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Sample records for adder acanthophis antarcticus

  1. Analysis of intraspecific variation in venoms of Acanthophis antarcticus death adders from South Australia

    PubMed Central

    Herzig, Volker; Kohler, Maxie; Grund, Kai F; Reeve, Shane; Smith, A Ian; Hodgson, Wayne C

    2013-01-01

    Intraspecific variation in venom composition and activity has been reported from a wide range of snakes. Geographical origin can be one cause for this variation and has recently been documented from Acanthophis antarcticus death adders sampled across four different Australian states. The present study examined whether a narrower sampling range of A. antarcticus from four collection sites within one Australian state (i.e., South Australia) would also exhibit variation in venom composition and/or activity. The present LC-MS results reveal marked differences in the venom composition from different collection sites. The most striking difference was the reduced venom complexity found in the only venom originating from a mallee scrub habitat in comparison to the venoms from coastal heath scrub habitats. Interestingly, the pharmacological activity of all venoms was found to be the same, independent of the collection site. PMID:24163732

  2. Characterisation of the biochemical and biological variations from the venom of the death adder species (Acanthophis antarcticus, A. praelongus and A. pyrrhus).

    PubMed

    van der Weyden, L; Hains, P G; Broady, K W

    2000-12-01

    We report on species variation in the venoms of the three species of death adder; the Common death adder (Acanthophis antarcticus), the Northern death adder (Acanthophis praelongus) and the Desert death adder (Acanthophis pyrrhus). The venoms were found to vary in their biochemical (chromatography) and biological (PLA(2) activity, anticoagulant activity and reactivity with commercial death adder antivenom) properties. Each species produced significant differences in the profile and distribution of PLA(2) activity, when whole venom was applied to a cation-exchange Mono-S column. PLA(2) enzymes were purified from each venom and termed acanthoxin B (from A. praelongus), acanthoxin C (from A. pyrrhus) and the previously characterised acanthoxin A (from A. antarcticus). Acanthoxin B and C showed lower enzymatic activities than acanthoxin A (4.0, 13.7 and 23.9 micromol of phospholipid hydrolyzed/min/mg protein, respectively). N-terminal sequencing revealed acanthoxin B to share highest homology with the numerous PLA(2) isozymes (Pa-12C, Pa-1G, Pa-12A) from the King brown snake (Pseudechis australis) and Acanthin I from the Common death adder. Similar to acanthoxin A, acanthoxin C showed highest homology with Acanthin I/II, and pseudexin A-chain from the Red-bellied black snake (Pseudechis porphyriacus). Whole venom from A. antarcticus, A. praelongus and A. pyrrhus each showed weak anticoagulant activity (being able to prolong coagulation of the plasma for 107, 220 and 195 s, respectively). By immunodiffusion, each venom produced precipitation bands against commercial death adder antivenom.

  3. Species-dependent variations in the in vitro myotoxicity of death adder (Acanthophis) venoms.

    PubMed

    Wickramaratna, Janith C; Fry, Bryan G; Hodgson, Wayne C

    2003-08-01

    Based on early studies on Acanthophis antarcticus (common death adder) venom, it has long been thought that death adder snake venoms are devoid of myotoxicity. However, a recent clinical study reported rhabdomyolysis in patients following death adder envenomations, in Papua New Guinea, by a species thought to be different to A. antarcticus. Subsequently, a myotoxic phospholipase A2 component was isolated from A. rugosus (Irian Jayan death adder) venom. The present study examined the venoms of A. praelongus (northern), A. pyrrhus (desert), A. hawkei (Barkly Tableland), A. wellsi (black head), A. rugosus, A. sp. Seram and the regional variants of A. antarcticus for in vitro myotoxicity. Venoms (10-50 microg/ml) were examined for myotoxicity using the chick directly (0.1 Hz, 2 ms, supramaximal V) stimulated biventer cervicis nerve-muscle preparation. A significant contracture of skeletal muscle and/or inhibition of direct twitches were considered signs of myotoxicity. This was confirmed by histological examination. All venoms displayed high phospholipase A2 activity. The venoms (10-50 microg/ml) of A. sp. Seram, A. praelongus, A. rugosus,and A. wellsi caused a significant inhibition of direct twitches and an increase in baseline tension compared to the vehicle (n=4-6; two-way ANOVA, p<0.05). Furthermore, these venoms caused dose-dependent morphological changes in skeletal muscle. In contrast, the venoms (10-50 microg/ml; n=3-6) of A. hawkei, A. pyrrhus, and regional variants of A. antarcticus were devoid of myotoxicity. Prior incubation (10 min) of CSL death adder antivenom (5 U/ml) prevented the myotoxicity caused by A. sp. Seram, A. praelongus, A. rugosus, and A. wellsi venoms (50 microg/ml; n=4-7). In conclusion, clinicians may need to be mindful of possible myotoxicity following envenomations by A. praelongus, A. rugosus, A. sp. Seram, and A. wellsi species.

  4. Morphology, reproduction and diet in Australian and Papuan death adders (Acanthophis, Elapidae).

    PubMed

    Shine, Richard; Spencer, Carol L; Keogh, J Scott

    2014-01-01

    Death adders (genus Acanthophis) differ from most other elapid snakes, and resemble many viperid snakes, in their thickset morphology and ambush foraging mode. Although these snakes are widely distributed through Australia and Papua New Guinea, their basic biology remains poorly known. We report morphological and ecological data based upon dissection of >750 museum specimens drawn from most of the range of the genus. Female death adders grow larger than conspecific males, to about the same extent in all taxa (20% in mean adult snout-vent length,  =  SVL). Most museum specimens were adult rather than juvenile animals, and adult males outnumbered females in all taxa except A. pyrrhus. Females have shorter tails (relative to SVL) than males, and longer narrower heads (relative to head length) in some but not all species. The southern A. antarcticus is wider-bodied (relative to SVL) than the other Australian species. Fecundity of these viviparous snakes was similar among taxa (mean litter sizes 8 to 14). Death adders encompass a broad range of ecological attributes, taking a wide variety of vertebrate prey, mostly lizards (55%), frogs and mammals (each 21%; based on 217 records). Dietary composition differed among species (e.g. frogs were more common in tropical than temperate-zone species), and shifted with snake body size (endotherms were taken by larger snakes) and sex (male death adders took more lizards than did females). Overall, death adders take a broader array of prey types, including active fast-moving taxa such as endotherms and large diurnal skinks, than do most other Australian elapids of similar body sizes. Ambush foraging is the key to capturing such elusive prey.

  5. Amino acid sequence of a neurotoxic phospholipase A2 enzyme from common death adder (Acanthophis antracticus) venom.

    PubMed

    van der Weyden, L; Hains, P; Broady, K; Shaw, D; Milburn, P

    2001-02-01

    The amino acid sequence of the first neurotoxic phospholipase A2, acanthoxin A1, purified from the venom of the Common death adder (Acanthophis antarcticus) was determined. Acanthoxin A1 shows high homology with other Australian elapid PLA2 neurotoxins, in particular Acanthin-I and -II, also from Death adder, Pseudexin A from the Red-bellied black snake (Pseudechis porphyriacus), and Pa-12a and Pa-9c from the King brown snake (Pseudechis australis). Acanthoxin A1 is a single-chain 118 amino acid residue PLA2, including 14 half cystine residues and the essential residues forming the ubiquitous calcium binding pocket and catalytic site. Critical analysis of the residues hypothesized to be important for neurotoxicity is presented.

  6. A new species of death adder (Acanthophis: Serpentes: Elapidae) from north-western Australia.

    PubMed

    Maddock, Simon T; Ellis, Ryan J; Doughty, Paul; Smith, Lawrence A; Wüster, Wolfgang

    2015-08-28

    Australian death adders (genus Acanthophis) are highly venomous snakes with conservative morphology and sit-and-wait predatory habits, with only moderate taxonomic diversity that nevertheless remains incompletely understood. Analyses of mitochondrial and nuclear gene sequences and morphological characteristics of death adders in northern Australia reveal the existence of a new species from the Kimberley region of Western Australia and the Northern Territory, which we describe as Acanthophis cryptamydros sp. nov. Although populations from the Kimberley were previously considered conspecific with Northern Territory death adders of the A. rugosus complex, our mtDNA analysis indicates that its closest relatives are desert death adders, A. pyrrhus. We found that A. cryptamydros sp. nov. is distinct in both mtDNA and nDNA analysis, and possesses multiple morphological characteristics that allow it to be distinguished from all other Acanthophis species. This study further supports the Kimberley region as an area with high endemic biodiversity.

  7. Isolation and pharmacological characterization of a phospholipase A2 myotoxin from the venom of the Irian Jayan death adder (Acanthophis rugosus)

    PubMed Central

    Wickramaratna, Janith C; Fry, Bryan G; Aguilar, Marie-Isabel; Kini, R Manjunatha; Hodgson, Wayne C

    2003-01-01

    It has long been thought that death adder venoms are devoid of myotoxic activity based on studies done on Acanthophis antarcticus (Common death adder) venom. However, a recent clinical study reported rhabdomyolysis in patients following death adder envenomations, in Papua New Guinea, by a species thought to be different to A. antarcticus. Consequently, the present study examined A. rugosus (Irian Jayan death adder) venom for myotoxicity, and isolated the first myotoxin (acanmyotoxin-1) from a death adder venom. A. rugosus (10–50 μg ml−1) and acanmyotoxin-1 (MW 13811; 0.1–1 μM) were screened for myotoxicity using the chick directly (0.1 Hz, 2 ms, supramaximal V) stimulated biventer cervicis nerve-muscle (CBCNM) preparation. A significant contracture of skeletal muscle and/or inhibition of direct twitches were considered signs of myotoxicity. This was confirmed by histological examination. High phospholipase A2 (PLA2) activity was detected in both A. rugosus venom (140.2±10.4 μmol min−1 mg−1; n=6) and acanmyotoxin-1 (153.4±11 μmol min−1 mg−1; n=6). Both A. rugosus venom (10–50 μg ml−1) and acanmyotoxin-1 (0.1–1 μM) caused dose-dependent inhibition of direct twitches and increase in baseline tension (n=4–6). In addition, dose-dependent morphological changes in skeletal muscle were observed. Prior incubation (10 min) of CSL death adder antivenom (5 units ml−1; n=4) or inactivation of PLA2 activity with 4-bromophenacyl bromide (1.8 mM; n=4) prevented the myotoxicity caused by acanmyotoxin-1 (1 μM). Acanmyotoxin-1 (0.1 μM; n=4) displayed no significant neurotoxicity when it was examined using the indirectly (0.1 Hz, 0.2 ms, supramaximal V) stimulated CBCNM preparation. In conclusion, clinicians may need to be mindful of possible myotoxicity following death adder envenomation in Irian Jaya. PMID:12540524

  8. Snakes across the Strait: trans-Torresian phylogeographic relationships in three genera of Australasian snakes (Serpentes: Elapidae: Acanthophis, Oxyuranus, and Pseudechis).

    PubMed

    Wüster, Wolfgang; Dumbrell, Alex J; Hay, Chris; Pook, Catharine E; Williams, David J; Fry, Bryan Grieg

    2005-01-01

    We analyze the phylogeny of three genera of Australasian elapid snakes (Acanthophis-death adders; Oxyuranus-taipans; Pseudechis-blacksnakes), using parsimony, maximum likelihood, and Bayesian analysis of sequences of the mitochondrial cytochrome b and ND4 genes. In Acanthophis and Pseudechis, we find evidence of multiple trans-Torresian sister-group relationships. Analyses of the timing of cladogenic events suggest crossings of the Torres Strait on several occasions between the late Miocene and the Pleistocene. These results support a hypothesis of repeated land connections between Australia and New Guinea in the late Cenozoic. Additionally, our results reveal undocumented genetic diversity in Acanthophis and Pseudechis, supporting the existence of more species than previously believed, and provide a phylogenetic framework for a reinterpretation of the systematics of these genera. In contrast, our Oxyuranus scutellatus samples from Queensland and two localities in New Guinea share a single haplotype, suggesting very recent (late Pleistocene) genetic exchange between New Guinean and Australian populations.

  9. ADDER CIRCUIT

    DOEpatents

    Jacobsohn, D.H.; Merrill, L.C.

    1959-01-20

    An improved parallel addition unit is described which is especially adapted for use in electronic digital computers and characterized by propagation of the carry signal through each of a plurality of denominationally ordered stages within a minimum time interval. In its broadest aspects, the invention incorporates a fast multistage parallel digital adder including a plurality of adder circuits, carry-propagation circuit means in all but the most significant digit stage, means for conditioning each carry-propagation circuit during the time period in which information is placed into the adder circuits, and means coupling carry-generation portions of thc adder circuit to the carry propagating means.

  10. Functional morphology of the palato-maxillary apparatus in "Palatine dragging" snakes (Serpentes: Elapidae: Acanthophis, Oxyuranus).

    PubMed

    Deufel, Alexandra; Cundall, David

    2010-01-01

    Elapid snakes have previously been divided into two groups (palatine erectors and palatine draggers) based on the morphology and inferred movements of their palatine bone during prey transport (swallowing). We investigated the morphology and the functioning of the feeding apparatus of several palatine draggers (Acanthophis antarcticus, Oxyuranus scutellatus, Pseudechis australis) and compared them to published records of palatine erectors. We found that the palatine in draggers does not move as a straight extension of the pterygoid as originally proposed. The dragger palato-pterygoid joint flexes laterally with maxillary rotation when the mouth opens and the jaw apparatus is protracted and slightly ventrally during mouth closing. In contrast, in palatine erectors, the palato-pterygoid joint flexes ventrally during upper jaw protraction. In draggers, the anterior end of the palatine also projects rostrally during protraction, unlike the stability of the anterior end seen in erectors. Palatine draggers differ from palatine erectors in four structural features of the palatine and its relationships to surrounding elements. The function of the palato-pterygoid bar in both draggers and erectors can be explained by a typical colubroid muscle contraction pattern, which acts on a set of core characters shared among all derived snakes. Although palatine dragging elapids share a fundamental design of the palato-maxillary apparatus with all higher snakes, they provide yet another demonstration of minor structural modifications producing functional variants.

  11. Death Adder Envenoming Causes Neurotoxicity Not Reversed by Antivenom - Australian Snakebite Project (ASP-16)

    PubMed Central

    Johnston, Christopher I.; O'Leary, Margaret A.; Brown, Simon G. A.; Currie, Bart J.; Halkidis, Lambros; Whitaker, Richard; Close, Benjamin; Isbister, Geoffrey K.

    2012-01-01

    Background Death adders (Acanthophis spp) are found in Australia, Papua New Guinea and parts of eastern Indonesia. This study aimed to investigate the clinical syndrome of death adder envenoming and response to antivenom treatment. Methodology/Principal Findings Definite death adder bites were recruited from the Australian Snakebite Project (ASP) as defined by expert identification or detection of death adder venom in blood. Clinical effects and laboratory results were collected prospectively, including the time course of neurotoxicity and response to treatment. Enzyme immunoassay was used to measure venom concentrations. Twenty nine patients had definite death adder bites; median age 45 yr (5–74 yr); 25 were male. Envenoming occurred in 14 patients. Two further patients had allergic reactions without envenoming, both snake handlers with previous death adder bites. Of 14 envenomed patients, 12 developed neurotoxicity characterised by ptosis (12), diplopia (9), bulbar weakness (7), intercostal muscle weakness (2) and limb weakness (2). Intubation and mechanical ventilation were required for two patients for 17 and 83 hours. The median time to onset of neurotoxicity was 4 hours (0.5–15.5 hr). One patient bitten by a northern death adder developed myotoxicity and one patient only developed systemic symptoms without neurotoxicity. No patient developed venom induced consumption coagulopathy. Antivenom was administered to 13 patients, all receiving one vial initially. The median time for resolution of neurotoxicity post-antivenom was 21 hours (5–168). The median peak venom concentration in 13 envenomed patients with blood samples was 22 ng/mL (4.4–245 ng/mL). In eight patients where post-antivenom bloods were available, no venom was detected after one vial of antivenom. Conclusions/Significance Death adder envenoming is characterised by neurotoxicity, which is mild in most cases. One vial of death adder antivenom was sufficient to bind all circulating venom. The

  12. On fast carry select adders

    NASA Technical Reports Server (NTRS)

    Shamanna, M.; Whitaker, S.

    1992-01-01

    This paper presents an architecture for a high-speed carry select adder with very long bit lengths utilizing a conflict-free bypass scheme. The proposed scheme has almost half the number of transistors and is faster than a conventional carry select adder. A comparative study is also made between the proposed adder and a Manchester carry chain adder which shows that the proposed scheme has the same transistor count, without suffering any performance degradation, compared to the Manchester carry chain adder.

  13. On fast carry select adders

    NASA Astrophysics Data System (ADS)

    Shamanna, M.; Whitaker, S.

    This paper presents an architecture for a high-speed carry select adder with very long bit lengths utilizing a conflict-free bypass scheme. The proposed scheme has almost half the number of transistors and is faster than a conventional carry select adder. A comparative study is also made between the proposed adder and a Manchester carry chain adder which shows that the proposed scheme has the same transistor count, without suffering any performance degradation, compared to the Manchester carry chain adder.

  14. The Forbidden Quantum Adder

    NASA Astrophysics Data System (ADS)

    Alvarez-Rodriguez, U.; Sanz, M.; Lamata, L.; Solano, E.

    2015-07-01

    Quantum information provides fundamentally different computational resources than classical information. We prove that there is no unitary protocol able to add unknown quantum states belonging to different Hilbert spaces. This is an inherent restriction of quantum physics that is related to the impossibility of copying an arbitrary quantum state, i.e., the no-cloning theorem. Moreover, we demonstrate that a quantum adder, in absence of an ancillary system, is also forbidden for a known orthonormal basis. This allows us to propose an approximate quantum adder that could be implemented in the lab. Finally, we discuss the distinct character of the forbidden quantum adder for quantum states and the allowed quantum adder for density matrices.

  15. Deinococcus antarcticus sp. nov., isolated from soil.

    PubMed

    Dong, Ning; Li, Hui-Rong; Yuan, Meng; Zhang, Xiao-Hua; Yu, Yong

    2015-02-01

    A pink-pigmented, non-motile, coccoid bacterial strain, designated G3-6-20(T), was isolated from a soil sample collected in the Grove Mountains, East Antarctica. This strain was resistant to UV irradiation (810 J m(-2)) and slightly more sensitive to desiccation as compared with Deinococcus radiodurans. Phylogenetic analyses based on the 16S rRNA gene sequence of the isolate indicated that the organism belongs to the genus Deinococcus. Highest sequence similarities were with Deinococcus ficus CC-FR2-10(T) (93.5 %), Deinococcus xinjiangensis X-82(T) (92.8 %), Deinococcus indicus Wt/1a(T) (92.5 %), Deinococcus daejeonensis MJ27(T) (92.3 %), Deinococcus wulumuqiensis R-12(T) (92.3 %), Deinococcus aquaticus PB314(T) (92.2 %) and Deinococcus radiodurans DSM 20539(T) (92.2 %). Major fatty acids were C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), anteiso-C15 : 0 and C16 : 0. The G+C content of the genomic DNA of strain G3-6-20(T) was 63.1 mol%. Menaquinone 8 (MK-8) was the predominant respiratory quinone. Based on its phylogenetic position, and chemotaxonomic and phenotypic characteristics, strain G3-6-20(T) represents a novel species of the genus Deinococcus, for which the name Deinococcus antarcticus sp. nov. is proposed. The type strain is G3-6-20(T) ( = DSM 27864(T) = CCTCC AB 2013263(T)).

  16. Genome Sequence of the Antarctic Psychrophile Bacterium Planococcus antarcticus DSM 14505

    PubMed Central

    Margolles, Abelardo; Gueimonde, Miguel

    2012-01-01

    Planococcus antarcticus DSM 14505 is a psychrophile bacterium that was isolated from cyanobacterial mat samples, originally collected from ponds in McMurdo, Antarctica. This orange-pigmented bacterium grows at 4°C and may possess interesting enzymatic activities at low temperatures. Here we report the first genomic sequence of P. antarcticus DSM 14505. PMID:22843594

  17. Desiccation tolerance and drought acclimation in the Antarctic collembolan Cryptopygus antarcticus.

    PubMed

    Elnitsky, Michael A; Benoit, Joshua B; Denlinger, David L; Lee, Richard E

    2008-01-01

    The availability of water is recognized as the most important determinant of the distribution and activity of terrestrial organisms within the maritime Antarctic. Within this environment, arthropods may be challenged by drought stress during both the austral summer, due to increased temperature, wind, insolation, and extended periods of reduced precipitation, and the winter, as a result of vapor pressure gradients between the surrounding icy environment and the body fluids. The purpose of the present study was to assess the desiccation tolerance of the Antarctic springtail, Cryptopygus antarcticus, under ecologically-relevant conditions characteristic of both summer and winter along the Antarctic Peninsula. In addition, this study examined the physiological changes and effects of mild drought acclimation on the subsequent desiccation tolerance of C. antarcticus. The collembolans possessed little resistance to water loss under dry air, as the rate of water loss was >20% h(-1) at 0% relative humidity (RH) and 4 degrees C. Even under ecologically-relevant desiccating conditions, the springtails lost water at all relative humidities below saturation (100% RH). However, slow dehydration at high RH dramatically increased the desiccation tolerance of C. antarcticus, as the springtails tolerated a greater loss of body water. Relative to animals maintained at 100% RH, a mild drought acclimation at 98.2% RH significantly increased subsequent desiccation tolerance. Drought acclimation was accompanied by the synthesis and accumulation of several sugars and polyols that could function to stabilize membranes and proteins during dehydration. Drought acclimation may permit C. antarcticus to maintain activity and thereby allow sufficient time to utilize behavioral strategies to reduce water loss during periods of reduced moisture availability. The springtails were also susceptible to desiccation at subzero temperatures in equilibrium with the vapor pressure of ice; they lost

  18. The LMF triaxial MITL voltage adder system

    SciTech Connect

    Mazarakis, M.G.; Smith, D.L.; Bennett, L.F.; Lockner, T.R.; Olson, R.E.; Poukey, J.W.

    1992-12-31

    The light-ion microfusion driver design consists of multiple accelerating modules fired in coincidence and sequentially in order to provide the desired ion energy, power pulse shape and energy deposition uniformity on an Inertial Confinement Fusion (ICF) target. The basic energy source is a number of Marx generators which, through the appropriate pulse power conditioning, provide the necessary voltage pulse wave form to the accelerating gaps or feeds of each module. The cavity gaps are inductively isolated, and the voltage addition occurs in the center conductor of the voltage adder which is the positive electrode while the electrons of the sheath flow closer to the outer cylinder which is the magnetically insulated cathode electrode. Each module powers a separate two-stage extraction diode which provides a low divergence ion beam. In order to provide the two separate voltage pulses required by the diode, a triaxial adder system is designed for each module. The voltage addition occurs in two separate MITLs. The center hollow cylinder (anode) of the second MITL also serves as the outer cathode electrode for the extension of the first voltage adder MITL. The voltage of the second stage is about twice that of the first stage. The cavities are connected in series to form the outer cylinder of each module. The accelerating modules are positioned radially in a symmetrical way around the fusion chamber. A preliminary conceptual design of the LMF modules with emphasis on the voltage adders and extension MITLs will be presented and discussed.

  19. Characteristics of "Adders" in Proportional Reasoning.

    ERIC Educational Resources Information Center

    Lin, Fou-Lai

    1991-01-01

    The errors and strategies made by students who consistently use the incorrect-addition strategy on "hard" ratio tasks were investigated. The characteristics of these "adders," such as awareness of noninteger multiples, the use of fractions and decimals, awareness of both within and between ratios, and distinguishing nonratio…

  20. Genome Sequence of Rhodoferax antarcticus ANT.BRT; A Psychrophilic Purple Nonsulfur Bacterium from an Antarctic Microbial Mat

    PubMed Central

    Baker, Jennifer M.; Riester, Carli J.; Skinner, Blair M.; Newell, Austin W.; Swingley, Wesley D.; Madigan, Michael T.; Jung, Deborah O.; Asao, Marie; Chen, Min; Loughlin, Patrick C.; Pan, Hao; Lin, Yuankui; Li, Yaqiong; Shaw, Jacob; Prado, Mindy; Sherman, Chris; Tang, Joseph Kuo-Hsiang; Blankenship, Robert E.; Zhao, Tingting; Touchman, Jeffrey W.; Sattley, W. Matthew

    2017-01-01

    Rhodoferax antarcticus is an Antarctic purple nonsulfur bacterium and the only characterized anoxygenic phototroph that grows best below 20 °C. We present here a high-quality draft genome of Rfx. antarcticus strain ANT.BRT, isolated from an Antarctic microbial mat. The circular chromosome (3.8 Mbp) of Rfx. antarcticus has a 59.1% guanine + cytosine (GC) content and contains 4036 open reading frames. In addition, the bacterium contains a sizable plasmid (198.6 kbp, 48.4% GC with 226 open reading frames) that comprises about 5% of the total genetic content. Surprisingly, genes encoding light-harvesting complexes 1 and 3 (LH1 and LH3), but not light-harvesting complex 2 (LH2), were identified in the photosynthesis gene cluster of the Rfx. antarcticus genome, a feature that is unique among purple phototrophs. Consistent with physiological studies that showed a strong capacity for nitrogen fixation in Rfx. antarcticus, a nitrogen fixation gene cluster encoding a molybdenum-type nitrogenase was present, but no alternative nitrogenases were identified despite the cold-active phenotype of this phototroph. Genes encoding two forms of ribulose 1,5-bisphosphate carboxylase/oxygenase were present in the Rfx. antarcticus genome, a feature that likely provides autotrophic flexibility under varying environmental conditions. Lastly, genes for assembly of both type IV pili and flagella are present, with the latter showing an unusual degree of clustering. This report represents the first genomic analysis of a psychrophilic anoxygenic phototroph and provides a glimpse of the genetic basis for maintaining a phototrophic lifestyle in a permanently cold, yet highly variable, environment. PMID:28230808

  1. A C-Testable Multiple-Block Carry Select Adder

    NASA Astrophysics Data System (ADS)

    Kito, Nobutaka; Fujii, Shinichi; Takagi, Naofumi

    We propose a C-testable multiple-block carry select adder with respect to the cell fault model. Full adders and 2: 1 multiplexers are considered as cells. By an additional external input, we obtain a C-testable carry select adder. We only modify the least significant position of each block. The adder is testable with a test set consisting of 16 patterns regardless of the size of each block and the number of blocks. This is the minimum test set for the adder. We show two gate-level implementations of the adder which are testable with a test set of 9 patterns and 7 patterns respectively, with respect to the single stuck-at fault model.

  2. Static power dissipation in adder circuits: the UDSM domain

    NASA Astrophysics Data System (ADS)

    Cayouette, Steve; Al-Khalili, Dhamin

    2009-05-01

    This paper presents adder circuits of various architectures aimed at reducing static power dissipation. Circuit topologies for basic building blocks were evaluated for fabrication technologies of 65nm down to 32nm, and simulation results are presented. This work has lead to the development of various low power adder circuits and provides comparative analysis leading to the recommendation that a variable size block carry select adder is the best performer, taking into consideration both static and dynamic power dissipation.

  3. High performance pipelined multiplier with fast carry-save adder

    NASA Technical Reports Server (NTRS)

    Wu, Angus

    1990-01-01

    A high-performance pipelined multiplier is described. Its high performance results from the fast carry-save adder basic cell which has a simple structure and is suitable for the Gate Forest semi-custom environment. The carry-save adder computes the sum and carry within two gate delay. Results show that the proposed adder can operate at 200 MHz for a 2-micron CMOS process; better performance is expected in a Gate Forest realization.

  4. Detection of proteases from Sporosarcina aquimarina and Algoriphagus antarcticus isolated from Antarctic soil.

    PubMed

    Santos, Anderson F; Pires, Fabiano; Jesus, Hugo E; Santos, André L S; Peixoto, Raquel; Rosado, Alexandre S; D'Avila-Levy, Claudia M; Branquinha, Marta H

    2015-03-01

    Two psychrophilic bacterial samples were isolated from King George Island soil, in Antarctica. The phylogenetic analysis based on the 16S rRNA (rrs) gene led to the correlation with the closest related isolates as Sporosarcina aquimarina (99%) and Algoriphagus antarcticus (99%), with query coverage of 99% and 98%, respectively. The spent culture media from both isolates displayed proteolytic activities detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis containing gelatin as protein substrate. Under the employed conditions, S. aquimarina showed a 55 kDa protease with the best activity detected at pH 7.0 and at 27°C. A. antarcticus also showed a single extracellular protease, however its molecular mass was around 90kDa and its best activity was detected at pH 9.0 and at 37°C. The proteases from both isolates were inhibited by 1,10-phenanthroline and EDTA, two metalloprotease inhibitors. This is the first record of protease detection in both species, and our results may contribute to broaden the basic knowledge of proteases from the Antarctica environment and may help prospecting future biotechnological applications of these enzymes.

  5. Efficient radix-r adders for nanoelectronics

    NASA Astrophysics Data System (ADS)

    Moaiyeri, Mohammad Hossein; Chavoshisani, Reza; Jalali, Ali; Navi, Keivan; Hashemipour, Omid

    2016-02-01

    In this study, a new design method and efficient designs for radix-r adders are proposed for carbon nanotube field effect transistor (CNFET) FET nanotechnology. This application also investigates the capability of the nanoscale device for designing high-performance analogue circuits. The proposed designs benefit from the unique electrical properties of CNFET, such as near-ideal current voltage characteristics, very high transconductance, high-performance switches and very high-performance and high-gain binary inverters, at nanoscale. Moreover, adjustable threshold voltage and the same mobility of electrons and holes in a CNFET facilitate the design and modification procedures. The proposed design can be considered as an instance of a general adder, capable of adding radix-r digits with high precision. It is noteworthy that a very limited number of carbon nanotube diameters for designing the proposed adder are needed, which enhance the manufacturability. The proposed circuits are designed based on arithmetic relations and are also verified at 32 nm feature size using HSPICE and the Stanford standard SPICE model.

  6. A novel reversible carry-selected adder with low latency

    NASA Astrophysics Data System (ADS)

    Li, Ming-Cui; Zhou, Ri-Gui

    2016-07-01

    Reversible logic is getting more and more attention in quantum computing, optical computing, nanotechnology and low-power complementary metal oxide semiconductor designs since reversible circuits do not loose information during computation and have only small energy dissipation. In this paper, a novel carry-selected reversible adder is proposed primarily optimised for low latency. A 4-bit reversible full adder with two kinds of outputs, minimum delay and optimal quantum cost is presented as the building block for ?-bit reversible adder. Three new reversible gates NPG (new Peres gate), TEPG (triple extension of Peres gate) and RMUX21 (reversible 2-to-1 multiplexer) are proposed and utilised to design efficient adder units. The secondary carry propagation chain is carefully designed to reduce the time consumption. The novelty of the proposed design is the consideration of low latency. The comparative study shows that the proposed adder achieves the improvement from 61.46% to 95.29% in delay over the existing designs.

  7. Switchable optical image adder/subtractor.

    PubMed

    Hengst, G T; Roh, W B

    1991-02-01

    We demonstrate a switchable, parallel optical image adder/subtractor, using a Michelson interferometer configured with a phase-conjugating mirror. With the path difference of the interferometer legs within the coherence length of the laser, coherent image subtraction is obtained. By electronically switching the beam in one of the legs in the interferometer into an extra length, beyond the coherence length of the laser, incoherent image addition is performed. Two simple experiments showing the switching characteristics and the arithmetic operations are described. This kind of device should find applications in image processing and optical computing.

  8. Error correction in adders using systematic subcodes.

    NASA Technical Reports Server (NTRS)

    Rao, T. R. N.

    1972-01-01

    A generalized theory is presented for the construction of a systematic subcode for a given AN code in such a way that error control properties of the AN code are preserved in this new code. The 'systematic weight' and 'systematic distance' functions in this new code depend not only on its number representation system but also on its addition structure. Finally, to illustrate this theory, a simple error-correcting adder organization using a systematic subcode of 29 N code is sketched in some detail.

  9. High Speed Capacitor-Inverter Based Carbon Nanotube Full Adder

    PubMed Central

    2010-01-01

    Carbon Nanotube filed-effect transistor (CNFET) is one of the promising alternatives to the MOS transistors. The geometry-dependent threshold voltage is one of the CNFET characteristics, which is used in the proposed Full Adder cell. In this paper, we present a high speed Full Adder cell using CNFETs based on majority-not (Minority) function. Presented design uses eight transistors and eight capacitors. Simulation results show significant improvement in terms of delay and power-delay product in comparison to contemporary CNFET Adder Cells. Simulations were carried out using HSPICE based on CNFET model with 0.6 V VDD. PMID:20671796

  10. High speed capacitor-inverter based carbon nanotube full adder.

    PubMed

    Navi, K; Rashtian, M; Khatir, A; Keshavarzian, P; Hashemipour, O

    2010-03-18

    Carbon Nanotube filed-effect transistor (CNFET) is one of the promising alternatives to the MOS transistors. The geometry-dependent threshold voltage is one of the CNFET characteristics, which is used in the proposed Full Adder cell. In this paper, we present a high speed Full Adder cell using CNFETs based on majority-not (Minority) function. Presented design uses eight transistors and eight capacitors. Simulation results show significant improvement in terms of delay and power-delay product in comparison to contemporary CNFET Adder Cells. Simulations were carried out using HSPICE based on CNFET model with 0.6 V VDD.

  11. Temperature Insensitivity and Behavioural Reduction of the Physiological Stress Response to Longline Capture by the Gummy Shark, Mustelus antarcticus

    PubMed Central

    Guida, Leonardo; Walker, Terence I.; Reina, Richard D.

    2016-01-01

    Many factors influence the physiological stress response to fisheries capture in elasmobranchs. However, the influence of sea surface temperatures (SST) and behaviour are unknown and crucial considering global fishing pressures. We investigated the effect of SST and behaviour on the physiological stress response to capture of the gummy shark, Mustelus antarcticus, and compared our results to a laboratory study using similar conditions to test whether stress responses of in situ capture are consistent with those from laboratory simulations. Capture time for 23 M. antarcticus ranged 32–241 min as measured by hook timers or time depth recorders (TDR) in SSTs ranging 12–20°C. TDR data from 13 M. antarcticus were analysed to quantify capture behaviour as the percentage of time spent moving during capture. Several physiological variables measured from blood samples obtained immediately upon the animals’ landing indicated that although warmer SSTs increased metabolic rate, the stress response to capture was not exacerbated by capture duration. During capture movement occurred for an average of 10% of the time and since M. antarcticus can respire whilst stationary, restricted movement probably mitigated potential influences of increased SSTs and capture duration on the stress response. Previous laboratory findings were also shown to be indicative of in situ conditions and we thus advise that studies control for water temperature given the influence it has on variables (e.g. lactate) used to measure capture stress in elasmobranchs. We highlight the importance of seasonal water temperatures and capture behaviour when assessing the resilience to fisheries capture and the implementation of appropriate fisheries management strategies. PMID:26886126

  12. Low Power Adder Based Auditory Filter Architecture

    PubMed Central

    Jayanthi, V. S.

    2014-01-01

    Cochlea devices are powered up with the help of batteries and they should possess long working life to avoid replacing of devices at regular interval of years. Hence the devices with low power consumptions are required. In cochlea devices there are numerous filters, each responsible for frequency variant signals, which helps in identifying speech signals of different audible range. In this paper, multiplierless lookup table (LUT) based auditory filter is implemented. Power aware adder architectures are utilized to add the output samples of the LUT, available at every clock cycle. The design is developed and modeled using Verilog HDL, simulated using Mentor Graphics Model-Sim Simulator, and synthesized using Synopsys Design Compiler tool. The design was mapped to TSMC 65 nm technological node. The standard ASIC design methodology has been adapted to carry out the power analysis. The proposed FIR filter architecture has reduced the leakage power by 15% and increased its performance by 2.76%. PMID:25506073

  13. Low power adder based auditory filter architecture.

    PubMed

    Rahiman, P F Khaleelur; Jayanthi, V S

    2014-01-01

    Cochlea devices are powered up with the help of batteries and they should possess long working life to avoid replacing of devices at regular interval of years. Hence the devices with low power consumptions are required. In cochlea devices there are numerous filters, each responsible for frequency variant signals, which helps in identifying speech signals of different audible range. In this paper, multiplierless lookup table (LUT) based auditory filter is implemented. Power aware adder architectures are utilized to add the output samples of the LUT, available at every clock cycle. The design is developed and modeled using Verilog HDL, simulated using Mentor Graphics Model-Sim Simulator, and synthesized using Synopsys Design Compiler tool. The design was mapped to TSMC 65 nm technological node. The standard ASIC design methodology has been adapted to carry out the power analysis. The proposed FIR filter architecture has reduced the leakage power by 15% and increased its performance by 2.76%.

  14. Rhodoferax antarcticus sp. nov., a moderately psychrophilic purple nonsulfur bacterium isolated from an Antarctic microbial mat

    NASA Technical Reports Server (NTRS)

    Madigan, M. T.; Jung, D. O.; Woese, C. R.; Achenbach, L. A.

    2000-01-01

    A new species of purple nonsulfur bacteria isolated from an Antarctic microbial mat is described. The organism, designated strain ANT.BR, was mildly psychrophilic, growing optimally at 15-18 degrees C with a growth temperature range of 0-25 degrees C. Cells of strain ANT.BR were highly motile curved rods and spirals, contained bacteriochlorophyll a, and showed a multicomponent in vivo absorption spectrum. A specific phylogenetic relationship was observed between strain ANT.BR and the purple bacterium Rhodoferax fermentans FR2T, and the two organisms shared several physiological and other phenotypic properties, with the notable exception of growth temperature optimum. Tests of genomic DNA hybridization, however, showed Rfx. fermentans FR2T and strain ANT.BR to be genetically distinct bacteria. Because of its unique set of properties, especially its requirement for low growth temperatures, we propose to recognize strain ANT.BR as a new species of the genus Rhodoferax, Rhodoferax antarcticus, named for its known habitat, the Antarctic.

  15. Constrictibacter antarcticus gen. nov., sp. nov., a cryptoendolithic micro-organism from Antarctic white rock.

    PubMed

    Yamada, Kozo; Fukuda, Wakao; Kondo, Yuka; Miyoshi, Yuki; Atomi, Haruyuki; Imanaka, Tadayuki

    2011-08-01

    A Gram-negative, non-spore-forming, ovoid to rod-shaped aerobic or microaerobic bacterium, strain 262-8(T), was isolated from a cavity within white rock collected in Antarctica. Strain 262-8(T) grew at 5-30 °C (optimum 25 °C), at pH 6-8 (optimum approximately pH 7) and with 0.1-2.0 % (w/v) NaCl (optimum 0.5 % NaCl). The addition of tryptone or yeast extract was essential for growth. Strain 262-8(T) was able to utilize organic compounds such as ribose, pyruvate and succinate in the presence of a low concentration of tryptone. Ubiquinone 10 was the major respiratory quinone. The major fatty acids were C(18 : 1), C(16 : 0) and C(18 : 0). The G+C content of the genomic DNA was 69.8 mol%. Comparative analyses of 16S rRNA gene sequences and physiological characteristics indicated that strain 262-8(T) was a phylogenetically novel bacterium that should be classified in a new genus of the family Rhodospirillaceae, for which the name Constrictibacter antarcticus gen. nov., sp. nov. is proposed. The type strain of the type species is 262-8(T) ( = JCM 16422(T) = ATCC BAA-1906(T)).

  16. Partitioning and characterization of high speed adder structures in deep-submicron technologies

    NASA Astrophysics Data System (ADS)

    Estrada, Adrián; Sassaw, Gashaw; Jiménez, Carlos J.; Valencia, Manuel

    2007-05-01

    The availability of higher performance (in area, time and power consumption) and greater precision binary adders is a constant requirement in digital systems. Consequently, the design and characterization of adders and, most of all, their adaptation to the requisites of present-day deep-submicron technologies, are today still issues of concern. The binary adder structures in deep-submicron technologies must be revised to achieve the best balance between the number of bits in the adder and its delay, area and power consumption. It is therefore very important to make an effort to carefully optimize adder structures, thus obtaining improvements in digital systems. This communication presents the optimization of adder structures for implementations in deep-submicron technologies through their partitioning into blocks. This partitioning consists of dividing the number of input bits to the adder into several subsets of bits that will constitute the inputs to several adder structures of the same or of different types. The structures used to accomplish this study range from the more traditional types, such as the carry look ahead adder, the ripple carry adder or the carry select adder, to more innovative kinds, like the parallel prefix adders of the type proposed by Brent-Kung, Han-Carlson, Kogge-Stone or Ladner-Fischer. The analyses carried out allow the characterization of structures implemented in deep-submicron technologies for area, delay and power consumption parameters.

  17. Inductive voltage adder (IVA) for submillimeter radius electron beam

    SciTech Connect

    Mazarakis, M.G.; Poukey, J.W.; Maenchen, J.E.

    1996-12-31

    The authors have already demonstrated the utility of inductive voltage adder accelerators for production of small-size electron beams. In this approach, the inductive voltage adder drives a magnetically immersed foilless diode to produce high-energy (10--20 MeV), high-brightness pencil electron beams. This concept was first demonstrated with the successful experiments which converted the linear induction accelerator RADLAC II into an IVA fitted with a small 1-cm radius cathode magnetically immersed foilless diode (RADLAC II/SMILE). They present here first validations of extending this idea to mm-scale electron beams using the SABRE and HERMES-III inductive voltage adders as test beds. The SABRE experiments are already completed and have produced 30-kA, 9-MeV electron beams with envelope diameter of 1.5-mm FWHM. The HERMES-III experiments are currently underway.

  18. Internal anatomy of Haliclystus antarcticus (Cnidaria, Staurozoa) with a discussion on histological features used in Staurozoan taxonomy.

    PubMed

    Miranda, Lucília S; Collins, Allen G; Marques, Antonio C

    2013-12-01

    Stauromedusae have relatively few macromorphological characters, making both their taxonomy and identification difficult. For this reason, histological characters are also employed in the taxonomy of the group. This study presents a detailed description of the histomorphology of Haliclystus antarcticus Pfeffer, 1889 (Cnidaria, Staurozoa). We make new observations for the species and for the class, and address functional, taxonomical, and evolutionary aspects of staurozoan histo-anatomy. A complete reconstruction of H. antarcticus body plan is used to guide a more detailed observation, based on light microscopy, of structures rarely cited in the literature, such as the intertentacular lobules, the ostia between adjacent perradial pockets, and the male and female gonadal vesicles. Two possible regions of nematocyst formation are hypothesized and discussed. We also provide a review of the current use of histological characters in the taxonomy of the group. Understanding the body plan of stauromedusae is a challenge, because each single individual presents characters found in medusae and in polyps of other medusozoans. Comprehensive histological descriptions are important to establish relations of homology within Staurozoa and Cnidaria, providing crucial data on their evolution.

  19. Excitation of voltage oscillations in an induction voltage adder

    NASA Astrophysics Data System (ADS)

    Bruner, Nichelle; Genoni, Thomas; Madrid, Elizabeth; Welch, Dale; Hahn, Kelly; Oliver, Bryan

    2009-07-01

    The induction voltage adder is an accelerator architecture used in recent designs of pulsed-power driven x-ray radiographic systems such as Sandia National Laboratories’ Radiographic Integrated Test Stand (RITS), the Atomic Weapons Establishment’s planned Hydrus Facility, and the Naval Research Laboratory’s Mercury. Each of these designs relies on magnetic insulation to prevent electron loss across the anode-cathode gap in the vicinity of the adder as well as in the coaxial transmission line. Particle-in-cell simulations of the RITS adder and transmission line show that, as magnetic insulation is being established during a pulse, some electron loss occurs across the gap. Sufficient delay in the cavity pulse timings provides an opportunity for high-momentum electrons to deeply penetrate the cavities of the adder cells where they can excite radio-frequency resonances. These oscillations may be amplified in subsequent gaps, resulting in oscillations in the output power. The specific modes supported by the RITS-6 accelerator and details of the mechanism by which they are excited are presented in this paper.

  20. Nothing special in the specialist? Draft genome sequence of Cryomyces antarcticus, the most extremophilic fungus from Antarctica.

    PubMed

    Sterflinger, Katja; Lopandic, Ksenija; Pandey, Ram Vinay; Blasi, Barbara; Kriegner, Albert

    2014-01-01

    The draft genome of the Antarctic endemic fungus Cryomyces antarcticus is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with Neurospora crassa as well as with other microcolonial fungi shows that the fungus has a genome size of 24 Mbp, which is the average in the fungal kingdom. Although sexual reproduction was never observed in this fungus, 34 mating genes are present with protein homologs in the classes Eurotiomycetes, Sordariomycetes and Dothideomycetes. The first analysis of the draft genome did not reveal any significant deviations of this genome from comparative species and mesophilic hyphomycetes.

  1. Nothing Special in the Specialist? Draft Genome Sequence of Cryomyces antarcticus, the Most Extremophilic Fungus from Antarctica

    PubMed Central

    Sterflinger, Katja; Lopandic, Ksenija; Pandey, Ram Vinay; Blasi, Barbara; Kriegner, Albert

    2014-01-01

    The draft genome of the Antarctic endemic fungus Cryomyces antarcticus is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with Neurospora crassa as well as with other microcolonial fungi shows that the fungus has a genome size of 24 Mbp, which is the average in the fungal kingdom. Although sexual reproduction was never observed in this fungus, 34 mating genes are present with protein homologs in the classes Eurotiomycetes, Sordariomycetes and Dothideomycetes. The first analysis of the draft genome did not reveal any significant deviations of this genome from comparative species and mesophilic hyphomycetes. PMID:25296285

  2. INDUCTIVE VOLTAGE ADDER NETWORK ANALYSIS AND MODEL SIMPLIFICATION.

    SciTech Connect

    ZHANG,W.; NG, W.; PAI, C.; SANDBERG, J.; TAN, Y.; TIAN, Y.

    2007-06-17

    Inductive voltage adder topology has attracted great attentions in pulse power community for near two decades. However, there has been lack of literatures on inductive voltage adder network analysis and circuit design model. We have recently developed a simplified model and a set of simple formulas. An expanded model and more detailed analysis are presented in this paper. Our model reveals the relationship of output waveform parameters and hardware designs. Computer simulations have demonstrated that parameter estimation based on this approach is accurate. This approach can be used in early stages of project development to assist feasibility study, geometry selection in engineering design, and parameter selection of critical components. A set of fundamental estimation formulas including system impedance, rise time, and number of stages are presented. This approach is also applicable to induction LINAC design. In addition, the model presented in this paper shows a new topology of high voltage waveform generator.

  3. An enhanced high-speed multi-digit BCD adder using quantum-dot cellular automata

    NASA Astrophysics Data System (ADS)

    Ajitha, D.; Ramanaiah, K. V.; Sumalatha, V.

    2017-02-01

    The advent of development of high-performance, low-power digital circuits is achieved by a suitable emerging nanodevice called quantum-dot cellular automata (QCA). Even though many efficient arithmetic circuits were designed using QCA, there is still a challenge to implement high-speed circuits in an optimized manner. Among these circuits, one of the essential structures is a parallel multi-digit decimal adder unit with significant speed which is very attractive for future environments. To achieve high speed, a new correction logic formulation method is proposed for single and multi-digit BCD adder. The proposed enhanced single-digit BCD adder (ESDBA) is 26% faster than the carry flow adder (CFA)-based BCD adder. The multi-digit operations are also performed using the proposed ESDBA, which is cascaded innovatively. The enhanced multi-digit BCD adder (EMDBA) performs two 4-digit and two 8-digit BCD addition 50% faster than the CFA-based BCD adder with the nominal overhead of the area. The EMDBA performs two 4-digit BCD addition 24% faster with 23% decrease in the area, similarly for 8-digit operation the EMDBA achieves 36% increase in speed with 21% less area compared to the existing carry look ahead (CLA)-based BCD adder design. The proposed multi-digit adder produces significantly less delay of (N –1) + 3.5 clock cycles compared to the N* One digit BCD adder delay required by the conventional BCD adder method. It is observed that as per our knowledge this is the first innovative proposal for multi-digit BCD addition using QCA.

  4. Two novel low-power and high-speed dynamic carbon nanotube full-adder cells

    PubMed Central

    2011-01-01

    In this paper, two novel low-power and high-speed carbon nanotube full-adder cells in dynamic logic style are presented. Carbon nanotube field-effect transistors (CNFETs) are efficient in designing a high performance circuit. To design our full-adder cells, CNFETs with three different threshold voltages (low threshold, normal threshold, and high threshold) are used. First design generates SUM and COUT through separate transistors, and second design is a multi-output dynamic full adder. Proposed full adders are simulated using HSPICE based on CNFET model with 0.9 V supply voltages. Simulation result shows that the proposed designs consume less power and have low power-delay product compared to other CNFET-based full-adder cells. PMID:21888634

  5. BIOMEX Experiment: Ultrastructural Alterations, Molecular Damage and Survival of the Fungus Cryomyces antarcticus after the Experiment Verification Tests

    NASA Astrophysics Data System (ADS)

    Pacelli, Claudia; Selbmann, Laura; Zucconi, Laura; De Vera, Jean-Pierre; Rabbow, Elke; Horneck, Gerda; de la Torre, Rosa; Onofri, Silvano

    2016-04-01

    The search for traces of extinct or extant life in extraterrestrial environments is one of the main goals for astrobiologists; due to their ability to withstand stress producing conditions, extremophiles are perfect candidates for astrobiological studies. The BIOMEX project aims to test the ability of biomolecules and cell components to preserve their stability under space and Mars-like conditions, while at the same time investigating the survival capability of microorganisms. The experiment has been launched into space and is being exposed on the EXPOSE-R2 payload, outside of the International Space Station (ISS) over a time-span of 1.5 years. Along with a number of other extremophilic microorganisms, the Antarctic cryptoendolithic black fungus Cryomyces antarcticus CCFEE 515 has been included in the experiment. Before launch, dried colonies grown on Lunar and Martian regolith analogues were exposed to vacuum, irradiation and temperature cycles in ground based experiments (EVT1 and EVT2). Cultural and molecular tests revealed that the fungus survived on rock analogues under space and simulated Martian conditions, showing only slight ultra-structural and molecular damage.

  6. Low Power Adder Based Digital Filter for QRS Detector

    PubMed Central

    Murali, L.; Chitra, D.; Manigandan, T.

    2014-01-01

    Most of the Biomedical applications use dedicated processors for the implementation of complex signal processing. Among them, sensor network is also a type, which has the constraint of low power consumption. Since the processing elements are the most copiously used operations in the signal processors, the power consumption of this has the major impact on the system level application. In this paper, we introduce low power concept of transistor stacking to reduce leakage power; and new architectures based on stacking to implement the full adder and its significance at the digital filter level for QRS detector are implemented. The proposed concept has lesser leakage power at the adder as well as filter level with trade-off in other quality metrics of the design. This enabled the design to be dealt with as the low-power corner and can be made adaptable to any level of hierarchical abstractions as per the requirement of the application. The proposed architectures are designed, modeled at RTL level using the Verilog-HDL, and synthesized in Synopsys Design Compiler by mapping the design to 65 nm technology library standard cells. PMID:24895649

  7. Low power adder based digital filter for QRS detector.

    PubMed

    Murali, L; Chitra, D; Manigandan, T

    2014-01-01

    Most of the Biomedical applications use dedicated processors for the implementation of complex signal processing. Among them, sensor network is also a type, which has the constraint of low power consumption. Since the processing elements are the most copiously used operations in the signal processors, the power consumption of this has the major impact on the system level application. In this paper, we introduce low power concept of transistor stacking to reduce leakage power; and new architectures based on stacking to implement the full adder and its significance at the digital filter level for QRS detector are implemented. The proposed concept has lesser leakage power at the adder as well as filter level with trade-off in other quality metrics of the design. This enabled the design to be dealt with as the low-power corner and can be made adaptable to any level of hierarchical abstractions as per the requirement of the application. The proposed architectures are designed, modeled at RTL level using the Verilog-HDL, and synthesized in Synopsys Design Compiler by mapping the design to 65 nm technology library standard cells.

  8. Characteristics of pulsed power generator by versatile inductive voltage adder

    NASA Astrophysics Data System (ADS)

    Yatsui, Kiyoshi; Shimiya, Kouichi; Masugata, Katsumi; Shigeta, Masao; Shibata, Kazuhiko

    2005-10-01

    A pulsed power generator by inductive voltage adder, versatile inductive voltage adder (VIVA-I), which features a high average potential gradient (2.5 MV/m), was designed and is currently in operation,. It was designed to produce an output pulse of 4 MV/60 ns by adding 2 MV pulses in two-stages of induction cells, where amorphous cores are installed. As a pulse forming line, we used a Blumlein line with the switching reversed, where cores are automatically biased due to the presence of prepulse. Good reproducibility was obtained even in the absence of the reset pulse. Within [similar]40% of full charge voltage, pulsed power characteristics of Marx generator, pulse forming line (PFL), transmission line (TL), and induction cells were tested for three types of loads; open-circuit, dummy load of liquid (CuSO4) resistor, and electron beam diode. In the open-circuit test, [similar]2.0 MV of output voltage was obtained with good reproducibility. Dependences of output voltage on diode impedances were evaluated by using various dummy loads, and the results were found as expected. An electron-beam diode was operated successfully, and [similar]18 kA of beam current was obtained at the diode voltage of [similar]1 MV.

  9. Specific amino acids responsible for the cold adaptedness of Micrococcus antarcticus β-glucosidase BglU.

    PubMed

    Miao, Li-Li; Fan, Hong-Xia; Qu, Jie; Liu, Ying; Liu, Zhi-Pei

    2017-03-01

    Psychrophilic enzymes display efficient activity at moderate or low temperatures (4-25 °C) and are therefore of great interest in biotechnological industries. We previously examined the crystal structure of BglU, a psychrophilic β-glucosidase from the bacterium Micrococcus antarcticus, at 2.2 Å resolution. In structural comparison and sequence alignment with mesophilic (BglB) and thermophilic (GlyTn) counterpart enzymes, BglU showed much lower contents of Pro residue and of charged amino acids (particularly positively charged) on the accessible surface area. In the present study, we investigated the roles of specific amino acid residues in the cold adaptedness of BglU. Mutagenesis assays showed that the mutations G261R and Q448P increased optimal temperature (from 25 to 40-45 °C) at the expense of low-temperature activity, but had no notable effects on maximal activity or heat lability. Mutations A368P, T383P, and A389E significantly increased optimal temperature (from 25 to 35-40 °C) and maximal activity (~1.5-fold relative to BglU). Thermostability of A368P and A389E increased slightly at 30 °C. Mutations K163P, N228P, and H301A greatly reduced enzymatic activity-almost completely in the case of H301A. Low contents of Pro, Arg, and Glu are important factors contributing to BglU's psychrophilic properties. Our findings will be useful in structure-based engineering of psychrophilic enzymes and in production of mutants suitable for a variety of industrial processes (e.g., food production, sewage treatment) at cold or moderate temperatures.

  10. Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus

    PubMed Central

    Miao, Li-Li; Hou, Yan-Jie; Fan, Hong-Xia; Qu, Jie; Qi, Chao; Liu, Ying

    2016-01-01

    Psychrophilic enzymes play crucial roles in cold adaptation of microbes and provide useful models for studies of protein evolution, folding, and dynamic properties. We examined the crystal structure (2.2-Å resolution) of the psychrophilic β-glucosidase BglU, a member of the glycosyl hydrolase 1 (GH1) enzyme family found in the cold-adapted bacterium Micrococcus antarcticus. Structural comparison and sequence alignment between BglU and its mesophilic and thermophilic counterpart enzymes (BglB and GlyTn, respectively) revealed two notable features distinct to BglU: (i) a unique long-loop L3 (35 versus 7 amino acids in others) involved in substrate binding and (ii) a unique amino acid, His299 (Tyr in others), involved in the stabilization of an ordered water molecule chain. Shortening of loop L3 to 25 amino acids reduced low-temperature catalytic activity, substrate-binding ability, the optimal temperature, and the melting temperature (Tm). Mutation of His299 to Tyr increased the optimal temperature, the Tm, and the catalytic activity. Conversely, mutation of Tyr301 to His in BglB caused a reduction in catalytic activity, thermostability, and the optimal temperature (45 to 35°C). Loop L3 shortening and H299Y substitution jointly restored enzyme activity to the level of BglU, but at moderate temperatures. Our findings indicate that loop L3 controls the level of catalytic activity at low temperatures, residue His299 is responsible for thermolability (particularly heat lability of the active center), and long-loop L3 and His299 are jointly responsible for the psychrophilic properties. The described structural basis for the cold adaptedness of BglU will be helpful for structure-based engineering of new cold-adapted enzymes and for the production of mutants useful in a variety of industrial processes at different temperatures. PMID:26801571

  11. Design of efficient full adder in quantum-dot cellular automata.

    PubMed

    Sen, Bibhash; Rajoria, Ayush; Sikdar, Biplab K

    2013-01-01

    Further downscaling of CMOS technology becomes challenging as it faces limitation of feature size reduction. Quantum-dot cellular automata (QCA), a potential alternative to CMOS, promises efficient digital design at nanoscale. Investigations on the reduction of QCA primitives (majority gates and inverters) for various adders are limited, and very few designs exist for reference. As a result, design of adders under QCA framework is gaining its importance in recent research. This work targets developing multi-layered full adder architecture in QCA framework based on five-input majority gate proposed here. A minimum clock zone (2 clock) with high compaction (0.01 μ m(2)) for a full adder around QCA is achieved. Further, the usefulness of such design is established with the synthesis of high-level logic. Experimental results illustrate the significant improvements in design level in terms of circuit area, cell count, and clock compared to that of conventional design approaches.

  12. Design of Efficient Full Adder in Quantum-Dot Cellular Automata

    PubMed Central

    Sen, Bibhash; Sikdar, Biplab K.

    2013-01-01

    Further downscaling of CMOS technology becomes challenging as it faces limitation of feature size reduction. Quantum-dot cellular automata (QCA), a potential alternative to CMOS, promises efficient digital design at nanoscale. Investigations on the reduction of QCA primitives (majority gates and inverters) for various adders are limited, and very few designs exist for reference. As a result, design of adders under QCA framework is gaining its importance in recent research. This work targets developing multi-layered full adder architecture in QCA framework based on five-input majority gate proposed here. A minimum clock zone (2 clock) with high compaction (0.01 μm2) for a full adder around QCA is achieved. Further, the usefulness of such design is established with the synthesis of high-level logic. Experimental results illustrate the significant improvements in design level in terms of circuit area, cell count, and clock compared to that of conventional design approaches. PMID:23844385

  13. Design, Implementation, and Testing of a High Performance Summation Adder for Radar Image Synthesis

    DTIC Science & Technology

    2001-09-01

    QUINE - MCCLUSKEY MINIMIZATION ROUTINE ......... 149 A. OVERVIEW ........................................ 149 B. ADDER.M...increased in complexity it was necessary to write a logic minimization computer routine, based on the Quine - McCluskey tabular technique [13]. In... Quine - McCluskey tabular technique [13] to optimize the 4-bit MSI adder with NOR gate logic. Optimized to NOR gate logic, the S0 bit can be realized by

  14. Bit-Serial Adder Based on Quantum Dots

    NASA Technical Reports Server (NTRS)

    Fijany, Amir; Toomarian, Nikzad; Modarress, Katayoon; Spotnitz, Mathew

    2003-01-01

    A proposed integrated circuit based on quantum-dot cellular automata (QCA) would function as a bit-serial adder. This circuit would serve as a prototype building block for demonstrating the feasibility of quantum-dots computing and for the further development of increasingly complex and increasingly capable quantum-dots computing circuits. QCA-based bit-serial adders would be especially useful in that they would enable the development of highly parallel and systolic processors for implementing fast Fourier, cosine, Hartley, and wavelet transforms. The proposed circuit would complement the QCA-based circuits described in "Implementing Permutation Matrices by Use of Quantum Dots" (NPO-20801), NASA Tech Briefs, Vol. 25, No. 10 (October 2001), page 42 and "Compact Interconnection Networks Based on Quantum Dots" (NPO-20855), which appears elsewhere in this issue. Those articles described the limitations of very-large-scale-integrated (VLSI) circuitry and the major potential advantage afforded by QCA. To recapitulate: In a VLSI circuit, signal paths that are required not to interact with each other must not cross in the same plane. In contrast, for reasons too complex to describe in the limited space available for this article, suitably designed and operated QCA-based signal paths that are required not to interact with each other can nevertheless be allowed to cross each other in the same plane without adverse effect. In principle, this characteristic could be exploited to design compact, coplanar, simple (relative to VLSI) QCA-based networks to implement complex, advanced interconnection schemes. To enable a meaningful description of the proposed bit-serial adder, it is necessary to further recapitulate the description of a quantum-dot cellular automation from the first-mentioned prior article: A quantum-dot cellular automaton contains four quantum dots positioned at the corners of a square cell. The cell contains two extra mobile electrons that can tunnel (in the

  15. Simple novel all-optical half-adder

    NASA Astrophysics Data System (ADS)

    Chen, Zhixin

    2010-04-01

    On the basis of Sagnac interferometric structure, a simple novel ultrafast scheme of all-optical half-adder is proposed. The structure comprises two of the same balanced terahertz optical asymmetric demultiplexers (TOADs). One TOAD is utilized to achieve an all-optical XOR gate, which is logic SUM. The other is utilized to obtain an all-optical AND gate, which is logic CARRY. Logical SUM and CARRY are simultaneously realized at 80 Gbit/s. Through numerical analysis, the operating characteristics of the scheme are illustrated at 80 Gbit/s. Furthermore, the carrier recovery time of the semiconductor optical amplifier is no longer a crucial parameter to restrict the operation speed of this scheme.

  16. A SIMPLIFIED APPROACH TO ANALYZE AND MODEL INDUCTIVE VOLTAGE ADDER

    SciTech Connect

    ZHANG,W.; ENG, W.; PAI, C.; SANDBERG, J.; TAN, Y.; TIAN, Y.

    2007-06-25

    We have recently developed a simplified model and a set of simple formulas for inductive voltage adder design. This model reveals the relationship of output waveform parameters and hardware designs. A computer simulation has demonstrated that parameter estimation based on this approach is accurate as compared to an actual circuit. This approach can be used in early stages of project development to assist feasibility study, geometry selection in engineering design, and parameter selection of critical components. In this paper, we give the deduction of a simplified model. Among the estimation formulas we present are those for pulse rise time, system impedance, and number of stages. Examples are used to illustrate the advantage of this approach. This approach is also applicable to induction LINAC design.

  17. Towards constructing multi-bit binary adder based on Belousov-Zhabotinsky reaction

    NASA Astrophysics Data System (ADS)

    Zhang, Guo-Mao; Wong, Ieong; Chou, Meng-Ta; Zhao, Xin

    2012-04-01

    It has been proposed that the spatial excitable media can perform a wide range of computational operations, from image processing, to path planning, to logical and arithmetic computations. The realizations in the field of chemical logical and arithmetic computations are mainly concerned with single simple logical functions in experiments. In this study, based on Belousov-Zhabotinsky reaction, we performed simulations toward the realization of a more complex operation, the binary adder. Combining with some of the existing functional structures that have been verified experimentally, we designed a planar geometrical binary adder chemical device. Through numerical simulations, we first demonstrated that the device can implement the function of a single-bit full binary adder. Then we show that the binary adder units can be further extended in plane, and coupled together to realize a two-bit, or even multi-bit binary adder. The realization of chemical adders can guide the constructions of other sophisticated arithmetic functions, ultimately leading to the implementation of chemical computer and other intelligent systems.

  18. Design of RSFQ wave pipelined Kogge-Stone Adder and developing custom compound gates

    NASA Astrophysics Data System (ADS)

    Ozer, M.; Eren Çelik, M.; Tukel, Y.; Bozbey, A.

    2014-09-01

    Since the invention of computers, the calculation of arithmetic and logic operations using digital circuits has been one of the leading problems in processor designs. The challenge has been to compute more operations with less clock cycles by using additional specific logic circuits. One of the most fundamental processes is addition; in which the carry bit should be transferred from the least significant bit to the most significant one. A wide range of digital circuit designs have been sustained for specialized faster addition operation. One of these adder algorithms is Kogge Stone Adder which does faster calculation with fewer levels and minimum fan-out compared to today’s adders despite the only disadvantage of having an excessive amount of wiring. In this study, a custom Rapid Single Flux Quantum (RSFQ) based, wave pipelined, Kogge Stone Adder is proposed to be used later in an Arithmetic Logic Unit (ALU). Two different design methodologies have been considered. In the first approach, we used standard logic gates for the whole adder design. In the second approach, utilization to compound gate design with adjustments over component parameters is done by using Particle Swarm Optimization and Statistical Timing Analysis Tools, to increase both efficiency and bias margin.

  19. The adder (Vipera berus) in Southern Altay Mountains: population characteristics, distribution, morphology and phylogenetic position

    PubMed Central

    Cui, Shaopeng; Luo, Xiao; Chen, Daiqiang; Sun, Jizhou; Chu, Hongjun

    2016-01-01

    As the most widely distributed snake in Eurasia, the adder (Vipera berus) has been extensively investigated in Europe but poorly understood in Asia. The Southern Altay Mountains represent the adder’s southern distribution limit in Central Asia, whereas its population status has never been assessed. We conducted, for the first time, field surveys for the adder at two areas of Southern Altay Mountains using a combination of line transects and random searches. We also described the morphological characteristics of the collected specimens and conducted analyses of external morphology and molecular phylogeny. The results showed that the adder distributed in both survey sites and we recorded a total of 34 sightings. In Kanas river valley, the estimated encounter rate over a total of 137 km transects was 0.15 ± 0.05 sightings/km. The occurrence of melanism was only 17%. The small size was typical for the adders in Southern Altay Mountains in contrast to other geographic populations of the nominate subspecies. A phylogenetic tree obtained by Bayesian Inference based on DNA sequences of the mitochondrial cytochrome b (1,023 bp) grouped them within the Northern clade of the species but failed to separate them from the subspecies V. b. sachalinensis. Our discovery extends the distribution range of V. berus and provides a basis for further researches. We discuss the hypothesis that the adder expands its distribution border to the southwest along the mountains’ elevation gradient, but the population abundance declines gradually due to a drying climate. PMID:27602300

  20. 18 CFR 35.22 - Limits for percentage adders in rates for transmission services; revision of rate schedules...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... adders in rates for transmission services; revision of rate schedules, tariffs or service agreements. 35..., DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT FILING OF RATE SCHEDULES AND TARIFFS Other Filing Requirements § 35.22 Limits for percentage adders in rates for transmission services; revision...

  1. Linear inductive voltage adders (IVA) for advanced hydrodynamic radiography

    SciTech Connect

    Mazarakis, M.G.; Boyes, J.D.; Johnson, D.L.

    1998-09-01

    The electron beam which drifts through the multiple cavities of conventional induction linacs (LIA) is replaced in an IVA by a cylindrical metal conductor which extends along the entire length of the device and effectuates the addition of the accelerator cavity voltages. In the approach to radiography, the linear inductive voltage adder drives a magnetically immersed electron diode with a millimeter diameter cathode electrode and a planar anode/bremsstrahlung converter. Both anode and cathode electrodes are immersed in a strong (15--50 T) solenoidal magnetic field. The electron beam cross section is approximately of the same size as the cathode needle and generates a similar size, very intense x-ray beam when it strikes the anode converter. An IVA driven diode can produce electron beams of equal size and energy as a LIA but with much higher currents (40--50 kA versus 4--5 kA), simpler hardware and thus lower cost. The authors present here first experimental validations of the technology utilizing HERMES 3 and SABRE IVA accelerators. The electron beam voltage and current were respectively of the order of 10 MV and 40 kA. X-ray doses of up to 1 kR {at} 1 m and spot sizes as small as 1.7 mm (at 200 R doses) were measured.

  2. Quaternary Galois field adder based all-optical multivalued logic circuits.

    PubMed

    Chattopadhyay, Tanay; Taraphdar, Chinmoy; Roy, Jitendra Nath

    2009-08-01

    Galois field (GF) algebraic expressions have been found to be promising choices for reversible and quantum implementation of multivalued logic. For the first time to our knowledge, we developed GF(4) adder multivalued (four valued) logic circuits in an all-optical domain. The principle and possibilities of an all-optical GF(4) adder circuit are described. The theoretical model is presented and verified through numerical simulation. The quaternary inverter, successor, clockwise cycle, and counterclockwise cycle gates are proposed with the help of the all-optical GF(4) adder circuit. In this scheme different quaternary logical states are represented by different polarized light. A terahertz optical asymmetric demultiplexer interferometric switch plays an important role in this scheme.

  3. Adder bite: an uncommon cause of compartment syndrome in northern hemisphere

    PubMed Central

    2010-01-01

    Snakebite envenomation is an uncommon condition in the northern hemisphere, but requires high vigilance with regard to both the systemic effects of the venom and the locoregional impact on the soft tissues. Bites from the adder, Vipera Berus, may have serious clinical consequences due to systemic effects. A case of a 44-year-old man is reported. The patient was bitten in the right hand. He developed fasciotomy-requiring compartment syndrome of the upper limb. Recognition of this most seldom complication of an adder bite is vital to save the limb. We recommend that the classical signs and symptoms of compartment syndrome serve as indication for surgical decompression. PMID:20854675

  4. Development of an Adder-Topology ILC Damping Ring Kicker Modulator

    SciTech Connect

    Tang, Tao; Burkhart, Craig; /SLAC

    2009-05-08

    The ILC damping ring injection and extraction kickers will require high availability modulators that can deliver {+-}5 kV pulses into 50 {Omega} with a 2 ns flattop ({approx}1 ns rise and fall time) at up to 6 MHz. An effort is underway at SLAC National Accelerator Laboratory to meet these requirements using a transmission line adder topology to combine the output of an array of {approx}1 kV modules. The modules employ an ultra-fast hybrid MOSFET/driver that can switch 33 A in 1.2 ns. Experimental results for a scale adder structure are presented.

  5. The symmetric MSD encoder for one-step adder of ternary optical computer

    NASA Astrophysics Data System (ADS)

    Kai, Song; LiPing, Yan

    2016-08-01

    The symmetric Modified Signed-Digit (MSD) encoding is important for achieving the one-step MSD adder of Ternary Optical Computer (TOC). The paper described the symmetric MSD encoding algorithm in detail, and developed its truth table which has nine rows and nine columns. According to the truth table, the state table was developed, and the optical-path structure and circuit-implementation scheme of the symmetric MSD encoder (SME) for one-step adder of TOC were proposed. Finally, a series of experiments were designed and performed. The observed results of the experiments showed that the scheme to implement SME was correct, feasible and efficient.

  6. Inductive voltage adder advanced hydrodynamic radiographic technology demonstration

    SciTech Connect

    Mazarakis, M.G.; Poukey, J.W.; Maenchen; Rovang, D.C.

    1997-04-01

    This paper presents the design, results, and analysis of a high-brightness electron beam technology demonstration experiment completed at Sandia National Laboratories, performed in collaboration with Los Alamos National Laboratory. The anticipated electron beam parameters were: 12 MeV, 35-40 kA, 0.5-mm rms radius, and 40-ns full width half maximum (FWHM) pulse duration. This beam, on an optimum thickness tantalum converter, should produce a very intense x-ray source of {approximately} 1.5-mm spot size and 1 kR dose @ 1 m. The accelerator utilized was SABRE, a pulsed inductive voltage adder, and the electron source was a magnetically immersed foilless electron diode. For these experiments, SABRE was modified to high-impedance negative-polarity operation. A new 100-ohm magnetically insulated transmission line cathode electrode was designed and constructed; the cavities were rotated 180{degrees} poloidally to invert the central electrode polarity to negative; and only one of the two pulse forming lines per cavity was energized. A twenty- to thirty-Tesla solenoidal magnet insulated the diode and contained the beam at its extremely small size. These experiments were designed to demonstrate high electron currents in submillimeter radius beams resulting in a high-brightness high-intensity flash x-ray source for high-resolution thick-object hydrodynamic radiography. The SABRE facility high-impedance performance was less than what was hoped. The modifications resulted in a lower amplitude (9 MV), narrower-than-anticipated triangular voltage pulse, which limited the dose to {approximately} 20% of the expected value. In addition, halo and ion-hose instabilities increased the electron beam spot size to > 1.5 mm. Subsequent, more detailed calculations explain these reduced output parameters. An accelerator designed (versus retrofit) for this purpose would provide the desired voltage and pulse shape.

  7. Power and area-optimised Carry-Select Adder architecture for standard cell-based design

    NASA Astrophysics Data System (ADS)

    Shanmugam, Muthukumar; Choi, GoangSeog

    2015-08-01

    A Carry-Select Adder (CSA) is one of the most suitable adders for high-speed applications, but the power and area penalties are greater, because it requires a double Ripple-Carry Adder (RCA) structure corresponding to carry inputs 0 and 1. Current low-power and low-area techniques are not suitable for a standard cell-based design which is one of the widely adopted design methodologies. Our work proposes two simple optimised architectures suitable for standard cell-based designs. A simple decision logic that replaces the RCA for Carry input 1 in a conventional CSA is proposed. One of the proposed architectures reduces power and area significantly with a small delay penalty compared to the existing techniques. Another proposed architecture improves the speed of operation and reduces the power and area considerably. The first one is more suitable for high-speed arithmetic in battery-operated applications where there is a trade-off between speed and power, while the other one is suitable for high-performance applications which also require area and power optimisation. The proposed architectures were implemented in TSMC 0.18um CMOS technology, and compared with conventional Square Root Carry-Select Adders and an existing standard cell-based design.

  8. Power efficient, clock gated multiplexer based full adder cell using 28 nm technology

    NASA Astrophysics Data System (ADS)

    Gupta, Ashutosh; Murgai, Shruti; Gulati, Anmol; Kumar, Pradeep

    2016-03-01

    Clock gating is a leading technique used for power saving. Full adders is one of the basic circuit that can be found in maximum VLSI circuits. In this paper clock gated multiplexer based full adder cell is implemented on 28 nm technology. We have designed a full adder cell using a multiplexer with a gated clock without degrading its performance of the cell. We have negative latch circuit for generating gated clock. This gated clock is used to control the multiplexer based full adder cell. The circuit has been synthesized on kintex FPGA through Xilinx ISE Design Suite 14.7 using 28 nm technology in Verilog HDL. The circuit has been simulated on Modelsim 10.3c. The design is verified using System Verilog on QuestaSim in UVM environment. The total power of the circuit has been reduced by 7.41% without degrading the performance of original circuit. The power has been calculated using XPower Analyzer tool of XILINX ISE DESIGN SUITE 14.3.

  9. Immediate and delayed effects of gill-net capture on acid-base balance and intramuscular lactate concentration of gummy sharks, Mustelus antarcticus.

    PubMed

    Frick, Lorenz H; Walker, Terence I; Reina, Richard D

    2012-06-01

    Many sharks are captured as untargeted by-catch during commercial fishing operations and are subsequently discarded. A reliable assessment of the proportion of discarded sharks that die post-release as a result of excessive physiological stress is important for fisheries management and conservation purposes, but a reliable physiological predictor of post-release mortality has not been identified. To investigate effects of gill-net capture on the acid-base balance of sharks, we exposed gummy sharks, Mustelus antarcticus, to 60 min of gill-net capture in a controlled setting, and obtained multiple blood and muscle tissue samples during a 72-h recovery period following the capture event. Overall mortality of gummy sharks was low (9%). Blood pH was significantly depressed immediately after the capture event due to a combination of respiratory and metabolic acidosis. Maximum concentrations of plasma lactate (9.9 ± 1.5 mmol L(-1)) were measured 3h after the capture event. Maximum intramuscular lactate concentrations (37.0 ± 4.6 μmol g(-1)) were measured immediately after the capture event, and intramuscular lactate concentrations were substantially higher than plasma lactate concentrations at all times. Sharks in poor condition had low blood pH and high intramuscular lactate concentration, but blood pH does not appear to be a reliable predictor of survival. Suitability of intramuscular lactate concentration as predictor of delayed mortality deserves further investigation.

  10. Modeling of an inductive adder kicker pulser for DARHT-II

    SciTech Connect

    Wang, L; Caporaso, G J; Cook, E G

    2000-09-25

    An all solid-state kicker pulser for a high current induction accelerator (the Dual-Axis Radiographic Hydrodynamic Test facility DARHT-2) has been designed and fabricated. This kicker pulser uses multiple solid state modulators stacked in an inductive-adder configuration. Each modulator is comprised of multiple metal-oxide-semiconductor field-effect transistors (MOSFETs) which quickly switch the energy storage capacitors across a magnetic induction core. Metglas is used as the core material to minimize loss. Voltage from each modulator is inductively added by a voltage summing stalk and delivered to a 50 ohm output cable. A lumped element circuit model of the inductive adder has been developed to optimize the performance of the pulser. Results for several stalk geometries will be compared with experimental data.

  11. Numerical Simulation of Azimuthal Uniformity of Injection Currents in Single-Point-Feed Induction Voltage Adders

    NASA Astrophysics Data System (ADS)

    WEI, Hao; SUN, Fengju; YIN, Jiahui; HU, Yixiang; LIANG, Tianxue; Peitian, CONG; Aici, QIU

    2015-03-01

    In order to investigate the injection current uniformity around the induction cell bores, two fully electromagnetic (EM) models are respectively established for a single-stage induction cell and an induction voltage adder (IVA) with three cells stacked in series, without considering electron emission. By means of these two models, some factors affecting the injection current uniformity are simulated and analyzed, such as the impedances of adders and loads, cell locations, and feed timing of parallel driving pulses. Simulation results indicate that higher impedances of adder and loads are slightly beneficial to improve injection current uniformity. As the impedances of adder and loads increase from 5 Ω to 30 Ω, the asymmetric coefficient of feed currents decreases from 10.3% to 6.6%. The current non-uniformity within the first cell is a little worse than that in other downstream cells. Simulation results also show that the feed timing would greatly affect current waveforms, and consequently cause some distortion in pulse fronts of cell output voltages. For a given driving pulse with duration time of 70-80 ns, the feed timing with a time deviation of less than 20 ns is acceptable for the three-cell IVAs, just causing the rise time of output voltages to increase about 5 ns at most and making the peak voltage decrease by 3.5%. supported by National Natural Science Foundation of China (No. 51307141), and partly by the State Key Laboratory of Intense Pulsed Radiation Simulation (Northwest Institute of Nuclear Technology) under Contract SKLIPR 1206

  12. Proposed inductive voltage adder based accelerator concepts for the second axis of DARHT

    SciTech Connect

    Smith, D.L.; Johnson, D.L.; Boyes, J.D.

    1997-06-01

    As participants in the Technology Options Study for the second axis of the Dual Axis Radiographic HydroTest (DARHT) facility located at Los Alamos National Laboratories, the authors have considered several accelerator concepts based on the Inductive Voltage Adder (IVA) technology that is being used successfully at Sandia on the SABRE and HERMES-III facilities. The challenging accelerator design requirements for the IVA approach include: {ge}12-MeV beam energy; {approximately}60-ns electrical pulse width; {le}40-kA electron beam current; {approximately}1-mm diameter e-beam; four pulses on the same axis or as close as possible to that axis; and an architecture that fits within the existing building envelope. To satisfy these requirements the IVA concepts take a modular approach. The basic idea is built upon a conservative design for eight ferromagnetically isolated 2-MV cavities that are driven by two 3 to 4-{Omega} water dielectric pulse forming lines (PFLs) synchronized with laser triggered gas switches. The 100-{Omega} vacuum magnetically insulated transmission line (MITL) would taper to a needle cathode that produces the electron beam(s). After considering many concepts the authors narrowed their study to the following options: (A) Four independent single pulse drivers powering four single pulse diodes; (B) Four series adders with interleaved cavities feeding a common MITL and diode; (C) Four stages of series PFLs, isolated from each other by triggered spark gap switches, with single-point feeds to a common adder, MITL, and diode; and (D) Isolated PFLs with multiple-feeds to a common adder using spark gap switches in combination with saturable magnetic cores to isolate the non-energized lines. The authors will discuss these options in greater detail identifying the challenges and risks associated with each.

  13. Memstor, memstance simulations via a versatile 4-port built with new adder and subtractor circuits

    NASA Astrophysics Data System (ADS)

    Minaei, Shahram; Cem Göknar, Izzet; Yıldız, Merih; Yuce, Erkan

    2015-06-01

    In this paper, novel voltage-mode (VM) n-channel metal-oxide semiconductor (NMOS) transistor-based analogue adder and subtractor circuits, which, respectively, perform V1+V2 and V1-V2 operations, are presented. The most important feature of the proposed circuits is their extremely simple structures containing only six NMOS transistors. Further, the presented adder and subtractor circuits have high input and low output impedances, resulting in easy cascadability. The post-layout simulations of the proposed circuits have been executed using TSMC 0.25 µm process parameters with ±1.25 V. The area of the suggested circuits is approximately 30 × 13 µm2. Moreover, the topology of a generalised mutator, a versatile 4-port built with an adder and a subtractor, which acts as an ordinary mutator when properly reduced to a 2-port, is offered. A table for simulating lossless inductance, memristor, meminductor, memcapacitor and other elements under suitable termination of the 4-port is given, and three of these elements' simulations with SPICE are also presented.

  14. Low impedance z-pinch drivers without post-hole convolute current adders.

    SciTech Connect

    Savage, Mark Edward; Seidel, David Bruce; Mendel, Clifford Will, Jr.

    2009-09-01

    Present-day pulsed-power systems operating in the terawatt regime typically use post-hole convolute current adders to operate at sufficiently low impedance. These adders necessarily involve magnetic nulls that connect the positive and negative electrodes. The resultant loss of magnetic insulation results in electron losses in the vicinity of the nulls that can severely limit the efficiency of the delivery of the system's energy to a load. In this report, we describe an alternate transformer-based approach to obtaining low impedance. The transformer consists of coils whose windings are in parallel rather than in series, and does not suffer from the presence of magnetic nulls. By varying the pitch of the coils windings, the current multiplication ratio can be varied, leading to a more versatile driver. The coupling efficiency of the transformer, its behavior in the presence of electron flow, and its mechanical strength are issues that need to be addressed to evaluate the potential of transformer-based current multiplication as a viable alternative to conventional current adder technology.

  15. Binary full adder, made of fusion gates, in a subexcitable Belousov-Zhabotinsky system

    NASA Astrophysics Data System (ADS)

    Adamatzky, Andrew

    2015-09-01

    In an excitable thin-layer Belousov-Zhabotinsky (BZ) medium a localized perturbation leads to the formation of omnidirectional target or spiral waves of excitation. A subexcitable BZ medium responds to asymmetric local perturbation by producing traveling localized excitation wave-fragments, distant relatives of dissipative solitons. The size and life span of an excitation wave-fragment depend on the illumination level of the medium. Under the right conditions the wave-fragments conserve their shape and velocity vectors for extended time periods. I interpret the wave-fragments as values of Boolean variables. When two or more wave-fragments collide they annihilate or merge into a new wave-fragment. States of the logic variables, represented by the wave-fragments, are changed in the result of the collision between the wave-fragments. Thus, a logical gate is implemented. Several theoretical designs and experimental laboratory implementations of Boolean logic gates have been proposed in the past but little has been done cascading the gates into binary arithmetical circuits. I propose a unique design of a binary one-bit full adder based on a fusion gate. A fusion gate is a two-input three-output logical device which calculates the conjunction of the input variables and the conjunction of one input variable with the negation of another input variable. The gate is made of three channels: two channels cross each other at an angle, a third channel starts at the junction. The channels contain a BZ medium. When two excitation wave-fragments, traveling towards each other along input channels, collide at the junction they merge into a single wave-front traveling along the third channel. If there is just one wave-front in the input channel, the front continues its propagation undisturbed. I make a one-bit full adder by cascading two fusion gates. I show how to cascade the adder blocks into a many-bit full adder. I evaluate the feasibility of my designs by simulating the evolution

  16. Nonlabens antarcticus sp. nov., a psychrophilic bacterium isolated from glacier ice, and emended descriptions of Nonlabens marinus Park et al. 2012 and Nonlabens agnitus Yi and Chun 2012.

    PubMed

    Kwon, Yong Min; Yang, Sung-Hyun; Kwon, Kae Kyoung; Kim, Sang-Jin

    2014-02-01

    A Gram-negative, proteorhodopsin-containing, orange pigmented, rod-shaped and strictly aerobic bacterium, designated strain AKS622(T), was isolated from a glacier core collected from the coast of King George Island, Antarctica. 16S rRNA gene sequence analysis revealed that strain AKS622(T) was affiliated to the genus Nonlabens of the family Flavobacteriaceae and showed highest similarity to Nonlabens marinus S1-08(T) (97.9%). The level of DNA-DNA relatedness between strain AKS622(T) and N. marinus S1-08(T) was 46%. Optimal growth of strain AKS622(T) was observed at pH 7.0, at 15 °C and with 2.0% NaCl. The predominant cellular fatty acids were anteiso-C(15 : 0), iso-C(16 : 0), iso-C(16 : 0) 3-OH, C17:0 2-OH and summed feature 3 (comprising C(16 : 1)ω7c and/or C(16 : 1)ω6c). The DNA G+C content was 37.9 mol%. The major respiratory quinone was MK-6. Phosphatidylethanolamine, four unidentified glycolipids, three unidentified aminolipids and one unidentified lipid were detected as major polar lipids. On the basis of the data from this polyphasic taxonomic study, it was concluded that strain AKS622(T) represents a novel species within the genus Nonlabens, for which the name Nonlabens antarcticus sp. nov. is proposed. The type strain is AKS622(T) ( = KCCM 43019(T) = JCM 14068(T)). Emended descriptions of N. marinus Park et al. 2012 and Nonlabens agnitus Yi and Chun 2012 are given.

  17. Pass the salt: physiological consequences of ecologically relevant hyposmotic exposure in juvenile gummy sharks (Mustelus antarcticus) and school sharks (Galeorhinus galeus)

    PubMed Central

    Morash, Andrea J.; Mackellar, Sara R. C.; Tunnah, Louise; Barnett, David A.; Stehfest, Kilian M.; Semmens, Jayson M.; Currie, Suzanne

    2016-01-01

    Estuarine habitats are frequently used as nurseries by elasmobranch species for their protection and abundant resources; however, global climate change is increasing the frequency and severity of environmental challenges in these estuaries that may negatively affect elasmobranch physiology. Hyposmotic events are particularly challenging for marine sharks that osmoconform, and species-specific tolerances are not well known. Therefore, we sought to determine the effects of an acute (48 h) ecologically relevant hyposmotic event (25.8 ppt) on the physiology of two juvenile shark species, namely the school shark (Galeorhinus galeus), listed by the Australian Environmental Protection and Biodiversity Conservation Act as ‘conservation dependent’, and the gummy shark (Mustelus antarcticus), from the Pittwater Estuary (Australia). In both species, we observed a decrease in plasma osmolality brought about by selective losses of NaCl, urea and trimethylamine N-oxide, as well as decreases in haemoglobin, haematocrit and routine oxygen consumption. Heat-shock protein levels varied between species during the exposure, but we found no evidence of protein damage in any of the tissues tested. Although both species seemed to be able to cope with this level of osmotic challenge, overall the school sharks exhibited higher gill Na+/K+-ATPase activity and ubiquitin concentrations in routine and experimental conditions, a larger heat-shock protein response and a smaller decrease in routine oxygen consumption during the hyposmotic exposure, suggesting that there are species-specific responses that could potentially affect their ability to withstand longer or more severe changes in salinity. Emerging evidence from acoustic monitoring of sharks has indicated variability in the species found in the Pittwater Estuary during hyposmotic events, and together, our data may help to predict species abundance and distribution in the face of future global climate change. PMID:27757235

  18. Fast low-power full-adders based on bridge style minority function and multiplexer for nanoscale

    NASA Astrophysics Data System (ADS)

    Ashkan Ebrahimi, Seyyed; Keshavarzian, Peiman

    2013-06-01

    Full-adders are essential parts of digital circuits whereby many arithmetic circuits can be implemented by applying these cells. Therefore speed and power consumption of full-adders affect the performance of digital circuits, FA cell performs a predominant arithmetic operation in them. We utilise carbon nanotube field effect transistors for implementing our proposed designs due to their unique mechanical and electrical properties such as lower delay, lower power consumption, very dense and lower current off. Extensive simulation results using HSpice are reported to demonstrate the acquired significant improvement in performance of FA circuit design in comparison with the state-of-the-art work.

  19. The mathematics of a quantum Hamiltonian computing half adder Boolean logic gate

    NASA Astrophysics Data System (ADS)

    Dridi, G.; Julien, R.; Hliwa, M.; Joachim, C.

    2015-08-01

    The mathematics behind the quantum Hamiltonian computing (QHC) approach of designing Boolean logic gates with a quantum system are given. Using the quantum eigenvalue repulsion effect, the QHC AND, NAND, OR, NOR, XOR, and NXOR Hamiltonian Boolean matrices are constructed. This is applied to the construction of a QHC half adder Hamiltonian matrix requiring only six quantum states to fullfil a half Boolean logical truth table. The QHC design rules open a nano-architectronic way of constructing Boolean logic gates inside a single molecule or atom by atom at the surface of a passivated semi-conductor.

  20. The mathematics of a quantum Hamiltonian computing half adder Boolean logic gate.

    PubMed

    Dridi, G; Julien, R; Hliwa, M; Joachim, C

    2015-08-28

    The mathematics behind the quantum Hamiltonian computing (QHC) approach of designing Boolean logic gates with a quantum system are given. Using the quantum eigenvalue repulsion effect, the QHC AND, NAND, OR, NOR, XOR, and NXOR Hamiltonian Boolean matrices are constructed. This is applied to the construction of a QHC half adder Hamiltonian matrix requiring only six quantum states to fullfil a half Boolean logical truth table. The QHC design rules open a nano-architectronic way of constructing Boolean logic gates inside a single molecule or atom by atom at the surface of a passivated semi-conductor.

  1. An Enzyme-Based Half-Adder and Half-Subtractor with a Modular Design.

    PubMed

    Fratto, Brian E; Lewer, Jessica M; Katz, Evgeny

    2016-07-18

    A half-adder and a half-subtractor have been realized using enzymatic reaction cascades performed in a flow cell device. The individual cells were modified with different enzymes and assembled in complex networks to perform logic operations and arithmetic functions. The modular design of the logic devices allowed for easy re-configuration, enabling them to perform various functions. The final output signals, represented by redox species [Fe(CN)6 ](3-/4-) or NADH/NAD(+) , were analyzed optically to derive the calculation results. These output signals might be applicable in the future for actuation processes, for example, substance release activated by logically processed signals.

  2. A 3-input all magnetic full adder with misalignment-free clocking mechanism

    NASA Astrophysics Data System (ADS)

    Li, Zheng; Krishnan, Kannan M.

    2017-01-01

    The clocking field misalignment is a critical issue for the application of Magnetic Quantum-dot Cellular Automata (MQCA). Recent work demonstrates a novel architecture to address this issue—by progressively tuning the shape anisotropy, we could enforce a misalignment-free signal propagation and logic operation. In this paper, we propose a novel architecture of a 3-input full adder based on the 45°-clocking field mechanism. The effectiveness of this design is confirmed through both simulation and experiments. Our work paves the way for the application of MQCA logic.

  3. Pygoscelis antarcticus feathers as bioindicator of trace element risk in marine environments from Barton Peninsula, 25 de Mayo (King George) Island, Antarctica.

    PubMed

    Catán, Soledad Perez; Bubach, Debora; Di Fonzo, Carla; Dopchiz, Laura; Arribére, Maria; Ansaldo, Martin

    2017-04-01

    We report the contents of elements in feathers of Chinstrap penguin (Pygoscelis antarcticus), which had not been informed up to now, such as silver and bromine and others listed as hazardous by the United States Environmental Protection Agency as arsenic, cobalt, chromium, and mercury. Analyses of the element concentrations in feathers, adult and chicken, from Barton Peninsulas at 25 de Mayo (King George) Island, South Shetlands, were made by Instrumental Neutron Activation Analysis. Samarium, lanthanum a, thorium, and uranium concentrations in Chinstrap penguin feathers were below 0.1 mg/kg. This suggests that the elements in feather do not come from atmospheric particles surface deposition. Arsenic (0.120 ± 0.050 mg/kg) and cobalt (0.030 ± 0.020 mg/kg) concentrations were lower than the reports for other colony of Chinstrap penguins, and essential elements as iron (26 ± 12 mg/kg), zinc (78.0 ± 5.3 mg/kg), and chromium (0.51 ± 0.27 mg/kg) were in the same range while Se (2.90 ± 0.65 mg/kg) content were the lowest reported. Mercury (0.43 ± 0.21 mg/kg), chromium (0.210 ± 0.060 mg/kg), and silver (0.083 ± 0.003 mg/kg) in chicks tended to be lower than in adults. Iron, cobalt, and arsenic concentrations in feathers found in this study were the lowest compared to measurements were in several penguin species in Antarctica. These results confirm to feathers like effective indicators for the trace elements incorporated in the penguins and it provide a data set which can adds to the baseline for bioindication studies using feathers.

  4. Design of Low Power 14T Full Adder Cell Using Double Gate Mosfet with Mtcmos Reduction Technique at 45 Nanometer Technology

    NASA Astrophysics Data System (ADS)

    Shrivastava, Anuj Kumar; Akashe, Shyam

    2013-01-01

    Full adder is the basic block of arithmetic circuit found in microcontroller and microprocessor inside arithmetic and logic unit (ALU). Improving the performance of the adder is essential for upgrading the performance of digital electronics circuit where adder is employed. In this paper, a single bit full adder circuit has been designed with the help of double gate (MOSFET), the used parameters value has been varied significantly for improving the performance of full adder circuit. Double gate transistor circuit considers as a promising candidate for low power application domain as well as used in radio frequency (RF) devices. Multi-threshold CMOS (MTCMOS) is the most used circuit technique to reduce the leakage current in idle circuit. In this paper, different parameters are analyzed on MTCMOS Technique. MTCMOS technique achieves 99.6% reduction of leakage current, active power is reduced by 42.64% and delay is reduced by 71.9% as compared with conventional double gate 14T full adder. Simulation results of double gate full adder have been performed on cadence virtuoso tool with 45 nm technology.

  5. An ambusher's arsenal: chemical crypsis in the puff adder (Bitis arietans)

    PubMed Central

    Miller, Ashadee Kay; Maritz, Bryan; McKay, Shannon; Glaudas, Xavier; Alexander, Graham J.

    2015-01-01

    Ambush foragers use a hunting strategy that places them at risk of predation by both visual and olfaction-oriented predators. Resulting selective pressures have driven the evolution of impressive visual crypsis in many ambushing species, and may have led to the development of chemical crypsis. However, unlike for visual crypsis, few studies have attempted to demonstrate chemical crypsis. Field observations of puff adders (Bitis arietans) going undetected by several scent-orientated predator and prey species led us to investigate chemical crypsis in this ambushing species. We trained dogs (Canis familiaris) and meerkats (Suricata suricatta) to test whether a canid and a herpestid predator could detect B. arietans using olfaction. We also tested for chemical crypsis in five species of active foraging snakes, predicted to be easily detectable. Dogs and meerkats unambiguously indicated active foraging species, but failed to correctly indicate puff adder, confirming that B. arietans employs chemical crypsis. This is the first demonstration of chemical crypsis anti-predatory behaviour, though the phenomenon may be widespread among ambushers, especially those that experience high mortality rates owing to predation. Our study provides additional evidence for the existence of an ongoing chemically mediated arms race between predator and prey species. PMID:26674950

  6. An ambusher's arsenal: chemical crypsis in the puff adder (Bitis arietans).

    PubMed

    Miller, Ashadee Kay; Maritz, Bryan; McKay, Shannon; Glaudas, Xavier; Alexander, Graham J

    2015-12-22

    Ambush foragers use a hunting strategy that places them at risk of predation by both visual and olfaction-oriented predators. Resulting selective pressures have driven the evolution of impressive visual crypsis in many ambushing species, and may have led to the development of chemical crypsis. However, unlike for visual crypsis, few studies have attempted to demonstrate chemical crypsis. Field observations of puff adders (Bitis arietans) going undetected by several scent-orientated predator and prey species led us to investigate chemical crypsis in this ambushing species. We trained dogs (Canis familiaris) and meerkats (Suricata suricatta) to test whether a canid and a herpestid predator could detect B. arietans using olfaction. We also tested for chemical crypsis in five species of active foraging snakes, predicted to be easily detectable. Dogs and meerkats unambiguously indicated active foraging species, but failed to correctly indicate puff adder, confirming that B. arietans employs chemical crypsis. This is the first demonstration of chemical crypsis anti-predatory behaviour, though the phenomenon may be widespread among ambushers, especially those that experience high mortality rates owing to predation. Our study provides additional evidence for the existence of an ongoing chemically mediated arms race between predator and prey species.

  7. a High-Level Technique for Estimation and Optimization of Leakage Power for Full Adder

    NASA Astrophysics Data System (ADS)

    Shrivas, Jayram; Akashe, Shyam; Tiwari, Nitesh

    2013-06-01

    Optimization of power is a very important issue in low-voltage and low-power application. In this paper, we have proposed power gating technique to reduce leakage current and leakage power of one-bit full adder. In this power gating technique, we use two sleep transistors i.e., PMOS and NMOS. PMOS sleep transistor is inserted between power supply and pull up network. And NMOS sleep transistor is inserted between pull down network and ground terminal. These sleep transistors (PMOS and NMOS) are turned on when the circuit is working in active mode. And sleep transistors (PMOS and NMOS) are turned off when circuit is working in standby mode. We have simulated one-bit full adder and compared with the power gating technique using cadence virtuoso tool in 45 nm technology at 0.7 V at 27°C. By applying this technique, we have reduced leakage current from 2.935 pA to 1.905 pA and leakage power from 25.04μw to 9.233μw. By using this technique, we have reduced leakage power up to 63.12%.

  8. Synchronization of multiple magnetically switched modules to power linear induction adder accelerators

    SciTech Connect

    Reed, K.W.; Kiekel, P.D.

    1997-02-01

    In applications where multiple magnetic modulators are used to drive a single Linear Induction Voltage Adder (LIVA) or Linear Accelerator (LINAC), it is essential that the outputs of the modulators by synchronized. Output rise times are typically in the 10ns to 20ns range, often making it necessary to synchronize to within less than 1ns. Microprocessor and electronic feedback schemes have been developed and demonstrated that achieve the required level of synchronization, however, they are sophisticated and potentially complex. In a quest for simplicity, this work seeks to determine the achievable level of modulator to modulator timing jitter that can be obtained with simple design practices and passive techniques. Sources of output pulse time jitter in magnetic modulators are reviewed and some basic modulator design principles that can be used to minimize the intrinsic time jitter between modulators are discussed. A novel technique for passive synchronization is presented.

  9. Pulse-power characteristic of VIVA-1 (Versatile Inductive Voltage Adder)

    NASA Astrophysics Data System (ADS)

    Shimiya, K.; Hozumi, Y.; Aoyama, T.; Shigeta, M.; Shibata, Kiyoshi; Sekimoto, Y.; Masugata, Katsumi; Yatsui, Kiyoshi

    1990-10-01

    Versatile Inductive Voltage Adder, (VIVA-1), with high potential gradient was successfully developed to be in operation. It was designed to produce output pulse of 4 MV, 60 ns by adding 2 MV pulses in 2 stages of induction cells, where amorphous cores are installed. Within approx. 40 percent of full charge voltage, pulse power characteristics of Marx generator, pulse forming line (PFL), transmission line (TL), and induction cells were tested for three types of loads: open circuit; dummy load of CuSO4 resistor; and electron diode. In open circuit test, approx. 2.0 MV of output voltage was obtained with good reproducibility. Dependence of output voltage on diode impedance was evaluated by using a dummy load, and good agreement was obtained with that expected. An E-beam diode was operated successfully, and approx. 18 kA of beam current was obtained at diode voltage of approx. 1 MV.

  10. Phylogeography of the widespread African puff adder (Bitis arietans) reveals multiple Pleistocene refugia in southern Africa.

    PubMed

    Barlow, Axel; Baker, Karis; Hendry, Catriona R; Peppin, Lindsay; Phelps, Tony; Tolley, Krystal A; Wüster, Catharine E; Wüster, Wolfgang

    2013-02-01

    Evidence from numerous Pan-African savannah mammals indicates that open-habitat refugia existed in Africa during the Pleistocene, isolated by expanding tropical forests during warm and humid interglacial periods. However, comparative data from other taxonomic groups are currently lacking. We present a phylogeographic investigation of the African puff adder (Bitis arietans), a snake that occurs in open-habitat formations throughout sub-Saharan Africa. Multiple parapatric mitochondrial clades occur across the current distribution of B. arietans, including a widespread southern African clade that is subdivided into four separate clades. We investigated the historical processes responsible for generating these phylogeographic patterns in southern Africa using species distribution modelling and genetic approaches. Our results show that interior regions of South Africa became largely inhospitable for B. arietans during glacial maxima, whereas coastal and more northerly areas remained habitable. This corresponds well with the locations of refugia inferred from mitochondrial data using a continuous phylogeographic diffusion model. Analysis of data from five anonymous nuclear loci revealed broadly similar patterns to mtDNA. Secondary admixture was detected between previously isolated refugial populations. In some cases, this is limited to individuals occurring near mitochondrial clade contact zones, but in other cases, more extensive admixture is evident. Overall, our study reveals a complex history of refugial isolation and secondary expansion for puff adders and a mosaic of isolated refugia in southern Africa. We also identify key differences between the processes that drove isolation in B. arietans and those hypothesized for sympatric savannah mammals.

  11. Toward defect guard-banding of EUV exposures by full chip optical wafer inspection of EUV mask defect adders

    NASA Astrophysics Data System (ADS)

    Halle, Scott D.; Meli, Luciana; Delancey, Robert; Vemareddy, Kaushik; Crispo, Gary; Bonam, Ravi; Burkhardt, Martin; Corliss, Daniel

    2015-03-01

    The detection of EUV mask adder defects has been investigated with an optical wafer defect inspection system employing a methodology termed Die-to-"golden" Virtual Reference Die (D2VRD). Both opaque and clear type mask absorber programmed defects were inspected and characterized over a range of defect sizes, down to (4x mask) 40 nm. The D2VRD inspection system was capable of identifying the corresponding wafer print defects down to the limit of the defect printability threshold at approximately 30 nm (1x wafer). The efficacy of the D2VRD scheme on full chip wafer inspection to suppress random process defects and identify real mask defects is demonstrated. Using defect repeater analysis and patch image classification of both the reference die and the scanned die enables the unambiguous identification of mask adder defects.

  12. Development of an optical parallel logic device and a half-adder circuit for digital optical processing

    NASA Technical Reports Server (NTRS)

    Athale, R. A.; Lee, S. H.

    1978-01-01

    The paper describes the fabrication and operation of an optical parallel logic (OPAL) device which performs Boolean algebraic operations on binary images. Several logic operations on two input binary images were demonstrated using an 8 x 8 device with a CdS photoconductor and a twisted nematic liquid crystal. Two such OPAL devices can be interconnected to form a half-adder circuit which is one of the essential components of a CPU in a digital signal processor.

  13. Energy logistics in an all-optical adder based on a 1D porous silicon photonic crystal

    NASA Astrophysics Data System (ADS)

    Glushko, E. Ya.

    2011-09-01

    The ideology of a photonic crystal resonator covered with optically nonlinear layers is proposed for binary adder and logic gates of various kinds. The all-optical way to transform a physically added sequence of signals into the logical sequence with corresponding shift of digital units is based on the nonlinear band shift effect. In this work, the electromagnetic field structure for optically linear 1D porous silicon photonic crystal is investigated. The optical parameters of a 1D photonic crystal resonator built on layered porous silicon covered with a nonlinear layer are calculated for various nonlinear materials. An approximate design of an all-optical adder based on 1D porous silicon resonator is considered. The adder heating by powered optical pulses and energy distribution inside the device are analyzed and the problem solution with the use of special semitransparent redirecting mirrors is proposed. It was found that from the point of view of heating the R-scheme of signal processing is more optimal.

  14. Pseudooceanicola atlanticus gen. nov. sp. nov., isolated from surface seawater of the Atlantic Ocean and reclassification of Oceanicola batsensis, Oceanicola marinus, Oceanicola nitratireducens, Oceanicola nanhaiensis, Oceanicola antarcticus and Oceanicola flagellatus, as Pseudooceanicola batsensis comb. nov., Pseudooceanicola marinus comb. nov., Pseudooceanicola nitratireducens comb. nov., Pseudooceanicola nanhaiensis comb. nov., Pseudooceanicola antarcticus comb. nov., and Pseudooceanicola flagellatus comb. nov.

    PubMed

    Lai, Qiliang; Li, Guizhen; Liu, Xiupian; Du, Yaping; Sun, Fengqin; Shao, Zongze

    2015-04-01

    be assigned to the genus Oceanicola; consequently strain 22II-S11g(T) is concluded to represent a novel species of a novel genus in the family Rhodobacteraceae, for which the name Pseudooceanicola atlanticus gen. nov., sp. nov. is proposed (type strain 22II-S11g(T) = KCTC 42004(T) = LMG 27424(T) = MCCC 1A09160(T)). Six misclassified species should be transferred to the novel genus Pseudooceanicola as follows: O. batsensis should be transferred to the genus Pseudooceanicola as Pseudooceanicola batsensis comb. nov. (type strain HTCC2597(T) = ATCC BAA-863(T) = DSM 15984(T) = KCTC 12145(T)); Oceanicola marinus should be transferred to the genus Pseudooceanicola as Pseudooceanicola marinus comb. nov. (type strain AZO-C(T) = LMG 23705(T) = BCRC 17591(T)); O. nitratireducens should be transferred to the genus Pseudooceanicola as Pseudooceanicola nitratireducens comb. nov. (type strain JLT1210(T) = LMG 24663(T) = CGMCC 1.7292(T)); Oceanicola nanhaiensis should be transferred to the genus Pseudooceanicola as Pseudooceanicola nanhaiensis comb. nov. (type strain SS011B1-20(T) = LMG 23508(T) = CGMCC 1.6293(T)); Oceanicola antarcticus should be transferred to the genus Pseudooceanicola as Pseudooceanicola antarcticus comb. nov. (type strain Ar-45(T) = CGMCC 1.12662(T) = LMG 27868(T)); and Oceanicola flagellatus should be transferred to the genus Pseudooceanicola as Pseudooceanicola flagellatus comb. nov. (type strain DY470(T) = CGMCC 1.12664(T) = LMG 27871(T)).

  15. SplAdder: identification, quantification and testing of alternative splicing events from RNA-Seq data

    PubMed Central

    Kahles, André; Ong, Cheng Soon; Zhong, Yi; Rätsch, Gunnar

    2016-01-01

    Motivation: Understanding the occurrence and regulation of alternative splicing (AS) is a key task towards explaining the regulatory processes that shape the complex transcriptomes of higher eukaryotes. With the advent of high-throughput sequencing of RNA (RNA-Seq), the diversity of AS transcripts could be measured at an unprecedented depth. Although the catalog of known AS events has grown ever since, novel transcripts are commonly observed when working with less well annotated organisms, in the context of disease, or within large populations. Whereas an identification of complete transcripts is technically challenging and computationally expensive, focusing on single splicing events as a proxy for transcriptome characteristics is fruitful and sufficient for a wide range of analyses. Results: We present SplAdder, an alternative splicing toolbox, that takes RNA-Seq alignments and an annotation file as input to (i) augment the annotation based on RNA-Seq evidence, (ii) identify alternative splicing events present in the augmented annotation graph, (iii) quantify and confirm these events based on the RNA-Seq data and (iv) test for significant quantitative differences between samples. Thereby, our main focus lies on performance, accuracy and usability. Availability: Source code and documentation are available for download at http://github.com/ratschlab/spladder. Example data, introductory information and a small tutorial are accessible via http://bioweb.me/spladder. Contacts: andre.kahles@ratschlab.org or gunnar.ratsch@ratschlab.org Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26873928

  16. Inductive Voltage Adder Driven X-Ray Sources for Hydrodynamic Radiography

    SciTech Connect

    Bailey, V.; Cordova, S.; Droemer, D.; Gustwiller, J.; Hunt, E.; Johnson, D.L.; MacLeod, G.; Maenchen, John; Menge, P.; Molina, I.; Oliver, B; Olson, C.; Rosenthal, S; Rovang, D.; Smith, I.; Welch, D.; Woo, L.

    1999-06-17

    Inductive Voltage Adder (IVA) accelerators were developed to provide high-current (100s of kA) power pulses at high voltage (up to 20 MV) using robust modular components. This architecture simultaneously resolves problems found in conventional pulsed and linear induction accelerators. A variety of high-brightness pulsed x-ray radiographic sources are needed from sub-megavolt to 16-MeV endpoints with greater source brightness (dose/spot) than presently available. We are applying IVA systems to produce very intense (up to 75 TW/cm{sup 2}) electron beams for these flash radiographic applications. The accelerator electromagnetic pulse is converted to a directed electron beam at the end of a self-magnetically insulated vacuum transmission line. The cantilevered cathode threading the accelerator cavities terminates in a small (1-mm diameter) needle, producing the electron beam which is transported to a grounded bremsstrahlung converter within a strong ({approximately}50-T) axial magnetic field. These systems produce mm-sized stable electron beams, yielding very intense x-ray sources. Detailed simulations of the electron beam generation, transport, and target interaction are presented along with scaling laws for the radiation production and x-ray spot size. Experimental studies confirm these simulations and show this reliable, compact, and inexpensive technology scales to 1000-R doses a meter from a mm-diameter source in 50 ns.

  17. Quantum half-adder Boolean logic gate with a nano-graphene molecule and graphene nano-electrodes

    NASA Astrophysics Data System (ADS)

    Srivastava, Saurabh; Kino, Hiori; Joachim, Christian

    2017-01-01

    A molecule Boolean 1 / 2 -adder is designed and the XOR and AND truth table calculated at +0.1 V using 4 graphene electrodes. It functions with level repulsion and destructive interferences effects using 4 molecule electronic states in a quantum Hamiltonian computing approach (QHC) with the abrupt change of the molecular orbital weight of those 4 calculating states as a function of the logical input configuration. The logical inputs enter rotating the two nitro groups of the central board. With QHC, a complex Boolean digital function can be implemented employing the same graphene material for interconnects and the molecule calculating parts.

  18. Ion diode performance on a positive polarity inductive voltage adder with layered magnetically insulated transmission line flow

    SciTech Connect

    Hinshelwood, D. D.; Schumer, J. W.; Allen, R. J.; Commisso, R. J.; Jackson, S. L.; Murphy, D. P.; Phipps, D.; Swanekamp, S. B.; Weber, B. V.; Ottinger, P. F.; Apruzese, J. P.; Cooperstein, G.; Young, F. C.

    2011-05-15

    A pinch-reflex ion diode is fielded on the pulsed-power machine Mercury (R. J. Allen, et al., 15th IEEE Intl. Pulsed Power Conf., Monterey, CA, 2005, p. 339), which has an inductive voltage adder (IVA) architecture and a magnetically insulated transmission line (MITL). Mercury is operated in positive polarity resulting in layered MITL flow as emitted electrons are born at a different potential in each of the adder cavities. The usual method for estimating the voltage by measuring the bound current in the cathode and anode of the MITL is not accurate with layered flow, and the interaction of the MITL flow with a pinched-beam ion diode load has not been studied previously. Other methods for determining the diode voltage are applied, ion diode performance is experimentally characterized and evaluated, and circuit and particle-in-cell (PIC) simulations are performed. Results indicate that the ion diode couples efficiently to the machine operating at a diode voltage of about 3.5 MV and a total current of about 325 kA, with an ion current of about 70 kA of which about 60 kA is proton current. It is also found that the layered flow impedance of the MITL is about half the vacuum impedance.

  19. A pulsed-power generator merging inductive voltage and current adders and its switch trigger application example

    NASA Astrophysics Data System (ADS)

    Li, Lee; Yafeng, Ge; Heqin, Zhong; Bin, Yu; Longjun, Xie

    2013-07-01

    A pulsed-power generator using inductive adder technology is proposed for the case of a discharge gap. The merit of this generator is to merge the pulsed-voltage and pulsed-current adders via the dual secondary windings with special circuit. For the nonlinear impedance in any discharge gap, the standalone voltage-pulse and current-pulse can be outputted successively by this generator. The proposed generator is especially useful for the common resolution of implementing pulse discharge at less cost. As an application example, a compact trigger prototype was developed to compatibly use in the gas-insulated and vacuum switches. Experiments achieved good results that the triggered switches showed stable performance and long life. If the basic circuit of this proposed generator is regarded as a pulsed-generating unit, a certain number of such units connected in parallel can be expected to form a general device with generating greater breakdown-voltage and sustained-current pulses for discharge gaps.

  20. A pulsed-power generator merging inductive voltage and current adders and its switch trigger application example.

    PubMed

    Li, Lee; Yafeng, Ge; Heqin, Zhong; Bin, Yu; Longjun, Xie

    2013-07-01

    A pulsed-power generator using inductive adder technology is proposed for the case of a discharge gap. The merit of this generator is to merge the pulsed-voltage and pulsed-current adders via the dual secondary windings with special circuit. For the nonlinear impedance in any discharge gap, the standalone voltage-pulse and current-pulse can be outputted successively by this generator. The proposed generator is especially useful for the common resolution of implementing pulse discharge at less cost. As an application example, a compact trigger prototype was developed to compatibly use in the gas-insulated and vacuum switches. Experiments achieved good results that the triggered switches showed stable performance and long life. If the basic circuit of this proposed generator is regarded as a pulsed-generating unit, a certain number of such units connected in parallel can be expected to form a general device with generating greater breakdown-voltage and sustained-current pulses for discharge gaps.

  1. [An overview on envenomings inflicted by the Common adder (Vipera berus) and their treatment in Hungary. Facts and beliefs -- part I].

    PubMed

    Malina, Tamás; Babocsay, Gergely; Krecsák, László; Schuller, Péter; Zacher, Gábor; Vasas, Gábor

    2012-07-15

    Consequences of bites by the Common adder (Vipera berus) were reviewed in this study. Patients bitten by snakes from different populations may develop variable symptoms due to geographical venom variation. The correct diagnosis of snake bites and the knowledge of the distribution of venomous snake taxa have a crucial impact on snake bite therapy. The characteristic symptoms of patients bitten by V. berus in Hungary are highlighted. The habitat characteristics, seasonal activity and the Hungarian distribution of the adder are described based on literature data, museum specimens and field observations. However, envenomings are uncommon in Hungary, the annual 3 to 4 incidents have to be taken seriously, regardless of the age and actual health condition of the patients. Contrary to beliefs persisting both among laymen and professionals, the venom of V. berus is powerful. Medical observation of the patients is necessary in the first 5 to 6 hours. Any systemic symptom or progression of the edema requires hospital admission.

  2. Quantum dot ternary-valued full-adder: Logic synthesis by a multiobjective design optimization based on a genetic algorithm

    SciTech Connect

    Klymenko, M. V.; Remacle, F.

    2014-10-28

    A methodology is proposed for designing a low-energy consuming ternary-valued full adder based on a quantum dot (QD) electrostatically coupled with a single electron transistor operating as a charge sensor. The methodology is based on design optimization: the values of the physical parameters of the system required for implementing the logic operations are optimized using a multiobjective genetic algorithm. The searching space is determined by elements of the capacitance matrix describing the electrostatic couplings in the entire device. The objective functions are defined as the maximal absolute error over actual device logic outputs relative to the ideal truth tables for the sum and the carry-out in base 3. The logic units are implemented on the same device: a single dual-gate quantum dot and a charge sensor. Their physical parameters are optimized to compute either the sum or the carry out outputs and are compatible with current experimental capabilities. The outputs are encoded in the value of the electric current passing through the charge sensor, while the logic inputs are supplied by the voltage levels on the two gate electrodes attached to the QD. The complex logic ternary operations are directly implemented on an extremely simple device, characterized by small sizes and low-energy consumption compared to devices based on switching single-electron transistors. The design methodology is general and provides a rational approach for realizing non-switching logic operations on QD devices.

  3. Control of a large vacuum wave precursor on the SABRE voltage adder MITL and extraction ion diode

    NASA Astrophysics Data System (ADS)

    Cuneo, M. E.; Hanson, D. L.; Poukey, J. W.; Menge, P. R.; Savage, M. E.; Smith, J. R.; Bernard, M. A.

    SABRE is a ten-cavity magnetically insulated voltage adder (6MV, 300 kA) used to study ion beam production in high voltage extraction applied-B ion diodes. Observations indicate that the machine power initially propagates in a large-amplitude vacuum wave prior to electron emission. This vacuum wave 'precursor' has an important impact on the turn-on and impedance history of ion diodes. Some typical precursor characteristics are shown using transmission line, diode, and beam current and voltage data and are compared to TWOQUICK simulations. Two techniques are under investigation to control the precursor and its effects on diode performance. A plasma opening switch (POS) has been used to erode the precursor. Field enhancing inserts are also planned to decrease the macroscopic field required for electron emission from the cathode. This will limit the distance over which vacuum and insulated waves separate by propagation at different velocities. Experimental data from the POS technique and TWOQUICK simulations of the insert technique are presented and discussed.

  4. Cloacal aerobic bacterial flora and absence of viruses in free-living slow worms (Anguis fragilis), grass snakes (Natrix natrix) and European Adders (Vipera berus) from Germany.

    PubMed

    Schmidt, Volker; Mock, Ronja; Burgkhardt, Eileen; Junghanns, Anja; Ortlieb, Falk; Szabo, Istvan; Marschang, Rachel; Blindow, Irmgard; Krautwald-Junghanns, Maria-Elisabeth

    2014-12-01

    Disease problems caused by viral or bacterial pathogens are common in reptiles kept in captivity. There is no information available on the incidence of viral pathogens or the physiological cloacal bacterial flora of common free-living reptiles in Germany. Therefore, 56 free-living reptiles including 23 European adders (Vipera berus), 12 grass snakes (Natrix natrix) and 21 slow worms (Anguis fragilis) were investigated on the island Hiddensee in northeastern Germany. Pharyngeal and cloacal swabs were taken immediately after capture. Bacteriological examination was performed from the cloacal swabs to study the aerobic cloacal flora. Molecular biological examination included amplification of DNA or RNA from adeno-, rana- and ferlaviruses as well as culturing on Russell's viper heart cells for virus isolation. Salmonella spp. were isolated from European adders but not from the other reptiles examined. The minimal inhibitory concentration was determined from the isolated Salmonella spp. However, some potentially human pathogenic bacteria, such as Proteus vulgaris, Aeromonas hydrophila, Klebsiella pneumoniae and Escherichia coli were isolated. Viruses were not detected in any of the examined reptiles. To the authors' best knowledge, the present study is the first survey of viral pathogens in free-living snakes and slow worms in Germany and the first survey of cloacal aerobic bacterial flora of slow worms.

  5. Fast Differential Adder

    NASA Technical Reports Server (NTRS)

    Arditti, Mort A.; Silva, Rosemary

    1993-01-01

    Differential adding circuit (or, equivalently, subtracting circuit) faster and consumes less power because it contains only one differential amplifier. Suitable for use in high-frequency-switching, high power-regulating circuit.

  6. Cross-Neutralisation of In Vitro Neurotoxicity of Asian and Australian Snake Neurotoxins and Venoms by Different Antivenoms

    PubMed Central

    Silva, Anjana; Hodgson, Wayne C.; Isbister, Geoffrey K.

    2016-01-01

    There is limited information on the cross-neutralisation of neurotoxic venoms with antivenoms. Cross-neutralisation of the in vitro neurotoxicity of four Asian and four Australian snake venoms, four post-synaptic neurotoxins (α-bungarotoxin, α-elapitoxin-Nk2a, α-elapitoxin-Ppr1 and α-scutoxin; 100 nM) and one pre-synaptic neurotoxin (taipoxin; 100 nM) was studied with five antivenoms: Thai cobra antivenom (TCAV), death adder antivenom (DAAV), Thai neuro polyvalent antivenom (TNPAV), Indian Polyvalent antivenom (IPAV) and Australian polyvalent antivenom (APAV). The chick biventer cervicis nerve-muscle preparation was used for this study. Antivenom was added to the organ bath 20 min prior to venom. Pre- and post-synaptic neurotoxicity of Bungarus caeruleus and Bungarus fasciatus venoms was neutralised by all antivenoms except TCAV, which did not neutralise pre-synaptic activity. Post-synaptic neurotoxicity of Ophiophagus hannah was neutralised by all antivenoms, and Naja kaouthia by all antivenoms except IPAV. Pre- and post-synaptic neurotoxicity of Notechis scutatus was neutralised by all antivenoms, except TCAV, which only partially neutralised pre-synaptic activity. Pre- and post-synaptic neurotoxicity of Oxyuranus scutellatus was neutralised by TNPAV and APAV, but TCAV and IPAV only neutralised post-synaptic neurotoxicity. Post-synaptic neurotoxicity of Acanthophis antarcticus was neutralised by all antivenoms except IPAV. Pseudonaja textillis post-synaptic neurotoxicity was only neutralised by APAV. The α-neurotoxins were neutralised by TNPAV and APAV, and taipoxin by all antivenoms except IPAV. Antivenoms raised against venoms with post-synaptic neurotoxic activity (TCAV) cross-neutralised the post-synaptic activity of multiple snake venoms. Antivenoms raised against pre- and post-synaptic neurotoxic venoms (TNPAV, IPAV, APAV) cross-neutralised both activities of Asian and Australian venoms. While acknowledging the limitations of adding antivenom prior to

  7. The human colonisation of Australia: optical dates of 53,000 and 60,000 years bracket human arrival at Deaf Adder Gorge, Northern Territory

    NASA Astrophysics Data System (ADS)

    Roberts, Richard G.; Jones, Rhys; Spooner, Nigel A.; Head, M. J.; Murray, Andrew S.; Smith, M. A.

    The date at which people entered Australia has important implications for the debate on modern human origins. Thermoluminescence dates of 50-60 ka, reported for initial occupation of the Malakunanja II site in northern Australia, have been used as a means of calibrating the rate of mitochondrial and nuclear DNA evolution in modern humans. Optical dating of unburnt quartzose sediments from a rock shelter site (Nauwalabila I, Lindner Site) in Deaf Adder Gorge, 70 km south of Malakunanja II, provides new evidence for the timing of the colonisation of the continent. Optical dates were determined for several stratigraphic levels within a 3 m deep excavation, in which flaked stone artefacts and ground pigments were found in primary depositional setting. The lowest human occupation levels are bracketed by dates of 53.4 ± 5.4 ka and 60.3 ± 6.7 ka, while the upper levels show good agreement between optical and calibrated 14C age estimates. High-quality haematite with ground facets and striations is associated directly with the 53 ka level and indicates the use of pigments by these early Australians. The optical dates independently confirm evidence for the colonisation of northern Australia shortly after 60 ka and should be seen in the context of this region as having been a likely entry route for the first human movements into Sahul.

  8. The effect of physiological levels of South African puff adder (Bitis arietans) snake venom on blood cells: an in vitro model

    PubMed Central

    Strydom, Morné A.; Bester, Janette; Mbotwe, Sthembile; Pretorius, Etheresia

    2016-01-01

    A significant burden of illness is caused globally by snakebites particularly by the puff adder, Bitis arietans. Presently there is no reliable and rapid method to confirm envenomation on blood chemistry; although coagulation parameters like prothrombin time, partial thromboplastin time, international normalized ratio and also serum electrolytes are tested. Here, we found that direct in vitro exposure of physiological relevant whole venom levels to human healthy blood (N = 32), caused significant physiological changes to platelet activity using a hematology analyzer, and measuring occlusion time, as well as lyses time, with the global thrombosis test (GTT). Disintegrated platelets were confirmed by scanning electron microscopy (SEM). We also confirmed the pathologic effects on erythrocytes (RBCs) (visible as eryptotic RBCs), by looking at both light microscopy and SEM. Thromboelastography showed that no clot formation in whole blood could be induced after addition of whole venom. We propose further clinical studies to investigate the use of light microscopy smears and hematology analyzer results immediately after envenomation, as a possible first-stage of clinical confirmation of envenomation. PMID:27775063

  9. Experiments investigating the generation and transport of 10--12 MeV, 30-kA, mm-size electron beams with linear inductive voltage adders

    SciTech Connect

    Mazarakis, M.G.; Poukey, J.W.; Maenchen, J.E.

    1997-06-01

    The authors present the design, analysis, and results of the high-brightness electron beam experiments currently under investigation at Sandia National Laboratories. The anticipated beam parameters are the following: 8--12 MeV, 35--50 kA, 30--60 ns FWHM, and 0.5-mm rms beam radius. The accelerators utilized are SABRE and HERMES III. Both are linear inductive voltage adders modified to higher impedance and fitted with magnetically immersed foil less electron diodes. In the strong 20--50 Tesla solenoidal magnetic field of the diode, mm-size electron beams are generated and propagated to a beam stop. The electron beam is field emitted from mm-diameter needle-shaped cathode electrode and is contained in a similar size envelop by the strong magnetic field. These extremely space charge dominated beams provide the opportunity to study beam dynamics and possible instabilities in a unique parameter space. The SABRE experiments are already completed and have produced 30-kA, 1.5-mm FWHM electron beams, while the HERMES-III experiments are on-going.

  10. Effects of seasonal variation in prey abundance on field metabolism, water flux, and activity of a tropical ambush foraging snake.

    PubMed

    Christian, Keith; Webb, Jonathan K; Schultz, Timothy; Green, Brian

    2007-01-01

    The responses of animals to seasonal food shortages can have important consequences for population dynamics and the structure and function of food webs. We investigated how an ambush foraging snake, the northern death adder Acanthophis praelongus, responds to seasonal fluctuations in prey availability in its tropical environment. In the dry season, field metabolic rates and water flux, as measured by doubly labeled water, were significantly lower than in the wet season. Unlike some other reptiles of the wet-dry tropics, death adders showed no seasonal difference in their resting metabolism. About 94% of the decrease in energy expended in the dry season was due to a decrease in activity and digestion, with lower body temperatures accounting for the remainder. In the dry season, death adders were less active and moved shorter distances between foraging sites than in the wet season. Analysis of energy expenditure suggested that adders fed no more than every 2-3 wk in the dry season but fed more frequently during the wet season. Unlike many lizards that cease feeding during the dry season, death adders remain active and attempt to maximize their energy intake year-round.

  11. MULTIPLE INPUT BINARY ADDER EMPLOYING MAGNETIC DRUM DIGITAL COMPUTING APPARATUS

    DOEpatents

    Cooke-Yarborough, E.H.

    1960-12-01

    A digital computing apparatus is described for adding a plurality of multi-digit binary numbers. The apparatus comprises a rotating magnetic drum, a recording head, first and second reading heads disposed adjacent to the first and second recording tracks, and a series of timing signals recorded on the first track. A series of N groups of digit-representing signals is delivered to the recording head at time intervals corresponding to the timing signals, each group consisting of digits of the same significance in the numbers, and the signal series is recorded on the second track of the drum in synchronism with the timing signals on the first track. The multistage registers are stepped cyclically through all positions, and each of the multistage registers is coupled to the control lead of a separate gate circuit to open the corresponding gate at only one selected position in each cycle. One of the gates has its input coupled to the bistable element to receive the sum digit, and the output lead of this gate is coupled to the recording device. The inputs of the other gates receive the digits to be added from the second reading head, and the outputs of these gates are coupled to the adding register. A phase-setting pulse source is connected to each of the multistage registers individually to step the multistage registers to different initial positions in the cycle, and the phase-setting pulse source is actuated each N time interval to shift a sum digit to the bistable element, where the multistage register coupled to bistable element is operated by the phase- setting pulse source to that position in its cycle N steps before opening the first gate, so that this gate opens in synchronism with each of the shifts to pass the sum digits to the recording head.

  12. The ecological impact of invasive cane toads on tropical snakes: field data do not support laboratory-based predictions.

    PubMed

    Brown, Gregory P; Phillips, Benjamin L; Shine, Richard

    2011-02-01

    Predicting which species will be affected by an invasive taxon is critical to developing conservation priorities, but this is a difficult task. A previous study on the impact of invasive cane toads (Bufo marinus) on Australian snakes attempted to predict vulnerability a priori based on the assumptions that any snake species that eats frogs, and is vulnerable to toad toxins, may be at risk from the toad invasion. We used time-series analyses to evaluate the accuracy of that prediction, based on >3600 standardized nocturnal surveys over a 138-month period on 12 species of snakes and lizards on a floodplain in the Australian wet-dry tropics, bracketing the arrival of cane toads at this site. Contrary to prediction, encounter rates with most species were unaffected by toad arrival, and some taxa predicted to be vulnerable to toads increased rather than declined (e.g., death adder Acanthophis praelongus; Children's python Antaresia childreni). Indirect positive effects of toad invasion (perhaps mediated by toad-induced mortality of predatory varanid lizards) and stochastic weather events outweighed effects of toad invasion for most snake species. Our study casts doubt on the ability of a priori desktop studies, or short-term field surveys, to predict or document the ecological impact of invasive species.

  13. Technology Development and Circuit Design for a Parallel Laser Programmable Floating Point Application Specific Processor

    DTIC Science & Technology

    1989-12-01

    select adder because the carry select adder is the largest consumer of the propagation delay through the adder. The result of the analysis of the carry ...multiplexed adder is the product of a three step evolution from the carry - select adder . The first step hierarchically expanded the idea of the carry - select adder into...select-type adder where the each ripple adder of the carry-select is expanded into a carry - select adder .

  14. Uropygial gland squamous cell carcinoma in chinstrap (Pygoscelis antarcticus) and gentoo (Pygoscelis papua) penguins at the Wildlife Conservation Society's Central Park Zoo.

    PubMed

    Rettenmund, Christy L; Newton, Alisa L; Calle, Paul P

    2015-03-01

    Uropygial, or preen, glands are found in a variety of avian species including penguins. These glands have a multitude of functions and can develop a variety of conditions including impaction, rupture, adenitis, squamous metaplasia, and neoplasia of various types, with squamous cell carcinoma the most commonly reported. A case series of uropygial gland squamous cell carcinoma in five penguins at the Wildlife Conservation Society's Central Park Zoo is described. Most birds were aged (>10 yr) with a history of chronic, recurrent uropygial gland problems including impaction, rupture, abscess formation, or a combination of conditions. Before and after neoplasia diagnosis, these cases were managed conservatively, and palliative care was provided. Because many of these cases were preceded by chronic inflammation, it is possible this inflammation predisposed the uropygial gland to neoplastic transformation, and more aggressive treatment early in the disease process may therefore be warranted.

  15. Clinical and biochemical changes in 53 Swedish dogs bitten by the European adder - Vipera berus

    PubMed Central

    2010-01-01

    Background Every year many dogs in Sweden are bitten by Vipera berus, the only venomous viper in Sweden. This prospective study investigated clinical signs, some biochemical parameters, treatment, and progress of disease after snakebite in 53 dogs. Effects of treatment with and without glucocorticoids were evaluated. Methods All fifty-three dogs bitten by Vipera berus were examined the same day the dog was bitten and the next day. Two more examinations during 23 days post snake bite were included. Creatinine, creatine kinase (CK), alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), alkaline phosphatase (ALP) and bile acid results were followed through 3 to 4 samplings from 34 of the dogs. Results All dogs had variable severity of local swelling in the bite area and 73 per cent had affected mental status. Initial cardiac auscultation examination was normal in all dogs, but six dogs had cardiac abnormalities at their second examination, including cardiac arrhythmias and cardiac murmurs. All dogs received fluid therapy, 36 dogs were given analgesics, 22 dogs were treated with glucocorticoids, and ten dogs were treated with antibiotics. Evidence of transient muscle damage (increased CK) was seen one day after the snake bite in 15 (54%) of 28 sampled dogs. Moderate changes in hepatic test results occurred in 1 dog and several dogs (22 of 34) had transient, minor increases in one or more hepatic test result. No dog died during the observation period as a consequence of the snake bite. Conclusions Snake bite caused local swelling in all dogs and mental depression of short duration in most dogs. Some dogs had transient clinical signs that could be indicative of cardiac injury and some other had transient biochemical signs of liver injury. Treatment with glucocorticoids did not have any clear positive or negative effect on clinical signs and mortality. PMID:20416040

  16. Pencil-like mm-size electron beams produced with linear inductive voltage adders (LIVA)

    SciTech Connect

    Mazarakis, M.G.; Poukey, J.W.; Rovang, D.C.

    1996-09-01

    This paper presents design, analysis, and first results of the high brightness electron beam experiments currently under investigation at Sandia. Anticipated beam parameters are: energy 12 MeV, current 35-40 kA, rms radius 0.5 mm, pulse duration 40 ns FWHM. The accelerator is SABRE, a pulsed LIVA modified to higher impedance, and the electron source is a magnetically immersed foilless electron diode. 20 to 30 Tesla solenoidal magnets are required to insulate the diode and contain the beam to its extremely small sized (1 mm) envelope. These experiments are designed to push the technology to produce the highest possible electron current in a submillimeter radius beam. Design, numercial simulations, and first experimental results are presented.

  17. Phylogeography and Pleistocene refugia of the adder (Vipera berus) as inferred from mitochondrial DNA sequence data.

    PubMed

    Ursenbacher, S; Carlsson, M; Helfer, V; Tegelström, H; Fumagalli, L

    2006-10-01

    In order to contribute to the debate about southern glacial refugia used by temperate species and more northern refugia used by boreal or cold-temperate species, we examined the phylogeography of a widespread snake species (Vipera berus) inhabiting Europe up to the Arctic Circle. The analysis of the mitochondrial DNA (mtDNA) sequence variation in 1043 bp of the cytochrome b gene and in 918 bp of the noncoding control region was performed with phylogenetic approaches. Our results suggest that both the duplicated control region and cytochrome b evolve at a similar rate in this species. Phylogenetic analysis showed that V. berus is divided into three major mitochondrial lineages, probably resulting from an Italian, a Balkan and a Northern (from France to Russia) refugial area in Eastern Europe, near the Carpathian Mountains. In addition, the Northern clade presents an important substructure, suggesting two sequential colonization events in Europe. First, the continent was colonized from the three main refugial areas mentioned above during the Lower-Mid Pleistocene. Second, recolonization of most of Europe most likely originated from several refugia located outside of the Mediterranean peninsulas (Carpathian region, east of the Carpathians, France and possibly Hungary) during the Mid-Late Pleistocene, while populations within the Italian and Balkan Peninsulas fluctuated only slightly in distribution range, with larger lowland populations during glacial times and with refugial mountain populations during interglacials, as in the present time. The phylogeographical structure revealed in our study suggests complex recolonization dynamics of the European continent by V. berus, characterized by latitudinal as well as altitudinal range shifts, driven by both climatic changes and competition with related species.

  18. Component Design, Development, and Testing of an Inductive Voltage Adder (IVA) System for Jupiter

    DTIC Science & Technology

    1995-07-01

    Jupiter is a proposed 15-20 MJ laboratory x-ray source. It would store 100 MJ in the Marx generators and deliver 500 TW to drive high power z-pinch...FWHM output pulse and will consist of four submodules. Each submodule is composed of a Marx generator, two Intermediate Energy Storage Capacitors (ISCs

  19. Multi-input and binary reproducible, high bandwidth floating point adder in a collective network

    SciTech Connect

    Chen, Dong; Eisley, Noel A.; Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2016-11-15

    To add floating point numbers in a parallel computing system, a collective logic device receives the floating point numbers from computing nodes. The collective logic devices converts the floating point numbers to integer numbers. The collective logic device adds the integer numbers and generating a summation of the integer numbers. The collective logic device converts the summation to a floating point number. The collective logic device performs the receiving, the converting the floating point numbers, the adding, the generating and the converting the summation in one pass. One pass indicates that the computing nodes send inputs only once to the collective logic device and receive outputs only once from the collective logic device.

  20. Multi-input and binary reproducible, high bandwidth floating point adder in a collective network

    DOEpatents

    Chen, Dong; Eisley, Noel A; Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2015-03-10

    To add floating point numbers in a parallel computing system, a collective logic device receives the floating point numbers from computing nodes. The collective logic devices converts the floating point numbers to integer numbers. The collective logic device adds the integer numbers and generating a summation of the integer numbers. The collective logic device converts the summation to a floating point number. The collective logic device performs the receiving, the converting the floating point numbers, the adding, the generating and the converting the summation in one pass. One pass indicates that the computing nodes send inputs only once to the collective logic device and receive outputs only once from the collective logic device.

  1. A Multiple-Valued Logic System for Circuit Extraction to VHDL 1076-1987

    DTIC Science & Technology

    1988-09-01

    79 31-Bit Carry Select Adder ................................. 82 Multiplier Chip.......................................... 87 VUI...Procedure for 31-Bit Carry Select Adder ........... 82 35. Full Adder Template ..................................... 83 36. Select Adder Layout...84 37. Prolog Representation for 31-Bit Carry Select Adder .......... 86 38. Block Diagram of the 31-Bit Carry

  2. Architecture and Design for a Laser Programmable Double Precision Floating Point Application Specific Processor

    DTIC Science & Technology

    1988-12-01

    4-18 4.13. ALU Carry - Select Adder ........ ............................... 4-20 4.14. Literal Inserter Circuitry...one clock cycle required a carry - select adder . SPICE simulations of the carry - select adder in the ALU showed that this operation could be done in 12...floating point subtraction. The interface to the adder is identical to that of the multiplier. The adder will use a carry - select adder to perform the

  3. How the Inductive Voltage Adder (IVA) output impedance affects impedance dynamics of a Self-Magnetic Pinch (SMP) diode

    NASA Astrophysics Data System (ADS)

    Renk, Timothy; Simpson, Sean; Webb, Timothy; Mazarakis, Michael; Kiefer, Mark

    2016-10-01

    The SMP diode, fielded on the RITS-6 (3.5-8.5 MV) IVA accelerator at Sandia National Laboratories, produces a focused electron beam (<3mm diameter) onto a high Z metal converter for flash x-ray applications. Experiments have been undertaken with two different magnetically insulated transmission line (MITL) center conductors, of 40 and 80 ohms flow impedance. We have operated in-situ heating and discharge-cleaning hardware in the load region, in order to address the tendency of some shots to undergo premature impedance (Z) collapse, defined as a fall in impedance beyond that due to normal movement of electrode plasmas that reduces the effective A-K gap. The goal of heating/cleaning was to reduce the volume of evolving gases near the A-K gap. Despite clear evidence that the cleaning techniques removed the proton portion of beam current, we observed no consistent increase in diode impedance (ZDIODE). This forced an examination of the role that the IVA flow impedance has on ZDIODE. A preliminary conclusion is that ZDIODE should be at least 1.5 times the flow impedance before ZDIODE is a parameter independent of flow impedance. This has implications for SMP as a load for a IVA, since ZDIODE >100 ohms has not been consistently demonstrated. Data analysis is ongoing, and latest results will be reported. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  4. Simultaneous all-optical half-adder, half-subtracter, comparator, and decoder based on nonlinear effects harnessing in highly nonlinear fibers

    NASA Astrophysics Data System (ADS)

    Singh, Karamdeep; Kaur, Gurmeet; Singh, Maninder Lal

    2016-07-01

    A multifunctional combinational logic module capable of performing several signal manipulation tasks all-optically, such as half-addition/subtraction, single-bit comparison, and 2-to-4 decoding simultaneously is proposed. Several logic functions (A+B¯, A.B, A¯.B, A.B¯, A⊕B, and A⊙B) between two input signals A and B are implemented by harnessing a number of nonlinear effects, such as cross-phase modulation (XPM), cross-gain modulation (XGM), and four-wave mixing (FWM) inside only two highly nonlinear fibers (HNLF) arranged in a parallel structure. The NOR gate (A+B¯) is realized by the means of XPM effect in the first HNLF, whereas, A‾.B, A.B¯, and A.B logics have relied on utilization of XGM and FWM processes, respectively, in parametric medium made up of the second HNLF of parallel arrangement. The remaining A⊕B and A⊙B logics required for successful implementation of the proposed simultaneous scheme are attained by temporally combining previously achieved (A‾.B and A.B‾) and (A.B and A+B‾) logics. Quality-factor ≥7.4 and extinction ratio ≥12.30 dB have been achieved at repetition rates of 100 Gbps for all logic functions (A+B‾, A.B, A¯.B, A.B¯, A⊕B, and A⊙B), suggesting successful simultaneous implementation.

  5. Signed-Digit High Speed Transcendental Function Processor Architecture

    DTIC Science & Technology

    1989-06-01

    carry - select adder . A carry - select adder is used to...maximum value of their sum is Tmax + Xm,. = 9 + 1 = 10. The addition is accomplished by using the same carry - select adder described in the preceding...8217 from A by using the functions Ko = (A, xor A 4) and (73 or A4) 5-4 SIGNED-DIGIT INPUT A DIGIT B DIGIT 5-BIT CARRY - SELECT ADDER CARRY OUT 2 BIT

  6. Sanguibacter gelidistatuariae sp. nov., a novel psychrotolerant anaerobe from an ice sculpture in Antarctica, and emendation of descriptions for the family Sanguibacteraceae, the genus Sanguibacter and species S. antarcticus, S. inulinus, S. kedieii, S. marinus, S.soli and S. suarezii.

    PubMed

    Pikuta, Elena V; Lyu, Zhe; Williams, Melissa D; Patel, Nisha B; Liu, Yuchen; Hoover, Richard Brice; Busse, Hans-Jürgen; Lawson, Paul A; Whitman, William B

    2017-02-01

    A novel psychrotolerant bacterium strain ISLP-3T was isolated from a sample of naturally formed ice sculpture on the shore of Lake Podprudnoye in Antarctica. Cells were motile, stained Gram positive, non-spore-forming, straight or slightly curved rods with the shape of a baseball bat. The new isolate was facultatively anaerobic and catalase positive. Growth occurred at 3-35 ºC with an optimum at 24 °C, 0-2 % w/v NaCl with an optimum at 0.3 % and pH 6.2 - 9.5 with an optimum 7.5. Strain ISLP-3T grew on several carbon sources, with the best growth on D-cellobiose. The isolate possessed ureolytic activity but growth was inhibited by urea. The strain was sensitive to: ampicillin, gentamycin, kanamycin rifampicin, tetracycline and chloramphenicol. Major fatty acids were: C 15:0 anteiso, C 16:0 iso, C 16:0, C14:0 and C15:0 iso. The predominant menaquinone was MK-9(H4). The genomic G+C content was 69.5 mol%.The 16S rRNA gene possessed 99 % sequence similarity to the gene of Sanguibacter suarezii ST-26T, but their recA genes demonstrated ≤91 % sequence similarity, suggesting that this isolate represented a novel species within genus Sanguibacter. This conclusion was supported by ANI, which was ≤91 % to the most closely related strain. The name Sanguibacter gelidistatuariae sp. nov. is proposed for the new species with the type strain ISLP-3T(= ATCC TSD-17T, = DSM 100501T, = JCM 30887T). Complete genome draft sequence of ISLP-3T was deposited under IMG OID 2657245272. Emendments of related taxa have been made based on experimental data of our comparative analysis.

  7. Power Analyzer for Pocket Computing (PAPC)

    DTIC Science & Technology

    2004-01-01

    time with the micro-architec- tural simulator. For this example, we consider a 32-bit carry - select adder consisting of eight 8-bit ripple-carry adders...corresponding HSPICE circuit simulation. Figure 15-(a) shows a calibration using the carry - select adder in the previous case study. Each point in the graph

  8. Design and Implementation of VLSI Prime Factor Algorithm Processor.

    DTIC Science & Technology

    1987-12-01

    for A, 1i ’ 1 1 Fh Ai ,,r equjAtIInI. art, ( , 4 10 4,t’ 4 ( - /’ cr tht, (-arr% sur ma% akL, be represented as Figure 36 Carry Select Adder Blocking... Select Adder Blocking .......................................................... 81 Figure 37: ALU Adder Cell...ALU Logic Implementation............................................................ 81 viii J,.. in List of Figures (continued) Figure 36: Carry

  9. [Starvation and chemoreception in Antarctic benthic invertebrates].

    PubMed

    Rakusa-Suszczewski, S; Janecki, T; Domanov, M M

    2010-01-01

    Sensitivity (chemoreception) to different amino acids was studied in six invertebrate species: Serolis polita, Glyptonotus antarcticus, Abyssochromene plebs, Waldeckia obesa, Odontaster validus, and Sterechinus neumayeri. The sensitivity was estimated by the changes in basic metabolism (respiration rate). Starvation increased the sensitivity in all the species. The metabolism rates increased in the presence of L-glutamic acid in G. antarcticus, A. plebs, O. validus, and S. neumayeri. The serine and arginine amino acids had a significant impact on the metabolism of the necrophagous species S. polita and W. obesa. The chemical information may be mediated by means of L-glutamic acid via glutamate receptors, which can be blocked by kynurenic acid, as occurs in the experiments with G. antarcticus and A. plebs.

  10. Diversity and Distribution of Deep-Sea Shrimps in the Ross Sea Region of Antarctica

    PubMed Central

    Basher, Zeenatul; Bowden, David A.; Costello, Mark J.

    2014-01-01

    Although decapod crustaceans are widespread in the oceans, only Natantia (shrimps) are common in the Antarctic. Because remoteness, depth and ice cover restrict sampling in the South Ocean, species distribution modelling is a useful tool for evaluating distributions. We used physical specimen and towed camera data to describe the diversity and distribution of shrimps in the Ross Sea region of Antarctica. Eight shrimp species were recorded: Chorismus antarcticus; Notocrangon antarcticus; Nematocarcinus lanceopes; Dendrobranchiata; Pasiphaea scotiae; Pasiphaea cf. ledoyeri; Petalidium sp., and a new species of Lebbeus. For the two most common species, N. antarcticus and N. lanceopes, we used maximum entropy modelling, based on records of 60 specimens and over 1130 observations across 23 sites in depths from 269 m to 3433 m, to predict distributions in relation to environmental variables. Two independent sets of environmental data layers at 0.05° and 0.5° resolution respectively, showed how spatial resolution affected the model. Chorismus antarcticus and N. antarcticus were found only on the continental shelf and upper slopes, while N. lanceopes, Lebbeus n. sp., Dendrobranchiata, Petalidium sp., Pasiphaea cf. ledoyeri, and Pasiphaea scotiae were found on the slopes, seamounts and abyssal plain. The environmental variables that contributed most to models for N. antarcticus were depth, chlorophyll-a concentration, temperature, and salinity, and for N. lanceopes were depth, ice concentration, seabed slope/rugosity, and temperature. The relative ranking, but not the composition of these variables changed in models using different spatial resolutions, and the predicted extent of suitable habitat was smaller in models using the finer-scale environmental layers. Our modelling indicated that shrimps were widespread throughout the Ross Sea region and were thus likely to play important functional role in the ecosystem, and that the spatial resolution of data needs to be

  11. Diversity and distribution of deep-sea shrimps in the Ross Sea region of Antarctica.

    PubMed

    Basher, Zeenatul; Bowden, David A; Costello, Mark J

    2014-01-01

    Although decapod crustaceans are widespread in the oceans, only Natantia (shrimps) are common in the Antarctic. Because remoteness, depth and ice cover restrict sampling in the South Ocean, species distribution modelling is a useful tool for evaluating distributions. We used physical specimen and towed camera data to describe the diversity and distribution of shrimps in the Ross Sea region of Antarctica. Eight shrimp species were recorded: Chorismus antarcticus; Notocrangon antarcticus; Nematocarcinus lanceopes; Dendrobranchiata; Pasiphaea scotiae; Pasiphaea cf. ledoyeri; Petalidium sp., and a new species of Lebbeus. For the two most common species, N. antarcticus and N. lanceopes, we used maximum entropy modelling, based on records of 60 specimens and over 1130 observations across 23 sites in depths from 269 m to 3433 m, to predict distributions in relation to environmental variables. Two independent sets of environmental data layers at 0.05° and 0.5° resolution respectively, showed how spatial resolution affected the model. Chorismus antarcticus and N. antarcticus were found only on the continental shelf and upper slopes, while N. lanceopes, Lebbeus n. sp., Dendrobranchiata, Petalidium sp., Pasiphaea cf. ledoyeri, and Pasiphaea scotiae were found on the slopes, seamounts and abyssal plain. The environmental variables that contributed most to models for N. antarcticus were depth, chlorophyll-a concentration, temperature, and salinity, and for N. lanceopes were depth, ice concentration, seabed slope/rugosity, and temperature. The relative ranking, but not the composition of these variables changed in models using different spatial resolutions, and the predicted extent of suitable habitat was smaller in models using the finer-scale environmental layers. Our modelling indicated that shrimps were widespread throughout the Ross Sea region and were thus likely to play important functional role in the ecosystem, and that the spatial resolution of data needs to be

  12. Integrated Circuits for Avionics

    DTIC Science & Technology

    1989-10-01

    49 0 3.2.3.1 Latch. .. ..... ........ ..... 51 o 3.2.3.2 Carry Select Adder . ........ ..... 51 3.2.3.3 Exclusive OR...3.8 Carry - Select Adder .. ... ..... ..... ...... .56 3.9 Exclusive OR Cell. .... ..... ..... ...... .57 3.10 Multiplier Block Diagram...98 4.17 Block Diagram of the Carry Select Adder ..... ..... ... 99 4.18 Stack Bus Timing. .. .. .. ..... ...... ..... 101 4.19 Block Diagram

  13. Linear induction accelerator

    DOEpatents

    Buttram, M.T.; Ginn, J.W.

    1988-06-21

    A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.

  14. Linear induction accelerator and pulse forming networks therefor

    DOEpatents

    Buttram, Malcolm T.; Ginn, Jerry W.

    1989-01-01

    A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities.

  15. Demonstration of Inexact Computing Implemented in the JPEG Compression Algorithm using Probabilistic Boolean Logic applied to CMOS Components

    DTIC Science & Technology

    2015-12-24

    competitive on the basis of speed , power, and noise immunity. This circuit is used at 3V and 15mW, but is rated at 8 V and 100 mW. Unpowered...algorithm using these inexact adders and multipliers. In the interests of high- speed simulation and of collecting large sample sizes, these simulations were...2isi. (28) For most applications, the ripple-carry adder is the slowest adder architecture. There are many adders which are optimized for speed , for

  16. Copper inducing effect on laccase production of white rot fungi native from Misiones (Argentina).

    PubMed

    Fonseca, María I; Shimizu, Ernesto; Zapata, Pedro D; Villalba, Laura L

    2010-05-05

    Fungi may be selected as models for gene expression studies and further adaptation for biotechnological enzyme production. The aim of this work was to evaluate laccase production and to analyze the effect of Cu(2+) on selected fungi natives of Misiones, Ganoderma applanatum (strain F), Peniophora sp. (BAFC 633), Pycnoporus sanguineus (BAFC 2126) and Coriolus versicolor f. antarcticus (BAFC 266). Fungi secretion system of G. applanatum, Peniophora sp., P. sanguineus and C. versicolor f. antarcticus is sensitive to stimulation by copper. Biomass values of G. applanatum, Peniophora sp. and C. versicolor f. antarcticus did not show differences between treatments. P. sanguineus biomass underwent a dramatic growth inhibition with 1mM Cu(2+) and marked delay in growth with 0.5mM Cu(2+). Proteins were increased with copper in Peniophora sp., C. versicolor and G. applanatum. G. applanatum and Peniophora sp. reached the highest enzyme activity at 10th day equivalent to 49.2-fold and 19.7-fold higher than the control samples, respectively. Copper produced an increase of constitutive laccases in all fungi and an additional inducible isoenzyme in Peniophora sp., C. versicolor f. antarcticus and G. applanatum.

  17. Simple circuit performs binary addition and subtraction

    NASA Technical Reports Server (NTRS)

    Cliff, R. A.; Schaefer, D. H.

    1965-01-01

    Ripple adder reduces the number of logic circuits required to preform binary addition and subtraction. The adder uses dual input and delayed output flip-flops in one register. The contents of this register are summed with those of a standard register through conventional AND/gates.

  18. Exploiting Symmetry for Quantum Error Suppression

    NASA Astrophysics Data System (ADS)

    Nam, Yunseong; Blümel, Reinhold

    2016-05-01

    In light of recent experimental progress in quantum computing, the time is ripe to discuss quantum computer hardware optimization. Taking the digital/analog hybrid nature of quantum computers into account, choosing a proper processor architecture for a given quantum algorithm becomes crucial in making quantum computing a practical reality. As a first step in this direction, we investigate the robustness of quantum adders with respect to naturally occurring hardware defects and errors. In particular, we compare the robustness of the ripple-carry adder to that of the quantum Fourier adder. We show that, surprisingly, when used in Shor's algorithm, the quantum Fourier adder may well be more robust than the ripple-carry adder. We present a noise suppression scheme, called symmetric noise, applicable to the quantum Fourier architecture, that, measured in terms of fidelity, results in an order-of-magnitude performance boost.

  19. MULTI-CHANNEL ELECTRIC PULSE HEIGHT ANALYZER

    DOEpatents

    Gallagher, J.D. et al.

    1960-11-22

    An apparatus is given for converting binary information into coded decimal form comprising means, in combination with a binary adder, a live memory and a source of bigit pulses, for synchronizing the bigit pulses and the adder output pulses; a source of digit pulses synchronized with every fourth bigit pulse; means for generating a conversion pulse in response to the time coincidence of the adder output pulse and a digit pulse: means having a delay equal to two bigit pulse periods coupling the adder output with the memory; means for promptly impressing said conversion pulse on the input of said memory: and means having a delay equal to one bigit pulse period for again impressing the conversion pulse on the input of the memory whereby a fourth bigit adder pulse results in the insertion into the memory of second, third and fourth bigits.

  20. Pipeline active filter utilizing a booth type multiplier

    NASA Technical Reports Server (NTRS)

    Nathan, Robert (Inventor)

    1987-01-01

    Multiplier units of the modified Booth decoder and carry-save adder/full adder combination are used to implement a pipeline active filter wherein pixel data is processed sequentially, and each pixel need only be accessed once and multiplied by a predetermined number of weights simultaneously, one multiplier unit for each weight. Each multiplier unit uses only one row of carry-save adders, and the results are shifted to less significant multiplier positions and one row of full adders to add the carry to the sum in order to provide the correct binary number for the product Wp. The full adder is also used to add this product Wp to the sum of products .SIGMA.Wp from preceding multiply units. If m.times.m multiplier units are pipelined, the system would be capable of processing a kernel array of m.times.m weighting factors.

  1. Benchmarks of a III-V TFET technology platform against the 10-nm CMOS FinFET technology node considering basic arithmetic circuits

    NASA Astrophysics Data System (ADS)

    Strangio, S.; Palestri, P.; Lanuzza, M.; Esseni, D.; Crupi, F.; Selmi, L.

    2017-02-01

    In this work, a benchmark for low-power digital applications of a III-V TFET technology platform against a conventional CMOS FinFET technology node is proposed. The analysis focuses on full-adder circuits, which are commonly identified as representative of the digital logic environment. 28T and 24T topologies, implemented in complementary-logic and transmission-gate logic, respectively, are investigated. Transient simulations are performed with a purpose-built test-bench on each single-bit full adder solution. The extracted delays and energy characteristics are post-processed and translated into figures-of-merit for multi-bit ripple-carry-adders. Trends related to the different full-adder implementations (for the same device technology platform) and to the different technology platforms (for the same full-adder topology) are presented and discussed.

  2. A Path to Discovery

    ERIC Educational Resources Information Center

    Stegemoller, William; Stegemoller, Rebecca

    2004-01-01

    The path taken and the turns made as a turtle traces a polygon are examined to discover an important theorem in geometry. A unique tool, the Angle Adder, is implemented in the investigation. (Contains 9 figures.)

  3. Antibacterial properties of KwaZulu natal snake venoms.

    PubMed

    Blaylock, R S

    2000-11-01

    The objective was to ascertain whether local snake venoms have antibacterial properties. The venoms of the common night adder (Causus rhombeatus), gaboon adder (Bitis gabonica), puff adder (Bitis arietans), black mamba (Dendroaspis polylepis), eastern green mamba (Dendroaspis augusticeps), forest cobra (Naja melanoleuca), snouted cobra (Naja annulifera) and Mozambique spitting cobra (Naja mossambica) were collected and, by gel diffusion, tested against the bacteria Staphylococcus aureus, Escherichia coli, Pseudomonas aeriginosa, Bacteriodes fragilis, Bacteroides intermedius, Clostridium sordellii and Clostridium perfringens. All snake venoms showed antibacterial activity, with the adders showing most activity against the aerobes while the cobras showed lesser, but equal activity against the aerobes and anaerobes. Black mamba venom only showed activity against C. perfringens. In conclusion, local snake venoms have antibacterial properties which are dependent on the venom and bacterial type; and in the Naja spp., for anaerobic bacteria, diminish in winter. There is liable to be more than one toxin component responsible.

  4. Image Transmission via Spread Spectrum Techniques. Part B

    DTIC Science & Technology

    1976-01-01

    received data, The decoder will group the filter outputs to form compound vectors that will-be correlated, using Fast Walsh Transform techniques, with...results. The ADDERS perform the Fast Walsh Transform calculations to generate the sign patterns of Table 14 and the Data Selectors perform the necessary...ten ADDERS (Figure 4-3) where two iterations of a Fast Walsh Transform (FWT) are performed. The resulting values held in LATCH 2 are sent to the

  5. A CAD Suite for High-Performance FPGA Design

    DTIC Science & Technology

    1999-01-01

    guage, it is possible to write VHDL programs that program- matically generate circuit structures when the VHDL code is enumerated. That is, rather...adders of any size and is reusable by any VHDL code that wishes to build an adder of some size. This programmatic approach to struc- tural circuit...best). Source -level debuggers for these lan- guages are also much more comprehensive and easier to use than their limited VHDL equivalents. All of the

  6. Optical Computing. Organization of the 1993 Photonics Science Topical Meetings Held in Palm Springs, California on March 16 - 19, 1993. Technical Digest Series, Volume 7

    DTIC Science & Technology

    1993-03-19

    network Implementation using 9:20 am asymmetric Fabry-Perot modulators, Andrew Jennings, Brian OWA3 Multiwavelength optical half adder, Pochi Yeh... multiwavelength optical half adder. (p. 68) nects. (p. 96) 9:40 am 2:50 pm OWA4 Wavelength multiplexed computer-generated volume OWC3 Content addramble...ATMOS and OSCAR are RACE projects, mentioned in the text shape this into new systems architectures, ("optical ether"). Broadly speaking, this has led to

  7. Second-degree heart block associated with envenomation by Vipera berus.

    PubMed Central

    Moore, R S

    1988-01-01

    Evenomation by the common European adder (Vipera berus) is well known for its significant morbidity but low mortality. Cardiac complications tend to take second place to the systemic upset and usually only comprise non-specific ECG changes. This case illustrates many of the classical features of adder bite but it is also the first account of heart block as a complication. Images Fig. 2 PMID:3408530

  8. Poles Apart: Arctic and Antarctic Octadecabacter strains Share High Genome Plasticity and a New Type of Xanthorhodopsin

    PubMed Central

    Vollmers, John; Voget, Sonja; Dietrich, Sascha; Gollnow, Kathleen; Smits, Maike; Meyer, Katja; Brinkhoff, Thorsten; Simon, Meinhard; Daniel, Rolf

    2013-01-01

    The genus Octadecabacter is a member of the ubiquitous marine Roseobacter clade. The two described species of this genus, Octadecabacter arcticus and Octadecabacter antarcticus, are psychrophilic and display a bipolar distribution. Here we provide the manually annotated and finished genome sequences of the type strains O. arcticus 238 and O. antarcticus 307, isolated from sea ice of the Arctic and Antarctic, respectively. Both genomes exhibit a high genome plasticity caused by an unusually high density and diversity of transposable elements. This could explain the discrepancy between the low genome synteny and high 16S rRNA gene sequence similarity between both strains. Numerous characteristic features were identified in the Octadecabacter genomes, which show indications of horizontal gene transfer and may represent specific adaptations to the habitats of the strains. These include a gene cluster encoding the synthesis and degradation of cyanophycin in O. arcticus 238, which is absent in O. antarcticus 307 and unique among the Roseobacter clade. Furthermore, genes representing a new subgroup of xanthorhodopsins as an adaptation to icy environments are present in both Octadecabacter strains. This new xanthorhodopsin subgroup differs from the previously characterized xanthorhodopsins of Salinibacter ruber and Gloeobacter violaceus in phylogeny, biogeography and the potential to bind 4-keto-carotenoids. Biochemical characterization of the Octadecabacter xanthorhodopsins revealed that they function as light-driven proton pumps. PMID:23671678

  9. Effects of late-cenozoic glaciation on habitat availability in Antarctic benthic shrimps (Crustacea: Decapoda: Caridea).

    PubMed

    Dambach, Johannes; Thatje, Sven; Rödder, Dennis; Basher, Zeenatul; Raupach, Michael J

    2012-01-01

    Marine invertebrates inhabiting the high Antarctic continental shelves are challenged by disturbance of the seafloor by grounded ice, low but stable water temperatures and variable food availability in response to seasonal sea-ice cover. Though a high diversity of life has successfully adapted to such conditions, it is generally agreed that during the Last Glacial Maximum (LGM) the large-scale cover of the Southern Ocean by multi-annual sea ice and the advance of the continental ice sheets across the shelf faced life with conditions, exceeding those seen today by an order of magnitude. Conditions prevailing at the LGM may have therefore acted as a bottleneck event to both the ecology as well as genetic diversity of today's fauna. Here, we use for the first time specific Species Distribution Models (SDMs) for marine arthropods of the Southern Ocean to assess effects of habitat contraction during the LGM on the three most common benthic caridean shrimp species that exhibit a strong depth zonation on the Antarctic continental shelf. While the shallow-water species Chorismus antarcticus and Notocrangon antarcticus were limited to a drastically reduced habitat during the LGM, the deep-water shrimp Nematocarcinus lanceopes found refuge in the Southern Ocean deep sea. The modeling results are in accordance with genetic diversity patterns available for C. antarcticus and N. lanceopes and support the hypothesis that habitat contraction at the LGM resulted in a loss of genetic diversity in shallow water benthos.

  10. Morphological and molecular evidence on the existence of a single estuarine and rocky intertidal acanthocephalan species of Profilicollis Meyer, 1931 (Acanthocephala: Polymorphidae) along the Atlantic and Pacific coasts of southern South America.

    PubMed

    Rodríguez, Sara M; Diaz, Julia I; D'Elía, Guillermo

    2017-03-23

    Profilicollis chasmagnathi Holcman-Spector, Mañé-Garzón & Dei-Cas, 1977 (Acanthocephala: Polymorphidae) has been reported to parasitise different grapsid species as intermediate hosts along the South Atlantic shores, i.e. Cyrtograpsus angulatus (Dana) and Neohelice granulata (Dana) in Uruguay and Cyrtograpsus altimanus (Rathbun) in Argentina. Larvae of a similar acanthocephalan described as Profilicollis antarcticus Zdzitowiecki, 1985 were recorded in the crab Hemigrapsus crenulatus (Milne-Edwards) from an estuarine habitat on the Southeast Pacific shore in Chile. Earlier studies have questioned the specific assignation of the Chilean estuarine populations of Profilicollis Meyer, 1931. The aim of this study was to re-examine the identification of these acanthocephalans by means of morphological and molecular analyses of cystacanths of Profilicollis spp. gathered from C. angulatus, N. granulata, C. altimanus and H. crenulatus. Our analyses showed that a single species of Profilicollis, P. chasmagnathi, parasitises these four crab species. The assessment of specimens from the South Shetlands Islands, the type-locality of P. antarcticus, is needed before formally proposing that P. antarcticus is a junior subjective synonym of P. chasmagnathi.

  11. FPGA-specific decimal sign-magnitude addition and subtraction

    NASA Astrophysics Data System (ADS)

    Vázquez, Martín; Todorovich, Elías

    2016-07-01

    The interest in sign-magnitude (SM) representation in decimal numbers lies in the IEEE 754-2008 standard, where the significand in floating-point numbers is coded as SM. However, software implementations do not meet performance constraints in some applications and more development is required in programmable logic, a key technology for hardware acceleration. Thus, in this work, two strategies for SM decimal adder/subtractors are studied and six new Field Programmable Gate Array (FPGA)-specific circuits are derived from these strategies. The first strategy is based on ten's complement (C10) adder/subtractors and the second one is based on parallel computation of an unsigned adder and an unsigned subtractor. Four of these alternative circuits are useful for at least one area-time-trade-off and specific operand size. For example, the fastest SM adder/subtractor for operand sizes of 7 and 16 decimal digits is based on the second proposed strategy with delays of 3.43 and 4.33 ns, respectively, but the fastest circuit for 34-digit operands is one of the three specific implementations based on C10 adder/subtractors with a delay of 4.65 ns.

  12. A CMOS floating point multiplier

    NASA Astrophysics Data System (ADS)

    Uya, M.; Kaneko, K.; Yasui, J.

    1984-10-01

    This paper describes a 32-bit CMOS floating point multiplier. The chip can perform 32-bit floating point multiplication (based on the proposed IEEE Standard format) and 24-bit fixed point multiplication (two's complement format) in less than 78.7 and 71.1 ns, respectively, and the typical power dissipation is 195 mW at 10 million operations per second. High-speed multiplication techniques - a modified Booth's allgorithm, a carry save adder scheme, a high-speed CMOS full adder, and a modified carry select adder - are used to achieve the above high performance. The chip is designed for compatibility with 16-bit microcomputer systems, and is fabricated in 2 micron n-well CMOS technology; it contains about 23000 transistors of 5.75 x 5.67 sq mm in size.

  13. ARC length control for plasma welding

    NASA Technical Reports Server (NTRS)

    Iceland, William F. (Inventor)

    1988-01-01

    A control system to be used with a plasma arc welding apparatus is disclosed. The plasma arc welding apparatus includes a plasma arc power supply, a contactor, and an electrode assembly for moving the electrode relative to a work piece. The electrode assembly is raised or lowered by a drive motor. The present apparatus includes a plasma arc adapter connected across the power supply to measure the voltage across the plasma arc. The plasma arc adapter forms a dc output signal input to a differential amplifier. A second input is defined by an adjustable resistor connected to a dc voltage supply to permit operator control. The differential amplifier forms an output difference signal provided to an adder circuit. The adder circuit then connects with a power amplifier which forms the driving signal for the motor. In addition, the motor connects to a tachometor which forms a feedback signal delivered to the adder to provide damping, therby avoiding servo loop overshoot.

  14. The Synchronization of Replication and Division Cycles in Individual E. coli Cells.

    PubMed

    Wallden, Mats; Fange, David; Lundius, Ebba Gregorsson; Baltekin, Özden; Elf, Johan

    2016-07-28

    Isogenic E. coli cells growing in a constant environment display significant variability in growth rates, division sizes, and generation times. The guiding principle appears to be that each cell, during one generation, adds a size increment that is uncorrelated to its birth size. Here, we investigate the mechanisms underlying this "adder" behavior by mapping the chromosome replication cycle to the division cycle of individual cells using fluorescence microscopy. We have found that initiation of chromosome replication is triggered at a fixed volume per chromosome independent of a cell's birth volume and growth rate. Each initiation event is coupled to a division event after a growth-rate-dependent time. We formalize our findings in a model showing that cell-to-cell variation in division timing and cell size is mainly driven by variations in growth rate. The model also explains why fast-growing cells display adder behavior and correctly predict deviations from the adder behavior at slow growth.

  15. Fine-Scale Movements of the Broadnose Sevengill Shark and Its Main Prey, the Gummy Shark

    PubMed Central

    Barnett, Adam; Abrantes, Kátya G.; Stevens, John D.; Bruce, Barry D.; Semmens, Jayson M.

    2010-01-01

    Information on the fine-scale movement of predators and their prey is important to interpret foraging behaviours and activity patterns. An understanding of these behaviours will help determine predator-prey relationships and their effects on community dynamics. For instance understanding a predator's movement behaviour may alter pre determined expectations of prey behaviour, as almost any aspect of the prey's decisions from foraging to mating can be influenced by the risk of predation. Acoustic telemetry was used to study the fine-scale movement patterns of the Broadnose Sevengill shark Notorynchus cepedianus and its main prey, the Gummy shark Mustelus antarcticus, in a coastal bay of southeast Tasmania. Notorynchus cepedianus displayed distinct diel differences in activity patterns. During the day they stayed close to the substrate (sea floor) and were frequently inactive. At night, however, their swimming behaviour continually oscillated through the water column from the substrate to near surface. In contrast, M. antarcticus remained close to the substrate for the entire diel cycle, and showed similar movement patterns for day and night. For both species, the possibility that movement is related to foraging behaviour is discussed. For M. antarcticus, movement may possibly be linked to a diet of predominantly slow benthic prey. On several occasions, N. cepedianus carried out a sequence of burst speed events (increased rates of movement) that could be related to chasing prey. All burst speed events during the day were across the substrate, while at night these occurred in the water column. Overall, diel differences in water column use, along with the presence of oscillatory behaviour and burst speed events suggest that N. cepedianus are nocturnal foragers, but may opportunistically attack prey they happen to encounter during the day. PMID:21151925

  16. Integrated-Circuit Active Digital Filter

    NASA Technical Reports Server (NTRS)

    Nathan, R.

    1986-01-01

    Pipeline architecture with parallel multipliers and adders speeds calculation of weighted sums. Picture-element values and partial sums flow through delay-adder modules. After each cycle or time unit of calculation, each value in filter moves one position right. Digital integrated-circuit chips with pipeline architecture rapidly move 35 X 35 two-dimensional convolutions. Need for such circuits in image enhancement, data filtering, correlation, pattern extraction, and synthetic-aperture-radar image processing: all require repeated calculations of weighted sums of values from images or two-dimensional arrays of data.

  17. Area-efficient nonvolatile carry chain based on pass-transistor/atom-switch hybrid logic

    NASA Astrophysics Data System (ADS)

    Bai, Xu; Tsuji, Yukihide; Sakamoto, Toshitsugu; Morioka, Ayuka; Miyamura, Makoto; Tada, Munehiro; Banno, Naoki; Okamoto, Koichiro; Iguchi, Noriyuki; Hada, Hiromitsu

    2016-04-01

    For the first time, an area-efficient nonvolatile carry chain combining look-up tables and a pass-transistor-logic-based adder is newly developed using complementary atom switches without additional CMOS circuits. A proposed tristate switch composed of three pairs of complementary atom switches selects one of “0”, “1”, and the “carry_in” signal as the input of a common multiplexer for both a look-up table and an adder. The developed nonvolatile carry chain achieves the reductions of 20% area, 17% delay, and 17% power consumption, respectively, in comparison with a conventional nonvolatile carry chain using dedicated CMOS gates.

  18. A Low Cost Correlator Structure in the Pseudo-Noise Code Acquisition System

    NASA Astrophysics Data System (ADS)

    Lu, Weijun; Li, Ying; Yu, Dunshan; Zhang, Xing

    The critical problem of the pseudo-noise (PN) code acquisition system is the contradiction between the acquisition performance and the calculation complexity. This paper presents a low cost correlator (LCC) structure that can search for two PN code phases in a single accumulation period by eliminating redundant computation. Compared with the part-parallel structure that is composed of two serial correlators (PARALLEL2), the proposed LCC structure has the same performance while saves about 22% chip area and 34% power consumption if uses the Carry-look-ahead (CLA) adder, 17% chip area and 25% power consumption if uses the Ripple-carry (RPL) adder.

  19. Survival, DNA Integrity, and Ultrastructural Damage in Antarctic Cryptoendolithic Eukaryotic Microorganisms Exposed to Ionizing Radiation.

    PubMed

    Pacelli, Claudia; Selbmann, Laura; Zucconi, Laura; Raguse, Marina; Moeller, Ralf; Shuryak, Igor; Onofri, Silvano

    2017-02-01

    Life dispersal between planets, planetary protection, and the search for biosignatures are main topics in astrobiology. Under the umbrella of the STARLIFE project, three Antarctic endolithic microorganisms, the melanized fungus Cryomyces antarcticus CCFEE 515, a hyaline strain of Umbilicaria sp. (CCFEE 6113, lichenized fungus), and a Stichococcus sp. strain (C45A, green alga), were exposed to high doses of space-relevant gamma radiation ((60)Co), up to 117.07 kGy. After irradiation survival, DNA integrity and ultrastructural damage were tested. The first was assessed by clonogenic test; viability and dose responses were reasonably described by the linear-quadratic formalism. DNA integrity was evaluated by PCR, and ultrastructural damage was observed by transmission electron microscopy. The most resistant among the tested organisms was C. antarcticus both in terms of colony formation and DNA preservation. Besides, results clearly demonstrate that DNA was well detectable in all the tested organisms even when microorganisms were dead. This high resistance provides support for the use of DNA as a possible biosignature during the next exploration campaigns. Implication in planetary protection and contamination during long-term space travel are put forward. Key Words: Biosignatures-Ionizing radiation-DNA integrity-Eukaryotic microorganisms-Fingerprinting-Mars exploration. Astrobiology 17, 126-135.

  20. Survival, DNA Integrity, and Ultrastructural Damage in Antarctic Cryptoendolithic Eukaryotic Microorganisms Exposed to Ionizing Radiation

    NASA Astrophysics Data System (ADS)

    Pacelli, Claudia; Selbmann, Laura; Zucconi, Laura; Raguse, Marina; Moeller, Ralf; Shuryak, Igor; Onofri, Silvano

    2017-02-01

    Life dispersal between planets, planetary protection, and the search for biosignatures are main topics in astrobiology. Under the umbrella of the STARLIFE project, three Antarctic endolithic microorganisms, the melanized fungus Cryomyces antarcticus CCFEE 515, a hyaline strain of Umbilicaria sp. (CCFEE 6113, lichenized fungus), and a Stichococcus sp. strain (C45A, green alga), were exposed to high doses of space-relevant gamma radiation (60Co), up to 117.07 kGy. After irradiation survival, DNA integrity and ultrastructural damage were tested. The first was assessed by clonogenic test; viability and dose responses were reasonably described by the linear-quadratic formalism. DNA integrity was evaluated by PCR, and ultrastructural damage was observed by transmission electron microscopy. The most resistant among the tested organisms was C. antarcticus both in terms of colony formation and DNA preservation. Besides, results clearly demonstrate that DNA was well detectable in all the tested organisms even when microorganisms were dead. This high resistance provides support for the use of DNA as a possible biosignature during the next exploration campaigns. Implication in planetary protection and contamination during long-term space travel are put forward.

  1. Resistance of Antarctic black fungi and cryptoendolithic communities to simulated space and Martian conditions

    PubMed Central

    Onofri, S.; Barreca, D.; Selbmann, L.; Isola, D.; Rabbow, E.; Horneck, G.; de Vera, J.P.P.; Hatton, J.; Zucconi, L.

    2008-01-01

    Dried colonies of the Antarctic rock-inhabiting meristematic fungi Cryomyces antarcticus CCFEE 515, CCFEE 534 and C. minteri CCFEE 5187, as well as fragments of rocks colonized by the Antarctic cryptoendolithic community, were exposed to a set of ground-based experiment verification tests (EVTs) at the German Aerospace Center (DLR, Köln, Germany). These were carried out to test the tolerance of these organisms in view of their possible exposure to space conditions outside of the International Space Station (ISS). Tests included single or combined simulated space and Martian conditions. Responses were analysed both by cultural and microscopic methods. Thereby, colony formation capacities were measured and the cellular viability was assessed using live/dead dyes FUN 1 and SYTOX Green. The results clearly suggest a general good resistance of all the samples investigated. C. minteri CCFEE 5187, C. antarcticus CCFEE 515 and colonized rocks were selected as suitable candidates to withstand space flight and long-term permanence in space on the ISS in the framework of the LIchens and Fungi Experiments (LIFE programme, European Space Agency). PMID:19287532

  2. Resistance of Antarctic black fungi and cryptoendolithic communities to simulated space and Martian conditions.

    PubMed

    Onofri, S; Barreca, D; Selbmann, L; Isola, D; Rabbow, E; Horneck, G; de Vera, J P P; Hatton, J; Zucconi, L

    2008-01-01

    Dried colonies of the Antarctic rock-inhabiting meristematic fungi Cryomyces antarcticus CCFEE 515, CCFEE 534 and C. minteri CCFEE 5187, as well as fragments of rocks colonized by the Antarctic cryptoendolithic community, were exposed to a set of ground-based experiment verification tests (EVTs) at the German Aerospace Center (DLR, Köln, Germany). These were carried out to test the tolerance of these organisms in view of their possible exposure to space conditions outside of the International Space Station (ISS). Tests included single or combined simulated space and Martian conditions. Responses were analysed both by cultural and microscopic methods. Thereby, colony formation capacities were measured and the cellular viability was assessed using live/dead dyes FUN 1 and SYTOX Green. The results clearly suggest a general good resistance of all the samples investigated. C. minteri CCFEE 5187, C. antarcticus CCFEE 515 and colonized rocks were selected as suitable candidates to withstand space flight and long-term permanence in space on the ISS in the framework of the LIchens and Fungi Experiments (LIFE programme, European Space Agency).

  3. Sustaining Soldier Health and Performance During Operation Support Hope: Guidance for Small Unit Leaders

    DTIC Science & Technology

    1994-08-01

    puff adders, mambas , and vipers. Without treatment, a snake bite can be rapidly fatal. Many snakes are well camouflaged and few give waming signals." ALL...of the Skin ................................. 19 G. Vaccines & Other Preventive Measures ............................ 21 PLANT, INSECT & SNAKE HAZARDS...Scorpions .... ................... 24 C. Snakes ............. ....... . ................ .. 25 ENVIRONMENTAL HEALTH HAZARDS

  4. 75 FR 35786 - White River Minimum Flows-Addendum to Final Determination of Federal and Non-Federal Hydropower...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... prices it is using to value the Ozark Beach hydroelectric facility lost energy. This would be calculated... price of energy is approximately $10 per MWh factored up to $12.50 per MWh for the loss of an in-state.... Comment. ``SWPA should include a $12.50 per MWH adder escalating at 2.1% per year to Platt's energy...

  5. Granulosicoccus undariae sp. nov., a member of the family Granulosicoccaceae isolated from a brown algae reservoir and emended description of the genus Granulosicoccus.

    PubMed

    Park, Sooyeon; Jung, Yong-Taek; Won, Sung-Min; Park, Ja-Min; Yoon, Jung-Hoon

    2014-11-01

    A Gram-stain-negative, aerobic, non-flagellated and coccoid bacterial strain, W-BA3(T), which was isolated from a brown algae reservoir in Wando of South Korea, was characterized taxonomically. Strain W-BA3(T) was found to grow optimally at 30 °C, at pH 7.0-8.0 and in presence of 2.0 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain W-BA3(T) clustered with the type strains of Granulosicoccus antarcticus and Granulosicoccus coccoides, with which it exhibited sequence similarity values of 98.4-99.3 %. Sequence similarity values of strain W-BA3(T) to the type strains of the other recognized species were less than 90.2 %. Strain W-BA3(T) was found to contain Q-8 as the predominant ubiquinone and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C18:1 ω7c and C16:0 as the major fatty acids. The major polar lipids of strain W-BA3(T), which were identified as phosphatidylethanolamine and phosphatidylglycerol, were similar to those of the type strains of G. antarcticus and G. coccoides. The DNA G+C content of strain W-BA3(T) was 56.0 mol % and its mean DNA-DNA relatedness values with the type strains of G. coccoides and G. antarcticus were 27 and 17 %, respectively. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, demonstrated that strain W-BA3(T) is separated from the two Granulosicoccus species. On the basis of the data presented, strain W-BA3(T) is considered to represent a novel species of the genus Granulosicoccus, for which the name Granulosicoccus undariae sp. nov. is proposed. The type strain is W-BA3(T) (=KCTC 42134(T) = NBRC 110411(T)). An emended description of the genus Granulosicoccus is also proposed.

  6. Protein patterns of black fungi under simulated Mars-like conditions.

    PubMed

    Zakharova, Kristina; Marzban, Gorji; de Vera, Jean-Pierre; Lorek, Andreas; Sterflinger, Katja

    2014-05-29

    Two species of microcolonial fungi - Cryomyces antarcticus and Knufia perforans - and a species of black yeasts-Exophiala jeanselmei - were exposed to thermo-physical Mars-like conditions in the simulation chamber of the German Aerospace Center. In this study the alterations at the protein expression level from various fungi species under Mars-like conditions were analyzed for the first time using 2D gel electrophoresis. Despite of the expectations, the fungi did not express any additional proteins under Mars simulation that could be interpreted as stress induced HSPs. However, up-regulation of some proteins and significant decreasing of protein number were detected within the first 24 hours of the treatment. After 4 and 7 days of the experiment protein spot number was increased again and the protein patterns resemble the protein patterns of biomass from normal conditions. It indicates the recovery of the metabolic activity under Martian environmental conditions after one week of exposure.

  7. Heavy metal distribution in organic and siliceous marine sponge tissues measured by square wave anodic stripping voltammetry.

    PubMed

    Illuminati, S; Annibaldi, A; Truzzi, C; Scarponi, G

    2016-10-15

    May sponge spicules represent a "tank" to accumulate heavy metals? In this study we test this hypothesis determining the distribution of Cd, Pb and Cu concentrations between organic and siliceous tissues in Antarctic Demospongia (Sphaerotylus antarcticus, Kirkpatrikia coulmani and Haliclona sp.) and in the Mediterranean species Petrosia ficiformis. Results show that although, in these sponges, spicules represent about 80% of the mass content, the accumulation of pollutant is lower in the spicules than in the corresponding organic fraction. The contribution of tissues to the total sponge content of Cd, Pb and Cu is respectively 99%, 82% and 97% for Antarctic sponges and 96%, 95% and 96% for P. ficiformis, similar in polar and temperate organisms. These results pave the way to a better understanding of the role of marine sponges in uptaking heavy metals and to their possible use as monitor of marine ecosystems, recommend by the Water Framework Directive.

  8. Protein patterns of black fungi under simulated Mars-like conditions

    PubMed Central

    Zakharova, Kristina; Marzban, Gorji; de Vera, Jean-Pierre; Lorek, Andreas; Sterflinger, Katja

    2014-01-01

    Two species of microcolonial fungi – Cryomyces antarcticus and Knufia perforans - and a species of black yeasts–Exophiala jeanselmei - were exposed to thermo-physical Mars-like conditions in the simulation chamber of the German Aerospace Center. In this study the alterations at the protein expression level from various fungi species under Mars-like conditions were analyzed for the first time using 2D gel electrophoresis. Despite of the expectations, the fungi did not express any additional proteins under Mars simulation that could be interpreted as stress induced HSPs. However, up-regulation of some proteins and significant decreasing of protein number were detected within the first 24 hours of the treatment. After 4 and 7 days of the experiment protein spot number was increased again and the protein patterns resemble the protein patterns of biomass from normal conditions. It indicates the recovery of the metabolic activity under Martian environmental conditions after one week of exposure. PMID:24870977

  9. Second generation DNA sequencing of the mitogenome of the Chinstrap penguin and comparative genomics of Antarctic penguins.

    PubMed

    Subramanian, Sankar; Lingala, Syamala Gowri; Swaminathan, Siva; Huynen, Leon; Lambert, David

    2014-08-01

    The complete mitochondrial genome of the Chinstrap penguin (Pygoscelis antarcticus) was sequenced and compared with other penguin mitogenomes. The genome is 15,972 bp in length with the number and order of protein coding genes and RNAs being very similar to that of other known penguin mitogenomes. Comparative nucleotide analysis showed the Chinstrap mitogenome shares 94% homology with the mitogenome of its sister species, Pygoscelis adelie (Adélie penguin). Divergence at nonsynonymous nucleotide positions was found to be up to 23 times less than that observed in synonymous positions of protein coding genes, suggesting high selection constraints. The complete mitogenome data will be useful for genetic and evolutionary studies of penguins.

  10. Statistical comparison of the results from six analytical chemistry laboratories of the mercury content of muscle tissue of two species of sharks.

    PubMed

    Walker, T I

    1977-01-01

    Statistical tests were carried out on the results of chemical analysis for total mercury concentrations of replicate samples of muscle tissue of school shark Galeorhinus australis (Macleay) and gummy shark Mustelus antarcticus Guenther from six independent analytical laboratories. These tests showed that one laboratory produced results 9% below the overall average of all results, another 1% below average while the other four were all 5% above average. Moreover, one laboratory had significantly lower scatter of results than the others, and the percentage scatter (standard error expressed as a percentage of the mean) in two of the laboratories tended to diminish as the magnitude of the results increased. Correction for what were concluded to be wild points indicated that the scatter for all laboratories was below 14%.

  11. Morphological divergence in a continental adaptive radiation: South American ovenbirds of the genus Cinclodes

    USGS Publications Warehouse

    Rader, Jonathan A.; Dillon, Michael E.; Chesser, R. Terry; Sabat, Pablo; Martinez del Rio, Carlos

    2015-01-01

    Cinclodes is an ecologically diverse genus of South American passerine birds and represents a case of continental adaptive radiation along multiple axes. We investigated morphological diversification in Cinclodes using a comprehensive set of morphometric measurements of study skins. Principal component analysis identified 2 primary axes of morphological variation: one describing body size and a second capturing differences in wing-tip shape and toe length. Phylogenetic analyses of the first principal component suggest an early divergence ofCinclodes into 2 main clades characterized by large and small body sizes. We suggest that 2 morphological outliers within these main clades (C. antarcticus and C. palliatus) may be cases of island gigantism and that a third (C. patagonicus) may reflect ecological character displacement. Despite its ecological and physiological diversity, the genus Cinclodes does not appear to show morphological diversity beyond what is typical of other avian genera.

  12. Paenibacillus tibetensis sp. nov., a psychrophilic bacterium isolated from alpine swamp meadow soil.

    PubMed

    Han, Li-Li; He, Ji-Zheng; Zheng, Yuan-Ming; Zeng, Jun; Zhang, Li-Mei

    2015-05-01

    A novel psychrophilic strain, SSB001(T), was isolated from an alpine swamp meadow soil in Tibet, China, and identified as a representative of a novel phylogenetic subclade in the genus Paenibacillus , with Paenibacillus antarcticus (96.2%), Paenibacillus macquariensis (96.53%) and Paenibacillus glacialis (96.2%) as the most closely related species on the basis of 16S rRNA gene sequence analyses. The strain was distinguished from defined species of the genus Paenibacillus by further study of rpoB gene sequences, phenotypic characterization, cellular fatty acid composition, quinones, polar lipids and meso-diaminopimelic acid in the peptidoglycan. Based upon these results, we propose the strain as a representative of a novel species named Paenibacillus tibetensis sp. nov., with SSB001(T) ( =ACCC 19728(T) =DSM 29321(T)) as the type strain. The DNA G+C content (mol%) of strain SSB001(T) was 40.18 mol% (HPLC).

  13. Design of Pipeline Multiplier Based on Modified Booth's Algorithm and Wallace Tree

    NASA Astrophysics Data System (ADS)

    Yao, Aihong; Li, Ling; Sun, Mengzhe

    A design of 32*32 bit pipelined multiplier is presented in this paper. The proposed multiplier is based on the modified booth algorithm and Wallace tree structure. In order to improve the throughput rate of the multiplier, pipeline architecture is introduced to the Wallace tree. Carry Select Adder is deployed to reduce the propagation delay of carry signal for the final level 64-bit adder. The multiplier is fully implemented with Verilog HDL and synthesized successfully with Quartus II. The experiment result shows that the resource consumption and power consumption is reduced to 2560LE and 120mW, the operating frequency is improved from 136.21MHz to 165.07MHz.

  14. System for adjusting frequency of electrical output pulses derived from an oscillator

    DOEpatents

    Bartholomew, David B.

    2006-11-14

    A system for setting and adjusting a frequency of electrical output pulses derived from an oscillator in a network is disclosed. The system comprises an accumulator module configured to receive pulses from an oscillator and to output an accumulated value. An adjustor module is configured to store an adjustor value used to correct local oscillator drift. A digital adder adds values from the accumulator module to values stored in the adjustor module and outputs their sums to the accumulator module, where they are stored. The digital adder also outputs an electrical pulse to a logic module. The logic module is in electrical communication with the adjustor module and the network. The logic module may change the value stored in the adjustor module to compensate for local oscillator drift or change the frequency of output pulses. The logic module may also keep time and calculate drift.

  15. Solid-State Kicker Pulser for DARHT-2

    SciTech Connect

    Cook, E G; Lee, B S; Hawkins, S A; Allen, F V; Hickman, B C; Sullivan, J S; Brooksby, C A

    2001-06-07

    To replace a hard tube design, a solid-state kicker pulser for the Dual-Axis Radiographic Hydrodynamic Test facility (DARHT-2) has been designed and tested. This kicker modulator uses multiple solid-state modules stacked in an inductive-adder configuration where the energy is switched into each section of the adder by a parallel array of MOSFETs. The modulator features very fast rise and fall times, pulse width agility and a high pulse-repetition rate in burst mode. The modulator can drive a 50{Omega} load with voltages up to 20 kV and can be easily configured for either positive or negative polarity. The presentation will include test and operational data.

  16. Design and Testing of a Fast, 50 kV Solid-State Kicker Pulser

    SciTech Connect

    Cook, E G; Hickman, B C; Lee, B S; Hawkins, S A; Gower, E J; Allen, F V; Walstrom, P L

    2002-06-24

    The ability to extract particle beam bunches from a ring accelerator in arbitrary order can greatly extend an accelerator's capabilities and applications. A prototype solid-state kicker pulser capable of generating asynchronous bursts of 50 kV pulses has been designed and tested into a 50{Omega} load. The pulser features fast rise and fall times and is capable of generating an arbitrary pattern of pulses with a maximum burst frequency exceeding 5 MHz If required, the pulse-width of each pulse in the burst is independently adjustable. This kicker modulator uses multiple solid-state modules stacked in an inductive-adder configuration where the energy is switched into each section of the adder by a parallel array of MOSFETs. Test data, capabilities, and limitations of the prototype pulser are described.

  17. Probing and exploiting the chaotic dynamics of a hydrodynamic photochemical oscillator to implement all the basic binary logic functions

    NASA Astrophysics Data System (ADS)

    Hayashi, Kenta; Gotoda, Hiroshi; Gentili, Pier Luigi

    2016-05-01

    The convective motions within a solution of a photochromic spiro-oxazine being irradiated by UV only on the bottom part of its volume, give rise to aperiodic spectrophotometric dynamics. In this paper, we study three nonlinear properties of the aperiodic time series: permutation entropy, short-term predictability and long-term unpredictability, and degree distribution of the visibility graph networks. After ascertaining the extracted chaotic features, we show how the aperiodic time series can be exploited to implement all the fundamental two-inputs binary logic functions (AND, OR, NAND, NOR, XOR, and XNOR) and some basic arithmetic operations (half-adder, full-adder, half-subtractor). This is possible due to the wide range of states a nonlinear system accesses in the course of its evolution. Therefore, the solution of the convective photochemical oscillator results in hardware for chaos-computing alternative to conventional complementary metal-oxide semiconductor-based integrated circuits.

  18. Design of CNTFET-based 2-bit ternary ALU for nanoelectronics

    NASA Astrophysics Data System (ADS)

    Lata Murotiya, Sneh; Gupta, Anu

    2014-09-01

    This article presents a hardware-efficient design of 2-bit ternary arithmetic logic unit (ALU) using carbon nanotube field-effect transistors (CNTFETs) for nanoelectronics. The proposed structure introduces a ternary adder-subtractor functional module to optimise ALU architecture. The full adder-subtractor (FAS) cell uses nearly 72% less transistors than conventional architecture, which contains separate ternary cells for addition as well as subtraction. The presented ALU also minimises ternary function expressions with utilisation of binary gates for optimisation at the circuit level, thus attaining a simple design. Hspice simulations results demonstrate that the ALU ternary circuits achieve great improvement in terms of power delay product with respect to their CMOS counterpart at 32 nm.

  19. ZX Pulsed-Power Design

    SciTech Connect

    Corley, J.P.; Johnson, D.L.; McDaniel, D.H.; Spielman, R.B.; Struve, K.W.; Stygar, W.A.

    1999-08-02

    ZX is a new z-pinch accelerator planned as the next generation z-pinch driver at SNL, and as an intermediate step towards X-1. It is planned to drive either a single 50 MA z-pinch load, or two 25 to 30 MA z pinches. Three designs for the ZX accelerator are presented. All require 7 to 8 MV at the insulator stack to drive the z-pinch load to implosion in 100 to 120 ns. Two of the designs are based on the Z accelerator, and use water-line technology; a transit-time-isolated water adder, and a water transformer. The third design uses inductive-voltage adders in water. They also describe a low-inductance insulator stack design that helps minimize voltage requirements. This design is evaluated for water and vacuum break-down using JCM, THM, and magnetic-flashover-inhibition criteria.

  20. Fish parasites in the Arctic deep-sea: Poor diversity in pelagic fish species vs. heavy parasite load in a demersal fish

    NASA Astrophysics Data System (ADS)

    Klimpel, Sven; Palm, Harry Wilhelm; Busch, Markus Wilhelm; Kellermanns, Esra; Rückert, Sonja

    2006-07-01

    A total of 219 deep-sea fishes belonging to five families were examined for the parasite fauna and stomach contents. The demersal fish Macrourus berglax, bathypelagic Bathylagus euryops, and mesopelagic Argentina silus, Borostomias antarcticus, Chauliodus sloani, and Lampanyctus macdonaldi were caught at 243-708 m trawling depth in the Greenland and the Irminger Sea in 2002. A total of 21 different parasite species, six Digenea, one Monogenea, two Cestoda, seven Nematoda, one Acanthocephala, and four Crustacea, were found. The parasite diversity in the meso- and bathypelagic environment was less diverse in comparison to the benthal. Macrourus berglax had the highest diversity (20 species), usually carrying 4-10 different parasite species (mean 7.1), whereas Bathylagus euryops harbored up to three and Argentina silus, Borostomias antarcticus, Chauliodus sloani and Lampanyctus macdonaldi each up to two species. Most Digenea, Cestoda, Nematoda, Acanthocephala, and Crustacea are known from a wide host range. Several of the encountered parasites occurred at a very low prevalence (<10%), indicating that the studied deep-sea fishes are most probably not instrumental to complete the parasite life cycles in the area of investigation. It is suggested that the lack of nutrients in the meso- and bathypelagial limits the abundance of potential first intermediate hosts of nematodes and cestodes, resulting in low infestation rates even of widely distributed, non-specific species. In contrast, the higher biomass in the benthic deep-sea environment increases the availability of potential intermediate hosts, such as molluscs for the digeneans, resulting in increased parasite diversity. Because many deep-sea fish have a generalistic feeding behavior, the observed different parasite diversity reflects a different depth range of the fish and not necessarily a specific fish feeding ecology.

  1. The diversity, extracellular enzymatic activities and photoprotective compounds of yeasts isolated in Antarctica

    PubMed Central

    Vaz, Aline B. M.; Rosa, Luiz H.; Vieira, Mariana L. A.; de Garcia, Virginia; Brandão, Luciana R.; Teixeira, Lia C. R. S.; Moliné, Martin; Libkind, Diego; van Broock, Maria; Rosa, Carlos A.

    2011-01-01

    The diversity of yeasts collected from different sites in Antarctica (Admiralty Bay, King George Island and Port Foster Bay and Deception Island) and their ability to produce extracellular enzymes and mycosporines were studied. Samples were collected during the austral summer season, between November 2006 and January 2007, from the rhizosphere of Deschampsia antarctica, ornithogenic (penguin guano) soil, soil, marine and lake sediments, marine water and freshwater from lakes. A total of 89 isolates belonging to the following genera were recovered: Bensingtonia, Candida, Cryptococcus, Debaryomyces, Dioszegia, Exophiala, Filobasidium, Issatchenkia (Pichia), Kodamaea, Leucosporidium, Leucosporidiella, Metschnikowia, Nadsonia, Pichia, Rhodotorula, and Sporidiobolus, and the yeast-like fungi Aureobasidium, Leuconeurospora and Microglossum. Cryptococcus victoriae was the most frequently identified species. Several species isolated in our study have been previously reported to be Antarctic psychophilic yeasts, including Cr. antarcticus, Cr. victoriae, Dioszegia hungarica and Leucosporidium scottii. The cosmopolitan yeast species A. pullulans, C. zeylanoides, D. hansenii, I. orientalis, K. ohmeri, P. guilliermondii, Rh. mucilaginosa, and S. salmonicolor were also isolated. Five possible new species were identified. Sixty percent of the yeasts had at least one detectable extracellular enzymatic activity. Cryptococcus antarcticus, D. aurantiaca, D. crocea, D. hungarica, Dioszegia sp., E. xenobiotica, Rh. glaciales, Rh. laryngis, Microglossum sp. 1 and Microglossum sp. 2 produced mycosporines. Of the yeast isolates, 41.7% produced pigments and/or mycosporines and could be considered adapted to survive in Antarctica. Most of the yeasts had extracellular enzymatic activities at 4°C and 20°C, indicating that they could be metabolically active in the sampled substrates. PMID:24031709

  2. Parametric time delay modeling for floating point units

    NASA Astrophysics Data System (ADS)

    Fahmy, Hossam A. H.; Liddicoat, Albert A.; Flynn, Michael J.

    2002-12-01

    A parametric time delay model to compare floating point unit implementations is proposed. This model is used to compare a previously proposed floating point adder using a redundant number representation with other high-performance implementations. The operand width, the fan-in of the logic gates and the radix of the redundant format are used as parameters to the model. The comparison is done over a range of operand widths, fan-in and radices to show the merits of each implementation.

  3. Binary arithmetic using optical symbolic substitution and integrated phototransistor surface-emitting laser logic

    NASA Astrophysics Data System (ADS)

    Cheng, Julian; Olbright, G. R.; Bryan, R. P.

    1991-10-01

    The architecture described in the paper supports binary addition by means of optical logic gates and symbolic substitution utilizing heterojunction phototransistors and lasers. The high-speed optical switches are compatible with surface-normal architecture, require low-input optical energies, and afford high optical gain. A highly compact binary half-adder is described to demonstrate the implementation of the binary arithmetic with heterojunction-phototransistor optical logic gates and surface emitting lasers.

  4. Design and analysis of various multifunctional operations at ultrahigh speed by using a semiconductor optical amplifier-Mach-Zehnder interferometer

    NASA Astrophysics Data System (ADS)

    Lovkesh; Marwaha, Anupma

    2016-03-01

    Various multifunctional operations are performed by proposing designs of optical adder, subtractor, comparator, and decoder at 60 Gb/s. In all operations, constructive interference is produced by choosing optimized parameters, i.e., optical pulse generator power, input power, semiconductor optical amplifier-Mach-Zehnder interferometer parameters, and so on, for delivering a true output signal. An optical pulse-generated signal is required for all operations except addition, subtraction and equal to in a comparator.

  5. Adiabatic circuits: converter for static CMOS signals

    NASA Astrophysics Data System (ADS)

    Fischer, J.; Amirante, E.; Bargagli-Stoffi, A.; Schmitt-Landsiedel, D.

    2003-05-01

    Ultra low power applications can take great advantages from adiabatic circuitry. In this technique a multiphase system is used which consists ideally of trapezoidal voltage signals. The input signals to be processed will often come from a function block realized in static CMOS. The static rectangular signals must be converted for the oscillating multiphase system of the adiabatic circuitry. This work shows how to convert the input signals to the proposed pulse form which is synchronized to the appropriate supply voltage. By means of adder structures designed for a 0.13µm technology in a 4-phase system there will be demonstrated, which additional circuits are necessary for the conversion. It must be taken into account whether the data arrive in parallel or serial form. Parallel data are all in one phase and therefore it is advantageous to use an adder structure with a proper input stage, e.g. a Carry Lookahead Adder (CLA). With a serial input stage it is possible to read and to process four signals during one cycle due to the adiabatic 4-phase system. Therefore input signals with a frequency four times higher than the adiabatic clock frequency can be used. This reduces the disadvantage of the slow clock period typical for adiabatic circuits. By means of an 8 bit Ripple Carry Adder (8 bit RCA) the serial reading will be introduced. If the word width is larger than 4 bits the word can be divided in 4 bit words which are processed in parallel. This is the most efficient way to minimize the number of input lines and pads. At the same time a high throughput is achieved.

  6. Logic operations in a doped solid driven by stimulated Raman adiabatic passage

    SciTech Connect

    Beil, F.; Halfmann, T.; Remacle, F.; Levine, R. D.

    2011-03-15

    We experimentally demonstrate classical-optical logic operations in a solid-state memory, coherently driven by variants of stimulated Raman adiabatic passage (STIRAP). Cyclic transfer of atomic populations permits the implementation of a flip-flop or xor gate, with up to eight optical input operations. Observation of stimulated emission as an additional output channel enables the setup of a STIRAP-driven full adder for three optical input bits (or two input bits and a memory bit).

  7. Pulse Power Performance of the Cygnus 1 and 2 Radiographic Sources

    DTIC Science & Technology

    2013-06-01

    Abstract between the two machines are the lengths of water coax that connect the pfl’s to the IVA cells and the angling of the diode axes which are...technology. Each machine employs a Marx generator, Pulse Forming Line (pfl), Water Coax Transmission Line, and Inductive Voltage Adder ( IVA ) that...drive a high vacuum rod-pinch diode. The pfl design was originally developed for the Radiographic Integrated Test stand (RITS) [2] and the IVA cells

  8. DUMPING COOLED MOLDS FROM THE SHAKE OUT RAILS ONTO A ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DUMPING COOLED MOLDS FROM THE SHAKE OUT RAILS ONTO A VIBRATING CONVEYOR WHICH TRANSPORTS CASTINGS AND SAND TO A SEPARATION SCREEN WHICH SIFTS SAND ONTO BELT CONVEYORS BELOW THAT CARRY IT PAST SWITCH-ACTIVATED WATER INJECTORS TO SIMILAR SWITCH-ACTIVATED FRESH SAND ADDERS BEFORE TRANSPORTING IT TO THE SAND STORAGE BIN WHILE CASTINGS ARE EITHER MANUALLY OR SMALL CRANE LIFTED TO DEGATING AREAS. - Southern Ductile Casting Company, Centerville Foundry, 101 Airport Road, Centreville, Bibb County, AL

  9. Terahertz-optical-asymmetric-demultiplexer (TOAD)-based arithmetic units for ultra-fast optical information processing

    NASA Astrophysics Data System (ADS)

    Cherri, Abdallah K.

    2010-04-01

    In this paper, designs of ultra-fast all-optical based Terahertz-optical-asymmetric-demultiplexer (TOAD)-based devices are reported. Using TOAD switches, adders/subtracters units are demonstrated. The high speed is achieved due to the use of the nonlinear optical materials and the nonbinary modified signed-digit (MSD) number representation. The proposed all-optical circuits are compared in terms of numbers TOAD switches, optical amplifiers and wavelength converters.

  10. Generalizing on Multiple Grounds: Performance Learning in Model-Based Troubleshooting

    DTIC Science & Technology

    1989-02-01

    several well-known advntages over heuristic expert systems. These include correctness of conclusions, explalations of conclusions, ease of modifiability...Introduction Consider a model-based diagnostic engine. Given a structural and behavioral description of a device, and a set of observed measurements at...single-fault candidates. That is, either multiplier Ml or adder Al alone could, by some misbehavior, account for all of the observed misbehavior of the

  11. Research in Computer Simulation of Integrated Circuits.

    DTIC Science & Technology

    1983-07-31

    bwadeid a -’. ate dew’.d or "mom 1640e 4 4 4 4.5 he ham ala ker 27601 519 6145 2549 "and 3.2 1.5 2.2 34 4230 TAME 4 A,4er Stsmao m CLAS From the show...from SPICEV it is expected that the speedup is Larger for t.(As) 4 4 4 4 6 the adder circuits compared to the filters. A first observe- iter 352 27601

  12. All-optical digital logic: Full addition or subtraction on a three-state system

    SciTech Connect

    Remacle, F.; Levine, R. D.

    2006-03-15

    Stimulated Raman adiabatic passage (STIRAP) is a well-studied pump-probe control scheme for manipulating the population of quantum states of atoms or molecules. By encoding the digits to be operated on as 'on' or 'off' laser input signals we show how STIRAP can be used to implement a finite-state logic machine. The physical conditions required for an effective STIRAP operation are related to the physical conditions expected for a logic machine. In particular, a condition is derived on the mean number of photons that represent an on pulse. A finite-state machine computes Boolean expressions that depend both on the input and on the present state of the machine. With two input signals we show how to implement a full adder where the carry-in digit is stored in the state of the machine. Furthermore, we show that it is possible to store the carry-out digit as the next state and thereby return the machine to a state ready for the next full addition. Such a machine operates as a cyclical full adder. We further show how this full adder can equally well be operated as a full subtractor. To the best of our knowledge this is the first example of a nanosized system that implements a full subtraction.

  13. High Power, Solid-State RF Generation for Plasma Heating

    NASA Astrophysics Data System (ADS)

    Prager, James; Ziemba, Timothy; Miller, Kenneth; Pierren, Chris

    2016-10-01

    Radio Frequency heating systems are rarely used by the small-scale validation platform experiments due to the high cost and complexity of these systems. Eagle Harbor Technologies (EHT), Inc. is developing an all-solid-state RF plasma heating system that uses EHT's nanosecond pulser technology in an inductive adder configuration to drive nonlinear transmission lines (NLTL). The system under development does not require the use of vacuum tube technology, is inherently lower cost, and is more robust than traditional high power RF heating schemes. The inductive adder can produce 0 to20 kV pulses into 50 Ohms with sub-10 ns rise times. The inductive adder has been used to drive NLTLs near 2 GHz with other frequencies to be tested in the future. EHT will present experimental results, including RF measurements with D-dot probes and capacitve voltage probes. During this program, EHT will test the system on Helicity Injected Torus at the University of Washington and the High Beta Tokamak at Columbia University.

  14. Novel designs of nanometric parity preserving reversible compressor

    NASA Astrophysics Data System (ADS)

    Shoaei, Soghra; Haghparast, Majid

    2014-08-01

    Reversible logic is a new field of study that has applications in optical information processing, low power CMOS design, DNA computing, bioinformatics, and nanotechnology. Low power consumption is a basic issue in VLSI circuits today. To prevent the distribution of errors in the quantum circuit, the reversible logic gates must be converted into fault-tolerant quantum operations. Parity preserving is used to realize fault tolerant in this circuits. This paper proposes a new parity preserving reversible gate. We named it NPPG gate. The most significant aspect of the NPPG gate is that it can be used to produce parity preserving reversible full adder circuit. The proposed parity preserving reversible full adder using NPPG gate is more efficient than the existing designs in term of quantum cost and it is optimized in terms of number of constant inputs and garbage outputs. Compressors are of importance in VLSI and digital signal processing applications. Effective VLSI compressors reduce the impact of carry propagation of arithmetic operations. They are built from the full adder blocks. We also proposed three new approaches of parity preservation reversible 4:2 compressor circuits. The third design is better than the previous two in terms of evaluation parameters. The important contributions have been made in the literature toward the design of reversible 4:2 compressor circuits; however, there are not efforts toward the design of parity preservation reversible 4:2 compressor circuits. All the scales are in the nanometric criteria.

  15. Dynamic SVL and body bias for low leakage power and high performance in CMOS digital circuits

    NASA Astrophysics Data System (ADS)

    Deshmukh, Jyoti; Khare, Kavita

    2012-12-01

    In this article, a new complementary metal oxide semiconductor design scheme called dynamic self-controllable voltage level (DSVL) is proposed. In the proposed scheme, leakage power is controlled by dynamically disconnecting supply to inactive blocks and adjusting body bias to further limit leakage and to maintain performance. Leakage power measurements at 1.8 V, 75°C demonstrate power reduction by 59.4% in case of 1 bit full adder and by 43.0% in case of a chain of four inverters using SVL circuit as a power switch. Furthermore, we achieve leakage power reduction by 94.7% in case of 1 bit full adder and by 91.8% in case of a chain of four inverters using dynamic body bias. The forward body bias of 0.45 V applied in active mode improves the maximum operating frequency by 16% in case of 1 bit full adder and 5.55% in case of a chain of inverters. Analysis shows that additional benefits of using the DSVL and body bias include high performance, low leakage power consumption in sleep mode, single threshold implementation and state retention even in standby mode.

  16. An examination of cardiovascular collapse induced by eastern brown snake (Pseudonaja textilis) venom.

    PubMed

    Chaisakul, Janeyuth; Isbister, Geoffrey K; Kuruppu, Sanjaya; Konstantakopoulos, Nicki; Hodgson, Wayne C

    2013-08-29

    The Pseudonaja genus (Brown snakes) is widely distributed across Australia and bites account for significant mortality. Venom-induced consumption coagulopathy (VICC) and, less often, early cardiovascular collapse occur following envenoming by these snakes. We have previously examined possible mechanism(s) behind the early cardiovascular collapse following Papuan taipan (Oxyuranus scutellatus) envenoming. In the present study, we investigate early cardiovascular collapse in anaesthetized rats following administration of eastern brown snake (Pseudonaja textilis) venom, and prevention of this effect with prior administration of 'priming' doses (i.e. doses of venom which caused a transient hypotensive response) of venom. P. textilis venom (5-10 μg/kg, i.v.) induced cardiovascular collapse in anaesthetized rats, characterized by a rapid decrease in systolic blood pressure until non recordable. Prior administration of 'priming' doses of P. textilis venom (2 and 3 μg/kg) or, at least, 4-5 doses of O. scutellatus (2 μg/kg, i.v.) or Daboia russelii limitis (20 μg/kg, i.v.) venoms prevented cardiovascular collapse induced by P. textilis venom. Moreover, early collapse was also inhibited by prior administration of 2 discrete doses of Acanthophis rugosus venom. Prior administration of commercial polyvalent snake antivenom (500-3000 units/kg, i.v.) or heparin (300 units/kg, i.v.) also inhibited P. textilis venom-induced cardiovascular collapse. Our results indicate that P. textilis venom-induced cardiovascular collapse can be prevented by prior administration of sub-lethal doses of venom from P. textilis, O. scutellatus, A. rugosus and D. russelii limitis. This suggests that sudden cardiovascular collapse following envenoming is likely to involve a common mechanism/pathway activated by different snake venoms.

  17. Resembling a viper: implications of mimicry for conservation of the endangered smooth snake.

    PubMed

    Valkonen, Janne K; Mappes, Johanna

    2014-12-01

    The phenomenon of Batesian mimicry, where a palatable animal gains protection against predation by resembling an unpalatable model, has been a core interest of evolutionary biologists for 150 years. An extensive range of studies has focused on revealing mechanistic aspects of mimicry (shared education and generalization of predators) and the evolutionary dynamics of mimicry systems (co-operation vs. conflict) and revealed that protective mimicry is widespread and is important for individual fitness. However, according to our knowledge, there are no case studies where mimicry theories have been applied to conservation of mimetic species. Theoretically, mimicry affects, for example, frequency dependency of predator avoidance learning and human induced mortality. We examined the case of the protected, endangered, nonvenomous smooth snake (Coronella austriaca) that mimics the nonprotected venomous adder (Vipera berus), both of which occur in the Åland archipelago, Finland. To quantify the added predation risk on smooth snakes caused by the rarity of vipers, we calculated risk estimates from experimental data. Resemblance of vipers enhances survival of smooth snakes against bird predation because many predators avoid touching venomous vipers. Mimetic resemblance is however disadvantageous against human predators, who kill venomous vipers and accidentally kill endangered, protected smooth snakes. We found that the effective population size of the adders in Åland is very low relative to its smooth snake mimic (28.93 and 41.35, respectively).Because Batesian mimicry is advantageous for the mimic only if model species exist in sufficiently high numbers, it is likely that the conservation program for smooth snakes will fail if adders continue to be destroyed. Understanding the population consequences of mimetic species may be crucial to the success of endangered species conservation. We suggest that when a Batesian mimic requires protection, conservation planners should

  18. Experimental study of particle-free mask handling

    NASA Astrophysics Data System (ADS)

    Amemiya, Mitsuaki; Ota, Kazuya; Taguchi, Takao; Suga, Osamu

    2009-03-01

    One of the critical issues for EUVL masks is clean and particle-free mask handling. We reported that the number of particle adders on the front side of a mask in the dual pod during the process from the load port to putting on the Electrostatic chuck (ESC) in vacuum could be reduce to less than 0.01 particle/cycle (>=46 nm). In addition, we found that chucking the mask on the ESC caused two serious issues. The first is that many particles stick to on the backside of the mask after chucking on the ESC, raising the question of whether the particle adders on the backside will travel to the front side. We examined the travel of these particles using the substrates after chucking and polystyrene latex (PSL) substrates that were dispersed on the backside. These experiments show that there is very little probability that particles on the backside will travel to the front side. The second issue is whether the mask blanks will charge up by chucking on the ESC and some particles will add on the front side. We measured the electric potential of the back and front sides of the mask and examined the particle adders. Our experiments revealed that to protect the mask from the particles, the mask must be grounded from the beginning to the end. For these two issues, we confirmed that a dual pod system works effectively to protect the mask from particles. This work is supported by NEDO as a part of the EUV mask program.

  19. [Salmonella in free living snakes of Northern Germany (author's transl)].

    PubMed

    Wuthe, H H; Rohde, R; Aleksić, S; Schubert, C; Wuthe, S

    1979-04-01

    Fourty-nine adders (Vipera berus L.) and thirty-one grass-snakes (Nitrix natrix L.) from northern Germany were investigated by cloacal swabs. The samples were usually taken in the field and preenriched in peptone water and further-on processed in three steps of tetrathionate. After each step of enrichment the material was transfered to salmonella shigella agar and fuchsine lactose agar (acc. to Endo). Salmonella screening was done by inoculation of lactose positive and lactose negative colonies into lysine iron agar (acc. to Edwards and Fife). Salmonella excretion was found in 59% of the adders and in 68% of the grass-snakes. Some specimens excreted several Salmonella species. 22 different species resp. variants were detected, of which 19 species belonged to subgenus III (Arizona). Subgenus I occured infrequently and was represented by S. duesseldorf, S. heidelberg and S. sunnycove. Three new triphasic variants S. III 17:Z10: e, n, x, z15: z56, S. III 38: (k): z35:z56 and S. III 50:z10:z:z56 of species already known and four so far unknown species S. III (6), 14: 1,v:z (Ar. 7a, 7c:23-31), S. III 21:1,v:z57 (Ar. 22:23-40a,40c), S. III 43:1,v:z56 (Ar. 21:23-38) and S. III 28:z10:z57 (Ar. 35:27-40a,40c) were discovered. The present results suggest that adders and grass-snakes in northern Germany represent autonomous reservoirs of salmonellae. There exist only few relations between the Salmonella species in these kinds of snakes and other European snakes.

  20. Champions of profitable growth.

    PubMed

    Stewart, G Bennett

    2004-01-01

    Many companies have posted impressive top-line growth over the past two decades in their respective economic regions--for instance, Wal-Mart in North America, BP in Europe, Toyota in Asia, and News Corporation in the Southern Hemisphere. But which were the best at converting all of that revenue growth into shareholder value? Harvard Business Review asked C. Bennett Stewart III, the senior partner of the consulting firm Stern Stewart & Company, and his colleagues to come up with the answer. For the period 1983 to 2003, they assembled a list of the top 20 high-growth value adders (and laggards) in each of the four regions cited above. Their calculations gave equal weight to companies' revenue growth and market-value-added scores, revealing the important effect of region on the performance of companies in the same industry. For instance, while automakers are positioned high on the Asian list of high-growth value adders, U.S. carmakers GM and Ford--each of which reported revenue growth in excess of 100 billion dollars between 1983 and 2003--are among the value laggards on the North American list, as are DaimlerChrysler and Volkswagen on the European list. The Japanese win through better efficiency, higher quality, and narrower product mixes, the author says. And while there are four telecom companies represented among the European high-growth value adders, there are none on the North American list. That's probably because the European telecoms enjoyed more protective regulation, made fewer high-priced acquisitions, and didn't bet as big on the overblown dot-com economy, the author says.

  1. A hybrid zone between Bathymodiolus mussel lineages from eastern Pacific hydrothermal vents

    PubMed Central

    2013-01-01

    Background The inhabitants of deep-sea hydrothermal vents occupy ephemeral island-like habitats distributed sporadically along tectonic spreading-centers, back-arc basins, and volcanically active seamounts. The majority of vent taxa undergo a pelagic larval phase, and thus varying degrees of geographical subdivision, ranging from no impedance of dispersal to complete isolation, often exist among taxa that span common geomorphological boundaries. Two lineages of Bathymodiolus mussels segregate on either side of the Easter Microplate, a boundary that separates the East Pacific Rise from spreading centers connected to the Pacific-Antarctic Ridge. Results A recent sample from the northwest flank of the Easter Microplate contained an admixture of northern and southern mitochondrial haplotypes and corresponding alleles at five nuclear gene loci. Genotypic frequencies in this sample did not fit random mating expectation. Significant heterozygote deficiencies at nuclear loci and gametic disequilibria between loci suggested that this transitional region might be a ‘Tension Zone’ maintained by immigration of parental types and possibly hybrid unfitness. An analysis of recombination history in the nuclear genes suggests a prolonged history of parapatric contact between the two mussel lineages. We hereby elevate the southern lineage to species status as Bathymodiolus antarcticus n. sp. and restrict the use of Bathymodiolus thermophilus to the northern lineage. Conclusions Because B. thermophilus s.s. exhibits no evidence for subdivision or isolation-by-distance across its 4000 km range along the EPR axis and Galápagos Rift, partial isolation of B. antarcticus n. sp. requires explanation. The time needed to produce the observed degree of mitochondrial differentiation is consistent with the age of the Easter Microplate (2.5 to 5.3 million years). The complex geomorphology of the Easter Microplate region forces strong cross-axis currents that might disrupt self

  2. Planococcus faecalis sp. nov., a carotenoid-producing species isolated from stools of Antarctic penguins.

    PubMed

    Kim, Jin Ho; Kang, Hyung Jun; Yu, Byung Jo; Kim, Sun Chang; Lee, Pyung Cheon

    2015-10-01

    Taxonomic studies were performed on a novel carotenoid-producing strain, designated AJ003T, isolated from faeces of Antarctic penguins. Cells of strain AJ003T were aerobic, Gram-stain-positive, cocci-shaped and orange. Strain AJ003T was capable of growing in a broad temperature range, including sub-zero growth (below − 20 to 30 °C). 16S rRNA gene sequence analysis revealed that strain AJ003T was closely related to Planococcus halocryophilus Or1T (97.4 % similarity), Planococcus antarcticus DSM 14505T (97.3 %), Planococcus kocurii NCIMB 629T (97.3 %), and Planococcus donghaensis JH1T (97.1 %). The predominant cellular fatty acids were anteiso-C15 : 0, and iso-C16 : 0.MK-7 and MK-8 were the quinones identified, and the major pigment was glycosyl-4,4′-diaponeurosporen-4′-ol-4-oic acid. The major polar lipid was phosphatidylglycerol. DNA–DNA relatedness of strain AJ003T with respect to its closest phylogenetic neighbours was 38.2 ± 0.5 % for Planococcus halocryophilus DSM 24743T, 32.2 ± 0.2 % for Planococcus antarcticus DSM 14505T, 21.0 ± 0.3 % for Planococcus kocurii DSM 20747T and 18.6 ± 1.4 % for Planococcus donghaensis KCTC 13050T. The DNA G+C content of strain AJ003T was 40.0 ± 0.6 mol%. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain AJ003T is concluded to represent a novel species of the genus Planococcus, for which the name Planococcus faecalis sp. nov. is proposed. The type strain is AJ003T ( = KCTC 33580T = CECT 8759T).

  3. Pelagic fishes in the Marguerite Bay region of the West Antarctic Peninsula continental shelf

    NASA Astrophysics Data System (ADS)

    Donnelly, Joseph; Torres, Joseph J.

    2008-02-01

    Pelagic fishes in the Marguerite Bay region of the western Antarctic Peninsula (WAP) continental margin were sampled using a 10-m 2 MOCNESS as part of the Southern Ocean Global Ocean Ecosystems Dynamics (SO GLOBEC) program. Sixty-two tows were completed during the course of four cruises conducted during the austral fall and winter, 22 each during the austral fall, and 9 each during the austral winter. Six thousand and sixty individuals of 34 species representing 13 families were collected in the fall, while 672 individuals of 22 species from 10 families were collected in the winter. Nearly all of the notothenioid specimens collected (families Artedraconidae, Bathydraconidae, Channichthyidae, and Nototheniidae) were either larvae or young juveniles (0-2 years). Conversely, except for the paralepidid Notolepis coatsi and the occasional juveniles of the bathylagid Bathylagus antarcticus, the gonostomatid Cyclothone kobayashii, or the myctophid Electrona antarctica, the non-notothenioid specimens collected were predominantly adults. In the fall, the nototheniids Pleuragramma antarcticum and Trematomus scotti, and the myctophid E. antarctica numerically dominated the overall assemblage, collectively accounting for 89.7% of the total catch. In the winter, E. antarctica, Cyclothone microdon, and B. antarcticus were the numerical dominants, each contributing 14-20% of the total. The pelagic fish community within the Marguerite Bay region of the WAP continental shelf is a variable mixture of mesopelagic and neritic fauna. At one extreme is an oceanic assemblage exhibiting high-diversity indices and characterized by the genera Electrona, Gymnoscopelus, Protomyctophum, Bathylagus, Cyclothone, and Notolepis. Minor components of this group include numerous less common mesopelagic genera (e.g., Paradiplospinus, Lampanyctus, Benthalbella, Borostomias) and the occasional larval/juvenile notothenioid. At the other extreme is a coastal assemblage with low-diversity indices dominated

  4. A check-list of the nematode parasites of South African Serpentes (snakes) and Sauria (lizards).

    PubMed

    Hering-Hagenbeck, S F; Boomker, J

    2000-03-01

    Published records, in combination with own data have been brought together to provide data on parasite/host relationships of reptiles that occur in the Republic of South Africa. A total of 62 nematode species belonging to 23 genera and 11 families are recorded from 20 snake and 21 lizard species. The genera Kalicephalus, Spauligodon, Ophidascaris and Abbreviata are especially well represented with between five and eight species per genus. The most nematode species were recorded from the flap-neck chameleon, Chamaeleo dilepis (eight), the puff-adder, Bitis arietans (eight) and the water monitor, Varanus niloticus (seven). All synonyms of parasites and hosts are given.

  5. A simple second-order digital phase-locked loop.

    NASA Technical Reports Server (NTRS)

    Tegnelia, C. R.

    1972-01-01

    A simple second-order digital phase-locked loop has been designed for the Viking Orbiter 1975 command system. Excluding analog-to-digital conversion, implementation of the loop requires only an adder/subtractor, two registers, and a correctable counter with control logic. The loop considers only the polarity of phase error and corrects system clocks according to a filtered sequence of this polarity. The loop is insensitive to input gain variation, and therefore offers the advantage of stable performance over long life. Predictable performance is guaranteed by extreme reliability of acquisition, yet in the steady state the loop produces only a slight degradation with respect to analog loop performance.

  6. Hemispheric Imaging of Galactic Neutral Hydrogen with a Phased Array Antenna System

    NASA Astrophysics Data System (ADS)

    Wijnholds, Stefan J.; De Bruyn, A. Ger; Bregman, Jaap D.; Bij De Vaate, Jan Geralt

    2004-06-01

    The thousand element array (THEA) system is a phased array system consisting of 1 m2 tiles having 64 Vivaldi elements each, arranged on a regular 8-by-8 grid, which has been developed as a demonstrator of technology and applicability for SKA. In this paper we present imaging results of Galactic neutral hydrogen with THEA. Measurements have been taken using a dense 2-by-2 array of four tiles as a four tile adder. The results are compared with results from the Leiden-Dwingeloo Survey, showing qualitative agreement, but also indicating that further studies are needed on the instrumental characteristics.

  7. Implementation of Arithmetic and Nonarithmetic Functions on a Label-free and DNA-based Platform

    PubMed Central

    Wang, Kun; He, Mengqi; Wang, Jin; He, Ronghuan; Wang, Jianhua

    2016-01-01

    A series of complex logic gates were constructed based on graphene oxide and DNA-templated silver nanoclusters to perform both arithmetic and nonarithmetic functions. For the purpose of satisfying the requirements of progressive computational complexity and cost-effectiveness, a label-free and universal platform was developed by integration of various functions, including half adder, half subtractor, multiplexer and demultiplexer. The label-free system avoided laborious modification of biomolecules. The designed DNA-based logic gates can be implemented with readout of near-infrared fluorescence, and exhibit great potential applications in the field of bioimaging as well as disease diagnosis. PMID:27713517

  8. Evaluation of floating-point sum or difference of products in carry-save domain

    NASA Technical Reports Server (NTRS)

    Wahab, A.; Erdogan, S.; Premkumar, A. B.

    1992-01-01

    An architecture to evaluate a 24-bit floating-point sum or difference of products using modified sequential carry-save multipliers with extensive pipelining is described. The basic building block of the architecture is a carry-save multiplier with built-in mantissa alignment for the summation during the multiplication cycles. A carry-save adder, capable of mantissa alignment, correctly positions products with the current carry-save sum. Carry propagation in individual multipliers is avoided and is only required once to produce the final result.

  9. Implementation of Arithmetic and Nonarithmetic Functions on a Label-free and DNA-based Platform

    NASA Astrophysics Data System (ADS)

    Wang, Kun; He, Mengqi; Wang, Jin; He, Ronghuan; Wang, Jianhua

    2016-10-01

    A series of complex logic gates were constructed based on graphene oxide and DNA-templated silver nanoclusters to perform both arithmetic and nonarithmetic functions. For the purpose of satisfying the requirements of progressive computational complexity and cost-effectiveness, a label-free and universal platform was developed by integration of various functions, including half adder, half subtractor, multiplexer and demultiplexer. The label-free system avoided laborious modification of biomolecules. The designed DNA-based logic gates can be implemented with readout of near-infrared fluorescence, and exhibit great potential applications in the field of bioimaging as well as disease diagnosis.

  10. Energy-Efficient Wide Datapath Integer Arithmetic Logic Units Using Superconductor Logic

    NASA Astrophysics Data System (ADS)

    Ayala, Christopher Lawrence

    Complementary Metal-Oxide-Semiconductor (CMOS) technology is currently the most widely used integrated circuit technology today. As CMOS approaches the physical limitations of scaling, it is unclear whether or not it can provide long-term support for niche areas such as high-performance computing and telecommunication infrastructure, particularly with the emergence of cloud computing. Alternatively, superconductor technologies based on Josephson junction (JJ) switching elements such as Rapid Single Flux Quantum (RSFQ) logic and especially its new variant, Energy-Efficient Rapid Single Flux Quantum (ERSFQ) logic have the capability to provide an ultra-high-speed, low power platform for digital systems. The objective of this research is to design and evaluate energy-efficient, high-speed 32-bit integer Arithmetic Logic Units (ALUs) implemented using RSFQ and ERSFQ logic as the first steps towards achieving practical Very-Large-Scale-Integration (VLSI) complexity in digital superconductor electronics. First, a tunable VHDL superconductor cell library is created to provide a mechanism to conduct design exploration and evaluation of superconductor digital circuits from the perspectives of functionality, complexity, performance, and energy-efficiency. Second, hybrid wave-pipelining techniques developed earlier for wide datapath RSFQ designs have been used for efficient arithmetic and logic circuit implementations. To develop the core foundation of the ALU, the ripple-carry adder and the Kogge-Stone parallel prefix carry look-ahead adder are studied as representative candidates on opposite ends of the design spectrum. By combining the high-performance features of the Kogge-Stone structure and the low complexity of the ripple-carry adder, a 32-bit asynchronous wave-pipelined hybrid sparse-tree ALU has been designed and evaluated using the VHDL cell library tuned to HYPRES' gate-level characteristics. The designs and techniques from this research have been implemented using

  11. Factors affecting the output pulse flatness of the linear transformer driver cavity systems with 5th harmonics

    DOE PAGES

    Alexeenko, V. M.; Mazarakis, M. G.; Kim, A. A.; ...

    2016-09-19

    Here, we describe the study we have undertaken to evaluate the effect of component tolerances in obtaining a voltage output flat top for a linear transformer driver (LTD) cavity containing 3rd and 5th harmonic bricks [A. A. Kim et al., in Proc. IEEE Pulsed Power and Plasma Science PPPS2013 (San Francisco, California, USA, 2013), pp. 1354–1356.] and for 30 cavity voltage adder. Our goal was to define the necessary component value precision in order to obtain a voltage output flat top with no more than ±0.5% amplitude variation.

  12. Implementation of large kernel 2-D convolution in limited FPGA resource

    NASA Astrophysics Data System (ADS)

    Zhong, Sheng; Li, Yang; Yan, Luxin; Zhang, Tianxu; Cao, Zhiguo

    2007-12-01

    2-D Convolution is a simple mathematical operation which is fundamental to many common image processing operators. Using FPGA to implement the convolver can greatly reduce the DSP's heavy burden in signal processing. But with the limit resource the FPGA can implement a convolver with small 2-D kernel. In this paper, An FIFO type line delayer is presented to serve as the data buffer for convolution to reduce the data fetching operation. A finite state machine is applied to control the reuse of multipliers and adders arrays. With these two techniques, a resource limited FPGA can be used to implement a larger kernel convolver which is commonly used in image process systems.

  13. Solid-State Modulator R&D at LLNL

    SciTech Connect

    Cook, E G; Allen, F V; Anaya, E M; Gower, E J; Hawkins, S A; Hickman, B C; Lee, B S; Sullivan, J S; Watson, J A; Brooksby, C A; Yuhas, J; Cassel, R; Nguyen, M; Pappas, C; deLamare, J

    2002-12-04

    The Beam Research Program at Lawrence Livermore National Laboratory (LLNL) has been developing solid-state modulators for accelerator applications for several years. These modulators are based on inductive adder circuit topology and have demonstrated great versatility with regard to pulse width and pulse repetition rate while maintaining fast pulse rise and fall times. These modulators are also capable of being scaled to higher output voltage and power levels. An explanation of the circuit operation will be presented along with test data of several different hardware systems.

  14. Universal programmable logic gate and routing method

    NASA Technical Reports Server (NTRS)

    Fijany, Amir (Inventor); Vatan, Farrokh (Inventor); Akarvardar, Kerem (Inventor); Blalock, Benjamin (Inventor); Chen, Suheng (Inventor); Cristoloveanu, Sorin (Inventor); Kolawa, Elzbieta (Inventor); Mojarradi, Mohammad M. (Inventor); Toomarian, Nikzad (Inventor)

    2009-01-01

    An universal and programmable logic gate based on G.sup.4-FET technology is disclosed, leading to the design of more efficient logic circuits. A new full adder design based on the G.sup.4-FET is also presented. The G.sup.4-FET can also function as a unique router device offering coplanar crossing of signal paths that are isolated and perpendicular to one another. This has the potential of overcoming major limitations in VLSI design where complex interconnection schemes have become increasingly problematic.

  15. Threshold-Logic Devices Consisting of Subthreshold CMOS Circuits

    NASA Astrophysics Data System (ADS)

    Ogawa, Taichi; Hirose, Tetsuya; Asai, Tetsuya; Amemiya, Yoshihito

    A threshold-logic gate device consisting of subthreshold MOSFET circuits is proposed. The gate device performs threshold-logic operation, using the technique of current-mode addition and subtraction. Sample digital subsystems, i.e., adders and morphological operation cells based on threshold logic, are designed using the gate devices, and their operations are confirmed by computer simulation. The device has a simple structure and operates at low power dissipation, so it is suitable for constructing cell-based, parallel processing LSIs such as cellular-automaton and neural-network LSIs.

  16. Techniques for Computing the DFT Using the Residue Fermat Number Systems and VLSI

    NASA Technical Reports Server (NTRS)

    Truong, T. K.; Chang, J. J.; Hsu, I. S.; Pei, D. Y.; Reed, I. S.

    1985-01-01

    The integer complex multiplier and adder over the direct sum of two copies of a finite field is specialized to the direct sum of the rings of integers modulo Fermat numbers. Such multiplications and additions can be used in the implementation of a discrete Fourier transform (DFT) of a sequence of complex numbers. The advantage of the present approach is that the number of multiplications needed for the DFT can be reduced substantially over the previous approach. The architectural designs using this approach are regular, simple, expandable and, therefore, naturally suitable for VLSI implementation.

  17. Environmental costing for agriculture: Will it be standard fare in the farm bill of 2000

    SciTech Connect

    Smith, V.K. )

    1992-12-01

    This paper starts by discussing and estimating the environmental costs of agricultural production. The author uses a separate benefit transfer intended to expose methodological issues to construct each cost category of agricultures's external effects. This is followed by a simple description of the framework for production decisions that account for environmental costs. Included are attribution of environmental externalities and measurement of environmental costs. Finally the author discusses research implications of environmental costing, including TQM and environmental policy analyses, environmental services and their unit values, strategies for measuring environmental values, and prognosis for agricultural adders. 42 refs., 1 fig., 1 tab.

  18. Fixed Wordsize Implementation of Lifting Schemes

    NASA Astrophysics Data System (ADS)

    Karp, Tanja

    2006-12-01

    We present a reversible nonlinear discrete wavelet transform with predefined fixed wordsize based on lifting schemes. Restricting the dynamic range of the wavelet domain coefficients due to a fixed wordsize may result in overflow. We show how this overflow has to be handled in order to maintain reversibility of the transform. We also perform an analysis on how large a wordsize of the wavelet coefficients is needed to perform optimal lossless and lossy compressions of images. The scheme is advantageous to well-known integer-to-integer transforms since the wordsize of adders and multipliers can be predefined and does not increase steadily. This also results in significant gains in hardware implementations.

  19. Factors affecting the output pulse flatness of the linear transformer driver cavity systems with 5th harmonics

    NASA Astrophysics Data System (ADS)

    Alexeenko, V. M.; Mazarakis, M. G.; Kim, A. A.; Kondratiev, S. S.; Sinebryukhov, V. A.; Volkov, S. N.; Cuneo, M. E.; Kiefer, M. L.; Leckby, J. J.; Oliver, B. V.; Maloney, P. D.

    2016-09-01

    We describe the study we have undertaken to evaluate the effect of component tolerances in obtaining a voltage output flat top for a linear transformer driver (LTD) cavity containing 3rd and 5th harmonic bricks [A. A. Kim et al., in Proc. IEEE Pulsed Power and Plasma Science PPPS2013 (San Francisco, California, USA, 2013), pp. 1354-1356.] and for 30 cavity voltage adder. Our goal was to define the necessary component value precision in order to obtain a voltage output flat top with no more than ±0.5 % amplitude variation.

  20. Repetitive High Energy Pulsed Power (RHEPP) temperature monitoring system utilizing Luxtron fluoroptic sensors and thermocouples technical reference manual

    NASA Astrophysics Data System (ADS)

    Laderach, G. E.

    1992-01-01

    This document describes the Temperature Monitoring System for the RHEPP project at Sandia National Laboratories. The system is designed to operate in the presence of severe repetitive high voltage and electromagnetic fields while providing real time thermal data on component behavior. The thermal data is used in the design and evaluation of the major RHEPP components such as the magnetically switched pulse compressor and the linear induction voltage adder. Particular attention is given to the integration of commercially available hardware and software components with a custom written control program. While this document is intended to be a reference guide, it may also serve as a template for similar applications.

  1. Gallium Arsenide Pilot Line for High Performance Components

    DTIC Science & Technology

    1992-05-28

    sacrificing layout regularity, a binary tree of 4-2 adders is used to reduce the Booth recoded partial products. This results in a time optimum...oot ins a" Pillo 13200’I !32 05 911W. 9W0 400 "/ P4A MA CS Pt 1 64 025 1 50. 1 W 400 soJL. Yes!. Yes.! G-M.- 1"d~t 6 025 -5W0.t’S0 W W W Neem Op ase m

  2. Serial multiplier arrays for parallel computation

    NASA Technical Reports Server (NTRS)

    Winters, Kel

    1990-01-01

    Arrays of systolic serial-parallel multiplier elements are proposed as an alternative to conventional SIMD mesh serial adder arrays for applications that are multiplication intensive and require few stored operands. The design and operation of a number of multiplier and array configurations featuring locality of connection, modularity, and regularity of structure are discussed. A design methodology combining top-down and bottom-up techniques is described to facilitate development of custom high-performance CMOS multiplier element arrays as well as rapid synthesis of simulation models and semicustom prototype CMOS components. Finally, a differential version of NORA dynamic circuits requiring a single-phase uncomplemented clock signal introduced for this application.

  3. Gills of antarctic fish.

    PubMed

    Rankin, J C; Tuurala, H

    1998-01-01

    We review the literature on the way the structure of icefish gills relates the physiology of these haemoglobin-less fishes. Vascular casting confirmed earlier reports that the only special feature of the gills is the large size of the blood vessels, especially the prominent and continuous marginal channels Isolated perfused gill arches were used to study the effects of changes in afferent and efferent pressure on gill resistance and tritiated water influx in Chionobathyscus dewitti. Increasing perfusion rate did not change gill resistance, but there were moderate proportional increases in water influx. Reducing efferent pressure increased gill resistance but did not affect water influx. In both C. dewitti and Cryodraco antarcticus gills perfused at constant flow rate, noradrenaline produced concentration-dependent decreases in gill resistance and, with high concentrations, increases in water influx. Fixation while perfusion continued was used to compare blood space dimensions in control, noradrenaline-treated and unperfused gills. Noradrenaline caused large increases in the thickness of the lamellar blood space and increased lamellar height, despite a greatly reduced afferent pressure. This suggests that modulation of pillar cell active tension might be involved in control of lamellar perfusion. The possible relationship between gill water fluxes and lamellar recruitment is discussed.

  4. Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin

    PubMed Central

    Aquilina, Alfred; Woulds, Clare; Glover, Adrian G.; Little, Crispin T. S.; Hepburn, Laura E.; Newton, Jason; Mills, Rachel A.

    2016-01-01

    Despite a number of studies in areas of focused methane seepage, the extent of transitional sediments of more diffuse methane seepage, and their influence upon biological communities is poorly understood. We investigated an area of reducing sediments with elevated levels of methane on the South Georgia margin around 250 m depth and report data from a series of geochemical and biological analyses. Here, the geochemical signatures were consistent with weak methane seepage and the role of sub-surface methane consumption was clearly very important, preventing gas emissions into bottom waters. As a result, the contribution of methane-derived carbon to the microbial and metazoan food webs was very limited, although sulfur isotopic signatures indicated a wider range of dietary contributions than was apparent from carbon isotope ratios. Macrofaunal assemblages had high dominance and were indicative of reducing sediments, with many taxa common to other similar environments and no seep-endemic fauna, indicating transitional assemblages. Also similar to other cold seep areas, there were samples of authigenic carbonate, but rather than occurring as pavements or sedimentary concretions, these carbonates were restricted to patches on the shells of Axinulus antarcticus (Bivalvia, Thyasiridae), which is suggestive of microbe–metazoan interactions. PMID:27703692

  5. Resistance to UV-B induced DNA damage in extreme-tolerant cryptoendolithic Antarctic fungi: detection by PCR assays.

    PubMed

    Selbmann, Laura; Isola, Daniela; Zucconi, Laura; Onofri, Silvano

    2011-10-01

    Cryptoendolithic Antarctic black fungi are adapted to the harshest terrestrial conditions as in the ice-free area of the McMurdo Dry Valleys. Recently, surviving space simulated conditions proves their bewildering extremotolerance. In order to investigate the potential DNA damage and their response after UV-B exposition, two strains of Antarctic cryptoendolithic black fungi, Cryomyces antarcticus CCFEE 534 and Cryomyces minteri CCFEE 5187, were irradiated at different UV-B doses. Since conventional methods cannot be applied to these organisms, the effect on the genome was assessed by RAPD and rDNA amplification PCR based assays; the results were compared with the responses of Saccharomyces pastorianus DBVPG 6283 treated with the same conditions. Results showed that template activity was drastically inhibited in S. pastorianus after irradiation. Dramatic changes in the RAPD profiles showed after 30 min of exposure while the rDNA amplification of SSU, LSU, and ITS portions failed after 30, 60, and 90 min of exposure respectively. No alteration was detected in the templates of the Antarctic strains where both RAPD profiles and rDNA PCR amplifications were unaffected even after 240 min of exposure. The electroferograms of the rDNA portions of Cryomyces strains were perfectly readable and conserved whilst the analyses revealed a marked alteration in S. pastorianus confirming the high resistance of the Antarctic strains to UV-B exposure.

  6. Spatial distribution of pelagic fish off Adélie and George V Land, East Antarctica in the austral summer 2008

    NASA Astrophysics Data System (ADS)

    Moteki, Masato; Koubbi, Philippe; Pruvost, Patrice; Tavernier, Eric; Hulley, Percy-Alexander

    2011-08-01

    Pelagic fish assemblages and community structure were examined along longitudinal and meridian transects off Adélie and George V Land, East Antarctica, in the austral summer 2008. Fish were sampled with an RMT 8 net principally from six discrete depth layers (0-50-100-200-500-1000-2000 m) in the oceanic zone and from three depth layers (0-50-100-200 m) over the continental shelf zone. A total of 20,281 individuals from 27 species were collected. Pleuragramma antarcticum was the most dominant species by number (18,710 inds), followed by Chionodraco hamatus (768), Trematomus newnesi (375), Cyclothone microdon (101), Electrona antarctica (92), Bathylagus antarcticus (51) and Notolepis coatsi (54). Cluster analysis revealed that the fish community was clearly divided at the Antarctic Slope Front into separate oceanic and shelf assemblages, being dominated by mesopelagic fish and notothenioids, respectively. The Southern Boundary of Antarctic Circumpolar Current likely restricted a more northern distribution of notothenioids in the upper 200 m. Mesopelagic fish dominated the large biomass below 500 m and notothenioids dominated that in the upper 100 m. It is considered that mesopelagic fish in the oceanic zone would unlikely be eaten by seabirds because no distinctive diel vertical migration to the surface layer was observed. In the neritic zone, notothenioids ( C. hamatus, T. newnesi and P. antarcticum) possibly play an important role as prey items for flying seabirds, penguins and other notothenioids fish especially in the shallow depth stratum (0-100 m).

  7. A new species of Wellsopsyllus (Copepoda, Harpacticoida, Paramesochridae) from the deep Southern Ocean and remarks on its biogeography

    NASA Astrophysics Data System (ADS)

    Kottmann, Johanna; Kihara, Terue Cristina; Glatzel, Thomas; Veit-Köhler, Gritta

    2013-03-01

    The new deep-sea copepod species of the family Paramesochridae (Copepoda, Harpacticoida) presented here was collected during the scientific ANtarctic benthic DEEP-sea biodiversity cruise II (ANDEEP II) to the Weddell Abyssal Plain and western Weddell Sea and the CROZet natural iron bloom and EXport experiment (CROZEX cruise) to the Crozet Isles in the Indian Ocean. The new species has been allocated to the subgenus Wellsopsyllus within the genus Wellsopsyllus Kunz, 1981, based on the 1-segmented endopods and 3-segmented exopods of swimming legs 2-4. Furthermore, the new species shows a 1-segmented exopod of the antenna. Wellsopsyllus ( W.) antarcticus sp. n. can be distinguished from its congeners by its small body size, the presence of two setae on the distal segment of the endopod of the first swimming leg, by the very small furcal rami, the extremely reduced endopods of second and third swimming legs, the reduced mandibular palp and maxillula, as well as by the size and armature of the fifth and sixth swimming legs in both sexes. Difficulties of the placement of the new species into a suitable genus show an insufficiency in the present family classification. In the future, a revision of the genus Wellsopsyllus is essential. With its presence in the western Weddell Sea and the Indian Ocean, the new species may have a wide distribution range. Furthermore, it is the first abyssal species of the genus Wellsopsyllus sampled outside of the Scotia Sea.

  8. Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin

    NASA Astrophysics Data System (ADS)

    Bell, James B.; Aquilina, Alfred; Woulds, Clare; Glover, Adrian G.; Little, Crispin T. S.; Reid, William D. K.; Hepburn, Laura E.; Newton, Jason; Mills, Rachel A.

    2016-09-01

    Despite a number of studies in areas of focused methane seepage, the extent of transitional sediments of more diffuse methane seepage, and their influence upon biological communities is poorly understood. We investigated an area of reducing sediments with elevated levels of methane on the South Georgia margin around 250 m depth and report data from a series of geochemical and biological analyses. Here, the geochemical signatures were consistent with weak methane seepage and the role of sub-surface methane consumption was clearly very important, preventing gas emissions into bottom waters. As a result, the contribution of methane-derived carbon to the microbial and metazoan food webs was very limited, although sulfur isotopic signatures indicated a wider range of dietary contributions than was apparent from carbon isotope ratios. Macrofaunal assemblages had high dominance and were indicative of reducing sediments, with many taxa common to other similar environments and no seep-endemic fauna, indicating transitional assemblages. Also similar to other cold seep areas, there were samples of authigenic carbonate, but rather than occurring as pavements or sedimentary concretions, these carbonates were restricted to patches on the shells of Axinulus antarcticus (Bivalvia, Thyasiridae), which is suggestive of microbe-metazoan interactions.

  9. Granulosicoccus coccoides sp. nov., isolated from leaves of seagrass (Zostera marina).

    PubMed

    Kurilenko, Valerie V; Christen, Richard; Zhukova, Natalia V; Kalinovskaya, Nataliya I; Mikhailov, Valery V; Crawford, Russell J; Ivanova, Elena P

    2010-04-01

    A non-pigmented, motile, Gram-negative bacterium, strain Z 271(T), was isolated from the surface of leaves of the seagrass Zostera marina which was collected in Troitza Bay (Sea of Japan, Pacific Ocean). The new isolate grew between 5 degrees C and 28 degrees C and was slightly halophilic, tolerating environments containing up to 5 % (w/v) NaCl. Strain Z 271(T) was able to degrade Tweens 20, 40 and 80 and partially degrade gelatin, but was unable to degrade casein. Phosphatidylethanolamine (36.9 %) and phosphatidylglycerol (63.1 %) were the predominant phospholipids. The major fatty acids included C(18 : 1)omega7c (43.7 %), C(16 : 1)omega7c (31.1 %) and C(16 : 0) (16.8 %). The main respiratory quinone was Q-8. The DNA-DNA relatedness value of strain Z 271(T) with Granulosicoccus antarcticus IMCC3135(T) was 35 %. The G+C content of the DNA of strain Z 271(T) was 60.2 mol%. On the basis of phenotypic and genotypic characteristics and 16S rRNA gene sequence analysis, strain Z 271(T) represents a novel species of the genus Granulosicoccus for which the name Granulosicoccus coccoides sp. nov. is proposed. The type strain is Z 271(T) (=KMM 6014(T)=CIP 109923(T)).

  10. Vestigial phragmocone in the gladius points to a deepwater origin of squid (Mollusca: Cephalopoda)

    NASA Astrophysics Data System (ADS)

    Arkhipkin, Alexander I.; Bizikov, Vyacheslav A.; Fuchs, Dirk

    2012-03-01

    The microstructure of the gladius cone was investigated in six species of nektonic squid: shallow-water Loligo gahi (Loliginidae), pelagic eurybathic Illex argentinus, Todarodes pacificus, Dosidicus gigas (Ommastrephidae), and deepwater Onykia ingens (Onychoteuthidae) and Gonatus antarcticus (Gonatidae) using state-of-the-art microscopy. Apart from L. gahi, all other species had septa-like layers in the gladius cone, which for the first time were investigated in detail and compared with those in extinct Cretaceous belemnites Hibolithes sp. and Pachyteuthis sp., and spirulid Cyrtobelus sp. It was found that the organic layers of the gladius cone in recent squid can be homologized with the organic components of the shell in fossil phragmocone-bearing coleoids. The septa-like layers in modern gladius cones therefore represent a vestigial phragmocone composed of organic septal rudiments of the ancestral phragmocone that has lost the siphuncle and gas-filled chambers. The well-developed rostrum in onychoteuthids and small rostrum of the gladius in ommastrephids and gonatids can be seen as homologous with the belemnoid rostrum, which may indicate a close phylogenetic relationship between belemnites and at least some squid. Possible evolutionary pathways of the reduction of the functional phragmocone in squid ancestors are discussed. Several features such as the loss of shell calcification, deep water speciation, and the structure of the equilibrium organ point to a deep-water origin of squids.

  11. Novel flame retardants (N-FRs), polybrominated diphenyl ethers (PBDEs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in fish, penguin, and skua from King George Island, Antarctica.

    PubMed

    Wolschke, Hendrik; Meng, Xiang-Zhou; Xie, Zhiyong; Ebinghaus, Ralf; Cai, Minghong

    2015-07-15

    Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), are frequently detected in biota from Antarctica, whereas no data are available for their replacements, such as novel flame retardants (N-FRs). This study presented the occurrence of several N-FRs, PBDEs, and PCBs in tissue samples of an Antarctic rock cod (Trematomus bernacchii), a young gentoo penguin (Pygoscelis papua), and a brown skua (Stercorarius antarcticus) collected from King George Island. The total concentrations of N-FRs (ΣN-FRs; mean: 931 pg/g dry weight (dw)) were comparable to PBDEs (Σ8PBDEs; 681 pg/gdw), which were much lower than PCBs (ΣDL-PCBs; 12,800 pg/gdw). Overall, skua contained two to three orders of magnitude higher contamination than penguin and fish. In the future, more attention should be focused on the fate of N-FRs in Antarctica, where usages have increased since PBDEs were banned. To our knowledge, this is the first report of N-FRs in biota from Antarctica.

  12. Chinstrap penguin foraging area associated with a seamount in Bransfield Strait, Antarctica

    NASA Astrophysics Data System (ADS)

    Kokubun, Nobuo; Lee, Won Young; Kim, Jeong-Hoon; Takahashi, Akinori

    2015-12-01

    Identifying marine features that support high foraging performance of predators is useful to determine areas of ecological importance. This study aimed to identify marine features that are important for foraging of chinstrap penguins (Pygoscelis antarcticus), an abundant upper-trophic level predator in the Antarctic Peninsula region. We investigated the foraging locations of penguins breeding on King George Island using GPS-depth loggers. Tracking data from 18 birds (4232 dives), 11 birds (2095 dives), and 19 birds (3947 dives) were obtained in 2007, 2010, and 2015, respectively. In all three years, penguins frequently visited an area near a seamount (Orca Seamount) in Bransfield Strait. The percentage of dives (27.8% in 2007, 36.1% in 2010, and 19.1% in 2015) and depth wiggles (27.1% in 2007, 37.2% in 2010, and 22.3% in 2015) performed in this area was higher than that expected from the size of the area and distance from the colony (8.4% for 2007, 14.7% for 2010, and 6.3% for 2015). Stomach content analysis showed that the penguins fed mainly on Antarctic krill. These results suggest that the seamount provided a favorable foraging area for breeding chinstrap penguins, with high availability of Antarctic krill, possibly related to local upwelling.

  13. Lepidasthenia loboi sp. n. from Puerto Madryn, Argentina (Polychaeta, Polynoidae)

    PubMed Central

    Salazar-Vallejo, Sergio I.; González, Norma Emilia; Salazar-Silva, Patricia

    2015-01-01

    Abstract Among polychaetes, polynoids have the highest number of symbiotic species found living with a wide variety of marine invertebrates, including other polychaetes. Lepidasthenia Malmgren, 1867 and Lepidametria Webster, 1879 were regarded as synonyms but belong to different subfamilies, although both have species associated with thelepodid or terebellid polychaetes. In this contribution Lepidasthenia loboi sp. n. is described from several specimens associated with the thelepodid Thelepus antarcticus Kinberg, 1867, collected on a rocky shore near Puerto Madryn, Argentina. Lepidasthenia loboi sp. n. can be confused with Lepidasthenia esbelta Amaral & Nonato, 1982 because both live with Thelepus, are of similar sizes with similar pigmentation patterns, and have giant neurochaetae. However, in Lepidasthenia loboi sp. n. all eyes are of the same size, cephalic and parapodial cirri are tapered and mucronate, the second pair of elytra is larger than the third, the ventral cirri arise at the base of parapodia such that they do not reach chaetal lobe tips, and neuraciculae are tapered. On the contrary, in Lepidasthenia esbelta the posterior eyes are larger than anterior ones, cephalic and parapodial appendages are swollen subdistally, the second and third pairs of elytra are of the same size, the ventral cirri arise medially such that their tips reach the neurochaetal lobe tips, and the neuraciculae have falcate tips. Some comments about other genera in the Lepidastheniinae, a simplified key to its genera, and a key to Lepidasthenia species with giant neurochaetae are also included. PMID:26798303

  14. Recovery and reproduction of an Antarctic tardigrade retrieved from a moss sample frozen for over 30 years.

    PubMed

    Tsujimoto, Megumu; Imura, Satoshi; Kanda, Hiroshi

    2016-02-01

    Long-term survival has been one of the most studied of the extraordinary physiological characteristics of cryptobiosis in micrometazoans such as nematodes, tardigrades and rotifers. In the available studies of long-term survival of micrometazoans, instances of survival have been the primary observation, and recovery conditions of animals or subsequent reproduction are generally not reported. We therefore documented recovery conditions and reproduction immediately following revival of tardigrades retrieved from a frozen moss sample collected in Antarctica in 1983 and stored at -20 °C for 30.5 years. We recorded recovery of two individuals and development of a separate egg of the Antarctic tardigrade, Acutuncus antarcticus, providing the longest records of survival for tardigrades as animals or eggs. One of the two resuscitated individuals and the hatchling successfully reproduced repeatedly after their recovery from long-term cryptobiosis. This considerable extension of the known length of long-term survival of tardigrades recorded in our study is interpreted as being associated with the minimum oxidative damage likely to have resulted from storage under stable frozen conditions. The long recovery times of the revived tardigrades observed is suggestive of the requirement for repair of damage accrued over 30 years of cryptobiosis. Further more detailed studies will improve understanding of mechanisms and conditions underlying the long-term survival of cryptobiotic organisms.

  15. New data on the occurrence of Acanthocephala in some fish in Admiralty Bay (South Shetland Islands).

    PubMed

    Zdzitowiecki, Krzysztof; Laskowski, Zdzisław

    2013-12-01

    New data on the infection with Acanthocephala of 33 fish caught in Admiralty Bay in November 2007 to January 2008 are given. These fish belong to 5 species: Notothenia rossii (22 immature specimens), Lindbergichthys nudifrons (n = 7), Trematomus bernacchii (n = 1), T. newnesi (n = 1) and Harpagifer antarcticus (n = 2). Three species of Echinorhynchida: Aspersentis megarhynchus, Metacanthocephalus dalmori and M. johnstoni and four species of Polymorphida: Corynosoma arctocephali, C. bullosum, C. hamanni and C. pseudohamanni, were found. Prevalence of N. rossii and L. nudifrons was 100%. The mean abundance of infection of N. rossii (125.09) was larger than that of Notothenia coriiceps (82.93). Data of infection of N. rossii in 2007 was almost identical with that in 1979 (mean abundance 118.66). The most abundant in this host were A. megarhynchus, M. johnstoni, C. hamanni and C. pseudohamanni (mean abundances 36.36, 29.77, 13.86 and 44.73, respectively). In total Echinorhynchida were more abundant than Polymorphida in 2007/08 (66.18 versus 58.91). Reverse situation was in 1979 (mean abundance 47.36 for Echinorhynchida and 71.3 for Polymorphida. Only 7 L. nudifrons were examined in 2007/08 and Echinorhynchida were more numerous in this host (mean abundance 26.71) than Polymorphida (10.29). Single specimens of other fish were infected with a few Acanthocephala belonging to species recorded in the same hosts with those found in 1978/79.

  16. Evolution of fungi at boundaries of life

    NASA Astrophysics Data System (ADS)

    Onofri, S.; Zucconi, L.; Selbmann, L.; de Hoog, G. S.; Grube, M.; Barreca, D.; Ruisi, S.

    The ice-free Antarctic areas in Victoria Land are characterized by high dryness high UV radiation very low temperatures reaching about --50 r C during the Austral Winter strong and sudden thermal fluctuations leading to very unstable environmental conditions Precipitations represented only by snow are less than 100 mm water equivalent per year which mostly sublime and only a small amount melts and remains available inside the rocks furthermore the strong evaporation causes soluble salts accumulation on the surface The rock surfaces appear mostly sterile and only rare epilithic lichens occur in protected niches microbial cryptoendolithic communities living under the rock crust at the absolute biological limits for life represent the predominant life form Among them the most widespread is the lichen-dominated community where black meristematic fungi have been currently isolated They belong to an enigmatic group of extremotolerant microorganisms with polyphyletic origins generally isolated from substrates hard to be colonized like sandstone marble and saltpans Recently two new Antarctic endemic genera isolated from rock samples Friedmanniomyces Onofri and Cryomyces Selbmann et al with four species F endolithicus Onofri F simplex Selbmann et al C antarcticus Selbmann et al and C minteri Selbmann et al were established Some other unidentified strains are still waiting to be described and one at least seems to be associated also with

  17. Bone-eating worms from the Antarctic: the contrasting fate of whale and wood remains on the Southern Ocean seafloor

    PubMed Central

    Glover, Adrian G.; Wiklund, Helena; Taboada, Sergio; Avila, Conxita; Cristobo, Javier; Smith, Craig R.; Kemp, Kirsty M.; Jamieson, Alan J.; Dahlgren, Thomas G.

    2013-01-01

    We report the results from the first experimental study of the fate of whale and wood remains on the Antarctic seafloor. Using a baited free-vehicle lander design, we show that whale-falls in the Antarctic are heavily infested by at least two new species of bone-eating worm, Osedax antarcticus sp. nov. and Osedax deceptionensis sp. nov. In stark contrast, wood remains are remarkably well preserved with the absence of typical wood-eating fauna such as the xylophagainid bivalves. The combined whale-fall and wood-fall experiment provides support to the hypothesis that the Antarctic circumpolar current is a barrier to the larvae of deep-water species that are broadly distributed in other ocean basins. Since humans first started exploring the Antarctic, wood has been deposited on the seafloor in the form of shipwrecks and waste; our data suggest that this anthropogenic wood may be exceptionally well preserved. Alongside the new species descriptions, we conducted a comprehensive phylogenetic analyses of Osedax, suggesting the clade is most closely related to the frenulate tubeworms, not the vestimentiferans as previous reported. PMID:23945684

  18. Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin.

    PubMed

    Bell, James B; Aquilina, Alfred; Woulds, Clare; Glover, Adrian G; Little, Crispin T S; Reid, William D K; Hepburn, Laura E; Newton, Jason; Mills, Rachel A

    2016-09-01

    Despite a number of studies in areas of focused methane seepage, the extent of transitional sediments of more diffuse methane seepage, and their influence upon biological communities is poorly understood. We investigated an area of reducing sediments with elevated levels of methane on the South Georgia margin around 250 m depth and report data from a series of geochemical and biological analyses. Here, the geochemical signatures were consistent with weak methane seepage and the role of sub-surface methane consumption was clearly very important, preventing gas emissions into bottom waters. As a result, the contribution of methane-derived carbon to the microbial and metazoan food webs was very limited, although sulfur isotopic signatures indicated a wider range of dietary contributions than was apparent from carbon isotope ratios. Macrofaunal assemblages had high dominance and were indicative of reducing sediments, with many taxa common to other similar environments and no seep-endemic fauna, indicating transitional assemblages. Also similar to other cold seep areas, there were samples of authigenic carbonate, but rather than occurring as pavements or sedimentary concretions, these carbonates were restricted to patches on the shells of Axinulus antarcticus (Bivalvia, Thyasiridae), which is suggestive of microbe-metazoan interactions.

  19. Effect of nitrogen sources and vitamins on ligninolytic enzyme production by some white-rot fungi. Dye decolorization by selected culture filtrates.

    PubMed

    Levin, Laura; Melignani, Eliana; Ramos, Araceli Marcela

    2010-06-01

    The effect of amino acids, complex nitrogen sources and vitamin addition on Trametes trogii, Trametes villosa and Coriolus versicolor var. antarcticus ligninolytic enzyme production, was evaluated. Dye decolorization by their culture filtrates was compared. Glutamic acid followed by peptone, were the best N sources for laccase and manganese peroxidase production. The three fungi produced two laccase isoenzymes (molecular weights from 38 up to 150 kDa); their pattern of production was not affected by medium composition. Although the response was not uniform, vitamin addition sometimes stimulated ligninolytic enzyme production, but never inhibited it. Thiamine induced manganese peroxidase production. T. trogii grown in glutamic acid produced culture filtrates with the highest laccase (188.3 U/ml) and manganese peroxidase activities (4.5 U/ml), rendering the best results in decolorization. These crude filtrates were able to decolorize in half hour (at pH 4.5, 30 degrees C): 13%, 23%, 40%, 46%, 82%, 94% and 95% of Gentian Violet, Xylidine, Congo Red, Malachite Green, Remazol Brilliant Blue R, Indigo Carmine and Anthraquinone Blue, respectively.

  20. Levels of essential and potentially toxic trace metals in Antarctic macro algae

    NASA Astrophysics Data System (ADS)

    Farías, Silvia; Arisnabarreta, Sebastián Pérez; Vodopivez, Cristian; Smichowski, Patricia

    2002-12-01

    Eleven species of Antarctic algae were examined for their accumulation ability in the uptake of different metals and metalloids from the Antarctic aquatic environment. Macro algae were collected during the 2000 austral summer season at Jubany Station (Argentinean base) around Potter Cove, King George Island. The elements quantified were: As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Sr, V, and Zn. An optimized microwave-assisted digestion procedure was used to digest the samples and the elements were determined by inductively coupled plasma optical emission spectrometry. A wide range of metal retention capacity among the different species was observed. The highest levels of trace elements were found in Monostroma hariotii and Phaeurus antarcticus, with concentrations up to 3095 μg g -1 for Fe. On the basis of the levels of trace elements observed in Monostroma hariotii and its wide distribution in the Antarctic Peninsula, this organism accomplishes a number of prerequisites to be considered as an adequate biomonitor for future studies.

  1. The limnology and biology of the Dufek Massif, Transantarctic Mountains 82° South

    NASA Astrophysics Data System (ADS)

    Hodgson, Dominic A.; Convey, Peter; Verleyen, Elie; Vyverman, Wim; McInnes, Sandra J.; Sands, Chester J.; Fernández-Carazo, Rafael; Wilmotte, Annick; De Wever, Aaike; Peeters, Karolien; Tavernier, Ines; Willems, Anne

    2010-08-01

    Very little is known about the higher latitude inland biology of continental Antarctica. In this paper we describe the limnology and biology of the Dufek Massif, using a range of observational, microscopic and molecular methods. Here two dry valleys are home to some of the southernmost biota on Earth. Cyanobacteria were the dominant life forms, being found in lakes and ponds, in hypersaline brines, summer melt water, relict pond beds and in exposed terrestrial habitats. Their species diversity was the lowest yet observed in Antarctic lakes. Green algae, cercozoa and bacteria were present, but diatoms were absent except for a single valve; likely windblown. Mosses were absent and only one lichen specimen was found. The Metazoa included three microbivorous tardigrades ( Acutuncus antarcticus, Diphascon sanae and Echiniscus (cf) pseudowendti) and bdelloid rotifer species, but no arthropods or nematodes. These simple faunal and floral communities are missing most of the elements normally present at lower latitudes in the Antarctic which is probably a result of the very harsh environmental conditions in the area.

  2. Diatom and silicoflagellate biostratigraphy for the late Eocene: ODP 1090 (sub-Antarctic Atlantic)

    USGS Publications Warehouse

    Barron, John A.; Bukry, David B.; Gersonde, Rainer

    2014-01-01

    Abundant and well-preserved diatoms and silicofl agellate assemblages are documented through a complete late Eocene sequence, ODP Hole 1090B, recovered from the southern Agulhas Ridge in the sub-Antarctic South Atlantic. A sequence of Cestodiscus (diatom) species occurrence events involving C. pulchellus var. novazealandica, C. fennerae, C. antarcticus, C. convexus, C. trochus, and C. robustus is tied with paleomagnetic stratigraphy and provides the basis of proposing a new diatom zonation for the latest middle Eocene to early Oligocene (~37.6–33.4 Ma) of the sub-Antarctic South Atlantic. Comparison with previously published diatom occurrence charts suggested this zonation should be applicable throughout the low latitude regions of the world’s oceans. Silicofl agellates belong to the Dictyocha hexacantha and the overlying Corbisema apiculata Zones. The late Eocene succession of silicofl agellate species is dominated by Naviculopsis (20–60%). Naviculopsis constricta and N. foliacea dominate the D. hexacantha Zone, followed by the N. constricta, then N. biapiculata in the C. apiculata Zone. Cold-water Distephanus is most abundant in the latest Eocene along with N. biapiculata. The tops of zonal guide fossils Dictyocha hexacantha and Hannaites quadria (both 36.6 Ma) and Dictyocha spinosa (37.1 Ma) are tied with paleomagnetic stratigraphy.

  3. The spatial segregation patterns of sharks from Western Australia

    PubMed Central

    2016-01-01

    The extent to which sharks segregate by size and sex determines the population structure and the scale at which populations should be managed. We summarized 20 years of fisheries-dependent and independent sampling to define the spatial patterns of size and sexual segregation for sharks in Western Australia. Carcharhinus obscurus and C. plumbeus showed a large-scale (more than 1000 km) latitudinal gradient in size. Large individuals occurred predominantly in the northwest and north whereas smaller individuals occurred predominantly in the southwest and south. Mustelus antarcticus and Furgaleus macki showed strong sexual segregation at very large scales. Females occurred predominantly in the west and southwest whereas the proportion of males in catches substantially increased in the southeast. The populations of other shark species did not show sex and size segregation patterns at very large scales; most species, however, showed varying degrees of segregation when data were analysed at a smaller scale. These findings highlight the importance of matching the scale of observation to the scale of the phenomenon observed. As many shark species are highly mobile, if sampling is opportunistic and constrained both temporally and spatially, the observed segregation patterns may not be representative of those at the population level, leading to inaccurate scientific advice. PMID:27853609

  4. Biogeography of circum-Antarctic springtails.

    PubMed

    McGaughran, Angela; Stevens, Mark I; Holland, Barbara R

    2010-10-01

    We examine the effects of isolation over both ancient and contemporary timescales on evolutionary diversification and speciation patterns of springtail species in circum-Antarctica, with special focus on members of the genus Cryptopygus (Collembola, Isotomidae). We employ phylogenetic analysis of mitochondrial DNA (cox1), and ribosomal DNA (18S and 28S) genes in the programmes MrBayes and RAxML. Our aims are twofold: (1) we evaluate existing taxonomy in light of previous work which found dubious taxonomic classification in several taxa based on cox1 analysis; (2) we evaluate the biogeographic origin of our chosen suite of springtail species based on dispersal/vicariance scenarios, the magnitude of genetic divergence among lineages and the age and accessibility of potential habitat. The dubious taxonomic characterisation of Cryptopygus species highlighted previously is confirmed by our multi-gene phylogenetic analyses. Specifically, according to the current taxonomy, Cryptopygus antarcticus subspecies are not completely monophyletic and neither are Cryptopygus species in general. We show that distribution patterns among species/lineages are both dispersal- and vicariance-driven. Episodes of colonisation appear to have occurred frequently, the routes of which may have followed currents in the Southern Ocean. In several cases, the estimated divergence dates among species correspond well with the timing of terrestrial habitat availability. We conclude that these isotomid springtails have a varied and diverse evolutionary history in the circum-Antarctic that consists of both ancient and recent elements and is reflected in a dynamic contemporary fauna.

  5. Revision of the taxonomy of Polycirrus Grube, 1850 (Annelida: Terebellida: Polycirridae).

    PubMed

    Glasby, Christopher J; Hutchings, Pat

    2014-10-21

    The large polychaete genus Polycirrus (Terebellida: Polycirridae) is revised based on a morphological study of the type material of most of the approximately 74 nominal species; 59 species, including a new species, P. coibensis n.sp., from the Pacific coast of Panama, are accepted as valid. All characters are reanalysed and discussed in the light of recent phylogenetic studies of terebellomorph taxa, and a standard set of characters is developed. Most of the 59 accepted species are redescribed and illustrations provided in order to facilitate future identifications of members of the genus. We designate a neotype for the type species of the genus, Polycirrus medusa Grube, 1850, and a lectotype for P. elisabethae McIntosh, 1915, in order to stabilize the concept and type locality of these taxa. A replacement name is proposed for Polycirrus kerguelensis McIntosh, 1885, which is a secondary junior homonym of Ereutho kergulenesis McIntosh, 1885, viz. Polycirrus macintoshi new name. Two species are newly synonymised: Polycirrus insignis Gravier, 1907 (senior synonym P. antarcticus (Willey, 1902)) and Polycirrus habitats Carrerette & Nogueira, 2013 (senior synonym, P. clavatus (Kinberg, 1867)). In addition, several previously synonymised species are reinstated. All available names in the genus are tabulated with type species and type localities and their taxonomic status is assessed. A key to all valid species is provided. 

  6. A mechanistic stochastic framework for regulating bacterial cell division

    PubMed Central

    Ghusinga, Khem Raj; Vargas-Garcia, Cesar A.; Singh, Abhyudai

    2016-01-01

    How exponentially growing cells maintain size homeostasis is an important fundamental problem. Recent single-cell studies in prokaryotes have uncovered the adder principle, where cells add a fixed size (volume) from birth to division, irrespective of their size at birth. To mechanistically explain the adder principle, we consider a timekeeper protein that begins to get stochastically expressed after cell birth at a rate proportional to the volume. Cell-division time is formulated as the first-passage time for protein copy numbers to hit a fixed threshold. Consistent with data, the model predicts that the noise in division timing increases with size at birth. Intriguingly, our results show that the distribution of the volume added between successive cell-division events is independent of the newborn cell size. This was dramatically seen in experimental studies, where histograms of the added volume corresponding to different newborn sizes collapsed on top of each other. The model provides further insights consistent with experimental observations: the distribution of the added volume when scaled by its mean becomes invariant of the growth rate. In summary, our simple yet elegant model explains key experimental findings and suggests a mechanism for regulating both the mean and fluctuations in cell-division timing for controlling size. PMID:27456660

  7. Non-linear dynamic compensation system

    NASA Technical Reports Server (NTRS)

    Lin, Yu-Hwan (Inventor); Lurie, Boris J. (Inventor)

    1992-01-01

    A non-linear dynamic compensation subsystem is added in the feedback loop of a high precision optical mirror positioning control system to smoothly alter the control system response bandwidth from a relatively wide response bandwidth optimized for speed of control system response to a bandwidth sufficiently narrow to reduce position errors resulting from the quantization noise inherent in the inductosyn used to measure mirror position. The non-linear dynamic compensation system includes a limiter for limiting the error signal within preselected limits, a compensator for modifying the limiter output to achieve the reduced bandwidth response, and an adder for combining the modified error signal with the difference between the limited and unlimited error signals. The adder output is applied to control system motor so that the system response is optimized for accuracy when the error signal is within the preselected limits, optimized for speed of response when the error signal is substantially beyond the preselected limits and smoothly varied therebetween as the error signal approaches the preselected limits.

  8. Detector for flow abnormalities in gaseous diffusion plant compressors

    DOEpatents

    Smith, S.F.; Castleberry, K.N.

    1998-06-16

    A detector detects a flow abnormality in a plant compressor which outputs a motor current signal. The detector includes a demodulator/lowpass filter demodulating and filtering the motor current signal producing a demodulated signal, and first, second, third and fourth bandpass filters connected to the demodulator/lowpass filter, and filtering the demodulated signal in accordance with first, second, third and fourth bandpass frequencies generating first, second, third and fourth filtered signals having first, second, third and fourth amplitudes. The detector also includes first, second, third and fourth amplitude detectors connected to the first, second, third and fourth bandpass filters respectively, and detecting the first, second, third and fourth amplitudes, and first and second adders connected to the first and fourth amplitude detectors and the second and third amplitude detectors respectively, and adding the first and fourth amplitudes and the second and third amplitudes respectively generating first and second added signals. Finally, the detector includes a comparator, connected to the first and second adders, and comparing the first and second added signals and detecting the abnormal condition in the plant compressor when the second added signal exceeds the first added signal by a predetermined value. 6 figs.

  9. Epidemiology of snakebite in Eshowe, KwaZulu-Natal, South Africa.

    PubMed

    Blaylock, Roger

    2004-02-01

    Three hundred and thirty-three patients admitted to Eshowe Hospital with snakebite were analysed. Forty-one were non-envenomed, 282 exhibited painful progressive swelling (PPS), seven showed progressive weakness (PW), and there were three cases of minor envenomations that were unclassifiable. Offending dead venomous snakes included Naja mossambica (Mozambique spitting cobra), Bitis arietans (puff adder), Atractaspis bibronii (stiletto snake), Causus rhombeatus (common night adder) and Dendroaspis polylepis (black mamba). Most bites occurred on the leg in the wet summer months during the first three decades of the patients' lives. The majority of patients used a first-aid measure. The snake was most commonly sighted if the patient was bitten on an upper limb or above the ankle. Severe envenomation was associated with quicker arrival at hospital, and multiple bites occurred more frequently in sleeping patients. Non-envenomation following snakebites was more common in winter, in adult females, and if the patient was bitten proximally on a limb or on a hand. Patients with PPS developed bite site complications (42), compartment syndromes (4), femoral vessel entrapment (1), deep vein thrombosis (1), and respiratory complications (4). Severe swelling was associated with spring and early summer, proximal limb bites and children who were most at risk of necrosis. Fingers and hands were most prone to necrosis and permanent disability. Four patients with PW developed respiratory failure. Antivenom was administered to 12 patients, five of whom developed an acute adverse reaction. There was one death.

  10. Initial results from the unipolar operation of the RHEPP module

    SciTech Connect

    Harjes, H.C.; Penn, K.J.; Reed, K.W.; McClenahan, C.R.; Laderach, G.E.; Wavrik, R.W.; Adcock, J.L.; Butler, M.E.; Mann, G.A.; Pena, G.E.; Weber, G.J.; VanDeValde, D.; Martinez, L.E.; Muirhead, D.; Kiekel, P.D.; Johnson, D.L.; Neau, E.L.

    1992-08-01

    Several potential applications such as medical waste treatment, chemical waste treatment, food treatment, and flue gas cleanup have been identified for high average power electron beam systems. The technology for such a system is being developed in the RHEPP (Repetitive High Energy Pulsed Power) project. The RHEPP module consists of a multistage magnetic pulse compressor driving a linear induction voltage adder with an e-beam diode load. It has been designed to operate continuously, delivering 350 kW of average power to the diode in 60-ns FWHM, 2.5-MV, 2.9-kJ pulses. The module is presently under construction with the first phase scheduled for completion in the summer of 1992. In the first phase, four of ten adder stages are being built so that testing can begin with a I-MV, 160-kW diode with the balance of the power from the compressor diverted to a resistive load. A description of the system and test results from the initial stages of the compressor will be presented.

  11. Initial results from the unipolar operation of the RHEPP module

    SciTech Connect

    Harjes, H.C.; Penn, K.J.; Reed, K.W.; McClenahan, C.R.; Laderach, G.E.; Wavrik, R.W.; Adcock, J.L.; Butler, M.E.; Mann, G.A.; Pena, G.E.; Weber, G.J.; VanDeValde, D.; Martinez, L.E.; Muirhead, D.; Kiekel, P.D.; Johnson, D.L.; Neau, E.L.

    1992-01-01

    Several potential applications such as medical waste treatment, chemical waste treatment, food treatment, and flue gas cleanup have been identified for high average power electron beam systems. The technology for such a system is being developed in the RHEPP (Repetitive High Energy Pulsed Power) project. The RHEPP module consists of a multistage magnetic pulse compressor driving a linear induction voltage adder with an e-beam diode load. It has been designed to operate continuously, delivering 350 kW of average power to the diode in 60-ns FWHM, 2.5-MV, 2.9-kJ pulses. The module is presently under construction with the first phase scheduled for completion in the summer of 1992. In the first phase, four of ten adder stages are being built so that testing can begin with a I-MV, 160-kW diode with the balance of the power from the compressor diverted to a resistive load. A description of the system and test results from the initial stages of the compressor will be presented.

  12. Back-streaming ion beam measurements in a Self Magnetic Insulated (SMP) electron diode

    NASA Astrophysics Data System (ADS)

    Mazarakis, Michael; Johnston, Mark; Kiefer, Mark; Leckbee, Josh; Webb, Timothy; Bennett, Nichelle; Droemer, Darryl; Welch, Dale; Nielsen, Dan; Ziska, Derek; Wilkins, Frank; Advance radiography department Team

    2014-10-01

    A self-magnetic pinch diode (SMP) is presently the electron diode of choice for high energy flash x-ray radiography utilizing pulsed power drivers. The Sandia National Laboratories RITS accelerator is presently fit with an SMP diode that generates very small electron beam spots. RITS is a Self-Magnetically Insulated Transmission Line (MITL) voltage adder that adds the voltage pulse of six 1.3 MV inductively insulated cavities. The diode's anode is made of high Z metal in order to produce copious and energetic flash x-rays for radiographic imaging of high areal density objects. In any high voltage inductive voltage adder (IVA) utilizing MITLs to transmit the power to the diode load, the precise knowledge of the accelerating voltage applied on the anode-cathode (A-K) gap is problematic. This is even more difficult in an SMP diode where the A-K gap is very small (~1 cm) and the diode region very hostile. We are currently measuring the back-streaming ion currents emitted from the anode and propagating through a hollow cathode tip. We then are evaluating the A-K gap voltage by ion time of flight measurements supplemented with filtered Rogowski coils. Sandia is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract No. DE- AC04-94AL850.

  13. Structure of High-Speed Modulo Multiplier Suitable for Repeated Operations

    NASA Astrophysics Data System (ADS)

    Kudou, Tadamichi; Tsunekawa, Yoshitaka; Suzuki, Masayuki

    In this paper, we propose a new modulo multiplier suitable for repeated operations using redundant representations. First, we consider a computation rule for radix-2 modulo multiplications. In radix-2 operation, we show two methods to calculate (2i-1 mod n) from (2i mod n) and decide product digits sequentially from upper side. These methods make it possible to perform (2i-1 mod n) and multiplications simultaneously. Second, we attempt to apply these methods to radix-4 operations which enables us to reduce clock cycles by only shift and sign change. We propose some structures to perform each part efficiently for radix-4 modulo multiplications. The high-speed redundant binary adder/subtractor which we have already proposed is applied to these structures. By using this adder/subtractor, the longest delay path of this modulo multiplier becomes very short. Finally, by using PARTHENON which is a design system for VLSI, this modulo multiplier is designed and evaluated. As a result, we show the speed of this proposed modulo multiplier becomes over 2.5 times as compared with the conventional structures.

  14. Detector for flow abnormalities in gaseous diffusion plant compressors

    DOEpatents

    Smith, Stephen F.; Castleberry, Kim N.

    1998-01-01

    A detector detects a flow abnormality in a plant compressor which outputs a motor current signal. The detector includes a demodulator/lowpass filter demodulating and filtering the motor current signal producing a demodulated signal, and first, second, third and fourth bandpass filters connected to the demodulator/lowpass filter, and filtering the demodulated signal in accordance with first, second, third and fourth bandpass frequencies generating first, second, third and fourth filtered signals having first, second, third and fourth amplitudes. The detector also includes first, second, third and fourth amplitude detectors connected to the first, second, third and fourth bandpass filters respectively, and detecting the first, second, third and fourth amplitudes, and first and second adders connected to the first and fourth amplitude detectors and the second and third amplitude detectors respectively, and adding the first and fourth amplitudes and the second and third amplitudes respectively generating first and second added signals. Finally, the detector includes a comparator, connected to the first and second adders, and comparing the first and second added signals and detecting the abnormal condition in the plant compressor when the second added signal exceeds the first added signal by a predetermined value.

  15. Hardware Implementation of 32-Bit High-Speed Direct Digital Frequency Synthesizer

    PubMed Central

    Ibrahim, Salah Hasan; Ali, Sawal Hamid Md.; Islam, Md. Shabiul

    2014-01-01

    The design and implementation of a high-speed direct digital frequency synthesizer are presented. A modified Brent-Kung parallel adder is combined with pipelining technique to improve the speed of the system. A gated clock technique is proposed to reduce the number of registers in the phase accumulator design. The quarter wave symmetry technique is used to store only one quarter of the sine wave. The ROM lookup table (LUT) is partitioned into three 4-bit sub-ROMs based on angular decomposition technique and trigonometric identity. Exploiting the advantages of sine-cosine symmetrical attributes together with XOR logic gates, one sub-ROM block can be removed from the design. These techniques, compressed the ROM into 368 bits. The ROM compressed ratio is 534.2 : 1, with only two adders, two multipliers, and XOR-gates with high frequency resolution of 0.029 Hz. These techniques make the direct digital frequency synthesizer an attractive candidate for wireless communication applications. PMID:24991635

  16. The quantum realization of Arnold and Fibonacci image scrambling

    NASA Astrophysics Data System (ADS)

    Jiang, Nan; Wu, Wen-Ya; Wang, Luo

    2014-05-01

    The quantum Fourier transform, the quantum wavelet transform, etc., have been shown to be a powerful tool in developing quantum algorithms. However, in classical computing, there is another kind of transforms, image scrambling, which are as useful as Fourier transform, wavelet transform, etc. The main aim of image scrambling, which is generally used as the preprocessing or postprocessing in the confidentiality storage and transmission, and image information hiding, was to transform a meaningful image into a meaningless or disordered image in order to enhance the image security. In classical image processing, Arnold and Fibonacci image scrambling are often used. In order to realize these two image scrambling in quantum computers, this paper proposes the scrambling quantum circuits based on the flexible representation for quantum images. The circuits take advantage of the plain adder and adder modulo to factor the classical transformations into basic unitary operators such as Control-NOT gates and Toffoli gates. Theoretical analysis indicates that the network complexity grows linearly with the size of the number to be operated.

  17. A mechanistic stochastic framework for regulating bacterial cell division.

    PubMed

    Ghusinga, Khem Raj; Vargas-Garcia, Cesar A; Singh, Abhyudai

    2016-07-26

    How exponentially growing cells maintain size homeostasis is an important fundamental problem. Recent single-cell studies in prokaryotes have uncovered the adder principle, where cells add a fixed size (volume) from birth to division, irrespective of their size at birth. To mechanistically explain the adder principle, we consider a timekeeper protein that begins to get stochastically expressed after cell birth at a rate proportional to the volume. Cell-division time is formulated as the first-passage time for protein copy numbers to hit a fixed threshold. Consistent with data, the model predicts that the noise in division timing increases with size at birth. Intriguingly, our results show that the distribution of the volume added between successive cell-division events is independent of the newborn cell size. This was dramatically seen in experimental studies, where histograms of the added volume corresponding to different newborn sizes collapsed on top of each other. The model provides further insights consistent with experimental observations: the distribution of the added volume when scaled by its mean becomes invariant of the growth rate. In summary, our simple yet elegant model explains key experimental findings and suggests a mechanism for regulating both the mean and fluctuations in cell-division timing for controlling size.

  18. Designing reversible arithmetic, logic circuit to implement micro-operation in quantum computation

    NASA Astrophysics Data System (ADS)

    Kalita, Gunajit; Saikia, Navajit

    2016-10-01

    The futuristic computing is desired to be more power full with low-power consumption. That is why quantum computing has been a key area of research for quite some time and is getting more and more attention. Quantum logic being reversible, a significant amount of contributions has been reported on reversible logic in recent times. Reversible circuits are essential parts of quantum computers, and hence their designs are of great importance. In this paper, designs of reversible circuits are proposed using a recently proposed reversible gate for arithmetic and logic operations to implement various micro-operations (simple add and subtract, add with carry, subtract with borrow, transfer, incrementing, decrementing etc., and logic operations like XOR, XNOR, complementing etc.) in a reversible computer like quantum computer. The two new reversible designs proposed here for half adder and full adders are also used in the presented reversible circuits to implement various microoperations. The quantum costs of these designs are comparable. Many of the implemented micro-operations are not seen in previous literatures. The performances of the proposed circuits are compared with existing designs wherever available.

  19. The probabilistic convolution tree: efficient exact Bayesian inference for faster LC-MS/MS protein inference.

    PubMed

    Serang, Oliver

    2014-01-01

    Exact Bayesian inference can sometimes be performed efficiently for special cases where a function has commutative and associative symmetry of its inputs (called "causal independence"). For this reason, it is desirable to exploit such symmetry on big data sets. Here we present a method to exploit a general form of this symmetry on probabilistic adder nodes by transforming those probabilistic adder nodes into a probabilistic convolution tree with which dynamic programming computes exact probabilities. A substantial speedup is demonstrated using an illustration example that can arise when identifying splice forms with bottom-up mass spectrometry-based proteomics. On this example, even state-of-the-art exact inference algorithms require a runtime more than exponential in the number of splice forms considered. By using the probabilistic convolution tree, we reduce the runtime to O(k log(k)2) and the space to O(k log(k)) where k is the number of variables joined by an additive or cardinal operator. This approach, which can also be used with junction tree inference, is applicable to graphs with arbitrary dependency on counting variables or cardinalities and can be used on diverse problems and fields like forward error correcting codes, elemental decomposition, and spectral demixing. The approach also trivially generalizes to multiple dimensions.

  20. Scalability of carbon-nanotube-based thin film transistors for flexible electronic devices manufactured using an all roll-to-roll gravure printing system

    PubMed Central

    Koo, Hyunmo; Lee, Wookyu; Choi, Younchang; Sun, Junfeng; Bak, Jina; Noh, Jinsoo; Subramanian, Vivek; Azuma, Yasuo; Majima, Yutaka; Cho, Gyoujin

    2015-01-01

    To demonstrate that roll-to-roll (R2R) gravure printing is a suitable advanced manufacturing method for flexible thin film transistor (TFT)-based electronic circuits, three different nanomaterial-based inks (silver nanoparticles, BaTiO3 nanoparticles and single-walled carbon nanotubes (SWNTs)) were selected and optimized to enable the realization of fully printed SWNT-based TFTs (SWNT-TFTs) on 150-m-long rolls of 0.25-m-wide poly(ethylene terephthalate) (PET). SWNT-TFTs with 5 different channel lengths, namely, 30, 80, 130, 180, and 230 μm, were fabricated using a printing speed of 8 m/min. These SWNT-TFTs were characterized, and the obtained electrical parameters were related to major mechanical factors such as web tension, registration accuracy, impression roll pressure and printing speed to determine whether these mechanical factors were the sources of the observed device-to-device variations. By utilizing the electrical parameters from the SWNT-TFTs, a Monte Carlo simulation for a 1-bit adder circuit, as a reference, was conducted to demonstrate that functional circuits with reasonable complexity can indeed be manufactured using R2R gravure printing. The simulation results suggest that circuits with complexity, similar to the full adder circuit, can be printed with a 76% circuit yield if threshold voltage (Vth) variations of less than 30% can be maintained. PMID:26411839

  1. Dual Brushless Resolver Rate Sensor

    NASA Technical Reports Server (NTRS)

    Howard, David E. (Inventor)

    1997-01-01

    A resolver rate sensor is disclosed in which dual brushless resolvers are mechanically coupled to the same output shaft. Diverse inputs are provided to each resolver by providing the first resolver with a DC input and the second resolver with an AC sinusoidal input. A trigonometric identity in which the sum of the squares of the sin and cosine components equal one is used to advantage in providing a sensor of increased accuracy. The first resolver may have a fixed or variable DC input to permit dynamic adjustment of resolver sensitivity thus permitting a wide range of coverage. In one embodiment of the invention the outputs of the first resolver are directly inputted into two separate multipliers and the outputs of the second resolver are inputted into the two separate multipliers, after being demodulated in a pair of demodulator circuits. The multiplied signals are then added in an adder circuit to provide a directional sensitive output. In another embodiment the outputs from the first resolver is modulated in separate modulator circuits and the output from the modulator circuits are used to excite the second resolver. The outputs from the second resolver are demodulated in separate demodulator circuit and added in an adder circuit to provide a direction sensitive rate output.

  2. Automatic oscillator frequency control system

    NASA Technical Reports Server (NTRS)

    Smith, S. F. (Inventor)

    1985-01-01

    A frequency control system makes an initial correction of the frequency of its own timing circuit after comparison against a frequency of known accuracy and then sequentially checks and corrects the frequencies of several voltage controlled local oscillator circuits. The timing circuit initiates the machine cycles of a central processing unit which applies a frequency index to an input register in a modulo-sum frequency divider stage and enables a multiplexer to clock an accumulator register in the divider stage with a cyclical signal derived from the oscillator circuit being checked. Upon expiration of the interval, the processing unit compares the remainder held as the contents of the accumulator against a stored zero error constant and applies an appropriate correction word to a correction stage to shift the frequency of the oscillator being checked. A signal from the accumulator register may be used to drive a phase plane ROM and, with periodic shifts in the applied frequency index, to provide frequency shift keying of the resultant output signal. Interposition of a phase adder between the accumulator register and phase plane ROM permits phase shift keying of the output signal by periodic variation in the value of a phase index applied to one input of the phase adder.

  3. Complementary code and digital filtering for detection of weak VHF radar signals from the mesoscale

    NASA Astrophysics Data System (ADS)

    Schmidt, G.; Ruster, R.; Czechowsky, P.

    1983-12-01

    The SOUSY-VHF-Radar operates at a frequency of 53.5 MHz in a valley in the Harz mountains, Germany, 90 km from Hanover. The radar controller, which is programmed by a 16-bit computer holds 1024 program steps in core and controls, via 8 channels, the whole radar system: in particular the master oscillator, the transmitter, the transmit-receive-switch, the receiver, the analog to digital converter, and the hardware adder. The high-sensitivity receiver has a dynamic range of 70 dB and a video bandwidth of 1 MHz. Phase coding schemes are applied, in particular for investigations at mesospheric heights, in order to carry out measurements with the maximum duty cycle and the maximum height resolution. The computer takes the data from the adder to store it in magnetic tape or disc. The radar controller is programmed by the computer using simple FORTRAN IV statements. After the program has been loaded and the computer has started the radar controller, it runs automatically, stopping at the program end. In case of errors or failures occurring during the radar operation, the radar controller is shut off caused either by a safety circuit or by a power failure circuit or by a parity check system.

  4. Ka-Band Wide-Bandgap Solid-State Power Amplifier: Prototype Combiner Spurious Mode Suppression and Power Constraints

    NASA Technical Reports Server (NTRS)

    Khan, P.; Epp, L.

    2006-01-01

    Results of prototype hardware activities related to a 120-W, 32-GHz (Ka-band) solid-state power amplifier (SSPA) architecture study are presented. Spurious mode suppression and the power-handling capability of a prototype 24-way radial combiner and a prototype 2-way septum binary combiner were investigated. Experimental data indicate that a commercial absorptive filter, designed to pass the circular TE01 mode, effectively suppressed the higher-order modes generated by a narrowband, flower-petal-type mode transducer. However, the same filter was not effective in suppressing higher-order modes generated by the broadband Marie mode transducer that is used in the prototype waveguide radial combiner. Should greater filtering be required by a particular SSPA application, a broadband mode filter that can suppress specifically those higher-order modes that are generated by the Marie transducer will need to be developed. A back-to-back configuration of the prototype radial combiner was tested with drive power up to approximately 50 W. No anomalous behavior was observed. Power measurements of the septum combiner indicate that up to 10-W radio frequency (RF) can be dissipated in the integrated resistive element before a permanent performance shift is observed. Thus, a given adder (a single-stage, 2-way combiner) can safely combine two 20-W sources, and the adder will not be damaged in the event of a source failure. This result is used to calculate the maximum source power that can be safely combined as a function of the number of sources combined and the number of source failures allowed in a multi-stage combiner. The analysis shows that SSPA power >140 W can be generated by power combining 16 sources producing 10 W each. In this configuration, up to three sources could fail with the guarantee that the combiner would not be damaged. Finally, a modified prototype septum combiner design was verified. The improved design reduced the assembly time from over 2 hours to about 15

  5. Large-area formation of self-aligned crystalline domains of organic semiconductors on transistor channels using CONNECT.

    PubMed

    Park, Steve; Giri, Gaurav; Shaw, Leo; Pitner, Gregory; Ha, Jewook; Koo, Ja Hoon; Gu, Xiaodan; Park, Joonsuk; Lee, Tae Hoon; Nam, Ji Hyun; Hong, Yongtaek; Bao, Zhenan

    2015-05-05

    The electronic properties of solution-processable small-molecule organic semiconductors (OSCs) have rapidly improved in recent years, rendering them highly promising for various low-cost large-area electronic applications. However, practical applications of organic electronics require patterned and precisely registered OSC films within the transistor channel region with uniform electrical properties over a large area, a task that remains a significant challenge. Here, we present a technique termed "controlled OSC nucleation and extension for circuits" (CONNECT), which uses differential surface energy and solution shearing to simultaneously generate patterned and precisely registered OSC thin films within the channel region and with aligned crystalline domains, resulting in low device-to-device variability. We have fabricated transistor density as high as 840 dpi, with a yield of 99%. We have successfully built various logic gates and a 2-bit half-adder circuit, demonstrating the practical applicability of our technique for large-scale circuit fabrication.

  6. Low cost high throughput pipelined architecture of 2-D 8 × 8 integer transforms for H.264/AVC

    NASA Astrophysics Data System (ADS)

    Sharma, Meeturani; Durga Tiwari, Honey; Cho, Yong Beom

    2013-08-01

    In this article, we present the implementation of high throughput two-dimensional (2-D) 8 × 8 forward and inverse integer DCT transform for H.264. Using matrix decomposition and matrix operation, such as the Kronecker product and direct sum, the forward and inverse integer transform can be represented using simple addition operations. The dual clocked pipelined structure of the proposed implementation uses non-floating point adders and does not require any transpose memory. Hardware synthesis shows that the maximum operating frequency of the proposed pipelined architecture is 1.31 GHz, which achieves 21.05 Gpixels/s throughput rate with the hardware cost of 42932 gates. High throughput and low hardware makes the proposed design useful for real time H.264/AVC high definition processing.

  7. Implementation of 14 bits floating point numbers of calculating units for neural network hardware development

    NASA Astrophysics Data System (ADS)

    Zoev, I. V.; Beresnev, A. P.; Mytsko, E. A.; Malchukov, A. N.

    2017-02-01

    An important aspect of modern automation is machine learning. Specifically, neural networks are used for environment analysis and decision making based on available data. This article covers the most frequently performed operations on floating-point numbers in artificial neural networks. Also, a selection of the optimum value of the bit to 14-bit floating-point numbers for implementation on FPGAs was submitted based on the modern architecture of integrated circuits. The description of the floating-point multiplication (multiplier) algorithm was presented. In addition, features of the addition (adder) and subtraction (subtractor) operations were described in the article. Furthermore, operations for such variety of neural networks as a convolution network - mathematical comparison of a floating point (‘less than’ and ‘greater than or equal’) were presented. In conclusion, the comparison with calculating units of Atlera was made.

  8. Highly efficient hybrid energy generator: coupled organic photovoltaic device and randomly oriented electrospun poly(vinylidene fluoride) nanofiber.

    PubMed

    Park, Boongik; Lee, Kihwan; Park, Jongjin; Kim, Jongmin; Kim, Ohyun

    2013-03-01

    A hybrid architecture consisting of an inverted organic photovoltaic device and a randomly-oriented electrospun PVDF piezoelectric device was fabricated as a highly-efficient energy generator. It uses the inverted photovoltaic device with coupled electrospun PVDF nanofibers as tandem structure to convert solar and mechanical vibrations energy to electricity simultaneously or individually. The power conversion efficiency of the photovoltaic device was also significantly improved up to 4.72% by optimized processes such as intrinsic ZnO, MoO3 and active layer. A simple electrospinning method with the two electrode technique was adopted to achieve a high voltage of - 300 mV in PVDF piezoelectric fibers. Highly-efficient HEG using voltage adder circuit provides the conceptual possibility of realizing multi-functional energy generator whenever and wherever various energy sources are available.

  9. Note: A pulsed laser ion source for linear induction accelerators

    SciTech Connect

    Zhang, H.; Zhang, K.; Shen, Y.; Jiang, X.; Dong, P.; Liu, Y.; Wang, Y.; Chen, D.; Pan, H.; Wang, W.; Jiang, W.; Long, J.; Xia, L.; Shi, J.; Zhang, L.; Deng, J.

    2015-01-15

    We have developed a high-current laser ion source for induction accelerators. A copper target was irradiated by a frequency-quadrupled Nd:YAG laser (266 nm) with relatively low intensities of 10{sup 8} W/cm{sup 2}. The laser-produced plasma supplied a large number of Cu{sup +} ions (∼10{sup 12} ions/pulse) during several microseconds. Emission spectra of the plasma were observed and the calculated electron temperature was about 1 eV. An induction voltage adder extracted high-current ion beams over 0.5 A/cm{sup 2} from a plasma-prefilled gap. The normalized beam emittance measured by a pepper-pot method was smaller than 1 π mm mrad.

  10. Magnetically Insulated Electron Flow in the 2.5-MeV URSA Minor LTD

    NASA Astrophysics Data System (ADS)

    Leckbee, Joshua; Pointon, Timothy; Oliver, Bryan

    2011-10-01

    The Linear Transformer Driver (LTD) is a compact type of inductive voltage adder (IVA) with the primary energy storage inside the IVA cells. The 2.5-MV URSA Minor LTD is designed to drive a magnetically insulated transmission line (MITL) and electron beam diode load. Because of its compact architecture, control of the electron power flow in the MITL (e.g. early time loss currents) is paramount to efficient operation. Results from experimental testing and 2-D particle-in-cell (PIC) simulations of magnetic insulation and electron loss in the MITL will be presented. The simulations compute the local energy deposition of electrons hitting the anode structures, including the dielectric insulator for each cavity. On URSA Minor, currents are measured in the cathode and anode conductors at four axial locations along the MITL. Measured currents and inferred voltages will be compared to the simulations.

  11. Simultaneous all-optical digital comparator and dual-directional half-subtractor for two-input 40 Gbit/s DPSK signals employing SOAs

    NASA Astrophysics Data System (ADS)

    Zhang, Yin; Lei, Lei; Dong, Jianji; Zhang, Xinliang

    2012-02-01

    A module of simultaneous implementation of all-optical digital comparator and dual-directional half-subtractor is proposed. Proof-of-concept experiment is performed at 40 Gbit/s employing the four-wave mixing and cross gain modulation in three parallel semiconductor optical amplifiers. All output results with over 10 dB extinction ratios, clear and wide open eye diagrams, are obtained without using assistant/holding light beam. All-optical half-adder can also be obtained by adjusting the phase shifter of delay interferometer in the proposed module because of its inherent reconfigurability and flexibility. The module would be a promising digital logic elementary circuit in all-optical networks and computing systems.

  12. Exploring hurdles to transfer : student experiences of applying knowledge across disciplines

    NASA Astrophysics Data System (ADS)

    Lappalainen, Jouni; Rosqvist, Juho

    2015-04-01

    This paper explores the ways students perceive the transfer of learned knowledge to new situations - often a surprisingly difficult prospect. The novel aspect compared to the traditional transfer studies is that the learning phase is not a part of the experiment itself. The intention was only to activate acquired knowledge relevant to the transfer target using a short primer immediately prior to the situation where the knowledge was to be applied. Eight volunteer students from either mathematics or computer science curricula were given a task of designing an adder circuit using logic gates: a new context in which to apply knowledge of binary arithmetic and Boolean algebra. The results of a phenomenographic classification of the views presented by the students in their post-experiment interviews are reported. The degree to which the students were conscious of the acquired knowledge they employed and how they applied it in a new context emerged as the differentiating factors.

  13. New architecture of fast parallel multiplier using fast parallel counter with FPA (first partial product addition)

    NASA Astrophysics Data System (ADS)

    Lee, Mike M.; Cho, Byung Lok

    2001-11-01

    In this paper, we proposed a new First Partial product Addition (FPA) architecture with new compressor (or parallel counter) to CSA tree built in the process of adding partial product for improving speed in the fast parallel multiplier to improve the speed of calculating partial product by about 20% compared with existing parallel counter using full Adder. The new circuit reduces the CLA bit finding final sum by N/2 using the novel FPA architecture. A 5.14ns of multiplication speed of the 16X16 multiplier is obtained using 0.25um CMOS technology. The architecture of the multiplier is easily opted for pipeline design and demonstrates high speed performance.

  14. Recent Advances in Photonic Devices for Optical Computing and the Role of Nonlinear Optics-Part II

    NASA Technical Reports Server (NTRS)

    Abdeldayem, Hossin; Frazier, Donald O.; Witherow, William K.; Banks, Curtis E.; Paley, Mark S.

    2007-01-01

    The twentieth century has been the era of semiconductor materials and electronic technology while this millennium is expected to be the age of photonic materials and all-optical technology. Optical technology has led to countless optical devices that have become indispensable in our daily lives in storage area networks, parallel processing, optical switches, all-optical data networks, holographic storage devices, and biometric devices at airports. This chapters intends to bring some awareness to the state-of-the-art of optical technologies, which have potential for optical computing and demonstrate the role of nonlinear optics in many of these components. Our intent, in this Chapter, is to present an overview of the current status of optical computing, and a brief evaluation of the recent advances and performance of the following key components necessary to build an optical computing system: all-optical logic gates, adders, optical processors, optical storage, holographic storage, optical interconnects, spatial light modulators and optical materials.

  15. Implementation of a pulse coupled neural network in FPGA.

    PubMed

    Waldemark, J; Millberg, M; Lindblad, T; Waldemark, K; Becanovic, V

    2000-06-01

    The Pulse Coupled neural network, PCNN, is a biologically inspired neural net and it can be used in various image analysis applications, e.g. time-critical applications in the field of image pre-processing like segmentation, filtering, etc. a VHDL implementation of the PCNN targeting FPGA was undertaken and the results presented here. The implementation contains many interesting features. By pipelining the PCNN structure a very high throughput of 55 million neuron iterations per second could be achieved. By making the coefficients re-configurable during operation, a complete recognition system could be implemented on one, or maybe two, chip(s). Reconsidering the ranges and resolutions of the constants may save a lot of hardware, since the higher resolution requires larger multipliers, adders, memories etc.

  16. Do aposematism and Batesian mimicry require bright colours? A test, using European viper markings.

    PubMed Central

    Wüster, Wolfgang; Allum, Christopher S. E.; Bjargardóttir, I. Birta; Bailey, Kimberley L.; Dawson, Karen J.; Guenioui, Jamel; Lewis, John; McGurk, Joe; Moore, Alix G.; Niskanen, Martti; Pollard, Christopher P.

    2004-01-01

    Predator avoidance of noxious prey, aposematism and defensive mimicry are normally associated with bright, contrasting patterns and colours. However, noxious prey may be unable to evolve conspicuous coloration because of other selective constraints, such as the need to be inconspicuous to their own prey or to specialist predators. Many venomous snakes, particularly most vipers, display patterns that are apparently cryptic, but nevertheless highly characteristic, and appear to be mimicked by other, non-venomous snakes. However, predator avoidance of viper patterns has never been demonstrated experimentally. Here, the analysis of 813 avian attacks on 12,636 Plasticine snake models in the field shows that models bearing the characteristic zigzag band of the adder (Vipera berus) are attacked significantly less frequently than plain models. This suggests that predator avoidance of inconspicuously but characteristically patterned noxious prey is possible. Our findings emphasize the importance of mimicry in the ecological and morphological diversification of advanced snakes. PMID:15590601

  17. Do aposematism and Batesian mimicry require bright colours? A test, using European viper markings.

    PubMed

    Wüster, Wolfgang; Allum, Christopher S E; Bjargardóttir, I Birta; Bailey, Kimberley L; Dawson, Karen J; Guenioui, Jamel; Lewis, John; McGurk, Joe; Moore, Alix G; Niskanen, Martti; Pollard, Christopher P

    2004-12-07

    Predator avoidance of noxious prey, aposematism and defensive mimicry are normally associated with bright, contrasting patterns and colours. However, noxious prey may be unable to evolve conspicuous coloration because of other selective constraints, such as the need to be inconspicuous to their own prey or to specialist predators. Many venomous snakes, particularly most vipers, display patterns that are apparently cryptic, but nevertheless highly characteristic, and appear to be mimicked by other, non-venomous snakes. However, predator avoidance of viper patterns has never been demonstrated experimentally. Here, the analysis of 813 avian attacks on 12,636 Plasticine snake models in the field shows that models bearing the characteristic zigzag band of the adder (Vipera berus) are attacked significantly less frequently than plain models. This suggests that predator avoidance of inconspicuously but characteristically patterned noxious prey is possible. Our findings emphasize the importance of mimicry in the ecological and morphological diversification of advanced snakes.

  18. Preliminary results of Linear Induction Accelerator LIA-200

    NASA Astrophysics Data System (ADS)

    Sharma, Archana; Senthil, K.; Praveen Kumar, D. D.; Mitra, S.; Sharma, V.; Patel, A.; Sharma, D. K.; Rehim, R.; Kolge, T. S.; Saroj, P. C.; Acharya, S.; Amitava, Roy; Rakhee, M.; Nagesh, K. V.; Chakravarthy, D. P.

    2010-05-01

    Repetitive Pulsed Power Technology is being developed keeping in mind the potential applications of this technology in material modifications, disinfections of water, timber, and food pasteurization etc. BARC has indigenously developed a Linear Induction Accelerator (LIA-200) rated for 200 kV, 4 kA, 100 ns, 10 Hz. The satisfactory performance of all the sub-systems including solid state power modulator, amorphous core based pulsed transformers, magnetic switches, water capacitors, water pulse- forming line, induction adder and field-emission diode have been demonstrated. This paper presents some design details and operational results of this pulsed power system. It also highlights the need for further research and development to build reliable and economic high-average power systems for industrial applications.

  19. Note: All-digital pulse-shrinking time-to-digital converter with improved dynamic range.

    PubMed

    Chen, Chun-Chi; Hwang, Chorng-Sii; Lin, Yi; Chen, Guan-Hong

    2016-04-01

    This paper proposes an all-digital pulse-shrinking time-to-digital converter (TDC) using the offset error cancellation circuitry to widen its dynamic range and to improve its accuracy. Although the TDC based on a pulse-shrinking mechanism can achieve a sub-gate resolution without circuit complexity, it possesses an undesired offset error that results in a nonzero lower bound appeared in its dynamic range and then affects its accuracy. The proposed cancellation circuitry for eliminating the offset error consists of a time adder with a delay line and a time subtractor with an identical delay line. The experimental TDC is implemented on Xilinx field programmable gate arrays and it also functions successfully in improving its dynamic range.

  20. Active Detection of Shielded Special Nuclear Material in the Presence of Variable High Backgrounds Using a Mixed Photon-Neutron Source

    NASA Astrophysics Data System (ADS)

    Martin, Philip N.; Clemett, Ceri D.; Hill, Cassie; O'Malley, John; Campbell, Ben

    This paper describes and compares two approaches to the analysis of active interrogation data containing high photon backgrounds associated with mixed photon-neutron source flash active interrogation. Results from liquid scintillation detectors (EJ301/EJ309) fielded at the Naval Research Laboratory (NRL), in collaboration with the Atomic Weapons Establishment (AWE), using the NRL Mercury Inductive Voltage Adder (IVA) operating in both a photon and mixed photon-neutron mode at a Depleted Uranium (DU) target are presented. The standard approach applying a Figure of Merit (FOM) consisting of background sigma above background is compared with an approach looking to fit only the time-decaying photon signal with standard delayed photon emission from ∼10-MeV end-point-energy Bremsstrahlung photofission of DU. Examples where each approach does well and less well are presented together with a discussion of the relative limitations of both approaches to the type of mixed photon-neutron flash active interrogation being considered.

  1. Application of a single-instruction computer to dilation and erosion of gray-valued images

    NASA Astrophysics Data System (ADS)

    Laplante, Phillip A.

    1992-11-01

    In this paper, the single instruction architecture is used to construct circuitry to perform dilation and erosion of gray valued images, where the gray values are discrete but limited only by the number of bits chosen for the binary encoding. In addition, methods for minimizing the number of cells needed, using basic digital techniques, are discussed. While others have constructed architectures for gray valued dilation and erosion, these are based on non- homogeneous circuits, and typically use Umbra transformations to handle the gray values, rather than binary encoding. Finally, it is shown that the half-adder elements used in the single instruction architecture can easily be replaced with uniform multiplexer cells in deference to the McCulloch-Pitts model of the neuron. This analogy between the single instruction architecture and the neuronal construction of the brain is intentional.

  2. A bit-serial VLSI array processing chip for image processing

    NASA Technical Reports Server (NTRS)

    Heaton, Robert; Blevins, Donald; Davis, Edward

    1990-01-01

    An array processing chip integrating 128 bit-serial processing elements (PEs) on a single die is discussed. Each PE has a 16-function logic unit, a single-bit adder, a 32-b variable-length shift register, and 1 kb of local RAM. Logic in each PE provides the capability to mask PEs individually. A modified grid interconnection scheme allows each PE to communicate with each of its eight nearest neighbors. A 32-b bus is used to transfer data to and from the array in a single cycle. Instruction execution is pipelined, enabling all instructions to be executed in a single cycle. The 1-micron CMOS design contains over 1.1 x 10 to the 6th transistors on an 11.0 x 11.7-mm die.

  3. VLSI processors for signal detection in SETI

    NASA Technical Reports Server (NTRS)

    Duluk, J. F.; Linscott, I. R.; Peterson, A. M.; Burr, J.; Ekroot, B.; Twicken, J.

    1989-01-01

    The objective of the Search for Extraterrestrial Intelligence (SETI) is to locate an artificially created signal coming from a distant star. This is done in two steps: (1) spectral analysis of an incoming radio frequency band, and (2) pattern detection for narrow-band signals. Both steps are computationally expensive and require the development of specially designed computer architectures. To reduce the size and cost of the SETI signal detection machine, two custom VLSI chips are under development. The first chip, the SETI DSP Engine, is used in the spectrum analyzer and is specially designed to compute Discrete Fourier Transforms (DFTs). It is a high-speed arithmetic processor that has two adders, one multiplier-accumulator, and three four-port memories. The second chip is a new type of Content-Addressable Memory. It is the heart of an associative processor that is used for pattern detection. Both chips incorporate many innovative circuits and architectural features.

  4. Implementation of Arithmetic Operations With Time-Free Spiking Neural P Systems.

    PubMed

    Liu, Xiangrong; Li, Ziming; Liu, Juan; Liu, Logan; Zeng, Xiangxiang

    2015-09-01

    Spiking neural P systems (SN P systems) are a class of distributed parallel computing devices inspired from the way neurons communicate by means of spikes. In most applications of SN P systems, synchronization plays a key role which means the execution of a rule is completed in exactly one time unit (one step). However, such synchronization does not coincide with the biological fact: in biological nervous systems, the execution times of spiking rules cannot be known exactly. Therefore, a "realistic" system called time-free SN P systems were proposed, where the precise execution time of rules is removed. In this paper, we consider building arithmetical operation systems based on time-free SN P systems. Specifically, adder, subtracter, multiplier, and divider are constructed by using time-free SN P systems. The obtained systems always produce the same computation result independently from the execution time of the rules.

  5. VLSI processors for signal detection in SETI.

    PubMed

    Duluk, J F; Linscott, I R; Peterson, A M; Burr, J; Ekroot, B; Twicken, J

    1989-01-01

    The objective of the Search for Extraterrestrial Intelligence (SETI) is to locate an artificially created signal coming from a distant star. This is done in two steps: (1) spectral analysis of an incoming radio frequency band, and (2) pattern detection for narrow-band signals. Both steps are computationally expensive and require the development of specially designed computer architectures. To reduce the size and cost of the SETI signal detection machine, two custom VLSI chips are under development. The first chip, the SETI DSP Engine, is used in the spectrum analyzer and is specially designed to compute Discrete Fourier Transforms (DFTs). It is a high-speed arithmetic processor that has two adders, one multiplier-accumulator, and three four-port memories. The second chip is a new type of Content-Addressable Memory. It is the heart of an associative processor that is used for pattern detection. Both chips incorporate many innovative circuits and architectural features.

  6. A HIGH CURRENT, HIGH VOLTAGE SOLID-STATE PULSE GENERATOR FOR THE NIF PLASMA ELECTRODE POCKELS CELL

    SciTech Connect

    Arnold, P A; Barbosa, F; Cook, E G; Hickman, B C; Akana, G L; Brooksby, C A

    2007-07-27

    A high current, high voltage, all solid-state pulse modulator has been developed for use in the Plasma Electrode Pockels Cell (PEPC) subsystem in the National Ignition Facility. The MOSFET-switched pulse generator, designed to be a more capable plug-in replacement for the thyratron-switched units currently deployed in NIF, offers unprecedented capabilities including burst-mode operation, pulse width agility and a steady-state pulse repetition frequency exceeding 1 Hz. Capable of delivering requisite fast risetime, 17 kV flattop pulses into a 6 {Omega} load, the pulser employs a modular architecture characteristic of the inductive adder technology, pioneered at LLNL for use in acceleration applications, which keeps primary voltages low (and well within the capabilities of existing FET technology), reduces fabrication costs and is amenable to rapid assembly and quick field repairs.

  7. Electrical addressing of confined quantum systems for quasiclassical computation and finite state logic machines.

    PubMed

    Remacle, F; Heath, J R; Levine, R D

    2005-04-19

    Conduction spectroscopy measures the current I through a nanosystem as a function of the voltage V between two electrodes. The differential conductance, dI/dV, has peaks that can be assigned to resonance conditions with different electronic levels of the system. Between these increments, the current has roughly constant plateaus. We discuss how measurements of the current vs. voltage can be used to perform Boolean operations and hence construct finite state logic machines and combinational circuits. The inputs to the device are the source-drain voltage, including its sign, and a gate voltage applied in a manner analogous to optical Stark spectroscopy. As simple examples, we describe a two-state set-reset machine (a machine whose output depends on the input and also on its present state) and a full adder circuit (a circuit that requires three inputs and provides two outputs).

  8. Signal processor chip implementation

    NASA Astrophysics Data System (ADS)

    Beraud, J. P.

    1985-03-01

    Advances in technology have made it now possible to integrate very large microprocessors on a single chip. Two basic design methodologies are available, including gate array and custom design. The present paper is concerned with a signal processor (SP) chip which is based on a mixture of the two technologies. Involved is a high-density chip which requires little manual effort for its production. The SP is characterized by separate instruction and data memories. The SP consists of three main parts which operate simultaneously. These parts include the sequencer, the address generator, and the computer portion. The chip comprises a library of predesigned building blocks. Attention is given to a signal processor block diagram, the basic TTL gate, a two-input master-slave latch, the physical library, aspects of logical design, the multiplier basic cell and adder line organization, and physical design methodology.

  9. An efficient FPGA architecture for integer ƞth root computation

    NASA Astrophysics Data System (ADS)

    Rangel-Valdez, Nelson; Barron-Zambrano, Jose Hugo; Torres-Huitzil, Cesar; Torres-Jimenez, Jose

    2015-10-01

    In embedded computing, it is common to find applications such as signal processing, image processing, computer graphics or data compression that might benefit from hardware implementation for the computation of integer roots of order ?. However, the scientific literature lacks architectural designs that implement such operations for different values of N, using a low amount of resources. This article presents a parameterisable field programmable gate array (FPGA) architecture for an efficient Nth root calculator that uses only adders/subtractors and ? location memory elements. The architecture was tested for different values of ?, using 64-bit number representation. The results show a consumption up to 10% of the logical resources of a Xilinx XC6SLX45-CSG324C device, depending on the value of N. The hardware implementation improved the performance of its corresponding software implementations in one order of magnitude. The architecture performance varies from several thousands to seven millions of root operations per second.

  10. Evolutionary Based Techniques for Fault Tolerant Field Programmable Gate Arrays

    NASA Technical Reports Server (NTRS)

    Larchev, Gregory V.; Lohn, Jason D.

    2006-01-01

    The use of SRAM-based Field Programmable Gate Arrays (FPGAs) is becoming more and more prevalent in space applications. Commercial-grade FPGAs are potentially susceptible to permanently debilitating Single-Event Latchups (SELs). Repair methods based on Evolutionary Algorithms may be applied to FPGA circuits to enable successful fault recovery. This paper presents the experimental results of applying such methods to repair four commonly used circuits (quadrature decoder, 3-by-3-bit multiplier, 3-by-3-bit adder, 440-7 decoder) into which a number of simulated faults have been introduced. The results suggest that evolutionary repair techniques can improve the process of fault recovery when used instead of or as a supplement to Triple Modular Redundancy (TMR), which is currently the predominant method for mitigating FPGA faults.

  11. Multi-bit binary decoder based on Belousov-Zhabotinsky reaction

    NASA Astrophysics Data System (ADS)

    Sun, Ming-Zhu; Zhao, Xin

    2013-03-01

    It is known that Belousov-Zhabotinsky (BZ) reaction can be applied to chemical computation, e.g., image processing, computational geometry, logical computation, and so on. In the field of logical computation, some basic logic gates and basic combinational logic circuits, such as adder, counter, memory cell, have already been implemented in simulations or in chemical experiments. In this paper, we focus on another important combinational logic circuit, binary decoder. Integrating AND gate and NOT gate, we first design and implement a one-bit binary decoder through numerical simulation. Then we show that one-bit decoder can be extended to design two-bit, three-bit, or even higher bit binary decoders by a cascade method. The simulation results demonstrate the effectiveness of these devices. The chemical realization of decoders can guide the construction of more sophisticated functions based on BZ reaction; meanwhile, the cascade method can facilitate the design of other combinational logic circuits.

  12. Integrated logic circuits using single-atom transistors.

    PubMed

    Mol, J A; Verduijn, J; Levine, R D; Remacle, F; Rogge, S

    2011-08-23

    Scaling down the size of computing circuits is about to reach the limitations imposed by the discrete atomic structure of matter. Reducing the power requirements and thereby dissipation of integrated circuits is also essential. New paradigms are needed to sustain the rate of progress that society has become used to. Single-atom transistors, SATs, cascaded in a circuit are proposed as a promising route that is compatible with existing technology. We demonstrate the use of quantum degrees of freedom to perform logic operations in a complementary-metal-oxide-semiconductor device. Each SAT performs multilevel logic by electrically addressing the electronic states of a dopant atom. A single electron transistor decodes the physical multivalued output into the conventional binary output. A robust scalable circuit of two concatenated full adders is reported, where by utilizing charge and quantum degrees of freedom, the functionality of the transistor is pushed far beyond that of a simple switch.

  13. Design and implementation of an efficient single layer five input majority voter gate in quantum-dot cellular automata.

    PubMed

    Bahar, Ali Newaz; Waheed, Sajjad

    2016-01-01

    The fundamental logical element of a quantum-dot cellular automata (QCA) circuit is majority voter gate (MV). The efficiency of a QCA circuit is depends on the efficiency of the MV. This paper presents an efficient single layer five-input majority voter gate (MV5). The structure of proposed MV5 is very simple and easy to implement in any logical circuit. This proposed MV5 reduce number of cells and use conventional QCA cells. However, using MV5 a multilayer 1-bit full-adder (FA) is designed. The functional accuracy of the proposed MV5 and FA are confirmed by QCADesigner a well-known QCA layout design and verification tools. Furthermore, the power dissipation of proposed circuits are estimated, which shows that those circuits dissipate extremely small amount of energy and suitable for reversible computing. The simulation outcomes demonstrate the superiority of the proposed circuit.

  14. An Approach for Self-Timed Synchronous CMOS Circuit Design

    NASA Technical Reports Server (NTRS)

    Walker, Alvernon; Lala, Parag K.

    2001-01-01

    In this letter we present a timing and control strategy that can be used to realize synchronous systems with a level of performance that approaches that of asynchronous circuits or systems. This approach is based upon a single-phase synchronous circuit/system architecture with a variable period clock. The handshaking signals required for asynchronous self-timed circuits are not needed. Dynamic power supply current monitoring is used to generate the timing information, that is comparable to the completion signal found in self-timed circuits; this timing information is used to modi@ the circuit clock period. This letter is concluded with an example of the proposed approach applied to a static CMOS ripple-carry adder.

  15. Multi-Agent Methods for the Configuration of Random Nanocomputers

    NASA Technical Reports Server (NTRS)

    Lawson, John W.

    2004-01-01

    As computational devices continue to shrink, the cost of manufacturing such devices is expected to grow exponentially. One alternative to the costly, detailed design and assembly of conventional computers is to place the nano-electronic components randomly on a chip. The price for such a trivial assembly process is that the resulting chip would not be programmable by conventional means. In this work, we show that such random nanocomputers can be adaptively programmed using multi-agent methods. This is accomplished through the optimization of an associated high dimensional error function. By representing each of the independent variables as a reinforcement learning agent, we are able to achieve convergence must faster than with other methods, including simulated annealing. Standard combinational logic circuits such as adders and multipliers are implemented in a straightforward manner. In addition, we show that the intrinsic flexibility of these adaptive methods allows the random computers to be reconfigured easily, making them reusable. Recovery from faults is also demonstrated.

  16. All-optical arithmetic unit with the help of terahertz-optical-asymmetric-demultiplexer-based tree architecture

    NASA Astrophysics Data System (ADS)

    Gayen, Dilip Kumar; Nath Roy, Jitendra

    2008-03-01

    An all-optical arithmetic unit with the help of terahertz-optical-asymmetric-demultiplexer (TOAD)-based tree architecture is proposed. We describe the all-optical arithmetic unit by using a set of all-optical multiplexer, all-optical full-adder, and optical switch. The all-optical arithmetic unit can be used to perform a fast central processor unit using optical hardware components. We have tried to exploit the advantages of both optical tree architecture and TOAD-based switch to design an integrated all-optical circuit that can perform binary addition, addition with carry, subtract with borrow, subtract (2's complement), double, increment, decrement, and transfer operations.

  17. [Bites of venomous snakes in Switzerland].

    PubMed

    Plate, Andreas; Kupferschmidt, Hugo; Schneemann, Markus

    2016-06-08

    Although snake bites are rare in Europe, there are a constant number of snake bites in Switzerland. There are two domestic venomous snakes in Switzerland: the aspic viper (Vipera aspis) and the common European adder (Vipera berus). Bites from venomous snakes are caused either by one of the two domestic venomous snakes or by an exotic venomous snake kept in a terrarium. Snake- bites can cause both a local and/or a systemic envenoming. Potentially fatal systemic complications are related to disturbances of the hemostatic- and cardiovascular system as well as the central or peripheral nervous system. Beside a symptomatic therapy the administration of antivenom is the only causal therapy to neutralize the venomous toxins.

  18. Vertical blind phase search for low-complexity carrier phase recovery of offset-QAM Nyquist WDM transmission

    NASA Astrophysics Data System (ADS)

    Lu, Jianing; Fu, Songnian; Tang, Haoyuan; Xiang, Meng; Tang, Ming; Liu, Deming

    2017-01-01

    Low complexity carrier phase recovery (CPR) scheme based on vertical blind phase search (V-BPS) for M-ary offset quadrature amplitude modulation (OQAM) is proposed and numerically verified. After investigating the constellations of both even and odd samples with respect to the phase noise, we identify that the CPR can be realized by measuring the verticality of constellation with respect to different test phase angles. Then measurement without multiplication in the complex plane is found with low complexity. Furthermore, a two-stage configuration is put forward to further reduce the computational complexity (CC). Compared with our recently proposed modified blind phase search (M-BPS) algorithm, the proposed algorithm shows comparable tolerance of phase noise, but reduces the CC by a factor of 3.81 (or 3.05) in the form of multipliers (or adders), taking the CPR of 16-OQAM into account.

  19. System Radiographic Characterization of 7MV Self-Magnetic Pinch Diode on RITS-6

    NASA Astrophysics Data System (ADS)

    Webb, Tim J.; Johnston, Mark D.; Oliver, Bryan V.

    2011-10-01

    The 7 MV, 160 kA induction voltage adder RITS-6 is used as a test bed for research and development of sub-100 ns flash x-ray radiography of which the self-magnetic pinch (SMP) diode is an example. The x-ray source properties such as dose, source spatial distribution, and energy spectrum couple with the imaging detector sensitivity and blur to form the radiologic system performance which is also highly dependent on the imaging geometry. The system performance of some SMP diode configurations will be presented. Sandia is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  20. New elements of the RSFQ logic family

    SciTech Connect

    Mukhanov, O.A. ); Polonsky, S.V.; Semenov, V.K. )

    1991-03-01

    Elements of the RSFQ logic/memory family have already reached operation frequency as large as 100 GHz and have a good chance to enter a sub-terahertz clock frequency range. Their parameter margins are as wide as {plus minus}25 + 30%, even one bit gates posses flip-flop features, and can be naturally self-times. This paper reports on RSFQ elements (OR-AND, NOR-AND), half adder, mutiplexer, demultiplexer, and shift registers are presented. Operation of these gates have been studied with the help of the Personal Superconductor Circuit Analyzer (PSCAN) within the standard RSJ model of Josephson junctions. Parameter margins and other performance limits of the new elements are thoroughly investigated.

  1. Performing four basic arithmetic operations with spiking neural P systems.

    PubMed

    Zeng, Xiangxiang; Song, Tao; Zhang, Xingyi; Pan, Linqiang

    2012-12-01

    Recently, Gutiérrez-Naranjo and Leporati considered performing basic arithmetic operations on a new class of bio-inspired computing devices-spiking neural P systems (for short, SN P systems). However, the binary encoding mechanism used in their research looks like the encoding approach in electronic circuits, instead of the style of spiking neurons (in usual SN P systems, information is encoded as the time interval between spikes). In this work, four SN P systems are constructed as adder, subtracter, multiplier, and divider, respectively. In these systems, a number is inputted to the system as the interval of time elapsed between two spikes received by input neuron, the result of a computation is the time between the moments when the output neuron spikes.

  2. Multiphonon scattering of light with direct transitions between optical modes in uniaxial single crystals and its application to an all-optical computing

    NASA Astrophysics Data System (ADS)

    Shcherbakov, Alexandre S.; Tepichin Rodriguez, Eduardo; Aguirre Lopez, Arturo

    2004-11-01

    A specific case of a multi-phonon non-collinear light scattering in optically uniaxial media is presented. Compared to our previous studies, an innovation lies in the fact that now we consider passing just the quartet of incident light beams through a single crystal that is perturbed by the triplet of coherent acoustic waves. The exact and closed analytical model for describing this strongly nonlinear phenomenon is developed. In fact, specially designed regime of a four-order light scattering whit direct coupling of all the light modes, when transitions of four input light beams into four output light modes are allowed and electronically controlled, is examined. The feasibility of applying such an effect to an all-optical computing and performing an all-optical adder is analyzed.

  3. Power optimization in logic isomers

    NASA Technical Reports Server (NTRS)

    Panwar, Ramesh; Rennels, David; Alkalaj, Leon

    1993-01-01

    Logic isomers are labeled, 2-isomorphic graphs that implement the same logic function. Logic isomers may have significantly different power requirements even though they have the same number of transistors in the implementation. The power requirements of the isomers depend on the transition activity of the input signals. The power requirements of isomorphic graph isomers of n-input NAND and NOR gates are shown. Choosing the less power-consuming isomer instead of the others can yield significant power savings. Experimental results on a ripple-carry adder are presented to show that the implementation using the least power-consuming isomers requires approximately 10 percent less power than the implementation using the most power-consuming isomers. Simulations of other random logic designs also confirm that designs using less power-consuming isomers can reduce the logic power demand by approximately 10 percent as compared to designs using more power-consuming isomers.

  4. Virtual gap dielectric wall accelerator

    DOEpatents

    Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

    2013-11-05

    A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

  5. Note: A pulsed laser ion source for linear induction accelerators

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Zhang, K.; Shen, Y.; Jiang, X.; Dong, P.; Liu, Y.; Wang, Y.; Chen, D.; Pan, H.; Wang, W.; Jiang, W.; Long, J.; Xia, L.; Shi, J.; Zhang, L.; Deng, J.

    2015-01-01

    We have developed a high-current laser ion source for induction accelerators. A copper target was irradiated by a frequency-quadrupled Nd:YAG laser (266 nm) with relatively low intensities of 108 W/cm2. The laser-produced plasma supplied a large number of Cu+ ions (˜1012 ions/pulse) during several microseconds. Emission spectra of the plasma were observed and the calculated electron temperature was about 1 eV. An induction voltage adder extracted high-current ion beams over 0.5 A/cm2 from a plasma-prefilled gap. The normalized beam emittance measured by a pepper-pot method was smaller than 1 π mm mrad.

  6. Multi-Agent Methods for the Configuration of Random Nanocomputers

    NASA Astrophysics Data System (ADS)

    Lawson, John

    2004-03-01

    As computational devices continue to shrink, the cost of manufacturing such devices is expected to grow exponentially. One alternative to the costly, detailed design and assembly of conventional computers is to place the nano-electronic components randomly on a chip. The price for such a trivial assembly process is that the resulting chip would not be programmable by conventional means. In this work, we show that such random nanocomputers can be adaptively programmed using multi-agent methods. This is accomplished through the optimization of an associated high dimensional error function. By representing each of the independent variables as a reinforcement learning agent, we are able to achieve convergence must faster than with other methods, including simulated annealing. Standard combinational logic circuits such as adders and multipliers are implemented in a straightforward manner. In addition, we show that the intrinsic flexibility of these adaptive methods allows the random computers to be reconfigured easily, making them reusable. Recovery from faults is also demonstrated.

  7. Conceptual design for a linear-transformer driver (LTD)-based refurbishment and upgrade of the Saturn accelerator pulse-power system.

    SciTech Connect

    Mazarakis, Michael Gerrassimos; Struve, Kenneth William

    2006-09-01

    The purpose of this work was to develop a conceptual design for the Saturn accelerator using the modular Liner-Transformer Driver (LTD) technology to identify risks and to focus development and research for this new technology. We present a reference design for a Saturn class driver based on a number of linear inductive voltage adders connected in parallel. This design is very similar to a design reported five years ago [1]. However, with the design reported here we use 1-MA, 100-kV LTD cavities as building blocks. These cavities have already been built and are currently in operation at the HCEI in Tomsk, Russia [2]. Therefore, this new design integrates already-proven individual components into a full system design.

  8. Hardware-efficient low-power 2-bit ternary ALU design in CNTFET technology

    NASA Astrophysics Data System (ADS)

    Lata Murotiya, Sneh; Gupta, Anu

    2016-05-01

    This paper proposes a hardware-efficient low-power 2-bit ternary arithmetic logic unit (TALU) design in carbon nano tube field effect transistor technology. The proposed TALU architecture combines adder-subtractor and Ex-OR cell in one cell, thereby reducing the number of transistors by 71% in comparison with other TALU architecture. Further, the proposed TALU is optimised at transistor level with a new pass-transistor logic-based encoder circuit. Hspice simulation results show that the proposed design attains great advantages in power and power-delay product for addition and multiplication operations than reported designs. For instant, at power supply of 0.9 V, the proposed TALU consumes on average 91% and 95% less energy compared to their existing counterparts, for addition and multiplication operations, respectively.

  9. Treatment of Solar Generation in Electric Utility Resource Planning (Presentation)

    SciTech Connect

    Cory, K.; Sterling, J.; Taylor, M.; McLaren, J.

    2014-01-01

    Today's utility planners have a different market and economic context than their predecessors, including planning for the growth of renewable energy. Through interviews and a questionnaire, the authors gathered information on utility supply planning and how solar is represented. Utilities were asked to provide their resource planning process details, key assumptions (e.g. whether DG is represented as supply or negative load), modeling methodology (e.g. type of risk analytics and candidate portfolio development), capacity expansion and production simulation model software, and solar project representation (project size, capacity value and integration cost adder). This presentation aims to begin the exchange of information between utilities, regulators and other stakeholders by capturing utility-provided information about: 1) how various utilities approach long-range resource planning; 2) methods and tools utilities use to conduct resource planning; and, 3) how solar technologies are considered in the resource planning process.

  10. Adiabatic quantum-flux-parametron cell library adopting minimalist design

    SciTech Connect

    Takeuchi, Naoki; Yamanashi, Yuki; Yoshikawa, Nobuyuki

    2015-05-07

    We herein build an adiabatic quantum-flux-parametron (AQFP) cell library adopting minimalist design and a symmetric layout. In the proposed minimalist design, every logic cell is designed by arraying four types of building block cells: buffer, NOT, constant, and branch cells. Therefore, minimalist design enables us to effectively build and customize an AQFP cell library. The symmetric layout reduces unwanted parasitic magnetic coupling and ensures a large mutual inductance in an output transformer, which enables very long wiring between logic cells. We design and fabricate several logic circuits using the minimal AQFP cell library so as to test logic cells in the library. Moreover, we experimentally investigate the maximum wiring length between logic cells. Finally, we present an experimental demonstration of an 8-bit carry look-ahead adder designed using the minimal AQFP cell library and demonstrate that the proposed cell library is sufficiently robust to realize large-scale digital circuits.

  11. Development of ferrite logic devices for an arithmetic processor

    NASA Technical Reports Server (NTRS)

    Heckler, C. H., Jr.

    1972-01-01

    A number of fundamentally ultra-reliable, all-magnetic logic circuits are developed using as a basis a single element ferrite structure wired as a logic delay element. By making minor additions or changes to the basic wiring pattern of the delay element other logic functions such as OR, AND, NEGATION, MAJORITY, EXCLUSIVE-OR, and FAN-OUT are developed. These logic functions are then used in the design of a full-adder, a set/reset flip-flop, and an edge detector. As a demonstration of the utility of all the developed devices, an 8-bit, all-magnetic, logic arithmetic unit capable of controlled addition, subtraction, and multiplication is designed. A new basic ferrite logic element and associated complementary logic scheme with the potential of improved performance is also described. Finally, an improved batch process for fabricating joint-free power drive and logic interconnect conductors for this basic class of all-magnetic logic is presented.

  12. Analog to digital converter for two-dimensional radiant energy array computers

    NASA Technical Reports Server (NTRS)

    Shaefer, D. H.; Strong, J. P., III (Inventor)

    1977-01-01

    The analog to digital converter stage derives a bit array of digital radiant energy signals representative of the amplitudes of an input radiant energy analog signal array and derives an output radiant energy analog signal array to serve as an input to succeeding stages. The converter stage includes a digital radiant energy array device which contains radiant energy array positions so that the analog array is less than a predetermined threshold level. A scaling device amplifies the radiant signal levels of the input array and the digital array so that the radiant energy signal level carried by the digital array corresponds to the threshold level. An adder device adds the signals of the scaled input and digital arrays at corresponding array positions to form the output analog array.

  13. Culturable bacteria in subglacial sediments and ice from two Southern Hemisphere glaciers.

    PubMed

    Foght, J; Aislabie, J; Turner, S; Brown, C E; Ryburn, J; Saul, D J; Lawson, W

    2004-05-01

    Viable prokaryotes have been detected in basal sediments beneath the few Northern Hemisphere glaciers that have been sampled for microbial communities. However, parallel studies have not previously been conducted in the Southern Hemisphere, and subglacial environments in general are a new and underexplored niche for microbes. Unfrozen subglacial sediments and overlying glacier ice samples collected aseptically from the Fox Glacier and Franz Josef Glacier in the Southern Alps of New Zealand now have been shown to harbor viable microbial populations. Total direct counts of 2-7 x 10(6) cells g(-1) dry weight sediment were observed, whereas culturable aerobic heterotrophs ranged from 6-9 x 10(5) colony-forming units g(-1) dry weight. Viable counts in the glacier ice typically were 3-4 orders of magnitude smaller than in sediment. Nitrate-reducing and ferric iron-reducing bacteria were detected in sediment samples from both glaciers, but were few or below detection limits in the ice samples. Nitrogen-fixing bacteria were detected only in the Fox Glacier sediment. Restriction fragment analysis of 16S rDNA amplified from 37 pure cultures of aerobic heterotrophs capable of growth at 4 degrees C yielded 23 distinct groups, of which 11 were identified as beta-Proteobacteria. 16S rDNA sequences from representatives of these 11 groups were analyzed phylogenetically and shown to cluster with bacteria such as Polaromonas vacuolata and Rhodoferax antarcticus, or with clones obtained from permanently cold environments. Chemical analysis of sediment and ice samples revealed a dilute environment for microbial life. Nevertheless, both the sediment samples and one ice sample demonstrated substantial aerobic mineralization of 14C-acetate at 8 degrees C, indicating that sufficient nutrients and viable psychrotolerant microbes were present to support metabolism. Unfrozen subglacial sediments may represent a significant global reservoir of biological activity with the potential to

  14. Fish muscle: the exceptional case of Notothenioids.

    PubMed

    Fernández, Daniel A; Calvo, Jorge

    2009-03-01

    Fish skeletal muscle is an excellent model for studying muscle structure and function, since it has a very well-structured arrangement with different fiber types segregated in the axial and pectoral fin muscles. The morphological and physiological characteristics of the different muscle fiber types have been studied in several teleost species. In fish muscle, fiber number and size varies with the species considered, limiting fish maximum final length due to constraints in metabolites and oxygen diffusion. In this work, we analyze some special characteristics of the skeletal muscle of the suborder Notothenioidei. They experienced an impressive radiation inside Antarctic waters, a stable and cold environment that could account for some of their special characteristics. The number of muscle fibers is very low, 12,700-164,000, in comparison to 550,000-1,200,000 in Salmo salar of similar sizes. The size of the fibers is very large, reaching 600 microm in diameter, while for example Salmo salar of similar sizes have fibers of 220 microm maximum diameter. Evolutionary adjustment in cell cycle length for working at low temperature has been shown in Harpagifer antarcticus (111 h at 0 degrees C), when compared to the closely related sub-Antarctic species Harpagifer bispinis (150 h at 5 degrees C). Maximum muscle fiber number decreases towards the more derived notothenioids, a trend that is more related to phylogeny than to geographical distribution (and hence water temperature), with values as low as 3,600 in Harpagifer bispinis. Mitochondria volume density in slow muscles of notothenioids is very high (reaching 0.56) and since maximal rates of substrate oxidation by mitochondria is not enhanced, at least in demersal notothenioids, volume density is the only means of overcoming thermal constraints on oxidative capacity. In brief, some characteristics of the muscles of notothenioids have an apparent phylogenetic component while others seem to be adaptations to low temperature.

  15. Occurrence of Legacy and New Persistent Organic Pollutants in Avian Tissues from King George Island, Antarctica.

    PubMed

    Kim, Jun-Tae; Son, Min-Hui; Kang, Jung-Ho; Kim, Jeong-Hoon; Jung, Jin-Woo; Chang, Yoon-Seok

    2015-11-17

    Legacy and new persistent organic pollutants (POPs), including polychlorinated naphthalenes (PCNs), Dechlorane Plus (DPs) and related compounds (Dechloranes), hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs), were analyzed in avian tissue samples from King George Island, Antarctica. The avian species consisted of the Gentoo penguin (Pygoscelis papua), the Adelie penguin (Pygoscelis adeliae), the South polar skua (Stercorarius maccormicki), and the Brown skua (Stercorarius antarcticus). HBCDs were detected in all samples and ranged from 1.67-713 pg/g-lipid. In the penguin samples, the concentrations of PCNs ranged from 0.69-2.07 ng/g-lipid, whereas those in the skua samples ranged from 7.41-175 ng/g-lipid. The levels of Dechloranes ranged from 0.60-1.30 ng/g-lipid in the penguin samples and from 6.57-47.4 ng/g-lipid in the skua samples. The concentrations and congener distributions of OCPs and PCBs were similar to the results of previous reports. The three new POPs were detected in all samples, and this study was one of the first reports on the occurrence of these pollutants in the Antarctic biota. Because Antarctica is one of the most pristine places on Earth, the detection of new POPs in the Antarctic birds, especially penguins, is direct evidence of the long-range transport of pollutants. Furthermore, the concentration ratios of the penguin to the skua samples (BMFs-p) were greater than 1 in most legacy and new POPs, and the BMFs-p values of the new POPs were comparable to those of some OCPs, suggesting a possibility of biomagnification. Despite the small sample size, the results of this study identified POP contamination of the Antarctic avian species and long-range transport and biomagnification of HBCDs, Dechloranes, and PCNs.

  16. Population Dynamics and Parasite Load of a Foraminifer on Its Antarctic Scallop Host with Their Carbonate Biomass Contributions

    PubMed Central

    Pérez-Huerta, Alberto; Bowser, Samuel S.

    2015-01-01

    We studied the population dynamics and parasite load of the foraminifer Cibicides antarcticus on its host the Antarctic scallop Adamussium colbecki from three localities differing by sea ice cover within western McMurdo Sound, Ross Sea, Antarctica: Explorers Cove, Bay of Sails and Herbertson Glacier. We also estimated CaCO3 biomass and annual production for both species. Cibicides populations varied by locality, valve type, and depth. Explorers Cove with multiannual sea ice had larger populations than the two annual sea ice localities, likely related to differences in nutrients. Populations were higher on Adamussium top valves, a surface that is elevated above the sediment. Depth did not affect Cibicides distributions except at Bay of Sails. Cibicides parasite load (the number of complete boreholes in Adamussium valves) varied by locality between 2% and 50%. For most localities the parasite load was < 20%, contrary to a previous report that ~50% of Cibicides were parasitic. The highest and lowest parasite load occurred at annual sea ice localities, suggesting that sea ice condition is not important. Rather, the number of adults that are parasitic could account for these differences. Cibicides bioerosion traces were categorized into four ontogenetic stages, ranging from newly attached recruits to parasitic adults. These traces provide an excellent proxy for population structure, revealing that Explorers Cove had a younger population than Bay of Sails. Both species are important producers of CaCO3. Cibicides CaCO3 biomass averaged 47-73 kg ha-1 and Adamussium averaged 4987-6806 kg ha-1 by locality. Annual production rates were much higher. Moreover, Cibicides represents 1.0-2.3% of the total host-parasite CaCO3 biomass. Despite living in the coldest waters on Earth, these species can contribute a substantial amount of CaCO3 to the Ross Sea and need to be incorporated into food webs, ecosystem models, and carbonate budgets for Antarctica. PMID:26186724

  17. Soil invertebrate community change over fuel-contaminated sites on a subantarctic island: An ecological field-based line of evidence for site risk assessment.

    PubMed

    Wasley, Jane; Mooney, Thomas J; King, Catherine K

    2016-04-01

    A number of fuel spills, of both recent and historic origins, have occurred on World Heritage-listed subantarctic Macquarie Island. Sites contaminated by mainly diesel fuels are undergoing remediation by the Australian Antarctic Division. The risks posed by these sites are being managed using a "weight of evidence" approach, for which this study provides a preliminary line of evidence for the ecological assessment component of this site management decision framework. This knowledge is pertinent, given the absence of environmental guidelines for fuel contaminants in subantarctic ecosystems. We provide a field-based, site-specific ecological risk assessment for soil invertebrate communities across the fuel spill sites, before the commencement of in situ remediation activities. Springtails (Collembola) were the most abundant taxa. Springtail community patterns showed only limited correlations with the level of fuel contamination at the soil surface, even when elevated levels occurred in the substratum layers. Of the environmental variables measured, community patterns were most strongly correlated with vegetation cover. We identify a suite of 6 species that contribute most to the community dynamics across these sites. A subset of these we propose as useful candidates for future development of single-species toxicity tests: Folsomotoma punctata, Cryptopygus caecus, Cryptopygus antarcticus and Parisotoma insularis. Findings from this study advance our understanding of soil invertebrate community dynamics within these contaminated sites, directly contributing to the improved management and restoration of the sites. Not only does this study provide an important line of evidence for the island's ecological risk assessment for fuel contaminants, it also enhances our understanding of the potential impact of fuels at other subantarctic islands.

  18. Ripple Clock Schemes for Quantum-dot Cellular Automata Circuits

    NASA Astrophysics Data System (ADS)

    Purohit, Prafull

    Quantum-dot cellular automata (QCA) is an emerging technology for building digital circuits at nano-scale. It is considered as an alternative to widely used complementary metal oxide semiconductor (CMOS) technology because of its key features, which include low power operation, high density and high operating frequency. Unlike conventional logic circuits in which information is transferred by electrical current, QCA operates with the help of coulomb interaction between two adjacent QCA cells. A QCA cell is a set of four quantum-dots that are placed near the corners of a square. Due to the fact that clocking provides power and control of data flow in QCA, it is considered to be the backbone of QCA operation. This thesis presents the design and simulation of a ripple clock scheme and an enhanced ripple clock scheme for QCA circuits. In the past, different clock schemes were proposed and studied which were focused on data flow in particular direction or reducing delay. This proposed thesis will study the design and simulation of new clock schemes which are more realistic for implementation, give a freedom to propagate logic in all directions, suitable for both combinational and sequential circuits and has potential to support testing and reconfiguration up to some extent. A variety of digital circuits including a 2--to--1 multiplexer, a 1--bit memory, an RS latch, a full adder, a 4--bit adder and a 2--to--4 decoder are implemented and simulated using these clock schemes. A 2--to--4 decoder is used to demonstrate the testing capabilities of these clock schemes. All QCA layouts are drawn and simulated in QCADesigner.

  19. Performance analysis of pseudo 4-phase dual-rail asynchronous protocol

    NASA Astrophysics Data System (ADS)

    Santhi, M.; Sarangan, Siddharth; Murali, K.; Lakshminarayanan, G.

    2012-08-01

    This article presents the performance analysis of novel pseudo 4-phase dual-rail protocol with self-reset and multiple-reset logic for high speed asynchronous applications. The self-reset logic eliminates the need for separate empty phase and hence reduces the number of transitions at the input and the output. The multiple-reset logic reduces the reset phase and hence increases the throughput. The performance of the pseudo 4-phase dual-rail protocol is compared with the existing 4-phase dual-rail protocol by implementing 8-bit and 16-bit asynchronously pipelined carry look ahead adders (CLA) in 0.35 µm technology. The time period decreases up to 32.58% and 35.93% respectively, the reset phase reduces up to 66.39% and 76.18%, respectively, and the operating frequency increases up to 48.4% and 56.2%, respectively, for 8- and 16-bit CLA adders with the pseudo 4-phase dual-rail protocol compared to the conventional 4-phase dual-rail protocol at the cost of increase in area of 8.8% and 3.3%, respectively. The delay-power product in ns-mW of the 8- and 16-bit CLAs is reduced at the maximum of 11.29% and 23.74%, respectively, with the pseudo 4-phase dual-rail protocol compared to the conventional 4-phase dual-rail protocol. The pseudo 4-phase dual-rail protocol is suitable for interfacing with synchronous environments.

  20. Snake bite in Nigeria.

    PubMed

    Habib, A G; Gebi, U I; Onyemelukwe, G C

    2001-09-01

    Four families of venomous snakes are found in Nigeria--Viperidae, Elapidae, Colubridae and Actraspididae but three species carpet viper (Echis ocellatus), black-necked spitting cobra (Naja nigricollis) and puff adder (Bitis arietans), belonging to the first two families, are the most important snakes associated with envenoming in Nigeria. The incidence of bites has been reported as 497 per 100,000 population per year with a 12 percent natural mortality, with Echis ocellatus accounting for at least 66 percent in certain foci. Bites occur more often while victims were farming, herding or walking although the spitting cobra may bite victims who roll upon it in their sleep. Carpet viper venom contains a prothrombin activating procoagulant, haemorrhagin and cytolytic fractions which cause haemorrhage, incoagulable blood, shock and local reactions/ necrosis. The spitting cobra bite manifests with local tissue reaction and occassionally with bleeding from the site of bite, but no classic neurotoxic feature has been observed except following Egyptian cobra (N. haje) bites. Cardiotoxicity and renal failure may occassionally occur following bites by the carpet viper and the puff adder. In the laboratory, haematological and other features are noted and immunodiagnosis has a role in species identification. Immobilisation of the bitten limb is probably the single most important first aid measure. Antivenom should be used cautiously when indicated. As only 8.5 percent of snake bite victims attend hospitals in Nigeria, health education should be the main preventive measure, mean-while, the study of immunisation of occupationally predisposed individuals in endemic areas should be intensified. A new Fab fragment antivenom specific to Nigerian Echis ocellatus was investigated clinically, just as the local herbs-Aristolochia spp, Guiera spp and Schummaniophyton spp are investigated experimentally.

  1. Design of a 5-MA 100-ns linear-transformer-driver accelerator for wire array Z-pinch experiments

    NASA Astrophysics Data System (ADS)

    Zhou, Lin; Li, Zhenghong; Wang, Zhen; Liang, Chuan; Li, Mingjia; Qi, Jianmin; Chu, Yanyun

    2016-03-01

    The linear-transformer-driver (LTD) is a recently developed pulsed-power technology that shows great promise for a number of applications. These include a Z -pinch-driven fission-fusion-hybrid reactor that is being developed by the Chinese Academy of Engineering Physics. In support of the reactor development effort, we are planning to build an LTD-based accelerator that is optimized for driving wire-array Z -pinch loads. The accelerator comprises six modules in parallel, each of which has eight series 0.8-MA LTD cavities in a voltage-adder configuration. Vacuum transmission lines are used from the interior of the adder to the central vacuum chamber where the load is placed. Thus the traditional stack-flashover problem is eliminated. The machine is 3.2 m tall and 12 m in outer diameter including supports. A prototype cavity was built and tested for more than 6000 shots intermittently at a repetition rate of 0.1 Hz. A novel trigger, in which only one input trigger pulse is needed by utilizing an internal trigger brick, was developed and successfully verified in these shots. A full circuit modeling was conducted for the accelerator. The simulation result shows that a current pulse rising to 5.2 MA in 91 ns (10%-90%) can be delivered to the wire-array load, which is 1.5 cm in height, 1.2 cm in initial radius, and 1 mg in mass. The maximum implosion velocity of the load is 32 cm /μ s when compressed to 0.1 of the initial radius. The maximum kinetic energy is 78 kJ, which is 11.7% of the electric energy stored in the capacitors. This accelerator is supposed to enable a radiation energy efficiency of 20%-30%, providing a high efficient facility for research on the fast Z pinch and technologies for repetition-rate-operated accelerators.

  2. Issues and methods in incorporating environmental externalities into the integrated resource planning process

    SciTech Connect

    Fang, J.M.; Galen, P.S.

    1994-11-01

    This report is a review of current practices and policies in considering environmental externalities in the integrated resource planning and performance based regulation (IRP/PBR) process. The following issues are presented and examined: What are the pros and cons of treating environmental externalities in the IRP process? How are potential future environmental regulations being treated? Are externalities being qualitatively or quantitatively considered, or monetized? Are offsets being allowed? How are externality policies being coordinated among different levels and branches of governments? Should environmental externalities be considered in dispatching a utility`s existing resources? What are the procedures for addressing uncertainty in incorporating environmental externalities into IRP? How are externalities valued? What are other approaches to addressing environmental externalities. This report describes seven major approaches for addressing environmental externalities in the IRP process: qualitative treatment, weighting and ranking, cost of control, damage function, percentage adders, monetization by emission, and multiattribute trade-off analysis. The discussion includes a taxonomy of the full range of alternative methods for addressing environmental externalities, a summary of state PUC actions, the role of state laws, the debate on environmental adders, and the choice of methodologies. In addition, this report characterizes the interests of stakeholders such as the electric industry, fuel suppliers, energy consumers, governmental agencies, public interest groups, consultants, and others. It appears that the views, positions, and interests of these stakeholders are affected by their perceptions of the potential impacts on their economic interests or the viability of their position on environmental policy, by the societal perspective they take, and by the orientation of the analysts toward market competition and their respective accumulated expertise.

  3. Square-wave anodic-stripping voltammetric determination of Cd, Pb, and Cu in a hydrofluoric acid solution of siliceous spicules of marine sponges (from the Ligurian Sea, Italy, and the Ross Sea, Antarctica).

    PubMed

    Truzzi, C; Annibaldi, A; Illuminati, S; Bassotti, E; Scarponi, G

    2008-09-01

    Square-wave anodic-stripping voltammetry (SWASV) was set up and optimized for simultaneous determination of cadmium, lead, and copper in siliceous spicules of marine sponges, directly in the hydrofluoric acid solution (approximately 0.55 mol L(-1) HF, pH approximately 1.9). A thin mercury-film electrode (TMFE) plated on to an HF-resistant epoxy-impregnated graphite rotating-disc support was used. The optimum experimental conditions, evaluated also in terms of the signal-to-noise ratio, were as follows: deposition potential -1100 mV vs. Ag/AgCl, KCl 3 mol L(-1), deposition time 3-10 min, electrode rotation 3000 rpm, SW scan from -1100 mV to +100 mV, SW pulse amplitude 25 mV, frequency 100 Hz, DeltaE(step) 8 mV, t(step) 100 ms, t(wait) 60 ms, t(delay) 2 ms, t(meas) 3 ms. Under these conditions the metal peak potentials were Cd -654 +/- 1 mV, Pb -458 +/- 1 mV, Cu -198 +/- 1 mV. The electrochemical behaviour was reversible for Pb, quasi-reversible for Cd, and kinetically controlled (possibly following chemical reaction) for Cu. The linearity of the response with concentration was verified up to approximately 4 microg L(-1) for Cd and Pb and approximately 20 microg L(-1) for Cu. The detection limits were 5.8 ng L(-1), 3.6 ng L(-1), and 4.3 ng L(-1) for Cd, Pb, and Cu, respectively, with t(d) = 5 min. The method was applied for determination of the metals in spicules of two specimens of marine sponges (Demosponges) from the Portofino natural reserve (Ligurian Sea, Italy, Petrosia ficiformis) and Terra Nova Bay (Ross Sea, Antarctica, Sphaerotylus antarcticus). The metal contents varied from tens of ng g(-1) to approximately 1 microg g(-1), depending on the metal considered and with significant differences between the two sponge species.

  4. Intestinal spirochaetes (genus Brachyspira) colonise wild birds in the southern Atlantic region and Antarctica

    PubMed Central

    Jansson, Désirée S.; Mushtaq, Memoona; Johansson, Karl-Erik; Bonnedahl, Jonas; Waldenström, Jonas; Andersson, Dan I.; Broman, Tina; Berg, Charlotte; Olsen, Björn

    2015-01-01

    Introduction The genus Brachyspira contains well-known enteric pathogens of veterinary significance, suggested agents of colonic disease in humans, and one potentially zoonotic agent. There are recent studies showing that Brachyspira are more widespread in the wildlife community than previously thought. There are no records of this genus in wildlife from the southern Atlantic region and Antarctica. Our aim was therefore, to determine whether intestinal spirochaetes of genus Brachyspira colonise marine and coastal birds in this region. Method Faecal samples were collected from marine and coastal birds in the southern Atlantic region, including sub-Antarctic islands and Antarctica, in 2002, 2009, and 2012, with the aim to isolate and characterise zoonotic agents. In total, 205 samples from 11 bird species were selectively cultured for intestinal spirochaetes of genus Brachyspira. To identify isolates to species level, they were subjected to phenotyping, species-specific polymerase chain reactions, sequencing of partial 16S rRNA, NADH oxidase (nox), and tlyA genes, and phylogenetic analysis. Antimicrobial susceptibility tests were performed. Results Fourteen unique strains were obtained from 10 birds of three species: four snowy sheathbills (Chionis albus), three kelp geese (Chloephaga hybrida subsp. malvinarum), and three brown skua (Stercorarius antarcticus subsp. lonnbergi) sampled on the Falkland Islands, Tierra del Fuego in Argentina, South Georgia, South Shetland Islands, and the Antarctic Peninsula. Five Brachyspira strains were closely related to potentially enteropathogenic Brachyspira sp. of chickens: B. intermedia (n=2, from snowy sheathbills), and B. alvinipulli (n=3, from a kelp goose and two snowy sheathbills). Three strains from kelp geese were most similar to the presumed non-pathogenic species ‘B. pulli’ and B. murdochii, whereas the remaining six strains could not be attributed to currently known species. No isolates related to human strains were

  5. Area- and energy-efficient CORDIC accelerators in deep sub-micron CMOS technologies

    NASA Astrophysics Data System (ADS)

    Vishnoi, U.; Noll, T. G.

    2012-09-01

    The COordinate Rotate DIgital Computer (CORDIC) algorithm is a well known versatile approach and is widely applied in today's SoCs for especially but not restricted to digital communications. Dedicated CORDIC blocks can be implemented in deep sub-micron CMOS technologies at very low area and energy costs and are attractive to be used as hardware accelerators for Application Specific Instruction Processors (ASIPs). Thereby, overcoming the well known energy vs. flexibility conflict. Optimizing Global Navigation Satellite System (GNSS) receivers to reduce the hardware complexity is an important research topic at present. In such receivers CORDIC accelerators can be used for digital baseband processing (fixed-point) and in Position-Velocity-Time estimation (floating-point). A micro architecture well suited to such applications is presented. This architecture is parameterized according to the wordlengths as well as the number of iterations and can be easily extended for floating point data format. Moreover, area can be traded for throughput by partially or even fully unrolling the iterations, whereby the degree of pipelining is organized with one CORDIC iteration per cycle. From the architectural description, the macro layout can be generated fully automatically using an in-house datapath generator tool. Since the adders and shifters play an important role in optimizing the CORDIC block, they must be carefully optimized for high area and energy efficiency in the underlying technology. So, for this purpose carry-select adders and logarithmic shifters have been chosen. Device dimensioning was automatically optimized with respect to dynamic and static power, area and performance using the in-house tool. The fully sequential CORDIC block for fixed-point digital baseband processing features a wordlength of 16 bits, requires 5232 transistors, which is implemented in a 40-nm CMOS technology and occupies a silicon area of 1560 μm2 only. Maximum clock frequency from circuit

  6. Fast and Scalable Computation of the Forward and Inverse Discrete Periodic Radon Transform.

    PubMed

    Carranza, Cesar; Llamocca, Daniel; Pattichis, Marios

    2016-01-01

    The discrete periodic radon transform (DPRT) has extensively been used in applications that involve image reconstructions from projections. Beyond classic applications, the DPRT can also be used to compute fast convolutions that avoids the use of floating-point arithmetic associated with the use of the fast Fourier transform. Unfortunately, the use of the DPRT has been limited by the need to compute a large number of additions and the need for a large number of memory accesses. This paper introduces a fast and scalable approach for computing the forward and inverse DPRT that is based on the use of: a parallel array of fixed-point adder trees; circular shift registers to remove the need for accessing external memory components when selecting the input data for the adder trees; an image block-based approach to DPRT computation that can fit the proposed architecture to available resources; and fast transpositions that are computed in one or a few clock cycles that do not depend on the size of the input image. As a result, for an N × N image (N prime), the proposed approach can compute up to N(2) additions per clock cycle. Compared with the previous approaches, the scalable approach provides the fastest known implementations for different amounts of computational resources. For example, for a 251×251 image, for approximately 25% fewer flip-flops than required for a systolic implementation, we have that the scalable DPRT is computed 36 times faster. For the fastest case, we introduce optimized just 2N + ⌈log(2) N⌉ + 1 and 2N + 3 ⌈log(2) N⌉ + B + 2 cycles, architectures that can compute the DPRT and its inverse in respectively, where B is the number of bits used to represent each input pixel. On the other hand, the scalable DPRT approach requires more 1-b additions than for the systolic implementation and provides a tradeoff between speed and additional 1-b additions. All of the proposed DPRT architectures were implemented in VHSIC Hardware Description Language

  7. An improved YEF-DCT based compression algorithm for video capsule endoscopy.

    PubMed

    Mostafa, Atahar; Khan, Tareq; Wahid, Khan

    2014-01-01

    Video capsule endoscopy is a non-invasive technique to receive images of intestine for medical diagnostics. The main design challenges of endoscopy capsule are accruing and transmitting acceptable quality images by utilizing as less hardware and battery power as possible. In order to save wireless transmission power and bandwidth, an efficient image compression algorithm needs to be implemented inside the endoscopy electronic capsule. In this paper, an integer discrete-cosine-transform (DCT) based algorithm is presented that works on a low-complexity color-space specially designed for wireless capsule endoscopy application. First of all, thousands of human endoscopic images and video frames have been analyzed to identify special intestinal features present in those frames. Then a color space, referred as YEF, is used. The YEF converter is lossless and takes only a few adders and shift operation to implement. A low-cost quantization scheme with variable chroma sub-sampling options is also implemented to achieve higher compression. Comparing with the existing works, the proposed transform coding based compressor performs strongly with an average compression ratio of 85% and a high image quality index, peak-signal-to-noise ratio (PSNR) of 52 dB.

  8. CMOS-based carbon nanotube pass-transistor logic integrated circuits.

    PubMed

    Ding, Li; Zhang, Zhiyong; Liang, Shibo; Pei, Tian; Wang, Sheng; Li, Yan; Zhou, Weiwei; Liu, Jie; Peng, Lian-Mao

    2012-02-14

    Field-effect transistors based on carbon nanotubes have been shown to be faster and less energy consuming than their silicon counterparts. However, ensuring these advantages are maintained for integrated circuits is a challenge. Here we demonstrate that a significant reduction in the use of field-effect transistors can be achieved by constructing carbon nanotube-based integrated circuits based on a pass-transistor logic configuration, rather than a complementary metal-oxide semiconductor configuration. Logic gates are constructed on individual carbon nanotubes via a doping-free approach and with a single power supply at voltages as low as 0.4 V. The pass-transistor logic configurarion provides a significant simplification of the carbon nanotube-based circuit design, a higher potential circuit speed and a significant reduction in power consumption. In particular, a full adder, which requires a total of 28 field-effect transistors to construct in the usual complementary metal-oxide semiconductor circuit, uses only three pairs of n- and p-field-effect transistors in the pass-transistor logic configuration.

  9. Capacitor blocks for linear transformer driver stages.

    PubMed

    Kovalchuk, B M; Kharlov, A V; Kumpyak, E V; Smorudov, G V; Zherlitsyn, A A

    2014-01-01

    In the Linear Transformer Driver (LTD) technology, the low inductance energy storage components and switches are directly incorporated into the individual cavities (named stages) to generate a fast output voltage pulse, which is added along a vacuum coaxial line like in an inductive voltage adder. LTD stages with air insulation were recently developed, where air is used both as insulation in a primary side of the stages and as working gas in the LTD spark gap switches. A custom designed unit, referred to as a capacitor block, was developed for use as a main structural element of the transformer stages. The capacitor block incorporates two capacitors GA 35426 (40 nF, 100 kV) and multichannel multigap gas switch. Several modifications of the capacitor blocks were developed and tested on the life time and self breakdown probability. Blocks were tested both as separate units and in an assembly of capacitive module, consisting of five capacitor blocks. This paper presents detailed design of capacitor blocks, description of operation regimes, numerical simulation of electric field in the switches, and test results.

  10. Plasmonic-multimode-interference-based logic circuit with simple phase adjustment

    NASA Astrophysics Data System (ADS)

    Ota, Masashi; Sumimura, Asahi; Fukuhara, Masashi; Ishii, Yuya; Fukuda, Mitsuo

    2016-04-01

    All-optical logic circuits using surface plasmon polaritons have a potential for high-speed information processing with high-density integration beyond the diffraction limit of propagating light. However, a number of logic gates that can be cascaded is limited by complicated signal phase adjustment. In this study, we demonstrate a half-adder operation with simple phase adjustment using plasmonic multimode interference (MMI) devices, composed of dielectric stripes on a metal film, which can be fabricated by a complementary metal-oxide semiconductor (MOS)-compatible process. Also, simultaneous operations of XOR and AND gates are substantiated experimentally by combining 1 × 1 MMI based phase adjusters and 2 × 2 MMI based intensity modulators. An experimental on-off ratio of at least 4.3 dB is confirmed using scanning near-field optical microscopy. The proposed structure will contribute to high-density plasmonic circuits, fabricated by complementary MOS-compatible process or printing techniques.

  11. Synchronous universal droplet logic and control

    NASA Astrophysics Data System (ADS)

    Katsikis, Georgios; Cybulski, James S.; Prakash, Manu

    2015-07-01

    Droplets are versatile digital materials; they can be produced at high throughput, perform chemical reactions as miniature beakers and carry biological entities. Droplets have been manipulated with electric, optical, acoustic and magnetic forces, but all these methods use serial controls to address individual droplets. An alternative is algorithmic manipulation based on logic operations that automatically compute where droplets are stored or directed, thereby enabling parallel control. However, logic previously implemented in low-Reynolds-number droplet hydrodynamics is asynchronous and thus prone to errors that prevent scaling up the complexity of logic operations. Here we present a platform for error-free physical computation via synchronous universal logic. Our platform uses a rotating magnetic field that enables parallel manipulation of arbitrary numbers of ferrofluid droplets on permalloy tracks. Through the coupling of magnetic and hydrodynamic interaction forces between droplets, we developed AND, OR, XOR, NOT and NAND logic gates, fanouts, a full adder, a flip-flop and a finite-state machine. Our platform enables large-scale integration of droplet logic, analogous to the scaling seen in digital electronics, and opens new avenues in mesoscale material processing.

  12. Qualification of local advanced cryogenic cleaning technology for 14nm photomask fabrication

    NASA Astrophysics Data System (ADS)

    Taumer, Ralf; Krome, Thorsten; Bowers, Chuck; Varghese, Ivin; Hopkins, Tyler; White, Roy; Brunner, Martin; Yi, Daniel

    2014-10-01

    The march toward tighter design rules, and thus smaller defects, implies stronger surface adhesion between defects and the photomask surface compared to past generations, thereby resulting in increased difficulty in photomask cleaning. Current state-of-the-art wet clean technologies utilize functional water and various energies in an attempt to produce similar yield to the acid cleans of previous generations, but without some of the negative side effects. Still, wet cleans have continued to be plagued with issues such as persistent particles and contaminations, SRAF and feature damages, leaving contaminants behind that accelerate photo-induced defect growth, and others. This paper details work done through a design of experiments (DOE) utilized to qualify an improved cryogenic cleaning technology for production in the Advanced Mask Technology Center (AMTC) advanced production lines for 20 and 14 nm processing. All work was conducted at the AMTC facility in Dresden, Germany utilizing technology developed by Eco-Snow Systems and RAVE LLC for their cryogenic local cleaning VC1200F platform. This system uses a newly designed nozzle, improved gaseous CO2 delivery, extensive filtration to remove hydrocarbons and minimize particle adders, and other process improvements to overcome the limitations of the previous generation local cleaning tool. AMTC has successfully qualified this cryogenic cleaning technology and is currently using it regularly to enhance production yields even at the most challenging technology nodes.

  13. A learnable parallel processing architecture towards unity of memory and computing.

    PubMed

    Li, H; Gao, B; Chen, Z; Zhao, Y; Huang, P; Ye, H; Liu, L; Liu, X; Kang, J

    2015-08-14

    Developing energy-efficient parallel information processing systems beyond von Neumann architecture is a long-standing goal of modern information technologies. The widely used von Neumann computer architecture separates memory and computing units, which leads to energy-hungry data movement when computers work. In order to meet the need of efficient information processing for the data-driven applications such as big data and Internet of Things, an energy-efficient processing architecture beyond von Neumann is critical for the information society. Here we show a non-von Neumann architecture built of resistive switching (RS) devices named "iMemComp", where memory and logic are unified with single-type devices. Leveraging nonvolatile nature and structural parallelism of crossbar RS arrays, we have equipped "iMemComp" with capabilities of computing in parallel and learning user-defined logic functions for large-scale information processing tasks. Such architecture eliminates the energy-hungry data movement in von Neumann computers. Compared with contemporary silicon technology, adder circuits based on "iMemComp" can improve the speed by 76.8% and the power dissipation by 60.3%, together with a 700 times aggressive reduction in the circuit area.

  14. Boolean gates on actin filaments

    NASA Astrophysics Data System (ADS)

    Siccardi, Stefano; Tuszynski, Jack A.; Adamatzky, Andrew

    2016-01-01

    Actin is a globular protein which forms long polar filaments in the eukaryotic cytoskeleton. Actin networks play a key role in cell mechanics and cell motility. They have also been implicated in information transmission and processing, memory and learning in neuronal cells. The actin filaments have been shown to support propagation of voltage pulses. Here we apply a coupled nonlinear transmission line model of actin filaments to study interactions between voltage pulses. To represent digital information we assign a logical TRUTH value to the presence of a voltage pulse in a given location of the actin filament, and FALSE to the pulse's absence, so that information flows along the filament with pulse transmission. When two pulses, representing Boolean values of input variables, interact, then they can facilitate or inhibit further propagation of each other. We explore this phenomenon to construct Boolean logical gates and a one-bit half-adder with interacting voltage pulses. We discuss implications of these findings on cellular process and technological applications.

  15. Hybrid VLSI/QCA Architecture for Computing FFTs

    NASA Technical Reports Server (NTRS)

    Fijany, Amir; Toomarian, Nikzad; Modarres, Katayoon; Spotnitz, Matthew

    2003-01-01

    A data-processor architecture that would incorporate elements of both conventional very-large-scale integrated (VLSI) circuitry and quantum-dot cellular automata (QCA) has been proposed to enable the highly parallel and systolic computation of fast Fourier transforms (FFTs). The proposed circuit would complement the QCA-based circuits described in several prior NASA Tech Briefs articles, namely Implementing Permutation Matrices by Use of Quantum Dots (NPO-20801), Vol. 25, No. 10 (October 2001), page 42; Compact Interconnection Networks Based on Quantum Dots (NPO-20855) Vol. 27, No. 1 (January 2003), page 32; and Bit-Serial Adder Based on Quantum Dots (NPO-20869), Vol. 27, No. 1 (January 2003), page 35. The cited prior articles described the limitations of very-large-scale integrated (VLSI) circuitry and the major potential advantage afforded by QCA. To recapitulate: In a VLSI circuit, signal paths that are required not to interact with each other must not cross in the same plane. In contrast, for reasons too complex to describe in the limited space available for this article, suitably designed and operated QCAbased signal paths that are required not to interact with each other can nevertheless be allowed to cross each other in the same plane without adverse effect. In principle, this characteristic could be exploited to design compact, coplanar, simple (relative to VLSI) QCA-based networks to implement complex, advanced interconnection schemes.

  16. Circuit and method for producing a flexible reference voltage

    NASA Technical Reports Server (NTRS)

    Thornton, Roger D. (Inventor)

    1993-01-01

    A flexible reference voltage circuit includes a circuit for producing a first digital signal representative of a range of reference voltage levels; a circuit for producing a second digital signal representative of a selected reference voltage level within the range of reference voltage levels; an adder for adding the first and second digital signals to produce a third digital signal; and a digital to analog converter for providing an output voltage in response to the third digital signal. The method of producing a flexible reference voltage performed by the circuit is also claimed. The invention can be used with a differential protection circuit to provide a series of trip level ranges, with a series of selectable trip levels in each range. This is accomplished in a high accuracy circuit which is relatively simple to construct, thereby minimizing size and complexity of the current sensor module, in differential protection applications, or the circuitry, if used in a power system controller. Standard digital logic components can be used to perform the necessary range/level decoding.

  17. Plasmonic-multimode-interference-based logic circuit with simple phase adjustment.

    PubMed

    Ota, Masashi; Sumimura, Asahi; Fukuhara, Masashi; Ishii, Yuya; Fukuda, Mitsuo

    2016-04-18

    All-optical logic circuits using surface plasmon polaritons have a potential for high-speed information processing with high-density integration beyond the diffraction limit of propagating light. However, a number of logic gates that can be cascaded is limited by complicated signal phase adjustment. In this study, we demonstrate a half-adder operation with simple phase adjustment using plasmonic multimode interference (MMI) devices, composed of dielectric stripes on a metal film, which can be fabricated by a complementary metal-oxide semiconductor (MOS)-compatible process. Also, simultaneous operations of XOR and AND gates are substantiated experimentally by combining 1 × 1 MMI based phase adjusters and 2 × 2 MMI based intensity modulators. An experimental on-off ratio of at least 4.3 dB is confirmed using scanning near-field optical microscopy. The proposed structure will contribute to high-density plasmonic circuits, fabricated by complementary MOS-compatible process or printing techniques.

  18. A 6 kV arbitrary waveform generator for the Tevatron Electron Lens

    NASA Astrophysics Data System (ADS)

    Pfeffer, H.; Saewert, G.

    2011-11-01

    This paper reports on a 6 kV modulator built and installed at Fermilab to drive the electron gun anode for the Tevatron Electron Lens (TEL). The TEL was built with the intention of shifting the individual (anti)proton bunch tunes to even out the tune spread among all 36 bunches with the desire of improving Tevatron integrated luminosity. This modulator is essentially a 6 kV arbitrary waveform generator that enables the TEL to define the electron beam intensity on a bunch-by-bunch basis. A voltage waveform is constructed having a 7 μs duration that corresponds to the tune shift requirements of a 12-bunch (anti)proton beam pulse train. This waveform is played out for any one or all three bunch trains in the Tevatron. The programmed waveform voltages transition to different levels at time intervals corresponding to the 395 ns bunch spacing. Thus, complex voltage waveforms can be played out at a sustained rate of 143 kHz over the full 6 kV output range. This paper describes the novel design of the inductive adder topology employing five transformers. It describes the design aspects that minimize switching losses for this multi-kilovolt, high repetition rate and high duty factor application.

  19. Chip-integrated ultrawide-band all-optical logic comparator in plasmonic circuits

    PubMed Central

    Lu, Cuicui; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2014-01-01

    Optical computing opens up the possibility for the realization of ultrahigh-speed and ultrawide-band information processing. Integrated all-optical logic comparator is one of the indispensable core components of optical computing systems. Unfortunately, up to now, no any nanoscale all-optical logic comparator suitable for on-chip integration applications has been realized experimentally. Here, we report a subtle and effective technical solution to circumvent the obstacles of inherent Ohmic losses of metal and limited propagation length of SPPs. A nanoscale all-optical logic comparator suitable for on-chip integration applications is realized in plasmonic circuits directly. The incident single-bit (or dual-bit) logic signals can be compared and the comparison results are endowed with different logic encodings. An ultrabroad operating wavelength range from 700 to 1000 nm, and an ultrahigh output logic-state contrast-ratio of more than 25 dB are realized experimentally. No high power requirement is needed. Though nanoscale SPP light source and the logic comparator device are integrated into the same plasmonic chip, an ultrasmall feature size is maintained. This work not only paves a way for the realization of complex logic device such as adders and multiplier, but also opens up the possibility for realizing quantum solid chips based on plasmonic circuits. PMID:24463956

  20. Realization of Low Power High-Speed Channel Filters with Stringent Adjacent Channel Attenuation Specifications for Wireless Communication Receivers

    NASA Astrophysics Data System (ADS)

    Mathew, Jimson; Mahesh, R.; Vinod, A. P.; Lai, Edmund M.-K.

    Finite impulse response (FIR) filtering is the most computationally intensive operation in the channelizer of a wireless communication receiver. Higher order FIR channel filters are needed in the channelizer to meet the stringent adjacent channel attenuation specifications of wireless communications standards. The computational cost of FIR filters is dominated by the complexity of the coefficient multipliers. Even though many methods for reducing the complexity of filter multipliers have been proposed in literature, these works focused on lower order filters. This paper presents a coefficient-partitioning-based binary subexpression elimination method for realizing low power FIR filters. We show that the FIR filters implemented using proposed method consume less power and achieve speed improvement compared to existing filter implementations. Design examples of the channel filters employed in the Digital Advanced Mobile Phone System (D-AMPS) and Personal Digital Cellular (PDC) receivers show that the proposed method achieved 23% average reductions of full adder and power consumption and 23.3% reduction of delay over the best existing method. Synthesis results show that the proposed method offers average area reduction of 8% and power reduction of 22% over the best known method in literature.

  1. Investigation of a simultaneous multifunctional photonic logic gate based on bidirectional FWM

    NASA Astrophysics Data System (ADS)

    Li, Lanlan; Lv, Tingting; Wu, Jian

    2013-11-01

    We demonstrate a multi-functional photonic logic gate for RZ-PolSK signals based on four wave mixing (FWM) in highly nonlinear fiber (HNLF). Bidirectional operation with one spool of HNLF is implemented numerically at 40 Gb/s. The basic logic arithmetics, such as XOR, AB¯,A¯B, XNOR, AND, NOR, and complex logic functions such as half-subtracter, half-adder, comparator and decoder are simultaneously realized by adjusting the polarization controllers. This novel structure is low-cost and rather flexible. Proper logic results, clear waveforms and high Q factors of eye diagrams are presented. Simulation analysis shows that bit error-free operation for the logic gate can be obtained when the wavelength separation is from -7 to 6 nm for two input signals. The impact of the input power on the Q factor is also investigated. Due to the femoto-second response time of Kerr-effect in HNLF we used in the scheme, the logic gate has great potential in future ultra-high speed optical transmission systems.

  2. Sensor activity and logic behaviour of PET based dihydroimidazonaphthalimide diester

    NASA Astrophysics Data System (ADS)

    Georgiev, Nikolai I.; Lyulev, Mihail P.; Bojinov, Vladimir B.

    2012-11-01

    An ester terminated dihydroimidazonaphthalimide as multi-functional logic device is presented. Due to the optical changes as a function of pH this simple molecule is able to act as a molecular pH metre, a digital comparator and a half-adder. It was demonstrated that the dihydroimidazonaphthalimide comparator could be used as a fundamental element of an optical device for control of pH windows. Also, the ability of the device to detect metal ions in DMF and in water/DMF (3:1, v/v) at different pHs has been evaluated by monitoring the changes of its fluorescence intensity. Among the tested metal ions (Cd2+, Co2+, Cu2+, Fe3+, Ni2+, Pb2+, Zn2+, Bi3+, Hg2+ and Ag+) only Fe3+ and Bi3+ were efficiently detected. In water/DMF (3:1, v/v) XOR and XNOR logic gates are presented using pH and Fe3+ as chemical inputs based on encoding binary digits of logical conventions.

  3. Sensor activity and logic behaviour of PET based dihydroimidazonaphthalimide diester.

    PubMed

    Georgiev, Nikolai I; Lyulev, Mihail P; Bojinov, Vladimir B

    2012-11-01

    An ester terminated dihydroimidazonaphthalimide as multi-functional logic device is presented. Due to the optical changes as a function of pH this simple molecule is able to act as a molecular pH metre, a digital comparator and a half-adder. It was demonstrated that the dihydroimidazonaphthalimide comparator could be used as a fundamental element of an optical device for control of pH windows. Also, the ability of the device to detect metal ions in DMF and in water/DMF (3:1, v/v) at different pHs has been evaluated by monitoring the changes of its fluorescence intensity. Among the tested metal ions (Cd(2+), Co(2+), Cu(2+), Fe(3+), Ni(2+), Pb(2+), Zn(2+), Bi(3+), Hg(2+) and Ag(+)) only Fe(3+) and Bi(3+) were efficiently detected. In water/DMF (3:1, v/v) XOR and XNOR logic gates are presented using pH and Fe(3+) as chemical inputs based on encoding binary digits of logical conventions.

  4. Chip-integrated ultrawide-band all-optical logic comparator in plasmonic circuits

    NASA Astrophysics Data System (ADS)

    Lu, Cuicui; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2014-01-01

    Optical computing opens up the possibility for the realization of ultrahigh-speed and ultrawide-band information processing. Integrated all-optical logic comparator is one of the indispensable core components of optical computing systems. Unfortunately, up to now, no any nanoscale all-optical logic comparator suitable for on-chip integration applications has been realized experimentally. Here, we report a subtle and effective technical solution to circumvent the obstacles of inherent Ohmic losses of metal and limited propagation length of SPPs. A nanoscale all-optical logic comparator suitable for on-chip integration applications is realized in plasmonic circuits directly. The incident single-bit (or dual-bit) logic signals can be compared and the comparison results are endowed with different logic encodings. An ultrabroad operating wavelength range from 700 to 1000 nm, and an ultrahigh output logic-state contrast-ratio of more than 25 dB are realized experimentally. No high power requirement is needed. Though nanoscale SPP light source and the logic comparator device are integrated into the same plasmonic chip, an ultrasmall feature size is maintained. This work not only paves a way for the realization of complex logic device such as adders and multiplier, but also opens up the possibility for realizing quantum solid chips based on plasmonic circuits.

  5. External cavity based single mode Fabry-Pérot laser diode and its application towards all-optical digital circuits

    NASA Astrophysics Data System (ADS)

    Nakarmi, Bikash; Zhang, Xuping; Won, Yong Hyub

    2012-11-01

    We have proposed a novel approach of realizing all-optical logic gates and combinational circuit using external cavity based single mode Fabry-Pérot laser diodes (SMFP-LDs). Different techniques and critical parameters for injection locking the any one of the modes of SMFP-LDs are discussed. Taking consideration of wavelength detuning and input injected power, we have proposed and demonstrated multi-input injection locking, supporting beam injection locking with the conventional injection locking which are used for demonstrating different logic gates (NAND, AND, XNOR, XOR, NOT, NOR) and digital circuits (Half adder and Comparator). Since we have used SMFP-LDs, there is no requirement of additional probe beam and associated components as required by other optical technologies making the realization simple in configuration, cost effective and power efficient. Clear output waveforms, eye diagrams, risingfalling times and BER are presented to verify the proposed method. All-optical logic units and digital circuit are demonstrated at the data rate of 10 Gbps with the waveform of NRZ signal waveform and measured eye diagram and BER of the PRBS of 231-1 signal. The maximum power penalty among all demonstrated units is below 1.4 dB at the BER of 10-9.

  6. Chip-integrated ultrawide-band all-optical logic comparator in plasmonic circuits.

    PubMed

    Lu, Cuicui; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2014-01-27

    Optical computing opens up the possibility for the realization of ultrahigh-speed and ultrawide-band information processing. Integrated all-optical logic comparator is one of the indispensable core components of optical computing systems. Unfortunately, up to now, no any nanoscale all-optical logic comparator suitable for on-chip integration applications has been realized experimentally. Here, we report a subtle and effective technical solution to circumvent the obstacles of inherent Ohmic losses of metal and limited propagation length of SPPs. A nanoscale all-optical logic comparator suitable for on-chip integration applications is realized in plasmonic circuits directly. The incident single-bit (or dual-bit) logic signals can be compared and the comparison results are endowed with different logic encodings. An ultrabroad operating wavelength range from 700 to 1000 nm, and an ultrahigh output logic-state contrast-ratio of more than 25 dB are realized experimentally. No high power requirement is needed. Though nanoscale SPP light source and the logic comparator device are integrated into the same plasmonic chip, an ultrasmall feature size is maintained. This work not only paves a way for the realization of complex logic device such as adders and multiplier, but also opens up the possibility for realizing quantum solid chips based on plasmonic circuits.

  7. High precision computing with charge domain devices and a pseudo-spectral method therefor

    NASA Technical Reports Server (NTRS)

    Barhen, Jacob (Inventor); Toomarian, Nikzad (Inventor); Fijany, Amir (Inventor); Zak, Michail (Inventor)

    1997-01-01

    The present invention enhances the bit resolution of a CCD/CID MVM processor by storing each bit of each matrix element as a separate CCD charge packet. The bits of each input vector are separately multiplied by each bit of each matrix element in massive parallelism and the resulting products are combined appropriately to synthesize the correct product. In another aspect of the invention, such arrays are employed in a pseudo-spectral method of the invention, in which partial differential equations are solved by expressing each derivative analytically as matrices, and the state function is updated at each computation cycle by multiplying it by the matrices. The matrices are treated as synaptic arrays of a neural network and the state function vector elements are treated as neurons. In a further aspect of the invention, moving target detection is performed by driving the soliton equation with a vector of detector outputs. The neural architecture consists of two synaptic arrays corresponding to the two differential terms of the soliton-equation and an adder connected to the output thereof and to the output of the detector array to drive the soliton equation.

  8. Parallelizing quantum circuit synthesis

    NASA Astrophysics Data System (ADS)

    Di Matteo, Olivia; Mosca, Michele

    2016-03-01

    Quantum circuit synthesis is the process in which an arbitrary unitary operation is decomposed into a sequence of gates from a universal set, typically one which a quantum computer can implement both efficiently and fault-tolerantly. As physical implementations of quantum computers improve, the need is growing for tools that can effectively synthesize components of the circuits and algorithms they will run. Existing algorithms for exact, multi-qubit circuit synthesis scale exponentially in the number of qubits and circuit depth, leaving synthesis intractable for circuits on more than a handful of qubits. Even modest improvements in circuit synthesis procedures may lead to significant advances, pushing forward the boundaries of not only the size of solvable circuit synthesis problems, but also in what can be realized physically as a result of having more efficient circuits. We present a method for quantum circuit synthesis using deterministic walks. Also termed pseudorandom walks, these are walks in which once a starting point is chosen, its path is completely determined. We apply our method to construct a parallel framework for circuit synthesis, and implement one such version performing optimal T-count synthesis over the Clifford+T gate set. We use our software to present examples where parallelization offers a significant speedup on the runtime, as well as directly confirm that the 4-qubit 1-bit full adder has optimal T-count 7 and T-depth 3.

  9. Integrated cleaning and handling automation of NXE3100 reticles

    NASA Astrophysics Data System (ADS)

    Jonckheere, Rik; Waehler, Tobias; Baudemprez, Bart; Dietze, Uwe; Dress, Peter; Brux, Oliver; Ronse, Kurt

    2012-02-01

    This paper focuses on imec's activities to minimize particle contamination on reticles (front- and backside) for the latest EUVL scanner, i.e. the NXE3100. Mask cleaning is performed on the HamaTech MaskTrack Pro® (MTP). Although also front-side particles and other contamination are being tackled by cleaning, the prime purpose is the avoidance of back-side particles which would lead to unacceptable overlay performance of the scanner and hence create yield loss, as well as cause unscheduled scanner down situations for cleaning of the reticle clamp. In the absence of a soft pellicle, the present approach to minimize particle adders during handling is to load EUV reticles into the scanner via so-called dual pods. The inner pod as such acts as a removable hard pellicle. Through the installation of the HamaTech MaskTrack Pro InSync® tool, interfaced to the MaskTrack Pro Cleaner, automated handling of EUV reticles in such pods is enabled. This integrated solution for handling and storage is additionally being equipped with an integrated reticle back-side inspection capability.

  10. A new interpolation arithmetic based readout signals process method for infrared imaging system applications

    NASA Astrophysics Data System (ADS)

    Li, Xinyi; Yao, Suying; Zhao, Yiqiang

    2009-07-01

    A new readout signals process circuit for infrared focal plane array (IR FPA) applications is proposed. In the proposed structure the continuous-time current signals from the detector array are mirrored, amplified, integrated on the integration capacitors and changed to discrete analog voltage signals. Next, these voltage signals are amplified and modulated by a group of encoded signals from the column buses, then fed to a multiple-input analog adder to generate a single serial output data stream. The generated single serial data stream is transferred to the mitigate noise circuit and is converted to digital signals by the A/D converter. For very large format detector arrays applications the speed restriction of the time-multiplexing circuitry and the A/D converter will be released. Since no scan technique has been used, all the output signals from an entire row in the detector array have been readout simultaneously without loss of optical power, the scalability of the photon-signals, the readout efficiency and the accuracy of the imaging system will be improved. Theory analysis and experimental results show that the proposed idea is reasonable and efficient. The proposed readout method is a solid option for large format infrared detector arrays and highly integrated infrared imaging system applications. In addition, the proposed idea also can be used for other active and passive imaging readout integrated circuits.

  11. An Enhanced Dual-Path ΔΣ A/D Converter

    NASA Astrophysics Data System (ADS)

    Nishida, Yoshio; Hamashita, Koichi; Temes, Gabor C.

    This paper presents an enhanced dual-path delta-sigma analog-to-digital converter. Compared with other architectures, the enhanced architecture increases the noise shaping order without any instability problems and displays analog complexity equivalent to the multi-stage noise shaping architecture. Our delta-sigma converter is based on this new architecture. It employs not only doubly-differential structure to reduce common-mode errors in the system-level but also delayed-feed-in structure to mitigate the timing constraint of the feedback signal. Regarding the circuit implementation, the first-order enhancement of the quantization noise shaping is achieved via the use of a switched capacitor circuit technique. The circuit is incorporated into the active adder in a low-distortion structure. The supporting clock generation circuit that provides additional phases of clocks with the enhancement block is also implemented in the CMOS logic gates. A digital dynamic element matching circuit (i.e., segmented data-weighted-average circuit) is designed to reduce mismatch errors caused by the feedback DAC of modulator. A test chip, fabricated in a 0.18-µm CMOS process, provides a signal-to-noise+distortion ratio (SNDR) of 75-dB for a 1.0-MHz signal bandwidth clocked at 40-MHz. The 2nd harmonic is -101dB and the 3rd harmonic is -94dB when a -4.5-dB 100-kHz input signal is applied.

  12. Snake poisoning in rural Zimbabwe--a prospective study.

    PubMed

    Nhachi, C F; Kasilo, O M

    1994-01-01

    Over a period of 2 years (January 1991 to December 1992) 274 cases of snake bite were admitted to hospital in the eight provinces of Zimbabwe. Of these patients, 54% were males and 88% belonged to the 6-40-year age group. Five deaths (1.8% of the total cases) were reported. The majority of snake bites (63%) occurred at night (between 6.30 p.m. and midnight) and over 74% took place during the hot rainy season, i.e. between November and April. In over 58% of the cases the victim accidentally stepped on the snake, the snake being cobra in 37%, puff adder in 20% and the black and green mamba in 18% of the cases. Most of the bites occurred on the leg, below the knee. Treatment of snake envenomation consisted mainly of the administration of antibiotics (151 cases), analgesics (144 cases), antivenom tropical snake polyvalent (ATT) (89 cases), antitoxoid tetanus (TT) (61 cases), antihistamines (47 cases) and traditional medicines (43 cases). This study indicates that snake envenomation in rural Zimbabwe is common but fatalities are relatively rare.

  13. An all solid state pulse power source for high PRF induction accelerators

    SciTech Connect

    Kirbie, H., LLNL

    1998-06-01

    Researchers at the Lawrence Livermore National Laboratory (LLNL) are developing a flexible, all solid-state pulsed power source that will enable an induction accelerator to produce mulitkiloampere electron beams at a maximum pulse repetition frequency (prf) of 2 MHz. The prototype source consists of three, 15-kV, 4.8-kA solid-state modulators stacked in an induction adder configuration. Each modulator contains over 1300 field-effect transistors (FETs) that quickly connect and disconnect four banks of energy storage capacitors to a magnetic induction core. The FETs are commanded on and off by an optical signal that determines the duration of the accelerating pulse. Further electronic circuitry is provided that resets the magnetic cores in each modulator immediately after the accelerating pulse. The system produces bursts of five or more pulses with an adjustable pulse width that ranges from 200 ns to 2 {micro}s The pulse duty factor within a burst can be as high as 25% while still allowing time for the induction core to reset. The solid-state modulator described above is called ARM-II and is named for the Advanced Radiographic Machine (ARM)-a powerful radiographic accelerator that will be the principal diagnostic device for the future Advanced Hydrotest Facility (AHF).

  14. Thermal management in high average power pulsed compression systems

    SciTech Connect

    Wavrik, R.W.; Reed, K.W.; Harjes, H.C.; Weber, G.J.; Butler, M.; Penn, K.J.; Neau, E.L.

    1992-08-01

    High average power repetitively pulsed compression systems offer a potential source of electron beams which may be applied to sterilization of wastes, treatment of food products, and other environmental and consumer applications. At Sandia National Laboratory, the Repetitive High Energy Pulsed Power (RHEPP) program is developing a 7 stage magnetic pulse compressor driving a linear induction voltage adder with an electron beam diode load. The RHEPP machine is being design to deliver 350 kW of average power to the diode in 60 ns FWHM, 2.5 MV, 3 kJ pulses at a repetition rate of 120 Hz. In addition to the electrical design considerations, the repetition rate requires thermal management of the electrical losses. Steady state temperatures must be kept below the material degradation temperatures to maximize reliability and component life. The optimum design is a trade off between thermal management, maximizing overall electrical performance of the system, reliability, and cost effectiveness. Cooling requirements and configurations were developed for each of the subsystems of RHEPP. Finite element models that combine fluid flow and heat transfer were used to screen design concepts. The analysis includes one, two, and three dimensional heat transfer using surface heat transfer coefficients and boundary layer models. Experiments were conducted to verify the models as well as to evaluate cooling channel fabrication materials and techniques in Metglas wound cores. 10 refs.

  15. A multi coding technique to reduce transition activity in VLSI circuits

    NASA Astrophysics Data System (ADS)

    Vithyalakshmi, N.; Rajaram, M.

    2014-02-01

    Advances in VLSI technology have enabled the implementation of complex digital circuits in a single chip, reducing system size and power consumption. In deep submicron low power CMOS VLSI design, the main cause of energy dissipation is charging and discharging of internal node capacitances due to transition activity. Transition activity is one of the major factors that also affect the dynamic power dissipation. This paper proposes power reduction analyzed through algorithm and logic circuit levels. In algorithm level the key aspect of reducing power dissipation is by minimizing transition activity and is achieved by introducing a data coding technique. So a novel multi coding technique is introduced to improve the efficiency of transition activity up to 52.3% on the bus lines, which will automatically reduce the dynamic power dissipation. In addition, 1 bit full adders are introduced in the Hamming distance estimator block, which reduces the device count. This coding method is implemented using Verilog HDL. The overall performance is analyzed by using Modelsim and Xilinx Tools. In total 38.2% power saving capability is achieved compared to other existing methods.

  16. Evaluation of a gamma camera system for the RITS-6 accelerator using the self-magnetic pinch diode

    NASA Astrophysics Data System (ADS)

    Webb, Timothy J.; Kiefer, Mark L.; Gignac, Raymond; Baker, Stuart A.

    2015-08-01

    The self-magnetic pinch (SMP) diode is an intense radiographic source fielded on the Radiographic Integrated Test Stand (RITS-6) accelerator at Sandia National Laboratories in Albuquerque, NM. The accelerator is an inductive voltage adder (IVA) that can operate from 2-10 MV with currents up to 160 kA (at 7 MV). The SMP diode consists of an annular cathode separated from a flat anode, holding the bremsstrahlung conversion target, by a vacuum gap. Until recently the primary imaging diagnostic utilized image plates (storage phosphors) which has generally low DQE at these photon energies along with other problems. The benefits of using image plates include a high-dynamic range, good spatial resolution, and ease of use. A scintillator-based X-ray imaging system or "gamma camera" has been fielded in front of RITS and the SMP diode which has been able to provide vastly superior images in terms of signal-to-noise with similar resolution and acceptable dynamic range.

  17. Impedance Dynamics in the Self-Magnetic Pinch (SMP) Diode on the RITS-6 Accelerator

    NASA Astrophysics Data System (ADS)

    Renk, Timothy; Johnston, Mark; Leckbee, Joshua; Webb, Timothy; Mazarakis, Michael; Kiefer, Mark; Bennett, Nichelle

    2014-10-01

    The RITS-6 inductive voltage adder (IVA) accelerator (3.5-8.5 MeV) at Sandia National Laboratories produces high-power (TW) focused electron beams (<3 mm diameter) for flash x-ray radiography applications. The Self-Magnetic Pinch (SMP) diode utilizes a hollowed metal cathode to produce a pinched focus onto a high Z metal converter. The electron flow from the IVA driver into the load region complicates understanding of diode evolution. There is growing evidence that reducing cathode size below some ``optimum'' value in order to achieve desired spot size reduction results in pinch instabilities leading to either reduced dose-rate, early radiation power termination, or both. We are studying evolving pinch dynamics with current and x-ray monitors, optical diagnostics, and spectroscopy, as well as with LSP [1] code simulations. We are also planning changes to anode-cathode materials as well as changes to the diode aspect ratio in an attempt to mitigate the above trends and improve pinch stability while achieving simultaneous spot size reduction. Experiments are ongoing, and latest results will be reported [1]. LSP is a software product of ATK Mission Research, Albuquerque, NM. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Adminis-tration under Contract DE-AC04-94AL85000.

  18. Mixed Source Interrogation of Steel Shielded Special Nuclear Material Using an Intense Pulsed Source

    NASA Astrophysics Data System (ADS)

    Hill, C.; Clemett, C. D.; Campbell, B.; Martin, P. N.; Threadgold, J.; O'Malley, J.

    This paper explores the benefits of using a mixed photon and neutron radiation source for active detection of special nuclear material. More than fifty irradiations were performed using an 8 MV electron accelerator employing and induction voltage adder (IVA). The experiments used a high atomic number converter to produce a Bremsstrahlung photon spectrum which was then used to create a neutron source via a nuclear interaction with heavy water (deuterium oxide, D2O). This mixed particle source was used to irradiate a depleted uranium (DU) sample, inducing fission in the sample. Several thicknesses of steel shielding were tested in order to compare the performance of the mixed photon and neutron source to a Bremsstrahlung-only source. An array of detectors were fielded to record both photons and neutrons emitted by the fission reactions. A correlation between steel shielding and a detection figure-of-merit can be seen in all cases where the Bremsstrahlung-only source was used. The same relationship for the mixed photon-neutron source is less consistent. The data collected from the fielded detectors is compared to MCNP6 calculations and good agreement is found.

  19. In-Situ Anode Heating and Its Effects on Atomic Constituents in the A-K Gap in Self-Magnetic Pinch (SMP) Experiments

    NASA Astrophysics Data System (ADS)

    Simpson, Sean; Renk, Timothy; Johnston, Mark; Mazarakis, Mike; Patel, Sonal

    2015-11-01

    The RITS-6 inductive voltage adder (IVA) accelerator (3.5-8.5 MeV) at Sandia National Laboratories produces high-power (TW) focused electron beams (<3mm diameter) for flash x-ray radiography applications. The Self-Magnetic Pinch (SMP) diode utilizes a hollowed metal cathode to produce a pinched focus onto a high-Z metal anode converter. There is not a clear understanding as to the effects various contaminants such as C, CO, H, H2O, HmCn, O2, and N2, on the anode surface or in the bulk may have on impedance dynamics, beam stability, beam spot size, and reproducibility. Heating pure Ta anodes with and without a thin Al coating have been investigated using temperatures ranging from 400 °C to 1000 °C. Initial experiments indicate a significant reduction in H and C as seen in high-speed spectral analysis of plasmas at the converter and a reduction in the back-streaming proton current. Experiments are ongoing, and latest results will be reported. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  20. Star sensing for an earth imaging sensor

    NASA Technical Reports Server (NTRS)

    Ellis, Kenneth K. (Inventor); Griffith, Paul C. (Inventor)

    2012-01-01

    A star sensor includes (a) a scan mirror for scanning at least one star; (b) a detector array, coupled to the scan mirror, for detecting the one star; and (c) a processor, coupled to the detector array. The processor includes a first filter configured to reduce noise spikes in the detected one star, and provide a detection mask of filtered data. Also included is a second filter configured to reduce non-contiguous samples in the detection mask. A centroid calculator is included to determine a location of the one star, after the first and second filtering. The first filter includes a median filter, followed by an averaging filter, both configured to filter the one star in an along-scan direction of the scan mirror. The first filter includes another median filter, which is configured to filter the detected one star in the cross-scan direction of the scan mirror. An adder is included to subtract (a) output data from the other median filter from (b) output data from the averaging filter and provide filtered star data to the second filter.

  1. Digital control of force microscope cantilevers using a field programmable gate array.

    PubMed

    Jacky, Jonathan P; Garbini, Joseph L; Ettus, Matthew; Sidles, John A

    2008-12-01

    This report describes a cantilever controller for magnetic resonance force microscopy based on a field programmable gate array, along with the hardware and software used to integrate the controller into an experiment. The controller is assembled from a low-cost commercially available software defined radio device and libraries of open-source software. The controller includes a digital filter comprising two cascaded second-order sections ("biquads"), which together can implement transfer functions for optimal cantilever controllers. An appendix in this report shows how to calculate filter coefficients for an optimal controller from measured cantilever characteristics. The controller also includes an input multiplexer and adder used in calibration protocols. Filter coefficients and multiplexer settings can be set and adjusted by control software while an experiment is running. The input is sampled at 64 MHz; the sampling frequency in the filters can be divided down under software control to achieve a good match with filter characteristics. Data reported here were sampled at 500 kHz, chosen for acoustic cantilevers with resonant frequencies near 8 kHz. Inputs are digitized with 12 bit resolution, and outputs are digitized with 14 bits. The experiment software is organized as a client and server to make it easy to adapt the controller to different experiments. The server encapsulates the details of controller hardware organization, connection technology, filter architecture, and number representation. The same server could be used in any experiment, while a different client encodes the particulars of each experiment.

  2. High speed multiplier using Nikhilam Sutra algorithm of Vedic mathematics

    NASA Astrophysics Data System (ADS)

    Pradhan, Manoranjan; Panda, Rutuparna

    2014-03-01

    This article presents the design of a new high-speed multiplier architecture using Nikhilam Sutra of Vedic mathematics. The proposed multiplier architecture finds out the compliment of the large operand from its nearest base to perform the multiplication. The multiplication of two large operands is reduced to the multiplication of their compliments and addition. It is more efficient when the magnitudes of both operands are more than half of their maximum values. The carry save adder in the multiplier architecture increases the speed of addition of partial products. The multiplier circuit is synthesised and simulated using Xilinx ISE 10.1 software and implemented on Spartan 2 FPGA device XC2S30-5pq208. The output parameters such as propagation delay and device utilisation are calculated from synthesis results. The performance evaluation results in terms of speed and device utilisation are compared with earlier multiplier architecture. The proposed design has speed improvements compared to multiplier architecture presented in the literature.

  3. Design and implementation of low power clock gated 64-bit ALU on ultra scale FPGA

    NASA Astrophysics Data System (ADS)

    Gupta, Ashutosh; Murgai, Shruti; Gulati, Anmol; Kumar, Pradeep

    2016-03-01

    64-bit energy efficient Arithmetic and Logic Unit using negative latch based clock gating technique is designed in this paper. The 64-bit ALU is designed using multiplexer based full adder cell. We have designed a 64-bit ALU with a gated clock. We have used negative latch based circuit for generating gated clock. This gated clock is used to control the multiplexer based 64-bit ALU. The circuit has been synthesized on kintex FPGA through Xilinx ISE Design Suite 14.7 using 28 nm technology in Verilog HDL. The circuit has been simulated on Modelsim 10.3c. The design is verified using System Verilog on QuestaSim in UVM environment. We have achieved 74.07%, 92. 93% and 95.53% reduction in total clock power, 89.73%, 91.35% and 92.85% reduction in I/Os power, 67.14%, 62.84% and 74.34% reduction in dynamic power and 25.47%, 29.05% and 46.13% reduction in total supply power at 20 MHz, 200 MHz and 2 GHz frequency respectively. The power has been calculated using XPower Analyzer tool of Xilinx ISE Design Suite 14.3.

  4. Radiographic X-Ray Pulse Jitter

    SciTech Connect

    Mitton, C. V., Good, D. E., Henderson, D. J., Hogge, K. W.

    2011-01-15

    The Dual Beam Radiographic Facility consists of two identical radiographic sources. Major components of the machines are: Marx generator, water-filled pulse-forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. The diode pulse has the following electrical specifications: 2.25-MV, 60-kA, 60-ns. Each source has the following x-ray parameters: 1-mm-diameter spot size, 4-rad at 1 m, 50-ns full width half max. The x-ray pulse is measured with PIN diode detectors. The sources were developed to produce high resolution images on single-shot, high-value experiments. For this application it is desirable to maintain a high level of reproducibility in source output. X-ray pulse jitter is a key metric for analysis of reproducibility. We will give measurements of x-ray jitter for each machine. It is expected that x-ray pulse jitter is predominantly due to PFL switch jitter, and therefore a correlation of the two will be discussed.

  5. DARPA/TTO program IR binary optics

    NASA Astrophysics Data System (ADS)

    Veldkamp, W. B.

    1984-06-01

    Binary grating optics consist of microfine rectangular (high-low) relief patterns on a dielectric or a metallic surface. By controlling the depth, width and periodicity of the binary pattern, the amplitude and the phase of an electromagnetic wave can be controlled to produce a variety of optical transfer functions. The lithographic tools for fabrication of binary optics are the ones developed for VLSI circuit fabrication. From a single lithographic mask, planar replica optics can be made in quantity. This technology has broad applicability for tactical missile systems as well as for space systems. In addition to making optics cheaper than by conventional means, binary optics allows the fabrication of unique devices that cannot be made conventionally. These include high-speed rotary scanners, multiplexers, filters, beam shapers and coherent laser adders. The goal of this program is the development of high quality planar optical components using VLSI circuit fabrication techniques. The main elements of the plan are: (1) the development of large aperture segmented and piezoelectrically active planar optical surfaces, (2) the development of raster scanning laser telescopes and extension to broadband applications, and (3) the application of diffractive optics technology to the coherent addition of beams from modular laser systems. This report covers progress in the setup of a reactive ion-beam etching laboratory, and the feasibility demonstrations of the coherent beam addition concept with gas lasers.

  6. Reliability automation tool (RAT) for fault tolerance computation

    NASA Astrophysics Data System (ADS)

    Singh, N. S. S.; Hamid, N. H.; Asirvadam, V. S.

    2012-09-01

    As CMOS transistors reduced in size, the circuit built using these nano-scale transistors naturally becomes less reliable. The reliability reduction, which is the measure of circuit performance, has brought up so many challenges in designing modern logic integrated circuit. Therefore, reliability modeling is increasingly important subject to be considered in designing modern logic integrated circuit. This drives a need to compute reliability measures for nano-scale circuits. This paper looks into the development of reliability automation tool (RAT) for circuit's reliability computation. The tool is developed using Matlab programming language based on the reliability evaluation model called Probabilistic Transfer Matrix (PTM). RAT allows users to significantly speed-up the reliability assessments of nano-scale circuits. Users have to provide circuit's netlist as the input to RAT for its reliability computation. The netlist signifies the circuit's description in terms of Gate Profile Matrix (GPM), Adjacency Computation Matrix (ACM) and Grid Layout Matrix (GLM). GPM, ACM and GLM indicate the types of logic gates, the interconnection between these logic gates and the layout matrix of these logic gates respectively in a given circuit design. Here, the reliability assessment by RAT is carried out on Full Adder circuit as the benchmark test circuit.

  7. Low complexity VLSI implementation of CORDIC-based exponent calculation for neural networks

    NASA Astrophysics Data System (ADS)

    Aggarwal, Supriya; Khare, Kavita

    2012-11-01

    This article presents a low hardware complexity for exponent calculations based on CORDIC. The proposed CORDIC algorithm is designed to overcome major drawbacks (scale-factor compensation, low range of convergence and optimal selection of micro-rotations) of the conventional CORDIC in hyperbolic mode of operation. The micro-rotations are identified using leading-one bit detection with uni-direction rotations to eliminate redundant iterations and improve throughput. The efficiency and performance of the processor are independent of the probability of rotation angles being known prior to implementation. The eight-staged pipelined architecture implementation requires an 8 × N ROM in the pre-processing unit for storing the initial coordinate values; it no longer requires the ROM for storing the elementary angles. It provides an area-time efficient design for VLSI implementation for calculating exponents in activation functions and Gaussain Potential Functions (GPF) in neural networks. The proposed CORDIC processor requires 32.68% less adders and 72.23% less registers compared to that of the conventional design. The proposed design when implemented on Virtex 2P (2vp50ff1148-6) device, dissipates 55.58% less power and has 45.09% less total gate count and 16.91% less delay as compared to Xilinx CORDIC Core. The detailed algorithm design along with FPGA implementation and area and time complexities is presented.

  8. Universal computing by DNA origami robots in a living animal

    PubMed Central

    Levner, Daniel; Ittah, Shmulik; Abu-Horowitz, Almogit; Bachelet, Ido

    2014-01-01

    Biological systems are collections of discrete molecular objects that move around and collide with each other. Cells carry out elaborate processes by precisely controlling these collisions, but developing artificial machines that can interface with and control such interactions remains a significant challenge. DNA is a natural substrate for computing and has been used to implement a diverse set of mathematical problems1-3, logic circuits4-6 and robotics7-9. The molecule also naturally interfaces with living systems, and different forms of DNA-based biocomputing have previously been demonstrated10-13. Here we show that DNA origami14-16 can be used to fabricate nanoscale robots that are capable of dynamically interacting with each other17-18 in a living animal. The interactions generate logical outputs, which are relayed to switch molecular payloads on or off. As a proof-of-principle, we use the system to create architectures that emulate various logic gates (AND, OR, XOR, NAND, NOT, CNOT, and a half adder). Following an ex vivo prototyping phase, we successfully employed the DNA origami robots in living cockroaches (Blaberus discoidalis) to control a molecule that targets the cells of the animal. PMID:24705510

  9. A high-speed multiplexer-based fine-grain pipelined architecture for digital fuzzy logic controllers

    NASA Astrophysics Data System (ADS)

    Rashidi, Bahram; Masoud Sayedi, Sayed

    2015-12-01

    Design and implementation of a high-speed multiplexer-based fine-grain pipelined architecture for a general digital fuzzy logic controller has been presented. All the operators have been designed at gate level. For the multiplication, a multiplexer-based modified Wallace tree multiplier has been designed, and for the division and addition multiplexer-based non-restoring parallel divider and multiplexer-based Manchester adder have been used, respectively. To further increase the processing speed, fine-grain pipelining technique has been employed. By using this technique, the critical path of the circuit is broken into finer pieces. Based on the proposed architecture, and by using Quartus II 9.1, a sample two-input, one-output digital fuzzy logic controller with eight rules has been successfully synthesised and implemented on Stratix II field programmable gate array. Simulations were carried out using DSP Builder in the MATLAB/Simulink tool at a maximum clock rate of 301.84 MHz.

  10. A learnable parallel processing architecture towards unity of memory and computing

    PubMed Central

    Li, H.; Gao, B.; Chen, Z.; Zhao, Y.; Huang, P.; Ye, H.; Liu, L.; Liu, X.; Kang, J.

    2015-01-01

    Developing energy-efficient parallel information processing systems beyond von Neumann architecture is a long-standing goal of modern information technologies. The widely used von Neumann computer architecture separates memory and computing units, which leads to energy-hungry data movement when computers work. In order to meet the need of efficient information processing for the data-driven applications such as big data and Internet of Things, an energy-efficient processing architecture beyond von Neumann is critical for the information society. Here we show a non-von Neumann architecture built of resistive switching (RS) devices named “iMemComp”, where memory and logic are unified with single-type devices. Leveraging nonvolatile nature and structural parallelism of crossbar RS arrays, we have equipped “iMemComp” with capabilities of computing in parallel and learning user-defined logic functions for large-scale information processing tasks. Such architecture eliminates the energy-hungry data movement in von Neumann computers. Compared with contemporary silicon technology, adder circuits based on “iMemComp” can improve the speed by 76.8% and the power dissipation by 60.3%, together with a 700 times aggressive reduction in the circuit area. PMID:26271243

  11. Field programmable gate arrays implementation of Dual Tree Complex Wavelet Transform.

    PubMed

    Canbay, Ferhat; Levent, Vecdi Emre; Serbes, Gorkem; Goren, Sezer; Aydin, Nizamettin

    2015-01-01

    Due to the inherent time-varying characteristics of physiological systems, most biomedical signals (BSs) are expected to have non-stationary character. Therefore, any appropriate analysis method for dealing with BSs should exhibit adjustable time-frequency (TF) resolution. The wavelet transform (WT) provides a TF representation of signals, which has good frequency resolution at low frequencies and good time resolution at high frequencies, resulting in an optimized TF resolution. Discrete wavelet transform (DWT), which is used in various medical signal processing applications such as denoising and feature extraction, is a fast and discretized algorithm for classical WT. However, the DWT has some very important drawbacks such as aliasing, lack of directionality, and shift-variance. To overcome these drawbacks, a new improved discrete transform named as Dual Tree Complex Wavelet Transform (DTCWT) can be used. Nowadays, with the improvements in embedded system technology, portable real-time medical devices are frequently used for rapid diagnosis in patients. In this study, in order to implement DTCWT algorithm in FPGAs, which can be used as real-time feature extraction or denoising operator for biomedical signals, a novel hardware architecture is proposed. In proposed architecture, DTCWT is implemented with only one adder and one multiplier. Additionally, considering the multi-channel outputs of biomedical data acquisition systems, this architecture is capable of running N channels in parallel.

  12. Laser Patterning of Optically Reconfigurable Transistor Channels in a Photochromic Diarylethene Layer.

    PubMed

    Tsuruoka, Tohru; Hayakawa, Ryoma; Kobashi, Kazuyoshi; Higashiguchi, Kenji; Matsuda, Kenji; Wakayama, Yutaka

    2016-12-14

    Optical switching organic field-effect transistors (OFETs) provide a new direction for optoelectronics based on photochromic molecules. However, the patterning of OFETs is difficult because conventional fabrication processes, including lithography and ion etching, inevitably cause severe damage to organic molecules. Here, we demonstrate laser patterning of one-dimensional (1D) channels on an OFET with a photochromic diarylethene (DAE) layer. The main findings are (i) a number of 1D channels can be repeatedly written and erased in the DAE layer by scanning focused ultraviolet and visible light laser beams alternately between the source and drain electrodes, (ii) the conductivity (or resistivity) of the 1D channel can be controlled by the illumination conditions, such as the laser power density and the scan speed, and (iii) it is possible to draw an analogue adder circuit by optically writing 1D channels so that a portion of the channels overlaps and to perform optical summing operations by local laser illumination of the respective channels. These findings will open new possibilities for realizing various optically reconfigurable, low-dimensional organic transistor circuits, which are not possible with conventional thin film OFETs.

  13. Novel design techniques for noise-tolerant power-gated CMOS circuits

    NASA Astrophysics Data System (ADS)

    Rastogi, Rumi; Pandey, Sujata

    2017-01-01

    In this paper we have investigated the single phase sleep signal modulation technique, step-wise {V}{gs} technique and the three-phase reactivation technique to evaluate the noise characteristics of multi-threshold CMOS circuits used in communication systems. The stacking technique is also implemented in this paper for the sleep transistor. The stacking approach helps to minimize leakage power. The mode transition noise minimization techniques have been applied to 32-bit dynamic TSPC adder with stacked sleep transistors in a standard 45-nm CMOS process. The reactivation noise, delay and energy consumption of all the three techniques have been evaluated. It has been shown that the three phase modulation technique significantly minimizes the reactivation delay when the peak noise level is maintained the same for all three techniques. The three phase modulation technique shows 67.3% and 35% reduction in delay compared to the single phase and step-wise {V}{gs} modulation techniques respectively. The reactivation energy is also suppressed by 49.3% and 39.14% with respect to the single-phase and stepwise {V}{gs} techniques.

  14. Capacitor blocks for linear transformer driver stages

    NASA Astrophysics Data System (ADS)

    Kovalchuk, B. M.; Kharlov, A. V.; Kumpyak, E. V.; Smorudov, G. V.; Zherlitsyn, A. A.

    2014-01-01

    In the Linear Transformer Driver (LTD) technology, the low inductance energy storage components and switches are directly incorporated into the individual cavities (named stages) to generate a fast output voltage pulse, which is added along a vacuum coaxial line like in an inductive voltage adder. LTD stages with air insulation were recently developed, where air is used both as insulation in a primary side of the stages and as working gas in the LTD spark gap switches. A custom designed unit, referred to as a capacitor block, was developed for use as a main structural element of the transformer stages. The capacitor block incorporates two capacitors GA 35426 (40 nF, 100 kV) and multichannel multigap gas switch. Several modifications of the capacitor blocks were developed and tested on the life time and self breakdown probability. Blocks were tested both as separate units and in an assembly of capacitive module, consisting of five capacitor blocks. This paper presents detailed design of capacitor blocks, description of operation regimes, numerical simulation of electric field in the switches, and test results.

  15. An accelerator facility for WDM, HEDP, and HIF investigations in Nazarbayev University

    NASA Astrophysics Data System (ADS)

    Kaikanov, M.; Baigarin, K.; Tikhonov, A.; Urazbayev, A.; Kwan, J. W.; Henestroza, E.; Remnev, G.; Shubin, B.; Stepanov, A.; Shamanin, V.; Waldron, W. L.

    2016-05-01

    Nazarbayev University (NU) in Astana, Kazakhstan, is planning to build a new multi-MV, ∼10 to several hundred GW/cm2 ion accelerator facility which will be used in studies of material properties at extreme conditions relevant to ion-beam-driven inertial fusion energy, and other applications. Two design options have been considered. The first option is a 1.2 MV induction linac similar to the NDCX-II at LBNL, but with modifications, capable of heating a 1 mm spot size thin targets to a few eV temperature. The second option is a 2 - 3 MV, ∼200 kA, single-gap-diode proton accelerator powered by an inductive voltage adder. The high current proton beam can be focused to ∼1 cm spot size to obtain power densities of several hundred GW/cm2, capable of heating thick targets to temperatures of tens of eV. In both cases, a common requirement to achieving high beam intensity on target and pulse length compression is to utilize beam neutralization at the final stage of beam focusing. Initial experiments on pulsed ion beam neutralization have been carried out on a 0.3 MV, 1.5 GW single-gap ion accelerator at Tomsk Polytechnic University with the goal of creating a plasma region in front of a target at densities exceeding ∼1012 cm-3.

  16. High-Performance Complementary Transistors and Medium-Scale Integrated Circuits Based on Carbon Nanotube Thin Films.

    PubMed

    Yang, Yingjun; Ding, Li; Han, Jie; Zhang, Zhiyong; Peng, Lian-Mao

    2017-03-29

    Solution-derived carbon nanotube (CNT) network films with high semiconducting purity are suitable materials for the wafer-scale fabrication of field-effect transistors (FETs) and integrated circuits (ICs). However, it is challenging to realize high-performance complementary metal-oxide semiconductor (CMOS) FETs with high yield and stability on such CNT network films, and this difficulty hinders the development of CNT-film-based ICs. In this work, we developed a doping-free process for the fabrication of CMOS FETs based on solution-processed CNT network films, in which the polarity of the FETs was controlled using Sc or Pd as the source/drain contacts to selectively inject carriers into the channels. The fabricated top-gated CMOS FETs showed high symmetry between the characteristics of n- and p-type devices and exhibited high-performance uniformity and excellent scalability down to a gate length of 1 μm. Many common types of CMOS ICs, including typical logic gates, sequential circuits, and arithmetic units, were constructed based on CNT films, and the fabricated ICs exhibited rail-to-rail outputs because of the high noise margin of CMOS circuits. In particular, 4-bit full adders consisting of 132 CMOS FETs were realized with 100% yield, thereby demonstrating that this CMOS technology shows the potential to advance the development of medium-scale CNT-network-film-based ICs.

  17. Low-complexity feed-forward carrier phase estimation for M-ary QAM based on phase search acceleration by quadratic approximation.

    PubMed

    Xiang, Meng; Fu, Songnian; Deng, Lei; Tang, Ming; Shum, Perry; Liu, Deming

    2015-07-27

    Blind phase search (BPS) algorithm for M-QAM has excellent tolerance to laser linewidth at the expense of rather high computation complexity (CC). Here, we first theoretically obtain the quadratic relationship between the test angle and corresponding distance matric during the BPS implementation. Afterwards, we propose a carrier phase estimation (CPE) based on a two-stage BPS with quadratic approximation (QA). Instead of searching the phase blindly with fixed step-size for the BPS algorithm, QA can significantly accelerate the speed of phase searching. As a result, a group factor of 2.96/3.05, 4.55/4.67 and 2.27/2.3 (in the form of multipliers/adders) reduction of CC is achieved for 16QAM, 64QAM and 256QAM, respectively, in comparison with the traditional BPS scheme. Meanwhile, a guideline for determining the summing filter block length is put forward during performance optimization. Under the condition of optimum filter block length, our proposed scheme shows similar performance as traditional BPS scheme. At 1 dB required E(S)/N(0) penalty @ BER = 10(-2), our proposed CPE scheme can tolerate a times symbol duration productΔf⋅T(S) of 1.7 × 10(-4), 6 × 10(-5) and 1.5 × 10(-5) for 16/64/256-QAM, respectively.

  18. Performance of the Cygnus X-ray Source

    NASA Astrophysics Data System (ADS)

    Smith, John R.; Carlson, Randolph; Fulton, Robert D.; Altes, R.; Carboni, V.; Chavez, Jacob R.; Corcoran, P.; Coulter, William L.; Douglas, J.; Droemer, D.; Gibson, William A.; Helvin, Thomas B.; Henderson, David J.; Johnson, David L.; Maenchen, John E.; Mitton, Charlas V.; Molina, Isidro; Nishimoto, H.; Ormond, Eugene C.; Ortega, Paul A.; Quicksilver, Robert J.; Ridlon, Rae N.; Rose, Evan A.; Scholfield, David W.; Smith, I.; Valerio, Antonio R.; White, R.

    2002-12-01

    Cygnus is a radiographic x-ray source developed for support of the Sub-Critical Experiments Program at the Nevada Test Site. Major requirements for this application are: a dramatically reduced spot size as compared to both Government Laboratory and existing commercial alternatives, layout flexibility, and reliability. Cygnus incorporates proven pulsed power technology (Marx Generator, Pulse Forming Line, Water Transmission Line, and Inductive Voltage Adder sub-components) to drive a high voltage vacuum diode. In the case of Cygnus, a relatively new approach (the rod pinch diode [1]) is employed to achieve a small source diameter. Design specifications are: 2.25 MeV endpoint energy, < 1 mm source diameter, and >3 rads dose at 1 meter. The pulsed power and system architecture design plan has been previously presented [2]. The first set of Cygnus shots were geared to verification of electrical parameters and, therefore, used a large area diode configuration offering increased shot rate as compared to that of the rod pinch diode. In this paper we present results of initial rod pinch operation in terms of electrical and radiation parameters.

  19. Initial Powerflow Studies on RITS

    NASA Astrophysics Data System (ADS)

    Hahn, K.; Rose, D.; Rovang, D.; Bailey, V.; Cordova, S.; Gignac, R.; Johnson, D. L.; Kincy, M.; Lucero, R.; Maenchen, J.; Molina, I.; Oliver, B.; Welch, D.; Wilkins, F.; Woodring, R.

    2002-12-01

    Sandia National Laboratories is investigating and developing high-dose and high-brightness flash radiographic sources. In collaboration with colleagues from MRC, AWE and Titan Pulsed Sciences Division, Sandia is conducting powerflow studies into paraxial diodes on the Radiographic Integrated Test Stand (RITS). Historically high-impedance accelerators have driven these diodes with little excess powerflow into the diode. However, a number of facilities now under design will use lower impedance Inductive Voltage Adder (IVA) technology to drive these diodes resulting in additional excess powerflow into the diode. The goals of these recent experiments conducted at Sandia were to assess these powerflow issues and to help benchmark LSP, the Particle-in-Cell code being used as a design tool for studying the coupling of powerflow from the accelerator into the diode. An integral part of the AWE-style paraxial diode is the non-emitting "knob". LSP was used early in the design of the experiments to study the effects of different size knobs on the powerflow into the diode region for both a hollow cathode load and a radiographic diode. These simulation results suggested that larger knobs are more effective in retrapping the upstream MITL bound current while keeping the excess power flow out of the diode region. Initial experiments were performed with a hollow cathode to diagnose how well each size knob works in diverting the excess powerflow. Preliminary results of these experiments and comparisons to LSP simulations are presented.

  20. Research on pinching characteristics of electron beams emitted from different cathode surfaces of a rod-pinch diode

    NASA Astrophysics Data System (ADS)

    Gao, Yi; Qiu, Aici; Zhang, Zhong; Zhang, Pengfei; Wang, Zhiguo; Yang, Hailiang

    2010-07-01

    The particle-in-cell code UNIPIC is used to simulate the working process of a rod-pinch diode and investigate the pinching characteristics of electron beams emitted from different cathode surfaces. The simulation results indicate that the electron beam emitted from the upstream surface pinches better than from other surfaces when all the three surfaces emit electrons. The charge-density deposition on the anode surface peaks at the rod tip while the deposited charge density is approximately uniform over the first 15 mm of the rod before rapidly increasing over the last 3 mm, indicating a large axial extent of electron deposition. For the case of single-surface emission, the pinching quality of the electron beam emitted from the downstream surface is better than those from other surfaces. The charge-density deposition peaks at the rod tip and decreases rapidly off the tip. Based on the relationship of Larmor radius, beam's self-magnetic field, and the spatial current distribution, the above simulation results are analyzed theoretically. The experiments are performed on the inductive voltage adder to examine the simulations. By comparing the axial distribution of the radiation on the anode rod measured with the pinhole camera and the on-axis forward x-ray dose measured with the LiF thermoluminescent detectors, the simulation results are verified. The electron emission suppression method and the impedance change for each case are investigated or discussed in this paper.

  1. Three-Dimensional, Inkjet-Printed Organic Transistors and Integrated Circuits with 100% Yield, High Uniformity, and Long-Term Stability.

    PubMed

    Kwon, Jimin; Takeda, Yasunori; Fukuda, Kenjiro; Cho, Kilwon; Tokito, Shizuo; Jung, Sungjune

    2016-11-22

    In this paper, we demonstrate three-dimensional (3D) integrated circuits (ICs) based on a 3D complementary organic field-effect transistor (3D-COFET). The transistor-on-transistor structure was achieved by vertically stacking a p-type OFET over an n-type OFET with a shared gate joining the two transistors, effectively halving the footprint of printed transistors. All the functional layers including organic semiconductors, source/drain/gate electrodes, and interconnection paths were fully inkjet-printed except a parylene dielectric which was deposited by chemical vapor deposition. An array of printed 3D-COFETs and their inverter logic gates comprising over 100 transistors showed 100% yield, and the uniformity and long-term stability of the device were also investigated. A full-adder circuit, the most basic computing unit, has been successfully demonstrated using nine NAND gates based on the 3D structure. The present study fulfills the essential requirements for the fabrication of organic printed complex ICs (increased transistor density, 100% yield, high uniformity, and long-term stability), and the findings can be applied to realize more complex digital/analogue ICs and intelligent devices.

  2. Challenges in constructing EUV metrology tools to qualify the EUV masks for HVM implementation

    NASA Astrophysics Data System (ADS)

    Houser, David C.; Dong, Feng; Perera, Chami N.; Perera, Rupert C. C.

    2015-09-01

    Extreme Ultraviolet (EUV) Lithography is still viewed as the most promising approach for maintaining the pace of Moore's Law. Recent real achievements in EUV Lithography (EUVL) have encouraged semiconductor manufacturers to reconsider their road maps. One of the principal challenges in the ongoing EUVL implementation for high volume manufacturing (HVM) is the availability of necessary clean at wavelength metrology tools. EUV Tech is the world's leading manufacturer of at-wavelength EUV metrology equipment. Founded in 1997, EUV Tech has pioneered the development of several stand-alone inspection, metrology, and calibration tools for EUV lithographic applications that can be operated in a clean room environment on the floor of a fab. In this paper, EUV Tech's R&D program to minimize particle adders in our EUV Reflectometer along with the ongoing effort to enhance the reflectivity and wavelength, precision and accuracy required to qualify the EUV masks for HVM. In addition to preliminary results from our stand alone EUV Scatterometer developed to characterize the phase roughness of a EUV mask and the introduction of EUV Tech's Pellicle test suite for testing EUV pellicles.

  3. Digital matched filter ASIC

    NASA Astrophysics Data System (ADS)

    Magill, D. T.; Edwards, G.

    The architecture of a digital matched filter (DMF) and the selected technology used is described. The characteristics of the DMF ASIC are summarized in tabular form. Three architectures are considered for the implementation of a DMF ASIC. First, there is the conventional trapped delay line architecture which requires a large adder tree. The second architecture is the systolic array DMF which consists of a number of identical stages cascaded together. The third architecture is the bank-of-correlators DMF, in which the reference code is recirculated around through the delay line. Since the objective is to maximize the length of the DMF, the tapped delay line architecture is selected. The tapped delay form is designed to support BPSK, QPSK, and OQPSK chip modulation. Matched filter lengths of up to 256 chips can be supported by cascading 4 ASICs. The DMF is designed as a gate array using an advanced double metal, 1.5 micron CMOS process. The regularity of FIR filter architecture allows the core of the device to be laid out very compactly, resulting in efficient usage of the gate array.

  4. A 6 kV arbitrary waveform generator for the Tevatron Electron Lens

    DOE PAGES

    Pfeffer, H.; Saewert, G.

    2011-11-09

    This paper reports on a 6 kV modulator built and installed at Fermilab to drive the electron gun anode for the Tevatron Electron Lens (TEL). The TEL was built with the intention of shifting the individual (anti)proton bunch tunes to even out the tune spread among all 36 bunches with the desire of improving Tevatron integrated luminosity. This modulator is essentially a 6 kV arbitrary waveform generator that enables the TEL to define the electron beam intensity on a bunch-by-bunch basis. A voltage waveform is constructed having a 7 μs duration that corresponds to the tune shift requirements of amore » 12-bunch (anti)proton beam pulse train. This waveform is played out for any one or all three bunch trains in the Tevatron. The programmed waveform voltages transition to different levels at time intervals corresponding to the 395 ns bunch spacing. In addition, complex voltage waveforms can be played out at a sustained rate of 143 kHz over the full 6 kV output range. This paper describes the novel design of the inductive adder topology employing five transformers. It describes the design aspects that minimize switching losses for this multi-kilovolt, high repetition rate and high duty factor application.« less

  5. All-optical switching with bacteriorhodopsin protein coated microcavities and its application to low power computing circuits

    NASA Astrophysics Data System (ADS)

    Roy, Sukhdev; Prasad, Mohit; Topolancik, Juraj; Vollmer, Frank

    2010-03-01

    We show all-optical switching of an input infrared laser beam at 1310 nm by controlling the photoinduced retinal isomerization to tune the resonances in a silica microsphere coated with three bacteriorhodopsin (BR) protein monolayers. The all-optical tunable resonant coupler re-routes the infrared beam between two tapered fibers in 50 μs using a low power (<200 μW) green (532 nm) and blue (405 nm) pump beams. The basic switching configuration has been used to design all-optical computing circuits, namely, half and full adder/subtractor, de-multiplexer, multiplexer, and an arithmetic unit. The design requires 2n-1 switches to realize n bit computation. The designs combine the exceptional sensitivities of BR and high-Q microcavities and the versatile tree architecture for realizing low power circuits and networks (approximately mW power budget). The combined advantages of high Q-factor, tunability, compactness, and low power control signals, with the flexibility of cascading switches to form circuits, and reversibility and reconfigurability to realize arithmetic and logic functions, makes the designs promising for practical applications. The designs are general and can be implemented (i) in both fiber-optic and integrated optic formats, (ii) with any other coated photosensitive material, or (iii) any externally controlled microresonator switch.

  6. Modeling the effects of anthropogenic habitat change on savanna snake invasions into African rainforest.

    PubMed

    Freedman, Adam H; Buermann, Wolfgang; Lebreton, Matthew; Chirio, Laurent; Smith, Thomas B

    2009-02-01

    We used a species-distribution modeling approach, ground-based climate data sets, and newly available remote-sensing data on vegetation from the MODIS and Quick Scatterometer sensors to investigate the combined effects of human-caused habitat alterations and climate on potential invasions of rainforest by 3 savanna snake species in Cameroon, Central Africa: the night adder (Causus maculatus), olympic lined snake (Dromophis lineatus), and African house snake (Lamprophis fuliginosus). Models with contemporary climate variables and localities from native savanna habitats showed that the current climate in undisturbed rainforest was unsuitable for any of the snake species due to high precipitation. Limited availability of thermally suitable nest sites and mismatches between important life-history events and prey availability are a likely explanation for the predicted exclusion from undisturbed rainforest. Models with only MODIS-derived vegetation variables and savanna localities predicted invasion in disturbed areas within the rainforest zone, which suggests that human removal of forest cover creates suitable microhabitats that facilitate invasions into rainforest. Models with a combination of contemporary climate, MODIS- and Quick Scatterometer-derived vegetation variables, and forest and savanna localities predicted extensive invasion into rainforest caused by rainforest loss. In contrast, a projection of the present-day species-climate envelope on future climate suggested a reduction in invasion potential within the rainforest zone as a consequence of predicted increases in precipitation. These results emphasize that the combined responses of deforestation and climate change will likely be complex in tropical rainforest systems.

  7. Results of initial testing of the four stage RHEPP accelerator

    SciTech Connect

    Johnson, D.L.; Reed, K.W.; Harjes, H.C.

    1993-08-01

    The low power checkout of the Repetitive High Energy Pulsed Power (RHEPP) pulse forming line (PFL) and linear induction voltage adder (LIVA) is complete. The accelerator has four LIVA cavities driven via coaxial cables from the PFL that utilizes magnetic switching to provide a 250-kV, 60-ns output pulse. The PFL is repetitively charged by a ten stage Marx generator to operate from single shot to five Hz. Results from these tests of the initial four stage RHEPP accelerator are presented and compared with design simulations. Data from a resistive cavity load and from preliminary electron diode experiments are included. While core temperatures remain low during five Hz operation, they are monitored and compared to extrapolated predictions from the design modeling. Performance of the Metglas magnetic switches and blocking cores, the voltage addition in the four LIVA cavities, and system efficiencies are discussed. Sources of discrepancies from the original design models are identified, and improved models that account for the discrepancies are presented. Improved performance potential based on these models is discussed. Plans for future testing of the 1-MV system up to 120 kW at 120 Hz and for the full system with ten LIVA cavities are presented.

  8. A 6 kV arbitrary waveform generator for the Tevatron Electron Lens

    SciTech Connect

    Pfeffer, H.; Saewert, G.

    2011-11-09

    This paper reports on a 6 kV modulator built and installed at Fermilab to drive the electron gun anode for the Tevatron Electron Lens (TEL). The TEL was built with the intention of shifting the individual (anti)proton bunch tunes to even out the tune spread among all 36 bunches with the desire of improving Tevatron integrated luminosity. This modulator is essentially a 6 kV arbitrary waveform generator that enables the TEL to define the electron beam intensity on a bunch-by-bunch basis. A voltage waveform is constructed having a 7 μs duration that corresponds to the tune shift requirements of a 12-bunch (anti)proton beam pulse train. This waveform is played out for any one or all three bunch trains in the Tevatron. The programmed waveform voltages transition to different levels at time intervals corresponding to the 395 ns bunch spacing. In addition, complex voltage waveforms can be played out at a sustained rate of 143 kHz over the full 6 kV output range. This paper describes the novel design of the inductive adder topology employing five transformers. It describes the design aspects that minimize switching losses for this multi-kilovolt, high repetition rate and high duty factor application.

  9. A learnable parallel processing architecture towards unity of memory and computing

    NASA Astrophysics Data System (ADS)

    Li, H.; Gao, B.; Chen, Z.; Zhao, Y.; Huang, P.; Ye, H.; Liu, L.; Liu, X.; Kang, J.

    2015-08-01

    Developing energy-efficient parallel information processing systems beyond von Neumann architecture is a long-standing goal of modern information technologies. The widely used von Neumann computer architecture separates memory and computing units, which leads to energy-hungry data movement when computers work. In order to meet the need of efficient information processing for the data-driven applications such as big data and Internet of Things, an energy-efficient processing architecture beyond von Neumann is critical for the information society. Here we show a non-von Neumann architecture built of resistive switching (RS) devices named “iMemComp”, where memory and logic are unified with single-type devices. Leveraging nonvolatile nature and structural parallelism of crossbar RS arrays, we have equipped “iMemComp” with capabilities of computing in parallel and learning user-defined logic functions for large-scale information processing tasks. Such architecture eliminates the energy-hungry data movement in von Neumann computers. Compared with contemporary silicon technology, adder circuits based on “iMemComp” can improve the speed by 76.8% and the power dissipation by 60.3%, together with a 700 times aggressive reduction in the circuit area.

  10. Inhibition of nicotinic acetylcholine receptors, a novel facet in the pleiotropic activities of snake venom phospholipases A2.

    PubMed

    Vulfius, Catherine A; Kasheverov, Igor E; Starkov, Vladislav G; Osipov, Alexey V; Andreeva, Tatyana V; Filkin, Sergey Yu; Gorbacheva, Elena V; Astashev, Maxim E; Tsetlin, Victor I; Utkin, Yuri N

    2014-01-01

    Phospholipases A2 represent the most abundant family of snake venom proteins. They manifest an array of biological activities, which is constantly expanding. We have recently shown that a protein bitanarin, isolated from the venom of the puff adder Bitis arietans and possessing high phospholipolytic activity, interacts with different types of nicotinic acetylcholine receptors and with the acetylcholine-binding protein. To check if this property is characteristic to all venom phospholipases A2, we have studied the capability of these enzymes from other snakes to block the responses of Lymnaea stagnalis neurons to acetylcholine or cytisine and to inhibit α-bungarotoxin binding to nicotinic acetylcholine receptors and acetylcholine-binding proteins. Here we present the evidence that phospholipases A2 from venoms of vipers Vipera ursinii and V. nikolskii, cobra Naja kaouthia, and krait Bungarus fasciatus from different snake families suppress the acetylcholine- or cytisine-elicited currents in L. stagnalis neurons and compete with α-bungarotoxin for binding to muscle- and neuronal α7-types of nicotinic acetylcholine receptor, as well as to acetylcholine-binding proteins. As the phospholipase A2 content in venoms is quite high, under some conditions the activity found may contribute to the deleterious venom effects. The results obtained suggest that the ability to interact with nicotinic acetylcholine receptors may be a general property of snake venom phospholipases A2, which add a new target to the numerous activities of these enzymes.

  11. NMR structure of bitistatin – a missing piece in the evolutionary pathway of snake venom disintegrins.

    PubMed

    Carbajo, Rodrigo J; Sanz, Libia; Perez, Alicia; Calvete, Juan J

    2015-01-01

    Extant disintegrins, as found in the venoms of Viperidae and Crotalidae snakes (vipers and rattlesnakes, represent a family of polypeptides that block the function of β1 and β3 integrin receptors, both potently and with a high degree of selectivity. This toxin family owes its origin to the neofunctionalization of the extracellular region of an ADAM (a disintegrin and metalloprotease) molecule recruited into the snake venom gland proteome in the Jurassic. The evolutionary structural diversification of the disintegrin scaffold, from the ancestral long disintegrins to the more recently evolved medium-sized, dimeric and short disintegrins, involved the stepwise loss of pairs of class-specific disulfide linkages and the processing of the N-terminal region. NMR and crystal structures of medium-sized, dimeric and short disintegrins have been solved. However, the structure of a long disintegrin remained unknown. The present study reports the NMR solution structures of two disulfide bond conformers of the long disintegrin bitistatin from the African puff adder Bitis arietans. The findings provide insight into how a structural domain of the extracellular region of an ADAM molecule, recruited into and selectively expressed in the snake venom gland proteome as a PIII metalloprotease in the Jurassic, has subsequently been tranformed into a family of integrin receptor antagonists.

  12. A Single Chip VLSI Implementation of a QPSK/SQPSK Demodulator for a VSAT Receiver Station

    NASA Technical Reports Server (NTRS)

    Kwatra, S. C.; King, Brent

    1995-01-01

    This thesis presents a VLSI implementation of a QPSK/SQPSK demodulator. It is designed to be employed in a VSAT earth station that utilizes the FDMA/TDM link. A single chip architecture is used to enable this chip to be easily employed in the VSAT system. This demodulator contains lowpass filters, integrate and dump units, unique word detectors, a timing recovery unit, a phase recovery unit and a down conversion unit. The design stages start with a functional representation of the system by using the C programming language. Then it progresses into a register based representation using the VHDL language. The layout components are designed based on these VHDL models and simulated. Component generators are developed for the adder, multiplier, read-only memory and serial access memory in order to shorten the design time. These sub-components are then block routed to form the main components of the system. The main components are block routed to form the final demodulator.

  13. Recent advances in the development of high average power induction accelerators for industrial and environmental applications

    SciTech Connect

    Neau, E.L.

    1994-09-01

    Short-pulse accelerator technology developed during the early 1960`s through the late 1980`s is being extended to high average power systems capable of use in industrial and environmental applications. Processes requiring high dose levels and/or high volume throughput will require systems with beam power levels from several hundreds of kilowatts to megawatts. Beam accelerating potentials can range from less than 1 MeV to as much as 10 MeV depending on the type of beam, depth of penetration required, and the density of the product being treated. This paper addresses the present status of a family of high average power systems, with output beam power levels up to 200 kW, now in operation that use saturable core switches to achieve output pulse widths of 50 to 80 nanoseconds. Inductive adders and field emission cathodes are used to generate beams of electrons or x-rays at up to 2.5 MeV over areas of 1000 cm{sup 2}. Similar high average power technology is being used at {le} 1 MeV to drive repetitive ion beam sources for treatment of material surfaces over 100`s of cm{sup 2}.

  14. Commissioned article: management of exotic snakebites.

    PubMed

    Warrell, D A

    2009-09-01

    Exotic (foreign or non-native) snakes, including venomous species, are becoming increasingly popular pets in Western countries. Some of them are kept illegally (as defined by the UK Dangerous Wild Animals Act of 1976). There is a large international market for such animals, with contraventions of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). In the UK, several other European countries and the USA the reported numbers of bites by venomous exotic snakes, although small, are increasing but still underestimate the occurrence of these occasionally fatal events because of the victims' reluctance to seek medical care. Victims are predominantly young men who have been drinking alcohol. Bites may be intentionally provoked. In Europe, the species most often involved are cobras, green mambas, American pit vipers particularly rattlesnakes, African adders, vipers and Asian green pit vipers. To illustrate the special problems involved, case histories are presented of bites by exotic species in the UK and of bites abroad, where patients were repatriated for treatment. In view of the relative rarity and diversity of these cases, expert advice must usually be sought. These requests should include information about the species thought to have been responsible and the history and timing of the evolution of envenoming. Sources of advice and antivenom are discussed together with recommendations for appropriate first aid and emergency treatment while this is being awaited. Respiratory and cardiovascular resuscitation may be required and when systemic or severe local envenoming develops, specific (equine or ovine) antivenom is indicated.

  15. Characterization of Salmonella isolated from captive and free-living snakes in Germany.

    PubMed

    Krautwald-Junghanns, Maria-Elisabeth; Stenkat, Julia; Szabo, Istvan; Ortlieb, Falk; Blindow, Irmgard; Neul, Ann-Kathrin; Pees, Michael; Schmidt, Volker

    2013-01-01

    Reptiles are well-known reservoirs of Salmonella spp. and cases of reptile-associated salmonellosis (RAS) are increasing since reptiles are becoming more popular as pets. In the present study, the presence, distribution and prevalence of serovars of Salmonella was investigated in captive snakes (n = 87) and in free-living snakes (n = 87) in Germany. A total of 43 S. enterica-isolates were recovered from organ samples and cloacal swabs, predominantly belonging to the subspecies diarizonae (IIIb) (n = 27), enterica (I) (n = 7) and houtenae (IV) (n = 6). S. enterica subsp. enterica (I) serovar Paratyphi B (n = 4) and S. enterica subsp. diarizonae (IIIb) serovar 47:l,v:z (n = 3) were the most frequently isolated serotypes. Nevertheless, the fact that most serotypes were only represented by a single isolate points out the high diversity of Salmonella present among snakes. Salmonella enterica subsp. diarizonae (IIIb) serotype 40:i:z53, which was isolated twice from two free-living Eurasian adders (Vipera berus) captured at different locations, has not been previously described. Our results confirm the role of both free-living and captive snakes as reservoirs of S. enterica in Germany.

  16. Design of efficient circularly symmetric two-dimensional variable digital FIR filters.

    PubMed

    Bindima, Thayyil; Elias, Elizabeth

    2016-05-01

    Circularly symmetric two-dimensional (2D) finite impulse response (FIR) filters find extensive use in image and medical applications, especially for isotropic filtering. Moreover, the design and implementation of 2D digital filters with variable fractional delay and variable magnitude responses without redesigning the filter has become a crucial topic of interest due to its significance in low-cost applications. Recently the design using fixed word length coefficients has gained importance due to the replacement of multipliers by shifters and adders, which reduces the hardware complexity. Among the various approaches to 2D design, transforming a one-dimensional (1D) filter to 2D by transformation, is reported to be an efficient technique. In this paper, 1D variable digital filters (VDFs) with tunable cut-off frequencies are designed using Farrow structure based interpolation approach, and the sub-filter coefficients in the Farrow structure are made multiplier-less using canonic signed digit (CSD) representation. The resulting performance degradation in the filters is overcome by using artificial bee colony (ABC) optimization. Finally, the optimized 1D VDFs are mapped to 2D using generalized McClellan transformation resulting in low complexity, circularly symmetric 2D VDFs with real-time tunability.

  17. Universal computing by DNA origami robots in a living animal.

    PubMed

    Amir, Yaniv; Ben-Ishay, Eldad; Levner, Daniel; Ittah, Shmulik; Abu-Horowitz, Almogit; Bachelet, Ido

    2014-05-01

    Biological systems are collections of discrete molecular objects that move around and collide with each other. Cells carry out elaborate processes by precisely controlling these collisions, but developing artificial machines that can interface with and control such interactions remains a significant challenge. DNA is a natural substrate for computing and has been used to implement a diverse set of mathematical problems, logic circuits and robotics. The molecule also interfaces naturally with living systems, and different forms of DNA-based biocomputing have already been demonstrated. Here, we show that DNA origami can be used to fabricate nanoscale robots that are capable of dynamically interacting with each other in a living animal. The interactions generate logical outputs, which are relayed to switch molecular payloads on or off. As a proof of principle, we use the system to create architectures that emulate various logic gates (AND, OR, XOR, NAND, NOT, CNOT and a half adder). Following an ex vivo prototyping phase, we successfully used the DNA origami robots in living cockroaches (Blaberus discoidalis) to control a molecule that targets their cells.

  18. Healing with animals in the Levant from the 10th to the 18th century

    PubMed Central

    Lev, Efraim

    2006-01-01

    Animals and products derived from different organs of their bodies have constituted part of the inventory of medicinal substances used in various cultures since ancient times. The article reviews the history of healing with animals in the Levant (The Land of Israel and parts of present-day Syria, Lebanon, and Jordan, defined by the Muslims in the Middle Ages as Bilad al-Sham) in the medieval and early Ottoman periods. Intensive research into the phenomenon of zootherapy in the medieval and early Ottoman Levant has yielded forty-eight substances of animal origin that were used medicinally. The vast majority of these substances were local and relatively easy to obtain. Most of the substances were domestic (honey, wax, silkworm, etc.), others were part of the local wildlife (adder, cuttle fish, flycatcher, firefly, frog, triton, scorpion, etc.), part of the usual medieval household (milk, egg, cheese, lamb, etc.), or parasites (louse, mouse, stinkbug, etc.). Fewer substances were not local but exotic, and therefore rare and expensive (beaver testicles, musk oil, coral, ambergris, etc.). The range of symptoms that the substances of animal origin were used to treat was extensive and included most of the known diseases and maladies of that era: mainly hemorrhoids, burns, impotence, wounds, and skin, eye, and stomach diseases. Changes in the moral outlook of modern societies caused the use of several substances of animal origin to cease in the course of history. These include mummy, silkworm, stinkbug, scarabees, snail, scorpion, and triton. PMID:16504024

  19. Measurements of the Backstreaming Proton IONS in the Self-Magnetic Pinch (SMP) Diode Utilizing Copper Activation Technique

    NASA Astrophysics Data System (ADS)

    Mazarakis, Michael; Cuneo, Michael; Fournier, Sean; Johnston, Mark; Kiefer, Mark; Leckbee, Joshua; Simpson, Sean; Renk, Timothy; Webb, Timothy; Bennett, Nichelle

    2016-10-01

    The results presented here were obtained with an SMP diode mounted at the front high voltage end of the 8-10-MV RITS Self-Magnetically Insulated Transmission Line (MITL) voltage adder. Our experiments had two objectives: first, to measure the contribution of the back-streaming proton currents emitted from the anode target, and second, to evaluate the energy of those ions and hence the actual Anode-Cathode (A-K) gap voltage. The accelerating voltage quoted in the literature is estimated utilizing para-potential flow theories. Thus, it is interesting to have another independent measurement of the A-K voltage. We have measured the back-streaming protons emitted from the anode and propagating through a hollow cathode tip for various diode configurations and different techniques of target cleaning treatment, namely, heating at very high temperatures with DC and pulsed current, with RF plasma cleaning, and with both plasma cleaning and heating. We have also evaluated the A-K gap voltage by energy filtering techniques. Sandia is operated by Sandia Corporation, a subsidiary of Lockheed Martin Company, for the US DOE NNSA under Contract No. DE-AC04-94AL85000.

  20. Influence of climate on the presence of colour polymorphism in two montane reptile species

    PubMed Central

    Broennimann, Olivier; Ursenbacher, Sylvain; Meyer, Andreas; Golay, Philippe; Monney, Jean-Claude; Schmocker, Hans; Guisan, Antoine; Dubey, Sylvain

    2014-01-01

    The coloration of ectotherms plays an important role in thermoregulation processes. Dark individuals should heat up faster and be able to reach a higher body temperature than light individuals and should therefore have benefits in cool areas. In central Europe, montane local populations of adder (Vipera berus) and asp viper (Vipera aspis) exhibit a varying proportion of melanistic individuals. We tested whether the presence of melanistic V. aspis and V. berus could be explained by climatic conditions. We measured the climatic niche position and breadth of monomorphic (including strictly patterned individuals) and polymorphic local populations, calculated their niche overlap and tested for niche equivalency and similarity. In accordance with expectations, niche overlap between polymorphic local populations of both species is high, and even higher than that of polymorphic versus monomorphic montane local populations of V. aspis, suggesting a predominant role of melanism in determining the niche of ectothermic vertebrates. However, unexpectedly, the niche of polymorphic local populations of both species is narrower than that of monomorphic ones, indicating that colour polymorphism does not always enable the exploitation of a greater variability of resources, at least at the intraspecific level. Overall, our results suggest that melanism might be present only when the thermoregulatory benefit is higher than the cost of predation. PMID:25392313

  1. Investigation of a Novel Common Subexpression Elimination Method for Low Power and Area Efficient DCT Architecture

    PubMed Central

    Siddiqui, M. F.; Reza, A. W.; Kanesan, J.; Ramiah, H.

    2014-01-01

    A wide interest has been observed to find a low power and area efficient hardware design of discrete cosine transform (DCT) algorithm. This research work proposed a novel Common Subexpression Elimination (CSE) based pipelined architecture for DCT, aimed at reproducing the cost metrics of power and area while maintaining high speed and accuracy in DCT applications. The proposed design combines the techniques of Canonical Signed Digit (CSD) representation and CSE to implement the multiplier-less method for fixed constant multiplication of DCT coefficients. Furthermore, symmetry in the DCT coefficient matrix is used with CSE to further decrease the number of arithmetic operations. This architecture needs a single-port memory to feed the inputs instead of multiport memory, which leads to reduction of the hardware cost and area. From the analysis of experimental results and performance comparisons, it is observed that the proposed scheme uses minimum logic utilizing mere 340 slices and 22 adders. Moreover, this design meets the real time constraints of different video/image coders and peak-signal-to-noise-ratio (PSNR) requirements. Furthermore, the proposed technique has significant advantages over recent well-known methods along with accuracy in terms of power reduction, silicon area usage, and maximum operating frequency by 41%, 15%, and 15%, respectively. PMID:25133249

  2. Global and Local Translation Designs of Quantum Image Based on FRQI

    NASA Astrophysics Data System (ADS)

    Zhou, Ri-Gui; Tan, Canyun; Ian, Hou

    2017-04-01

    In this paper, two kinds of quantum image translation are designed based on FRQI, including global translation and local translation. Firstly, global translation is realized by employing adder modulo N, where all pixels in the image will be moved, and the circuit of right translation is designed. Meanwhile, left translation can also be implemented by using right translation. Complexity analysis shows that the circuits of global translation in this paper have lower complexity and cost less qubits. Secondly, local translation, consisted of single-column translation, multiple-columns translation and translation in the restricted area, is designed by adopting Gray code. In local translation, any parts of pixels in the image can be translated while other pixels remain unchanged. In order to lower complexity when the number of columns needing to be translated are more than one, multiple-columns translation is proposed, which has the approximate complexity with single-column translation. To perform multiple-columns translation, three conditions must be satisfied. In addition, all translations in this paper are cyclic.

  3. Epidemiological aspects of snake bites on a Liberian rubber plantation.

    PubMed

    Stahel, E

    1980-12-01

    During a one-year period 95 patients with a history of snake bite were admitted to the hospital of a Liberian rubber plantation. The population at risk included the field workers (tappers and slashers) with an incidence of 4.2 symptomatic snake bites per thousand per year. The incidence of symptomatic bites was 1.7 per thousand in the group of non-field employees and 0.4 per thousand per year in the group of non-employees. The temporary disability was between 3 and 5 days, and the loss of workings days due to snake bites was one day per 10,000 working days on the plantation. Among the 95 patients 27 did not show any symptoms of envenoming except occasional fang marks. 64 patients developed cytotoxic symptoms alone. In this group, the night adder (Causus maculatus) was the main responsible snake. 4 patients showed signs of systemic envenoming. Two were haematological and two were neurological in nature and caused by Bitis species and Naja species, respectively. No fatalities were noted. A definite maximum of snake bites was observed during October and November which corresponds to the transition from rainy to dry season.

  4. Vertical zonation and distributions of calanoid copepods through the lower oxycline of the Arabian Sea oxygen minimum zone

    NASA Astrophysics Data System (ADS)

    Wishner, Karen F.; Gelfman, Celia; Gowing, Marcia M.; Outram, Dawn M.; Rapien, Mary; Williams, Rebecca L.

    2008-08-01

    >0.14 ml/L), but the rank order of abundance of species was similar in the Lower Oxycline and Sub-Oxycline. Some species were absent or much scarcer in the OMZ Core. Two copepod species common in the Lower Oxycline were primarily detritivorous but showed dietary differences suggesting feeding specialization. The copepod Spinocalanus antarcticus fed primarily on components of the vertical particulate flux and suspended material, a less versatile diet than the co-occurring copepod Lucicutia grandis. Vertical zonation of copepod species through the lower OMZ oxycline is probably a complex interplay between physiological limitation by low oxygen, potential predator control, and potential food resources. Pelagic OMZ and oxycline communities, and their ecological interactions in the water column and with the benthos, may become even more widespread and significant in the future ocean, if global warming increases the extent and intensity of OMZs as predicted.

  5. Acclimation effects on thermal tolerances of springtails from sub-Antarctic Marion Island: indigenous and invasive species.

    PubMed

    Slabber, Sarette; Worland, M Roger; Leinaas, Hans Petter; Chown, Steven L

    2007-02-01

    Collembola are abundant and functionally significant arthropods in sub-Antarctic terrestrial ecosystems, and their importance has increased as a consequence of the many invasive alien species that have been introduced to the region. It has also been predicted that current and future climate change will favour alien over indigenous species as a consequence of more favourable responses to warming in the former. It is therefore surprising that little is known about the environmental physiology of sub-Antarctic springtails and that few studies have explicitly tested the hypothesis that invasive species will outperform indigenous ones under warmer conditions. Here we present thermal tolerance data on three invasive (Pogonognathellus flavescens, Isotomurus cf. palustris, Ceratophysella denticulata) and two indigenous (Cryptopygus antarcticus, Tullbergia bisetosa) species of springtails from Marion Island, explicitly testing the idea that consistent differences exist between the indigenous and invasive species both in their absolute limits and the ways in which they respond to acclimation (at temperatures from 0 to 20 degrees C). Phenotypic plasticity is the first in a series of ways in which organisms might respond to altered environments. Using a poorly explored, but highly appropriate technique, we demonstrate that in these species the crystallization temperature (Tc) is equal to the lower lethal temperature. We also show that cooling rate (1 degree C min(-1); 0.1 degrees C min(-1); 0.5 degrees C h(-1) from 5 to -1 degrees C followed by 0.1 degrees C min(-1)) has little effect on Tc. The indigenous species typically have low Tcs (c. -20 to -13 degrees C depending on the acclimation temperature), whilst those of the invasive species tend to be higher (c. -12 to -6 degrees C) at the lower acclimation temperatures. However, Ceratophysella denticulata is an exception with a low Tc (c. -20 to -18 degrees C), and in P. flavescens acclimation to 20 degrees C results in a

  6. Hardware Implementation of a Bilateral Subtraction Filter

    NASA Technical Reports Server (NTRS)

    Huertas, Andres; Watson, Robert; Villalpando, Carlos; Goldberg, Steven

    2009-01-01

    A bilateral subtraction filter has been implemented as a hardware module in the form of a field-programmable gate array (FPGA). In general, a bilateral subtraction filter is a key subsystem of a high-quality stereoscopic machine vision system that utilizes images that are large and/or dense. Bilateral subtraction filters have been implemented in software on general-purpose computers, but the processing speeds attainable in this way even on computers containing the fastest processors are insufficient for real-time applications. The present FPGA bilateral subtraction filter is intended to accelerate processing to real-time speed and to be a prototype of a link in a stereoscopic-machine- vision processing chain, now under development, that would process large and/or dense images in real time and would be implemented in an FPGA. In terms that are necessarily oversimplified for the sake of brevity, a bilateral subtraction filter is a smoothing, edge-preserving filter for suppressing low-frequency noise. The filter operation amounts to replacing the value for each pixel with a weighted average of the values of that pixel and the neighboring pixels in a predefined neighborhood or window (e.g., a 9 9 window). The filter weights depend partly on pixel values and partly on the window size. The present FPGA implementation of a bilateral subtraction filter utilizes a 9 9 window. This implementation was designed to take advantage of the ability to do many of the component computations in parallel pipelines to enable processing of image data at the rate at which they are generated. The filter can be considered to be divided into the following parts (see figure): a) An image pixel pipeline with a 9 9- pixel window generator, b) An array of processing elements; c) An adder tree; d) A smoothing-and-delaying unit; and e) A subtraction unit. After each 9 9 window is created, the affected pixel data are fed to the processing elements. Each processing element is fed the pixel value for

  7. Operateurs et engins de calcul en virgule flottante et leur application a la simulation en temps reel sur FPGA

    NASA Astrophysics Data System (ADS)

    Ould Bachir, Tarek

    The real-time simulation of electrical networks gained a vivid industrial interest during recent years, motivated by the substantial development cost reduction that such a prototyping approach can offer. Real-time simulation allows the progressive inclusion of real hardware during its development, allowing its testing under realistic conditions. However, CPU-based simulations suffer from certain limitations such as the difficulty to reach time-steps of a few microsecond, an important challenge brought by modern power converters. Hence, industrial practitioners adopted the FPGA as a platform of choice for the implementation of calculation engines dedicated to the rapid real-time simulation of electrical networks. The reconfigurable technology broke the 5 kHz switching frequency barrier that is characteristic of CPU-based simulations. Moreover, FPGA-based real-time simulation offers many advantages, including the reduced latency of the simulation loop that is obtained thanks to a direct access to sensors and actuators. The fixed-point format is paradigmatic to FPGA-based digital signal processing. However, the format imposes a time penalty in the development process since the designer has to asses the required precision for all model variables. This fact brought an import research effort on the use of the floating-point format for the simulation of electrical networks. One of the main challenges in the use of the floating-point format are the long latencies required by the elementary arithmetic operators, particularly when an adder is used as an accumulator, an important building bloc for the implementation of integration rules such as the trapezoidal method. Hence, single-cycle floating-point accumulation forms the core of this research work. Our results help building such operators as accumulators, multiply-accumulators (MACs), and dot-product (DP) operators. These operators play a key role in the implementation of the proposed calculation engines. Therefore, this

  8. Use of a radial self-field diode geometry for intense pulsed ion beam generation at 6 MeV on Hermes III

    NASA Astrophysics Data System (ADS)

    Renk, T. J.; Harper-Slaboszewicz, V.; Mikkelson, K. A.; Ginn, W. C.; Ottinger, P. F.; Schumer, J. W.

    2014-12-01

    We investigate the generation of intense pulsed focused ion beams at the 6 MeV level using an inductive voltage adder (IVA) pulsed-power generator, which employs a magnetically insulated transmission line (MITL). Such IVA machines typical run at an impedance of few tens of Ohms. Previous successful intense ion beam generation experiments have often featured an "axial" pinch-reflex ion diode (i.e., with an axial anode-cathode gap) and operated on a conventional Marx generator/water line driver with an impedance of a few Ohms and no need for an MITL. The goals of these experiments are to develop a pinch-reflex ion diode geometry that has an impedance to efficiently match to an IVA, produces a reasonably high ion current fraction, captures the vacuum electron current flowing forward in the MITL, and focuses the resulting ion beam to small spot size. A new "radial" pinch-reflex ion diode (i.e., with a radial anode-cathode gap) is found to best demonstrate these properties. Operation in both positive and negative polarities was undertaken, although the negative polarity experiments are emphasized. Particle-in-cell (PIC) simulations are consistent with experimental results indicating that, for diode impedances less than the self-limited impedance of the MITL, almost all of the forward-going IVA vacuum electron flow current is incorporated into the diode current. PIC results also provide understanding of the diode-impedance and ion-focusing properties of the diode. In addition, a substantial high-energy ion population is also identified propagating in the "reverse" direction, i.e., from the back side of the anode foil in the electron beam dump.

  9. Incorporating global warming risks in power sector planning: A case study of the New England region. Volume 1

    SciTech Connect

    Krause, F.; Busch, J.; Koomey, J.

    1992-11-01

    Growing international concern over the threat of global climate change has led to proposals to buy insurance against this threat by reducing emissions of carbon (short for carbon dioxide) and other greenhouse gases below current levels. Concern over these and other, non-climatic environmental effects of electricity generation has led a number of states to adopt or explore new mechanisms for incorporating environmental externalities in utility resource planning. For example, the New York and Massachusetts utility commissions have adopted monetized surcharges (or adders) to induce emission reductions of federally regulated air pollutants (notably, SO{sub 2}, NO{sub x}, and particulates) beyond federally mandated levels. These regulations also include preliminary estimates of the cost of reducing carbon emissions, for which no federal regulations exist at this time. Within New England, regulators and utilities have also held several workshops and meetings to discuss alternative methods of incorporating externalities as well as the feasibility of regional approaches. This study examines the potential for reduced carbon emissions in the New England power sector as well as the cost and rate impacts of two policy approaches: environmental externality surcharges and a target- based approach. We analyze the following questions: Does New England have sufficient low-carbon resources to achieve significant reductions (10% to 20% below current levels) in fossil carbon emissions in its utility sector? What reductions could be achieved at a maximum? What is the expected cost of carbon reductions as a function of the reduction goal? How would carbon reduction strategies affect electricity rates? How effective are environmental externality cost surcharges as an instrument in bringing about carbon reductions? To what extent could the minimization of total electricity costs alone result in carbon reductions relative to conventional resource plans?

  10. Method and apparatus for enhancing microchannel plate data

    DOEpatents

    Thoe, R.S.

    1983-10-24

    A method and apparatus for determining centroid channel locations are disclosed for use in a system activated by one or more multichannel plates and including a linear diode array providing channels of information 1, 2, ...,n, ..., N containing signal amplitudes A/sub n/. A source of analog A/sub n/ signals, and a source of digital clock signals n, are provided. Non-zero A/sub n/ values are detected in a discriminator. A digital signal representing p, the value of n immediately preceding that whereat A/sub n/ takes its first non-zero value, is generated in a scaler. The analog A/sub n/ signals are converted to digital in an analog to digital converter. The digital A/sub n/ signals are added to produce a digital ..sigma..A/sub n/ signal in a full adder. Digital 1, 2, ..., m signals representing the number of non-zero A/sub n/ are produced by a discriminator pulse counter. Digital signals representing 1 A/sub p+1/, 2 A/sub p+2/, ..., m A/sub p+m/ are produced by pairwise multiplication in multiplier. These signal are added in multiplier summer to produce a digital ..sigma..nA/sub n/ - p..sigma..A/sub n/ signal. This signal is divided by the digital ..sigma..A/sub n/ signal in divider to provide a digital (..sigma..nA/sub n//..sigma..A/sub n/) -p signal. Finally, this last signal is added to the digital p signal in an offset summer to provide ..sigma..nA/sub n//..sigma..A/sub n/, the centroid channel locations.

  11. Hybridizing triboelectrification and electromagnetic induction effects for high-efficient mechanical energy harvesting.

    PubMed

    Hu, Youfan; Yang, Jin; Niu, Simiao; Wu, Wenzhuo; Wang, Zhong Lin

    2014-07-22

    The recently introduced triboelectric nanogenerator (TENG) and the traditional electromagnetic induction generator (EMIG) are coherently integrated in one structure for energy harvesting and vibration sensing/isolation. The suspended structure is based on two oppositely oriented magnets that are enclosed by hollow cubes surrounded with coils, which oscillates in response to external disturbance and harvests mechanical energy simultaneously from triboelectrification and electromagnetic induction. It extends the previous definition of hybrid cell to harvest the same type of energy with multiple approaches. Both the sliding-mode TENG and contact-mode TENG can be achieved in the same structure. In order to make the TENG and EMIG work together, transformers are used to match the output impedance between these two power sources with very different characteristics. The maximum output power of 7.7 and 1.9 mW on the same load of 5 kΩ was obtained for the TENG and EMIG, respectively, after impedance matching. Benefiting from the rational design, the output signal from the TENG and the EMIG are in phase. They can be added up directly to get an output voltage of 4.6 V and an output current of 2.2 mA in parallel connection. A power management circuit was connected to the hybrid cell, and a regulated voltage of 3.3 V with constant current was achieved. For the first time, a logic operation was carried out on a half-adder circuit by using the hybrid cell working as both the power source and the input digit signals. We also demonstrated that the hybrid cell can serve as a vibration isolator. Further applications as vibration dampers, triggers, and sensors are all promising.

  12. Optimization of current waveform tailoring for magnetically driven isentropic compression experiments

    NASA Astrophysics Data System (ADS)

    Waisman, E. M.; Reisman, D. B.; Stoltzfus, B. S.; Stygar, W. A.; Cuneo, M. E.; Haill, T. A.; Davis, J.-P.; Brown, J. L.; Seagle, C. T.; Spielman, R. B.

    2016-06-01

    The Thor pulsed power generator is being developed at Sandia National Laboratories. The design consists of up to 288 decoupled and transit time isolated capacitor-switch units, called "bricks," that can be individually triggered to achieve a high degree of pulse tailoring for magnetically driven isentropic compression experiments (ICE) [D. B. Reisman et al., Phys. Rev. Spec. Top.-Accel. Beams 18, 090401 (2015)]. The connecting transmission lines are impedance matched to the bricks, allowing the capacitor energy to be efficiently delivered to an ICE strip-line load with peak pressures of over 100 GPa. Thor will drive experiments to explore equation of state, material strength, and phase transition properties of a wide variety of materials. We present an optimization process for producing tailored current pulses, a requirement for many material studies, on the Thor generator. This technique, which is unique to the novel "current-adder" architecture used by Thor, entirely avoids the iterative use of complex circuit models to converge to the desired electrical pulse. We begin with magnetohydrodynamic simulations for a given material to determine its time dependent pressure and thus the desired strip-line load current and voltage. Because the bricks are connected to a central power flow section through transit-time isolated coaxial cables of constant impedance, the brick forward-going pulses are independent of each other. We observe that the desired equivalent forward-going current driving the pulse must be equal to the sum of the individual brick forward-going currents. We find a set of optimal brick delay times by requiring that the L2 norm of the difference between the brick-sum current and the desired forward-going current be a minimum. We describe the optimization procedure for the Thor design and show results for various materials of interest.

  13. Investigating the intrinsic cleanliness of automated handling designed for EUV mask pod-in-pod systems

    NASA Astrophysics Data System (ADS)

    Brux, O.; van der Walle, P.; van der Donck, J. C. J.; Dress, P.

    2011-11-01

    Extreme Ultraviolet Lithography (EUVL) is the most promising solution for technology nodes 16nm (hp) and below. However, several unique EUV mask challenges must be resolved for a successful launch of the technology into the market. Uncontrolled introduction of particles and/or contamination into the EUV scanner significantly increases the risk for device yield loss and potentially scanner down-time. With the absence of a pellicle to protect the surface of the EUV mask, a zero particle adder regime between final clean and the point-of-exposure is critical for the active areas of the mask. A Dual Pod concept for handling EUV masks had been proposed by the industry as means to minimize the risk of mask contamination during transport and storage. SuSS-HamaTech introduces MaskTrackPro InSync as a fully automated solution for the handling of EUV masks in and out of this Dual Pod System and therefore constitutes an interface between various tools inside the Fab. The intrinsic cleanliness of each individual handling and storage step of the inner shell (EIP) of this Dual Pod and the EUV mask inside the InSync Tool has been investigated to confirm the capability for minimizing the risk of cross-contamination. An Entegris Dual Pod EUV-1000A-A110 has been used for the qualification. The particle detection for the qualification procedure was executed with the TNO's RapidNano Particle Scanner, qualified for particle sizes down to 50nm (PSL equivalent). It has been shown that the target specification of < 2 particles @ 60nm per 25 cycles has been achieved. In case where added particles were measured, the EIP has been identified as a potential root cause for Ni particle generation. Any direct Ni-Al contact has to be avoided to mitigate the risk of material abrasion.

  14. Expanding the neutralization scope of the EchiTAb-plus-ICP antivenom to include venoms of elapids from Southern Africa.

    PubMed

    Sánchez, Andrés; Segura, Álvaro; Vargas, Mariángela; Herrera, María; Villalta, Mauren; Estrada, Ricardo; Wu, Francisco; Litschka-Koen, Thea; Perry, Michael Alfred; Alape-Girón, Alberto; León, Guillermo

    2017-01-01

    EchiTAb-plus-ICP is an antivenom prepared from plasma of horses hyperimmunized with the venoms of the carpet viper (Echis ocellatus), the puff adder (Bitis arietans) and the black-necked spitting cobra (Naja nigricollis). Therefore, the use of this antivenom has been limited to Western Africa. In order to expand the neutralization scope of EchiTAb-plus-ICP, we supplemented the immunogenic mixture with the venoms of B. arietans, the black mamba (Dendroaspis polylepis), the Mozambique spitting cobra (Naja mossambica), the snouted cobra (N. annulifera), and the rinkhals (Hemachatus haemachatus) from Swaziland. The ability of the expanded-scope antivenom, hereby named EchiTAb + ICP, to neutralize the venoms of B. arietans, D. polylepis, N. mossambica and H. haemachatus was similar to those of FAV Afrique and the SVA African antivenoms. In comparison to the SAIMR antivenom, the expanded-scope EchiTAb + ICP had lower ability to neutralize the venom of B. arietans, but similar ability to neutralize the venoms of D. polylepis, N. mossambica and H. haemachatus. Owing to its low protein concentration, the expanded-scope EchiTAb + ICP had lower ability to neutralize the venom of N. annulifera than FAV Afrique and the SAIMR antivenoms. However, when formulated at a protein concentration as high as FAV Afrique and SAIMR antivenoms, the expanded-scope EchiTAb + ICP showed similar capacity to neutralize this poorly immunogenic venom. Our results encourage the transition to the new EchiTAb + ICP antivenom, with an expanded neutralization scope that includes venoms of some of the most medically important elapids from Southern Africa. Clinical trials are required to determine the minimum effective-safe dose of the new EchiTAb + ICP for each type of envenomation.

  15. Allowance trading under the Clean Air Act: Who should regulate, and when?

    SciTech Connect

    Lock, R.

    1993-07-01

    The goal of this paper is to explore how compliance with the Clean Air Act Amendments of 1990 (CAAA), especially Title IV and emission trading under it, will affect the current relationship between state and federal regulation. It is difficult, with the limited experience we have had under Title IV, to be definitive about or to be a very strong advocate of too many policy positions. What may be most helpful at this point is to identify where the difficult issues in state/federal relations might arise; and then to explore ways in which tensions might be either avoided or resolved. One anticipated conclusion is that a traditional regulatory mindset could be very destructive if applied to this new area of oversight without due sensitivity to what Congress is trying to achieve in Title IV. That concern pervaded the early legislative debates; and it persists today. Title IV presents some unique challenges to state regulators and will require some creative solutions and fresh thinking if the goals of Congress are to be realized and the full benefits that allowance trading can offer are to be reaped by electricity consumers. In the ultimate analysis, Title IV amounts to a massive internalization of the external costs imposed on society by acid rain deposition. (This places in serious question the notion of additional externality {open_quotes}adders{close_quotes} for sulfur dioxide (SO{sub 2}) and nitrous oxide (NO{sub x}) at the state level for utility supply planning purposes.) The whole point of Title IV is to give those directly charged with compliance, namely power producers, the maximum flexibility to pursue least-cost compliance solutions. Perhaps the biggest single factor in how well they do this will be how state regulators respond to their compliance and allowance trading initiatives.

  16. The portable autonomous device on the basis straw-chambers for studying secondary space radiation in a soft x-ray range on board ISS

    NASA Astrophysics Data System (ADS)

    Bondarenko, Valery; Shurshakov, Vyacheslav; Bondarenko, Valentina; Markina, Irina

    The portable autonomous device for detection of soft x-ray radiation is described. Source of x-ray radiation is transition and brake radiations high-energy particles at passage through a material of a wall of the ISS and internal covering of the ship. A detecting elements of the device are gas proportional chambers of type straw in diameter 10 mm, length 140 mm. The wall chambers (cathode) is made from capton by thickness 70 microns. The anode of the chamber represents the gold-plated tungsten wire in diameter 30 microns. The general sensitive area of the detector is equal 110 cm2. Straw of the chambers (8 pieces) are connected consistently and are continuously blown by a gas mixture with a speed of 0,1 cm3/minute. The gas balloon in capacity of 200 cm3 under pressure 8 atm is used for flow. The device is capable to work long time in radiating fields. High radiating stability of the detector is reached by application of a radiation-steady material for manufacturing of chambers, constant gas flow during an irradiation and use of a clearing mixture on the basis of CF4. The electronic part of the device consists of the preamplifiers connected to chambers, the adder -splitter of analog signals, the spectrometer amplifier and amplitude - digitizer converter (АDC). From a splitter the signal acts on the discriminator for management ADC. Use of the discriminator allows to cut out registration of high-energy particles. The information is written on silicon disk.

  17. Reconfigurable Fault Tolerance for FPGAs

    NASA Technical Reports Server (NTRS)

    Shuler, Robert, Jr.

    2010-01-01

    The invention allows a field-programmable gate array (FPGA) or similar device to be efficiently reconfigured in whole or in part to provide higher capacity, non-redundant operation. The redundant device consists of functional units such as adders or multipliers, configuration memory for the functional units, a programmable routing method, configuration memory for the routing method, and various other features such as block RAM, I/O (random access memory, input/output) capability, dedicated carry logic, etc. The redundant device has three identical sets of functional units and routing resources and majority voters that correct errors. The configuration memory may or may not be redundant, depending on need. For example, SRAM-based FPGAs will need some type of radiation-tolerant configuration memory, or they will need triple-redundant configuration memory. Flash or anti-fuse devices will generally not need redundant configuration memory. Some means of loading and verifying the configuration memory is also required. These are all components of the pre-existing redundant FPGA. This innovation modifies the voter to accept a MODE input, which specifies whether ordinary voting is to occur, or if redundancy is to be split. Generally, additional routing resources will also be required to pass data between sections of the device created by splitting the redundancy. In redundancy mode, the voters produce an output corresponding to the two inputs that agree, in the usual fashion. In the split mode, the voters select just one input and convey this to the output, ignoring the other inputs. In a dual-redundant system (as opposed to triple-redundant), instead of a voter, there is some means to latch or gate a state update only when both inputs agree. In this case, the invention would require modification of the latch or gate so that it would operate normally in redundant mode, and would separately latch or gate the inputs in non-redundant mode.

  18. COBRA accelerator for Sandia ICF diode research at Cornell University

    SciTech Connect

    Smith, D.L.; Ingwersen, P.; Bennett, L.F.; Boyes, J.D.; Anderson, D.E.; Greenly, J.B.; Sudan, R.N.

    1995-05-01

    The new COBRA accelerator is being built in stages at the Laboratory of Plasma Studies in Cornell University where its applications will include extraction diode and ion beam research in support of the light ion inertial confinement fusion (ICF) program at Sandia National Laboratories. The 4- to 5-MV, 125- to 250-kA accelerator is based on a four-cavity inductive voltage adder (IVA) design. It is a combination of new ferromagnetically-isolated cavities and self magnetically insulated transmission line (MITL) hardware and components from existing Sandia and Cornell facilities: Marx generator capacitors, hardware, and power supply from the DEMON facility; water pulse forming lines (PFL) and gas switch from the Subsystem Test Facility (STF); a HERMES-III intermediate store capacitor (ISC); and a modified ion diode from Cornell`s LION. The present accelerator consists of a single modified cavity similar to those of the Sandia SABRE accelerator and will be used to establish an operating system for the first stage initial lower voltage testing. Four new cavities will be fabricated and delivered in the first half of FY96 to complete the COBRA accelerator. COBRA is unique in the sense that each cavity is driven by a single pulse forming line, and the IVA output polarity may be reversed by rotating the cavities 180{degrees} about their vertical axis. The site preparations, tank construction, and diode design and development are taking place at Cornell with growing enthusiasm as this machine becomes a reality. Preliminary results with the single cavity and short positive inner cylinder MITL configuration will soon be available.

  19. Evolution of Cell Size Homeostasis and Growth Rate Diversity during Initial Surface Colonization of Shewanella oneidensis.

    PubMed

    Lee, Calvin K; Kim, Alexander J; Santos, Giancarlo S; Lai, Peter Y; Lee, Stella Y; Qiao, David F; Anda, Jaime De; Young, Thomas D; Chen, Yujie; Rowe, Annette R; Nealson, Kenneth H; Weiss, Paul S; Wong, Gerard C L

    2016-09-06

    Cell size control and homeostasis are fundamental features of bacterial metabolism. Recent work suggests that cells add a constant size between birth and division ("adder" model). However, it is not known how cell size homeostasis is influenced by the existence of heterogeneous microenvironments, such as those during biofilm formation. Shewanella oneidensis MR-1 can use diverse energy sources on a range of surfaces via extracellular electron transport (EET), which can impact growth, metabolism, and size diversity. Here, we track bacterial surface communities at single-cell resolution to show that not only do bacterial motility appendages influence the transition from two- to three-dimensional biofilm growth and control postdivisional cell fates, they strongly impact cell size homeostasis. For every generation, we find that the average growth rate for cells that stay on the surface and continue to divide (nondetaching population) and that for cells that detach before their next division (detaching population) are roughly constant. However, the growth rate distribution is narrow for the nondetaching population, but broad for the detaching population in each generation. Interestingly, the appendage deletion mutants (ΔpilA, ΔmshA-D, Δflg) have significantly broader growth rate distributions than that of the wild type for both detaching and nondetaching populations, which suggests that Shewanella appendages are important for sensing and integrating environmental inputs that contribute to size homeostasis. Moreover, our results suggest multiplexing of appendages for sensing and motility functions contributes to cell size dysregulation. These results can potentially provide a framework for generating metabolic diversity in S. oneidensis populations to optimize EET in heterogeneous environments.

  20. Comparison between Frame-Constrained Fix-Pixel-Value and Frame-Free Spiking-Dynamic-Pixel ConvNets for Visual Processing.

    PubMed

    Farabet, Clément; Paz, Rafael; Pérez-Carrasco, Jose; Zamarreño-Ramos, Carlos; Linares-Barranco, Alejandro; Lecun, Yann; Culurciello, Eugenio; Serrano-Gotarredona, Teresa; Linares-Barranco, Bernabe

    2012-01-01

    Most scene segmentation and categorization architectures for the extraction of features in images and patches make exhaustive use of 2D convolution operations for template matching, template search, and denoising. Convolutional Neural Networks (ConvNets) are one example of such architectures that can implement general-purpose bio-inspired vision systems. In standard digital computers 2D convolutions are usually expensive in terms of resource consumption and impose severe limitations for efficient real-time applications. Nevertheless, neuro-cortex inspired solutions, like dedicated Frame-Based or Frame-Free Spiking ConvNet Convolution Processors, are advancing real-time visual processing. These two approaches share the neural inspiration, but each of them solves the problem in different ways. Frame-Based ConvNets process frame by frame video information in a very robust and fast way that requires to use and share the available hardware resources (such as: multipliers, adders). Hardware resources are fixed- and time-multiplexed by fetching data in and out. Thus memory bandwidth and size is important for good performance. On the other hand, spike-based convolution processors are a frame-free alternative that is able to perform convolution of a spike-based source of visual information with very low latency, which makes ideal for very high-speed applications. However, hardware resources need to be available all the time and cannot be time-multiplexed. Thus, hardware should be modular, reconfigurable, and expansible. Hardware implementations in both VLSI custom integrated circuits (digital and analog) and FPGA have been already used to demonstrate the performance of these systems. In this paper we present a comparison study of these two neuro-inspired solutions. A brief description of both systems is presented and also discussions about their differences, pros and cons.

  1. Recovery of soil physical properties and microbiology in foresty drained peatlands from the impact of forest machinery

    NASA Astrophysics Data System (ADS)

    Lepilin, Dmitrii; Kimura, Bryn; Uusitalo, Jori; Laiho, Raija; Fritze, Hannu; Lauren, Ari; Tuittila, Eeva-Stiina

    2016-04-01

    Forestry-drained peatlands occupy approximately 5.7 million ha and represent almost one fourth of the total forest surface in Finland. They are subjected to the same silvicultural harvesting operations as upland forests. However, although the potential of timber harvesting to cause detrimental effects on soil is well documented in upland forests, the knowledge on environmental impact of harvesting machinery on peat soils is still lacking. To assess the impact of harvesting machines on peat physical properties and biology we collected soil samples from six peatland forests that were harvested by commonly employed Harvester and Forwarder. Samples were taken from trails formed by harvesting machinery (treatment plots) and outside of trails (control plots unaffected by machinery traffic) to a depth of 15 cm. To adders the recovery of soil properties after disturbance we sampled sites that form a chronosequence in respect to time since harvesting: 1 month (class I), 3-4 years (class II) and 14-15 years (class III). The physical and microbiological properties of soil samples were analyzed in laboratory. Harvesting operations with heavy machinery appeared to significantly increase the bulk density of peat in the machines' trails at recently harvested sites in comparison to control plots. Following change in bulk density there was change of pore size distribution with decreasing macrospores quantity. This led to slight decrease of total porosity and decrease of air filled porosity. Water retention capacity increased with increasing bulk density. CO2 evolution increased in the trails of class I site with where dissolved organic carbon concurrently decreased. While there was not impact of harvesting on microbial biomass or carbon, PLFA analysis indicated that machinery traffic caused a shift in microbial community structure. Results of class II and class III sites showed a recovery of physical properties within 16 years: treatment plots and control plots started to resemble

  2. Fundamentals and applications of dry CO2 cryogenic aerosol for photomask cleaning

    NASA Astrophysics Data System (ADS)

    Varghese, Ivin; Balooch, Mehdi; Bowers, Charles W.

    2010-09-01

    There is a dire need for the removal of all printable defects on lithography masks. As the technology node advances, smaller particles need to be efficiently removed from smaller features without any damage or adders. CO2 cryogenic aerosol cleaning is a dry, residue-free and chemically inert technique that doesn't suffer from disadvantages of conventional wet cleaning methods such as transmission/reflectivity loss, phase change, CD change, haze/progressive defects, and/or limitation on number of cleaning cycles. Ultra-pure liquid CO2 when dispensed through an optimally designed nozzle results in CO2 clusters that impart the required momentum for defect removal. Historically nanomachining debris removal has been established with this technique. Several improvements have been incorporated for cleaning of advanced node masks, which has enabled Full Mask Final Clean, a new capability that has been successfully demonstrated. The properties of the CO2 clusters can be captured utilizing the Phase Doppler Anemometry (PDA) and effect of varying process and design parameters can be verified. New nozzles have been designed to widen the cleaning process window for advanced node optical masks, without any damage to the weak primary features and/or sub-resolution assist features (SRAFs). This capability has been experimentally proven for high aspect ratio SRAFs e.g. 2.79 (52nm wide by 145 nm tall) as well as SRAFs 45nm wide by 73 nm tall. In this paper, 100% removal of soft defects that would have printed on advanced node masks is demonstrated. No printed defects larger than 50nm is observed after the CO2 cleaning. Stability of the cleaning and handling mechanisms has been demonstrated over the last 4.5 months in a production environment. The CO2 cleaning technique is expected to be effective for more advanced masks and Extreme Ultra-Violet (EUV) lithography.

  3. Nanowire nanocomputer as a finite-state machine.

    PubMed

    Yao, Jun; Yan, Hao; Das, Shamik; Klemic, James F; Ellenbogen, James C; Lieber, Charles M

    2014-02-18

    Implementation of complex computer circuits assembled from the bottom up and integrated on the nanometer scale has long been a goal of electronics research. It requires a design and fabrication strategy that can address individual nanometer-scale electronic devices, while enabling large-scale assembly of those devices into highly organized, integrated computational circuits. We describe how such a strategy has led to the design, construction, and demonstration of a nanoelectronic finite-state machine. The system was fabricated using a design-oriented approach enabled by a deterministic, bottom-up assembly process that does not require individual nanowire registration. This methodology allowed construction of the nanoelectronic finite-state machine through modular design using a multitile architecture. Each tile/module consists of two interconnected crossbar nanowire arrays, with each cross-point consisting of a programmable nanowire transistor node. The nanoelectronic finite-state machine integrates 180 programmable nanowire transistor nodes in three tiles or six total crossbar arrays, and incorporates both sequential and arithmetic logic, with extensive intertile and intratile communication that exhibits rigorous input/output matching. Our system realizes the complete 2-bit logic flow and clocked control over state registration that are required for a finite-state machine or computer. The programmable multitile circuit was also reprogrammed to a functionally distinct 2-bit full adder with 32-set matched and complete logic output. These steps forward and the ability of our unique design-oriented deterministic methodology to yield more extensive multitile systems suggest that proposed general-purpose nanocomputers can be realized in the near future.

  4. A methodology for the characterization of arithmetic circuits on CMOS deep submicron technologies

    NASA Astrophysics Data System (ADS)

    Estrada, Adrian; Jimenez, Carlos J.; Valencia, Manuel

    2005-06-01

    Integration technologies have favored the design and implementation of more complex circuits. Thanks to this increased complexity, these circuits are capable of implementing algorithms which a few years ago were too expensive in both area and computational resources. However, they now offer interesting choices which should be considered. This new generation of integrated circuits nevertheless presents other kinds of restrictions that the designer should bear in mind. Parameters such as frequency of operation or power consumption are new restrictions that the designer has to deal with in order to fulfill the conditions established by the circuit functionality. Finally, the shrinking integration scale of current technologies makes the timing behavior of the design differ from previous technologies. Thus, a review of the timing behavior of the digital circuit should be done. So far, arithmetic circuits have been used as a benchmark for the analysis and design procedures of digital circuits. Therefore, it is our goal now to analyze both conventional and modern arithmetic circuits structures for different deep-submicron technologies. To achieve this goal, a good solution is to characterize a set of algorithmic circuits for several deep submicron processes, so that the designer can select the most suitable one depending upon the intended application and existing restrictions. In this paper, the first steps to attain such selection are presented. In particular, we propose a design and VHDL characterization methodology based on an RTL description of each component, on the utilization of an automated synthesis tool, and on the generation of logic characteristics from the logic level. This methodology is applied to a set of adders structures, the results of which are also presented.

  5. Cygnus Water Switch Jitter

    SciTech Connect

    Charles V. Mitton, George D. Corrow, Mark D. Hansen, David J. Henderson, et al.

    2008-03-01

    The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources - Cygnus 1 and Cygnus 2. Each source has the following x-ray output: 1-mm diameter spot size, 4 rad at 1 m, 50-ns Full Width Half Max. The diode pulse has the following electrical specifications: 2.25 MV, 60 kA, 60 ns. This Radiographic Facility is located in an underground tunnel test area at the Nevada Test Site (NTS). The sources were developed to produce high-resolution images on subcritical tests which are performed at NTS. Subcritical tests are single-shot, high-value events. For this application, it is desirable to maintain a high level of reproducibility in source output. The major components of the Cygnus machines are: Marx generator, water-filled pulse–forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. A primary source of fluctuation in Cygnus shot-to-shot performance is jitter in breakdown of the main PFL switch, which is a “self-break” switch. The PFL switch breakdown time determines the peak PFL charging voltage, which ultimately affects the diode pulse. Therefore, PFL switch jitter contributes to shot-to-shot variation in source endpoint energy and dose. In this paper we will present PFL switch jitter analysis for both Cygnus machines and give the correlation with diode performance. For this analysis the PFL switch on each machine was maintained at a single gap setting which has been used for the majority of shots at NTS. In addition to this analysis, PFL switch performance for different switch gap settings taken recently will be examined. Lastly, implications of source jitter for radiographic diagnosis of subcritical shots will be discussed.

  6. Ultrafast all-optical arithmetic logic based on hydrogenated amorphous silicon microring resonators

    NASA Astrophysics Data System (ADS)

    Gostimirovic, Dusan; Ye, Winnie N.

    2016-03-01

    For decades, the semiconductor industry has been steadily shrinking transistor sizes to fit more performance into a single silicon-based integrated chip. This technology has become the driving force for advances in education, transportation, and health, among others. However, transistor sizes are quickly approaching their physical limits (channel lengths are now only a few silicon atoms in length), and Moore's law will likely soon be brought to a stand-still despite many unique attempts to keep it going (FinFETs, high-k dielectrics, etc.). This technology must then be pushed further by exploring (almost) entirely new methodologies. Given the explosive growth of optical-based long-haul telecommunications, we look to apply the use of high-speed optics as a substitute to the digital model; where slow, lossy, and noisy metal interconnections act as a major bottleneck to performance. We combine the (nonlinear) optical Kerr effect with a single add-drop microring resonator to perform the fundamental AND-XOR logical operations of a half adder, by all-optical means. This process is also applied to subtraction, higher-order addition, and the realization of an all-optical arithmetic logic unit (ALU). The rings use hydrogenated amorphous silicon as a material with superior nonlinear properties to crystalline silicon, while still maintaining CMOS-compatibility and the many benefits that come with it (low cost, ease of fabrication, etc.). Our method allows for multi-gigabit-per-second data rates while maintaining simplicity and spatial minimalism in design for high-capacity manufacturing potential.

  7. Current-mode implementation of processing modules in ART-based neural networks

    NASA Astrophysics Data System (ADS)

    Lopez-Alcantud, Jose-Alejandro; Hauer, Hans; Diaz-Madrid, Jose-Angel; Ruiz-Merino, Ramon

    2003-04-01

    This paper describes implementation of neural network processing layers using basic current-mode operating modules. The research work has been focused on the implementation of neural networks based on the Adaptive Resonance Theory, developed by S. Grossberg and G.A. Carpenter. The ART-based neural network whose operating modules have been choosen for development is the one called MART, proposed by F. Delgado, because of its complex architecture, auto--adaptive self-learning process, able to discard unmeaningful cathegories. Our presentation starts introducing the behaviour of MART with an analysis of its structure. The development described by this research work is focused on the monochannel block included in the main signal processing part of the MART neural network. The description of the computing algorithm of the layers inside a monochannel block are also provided in order to show what operational current-mode modules are needed (multiplier, divider, square-rooter, adder, substractor, absolute value, maximum and minimum evaluator...). Descriptions at schematic and layout levels of all the processing layers are given. All of them have been designed using AMS 0.35 micron technology with a supply voltage of 3.3 volts. The modules are designed to deal with input currents in the range of 20 to 50 microamps, showing a lineal behaviour and an output error of less than 10%, which is good enough for neural signal processing systems. The maximum frecuency of operation is around 200 kHz. Simulation results are included to show that the operation performed by the hardware designed matches the behaviour described by the MART neural network. For testing purposes we show the design of a monochannel block hardware implementation restricted to five inputs and three cathegories.

  8. Surface confined assemblies and polymers for sensing and molecular logic

    NASA Astrophysics Data System (ADS)

    de Ruiter, Graham; Altman, Marc; Motiei, Leila; Lahav, Michal; van der Boom, Milko E.

    2013-05-01

    Since the development of molecule-based sensors and the introduction of molecules mimicking the behavior of the AND gate in solution by de Silva in 1993, molecular (Boolean) Logic and Computing (MBLC) has become increasingly popular. The molecular approach toward Boolean logic resulted in intriguing proofs of concepts in solution including logic gates, half-adders, multiplexers, and flip-flop logic circuits. Molecular assemblies can perform diverse logic tasks by reconfiguring their inputs. Our recent research activities focus on MBLC with electrochromic polymers and immobilized polypyridyl complexes on solid support. We have designed a series of coordination-based thin films that are formed linearly by stepwise wet-chemical deposition or by self-propagating molecular assembly. The electrochromic properties of these films can be used for (i) detecting various analytes in solution and in the air, (ii) MBLC, (iii) electron-transfer studies, and (iv) interlayers for efficient inverted bulk-heterojunction solar cells. Our concept toward MBLC with functionalized surfaces is applicable to electrochemical and chemical inputs coupled with optical readout. Using this approach, we demonstrated various logic architectures with redox-active functionalized surfaces. Electrochemically operated sequential logic systems (e.g., flip-flops), multi-valued logic, and multi-state memory have been designed, which can improve computational power without increasing spatial requirements. Applying multi-valued digits in data storage and information processing could exponentially increase memory capacity. Our approach is applicable to highly diverse electrochromic thin films that operate at practical voltages (< 1.5 V).

  9. EHF multifunction phased array antenna

    NASA Astrophysics Data System (ADS)

    Solbach, Klaus

    1986-07-01

    The design of a low cost demonstration EHF multifunction-phased array antenna is described. Both, the radiating elements and the phase-shifter circuits are realized on microstrip substrate material in order to allow photolithographic batch fabrication. Self-encapsulated beam-lead PIN-diodes are employed as the electronic switch elements to avoid expensive hermetic encapsulation of the semiconductors or complete circuits. A space-feed using a horn-radiator to illuminate the array from the front-side is found to be the simplest and most inexpensive feed. The phased array antenna thus operates as a reflect-array, the antenna elements employed in a dual role for the collection of energy from the feed-horn and for the re-radiation of the phase-shifted waves (in transmit-mode). The antenna is divided into modules containing the radiator/phase-shifter plate plus drive- and BITE-circuitry at the back. Both drive- and BITE-components use gate-array integrated circuits especially designed for the purpose. Several bus-systems are used to supply bias and logical data flows to the modules. The beam-steering unit utilizes several signal processors and high-speed discrete adder circuits to combine the pointing, frequency and beam-shape information from the radar system computer with the stored phase-shift codes for the array elements. Since space, weight and power consumption are prime considerations only the most advanced technology is used in the design of both the microwave and the digital/drive circuitry.

  10. Unified framework for magic state distillation and multiqubit gate synthesis with reduced resource cost

    NASA Astrophysics Data System (ADS)

    Campbell, Earl T.; Howard, Mark

    2017-02-01

    The standard approach to fault-tolerant quantum computation is to store information in a quantum error correction code, such as the surface code, and process information using a strategy that can be summarized as distill then synthesize. In the distill step, one performs several rounds of distillation to create high-fidelity logical qubits in a magic state. Each such magic state provides one good T gate. In the synthesize step, one seeks the optimal decomposition of an algorithm into a sequence of many T gates interleaved with Clifford gates. This gate-synthesis problem is well understood for multiqubit gates that do not use any Hadamards. We present an in-depth analysis of a unified framework that realizes one round of distillation and multiqubit gate synthesis in a single step. We call these synthillation protocols, and show they lead to a large reduction in resource overheads. This is because synthillation can implement a general class of circuits using the same number of T states as gate synthesis, yet with the benefit of quadratic error suppression. This general class includes all circuits primarily dominated by control-control-Z gates, such as adders and modular exponentiation routines used in Shor's algorithm. Therefore, synthillation removes the need for a costly round of magic state distillation. We also present several additional results on the multiqubit gate-synthesis problem. We provide an efficient algorithm for synthesizing unitaries with the same worst-case resource scaling as optimal solutions. For the special case of synthesizing controlled unitaries, our techniques are not just efficient but exactly optimal. We observe that the gate-synthesis cost, measured by T count, is often strictly subadditive. Numerous explicit applications of our techniques are also presented.

  11. Twentieth century toxinology and antivenom development in Australia.

    PubMed

    Winkel, Kenneth D; Mirtschin, Peter; Pearn, John

    2006-12-01

    It was not until the last decade of the 19th century that an experimental approach (led by Bancroft in Queensland and Martin in Sydney and Melbourne) brought a higher plane of scientific objectivity to usher in the modern era of Australian toxinology. This Australia era, 1895-1905, coincided with and in some respects was the result of the new knowledge emerging from Europe and the Americas of the therapeutic effects of antitoxins. The subsequent systematic study of Australian venoms and toxins through to the 1930s and beyond, by Tidswell, Fairley, Ross, Kellaway and Cleland, set the foundation for Australia's leading reputation in venom research. As elsewhere, this development was to revolutionise the medical management of those victims who in the past had died in Australia from our venomous and toxic fauna. Morgan, Graydon, Weiner, Lane and Baxter at the Commonwealth Serum Laboratories emphasised the importance of cooperation between those expert at catching and milking the venomous creatures and those developing the antivenoms. Commercial antivenom manufacture began in Australia in 1930 with the tiger snake antivenom. This was followed by other antivenoms for the other important species (1955: taipan; 1956: brown snake; 1958: death adder; 1959: Papuan black snake; 1961: sea snake; 1962: polyvalent) including the first marine antivenoms in the world (1956: stonefish antivenom; 1970: box jellyfish) culminating, in 1980, with the release of the funnel web spider antivenom. More recent activity has focused on veterinary antivenoms and production of new generation human antivenoms for export (CroFab and ViperaTAB). This paper reviews some of the milestones of Australian toxinology, and antivenom development in particular, during the 20th century.

  12. High Intensity e-beam Diode Development for Flash X-ray Radiography

    NASA Astrophysics Data System (ADS)

    Oliver, Bryan

    2007-11-01

    A variety of electron beam diodes are being used and developed for the purpose of creating high-brightness, flash x-ray radiography sources. In these diodes, high energy (multi MeV), high current (multi kA), small spot (multi mm) electron beams are generated and stopped in high atomic number anode-targets (typically Ta or W). Beam stopping in the target creates copious amounts of bremsstrahlung radiation. In addition, beam heating of the target liberates material, either in the form of low density (˜10^12-10^14 cm-3) ion emission or higher density (> 10^15 cm-3) plasma. In all cases, beam/target collective effects dominate the diode and beam characteristics, affecting the radiation properties (dose and spot-size). Recent experiments at Sandia National Laboratories have demonstrated diodes capable of producing > 350 rad@m with 1.7mm FWHM x-ray source distributions. A review of our present theoretical understanding of the diode (s) operation and our experimental and simulation methods to investigate them will be presented. Emphasis will be given to e- beam sources used on state-of-the-art Inductive Voltage Adder (IVA) pulsed-power accelerators. In particular, the physics of magnetically pinched diodes (e.g. the rod-pinch [1,2]), gas-cell focusing diodes [3] and the magnetically immersed [4] diode will be discussed. Various proposed methods to optimize the x-ray intensity and the direction of future diode research will be discussed. [1] G. Cooperstein, et al., Phys. Plasmas 8, 4618 (2001).[2] B.V. Oliver et al., Phys. Plasmas 11, 3976 (2004)[3] B.V. Oliver, et al., IEEE Trans. on Plasma Science 33, 704 (2005).[4] M.G. Mazarakis, et al., Appl. Phys. Lett. 70, 832 (1997)

  13. Comparison between Frame-Constrained Fix-Pixel-Value and Frame-Free Spiking-Dynamic-Pixel ConvNets for Visual Processing

    PubMed Central

    Farabet, Clément; Paz, Rafael; Pérez-Carrasco, Jose; Zamarreño-Ramos, Carlos; Linares-Barranco, Alejandro; LeCun, Yann; Culurciello, Eugenio; Serrano-Gotarredona, Teresa; Linares-Barranco, Bernabe

    2012-01-01

    Most scene segmentation and categorization architectures for the extraction of features in images and patches make exhaustive use of 2D convolution operations for template matching, template search, and denoising. Convolutional Neural Networks (ConvNets) are one example of such architectures that can implement general-purpose bio-inspired vision systems. In standard digital computers 2D convolutions are usually expensive in terms of resource consumption and impose severe limitations for efficient real-time applications. Nevertheless, neuro-cortex inspired solutions, like dedicated Frame-Based or Frame-Free Spiking ConvNet Convolution Processors, are advancing real-time visual processing. These two approaches share the neural inspiration, but each of them solves the problem in different ways. Frame-Based ConvNets process frame by frame video information in a very robust and fast way that requires to use and share the available hardware resources (such as: multipliers, adders). Hardware resources are fixed- and time-multiplexed by fetching data in and out. Thus memory bandwidth and size is important for good performance. On the other hand, spike-based convolution processors are a frame-free alternative that is able to perform convolution of a spike-based source of visual information with very low latency, which makes ideal for very high-speed applications. However, hardware resources need to be available all the time and cannot be time-multiplexed. Thus, hardware should be modular, reconfigurable, and expansible. Hardware implementations in both VLSI custom integrated circuits (digital and analog) and FPGA have been already used to demonstrate the performance of these systems. In this paper we present a comparison study of these two neuro-inspired solutions. A brief description of both systems is presented and also discussions about their differences, pros and cons. PMID:22518097

  14. Framework for Integrating Science Data Processing Algorithms Into Process Control Systems

    NASA Technical Reports Server (NTRS)

    Mattmann, Chris A.; Crichton, Daniel J.; Chang, Albert Y.; Foster, Brian M.; Freeborn, Dana J.; Woollard, David M.; Ramirez, Paul M.

    2011-01-01

    A software framework called PCS Task Wrapper is responsible for standardizing the setup, process initiation, execution, and file management tasks surrounding the execution of science data algorithms, which are referred to by NASA as Product Generation Executives (PGEs). PGEs codify a scientific algorithm, some step in the overall scientific process involved in a mission science workflow. The PCS Task Wrapper provides a stable operating environment to the underlying PGE during its execution lifecycle. If the PGE requires a file, or metadata regarding the file, the PCS Task Wrapper is responsible for delivering that information to the PGE in a manner that meets its requirements. If the PGE requires knowledge of upstream or downstream PGEs in a sequence of executions, that information is also made available. Finally, if information regarding disk space, or node information such as CPU availability, etc., is required, the PCS Task Wrapper provides this information to the underlying PGE. After this information is collected, the PGE is executed, and its output Product file and Metadata generation is managed via the PCS Task Wrapper framework. The innovation is responsible for marshalling output Products and Metadata back to a PCS File Management component for use in downstream data processing and pedigree. In support of this, the PCS Task Wrapper leverages the PCS Crawler Framework to ingest (during pipeline processing) the output Product files and Metadata produced by the PGE. The architectural components of the PCS Task Wrapper framework include PGE Task Instance, PGE Config File Builder, Config File Property Adder, Science PGE Config File Writer, and PCS Met file Writer. This innovative framework is really the unifying bridge between the execution of a step in the overall processing pipeline, and the available PCS component services as well as the information that they collectively manage.

  15. DNA logic gates.

    PubMed

    Okamoto, Akimitsu; Tanaka, Kazuo; Saito, Isao

    2004-08-04

    A conceptually new logic gate based on DNA has been devised. Methoxybenzodeazaadenine ((MD)A), an artificial nucleobase which we recently developed for efficient hole transport through DNA, formed stable base pairs with T and C. However, a reasonable hole-transport efficiency was observed in the reaction for the duplex containing an (MD)A/T base pair, whereas the hole transport was strongly suppressed in the reaction using a duplex where the base opposite (MD)A was replaced by C. The influence of complementary pyrimidines on the efficiency of hole transport through (MD)A was quite contrary to the selectivity observed for hole transport through G. The orthogonality of the modulation of these hole-transport properties by complementary pyrimidine bases is promising for the design of a new molecular logic gate. The logic gate system was executed by hole transport through short DNA duplexes, which consisted of the "logic gate strand", containing hole-transporting nucleobases, and the "input strand", containing pyrimidines which modulate the hole-transport efficiency of logic bases. A logic gate strand containing multiple (MD)A bases in series provided the basis for a sharp AND logic action. On the other hand, for OR logic and combinational logic, conversion of Boolean expressions to standard sum-of-product (SOP) expressions was indispensable. Three logic gate strands were designed for OR logic according to each product term in the standard SOP expression of OR logic. The hole-transport efficiency observed for the mixed sample of logic gate strands exhibited an OR logic behavior. This approach is generally applicable to the design of other complicated combinational logic circuits such as the full-adder.

  16. Use of a radial self-field diode geometry for intense pulsed ion beam generation at 6 MeV on Hermes III

    SciTech Connect

    Renk, T. J. Harper-Slaboszewicz, V.; Mikkelson, K. A.; Ginn, W. C.; Ottinger, P. F.; Schumer, J. W.

    2014-12-15

    We investigate the generation of intense pulsed focused ion beams at the 6 MeV level using an inductive voltage adder (IVA) pulsed-power generator, which employs a magnetically insulated transmission line (MITL). Such IVA machines typical run at an impedance of few tens of Ohms. Previous successful intense ion beam generation experiments have often featured an “axial” pinch-reflex ion diode (i.e., with an axial anode-cathode gap) and operated on a conventional Marx generator/water line driver with an impedance of a few Ohms and no need for an MITL. The goals of these experiments are to develop a pinch-reflex ion diode geometry that has an impedance to efficiently match to an IVA, produces a reasonably high ion current fraction, captures the vacuum electron current flowing forward in the MITL, and focuses the resulting ion beam to small spot size. A new “radial” pinch-reflex ion diode (i.e., with a radial anode-cathode gap) is found to best demonstrate these properties. Operation in both positive and negative polarities was undertaken, although the negative polarity experiments are emphasized. Particle-in-cell (PIC) simulations are consistent with experimental results indicating that, for diode impedances less than the self-limited impedance of the MITL, almost all of the forward-going IVA vacuum electron flow current is incorporated into the diode current. PIC results also provide understanding of the diode-impedance and ion-focusing properties of the diode. In addition, a substantial high-energy ion population is also identified propagating in the “reverse” direction, i.e., from the back side of the anode foil in the electron beam dump.

  17. Use of a radial self-field diode geometry for intense pulsed ion beam generation at 6 MeV on Hermes III

    SciTech Connect

    Renk, Timothy Jerome; Harper-Slaboszewicz, Victor Jozef; Mikkelson, Kenneth A.; Ginn, W. C.; Ottinger, P. F.; Schumer, J. W.

    2014-12-15

    We investigate the generation of intense pulsed focused ion beams at the 6 MeV level using an inductive voltage adder (IVA) pulsed-power generator, which employs a magnetically insulated transmission line (MITL). Such IVA machines typical run at an impedance of few tens of Ohms. Previous successful intense ion beam generation experiments have often featured an “axial” pinch-reflex ion diode (i.e., with an axial anode-cathode gap) and operated on a conventional Marx generator/water line driver with an impedance of a few Ohms and no need for an MITL. The goals of these experiments are to develop a pinch-reflex ion diode geometry that has an impedance to efficiently match to an IVA, produces a reasonably high ion current fraction, captures the vacuum electron current flowing forward in the MITL, and focuses the resulting ion beam to small spot size. Furthermore, a new “radial” pinch-reflex ion diode (i.e., with a radial anode-cathode gap) is found to best demonstrate these properties. Operation in both positive and negative polarities was undertaken, although the negative polarity experiments are emphasized. Particle-in-cell (PIC) simulations are consistent with experimental results indicating that, for diode impedances less than the self-limited impedance of the MITL, almost all of the forward-going IVA vacuum electron flow current is incorporated into the diode current. PIC results also provide understanding of the diode-impedance and ion-focusing properties of the diode. Additionally, a substantial high-energy ion population is also identified propagating in the “reverse” direction, i.e., from the back side of the anode foil in the electron beam dump.

  18. Use of a radial self-field diode geometry for intense pulsed ion beam generation at 6 MeV on Hermes III

    DOE PAGES

    Renk, Timothy Jerome; Harper-Slaboszewicz, Victor Jozef; Mikkelson, Kenneth A.; ...

    2014-12-15

    We investigate the generation of intense pulsed focused ion beams at the 6 MeV level using an inductive voltage adder (IVA) pulsed-power generator, which employs a magnetically insulated transmission line (MITL). Such IVA machines typical run at an impedance of few tens of Ohms. Previous successful intense ion beam generation experiments have often featured an “axial” pinch-reflex ion diode (i.e., with an axial anode-cathode gap) and operated on a conventional Marx generator/water line driver with an impedance of a few Ohms and no need for an MITL. The goals of these experiments are to develop a pinch-reflex ion diode geometrymore » that has an impedance to efficiently match to an IVA, produces a reasonably high ion current fraction, captures the vacuum electron current flowing forward in the MITL, and focuses the resulting ion beam to small spot size. Furthermore, a new “radial” pinch-reflex ion diode (i.e., with a radial anode-cathode gap) is found to best demonstrate these properties. Operation in both positive and negative polarities was undertaken, although the negative polarity experiments are emphasized. Particle-in-cell (PIC) simulations are consistent with experimental results indicating that, for diode impedances less than the self-limited impedance of the MITL, almost all of the forward-going IVA vacuum electron flow current is incorporated into the diode current. PIC results also provide understanding of the diode-impedance and ion-focusing properties of the diode. Additionally, a substantial high-energy ion population is also identified propagating in the “reverse” direction, i.e., from the back side of the anode foil in the electron beam dump.« less

  19. Optimization of current waveform tailoring for magnetically driven isentropic compression experiments.

    PubMed

    Waisman, E M; Reisman, D B; Stoltzfus, B S; Stygar, W A; Cuneo, M E; Haill, T A; Davis, J-P; Brown, J L; Seagle, C T; Spielman, R B

    2016-06-01

    The Thor pulsed power generator is being developed at Sandia National Laboratories. The design consists of up to 288 decoupled and transit time isolated capacitor-switch units, called "bricks," that can be individually triggered to achieve a high degree of pulse tailoring for magnetically driven isentropic compression experiments (ICE) [D. B. Reisman et al., Phys. Rev. Spec. Top.-Accel. Beams 18, 090401 (2015)]. The connecting transmission lines are impedance matched to the bricks, allowing the capacitor energy to be efficiently delivered to an ICE strip-line load with peak pressures of over 100 GPa. Thor will drive experiments to explore equation of state, material strength, and phase transition properties of a wide variety of materials. We present an optimization process for producing tailored current pulses, a requirement for many material studies, on the Thor generator. This technique, which is unique to the novel "current-adder" architecture used by Thor, entirely avoids the iterative use of complex circuit models to converge to the desired electrical pulse. We begin with magnetohydrodynamic simulations for a given material to determine its time dependent pressure and thus the desired strip-line load current and voltage. Because the bricks are connected to a central power flow section through transit-time isolated coaxial cables of constant impedance, the brick forward-going pulses are independent of each other. We observe that the desired equivalent forward-going current driving the pulse must be equal to the sum of the individual brick forward-going currents. We find a set of optimal brick delay times by requiring that the L2 norm of the difference between the brick-sum current and the desired forward-going current be a minimum. We describe the optimization procedure for the Thor design and show results for various materials of interest.

  20. Efficient readout electronics for multi-anode photomultiplier

    NASA Astrophysics Data System (ADS)

    Lerche, Christoph W.; Herrero-Bosch, Vicente; Ferrando-Jodar, Nestor; Gadea-Girones, Rafa; Sanchez-Martinez, Filomeno; Mora-Más, Francisco J.

    2010-08-01

    We present a novel active and analog readout and preprocessing topology for position sensitive photodetectors (PSPD) that allows to readout a large variety of PSPD devices with different pixel numbers. Additionally, the topology was designed to allow for a significant reduction of analog-to-digital conversion channels. The circuit topology replaces the common passive charge divider and consists of N input stages, N × M weighting stages and M analog adder stages, where N is the number of the input channels, i.e. the number of photodetector pixels and M is the number of outputs. The circuit performs the multiplication of a matrix (the weights) with a vector (signals). For this, the input stage makes M copies of each of the N input signals, the weighting stage multiplies these signal copies with N × M different weights and the output stage adds all weighted copies with the same copy index. For high flexibility, the weights are programmable and the topology allows to interconnect several identical circuits for larger N. Measurements with a first prototype ASIC show that the achieved energy and centroid resolutions equal the resolutions from detectors with passive charge division circuits. However, the presented topology presents important advantages such as scalability. As a first application, we used the prototype ASIC to correct the sensitivity inhomogeneity of position sensitive photomultiplier tubes. As a second application for the circuit, we present a Neural Network based positioning scheme for γ-ray imaging detectors with thick, monolithic scintillation crystals. This allows to correct the strong border artifacts of the center of gravity positioning scheme in monolithic scintillation crystals and thus enhances the spatial resolution of the γ-ray imaging detector.

  1. Characterization of spectral optical responsivity of Si-photodiode junction combinations available in a 0.35μm HV-CMOS technology

    NASA Astrophysics Data System (ADS)

    Kraxner, A.; Wachmann, E.; Jonak-Auer, I.; Teva, J.; Park, J. M.; Minixhofer, R.

    2013-05-01

    The 0.35μm HV-CMOS process technology utilizes several junctions with different doping levels and depths. This process supports complete modular 3V and 5V standard CMOS functionality and offers a wide set of HV transistor types capable for operating voltages from 20V to 120V made available with only 2 more mask adders [1]. Compared to other reported integration of photo detection functionalities in normal CMOS processes [2] or special modified process technologies [3] a much wider variety of junction combinations is already intrinsically available in the investigated technology. Such junctions include beside the standard n+ and p+ source/drain dopings also several combinations of shallow and deep tubs for both p-wells and n-wells. The availability of junction from submicron to 7μm depths enables the selection of appropriate spectral sensitivity ranging from ultraviolet to infrared wavelengths. On the other side by appropriate layouts the contributions of photocurrents of shallower or deeper photo carrier generation can be kept to a minimum. We also show that by analytically modelling the space charge regions of the selected junctions the drift and diffusion carrier contributions can be calculated with a very good match indicating also the suppression of diffusion current contribution. We present examples of spectral responsivity of junction combinations optimized for peak sensitivity in the ranges of 380-450nm, 450-600nm or 700-900nm. By appropriate junction choice the ratios of the generated photo currents in their respective peak zones can exhibit more than a factor of 10 compared to the other photo diode combinations. This enables already without further filter implementation a very good spectral resolution for colour sensing applications. Finally the possible junction combinations are also assessed by the achievable dark current for optimized signal to noise characteristic.

  2. COBRA accelerator for Sandia ICF diode research at Cornell University

    NASA Astrophysics Data System (ADS)

    Smith, David L.; Ingwersen, Pete; Bennett, Lawrence F.; Boyes, John D.; Anderson, David E.; Greenly, John B.; Sudan, Ravi N.

    The new COBRA accelerator is being built in stages at the Laboratory of Plasma Studies in Cornell University where its applications will include extraction diode and ion beam research in support of the light ion inertial confinement fusion (ICF) program at Sandia National Laboratories. The 4- to 5-MV, 125- to 250-kA accelerator is based on a four-cavity inductive voltage adder (IVA) design. It is a combination of new ferromagnetically-isolated cavities and self magnetically insulated transmission line (MITL) hardware and components from existing Sandia and Cornell facilities: Marx generator capacitors, hardware, and power supply from the DEMON facility; water pulse forming lines (PFL) and gas switch from the Subsystem Test Facility (STF); a HERMES-3 intermediate store capacitor (ISC); and a modified ion diode from Cornell's LION. The present accelerator consists of a single modified cavity similar to those of the Sandia SABRE accelerator and will be used to establish an operating system for the first stage initial lower voltage testing. Four new cavities will be fabricated and delivered in the first half of FY96 to complete the COBRA accelerator. COBRA is unique in the sense that each cavity is driven by a single pulse forming line, and the IVA output polarity may be reversed by rotating the cavities 180(degrees) about their vertical axis. The site preparations, tank construction, and diode design and development are taking place at Cornell with growing enthusiasm as this machine becomes a reality. Preliminary results with the single cavity and short positive inner cylinder MITL configuration will soon be available.

  3. Towards reduced impact of EUV mask defectivity on wafer

    NASA Astrophysics Data System (ADS)

    Jonckheere, R.; Van den Heuvel, D.; Pacco, A.; Pollentier, I.; Baudemprez, B.; Jehoul, C.; Hermans, J.; Hendrickx, E.

    2014-07-01

    The defectivity challenges of extreme ultraviolet (EUV) masks, that need to be addressed before production readiness of EUV lithography is assured from the mask perspective, are twofold. First, the EUV-specific defect type relating to the multi-layer (ML) mirror, the so-called ML-defects, require to become more detectable than they are printable. This not only requires proven capability of blank inspection, but also the existence of satisfactory printability mitigation strategies (comprising avoidance, pattern shift methodology, compensation repair). Both these assets need to become available within the mask supply chain, as there is little that can still be done about such residual defects at the wafer fab. In a production phase, finding unexpected printing ML-defects is unacceptable. It is shown how the specific way-of-working in use at imec, starting from the printed wafer, contributes to related learning and identification of remaining gaps, in getting this issue fully dealt with. The second challenge relates to particle contamination during use of the reticle at the wafer fab. Avoiding overlaycritical particles on the backside of NXE3100 reticles is facilitated by the established way-of-working. Minimizing the occurrence of particles "hopping" between reticles via the electrostatic clamp of the scanner (so-called clamp-traveling particles) is a major driver for appropriate mask cleaning. The latter may not have negative impact by frequent use, in view of the highly vulnerable EUV mask stack, and especially for the present "black-border" solution in which the ML is etched away at the image border on the reticle. A lot of effort is spent into monitoring of NXE3100 reticles for particle adders on the pattern side. This is realized by comparing past and present mask defect maps obtained by inspection of printed wafers with subsequent repeater analysis.

  4. NASA Tech Briefs, January 2003

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Topics covered include: Optoelectronic Tool Adds Scale Marks to Photographic Images; Compact Interconnection Networks Based on Quantum Dots; Laterally Coupled Quantum-Dot Distributed-Feedback Lasers; Bit-Serial Adder Based on Quantum Dots; Stabilized Fiber-Optic Distribution of Reference Frequency; Delay/Doppler-Mapping GPS-Reflection Remote-Sensing System; Ladar System Identifies Obstacles Partly Hidden by Grass; Survivable Failure Data Recorders for Spacecraft; Fiber-Optic Ammonia Sensors; Silicon Membrane Mirrors with Electrostatic Shape Actuators; Nanoscale Hot-Wire Probes for Boundary-Layer Flows; Theodolite with CCD Camera for Safe Measurement of Laser-Beam Pointing; Efficient Coupling of Lasers to Telescopes with Obscuration; Aligning Three Off-Axis Mirrors with Help of a DOE; Calibrating Laser Gas Measurements by Use of Natural CO2; Laser Ranging Simulation Program; Micro-Ball-Lens Optical Switch Driven by SMA Actuator; Evaluation of Charge Storage and Decay in Spacecraft Insulators; Alkaline Capacitors Based on Nitride Nanoparticles; Low-EC-Content Electrolytes for Low-Temperature Li-Ion Cells; Software for a GPS-Reflection Remote-Sensing System; Software for Building Models of 3D Objects via the Internet; "Virtual Cockpit Window" for a Windowless Aerospacecraft; CLARAty Functional-Layer Software; Java Library for Input and Output of Image Data and Metadata; Software for Estimating Costs of Testing Rocket Engines; Energy-Absorbing, Lightweight Wheels; Viscoelastic Vibration Dampers for Turbomachine Blades; Soft Landing of Spacecraft on Energy-Absorbing Self-Deployable Cushions; Pneumatically Actuated Miniature Peristaltic Vacuum Pumps; Miniature Gas-Turbine Power Generator; Pressure-Sensor Assembly Technique; Wafer-Level Membrane-Transfer Process for Fabricating MEMS; A Reactive-Ion Etch for Patterning Piezoelectric Thin Film; Wavelet-Based Real-Time Diagnosis of Complex Systems; Quantum Search in Hilbert Space; Analytic Method for Computing Instrument

  5. Method and apparatus for enhancing microchannel plate data

    DOEpatents

    Thoe, Robert S.

    1987-01-01

    A method and apparatus for determining centroid channel locations is disclosed for use in a system activated by one or more multichannel plates (16,18) and including a linear diode array (24) providing channels of information 1, 2, . . . , n, . . . , N containing signal amplitudes A.sub.n. A source of analog A.sub.n signals (40), and a source of digital clock signals n (48), are provided. Non-zero A.sub.n values are detected in a discriminator (42). A digital signal representing p, the value of n immediately preceding that whereat A.sub.n takes its first non-zero value, is generated in a scaler (50). The analog A.sub.n signals are converted to digital in an analog to digital converter (44). The digital A.sub.n signals are added to produce a digital .SIGMA.A.sub.n signal in a full adder (46). Digital 1, 2, . . . , m signals representing the number of non-zero A.sub.n are produced by a discriminator pulse counter (52). Digital signals representing 1 A.sub.p+ 1, 2 A.sub.p+2, . . . , m A.sub.p+m are produced by pairwise multiplication in multiplier (54). These signals are added in multiplier summer (56) to produce a digital .SIGMA.nA.sub.n -p.SIGMA.A.sub.n signal. This signal is divided by the digital .SIGMA.A.sub.n signal in divider (58) to provide a digital (.SIGMA.nA.sub.n /.SIGMA.A.sub.n) -p signal. Finally, this last signal is added to the digital p signal in an offset summer (60) to provide .SIGMA.nA.sub.n /.SIGMA.A.sub.n, the centroid channel locations.

  6. Systems chemistry: logic gates, arithmetic units, and network motifs in small networks.

    PubMed

    Wagner, Nathaniel; Ashkenasy, Gonen

    2009-01-01

    A mixture of molecules can be regarded as a network if all the molecular components participate in some kind of interaction with other molecules--either physical or functional interactions. Template-assisted ligation reactions that direct replication processes can serve as the functional elements that connect two members of a chemical network. In such a process, the template does not necessarily catalyze its own formation, but rather the formation of another molecule, which in turn can operate as a template for reactions within the network medium. It was postulated that even networks made up of small numbers of molecules possess a wealth of molecular information sufficient to perform rather complex behavior. To probe this assumption, we have constructed virtual arrays consisting of three replicating molecules, in which dimer templates are capable of catalyzing reactants to form additional templates. By using realistic parameters from peptides or DNA replication experiments, we simulate the construction of various functional motifs within the networks. Specifically, we have designed and implemented each of the three-element Boolean logic gates, and show how these networks are assembled from four basic "building blocks". We also show how the catalytic pathways can be wired together to perform more complex arithmetic units and network motifs, such as the half adder and half subtractor computational modules, and the coherent feed-forward loop network motifs under different sets of parameters. As in previous studies of chemical networks, some of the systems described display behavior that would be difficult to predict without the numerical simulations. Furthermore, the simulations reveal trends and characteristics that should be useful as "recipes" for future design of experimental functional motifs and for potential integration into modular circuits and molecular computation devices.

  7. Optical analog-to-digital converter

    NASA Technical Reports Server (NTRS)

    Evanchuk, Vincent L. (Inventor)

    1984-01-01

    A method and apparatus for converting the intensity of an unknown optical signal (B) into an electrical signal in digital form utilizes two elongated optical attenuators (11, 13), one for the unknown optical signal from a source (10) and one for a known optical signal (A) from a variable source (12), a plurality of photodetectors (e.g., 17, 18) along each attenuator for detecting the intensity of the optical signals, and a plurality of comparators (e.g., 21) connected to the photodetectors in pairs to determine at what points being compared the attenuated known signal equals the attenuated unknown signal. The intensity of the unknown relative to the known is thus determined by the output of a particular comparator. That output is automatically encoded to a relative intensity value in digital form through a balancing feedback control (24) and encoder (23). The digital value may be converted to analog form in a D-to-A converter (27) and used to vary the source of the known signal so that the attenuated intensity of the known signal at a predetermined point (comparator 16) equals the attenuated intensity of the unknown signal at the predetermined point of comparison. If the known signal is then equal to the unknown, there is verification of the analog-to-digital conversion being complete. Otherwise the output of the comparator indicating equality at some other point along the attenuators will provide an output which is encoded and added, through an accumulator comprised of a register (25) and an adder (26), to a previous relative intensity value thereby to further vary the intensity of the known signal source. The steps are repeated until full conversion is verified.

  8. Surface-confined assemblies and polymers for molecular logic.

    PubMed

    de Ruiter, Graham; van der Boom, Milko E

    2011-08-16

    Stimuli responsive materials are capable of mimicking the operation characteristics of logic gates such as AND, OR, NOR, and even flip-flops. Since the development of molecular sensors and the introduction of the first AND gate in solution by de Silva in 1993, Molecular (Boolean) Logic and Computing (MBLC) has become increasingly popular. In this Account, we present recent research activities that focus on MBLC with electrochromic polymers and metal polypyridyl complexes on a solid support. Metal polypyridyl complexes act as useful sensors to a variety of analytes in solution (i.e., H(2)O, Fe(2+/3+), Cr(6+), NO(+)) and in the gas phase (NO(x) in air). This information transfer, whether the analyte is present, is based on the reversible redox chemistry of the metal complexes, which are stable up to 200 °C in air. The concurrent changes in the optical properties are nondestructive and fast. In such a setup, the input is directly related to the output and, therefore, can be represented by one-input logic gates. These input-output relationships are extendable for mimicking the diverse functions of essential molecular logic gates and circuits within a set of Boolean algebraic operations. Such a molecular approach towards Boolean logic has yielded a series of proof-of-concept devices: logic gates, multiplexers, half-adders, and flip-flop logic circuits. MBLC is a versatile and, potentially, a parallel approach to silicon circuits: assemblies of these molecular gates can perform a wide variety of logic tasks through reconfiguration of their inputs. Although these developments do not require a semiconductor blueprint, similar guidelines such as signal propagation, gate-to-gate communication, propagation delay, and combinatorial and sequential logic will play a critical role in allowing this field to mature. For instance, gate-to-gate communication by chemical wiring of the gates with metal ions as electron carriers results in the integration of stand-alone systems: the

  9. Block QCA Fault-Tolerant Logic Gates

    NASA Technical Reports Server (NTRS)

    Firjany, Amir; Toomarian, Nikzad; Modarres, Katayoon

    2003-01-01

    Suitably patterned arrays (blocks) of quantum-dot cellular automata (QCA) have been proposed as fault-tolerant universal logic gates. These block QCA gates could be used to realize the potential of QCA for further miniaturization, reduction of power consumption, increase in switching speed, and increased degree of integration of very-large-scale integrated (VLSI) electronic circuits. The limitations of conventional VLSI circuitry, the basic principle of operation of QCA, and the potential advantages of QCA-based VLSI circuitry were described in several NASA Tech Briefs articles, namely Implementing Permutation Matrices by Use of Quantum Dots (NPO-20801), Vol. 25, No. 10 (October 2001), page 42; Compact Interconnection Networks Based on Quantum Dots (NPO-20855) Vol. 27, No. 1 (January 2003), page 32; Bit-Serial Adder Based on Quantum Dots (NPO-20869), Vol. 27, No. 1 (January 2003), page 35; and Hybrid VLSI/QCA Architecture for Computing FFTs (NPO-20923), which follows this article. To recapitulate the principle of operation (greatly oversimplified because of the limitation on space available for this article): A quantum-dot cellular automata contains four quantum dots positioned at or between the corners of a square cell. The cell contains two extra mobile electrons that can tunnel (in the quantummechanical sense) between neighboring dots within the cell. The Coulomb repulsion between the two electrons tends to make them occupy antipodal dots in the cell. For an isolated cell, there are two energetically equivalent arrangements (denoted polarization states) of the extra electrons. The cell polarization is used to encode binary information. Because the polarization of a nonisolated cell depends on Coulomb-repulsion interactions with neighboring cells, universal logic gates and binary wires could be constructed, in principle, by arraying QCA of suitable design in suitable patterns. Heretofore, researchers have recognized two major obstacles to realization of QCA

  10. Nowhere to Go but Up: Impacts of Climate Change on Demographics of a Short-Range Endemic (Crotalus willardi obscurus) in the Sky-Islands of Southwestern North America

    PubMed Central

    Davis, Mark A.; Douglas, Marlis R.; Webb, Colleen T.; Collyer, Michael L.; Holycross, Andrew T.; Painter, Charles W.; Kamees, Larry K.; Douglas, Michael E.

    2015-01-01

    Biodiversity elements with narrow niches and restricted distributions (i.e., ‘short range endemics,’ SREs) are particularly vulnerable to climate change. The New Mexico Ridge-nosed Rattlesnake (Crotalus willardi obscurus, CWO), an SRE listed under the U.S. Endangered Species Act within three sky islands of southwestern North America, is constrained at low elevation by drought and at high elevation by wildfire. We combined long-term recapture and molecular data with demographic and niche modeling to gauge its climate-driven status, distribution, and projected longevity. The largest population (Animas) is numerically constricted (N = 151), with few breeding adults (Nb = 24) and an elevated inbreeding coefficient (ΔF = 0.77; 100 years). Mean home range (0.07km2) is significantly smaller compared to other North American rattlesnakes, and movements are within, not among sky islands. Demographic values, when gauged against those displayed by other endangered/Red-Listed reptiles [e.g., Loggerhead Sea Turtle (Caretta caretta)], are either comparable or markedly lower. Survival rate differs significantly between genders (femaleAdder (Vipera berus), a conservation icon in southern Sweden. Genetic rescue, a management approach successfully employed in similar situations, is ill advised in this situation due to climate-driven habitat change in the sky islands. CWO is a rare organism in a unique environment, with a conserved niche and a predisposition towards extinction. It is a bellwether for the

  11. A Quantum Annealing Computer Team Addresses Climate Change Predictability

    NASA Technical Reports Server (NTRS)

    Halem, M. (Principal Investigator); LeMoigne, J.; Dorband, J.; Lomonaco, S.; Yesha, Ya.; Simpson, D.; Clune, T.; Pelissier, C.; Nearing, G.; Gentine, P.; Fang, B.; Shehab, A.; Radov, Asen; Tikak, N.; Prouty, Roy; Harrison, Kenneth

    2016-01-01

    converted to a BM algorithm implementation on the QAC. The first integer adder has been implemented on the D-Wave 2X by A. Shehab that will perform HAAR wavelets for image compression of MODIS scenes. Finally, based on the next generations of QACs, we are preparing a 5-year performance road map on the scalability of the current QAC algorithms.

  12. Nanoscale Magnetic Materials for Energy-Efficient Spin Based Transistors

    NASA Astrophysics Data System (ADS)

    Incorvia, Jean Anne Currivan

    In this dissertation, I study the physical behavior of nanoscale magnetic materials and build spin-based transistors that encode information in magnetic domain walls. It can be argued that energy dissipation is the most serious problem in modern electronics, and one that has been resistant to a breakthrough. Wasted heat during computing both wastes energy and hinders further technology scaling. This is an opportunity for physicists and engineers to come up with creative solutions for more energy-efficient computing. I present the device we have designed, called domain wall logic (DW-Logic). Information is stored in the position of a magnetic domain wall in a ferromagnetic wire and read out using a magnetic tunnel junction. This hybrid design uses electrical current as the input and output, keeping the device compatible with charge- based transistors. I build an iterative model to predict both the micromagnetic and circuit behavior of DW- Logic, showing a single device can operate as a universal gate. The model shows we can build complex circuits including an 18-gate Full Adder, and allows us to predict the device switching energy compared to complementary metal-oxide semiconductor (CMOS) transistors. Comparing ?15 nm feature nodes, I find DW-Logic made with perpendicular magnetic anisotropy materials, and utilizing both spin torque transfer and the Spin Hall effect, could operate with 1000x reduced switching energy compared to CMOS. I fabricate DW-Logic device prototypes and show in experiment they can act as AND and NAND gates. I demonstrate that one device can drive two subsequent devices, showing gain, which is a necessary requirement for fanout. I also build a clocked ring oscillator circuit to demonstrate successful bit propagation in a DW-Logic circuit and show that properly scaled devices can have improved operation. Through building the devices, I develop a novel fabrication method for patterning sub-25 nm magnetic wires with very low (˜ 2 nm) average edge

  13. Nowhere to Go but Up: Impacts of Climate Change on Demographics of a Short-Range Endemic (Crotalus willardi obscurus) in the Sky-Islands of Southwestern North America.

    PubMed

    Davis, Mark A; Douglas, Marlis R; Webb, Colleen T; Collyer, Michael L; Holycross, Andrew T; Painter, Charles W; Kamees, Larry K; Douglas, Michael E

    2015-01-01

    Biodiversity elements with narrow niches and restricted distributions (i.e., 'short range endemics,' SREs) are particularly vulnerable to climate change. The New Mexico Ridge-nosed Rattlesnake (Crotalus willardi obscurus, CWO), an SRE listed under the U.S. Endangered Species Act within three sky islands of southwestern North America, is constrained at low elevation by drought and at high elevation by wildfire. We combined long-term recapture and molecular data with demographic and niche modeling to gauge its climate-driven status, distribution, and projected longevity. The largest population (Animas) is numerically constricted (N = 151), with few breeding adults (Nb = 24) and an elevated inbreeding coefficient (ΔF = 0.77; 100 years). Mean home range (0.07 km2) is significantly smaller compared to other North American rattlesnakes, and movements are within, not among sky islands. Demographic values, when gauged against those displayed by other endangered/Red-Listed reptiles [e.g., Loggerhead Sea Turtle (Caretta caretta)], are either comparable or markedly lower. Survival rate differs significantly between genders (femaleAdder (Vipera berus), a conservation icon in southern Sweden. Genetic rescue, a management approach successfully employed in similar situations, is ill advised in this situation due to climate-driven habitat change in the sky islands. CWO is a rare organism in a unique environment, with a conserved niche and a predisposition towards extinction. It is a bellwether for the

  14. P-23 Highlights 6/10/12: Cygnus Dual Beam Radiographic Facility Refurbishment completed at U1A tunnel in Nevada NNSS meeting Level 2 milestone

    SciTech Connect

    Deyoung, Anemarie; Smith, John R.

    2012-05-03

    A moratorium was placed on U.S. underground nuclear testing in 1992. In response, the Stockpile Stewardship Program was created to maintain readiness of the existing nuclear inventory through several efforts such as computer modeling, material analysis, and subcritical nuclear experiments (SCEs). As in the underground test era, the Nevada National Security Site (NNSS), formerly the Nevada Test Site, provides a safe and secure environment for SCEs by the nature of its isolated and secure facilities. A major tool for SCE diagnosis installed in the 05 drift laboratory is a high energy x-ray source used for time resolved imaging. This tool consists of two identical sources (Cygnus 1 and Cygnus 2) and is called the Cygnus Dual Beam Radiographic Facility (Figs. 2-6). Each Cygnus machine has 5 major elements: Marx Generator, Pulse Forming Line (PFL), Coaxial Transmission Line (CTL), 3-cell Inductive Voltage Adder (IVA), and Rod Pinch Diode. Each machine is independently triggered and may be fired in separate tests (staggered mode), or in a single test where there is submicrosecond separation between the pulses (dual mode). Cygnus must operate as a single shot machine since on each pulse the diode electrodes are destroyed. The diode is vented to atmosphere, cleaned, and new electrodes are inserted for each shot. There is normally two shots per day on each machine. Since its installation in 2003, Cygnus has participated in: 4 Subcritical Experiments (Armando, Bacchus, Barolo A, and Barolo B), a 12 shot plutonium physics series (Thermos), and 2 plutonium step wedge calibration series (2005, 2011), resulting in well over 1000 shots. Currently the Facility is in preparation for 2 SCEs scheduled for this calendar year - Castor and Pollux. Cygnus has performed well during 8 years of operations at NNSS. Many improvements in operations and performance have been implemented during this time. Throughout its service at U1a, major maintenance and replacement of many hardware items

  15. Cost-efficient design of a quantum multiplier-accumulator unit

    NASA Astrophysics Data System (ADS)

    Babu, Hafiz Md. Hasan

    2017-01-01

    This paper proposes a cost-efficient quantum multiplier-accumulator unit. The paper also presents a fast multiplication algorithm and designs a novel quantum multiplier device based on the proposed algorithm with the optimum time complexity as multiplier is the major device of a multiplier-accumulator unit. We show that the proposed multiplication technique has time complexity O((3 log2n)+1), whereas the best known existing technique has O(n log2 n), where n is the number of qubits. In addition, our design proposes three new quantum circuits: a circuit representing a quantum full-adder, a circuit known as quantum ANDing circuit, which performs the ANDing operation and a circuit presenting quantum accumulator. Moreover, the proposed quantum multiplier-accumulator unit is the first ever quantum multiplier-accumulator circuit in the literature till now, which has reduced garbage outputs and ancillary inputs to a great extent. The comparative study shows that the proposed quantum multiplier performs better than the existing multipliers in terms of depth, quantum gates, delays, area and power with the increasing number of qubits. Moreover, we design the proposed quantum multiplier-accumulator unit, which performs better than the existing ones in terms of hardware and delay complexities, e.g., the proposed (n× n)—qubit quantum multiplier-accumulator unit requires O(n2) hardware and O(log2n) delay complexities, whereas the best known existing quantum multiplier-accumulator unit requires O(n3) hardware and O((n-1)2 +1+n) delay complexities. In addition, the proposed design achieves an improvement of 13.04, 60.08 and 27.2% for 4× 4, 7.87, 51.8 and 27.1% for 8× 8, 4.24, 52.14 and 27% for 16× 16, 2.19, 52.15 and 27.26% for 32 × 32 and 0.78, 52.18 and 27.28% for 128 × 128-qubit multiplications over the best known existing approach in terms of number of quantum gates, ancillary inputs and garbage outputs, respectively. Moreover, on average, the proposed design gains an

  16. Single Element 2-DIMENSIONAL Acousto-Optic Deflectors Design, Fabrication and Implementation for Digital Optical Computing

    NASA Astrophysics Data System (ADS)

    Rosemeier, Jolanta Iwona

    1992-09-01

    With the need to develop very fast computers compared to the conventional digital chip based systems, the future is very bright for optical based signal processing. Attention has turned to a different application of optics utilizing mathematical operations, in which case operations are numerical, sometimes discrete, and often algebraic in nature. Interest has been so vigorous that many view it as a small revolution in optics whereby optical signal processing is beginning to encompass what many frequently describe as optical computing. The term is fully intended to imply close comparison with the operations performed by scientific digital computers. Most present computer intensive problem solving processors rely on a common set of linear equations found in numerical matrix algebra. Recently, considerable research focused on the use of systolic array, which can operate at high speeds with great efficiency. This approach addresses the acousto-optic digital and analog arrays utilizing three dimensional optical interconnect technology. In part I of this dissertation the first single element 2-dimensional (2-D) acousto-optic deflector was designed, fabricated and incorporated into an optical 3 x 3 vector-vector or matrix-matrix multiplier system. This single element deflector is used as a outer-product device. The input vectors are addressed by electronic means and the outer product matrix is displayed as a 2-D array of optical (laser) pixels. In part II of this work a multichannel single element 2-D deflector was designed, fabricated and implemented into a Programmable Logic Array (PLA) optical computing system. This system can be used for: word equality detection, free space optical interconnections, half adder optical system implementation. The PLA system described in this dissertation has capability of word equality detection. The 2-D multichannel deflector that was designed and fabricated is capable of comparing 16 x 16 words every 316 nanoseconds. Each word is 8

  17. Harpacticoid copepods-their symbiotic associations and biogenic substrata: a review.

    PubMed

    Huys, Rony

    2016-10-11

    presented by host group. Dichotomous keys are provided for the identification of most species while accidental and doubtful records are discussed where appropriate.The genus Idomenella T. Scott, 1906a (Pseudotachidiidae), previously a junior subjective synonym of Dactylopodella Sars, 1905a, is reinstated to accommodate Dactylopodella rostrata (T. Scott, 1893), D. janetae Hicks, 1989, Xouthous coronatus (T. Scott, 1894b), X. antarcticus (Giesbrecht, 1902), X. intermedius (Lang, 1934) and Idomenella paracoronata sp. nov. Kioloaria Harris, 1994 (Porcellidiidae) is adopted as the valid replacement name for the preoccupied Acutiramus Harris, 2014a. The name of a second porcellidiid genus, Murramia Harris, 1994, lacks the mandatory type fixation and is made available here by adopting the original name but taking the present authorship and date. The generic name Ellucana Sewell, 1940 is currently unavailable and must instead be attributed to Coull (1971b). Laophonte commensalis Raibaut, 1962a is fixed as the type of Raibautius gen. nov. in the family Laophontidae, Tegastes cnidicus Humes, 1981b as the type of Aglaogastes gen. nov. in the Tegastidae, and Canuella (Canuella) indica Krishnaswamy, 1957 as the type of Indicanuella gen. nov.A number of new names are proposed for species that had previously been misidentified: Diarthrodes septemtrionalis sp. nov. for D. roscoffensis (Monard, 1935b) sensu Kornev & Chertoprud (2008), Kioloaria jejuensis sp. nov. for Porcellidium brevicaudatum Thompson & Scott, 1903 sensu Kim & Kim (1996), Xouthous andamanensis sp. nov. for X. maldivae [sic] Sewell, 1940 sensu Wells & Rao (1987), X. wellsi sp. nov. for X. laticaudatus (Thompson & Scott, 1903) sensu Wells (1967), X. namibiensis sp. nov. for X. pectinatus (Scott & Scott, 1898) sensu Kunz (1963), and Idomenella paracoronata sp. nov. for Idomene coronata (T. Scott, 1894b) sensu Sars (1909a). The inadequately described Amenophia ovalis Brady, 1910 is relegated to a species inquirenda in

  18. An open-architecture approach to defect analysis software for mask inspection systems

    NASA Astrophysics Data System (ADS)

    Pereira, Mark; Pai, Ravi R.; Reddy, Murali Mohan; Krishna, Ravi M.

    2009-04-01

    possible for the end-users to make use of their collected knowledge through the years of experience in mask inspection process by encapsulating the knowledge into software utilities and plugging them into NxDAT. The plug-in interface is designed with the intent of enabling the pro-active mask defect analysis teams to build competitive differentiation into their defect analysis process while protecting their knowledge internally within their company. By providing interface with all major standard layout and mask data formats, NxDAT enables correlation of defect data on reticles with design and mask databases, further extending the effectiveness of defect analysis for D2DB inspection. NxDAT also includes many other advanced features for easy and fast navigation, visual display of defects, defect selection, multi-tier classification, defect clustering and gridding, sophisticated CD and contact measurement analysis, repeatability analysis such as adder analysis, defect trend, capture rate etc.

  19. Wide Range SET Pulse Measurement

    NASA Technical Reports Server (NTRS)

    Shuler, Robert L.; Chen, Li

    2012-01-01

    A method for measuring a wide range of SET pulses is demonstrated. Use of dynamic logic, faster than ordinary CMOS, allows capture of short pulses. A weighted binning of SET lengths allows measurement of a wide range of pulse lengths with compact circuitry. A pulse-length-conservative pulse combiner tree routes SETs from combinational logic to the measurement circuit, allowing SET measurements in circuits that cannot easily be arranged in long chains. The method is applied to add-multiplex combinational logic, and to an array of NFET routing switches, at .35 micron. Pulses are captured in a chain of Domino Logic AND gates. Propagation through the chain is frozen on the trailing edge by dropping low the second "enable" input to the AND gates. Capacitive loading is increased in the latter stages to create an approximately logarithmic weighted binning, so that a broad range of pulse lengths can be captured with a 10 stage capture chain. Simulations show pulses can be captured which are 1/5th the length of those typically captured with leading edge triggered latch methods, and less than the length of those captured with a trailing edge latch method. After capture, the pulse pattern is transferred to an SEU protected shift register for readout. 64 instances of each of two types of logic are used as targets. One is a full adder with a 4 to 1 mux on its inputs. The other is a 4 x 4 NFET routing matrix. The outputs are passed through buffered XNOR comparators to identify pulses, which are merged in a buffered not-nand (OR) tree designed to avoid pulse absorption as much as possible. The output from each of the two test circuits are input into separate pulse measurement circuits. Test inputs were provided so that the circuit could be bench tested and calibrated. A third SET measurement circuit with no inputs was used to judge the contribution from direct hits on the measurement circuit. Heavy ions were used with an LET range from 12 to 176. At LET of 21 and below, the very

  20. Recyclable transmission line (RTL) and linear transformer driver (LTD) development for Z-pinch inertial fusion energy (Z-IFE) and high yield.

    SciTech Connect

    Sharpe, Robin Arthur; Kingsep, Alexander S. (Kurchatov Institute, Moscow, Russia); Smith, David Lewis; Olson, Craig Lee; Ottinger, Paul F. (Naval Research Laboratory, Washington, DC); Schumer, Joseph Wade (Naval Research Laboratory, Washington, DC); Welch, Dale Robert (Voss Scientific, Albuquerque, NM); Kim, Alexander (High Currents Institute, Tomsk, Russia); Kulcinski, Gerald L. (University of Wisconsin, Madison, WI); Kammer, Daniel C. (University of Wisconsin, Madison, WI); Rose, David Vincent (Voss Scientific, Albuquerque, NM); Nedoseev, Sergei L. (Kurchatov Institute, Moscow, Russia); Pointon, Timothy David; Smirnov, Valentin P.; Turgeon, Matthew C.; Kalinin, Yuri G. (Kurchatov Institute, Moscow, Russia); Bruner, Nichelle "Nicki" (Voss Scientific, Albuquerque, NM); Barkey, Mark E. (University of Alabama, Tuscaloosa, AL); Guthrie, Michael (University of Wisconsin, Madison, WI); Thoma, Carsten (Voss Scientific, Albuquerque, NM); Genoni, Tom C. (Voss Scientific, Albuquerque, NM); Langston, William L.; Fowler, William E.; Mazarakis, Michael Gerrassimos

    2007-01-01

    demonstrated at the SNL Z-IFE LTD laboratory with rep-rates up to 10.3 seconds between shots (this is essentially at the goal of 10 seconds for Z-IFE). (7) A single LTD switch at Tomsk was fired repetitively every 12 seconds for 36,000 shots with no failures. (8) Five 1.0 MA, 100 kV, 100 ns, LTD cavities have been combined into a voltage adder configuration with a test load to successfully study the system operation. (9) The combination of multiple LTD coaxial lines into a tri-plate transmission line is examined. The 3D Quicksilver code is used to study the electron flow losses produced near the magnetic nulls that occur where coax LTD lines are added together. (10) Circuit model codes are used to model the complete power flow circuit with an inductive isolator cavity. (11) LTD architectures are presented for drivers for Z-IFE and high yield. A 60 MA LTD driver and a 90 MA LTD driver are proposed. Present results from all of these power flow studies validate the whole LTD/RTL concept for single-shot ICF high yield, and for repetitive-shot IFE.