With the complete parallel readout, very fast pn-CCD readout modi can be implemented in the system which allow for high resolution photon spectroscopy of even the brightest x-ray sources in the sky.
Howard, Richard; Finn, Peter; Jose, Paul; Gallagher, Jennifer
2012-01-01
This study tested the hypothesis that adolescent-onset alcohol abuse (AOAA) would both mediate and moderate the effect of childhood conduct disorder on antisocial behaviour in late adolescence and early adulthood. A sample comprising 504 young men and women strategically recruited from the community were grouped using the criteria of the Diagnostic and Statistical Manual (DSM-IV, American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: APA), as follows: neither childhood conduct disorder (CCD) nor alcohol abuse/dependence; CCD but no alcohol abuse or dependence; alcohol abuse/dependence but no CCD; both CCD and alcohol abuse/dependence. The outcome measure was the sum of positive responses to 55 interview items capturing a variety of antisocial behaviours engaged in since age 15. Severity of lifetime alcohol-related and CCD problems served as predictor variables in regression analysis. Antisocial behaviour problems were greatest in individuals with a history of co-occurring conduct disorder (CD) and alcohol abuse/dependence. While CCD was strongly predictive of adult antisocial behaviour, this effect was both mediated and moderated (exacerbated) by AOAA. PMID:23459369
NASA Astrophysics Data System (ADS)
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.
pnCCD for photon detection from near-infrared to X-rays
NASA Astrophysics Data System (ADS)
Meidinger, Norbert; Andritschke, Robert; Hartmann, Robert; Herrmann, Sven; Holl, Peter; Lutz, Gerhard; Strüder, Lothar
2006-09-01
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-Kα 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-Kα 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 °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 photons. A novel type of pnCCD is in preparation, which allows single optical photon counting. This feature is accomplished by implementation of an avalanche-type amplifier in the pnCCD concept.
Beeman, J.W.; Maule, A.G.
2006-01-01
The in situ depths of juvenile salmonids Oncorhynchus spp. were studied to determine whether hydrostatic compensation was sufficient to protect them from gas bubble disease (GBD) during exposure to total dissolved gas (TDG) supersaturation from a regional program of spill at dams meant to improve salmonid passage survival. Yearling Chinook salmon O. tshawytscha and juvenile steelhead O. mykiss implanted with pressure-sensing radio transmitters were monitored from boats while they were migrating between the tailrace of Ice Harbor Dam on the Snake River and the forebay of McNary Dam on the Columbia River during 1997-1999. The TDG generally decreased with distance from the tailrace of the dam and was within levels known to cause GBD signs and mortality in laboratory bioassays. Results of repeated-measures analysis of variance indicated that the mean depths of juvenile steelhead were similar throughout the study area, ranging from 2.0 m in the Snake River to 2.3 m near the McNary Dam forebay. The mean depths of yearling Chinook salmon generally increased with distance from Ice Harbor Dam, ranging from 1.5 m in the Snake River to 3.2 m near the forebay. Juvenile steelhead were deeper at night than during the day, and yearling Chinook salmon were deeper during the day than at night. The TDG level was a significant covariate in models of the migration depth and rates of each species, but no effect of fish size was detected. Hydrostatic compensation, along with short exposure times in the area of greatest TDG, reduced the effects of TDG exposure below those generally shown to elicit GBD signs or mortality. Based on these factors, our results indicate that the TDG limits of the regional spill program were safe for these juvenile salmonids.
NASA Astrophysics Data System (ADS)
Diodato, A.; Cafarelli, A.; Schiappacasse, A.; Tognarelli, S.; Ciuti, G.; Menciassi, A.
2018-02-01
High intensity focused ultrasound (HIFU) is an emerging therapeutic solution that enables non-invasive treatment of several pathologies, mainly in oncology. On the other hand, accurate targeting of moving abdominal organs (e.g. liver, kidney, pancreas) is still an open challenge. This paper proposes a novel method to compensate the physiological respiratory motion of organs during HIFU procedures, by exploiting a robotic platform for ultrasound-guided HIFU surgery provided with a therapeutic annular phased array transducer. The proposed method enables us to keep the same contact point between the transducer and the patient’s skin during the whole procedure, thus minimizing the modification of the acoustic window during the breathing phases. The motion of the target point is compensated through the rotation of the transducer around a virtual pivot point, while the focal depth is continuously adjusted thanks to the axial electronically steering capabilities of the HIFU transducer. The feasibility of the angular motion compensation strategy has been demonstrated in a simulated respiratory-induced organ motion environment. Based on the experimental results, the proposed method appears to be significantly accurate (i.e. the maximum compensation error is always under 1 mm), thus paving the way for the potential use of this technique for in vivo treatment of moving organs, and therefore enabling a wide use of HIFU in clinics.
NASA Astrophysics Data System (ADS)
Garza, Alejandro J.
Perhaps the most important approximations to the electronic structure problem in quantum chemistry are those based on coupled cluster and density functional theories. Coupled cluster theory has been called the ``gold standard'' of quantum chemistry due to the high accuracy that it achieves for weakly correlated systems. Kohn-Sham density functionals based on semilocal approximations are, without a doubt, the most widely used methods in chemistry and material science because of their high accuracy/cost ratio. The root of the success of coupled cluster and density functionals is their ability to efficiently describe the dynamic part of the electron correlation. However, both traditional coupled cluster and density functional approximations may fail catastrophically when substantial static correlation is present. This severely limits the applicability of these methods to a plethora of important chemical and physical problems such as, e.g., the description of bond breaking, transition states, transition metal-, lanthanide- and actinide-containing compounds, and superconductivity. In an attempt to tackle this problem, nonstandard (single-reference) coupled cluster-based techniques that aim to describe static correlation have been recently developed: pair coupled cluster doubles (pCCD) and singlet-paired coupled cluster doubles (CCD0). The ability to describe static correlation in pCCD and CCD0 comes, however, at the expense of important amounts of dynamic correlation so that the high accuracy of standard coupled cluster becomes unattainable. Thus, the reliable and efficient description of static and dynamic correlation in a simultaneous manner remains an open problem for quantum chemistry and many-body theory in general. In this thesis, different ways to combine pCCD and CCD0 with density functionals in order to describe static and dynamic correlation simultaneously (and efficiently) are explored. The combination of wavefunction and density functional methods has a long history in quantum chemistry (practical implementations have appeared in the literature since the 1970s). However, this kind of techniques have not achieved widespread use due to problems such as double counting of correlation and the symmetry dilemma--the fact that wavefunction methods respect the symmetries of Hamiltonian, while modern functionals are designed to work with broken symmetry densities. Here, particular mathematical features of pCCD and CCD0 are exploited to avoid these problems in an efficient manner. The two resulting families of approximations, denoted as pCCD+DFT and CCD0+DFT, are shown to be able to describe static and dynamic correlation in standard benchmark calculations. Furthermore, it is also shown that CCD0+DFT lends itself to combination with correlation from the direct random phase approximation (dRPA). Inclusion of dRPA in the long-range via the technique of range-separation allows for the description of dispersion correlation, the remaining part of the correlation. Thus, when combined with the dRPA, CCD0+DFT can account for all three-types of electron correlation that are necessary to accurately describe molecular systems. Lastly, applications of CCD0+DFT to actinide chemistry are considered in this work. The accuracy of CCD0+DFT for predicting equilibrium geometries and vibrational frequencies of actinide molecules and ions is assessed and compared to that of well-established quantum chemical methods. For this purpose, the f0 actinyl series (UO2 2+, NpO 23+, PuO24+, the isoelectronic NUN, and Thorium (ThO, ThO2+) and Nobelium (NoO, NoO2) oxides are studied. It is shown that the CCD0+DFT description of these species agrees with available experimental data and is comparable with the results given by the highest-level calculations that are possible for such heavy compounds while being, at least, an order of magnitude lower in computational cost.
Compensated Ferrimagnetism in the Zero-Moment Heusler Alloy Mn3Al
NASA Astrophysics Data System (ADS)
Jamer, Michelle E.; Wang, Yung Jui; Stephen, Gregory M.; McDonald, Ian J.; Grutter, Alexander J.; Sterbinsky, George E.; Arena, Dario A.; Borchers, Julie A.; Kirby, Brian J.; Lewis, Laura H.; Barbiellini, Bernardo; Bansil, Arun; Heiman, Don
2017-06-01
While antiferromagnets have been proposed as components to limit stray magnetic fields, their inability to be spin polarized inhibits their use in spintronic devices. Compensated ferrimagnets are a unique solution to this dilemma since they have zero net moment, but their nonsymmetric density of states allows the achievement of high spin polarization. Density-functional theory predicts Mn3Al in the D 03 structure to be fully compensated and retain half-metallicity at room temperature. In this work, 50-nm Mn3Al thin films are synthesized using molecular beam epitaxy and annealed at various temperatures in order to investigate their magnetic properties. Magnetometry measurements confirm the high Curie temperature of 605 K. Polarized-neutron reflectometry (PNR) indicates a low net magnetic moment, along with depth profiles of the structure and magnetization. From the PNR data, a saturation moment of 0.11 ±0.04 μB/f .u . is extracted, confirming the nominal zero moment present in these thin films.
The prevalence and geographic distribution of complex co-occurring disorders: a population study.
Somers, J M; Moniruzzaman, A; Rezansoff, S N; Brink, J; Russolillo, A
2016-06-01
A subset of people with co-occurring substance use and mental disorders require coordinated support from health, social welfare and justice agencies to achieve diversion from homelessness, criminal recidivism and further health and social harms. Integrated models of care are typically concentrated in large urban centres. The present study aimed to empirically measure the prevalence and distribution of complex co-occurring disorders (CCD) in a large geographic region that includes urban as well as rural and remote settings. Linked data were examined in a population of roughly 3.7 million adults. Inclusion criteria for the CCD subpopulation were: physician diagnosed substance use and mental disorders; psychiatric hospitalisation; shelter assistance; and criminal convictions. Prevalence per 100 000 was calculated in 91 small areas representing urban, rural and remote settings. 2202 individuals met our inclusion criteria for CCD. Participants had high rates of hospitalisation (8.2 admissions), criminal convictions (8.6 sentences) and social assistance payments (over $36 000 CDN) in the past 5 years. There was wide variability in the geographic distribution of people with CCD, with high prevalence rates in rural and remote settings. People with CCD are not restricted to areas with large populations or to urban settings. The highest per capita rates of CCD were observed in relatively remote locations, where mental health and substance use services are typically in limited supply. Empirically supported interventions must be adapted to meet the needs of people living outside of urban settings with high rates of CCD.
Soriano-Arandes, Antoni; Angheben, Andrea; Serre-Delcor, Nuria; Treviño-Maruri, Begoña; Gómez I Prat, Jordi; Jackson, Yves
2016-05-01
Identifying pregnant women infected with Trypanosoma cruzi is one of the major challenges for preventing and controlling Chagas disease (CD) in non-endemic countries. The aim of this paper was to perform a policy evaluation of the current practices of congenital Chagas disease (CCD) control in non-endemic countries and to propose specific targets for enhanced interventions to tackle this emerging health problem outside the endemic areas of Latin America. We conducted a mixed method review of CCD policy strategies by searching the literature in the PubMed, Google Scholar and the World Health Organization (WHO) databases using the key terms 'CCD', 'paediatric Chagas disease' and 'non-endemic countries'; as free text and combined as one phrase to increase the search sensitivity. Reviews, recommendations, guidelines and control/surveillance programme reports were included. Of 427 CCD papers identified in non-endemic countries, 44 matched the inclusion. Although local programmes were launched in different countries with large numbers of Latin American immigrants, there were considerable disparities in terms of the programmes' distribution, delivery, integration and appropriated CCD control strategies. Moreover, Catalonia, Spain is the only region/country with an established systematic monitoring of CCD in pregnant women from Latin American countries. Given the worldwide dissemination of CD, the nature of its vertical transmission, and the gaps of the current strategies in non-endemic countries, there is an urgent need to standardise, expand and reinforce the control measures against CCD transmission. © 2016 John Wiley & Sons Ltd.
Development and use of an L3CCD high-cadence imaging system for Optical Astronomy
NASA Astrophysics Data System (ADS)
Sheehan, Brendan J.; Butler, Raymond F.
2008-02-01
A high cadence imaging system, based on a Low Light Level CCD (L3CCD) camera, has been developed for photometric and polarimetric applications. The camera system is an iXon DV-887 from Andor Technology, which uses a CCD97 L3CCD detector from E2V technologies. This is a back illuminated device, giving it an extended blue response, and has an active area of 512×512 pixels. The camera system allows frame-rates ranging from 30 fps (full frame) to 425 fps (windowed & binned frame). We outline the system design, concentrating on the calibration and control of the L3CCD camera. The L3CCD detector can be either triggered directly by a GPS timeserver/frequency generator or be internally triggered. A central PC remotely controls the camera computer system and timeserver. The data is saved as standard `FITS' files. The large data loads associated with high frame rates, leads to issues with gathering and storing the data effectively. To overcome such problems, a specific data management approach is used, and a Python/PYRAF data reduction pipeline was written for the Linux environment. This uses calibration data collected either on-site, or from lab based measurements, and enables a fast and reliable method for reducing images. To date, the system has been used twice on the 1.5 m Cassini Telescope in Loiano (Italy) we present the reduction methods and observations made.
Janossy, G; Coustan-Smith, E; Campana, D
1989-03-01
Current views about the origin of acute lymphoid leukemia (ALL) emphasize the importance of maturation arrest at a precursor cell level. Recently, the CD22 antigen has been identified in the cytoplasm of normal bone marrow-borne immature B lineage cells, while the CD3 antigen (epsilon chain) has been detected within normal immature thymic blasts. In the first part our study performed on 100 cases of known acute leukemias, the expression of such cytoplasmic molecules, referred to as cCD22 and cCD3, was analyzed together with their appearance in the leukemic cells' membrane (mCD22 and mCD3). The presence of cCD22 in B-lineage ALL and that of cCD3 in T-ALL has indeed fully confirmed the diagnosis reached by other markers, and mCD22 and mCD3 were expressed on only a few cases of B- and T-lineage ALL, also revealing a degree of developmental asynchrony within leukemic blasts. In the subsequent analysis both cCD22 and cCD3 have been included in a standard panel of diagnostic reagents applied on 500 consecutive cases of acute leukemia. Here the aim was to analyze both the diagnostic precision of individual markers and the heterogeneity of various leukemic types in terms of the expression of membrane and intracellular antigens and their cytochemical features (Sudan Black B and esterases). It has been found that cCD22 and cCD3 are exquisitely specific for B-precursor ALL (TdT+, CD19+) and T-ALL (TdT+, CD7+), respectively, while both markers are absent in acute myeloblastic leukemia (AML) and acute myelomonocytic and monocytic leukemia (AMML/AMoL). These observations contrast the findings which demonstrate that 31% of cases among nonlymphoid acute leukemia (including AML and AMML) express CD7 and/or TdT. The study of myeloid antigens detected by CD13, CD33, and CD14 is also informative and complementary, both in diagnosing and subdividing the AML and AMML/AMoL groups. The peculiar main observation of this study is that only with the combined use of these markers in a microplate assay for membrane antigens, followed by double staining for intracellular antigens such as terminal deoxynucleotidyl transferase, cCD3, cCD22, c mu heavy chain, and T cell receptor beta, it is possible to safely establish the lineage affiliation and subgrouping of virtually all acute leukemias. Among these cases are those with aberrant combinations of markers, including 14% of B-lineage ALL (cCD22+,CD19+,TdT+) and a single case T-ALL (cCD3+,CD7+,TdT+), which exhibit CD13 and/or CD33 antigens, cases with mixtures of ALL and AML blasts, and 1.2% of acute leukemias which lack lineage affiliation and can be regarded as acute undifferentiated leukemia.
Short-term visual memory for location in depth: A U-shaped function of time.
Reeves, Adam; Lei, Quan
2017-10-01
Short-term visual memory was studied by displaying arrays of four or five numerals, each numeral in its own depth plane, followed after various delays by an arrow cue shown in one of the depth planes. Subjects reported the numeral at the depth cued by the arrow. Accuracy fell with increasing cue delay for the first 500 ms or so, and then recovered almost fully. This dipping pattern contrasts with the usual iconic decay observed for memory traces. The dip occurred with or without a verbal or color-shape retention load on working memory. In contrast, accuracy did not change with delay when a tonal cue replaced the arrow cue. We hypothesized that information concerning the depths of the numerals decays over time in sensory memory, but that cued recall is aided later on by transfer to a visual memory specialized for depth. This transfer is sufficiently rapid with a tonal cue to compensate for the sensory decay, but it is slowed by the need to tag the arrow cue's depth relative to the depths of the numerals, exposing a dip when sensation has decayed and transfer is not yet complete. A model with a fixed rate of sensory decay and varied transfer rates across individuals captures the dip as well as the cue modality effect.
Test of CCD Precision Limits for Differential Photometry
NASA Technical Reports Server (NTRS)
Robinson, L. B.; Wei, M. Z.; Borucki, W. J.; Dunham, E. W.; Ford, C. H.; Granados, A. F.
1995-01-01
Results of tests to demonstrate the very high differential-photometric stability of CCD light sensors are presented. The measurements reported here demonstrate that in a controlled laboratory environment, a front-illuminated CCD can provide differential-photometric measurements with reproducible precision approaching one part in 10(exp 5). Practical limitations to the precision of differential-photometric measurements with CCDs and implications for spaceborne applications are discussed.
Scale dependant compensational stacking of channelized sedimentary deposits
NASA Astrophysics Data System (ADS)
Wang, Y.; Straub, K. M.; Hajek, E. A.
2010-12-01
Compensational stacking, the tendency for sediment transport system to preferentially fill topographic lows, thus smoothing out topographic relief is a concept used in the interpretation of the stratigraphic record. Recently, a metric was developed to quantify the strength of compensation in sedimentary basins by comparing observed stacking patterns to what would be expected from simple, uncorrelated stacking. This method uses the rate of decay of spatial variability in sedimentation between picked depositional horizons with increasing vertical stratigraphic averaging distance. We explore how this metric varies as a function of stratigraphic scale using data from physical experiments, stratigraphy exposed in outcrops and numerical models. In an experiment conducted at Tulane University’s Sediment Dynamics Laboratory, the topography of a channelized delta formed by weakly cohesive sediment was monitored along flow-perpendicular transects at a high temporal resolution relative to channel kinematics. Over the course of this experiment a uniform relative subsidence pattern, designed to isolate autogenic processes, resulted in the construction of a stratigraphic package that is 25 times as thick as the depth of the experimental channels. We observe a scale-dependence on the compensational stacking of deposits set by the system’s avulsion time-scale. Above the avulsion time-scale deposits stack purely compensationally, but below this time-scale deposits stack somewhere between randomly and deterministically. The well-exposed Ferris Formation (Cretaceous/Paleogene, Hanna Basin, Wyoming, USA) also shows scale-dependant stratigraphic organization which appears to be set by an avulsion time-scale. Finally, we utilize simple object-based models to illustrate how channel avulsions influence compensation in alluvial basins.
Double peacock eye optical element for extended focal depth imaging with ophthalmic applications.
Romero, Lenny A; Millán, María S; Jaroszewicz, Zbigniew; Kolodziejczyk, Andrzej
2012-04-01
The aged human eye is commonly affected by presbyopia, and therefore, it gradually loses its capability to form images of objects placed at different distances. Extended depth of focus (EDOF) imaging elements can overcome this inability, despite the introduction of a certain amount of aberration. This paper evaluates the EDOF imaging performance of the so-called peacock eye phase diffractive element, which focuses an incident plane wave into a segment of the optical axis and explores the element's potential use for ophthalmic presbyopia compensation optics. Two designs of the element are analyzed: the single peacock eye, which produces one focal segment along the axis, and the double peacock eye, which is a spatially multiplexed element that produces two focal segments with partial overlapping along the axis. The performances of the peacock eye elements are compared with those of multifocal lenses through numerical simulations as well as optical experiments in the image space. The results demonstrate that the peacock eye elements form sharper images along the focal segment than the multifocal lenses and, therefore, are more suitable for presbyopia compensation. The extreme points of the depth of field in the object space, which represent the remote and the near object points, have been experimentally obtained for both the single and the double peacock eye optical elements. The double peacock eye element has better imaging quality for relatively short and intermediate distances than the single peacock eye, whereas the latter seems better for far distance vision.
NASA Astrophysics Data System (ADS)
Sinefeld, David; Paudel, Hari P.; Wang, Tianyu; Wang, Mengran; Ouzounov, Dimitre G.; Bifano, Thomas G.; Xu, Chris
2017-02-01
Multiphoton fluorescence microscopy is a well-established technique for deep-tissue imaging with subcellular resolution. Three-photon microscopy (3PM) when combined with long wavelength excitation was shown to allow deeper imaging than two-photon microscopy (2PM) in biological tissues, such as mouse brain, because out-of-focus background light can be further reduced due to the higher order nonlinear excitation. As was demonstrated in 2PM systems, imaging depth and resolution can be improved by aberration correction using adaptive optics (AO) techniques which are based on shaping the scanning beam using a spatial light modulator (SLM). In this way, it is possible to compensate for tissue low order aberration and to some extent, to compensate for tissue scattering. Here, we present a 3PM AO microscopy system for brain imaging. Soliton self-frequency shift is used to create a femtosecond source at 1675 nm and a microelectromechanical (MEMS) SLM serves as the wavefront shaping device. We perturb the 1020 segment SLM using a modified nonlinear version of three-point phase shifting interferometry. The nonlinearity of the fluorescence signal used for feedback ensures that the signal is increasing when the spot size decreases, allowing compensation of phase errors in an iterative optimization process without direct phase measurement. We compare the performance for different orders of nonlinear feedback, showing an exponential growth in signal improvement as the nonlinear order increases. We demonstrate the impact of the method by applying the 3PM AO system for in-vivo mouse brain imaging, showing improvement in signal at 1-mm depth inside the brain.
Measuring the effective pixel positions for the HARPS3 CCD
NASA Astrophysics Data System (ADS)
Hall, Richard D.; Thompson, Samantha; Queloz, Didier
2016-07-01
We present preliminary results from an experiment designed to measure the effective pixel positions of a CCD to sub-pixel precision. This technique will be used to characterise the 4k x 4k CCD destined for the HARPS-3 spectrograph. The principle of coherent beam interference is used to create intensity fringes along one axis of the CCD. By sweeping the physical parameters of the experiment, the geometry of the fringes can be altered which is used to probe the pixel structure. We also present the limitations of the current experimental set-up and suggest what will be implemented in the future to vastly improve the precision of the measurements.
Vacuum compatible miniature CCD camera head
Conder, Alan D.
2000-01-01
A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close(0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.
NASA Astrophysics Data System (ADS)
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.
The presence of isolated hydrogen donors in heavily carbon-doped GaAs
NASA Astrophysics Data System (ADS)
Fushimi, Hiroshi; Wada, Kazumi
1994-12-01
The deactivation mechanism of carbon acceptors in GaAs has systematically been studied by measuring the annealing behavior and depth profiles of the carrier concentration. It is found that hydrogen impurities dominate carbon deactivation. Their deactivation undergoes two different ways: Hydrogen donors isolated from carbon acceptors compensate carbon and hydrogen impurities neutralize the carbon by forming neutral carbon-hydrogen complexes. The compensating hydrogen donors diffuse out extremely fast at relatively low temperatures. This is, to the best of our knowledge, the first report on the presence of isolated hydrogen donors in heavily carbon-doped GaAs. The dissociation of carbon-hydrogen complexes is much slower than reported. The mechanism is discussed in terms of a hydrogen retrapping effect by carbon.
Applying Neural Networks in Optical Communication Systems: Possible Pitfalls
NASA Astrophysics Data System (ADS)
Eriksson, Tobias A.; Bulow, Henning; Leven, Andreas
2017-12-01
We investigate the risk of overestimating the performance gain when applying neural network based receivers in systems with pseudo random bit sequences or with limited memory depths, resulting in repeated short patterns. We show that with such sequences, a large artificial gain can be obtained which comes from pattern prediction rather than predicting or compensating the studied channel/phenomena.
The Construct of Teachers' Pay Satisfaction: A Case Study of Primary and Secondary Schools in China
ERIC Educational Resources Information Center
Cai, Yonghong; Bi, Yan; Wang, Li; Cravens, Xiu Chen; Li, Yanli
2018-01-01
The construct of teachers' pay satisfaction is important to the systemic appraisal of teachers' compensation. The study aims to probe the components of teachers' pay satisfaction and verify this construct in primary and secondary schools in China. In-depth interviews with 24 teachers were conducted to propose a construct model for teachers' pay…
NASA Astrophysics Data System (ADS)
Pandiyan, Vimal Prabhu; John, Renu
2015-12-01
Digital holographic microscope (DHM) is an emerging quantitative phase imaging technique with unique imaging scales and resolutions leading to multitude of applications. DHM is promising as a novel investigational and applied tool for cell imaging, studying the morphology and real time dynamics of cells and a number of related applications. The use of numerical propagation and computational digital optics offer unique flexibility to tune the depth of focus, and compensate for image aberrations. In this work, we report imaging the dynamics of cell division in E.coli and yeast cells using a DHM platform. We demonstrate 3-D and depth imaging as well as reconstruction of phase profiles of E.coli and yeast cells using the system. We record a digital hologram of E.coli and yeast cells and reconstruct the image using Fresnel propagation algorithm. We also use aberration compensation algorithms for correcting the aberrations that are introduced by the microscope objective in the object path using linear least square fitting techniques. This work demonstrates the strong potential of a DHM platform in 3-D live cell imaging, fast clinical quantifications and pathological applications.
Characterization of viral siRNA populations in honey bee colony collapse disorder.
Chejanovsky, Nor; Ophir, Ron; Schwager, Michal Sharabi; Slabezki, Yossi; Grossman, Smadar; Cox-Foster, Diana
2014-04-01
Colony Collapse Disorder (CCD), a special case of collapse of honey bee colonies, has resulted in significant losses for beekeepers. CCD-colonies show abundance of pathogens which suggests that they have a weakened immune system. Since honey bee viruses are major players in colony collapse and given the important role of viral RNA interference (RNAi) in combating viral infections we investigated if CCD-colonies elicit an RNAi response. Deep-sequencing analysis of samples from CCD-colonies from US and Israel revealed abundant small interfering RNAs (siRNA) of 21-22 nucleotides perfectly matching the Israeli acute paralysis virus (IAPV), Kashmir virus and Deformed wing virus genomes. Israeli colonies showed high titers of IAPV and a conserved RNAi-pattern of matching the viral genome. That was also observed in sample analysis from colonies experimentally infected with IAPV. Our results suggest that CCD-colonies set out a siRNA response that is specific against predominant viruses associated with colony losses. Copyright © 2014 Elsevier Inc. All rights reserved.
Dolin, Robert H.; Giannone, Gay; Schadow, Gunther
2007-01-01
We sought to determine how well the HL7 / ASTM Continuity of Care Document (CCD) standard supports the requirements underlying the Joint Commission medication reconciliation recommendations. In particular, the Joint Commission emphasizes that transition points in the continuum of care are vulnerable to communication breakdowns, and that these breakdowns are a common source of medication errors. These transition points are the focus of communication standards, suggesting that CCD can support and enable medication related patient safety initiatives. Data elements needed to support the Joint Commission recommendations were identified and mapped to CCD, and a detailed clinical scenario was constructed. The mapping identified minor gaps, and identified fields present in CCD not specifically identified by Joint Commission, but useful nonetheless when managing medications across transitions of care, suggesting that a closer collaboration between the Joint Commission and standards organizations will be mutually beneficial. The nationally recognized CCD specification provides a standards-based solution for enabling Joint Commission medication reconciliation objectives. PMID:18693823
Dolin, Robert H; Giannone, Gay; Schadow, Gunther
2007-10-11
We sought to determine how well the HL7/ASTM Continuity of Care Document (CCD) standard supports the requirements underlying the Joint Commission medication reconciliation recommendations. In particular, the Joint Commission emphasizes that transition points in the continuum of care are vulnerable to communication breakdowns, and that these breakdowns are a common source of medication errors. These transition points are the focus of communication standards, suggesting that CCD can support and enable medication related patient safety initiatives. Data elements needed to support the Joint Commission recommendations were identified and mapped to CCD, and a detailed clinical scenario was constructed. The mapping identified minor gaps, and identified fields present in CCD not specifically identified by Joint Commission, but useful nonetheless when managing medications across transitions of care, suggesting that a closer collaboration between the Joint Commission and standards organizations will be mutually beneficial. The nationally recognized CCD specification provides a standards-based solution for enabling Joint Commission medication reconciliation objectives.
The Speckle Toolbox: A Powerful Data Reduction Tool for CCD Astrometry
NASA Astrophysics Data System (ADS)
Harshaw, Richard; Rowe, David; Genet, Russell
2017-01-01
Recent advances in high-speed low-noise CCD and CMOS cameras, coupled with breakthroughs in data reduction software that runs on desktop PCs, has opened the domain of speckle interferometry and high-accuracy CCD measurements of double stars to amateurs, allowing them to do useful science of high quality. This paper describes how to use a speckle interferometry reduction program, the Speckle Tool Box (STB), to achieve this level of result. For over a year the author (Harshaw) has been using STB (and its predecessor, Plate Solve 3) to obtain measurements of double stars based on CCD camera technology for pairs that are either too wide (the stars not sharing the same isoplanatic patch, roughly 5 arc-seconds in diameter) or too faint to image in the coherence time required for speckle (usually under 40ms). This same approach - using speckle reduction software to measure CCD pairs with greater accuracy than possible with lucky imaging - has been used, it turns out, for several years by the U. S. Naval Observatory.
Single-Electron and Single-Photon Sensitivity with a Silicon Skipper CCD
Tiffenberg, Javier; Sofo-Haro, Miguel; Drlica-Wagner, Alex; ...
2017-09-26
Here, 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.more » 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.« less
Development of a Portable 3CCD Camera System for Multispectral Imaging of Biological Samples
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
Odlum, Michelle; Gordon, Peter; Camhi, Eli; Schnall, Rebecca; Teixeira, Paul; Bakken, Suzanne
2012-11-01
The provision of personal health information through electronic personal health management tools (EPHMT) has the potential to improve health outcomes. However, little is known about factors that affect EPHMT use in special needs people living with HIV/AIDS (PLWH). The purpose of this study was to describe PLWH perceptions of predisposing, enabling, and reinforcing factors affecting use of one type of EPHMT, a continuity of care document (CCD). Data were collected through focus groups and qualitative interviews with PLWH (n=35), health care providers (N=19) and care site managers (N=5). All participant types identified predisposing barriers to CCD use including literacy, privacy, and technology access and enabling factors to promote CCD use including user support and password simplicity. People living with HIV/AIDS also identified reinforcing factors for recurring CCD use including emergent situations and reducing test redundancy. Results inform methods to promote use of the CCD and other EPHMT by special needs PLWH.
CCD Measurements of Double and Multiple Stars at NAO Rozhen and ASV in 2015
NASA Astrophysics Data System (ADS)
Cvetković, Z.; Pavlović, R.; Boeva, S.
2017-04-01
Results of CCD observations of 154 double or multiple stars, made with the 2 m telescope of the Bulgarian National Astronomical Observatory at Rozhen over five nights in 2015, are presented. This is the ninth series of measurements of CCD frames obtained at Rozhen. We also present results of CCD observations of 323 double or multiple stars made with the 0.6 m telescope of the Serbian Astronomical Station on the mountain of Vidojevica over 23 nights in 2015. This is the fourth series of measurements of CCD frames obtained at this station. This paper contains the results for the position angle and angular separation for 801 pairs and residuals for 127 pairs with published orbital elements or linear solutions. The angular separations are in the range from 1.″52 to 201.″56, with a median angular separation of 8.″26. We also present eight pairs that are measured for the first time and linear elements for five pairs.
Single-Electron and Single-Photon Sensitivity with a Silicon Skipper CCD
NASA Astrophysics Data System (ADS)
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.
Single-Electron and Single-Photon Sensitivity with a Silicon Skipper CCD.
Tiffenberg, Javier; Sofo-Haro, Miguel; Drlica-Wagner, Alex; Essig, Rouven; Guardincerri, Yann; Holland, Steve; Volansky, Tomer; Yu, Tien-Tien
2017-09-29
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.
VizieR Online Data Catalog: IC 361 Vilnius photometry (Zdanavicius+, 2010)
NASA Astrophysics Data System (ADS)
Zdanavicius, J.; Bartasiute, S.; Boyle, R. P.; Vrba, F. J.; Zdanavicius, K.
2015-03-01
CCD observations in seven filters U,P,X,Y,Z,V,S of the Vilnius system plus the filter I of the Cousins system were carried out in December of 1999 with a 2K CCD camera on the 1m telescope of the USNO Flagstaff Station (Arizona), which gives a field of the diameter of 20'. Repeated observations in the Vilnius filters were done with the same telescope and a new 2Kx2K CCD camera in March of 2009. During the latter run we have obtained well-calibrated CCD data only for filters Y, Z, V, S, since observations through the remaining three filters on the succeeding night were curtailed by cirrus clouds. Additional frames in the Vilnius filters U,Y,V were taken for the central part of the field (12'x12') in December of 2008 with a 4K CCD camera on the 1.8m Vatican Advanced Technology Telescope (VATT) on Mt. Graham (Arizona). (1 data file).
Colony collapse disorder in Europe.
Dainat, Benjamin; Vanengelsdorp, Dennis; Neumann, Peter
2012-02-01
Colony collapse disorder (CCD) is a condition of honey bees, which has contributed in part to the recent major losses of honey bee colonies in the USA. Here we report the first CCD case from outside of the USA. We suggest that more standardization is needed for the case definition to diagnose CCD and to compare data on a global scale. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.
Performance of the STIS CCD Dark Rate Temperature Correction
NASA Astrophysics Data System (ADS)
Branton, Doug; STScI STIS Team
2018-06-01
Since July 2001, the Space Telescope Imaging Spectrograph (STIS) onboard Hubble has operated on its Side-2 electronics due to a failure in the primary Side-1 electronics. While nearly identical, Side-2 lacks a functioning temperature sensor for the CCD, introducing a variability in the CCD operating temperature. Previous analysis utilized the CCD housing temperature telemetry to characterize the relationship between the housing temperature and the dark rate. It was found that a first-order 7%/°C uniform dark correction demonstrated a considerable improvement in the quality of dark subtraction on Side-2 era CCD data, and that value has been used on all Side-2 CCD darks since. In this report, we show how this temperature correction has performed historically. We compare the current 7%/°C value against the ideal first-order correction at a given time (which can vary between ~6%/°C and ~10%/°C) as well as against a more complex second-order correction that applies a unique slope to each pixel as a function of dark rate and time. At worst, the current correction has performed ~1% worse than the second-order correction. Additionally, we present initial evidence suggesting that the variability in pixel temperature-sensitivity is significant enough to warrant a temperature correction that considers pixels individually rather than correcting them uniformly.
Cross-reacting carbohydrate determinants and hymenoptera venom allergy.
Brehler, Randolf; Grundmann, Sonja; Stöcker, Benedikt
2013-08-01
Insect venom allergy is an important cause of anaphylaxis. Venom immunotherapy assume the clear identification of the culprit insect, but this is impeded by Immunoglobulin E (IgE) antibodies to cross reactive carbohydrate determinant (CCD) epitopes of common glycoproteins. Here we give an overview about inducers, importance, and relevance of anti-N-Glycan CCD IgE antibodies. Pollen exposure and insect stings induce anti-CCD IgE antibodies interfering with in-vitro tests for allergy diagnosis due to extensive IgE cross-reactivity. Instead of being biologically active these antibodies are irrelevant for allergic reactions due to hymenoptera stings. The general response of the immune system to the ubiquitous exposure to N-glycan containing glycoproteins is still a matter of debate. CCD specific IgG antibodies in sera of bee keepers suggest tolerance induction due to high-dose exposure. Tolerance induction by pollen and food glycoproteins has not been proved. Hymenoptera stings and pollen exposure induce anti-CCD IgE. In regard to anaphylaxis due to Hymenoptera stings these antibodies are not clinically relevant, but they are important for the specificity of in-vitro tests proving insect venom allergy. The introduction of component based diagnostic IgE testing improves the specificity of in-vitro tests if proteins devoid of CCD epitopes are used.
Typical effects of laser dazzling CCD camera
NASA Astrophysics Data System (ADS)
Zhang, Zhen; Zhang, Jianmin; Shao, Bibo; Cheng, Deyan; Ye, Xisheng; Feng, Guobin
2015-05-01
In this article, an overview of laser dazzling effect to buried channel CCD camera is given. The CCDs are sorted into staring and scanning types. The former includes the frame transfer and interline transfer types. The latter includes linear and time delay integration types. All CCDs must perform four primary tasks in generating an image, which are called charge generation, charge collection, charge transfer and charge measurement. In camera, the lenses are needed to input the optical signal to the CCD sensors, in which the techniques for erasing stray light are used. And the electron circuits are needed to process the output signal of CCD, in which many electronic techniques are used. The dazzling effects are the conjunct result of light distribution distortion and charge distribution distortion, which respectively derive from the lens and the sensor. Strictly speaking, in lens, the light distribution is not distorted. In general, the lens are so well designed and fabricated that its stray light can be neglected. But the laser is of much enough intensity to make its stray light obvious. In CCD image sensors, laser can induce a so large electrons generation. Charges transfer inefficiency and charges blooming will cause the distortion of the charge distribution. Commonly, the largest signal outputted from CCD sensor is restricted by capability of the collection well of CCD, and can't go beyond the dynamic range for the subsequent electron circuits maintaining normal work. So the signal is not distorted in the post-processing circuits. But some techniques in the circuit can make some dazzling effects present different phenomenon in final image.
Effects of biomechanical forces on signaling in the cortical collecting duct (CCD)
Carrisoza-Gaytan, Rolando; Liu, Yu; Flores, Daniel; Else, Cindy; Lee, Heon Goo; Rhodes, George; Sandoval, Ruben M.; Kleyman, Thomas R.; Lee, Francis Young-In; Molitoris, Bruce; Satlin, Lisa M.
2014-01-01
An increase in tubular fluid flow rate (TFF) stimulates Na reabsorption and K secretion in the cortical collecting duct (CCD) and subjects cells therein to biomechanical forces including fluid shear stress (FSS) and circumferential stretch (CS). Intracellular MAPK and extracellular autocrine/paracrine PGE2 signaling regulate cation transport in the CCD and, at least in other systems, are affected by biomechanical forces. We hypothesized that FSS and CS differentially affect MAPK signaling and PGE2 release to modulate cation transport in the CCD. To validate that CS is a physiological force in vivo, we applied the intravital microscopic approach to rodent kidneys in vivo to show that saline or furosemide injection led to a 46.5 ± 2.0 or 170 ± 32% increase, respectively, in distal tubular diameter. Next, murine CCD (mpkCCD) cells were grown on glass or silicone coated with collagen type IV and subjected to 0 or 0.4 dyne/cm2 of FSS or 10% CS, respectively, forces chosen based on prior biomechanical modeling of ex vivo microperfused CCDs. Cells exposed to FSS expressed an approximately twofold greater abundance of phospho(p)-ERK and p-p38 vs. static cells, while CS did not alter p-p38 and p-ERK expression compared with unstretched controls. FSS induced whereas CS reduced PGE2 release by ∼40%. In conclusion, FSS and CS differentially affect ERK and p38 activation and PGE2 release in a cell culture model of the CD. We speculate that TFF differentially regulates biomechanical signaling and, in turn, cation transport in the CCD. PMID:24872319
Kawakami, Hiroshi; Ogimoto, Akiyoshi; Tokunaga, Naohito; Nishimura, Kazuhisa; Kawakami, Hideo; Higashi, Haruhiko; Iio, Chiharuko; Kono, Tamami; Aono, Jun; Uetani, Teruyoshi; Nagai, Takayuki; Inoue, Katsuji; Suzuki, Jun; Ikeda, Shuntaro; Okura, Takafumi; Ohyagi, Yasumasa; Tabara, Yasuharu; Higaki, Jitsuo
2018-05-30
The cardiac phenotype of laminopathies is characterized by cardiac conduction disorders (CCDs) and dilated cardiomyopathy (DCM). Although laminopathies have been considered monogenic, they exhibit a remarkable degree of clinical variability. This case series aimed to detect the causal mutation and to investigate the causes of clinical variability in a Japanese family with inherited CCD and DCM.Of the five family members investigated, four had either CCD/DCM or CCD alone, while one subject had no cardiovascular disease and acted as a normal control. We performed targeted resequencing of 174 inherited cardiovascular disease-associated genes in this family and pathological mutations were confirmed using Sanger sequencing. The degree of clinical severity and variability were also evaluated using long-term medical records. We discovered a novel heterozygous truncating lamin A/C (LMNA) mutation (c.774delG) in all four subjects with CCD. Because this mutation was predicted to cause a frameshift mutation and premature termination (p.Gln258HisfsTer222) in LMNA, we believe that this LMNA mutation was the causal mutation in this family with CCD and laminopathies. In addition, gender-specific intra-familiar clinical variability was observed in this Japanese family where affected males exhibited an earlier onset of CCD and more severe DCM compared to affected females. Using targeted resequencing, we discovered a novel truncating LMNA mutation associated with CCD and DCM in this family characterized by gender differences in clinical severity in LMNA carriers. Our results suggest that in patients with laminopathy, clinical severity may be the result of multiple factors.
Kohrt, Brandon A; Rasmussen, Andrew; Kaiser, Bonnie N; Haroz, Emily E; Maharjan, Sujen M; Mutamba, Byamah B; de Jong, Joop TVM; Hinton, Devon E
2014-01-01
Background Burgeoning global mental health endeavors have renewed debates about cultural applicability of psychiatric categories. This study’s goal is to review strengths and limitations of literature comparing psychiatric categories with cultural concepts of distress (CCD) such as cultural syndromes, culture-bound syndromes, and idioms of distress. Methods The Systematic Assessment of Quality in Observational Research (SAQOR) was adapted based on cultural psychiatry principles to develop a Cultural Psychiatry Epidemiology version (SAQOR-CPE), which was used to rate quality of quantitative studies comparing CCD and psychiatric categories. A meta-analysis was performed for each psychiatric category. Results Forty-five studies met inclusion criteria, with 18 782 unique participants. Primary objectives of the studies included comparing CCD and psychiatric disorders (51%), assessing risk factors for CCD (18%) and instrument validation (16%). Only 27% of studies met SAQOR-CPE criteria for medium quality, with the remainder low or very low quality. Only 29% of studies employed representative samples, 53% used validated outcome measures, 44% included function assessments and 44% controlled for confounding. Meta-analyses for anxiety, depression, PTSD and somatization revealed high heterogeneity (I2 > 75%). Only general psychological distress had low heterogeneity (I2 = 8%) with a summary effect odds ratio of 5.39 (95% CI 4.71-6.17). Associations between CCD and psychiatric disorders were influenced by methodological issues, such as validation designs (β = 16.27, 95%CI 12.75-19.79) and use of CCD multi-item checklists (β = 6.10, 95%CI 1.89-10.31). Higher quality studies demonstrated weaker associations of CCD and psychiatric disorders. Conclusions Cultural concepts of distress are not inherently unamenable to epidemiological study. However, poor study quality impedes conceptual advancement and service application. With improved study design and reporting using guidelines such as the SAQOR-CPE, CCD research can enhance detection of mental health problems, reduce cultural biases in diagnostic criteria and increase cultural salience of intervention trial outcomes. PMID:24366490
Remote operation: a selective review of research into visual depth perception.
Reinhardt-Rutland, A H
1996-07-01
Some perceptual motor operations are performed remotely; examples include the handling of life-threatening materials and surgical procedures. A camera conveys the site of operation to a TV monitor, so depth perception relies mainly on pictorial information, perhaps with enhancement of the occlusion cue by motion. However, motion information such as motion parallax is not likely to be important. The effectiveness of pictorial information is diminished by monocular and binocular information conveying flatness of the screen and by difficulties in scaling: Only a degree of relative depth can be conveyed. Furthermore, pictorial information can mislead. Depth perception is probably adequate in remote operation, if target objects are well separated, with well-defined edges and familiar shapes. Stereoscopic viewing systems are being developed to introduce binocular information to remote operation. However, stereoscopic viewing is problematic because binocular disparity conflicts with convergence and monocular information. An alternative strategy to improve precision in remote operation may be to rely on individuals who lack binocular function: There is redundancy in depth information, and such individuals seem to compensate for the lack of binocular function.
The design and development of low- and high-voltage ASICs for space-borne CCD cameras
NASA Astrophysics Data System (ADS)
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 replaces the many discrete components required in current cameras. We also describe a CCD clock driver ASIC that provides six independent and programmable drivers with high-current capacity. The device enables various CCD clock parameters to be programmed independently, for example the clock-low and clock-high voltage levels, and the clock-rise and clock-fall times, allowing configuration for serial clock frequencies in the range 0.1-2 MHz and image clock frequencies in the range 10-100 kHz. Finally, we demonstrate the impact and importance of this technology for the development of compact, high-performance and low-power integrated focal plane electronics.
Liu, H; Puangmali, P; Zbyszewski, D; Elhage, O; Dasgupta, P; Dai, J S; Seneviratne, L; Althoefer, K
2010-01-01
This paper presents a novel wheeled probe for the purpose of aiding a surgeon in soft tissue abnormality identification during minimally invasive surgery (MIS), compensating the loss of haptic feedback commonly associated with MIS. Initially, a prototype for validating the concept was developed. The wheeled probe consists of an indentation depth sensor employing an optic fibre sensing scheme and a force/torque sensor. The two sensors work in unison, allowing the wheeled probe to measure the tool-tissue interaction force and the rolling indentation depth concurrently. The indentation depth sensor was developed and initially tested on a homogenous silicone phantom representing a good model for a soft tissue organ; the results show that the sensor can accurately measure the indentation depths occurring while performing rolling indentation, and has good repeatability. To validate the ability of the wheeled probe to identify abnormalities located in the tissue, the device was tested on a silicone phantom containing embedded hard nodules. The experimental data demonstrate that recording the tissue reaction force as well as rolling indentation depth signals during rolling indentation, the wheeled probe can rapidly identify the distribution of tissue stiffness and cause the embedded hard nodules to be accurately located.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, L.; Qian, S.-B.; Zhu, L.-Y.
The secured four-color light curves of VW Boo were analyzed with the 2003 version of the Wilson-Devinney code. It is confirmed that VW Boo is a shallow W-type contact binary system with a degree of contact factor f = 10.8%({+-} 0.5%). Two dark spots were found on the massive cool component this time. They cause an unequal depth of the two maxima. A period investigation based on all available visual, photographic, CCD, and photoelectric data shows that the period of the system includes a long-term decrease (dP/dt = -1.454 x 10{sup -7} days yr{sup -1}) and an oscillation (A{sub 3}more » = 0.0059 days; T{sub 3} = 25.96 years). These may be caused by mass transfer, angular momentum loss, and cyclic magnetic activity.« less
Development of a CCD array as an imaging detector for advanced X-ray astrophysics facilities
NASA Technical Reports Server (NTRS)
Schwartz, D. A.
1981-01-01
The development of a charge coupled device (CCD) X-ray imager for a large aperture, high angular resolution X-ray telescope is discussed. Existing CCDs were surveyed and three candidate concepts were identified. An electronic camera control and computer interface, including software to drive a Fairchild 211 CCD, is described. In addition a vacuum mounting and cooling system is discussed. Performance data for the various components are given.
CCD Astrometry with Robotic Telescopes
NASA Astrophysics Data System (ADS)
AlZaben, Faisal; Li, Dewei; Li, Yongyao; Dennis, Aren Fene, Michael; Boyce, Grady; Boyce, Pat
2016-01-01
CCD images were acquired of three binary star systems: WDS06145+1148, WDS06206+1803, and WDS06224+2640. The astrometric solution, position angle, and separation of each system were calculated with MaximDL v6 and Mira Pro x64 software suites. The results were consistent with historical measurements in the Washington Double Star Catalog. Our analysis found some differences in measurements between single-shot color CCD cameras and traditional monochrome CCDs using a filter wheel.
A FORTRAN version implementation of block adjustment of CCD frames and its preliminary application
NASA Astrophysics Data System (ADS)
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.
Applications of charge-coupled device transversal filters to communication
NASA Technical Reports Server (NTRS)
Buss, D. D.; Bailey, W. H.; Brodersen, R. W.; Hewes, C. R.; Tasch, A. F., Jr.
1975-01-01
The paper discusses the computational power of state-of-the-art charged-coupled device (CCD) transversal filters in communications applications. Some of the performance limitations of CCD transversal filters are discussed, with attention given to time delay and bandwidth, imperfect charge transfer efficiency, weighting coefficient error, noise, and linearity. The application of CCD transversal filters to matched filtering, spectral filtering, and Fourier analysis is examined. Techniques for making programmable transversal filters are briefly outlined.
CCD imaging system for the EUV solar telescope
NASA Astrophysics Data System (ADS)
Gong, Yan; Song, Qian; Ye, Bing-Xun
2006-01-01
In order to develop the detector adapted to the space solar telescope, we have built a CCD camera system capable of working in the extra ultraviolet (EUV) band, which is composed of one phosphor screen, one intensified system using a photocathode/micro-channel plate(MCP)/ phosphor, one optical taper and one chip of front-illuminated (FI) CCD without screen windows. All of them were stuck one by one with optical glue. The working principle of the camera system is presented; moreover we have employed the mesh experiment to calibrate and test the CCD camera system in 15~24nm, the position resolution of about 19 μm is obtained at the wavelength of 17.1nm and 19.5nm.
CCD centroiding analysis for Nano-JASMINE observation data
NASA Astrophysics Data System (ADS)
Niwa, Yoshito; Yano, Taihei; Araki, Hiroshi; Gouda, Naoteru; Kobayashi, Yukiyasu; Yamada, Yoshiyuki; Tazawa, Seiichi; Hanada, Hideo
2010-07-01
Nano-JASMINE is a very small satellite mission for global space astrometry with milli-arcsecond accuracy, which will be launched in 2011. In this mission, centroids of stars in CCD image frames are estimated with sub-pixel accuracy. In order to realize such a high precision centroiding an algorithm utilizing a least square method is employed. One of the advantages is that centroids can be calculated without explicit assumption of the point spread functions of stars. CCD centroiding experiment has been performed to investigate whether this data analysis is available, and centroids of artificial star images on a CCD are determined with a precision of less than 0.001 pixel. This result indicates parallaxes of stars within 300 pc from Sun can be observed in Nano-JASMINE.
Printed circuit board for a CCD camera head
Conder, Alan D.
2002-01-01
A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close (0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.
CCD BVI c observations of Cepheids
NASA Astrophysics Data System (ADS)
Berdnikov, L. N.; Kniazev, A. Yu.; Sefako, R.; Kravtsov, V. V.; Zhujko, S. V.
2014-02-01
In 2008-2013, we obtained 11333 CCD BVI c frames for 57 Cepheids from the General Catalogue of Variable Stars. We performed our observations with the 76-cm telescope of the South African Astronomical Observatory (SAAO, South Africa) and the 40-cm telescope of the Cerro Armazones Astronomical Observatory of the Universidad Católica del Norte (OCA, Chile) using the SBIG ST-10XME CCD camera. The tables of observations, the plots of light curves, and the current light elements are presented. Comparison of our light curves with those constructed from photoelectric observations shows that the differences between their mean magnitudes exceed 0ṃ05 in 20% of the cases. This suggests the necessity of performing CCD observations for all Cepheids.
SNR improvement for hyperspectral application using frame and pixel binning
NASA Astrophysics Data System (ADS)
Rehman, Sami Ur; Kumar, Ankush; Banerjee, Arup
2016-05-01
Hyperspectral imaging spectrometer systems are increasingly being used in the field of remote sensing for variety of civilian and military applications. The ability of such instruments in discriminating finer spectral features along with improved spatial and radiometric performance have made such instruments a powerful tool in the field of remote sensing. Design and development of spaceborne hyper spectral imaging spectrometers poses lot of technological challenges in terms of optics, dispersion element, detectors, electronics and mechanical systems. The main factors that define the type of detectors are the spectral region, SNR, dynamic range, pixel size, number of pixels, frame rate, operating temperature etc. Detectors with higher quantum efficiency and higher well depth are the preferred choice for such applications. CCD based Si detectors serves the requirement of high well depth for VNIR band spectrometers but suffers from smear. Smear can be controlled by using CMOS detectors. Si CMOS detectors with large format arrays are available. These detectors generally have smaller pitch and low well depth. Binning technique can be used with available CMOS detectors to meet the large swath, higher resolution and high SNR requirements. Availability of larger dwell time of satellite can be used to bin multiple frames to increase the signal collection even with lesser well depth detectors and ultimately increase the SNR. Lab measurements reveal that SNR improvement by frame binning is more in comparison to pixel binning. Effect of pixel binning as compared to the frame binning will be discussed and degradation of SNR as compared to theoretical value for pixel binning will be analyzed.
The Use of Aerosol Optical Depth in Estimating Trace Gas Emissions from Biomass Burning Plumes
NASA Astrophysics Data System (ADS)
Jones, N.; Paton-Walsh, C.; Wilson, S.; Meier, A.; Deutscher, N.; Griffith, D.; Murcray, F.
2003-12-01
We have observed significant correlations between aerosol optical depth (AOD) at 500 nm and column amounts of a number of biomass burning indicators (carbon monoxide, hydrogen cyanide, formaldehyde and ammonia) in bushfire smoke plumes over SE Australia during the 2001/2002 and 2002/2003 fire seasons from remote sensing measurements. The Department of Chemistry, University of Wollongong, operates a high resolution Fourier Transform Spectrometer (FTS), in the city of Wollongong, approximately 80 km south of Sydney. During the recent bushfires we collected over 1500 solar FTIR spectra directly through the smoke over Wollongong. The total column amounts of the biomass burning indicators were calculated using the profile retrieval software package SFIT2. Using the same solar beam, a small grating spectrometer equipped with a 2048 pixel CCD detector array, was used to calculate simultaneous aerosol optical depths. This dataset is therefore unique in its temporal sampling, location to active fires, and range of simultaneously measured constituents. There are several important applications of the AOD to gas column correlation. The estimation of global emissions from biomass burning currently has very large associated uncertainties. The use of visible radiances measured by satellites, and hence AOD, could significantly reduce these uncertainties by giving a direct estimate of global emissions of gases from biomass burning through application of the AOD to gas correlation. On a more local level, satellite-derived aerosol optical depth maps could be inverted to infer approximate concentration levels of smoke-related pollutants at the ground and in the lower troposphere, and thus can be used to determine the nature of any significant health impacts.
Assessment of the equivalence of a generic to a branded femoral stem
Hothi, H.; Henckel, J.; Shearing, P.; Holme, T.; Cerquiglini, A.; Laura, A. Di; Atrey, A.; Skinner, J.; Hart, A.
2017-01-01
Aims The aim of this study was to compare the design of the generic OptiStem XTR femoral stem with the established Exeter femoral stem. Materials and Methods We obtained five boxed, as manufactured, implants of both designs at random (ten in total). Two examiners were blinded to the implant design and independently measured the mass, volume, trunnion surface topography, trunnion roughness, trunnion cone angle, Caput-Collum-Diaphyseal (CCD) angle, femoral offset, stem length, neck length, and the width and roughness of the polished stem shaft using peer-reviewed methods. We then compared the stems using these parameters. Results We found that the OptiStems were lighter (p < 0.001), had a rougher trunnion surface (p < 0.001) with a greater spacing and depth of the machined threads (p < 0.001), had greater trunnion cone angles (p = 0.007), and a smaller radius at the top of the trunnion (p = 0.007). There was no difference in stem volume (p = 0.643), CCD angle (p = 0.788), offset (p = 0.993), neck length (p = 0.344), stem length (p = 0.808), shaft width (p = 0.058 to 0.720) or roughness of the polished surface (p = 0.536). Conclusion This preliminary investigation found that whilst there were similarities between the two designs, the generic OptiStem is different to the branded Exeter design. Cite this article: Bone Joint J 2017;99-B:310–16. PMID:28249969
Integrated bio-magnetostratigraphy of ODP Site 709 (equatorial Indian Ocean).
NASA Astrophysics Data System (ADS)
Villa, Giuliana; Fioroni, Chiara; Florindo, Fabio
2015-04-01
Over the last decade, calcareous nannofossil biostratigraphy of the lower Eocene-Oligocene sediments has shown great potential, through identification of several new nannofossil species and bioevents (e.g. Fornaciari et al., 2010; Bown and Dunkley Jones, 2012; Toffanin et al., 2013). These studies formed the basis for higher biostratigraphic resolution leading to definition of a new nannofossil biozonation (Agnini et al., 2014). In this study, we investigate the middle Eocene-lower Oligocene sediments from ODP Hole 709C (ODP Leg 115) by means of calcareous nannofossils and magnetostratigraphy. Ocean Drilling Program (ODP) Site 709 was located in the equatorial Indian Ocean and biostratigraphy has been investigated in the nineties (Okada, 1990; Fornaciari et al., 1990) while paleomagnetic data from the Initial Report provided only a poorly constrained magnetostratigraphic interpretation, thus the cored succession was dated only by means of biostratigraphy. Our goal is to test the reliability in the Indian Ocean of the biohorizons recently identified at Site 711 (Fioroni et al., in press), by means of high resolution sampling, new taxonomic updates, quantitative analyses on calcareous nannofossils allowed to increase the number of useful bioevents and to compare their reliability and synchroneity. The new magnetostratigraphic analyses and integrated stratigraphy allow also to achieve an accurate biochronology of the time interval spanning Chrons C20 (middle Eocene) and C12 (early Oligocene). In addition, this equatorial site represents an opportunity to study the carbonate accumulation history and the large fluctuations of the carbonate compensation depth (CCD) during the Eocene (e.g. Pälike et al., 2012). The investigated interval encompasses the Middle Eocene Climatic Optimum (MECO), and the long cooling trend that leads to the Oligocene glacial state. By means of our new bio-magnetostratigraphic data and paleoecological results we provide further insights on nannofossil assemblage response to the paleoclimatic changes that led to the Oligocene glacial state. References Agnini, C., Fornaciari, E., Raffi, I., Catanzariti, R., Pälike, H., Backman, J., Rio, D., 2014. Biozonation and biochronology of Paleogene calcareous nannofossils from low and middle latitudes. Newsletters on Stratigraphy, doi:10.1127/0078-0421/2014/0042. Bown, P. R., Dunkley Jones, T., 2012. Calcareous nannofossils from the Paleogene equatorial Pacific (IODP Expedition 320 Sites U1331-1334). Journal of Nannoplankton Research 32(2), 3-51. Fioroni, C., Villa, G., Persico, D., Jovane L. (in press). Middle Eocene-lower Oligocene Calcareous Nannofossil biostratigraphy and paleoceanographic implications from Site 711(equatorial Indian Ocean). Mar. Micropal. Fornaciari, E., Raffi, I., Rio, D., Villa, G., Backman, J., Olaffson, G., 1990. Quantitative distribution patterns of Oligocene and Miocene calcareous nannofossils from the western equatorial Indian Ocean. In: Duncan, R. A., Backman, J., Peterson, L. C., Proceedings of the Ocean Drilling Program, Scientific Resuls, 115, 237-254. Fornaciari, E., Agnini, C., Catanzariti, R., Rio, D., Bolla, E.M. , Valvasoni, E. 2010. Mid-latitude calcareous nannofossil biostratigraphy, biochronology and evolution across the middle to late Eocene transition. Stratigraphy 7, 229-264. Okada, H., 1990. Quaternary and Paleogene calcareous nannofossils, Leg 115. In Duncan, R.A., Backman, J., Peterson, L.C., et al., (Eds), Proceedings ODP, Scientific Results 115, 129-174. College Station, TX: Ocean Drilling Program. Pälike, H. et al., 2012. A Cenozoic record of the equatorial Pacific carbonate compensation depth. Nature 488, 609-615, doi:10.1038/nature11360. Toffanin, F., Agnini, C., Rio, D., Acton, G., Westerhold, T., 2013. Middle Eocene to early Oligocene calcareous nannofossil biostratigraphy at IODP Site U1333(equatorial Pacific). Micropaleontology 59(1), 69-82.
Eliminating the rugosity effect from compensated density logs by geometrical response matching
DOE Office of Scientific and Technical Information (OSTI.GOV)
Flaum, C.; Holenka, J.M.; Case, C.R.
1991-06-01
A theoretical and experimental effort to understand the effects of borehole rugosity on individual detector responses yielded an improved method of processing compensated density logs. Historically, the spine/ribs technique for obtaining borehole and mudcake compensation of dual-detector, gamma-gamma density logs has been very successful as long as the borehole and other environmental effects vary slowly with depth and the interest in limited to vertical features broader than several feet. With the increased interest in higher vertical resolution, a more detailed analysis of the effect of such quickly varying environmental effects as rugosity was required. A laboratory setup simulating the effectmore » of rugosity on Schlumberger Litho-Density{sup SM} tools (LDT) was used to study vertical response in the presence of rugosity. The data served as the benchmark for the Nonte Carlo models used to generate synthetic density logs in the presence of more complex rugosity patterns. The results provided in this paper show that proper matching of the two detector responses before application of conventional compensation methods can eliminate rugosity effects without degrading the measurements vertical resolution. The accuracy of the results is a good as the obtained in a parallel mudcake or standoff with the conventional method. Application to both field and synthetic log confirmed the validity of these results.« less
Return-to-work challenges following a work-related mild TBI: The injured worker perspective.
Mansfield, Elizabeth; Stergiou-Kita, Mary; Cassidy, John David; Bayley, Mark; Mantis, Steve; Kristman, Vicki; Kirsh, Bonnie; Gomez, Manuel; Jeschke, Mark G; Vartanian, Oshin; Moody, Joel; Colantonio, Angela
2015-01-01
To explore how individuals with work-related mild traumatic brain injury (wrMTBI) experience return-to-work (RTW) processes when returning to the workplace where the injury occurred. RTW experiences were explored using in-depth interviews and an inductive analytic approach. Qualitative analysis guided by the research question moved through phases of line-by-line and thematic coding through which categories and the interaction between categories emerged. Twelve workers diagnosed with a wrMTBI reported on their RTW experiences following wrMTBIs that occurred 3-5 years prior to the time of the interview. Participants perceived employer and workers' compensation factors as profoundly influencing their RTW experiences. Participants consistently reported that employers and workers' compensation representatives had an inadequate understanding of wrMTBI sequelae. Six of 12 participants were re-injured following their wrMTBI, with three of these injuries occurring at work. Employers, co-workers and workers' compensation representatives should be aware of wrMTBI sequelae so injured workers can receive appropriate supports and both stigmatization and re-injury can be mitigated. Greater attention to the structural and social elements of workplace and compensation environments could inform strategies to break down barriers to successful return-to-work following a wrMTBI.
Return-to-work challenges following a work-related mild TBI: The injured worker perspective.
Mansfield, Elizabeth; Stergiou-Kita, Mary; Cassidy, John David; Bayley, Mark; Mantis, Steve; Kristman, Vicki; Kirsh, Bonnie; Gomez, Manuel; Jeschke, Mark G; Vartanian, Oshin; Moody, Joel; Colantonio, Angela
2015-08-07
To explore how individuals with work-related mild traumatic brain injury (wrMTBI) experience return-to-work (RTW) processes when returning to the workplace where the injury occurred. RTW experiences were explored using in-depth interviews and an inductive analytic approach. Qualitative analysis guided by the research question moved through phases of line-by-line and thematic coding through which categories and the interaction between categories emerged. Twelve workers diagnosed with a wrMTBI reported on their RTW experiences following wrMTBIs that occurred 3-5 years prior to the time of the interview. Participants perceived employer and workers' compensation factors as profoundly influencing their RTW experiences. Participants consistently reported that employers and workers' compensation representatives had an inadequate understanding of wrMTBI sequelae. Six of 12 participants were re-injured following their wrMTBI, with three of these injuries occurring at work. Employers, co-workers and workers' compensation representatives should be aware of wrMTBI sequelae so injured workers can receive appropriate supports and both stigmatization and re-injury can be mitigated. Greater attention to the structural and social elements of workplace and compensation environments could inform strategies to break down barriers to successful return-to-work following a wrMTBI.
NASA Astrophysics Data System (ADS)
Swain, Pradyumna; Mark, David
2004-09-01
The emergence of curved CCD detectors as individual devices or as contoured mosaics assembled to match the curved focal planes of astronomical telescopes and terrestrial stereo panoramic cameras represents a major optical design advancement that greatly enhances the scientific potential of such instruments. In altering the primary detection surface within the telescope"s optical instrumentation system from flat to curved, and conforming the applied CCD"s shape precisely to the contour of the telescope"s curved focal plane, a major increase in the amount of transmittable light at various wavelengths through the system is achieved. This in turn enables multi-spectral ultra-sensitive imaging with much greater spatial resolution necessary for large and very large telescope applications, including those involving infrared image acquisition and spectroscopy, conducted over very wide fields of view. For earth-based and space-borne optical telescopes, the advent of curved CCD"s as the principle detectors provides a simplification of the telescope"s adjoining optics, reducing the number of optical elements and the occurrence of optical aberrations associated with large corrective optics used to conform to flat detectors. New astronomical experiments may be devised in the presence of curved CCD applications, in conjunction with large format cameras and curved mosaics, including three dimensional imaging spectroscopy conducted over multiple wavelengths simultaneously, wide field real-time stereoscopic tracking of remote objects within the solar system at high resolution, and deep field survey mapping of distant objects such as galaxies with much greater multi-band spatial precision over larger sky regions. Terrestrial stereo panoramic cameras equipped with arrays of curved CCD"s joined with associative wide field optics will require less optical glass and no mechanically moving parts to maintain continuous proper stereo convergence over wider perspective viewing fields than their flat CCD counterparts, lightening the cameras and enabling faster scanning and 3D integration of objects moving within a planetary terrain environment. Preliminary experiments conducted at the Sarnoff Corporation indicate the feasibility of curved CCD imagers with acceptable electro-optic integrity. Currently, we are in the process of evaluating the electro-optic performance of a curved wafer scale CCD imager. Detailed ray trace modeling and experimental electro-optical data performance obtained from the curved imager will be presented at the conference.
Saito, Akiko; Ooki, Akio; Nakamura, Takashi; Onodera, Shoko; Hayashi, Kamichika; Hasegawa, Daigo; Okudaira, Takahito; Watanabe, Katsuhito; Kato, Hiroshi; Onda, Takeshi; Watanabe, Akira; Kosaki, Kenjiro; Nishimura, Ken; Ohtaka, Manami; Nakanishi, Mahito; Sakamoto, Teruo; Yamaguchi, Akira; Sueishi, Kenji; Azuma, Toshifumi
2018-01-22
Runt-related transcription factor 2 (RUNX2) haploinsufficiency causes cleidocranial dysplasia (CCD) which is characterized by supernumerary teeth, short stature, clavicular dysplasia, and osteoporosis. At present, as a therapeutic strategy for osteoporosis, mesenchymal stem cell (MSC) transplantation therapy is performed in addition to drug therapy. However, MSC-based therapy for osteoporosis in CCD patients is difficult due to a reduction in the ability of MSCs to differentiate into osteoblasts resulting from impaired RUNX2 function. Here, we investigated whether induced pluripotent stem cells (iPSCs) properly differentiate into osteoblasts after repairing the RUNX2 mutation in iPSCs derived from CCD patients to establish normal iPSCs, and whether engraftment of osteoblasts derived from properly reverted iPSCs results in better regeneration in immunodeficient rat calvarial bone defect models. Two cases of CCD patient-derived induced pluripotent stem cells (CCD-iPSCs) were generated using retroviral vectors (OCT3/4, SOX2, KLF4, and c-MYC) or a Sendai virus SeVdp vector (KOSM302L). Reverted iPSCs were established using programmable nucleases, clustered regularly interspaced short palindromic repeats (CRISPR)/Cas-derived RNA-guided endonucleases, to correct mutations in CCD-iPSCs. The mRNA expressions of osteoblast-specific markers were analyzed using quantitative reverse-transcriptase polymerase chain reaction. iPSCs-derived osteoblasts were transplanted into rat calvarial bone defects, and bone regeneration was evaluated using microcomputed tomography analysis and histological analysis. Mutation analysis showed that both contained nonsense mutations: one at the very beginning of exon 1 and the other at the initial position of the nuclear matrix-targeting signal. The osteoblasts derived from CCD-iPSCs (CCD-OBs) expressed low levels of several osteoblast differentiation markers, and transplantation of these osteoblasts into calvarial bone defects created in rats with severe combined immunodeficiency showed poor regeneration. However, reverted iPSCs improved the abnormal osteoblast differentiation which resulted in much better engraftment into the rat calvarial bone defect. Taken together, these results demonstrate that patient-specific iPSC technology can not only provide a useful disease model to elucidate the role of RUNX2 in osteoblastic differentiation but also raises the tantalizing prospect that reverted iPSCs might provide a practical medical treatment for CCD.
Wang, Yong; Ding, Guanqun; Gu, Tingting; Ding, Jing; Li, Yi
2017-08-01
Carotenoid dioxygenases, including 9-cis-epoxycarotenoid dioxygenases (NCEDs) and carotenoid cleavage dioxygenases (CCDs), can selectively cleave carotenoids into various apocarotenoid products that play important roles in fleshy fruit development and abiotic stress response. In this study, we identified 12 carotenoid dioxygenase genes in diploid strawberry Fragaria vesca, and explored their evolution with orthologous genes from nine other species. Phylogenetic analyses suggested that the NCED and CCDL groups moderately expanded during their evolution, whereas gene numbers of the CCD1, CCD4, CCD7, and CCD8 groups maintained conserved. We characterized the expression profiles of FveNCED and FveCCD genes during flower and fruit development, and in response to several abiotic stresses. FveNCED1 expression positively responded to osmotic, cold, and heat stresses, whereas FveNCED2 was only induced under cold stress. In contrast, FveNCED2 was the unique gene highly and continuously increasing in receptacle during fruit ripening, which co-occurred with the increase in endogenous abscisic acid (ABA) content previously reported in octoploid strawberry. The differential expression patterns suggested that FveNCED1 and FveNCED2 were key genes for ABA biosynthesis in abiotic stress responses and fruit ripening, respectively. FveCCD1 exhibited the highest expression in most stages of flower and fruit development, while the other FveCCDs were expressed in a subset of stages and tissues. Our study suggests distinct functions of FveNCED and FveCCD genes in fruit development and stress responses and lays a foundation for future study to understand the roles of these genes and their metabolites, including ABA and other apocarotenoid products, in the growth and development of strawberry.
SU-E-T-161: SOBP Beam Analysis Using Light Output of Scintillation Plate Acquired by CCD Camera.
Cho, S; Lee, S; Shin, J; Min, B; Chung, K; Shin, D; Lim, Y; Park, S
2012-06-01
To analyze Bragg-peak beams in SOBP (spread-out Bragg-peak) beam using CCD (charge-coupled device) camera - scintillation screen system. We separated each Bragg-peak beam using light output of high sensitivity scintillation material acquired by CCD camera and compared with Bragg-peak beams calculated by Monte Carlo simulation. In this study, CCD camera - scintillation screen system was constructed with a high sensitivity scintillation plate (Gd2O2S:Tb) and a right-angled prismatic PMMA phantom, and a Marlin F-201B, EEE-1394 CCD camera. SOBP beam irradiated by the double scattering mode of a PROTEUS 235 proton therapy machine in NCC is 8 cm width, 13 g/cm 2 range. The gain, dose rate and current of this beam is 50, 2 Gy/min and 70 nA, respectively. Also, we simulated the light output of scintillation plate for SOBP beam using Geant4 toolkit. We evaluated the light output of high sensitivity scintillation plate according to intergration time (0.1 - 1.0 sec). The images of CCD camera during the shortest intergration time (0.1 sec) were acquired automatically and randomly, respectively. Bragg-peak beams in SOBP beam were analyzed by the acquired images. Then, the SOBP beam used in this study was calculated by Geant4 toolkit and Bragg-peak beams in SOBP beam were obtained by ROOT program. The SOBP beam consists of 13 Bragg-peak beams. The results of experiment were compared with that of simulation. We analyzed Bragg-peak beams in SOBP beam using light output of scintillation plate acquired by CCD camera and compared with that of Geant4 simulation. We are going to study SOBP beam analysis using more effective the image acquisition technique. © 2012 American Association of Physicists in Medicine.
Tuan, Pham Anh; Park, Sang Un
2013-01-01
Carotenoid cleavage dioxygenases (CCDs) are a family of enzymes that catalyze the oxidative cleavage of carotenoids at various chain positions to form a broad spectrum of apocarotenoids, including aromatic substances, pigments and phytohormones. Using the rapid amplification of cDNA ends (RACE) PCR method, we isolated three cDNA-encoding CCDs (McCCD1, McCCD4, and McNCED) from Momordica charantia. Amino acid sequence alignments showed that they share high sequence identity with other orthologous genes. Quantitative real-time RT PCR (reverse transcriptase PCR) analysis revealed that the expression of McCCD1 and McCCD4 was highest in flowers, and lowest in roots and old leaves (O-leaves). During fruit maturation, the two genes displayed differential expression, with McCCD1 peaking at mid-stage maturation while McCCD4 showed the lowest expression at that stage. The mRNA expression level of McNCED, a key enzyme involved in abscisic acid (ABA) biosynthesis, was high during fruit maturation and further increased at the beginning of seed germination. When first-leaf stage plants of M. charantia were exposed to dehydration stress, McNCED mRNA expression was induced primarily in the leaves and, to a lesser extend, in roots and stems. McNCED expression was also induced by high temperature and salinity, while treatment with exogenous ABA led to a decrease. These results should be helpful in determining the substrates and cleavage sites catalyzed by CCD genes in M. charantia, and also in defining the roles of CCDs in growth and development, and in the plant's response to environmental stress. Copyright © 2012 Elsevier GmbH. All rights reserved.
CCD sensors in synchrotron X-ray detectors
NASA Astrophysics Data System (ADS)
Strauss, M. G.; Naday, I.; Sherman, I. S.; Kraimer, M. R.; Westbrook, E. M.; Zaluzec, N. J.
1988-04-01
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 × 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 a rate of ˜ 1 frame/s or a complete 3-dimensional data set from a single crystal in ˜ 2 min. In electron energy-loss spectroscopy (EELS), the CCD was used in a parallel detection mode which is similar to the mode array detectors are used in dispersive EXAFS. With a beam current corresponding to 3 × 10 9 electron/s on the detector, a series of 64 spectra were recorded on the CCD in a continuous sequence without interruption due to readout. The frame-to-frame pixel signal fluctuations had σ = 0.4% from which DQE = 0.4 was obtained, where the detector conversion efficiency was 2.6 CCD electrons/X-ray photon. These multiple frame series also showed the time-resolved modulation of the electron microscope optics by stray magnetic fields.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Hsu-Pin; Hsu, Shu-Yuan; Wu, Wen-Ai
Highlights: •Pnn CCD domain functions as a dominant negative mutant regulating Pnn expression and function. •Pnn CCD mutant Tg mice have a muscle wasting phenotype during development and show dystrophic histological features. •Pnn mutant muscles are susceptible to slow fiber type gene transition and NEB reduction. •The Tg mouse generated by overexpression of the Pnn CCD domain displays many characteristics resembling NEB{sup +/−} mice. -- Abstract: Pinin (Pnn) is a nuclear speckle-associated SR-like protein. The N-terminal region of the Pnn protein sequence is highly conserved from mammals to insects, but the C-terminal RS domain-containing region is absent in lower species.more » The N-terminal coiled-coil domain (CCD) is, therefore, of interest not only from a functional point of view, but also from an evolutionarily standpoint. To explore the biological role of the Pnn CCD in a physiological context, we generated transgenic mice overexpressing Pnn mutant in skeletal muscle. We found that overexpression of the CCD reduces endogenous Pnn expression in cultured cell lines as well as in transgenic skeletal muscle fibers. Pnn mutant mice exhibited reduced body mass and impaired muscle function during development. Mutant skeletal muscles show dystrophic histological features with muscle fibers heavily loaded with centrally located myonuclei. Expression profiling and pathway analysis identified over-representation of genes in gene categories associated with muscle contraction, specifically those related to slow type fiber. In addition nebulin (NEB) expression level is repressed in Pnn mutant skeletal muscle. We conclude that Pnn downregulation in skeletal muscle causes a muscular dystrophic phenotype associated with NEB deficiency and the CCD domain is incapable of replacing full length Pnn in terms of functional capacity.« less
Stock, David; Paszat, Lawrence F; Rabeneck, Linda
2016-07-01
Colonoscopy has been demonstrated to be effective in colorectal cancer (CRC) mortality reduction, although current screening guidelines have yet to be evaluated. We assessed the protective benefit of colonoscopy within the previous 10 years and whether this effect is maintained with age. We used administrative data to compare risk of CRC death (CCD) across colonoscopy utilization among a population-wide cohort comprising individuals aged 60 to 80 years (N = 1,509,423). Baseline and time-dependent colonoscopy exposure models were assessed in the context of competing "other causes of death" (OCDs). Cumulative incidence of CCD and OCD across colonoscopy exposure, over follow-up, was estimated. Relative hazards were computed by age strata (60-69 years, 70-74 years, 75+ years) and proximal and distal cancer subsites. At least 1 colonoscopy during 10 years before baseline was estimated to provide a 51% reduced hazard of CCD (hazard ratio [HR] 0.49; 95% confidence interval [CI], 0.45-0.54) over the following 8 years. When colonoscopy was modeled as a time-dependent covariate, the risk of CCD was further diminished (multivariable-adjusted HR 0.36; 95% CI, 0.33-0.38). Stratified analyses suggested moderately attenuated CCD risk reduction among the oldest age group; however, consideration of OCDs suggest that this is related to competing risks. CCD risk reduction related to colonoscopy was lower for proximal cancers. Colonoscopy within the previous 10 years provides substantial protective benefit for average-risk individuals over 60 years. CCD risk reduction may be maintained well beyond 74 years, a common upper age limit recommended by screening guidelines. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.
Effects of biomechanical forces on signaling in the cortical collecting duct (CCD).
Carrisoza-Gaytan, Rolando; Liu, Yu; Flores, Daniel; Else, Cindy; Lee, Heon Goo; Rhodes, George; Sandoval, Ruben M; Kleyman, Thomas R; Lee, Francis Young-In; Molitoris, Bruce; Satlin, Lisa M; Rohatgi, Rajeev
2014-07-15
An increase in tubular fluid flow rate (TFF) stimulates Na reabsorption and K secretion in the cortical collecting duct (CCD) and subjects cells therein to biomechanical forces including fluid shear stress (FSS) and circumferential stretch (CS). Intracellular MAPK and extracellular autocrine/paracrine PGE2 signaling regulate cation transport in the CCD and, at least in other systems, are affected by biomechanical forces. We hypothesized that FSS and CS differentially affect MAPK signaling and PGE2 release to modulate cation transport in the CCD. To validate that CS is a physiological force in vivo, we applied the intravital microscopic approach to rodent kidneys in vivo to show that saline or furosemide injection led to a 46.5 ± 2.0 or 170 ± 32% increase, respectively, in distal tubular diameter. Next, murine CCD (mpkCCD) cells were grown on glass or silicone coated with collagen type IV and subjected to 0 or 0.4 dyne/cm(2) of FSS or 10% CS, respectively, forces chosen based on prior biomechanical modeling of ex vivo microperfused CCDs. Cells exposed to FSS expressed an approximately twofold greater abundance of phospho(p)-ERK and p-p38 vs. static cells, while CS did not alter p-p38 and p-ERK expression compared with unstretched controls. FSS induced whereas CS reduced PGE2 release by ∼40%. In conclusion, FSS and CS differentially affect ERK and p38 activation and PGE2 release in a cell culture model of the CD. We speculate that TFF differentially regulates biomechanical signaling and, in turn, cation transport in the CCD. Copyright © 2014 the American Physiological Society.
USSR and Eastern Europe Scientific Abstracts, Geophysics, Astronomy and Space, Number 398
1977-05-25
Determining Ship’s Speed 25 Compensation of Cross Coupling Effect in Marine Gravimetry ... 26 Korteweg-De Vries Equation for Internal Waves in...winters and increased precipitation , favorable conditions for vegetation. [287] RADIOACOUSTIC SOUNDING OF THE ATMOSPHERE Moscow IZVESTIYA AKADEMII...complex of geophys- ical and geological methods was used: seismic profiling, gravimetry , mag- netometry, depth sounding and dredging. The director
Terrestrial catastrophe caused by cometary impact at the end of Cretaceous
NASA Astrophysics Data System (ADS)
Hsü, Kenneth J.
1980-05-01
Evidence is presented indicating that the extinction, at the end of the Cretaceous, of large terrestrial animals was caused by atmospheric heating during a cometary impact and that the extinction of calcareous marine plankton was a consequence of poisoning by cyanide released by the fallen comet and of a catastrophic rise in calcite-compensation depth in the oceans after the detoxification of the cyanide.
CTK: A new CCD Camera at the University Observatory Jena
NASA Astrophysics Data System (ADS)
Mugrauer, M.
2009-05-01
The Cassegrain-Teleskop-Kamera (CTK) is a new CCD imager which is operated at the University Observatory Jena since begin of 2006. This article describes the main characteristics of the new camera. The properties of the CCD detector, the CTK image quality, as well as its detection limits for all filters are presented. Based on observations obtained with telescopes of the University Observatory Jena, which is operated by the Astrophysical Institute of the Friedrich-Schiller-University.
Astronomical Archive at Tartu Observatory
NASA Astrophysics Data System (ADS)
Annuk, K.
2007-10-01
Archiving astronomical data is important task not only at large observatories but also at small observatories. Here we describe the astronomical archive at Tartu Observatory. The archive consists of old photographic plate images, photographic spectrograms, CCD direct--images and CCD spectroscopic data. The photographic plate digitizing project was started in 2005. An on-line database (based on MySQL) was created. The database includes CCD data as well photographic data. A PHP-MySQL interface was written for access to all data.
Evaluation of tellurium toxicity in transformed and non-transformed human colon cells.
Vij, Puneet; Hardej, Diane
2012-11-01
Diphenyl ditelluride (DPDT) and tellurium tetrachloride (TeCl(4)) were evaluated for toxicity in transformed (HT-29, Caco-2) and non-transformed colon cells (CCD-18Co). Significant decreases in viability were observed with DPDT exposure in HT-29 (62.5-1000 μM), Caco-2 (31.25-1000 μM) and CCD-18Co cells (500-1000 μM) and with TeCl(4) in HT-29 (31.25-1000 μM), Caco-2 (31.25-1000 μM) and CCD-18Co cells (500-1000 μM). Light microscopy confirmed viability analysis. Significant increases in caspase 3/7 and 9 activity were observed with DPDT in HT-29 (500-1000 μM) and CCD-18Co cells (1000 μM) indicating apoptosis. No significant increases in caspases were seen with TeCl(4) indicating necrosis. Apoptosis or necrosis was confirmed with fluorescent staining (FITC-Annexin, Hoechst 33342 and Ethidium Homodimer). Significant decreases in GSH/GSSG ratio were observed with DPDT in HT-29 (62.5-1000 μM), and CCD-18Co cells (1000 μM) and with TeCl(4) in HT-29 (62.5-1000 μM) and CCD-18Co cells (250-1000 μM). We concluded that cells treated with DPDT resulted in apoptosis and TeCl(4) treatment in necrosis. GSH/GSSG ratio shifts indicate oxidative mechanisms are involved. Copyright © 2012 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Chatterjee, Abhijit; Verma, Anurag
2016-05-01
The Advanced Wide Field Sensor (AWiFS) camera caters to high temporal resolution requirement of Resourcesat-2A mission with repeativity of 5 days. The AWiFS camera consists of four spectral bands, three in the visible and near IR and one in the short wave infrared. The imaging concept in VNIR bands is based on push broom scanning that uses linear array silicon charge coupled device (CCD) based Focal Plane Array (FPA). On-Board Calibration unit for these CCD based FPAs is used to monitor any degradation in FPA during entire mission life. Four LEDs are operated in constant current mode and 16 different light intensity levels are generated by electronically changing exposure of CCD throughout the calibration cycle. This paper describes experimental setup and characterization results of various flight model visible LEDs (λP=650nm) for development of On-Board Calibration unit of Advanced Wide Field Sensor (AWiFS) camera of RESOURCESAT-2A. Various LED configurations have been studied to meet dynamic range coverage of 6000 pixels silicon CCD based focal plane array from 20% to 60% of saturation during night pass of the satellite to identify degradation of detector elements. The paper also explains comparison of simulation and experimental results of CCD output profile at different LED combinations in constant current mode.
López-Ráez, Juan A; Fernández, Iván; García, Juan M; Berrio, Estefanía; Bonfante, Paola; Walter, Michael H; Pozo, María J
2015-01-01
Apocarotenoids are a class of compounds that play important roles in nature. In recent years, a prominent role for these compounds in arbuscular mycorrhizal (AM) symbiosis has been shown. They are derived from carotenoids by the action of the carotenoid cleavage dioxygenase (CCD) enzyme family. In the present study, using tomato as a model, the spatio-temporal expression pattern of the CCD genes during AM symbiosis establishment and functioning was investigated. In addition, the levels of the apocarotenoids strigolactones (SLs), C13 α-ionol and C14 mycorradicin (C13/C14) derivatives were analyzed. The results suggest an increase in SLs promoted by the presence of the AM fungus at the early stages of the interaction, which correlated with an induction of the SL biosynthesis gene SlCCD7. At later stages, induction of SlCCD7 and SlCCD1 expression in arbusculated cells promoted the production of C13/C14 apocarotenoid derivatives. We show here that the biosynthesis of apocarotenoids during AM symbiosis is finely regulated throughout the entire process at the gene expression level, and that CCD7 constitutes a key player in this regulation. Once the symbiosis is established, apocarotenoid flux would be turned towards the production of C13/C14 derivatives, thus reducing SL biosynthesis and maintaining a functional symbiosis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Dynamic compensation in the central Pacific Ocean
NASA Technical Reports Server (NTRS)
Hinojosa, Juan Homero; Marsh, Bruce D.
1988-01-01
The intermediate-wavelength geoid (lambda similar to 2000 km) and sea-floor topography fields in the central Pacific Ocean were studied in terms of static and dynamic compensation models. Topographic features on the sea-floor with lambda less than 1000 km were found to be compensated both regionally, by the elastic strength of the lithosphere, and locally, by displacing mantle material to reach isostatic adjustment. The larger-scale sea-floor topography and the corresponding geoid anomalies with lambda similar to 2000 km cannot be explained by either local or regional compensation. The topography and the resulting geoid anomaly at this wavelength were modeled by considering the dynamic effects arising from viscous stresses in a layer of fluid with a highly temperature-dependent viscosity for the cases of: (1) surface cooling, and (2) basal heating. In this model, the mechanical properties of the elastic part of the lithosphere were taken into account by considering an activation energy of about 520 kJ/mol in the Arrhenius law for the viscosity. Numerical predictions of the topography, total geoid anomaly, and admittance were obtained, and the results show that the thermal perturbation in the layer, which accounts for the mass deficit, must be located close to the surface to compensate the gravitational effect of the surface deformation. For the case of basal heating, the temperature dependence of viscosity results in a separation of the upper, quasi-rigid lid from the lower mobile fluid, hence inhibiting the development of a compensating thermal perturbation at shallow depths. The results clearly rule out small-scale, upper-mantle convection as the source of these anomalies. Instead, the geophysical observables can be well explained by a shallow, transient thermal perturbation.
Yang, Yuan-Zheng; Chang, Yu; Hu, Yuan-Man; Liu, Miao; Li, Yue-Hui
2011-06-01
To timely and accurately acquire the spatial distribution pattern of wetlands is of significance for the dynamic monitoring, conservation, and sustainable utilization of wetlands. The small remote sensing satellite constellations A/B stars (HJ-1A/1B stars) for environmental hazards were launched by China for monitoring terrestrial resources, which could provide a new data source of remote sensing image acquisition for retrieving wetland types. Taking Liaohe Delta as a case, this paper compared the accuracy of wetland classification map and the area of each wetland type retrieved from CCD data (HJ CCD data) and TM5 data, and validated and explored the applicability and the applied potential of HJ CCD data in wetland resources dynamic monitoring. The results showed that HJ CCD data could completely replace Landsat TM5 data in feature extraction and remote sensing classification. In real-time monitoring, due to its 2 days of data acquisition cycle, HJ CCD data had the priority to Landsat TM5 data (16 days of data acquisition cycle).
Replacing a technology - The Large Space Telescope and CCDs
NASA Astrophysics Data System (ADS)
Smith, R. W.; Tatarewicz, J. H.
1985-07-01
The technological improvements, design choices and mission goals which led to the inclusion of CCD detectors in the wide field camera of the Large Space Telescope (LST) to be launched by the STS are recounted. Consideration of CCD detectors began before CCDs had seen wide astronomical applications. During planning for the ST, in the 1960s, photographic methods and a vidicon were considered, and seemed feasible provided that periodic manual maintenance could be performed. The invention of CCDs was first reported in 1970 and by 1973 the CCDs were receiving significant attention as potential detectors instead of a vidicon, which retained its own technological challenges. The CCD format gained new emphasis when success was achieved in developments for planetary-imaging spacecraft. The rapidity of progress in CCD capabilities, coupled with the continued shortcomings of the vidicon, resulted in a finalized choice for a CCD device by 1977. The decision was also prompted by continuing commercial and military interest in CCDs, which was spurring the development of the technology and improving the sensitivities and reliability while lowering the costs.
Final Report, January 1991 - July 1992
NASA Astrophysics Data System (ADS)
Ferrara, Jon
1992-07-01
This report covers final schedules, expenses and billings, monthly reports, testing, and deliveries for this contract. The goal of the detector development program for the Solar and Heliospheric Spacecraft (SOHO) EUV Imaging Telescope (EIT) is an Extreme UltraViolet (EUV) CCD (Change Collecting Device) camera. As a part of the CCD screening effort, the quantum efficiency (QE) of a prototype CCD has been measured in the NRL EUV laboratory over the wavelength range of 256 to 735 Angstroms. A simplified model has been applied to these QE measurements to illustrate the relevant physical processes that determine the performance of the detector. The charge transfer efficiency (CTE) characteristics of the Tektronix 1024 X 1024 CCD being developed for STIS/SOHO space imaging applications have been characterized at different signal levels, operating conditions, and temperatures using a variety of test methods. A number of CCD's have been manufactured using processing techniques developed to improve CTE, and test results on these devices will be used in determining the final chip design. In this paper, we discuss the CTE test methods used and present the results and conclusions of these tests.
Westbrook, John D.; Shao, Chenghua; Feng, Zukang; Zhuravleva, Marina; Velankar, Sameer; Young, Jasmine
2015-01-01
Summary: The Chemical Component Dictionary (CCD) is a chemical reference data resource that describes all residue and small molecule components found in Protein Data Bank (PDB) entries. The CCD contains detailed chemical descriptions for standard and modified amino acids/nucleotides, small molecule ligands and solvent molecules. Each chemical definition includes descriptions of chemical properties such as stereochemical assignments, chemical descriptors, systematic chemical names and idealized coordinates. The content, preparation, validation and distribution of this CCD chemical reference dataset are described. Availability and implementation: The CCD is updated regularly in conjunction with the scheduled weekly release of new PDB structure data. The CCD and amino acid variant reference datasets are hosted in the public PDB ftp repository at ftp://ftp.wwpdb.org/pub/pdb/data/monomers/components.cif.gz, ftp://ftp.wwpdb.org/pub/pdb/data/monomers/aa-variants-v1.cif.gz, and its mirror sites, and can be accessed from http://wwpdb.org. Contact: jwest@rcsb.rutgers.edu. Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25540181
Quantum efficiency measurement of the Transiting Exoplanet Survey Satellite (TESS) CCD detectors
NASA Astrophysics Data System (ADS)
Krishnamurthy, A.; Villasenor, J.; Thayer, C.; Kissel, S.; Ricker, G.; Seager, S.; Lyle, R.; Deline, A.; Morgan, E.; Sauerwein, T.; Vanderspek, R.
2016-07-01
Very precise on-ground characterization and calibration of TESS CCD detectors will significantly assist in the analysis of the science data from the mission. An accurate optical test bench with very high photometric stability has been developed to perform precise measurements of the absolute quantum efficiency. The setup consists of a vacuum dewar with a single MIT Lincoln Lab CCID-80 device mounted on a cold plate with the calibrated reference photodiode mounted next to the CCD. A very stable laser-driven light source is integrated with a closed-loop intensity stabilization unit to control variations of the light source down to a few parts-per-million when averaged over 60 s. Light from the stabilization unit enters a 20 inch integrating sphere. The output light from the sphere produces near-uniform illumination on the cold CCD and on the calibrated reference photodiode inside the dewar. The ratio of the CCD and photodiode signals provides the absolute quantum efficiency measurement. The design, key features, error analysis, and results from the test campaign are presented.
Determination of water depth with high-resolution satellite imagery over variable bottom types
Stumpf, Richard P.; Holderied, Kristine; Sinclair, Mark
2003-01-01
A standard algorithm for determining depth in clear water from passive sensors exists; but it requires tuning of five parameters and does not retrieve depths where the bottom has an extremely low albedo. To address these issues, we developed an empirical solution using a ratio of reflectances that has only two tunable parameters and can be applied to low-albedo features. The two algorithms--the standard linear transform and the new ratio transform--were compared through analysis of IKONOS satellite imagery against lidar bathymetry. The coefficients for the ratio algorithm were tuned manually to a few depths from a nautical chart, yet performed as well as the linear algorithm tuned using multiple linear regression against the lidar. Both algorithms compensate for variable bottom type and albedo (sand, pavement, algae, coral) and retrieve bathymetry in water depths of less than 10-15 m. However, the linear transform does not distinguish depths >15 m and is more subject to variability across the studied atolls. The ratio transform can, in clear water, retrieve depths in >25 m of water and shows greater stability between different areas. It also performs slightly better in scattering turbidity than the linear transform. The ratio algorithm is somewhat noisier and cannot always adequately resolve fine morphology (structures smaller than 4-5 pixels) in water depths >15-20 m. In general, the ratio transform is more robust than the linear transform.
NASA Astrophysics Data System (ADS)
Hayashida, T.,; Yonai, J.; Kitamura, K.; Arai, T.; Kurita, T.; Tanioka, K.; Maruyama, H.; Etoh, T. Goji; Kitagawa, S.; Hatade, K.; Yamaguchi, T.; Takeuchi, H.; Iida, K.
2008-02-01
We are advancing the development of ultrahigh-speed, high-sensitivity CCDs for broadcast use that are capable of capturing smooth slow-motion videos in vivid colors even where lighting is limited, such as at professional baseball games played at night. We have already developed a 300,000 pixel, ultrahigh-speed CCD, and a single CCD color camera that has been used for sports broadcasts and science programs using this CCD. However, there are cases where even higher sensitivity is required, such as when using a telephoto lens during a baseball broadcast or a high-magnification microscope during science programs. This paper provides a summary of our experimental development aimed at further increasing the sensitivity of CCDs using the light-collecting effects of a microlens array.
Tests of commercial colour CMOS cameras for astronomical applications
NASA Astrophysics Data System (ADS)
Pokhvala, S. M.; Reshetnyk, V. M.; Zhilyaev, B. E.
2013-12-01
We present some results of testing commercial colour CMOS cameras for astronomical applications. Colour CMOS sensors allow to perform photometry in three filters simultaneously that gives a great advantage compared with monochrome CCD detectors. The Bayer BGR colour system realized in colour CMOS sensors is close to the astronomical Johnson BVR system. The basic camera characteristics: read noise (e^{-}/pix), thermal noise (e^{-}/pix/sec) and electronic gain (e^{-}/ADU) for the commercial digital camera Canon 5D MarkIII are presented. We give the same characteristics for the scientific high performance cooled CCD camera system ALTA E47. Comparing results for tests of Canon 5D MarkIII and CCD ALTA E47 show that present-day commercial colour CMOS cameras can seriously compete with the scientific CCD cameras in deep astronomical imaging.
Ion-molecule calculation of the abundance ratio of CCD to CCH in dense interstellar clouds
NASA Technical Reports Server (NTRS)
Herbst, Eric; Adams, Nigel G.; Smith, David; Defrees, D. J.
1987-01-01
Laboratory measurements and calculations have been performed to determine the abundance ratio of the deuterated ethynyl radical (CCD) to the normal radical (CCH) which can be achieved in dense interstellar clouds via isotopic fractionation in the C2H2(+) (HD)=C2HD(+)(H2) system of reactions. According to this limited treatment, the CCD/CCH abundance ratio which can be attained is in the range 0.02-0.03 for the Orion molecular cloud and 0.0l-0.02 for TMC-1. These ranges of numbers are in reasonable agreement with the observed values in Orion and TMC-1. However, the analysis of the CCD/CCH abundance ratio is complicated via the presence of competing fractionation mechanisms, especially in the low-temperature source TMC-1.
Solid state television camera (CCD-buried channel)
NASA Technical Reports Server (NTRS)
1976-01-01
The development of an all solid state television camera, which uses a buried channel charge coupled device (CCD) as the image sensor, was undertaken. A 380 x 488 element CCD array is utilized to ensure compatibility with 525 line transmission and display monitor equipment. Specific camera design approaches selected for study and analysis included (a) optional clocking modes for either fast (1/60 second) or normal (1/30 second) frame readout, (b) techniques for the elimination or suppression of CCD blemish effects, and (c) automatic light control and video gain control (i.e., ALC and AGC) techniques to eliminate or minimize sensor overload due to bright objects in the scene. Preferred approaches were determined and integrated into a deliverable solid state TV camera which addressed the program requirements for a prototype qualifiable to space environment conditions.
Solid state television camera (CCD-buried channel), revision 1
NASA Technical Reports Server (NTRS)
1977-01-01
An all solid state television camera was designed which uses a buried channel charge coupled device (CCD) as the image sensor. A 380 x 488 element CCD array is utilized to ensure compatibility with 525-line transmission and display monitor equipment. Specific camera design approaches selected for study and analysis included (1) optional clocking modes for either fast (1/60 second) or normal (1/30 second) frame readout, (2) techniques for the elimination or suppression of CCD blemish effects, and (3) automatic light control and video gain control techniques to eliminate or minimize sensor overload due to bright objects in the scene. Preferred approaches were determined and integrated into a deliverable solid state TV camera which addressed the program requirements for a prototype qualifiable to space environment conditions.
Solid state, CCD-buried channel, television camera study and design
NASA Technical Reports Server (NTRS)
Hoagland, K. A.; Balopole, H.
1976-01-01
An investigation of an all solid state television camera design, which uses a buried channel charge-coupled device (CCD) as the image sensor, was undertaken. A 380 x 488 element CCD array was utilized to ensure compatibility with 525 line transmission and display monitor equipment. Specific camera design approaches selected for study and analysis included (a) optional clocking modes for either fast (1/60 second) or normal (1/30 second) frame readout, (b) techniques for the elimination or suppression of CCD blemish effects, and (c) automatic light control and video gain control techniques to eliminate or minimize sensor overload due to bright objects in the scene. Preferred approaches were determined and integrated into a design which addresses the program requirements for a deliverable solid state TV camera.
Depth-of-Interaction Compensation Using a Focused-Cut Scintillator for a Pinhole Gamma Camera.
Alhassen, Fares; Kudrolli, Haris; Singh, Bipin; Kim, Sangtaek; Seo, Youngho; Gould, Robert G; Nagarkar, Vivek V
2011-06-01
Preclinical SPECT offers a powerful means to understand the molecular pathways of drug interactions in animal models by discovering and testing new pharmaceuticals and therapies for potential clinical applications. A combination of high spatial resolution and sensitivity are required in order to map radiotracer uptake within small animals. Pinhole collimators have been investigated, as they offer high resolution by means of image magnification. One of the limitations of pinhole geometries is that increased magnification causes some rays to travel through the detection scintillator at steep angles, introducing parallax errors due to variable depth-of-interaction in scintillator material, especially towards the edges of the detector field of view. These parallax errors ultimately limit the resolution of pinhole preclinical SPECT systems, especially for higher energy isotopes that can easily penetrate through millimeters of scintillator material. A pixellated, focused-cut (FC) scintillator, with its pixels laser-cut so that they are collinear with incoming rays, can potentially compensate for these parallax errors and thus improve the system resolution. We performed the first experimental evaluation of a newly developed focused-cut scintillator. We scanned a Tc-99m source across the field of view of pinhole gamma camera with a continuous scintillator, a conventional "straight-cut" (SC) pixellated scintillator, and a focused-cut scintillator, each coupled to an electron-multiplying charge coupled device (EMCCD) detector by a fiber-optic taper, and compared the measured full-width half-maximum (FWHM) values. We show that the FWHMs of the focused-cut scintillator projections are comparable to the FWHMs of the thinner SC scintillator, indicating the effectiveness of the focused-cut scintillator in compensating parallax errors.
Depth-of-Interaction Compensation Using a Focused-Cut Scintillator for a Pinhole Gamma Camera
Alhassen, Fares; Kudrolli, Haris; Singh, Bipin; Kim, Sangtaek; Seo, Youngho; Gould, Robert G.; Nagarkar, Vivek V.
2011-01-01
Preclinical SPECT offers a powerful means to understand the molecular pathways of drug interactions in animal models by discovering and testing new pharmaceuticals and therapies for potential clinical applications. A combination of high spatial resolution and sensitivity are required in order to map radiotracer uptake within small animals. Pinhole collimators have been investigated, as they offer high resolution by means of image magnification. One of the limitations of pinhole geometries is that increased magnification causes some rays to travel through the detection scintillator at steep angles, introducing parallax errors due to variable depth-of-interaction in scintillator material, especially towards the edges of the detector field of view. These parallax errors ultimately limit the resolution of pinhole preclinical SPECT systems, especially for higher energy isotopes that can easily penetrate through millimeters of scintillator material. A pixellated, focused-cut (FC) scintillator, with its pixels laser-cut so that they are collinear with incoming rays, can potentially compensate for these parallax errors and thus improve the system resolution. We performed the first experimental evaluation of a newly developed focused-cut scintillator. We scanned a Tc-99m source across the field of view of pinhole gamma camera with a continuous scintillator, a conventional “straight-cut” (SC) pixellated scintillator, and a focused-cut scintillator, each coupled to an electron-multiplying charge coupled device (EMCCD) detector by a fiber-optic taper, and compared the measured full-width half-maximum (FWHM) values. We show that the FWHMs of the focused-cut scintillator projections are comparable to the FWHMs of the thinner SC scintillator, indicating the effectiveness of the focused-cut scintillator in compensating parallax errors. PMID:21731108
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yi, B; Xu, H; Mutaf, Y
2015-06-15
Purpose: Enable a scanning field total body irradiation (TBI) technique, using dynamic arcs, which is biologically equivalent to a moving couch TBI. Methods: Patient is treated slightly above the floor and the treatment field scans across the patient by a moving gantry. MLC positions change during gantry motion to keep same field opening at the level of the treatment plane (170 cm). This is done to mimic the same geometry as the moving couch TBI technique which has been used in our institution for over 10 years. The dose rate and the gantry speed are determined considering a constant speedmore » of the moving field, variations in SSD and slanted depths resulting from oblique gantry angles. An Eclipse (Varian) planning system is commissioned to accommodate the extended SSD. The dosimetric foundations of the technique have been thoroughly investigated using phantom measurements. Results: Dose uniformity better than 2% across 180 cm length at 10cm depth is achieved by moving the gantry from −55 to +55 deg. Treatment range can be extended by increasing gantry range. No device such as a gravity-oriented compensator is needed to achieve a uniform dose. It is feasible to modify the dose distribution by adjusting the dose rate at each gantry angle to compensate for body thickness differences. Total treatment time for 2 Gy AP/PA fields is 40–50 minutes excluding patient set up time, at the machine dose rate of 100 MU/min. Conclusion: This novel yet transportable moving field technique enables TBI treatment in a small treatment room with less program development preparation than other techniques. Treatment length can be extended per need, and. MLC-based thickness compensation and partial lung blocking are also possible.« less
Depth-of-Interaction Compensation Using a Focused-Cut Scintillator for a Pinhole Gamma Camera
NASA Astrophysics Data System (ADS)
Alhassen, Fares; Kudrolli, Haris; Singh, Bipin; Kim, Sangtaek; Seo, Youngho; Gould, Robert G.; Nagarkar, Vivek V.
2011-06-01
Preclinical SPECT offers a powerful means to understand the molecular pathways of drug interactions in animal models by discovering and testing new pharmaceuticals and therapies for potential clinical applications. A combination of high spatial resolution and sensitivity are required in order to map radiotracer uptake within small animals. Pinhole collimators have been investigated, as they offer high resolution by means of image magnification. One of the limitations of pinhole geometries is that increased magnification causes some rays to travel through the detection scintillator at steep angles, introducing parallax errors due to variable depth-of-interaction in scintillator material, especially towards the edges of the detector field of view. These parallax errors ultimately limit the resolution of pinhole preclinical SPECT systems, especially for higher energy isotopes that can easily penetrate through millimeters of scintillator material. A pixellated, focused-cut (FC) scintillator, with its pixels laser-cut so that they are collinear with incoming rays, can potentially compensate for these parallax errors and thus improve the system resolution. We performed the first experimental evaluation of a newly developed focused-cut scintillator. We scanned a Tc-99 m source across the field of view of pinhole gamma camera with a continuous scintillator, a conventional “straight-cut” (SC) pixellated scintillator, and a focused-cut scintillator, each coupled to an electron-multiplying charge coupled device (EMCCD) detector by a fiber-optic taper, and compared the measured full-width half-maximum (FWHM) values. We show that the FWHMs of the focused-cut scintillator projections are comparable to the FWHMs of the thinner SC scintillator, indicating the effectiveness of the focused-cut scintillator in compensating parallax errors.
An Overview of the CBERS-2 Satellite and Comparison of the CBERS-2 CCD Data with the L5 TM Data
NASA Technical Reports Server (NTRS)
Chandler, Gyanesh
2007-01-01
CBERS satellite carries on-board a multi sensor payload with different spatial resolutions and collection frequencies. HRCCD (High Resolution CCD Camera), IRMSS (Infrared Multispectral Scanner), and WFI (Wide-Field Imager). The CCD and the WFI camera operate in the VNIR regions, while the IRMSS operates in SWIR and thermal region. In addition to the imaging payload, the satellite carries a Data Collection System (DCS) and Space Environment Monitor (SEM).
Design of a CCD Camera for Space Surveillance
2016-03-05
Laboratory fabricated CCID-51M, a 2048x1024 pixel Charge Couple Device (CCD) imager. [1] The mission objective is to observe and detect satellites in...phased to transfer the charge to the outputs. An electronic shutter is created by having an equal area of pixels covered by an opaque metal mask. The...Figure 4 CDS Timing Diagram By design the CCD readout rate is 400 KHz. This rate was chosen so reading the 2E6 pixels from one output is less than
Perkins, David Nikolaus; Gonzales, Antonio I
2014-04-08
A set of co-registered coherent change detection (CCD) products is produced from a set of temporally separated synthetic aperture radar (SAR) images of a target scene. A plurality of transformations are determined, which transformations are respectively for transforming a plurality of the SAR images to a predetermined image coordinate system. The transformations are used to create, from a set of CCD products produced from the set of SAR images, a corresponding set of co-registered CCD products.
NASA Astrophysics Data System (ADS)
Lyuty, V. M.; Abdullayev, B. I.; Alekberov, I. A.; Gulmaliyev, N. I.; Mikayilov, Kh. M.; Rustamov, B. N.
2009-12-01
Short description of optical and electric scheme of CCD photometer with camera U-47 installed on the Cassegrain focus of ZEISS-600 telescope of the ShAO NAS Azerbaijan is provided. The reducer of focus with factor of reduction 1.7 is applied. It is calculated equivalent focal distances of a telescope with a focus reducer. General calculations of optimum distance from focal plane and t sizes of optical filters of photometer are presented.
Development of CCD imaging sensors for space applications, phase 1
NASA Technical Reports Server (NTRS)
Antcliffe, G. A.
1975-01-01
The results of an experimental investigation to develop a large area charge coupled device (CCD) imager for space photography applications are described. Details of the design and processing required to achieve 400 X 400 imagers are presented together with a discussion of the optical characterization techniques developed for this program. A discussion of several aspects of large CCD performance is given with detailed test reports. The areas covered include dark current, uniformity of optical response, square wave amplitude response, spectral responsivity and dynamic range.
Tidemand, Kasper D; Schönbeck, Christian; Holm, René; Westh, Peter; Peters, Günther H
2014-09-18
The inclusion complexes of glycoconjugated bile salts with β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrins (HP-β-CD) in aqueous solution were investigated by molecular dynamics simulations to provide a molecular explanation of the experimentally observed destabilizing effect of the HP substituents. Good agreement with experimental data was found with respect to penetration depths of CDs. An increased degree of HP substitution (DS) resulted in an increased probability of blocking the cavity opening, thereby hindering the bile salt from entering CD. Further, the residence time of water molecules in the cavity increased with the DS. Release of water from the cavity resulted in a positive enthalpy change, which correlates qualitatively with the experimentally determined increase in complexation enthalpy and contributes to the enthalpy-entropy compensation. The positive change in complexation entropy with DS was not able to compensate for this unfavorable change in enthalpy induced by the HP substituents, resulting in a destabilizing effect. This was found to originate from fixation of the HP substituents and decreased free rotation of the bile salts within the CD cavities.
Banyini, Audrey V.; Rees, David; Gilbert, Leah
2013-01-01
Context In the South African mining sector, cardiorespiratory-specific autopsies are conducted under the Occupational Diseases in Mines and Works Act (ODMWA) on deceased mineworkers to determine eligibility for compensation. However, low levels of autopsy utilisation undermine the value of the service. Objective To explore enablers and barriers to consent that impact on ODMWA autopsy utilisation for posthumous monetary compensation. Methods In-depth interviews were conducted with mineworkers, widows and relatives of deceased mineworkers as well as traditional healers and mine occupational health practitioners. Results A range of socio-cultural barriers to consent for an autopsy was identified. These barriers were largely related to gendered power relations, traditional and religious beliefs, and communication and trust. Understanding these barriers presents opportunities to intervene so as to increase autopsy utilisation. Conclusions Effective interventions could include engagement with healthy mine-workers and their families and re-evaluating the permanent removal of organs. The study adds to our understanding of utilisation of the autopsy services. PMID:23364088
Are we fully utilizing the functionalities of modern operating room ventilators?
Liu, Shujie; Kacmarek, Robert M; Oto, Jun
2017-12-01
The modern operating room ventilators have become very sophisticated and many of their features are comparable with those of an ICU ventilator. To fully utilize the functionality of modern operating room ventilators, it is important for clinicians to understand in depth the working principle of these ventilators and their functionalities. Piston ventilators have the advantages of delivering accurate tidal volume and certain flow compensation functions. Turbine ventilators have great ability of flow compensation. Ventilation modes are mainly volume-based or pressure-based. Pressure-based ventilation modes provide better leak compensation than volume-based. The integration of advanced flow generation systems and ventilation modes of the modern operating room ventilators enables clinicians to provide both invasive and noninvasive ventilation in perioperative settings. Ventilator waveforms can be used for intraoperative neuromonitoring during cervical spine surgery. The increase in number of new features of modern operating room ventilators clearly creates the opportunity for clinicians to optimize ventilatory care. However, improving the quality of ventilator care relies on a complete understanding and correct use of these new features. VIDEO ABSTRACT: http://links.lww.com/COAN/A47.
Vail, W.B. III.
1991-12-24
Methods of operation are described for an apparatus having at least two pairs of voltage measurement electrodes vertically disposed in a cased well to measure the resistivity of adjacent geological formations from inside the cased well. During stationary measurements with the apparatus at a fixed vertical depth within the cased well, the invention herein discloses methods of operation which include a measurement step and subsequent first and second compensation steps respectively resulting in improved accuracy of measurement. The invention also discloses multiple frequency methods of operation resulting in improved accuracy of measurement while the apparatus is simultaneously moved vertically in the cased well. The multiple frequency methods of operation disclose a first A.C. current having a first frequency that is conducted from the casing into formation and a second A.C. current having a second frequency that is conducted along the casing. The multiple frequency methods of operation simultaneously provide the measurement step and two compensation steps necessary to acquire accurate results while the apparatus is moved vertically in the cased well. 6 figures.
Vail, III, William B.
1991-01-01
Methods of operation of an apparatus having at least two pairs of voltage measurement electrodes vertically disposed in a cased well to measure the resistivity of adjacent geological formations from inside the cased well. During stationary measurements with the apparatus at a fixed vertical depth within the cased well, the invention herein discloses methods of operation which include a measurement step and subsequent first and second compensation steps respectively resulting in improved accuracy of measurement. The invention also discloses multiple frequency methods of operation resulting in improved accuracy of measurement while the apparatus is simultaneously moved vertically in the cased well. The multiple frequency methods of operation disclose a first A.C. current having a first frequency that is conducted from the casing into formation and a second A.C. current having a second frequency that is conducted along the casing. The multiple frequency methods of operation simultaneously provide the measurement step and two compensation steps necessary to acquire accurate results while the apparatus is moved vertically in the cased well.
NASA Astrophysics Data System (ADS)
Bailey, M.; Shipley, D. R.; Manning, J. W.
2015-02-01
Empirical fits are developed for depth-compensated wall- and cavity-replacement perturbations in the PTW Roos 34001 and IBA / Scanditronix NACP-02 parallel-plate ionisation chambers, for electron beam qualities from 4 to 22 MeV for depths up to approximately 1.1 × R50,D. These are based on calculations using the Monte Carlo radiation transport code EGSnrc and its user codes with a full simulation of the linac treatment head modelled using BEAMnrc. These fits are used with calculated restricted stopping-power ratios between air and water to match measured depth-dose distributions in water from an Elekta Synergy clinical linear accelerator at the UK National Physical Laboratory. Results compare well with those from recent publications and from the IPEM 2003 electron beam radiotherapy Code of Practice.
NASA Astrophysics Data System (ADS)
Radhakrishna, M.; Searle, R. C.
2006-04-01
The Alula-Fartak and Owen transforms are the active parts of major fracture zones with a distinct topographic expression in the Eastern Gulf of Aden and the Arabian Sea, respectively. While the Alula-Fartak transform offsets the Sheba Ridge by about 180 km and is associated with a broad steep-sided valley with a relief of nearly 3.5 km, the Owen transform offsets the Carlsberg Ridge by nearly 300 km and is associated with a broad step-like valley surrounded by deeper water depths. The gravity and topography data along several profiles selected across these two transforms have been analysed using cross-spectral analysis in order to investigate their isostatic compensation. The observed admittance estimates have been compared with three theoretical isostatic compensation models, two local compensation models (Airy I and II) and one regional compensation (plate) model. Comparing the longer wavelength admittance estimates suggests that the regional compensation model gives the best fit for both the Alula-Fartak transform and the Owen transform, with effective elastic thickness (Te) of 5 km and slightly less than 10 km, respectively. For the Alula-Fartak transform, the Airy II model might also be acceptable, though with large scatter in the observed values: it suggests a mean value of 9 km for the mantle layer with a 6 km thick crust. For the Owen transform, on the other hand, the two local compensation models failed. The difference in Te estimate between the two transforms could be ascribed to differences in thermal structure arising from their varied tectonic history. A comparison with the isostatic response estimates of transform/fracture zones along the slow-spreading Mid-Atlantic Ridge suggests that the regional compensation model is generally applicable for transform/fracture zone topography along such mid-ocean ridges.
An integrated optical sensor for GMAW feedback control
DOE Office of Scientific and Technical Information (OSTI.GOV)
Taylor, P.L.; Watkins, A.D.; Larsen, E.D.
1992-08-01
The integrated optical sensor (IOS) is a multifunction feedback control sensor for arc welding, that is computer automated and independent of significant operator interaction. It is based on three major ``off-the-shelf`` components: a charged coupled device (CCD) camera, a diode laser, and a processing computer. The sensor head is compact and lightweight to avoid interference with weld head mobility, hardened to survive the harsh operating environment, and free of specialized cooling and power requirements. The sensor is positioned behind the GMAW torch and measures weld pool position and width, standoff distance, and postweld centerline cooling rate. Weld pool position andmore » width are used in a feedback loop, by the weld controller, to track the weld pool relative to the weld joint, thus allowing compensation for such phenomena as arc blow. Sensor stand off distance is used in a feedback loop to control the contact tip to base metal distance during the welding process. Cooling rate information is used to infer the final metallurgical state of the weld bead and heat affected zone, thereby providing a means of controlling post weld mechanical properties.« less
An integrated optical sensor for GMAW feedback control
DOE Office of Scientific and Technical Information (OSTI.GOV)
Taylor, P.L.; Watkins, A.D.; Larsen, E.D.
1992-01-01
The integrated optical sensor (IOS) is a multifunction feedback control sensor for arc welding, that is computer automated and independent of significant operator interaction. It is based on three major off-the-shelf'' components: a charged coupled device (CCD) camera, a diode laser, and a processing computer. The sensor head is compact and lightweight to avoid interference with weld head mobility, hardened to survive the harsh operating environment, and free of specialized cooling and power requirements. The sensor is positioned behind the GMAW torch and measures weld pool position and width, standoff distance, and postweld centerline cooling rate. Weld pool position andmore » width are used in a feedback loop, by the weld controller, to track the weld pool relative to the weld joint, thus allowing compensation for such phenomena as arc blow. Sensor stand off distance is used in a feedback loop to control the contact tip to base metal distance during the welding process. Cooling rate information is used to infer the final metallurgical state of the weld bead and heat affected zone, thereby providing a means of controlling post weld mechanical properties.« less
WINDII, the wind imaging interferometer on the Upper Atmosphere Research Satellite
NASA Technical Reports Server (NTRS)
Shepherd, G. G.; Thuillier, G.; Gault, W. A.; Solheim, B. H.; Hersom, C.; Alunni, J. M.; Brun, J.-F.; Brune, S.; Charlot, P.; Cogger, L. L.
1993-01-01
The WIND imaging interferometer (WINDII) was launched on the Upper Atmosphere Research Satellite (UARS) on September 12, 1991. This joint project, sponsored by the Canadian Space Agency and the French Centre National d'Etudes Spatiales, in collaboration with NASA, has the responsibility of measuring the global wind pattern at the top of the altitude range covered by UARS. WINDII measures wind, temperature, and emission rate over the altitude range 80 to 300 km by using the visible region airglow emission from these altitudes as a target and employing optical Doppler interferometry to measure the small wavelength shifts of the narrow atomic and molecular airglow emission lines induced by the bulk velocity of the atmosphere carrying the emitting species. The instrument used is an all-glass field-widened achromatically and thermally compensated phase-stepping Michelson interferometer, along with a bare CCD detector that images the airglow limb through the interferometer. A sequence of phase-stepped images is processed to derive the wind velocity for two orthogonal view directions, yielding the vector horizontal wind. The process of data analysis, including the inversion of apparent quantities to vertical profiles, is described.
Studies on space charge neutralization and emittance measurement of beam from microwave ion source.
Misra, Anuraag; Goswami, A; Sing Babu, P; Srivastava, S; Pandit, V S
2015-11-01
A 2.45 GHz microwave ion source together with a beam transport system has been developed at VECC to study the problems related with the injection of high current beam into a compact cyclotron. This paper presents the results of beam profile measurement of high current proton beam at different degrees of space charge neutralisation with the introduction of neon gas in the beam line using a fine leak valve. The beam profiles have been measured at different pressures in the beam line by capturing the residual gas fluorescence using a CCD camera. It has been found that with space charge compensation at the present current level (∼5 mA at 75 keV), it is possible to reduce the beam spot size by ∼34%. We have measured the variation of beam profile as a function of the current in the solenoid magnet under the neutralised condition and used these data to estimate the rms emittance of the beam. Simulations performed using equivalent Kapchinsky-Vladimirsky beam envelope equations with space charge neutralization factor are also presented to interpret the experimental results.
Studies on space charge neutralization and emittance measurement of beam from microwave ion source
NASA Astrophysics Data System (ADS)
Misra, Anuraag; Goswami, A.; Sing Babu, P.; Srivastava, S.; Pandit, V. S.
2015-11-01
A 2.45 GHz microwave ion source together with a beam transport system has been developed at VECC to study the problems related with the injection of high current beam into a compact cyclotron. This paper presents the results of beam profile measurement of high current proton beam at different degrees of space charge neutralisation with the introduction of neon gas in the beam line using a fine leak valve. The beam profiles have been measured at different pressures in the beam line by capturing the residual gas fluorescence using a CCD camera. It has been found that with space charge compensation at the present current level (˜5 mA at 75 keV), it is possible to reduce the beam spot size by ˜34%. We have measured the variation of beam profile as a function of the current in the solenoid magnet under the neutralised condition and used these data to estimate the rms emittance of the beam. Simulations performed using equivalent Kapchinsky-Vladimirsky beam envelope equations with space charge neutralization factor are also presented to interpret the experimental results.
2-COLOR Pupil Imaging Method to Detect Stellar Oscillations
NASA Astrophysics Data System (ADS)
Costantino, Sigismondi; Alessandro, Cacciani; Mauro, Dolci; Stuart, Jeffries; Eric, Fossat; Ludovico, Cesario; Paolo, Rapex; Luca, Bertello; Ferenc, Varadi; Wolfgang, Finsterle
Stellar intensity oscillations from the ground are strongly affected by atmospheric noise. For solar-type stars even Antarctic scintillation noise is still overwhelming. We proposed and tested a differential method that images on the same CCD detector two-color pupils of the telescope in order to compensate for intensity sky fluctuations guiding and saturation problems. SOHO data reveal that our method has an efficiency of 70% respect to the absolute amplitude variations. Using two instruments at Dome C and South Pole we can further minimize atmospheric color noise with cross-spectrum methods. This way we also decrease the likelihood of gaps in the data string due to bad weather. Observationally while waiting for the South Pole/Dome-C sites we are carrying on tests from available telescopes and Big Bear Mt. Wilson Teramo Milano. On the data analysis side we use the Random Lag Singular Cross-Spectrum Analysis which eliminates noise from the observed signal better than traditional Fourier transform. This method is also well-suited for extracting common oscillatory components from two or more observations including their relative phases as we are planning to do
The MROI fast tip-tilt correction and target acquisition system
NASA Astrophysics Data System (ADS)
Young, John; Buscher, David; Fisher, Martin; Haniff, Christopher; Rea, Alexander; Seneta, Eugene B.; Sun, Xiaowei; Wilson, Donald; Farris, Allen; Olivares, Andres; Selina, Robert
2012-07-01
The fast tip-tilt correction system for the Magdalena Ridge Observatory Interferometer (MROI) is being designed and fabricated by the University of Cambridge. The design of the system is currently at an advanced stage and the performance of its critical subsystems has been verified in the laboratory. The system has been designed to meet a demanding set of specifications including satisfying all performance requirements in ambient temperatures down to -5 °C, maintaining the stability of the tip-tilt fiducial over a 5 °C temperature change without recourse to an optical reference, and a target acquisition mode with a 60” field-of-view. We describe the important technical features of the system, which uses an Andor electron-multiplying CCD camera protected by a thermal enclosure, a transmissive optical system with mounts incorporating passive thermal compensation, and custom control software running under Xenomai real-time Linux. We also report results from laboratory tests that demonstrate (a) the high stability of the custom optic mounts and (b) the low readout and compute latencies that will allow us to achieve a 40 Hz closed-loop bandwidth on bright targets.
Accurate attitude determination of the LACE satellite
NASA Technical Reports Server (NTRS)
Miglin, M. F.; Campion, R. E.; Lemos, P. J.; Tran, T.
1993-01-01
The Low-power Atmospheric Compensation Experiment (LACE) satellite, launched in February 1990 by the Naval Research Laboratory, uses a magnetic damper on a gravity gradient boom and a momentum wheel with its axis perpendicular to the plane of the orbit to stabilize and maintain its attitude. Satellite attitude is determined using three types of sensors: a conical Earth scanner, a set of sun sensors, and a magnetometer. The Ultraviolet Plume Instrument (UVPI), on board LACE, consists of two intensified CCD cameras and a gimbal led pointing mirror. The primary purpose of the UVPI is to image rocket plumes from space in the ultraviolet and visible wavelengths. Secondary objectives include imaging stars, atmospheric phenomena, and ground targets. The problem facing the UVPI experimenters is that the sensitivity of the LACF satellite attitude sensors is not always adequate to correctly point the UVPI cameras. Our solution is to point the UVPI cameras at known targets and use the information thus gained to improve attitude measurements. This paper describes the three methods developed to determine improved attitude values using the UVPI for both real-time operations and post observation analysis.
Experimental research on femto-second laser damaging array CCD cameras
NASA Astrophysics Data System (ADS)
Shao, Junfeng; Guo, Jin; Wang, Ting-feng; Wang, Ming
2013-05-01
Charged Coupled Devices (CCD) are widely used in military and security applications, such as airborne and ship based surveillance, satellite reconnaissance and so on. Homeland security requires effective means to negate these advanced overseeing systems. Researches show that CCD based EO systems can be significantly dazzled or even damaged by high-repetition rate pulsed lasers. Here, we report femto - second laser interaction with CCD camera, which is probable of great importance in future. Femto - second laser is quite fresh new lasers, which has unique characteristics, such as extremely short pulse width (1 fs = 10-15 s), extremely high peak power (1 TW = 1012W), and especially its unique features when interacting with matters. Researches in femto second laser interaction with materials (metals, dielectrics) clearly indicate non-thermal effect dominates the process, which is of vast difference from that of long pulses interaction with matters. Firstly, the damage threshold test are performed with femto second laser acting on the CCD camera. An 800nm, 500μJ, 100fs laser pulse is used to irradiate interline CCD solid-state image sensor in the experiment. In order to focus laser energy onto tiny CCD active cells, an optical system of F/5.6 is used. A Sony production CCDs are chose as typical targets. The damage threshold is evaluated with multiple test data. Point damage, line damage and full array damage were observed when the irradiated pulse energy continuously increase during the experiment. The point damage threshold is found 151.2 mJ/cm2.The line damage threshold is found 508.2 mJ/cm2.The full-array damage threshold is found to be 5.91 J/cm2. Although the phenomenon is almost the same as that of nano laser interaction with CCD, these damage thresholds are substantially lower than that of data obtained from nano second laser interaction with CCD. Then at the same time, the electric features after different degrees of damage are tested with electronic multi meter. The resistance values between clock signal lines are measured. Contrasting the resistance values of the CCD before and after damage, it is found that the resistances decrease significantly between the vertical transfer clock signal lines values. The same results are found between the vertical transfer clock signal line and the earth electrode (ground).At last, the damage position and the damage mechanism were analyzed with above results and SEM morphological experiments. The point damage results in the laser destroying material, which shows no macro electro influence. The line damage is quite different from that of point damage, which shows deeper material corroding effect. More importantly, short circuits are found between vertical clock lines. The full array damage is even more severe than that of line damage starring with SEM, while no obvious different electrical features than that of line damage are found. Further researches are anticipated in femto second laser caused CCD damage mechanism with more advanced tools. This research is valuable in EO countermeasure and/or laser shielding applications.
Total Dissolved Gas Monitoring in Chum Salmon Spawning Gravels Below Bonneville Dam
DOE Office of Scientific and Technical Information (OSTI.GOV)
Arntzen, Evan V.; Geist, David R.; Panther, Jennifer L.
2007-01-30
At the request of the U.S. Army Corps of Engineers (Portland District), Pacific Northwest National Laboratory (PNNL) conducted research to determine whether total dissolved gas concentrations are elevated in chum salmon redds during spring spill operations at Bonneville Dam. The study involved monitoring the total dissolved gas levels at egg pocket depth and in the river at two chum salmon spawning locations downstream from Bonneville Dam. Dissolved atmospheric gas supersaturation generated by spill from Bonneville Dam may diminish survival of chum (Oncorhynchus keta) salmon when sac fry are still present in the gravel downstream from Bonneville Dam. However, no previousmore » work has been conducted to determine whether total dissolved gas (TDG) levels are elevated during spring spill operations within incubation habitats. The guidance used by hydropower system managers to provide protection for pre-emergent chum salmon fry has been to limit TDG to 105% after allowing for depth compensation. A previous literature review completed in early 2006 shows that TDG levels as low as 103% have been documented to cause mortality in sac fry. Our study measured TDG in the incubation environment to evaluate whether these levels were exceeded during spring spill operations. Total dissolved gas levels were measured within chum salmon spawning areas near Ives Island and Multnomah Falls on the Columbia River. Water quality sensors screened at egg pocket depth and to the river were installed at both sites. At each location, we also measured dissolved oxygen, temperature, specific conductance, and water depth to assist with the interpretation of TDG results. Total dissolved gas was depth-compensated to determine when levels were high enough to potentially affect sac fry. This report provides detailed descriptions of the two study sites downstream of Bonneville Dam, as well as the equipment and procedures employed to monitor the TDG levels at the study sites. Results of the monitoring at both sites are then presented in both text and graphics. The findings and recommendations for further research are discussed, followed by a listing of the references cited in the report.« less
CCD Times of Minima of Selected Eclipsing Binaries
NASA Astrophysics Data System (ADS)
Zejda, Miloslav
2004-12-01
682 CCD minima observations of 259 eclipsing binaries made mainly by author are presented. The observed stars were chosen mainly from catalogue BRKA of observing programme of BRNO-Variable Star Section of CAS.
Modeling colony collapse disorder in honeybees as a contagion.
Kribs-Zaleta, Christopher M; Mitchell, Christopher
2014-12-01
Honeybee pollination accounts annually for over $14 billion in United States agriculture alone. Within the past decade there has been a mysterious mass die-off of honeybees, an estimated 10 million beehives and sometimes as much as 90% of an apiary. There is still no consensus on what causes this phenomenon, called Colony Collapse Disorder, or CCD. Several mathematical models have studied CCD by only focusing on infection dynamics. We created a model to account for both healthy hive dynamics and hive extinction due to CCD, modeling CCD via a transmissible infection brought to the hive by foragers. The system of three ordinary differential equations accounts for multiple hive population behaviors including Allee effects and colony collapse. Numerical analysis leads to critical hive sizes for multiple scenarios and highlights the role of accelerated forager recruitment in emptying hives during colony collapse.
NASA Technical Reports Server (NTRS)
Gassaway, J. D.
1976-01-01
Two approaches have been taken to study CCD's and some of their fundamental limitations. First a numerical analysis approach has been developed to solve the coupled transport and Poisson's equation for a thorough analysis of charge transfer in a CCD structure. The approach is formulated by treating the minority carriers as a surface distribution at the Si-SiO2 interface and setting up coupled difference equations for the charge and the potential. The SOR method is proposed for solving the two dimensional Poisson's equation for the potential. Methods are suggested for handling the discontinuities to improve convergence. Second, CCD shift registers were fabricated with parameters which should allow complete charge transfer independent of the transfer electrode gap width. A test instrument was designed and constructed which can be used to test this, or any similar, three phase CCD shift register.
NASA Astrophysics Data System (ADS)
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.
Noise analysis for CCD-based ultraviolet and visible spectrophotometry.
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.
Realization of Vilnius UPXYZVS photometric system for AltaU42 CCD camera at the MAO NAS of Ukraine
NASA Astrophysics Data System (ADS)
Vid'Machenko, A. P.; Andruk, V. M.; Samoylov, V. S.; Delets, O. S.; Nevodovsky, P. V.; Ivashchenko, Yu. M.; Kovalchuk, G. U.
2005-06-01
The description of two-inch glass filters of the Vilnius UPXYZVS photometric system, which are made at the Main Astronomical Observatory of NAS of Ukraine for AltaU42 CCD camera with format of 2048×2048 pixels, is presented in the paper. Reaction curves of instrumental system are shown. Estimations of minimal star's magnitudes for each filter's band in comparison with the visual V one are obtained. New software for automation of CCD frames processing is developed in program shell of LINUX/MIDAS/ROMAFOT. It is planned to carry out observations with the purpose to create the catalogue of primary UPXYZVS CCD standards in selected field of the sky for some radio-sources, globular and open clusters, etc. Numerical estimations of astrometric and photometric accuracy are obtained.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aoyagi, Yasuyuki; Department of Genome Research and Clinical Application, Graduate School of Medicine, Chiba University, Chiba; Kuroda, Masayuki, E-mail: kurodam@faculty.chiba-u.jp
Adipose tissue is expected to provide a source of cells for protein replacement therapies via auto-transplantation. However, the conditioning of the environment surrounding the transplanted adipocytes for their long-term survival and protein secretion properties has not been established. We have recently developed a preparation procedure for preadipocytes, ceiling culture-derived proliferative adipocytes (ccdPAs), as a therapeutic gene vehicle suitable for stable gene product secretion. We herein report the results of our evaluation of using fibrin glue as a scaffold for the transplanted ccdPAs for the expression of a transduced gene in a three-dimensional culture system. The ccdPAs secreted the functional proteinmore » translated from an exogenously transduced gene, as well as physiological adipocyte proteins, and the long viability of ccdPAs (up to 84 days) was dependent on the fibrinogen concentrations. The ccdPAs spontaneously accumulated lipid droplets, and their expression levels of the transduced exogenous gene with its product were maintained for at least 56 days. The fibrinogen concentration modified the adipogenic differentiation of ccdPAs and their exogenous gene expression levels, and the levels of exogenously transduced gene expression at the different fibrinogen concentrations were dependent on the extent of adipogenic differentiation in the gel. These results indicate that fibrin glue helps to maintain the high adipogenic potential of cultured adipocytes after passaging in a 3D culture system, and suggests that once they are successfully implanted at the transplantation site, the cells exhibit increased expression of the transduced gene with adipogenic differentiation.« less
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.
Lopatiuk-Tirpak, O; Su, Z; Hsi, W; Zeidan, O; Meeks, S
2012-06-01
to present and validate a method for modeling three-dimensional positron emission (PE) activity distributions induced by proton beam irradiation for PET/CT delivery verification studies in homogeneous media. the method relies on modeling the 3D proton flux distribution by combining the analytical expression for the depth reduction of proton flux with the empirically obtained lateral distribution. The latter is extracted from the corresponding dose distribution under the assumption that the projectile energy is nearly constant in the lateral plane. The same assumption allows calculating the 3D induced activity distributions from proton flux distributions by parameterizing the energy-dependent activation cross-sections in terms of depth via the energy-range relation. Results of this modeling approach were validated against experimental PET/CT data from three phantom deliveries: unmodulated (pristine) beam, spread-out Bragg peak (SOBP) delivery without a range compensator, and SOBP with a range compensator. BANG3-Pro2 polymer gel was used as a phantom material because of its elemental soft-tissue equivalence. the agreement between modeled and measured activity distributions was evaluated using 3D gamma index analysis method, which, despite being traditionally reserved for dose distribution comparisons, is sufficiently general to be applied to other quantities. The evaluation criteria were dictated by limitations of PET imaging and were chosen to correspond to count rate uncertainty (6% value difference) and spatial resolution (4 mm distance to agreement). With these criteria and the threshold of 6%, the fraction of evaluated voxels passing the gamma evaluation was 97.9% for the pristine beam, 98.9% for the SOBP without compensator, and 98.5% for SOBP with compensator. results of gamma evaluation indicate that the activity distributions produced by the model are consistent with experimental data within the uncertainties of PET imaging for clinical proton beams deliveries. This work was supported by the Bankhead-Coley Florida Biomedical Research Program under Grant No. 1BD10-34212. © 2012 American Association of Physicists in Medicine.
Development of a Magnetic Nanoparticle Susceptibility Magnitude Imaging Array
Ficko, Bradley W.; Nadar, Priyanka M.; Hoopes, P. Jack; Diamond, Solomon G.
2014-01-01
There are several emerging diagnostic and therapeutic applications of magnetic nanoparticles (mNPs) in medicine. This study examines the potential for developing an mNP imager that meets these emerging clinical needs with a low cost imaging solution that uses arrays of digitally controlled drive coils in a multiple-frequency, continuous-wave operating mode and compensated fluxgate magnetometers. The design approach is described and a mathematical model is developed to support measurement and imaging. A prototype is used to demonstrate active compensation of up to 185 times the primary applied magnetic field, depth sensitivity up to 2.5 cm (p < 0.01), and linearity over 5 dilutions (R2 > 0.98, p <0.001). System frequency responses show distinguishable readouts for iron oxide mNPs with single magnetic domain core diameters of 10 nm and 40 nm, and multi-domain mNPs with a hydrodynamic diameter of 100 nm. Tomographic images show a contrast-to-noise ratio of 23 for 0.5 ml of 12.5 mg Fe/ml mNPs at 1 cm depth. A demonstration involving the injection of mNPs into pork sausage shows the potential for use in biological systems. These results indicate that the proposed mNP imaging approach can potentially be extended to a larger array system with higher-resolution. PMID:24504184
NASA Astrophysics Data System (ADS)
Ma, Zhichao; Hu, Leilei; Zhao, Hongwei; Wu, Boda; Peng, Zhenxing; Zhou, Xiaoqin; Zhang, Hongguo; Zhu, Shuai; Xing, Lifeng; Hu, Huang
2010-08-01
The theories and techniques for improving machining accuracy via position control of diamond tool's tip and raising resolution of cutting depth on precise CNC lathes have been extremely focused on. A new piezo-driven ultra-precision machine tool servo system is designed and tested to improve manufacturing accuracy of workpiece. The mathematical model of machine tool servo system is established and the finite element analysis is carried out on parallel plate flexure hinges. The output position of diamond tool's tip driven by the machine tool servo system is tested via a contact capacitive displacement sensor. Proportional, integral, derivative (PID) feedback is also implemented to accommodate and compensate dynamical change owing cutting forces as well as the inherent non-linearity factors of the piezoelectric stack during cutting process. By closed loop feedback controlling strategy, the tracking error is limited to 0.8 μm. Experimental results have shown the proposed machine tool servo system could provide a tool positioning resolution of 12 nm, which is much accurate than the inherent CNC resolution magnitude. The stepped shaft of aluminum specimen with a step increment of cutting depth of 1 μm is tested, and the obtained contour illustrates the displacement command output from controller is accurately and real-time reflected on the machined part.
Concept for tremor compensation for a handheld OCT-laryngoscope
NASA Astrophysics Data System (ADS)
Donner, Sabine; Deutsch, Stefanie; Bleeker, Sebastian; Ripken, Tammo; Krüger, Alexander
2013-06-01
Optical coherence tomography (OCT) is a non-invasive imaging technique which can create optical tissue sections, enabling diagnosis of vocal cord tissue. To take full advantage from the non-contact imaging technique, OCT was adapted to an indirect laryngoscope to work on awake patients. Using OCT in a handheld diagnostic device the challenges of rapid working distance adjustment and tracking of axial motion arise. The optical focus of the endoscopic sample arm and the reference-arm length can be adjusted in a range of 40 mm to 90 mm. Automatic working distance adjustment is based on image analysis of OCT B-scans which identifies off depth images as well as position errors. The movable focal plane and reference plane are used to adjust working distance to match the sample depth and stabilise the sample in the desired axial position of the OCT scans. The autofocus adjusts the working distance within maximum 2.7 seconds for the maximum initial displacement of 40 mm. The amplitude of hand tremor during 60 s handheld scanning was reduced to 50 % and it was shown that the image stabilisation keeps the position error below 0.5 mm. Fast automatic working distance adjustment is crucial to minimise the duration of the diagnostic procedure. The image stabilisation compensates relative axial movements during handheld scanning.
Xue, Jingyuan; Huo, Zailin; Wang, Fengxin; Kang, Shaozhong; Huang, Guanhua
2018-04-01
Water scarcity and salt stress are two main limitations for agricultural production. Groundwater evapotranspiration (ET g ) with upward salt movement plays an important role in crop water use and water productivity in arid regions, and it can compensate the impact of deficit irrigation on crop production. Thus, comprehensive impacts of shallow groundwater and deficit irrigation on crop water use results in an improvement of irrigation water productivity (IWP). However, it is difficult to quantify the effects of groundwater and deficit irrigation on IWP. In this study, we built an IWP evaluation model coupled with a water and salt balance model and a crop yield estimation model. As a valuable tool of IWP simulation, the calibrated model was used to investigate the coupling response of sunflower IWP to irrigation water depths (IWDs), groundwater table depth (GTDs) and groundwater salinities (GSs). A total of 210 scenarios were run in which five irrigation water depths (IWDs) and seven groundwater table depths (GTDs) and six groundwater salinities (GSs) were used. Results indicate that increasing GS clearly increases the negative effect on a crop's actual evapotranspiration (ET a ) as salt accumulation in root zone. When GS is low (0.5-1g/L), increasing GTD produces more positive effect than negative effect. In regard to relatively high GS (2-5g/L), the negative effect of shallow-saline groundwater reaches a maximum at 2m GTD. Additionally, the salt concentration in the root zone maximizes its value at 2.0m GTD. In most cases, increasing GTD and GS reduces the benefits of irrigation water and IWP. The IWP increases with decreasing irrigation water. Overall, in arid regions, capillary rise of shallow groundwater can compensate for the lack of irrigation water and improve IWP. By improving irrigation schedules and taking advantages of shallow saline groundwater, we can obtain higher IWP. Copyright © 2017 Elsevier B.V. All rights reserved.
Integrated Dual Imaging Detector
NASA Technical Reports Server (NTRS)
Rust, David M.
1999-01-01
A new type of image detector was designed to simultaneously analyze the polarization of light at all picture elements in a scene. The integrated Dual Imaging detector (IDID) consists of a lenslet array and a polarizing beamsplitter bonded to a commercial charge coupled device (CCD). The IDID simplifies the design and operation of solar vector magnetographs and the imaging polarimeters and spectroscopic imagers used, for example, in atmosphere and solar research. When used in a solar telescope, the vector magnetic fields on the solar surface. Other applications include environmental monitoring, robot vision, and medical diagnoses (through the eye). Innovations in the IDID include (1) two interleaved imaging arrays (one for each polarization plane); (2) large dynamic range (well depth of 10(exp 5) electrons per pixel); (3) simultaneous readout and display of both images; and (4) laptop computer signal processing to produce polarization maps in field situations.
Westbrook, John D; Shao, Chenghua; Feng, Zukang; Zhuravleva, Marina; Velankar, Sameer; Young, Jasmine
2015-04-15
The Chemical Component Dictionary (CCD) is a chemical reference data resource that describes all residue and small molecule components found in Protein Data Bank (PDB) entries. The CCD contains detailed chemical descriptions for standard and modified amino acids/nucleotides, small molecule ligands and solvent molecules. Each chemical definition includes descriptions of chemical properties such as stereochemical assignments, chemical descriptors, systematic chemical names and idealized coordinates. The content, preparation, validation and distribution of this CCD chemical reference dataset are described. The CCD is updated regularly in conjunction with the scheduled weekly release of new PDB structure data. The CCD and amino acid variant reference datasets are hosted in the public PDB ftp repository at ftp://ftp.wwpdb.org/pub/pdb/data/monomers/components.cif.gz, ftp://ftp.wwpdb.org/pub/pdb/data/monomers/aa-variants-v1.cif.gz, and its mirror sites, and can be accessed from http://wwpdb.org. jwest@rcsb.rutgers.edu. Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
GPS-CCD: A Novel Computational Program for the Prediction of Calpain Cleavage Sites
Gao, Xinjiao; Ma, Qian; Ren, Jian; Xue, Yu
2011-01-01
As one of the most essential post-translational modifications (PTMs) of proteins, proteolysis, especially calpain-mediated cleavage, plays an important role in many biological processes, including cell death/apoptosis, cytoskeletal remodeling, and the cell cycle. Experimental identification of calpain targets with bona fide cleavage sites is fundamental for dissecting the molecular mechanisms and biological roles of calpain cleavage. In contrast to time-consuming and labor-intensive experimental approaches, computational prediction of calpain cleavage sites might more cheaply and readily provide useful information for further experimental investigation. In this work, we constructed a novel software package of GPS-CCD (Calpain Cleavage Detector) for the prediction of calpain cleavage sites, with an accuracy of 89.98%, sensitivity of 60.87% and specificity of 90.07%. With this software, we annotated potential calpain cleavage sites for hundreds of calpain substrates, for which the exact cleavage sites had not been previously determined. In this regard, GPS-CCD 1.0 is considered to be a useful tool for experimentalists. The online service and local packages of GPS-CCD 1.0 were implemented in JAVA and are freely available at: http://ccd.biocuckoo.org/. PMID:21533053
3D morphology reconstruction using linear array CCD binocular stereo vision imaging system
NASA Astrophysics Data System (ADS)
Pan, Yu; Wang, Jinjiang
2018-01-01
Binocular vision imaging system, which has a small field of view, cannot reconstruct the 3-D shape of the dynamic object. We found a linear array CCD binocular vision imaging system, which uses different calibration and reconstruct methods. On the basis of the binocular vision imaging system, the linear array CCD binocular vision imaging systems which has a wider field of view can reconstruct the 3-D morphology of objects in continuous motion, and the results are accurate. This research mainly introduces the composition and principle of linear array CCD binocular vision imaging system, including the calibration, capture, matching and reconstruction of the imaging system. The system consists of two linear array cameras which were placed in special arrangements and a horizontal moving platform that can pick up objects. The internal and external parameters of the camera are obtained by calibrating in advance. And then using the camera to capture images of moving objects, the results are then matched and 3-D reconstructed. The linear array CCD binocular vision imaging systems can accurately measure the 3-D appearance of moving objects, this essay is of great significance to measure the 3-D morphology of moving objects.
Designing payment for Collaborative Care for Depression in primary care.
Bao, Yuhua; Casalino, Lawrence P; Ettner, Susan L; Bruce, Martha L; Solberg, Leif I; Unützer, Jürgen
2011-10-01
To design a bundled case rate for Collaborative Care for Depression (CCD) that aligns incentives with evidence-based depression care in primary care. A clinical information system used by all care managers in a randomized controlled trial of CCD for older primary care patients. We conducted an empirical investigation of factors accounting for variation in CCD resource use over time and across patients. CCD resource use at the patient-episode and patient-month levels was measured by number of care manager contacts and direct patient contact time and analyzed with count data (Poisson or negative binomial) models. Episode-level resource use varies substantially with patient's time in the program. Monthly use declines sharply in the first 6 months regardless of treatment response or remission status, but it remains stable afterwards. An adjusted episode or monthly case rate design better matches payment with variation in resource use compared with a fixed design. Our findings lend support to an episode payment adjusted by number of months receiving CCD and a monthly payment adjusted by the ordinal month. Nonpayment tools including program certification and performance evaluation and reward systems are needed to fully align incentives. © Health Research and Educational Trust.
Research of optical coherence tomography microscope based on CCD detector
NASA Astrophysics Data System (ADS)
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.
Potyrailo, R A; Ruddy, V P; Hieftje, G M
1999-11-01
A new method is described for the simultaneous determination of absorbance and refractive index of a sample medium. The method is based on measurement of the analyte-modulated modal power distribution (MPD) in a multimode waveguide. In turn, the MPD is quantified by the far-field spatial pattern and intensity of light, i.e., the Fraunhofer diffraction pattern (registered on a CCD camera), that emerges from a multimode optical fiber. Operationally, light that is sent down the fiber interacts with the surrounding analyte-containing medium by means of the evanescent wave at the fiber boundary. The light flux in the propagating beam and the internal reflection angles within the fiber are both affected by optical absorption connected with the analyte and by the refractive index of the analyte-containing medium. In turn, these angles are reflected in the angular divergence of the beam as it leaves the fiber. As a result, the Fraunhofer diffraction pattern of that beam yields two parameters that can, together, be used to deduce refractive index and absorbance. This MPD based detection offers important advantages over traditional evanescent-wave detection strategies which rely on recording only the total transmitted optical power or its lost fraction. First, simultaneous determination of sample refractive index and absorbance is possible at a single probe wavelength. Second, the sensitivity of refractometric and absorption measurements can be controlled simply, either by adjusting the distance between the end face of the fiber and the CCD detector or by monitoring selected modal groups at the fiber output. As a demonstration of these capabilities, several weakly absorbing solutions were examined, with refractive indices in the range from 1.3330 to 1.4553 and with absorption coefficients in the range 0-16 cm-1. The new detection strategy is likely to be important in applications in which sample coloration varies and when it is necessary to compensate for variations in the refractive index of a sample.
Institute CCD School Videos Student Projects Two Eyes, 3D Variable Star Astronomy H-R Diagram Plotting CHOICE Online Institute CCD School Videos Student Projects Two Eyes, 3D Variable Star Astronomy H-R
Evaluation of large format electron bombarded virtual phase CCDs as ultraviolet imaging detectors
NASA Technical Reports Server (NTRS)
Opal, Chet B.; Carruthers, George R.
1989-01-01
In conjunction with an external UV-sensitive cathode, an electron-bombarded CCD may be used as a high quantum efficiency/wide dynamic range photon-counting UV detector. Results are presented for the case of a 1024 x 1024, 18-micron square pixel virtual phase CCD used with an electromagnetically focused f/2 Schmidt camera, which yields excellent simgle-photoevent discrimination and counting efficiency. Attention is given to the vacuum-chamber arrangement used to conduct system tests and the CCD electronics and data-acquisition systems employed.
Optical synthesizer for a large quadrant-array CCD camera: Center director's discretionary fund
NASA Technical Reports Server (NTRS)
Hagyard, Mona J.
1992-01-01
The objective of this program was to design and develop an optical device, an optical synthesizer, that focuses four contiguous quadrants of a solar image on four spatially separated CCD arrays that are part of a unique CCD camera system. This camera and the optical synthesizer will be part of the new NASA-Marshall Experimental Vector Magnetograph, and instrument developed to measure the Sun's magnetic field as accurately as present technology allows. The tasks undertaken in the program are outlined and the final detailed optical design is presented.
InSb arrays with CCD readout for 1.0- to 5.5-microns infrared applications
NASA Technical Reports Server (NTRS)
Phillips, J. D.; Scorso, J. B.; Thom, R. D.
1976-01-01
There were two approaches for fabricating indium antimonide (InSb) arrays with CCD readout discussed. The hybrid approach integrated InSb detectors and silicon CCDs in a modular assembly via an advanced interconnection technology. In the monolithic approach, the InSb infrared detectors and the CCD readout were integrated on the same InSb chip. Both approaches utilized intrinsic (band-to-band) photodetection with the attendant advantages over extrinsic detectors. The status of each of these detector readout concepts, with pertinent performance characteristics, was presented.
A design of driving circuit for star sensor imaging camera
NASA Astrophysics Data System (ADS)
Li, Da-wei; Yang, Xiao-xu; Han, Jun-feng; Liu, Zhao-hui
2016-01-01
The star sensor is a high-precision attitude sensitive measuring instruments, which determine spacecraft attitude by detecting different positions on the celestial sphere. Imaging camera is an important portion of star sensor. The purpose of this study is to design a driving circuit based on Kodak CCD sensor. The design of driving circuit based on Kodak KAI-04022 is discussed, and the timing of this CCD sensor is analyzed. By the driving circuit testing laboratory and imaging experiments, it is found that the driving circuits can meet the requirements of Kodak CCD sensor.
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.
NEUTRON RADIATION DAMAGE IN CCD CAMERAS AT JOINT EUROPEAN TORUS (JET).
Milocco, Alberto; Conroy, Sean; Popovichev, Sergey; Sergienko, Gennady; Huber, Alexander
2017-10-26
The neutron and gamma radiations in large fusion reactors are responsible for damage to charged couple device (CCD) cameras deployed for applied diagnostics. Based on the ASTM guide E722-09, the 'equivalent 1 MeV neutron fluence in silicon' was calculated for a set of CCD cameras at the Joint European Torus. Such evaluations would be useful to good practice in the operation of the video systems. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
NASA Astrophysics Data System (ADS)
Strojie, W. M.; Harper, D. T.; Zachos, J. C.
2017-12-01
The late Paleocene and Early Eocene were characterized by a series of brief hyperthermal events, the largest of which is the Paleocene-Eocene Thermal Maximum (PETM, 55.5 Ma) followed by a lower magnitude Eocene Thermal Maximum 2 (ETM2, 53.7 Ma), also known as H1. These events are characterized by a global negative Carbon Isotope Excursion (CIE) coincident with a dissolution horizon in pelagic sediment cores indicative of Carbonate Compensation Depth (CCD) shoaling and significant ocean acidification. The S.E. Atlantic Walvis Ridge ETM2 CIE is a δ13CCarb 1.0‰ - 1.5‰ and δ13CBulk 3.5‰ with an estimated 3oC surface and benthic warming. The record of transient hyperthermals such as ETM2 is not as extensive in the Pacific as the Atlantic. Given the size of the Pacific, this represents a critical gap in our understanding of the overall carbon cycle and oceanographic response of this event. Our research investigates the evolution of ocean thermal structure in the equatorial Pacific preceding, during, and after ETM-2. We generated new data on thermocline temperature from ODP Site 1209 Shatsky Rise using planktonic foraminifera δ18O and Mg/Ca while inferring carbon cycle dynamics from δ13C. The data shows 3 CIE's from 53.7Ma - 53.6Ma (ETM2, H2, and I1). ETM2 is preceded by 40kyr of bulk and thermocline δ13C convergence with two transient warming steps. The CIE duration 90kyr with an 50kyr recovery phase. The total magnitude of peak thermocline warming 2.0oC to 2.2oC for ETM2. No thermocline warming is observed for H2. I1 peak magnitude of thermocline warming 3.0oC. Orbital pacing of the carbon cycle is also evident from 100kyr separation of ETM2 and H2, an 300kyr separation of ETM2 and I1, and an 40kyr pre-CIE convergence of δ13Ccarb & δ13Cbulk with an apparent two warming steps 15-20kyr apart.
A method of immediate detection of objects with a near-zero apparent motion in series of CCD-frames
NASA Astrophysics Data System (ADS)
Savanevych, V. E.; Khlamov, S. V.; Vavilova, I. B.; Briukhovetskyi, A. B.; Pohorelov, A. V.; Mkrtichian, D. E.; Kudak, V. I.; Pakuliak, L. K.; Dikov, E. N.; Melnik, R. G.; Vlasenko, V. P.; Reichart, D. E.
2018-01-01
The paper deals with a computational method for detection of the solar system minor bodies (SSOs), whose inter-frame shifts in series of CCD-frames during the observation are commensurate with the errors in measuring their positions. These objects have velocities of apparent motion between CCD-frames not exceeding three rms errors (3σ) of measurements of their positions. About 15% of objects have a near-zero apparent motion in CCD-frames, including the objects beyond the Jupiter's orbit as well as the asteroids heading straight to the Earth. The proposed method for detection of the object's near-zero apparent motion in series of CCD-frames is based on the Fisher f-criterion instead of using the traditional decision rules that are based on the maximum likelihood criterion. We analyzed the quality indicators of detection of the object's near-zero apparent motion applying statistical and in situ modeling techniques in terms of the conditional probability of the true detection of objects with a near-zero apparent motion. The efficiency of method being implemented as a plugin for the Collection Light Technology (CoLiTec) software for automated asteroids and comets detection has been demonstrated. Among the objects discovered with this plugin, there was the sungrazing comet C/2012 S1 (ISON). Within 26 min of the observation, the comet's image has been moved by three pixels in a series of four CCD-frames (the velocity of its apparent motion at the moment of discovery was equal to 0.8 pixels per CCD-frame; the image size on the frame was about five pixels). Next verification in observations of asteroids with a near-zero apparent motion conducted with small telescopes has confirmed an efficiency of the method even in bad conditions (strong backlight from the full Moon). So, we recommend applying the proposed method for series of observations with four or more frames.
Beumer, Wouter; Welzen-Coppens, Jojanneke M. C.; van Helden-Meeuwsen, Cornelia G.; Gibney, Sinead M.; Drexhage, Hemmo A.; Versnel, Marjan A.
2014-01-01
Two major dendritic cell (DC) subsets have been described in the pancreas of mice: The CD11c+CD8α− DCs (strong CD4+ T cell proliferation inducers) and the CD8α+CD103+ DCs (T cell apoptosis inducers). Here we analyzed the larger subset of CD11c+CD8α− DCs isolated from the pancreas of pre-diabetic NOD mice for genome-wide gene expression (validated by Q-PCR) to elucidate abnormalities in underlying gene expression networks. CD11c+CD8α− DCs were isolated from 5 week old NOD and control C57BL/6 pancreas. The steady state pancreatic NOD CD11c+CD8α− DCs showed a reduced expression of several gene networks important for the prime functions of these cells, i.e. for cell renewal, immune tolerance induction, migration and for the provision of growth factors including those for beta cell regeneration. A functional in vivo BrdU incorporation test showed the reduced proliferation of steady state pancreatic DC. The reduced expression of tolerance induction genes (CD200R, CCR5 and CD24) was supported on the protein level by flow cytometry. Also previously published functional tests on maturation, immune stimulation and migration confirm the molecular deficits of NOD steady state DC. Despite these deficiencies NOD pancreas CD11c+CD8α− DCs showed a hyperreactivity to LPS, which resulted in an enhanced pro-inflammatory state characterized by a gene profile of an enhanced expression of a number of classical inflammatory cytokines. The enhanced up-regulation of inflammatory genes was supported by the in vitro cytokine production profile of the DCs. In conclusion, our data show that NOD pancreatic CD11c+CD8α− DCs show various deficiencies in steady state, while hyperreactive when encountering a danger signal such as LPS. PMID:25166904
Application of the CCD Fabry-Perot Annular Summing Technique to Thermospheric O(1)D.
NASA Astrophysics Data System (ADS)
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 of bright neutral species in the daysky as well as the potential for twenty-four hour coverage.
Flat Field Anomalies in an X-ray CCD Camera Measured Using a Manson X-ray Source
DOE Office of Scientific and Technical Information (OSTI.GOV)
M. J. Haugh and M. B. Schneider
2008-10-31
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 μm square pixels, and 15 μm thick. Amore » 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.« less
Mental health claims management and return to work: qualitative insights from Melbourne, Australia.
Brijnath, Bianca; Mazza, Danielle; Singh, Nabita; Kosny, Agnieszka; Ruseckaite, Rasa; Collie, Alex
2014-12-01
Mental health conditions (MHC) are an increasing reason for claiming injury compensation in Australia; however little is known about how these claims are managed by different gatekeepers to injury entitlements. This study, drawing on the views of four stakeholders-general practitioners (GPs), injured persons, employers and compensation agents, aims to describe current management of MHC claims and to identify the current barriers to return to work (RTW) for injured persons with a MHC claim and/or mental illness. Ninety-three in-depth interviews were undertaken with GPs, compensation agents, employers and injured persons. Data were collected in Melbourne, Australia. Thematic techniques were used to analyse data. MHC claims were complex to manage because of initial assessment and diagnostic difficulties related to the invisibility of the injury, conflicting medical opinions and the stigma associated with making a MHC claim. Mental illness also developed as a secondary issue in the recovery process. These factors made MHC difficult to manage and impeded timely RTW. It is necessary to undertake further research (e.g. guideline development) to improve current practice in order to enable those with MHC claims to make a timely RTW. Further education and training interventions (e.g. on diagnosis and management of MHC) are also needed to enable GPs, employers and compensation agents to better assess and manage MHC claims.
CCD Times of Minima of Faint Eclipsing Binaries in 2000
NASA Astrophysics Data System (ADS)
Zejda, Miloslav
2002-06-01
196 CCD minima observations of 122 eclipsing binaries made by the author in 2000 are presented. The observed stars were chosen from the catalogue BRKA of observing programme of BRNO-Variable Star Section of CAS.
Active Pixel Sensors: Are CCD's Dinosaurs?
NASA Technical Reports Server (NTRS)
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.
Degradation of optical components in space
NASA Technical Reports Server (NTRS)
Blue, M. D.
1993-01-01
This report concerns two types of optical components: multilayer filters and mirrors, and self-scanned imaging arrays using charge coupled device (CCD) readouts. For the filters and mirrors, contamination produces a strong reduction in transmittance in the ultraviolet spectral region, but has little or no effect in the visible and infrared spectral regions. Soft substrates containing halides are unsatisfactory as windows or substrates. Materials choice for dielectric layers should also reflect such considerations. Best performance is also found for the harder materials. Compaction of the layers and interlayer diffusion causes a blue shift in center wavelength and loss of throughput. For sensors using CCD's, shifts in gate voltage and reductions in transfer efficiency occur. Such effects in CCD's are in accord with expectations of the effects of the radiation dose on the device. Except for optical fiber, degradation of CCD's represents the only ionizing-radiation induced effect on the Long Duration Exposure Facility (LDEF) optical systems components that has been observed.
Measurement of phase function of aerosol at different altitudes by CCD Lidar
NASA Astrophysics Data System (ADS)
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.
Direct detection of x-rays for protein crystallography employing a thick, large area CCD
Atac, Muzaffer; McKay, Timothy
1999-01-01
An apparatus and method for directly determining the crystalline structure of a protein crystal. The crystal is irradiated by a finely collimated x-ray beam. The interaction of the x-ray beam with the crystal produces scattered x-rays. These scattered x-rays are detected by means of a large area, thick CCD which is capable of measuring a significant number of scattered x-rays which impact its surface. The CCD is capable of detecting the position of impact of the scattered x-ray on the surface of the CCD and the quantity of scattered x-rays which impact the same cell or pixel. This data is then processed in real-time and the processed data is outputted to produce a image of the structure of the crystal. If this crystal is a protein the molecular structure of the protein can be determined from the data received.
NASA Astrophysics Data System (ADS)
Butner, Melissa Jean
The DaMIC (Dark Matter in CCDs) experiment searches for dark matter particles using charge coupled devices (CCDs) operated at a low detection threshold of ˜40 eV electron equivalent energy (eVee). A multiplexor board is tested for DAMIC100+ which has the ability to control up to 16 CCDs at one time allowing for the selection of a single CCD for readout while leaving all others static and maintaining sub-electron noise. A dark matter limit is produced using the results of physics data taken with the DAMIC experiment. Next, the contribution from neutrino-nucleus coherent scattering is investigated using data from the Coherent Neutrino Nucleus Interaction Experiment (CONnuIE) using the same CCD technology. The results are used to explore the performance of CCD detectors that ultimately will limit the ability to differentiate incident solar and atmospheric neutrinos from dark matter particles.
A wide bandwidth CCD buffer memory system
NASA Technical Reports Server (NTRS)
Siemens, K.; Wallace, R. W.; Robinson, C. R.
1978-01-01
A prototype system was implemented to demonstrate that CCD's can be applied advantageously to the problem of low power digital storage and particularly to the problem of interfacing widely varying data rates. CCD shift register memories (8K bit) were used to construct a feasibility model 128 K-bit buffer memory system. Serial data that can have rates between 150 kHz and 4.0 MHz can be stored in 4K-bit, randomly-accessible memory blocks. Peak power dissipation during a data transfer is less than 7 W, while idle power is approximately 5.4 W. The system features automatic data input synchronization with the recirculating CCD memory block start address. System expansion to accommodate parallel inputs or a greater number of memory blocks can be performed in a modular fashion. Since the control logic does not increase proportionally to increase in memory capacity, the power requirements per bit of storage can be reduced significantly in a larger system.
NASA Technical Reports Server (NTRS)
Solomon, S. C.; Comer, R. P.; Head, J. W.
1982-01-01
A topographic profile of the young large lunar basin, Orientale, is presented in order to examine the effects of viscous relaxation on basin topography. Analytical models for viscous flow are considered, showing a wavelength-dependence of time constants for viscous decay on the decrease in viscosity with depth and on the extent of the isostatic compensation of the initial topography. Lunar rheological models which are developed include a half-space model for uniform Newtonian viscosity, density, and gravitational acceleration, a layer over inviscid half space model with material inviscid over geological time scales, and a layer with isostatic compensation where a uniformly viscous layer overlies an inviscid half space of higher density. Greater roughness is concluded, and has been observed, on the moon's dark side due to continued lower temperatures since the time of heavy bombardment.
On the equipotential surface hypothesis of lunar maria floors
NASA Astrophysics Data System (ADS)
Arkani-Hamed, Jafar; Konopliv, A. S.; Sjogren, W. L.
1999-03-01
The equipotential surface hypothesis suggests that lunar maria floors lie on a surface parallel to the selenoid. This is examined using the spherical harmonic representations of the Clementine topography and Lunar Prospector gravity data. It is demonstrated that the floors of both circular and noncircular maria significantly deviate from an equipotential surface. Deeper circular maria and the deeper part of the noncircular Mare Tranquillitatis have been subsided under larger mass loads in the crust. We calculate the mass beneath the maria to be in excess to the mass required for isostatic compensation of the topography at 60 km depth. A global map of this excess mass shows that the noncircular maria are isostatically compensated, unlike the circular maria. The map also reveals seven new sizable mascons: the three largest are associated with Mendel-Rydberg, Mare Humboldtianum, and Mare Moscoviense.
NASA Astrophysics Data System (ADS)
Xue, Bo; Mao, Bingjing; Chen, Xiaomei; Ni, Guoqiang
2010-11-01
This paper renders a configurable distributed high performance computing(HPC) framework for TDI-CCD imaging simulation. It uses strategy pattern to adapt multi-algorithms. Thus, this framework help to decrease the simulation time with low expense. Imaging simulation for TDI-CCD mounted on satellite contains four processes: 1) atmosphere leads degradation, 2) optical system leads degradation, 3) electronic system of TDI-CCD leads degradation and re-sampling process, 4) data integration. Process 1) to 3) utilize diversity data-intensity algorithms such as FFT, convolution and LaGrange Interpol etc., which requires powerful CPU. Even uses Intel Xeon X5550 processor, regular series process method takes more than 30 hours for a simulation whose result image size is 1500 * 1462. With literature study, there isn't any mature distributing HPC framework in this field. Here we developed a distribute computing framework for TDI-CCD imaging simulation, which is based on WCF[1], uses Client/Server (C/S) layer and invokes the free CPU resources in LAN. The server pushes the process 1) to 3) tasks to those free computing capacity. Ultimately we rendered the HPC in low cost. In the computing experiment with 4 symmetric nodes and 1 server , this framework reduced about 74% simulation time. Adding more asymmetric nodes to the computing network, the time decreased namely. In conclusion, this framework could provide unlimited computation capacity in condition that the network and task management server are affordable. And this is the brand new HPC solution for TDI-CCD imaging simulation and similar applications.
Davila, Stephen J; Hadjar, Omar; Eiceman, Gary A
2013-07-16
A linear pixel-based detector array, the IonCCD, is characterized for use under ambient conditions with thermal (<1 eV) positive ions derived from purified air and a 10 mCi (63)Ni foil. The IonCCD combined with a drift tube-ion mobility spectrometer permitted the direct detection of gas phase ions at atmospheric pressure and confirmed a limit of detection of 3000 ions/pixel/frame established previously in both the keV (1-2 keV) and the hyper-thermal (10-40 eV) regimes. Results demonstrate the "broad-band" application of the IonCCD over 10(5) orders in ion energy and over 10(10) in operating pressure. The Faraday detector of a drift tube for an ion mobility spectrometer was replaced with the IonCCD providing images of ion profiles over the cross-section of the drift tube. Patterns in the ion profiles were developed in the drift tube cross-section by control of electric fields between wires of Bradbury Nielson and Tyndall Powell shutter designs at distances of 1-8 cm from the detector. Results showed that ion beams formed in wire sets, retained their shape with limited mixing by diffusion and Coulombic repulsion. Beam broadening determined as 95 μm/cm for hydrated protons in air with moisture of ~10 ppmv. These findings suggest a value of the IonCCD in further studies of ion motion and diffusion of thermalized ions, enhancing computational results from simulation programs, and in the design or operation of ion mobility spectrometers.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Glover, Karen; Li, Yue; Mukhopadhyay, Shreya
Beclin 1 (BECN1) is a key regulator of autophagy, a critical catabolic homeostasis pathway that involves sequestration of selected cytoplasmic components by multilayered vesicles called autophagosomes, followed by lysosomal fusion and degradation. BECN1 is a core component of class III phosphatidylinositol-3-kinase complexes responsible for autophagosome nucleation. Without heterologous binding partners, BECN1 forms an antiparallel homodimer via its coiled-coil domain (CCD). However, the last 16 CCD residues, composing an “overlap helix” (OH), have been crystallized in two mutually exclusive states: either as part of the CCD or packed against the C-terminal β-α repeated, autophagy-specific domain (BARAD). Here, using CD spectroscopy, isothermalmore » titration calorimetry, and small-angle X-ray scattering, we show that in the homodimeric state, the OH transitions between these two different packing states, with the predominant state comprising the OH packed against the BARAD, contrary to expectations based on known BECN1 interactions with heterologous partners. We confirmed this observation by comparing the impact of mutating four residues that mediate packing of the OH against both the CCD and BARAD on structure and stability of the CCD, the OH+BARAD, and the two-domain CCD–BARAD. Last, we used cellular assays to demonstrate that mutation of these OH-interface residues abrogates starvation-induced up-regulation of autophagy but does not affect basal autophagy. In summary, we have identified a BECN1 helical region that transitions between packing as part of either one of two conserved domains (i.e. the CCD or the BARAD). Our findings have important implications for the relative stability of autophagy-inactive and autophagy-active BECN1 complexes.« less
A New Serial-direction Trail Effect in CCD Images of the Lunar-based Ultraviolet Telescope
NASA Astrophysics Data System (ADS)
Wu, C.; Deng, J. S.; Guyonnet, A.; Antilogus, P.; Cao, L.; Cai, H. B.; Meng, X. M.; Han, X. H.; Qiu, Y. L.; Wang, J.; Wang, S.; Wei, J. Y.; Xin, L. P.; Li, G. W.
2016-10-01
Unexpected trails have been seen subsequent to relative bright sources in astronomical images taken with the CCD camera of the Lunar-based Ultraviolet Telescope (LUT) since its first light on the Moon’s surface. The trails can only be found in the serial-direction of CCD readout, differing themselves from image trails of radiation-damaged space-borne CCDs, which usually appear in the parallel-readout direction. After analyzing the same trail defects following warm pixels (WPs) in dark frames, we found that the relative intensity profile of the LUT CCD trails can be expressed as an exponential function of the distance i (in number of pixels) of the trailing pixel to the original source (or WP), i.e., {\\mathtt{\\exp }}(α {\\mathtt{i}}+β ). The parameters α and β seem to be independent of the CCD temperature, intensity of the source (or WP), and its position in the CCD frame. The main trail characteristics show evolution occurring at an increase rate of ˜(7.3 ± 3.6) × 10-4 in the first two operation years. The trails affect the consistency of the profiles of different brightness sources, which make smaller aperture photometry have larger extra systematic error. The astrometric uncertainty caused by the trails is too small to be acceptable based on LUT requirements for astrometry accuracy. Based on the empirical profile model, a correction method has been developed for LUT images that works well for restoring the fluxes of astronomical sources that are lost in trailing pixels.
Analysis of view synthesis prediction architectures in modern coding standards
NASA Astrophysics Data System (ADS)
Tian, Dong; Zou, Feng; Lee, Chris; Vetro, Anthony; Sun, Huifang
2013-09-01
Depth-based 3D formats are currently being developed as extensions to both AVC and HEVC standards. The availability of depth information facilitates the generation of intermediate views for advanced 3D applications and displays, and also enables more efficient coding of the multiview input data through view synthesis prediction techniques. This paper outlines several approaches that have been explored to realize view synthesis prediction in modern video coding standards such as AVC and HEVC. The benefits and drawbacks of various architectures are analyzed in terms of performance, complexity, and other design considerations. It is hence concluded that block-based VSP prediction for multiview video signals provides attractive coding gains with comparable complexity as traditional motion/disparity compensation.
Underwater image enhancement through depth estimation based on random forest
NASA Astrophysics Data System (ADS)
Tai, Shen-Chuan; Tsai, Ting-Chou; Huang, Jyun-Han
2017-11-01
Light absorption and scattering in underwater environments can result in low-contrast images with a distinct color cast. This paper proposes a systematic framework for the enhancement of underwater images. Light transmission is estimated using the random forest algorithm. RGB values, luminance, color difference, blurriness, and the dark channel are treated as features in training and estimation. Transmission is calculated using an ensemble machine learning algorithm to deal with a variety of conditions encountered in underwater environments. A color compensation and contrast enhancement algorithm based on depth information was also developed with the aim of improving the visual quality of underwater images. Experimental results demonstrate that the proposed scheme outperforms existing methods with regard to subjective visual quality as well as objective measurements.
Wang, Jinyu; Léger, Jean-François; Binding, Jonas; Boccara, A. Claude; Gigan, Sylvain; Bourdieu, Laurent
2012-01-01
Aberrations limit the resolution, signal intensity and achievable imaging depth in microscopy. Coherence-gated wavefront sensing (CGWS) allows the fast measurement of aberrations in scattering samples and therefore the implementation of adaptive corrections. However, CGWS has been demonstrated so far only in weakly scattering samples. We designed a new CGWS scheme based on a Linnik interferometer and a SLED light source, which is able to compensate dispersion automatically and can be implemented on any microscope. In the highly scattering rat brain tissue, where multiply scattered photons falling within the temporal gate of the CGWS can no longer be neglected, we have measured known defocus and spherical aberrations up to a depth of 400 µm. PMID:23082292
Wang, Jinyu; Léger, Jean-François; Binding, Jonas; Boccara, A Claude; Gigan, Sylvain; Bourdieu, Laurent
2012-10-01
Aberrations limit the resolution, signal intensity and achievable imaging depth in microscopy. Coherence-gated wavefront sensing (CGWS) allows the fast measurement of aberrations in scattering samples and therefore the implementation of adaptive corrections. However, CGWS has been demonstrated so far only in weakly scattering samples. We designed a new CGWS scheme based on a Linnik interferometer and a SLED light source, which is able to compensate dispersion automatically and can be implemented on any microscope. In the highly scattering rat brain tissue, where multiply scattered photons falling within the temporal gate of the CGWS can no longer be neglected, we have measured known defocus and spherical aberrations up to a depth of 400 µm.
The MVACS Surface Stereo Imager on Mars Polar Lander
NASA Astrophysics Data System (ADS)
Smith, P. H.; Reynolds, R.; Weinberg, J.; Friedman, T.; Lemmon, M. T.; Tanner, R.; Reid, R. J.; Marcialis, R. L.; Bos, B. J.; Oquest, C.; Keller, H. U.; Markiewicz, W. J.; Kramm, R.; Gliem, F.; Rueffer, P.
2001-08-01
The Surface Stereo Imager (SSI), a stereoscopic, multispectral camera on the Mars Polar Lander, is described in terms of its capabilities for studying the Martian polar environment. The camera's two eyes, separated by 15.0 cm, provide the camera with range-finding ability. Each eye illuminates half of a single CCD detector with a field of view of 13.8° high by 14.3° wide and has 12 selectable filters between 440 and 1000 nm. The
Measuring Compositions in Organic Depth Profiling: Results from a VAMAS Interlaboratory Study.
Shard, Alexander G; Havelund, Rasmus; Spencer, Steve J; Gilmore, Ian S; Alexander, Morgan R; Angerer, Tina B; Aoyagi, Satoka; Barnes, Jean-Paul; Benayad, Anass; Bernasik, Andrzej; Ceccone, Giacomo; Counsell, Jonathan D P; Deeks, Christopher; Fletcher, John S; Graham, Daniel J; Heuser, Christian; Lee, Tae Geol; Marie, Camille; Marzec, Mateusz M; Mishra, Gautam; Rading, Derk; Renault, Olivier; Scurr, David J; Shon, Hyun Kyong; Spampinato, Valentina; Tian, Hua; Wang, Fuyi; Winograd, Nicholas; Wu, Kui; Wucher, Andreas; Zhou, Yufan; Zhu, Zihua; Cristaudo, Vanina; Poleunis, Claude
2015-08-20
We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study on the measurement of composition in organic depth profiling. Layered samples with known binary compositions of Irganox 1010 and either Irganox 1098 or Fmoc-pentafluoro-l-phenylalanine in each layer were manufactured in a single batch and distributed to more than 20 participating laboratories. The samples were analyzed using argon cluster ion sputtering and either X-ray photoelectron spectroscopy (XPS) or time-of-flight secondary ion mass spectrometry (ToF-SIMS) to generate depth profiles. Participants were asked to estimate the volume fractions in two of the layers and were provided with the compositions of all other layers. Participants using XPS provided volume fractions within 0.03 of the nominal values. Participants using ToF-SIMS either made no attempt, or used various methods that gave results ranging in error from 0.02 to over 0.10 in volume fraction, the latter representing a 50% relative error for a nominal volume fraction of 0.2. Error was predominantly caused by inadequacy in the ability to compensate for primary ion intensity variations and the matrix effect in SIMS. Matrix effects in these materials appear to be more pronounced as the number of atoms in both the primary analytical ion and the secondary ion increase. Using the participants' data we show that organic SIMS matrix effects can be measured and are remarkably consistent between instruments. We provide recommendations for identifying and compensating for matrix effects. Finally, we demonstrate, using a simple normalization method, that virtually all ToF-SIMS participants could have obtained estimates of volume fraction that were at least as accurate and consistent as XPS.
Measuring Compositions in Organic Depth Profiling: Results from a VAMAS Interlaboratory Study
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shard, A. G.; Havelund, Rasmus; Spencer, Steve J.
We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study on the measurement of composition in organic depth profiling. Layered samples with known binary compositions of Irganox 1010 and either Irganox 1098 or Fmoc-pentafluoro-L-phenylalanine in each layer were manufactured in a single batch and distributed to more than 20 participating laboratories. The samples were analyzed using argon cluster ion sputtering and either X-ray Photoelectron Spectroscopy (XPS) or Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) to generate depth profiles. Participants were asked to estimate the volume fractions in two of the layers and were provided withmore » the compositions of all other layers. Participants using XPS provided volume fractions within 0.03 of the nominal values. Participants using ToF-SIMS either made no attempt, or used various methods that gave results ranging in error from 0.02 to over 0.10 in volume fraction, the latter representing a 50% relative error for a nominal volume fraction of 0.2. Error was predominantly caused by inadequacy in the ability to compensate for primary ion intensity variations and the matrix effect in SIMS. Matrix effects in these materials appear to be more pronounced as the number of atoms in both the primary analytical ion and the secondary ion increase. Using the participants’ data we show that organic SIMS matrix effects can be measured and are remarkably consistent between instruments. We provide recommendations for identifying and compensating for matrix effects. Finally we demonstrate, using a simple normalization method, that virtually all ToF-SIMS participants could have obtained estimates of volume fraction that were at least as accurate and consistent as XPS.« less
Event-Driven X-Ray CCD Detectors for High Energy Astrophysics
NASA Technical Reports Server (NTRS)
Ricker, George R.
2004-01-01
A viewgraph presentation describing the Event-Driven X- Ray CCD (EDCCD) detector system for high energy astrophysics is presented. The topics include: 1) EDCCD: Description and Advantages; 2) Summary of Grant Activity Carried Out; and 3) EDCCD Test System.
Study of digital charge coupled devices
NASA Technical Reports Server (NTRS)
Wilson, D. D.; Young, V. F.
1980-01-01
Charge coupled devices represent unique usage of the metal oxide semiconductor concept. These devices can sample an AC signal at the input, transfer charge proportional to this signal through the CCD shift register and then provide an output of the same frequency and shape as the input. The delay time between input and output is controlled by the CCD operating frequency and the number of stages in the shift resistor. This work is a reliability evaluation of the buried channel and surface channel CCD technologies. The constructions are analyzed, failure modes are described, and test results are reported.
NASA Astrophysics Data System (ADS)
Vishnevsky, G. I.; Galyatkin, I. A.; Zhuk, A. A.; Iblyaminova, A. F.; Kossov, V. G.; Levko, G. V.; Nesterov, V. K.; Rivkind, V. L.; Rogalev, Yu. N.; Smirnov, A. V.; Gumerov, R. I.; Bikmaev, I. F.; Pinigin, G. I.; Shulga, A. V.; Kovalchyk, A. V.; Protsyuk, Yu. I.; Malevinsky, S. V.; Abrosimov, V. M.; Mironenko, V. N.; Savchenko, V. V.; Ivaschenko, Yu. N.; Andruk, V. M.; Dalinenko, I. N.; Vydrevich, M. G.
2003-01-01
The paper presents the possibilities and a list of tasks that are solved by collaboration between research and production companies, and astronomical observatories of Russia and Ukraine in the field of development, modernization and equipping of various telescopes (the AMC, RTT-150, Zeiss-600 and quantum-optical system Sazhen-S types) with advanced charge-coupled device (CCD) cameras. CCD imagers and ditital CCD cameras designed and manufactured by the "Electron-Optronic" Research & Production Company, St Petersburg, to equip astronomical telescopes and scientific instruments are described.