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Sample records for short communication high

  1. Robust Short-Pulse, High-Peak-Power Laser Transmitter for Optical Communications

    NASA Technical Reports Server (NTRS)

    Wright, Malcolm W.

    2009-01-01

    We report on a pulsed fiber based master oscillator power amplifier laser at 1550 nm to support moderate data rates with high peak powers in a compact package suitable for interplanetary optical communications. To accommodate pulse position modulation, the polarization maintaining laser transmitter generates pulses from 0.1 to 1 ns with variable duty cycle over a pulse repetition frequency range of 10 to 100 MHz.

  2. Short-range communication system

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

    2012-01-01

    A short-range communication system includes an antenna, a transmitter, and a receiver. The antenna is an electrical conductor formed as a planar coil with rings thereof being uniformly spaced. The transmitter is spaced apart from the plane of the coil by a gap. An amplitude-modulated and asynchronous signal indicative of a data stream of known peak amplitude is transmitted into the gap. The receiver detects the coil's resonance and decodes same to recover the data stream.

  3. SHORT COMMUNICATION Widespread occurrence of the

    E-print Network

    Hays, Graeme

    SHORT COMMUNICATION Widespread occurrence of the jellyfish Pelagia noctiluca in Irish coastal. Constrained by a benthic polyp stage, most scyphozoan jellyfish have a predominantly coastal distribution

  4. SHORT COMMUNICATIONS ORNITOLOGIA NEOTROPICAL 15: 543545, 2004

    E-print Network

    McCracken, Kevin G.

    , Department of Biology and Wildlife, and University of Alaska Museum, University of Alaska Fairbanks collection database at http://arctos.database.museum. #12;545 SHORT COMMUNICATIONS solid black in 100

  5. Intentionally Short-Range Communications (ISRC)

    NASA Astrophysics Data System (ADS)

    Yen, J.; Poirier, P.; Obrien, M.

    1994-02-01

    The U.S. Marine Corps (USMC) desired to develop short-range communications links whose ranges are intentionally limited to very short distances. These links support tactical missions such as LAN Backbone, Wideband Data Link, and Company Radio. The short-range limitation arises from the need for low probability of detection and intercept (LPD/LPI). Since the detection of an undecipherable transmission would still provide an enemy with information regarding transmitter location and allow him to take countermeasures, the Marine Corps Systems Command (MARCORSYSCOM) is sponsoring the development of technologies that can be LPD by their very nature. The Intentionally Short-Range Communications (ISRC) project at the Naval Command, Control and Ocean Surveillance Center (NCCOSC) RDT&E Division (NRaD) is pursuing feasibility studies for these USMC missions based on such technologies as ultraviolet (LTV) lamps, UV lasers, infrared (IR) lasers, millimeter waves and direct sequence spread spectrum (DSSS) at radio frequencies.

  6. SHORT COMMUNICATION Chiral Enrichment of Serine

    E-print Network

    Clemmer, David E.

    SHORT COMMUNICATION Chiral Enrichment of Serine via Formation, Dissociation, and Soft University, Bloomington, Indiana, USA Chiral enrichment of serine is achieved in experiments that involve of chirally-enriched octameric cluster ions and their dissociation, viz. Ser1 3 Ser8 3 Ser1, allows serine

  7. Vaccine 24 (2006) 38813888 Short communication

    E-print Network

    Earl, David J.

    2006-01-01

    Vaccine 24 (2006) 3881­3888 Short communication Quantifying influenza vaccine efficacy 2006 Abstract We introduce a new measure of antigenic distance between influenza A vaccine of the annual vaccine between 1971 and 2004, as do results of a theory of the immune response to influenza

  8. Short Communication Catalytic coal gasification: use of calcium versus potassium*

    E-print Network

    Short Communication Catalytic coal gasification: use of calcium versus potassium* Ljubisa R November 7983) A comparative study is made of the relative catalytic effects of potassium and calcium conditions. It is indicated that potassium achieves relatively high catalytic activity by chemical

  9. SHORT COMMUNICATION Sexually differentiated, androgen-regulated, larynx-specific

    E-print Network

    Kelley, Darcy B.

    SHORT COMMUNICATION Sexually differentiated, androgen-regulated, larynx-specific myosin heavy that the sarcoplasmic myosin heavy-chain (MyHC) isoform xtMyHC-101d is highly and specifically expressed in the larynx-treated juveniles but not in larynges of untreated juveniles. We compared the larynx-specific expression of xt

  10. Biosensors and Bioelectronics 21 (2005) 523527 Short communication

    E-print Network

    Chen, Wilfred

    2005-01-01

    Biosensors and Bioelectronics 21 (2005) 523­527 Short communication Amperometric microbial biosensor for p-nitrophenol using Moraxella sp.-modified carbon paste electrode Priti Mulchandani, Carlos M microbial biosensor for highly specific, sensitive and rapid quantitative determination of p

  11. Short communication: low-fat ice cream flavor not modified by high hydrostatic pressure treatment of whey protein concentrate.

    PubMed

    Chauhan, J M; Lim, S-Y; Powers, J R; Ross, C F; Clark, S

    2010-04-01

    The purpose of this study was to examine flavor binding of high hydrostatic pressure (HHP)-treated whey protein concentrate (WPC) in a real food system. Fresh Washington State University (WSU, Pullman) WPC, produced by ultrafiltration of separated Cheddar cheese whey, was treated at 300 MPa for 15 min. Commercial WPC 35 powder was reconstituted to equivalent total solids as WSU WPC (8.23%). Six batches of low-fat ice cream were produced: A) HHP-treated WSU WPC without diacetyl; B) and E) WSU WPC with 2 mg/L of diacetyl added before HHP; C) WSU WPC with 2 mg/L of diacetyl added after HHP; D) untreated WSU WPC with 2 mg/L of diacetyl; and F) untreated commercial WPC 35 with 2 mg/L of diacetyl. The solution of WSU WPC or commercial WPC 35 contributed 10% to the mix formulation. Ice creams were produced by using standard ice cream ingredients and processes. Low-fat ice creams containing HHP-treated WSU WPC and untreated WSU WPC were analyzed using headspace-solid phase microextraction-gas chromatography. Sensory evaluation by balanced reference duo-trio test was carried out using 50 untrained panelists in 2 sessions on 2 different days. The headspace-solid phase microextraction-gas chromatography analysis revealed that ice cream containing HHP-treated WSU WPC had almost 3 times the concentration of diacetyl compared with ice cream containing untreated WSU WPC at d 1 of storage. However, diacetyl was not detected in ice creams after 14 d of storage. Eighty percent of panelists were able to distinguish between low-fat ice creams containing untreated WSU WPC with and without diacetyl, confirming panelists' ability to detect diacetyl. However, panelists were not able to distinguish between low-fat ice creams containing untreated and HHP-treated WSU WPC with diacetyl. These results show that WPC diacetyl-binding properties were not enhanced by 300-MPa HHP treatment for 15 min, indicating that HHP may not be suitable for such applications. PMID:20338422

  12. SHORT COMMUNICATION Delineating geographic boundaries of the woolly mouse opossums,

    E-print Network

    DeSalle, Rob

    SHORT COMMUNICATION Delineating geographic boundaries of the woolly mouse opossums, Micoureus on molecular classification of the woolly mouse opossum, Micoureus spp., in the southeastern Atlantic Forest

  13. SHORT COMMUNICATION Left hemisphere motor facilitation in response to manual

    E-print Network

    Aziz-Zadeh, Lisa

    in establishing a means of nonverbal communication and, from this system, neural properties supporting languageSHORT COMMUNICATION Left hemisphere motor facilitation in response to manual action sounds Lisa a communication system based on `mirror' neurons, premotor neurons that ®re when monkeys perform goal

  14. SHORT COMMUNICATION Gallium induces the production of virulence factors in Pseudomonas

    E-print Network

    Wood, Thomas K.

    SHORT COMMUNICATION Gallium induces the production of virulence factors in Pseudomonas aeruginosa the authors show that gallium, which has antimicrobial properties, interferes with iron homeostasis highly relevant for treatment of Pseudomonas infections. Keywords Pseudomonas aeruginosa; gallium nitrate

  15. Short communication Fabrication of solid lipid microcapsules containing ascorbic acid

    E-print Network

    Short communication Fabrication of solid lipid microcapsules containing ascorbic acid using Encapsulation efficiency Lipid shell a b s t r a c t The importance of ascorbic acid (AA) in the human diet has

  16. Short communication DNA Commission of the International Society of Forensic

    E-print Network

    Forensic Science Service, Birmingham, UK e Department of Forensic Molecular Biology, Erasmus University Science International 157 (2006) 187­197 § DNA Commission, International Society for Forensic GeneticsShort communication DNA Commission of the International Society of Forensic Genetics (ISFG

  17. SHORT COMMUNICATION Open Access Extracellular matrix rigidity modulates

    E-print Network

    Kumar, Sanjay

    SHORT COMMUNICATION Open Access Extracellular matrix rigidity modulates neuroblastoma cell1 , Sanjay Kumar1* Abstract Neuroblastoma is a pediatric malignancy characterized by tremendous to identifying critical regulators of neuroblastoma differentia- tion in the cellular microenvironment, including

  18. Short communication Detecting recombination and diversifying selection in human

    E-print Network

    Carvajal-Rodríguez, Antonio

    Short communication Detecting recombination and diversifying selection in human alpha-papillomavirus´a, Universidad de Vigo, 36310 Vigo, Spain 1. Introduction Human papillomavirus (HPV) is etiological agent). Phylogenetic studies of papillomavirus have shown that different genes have different evolutionary rates

  19. Short communication Origin of arrhythmias in a heart model

    E-print Network

    Rand, Richard H.

    Short communication Origin of arrhythmias in a heart model Hiba Sheheitli, Richard Rand * Dept.19.Hh Keywords: Nonlinear vibrations Cardiology Relaxation oscillations Alternans Arrhythmias Coupled rights reserved. 1. Introduction It is well known that heart arrhythmias are often characterized

  20. Short communication Modulation of hydrophobic interactions in denatured whey

    E-print Network

    Khan, Saad A.

    Short communication Modulation of hydrophobic interactions in denatured whey proteins association in chemically denatured whey protein isolates (WPI) is examined. WPI samples denatured by transglutaminase on the extent of hydrophobic interactions under denatured con- ditions. Protein molecules

  1. SHORT COMMUNICATION DOI: 10.1002/ejic.200700302

    E-print Network

    SHORT COMMUNICATION DOI: 10.1002/ejic.200700302 [Bis(catechol)salen]MnIII Coordination Polymers,2] Although the coordination polymerization of chiral homogeneous catalysts has been suggested as a strategy

  2. 47 CFR 90.371 - Dedicated short range communications service.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Dedicated short range communications service. 90.371 Section 90.371 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Intelligent Transportation Systems Radio Service Regulations Governing the Licensing and Use...

  3. A Short History of Electrical Communication.

    ERIC Educational Resources Information Center

    Federal Communications Commission, Washington, DC.

    Electrical communication progressed rapidly after Samuel Morse demonstrated the telegraph in 1838. Western Union completed the first transcontinental telegraph line in 1861. Five years later the first transoceanic cable was laid. In 1875 A.G. Bell transmitted the first complete sentence heard over wire, and the first Bell telephone company was…

  4. SHORT COMMUNICATIONS ORNITOLOGIA NEOTROPICAL 23: 287290, 2012

    E-print Network

    McCracken, Kevin G.

    Society PARASITISM AND JOINT INCUBATION OF UPLAND GOOSE (CHLOEPHAGA PICTA) NEST BY YELLOW-BILLED PINTAIL the next bowl. On 1 November 2011, we observed a Yel- low-billed Pintail and Upland Goose (Chloe- phaga and Upland Goose flushed together for a short period of flight (Fig. 1B). The nest contained five Upland

  5. AC 2007-1166: BUILDING ENGINEERING COMMUNICATION SKILLS THROUGH SHORT ASSIGNMENTS

    E-print Network

    Tranquillo, Joseph V.

    AC 2007-1166: BUILDING ENGINEERING COMMUNICATION SKILLS THROUGH SHORT ASSIGNMENTS Joseph Tranquillo © American Society for Engineering Education, 2007 #12;Building Engineering Communication Skills 1 Building Engineering Communication Skills Through Short Assignments Abstract Engineers are expected to be able

  6. Short communication Stability of strongly nonlinear normal modes

    E-print Network

    Rand, Richard H.

    Short communication Stability of strongly nonlinear normal modes Geoffrey Recktenwald, Richard Rand as a simple cosine function. This enables the stability of strongly nonlinear normal modes in multidegree These equations possess an invariant manifold y = 0, on which lies a family of nonlinear normal modes (NNMs) which

  7. Polymer Testing 26 (2007) 614618 Short Communication: Test Method

    E-print Network

    Natelson, Douglas

    2007-01-01

    -line measurements using, e.g. the pressure filter test [3], ultrasonic testing [4] and spectroscopic monitoring concentrations and does not work with fibres. Ultrasonic testing is limited to applications that only requirePOLYMER TESTING Polymer Testing 26 (2007) 614­618 Short Communication: Test Method Determination

  8. SHORT COMMUNICATION A Novel Technique for the Reattachment of Large

    E-print Network

    Pawlik, Joseph

    #12;SHORT COMMUNICATION A Novel Technique for the Reattachment of Large Coral Reef Sponges Steven E. McMurray1 and Joseph R. Pawlik1,2 Abstract Sponges are dominant components of coral reef ecosys- tems, often exceeding reef-building corals in abundance. Large sponges, often more than 1 m in diameter, may

  9. Z .Molecular Brain Research 48 1997 140144 Short communication

    E-print Network

    Vogel, Zvi

    system. In primary hippocampal cultures, the expression of Ras-GRF increases in parallel with the onsetZ .Molecular Brain Research 48 1997 140­144 Short communication Ras-GRF, the activator of Ras, is expressed preferentially in mature neurons of the central nervous system Zippel Renata a,) , Gnesutta Nerina

  10. SHORT COMMUNICATION Wild turkey (Meleagris gallopavo) detectability from helicopters

    E-print Network

    Wallace, Mark C.

    SHORT COMMUNICATION Wild turkey (Meleagris gallopavo) detectability from helicopters for wild turkey (Meleagris gallopavo) populations has been limited. We surveyed Rio Grande wild turkey (M and examine power to detect trends in population change. We observed that wild turkey flock detectability

  11. Short communication Hydrogen peroxide induce modifications of human extracellular

    E-print Network

    Schierup, Mikkel Heide

    Short communication Hydrogen peroxide induce modifications of human extracellular superoxide of superoxide in the extracellular space by catalyzing the dismutation of superoxide into hydrogen peroxide and molecular oxygen. In addition, the enzyme reacts with hydrogen peroxide in a peroxidase reaction which

  12. Short communication Buried relic seawall mitigates Hurricane Sandy's impacts

    E-print Network

    Lynett, Patrick

    Short communication Buried relic seawall mitigates Hurricane Sandy's impacts Jennifer L. Irish a Accepted 6 June 2013 Available online xxxx Keywords: Hurricanes Storm surge Waves Storm damage Seawalls of Hurricane Sandy revealed clear differences in patterns of the impact between two neighboring boroughs along

  13. SHORT COMMUNICATION Influence of host plant and prey availability on

    E-print Network

    Ma, Lena

    SHORT COMMUNICATION Influence of host plant and prey availability on developmental time component for N. tenuis, and also that survival time on a strict plant diet is host plant dependent, leafminers, lepidopterans and spider mites (Arzone et al. 1990; Marcos & Rejesus 1992; Solsoloy et al. 1994

  14. Short communication Infrageneric phylogenies: a comparison of chloroplast-expressed

    E-print Network

    synthetase, cytosol-expressed glutamine synthetase and cpDNA maturase K in Passiflora Roxana Yockteng; Sang, 2002). This paper presents a case study of the cytosol-ex- pressed Glutamine Synthetase (cytShort communication Infrageneric phylogenies: a comparison of chloroplast-expressed glutamine

  15. Short Communication Evidence of systematic expressed sequence tag IMAGE clone

    E-print Network

    Spirtes, Peter

    Short Communication Evidence of systematic expressed sequence tag IMAGE clone cross of a potentially serious source of error intrinsic to all spotted cDNA microarrays that use IMAGE clones used to generate EST cDNA for sequence clone libraries. Analysis of expression data from two single

  16. Short communication Quantitative measures of sagittal plane headneck

    E-print Network

    Choi, Jongeun

    with neck pain and asymptomatic controls (Chen and Treleaven, 2013; Descarreaux et al., 2010; WoodhouseShort communication Quantitative measures of sagittal plane head­neck control: A test the reliability of measurements used to quantify head­neck motor control is necessary before they can be used

  17. SHORT COMMUNICATION Fusarium mangiferae associated with mango malformation

    E-print Network

    SHORT COMMUNICATION Fusarium mangiferae associated with mango malformation in the Sultanate of Oman /Published online: 20 October 2007 # KNPV 2007 Abstract Mango malformation, caused by Fusarium mangiferae, represents the most important floral disease of mango. The first symptoms of this disease were noticed

  18. Short Communication Application of a bioenergetics model to roach

    E-print Network

    Short Communication Application of a bioenergetics model to roach By F. Ho¨ lker1 and S. S. Haertel, Limnological Institute, Konstanz, Germany Summary A new set of bioenergetic parameters for adult roach (Rutilus laboratory studies with adult roach over a wide range of fish sizes (1.2­300 g) and water temperatures (5

  19. SHORT COMMUNICATION A rare fight in female plains zebra

    E-print Network

    Rubenstein, Daniel I.

    SHORT COMMUNICATION A rare fight in female plains zebra Ilya R. Fischhoff · Siva R. Sundaresan and Springer 2009 Abstract We describe a fight between two female plains zebra (Equus burchelli). Plains zebra observed. The fight immediately followed the birth of a foal to one of the females. The initiating female

  20. Short Communication Moraine pebbles and boulders yield indistinguishable 10

    E-print Network

    Briner, Jason P.

    Short Communication Moraine pebbles and boulders yield indistinguishable 10 Be ages: A case study: Cosmogenic exposure dating Glaciation Moraine Pinedale 10 Be a b s t r a c t Cosmogenic exposure dating of moraines during the last two decades has vastly improved knowledge on the timing of glaciation worldwide

  1. SHORT COMMUNICATION Gas-Phase Separations of Protease Digests

    E-print Network

    Clemmer, David E.

    SHORT COMMUNICATION Gas-Phase Separations of Protease Digests Stephen J. Valentine, Anne E University, Bloomington, Indiana, USA A mixture of peptides from a complete tryptic digest of ubiquitin has and identify peptides from a tryptic digest of ubiquitin. The mixture was electrosprayed into the gas phase

  2. SHORT COMMUNICATION The amygdalar circuit that acquires taste aversion

    E-print Network

    Dudai, Yadin

    SHORT COMMUNICATION The amygdalar circuit that acquires taste aversion memory differs from the circuit that extinguishes it Amir Bahar, Anat Samuel, Shoshi Hazvi and Yadin Dudai Department, are the neuronal circuits that subserve learning and extinction identical? We address this question by double

  3. Short communication A modified isoparametric mapping fill method

    E-print Network

    Qin, Qinghua

    presents a reliable and efficient technique for displaying color mapping of data for post-processingShort communication A modified isoparametric mapping fill method to display color mapping of data of the Hybrid-Trefftz (HT) finite element method (FEM). The isoparametric mapping fill method developed

  4. Short communication Illumina metabarcoding of a soil fungal community

    E-print Network

    Short communication Illumina metabarcoding of a soil fungal community Philipp-André Schmidt a form 6 May 2013 Accepted 10 May 2013 Available online 5 June 2013 Keywords: Illumina MiSeq Soil fungi. Here we tested Illumina metabarcoding, a method that generates shorter reads but achieves deeper

  5. Short communication: An interpretation of the Linux entropy estimator

    E-print Network

    International Association for Cryptologic Research (IACR)

    Short communication: An interpretation of the Linux entropy estimator Benjamin Pousse benjamin(dot)pousse(at)gmail(dot)com Institute: None Abstract. The Linux [1] random number generator (LRNG) aims to produce random numbers of the inputs must be estimated by these generator for ensuring security. In this paper, we focus on the Linux

  6. Short Communication Mitochondrial DNA variation among host races of Eurosta

    E-print Network

    Cronin, James T.

    Short Communication Mitochondrial DNA variation among host races of Eurosta solidaginis Fitch. Sequencing analysis was used to characterize two mitochondrial gene fragments: (1) NADH1 dehydrogenase (ND1 (RFLPs), and DNA sequencing (e.g., Brown et al., 1996; Feder et al., 1988, 1990; McPheron, 1990; Mc

  7. Placenta (1995), 16, 749-756 Short Communication: Selective

    E-print Network

    1995-01-01

    Placenta (1995), 16, 749-756 Short Communication: Selective Placental Transport of Maternal Ig biosynthesis of the GOIgG glycoform by the mother, and a restriction of its transport across the placenta, and in particular the active transport of IgG, across the placenta during gestation. Our data suggest

  8. Z .Brain Research 760 1997 261265 Short communication

    E-print Network

    West, Mark O.

    Z .Brain Research 760 1997 261­265 Short communication Firing rate dependent effect of cocaine March 1997 Abstract Cocaine's effects on striatal neurons related to vertical head movement were studied Science B.V. Keywords: Motor behavior; Psychomotor stimulant; Cocaine; Single unit recording; Striatum

  9. Short Communication Rapid Phasic Activity of Ventral Pallidal

    E-print Network

    West, Mark O.

    Short Communication Rapid Phasic Activity of Ventral Pallidal Neurons During Cocaine Self) in cocaine-seeking behavior, in contrast with considerable documentation of the involvement of its major VP in cocaine-seeking behavior, but the electrophysiological mechanisms underlying this behavior

  10. Short communication Leaf optical properties and photosynthetic leaf absorptances

    E-print Network

    Durako, Michael J.

    characteristics indicates relatively low variability in light absorption across a wide range of leaf morphologies and environments consistent with previous suggestions of constraints on light absorption by aquatic plants. # 2007Short communication Leaf optical properties and photosynthetic leaf absorptances in several

  11. SHORT COMMUNICATION Attraction of ants by an invasive Acacia

    E-print Network

    Obbard, Darren

    SHORT COMMUNICATION Attraction of ants by an invasive Acacia MARKUS P. EICHHORN, LOUISE C. RATLIFFE be deprived of their co-evolved mutualists. In southern Portugal Acacia dealbata has become naturalised induction, extra-floral nectaries, invasive species, Linepithema humile, Portugal. Introduction Acacia trees

  12. Little Green Codes: Energy-Efficient Short-Range Communication

    E-print Network

    California at Berkeley, University of

    Little Green Codes: Energy-Efficient Short-Range Communication Pulkit Grover and Anant Sahai a noisy channel. The classical information-theoretic approach neglects the energy expended in processing the data at the encoder and the decoder and only minimizes the energy required for transmissions. Since

  13. SHORT COMMUNICATION A new procedure for making observations of embryo

    E-print Network

    Herrera, Carlos M.

    SHORT COMMUNICATION A new procedure for making observations of embryo morphology in dust-like seeds Uberla^ndia, Caixa Postal 593, Uberla^ndia, MG, 38400-902, Brazil Abstract Observing the embryo in dust is remarkably effective for direct observations of embryos in minute seeds, is reported here. Moreover

  14. Z .Brain Research 745 1997 331335 Short communication

    E-print Network

    West, Mark O.

    Z .Brain Research 745 1997 331­335 Short communication Low-dose amphetamine elevates movement 27157, USA Accepted 8 October 1996 Abstract To study the striatal role in amphetamine's stimulant rats before and after amphetamine injection 0.5 or 1.0 mgrkg, i.p. . Comparisons of firing were made

  15. Short Communication J Mol Microbiol Biotechnol 2003;5:1116

    E-print Network

    Steinhoff, Heinz-Jürgen

    Short Communication J Mol Microbiol Biotechnol 2003;5:11­16 DOI: 10.1159/000068720 MASE1 and MASE2 receptor proteins. The MASE1 (mem- brane-associated sensor) domain, consisting of 8 pre- #12;12 J Mol

  16. SHORT COMMUNICATIONS APPLICATION OF THERMOLUMINESCENCE THEORY TO THE

    E-print Network

    Chen, Reuven

    SHORT COMMUNICATIONS APPLICATION OF THERMOLUMINESCENCE THEORY TO THE INVESTIGATION of thermoluminescence (TL) and thermoremanent magnetization (TRM), it is shown here that previously established methods, equation (1) is identical with the equation governing the behaviour of a first-order thermoluminescence (TL

  17. SHORT COMMUNICATION Dynamical analysis of winter terrain park jumps

    E-print Network

    SHORT COMMUNICATION Dynamical analysis of winter terrain park jumps James A. McNeil Æ James B. Mc to their less accomplished patrons. The industry is understandably ret- icent to provide injury details, but suggested design strategies for improving safety. Other related work includes J. A. McNeil (&) Department

  18. SHORT COMMUNICATION Extraordinarily long sperm in the socially monogamous

    E-print Network

    SHORT COMMUNICATION Extraordinarily long sperm in the socially monogamous cichlid fish fertilisation. In animals in general and in fishes in particular, there is huge variation in sperm size. In fishes, sperm size ranges from 13 m in Mugil cephlus to nearly 100 m in the channel catfish Ictalurus

  19. Short Communication Comparative Proteomics of Symbiotic and Aposymbiotic Juvenile

    E-print Network

    : zooxanthellae -- symbiosis-related proteins -- 2D-PAGE -- symbiosis -- soft corals Introduction SymbioticShort Communication Comparative Proteomics of Symbiotic and Aposymbiotic Juvenile Soft Corals O Abstract The symbiotic association between corals and photosynthetic unicellular algae is of great impor

  20. SHORT COMMUNICATION Environmental distribution of coral-associated

    E-print Network

    Keeling, Patrick

    SHORT COMMUNICATION Environmental distribution of coral-associated relatives of apicomplexan was recently found in a specific association with coral reefs (apicomplexan-related lineage-V, or ARL-V). Here-scale bacterial sequence surveys. In a transect between corals and associated macroalgae, ARL-V is specifically

  1. SHORT COMMUNICATION Guidance by odors in honeybee navigation

    E-print Network

    Menzel, Randolf - Institut für Biologie

    SHORT COMMUNICATION Guidance by odors in honeybee navigation Randolf Menzel · Uwe Greggers Received of honeybees. The flight trajectories of individual bees were registered using harmonic radar tracking. Sensory in the context of odor guidance of honeybees over longer distances ([300 m from the hive). Keywords Navigation Á

  2. SHORT COMMUNICATION Microarray analysis and establishment of drug

    E-print Network

    Lee, H.C. Paul

    Z 5-fluorouracil. 22 A.H. Tseng et al. #12;Microarray technology and the associated databasesSHORT COMMUNICATION Microarray analysis and establishment of drug screening platform using 5 Available online 5 May 2012 KEYWORDS chemoresistance; colorectal cancer; gene expression microarray Abstract

  3. Journal of Power Sources 162 (2006) 13951400 Short communication

    E-print Network

    Popov, Branko N.

    2006-01-01

    Journal of Power Sources 162 (2006) 1395­1400 Short communication Simulation of charge.jpowsour.2006.07.045 #12;1396 J.-W. Lee et al. / Journal of Power Sources 162 (2006) 1395­1400 Nomenclatu- ventional alkaline and nickel­hydrogen batteries, and have been considered as alternative power sources

  4. Journal of Power Sources 143 (2005) 173178 Short communication

    E-print Network

    Subramanian, Venkat

    2005-01-01

    Journal of Power Sources 143 (2005) 173­178 Short communication An approximate closed form solution.R. Subramanian / Journal of Power Sources 143 (2005) 173­178 Fig. 1. Schematic of the cathode chamber modeled energy. Fuel cells are believed to be a most promising power source for a wide range of applications

  5. Journal of Power Sources 132 (2004) 256260 Short communication

    E-print Network

    Rubloff, Gary W.

    2004-01-01

    Journal of Power Sources 132 (2004) 256­260 Short communication Nanoscale battery materials based.1016/j.jpowsour.2003.12.045 #12;S.E. Bullock, P. Kofinas / Journal of Power Sources 132 (2004) 256. Introduction Research in electronics and power supplies have pro- gressed at a tremendous rate since the 1990s

  6. Short communication Modelling respiration of vegetation: evidence for a

    E-print Network

    Thomas, David D.

    Short communication Modelling respiration of vegetation: evidence for a general temperature, boreal tree species, dark respiration, elevated carbon dioxide, Q10, temperature response function a broad range of tempera- tures. In plants, dark respiration (see reviews by James 1953; Forward 1960

  7. Short Communication Phylogenetic relationships of leopard frogs (Rana pipiens complex)

    E-print Network

    Markow, Therese

    Short Communication Phylogenetic relationships of leopard frogs (Rana pipiens complex) from June 2008 Available online xxxx Keywords: Control region Cryptic species Mexican leopard frogs the control region and 12S rRNA in leopard frogs from the Sierra El Aguaje of southern Sonora, Mexico

  8. SHORT COMMUNICATION Flow rate-modified streaming effects in heterogeneous

    E-print Network

    Xuan, Xiangchun "Schwann"

    SHORT COMMUNICATION Flow rate-modified streaming effects in heterogeneous microchannels Junjie Zhu relations is developed to study the streaming potential and streaming current in heterogeneous micro or perpendicular to the flow axis. Both streaming effects are modified by the flow rate through the heterogeneous

  9. SHORT COMMUNICATION Morphological and genetic variation in the endangered Sulawesi

    E-print Network

    Shaffer, H. Bradley

    SHORT COMMUNICATION Morphological and genetic variation in the endangered Sulawesi tortoise that allopatric populations of the endangered Su- lawesi tortoise (Indotestudo forstenii) differ in size of genetically differentiated lineages. Keywords Indotestudo Á Tortoise Á Nuclear introns Á Nuchal scute Á Asian

  10. SHORT COMMUNICATION Adaptive eukaryote-to-eukaryote lateral gene transfer

    E-print Network

    Nedelcu, Aurora M.

    SHORT COMMUNICATION Adaptive eukaryote-to-eukaryote lateral gene transfer: stress-related genes exchanges on the evolution of eukaryotes are yet to be determined (e.g. Boucher et al., 2003; Andersson, 2005; Keeling & Palmer, 2008). Two types of gene transfer are generally described in eukaryotes

  11. proteinsSTRUCTURE O FUNCTION O BIOINFORMATICS SHORT COMMUNICATION

    E-print Network

    Kihara, Daisuke

    proteinsSTRUCTURE O FUNCTION O BIOINFORMATICS SHORT COMMUNICATION Rapid comparison of properties, and the complex relationship among them. Commonly proteins are compared and classified based on their sequence2 was used to analyze the relationship of electrostatic potentials and biological function of several

  12. Short Communication Proceedings: Impacts of Air Pollution and Climate Change

    E-print Network

    Short Communication Proceedings: Impacts of Air Pollution and Climate Change on Forest Ecosystems Pollution Effects on Forest Ecosystems "Forests under Anthropogenic Pressure ­ Effects of Air Pollution or ground-level ozone (O3) is still the phytotoxic air pollutant of major interest. Challenging issues

  13. Short Communication Substance abuse as a dynamical disease

    E-print Network

    Sprott, Julien Clinton

    to the treatment of substance abuse, whether controlled drinking or abstinence is a preferred strategyShort Communication Substance abuse as a dynamical disease: Evidence and clinical implications phenomena, might yield insight into substance-related disorders. In this article, we examine the dynamics

  14. Short communication Targeting of a tetracycline-inducible expression system to the

    E-print Network

    Schnaufer, Achim

    . Introduction Tetracycline-regulated ectopic gene expression [1,2] has come to form the backbone of transgenic of `leaky' (i.e. undesirably high) expression of the regulated genes in the absence of induction. Here weShort communication Targeting of a tetracycline-inducible expression system

  15. SHORT COMMUNICATION Stress in the wild: Chronic predator pressure and acute restraint affect

    E-print Network

    Zanette, Liana

    SHORT COMMUNICATION Stress in the wild: Chronic predator pressure and acute restraint affect plasma circulating steroid levels at baseline and after acute restraint in the breeding and nonbreeding seasons levels than males in high predator pressure (HPP) environments. Also, acute restraint decreased DHEA

  16. Short communication Air humidity and water pressure effects on the performance of

    E-print Network

    that there was salt precipitation in the cathode that was enhanced by higher relative humidity or water pressureShort communication Air humidity and water pressure effects on the performance of air t s High humidity or increased water pressure reduced power production. Cathode performance decreased due

  17. SHORT COMMUNICATION Identifying energy constraints to parasite resistance

    E-print Network

    Obbard, Darren

    SHORT COMMUNICATION Identifying energy constraints to parasite resistance D. E. ALLEN & T. J U R O P E A N S O C I E T Y F O R E V O L U T I O N A R Y B I O L O G Y Keywords: costs; Daphnia development rate in juvenile Daphnia would reveal energetic constraints to its ability to resist infection

  18. Short communication Fractal in fracture of bulk metallic glass

    E-print Network

    Gao, Jianbo

    ,19], Co-based [17], and rare earth-based [19], less brittle Ni-based [20] and even tough Zr-based [21e25Short communication Fractal in fracture of bulk metallic glass M.Q. Jiang a,b , J.X. Meng a , J. Bulk metallic glass B. Dynamic fracture C. Nanoscale periodic corrugation C. Fractal a b s t r a c t We

  19. When the facts are just not enough: Credibly communicating about risk is riskier when emotions run high and time is short

    SciTech Connect

    Reynolds, Barbara J.

    2011-07-15

    When discussing risk with people, commonly subject matter experts believe that conveying the facts will be enough to allow people to assess a risk and respond rationally to that risk. Because of this expectation, experts often become exasperated by the seemingly illogical way people assess personal risk and choose to manage that risk. In crisis situations when the risk information is less defined and choices must be made within impossible time constraints, the thought processes may be even more susceptible to faulty heuristics. Understanding the perception of risk is essential to understanding why the public becomes more or less upset by events. This article explores the psychological underpinnings of risk assessment within emotionally laden events and the risk communication practices that may facilitate subject matter experts to provide the facts in a manner so they can be more certain those facts are being heard. Source credibility is foundational to risk communication practices. The public meeting is one example in which these best practices can be exercised. Risks are risky because risk perceptions differ and the psychosocial environment in which risk is discussed complicates making risk decisions. Experts who want to influence the actions of the public related to a threat or risk should understand that decisions often involve emotional as well as logical components. The media and other social entities will also influence the risk context. The Center for Disease Control and Prevention's crisis and emergency-risk communication (CERC) principles are intended to increase credibility and recognize emotional components of an event. During a risk event, CERC works to calm emotions and increase trust which can help people apply the expertise being offered by response officials.

  20. Short communication: Quantification of carbohydrates in whey permeate products using high-performance anion-exchange chromatography with pulsed amperometric detection.

    PubMed

    Lee, Hyeyoung; MeloSilva, Vitor Luiz de; Liu, Yan; Barile, Daniela

    2015-11-01

    A method was developed for the characterization and quantification of the disaccharide lactose and 3 major bovine milk oligosaccharides (BMO) in dairy streams. Based on high-performance anion-exchange chromatography-pulsed amperometric detection (HPAE-PAD), this method is advantageous because it requires minimal sample preparation and achieves good chromatographic separation of oligosaccharide isomers within 30min. The linear dynamic range and limit of detection were 0.1 to 10mg/L and 0.03 to 0.22mg/L, respectively. Mean recoveries of the BMO were excellent and ranged from 98.4 to 100.4%. Without complicated sample preparation procedures, this HPAE-PAD method measured BMO [3'-sialyllactose (3'SL), 6'-sialyllactose (6'SL), and 6'-sialyllactosamine (6'SLN)] and lactose using a single instrument, therefore increasing the accuracy of the measurement and applicability for the dairy industry. In colostrum whey permeate, 3'SL, 6'SL, and 6'SLN were 94, 29, and 46mg/L, respectively. This work is the first to demonstrate that some commercial products, currently marketed for supporting a healthy immune system, contain significant amounts of bioactive BMO and therefore, carry additional bioactivities. PMID:26364096

  1. Ultra-short Pulsed FSO Communications System with Wavelet Fractal Modulation

    E-print Network

    Kavehrad, Mohsen

    Ultra-short Pulsed FSO Communications System with Wavelet Fractal Modulation Mohsen Kavehrad (FIEEE system based on integration of ultra-short pulse lasers and advanced signal processing techniques an ultra-short pulsed FSO communications system, operating with multi-rate parallel streams capable

  2. Short Communication Evolution of RNases in leaf monkeys: Being parallel gene duplications

    E-print Network

    Gu, Xun

    Short Communication Evolution of RNases in leaf monkeys: Being parallel gene duplications of phylogenetic relationship becomes a difficult task, particularly when the coding sequence is short. In this short communication, we reanalyzed a recent study (Zhang, 2006) and demonstrated that the uncertainty

  3. Short communication: Milk fat depression induced by conjugated linoleic acid and a high-oil and low-fiber diet occurs equally across the day in Holstein cows.

    PubMed

    Ma, L; Cook, K L; Bauman, D E; Harvatine, K J

    2015-03-01

    Recently, a circadian rhythm of milk and milk component synthesis has been characterized that is partially dependent on the timing of feed intake. Our objective was to determine if inhibition of milk fat synthesis during diet-induced milk fat depression occurred to a higher degree during certain phases of the day. A retrospective analysis was conducted on 2 experiments that induced milk fat depression while milking cows 3 times per day at equal intervals. The response at each milking was analyzed using mixed model ANOVA with repeated measures. In experiment 1, nine multiparous Holstein cows were arranged in a 3×3 Latin square design, and treatments were control, 3-d intravenous infusion of 10 g/d of trans-10,cis-12 conjugated linoleic acid (CLA), and a low-forage and high-fat diet for 10 d. In experiment 2, ten multiparous ruminally cannulated cows were arranged in a replicated design and milk samples were collected during a control period or after 5 d of abomasal infusion of 10 g/d of CLA. The daily pattern of milk fat concentration and yield did not differ between treatments in either experiment. In experiment 1, an effect was found of treatment and milking time on milk fat concentration and yield. Similarly, in experiment 2, main effects were found of treatment and milking time on milk fat concentration and an effect of treatment, but no effect of milking time on milk fat yield. Milk fat percent was increased from 3.41 to 4.06% and 3.25 to 3.48% from the morning to the afternoon milking in experiments 1 and 2, respectively. Additionally, milk fatty acid profile, including trans intermediates, was changed over the day in experiment 1, but the magnitude of the changes were small and the pattern did not differ among treatments. A daily rhythm of milk fat concentration and yield was observed in cows milked 3 times a day, but milk fat depression decreases milk fat yield equally over the day. PMID:25529418

  4. Short communication: Effects of molasses products on productivity and milk fatty acid profile of cows fed diets high in dried distillers grains with solubles.

    PubMed

    Siverson, A; Vargas-Rodriguez, C F; Bradford, B J

    2014-01-01

    Previous research has shown that replacing up to 5% [of dietary dry matter (DM)] corn with cane molasses can partially alleviate milk fat depression when cows are fed high-concentrate, low-fiber rations containing dried distillers grains with solubles. The primary objective of this study was to determine whether dietary molasses alters milk fatty acid (FA) profile or improves solids-corrected milk yield in the context of a more typical lactation diet. A secondary objective was to assess production responses to increasing rumen-degradable protein supply when molasses was fed. Twelve primiparous and 28 multiparous Holstein cows (196 ± 39 d in milk) were blocked by parity and assigned to 4 pens. Pens were randomly allocated to treatment sequence in a 4 × 4 Latin square design, balanced for carryover effects. Treatment periods were 21 d, with 17 d for diet adaptation and 4 d for sample and data collection. Treatments were a control diet, providing 20% dried distillers grains with solubles (DM basis), 35% neutral detergent fiber, 30% starch, and 5% ether extract; a diet with 4.4% cane molasses replacing a portion of the corn grain; a diet with 2.9% molasses supplement containing 32% crude protein on a DM basis; and a diet with 5.8% (DM basis) molasses supplement. Animal-level data were analyzed using mixed models, including the fixed effect of treatment and the random effects of period, pen, period × pen interaction, and cow within pen to recognize pen as the experimental unit. Diets did not alter DM intake, milk production, milk component concentration or yield, feed efficiency (DM intake/milk yield), body weight change, or milk somatic cell count. Milk stearic acid content was increased by the diet containing 5.8% molasses supplement compared with the control diet and the diet containing 2.9% molasses supplement, but the magnitude of the effect was small (12.27, 11.75, and 11.69 ± 0.29 g/100g of FA). Production data revealed a dramatic effect of period on milk fat content and yield. Milk fat content decreased during the course of the experiment (least squares means = 3.16, 2.81, 2.93, and 2.64 ± 0.09% for periods 1 to 4, respectively), as did milk fat yield (1.20, 1.03, 0.98, and 0.79 ± 0.05 kg/d). Exchanging molasses-based products for corn at 2.9 to 5.8% of dietary DM did not influence productivity and had minute effects on milk FA profile. The limited responses in this study may have been influenced by dietary unsaturated FA content or the advancing stage of lactation of cows in the study. PMID:24746128

  5. Short Paper: An Ultrasonic Communication System for Biotelemetry in Extremely Shallow Waters

    E-print Network

    Dean, Alexander G.

    Short Paper: An Ultrasonic Communication System for Biotelemetry in Extremely Shallow Waters_dean@ncsu.edu ABSTRACT This paper introduces an ultrasonic communication system for biotelemetry in extremely shallow. This paper's primary contribution is hardware and soft- ware for an ultrasonic communications system which

  6. Design and Analysis of Highway Safety Communication Protocol in 5.9 GHz Dedicated Short Range Communication Spectrum

    E-print Network

    Sengupta, Raja

    Communication Spectrum Qing Xu* Raja Sengupta * Department of Mechanical Engineering Department of CivilDesign and Analysis of Highway Safety Communication Protocol in 5.9 GHz Dedicated Short Range and Environmental Engineering University of California Berkeley, CA 90720­1740 Email: * qingxu

  7. Short Communication Anisometric charge dependent swelling of porous carbon in an

    E-print Network

    Bazant, Martin Z.

    Short Communication Anisometric charge dependent swelling of porous carbon in an ionic liquid F: Electrochemical dilatometry Ionic liquid Electrical double layer capacitor Porous amorphous carbon Carbide of a porous carbon electrode in a pure ionic liquid, 1-ethyl-3-methyl

  8. Short communication Phenoloxidase and QX disease resistance in Sydney rock oysters

    E-print Network

    Raftos, David

    Short communication Phenoloxidase and QX disease resistance in Sydney rock oysters (Saccostrea October 2003 Abstract QX is a fatal disease in Sydney rock oysters (Saccostrea glomerata) that results glomerata; Phenoloxidase; Disease resistance; Oyster 1. Introduction The Sydney rock oyster, Saccostrea

  9. Short communication Trace elements, PCBs and organochlorine pesticides in New Zealand

    E-print Network

    Short communication Trace elements, PCBs and organochlorine pesticides in New Zealand common, polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticide levels were determined in tissues collected pesticides including dieldrin, hexachlorocyclohexane (HCH) and dichlorodiphenyltri- chloroethane (DDT

  10. Short Communication Revisit on the evolutionary relationship between alternative splicing and

    E-print Network

    Gu, Xun

    Short Communication Revisit on the evolutionary relationship between alternative splicing and gene duplication Alternative splicing Copy number variation Exon­intron structure Gene duplications and alternative sophisticated hypothesis, invoking that less alternative splicing genes tend to be duplicated more frequently

  11. Short communication Diversity and distribution of co-infecting Botryosphaeriaceae from Eucalyptus grandis

    E-print Network

    Short communication Diversity and distribution of co-infecting Botryosphaeriaceae from Eucalyptus by J Van Staden Keywords: Botryosphaeriaceae Endophytes Eucalyptus Syzygium Myrtaceae South Africa sequence iden- tification on a recent collection of Botryosphaeriaceae from Eucalyptus grandis and Syzygium

  12. A high temperature superconductivity communications flight experiment

    NASA Technical Reports Server (NTRS)

    Ngo, P.; Krishen, K.; Arndt, D.; Raffoul, G.; Karasack, V.; Bhasin, K.; Leonard, R.

    1992-01-01

    The proposed high temperature superconductivity (HTSC) millimeter-wave communications flight experiment from the payload bay of the Space Shuttle Orbiter to the Advanced Communications Technology Satellite (ACTS) in geosynchronous orbit is described. The experiment will use a Ka-band HTSC phased array antenna and front-end electronics to receive a downlink communications signal from the ACTS. The discussion covers the system configuration, a description of the ground equipment, the spacecraft receiver, link performance, thermal loading, and the superconducting antenna array.

  13. Short communication Real-time estimation of lead-acid battery parameters: A dynamic

    E-print Network

    Ray, Asok

    Short communication Real-time estimation of lead-acid battery parameters: A dynamic data of State of charge (SOC) and State of health (SOH) in lead-acid batteries. Algorithm development based Lead-acid battery Symbolic dynamic filtering k-NN regression a b s t r a c t This short paper presents

  14. 593Neumann et al.--Photo-identification of common dolphins Short communication

    E-print Network

    593Neumann et al.--Photo-identification of common dolphins Short communication Photo-identification of short-beaked common dolphins (Delphinus delphis) in north-east New Zealand: a photo-beaked common dolphins (Delphinus delphis L.). We present here the results of two studies that were conducted

  15. High speed quantum communication testbed

    NASA Astrophysics Data System (ADS)

    Williams, Carl J.; Tang, Xiao; Heikkero, Mikko; Rouzaud, Julie; Lu, Richang; Goedecke, Andreas; Migdall, Alan L.; Mink, Alan; Nakassis, Anastase; Pibida, Leticia S.; Wen, Jesse; Hagley, Edward; Clark, Charles W.

    2002-12-01

    We describe the status of the NIST Quantum Communication Testbed (QCT) facility. QCT is a facility for exploring quantum communication in an environment similar to that projected for early commercial implementations: quantum cryptographic key exchange on a gigabit/second free-space optical (FSO) channel. Its purpose is to provide an open platform for testing and validating performance in the application, network, and physical layers of quantum communications systems. The channel uses modified commercial FSO equipment to link two buildings on the Gaithersburg, MD campus of the National Institute of Standards and Technology (NIST), separated by approximately 600 meters. At the time of writing, QCT is under construction; it will eventually be made available to the research community as a user facility. This paper presents the basic design considerations underlying QCT, and reports the status of the project.

  16. High performance computing and communications program

    NASA Technical Reports Server (NTRS)

    Holcomb, Lee

    1992-01-01

    A review of the High Performance Computing and Communications (HPCC) program is provided in vugraph format. The goals and objectives of this federal program are as follows: extend U.S. leadership in high performance computing and computer communications; disseminate the technologies to speed innovation and to serve national goals; and spur gains in industrial competitiveness by making high performance computing integral to design and production.

  17. Short communication Energy storage via polyvinylidene fluoride dielectric on the

    E-print Network

    Jiang, Hongrui

    - response, rechargeability, and long-term storage properties [10]. It implied that the two parts of the PSCShort communication Energy storage via polyvinylidene fluoride dielectric on the counterelectrode) for combined energy conver- sion and storage. PVDF dielectric layer contributes significantly to the energy

  18. High Average Power, High Energy Short Pulse Fiber Laser System

    SciTech Connect

    Messerly, M J

    2007-11-13

    Recently continuous wave fiber laser systems with output powers in excess of 500W with good beam quality have been demonstrated [1]. High energy, ultrafast, chirped pulsed fiber laser systems have achieved record output energies of 1mJ [2]. However, these high-energy systems have not been scaled beyond a few watts of average output power. Fiber laser systems are attractive for many applications because they offer the promise of high efficiency, compact, robust systems that are turn key. Applications such as cutting, drilling and materials processing, front end systems for high energy pulsed lasers (such as petawatts) and laser based sources of high spatial coherence, high flux x-rays all require high energy short pulses and two of the three of these applications also require high average power. The challenge in creating a high energy chirped pulse fiber laser system is to find a way to scale the output energy while avoiding nonlinear effects and maintaining good beam quality in the amplifier fiber. To this end, our 3-year LDRD program sought to demonstrate a high energy, high average power fiber laser system. This work included exploring designs of large mode area optical fiber amplifiers for high energy systems as well as understanding the issues associated chirped pulse amplification in optical fiber amplifier systems.

  19. A study of Stokes vector direct detection in short-reach optical communication

    NASA Astrophysics Data System (ADS)

    Zhang, Yue; Zhang, Jinnan; Zhang, Yang'an; Hong, Yan; Ma, Huihui; Wang, Limeng

    2015-08-01

    We propose a detection scheme called Stokes vector direct detection (SV-DD) to realize high electrical spectral efficiency and cost-effective optical communication , which is more suitable than coherent detection for short-reach. At reception, the signal is detected in Stokes space.SV-DD is different from conventional DD technique in the parts of not requiring polarization tracking or narrow band optical filtering for carrier extraction. 2nd-order nonlinearity due to photodetection is a fundamental limitation for DD. The conventional SV-DD systems use 2*4 coupler in the receiver, it makes 2nd-order nonlinearity much serious since there are four photodetections or two balance photodetections. In this paper, we experimentally demonstrate the SVDD scheme in single-carrier system using a 3*3 coupler with three photodetections in the receiver.

  20. Spacecraft design project: High latitude communications satellite

    NASA Technical Reports Server (NTRS)

    Josefson, Carl; Myers, Jack; Cloutier, Mike; Paluszek, Steve; Michael, Gerry; Hunter, Dan; Sakoda, Dan; Walters, Wes; Johnson, Dennis; Bauer, Terry

    1989-01-01

    The spacecraft design project was part of AE-4871, Advanced Spacecraft Design. The project was intended to provide experience in the design of all major components of a satellite. Each member of the class was given primary responsibility for a subsystem or design support function. Support was requested from the Naval Research Laboratory to augment the Naval Postgraduate School faculty. Analysis and design of each subsystem was done to the extent possible within the constraints of an eleven week quarter and the design facilities (hardware and software) available. The project team chose to evaluate the design of a high latitude communications satellite as representative of the design issues and tradeoffs necessary for a wide range of satellites. The High-Latitude Communications Satellite (HILACS) will provide a continuous UHF communications link between stations located north of the region covered by geosynchronous communications satellites, i.e., the area above approximately 60 N latitude. HILACS will also provide a communications link to stations below 60 N via a relay Net Control Station (NCS), which is located with access to both the HILACS and geosynchronous communications satellites. The communications payload will operate only for that portion of the orbit necessary to provide specified coverage.

  1. Systems and methods for short range RF communication

    NASA Technical Reports Server (NTRS)

    Ross, John Anderson Fergus (Inventor); Tomlinson, Harold Woodruff (Inventor); Sexton, Daniel White (Inventor); Hershey, John Erik (Inventor); DeCristofaro, Richard Anthony (Inventor)

    2012-01-01

    A method transmitting a message over at least one of a plurality of channels of a communications network is provided. The method comprises the steps of detecting a presence of jamming pulses in the at least one of the plurality of channels. The characteristics of the jamming pulses in the at least one of the plurality of channels is determined wherein the determined characteristics define at least interstices between the jamming pulses. The message is transmitted over the at least one of the plurality of channels wherein the message is transmitted within the interstices of the jamming pulse determined from the step of determining characteristics of the jamming pulses.

  2. Short range RF communication for jet engine control

    NASA Technical Reports Server (NTRS)

    Sexton, Daniel White (Inventor); Hershey, John Erik (Inventor)

    2007-01-01

    A method transmitting a message over at least one of a plurality of radio frequency (RF) channels of an RF communications network is provided. The method comprises the steps of detecting a presence of jamming pulses in the at least one of the plurality of RF channels. The characteristics of the jamming pulses in the at least one of the plurality of RF channels is determined wherein the determined characteristics define at least interstices between the jamming pulses. The message is transmitted over the at least one of the plurality of RF channels wherein the message is transmitted within the interstices of the jamming pulse determined from the step of determining characteristics of the jamming pulses.

  3. Acoustic communication in two freshwater gobies: ambient noise and short-range propagation in shallow streams.

    PubMed

    Lugli, M; Fine, M L

    2003-07-01

    Noise is an important theoretical constraint on the evolution of signal form and sensory performance. In order to determine environmental constraints on the communication of two freshwater gobies Padogobius martensii and Gobius nigricans, numerous noise spectra were measured from quiet areas and ones adjacent to waterfalls and rapids in two shallow stony streams. Propagation of goby sounds and waterfall noise was also measured. A quiet window around 100 Hz is present in many noise spectra from noisy locations. The window lies between two noise sources, a low-frequency one attributed to turbulence, and a high-frequency one (200-500 Hz) attributed to bubble noise from water breaking the surface. Ambient noise from a waterfall (frequencies below 1 kHz) attenuates as much as 30 dB between 1 and 2 m, after which values are variable without further attenuation (i.e., buried in the noise floor). Similarly, courtship sounds of P. martensii attenuate as much as 30 dB between 5 and 50 cm. Since gobies are known to court in noisy as well as quiet locations in these streams, their acoustic communication system (sounds and auditory system) must be able to cope with short-range propagation dictated by shallow depths and ambient noise in noisy locations. PMID:12880062

  4. Short Communication The flight of the Passenger Pigeon: Phylogenetics and biogeographic history

    E-print Network

    Clayton, Dale H.

    Short Communication The flight of the Passenger Pigeon: Phylogenetics and biogeographic history of the Passenger Pigeon (Ectopistes migratorius) is one of the best known and documented of any bird. This event was particularly alarming because the Passenger Pigeon went from being one of the most numerous avian species

  5. Short communication Cost-effective abundance estimation of rare animals: Testing performance

    E-print Network

    Thomas, Len

    Short communication Cost-effective abundance estimation of rare animals: Testing performance from rel- atively low-cost surveys can be thought of as hypotheses to be tested as new data, but estimating abundance of rare species can be more chal- lenging than for common ones. Cost-effective methods

  6. Short communication A nonlinear model to generate the winner-take-all competition

    E-print Network

    Massachusetts at Amherst, University of

    Short communication A nonlinear model to generate the winner-take-all competition Shuai Li a August 2012 Keywords: winner-take-all Positive feedback Negative feedback Nonlinear Competition a b s t r a c t This paper is concerned with the phenomenon of winner-take-all competition. In this paper, we

  7. SHORT COMMUNICATION Gold nanoparticles: a new X-ray contrast agent

    E-print Network

    Terasaki, Mark

    evidence of toxicity 11 days and 30 days after injection. Gold nanoparticles can be used as X-ray contrastSHORT COMMUNICATION Gold nanoparticles: a new X-ray contrast agent 1 J F HAINFELD, PhD, 1 D N, and poor contrast in large patients. This report is the first demonstration that gold nanoparticles may

  8. Short Communication Non-invasive measurement of thyroid hormone in feces of a diverse array

    E-print Network

    Wasser, Samuel

    Short Communication Non-invasive measurement of thyroid hormone in feces of a diverse array Accepted 13 April 2010 Available online xxxx Keywords: Thyroid hormone Triiodothyronine Thyroxine Feces Wildlife Birds Mammals a b s t r a c t We developed and validated a non-invasive thyroid hormone measure

  9. Short Communication New Spiroplasma in parasitic Leptus mites and their Agathemera walking stick

    E-print Network

    Clayton, Dale H.

    Short Communication New Spiroplasma in parasitic Leptus mites and their Agathemera walking stick (Leptus sayi; Leptus lomani) and their Agathemera walking stick hosts. In walking sticks Spiroplasmas were detected by exploratory PCR screens in understudied parasitic Leptus mites (Leptidae) and their walking

  10. SHORT COMMUNICATION A database of vertebrate longevity records and their relation

    E-print Network

    de Magalhães, João Pedro

    SHORT COMMUNICATION A database of vertebrate longevity records and their relation to other life, Liverpool, UK Department of Genetics, Liverpool Women's Hospital, Liverpool, UK Introduction The longevity of animals has long fascinated scientists. Already Aristotle in his c. 350 BCBC treatise On Longevity

  11. Short communication All joint moments significantly contribute to trunk angular acceleration

    E-print Network

    Short communication All joint moments significantly contribute to trunk angular acceleration: Accepted 19 April 2010 Keywords: Gait Trunk control Balance Angular acceleration Sensitivity a b s t r a c can produce linear and angular acceleration of all body segments (including those on which the moment

  12. Short communication The effect of an ant-hemipteran mutualism on the coffee berry

    E-print Network

    Short communication The effect of an ant-hemipteran mutualism on the coffee berry borer The indirect effect of an ant-hemipteran mutualism was investigated in the coffee agroecosystem of Southern, on coffee plants. Through field surveys and experimental studies, the indirect effect of this mutualism

  13. Z .Journal of Volcanology and Geothermal Research 88 1999 201207 Short communication

    E-print Network

    Zhang, Youxue

    . Geotherm. Res. 74, 19­38 also found an increase of the exsolution enthalpy with pressure up to 20 bar of the exsolution enthalpy at low pressures they inferred is probably an artifact of their treatment. The methodZ .Journal of Volcanology and Geothermal Research 88 1999 201­207 Short communication Exsolution

  14. Short communication Termites promote soil carbon and nitrogen depletion: Results from an

    E-print Network

    Malhi, Yadvinder

    Short communication Termites promote soil carbon and nitrogen depletion: Results from an in situ one of the first in situ soil termite exclusion experiments using translocated soil that was not colonised by termites prior to the experiment. Macrofauna were excluded or included using fine (0.3 mm

  15. Short Communication Differential effect of p7 inhibitors on hepatitis C virus cell-to-cell

    E-print Network

    Short Communication Differential effect of p7 inhibitors on hepatitis C virus cell Accepted 14 October 2013 Available online 21 October 2013 Keywords: p7 Hepatitis C Assembly Inhibitors Cell-to-cell a b s t r a c t Inhibitors targeting the hepatitis C virus (HCV) encoded viroporin, p7 prevent virus

  16. SHORT COMMUNICATION Effect of Salt Marsh Drainage on the Distribution ofTabamis

    E-print Network

    15TO7 SHORT COMMUNICATION Effect of Salt Marsh Drainage on the Distribution ofTabamis mgromttatus Macquart inhabit salt marsh sod. A study ofthe distribution oflarvae in relation the presence absence ofsurface showed that larval densities higher in salt marsh that appeared well drained. Late instars

  17. Short Communication ELUCIDATING THE GENETIC BASIS FOR ESCHERICHIA COLI DEFENSE AGAINST

    E-print Network

    Alvarez, Pedro J.

    Short Communication ELUCIDATING THE GENETIC BASIS FOR ESCHERICHIA COLI DEFENSE AGAINST SILVER,x and PEDRO J.J. ALVAREZ*y yDepartment of Civil and Environmental Engineering, Rice University, Houston, Texas, USA zCollege of Environmental Science and Engineering, Key Laboratory of Environmental Biology

  18. Short Communication Molecular phylogeny of Hemidactylus geckos (Squamata: Gekkonidae) of the

    E-print Network

    Karanth, K Praveen

    Short Communication Molecular phylogeny of Hemidactylus geckos (Squamata: Gekkonidae) of the Indian subcontinent reveals a unique Indian radiation and an Indian origin of Asian house geckos Rohini Bansal, K the phylogeny of the Indian Hemidactylus geckos based on mitochondrial and nuclear DNA markers sequenced from

  19. SHORT COMMUNICATION The possible origin of Zostera noltii in the Canary Islands

    E-print Network

    Borges, Rita

    SHORT COMMUNICATION The possible origin of Zostera noltii in the Canary Islands and guidelines are declining worldwide. Zostera noltii in the Canary Islands has been drastically reduced, mainly of the Canary Islands (Pavo´n-Salas et al. 2000). Cymodocea nodosa (Ucria) Ascherson is the most abundant

  20. 126 SHORT COMMUNICATIONS Binocular interaction on cells of the dorsal lateral geniculate nucleus of

    E-print Network

    Sherman, S. Murray

    126 SHORT COMMUNICATIONS Binocular interaction on cells of the dorsal lateral geniculate nucleus) in monocularly deprived (MD) and binocularly deprived (BD) cats had the normal concentricreceptive fields, but that early visual deprivation decreased this binocular interaction. In MD cats, where the effect was more

  1. Short communication Effect of vanadium redox species on photoelectrochemical behavior of TiO2

    E-print Network

    Liu, Fuqiang

    Short communication Effect of vanadium redox species on photoelectrochemical behavior of TiO2 TiO2/WO3 Photoelectrochemical cell Vanadium redox Photocharge/discharge a b s t r a c by using a vanadium redox (VO2þ ) species. The goal is to explore regenerative solar energy storage using

  2. SHORT COMMUNICATION Development of diet-induced fatty liver disease in

    E-print Network

    SHORT COMMUNICATION Development of diet-induced fatty liver disease in the aging mouse and age on liver morphology and biochemistry was characterized, while evaluating the potential of 15 min) to suppress lipid accumulation in the liver. Following a 36-week protocol (animals 43 weeks of age

  3. Short Communication A revised nomenclature for the human and rodent -tubulin gene family

    E-print Network

    Dutcher, Susan

    Short Communication A revised nomenclature for the human and rodent -tubulin gene family Varsha K of microtubules, -tubulin is also a multigene family in many species. An orthology-based nomenclature of human, mouse, and rat -tubulin genes has enabled an updated nomenclature to be generated. This revised

  4. Short communication Secretion of a collectin-like protein in tunicates is enhanced during

    E-print Network

    Raftos, David

    Short communication Secretion of a collectin-like protein in tunicates is enhanced during the solitary tunicate, Styela plicata, were measured after in vivo challenge with the inflammatory agent, zymosan. Tunicates were injected with zymosan before hemocytes and serum were harvested, subjected

  5. A short workshop to highlight the importance of business language through all communication

    E-print Network

    Davies, John N.

    and oral communications Identify training needs for Basic Skills in· English Trainer Profile Hayley HandOverview A short workshop to highlight the importance of business language through all at all levels within private and public sector organisations. Hayley has a background in Business

  6. Short Communication A note on ``Two-warehouse inventory model with

    E-print Network

    Xie, Jinxing

    Short Communication A note on ``Two-warehouse inventory model with deterioration under FIFO A recently published paper by Lee [C.C. Lee, Two-warehouse inventory model with deterioration under FIFO dispatching models for the two-warehouse inventory system with deteriorating items, in which Pakkala

  7. SHORT COMMUNICATION Habitat patch size and isolation as predictors of occupancy

    E-print Network

    Agnarsson, Ingi

    SHORT COMMUNICATION Habitat patch size and isolation as predictors of occupancy and number Abstract How fully a suitable habitat patch is utilized by organisms depends crucially on patch size a "habitat patch", measuring its boarders, and relatively low detection probability of the inhabitants

  8. Short communication Satellite-derived surface water pCO2 and airsea CO2 fluxes

    E-print Network

    Short communication Satellite-derived surface water pCO2 and air­sea CO2 fluxes in the northern China Sea in summer using satellite-derived sea surface temperatures (SSTs), chlorophyll-a (Chl a that the satellite-derived pCO2 was in general agreement with the in situ observations. The air­sea CO2 flux

  9. SHORT COMMUNICATION Sensitivity to self-administered cocaine within the lateral

    E-print Network

    West, Mark O.

    SHORT COMMUNICATION Sensitivity to self-administered cocaine within the lateral preoptic firing patterns are known to be modulated by fluctuating levels of cocaine, studies of the LPH's drug-access cocaine self-administration task. Results demonstrated that a majority of neurons in the LPH exhibited

  10. Short communication Inaccessible food cues affect stress and weight gain in calorically-restricted

    E-print Network

    Sokolowski, Marla

    palatable food. Typically, CR animals are provided with a limited amount of food, with no additional foodShort communication Inaccessible food cues affect stress and weight gain in calorically will respond to CR. Unlike animals subjected to CR, humans are bombarded with food cues, making over 200 food

  11. SHORT COMMUNICATION Male-biased predation of a cave fish by a giant water bug

    E-print Network

    Schlupp, Ingo

    SHORT COMMUNICATION Male-biased predation of a cave fish by a giant water bug Michael Tobler-and-wait predator that catches fish near the water surface. Our finding is novel, because male vulnerability siphon extension into the water column during severe hypoxia, thereby increasing the susceptibility

  12. ELSEVIER Wear 181-183 (1995) 810-820 Short Communication

    E-print Network

    DuPont, John N.

    1995-01-01

    ELSEVIER Wear 181-183 (1995) 810-820 Short Communication Weld overlay coatings for erosion control of research conducted to understand abrasive wear resistance of weld overlay coatings [2], few investigations have dealt with the erosion aspect of wear, making the selection of welding alloys for erosion

  13. Short Communication Grapheme-color synaesthesia benefits rule-based Category learning

    E-print Network

    Handy, Todd C.

    Short Communication Grapheme-color synaesthesia benefits rule-based Category learning Marcus R of Psychology, University of British Columbia, 2136 West Mall, Vancouver, BC, Canada V6T 1Z4 b Cognitive Science Program and Department of Psychology, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada

  14. Short communication Metatranscriptome analysis of lactic acid bacteria during kimchi fermentation with

    E-print Network

    Bae, Jin-Woo

    Short communication Metatranscriptome analysis of lactic acid bacteria during kimchi fermentation microbial diversity and biological activity during the fermentation of kimchi, a traditional Korean. Metagenomic analysis revealed 23 LAB related to kimchi fermentation [defined as bacteria with more than a 1

  15. Short Communication Amphibian-killing fungus loses genetic diversity as it spreads across the New World

    E-print Network

    Zamudio, Kelly R.

    Short Communication Amphibian-killing fungus loses genetic diversity as it spreads across the New December 2011 Available online 29 December 2011 Keywords: Amphibian declines Batrachochytrium dendrobatidis to identify factors driving disease out- breaks. Amphibian chytridiomycosis is a recently emerged amphibian

  16. Short communication Control of brown rot of stone fruits by brief heated water immersion treatments

    E-print Network

    Crisosto, Carlos H.

    Short communication Control of brown rot of stone fruits by brief heated water immersion treatments t The effectiveness of brief (30 or 60 s) immersion in water at 24, 50, 55, 60, 65, or 70 C was evaluated followed by 5 days at 20 C to simulate commercial marketing conditions. Immersion in water at 55 C for 60

  17. Short Communication Effects of enzyme loading and b-glucosidase supplementation

    E-print Network

    California at Riverside, University of

    Short Communication Effects of enzyme loading and b-glucosidase supplementation on enzymatic treated substrates. For all pretreatments, 72 h glucan/xylan digestibilities increased sharply with enzyme. For a fixed level of enzyme loading, dilute sulfuric acid (DA), SO2, and Lime pretreatments exhibited higher

  18. Short communication All-vanadium redox photoelectrochemical cell: An approach to store

    E-print Network

    Liu, Fuqiang

    demonstrated combin- ing PEC energy storage with a vanadium redox-flow battery (VRB), a well commercializedShort communication All-vanadium redox photoelectrochemical cell: An approach to store solar energy 24 May 2014 Keywords: Photoelectrochemical reaction Solar energy storage Vanadium redox Solar energy

  19. Short Communication Kinetics and thermodynamics of heavy metal ions sequestration onto novel

    E-print Network

    Gong, Jian Ru

    Short Communication Kinetics and thermodynamics of heavy metal ions sequestration onto novel of Cadmium and Mercury ions. " Kinetics and thermodynamics of biosorption. " Biosorption feasible, spontaneous and endothermic. a r t i c l e i n f o Article history: Received 6 January 2012 Received

  20. Short Communication Plasma choline concentration varies with different dietary levels of

    E-print Network

    Wurtman, Richard

    Short Communication Plasma choline concentration varies with different dietary levels of vitamins B by the sequential methylation of phosphatidylethanolamine to phos- phatidylcholine. Vitamins B6, B12 and folate can determined whether combined supplementation of these B vitamins affects plasma choline concentration in a rat

  1. Short Communication Parasites reveal movement of bats between the New and Old Worlds

    E-print Network

    Tyler, Charles

    Short Communication Parasites reveal movement of bats between the New and Old Worlds Patrick B barcoding Ribosomal DNA GAPDH a b s t r a c t The global distribution of bat taxa indicates, and within the other, Yangochiroptera, no species and only five genera are common to both. However, as bats

  2. DOI 10.1007/s10071-010-0347-4 SHORT COMMUNICATION

    E-print Network

    Indiana University

    and used to test causal reasoning in diVerent animal groups including apes (e.g. Mulcahy and Call 2006Anim Cogn DOI 10.1007/s10071-010-0347-4 123 SHORT COMMUNICATION Big brains are not enough August 2010 © Springer-Verlag 2010 Abstract The trap-tube task has become a benchmark test

  3. Short communication Absorption spectra response of XRQA radiochromic film to x-ray radiation

    E-print Network

    Yu, Peter K.N.

    Short communication Absorption spectra response of XRQA radiochromic film to x-ray radiation Hani Alnawaf c , Tsang Cheung a , Martin J. Butson a,b,c,*, Peter K.N. Yu a a Dept. of Physics and Materials Radiation Physics, University of Wollongong, NSW, Australia a r t i c l e i n f o Article history: Received

  4. Short Communication Contribution of ozone to airborne aldehyde formation in Paris homes

    E-print Network

    Short, Daniel

    Short Communication Contribution of ozone to airborne aldehyde formation in Paris homes Fanny Momas a,b, a Université Paris Descartes EA 4064, Faculté des Sciences Pharmaceutiques et Biologiques, Laboratoire Santé Publique et Environnement, 4 avenue de l'Observatoire, 75006 Paris, France b Mairie de Paris

  5. Short communication The sea urchin embryo as a model for studying

    E-print Network

    Short communication The sea urchin embryo as a model for studying efflux transporters: Roles the embryo from cyto- toxic drugs that can disrupt cell division or induce apoptosis. The energy cost and the sea urchin embryo as a convenient aquatic model organism; their combined use allows reproducible

  6. Short communication Using lipid analysis and hyphal length to quantify AM and saprotrophic

    E-print Network

    Chen, Zhongping

    Short communication Using lipid analysis and hyphal length to quantify AM and saprotrophic fungal) and saprotrophic fungal (SF) biomass in three Hawaiian soils along a natural soil fertility gradient. Phospholipids16:1u5c and 18:2u6,9c were used as an index of AM and saprotrophic fungal biomass, respectively. Both

  7. Short Communication CORAL: QSPR model of water solubility based on local and global SMILES attributes

    E-print Network

    Gini, Giuseppina

    Short Communication CORAL: QSPR model of water solubility based on local and global SMILES 17910, Jackson, MS 39217, USA h i g h l i g h t s " The CORAL software for the building up of QSPR/QSAR models is suggested. " The SMILES is used as the representation of the molecular structure. " The CORAL

  8. SHORT COMMUNICATION Testing taxonomic boundaries and the limit of DNA barcoding in the

    E-print Network

    DeSalle, Rob

    SHORT COMMUNICATION Testing taxonomic boundaries and the limit of DNA barcoding in the Siberian Canadian Barcode of Life Network, Biodiversity Institute of Ontario, Guelph, Ont., Canada, 5 Department; accepted 7 July 2009) Abstract DNA barcoding efforts involving animals have focused on the mitochondrial

  9. Short communication Litter contribution to diurnal and annual soil respiration in a tropical

    E-print Network

    Malhi, Yadvinder

    Short communication Litter contribution to diurnal and annual soil respiration in a tropical soil respiration variation Tropical montane cloud forest Litter respiration a b s t r a c t Respiration in respiration rate in the litter, which were partly correlated with the soil surface air temperature. Most

  10. Short communication The genetic legacy of Lonesome George survives: Giant tortoises with Pinta

    E-print Network

    Garrick, Ryan

    Short communication The genetic legacy of Lonesome George survives: Giant tortoises with Pinta October 2012 Keywords: Ancient DNA Chelonoidis abingdoni Conservation genetics Galápagos giant tortoise of Chelonoidis abingdoni native to Pinta Island, marked the extinction of one of 10 surviving giant tortoise

  11. SHORT COMMUNICATIONSHORT COMMUNICATION Mutualism variation in the nodulation response to nitrate

    E-print Network

    Stinchcombe, John

    SHORT COMMUNICATIONSHORT COMMUNICATION Mutualism variation in the nodulation response to nitrate K) and nitrogen (N)-fixing rhizobia. Rhizobia live in symbiotic nodules on the roots of host plants and therein in legume-rhizobium coevolution is the number of root nodules formed. Nodule number is truly a trait

  12. Amer J of Potato Res (2001) 78:319-322 319 Short Communication

    E-print Network

    Douches, David S.

    2001-01-01

    Amer J of Potato Res (2001) 78:319-322 319 Short Communication Susceptibility of Potato (Solanum:kirkw@msu.edu ABSTRACT Late blight is an important disease of potato (Solanum tuberosum L.) worldwide, and therefore, many potato-breeding programs have prioritized the develop- ment of late blight-resistant potato

  13. Short-Form Versions of the Spanish MacArthur-Bates Communicative Development Inventories

    ERIC Educational Resources Information Center

    Jackson-Maldonodo, Donna; Marchman, Virginia A.; Fernald, Lia C. H.

    2013-01-01

    The Spanish-language MacArthur-Bates Communicative Development Inventories (S-CDIs) are well-established parent report tools for assessing the language development of Spanish-speaking children under 3 years. Here, we introduce the short-form versions of the S-CDIs (SFI and SFII), offered as alternatives to the long forms for screening purposes or…

  14. Monolithically integrated quantum dot optical modulator with Semiconductor optical amplifier for short-range optical communications

    NASA Astrophysics Data System (ADS)

    Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Kawanishi, Tetsuya

    2015-04-01

    A monolithically integrated quantum dot (QD) optical gain modulator (OGM) with a QD semiconductor optical amplifier (SOA) was successfully developed. Broadband QD optical gain material was used to achieve Gbps-order high-speed optical data transmission, and an optical gain change as high as approximately 6-7 dB was obtained with a low OGM voltage of 2.0 V. Loss of optical power due to insertion of the device was also effectively compensated for by the SOA section. Furthermore, it was confirmed that the QD-OGM/SOA device helped achieve 6.0-Gbps error-free optical data transmission over a 2.0-km-long photonic crystal fiber. We also successfully demonstrated generation of Gbps-order, high-speed, and error-free optical signals in the >5.5-THz broadband optical frequency bandwidth larger than the C-band. These results suggest that the developed monolithically integrated QD-OGM/SOA device will be an advantageous and compact means of increasing the usable optical frequency channels for short-reach communications.

  15. Solar Cells, 14 (1985) 289 -291 289 Short Communication

    E-print Network

    Rocca, Jorge J.

    1985-01-01

    thermally evaporated SiOx (1 and of scaling this ARC technique to the large area high throughput re- quirements of a thin film manufacturing for CdS/CuInSe2 thin film solar cells by electron beam assisted chemical vapor deposition B. J. STANBERY

  16. SHORT COMMUNICATION The Chlorophyll Fluorescence Ratio F735/F700

    E-print Network

    Gitelson, Anatoly

    and Lichtenthaler, 1988; Guyot and Major,The technique was tested and validated in three plant species: beech (Fagus the sensitivity of the ratio F685/F735 to mod-1987a; Lichtenthaler and Buschmann, 1987; Guyot and erate to high

  17. Short Communication Lens Defects and Age-Related Fiber Cell

    E-print Network

    Frederikse, Peter

    of Increased A PP Gene Dosage in Down Syndrome Peter H. Frederikse and Xiao-Ou Ren From the Department Early-onset cataract and Alzheimer's disease occur with high frequency in Down syndrome (trisomy 21 report on mice carrying a com- plete copy of a wild-type human A PP (hA PP) gene from the Down syndrome

  18. SHORT COMMUNICATION: An image processing approach to calibration of hydrometers

    NASA Astrophysics Data System (ADS)

    Lorefice, S.; Malengo, A.

    2004-06-01

    The usual method adopted for multipoint calibration of glass hydrometers is based on the measurement of the buoyancy by hydrostatic weighing when the hydrometer is plunged in a reference liquid up to the scale mark to be calibrated. An image processing approach is proposed by the authors to align the relevant scale mark with the reference liquid surface level. The method uses image analysis with a data processing technique and takes into account the perspective error. For this purpose a CCD camera with a pixel matrix of 604H × 576V and a lens of 16 mm focal length were used. High accuracy in the hydrometer reading was obtained as the resulting reading uncertainty was lower than 0.02 mm, about a fifth of the usual figure with the visual reading made by an operator.

  19. Short communication: A comparative analysis of recombinant chymosins.

    PubMed

    Vallejo, J A; Ageitos, J M; Poza, M; Villa, T G

    2012-02-01

    The first step in cheesemaking is the milk clotting process, in which ?-caseinolytic enzymes contribute to micelle precipitation. The best enzyme for this purpose is chymosin because of its high degree of specificity toward ?-casein. Although recombinant bovine chymosin is the most frequently used chymosin in the industry, new sources of recombinant chymosin, such as goat, camel, or buffalo, are now available. The present work represents a comparative study of 4 different recombinant chymosins (goat and buffalo chymosins expressed in Pichia pastoris, and bovine and camel chymosin expressed in Aspergillus niger). Recombinant goat chymosin exhibited the best catalytic efficiency compared with the buffalo, bovine, or camel recombinant enzymes. Moreover, recombinant goat chymosin exhibited the best specific proteolytic activity, a wider pH range of action, and a lower glycosylation degree than the other 3 enzymes. In conclusion, we propose that recombinant goat chymosin represents a serious alternative to recombinant bovine chymosin for use in the cheesemaking industry. PMID:22281325

  20. Short communication: Reactivity of diacetyl with cleaning and sanitizing agents.

    PubMed

    Rincon-Delgadillo, M I; Lopez-Hernandez, A; Rankin, S A

    2013-01-01

    Diacetyl is used to impart a buttery flavor to numerous food products such as sour cream, cottage cheese, vegetable oil-based spreads, baked goods, and beverages. Recent studies have linked exposure to high concentrations of diacetyl and the onset of bronchiolitis obliterans. Due to the reported risks that diacetyl may pose, many food companies have altered practices to reduce worker exposure to diacetyl, including the use of personal respirators, improved air handling systems, and adequate cleaning practices. Commonly used cleaning and sanitizing agents may be reactive with diacetyl; however, the efficacy of these chemicals has not been studied in detail and remains unclear. The objective of this work was to study the reaction chemistry of diacetyl with common industrial cleaning and sanitizing chemicals. The reactions were assessed at equimolar concentrations and analyzed by gas chromatography-mass spectrometry. Peroxyacetic acid was most reactive with diacetyl (95% reduction in diacetyl), followed by sodium hypochlorite (76% reduction), and hydrogen peroxide (26% reduction). Benzalkonium chloride (BAC) did not react with diacetyl. Acetic acid was detected as the main product of reactions of diacetyl with peroxyacetic acid, sodium hypochlorite, and hydrogen peroxide. 1,1-Dichloro-2-propanone and 1,1,1-trichloropropanone were also identified as volatile reaction products in the sodium hypochlorite reactions. PMID:23063162

  1. Short communication: Genetic variation of riboflavin content in bovine milk.

    PubMed

    Poulsen, Nina A; Rybicka, Iga; Larsen, Lotte B; Buitenhuis, Albert J; Larsen, Mette K

    2015-05-01

    Riboflavin (vitamin B2) is an essential water-soluble vitamin; elderly people and adolescents in particular can have poor riboflavin status. In Western diets, milk and dairy products are primary sources of riboflavin, but little is known about the natural variation within and among bovine breeds, and how genetic and environmental factors can affect the riboflavin content in milk. As a part of the Danish-Swedish Milk Genomics Initiative, the aim of the study was to quantify milk riboflavin content using reverse-phase HPLC in 2 major Danish dairy breeds. The results showed substantial interbreed differences in milk riboflavin content. Milk from Danish Jersey cows contained significantly higher levels of riboflavin (1.93mg/L of milk) than milk from Danish Holstein cows (1.40mg/L of milk). Furthermore, genetic analyses revealed high heritabilities in both breeds (0.52 for Danish Holstein and 0.31 for Danish Jersey). A genomic association study found 35 significant single nucleotide polymorphisms (false discovery rate<0.10) to be associated with riboflavin content in milk in Jersey cows (all on BTA14 and BTA17), and 511 significant single nucleotide polymorphisms in Holstein cows spread over 25 different autosomes with BTA13 and BTA14 having the most promising quantitative trait loci. The best candidate gene found within the identified quantitative trait loci was SLC52A3, a riboflavin transporter gene, which was among the significant markers on BTA13 in Holstein cows. PMID:25771056

  2. Short communication Land use change patterns in the Rio de la Plata grasslands: The influence of

    E-print Network

    Nacional de San Luis, Universidad

    Short communication Land use change patterns in the Ri´o de la Plata grasslands: The influence) hold one of the largest area of temperate grasslands of the world, the Ri´o de la Plata grasslands (RPG­387) (Fig. 1). Ri´o de la Plata grasslands have an area of 3.4 Â 106 km2 at the center-east of Argentina

  3. Efficient High Performance Collective Communication for Distributed Memory Environments

    ERIC Educational Resources Information Center

    Ali, Qasim

    2009-01-01

    Collective communication allows efficient communication and synchronization among a collection of processes, unlike point-to-point communication that only involves a pair of communicating processes. Achieving high performance for both kernels and full-scale applications running on a distributed memory system requires an efficient implementation of…

  4. Fiber Laser Front Ends for High Energy, Short Pulse Lasers

    SciTech Connect

    Dawson, J; Messerly, M; Phan, H; Siders, C; Beach, R; Barty, C

    2007-06-21

    We are developing a fiber laser system for short pulse (1-10ps), high energy ({approx}1kJ) glass laser systems. Fiber lasers are ideal for these systems as they are highly reliable and enable long term stable operation.

  5. High-Capacity Communications from Martian Distances

    NASA Technical Reports Server (NTRS)

    Williams, W. Dan; Collins, Michael; Hodges, Richard; Orr, Richard S.; Sands, O. Scott; Schuchman, Leonard; Vyas, Hemali

    2007-01-01

    High capacity communications from Martian distances, required for the envisioned human exploration and desirable for data-intensive science missions, is challenging. NASA s Deep Space Network currently requires large antennas to close RF telemetry links operating at kilobit-per-second data rates. To accommodate higher rate communications, NASA is considering means to achieve greater effective aperture at its ground stations. This report, focusing on the return link from Mars to Earth, demonstrates that without excessive research and development expenditure, operational Mars-to-Earth RF communications systems can achieve data rates up to 1 Gbps by 2020 using technology that today is at technology readiness level (TRL) 4-5. Advanced technology to achieve the needed increase in spacecraft power and transmit aperture is feasible at an only moderate increase in spacecraft mass and technology risk. In addition, both power-efficient, near-capacity coding and modulation and greater aperture from the DSN array will be required. In accord with these results and conclusions, investment in the following technologies is recommended:(1) lightweight (1 kg/sq m density) spacecraft antenna systems; (2) a Ka-band receive ground array consisting of relatively small (10-15 m) antennas; (3) coding and modulation technology that reduces spacecraft power by at least 3 dB; and (4) efficient generation of kilowatt-level spacecraft RF power.

  6. High-performance computing and communications

    SciTech Connect

    Stevens, R.

    1993-11-01

    This presentation has two parts. The first part discusses the US High-Performance Computing and Communications program -- its goals, funding, process, revisions, and research in high-performance computing systems, advanced software technology, and basic research and human resources. The second part of the presentation covers specific work conducted under this program at Argonne National Laboratory. Argonne`s efforts focus on computational science research, software tool development, and evaluation of experimental computer architectures. In addition, the author describes collaborative activities at Argonne in high-performance computing, including an Argonne/IBM project to evaluate and test IBM`s newest parallel computers and the Scalable I/O Initiative being spearheaded by the Concurrent Supercomputing Consortium.

  7. Dynamic Communicating Automata and Branching High-Level MSCs

    E-print Network

    Bollig, Benedikt

    Communicating Automata · Branching High-Level MSCs ... x := new(s,x) x ? comx ! req(y) #12;Outline · Dynamic Communicating Automata · Branching High-Level MSCs ... x y x y req(y) x y com com x := new(s,x) x ? comx ! req com x := new(s,x) x ? comx ! req(y) implementable? #12;Outline · Dynamic Communicating Automata

  8. Spontaneous Radiation Emission from Short, High Field Strength Insertion Devices

    SciTech Connect

    Geoffrey Krafft

    2005-09-15

    Since the earliest papers on undulaters were published, it has been known how to calculate the spontaneous emission spectrum from ''short'' undulaters when the magnetic field strength parameter is small compared to unity, or in ''single'' frequency sinusoidal undulaters where the magnetic field strength parameter is comparable to or larger than unity, but where the magnetic field amplitude is constant throughout the undulater. Fewer general results have been obtained in the case where the insertion device is both short, i.e., the magnetic field strength parameter changes appreciably throughout the insertion device, and the magnetic field strength is high enough that ponderomotive effects, radiation retardation, and harmonic generation are important physical phenomena. In this paper a general method is presented for calculating the radiation spectrum for short, high-field insertion devices. It is used to calculate the emission from some insertion device designs of recent interest.

  9. Beam divergence changing mechanism for short-range inter-unmanned aerial vehicle optical communications.

    PubMed

    Heng, Kiang Huat; Zhong, Wen-De; Cheng, Tee Hiang; Liu, Ning; He, Yingjie

    2009-03-10

    The problems associated with using a single fixed beam divergence for short-range inter-unmanned aerial vehicle free-space optical communications are discussed. To overcome the problems, a beam divergence changing mechanism is proposed. Four different methods are then proposed to implement the beam divergence changing mechanism. The performance of these methods is evaluated in terms of transmission distance under adverse weather conditions. The results show that the performance is greatly improved when the beam divergence changing mechanism is used. PMID:19277090

  10. Short communication On the pressure drop prediction of filter media composed of fibers with

    E-print Network

    Tafreshi, Hooman Vahedi

    with widely different average diameters. This is often the case where mechanical strength and filtration efficiency are both important. The fine fibers contribute to the high filtration efficiency (high collection. The fibers may be intimately blended in the case of short fibers like in carded, air-laid, or wet-laid fiber

  11. SHORT COMMUNICATION High temperature intensifies negative density dependence

    E-print Network

    Blouin-Demers, Gabriel

    thus modulate density-dependent processes in ectotherms. Therefore, models of pop- ulation growth for ectotherms should incorporate the effects of temperature. Introduction Competition is an important mechanism a limiting factor for all ectotherms, as they rely on environmental temperature to maintain internal body

  12. Applications of High Technology to Communication Instruction.

    ERIC Educational Resources Information Center

    Behnke, Ralph R.; O'Hair, H. Dan

    1984-01-01

    Discusses classroom design and uses of interactive media. Covers the design of public speaking/interpersonal/small group communication classrooms, the simulation laboratory, the communication effectiveness trainer (ComET system), audience response systems, speech evaluation using computers, and system design considerations. (PD)

  13. Iridium: Global OTH data communications for high altitude scientific ballooning

    NASA Astrophysics Data System (ADS)

    Denney, A.

    While the scientific community is no stranger to embracing commercially available technologies, the growth and availability of truly affordable cutting edge technologies is opening the door to an entirely new means of global communications. For many years high altitude ballooning has provided science an alternative to costly satellite based experimental platforms. As with any project, evolution becomes an integral part of development. Specifically in the NSBF ballooning program, where flight durations have evolved from the earlier days of hours to several weeks and plans are underway to provide missions up to 100 days. Addressing increased flight durations, the harsh operational environment, along with cumbersome and outdated systems used on existing systems, such as the balloon vehicles Support Instrumentation Package (SIP) and ground-based systems, a new Over-The-Horizon (OTH) communications medium is sought. Current OTH equipment planning to be phased-out include: HF commanding systems, ARGOS PTT telemetry downlinks and INMARSAT data terminals. Other aspects up for review in addition to the SIP to utilize this communications medium include pathfinder balloon platforms - thereby, adding commanding abilities and increased data rates, plus providing a package for ultra-small experiments to ride aloft. Existing communication systems employed by the National Scientific Balloon Facility ballooning program have been limited not only by increased cost, slow data rates and "special government use only" services such as TDRSS (Tracking and Data Relay Satellite System), but have had to make special provisions to geographical flight location. Development of the Support Instrumentation Packages whether LDB (Long Duration Balloon), ULDB (Ultra Long Duration Balloon) or conventional ballooning have been plagued by non-standard systems configurations requiring additional support equipment for different regions and missions along with a myriad of backup for redundancy. Several beneficial points provided by the Iridium platform include pure global accessibility (as well as polar), cost effectiveness because it is available as a COTS (Commercially Off The Shelf) technology, reliability in that the equipment must operate in extreme conditions (near space), integration and development time into current systems must be minimized. As a bonus Motorola and NAL Research Corporation are developing SBD (Short Burst Data) into the Iridium network. This may lead the way to a global IP (Internet Protocol) node based ballooning platform. The Iridium satellite data modems employ the Iridium Low-Earth Orbit (LEO) satellite network. The scope of this paper is to introduce an OTH communications alternative, albeit not necessarily a primary one, to existing ballooning platforms using COTS based emerging technologies. Design aspects, characteristics, actual flight testing statistics, principles of the Iridium modems and communication paths are described including payload and support instrumentation interfacing. Not limited to high altitude ballooning, the Iridium communications platform opens a new era in remote commanding and data retrieval.

  14. TDX: A high-bandwidth crossbar-switched communication paradigm

    SciTech Connect

    Pierce, P.E.; Eilers, D.L.; Schreiber, A.L.

    1994-08-01

    Digital signal processing systems under development today require scalable and reconfigurable high bandwidth communication resources between processing elements. Shared memory architectures require the ability to transfer data from one processor node to another, as well as maintaining data coherency such as provided by the Scalable Coherent Interface (SCI). Signal processing systems that must move large amounts of data between processor nodes, are best served by a communication system that allows reconfigurable streams of data to flow at deterministic rates with minimal overhead. A Time Domain Crossbar (TDX) communication system providing scalable, programmable, high-bandwidth, streaming communication has been developed and is described in this paper.

  15. High-Latitude Communications Satellite (HILACS)

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Naval Postgraduate School in the AE 4871 Advanced Spacecraft Design course designed a communications satellite (HILACS) that will provide a continuous UHF communications link between stations located north of the region covered by geosynchronous communications satellites. The communications payload will operate only for that portion of the orbit necessary to provide specific coverage. The satellite orbit is elliptic with perigee at 1204 km in the Southern Hemisphere and an apogee at 14,930 km with 63.4 degrees inclination. Analysis and design of each of the subsystems was done to the extent possible within the constraints of an eleven week quarter and the design and analysis tools available. Work was completed in orbital analysis, the reaction control system, attitude control subsystem, electric power subsystem, telemetry, tracking, and control, thermal control subsystem, and the structures subsystem. The design team consisted of 12 students. Additional support was provided by the Jet Propulsion Laboratory and the Naval Research Laboratory.

  16. Analysis of High Power IGBT Short Circuit Failures

    SciTech Connect

    Pappas, G.

    2005-02-11

    The Next Linear Collider (NLC) accelerator proposal at SLAC requires a highly efficient and reliable, low cost, pulsed-power modulator to drive the klystrons. A solid-state induction modulator has been developed at SLAC to power the klystrons; this modulator uses commercial high voltage and high current Insulated Gate Bipolar Transistor (IGBT) modules. Testing of these IGBT modules under pulsed conditions was very successful; however, the IGBTs failed when tests were performed into a low inductance short circuit. The internal electrical connections of a commercial IGBT module have been analyzed to extract self and mutual partial inductances for the main current paths as well as for the gate structure. The IGBT module, together with the partial inductances, has been modeled using PSpice. Predictions for electrical paths that carry the highest current correlate with the sites of failed die under short circuit tests. A similar analysis has been carried out for a SLAC proposal for an IGBT module layout. This paper discusses the mathematical model of the IGBT module geometry and presents simulation results.

  17. Highly stabilized laser intensity during ultra-short laser filamentation

    NASA Astrophysics Data System (ADS)

    Xu, Shengqi; Zhang, Yizhu; Liu, Weiwei

    2008-12-01

    In this work, we investigate the stability of the nitrogen fluorescence signal emitted by a femtosecond laser filament as an example of a high order nonlinear optical process. It is found that the root-mean-square fluctuation of the fluorescence signal emitted from the filament is less than 1 %. The corresponding estimated laser intensity fluctuation is as low as 0.14%, which is at least one order of magnitude lower than the input laser pulse power fluctuation. Further numerical simulation has confirmed that the intensity clamping phenomenon is responsible for this observation. Since the intensity clamping is an intrinsic property of filamentation phenomenon, it is expected that any intensity sensitive optical interaction taking place inside filament could lead to highly stabilized outcome. This conclusion potentially affects various applications of ultra-short laser filamentation.

  18. SHORT COMMUNICATION The utility of ITS2 in spider phylogenetics: notes on prior work and an example from Anelosimus

    E-print Network

    Agnarsson, Ingi

    SHORT COMMUNICATION The utility of ITS2 in spider phylogenetics: notes on prior work and an example nuclear DNA marker used to examine relationships among and within species in animals and plants. ITS2 of spiders. Here, I examine the potential utility of this marker for spider phylogenetics based

  19. Short communication The December 7, 2012 Japan Trench intraplate doublet (Mw 7.2, 7.1) and

    E-print Network

    Duputel, Zacharie

    Short communication The December 7, 2012 Japan Trench intraplate doublet (Mw 7.2, 7.1) and interactions between near-trench intraplate thrust and normal faulting Thorne Lay a, , Zacharie Duputel b Keywords: Japan Trench intraplate earthquake doublet Plate bending stress Earthquake triggering a b s t r

  20. Interference of Short Optical Pulses from Independent Gain-Switched Laser Diodes for Quantum Secure Communications

    NASA Astrophysics Data System (ADS)

    Yuan, Z. L.; Lucamarini, M.; Dynes, J. F.; Fröhlich, B.; Ward, M. B.; Shields, A. J.

    2014-12-01

    Since the introduction of the decoy-state technique, phase-randomized weak coherent light pulses have been the key to increase the practicality of quantum-based communications. Their ultrafast generation was accomplished via compact gain-switched (GS) lasers, leading to high key rates in quantum key distribution (QKD). Recently, the question arose whether the same laser could be employed to achieve high-speed measurement-device-independent QKD, a scheme that promises long-haul quantum communications immune to all detector attacks. For that, a challenging high-visibility interference between independent picosecond optical pulses is required. Here, we answer the above question in the affirmative by demonstrating high-visibility interference from two independent GS lasers triggered at 1 GHz. The result is obtained through a careful characterization of the laser frequency chirp and time jitter. By relating these quantities to the interference visibility, we obtain a parameter-free verification of the experimental data and a numerical simulation of the achievable key rates. These findings are beneficial to other applications making use of GS lasers, including random number generation and standard QKD.

  1. Trend on High-speed Power Line Communication Technology

    NASA Astrophysics Data System (ADS)

    Ogawa, Osamu

    High-speed power line communication (PLC) is useful technology to easily build the communication networks, because construction of new infrastructure is not necessary. In Europe and America, PLC has been used for broadband networks since the beginning of 21th century. In Japan, high-speed PLC was deregulated only indoor usage in 2006. Afterward it has been widely used for home area network, LAN in hotels and school buildings and so on. And recently, PLC is greatly concerned as communication technology for smart grid network. In this paper, the author surveys the high-speed PLC technology and its current status.

  2. Methods for UGV teleoperation with high latency communications

    NASA Astrophysics Data System (ADS)

    Witus, Gary; Hunt, Shawn; Janicki, Phil

    2011-05-01

    In this project, we developed and demonstrated complementary UGV control methods for teleoperation with highlatency communications. The methods included latency protection, predictive displays, and supervisory control. Latency protection mitigate against typical types of high-latency teleoperation input errors. The Phase I latency protection methods included filtering the joysick commands, limiting the commanded rates as a function of latency, and emergency stop when the operator commands and OCU navigation video were out of phase. Predictive displays indicate to the operator the current state of the UGV, i.e., the state after all of the latent commands are executed (latent commands are those that have been issued but whose effects do not yet appear in the OCU display). We implemented two alternative predictive display methods: augmented reality using iconography to indicate the effects of the latent commands, and virtual reality which warps the image to show the view to reflect the latent commands. Supervisory control allows the operator to specify simple, short-range objectives that the UGV can accomplish on its own, without advanced sensing, path planning, etc. We implemented an effective "point-and-go" supervisory control system. We successfully implemented and demonstrated these methods on a Packbot510 EOD robot (made by iRobot Corporation), currently being used in-theater.

  3. Underground wireless communications systems using high temperature superconducting receivers

    SciTech Connect

    Reagor, D.; Goff, S.; Fan, Y.; Mombourquette, C.; Jia, Q.X.

    1997-12-31

    The ability to effectively communicate with both people and equipment in underground environments such as mines, tunnels, and boreholes is important from both an operations and safety perspective. Radio waves with frequencies above 10Mhz, such as cellular phones, do not propagate more than a few meters in a typical rock mass. Although these systems can be used in tunnels for line-of-sight communications, signal strength decreases drastically around corners. Many mines rely on hard-wired phone systems, but this is expensive, requires constant changing as tunnel systems change, and fails easily during tunnel collapse or fire. Near-field wireless systems typically use a system of repeaters and poorly shielded wiring that allow the signal to radiate weakly to be picked up by a receiver a short distance from the wiring. Ground penetrating signals are much greater at low frequencies, but the receivers for these low frequencies usually require a very large antenna (on either the transmit or receive side) to overcome the electrical noise of typical semiconductor components. One common mine paging system uses a transmit antenna several kilometers in diameter to achieve sufficient amplitude to drive a conveniently sized wire-wound ferrite core receiver. Superconducting components are the lowest noise of any electronics technology and have traditionally been used in applications where a low noise floor is critical, such as radio astronomy and noninvasive magnetoencephalography. The authors have developed a receiver for deeply penetrating low frequency radio waves using high temperature superconducting quantum interference devices (SQUIDS). The receiver consists of a SQUID, a small dewar, control electronics, and a battery pack. The receiver is several orders of magnitude more sensitive than conventional receivers of the same size and weight. SQUIDs also allow the compact construction of 3-axis receivers that are necessary to overcome a dominant source of vibrational or motional noise. The goal is to demonstrate an effective and reliable two-way voice underground wireless communication system. The low noise compact receivers also have application in geophysical tool development, survey techniques, and underground structure detection.

  4. Multimethod communication for high-performance metacomputing applications

    SciTech Connect

    Foster, I.; Geisler, J.; Tuecke, S.; Kesselman, C.

    1996-12-31

    Metacomputing systems use high-speed networks to connect supercomputers, mass storage systems, scientific instruments, and display devices with the objective of enabling parallel applications to access geographically distributed computing resources. However, experience shows that high performance often can be achieved only if applications can integrate diverse communication substrates, transport mechanisms, and protocols, chosen according to where communication is directed, what is communicated, or when communication is performed. In this article, we describe a software architecture that addresses this requirement. This architecture allows multiple communication methods to be supported transparently in a single application, with either automatic or user-specified selection criteria guiding the methods used for each communication. We describe an implementation of this architecture, based on the Nexus communication library, and use this implementation to evaluate performance issues. The implementation supported a wide variety of applications in the I-WAY metacomputing experiment at Supercomputing 95; we use one of these applications to provide a quantitative demonstration of the advantages of multimethod communication in a heterogeneous networked environment.

  5. A high current, short pulse electron source for wakefield accelerators

    SciTech Connect

    Ho, Ching-Hung.

    1992-01-01

    Design studies for the generation of a high current, short pulse electron source for the Argonne Wakefield Accelerator are presented. An L-band laser photocathode rf gun cavity is designed using the computer code URMEL to maximize the electric field on the cathode surface for fixed frequency and rf input power. A new technique using a curved incoming laser wavefront to minimize the space charge effect near the photocathode is studied. A preaccelerator with large iris to minimize wakefield effects is used to boost the drive beam to a useful energy of around 20 MeV for wakefield acceleration experiments. Focusing in the photocathode gun and the preaccelerator is accomplished with solenoids. Beam dynamics simulations throughout the preaccelerator are performed using particle simulation codes TBCI-SF and PARMELA. An example providing a useful set of operation parameters for the Argonne Wakefield Accelerator is given. The effects of the sagitta of the curved beam and laser amplitude and timing jitter effects are discussed. Measurement results of low rf power level bench tests and a high power test for the gun cavity are presented and discussed.

  6. A high current, short pulse electron source for wakefield accelerators

    SciTech Connect

    Ho, Ching-Hung

    1992-12-31

    Design studies for the generation of a high current, short pulse electron source for the Argonne Wakefield Accelerator are presented. An L-band laser photocathode rf gun cavity is designed using the computer code URMEL to maximize the electric field on the cathode surface for fixed frequency and rf input power. A new technique using a curved incoming laser wavefront to minimize the space charge effect near the photocathode is studied. A preaccelerator with large iris to minimize wakefield effects is used to boost the drive beam to a useful energy of around 20 MeV for wakefield acceleration experiments. Focusing in the photocathode gun and the preaccelerator is accomplished with solenoids. Beam dynamics simulations throughout the preaccelerator are performed using particle simulation codes TBCI-SF and PARMELA. An example providing a useful set of operation parameters for the Argonne Wakefield Accelerator is given. The effects of the sagitta of the curved beam and laser amplitude and timing jitter effects are discussed. Measurement results of low rf power level bench tests and a high power test for the gun cavity are presented and discussed.

  7. NASA high performance computing and communications program

    NASA Technical Reports Server (NTRS)

    Holcomb, Lee; Smith, Paul; Hunter, Paul

    1993-01-01

    The National Aeronautics and Space Administration's HPCC program is part of a new Presidential initiative aimed at producing a 1000-fold increase in supercomputing speed and a 100-fold improvement in available communications capability by 1997. As more advanced technologies are developed under the HPCC program, they will be used to solve NASA's 'Grand Challenge' problems, which include improving the design and simulation of advanced aerospace vehicles, allowing people at remote locations to communicate more effectively and share information, increasing scientist's abilities to model the Earth's climate and forecast global environmental trends, and improving the development of advanced spacecraft. NASA's HPCC program is organized into three projects which are unique to the agency's mission: the Computational Aerosciences (CAS) project, the Earth and Space Sciences (ESS) project, and the Remote Exploration and Experimentation (REE) project. An additional project, the Basic Research and Human Resources (BRHR) project exists to promote long term research in computer science and engineering and to increase the pool of trained personnel in a variety of scientific disciplines. This document presents an overview of the objectives and organization of these projects as well as summaries of individual research and development programs within each project.

  8. NASA High Performance Computing and Communications program

    NASA Technical Reports Server (NTRS)

    Holcomb, Lee; Smith, Paul; Hunter, Paul

    1994-01-01

    The National Aeronautics and Space Administration's HPCC program is part of a new Presidential initiative aimed at producing a 1000-fold increase in supercomputing speed and a 1(X)-fold improvement in available communications capability by 1997. As more advanced technologies are developed under the HPCC program, they will be used to solve NASA's 'Grand Challenge' problems, which include improving the design and simulation of advanced aerospace vehicles, allowing people at remote locations to communicate more effectively and share information, increasing scientists' abilities to model the Earth's climate and forecast global environmental trends, and improving the development of advanced spacecraft. NASA's HPCC program is organized into three projects which are unique to the agency's mission: the Computational Aerosciences (CAS) project, the Earth and Space Sciences (ESS) project, and the Remote Exploration and Experimentation (REE) project. An additional project, the Basic Research and Human Resources (BRHR) project, exists to promote long term research in computer science and engineering and to increase the pool of trained personnel in a variety of scientific disciplines. This document presents an overview of the objectives and organization of these projects, as well as summaries of early accomplishments and the significance, status, and plans for individual research and development programs within each project. Areas of emphasis include benchmarking, testbeds, software and simulation methods.

  9. An Outcome Study of Short-Term Communication Training with Married Couples.

    ERIC Educational Resources Information Center

    Epstein, Norman; Jackson, Elizabeth

    1978-01-01

    Compared communication training, interaction insight training, and no treatment for changes in marital verbal interaction and spouses' ratings of each other on the Barrett-Lennard Relationship Inventory. Communication training produced increases in assertive requests. Both treatments reduced disagreement. Communication training produced a decrease…

  10. NASA satellite communications application research. Phase 2: Efficient high power, solid state amplifier for EFH communications

    NASA Technical Reports Server (NTRS)

    Benet, James

    1993-01-01

    The final report describes the work performed from 9 Jun. 1992 to 31 Jul. 1993 on the NASA Satellite Communications Application Research (SCAR) Phase 2 program, Efficient High Power, Solid State Amplifier for EHF Communications. The purpose of the program was to demonstrate the feasibility of high-efficiency, high-power, EHF solid state amplifiers that are smaller, lighter, more efficient, and less costly than existing traveling wave tube (TWT) amplifiers by combining the output power from up to several hundred solid state amplifiers using a unique orthomode spatial power combiner (OSPC).

  11. Short Communication: Atmospheric moisture transport, the bridge between ocean evaporation and Arctic ice melting

    NASA Astrophysics Data System (ADS)

    Gimeno, L.; Vázquez, M.; Nieto, R.; Trigo, R. M.

    2015-06-01

    If we could choose a region where the effects of global warming are likely to be pronounced and considerable, and at the same time one where the changes could affect the global climate in similarly asymmetric way with respect to other regions, this would unequivocally be the Arctic. The atmospheric branch of the hydrological cycle lies behind the linkages between the Arctic system and the global climate. Changes in the atmospheric moisture transport have been proposed as a vehicle for interpreting the most significant changes in the Arctic region. This is because the transport of moisture from the extratropical regions to the Arctic has increased in recent decades, and is expected to increase within a warming climate. This increase could be due either to changes in circulation patterns which have altered the moisture sources, or to changes in the intensity of the moisture sources because of enhanced evaporation, or a combination of these two mechanisms. In this short communication we focus on the assessing more objectively the strong link between ocean evaporation trends and Arctic Sea ice melting. We will critically analyze several recent results suggesting links between moisture transport and the extent of sea-ice in the Arctic, this being one of the most distinct indicators of continuous climate change both in the Arctic and on a global scale. To do this we will use a sophisticated Lagrangian approach to develop a more robust framework on some of these previous disconnect ng results, using new information and insights. Among the many mechanisms that could be involved are hydrological (increased Arctic river discharges), radiative (increase of cloud cover and water vapour) and meteorological (increase in summer storms crossing the Arctic, or increments in precipitation).

  12. Quantum data locking for high-rate private communication

    E-print Network

    Cosmo Lupo; Seth Lloyd

    2015-03-31

    We show that, if the accessible information is used as a security quantifier, quantum channels with a certain symmetry can convey private messages at a tremendously high rate, as high as less than one bit below the rate of non-private classical communication. This result is obtained by exploiting the quantum data locking effect. The price to pay to achieve such a high private communication rate is that accessible information security is in general not composable. However, composable security holds against an eavesdropper who is forced to measure her share of the quantum system within a finite time after she gets it.

  13. SLIM, Short-pulse Technology for High Gradient Induction Accelerators

    SciTech Connect

    Arntz, Floyd; Kardo-Sysoev, A.; Krasnykh, A.; /SLAC

    2008-12-16

    A novel short-pulse concept (SLIM) suited to a new generation of a high gradient induction particle accelerators is described herein. It applies advanced solid state semiconductor technology and modern microfabrication techniques to a coreless induction method of charged particle acceleration first proven on a macro scale in the 1960's. Because this approach avoids use of magnetic materials there is the prospect of such an accelerator working efficiently with accelerating pulses in the nanosecond range and, potentially, at megahertz pulse rates. The principal accelerator section is envisioned as a stack of coreless induction cells, the only active element within each being a single, extremely fast (subnanosecond) solid state opening switch: a Drift Step Recovery Diode (DSRD). Each coreless induction cell incorporates an electromagnetic pulse compressor in which inductive energy developed within a transmission-line feed structure over a period of tens of nanoseconds is diverted to the acceleration of the passing charge packet for a few nanoseconds by the abrupt opening of the DSRD switch. The duration of this accelerating output pulse--typically two-to-four nanoseconds--is precisely determined by a microfabricated pulse forming line connected to the cell. Because the accelerating pulse is only nanoseconds in duration, longitudinal accelerating gradients approaching 100 MeV per meter are believed to be achievable without inciting breakdown. Further benefits of this approach are that, (1) only a low voltage power supply is required to produce the high accelerating gradient, and, (2) since the DSRD switch is normally closed, voltage stress is limited to a few nanoseconds per period, hence the susceptibility to hostile environment conditions such as ionizing radiation, mismatch (e.g. in medical applications the peak beam current may be low), strong electromagnetic noise levels, etc is expected to be minimal. Finally, we observe the SLIM concept is not limited to linac applications; for instance, it could be employed to both accelerate the beam and to stabilize the superbunch mode of operation in circular track machines.

  14. BRIEF REPORT Does visual short-term memory have a high-capacity stage?

    E-print Network

    Hollingworth, Andrew

    BRIEF REPORT Does visual short-term memory have a high-capacity stage? Michi Matsukura & Andrew memory and visual short-term memory (VSTM).1 Iconic memory is the persistence of sensory processing Hollingworth Published online: 21 September 2011 # Psychonomic Society, Inc. 2011 Abstract Visual short-term

  15. High bandwidth electro-optic technology for intersatellite optical communications

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.

    1992-01-01

    The research and development of electronic and electro-optic components for geosynchronous and low earth orbiting satellite optical high bandwidth communications at the NASA-Goddard Space Flight Center is reviewed. Intersatellite optical communications retains a strong reliance on microwave circuit technology in several areas - the microwave to optical interface, the laser transmitter modulation driver and the optical receiver. A microwave to optical interface is described requiring high bandwidth electronic downconverters and demodulators. Electrical bandwidth and current drive requirements for the laser modulation driver for three laser alternatives are discussed. Bandwidth and noise requirements are presented for optical receiver architectures.

  16. System and method that suppresses intensity fluctuations for free space high-speed optical communication

    DOEpatents

    Berman, Gennady P. (Los Alamos, NM); Bishop, Alan R. (Los Alamos, NM); Nguyen, Dinh C. (Los Alamos, NM); Chernobrod, Boris M. (Santa Fe, NM); Gorshkov, Vacheslav N. (Kiev, UA)

    2009-10-13

    A high-speed (Gbps), free space optical communication system is based on spectral encoding of radiation from a wide band light source, such as a laser. By using partially coherent laser beams in combination with a relatively slow photosensor, scintillations can be suppressed by orders of magnitude for distances of more than 10 km. To suppress the intensity fluctuations due to atmospheric turbulence, a source with partial transverse coherence in combination with slow response time photodetector is used. Information is encoded in the spectral domain of a wideband optical source by modulation of spectral amplitudes. A non-coherent light source with wide spectrum (an LED, for example) may be used for high-speed communication over short (less than about a mile) distances.

  17. Short communication Demonstration of rapid multiplex PCR amplification involving 16 genetic loci

    E-print Network

    amplification using the polymerase chain reaction (PCR) copies these STR regions to detectable levels and labels DNA extraction, quantification, polymerase chain reaction (PCR) amplification of multiple short tandem

  18. High Bandwidth Communications: 2000-2004

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This custom bibliography from the NASA Scientific and Technical Information Program lists a sampling of records found in the NASA Aeronautics and Space Database. The scope of this topic includes optical and high-frequency microwave systems to enhance data transmission rates. This area of focus is one of the enabling technologies as defined by NASA s Report of the President s Commission on Implementation of United States Space Exploration Policy, published in June 2004.

  19. Mobile satellite communications from highly inclined elliptic orbits

    NASA Astrophysics Data System (ADS)

    Stuart, J. R.; Norbury, J. A.; Barton, S. K.

    This paper is concerned with the feasibility of developing a commercially profitable land mobile satellite system capable of providing two way voice communications throughout Europe. The traditional Geostationary orbit configuration is compared with two highly inclined elliptical non-GEO orbits; the 12 hour Molniya and 24 hour Tundra. Potentials advantages of elliptical orbits, including resistance to signal fade and blockage and simplicity of a zenith pointing antenna, are assessed against the cost and risks of supporting the two or three satellite constellation necessary to provide continuous 24 hour coverage. Other considerations such as AOCS philosophy, injection strategy, radiation environment and satellite handover strategy are also discussed. The relative merits of the different orbit options are compared in terms of technical performance and overall system cost. The paper concludes that customer needs for low cost reliable mobile voice communications in Europe can best be achieved using a set of communications satellites placed in a highly inclined elliptical orbit.

  20. The Communicative Participation Item Bank (CPIB): Item bank calibration and development of a disorder-generic short form

    PubMed Central

    Baylor, Carolyn; Yorkston, Kathryn; Eadie, Tanya; Kim, Jiseon; Chung, Hyewon; Amtmann, Dagmar

    2015-01-01

    Purpose The purpose of this study was to calibrate the items for the Communicative Participation Item Bank (CPIB) using Item Response Theory (IRT). One overriding objective was to examine if the IRT item parameters would be consistent across different diagnostic groups, thereby allowing creation of a disorder-generic instrument. The intended outcomes were the final item bank and a short form ready for clinical and research applications. Methods Self-report data were collected from 701 individuals representing four diagnoses: multiple sclerosis, Parkinson’s disease, amyotrophic lateral sclerosis and head and neck cancer. Participants completed the CPIB and additional self-report questionnaires. CPIB data were analyzed using the IRT Graded Response Model (GRM). Results The initial set of 94 candidate CPIB items were reduced to an item bank of 46 items demonstrating unidimensionality, local independence, good item fit, and good measurement precision. Differential item function (DIF) analyses detected no meaningful differences across diagnostic groups. A 10-item, disorder-generic short form was generated. Conclusions The CPIB provides speech-language pathologists with a unidimensional, self-report outcomes measurement instrument dedicated to the construct of communicative participation. This instrument may be useful to clinicians and researchers wanting to implement measures of communicative participation in their work. PMID:23816661

  1. Multipoint free-space optics system for short-range communications between flight platforms.

    PubMed

    Heng, Kiang Huat; Zhong, Wen-De; Cheng, Tee Hiang

    2010-01-10

    The problems associated with using typical free-space optics (FSO) transceivers for multipoint communications on flight platforms, such as satellites and unmanned aerial vehicles, in a cluster are discussed and the transceivers are found to be unsuitable for concurrent multipoint communications in those platforms. To overcome the problems, a multipoint FSO system design is proposed. The design of the multipoint system is described and the performance of the multipoint receiver is evaluated in terms of receive gain under different conditions. The proposed multipoint system design offers a promising way to implement concurrent multipoint communications on flight platforms with power, weight, and size advantages compared to the use of multiple transceivers. PMID:20062513

  2. Stagings: Short Scripts for Middle and High School Students.

    ERIC Educational Resources Information Center

    Garner, Joan

    Introducing students to the magic of theater and helping them develop dramatic skills, this book presents nine reproducible scripts for short plays (15 to 25 minutes) with characters and story lines that will appeal to young people. The scripts in the book encompass a variety of story types, from adaptations of well-known fairy tales to original…

  3. A Family Drama Workshop: Communications Seminar for High School Students.

    ERIC Educational Resources Information Center

    Stanton, Timothy; Sheiner, Michaele

    This paper was written for high school teachers and other youth workers, who are looking for effective ways to support and assist adolescents as they deal with their complex, and often painful, changing family relationships. It describes A Family Drama Workshop, a series of seminars on families and communication, which was developed and presented…

  4. Short communication: Feed sorting of dairy heifers is influenced by method of dietary transition.

    PubMed

    Miller-Cushon, E K; Vogel, J P; DeVries, T J

    2015-04-01

    This study investigated the effect of exposing heifers to individual feed components on the extent and pattern of feed sorting upon transition to a novel ration. Holstein heifers (394 ± 62 d old, weighing 409.8 ± 37.3 kg; mean ± SD), consuming a familiar mixed silage-based ration [55% corn silage and 45% haylage, dry matter (DM) basis], were transitioned to a novel total mixed ration [TMR; 41.6% haylage, 36.5% corn silage, 14.6% high-moisture corn, and 7.3% protein supplement, DM basis] by 1 of 2 treatments: direct transition to novel TMR (DIR; n = 5) or exposure to novel TMR components individually before receiving novel TMR (COM; n = 6). During the baseline period (d 1 to 4), all heifers were offered the familiar silage-based ration. During transition (d 5 to 12), DIR heifers received the novel TMR, whereas COM heifers received the novel TMR components offered separately, in amounts according to TMR composition (target 15% orts). After transition (d 13 to 20), all heifers received the novel TMR. Feed intake and feeding time were determined daily and fresh feed and individual orts were sampled every 2d for particle size analysis and neutral detergent fiber content. The particle size separator consisted of 3 screens (18, 9, and 1.18 mm) and a bottom pan, resulting in 4 fractions (long, medium, short, and fine). Sorting activity for each fraction was calculated as actual intake expressed as a percentage of predicted intake. We detected no effect of treatment on dry matter intake or feeding time. After transition to the novel TMR, COM heifers sorted to a greater extent than did DIR heifers, sorting against long particles (95.4 vs. 98.9%) and for short particles (101.7 vs. 100.6%). Differences in sorting patterns resulted in COM heifers tending to have lower neutral detergent fiber intake as a percentage of predicted intake (98.9 vs. 100.5%). The results of this study suggest that the degree of feed sorting may be influenced by method of transition to a novel ration. PMID:25622873

  5. High power, high efficiency millimeter wavelength traveling wave tubes for high rate communications from deep space

    NASA Technical Reports Server (NTRS)

    Dayton, James A., Jr.

    1991-01-01

    The high-power transmitters needed for high data rate communications from deep space will require a new class of compact, high efficiency traveling wave tubes (TWT's). Many of the recent TWT developments in the microwave frequency range are generically applicable to mm wave devices, in particular much of the technology of computer aided design, cathodes, and multistage depressed collectors. However, because TWT dimensions scale approximately with wavelength, mm wave devices will be physically much smaller with inherently more stringent fabrication tolerances and sensitivity to thermal dissipation.

  6. Ka-band MMIC microstrip array for high rate communications

    NASA Technical Reports Server (NTRS)

    Lee, R. Q.; Raquet, C. A.; Tolleson, J. B.; Sanzgiri, S. M.

    1991-01-01

    In a recent technology assessment of alternative communication systems for the space exploration initiative (SEI), Ka-band (18 to 40 GHz) communication technology was identified to meet the mission requirements of telecommunication, navigation, and information management. Compared to the lower frequency bands, Ka-band antennas offer higher gain and broader bandwidths; thus, they are more suitable for high data rate communications. Over the years, NASA has played an important role in monolithic microwave integrated circuit (MMIC) phased array technology development, and currently, has an ongoing contract with Texas Instrument (TI) to develop a modular Ka-band MMIC microstrip subarray (NAS3-25718). The TI contract emphasizes MMIC integration technology development and stipulates using existing MMIC devices to minimize the array development cost. The objective of this paper is to present array component technologies and integration techniques used to construct the subarray modules.

  7. A secure communications infrastructure for high-performance distributed computing

    SciTech Connect

    Foster, I.; Koenig, G.; Tuecke, S.

    1997-08-01

    Applications that use high-speed networks to connect geographically distributed supercomputers, databases, and scientific instruments may operate over open networks and access valuable resources. Hence, they can require mechanisms for ensuring integrity and confidentially of communications and for authenticating both users and resources. Security solutions developed for traditional client-server applications do not provide direct support for the program structures, programming tools, and performance requirements encountered in these applications. The authors address these requirements via a security-enhanced version of the Nexus communication library; which they use to provide secure versions of parallel libraries and languages, including the Message Passing Interface. These tools permit a fine degree of control over what, where, and when security mechanisms are applied. In particular, a single application can mix secure and nonsecure communication, allowing the programmer to make fine-grained security/performance tradeoffs. The authors present performance results that quantify the performance of their infrastructure.

  8. Photonics and other approaches to high speed communications

    NASA Technical Reports Server (NTRS)

    Maly, Kurt

    1992-01-01

    Our research group of 4 faculty and about 10-15 graduate students was actively involved (as a group) in the development of computer communication networks for the last five years. Many of its individuals have been involved in related research for a much longer period. The overall research goal is to extend network performance to higher data rates, to improve protocol performance at most ISO layers and to improve network operational performance. We briefly state our research goals, then discuss the research accomplishments and direct your attention to attached and/or published papers which cover the following topics: scalable parallel communications; high performance interconnection between high data rate networks; and a simple, effective media access protocol system for integrated, high data rate networks.

  9. Terahertz oscillators and receivers using electron devices for high-capacity wireless communication

    NASA Astrophysics Data System (ADS)

    Suzuki, Safumi; Asada, Masahiro

    2015-05-01

    Recent progress in room-temperature resonant-tunneling-diode (RTD) terahertz (THz) oscillators and high-electron-mobility- transistor (HEMT) THz receivers is reported in this paper. In this study, oscillations up to 1.86 THz were obtained using an optimized antenna and RTD. Using a two-element oscillator array, high output power of 0.6 mW at 620 GHz was obtained. THz communication up to 3 Gbps was demonstrated. A structure for high-speed direct modulation was fabricated, and the intensity modulation up to 30 GHz was achieved. A novel oscillator structure was proposed and fabricated for extraction of output power without using a Si lens. A short-gate InGaAs HEMT detector integrated with a broadband bow-tie antenna was fabricated, and a high current sensitivity of ~5 A/W was obtained at 280 GHz.

  10. High Data Rate Satellite Communications for Environmental Remote Sensing

    NASA Astrophysics Data System (ADS)

    Jackson, J. M.; Munger, J.; Emch, P. G.; Sen, B.; Gu, D.

    2014-12-01

    Satellite to ground communication bandwidth limitations place constraints on current earth remote sensing instruments which limit the spatial and spectral resolution of data transmitted to the ground for processing. Instruments such as VIIRS, CrIS and OMPS on the Soumi-NPP spacecraft must aggregate data both spatially and spectrally in order to fit inside current data rate constraints limiting the optimal use of the as-built sensors. Future planned missions such as HyspIRI, SLI, PACE, and NISAR will have to trade spatial and spectral resolution if increased communication band width is not made available. A number of high-impact, environmental remote sensing disciplines such as hurricane observation, mega-city air quality, wild fire detection and monitoring, and monitoring of coastal oceans would benefit dramatically from enabling the downlinking of sensor data at higher spatial and spectral resolutions. The enabling technologies of multi-Gbps Ka-Band communication, flexible high speed on-board processing, and multi-Terabit SSRs are currently available with high technological maturity enabling high data volume mission requirements to be met with minimal mission constraints while utilizing a limited set of ground sites from NASA's Near Earth Network (NEN) or TDRSS. These enabling technologies will be described in detail with emphasis on benefits to future remote sensing missions currently under consideration by government agencies.

  11. An International Short Course for Training Professionals as Effective Science Communicators

    ERIC Educational Resources Information Center

    Sarathchandra, Dilshani; Maredia, Karim M.

    2014-01-01

    Scholars have recognized a need for educational programs that prepare scientists, Extension practitioners, and other stakeholders to communicate science effectively. Such programs have the potential to increase public awareness and aid policy development. Having recognized this need, faculty at Michigan State University (MSU) developed an…

  12. High performance computing and communications: FY 1996 implementation plan

    SciTech Connect

    1995-05-16

    The High Performance Computing and Communications (HPCC) Program was formally authorized by passage of the High Performance Computing Act of 1991, signed on December 9, 1991. Twelve federal agencies, in collaboration with scientists and managers from US industry, universities, and research laboratories, have developed the Program to meet the challenges of advancing computing and associated communications technologies and practices. This plan provides a detailed description of the agencies` HPCC implementation plans for FY 1995 and FY 1996. This Implementation Plan contains three additional sections. Section 3 provides an overview of the HPCC Program definition and organization. Section 4 contains a breakdown of the five major components of the HPCC Program, with an emphasis on the overall directions and milestones planned for each one. Section 5 provides a detailed look at HPCC Program activities within each agency.

  13. High Temperature Wireless Communication And Electronics For Harsh Environment Applications

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Neudeck, P. G.; Beheim, G. M.; Ponchak, G. E.; Chen, L.-Y

    2007-01-01

    In order for future aerospace propulsion systems to meet the increasing requirements for decreased maintenance, improved capability, and increased safety, the inclusion of intelligence into the propulsion system design and operation becomes necessary. These propulsion systems will have to incorporate technology that will monitor propulsion component conditions, analyze the incoming data, and modify operating parameters to optimize propulsion system operations. This implies the development of sensors, actuators, and electronics, with associated packaging, that will be able to operate under the harsh environments present in an engine. However, given the harsh environments inherent in propulsion systems, the development of engine-compatible electronics and sensors is not straightforward. The ability of a sensor system to operate in a given environment often depends as much on the technologies supporting the sensor element as the element itself. If the supporting technology cannot handle the application, then no matter how good the sensor is itself, the sensor system will fail. An example is high temperature environments where supporting technologies are often not capable of operation in engine conditions. Further, for every sensor going into an engine environment, i.e., for every new piece of hardware that improves the in-situ intelligence of the components, communication wires almost always must follow. The communication wires may be within or between parts, or from the engine to the controller. As more hardware is added, more wires, weight, complexity, and potential for unreliability is also introduced. Thus, wireless communication combined with in-situ processing of data would significantly improve the ability to include sensors into high temperature systems and thus lead toward more intelligent engine systems. NASA Glenn Research Center (GRC) is presently leading the development of electronics, communication systems, and sensors capable of prolonged stable operation in harsh 500C environments. This has included world record operation of SiC-based transistor technology (including packaging) that has demonstrated continuous electrical operation at 500C for over 2000 hours. Based on SiC electronics, development of high temperature wireless communication has been on-going. This work has concentrated on maturing the SiC electronic devices for communication purposes as well as the passive components such as resistors and capacitors needed to enable a high temperature wireless system. The objective is to eliminate wires associated with high temperature sensors which add weight to a vehicle and can be a cause of sensor unreliability. This paper discusses the development of SiC based electronics and wireless communications technology for harsh environment applications such as propulsion health management systems and in Venus missions. A brief overview of the future directions in sensor technology is given including maturing of near-room temperature "Lick and Stick" leak sensor technology for possible implementation in the Crew Launch Vehicle program. Then an overview of high temperature electronics and the development of high temperature communication systems is presented. The maturity of related technologies such as sensor and packaging will also be discussed. It is concluded that a significant component of efforts to improve the intelligence of harsh environment operating systems is the development and implementation of high temperature wireless technology

  14. Low Cost Cryocoolers for High Temperature Superconductor Communication Filters

    NASA Technical Reports Server (NTRS)

    Brown, Davina

    1998-01-01

    This final report describes the work performed by a consortium of Industry and Government to develop low cost cryocoolers. The specific application was for low cost commercial based high temperature superconductor communication filters. This program was initiated in January 1995 and resulted in the successful demonstration of an HTS filter dewar cooled by a low cost pulse tube cryocooler. Further development of this cryocooler technology is proceeding through various contracts underway and proposed at this time.

  15. High Performance Remote Memory Access Communication: The ARMCI Approach

    SciTech Connect

    Nieplocha, Jarek; Tipparaju, Vinod; Krishnan, Manoj Kumar; Panda, Dhabaleswar K.

    2006-07-01

    This paper describes the Aggregate Remote Memory Copy Interface (ARMCI), a portable high performance remote memory access (RMA) communication interface, developed originally under the DoE-2000 ACTS Toolkit project and currently used as a part of the run-time layer of the DoE project Programming Models for Scalable Parallel Computing. The paper discusses the model, portable implementation, and performance of ARMCI. Special emphasis is placed on the latency hiding mechanisms and ability to optimize noncontiguous data transfers.

  16. Physics of the Earth and Planetary Interiors 161 (2007) 134141 Short communication

    E-print Network

    Jones, Alan G.

    2007-01-01

    broadband and long period magnetotelluric measurements along a 200-km-long NNW-SSE profile. The model resulting from the collision between Laurentia and Avalonia during the early-Devonian (400 million years ago at the ISZ, but the short period data acquired in that survey provided only upper crustal structure

  17. Short communication The impact of additional Y-STR loci on resolving common

    E-print Network

    : Short tandem repeat; STR; Y-chromosome; Y-STR; DYS449; DYS570; DYS576; DYS534; NIST 1. Introduction Y-chromosome genealogy commu- nity. Two commercial Y-chromosome STR kits are widely available for amplifying 12 [1] or 17 of the locus on the Y- chromosome. The loci evaluated were either from the Yfiler kit [2] or were selected

  18. Iridium Short Burst Data: Two-Way, Robust, Reliable, Low Power Communications for Oceanographic Data Transmission Applications

    NASA Astrophysics Data System (ADS)

    Roggenstein, E. B.; Hensley, W.

    2011-12-01

    Over the past two hundred years, water level observations in coastal areas have been used to help mariners navigate oceans and estuaries, cartographers develop nautical charts, government agencies regulate boundaries, and scientists gain a better understanding of various physical processes in the ocean. As technology has progressed the latency in providing these data to the user has been reduced. The National Oceanic and Atmospheric Administration's (NOAA) Center for Operational Oceanographic Products and Services (CO-OPS) provides near real-time oceanographic and meteorological data to support navigation, coastal managers, and storm surge and tsunami warning programs. CO-OPS maintains the National Water Level Observation Network (NWLON), a system of over 200 stations for the coastal United States, Great Lakes, Caribbean islands, and Pacific island territories. CO-OPS also supports the NOAA Physical Oceanographic Real Time Systems° (PORTS), which are currently operating in 21 US ports. With an expanding role in Arctic and Alaska support, CO-OPS has identified a need for a robust and reliable data communications pathway to supplement the existing Geostationary Operational Environmental Systems (GOES) network, which has limitations at high latitudes. Iridium satellite Short Burst Data (SBD) services offer a global coverage, including remote Arctic regions outside of GOES coverage. Previous testing conducted by CO-OPS has shown a great potential for the SBD service including continuous near-real-time 6 minute data transmissions from two CO-OPS test water level stations located in Guam, with >99.9% data return. Also, successful transmissions of hourly wave statistics were demonstrated with a with a test system that employed a Nortek Acoustic Wave and Current (AWAC) instrument in Chesapeake Bay were accomplished. Data transmissions involved a buoy-mounted SIM-less SBD modem. Independent of location, data can be transmitted from a remote instrument platform to Iridium satellites with a latency of just 15 seconds. Successful test demonstrations have led to discussions regarding prospective work to integrate these small modems into CO-OPS current meters that are mounted on United States Coast Guard (USCG) Aid to Navigation (ATON) buoys, improving the reliability of the real-time transmission pathway between data collection and data reporting via PORTS °. Overall, this work has shown that with careful evaluation of data needs, commercial Iridium service can be economically used to accomplish telemetry requirements. It also shows potential for event-driven high frequency data transmission options, for applications such as marine warning systems. CO-OPS efforts to test and evaluate Iridium communications oceanographic observatories reported on here has been a collaborative endeavor with the United States Army Corp Engineers (USACE) Field Research Facility (FRF) in Duck, NC, the USACE Cold Regions Research Engineering Laboratory (CRREL) in Hanover, NH, NAL Research Inc, Sutron Corporation,and Nortek USA.

  19. High frequency sound attenuation in short flow ducts

    NASA Technical Reports Server (NTRS)

    Posey, J. W.

    1978-01-01

    A geometrical acoustics approach is proposed as a practical design tool for absorbent liners in such short flow ducts as may be found in turbofan engine nacelles. As an example, a detailed methodology is presented for three different types of sources in a parallel plate duct containing uniform ambient flow. A plane wave whose wavefronts are not normal to the duct walls, an arbitrarily located point source, and a spatially harmonic line source are each considered. Optimal wall admittance distributions are found, and it is shown how to estimate the insertion loss for any admittance distribution. The extension of the methodology to realistic source distributions in variable area cylindrical or annular ducts containing arbitrary flow is shown to be conceptually straightforward and computationally practical on a vector-hardware digital computer.

  20. Why Segregating Short Jobs from Long Jobs under High Variability is Not Always a Win

    E-print Network

    Harchol-Balter, Mor

    Why Segregating Short Jobs from Long Jobs under High Variability is Not Always a Win Mor Harchol assignment policies for server farms as the variability of job sizes (service demands) approaches infinity. The Size-Interval- Task-Assignment policy (SITA), which separates short jobs from long jobs, has long been

  1. Bachelor's Project Short-Term Prediction of Dangerous High Water Levels

    E-print Network

    Di Bucchianico, Alessandro

    Bachelor's Project Short-Term Prediction of Dangerous High Water Levels A. Di Bucchianico Keywords linear regression, nonlinear regression, short-term prediction, water levels, harbour induced. By the law the barrier should be closed only when the water is 3 metres above sea level in 10 minute average

  2. Non-chemical and non-contact cell-to-cell communication: a short review

    PubMed Central

    Scholkmann, Felix; Fels, Daniel; Cifra, Michal

    2013-01-01

    Cell-to-cell communication is the basis of coordinated cellular activity and thus fundamental for the functioning of biological systems. In a recently published research article by Chaban et al. (Am. J. Transl. Res., 5(1), 69-79), the authors report on interesting new experimental findings supporting a neuro-hormonal independent, non-diffusible cell-to-cell signaling. Our paper aims to (i) discuss some critical notions used by the authors to describe their findings, and (ii) briefly review related experimental work performed so far but not discussed in the original work of Chaban et al. In our opinion, the research on principles of non-chemical and non-contact cell-to-cell communication has the potential to offer new fundamental insights into biological processes. With this paper, we want to encourage future research on this topic by discussing critical issues and giving an overview of the current state of research. PMID:24093056

  3. Multiply-agile encryption in high speed communication networks

    SciTech Connect

    Pierson, L.G.; Witzke, E.L.

    1997-05-01

    Different applications have different security requirements for data privacy, data integrity, and authentication. Encryption is one technique that addresses these requirements. Encryption hardware, designed for use in high-speed communications networks, can satisfy a wide variety of security requirements if that hardware is key-agile, robustness-agile and algorithm-agile. Hence, multiply-agile encryption provides enhanced solutions to the secrecy, interoperability and quality of service issues in high-speed networks. This paper defines these three types of agile encryption. Next, implementation issues are discussed. While single-algorithm, key-agile encryptors exist, robustness-agile and algorithm-agile encryptors are still research topics.

  4. High performance computing and communications: FY 1997 implementation plan

    SciTech Connect

    1996-12-01

    The High Performance Computing and Communications (HPCC) Program was formally authorized by passage, with bipartisan support, of the High-Performance Computing Act of 1991, signed on December 9, 1991. The original Program, in which eight Federal agencies participated, has now grown to twelve agencies. This Plan provides a detailed description of the agencies` FY 1996 HPCC accomplishments and FY 1997 HPCC plans. Section 3 of this Plan provides an overview of the HPCC Program. Section 4 contains more detailed definitions of the Program Component Areas, with an emphasis on the overall directions and milestones planned for each PCA. Appendix A provides a detailed look at HPCC Program activities within each agency.

  5. High-speed laser communications in UAV scenarios

    NASA Astrophysics Data System (ADS)

    Griethe, Wolfgang; Gregory, Mark; Heine, Frank; Kämpfner, Hartmut

    2011-05-01

    Optical links, based on coherent homodyne detection and BPSK modulation with bidirectional data transmission of 5.6 Gbps over distances of about 5,000 km and BER of 10-8, have been sufficiently verified in space. The verification results show that this technology is suitable not only for space applications but also for applications in the troposphere. After a brief description of the Laser Communication Terminal (LCT) for space applications, the paper consequently discusses the future utilization of satellite-based optical data links for Beyond Line of Sight (BLOS) operations of High Altitude Long Endurance (HALE) Unmanned Aerial Vehicles (UAV). It is shown that the use of optical frequencies is the only logical consequence of an ever-increasing demand for bandwidth. In terms of Network Centric Warfare it is highly recommended that Unmanned Aircraft Systems (UAS) of the future should incorporate that technology which allows almost unlimited bandwidth. The advantages of optical communications especially for Intelligence, Surveillance and Reconnaissance (ISR) are underlined. Moreover, the preliminary design concept of an airborne laser communication terminal is described. Since optical bi-directional links have been tested between a LCT in space and a TESAT Optical Ground Station (OGS), preliminary analysis on tracking and BER performance and the impact of atmospheric disturbances on coherent links will be presented.

  6. Emerging applications of high temperature superconductors for space communications

    NASA Technical Reports Server (NTRS)

    Heinen, Vernon O.; Bhasin, Kul B.; Long, Kenwyn J.

    1990-01-01

    Proposed space missions require longevity of communications system components, high input power levels, and high speed digital logic devices. The complexity of these missions calls for a high data bandwidth capacity. Incorporation of high temperature superconducting (HTS) thin films into some of these communications system components may provide a means of meeting these requirements. Space applications of superconducting technology has previously been limited by the requirement of cooling to near liquid helium temperatures. Development of HTS materials with transition temperatures above 77 K along with the natural cooling ability of space suggest that space applications may lead the way in the applications of high temperature superconductivity. In order for HTS materials to be incorporated into microwave and millimeter wave devices, the material properties such as electrical conductivity, current density, surface resistivity and others as a function of temperature and frequency must be well characterized and understood. The millimeter wave conductivity and surface resistivity were well characterized, and at 77 K are better than copper. Basic microwave circuits such as ring resonators were used to determine transmission line losses. Higher Q values than those of gold resonator circuits were observed below the transition temperature. Several key HTS circuits including filters, oscillators, phase shifters and phased array antenna feeds are feasible in the near future. For technology to improve further, good quality, large area films must be reproducibly grown on low dielectric constant, low loss microwave substrates.

  7. Demonstration of high-rate laser communications from fast airborne platform: flight campaign and results

    NASA Astrophysics Data System (ADS)

    Moll, Florian; Mitzkus, Wolfgang; Horwath, Joachim; Shrestha, Amita; Brechtelsbauer, Martin; Martin, Luis; Lozano, Alberto; Diaz Gonzalez, Dionisio

    2014-10-01

    Some current and future airborne payloads like high resolution cameras and radar systems need high channel capacity to transmit their data from air to ground in near real-time. Especially in reconnaissance and surveillance missions, it is important to downlink huge amount of data in very short contact times to a ground station during a flyby. Aeronautical laser communications can supply the necessary high data-rates for this purpose. Within the project DODfast (Demonstration of Optical Data link fast) a laser link from a fast flying platform was demonstrated. The flight platform was a Panavia Tornado with the laser communication terminal installed in an attached avionic demonstrator pod. The air interface was a small glass dome protecting the beam steering assembly. All other elements were integrated in a small box inside the Pod's fuselage. The receiver station was DLR's Transportable Optical Ground Station equipped with a free-space receiver front-end. Downlink wavelength for communication and uplink wavelength for beacon laser were chosen from the optical C-band DWDM grid. The test flights were carried out at the end of November 2013 near the Airbus Defence and Space location in Manching, Germany. The campaign successfully demonstrated the maturity and readiness of laser communication with a data-rate of 1.25 Gbit/s for aircraft downlinks. Pointing, acquisition and tracking performance of the airborne terminal and the ground station could be measured at aircraft speed up to 0.7 Mach and video data from an onboard camera has been transmitted. Link distances with stable tracking were up to 79 km and distance with data transmission over 50 km. In this paper, we describe the system architecture, the flight campaign and the results.

  8. SIMULATION OF ORIENTATION IN INJECTION MOLDING OF A HIGHLY CONCENTRATED, SHORT GLASS FIBER THERMOPLASTIC COMPOSITES

    E-print Network

    Wapperom, Peter

    SIMULATION OF ORIENTATION IN INJECTION MOLDING OF A HIGHLY CONCENTRATED, SHORT GLASS FIBER approximation for predicting the flow-induced orientation of injection molded composite parts within of the fiber orientation. Introduction Fiber reinforced thermoplastic made by injection molding

  9. High voltage electrical amplifier having a short rise time

    DOEpatents

    Christie, David J. (Pleasanton, CA); Dallum, Gregory E. (Livermore, CA)

    1991-01-01

    A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage.

  10. High speed energy efficient incoherent optical wireless communications 

    E-print Network

    Tsonev, Dobroslav Antonov

    2015-06-29

    The growing demand for wireless communication capacity and the overutilisation of the conventional radio frequency (RF) spectrum have inspired research into using alternative spectrum regions for communication. Using ...

  11. SLIM, Short-pulse Technology for High Gradient Induction Accelerators

    SciTech Connect

    Krasnykh, A.; Kardo-Sysoev, A.; Arntz, F.; /Diversified Tech., Bedford

    2009-12-09

    The conclusions of this paper are: (1) The gradient of the SLIM-based technology is believed to be achievable in the same range as it is for the gradient of a modern rf-linac technology ({approx}100 MeV per meter). (2) The SLIM concept is based on the nsec TEM pulse mode operation with no laser or rf systems. (3) Main components of SLIM are not stressed while the energy is pumped into the induction system. Components can accept the hard environment conditions such as a radiation dose, mismatch, hard electromagnetic nose level, etc. Only for several nanoseconds the switch is OFF and produces a stress in the induction system. At that time, the delivery of energy to the beam takes place. (4) The energy in the induction system initially is storied in the magnetic field when the switch is ON. That fact makes another benefit: a low voltage power supplies can be used. The reliability of a lower voltage power supply is higher and they are cheaper. (5) The coreless SLIM concept offers to work in the MHz range of repetition rate. The induction system has the high electric efficiency (much higher than the DWA). (6) The array of lined up and activated SLIM cells is believed to be a solid state structure of novel accelerating technology. The electron-hole plasma in the high power solid state structure is precisely controlled by the electromagnetic process of a pulsed power supply.

  12. High power microwave components for space communications satellite

    NASA Technical Reports Server (NTRS)

    Jankowski, H.; Geia, A.

    1972-01-01

    Analyzed, developed, and tested were high power microwave components for communications satellites systems. Included were waveguide and flange configurations with venting, a harmonic filter, forward and reverse power monitors, electrical fault sensors, and a diplexer for two channel simultaneous transmission. The assembly of 8.36 GHz components was bench tested, and then operated for 60 hours at 3.5 kW CW in a high vacuum. The diplexer was omitted from this test pending a modification of its end irises. An RF leakage test showed only that care is required at flange junctions; all other components were RF tight. Designs were extrapolated for 12 GHz and 2.64 GHz high power satellite systems.

  13. Radio Synthesis Imaging - A High Performance Computing and Communications Project

    NASA Astrophysics Data System (ADS)

    Crutcher, Richard M.

    The National Science Foundation has funded a five-year High Performance Computing and Communications project at the National Center for Supercomputing Applications (NCSA) for the direct implementation of several of the computing recommendations of the Astronomy and Astrophysics Survey Committee (the "Bahcall report"). This paper is a summary of the project goals and a progress report. The project will implement a prototype of the next generation of astronomical telescope systems - remotely located telescopes connected by high-speed networks to very high performance, scalable architecture computers and on-line data archives, which are accessed by astronomers over Gbit/sec networks. Specifically, a data link has been installed between the BIMA millimeter-wave synthesis array at Hat Creek, California and NCSA at Urbana, Illinois for real-time transmission of data to NCSA. Data are automatically archived, and may be browsed and retrieved by astronomers using the NCSA Mosaic software. In addition, an on-line digital library of processed images will be established. BIMA data will be processed on a very high performance distributed computing system, with I/O, user interface, and most of the software system running on the NCSA Convex C3880 supercomputer or Silicon Graphics Onyx workstations connected by HiPPI to the high performance, massively parallel Thinking Machines Corporation CM-5. The very computationally intensive algorithms for calibration and imaging of radio synthesis array observations will be optimized for the CM-5 and new algorithms which utilize the massively parallel architecture will be developed. Code running simultaneously on the distributed computers will communicate using the Data Transport Mechanism developed by NCSA. The project will also use the BLANCA Gbit/s testbed network between Urbana and Madison, Wisconsin to connect an Onyx workstation in the University of Wisconsin Astronomy Department to the NCSA CM-5, for development of long-distance distributed computing. Finally, the project is developing 2D and 3D visualization software as part of the international AIPS++ project. This research and development project is being carried out by a team of experts in radio astronomy, algorithm development for massively parallel architectures, high-speed networking, database management, and Thinking Machines Corporation personnel. The development of this complete software, distributed computing, and data archive and library solution to the radio astronomy computing problem will advance our expertise in high performance computing and communications technology and the application of these techniques to astronomical data processing.

  14. High-Specificity Targeted Functional Profiling in Microbial Communities with ShortBRED

    PubMed Central

    Franzosa, Eric A.; Segata, Nicola; Dantas, Gautam; Huttenhower, Curtis

    2015-01-01

    Profiling microbial community function from metagenomic sequencing data remains a computationally challenging problem. Mapping millions of DNA reads from such samples to reference protein databases requires long run-times, and short read lengths can result in spurious hits to unrelated proteins (loss of specificity). We developed ShortBRED (Short, Better Representative Extract Dataset) to address these challenges, facilitating fast, accurate functional profiling of metagenomic samples. ShortBRED consists of two components: (i) a method that reduces reference proteins of interest to short, highly representative amino acid sequences (“markers”) and (ii) a search step that maps reads to these markers to quantify the relative abundance of their associated proteins. After evaluating ShortBRED on synthetic data, we applied it to profile antibiotic resistance protein families in the gut microbiomes of individuals from the United States, China, Malawi, and Venezuela. Our results support antibiotic resistance as a core function in the human gut microbiome, with tetracycline-resistant ribosomal protection proteins and Class A beta-lactamases being the most widely distributed resistance mechanisms worldwide. ShortBRED markers are applicable to other homology-based search tasks, which we demonstrate here by identifying phylogenetic signatures of antibiotic resistance across more than 3,000 microbial isolate genomes. ShortBRED can be applied to profile a wide variety of protein families of interest; the software, source code, and documentation are available for download at http://huttenhower.sph.harvard.edu/shortbred PMID:26682918

  15. High-Specificity Targeted Functional Profiling in Microbial Communities with ShortBRED.

    PubMed

    Kaminski, James; Gibson, Molly K; Franzosa, Eric A; Segata, Nicola; Dantas, Gautam; Huttenhower, Curtis

    2015-12-01

    Profiling microbial community function from metagenomic sequencing data remains a computationally challenging problem. Mapping millions of DNA reads from such samples to reference protein databases requires long run-times, and short read lengths can result in spurious hits to unrelated proteins (loss of specificity). We developed ShortBRED (Short, Better Representative Extract Dataset) to address these challenges, facilitating fast, accurate functional profiling of metagenomic samples. ShortBRED consists of two components: (i) a method that reduces reference proteins of interest to short, highly representative amino acid sequences ("markers") and (ii) a search step that maps reads to these markers to quantify the relative abundance of their associated proteins. After evaluating ShortBRED on synthetic data, we applied it to profile antibiotic resistance protein families in the gut microbiomes of individuals from the United States, China, Malawi, and Venezuela. Our results support antibiotic resistance as a core function in the human gut microbiome, with tetracycline-resistant ribosomal protection proteins and Class A beta-lactamases being the most widely distributed resistance mechanisms worldwide. ShortBRED markers are applicable to other homology-based search tasks, which we demonstrate here by identifying phylogenetic signatures of antibiotic resistance across more than 3,000 microbial isolate genomes. ShortBRED can be applied to profile a wide variety of protein families of interest; the software, source code, and documentation are available for download at http://huttenhower.sph.harvard.edu/shortbred. PMID:26682918

  16. ISS Update: High Rate Communications System - Duration: 9 minutes, 26 seconds.

    NASA Video Gallery

    ISS Update Commentator Pat Ryan interviews Diego Serna, Communications and Tracking Officer, about the High Rate Communications System. Questions? Ask us on Twitter @NASA_Johnson and include the ha...

  17. Journal of Insect Behavior, Vol. 15, No. 5, September 2002 ( C 2002) Short Communication

    E-print Network

    Carrel, James E.

    ) prefer floral nectars rich in amino acids, but males dis- criminate among nectars in favor of sugar a binary choice between a low-protein/high-carbohydrate item (raw apple) and a high in eight laboratory colonies which had been isolated since 1990 in plastic cages (50×35×23 cm) containing

  18. SHORT COMMUNICATION: Comments on recent proposals for redefining the mole and kilogram

    NASA Astrophysics Data System (ADS)

    Leonard, B. P.

    2010-06-01

    The fundamental concept of the mole requires the number of entities comprising one mole, i.e. Avogadro's number, to be exactly equal to the gram-to-dalton mass ratio. If this compatibility condition is to be satisfied, the mole, the kilogram and the dalton cannot all be defined independently. This note concerns recent Metrologia publications that do, however, propose independent definitions of all three quantities: the mole by fixing the value of Avogadro's number and the kilogram by fixing the value of the Planck constant, while retaining the current carbon-12-based dalton. Adoption of these incompatible definitions would likely cause serious widespread confusion and might even result in a split in scholarly and technical communication between the quantum physics and chemistry communities. Other entirely compatible alternatives are possible: either retaining the current (inexact) carbon-12-based mole and dalton with an independently redefined kilogram or redefining the mole by fixing the value of Avogadro's number, with a compatible dalton that is exact in terms of the redefined kilogram.

  19. High performance computing and communications: FY 1995 implementation plan

    SciTech Connect

    1994-04-01

    The High Performance Computing and Communications (HPCC) Program was formally established following passage of the High Performance Computing Act of 1991 signed on December 9, 1991. Ten federal agencies in collaboration with scientists and managers from US industry, universities, and laboratories have developed the HPCC Program to meet the challenges of advancing computing and associated communications technologies and practices. This plan provides a detailed description of the agencies` HPCC implementation plans for FY 1994 and FY 1995. This Implementation Plan contains three additional sections. Section 3 provides an overview of the HPCC Program definition and organization. Section 4 contains a breakdown of the five major components of the HPCC Program, with an emphasis on the overall directions and milestones planned for each one. Section 5 provides a detailed look at HPCC Program activities within each agency. Although the Department of Education is an official HPCC agency, its current funding and reporting of crosscut activities goes through the Committee on Education and Health Resources, not the HPCC Program. For this reason the Implementation Plan covers nine HPCC agencies.

  20. A UHF RFID system with on-chip-antenna tag for short range communication

    NASA Astrophysics Data System (ADS)

    Qi, Peng; Chun, Zhang; Xijin, Zhao; Zhihua, Wang

    2015-05-01

    A UHF RF identification system based on the 0.18 ?m CMOS process has been developed for short range and harsh size requirement applications, which is composed of a fully integrated tag and a special reader. The whole tag chip with the antenna takes up an area of 0.36 mm2, which is smaller than other reported tags with an on-chip antenna (OCA) using the standard CMOS process. A self-defined protocol is proposed to reduce the power consumption, and minimize the size of the tag. The specialized SOC reader system consists of the RF transceiver, digital baseband, MCU and host interface. Its power consumption is about 500 mW. Measurement results show that the system's reading range is 2 mm with 20 dBm reader output power. With an inductive antenna printed on a paper substrate around the OCA tag, the reading range can be extended from several centimeters to meters, depending on the shape and size of the inductive antenna.

  1. High performance broadband photodetector and its array for optical communication

    NASA Astrophysics Data System (ADS)

    Bregman, Jeremy; Nagi, Ritchie; Olah, Robert; Oduor, Patrick; Dutta, Achyut K.

    2015-01-01

    Device-level reduction of dark current is critical for improving the Signal to Noise ratio and dynamic range of system using III-V based optical components. We report on low-noise, back-illuminated p-i-n photodetector and its arrays with high spectral response for optical communication and also optical interconnects applications at 1.3 ?m and 1.55 ?m wavelengths. The photodetector is based on planar structure fabricated from InP having a latticematched InGaAs-absorber layer, and it is designed specifically for high sensitivity and low dark current (nA) at room temperature by minimizing leakage current. Electrical and optical performance of both individual diodes and small-pixel array test structures will be presented in this paper.

  2. SHORT COMMUNICATION Impact of growing conditions on the competitive ability of

    E-print Network

    Maxwell, Bruce D.

    antioxidants (Pilgeram et al. 2007). Although it has been claimed that C. sativa is highly competitive against canola as a model broad- leaf weed species for which much research has been conducted on its competitive

  3. Characterisation and Modelling of Indoor and Short-Range MIMO Communications 

    E-print Network

    Matthaiou, Michail

    2008-01-01

    Over the last decade, we have witnessed the rapid evolution of Multiple-Input Multiple-Output (MIMO) systems which promise to break the frontiers of conventional architectures and deliver high throughput by employing ...

  4. Measurement of endogenous allergens in genetically modified soybeans--short communication.

    PubMed

    Ladics, Gregory S; Budziszewski, Gregory J; Herman, Rod A; Herouet-Guicheney, Corinne; Joshi, Saurabh; Lipscomb, Elizabeth A; McClain, Scott; Ward, Jason M

    2014-10-01

    The measurement of endogenous allergens is required by the European Commission (EC) as part of the compositional analysis for GM products from host plants that are common causes of food allergy, such as soybean (EC Implementing Regulation No. 503/2013). In each case, the EC Implementing Regulation indicates that analysis be conducted on identified allergens as specified in the Organization of Economic Cooperation and Development (OECD) consensus documents on compositional considerations for new plant varieties. This communication discusses the methods available to measure endogenous allergens as well as the endogenous soybean allergens that should be analyzed. It is suggested herein that in conjunction with the 2012 OECD consensus document on soybean, any list of soybean allergens should be based on clinically relevant data among publicly available allergen databases and peer-reviewed scientific publications, and the ability to measure the identified allergen. Based on a detailed analysis of the scientific literature, the following key points are recommended: (1) the acceptance of serum-free, quantitative analytical method data as an alternative to traditional IgE reactivity qualitative or semi-quantitative data for evaluation of endogenous soybean allergen content; (2) eight of the 15 potential allergens listed in the OECD soybean consensus document (Gly m 3, Gly m 4, Gly m Bd28K, Gly m Bd30K, Gly m 5, Gly m 6, Gly m 8, and Kunitz trypsin inhibitor) have both appropriate supporting clinical data and sufficient sequence information to be evaluated in comparative endogenous soybean allergen studies; and (3) the remaining seven proteins (Gly m 1, Gly m 2, unknown 50kDa protein, unknown 39kDa protein, P-22-25, lipoxygenase and lectin) lack sufficient data for clear classification as confirmed allergens and/or available sequence information and should not be currently included in the measurement of endogenous soybean allergens in the compositional analysis for the EU. PMID:24945742

  5. Evaluation of components, subsystems, and networks for high rate, high frequency space communications

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Ivancic, William D.; Zuzek, John E.

    1991-01-01

    The development of new space communications technologies by NASA has included both commercial applications and space science requirements. NASA's Systems Integration, Test and Evaluation (SITE) Space Communication System Simulator is a hardware based laboratory simulator for evaluating space communications technologies at the component, subsystem, system, and network level, geared toward high frequency, high data rate systems. The SITE facility is well-suited for evaluation of the new technologies required for the Space Exploration Initiative (SEI) and advanced commercial systems. Described here are the technology developments and evaluation requirements for current and planned commercial and space science programs. Also examined are the capabilities of SITE, the past, present and planned future configurations of the SITE facility, and applications of SITE to evaluation of SEI technology.

  6. Evaluation of components, subsystems, and networks for high rate, high frequency space communications

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Ivancic, William D.; Zuzek, John E.

    1991-01-01

    The development of new space communications technologies by NASA has included both commercial applications and space science requirements. At NASA's Lewis Research Center, methods and facilities have been developed for evaluating these new technologies in the laboratory. NASA's Systems Integration, Test and Evaluation (SITE) Space Communication System Simulator is a hardware-based laboratory simulator for evaluating space communications technologies at the component, subsystem, system, and network level, geared toward high frequency, high data rate systems. The SITE facility is well-suited for evaluation of the new technologies required for the Space Exploration Initiative (SEI) and advanced commercial systems. This paper describes the technology developments and evaluation requirements for current and planned commercial and space science programs. Also examined are the capabilities of SITE, the past, present, and planned future configurations of the SITE facility, and applications of SITE to evaluation of SEI technology.

  7. Short communication: Factors affecting hair cortisol concentrations in lactating dairy cows.

    PubMed

    Burnett, Tracy A; Madureira, Augusto M L; Silper, Bruna F; Nadalin, Audrey; Tahmasbi, Abdolmansour; Veira, Douglas M; Cerri, Ronaldo L A

    2014-12-01

    Cortisol has long been used as a marker of the stress response in animals. Cortisol can be analyzed from different media, most notably from the blood, saliva, and feces; however, the collection of cortisol from some of these media requires invasive procedures or excessive handling of the animals. Furthermore, it is not possible to capture long-term increases in circulating concentrations of cortisol from the blood, saliva, or feces. Hair cortisol has been found to be a reliable alternative for measuring chronic stress. With this emerging measure, appropriate sampling methodology must be developed and validated. The aim of this study was to determine the effects of hair color, sampling location, and processing method on cortisol concentrations in hair from lactating black and white Holstein cows (n=18). Furthermore, we aimed to measure the hair growth rates at different body locations (n=12) and test hair cortisol levels when resampled over short intervals (n=37). Both black- and white-colored hair was collected from the shoulder, top line, hip, and tail switch of Holsteins; due to breed characteristics only white hair was harvested from the tail switch. All samples were cleaned with water and isopropanol, and then ground in a ball mill or finely cut with scissors once dry. Cortisol was extracted with methanol before being measured using a commercially available ELISA kit. Concentrations of cortisol were greater in white than in black hair (7.8 ± 1.1 vs. 3.8 ± 1.1 pg/mg). When only white samples were analyzed, hair from the tail switch had more cortisol than hair from the shoulder (11.0 ± 1.2 vs. 6.2 ± 1.2 pg/mg), whereas no difference was found when compared with the hip and top line. Samples ground with a ball mill had greater concentrations of cortisol extracted than those minced with scissors (10.4 ± 1.2 vs. 4.7 ± 1.2 pg/mg). The growth rate of hair was significantly greater at the tail switch compared with the hip and shoulder (0.51 ± 0.05 vs. 0.04 ± 0.05 vs. 0.03 ± 0.05 mm/d). When hair was collected every 3 wk after calving, a tendency was detected for multiparous cows to have greater concentrations of hair cortisol and significantly greater concentrations of cortisol on d 0 and 21 after calving compared with d 42, 84, and 126. In Holsteins, the hair on the tail switch is always white, grows more rapidly than other sites, and is sensitive enough to capture changes in cortisol over intervals as short as 3 wk, making it the ideal location for measuring hair cortisol. PMID:25282411

  8. Short communication MYCN/LIN28B/Let-7/HMGA2 pathway implicated by meta-analysis of GWAS in

    E-print Network

    de Magalhães, João Pedro

    Short communication MYCN/LIN28B/Let-7/HMGA2 pathway implicated by meta-analysis of GWAS (GWAS) from the National Human Genome Research Institute GWAS catalog (Hindorff et al., 2009) was performed. The 9217 SNPs in the GWAS catalog were filtered for growth and development-related traits

  9. SHORT COMMUNICATION doi:10.1111/j.1365-2052.2006.01506.x Mitochondrial DNA sequence diversity in extant Irish horse

    E-print Network

    Edwards, Ceiridwen J.

    SHORT COMMUNICATION doi:10.1111/j.1365-2052.2006.01506.x Mitochondrial DNA sequence diversity Dublin, Belfield, Dublin 4, Ireland Summary Equine mitochondrial DNA sequence variation was investigated stallion numbers at 1043 and breeding mare numbers at 11,621. Mitochondrial DNA (mtDNA) has been used

  10. 1710 Hans-Willi Mittr ucker et al. Eur. J. Immunol. 2014. 44: 17101715DOI: 10.1002/eji.201343927 SHORT COMMUNICATION

    E-print Network

    Higgins, Darren

    SHORT COMMUNICATION Lack of microbiota reduces innate responses and enhances adaptive immunity against the mucosal and systemic immune systems. Here, we compare innate and adaptive immune responses against monocy- togenes [9] is impaired, the extent to which different components of innate and adaptive immunity

  11. All-plasmonic Mach-Zehnder modulator enabling optical high-speed communication at the microscale

    NASA Astrophysics Data System (ADS)

    Haffner, C.; Heni, W.; Fedoryshyn, Y.; Niegemann, J.; Melikyan, A.; Elder, D. L.; Baeuerle, B.; Salamin, Y.; Josten, A.; Koch, U.; Hoessbacher, C.; Ducry, F.; Juchli, L.; Emboras, A.; Hillerkuss, D.; Kohl, M.; Dalton, L. R.; Hafner, C.; Leuthold, J.

    2015-08-01

    Optical modulators encode electrical signals to the optical domain and thus constitute a key element in high-capacity communication links. Ideally, they should feature operation at the highest speed with the least power consumption on the smallest footprint, and at low cost. Unfortunately, current technologies fall short of these criteria. Recently, plasmonics has emerged as a solution offering compact and fast devices. Yet, practical implementations have turned out to be rather elusive. Here, we introduce a 70?GHz all-plasmonic Mach-Zehnder modulator that fits into a silicon waveguide of 10??m length. This dramatic reduction in size by more than two orders of magnitude compared with photonic Mach-Zehnder modulators results in a low energy consumption of 25?fJ?per bit up to the highest speeds. The technology suggests a cheap co-integration with electronics.

  12. Short Pulse Duration High-Power Laser Photocoagulation during Vitrectomy for Diabetic Retinopathy Reduces Postoperative Inflammation

    PubMed Central

    Sugimoto, Masahiko; Ichio, Atsushi; Kondo, Mineo

    2015-01-01

    The aim of this preliminary study was to determine the effectiveness of short pulse duration, high-power laser photocoagulation (PC) during vitrectomy for diabetic retinopathy (DR).The effects of short pulse duration PC with power of 340–360 mW and duration of 0.02 second were compared to conventional PC with power of 120–150 mW and duration of 0.2 second. The degree of inflammation was quantified by laser flare cell photometry before and at 1 day, 1 week, 4 week, and 12 weeks postoperatively. Twenty-two eyes of 22 consecutive patients were studied. Ten eyes were treated with short pulse duration PC and 12 eyes with conventional PC. The total energy was significantly lower in the short pulse duration PC group than in the conventional PC group (P = 0.007). The flare cell values were not significantly different between the two groups after 1 day, but at 1 week, the flare cell value was significantly lower in the short pulse duration PC group than in the conventional PC group (P = 0.04). This difference was also present at 4 and 12 weeks (P<0.05). The significant lower inflammation after short pulse duration PC than conventional PC indicates that the short pulse duration PC protocol should be considered to treat DR. PMID:26273824

  13. SHORT COMMUNICATION Somatic energy of sockeye salmon Oncorhynchus nerka at the

    E-print Network

    Hinch, Scott G.

    levels of somatic energy in years with high open ocean productivity (1956, 1957, 2001 and 2002), and relatively low levels in years with poor open ocean productivity (1999 and 2000). For Early Stuart sockeye migration: a comparison among ocean climate regimes GLENN T. CROSSIN,1,2, * SCOTT G. HINCH,1,2 ANTHONY P

  14. Short communication Poly(vinyl alcohol) separators improve the coulombic efficiency of

    E-print Network

    cathodes are lower in cost than previous designs by avoiding the use of expensive porous carbon cloth carbon cathodes in microbial fuel cells Guang Chen a,b , Fang Zhang b , Bruce E. Logan b, , Michael A Keywords: Microbial fuel cell Activated carbon Separator Cathode Poly(vinyl alcohol) High

  15. Non-primate hepacivirus infection with apparent hepatitis in a horse - Short communication.

    PubMed

    Reuter, Gábor; Maza, Norbert; Pankovics, Péter; Boros, Akos

    2014-09-01

    Non-primate hepacivirus (NPHV) is a recently identified hepacivirus (family Flaviviridae) in dog and horse; however, the disease associations remain unknown. This study reports the detection of natural NPHV infection in a horse with apparent hepatitis, liver damage and high-level viraemia. NPHV could be hepatotropic and associated with hepatitis in horses. PMID:25038950

  16. short communications 1004 doi:10.1107/S0907444909026821 Acta Cryst. (2009). D65, 10041006

    E-print Network

    2009-01-01

    promising were ascorbic acid (Murray & Garman, 2002; Southworth-Davies & Garman, 2007; Barker et al., 2009 nicotinic acid-soaked crystals of trypsin at 100 K shows a high variability in radiation-sensitivity among individual crystals for both nicotinic acid-soaked and native crystals. The level of radiation

  17. SHORT COMMUNICATION Colorful displays signal male quality in a tropical anole lizard

    E-print Network

    Murphy, Troy G.

    influence colorful ornaments and their be- havioral display in many animal hosts. Because coloration of whether ectoparasites alter the information sig- naled by colorful animal structures. Anolis lizards allocate suffi- cient pigment resources to produce high quality coloration (but see Steffen et al. 2010

  18. Short Communications The Wilson Journal of Ornithology 121(1):148153, 2009

    E-print Network

    Reed, Michael

    . 2 Oahu National Wildlife Refuge Complex, U.S. Fish and Wildlife Service, 66-590 Kamehameha High- way April 2005 to July 2007 (with the exception of Jun­Jul 2006) at James Campbell National Wildlife Refuge of Kauai and Oahu (Taylor 1998, U.S. Fish and Wildlife Service 2005). Little is known about how, when

  19. Short Communication Electricity generation from fermented primary sludge using single-chamber

    E-print Network

    significantly reduce the total costs for wastewater treatment. Sludge collected from WWTPs often contains high levels of organics, with $66% of the energy content of the wastewater stored in the primary sludge (Ting wastewater sludge too low to be practical (Min et al., 2005; Ting and Lee, 2007). Anaerobic digestion

  20. Short Communication: Variance estimates among herds stratified by individual herd heritability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to compare genetic parameter estimates among herds stratified by high, medium and low individual herd heritability estimates. A regression model was applied to milk yield, fat yield, protein yield and somatic cell score (SCS) records from 20,902 herds to generate indi...

  1. SHORT COMMUNICATION Star-PAP controls HPV E6 regulation of p53 and sensitizes cells

    E-print Network

    Anderson, Richard

    papillomaviruses (HPV type 16, 18 and 31, and so on) are major agents for its cause. A key switch for the onset of E6/E6-associated protein (E6AP)-mediated degradation.3 The high-risk human papillomavirus (HPV) E6/E

  2. Short Communication It's a family matter: Molecular phylogenetics of Atheriniformes and the polyphyly

    E-print Network

    Piller, Kyle R.

    and the polyphyly of the surf silversides (Family: Notocheiridae) Devin D. Bloom a,e, , Peter J. Unmack b, , Atila E of Atheriniformes have long been problematic. The affinities of one of the most enigmatic lineages, surf silversides of Notocheirus and Iso is a result of adaptive convergent evolution to the high-energy surf habitat where

  3. Short Communication Saline catholytes as alternatives to phosphate buffers in microbial

    E-print Network

    2013 Keywords: Microbial fuel cell Buffer Sodium chloride Ion exchange membrane a b s t r a c t HighlyH conditions and increase the solution conduc- tivity, including phosphate, bicarbonate, and zwitterionic (Fan into the environment. Bicarbonate buffers are more useful, but they can enhance the growth of methanogens (Fan et al

  4. Short Communication: Evidence for non-Gaussian distribution of rock weathering rates

    NASA Astrophysics Data System (ADS)

    Emmanuel, S.

    2015-09-01

    The weathering of rocks influences the geochemistry of the oceans, the erosion of landscapes and man-made structures, and even the global climate. Although a high degree of variance is often observed in rate measurements, little is understood about the statistical characteristics of weathering rate distributions. This preliminary study demonstrates that the weathering rates of limestone, determined from measurements of an ancient eroded limestone edifice, can exhibit highly non-Gaussian behavior. While a Gaussian model produced a poor fit with the data, an alternative model - the generalized extreme value (GEV) framework - was capable of capturing the asymmetric long-tailed distribution, in good agreement with the measured curve. Furthermore, the non-Gaussian distribution of these field rates was found to have similar characteristics to the distribution of rates measured over much smaller microscopic regions of limestone surfaces in laboratory experiments. Such similar behavior could be indicative of analogous chemical and mechanical weathering processes acting over a range of spatial and temporal scales. Moreover, highly asymmetric rate distributions with high variance could be characteristic of rates not only in carbonate rocks, but also in other rock types, suggesting that the use of a small number of measurements to determine field weathering rates may be insufficient to fully characterize the range of rates in natural systems.

  5. Communications

    NASA Technical Reports Server (NTRS)

    Stouffer, Donald D.

    1990-01-01

    Communication in its many forms is a critical component for an effective Space Grant Program. Good communication is needed within individual Space Grant College/Consortia, for example between consortium affiliates and the consortium program office. Effective communication between the several programs, NASA Headquarters, and NASA field centers also is required. Further, communication among the above program elements, industry, local and state government, and the public also are necessary for meeting program objectives.

  6. Simple Short-Pulse CO2 Laser Excited by Longitudinal Discharge without High-Voltage Switch

    NASA Astrophysics Data System (ADS)

    Uno, Kazuyuki; Jitsuno, Takahisa; Akitsu, Tetsuya

    2012-05-01

    We have developed a longitudinally excited CO2 laser without a high-voltage switch. The laser produces a short laser pulse similar to those from TEA and Q-switched CO2 lasers. This system, which is the simplest short-pulse CO2 laser yet constructed, includes a pulsed power supply, a high-speed step-up transformer, a storage capacitor, and a laser tube. At high pressure (4.2 kPa and above), a rapid discharge produces a short laser pulse with a sharp spike pulse. In mixed gas (CO2: N2: He = 1: 1: 2) at a pressure of 9.0 kPa, the laser pulse contains a spike pulse of 218 ns and has a pulse tail length of 16.7 ?s.

  7. Communication.

    ERIC Educational Resources Information Center

    Hancock, Alan

    An informal introduction to the study of communication deals with the major topics in the field. It presents basic theories of communication and language, reviews how language takes on meaning, explains the stimulus-response and Piaget theories of learning, and presents major theories dealing with communications and society. These theories include…

  8. High efficiency switching-mode amplifiers for wireless communication systems

    E-print Network

    Hung, Tsai-Pi

    2008-01-01

    June 2001 M.S. Communication Engineering, National Chiao-Communication Systems by Tsai-Pi Hung Doctor of Philosophy in Electrical Engineering (Communication Systems A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Electrical Engineering (

  9. Advanced communications technology satellite high burst rate link evaluation terminal communication protocol software user's guide, version 1.0

    NASA Technical Reports Server (NTRS)

    Reinhart, Richard C.

    1993-01-01

    The Communication Protocol Software was developed at the NASA Lewis Research Center to support the Advanced Communications Technology Satellite High Burst Rate Link Evaluation Terminal (ACTS HBR-LET). The HBR-LET is an experimenters terminal to communicate with the ACTS for various experiments by government, university, and industry agencies. The Communication Protocol Software is one segment of the Control and Performance Monitor (C&PM) Software system of the HBR-LET. The Communication Protocol Software allows users to control and configure the Intermediate Frequency Switch Matrix (IFSM) on board the ACTS to yield a desired path through the spacecraft payload. Besides IFSM control, the C&PM Software System is also responsible for instrument control during HBR-LET experiments, uplink power control of the HBR-LET to demonstrate power augmentation during signal fade events, and data display. The Communication Protocol Software User's Guide, Version 1.0 (NASA CR-189162) outlines the commands and procedures to install and operate the Communication Protocol Software. Configuration files used to control the IFSM, operator commands, and error recovery procedures are discussed. The Communication Protocol Software Maintenance Manual, Version 1.0 (NASA CR-189163, to be published) is a programmer's guide to the Communication Protocol Software. This manual details the current implementation of the software from a technical perspective. Included is an overview of the Communication Protocol Software, computer algorithms, format representations, and computer hardware configuration. The Communication Protocol Software Test Plan (NASA CR-189164, to be published) provides a step-by-step procedure to verify the operation of the software. Included in the Test Plan is command transmission, telemetry reception, error detection, and error recovery procedures.

  10. 1001Ellis et al.--Acidic hot spring microorganisms Short communication

    E-print Network

    Kelley, Scott

    are reported for the first time in the low pH high temperature springs of Waiotapu, North Island, New Zealand, the highest temperature at which microbes were observed was 77°C and at pH 4.5, it was 87°C. Cells at pH 2, 77 of temperature, pH, and redox potential (Eh) in the Taupo Volcanic Zone (TVZ). One of the study sites

  11. Short communication: cheminformatics analysis to identify predictors of antiviral drug penetration into the female genital tract.

    PubMed

    Thompson, Corbin G; Sedykh, Alexander; Nicol, Melanie R; Muratov, Eugene; Fourches, Denis; Tropsha, Alexander; Kashuba, Angela D M

    2014-11-01

    The exposure of oral antiretroviral (ARV) drugs in the female genital tract (FGT) is variable and almost unpredictable. Identifying an efficient method to find compounds with high tissue penetration would streamline the development of regimens for both HIV preexposure prophylaxis and viral reservoir targeting. Here we describe the cheminformatics investigation of diverse drugs with known FGT penetration using cluster analysis and quantitative structure-activity relationships (QSAR) modeling. A literature search over the 1950-2012 period identified 58 compounds (including 21 ARVs and representing 13 drug classes) associated with their actual concentration data for cervical or vaginal tissue, or cervicovaginal fluid. Cluster analysis revealed significant trends in the penetrative ability for certain chemotypes. QSAR models to predict genital tract concentrations normalized to blood plasma concentrations were developed with two machine learning techniques utilizing drugs' molecular descriptors and pharmacokinetic parameters as inputs. The QSAR model with the highest predictive accuracy had R(2)test=0.47. High volume of distribution, high MRP1 substrate probability, and low MRP4 substrate probability were associated with FGT concentrations ?1.5-fold plasma concentrations. However, due to the limited FGT data available, prediction performances of all models were low. Despite this limitation, we were able to support our findings by correctly predicting the penetration class of rilpivirine and dolutegravir. With more data to enrich the models, we believe these methods could potentially enhance the current approach of clinical testing. PMID:24512359

  12. Proton stopping power measurements using high intensity short pulse lasers produced proton beams

    NASA Astrophysics Data System (ADS)

    Chen, S. N.; Atzeni, S.; Gauthier, M.; Higginson, D. P.; Mangia, F.; Marques, J.-R.; Riquier, R.; Fuchs, J.

    2014-03-01

    Proton stopping power measurements in solids and gases, typically made using proton accelerators, Van de Graf machines, etc., have existed now for many decades for many elements and compounds. We propose a new method of making this type of measurement using a different source, namely proton beams created by high intensity short pulse lasers. The advantage of this type of source is that there is the high number of particles and short bunch lengths, which is ideal for measurements of evolving mediums such as hot dense plasmas. Our measurements are consistent with exiting data and theory which validates this method.

  13. Short communication: in vitro assessment of antioxidant, antibacterial and phytochemical analysis of peel of Citrus sinensis.

    PubMed

    Mehmood, Basharat; Dar, Kamran Khurshid; Ali, Shaukat; Awan, Uzma Azeem; Nayyer, Abdul Qayyum; Ghous, Tahseen; Andleeb, Saiqa

    2015-01-01

    Antibacterial effect of Citrus sinensis peel extracts was evaluated against several pathogenic bacteria associated with human and fish infections viz., Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus, Streptococcus pyogenes, Staphylococcus epidermidis, Serratia marcesnces, Shigella flexneri, Enterobacter amnigenus, Salmonella Typhimurium and Serratia odorifera. Methanol, ethanol, chloroform and diethyl ether solvents were used for extraction. In vitro antibacterial activity was analyzed by agar well and agar disc diffusion methods. It was found that ethanol extract showed highly significant inhibition of E. coli and K. pneumonia (12.6±0.94 mm and 11.6±1.2 mm) whereas methanol extract of C. sinensis also showed high zone of inhibition of S. odorifera (10.0±2.16 mm). The potential activity of active extracts was assessed and also compared with standard antibiotics through activity index formulation. The order of antioxidant activity through ABTS·+ and DPPH free radical scavenging activity was ethanol>methanol>chloroform>diethyl ether. Phytochemical screening of all solvents had determined the presence of terpenoids, alkaloids, steroids, glycosides and flavonoids. It was also found that Chloroform/Methanol (5:5) and Butanol/Ethanol/Water (4:1:2.2) solvent systems showed significant separation of active phytochemical constituents. These findings reveal the potential use of C. sinensis peel to treat infectious diseases, which are being caused by microorganisms. PMID:25553700

  14. Short communication-Evaluation of antianxiety and antidepressant properties of Carthamus tinctorius L. (Safflower) petal extract.

    PubMed

    Qazi, Nasreen; Khan, Rafeeq Alam; Rizwani, Ghazala H

    2015-05-01

    Nowadays anxiety and depression are most commonly encountered diseases. They are not only difficult to diagnose but even difficult to treat since both are sometimes seen together or one predisposes the other. Apart from this side effect profile of these drugs is also high; hence there is immense scope for the herbal drugs to treat these disorders. Present study was therefore performed to evaluate the antianxiety and antidepressant effect of Carthamus tinctorius petal extract. 28 white albino rats bred in the animal house of Department of Pharmacology, University of Karachi weighing 180-220gm were randomly divided into four groups (n=7/group) to assess behavioral effects. The anxiolytic and antidepressant effects of Carthamus tinctorius petal extract were evaluated using elevated plus maize and forced swim test respectively at100 and 200mg/kg. These effects were compared with standard drugs Diazepam (anxiolytic) 2mg/kg and Nortriptyline (antidepressant) 12.5mg/kg. Results show that CT produced highly significant anxiolytic and anti-depressant effects at both doses as compared to control, similar to standard anxiolytic and antidepressant drugs diazepam and nortriptyline. It increased the latency of first entry to closed arms and the time spent in open arms very significantly at both doses while entries to open arm were increased significantly at 100mg/kg and very significantly at 200mg/kg in EPM test and increased the immobility time very significantly in FST. Hence it can be concluded that CT may be used as an alternative therapeutic agent while treating patients with anxiety and depressive disorders. PMID:26004733

  15. High performance computing and communications: Investment in American competitiveness

    NASA Astrophysics Data System (ADS)

    1991-03-01

    This report presents the results of a study performed by Gartner Group, Inc. for the U.S. Department of Energy (DOE), through a contract with the Los Alamos National Laboratory (LANL). The purpose of the study is to estimate the economic impact of the Federal High Performance Computing and Communications (HPCC) Program which was proposed by the Office of Science and Technology Policy (OSTP), Executive Office of the President, on September 8, 1989. That Program is an implementation of the Research and Development Strategy for High Performance Computing, which was transmitted to Congress by OSTP on November 20, 1988. The objective of this Gartner Group study to provide an assessment of the likely economic impact and benefits of the Federal HPCC Program and the risks of non-support of this program. The goals of the HPCC Program are to: support computational advances through R and D effort; Reduce uncertainties to industry through increased cooperation and continued use of government as a market for High Performance Computing (HPC) prototypes; Support underlying research, network, and computational infrastructures; and support the U.S. human resource base.

  16. Short communication: rapid detection of milk fat adulteration with vegetable oil by fluorescence spectroscopy.

    PubMed

    Ntakatsane, M P; Liu, X M; Zhou, P

    2013-04-01

    This study assessed the potential application of fluorescence spectroscopy in detecting adulteration of milk fat with vegetable oil and characterizing the samples according to the source of the fat. Pure butterfat was adulterated with different vegetable oils at various concentrations (0, 5, 10, 15, 20, 30, and 40%). Nonfat and reduced-fat milk were also adulterated with vegetable oils to simulate full-fat milk (3.2%). The 2- and 3-dimensional front-face fluorescence spectroscopy and gas chromatography were used to obtain the fluorescence spectra and fatty acid profile, respectively. Principal component analysis and 3-way partial least squares regression analysis were applied to analyze the data. The pure and adulterated samples were discriminated based on the total concentration of saturated fatty acids and unsaturated fatty acids, and also on the 3 major fluorophores: tryptophan, tocopherols, and riboflavin. Fluorescence spectroscopy was able to detect up to 5% of adulteration of vegetable oil into the butterfat. The saturated fatty acids showed higher predictability than the unsaturated fatty acids (R(2) = 0.73-0.92 vs. 0.20-0.65, respectively). The study demonstrated the high potential of fluorescence spectroscopy to rapidly detect adulteration of milk fat with vegetable oil, and discriminate commercial butter and milk according to the source of the fat. PMID:23415535

  17. Short communication: Suitability of fluorescence spectroscopy for characterization of commercial milk of different composition and origin.

    PubMed

    Ntakatsane, M P; Yang, X Q; Lin, M; Liu, X M; Zhou, P

    2011-11-01

    Thirteen milk brands comprising 76 pasteurized and UHT milk samples of various compositions (whole, reduced fat, skimmed, low lactose, and high protein) were obtained from local supermarkets, and milk samples manufactured in various countries were discriminated using front-face fluorescence spectroscopy (FFFS) coupled with chemometric tools. The emission spectra of Maillard reaction products and riboflavin (MRP/RF; 400 to 600 nm) and tryptophan (300 to 400 nm) were recorded using FFFS, and the excitation wavelengths were set at 360 nm for MRP/RF and 290 nm for tryptophan. Principal component analysis (PCA) was applied to analyze the normalized spectra. The PCA of spectral information from MRP/RF discriminated the milk samples originating in different countries, and PCA of spectral information from tryptophan discriminated the samples according to composition. The fluorescence spectral data were compared with liquid chromatography-mass spectrometry results for the glycation extent of the milk samples, and a positive association (R(2)=0.84) was found between the degree of glycation of ?-lactalbumin and the MRP/RF spectral data. This study demonstrates the ability and sensitivity of FFFS to rapidly discriminate and classify commercial milk with various compositions and processing conditions. PMID:22032360

  18. Short communication: new HIV infections at Southern New England academic institutions: implications for prevention.

    PubMed

    Chan, Philip A; Kazi, Shahzeb; Rana, Amaad; Blazar, Ilyse; Dejong, Colette C; Mayer, Kenneth H; Huard, Thomas K; Carleton, Kim; Gillani, Fizza; Alexander, Nicole; Parillo, Zoanne; Flanigan, Timothy P; Kantor, Rami

    2013-01-01

    New HIV infections among younger men who have sex with men (MSM) in the United States are escalating. Data on HIV infections in college students are limited. In 2010, three MSM college students presented to our clinic with primary HIV infection (PHI) in a single month. To determine the number of college students among new HIV diagnoses, we reviewed clinical characteristics and molecular epidemiology of HIV-diagnosed individuals from January to December 2010 at the largest HIV clinic in Southern New England. PHI was defined as acute HIV infection or seroconversion within the last 6 months. Of 66 individuals diagnosed with HIV in 2010, 62% were MSM and 17% were academic students (12% college or university, 5% other). Seventy-three percent of students were MSM. Compared to nonstudents, students were more likely to be younger (24 versus 39 years), born in the United States (91% versus 56%), have another sexually transmitted disease (45% versus 11%), and present with PHI (73% versus 16%, all p-values<0.05). Thirty percent of individuals formed eight transmission clusters including four students. MSM were more likely to be part of clusters. Department of Health contact tracing of cluster participants allowed further identification of epidemiological linkages. Given these high rates of PHI in recently diagnosed students, institutions of higher education should be aware of acute HIV presentation and the need for rapid diagnosis. Prevention strategies should focus on younger MSM, specifically college-age students who may be at increased risk of HIV infection. PMID:22724920

  19. Short Communication: New HIV Infections at Southern New England Academic Institutions: Implications for Prevention

    PubMed Central

    Kazi, Shahzeb; Rana, Amaad; Blazar, Ilyse; Dejong, Colette C.; Mayer, Kenneth H.; Huard, Thomas K.; Carleton, Kim; Gillani, Fizza; Alexander, Nicole; Parillo, Zoanne; Flanigan, Timothy P.; Kantor, Rami

    2013-01-01

    Abstract New HIV infections among younger men who have sex with men (MSM) in the United States are escalating. Data on HIV infections in college students are limited. In 2010, three MSM college students presented to our clinic with primary HIV infection (PHI) in a single month. To determine the number of college students among new HIV diagnoses, we reviewed clinical characteristics and molecular epidemiology of HIV-diagnosed individuals from January to December 2010 at the largest HIV clinic in Southern New England. PHI was defined as acute HIV infection or seroconversion within the last 6 months. Of 66 individuals diagnosed with HIV in 2010, 62% were MSM and 17% were academic students (12% college or university, 5% other). Seventy-three percent of students were MSM. Compared to nonstudents, students were more likely to be younger (24 versus 39 years), born in the United States (91% versus 56%), have another sexually transmitted disease (45% versus 11%), and present with PHI (73% versus 16%, all p-values<0.05). Thirty percent of individuals formed eight transmission clusters including four students. MSM were more likely to be part of clusters. Department of Health contact tracing of cluster participants allowed further identification of epidemiological linkages. Given these high rates of PHI in recently diagnosed students, institutions of higher education should be aware of acute HIV presentation and the need for rapid diagnosis. Prevention strategies should focus on younger MSM, specifically college-age students who may be at increased risk of HIV infection. PMID:22724920

  20. Short communication: genetic parameters for fertility-related disorders in Norwegian Red.

    PubMed

    Haugaard, Katrine; Heringstad, Bjørg

    2015-02-01

    Heritabilities and genetic correlations were estimated for the 4 most common fertility-related disorders in Norwegian Red: retained placenta, cystic ovaries, silent heat, and metritis. Data on 1,747,500 lactations from 780,114 cows calving from January 2001 through December 2011 were analyzed using multivariate threshold sire models to estimate variance components for the 4 disorders in the first 5 lactations. The traits were defined as binary within lactation (0=unaffected, 1=affected), and each fertility-related disorder was analyzed separately with the 5 lactations as correlated traits. The mean frequency of affected cows ranged from 0.5 to 1.7% for cystic ovaries, 0.7 to 1.1% for metritis, 1.3 to 3.4% for retained placenta, and 1.7 to 2.7% for silent heat. Posterior means (standard deviations) of heritability of liability ranged from 0.02 (0.01) to 0.12 (0.01), and were lowest for silent heat and highest for cystic ovaries. Genetic correlations across lactation within disorder were positive and moderate to high, ranging from 0.79 to 0.95 for cystic ovaries, 0.40 to 0.75 for metritis, 0.53 to 0.94 for retained placenta, and 0.39 to 0.83 for silent heat. PMID:25497813

  1. Short communication: Antimicrobial susceptibility profiling and genotyping of Staphylococcus aureus isolates from bovine mastitis in Poland.

    PubMed

    Jagielski, T; Puacz, E; Lisowski, A; Siedlecki, P; Dudziak, W; Mi?dzobrodzki, J; Krukowski, H

    2014-10-01

    Staphylococcus aureus is the predominant causative agent of bovine mastitis, a disease that remains a major economic burden for the dairy industry worldwide. In this study, the antimicrobial resistance patterns and the genetic composition of 80 S. aureus mastitis isolates collected from 14 dairy farms in Eastern Poland were determined. Of the 10 antimicrobial agents evaluated, only testing for penicillin G produced drug resistance. As 41% of the S. aureus isolates were penicillin resistant, this drug along with other ?-lactamase-sensitive ?-lactams, should rather not be considered for the treatment of bovine mastitis caused by S. aureus. Upon genotyping, with a triplex PCR method, a total of 11 distinct PCR types were produced. The population structure of S. aureus isolates was highly clonal, with 1 predominant genotype circulating on each farm. The observed similarities in the genotype composition of S. aureus populations from geographically distant farms underscore the significance of interfarm transmission of S. aureus in Poland. This, in turn, argues for the establishment of a nationwide surveillance program for bovine mastitis due to this pathogen. PMID:25087034

  2. Short communication: Ability of dogs to detect cows in estrus from sniffing saliva samples.

    PubMed

    Fischer-Tenhagen, C; Tenhagen, B-A; Heuwieser, W

    2013-02-01

    Efficient estrus detection in high-producing dairy cows is a permanent challenge for successful reproductive performance. In former studies, dogs have been trained to identify estrus-specific odor in vaginal fluid, milk, urine, and blood samples under laboratory conditions with an accuracy of more than 80%. For on-farm utilization of estrus-detection dogs it would be beneficial in terms of hygiene and safety if dogs could identify cows from the feed alley. The objective of this proof of concept study was to test if dogs can be trained to detect estrus-specific scent in saliva of cows. Saliva samples were collected from cows in estrus and diestrus. Thirteen dogs of various breeds and both sexes were trained in this study. Five dogs had no experience in scent detection, whereas 8 dogs had been formerly trained for detection of narcotics or cancer. In the training and test situation, dogs had to detect 1 positive out of 4 samples. Dog training was based on positive reinforcement and dogs were rewarded with a clicker and food for indicating saliva samples of cows in estrus. A false indication was ignored and documented in the test situation. Dogs with and without prior training were trained for 1 and 5 d, respectively. For determining the accuracy of detection, the position of the positive sample was unknown to the dog handler, to avoid hidden cues to the dog. The overall percentage of correct positive indications was 57.6% (175/304), with a range from 40 (1 dog) to 75% (3 dogs). To our knowledge, this is the first indication that dogs are able to detect estrus-specific scent in saliva of cows. PMID:23261382

  3. Short communication: Regulation of hepatic gluconeogenic enzymes by dietary glycerol in transition dairy cows.

    PubMed

    White, H M; Carvalho, E R; Koser, S L; Schmelz-Roberts, N S; Pezzanite, L M; Slabaugh, A C; Doane, P H; Donkin, S S

    2016-01-01

    Nutritional status and glucose precursors are known regulators of gluconeogenic gene expression. Glycerol can replace corn in diets fed to dairy cows and use of glycerol is linked to increased rumen propionate production. The effect of dietary glycerol on the regulation of gluconeogenic enzymes is unknown. The objective of this study was to examine the effect of glycerol on expression of pyruvate carboxylase (PC), cytosolic and mitochondrial phosphoenolpyruvate carboxykinase (PEPCK-C and PEPCK-M), and glucose-6-phosphatase. Twenty-six multiparous Holstein cows were fed either a control diet or a diet where high-moisture corn was replaced by glycerol from -28 through +56 d relative to calving (DRTC). Liver tissue was collected via percutaneous liver biopsy at -28, -14, +1, +14, +28, and +56 DRTC for RNA analysis. Expression of PC mRNA increased 6-fold at +1 and 4-fold at +14 DRTC relative to precalving levels. Dietary glycerol did not alter expression of PC mRNA expression. Expression of PEPCK-C increased 2.5-fold at +14 and 3-fold at +28 DRTC compared with +1 DRTC. Overall, dietary glycerol increased PEPCK-C expression compared with that of cows fed control diets. The ratio of PC to PEPCK-C was increased 6.3-fold at +1 DRTC compared with precalving and tended to be decreased in cows fed glycerol. We detected no effect of diet or DRTC on PEPCK-M or glucose-6-phosphatase mRNA, and there were no interactions of dietary treatment and DRTC for any transcript measured. Substituting corn with glycerol increased the expression of PEPCK-C mRNA during transition to lactation and suggests that dietary energy source alters hepatic expression. The observed increase in PEPCK-C expression with glycerol feeding may indicate regulation of hepatic gene expression by changes in rumen propionate production. PMID:26547649

  4. Short communication: The effect of water temperature on the viability of silage inoculants.

    PubMed

    Mulrooney, C N; Kung, L

    2008-01-01

    The objective of this study was to determine if exposure to high temperatures in water affects the viability of various silage inoculants. Inoculants were enumerated on De Man, Rogosa, Sharpe agar to standardize a final count (colony-forming units) in water such that about 500 mL added to 1 tonne of wet forage would achieve a recommended application rate of about 100,000 cfu of lactic acid bacteria (LAB) per gram of wet forage. Testing was done in 4 sequences (SEQ). For each SEQ, inoculants were mixed in deionized water for 45 min at 30 degrees C followed by incubation for 6 h at 30 degrees C (SEQ 1), 35 degrees C (SEQ 2), 40 degrees C (SEQ 3), or 45 degrees C (SEQ 4) in duplicate 125-mL flasks rotating at 125 rpm. After 6 h, rotation was stopped and the temperature was lowered to 30 degrees C for the next 18 h for all SEQ. Numbers of LAB were enumerated at 0, 3, 6, and 24 h. Each sequence was repeated twice. Incubation at a moderate temperature (SEQ 1) did not affect the viability of the microbial inoculants. The viability of the inoculants declined with increasing temperature (SEQ 2 to 4) but the effect varied by inoculant. For some inoculants exposure to 35 degrees C resulted in substantial decreases in viable cells (loss of 0.5 to 1 log cfu/mL). Incubation at higher temperatures resulted in even greater losses in viability for some inoculants. Losses of more than 0.5 log cfu/mL would most likely make the application of these inoculants ineffective in the field. Lactobacillus plantarum MTD/1 was the most thermotolerant organism tested, because it was unaffected by all temperatures (30 to 45 degrees C) after 3 h of incubation. Lactobacillus plantarum MTD/1 and Lactobacillus buchneri 40788 also appeared to have better thermotolerance as their numbers substantially increased between 6 and 24 h in SEQ 4. These data show that some silage inoculants are more thermotolerant than others and that precautions should be taken to ensure that microbial inoculants that are applied to forage do not reach elevated temperatures during use. PMID:18096945

  5. Short communication: limit feeding affects behavior patterns and feeding motivation of dairy heifers.

    PubMed

    Greter, A M; Miller-Cushon, E K; McBride, B W; Widowski, T M; Duffield, T F; DeVries, T J

    2015-02-01

    The study objective was to assess the effects of limit feeding dairy heifers on behavior patterns and feeding motivation. Ten Holstein heifers (291.6±39.2d of age, weighing 324.2±61.2kg; mean ± SD) were exposed to each of 2 dietary treatments, in a random order, over 2 successive 26-d treatment periods (14-d adaptation period and a 12-d data collection period) using a crossover design: (1) a high-forage total mixed ration (TMR), provided ad libitum (CON) and (2) a low-forage TMR, limit-fed at 2.05% body weight (LF). Heifers were fed daily at 1100h and motivation to access a low-nutritive feedstuff (straw) was assessed using a push-door apparatus at 2 time points: 3h after feed delivery (1400h) and 21h after feed delivery (0800h). The amount of weight pushed, weight pushed as percentage of body weight, and latency to access the push door were recorded on 3 different days for each heifer at each time point on each treatment. When fed CON, heifers had greater dry matter intake (12.9 vs. 7.2kg/d), greater feeding time (209.3 vs. 82.4min/d), greater ruminating time (452.2 vs. 318.3min/d), and slower rates of intake (0.06 vs. 0.09kg of dry matter/min) than when fed LF. Heifers fed LF pushed more weight as a percentage of body weight at 3h (4.5 vs. 1.9%) and 21h (9.3 vs. 2.8%) after feed delivery. At both 3 and 21h after feed delivery, latency to access the door was shorter for the LF heifers compared with the CON heifers (65 vs. 145 s). These results indicate that, in addition to decreasing feeding time, limit feeding increases motivation of heifers to access a low-nutritive feedstuff, possibly due to lack of satiety resulting from lack of physical fill or insufficient time spent foraging. PMID:25497811

  6. Forecasting the Short-Term Passenger Flow on High-Speed Railway with Neural Networks

    PubMed Central

    Xie, Mei-Quan; Li, Xia-Miao; Zhou, Wen-Liang; Fu, Yan-Bing

    2014-01-01

    Short-term passenger flow forecasting is an important component of transportation systems. The forecasting result can be applied to support transportation system operation and management such as operation planning and revenue management. In this paper, a divide-and-conquer method based on neural network and origin-destination (OD) matrix estimation is developed to forecast the short-term passenger flow in high-speed railway system. There are three steps in the forecasting method. Firstly, the numbers of passengers who arrive at each station or depart from each station are obtained from historical passenger flow data, which are OD matrices in this paper. Secondly, short-term passenger flow forecasting of the numbers of passengers who arrive at each station or depart from each station based on neural network is realized. At last, the OD matrices in short-term time are obtained with an OD matrix estimation method. The experimental results indicate that the proposed divide-and-conquer method performs well in forecasting the short-term passenger flow on high-speed railway. PMID:25544838

  7. Use of a lateral offset short-leg walking cast before high tibial osteotomy.

    PubMed

    Cole, Brian J; Freedman, Kevin B; Taksali, Sudeep; Hingtgen, Brooke; DiMasi, Michelle; Bach, Bernard R; Hurwitz, Debra E

    2003-03-01

    The clinical results after high tibial osteotomy for the treatment of symptomatic varus gonarthrosis are unpredictable. Although preoperative gait analysis has been shown to be useful in predicting successful outcome after high tibial osteotomy, there are no readily available preoperative clinical tests for predicting success. The authors did a study to determine the effects of an offset short-leg walking cast as a potential predictor of clinical success after high tibial osteotomy. Specifically, the authors evaluated the effect of an offset short-leg walking cast on pain relief and changes in the peak external adduction moments in patients with symptomatic varus gonarthrosis indicated for high tibial osteotomy. Nineteen consecutive patients indicated for high tibial osteotomy were enrolled and completed the study. All patients had precast gait analysis to determine baseline parameters. Immediately after gait analysis, a short-leg lateral offset walking cast was applied and worn for 3 days to allow time for adaptation. Gait analysis then was repeated. Western Ontario and McMaster Universities Osteoarthritis Index pain scores were obtained before and after the cast was applied. The cast resulted in a mean reduction in pain of 53%, and a mean reduction in the peak external adduction moment of 36% in the 17 of 19 patients who tolerated the cast. The reduction in pain was correlated with the reduction in the peak adduction moment (r = 0.63). The authors conclude that an offset short-leg walking cast results in pain reduction that correlates with changes in external adduction moments about the knee. Therefore, an offset short-leg walking cast may prove to be an effective tool for predicting patients who ultimately will benefit from valgus high tibial osteotomy. PMID:12616061

  8. EUROGRAPHICS 2003 / M. Chover, H. Hagen and D. Tost Short Presentations Automatic High Level Avatar Guidance

    E-print Network

    Chrysanthou, Yiorgos

    EUROGRAPHICS 2003 / M. Chover, H. Hagen and D. Tost Short Presentations Automatic High Level Avatar of the avatars. We introduce to the Graphics community a new method adapted from ideas recently presented in the Architecture literature. In this method, the general avatar movements are derived from an analysis

  9. High-Field Quasiballistic Transport in Short Carbon Nanotubes Ali Javey,1

    E-print Network

    Javey, Ali

    , and lift-off to form Pd source/drain (S/D) top contacts. The lengths of SWNTs were defined by the distances-bias voltage limits, respectively. High currents of up to 70 A can flow through a short nanotube. Possible strategies, several groups have observed ballistic electron transport in metallic nanotubes [2,3] and, more

  10. Yields in High Density, Short Rotation Intensive Culture (SRIC)--Plantations of

    E-print Network

    Yields in High Density, Short Rotation Intensive Culture (SRIC)--Plantations of Eucalyptus been to determine the feasibility of growing fuelwood as an alternate crop on underutilized field crops. A goal of our research was to verify or alter the assumed costs that we have used in our

  11. Toward High-Performance Communications Interfaces for Science Problem Solving

    NASA Astrophysics Data System (ADS)

    Oviatt, Sharon L.; Cohen, Adrienne O.

    2010-12-01

    From a theoretical viewpoint, educational interfaces that facilitate communicative actions involving representations central to a domain can maximize students' effort associated with constructing new schemas. In addition, interfaces that minimize working memory demands due to the interface per se, for example by mimicking existing non-digital work practice, can preserve students' attentional focus on their learning task. In this research, we asked the question: What type of interface input capabilities provide best support for science problem solving in both low- and high- performing students? High school students' ability to solve a diverse range of biology problems was compared over longitudinal sessions while they used: (1) hardcopy paper and pencil (2) a digital paper and pen interface (3) pen tablet interface, and (4) graphical tablet interface. Post-test evaluations revealed that time to solve problems, meta-cognitive control, solution correctness, and memory all were significantly enhanced when using the digital pen and paper interface, compared with tablet interfaces. The tangible pen and paper interface also was the only alternative that significantly facilitated skill acquisition in low-performing students. Paradoxically, all students nonetheless believed that the tablet interfaces provided best support for their performance, revealing a lack of self-awareness about how to use computational tools to best advantage. Implications are discussed for how pen interfaces can be optimized for future educational purposes, and for establishing technology fluency curricula to improve students' awareness of the impact of digital tools on their performance.

  12. Laser-induced resonance states as dynamic suppressors of ionization in high-frequency short pulses

    SciTech Connect

    Barash, Danny; Orel, Ann E.; Baer, Roi

    2000-01-01

    An adiabatic-Floquet formalism is used to study the suppression of ionization in short laser pulses. In the high-frequency limit the adiabatic equations involve only the pulse envelope where transitions are purely ramp effects. For a short-ranged potential having a single-bound state we show that ionization suppression is caused by the appearance of a laser-induced resonance state, which is coupled by the pulse ramp to the ground state and acts to trap ionizing flux. (c) 1999 The American Physical Society.

  13. Anomalous high photoconductivity in short channel indium-zinc-oxide photo-transistors

    NASA Astrophysics Data System (ADS)

    Choi, Hyun-Sik; Jeon, Sanghun

    2015-01-01

    Upon light exposure, an indium-zinc-oxide (IZO) thin-film transistor (TFT) presents higher photoconductivity by several orders of magnitude at the negative gate bias region. Among various device geometrical factors, scaling down the channel length of the photo-transistor results in an anomalous increase in photoconductivity. To probe the origin of this high photoconductivity in short-channel device, we measured transient current, current-voltage, and capacitance-voltage characteristics of IZO-TFTs with various channel lengths and widths before and after illumination. Under the illumination, the equilibrium potential region which lies far from front interface exists only in short-channel devices, forming the un-depleted conducting back channel. This region plays an important role in carrier transport under the illumination, leading to high photoconductivity in short-channel devices. Photon exposure coupled with gate-modulated band bending for short-channel devices leads to the accumulation of Vo++ at the front channel and screening negative gate bias, thereby generating high current flow in the un-depleted back-channel region.

  14. Anomalous high photoconductivity in short channel indium-zinc-oxide photo-transistors

    SciTech Connect

    Choi, Hyun-Sik; Jeon, Sanghun

    2015-01-05

    Upon light exposure, an indium-zinc-oxide (IZO) thin-film transistor (TFT) presents higher photoconductivity by several orders of magnitude at the negative gate bias region. Among various device geometrical factors, scaling down the channel length of the photo-transistor results in an anomalous increase in photoconductivity. To probe the origin of this high photoconductivity in short-channel device, we measured transient current, current–voltage, and capacitance–voltage characteristics of IZO–TFTs with various channel lengths and widths before and after illumination. Under the illumination, the equilibrium potential region which lies far from front interface exists only in short-channel devices, forming the un-depleted conducting back channel. This region plays an important role in carrier transport under the illumination, leading to high photoconductivity in short-channel devices. Photon exposure coupled with gate-modulated band bending for short-channel devices leads to the accumulation of V{sub o}{sup ++} at the front channel and screening negative gate bias, thereby generating high current flow in the un-depleted back-channel region.

  15. The Investigation of Teacher Communication Practices in Virtual High School

    ERIC Educational Resources Information Center

    Belair, Marley

    2011-01-01

    Virtual schooling is an increasing trend for secondary education. Research of the communication practices in virtual schools has provided a myriad of suggestions for virtual school policies. Although transactional distance has been investigated in relation to certain aspects of the communication process, a small-scale qualitative study has not…

  16. Application of advanced high speed turboprop technology to future civil short-haul transport aircraft design

    NASA Technical Reports Server (NTRS)

    Conlon, J. A.; Bowles, J. V.

    1978-01-01

    With an overall goal of defining the needs and requirements for short-haul transport aircraft research and development, the objective of this paper is to determine the performance and noise impact of short-haul transport aircraft designed with an advanced turboprop propulsion system. This propulsion system features high-speed propellers that have more blades and reduced diameters. Aircraft are designed for short and medium field lengths; mission block fuel and direct operating costs (DOC) are used as performance measures. The propeller diameter was optimized to minimize DOC. Two methods are employed to estimate the weight of the acoustic treatment needed to reduce interior noise to an acceptable level. Results show decreasing gross weight, block fuel, DOC, engine size, and optimum propfan diameter with increasing field length. The choice of acoustic treatment method has a significant effect on the aircraft design.

  17. A Universal BCD-on-SOI Based High Temperature Short Circuit Protection for SiC Power Switches

    E-print Network

    Tolbert, Leon M.

    A Universal BCD-on-SOI Based High Temperature Short Circuit Protection for SiC Power Switches Liang°C) than conventional bulk silicon based devices. As with any other power devices, SiC switches also presents a high-temperature (200°C), high-voltage short circuit protection (SCP) for SiC power devices

  18. Transformation of short-periodic high-inclination orbits of circumsolar submillimeter dust

    SciTech Connect

    Bazei, A.A.; Kramer, E.N.

    1995-11-01

    Disintegration of short-periodic comets is one of the sources of cosmic dust in the Solar System. Initially dust particles move approximately in the orbits of parent comets, in particular, in high-inclination orbits. In a few million years, some of these particles (the smallest ones) go over to the short-periodic, high-inclination orbits due to the Poynting-Robertson effect. The numerical integration of the equations of motion at this stage of evolution gives rise to somewhat surprising results. For example, when integrating the equations of motion as far back as 6000 years from the time of meteor observation, the real meteor particle gains the perihelion distance smaller than the solar radius (!). Our calculations show that the time of falling onto the Sun is shorter for a article moving in a high-inclination orbit. This is due to the superposition of gravitational perturbation and radiation effects.

  19. Short-wavelength electroluminescence from single-walled carbon nanotubes with high bias voltage.

    PubMed

    Hibino, Norihito; Suzuki, Satoru; Wakahara, Hiroyuki; Kobayashi, Yoshihiro; Sato, Tetsuya; Maki, Hideyuki

    2011-02-22

    Short-wavelength electroluminescence (EL) emission is observed from unipolar and ambipolar carbon nanotube field-effect transistors (CNFETs) under high bias voltage. EL measurements were carried out with an unsuspended single-walled carbon nanotube (SWNT) in high vacuum to prevent the oxidation damage induced by current heating. Short-wavelength emission under high bias voltage is obtained because of the Schottky barrier reduction and the electric field increase in a SWNT. The simultaneous measurements of transport and EL spectra revealed the excitation mechanism of impact excitation or electron and hole injection dependent on the conduction type of unipolar or ambipolar characteristics. In addition to the EL emission, blackbody radiation was also observed in a p-type CNFET. Taking into account the device temperature estimated from blackbody radiation, the contribution of impact excitation and thermal effect to the exciton production rate was evaluated. PMID:21204568

  20. Short-time dynamics at a conical intersection in high-harmonic spectroscopy.

    PubMed

    Patchkovskii, Serguei; Schuurman, Michael S

    2014-12-26

    High-harmonic spectroscopy probes molecular dynamics using electrons liberated from the same molecule earlier in the laser cycle. It affords sub-Ångstrom spatial and subfemtosecond temporal resolution. Nuclear dynamics in the intermediate cation influence the spectrum of the emitted high-harmonic photons through an autocorrelation function. Here, we develop an analytical approach for computing short-time nuclear autocorrelation functions in the vicinity of conical intersections, including laser-induced and nonadiabatic coupling between the surfaces. We apply the technique to two molecules of current experimental interest, C6H6 and C6H5F. In both molecules, high-harmonics generated within the same electronic channel are not sensitive to nonadiabatic dynamics, even in the presence of substantial population transfer. Calculated autocorrelation functions exhibit significant deviations from the expected Gaussian decay and may undergo revivals at short (?1.5 fs) times. The associated phase of the nuclear wavepacket provides a possible experimental signature. PMID:25314638

  1. Identification of mammalian species using the short and highly variable regions of mitochondrial DNA.

    PubMed

    Xie, Jianhui; Zhu, Wei; Zhou, Yueqin; Liu, Zhiping; Chen, Yang; Zhao, Ziqin

    2015-08-01

    The mitochondrial DNA (mtDNA) typing is useful for the species determination of degraded samples and the nucleotide diversity of target fragments across species is crucial for the discrimination. In this study, the short and highly polymorphic regions flanked by two conserved termini were sought by the sequence alignment of mtDNA across species and two target regions located at 12S rRNA gene were characterized. Two universal primer sets were developed that appear to be effective for a wide variety of mammalian species, even for domestic birds. The two target regions could be efficiently amplified using their universal primer sets on degraded samples and provide sufficient information for species determination. Therefore, the two short and highly variable target regions might provide a high discriminative capacity and should be suitable for the species determination of degraded samples. PMID:24438314

  2. Modelling high data rate communication network access protocol

    NASA Technical Reports Server (NTRS)

    Khanna, S.; Foudriat, E. C.; Paterra, Frank; Maly, Kurt J.; Overstreet, C. Michael

    1990-01-01

    Modeling of high data rate communication systems is different from the low data rate systems. Three simulations were built during the development phase of Carrier Sensed Multiple Access/Ring Network (CSMA/RN) modeling. The first was a model using SIMCRIPT based upon the determination and processing of each event at each node. The second simulation was developed in C based upon isolating the distinct object that can be identified as the ring, the message, the node, and the set of critical events. The third model further identified the basic network functionality by creating a single object, the node which includes the set of critical events which occur at the node. The ring structure is implicit in the node structure. This model was also built in C. Each model is discussed and their features compared. It should be stated that the language used was mainly selected by the model developer because of his past familiarity. Further the models were not built with the intent to compare either structure or language but because the complexity of the problem and initial results contained obvious errors, so alternative models were built to isolate, determine, and correct programming and modeling errors. The CSMA/RN protocol is discussed in sufficient detail to understand modeling complexities. Each model is described along with its features and problems. The models are compared and concluding observations and remarks are presented.

  3. Investigation of the Effect of Sport on Submissive Behavior and Communication Skills of High School Students

    ERIC Educational Resources Information Center

    Abakay, Ugur

    2013-01-01

    This study was carried out to detect the differences in submissive behaviors and communication skills of high school students in terms of sports activities and relationship between communication skills and properties of submissive behavior of high school students who are actively involved in sports activities. In this respect at the study, 728…

  4. Communicating with parents of high-risk infants in neonatal intensive care

    PubMed Central

    Yee, Wendy; Ross, Sue

    2006-01-01

    Good communication between parents and staff about the likely outcome of high-risk infants is essential to ensure parents’ full involvement in decision-making. The present paper discusses the literature on this topic to explore the best practices for professionals communicating with parents of high-risk infants. PMID:19030293

  5. Whole-Genome Sequencing and Assembly with High-Throughput, Short-Read Technologies

    PubMed Central

    Sundquist, Andreas; Ronaghi, Mostafa; Tang, Haixu; Pevzner, Pavel; Batzoglou, Serafim

    2007-01-01

    While recently developed short-read sequencing technologies may dramatically reduce the sequencing cost and eventually achieve the $1000 goal for re-sequencing, their limitations prevent the de novo sequencing of eukaryotic genomes with the standard shotgun sequencing protocol. We present SHRAP (SHort Read Assembly Protocol), a sequencing protocol and assembly methodology that utilizes high-throughput short-read technologies. We describe a variation on hierarchical sequencing with two crucial differences: (1) we select a clone library from the genome randomly rather than as a tiling path and (2) we sample clones from the genome at high coverage and reads from the clones at low coverage. We assume that 200 bp read lengths with a 1% error rate and inexpensive random fragment cloning on whole mammalian genomes is feasible. Our assembly methodology is based on first ordering the clones and subsequently performing read assembly in three stages: (1) local assemblies of regions significantly smaller than a clone size, (2) clone-sized assemblies of the results of stage 1, and (3) chromosome-sized assemblies. By aggressively localizing the assembly problem during the first stage, our method succeeds in assembling short, unpaired reads sampled from repetitive genomes. We tested our assembler using simulated reads from D. melanogaster and human chromosomes 1, 11, and 21, and produced assemblies with large sets of contiguous sequence and a misassembly rate comparable to other draft assemblies. Tested on D. melanogaster and the entire human genome, our clone-ordering method produces accurate maps, thereby localizing fragment assembly and enabling the parallelization of the subsequent steps of our pipeline. Thus, we have demonstrated that truly inexpensive de novo sequencing of mammalian genomes will soon be possible with high-throughput, short-read technologies using our methodology. PMID:17534434

  6. High-performance signal acquisition algorithms for wireless communications receivers 

    E-print Network

    Shi, Kai

    2006-10-30

    Due to the uncertainties introduced by the propagation channel, and RF and mixed signal circuits imperfections, digital communication receivers require efficient and robust signal acquisition algorithms for timing and ...

  7. Nonlinear excitation of longitudinal photons and plasmons by high-power, short pulse lasers.

    PubMed

    Tsintsadze, Levan N; Hojo, Hitoshi

    2008-12-01

    Modulational excitation of longitudinal photons and electron Langmuir waves, as well as ion sound waves by an incoherent strong and superstrong radiation (high-power short pulse lasers, nonthermal equilibrium cosmic field radiation, etc.), in plasmas, is investigated. A simultaneous generation of longitudinal photons and plasmons is demonstrated. Furthermore, the kinetic instability is considered when low-frequency longitudinal photons are generated alone. The growth rates of these modes are obtained. PMID:19256895

  8. Nonlinear excitation of photonikos and plasmons by high-power, short pulse lasers

    E-print Network

    Tsintsadze, Levan N

    2008-01-01

    Modulational excitation of longitudinal photons (photonikos) and electron Langmuir waves, as well as ion sound waves by an incoherent strong and superstrong radiation (high-power short pulse lasers, non-thermal equilibrium cosmic field radiation, etc.) in plasmas are investigated. A simultaneous generation of photonikos and plasmons are demonstrated. Furthermore, the kinetic instability is considered when a low frequency photonikos are generated alone. Growth rates of these new modes are obtained.

  9. Nonlinear excitation of photonikos and plasmons by high-power, short pulse lasers

    E-print Network

    Levan N. Tsintsadze; Hitoshi Hojo

    2008-10-29

    Modulational excitation of longitudinal photons (photonikos) and electron Langmuir waves, as well as ion sound waves by an incoherent strong and superstrong radiation (high-power short pulse lasers, non-thermal equilibrium cosmic field radiation, etc.) in plasmas are investigated. A simultaneous generation of photonikos and plasmons are demonstrated. Furthermore, the kinetic instability is considered when a low frequency photonikos are generated alone. Growth rates of these new modes are obtained.

  10. Ionization and high-order harmonic generation in aligned benzene by a short intense circularly polarized laser pulse

    E-print Network

    Moiseyev, Nimrod

    Ionization and high-order harmonic generation in aligned benzene by a short intense circularly and high-order harmonic generation by benzene aligned in the polarization plane of a short circularly pulses 4 . Recently, other types of HHG processes have been dis- covered in molecules. The planar benzene

  11. NASA satellite communications application research, phase 2 addendum. Efficient high power, solid state amplifier for EHF communications

    NASA Technical Reports Server (NTRS)

    Benet, James

    1994-01-01

    This document is an addendum to the NASA Satellite Communications Application Research (SCAR) Phase 2 Final Report, 'Efficient High Power, Solid State Amplifier for EHF Communications.' This report describes the work performed from 1 August 1993 to 11 March 1994, under contract number NASW-4513. During this reporting period an array of transistor amplifiers was repaired by replacing all MMIC amplifier chips. The amplifier array was then tested using three different feedhorn configurations. Descriptions, procedures, and results of this testing are presented in this report, and conclusions are drawn based on the test results obtained.

  12. Short and Long-Term Impacts of Biotechnology Education on Professionals Who Communicate Science to the Public

    ERIC Educational Resources Information Center

    Fritz, Susan M.; Ward, Sarah M.; Byrne, Pat F.; Namuth, Deana M.; Egger, Valerie A.

    2004-01-01

    Consumer acceptance or rejection of biotechnology is often shaped by information prepared by communicators with varying levels of scientific knowledge, awareness, and acceptance. This study compared the prior, post-workshop, and sustained (1 year) biotechnology awareness, acceptance, and attitudes of professionals who communicate biotechnology to…

  13. A low-complexity and high performance concatenated coding scheme for high-speed satellite communications

    NASA Technical Reports Server (NTRS)

    Lin, Shu; Rhee, Dojun; Rajpal, Sandeep

    1993-01-01

    This report presents a low-complexity and high performance concatenated coding scheme for high-speed satellite communications. In this proposed scheme, the NASA Standard Reed-Solomon (RS) code over GF(2(exp 8) is used as the outer code and the second-order Reed-Muller (RM) code of Hamming distance 8 is used as the inner code. The RM inner code has a very simple trellis structure and is decoded with the soft-decision Viterbi decoding algorithm. It is shown that the proposed concatenated coding scheme achieves an error performance which is comparable to that of the NASA TDRS concatenated coding scheme in which the NASA Standard rate-1/2 convolutional code of constraint length 7 and d sub free = 10 is used as the inner code. However, the proposed RM inner code has much smaller decoding complexity, less decoding delay, and much higher decoding speed. Consequently, the proposed concatenated coding scheme is suitable for reliable high-speed satellite communications, and it may be considered as an alternate coding scheme for the NASA TDRS system.

  14. A low-complexity and high performance concatenated coding scheme for high-speed satellite communications

    NASA Astrophysics Data System (ADS)

    Lin, Shu; Rhee, Dojun; Rajpal, Sandeep

    1993-02-01

    This report presents a low-complexity and high performance concatenated coding scheme for high-speed satellite communications. In this proposed scheme, the NASA Standard Reed-Solomon (RS) code over GF(2(exp 8) is used as the outer code and the second-order Reed-Muller (RM) code of Hamming distance 8 is used as the inner code. The RM inner code has a very simple trellis structure and is decoded with the soft-decision Viterbi decoding algorithm. It is shown that the proposed concatenated coding scheme achieves an error performance which is comparable to that of the NASA TDRS concatenated coding scheme in which the NASA Standard rate-1/2 convolutional code of constraint length 7 and d sub free = 10 is used as the inner code. However, the proposed RM inner code has much smaller decoding complexity, less decoding delay, and much higher decoding speed. Consequently, the proposed concatenated coding scheme is suitable for reliable high-speed satellite communications, and it may be considered as an alternate coding scheme for the NASA TDRS system.

  15. Highly Efficient Amplifier for Ka-Band Communications

    NASA Technical Reports Server (NTRS)

    1996-01-01

    An amplifier developed under a Small Business Innovation Research (SBIR) contract will have applications for both satellite and terrestrial communications. This power amplifier uses an innovative series bias arrangement of active devices to achieve over 40-percent efficiency at Ka-band frequencies with an output power of 0.66 W. The amplifier is fabricated on a 2.0- by 3.8-square millimeter chip through the use of Monolithic Microwave Integrated Circuit (MMIC) technology, and it uses state-of-the-art, Pseudomorphic High-Electron-Mobility Transistor (PHEMT) devices. Although the performance of the MMIC chip depends on these high-performance devices, the real innovations here are a unique series bias scheme, which results in a high-voltage chip supply, and careful design of the on-chip planar output stage combiner. This design concept has ramifications beyond the chip itself because it opens up the possibility of operation directly from a satellite power bus (usually 28 V) without a dc-dc converter. This will dramatically increase the overall system efficiency. Conventional microwave power amplifier designs utilize many devices all connected in parallel from the bias supply. This results in a low-bias voltage, typically 5 V, and a high bias current. With this configuration, substantial I(sup 2) R losses (current squared times resistance) may arise in the system bias-distribution network. By placing the devices in a series bias configuration, the total current is reduced, leading to reduced distribution losses. Careful design of the on-chip planar output stage power combiner is also important in minimizing losses. Using these concepts, a two-stage amplifier was designed for operation at 33 GHz and fabricated in a standard MMIC foundry process with 0.20-m PHEMT devices. Using a 20-V bias supply, the amplifier achieved efficiencies of over 40 percent with an output power of 0.66 W and a 16-dB gain over a 2-GHz bandwidth centered at 33 GHz. With a 28-V bias, a power level of 1.1 W was achieved with a 12-dB gain and a 36-percent efficiency. This represents the best reported combination of power and efficiency at this frequency. In addition to delivering excellent power and gain, this Ka-band MMIC power amplifier has an efficiency that is 10 percent greater than existing designs. The unique design offers an excellent match for spacecraft applications since the amplifier supply voltage is closely matched to the typical value of spacecraft bus voltage. These amplifiers may be used alone in applications of 1 W or less, or several may be combined or used in an array to produce moderate power, Ka-band transmitters with minimal power combining and less thermal stress owing to the combination of excellent efficiency and power output. The higher voltage operation of this design may also save mass and power because the dc-dc power converter is replaced with a simpler voltage regulator.

  16. Ultra high frequency follow-on communications satellite system

    NASA Astrophysics Data System (ADS)

    Hassien, Michael J.

    1992-03-01

    The existing constellation of UHF communications satellites (LEASAT and FLTSAT) provide key command and control links for mobile forces of the DoD and other government agencies. The UHF Follow-On satellite program will provide for a new generation of communications satellites to replace the existing ones as they reach the end of their life cycle beginning in 1992. Continued coverage is required for both peacetime and crisis environments, and must be maintained indefinitely. An eight-satellite UFO constellation (two per coverage area) will replenish the existing FLTSATCOM constellation.

  17. The Effects of Music on High-intensity Short-term Exercise in Well Trained Athletes

    PubMed Central

    Jarraya, Mohamed; Chtourou, Hamdi; Aloui, Asma; Hammouda, Omar; Chamari, Karim; Chaouachi, Anis; Souissi, Nizar

    2012-01-01

    Purpose The purpose of this investigation was to assess the effects of listening to music during warm-up on short-term supramaximal performances during the 30-s Wingate test in highly trained athletes. Methods Twelve young male athletes (20.6±1.8 yrs, 177±4.4 cm and 72.3±5.3 kg) underwent two Wingate tests in separate sessions with a recovery period of 48 h in-between, either after a 10 min of warm-up with (MWU) or without (NMWU) music. High tempo music (>120 to 140bpm) was selected for the study. Heart rate (HR) and rate of perceived exertion (RPE) were recorded after the warm-up (for HR = average of warm-up) and immediately after the Wingate test. Results HR, RPE and the fatigue index during the Wingate test are not affected by the incorporation of music during warm-up. However, power output (Ppeak and Pmean) was significantly higher after MWU than NMWU (P<0.05). The relative increases were 4.1 ± 3.6 and 4.0 ± 3.7 W·kg?1 for Ppeak and Pmean respectively. These findings demonstrated the beneficial effect of music during warm-up on short-term supramaximal performances. Conclusions As it's a legal method and an additional aid, music may be used during warm-up before performing activities requiring powerful lower limbs’ muscles contractions during short-term supramaximal exercises. PMID:23342221

  18. Neonatal overfeeding attenuates acute central pro-inflammatory effects of short-term high fat diet

    PubMed Central

    Cai, Guohui; Dinan, Tara; Barwood, Joanne M.; De Luca, Simone N.; Soch, Alita; Ziko, Ilvana; Chan, Stanley M. H.; Zeng, Xiao-Yi; Li, Songpei; Molero, Juan; Spencer, Sarah J.

    2015-01-01

    Neonatal obesity predisposes individuals to obesity throughout life. In rats, neonatal overfeeding also leads to early accelerated weight gain that persists into adulthood. The phenotype is associated with dysfunction in a number of systems including paraventricular nucleus of the hypothalamus (PVN) responses to psychological and immune stressors. However, in many cases weight gain in neonatally overfed rats stabilizes in early adulthood so the animal does not become more obese as it ages. Here we examined if neonatal overfeeding by suckling rats in small litters predisposes them to exacerbated metabolic and central inflammatory disturbances if they are also given a high fat diet in later life. In adulthood we gave the rats normal chow, 3 days, or 3 weeks high fat diet (45% kcal from fat) and measured peripheral indices of metabolic disturbance. We also investigated hypothalamic microglial changes, as an index of central inflammation, as well as PVN responses to lipopolysaccharide (LPS). Surprisingly, neonatal overfeeding did not predispose rats to the metabolic effects of a high fat diet. Weight changes and glucose metabolism were unaffected by the early life experience. However, short term (3 day) high fat diet was associated with more microglia in the hypothalamus and a markedly exacerbated PVN response to LPS in control rats; effects not seen in the neonatally overfed. Our findings indicate neonatally overfed animals are not more susceptible to the adverse metabolic effects of a short-term high fat diet but may be less able to respond to the central effects. PMID:25628527

  19. New Prospects for High Performance SONAR, Chemical Sensor, and Communication Device Materials

    E-print Network

    Rappe, Andrew M.

    New Prospects for High Performance SONAR, Chemical Sensor, and Communication Device Materials in Naval SONAR, chemical sensor and communications devices. We elucidate the influence of the constituent of applications, such as sensing, data storage, and energy conversion. In current military SONAR devices

  20. Using Mobile Communication Technology in High School Education: Motivation, Pressure, and Learning Performance

    ERIC Educational Resources Information Center

    Rau, Pei-Luen Patrick; Gao, Qin; Wu, Li-Mei

    2008-01-01

    Motivation and pressure are considered two factors impacting vocational senior high school student learning. New communication technology, especially mobile communication technology, is supposed to be effective in encouraging interaction between the student and the instructor and improving learning efficiency. Social presence and information…

  1. Space Link Extension (SLE) Emulation for High-Throughput Network Communication

    NASA Technical Reports Server (NTRS)

    Murawski, Robert W.; Tchorowski, Nicole; Golden, Bert

    2014-01-01

    As the data rate requirements for space communications increases, significant stress is placed not only on the wireless satellite communication links, but also on the ground networks which forward data from end-users to remote ground stations. These wide area network (WAN) connections add delay and jitter to the end-to-end satellite communication link, effects which can have significant impacts on the wireless communication link. It is imperative that any ground communication protocol can react to these effects such that the ground network does not become a bottleneck in the communication path to the satellite. In this paper, we present our SCENIC Emulation Lab testbed which was developed to test the CCSDS SLE protocol implementations proposed for use on future NASA communication networks. Our results show that in the presence of realistic levels of network delay, high-throughput SLE communication links can experience significant data rate throttling. Based on our observations, we present some insight into why this data throttling happens, and trace the probable issue back to non-optimal blocking communication which is sup-ported by the CCSDS SLE API recommended practices. These issues were presented as well to the SLE implementation developers which, based on our reports, developed a new release for SLE which we show fixes the SLE blocking issue and greatly improves the protocol throughput. In this paper, we also discuss future developments for our end-to-end emulation lab and how these improvements can be used to develop and test future space communication technologies.

  2. Communications

    ERIC Educational Resources Information Center

    Bailenson, Jeremy; Buzzanell, Patrice; Deetz, Stanley; Tewksbury, David; Thompson, Robert J.; Turow, Joseph; Bichelmeyer, Barbara; Bishop, M. J.; Gayeski, Diane

    2013-01-01

    Scholars representing the field of communications were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Jeremy Bailenson, Patrice Buzzanell, Stanley Deetz, David Tewksbury, Robert J. Thompson, and…

  3. An Investigation of Communication in Virtual High Schools

    ERIC Educational Resources Information Center

    Belair, Marley

    2012-01-01

    Virtual schooling is an increasing trend for secondary education. Research of the communication practices in virtual schools has provided a myriad of suggestions for virtual school policies. The purpose of this qualitative study was to investigate the activities and processes involved in the daily rituals of virtual school teachers and learners…

  4. High-Tech PR: Five Case Studies in Computerized Communication.

    ERIC Educational Resources Information Center

    Malaspina, Rick; And Others

    1993-01-01

    Use of computer technology for specialized communication networks at University of California (Oakland), Lafayette College (Pennsylvania), Carnegie Mellon University (Pennsylvania), the University of Wisconsin at Eau Claire, and the State University of New York at Stony Brook is described. The systems feature different forms of internal and…

  5. When Are High-Tech Communicators Effective in Parkinson's Disease?

    ERIC Educational Resources Information Center

    Ferriero, Giorgio; Caligari, Marco; Ronconi, Gianpaolo; Franchignoni, Franco

    2012-01-01

    This report describes a 63-year-old woman with Parkinson's disease showing loss of intelligibility of speech and severely impaired handwriting, despite undergoing physical and speech therapies. As the patient had sufficient residual motor abilities and adequate cognitive function and motivation, a computer-based communication aid with a software…

  6. The life cycle of infrared ultra-short high intensity laser pulses in air

    NASA Astrophysics Data System (ADS)

    Ma, Cunliang; Lin, Wenbin

    2015-08-01

    The life cycle of ultra-short high intensity laser pulses propagation in air is studied. As the controversial of the high-order Kerr indices measured by Loriot et al. [Opt. Express 18, 3011 (2010)], we focus on two models which are high-order Kerr effect included and not included. Two factors are mainly analyzed, group-velocity-dispersion and the energy evolution of the pulse. It is found that the group-velocity-dispersion can not be simply ignored even though the pulse's duration is as long as several hundreds femtoseconds. The energy loss due to the multi-photon-absorption is very small, and it may hardly change the propagation length of the pulse. Another contribution of this work is to introduce a probability quantity, which may be useful in validating the positive and negative alternating of the Kerr and high-order Kerr indices.

  7. Short-term high-fat diet increases postprandial trimethylamine-N-oxide in humans.

    PubMed

    Boutagy, Nabil E; Neilson, Andrew P; Osterberg, Kristin L; Smithson, Andrew T; Englund, Tessa R; Davy, Brenda M; Hulver, Matthew W; Davy, Kevin P

    2015-10-01

    The gut microbiota plays an obligatory role in the metabolism of nutrients containing trimethylamine moieties, such as L-carnitine and choline, leading to the production of the proatherogenic trimethylamine-N-oxide (TMAO). We hypothesized that a short-term, high-fat diet would increase fasting and postprandial plasma concentrations of TMAO in response to a high-fat meal challenge. Following a 2-week eucaloric control diet, 10 nonobese men (18-30 years) consumed a eucaloric, high-fat diet (55% fat) for 5 days. Plasma TMAO was measured after a 12-hour fast and each hour after for 4 hours following a high-fat meal (63% fat) at baseline and after the high-fat diet using ultraperformance liquid chromatography/ tandem mass spectrometry. Fasting plasma TMAO did not increase significantly following the high-fat diet (1.83 ± 0.21 vs 1.6 ± 0.24 ?mol/L). However, plasma TMAO was higher at hour 1 (2.15 ± 0.28 vs 1.7 ± 0.30 ?mol/L), hour 2 (2.3 ± 0.29 vs 1.8 ± 0.32 ?mol/L), hour 3 (2.4 ± 0.34 vs 1.58 ± 0.19 ?mol/L), and hour 4 (2.51 ± 0.33 vs 1.5 ± 0.12 ?mol/L) (all P < .05) following the high-fat diet as compared with the baseline postprandial response. In conclusion, a short-term, high-fat diet does not increase fasting plasma TMAO concentrations but appears to increase postprandial TMAO concentrations in healthy, nonobese, young men. Future studies are needed to determine the mechanisms responsible for these observations. PMID:26265295

  8. Short-course Astronomical Research Seminars for High School and College Students

    NASA Astrophysics Data System (ADS)

    Johnson, Jolyon

    2011-05-01

    Since 2008, I have helped lead several short-course astronomical research seminars with Russell M. Genet. These seminars have ranged from semester-long courses at Cuesta College in San Luis Obispo, California to long weekends at the University of Oregon's Pine Mountain Observatory. Each seminar is led by an experienced observer or group of observers who guide high school and college students through the scientific process from observations to publication. The students (anywhere from half a dozen to twenty in number) participate in and contribute to every step. Being a coauthor on one or more research papers offers students an advantage on college and scholarship applications. Similarly, graduate schools often prefer students with research experience. Many topics of research are appropriate for these short-courses including variable star, exoplanet, and asteroid photometry. However, the most successful topic has been visual double stars because the observations required are straitforward and the equipment is relatively inexpensive. The Journal of Double Star Observations is also welcoming of student research and provides swift publication. A detailed description of the short-course seminars can be found in the recent Collins Foundation Press volume titled Small Telescopes and Astronomical Research.

  9. Lifetime measurements of high-lying short lived states in {sup 69}As

    SciTech Connect

    Matejska-Minda, M.; Bednarczyk, P.; Fornal, B.; Ciemala, M.; Kmiecik, M.; Krzysiek, M.; Maj, A.; Meczynski, W.; Myalski, S.; Styczen, J.; Zieblinski, M.; Angelis, G. de; Huyuk, T.; Michelagnoli, C.; Sahin, E.; Aydin, S.; Farnea, E.; Menegazzo, R.; Recchia, F.; Ur, C. A.; and others

    2012-10-20

    Lifetimes of high-spin states in {sup 69}As have been measured using Doppler shift attenuation technique with the GASP and RFD setup. The determined transition probabilities indicate large deformation associated with some rotational bands in this nucleus.

  10. High nitrogen removal rate using ANAMMOX process at short hydraulic retention time.

    PubMed

    Casagrande, C G; Kunz, A; De Prá, M C; Bressan, C R; Soares, H M

    2013-01-01

    The anaerobic ammonium oxidation (ANAMMOX) is a chemolithoautotrophic process, which converts NH(4)(+) to N(2) using nitrite (NO(2)(-)) as the electron acceptor. This process has very high nitrogen removal rates (NRRs) and is an alternative to classical nitrification/denitrification wastewater treatment. In the present work, a strategy for nitrogen removal using ANAMMOX process was tested evaluating their performance when submitted to high loading rates and very short hydraulic retention times (HRTs). An up-flow ANAMMOX column reactor was inoculated with 30% biomass (v v(-1)) fed from 100 to 200 mg L(-1) of total N (NO(2)(-)-N + NH(4)(+)-N) at 35 °C. After start-up and process stability the maximum NRR in the up-flow anaerobic sludge blanket (UASB) reactor was 18.3 g-N L(-1) d(-1) operated at 0.2 h of HRT. FISH (fluorescence in situ hybridization) analysis and process stoichiometry confirmed that ANAMMOX was the prevalent process for nitrogen removal during the experiments. The results point out that high NRRs can be obtained at very short HRTs using up-flow ANAMMOX column reactor configuration. PMID:23416586

  11. Diaphragm does not produce ammonia or lactate during high-intensity short-term exercise.

    PubMed

    Manohar, M; Hassan, A S

    1990-10-01

    To ascertain whether costal diaphragm engages in ammonia and lactate production (like limb muscles) during high-intensity short-term exercise, experiments were carried out on six healthy trained ponies in which phrenic venous catheters had been implanted 5-9 days earlier. Simultaneous anaerobically obtained blood samples from abdominal aorta and the phrenic vein at rest and during 4 min of exertion at 32 km/h and at a 7% grade were analyzed for blood-gas variables as well as lactate and ammonia concentrations using standard procedures. At rest, heart rate was 47 +/- 4 beats/min and the diaphragmatic O2 extraction was 26.5%. With exercise, heart rate rose to 218 +/- 6 beats/min, marked acidosis and hyperventilation occurred, and the diaphragmatic O2 extraction increased threefold (80.9%). Such exercise is known to dramatically increase the work of breathing as respiratory frequency and change in pleural pressure approach 138 +/- 4 breaths/min and 30 +/- 3 cmH2O, respectively. Despite the fact that phrenic-venous O2 tension of exercised ponies decreased to 15.5 +/- 0.6 Torr, the phrenic-venous lactate and ammonia concentrations did not exceed corresponding arterial values. These data thus revealed that the diaphragm is uniquely unlike limb muscles, which at high workloads readily engage in net ammonia and lactate production, and that the diaphragmatic energy needs during high-intensity short-term exercise are primarily met by aerobic metabolism. PMID:2221124

  12. Implementing Molecular Dynamics for Hybrid High Performance Computers - 1. Short Range Forces

    SciTech Connect

    Brown, W Michael; Wang, Peng; Plimpton, Steven J; Tharrington, Arnold N

    2011-01-01

    The use of accelerators such as general-purpose graphics processing units (GPGPUs) have become popular in scientific computing applications due to their low cost, impressive floating-point capabilities, high memory bandwidth, and low electrical power requirements. Hybrid high performance computers, machines with more than one type of floating-point processor, are now becoming more prevalent due to these advantages. In this work, we discuss several important issues in porting a large molecular dynamics code for use on parallel hybrid machines - 1) choosing a hybrid parallel decomposition that works on central processing units (CPUs) with distributed memory and accelerator cores with shared memory, 2) minimizing the amount of code that must be ported for efficient acceleration, 3) utilizing the available processing power from both many-core CPUs and accelerators, and 4) choosing a programming model for acceleration. We present our solution to each of these issues for short-range force calculation in the molecular dynamics package LAMMPS. We describe algorithms for efficient short range force calculation on hybrid high performance machines. We describe a new approach for dynamic load balancing of work between CPU and accelerator cores. We describe the Geryon library that allows a single code to compile with both CUDA and OpenCL for use on a variety of accelerators. Finally, we present results on a parallel test cluster containing 32 Fermi GPGPUs and 180 CPU cores.

  13. Experimental demonstration of 10 Gb/s multi-level carrier-less amplitude and phase modulation for short range optical communication systems.

    PubMed

    Tao, Li; Wang, Yiguang; Gao, Yuliang; Lau, Alan Pak Tao; Chi, Nan; Lu, Chao

    2013-03-11

    Carrier-less amplitude and phase (CAP) modulation can be a good candidate for short range optical communications for considerable computational complexity reduction and simple system structure. In this paper, a detailed investigation on the digital filters in CAP modulation system is presented. An adaptive equalizer based on cascaded multi-modulus algorithm (CMMA) is used for the demodulation at the receiver. The impact of digital filter taps on system performance is investigated through comprehensive simulations and a 10 Gb/s CAP16 modulation system is demonstrated experimentally. The BER performance for different length of fiber link is measured. Compared with back-to-back (BTB) transmissions, 2 dB and 3.5 dB receiver power penalty are observed at BER of 10(-3) for 20 km and 40 km fiber link respectively. It clearly demonstrates the feasibility of the CAP16 modulation for the short range transmission systems. PMID:23482215

  14. Ultrafast terawatt laser sources for high-field particle acceleration and short wavelength generation

    SciTech Connect

    Downer, M.C.; Siders, C.W.

    1996-12-31

    The Laser Sources working group concerned itself with recent advances in and future requirements for the development of laser sources relevant to high-energy physics (HEP) colliders, small scale accelerators, and the generation of short wave-length radiation. We heavily emphasized pulsed terawatt peak power laser sources for several reasons. First, their development over the past five years has been rapid and multi-faceted, and has made relativistic light intensity available to the advanced accelerator community, as well as the wider physics community, for the first time. Secondly, they have strongly impacted plasma-based accelerator research over the past two years, producing the first experimental demonstrations of the laser wakefield accelerator (LWFA) in both its resonantly-driven and self-modulated forms. Thirdly, their average power and wall-plug efficiency currently fall well short of projected requirements for future accelerators and other high average power applications, but show considerable promise for improving substantially over the next few years. A review of this rapidly emerging laser technology in the context of advanced accelerator research is therefore timely.

  15. Resonant micro-optic gyro using a short and high-finesse fiber ring resonator.

    PubMed

    Ma, Huilian; Zhang, Jianjie; Wang, Linglan; Lu, Ying; Ying, Diqing; Jin, Zhonghe

    2015-12-15

    A novel hybrid integrated scheme is proposed for a high-performance resonant micro-optic gyro (RMOG), which requires a low-loss micro-ring resonator for mass production. A new record for the RMOG is established experimentally with a short fiber ring resonator and an integrated signal detecting and processing circuit. The finesse of the short fiber ring resonator with a length of 60 cm and a diameter of 4.77 cm is as high as 202, and the theoretical sensitivity of the RMOG is better than 0.3°/h assuming the average optical intensity at the photodetector is 1 mW. The 60 cm long spliceless micro-ring resonator is experimentally proved to be sufficient for a tactical-grade RMOG. An angle random walk coefficient of 0.64°/?h and a typical bias stability below 9.6°/h for the integration time of 50 s are successfully demonstrated using an innovative open-loop approach for an operation time of 1600 s. PMID:26670531

  16. Communications

    E-print Network

    Levine, Stuart

    1986-01-01

    to my opinion that I quote parts of it to suggest that my reaction is not isolated. Paul Boyer calls it "this flawed but interesting little book." He concludes: Unfortunately, Technological Utopianism in American Culture adds up to somewhat less than...>^ Communications To T H E E D I T O R S : Stuart Levine's review of my book, Technological Utopianism in American Culture (March 1986), so misrepresents and oversimpli­ fies its contents as, I believe, to warrant a reply. Contrary to Levine's summary, I discuss...

  17. Short communication: high cellular iron levels are associated with increased HIV infection and replication.

    PubMed

    Chang, Hsiang-Chun; Bayeva, Marina; Taiwo, Babafemi; Palella, Frank J; Hope, Thomas J; Ardehali, Hossein

    2015-03-01

    HIV is a pandemic disease, and many cellular and systemic factors are known to alter its infectivity and replication. Earlier studies had suggested that anemia is common in HIV-infected patients; however, higher iron was also observed in AIDS patients prior to the introduction of antiretroviral therapy (ART). Therefore, the relationship between iron and viral infection is not well delineated. To address this issue, we altered the levels of cellular iron in primary CD4(+) T cells and showed that higher iron is associated with increased HIV infection and replication. In addition, HIV infection alone leads to increased cellular iron, and several ART drugs increase cellular iron independent of HIV infection. Finally, HIV infection is associated with increased serum iron in HIV-positive patients regardless of treatment with ART. These results establish a relationship between iron and HIV infection and suggest that iron homeostasis may be a viable therapeutic target for HIV. PMID:25291189

  18. Effects of High Intensity White Noise on Short-Term Memory for Position in a List and Sequence

    ERIC Educational Resources Information Center

    Daee, Safar; Wilding, J. M.

    1977-01-01

    Seven experiments are described investigating the effecy of high intensity white noise during the visual presentation of words on a number of short-term memory tasks. Examines results relative to position learning and sequence learning. (Editor/RK)

  19. High Capacity Communications From Martian Distances. Part 1; Spacecraft Link Design Analysis

    NASA Technical Reports Server (NTRS)

    Vyas, Hemali N.; Schuchman, Leonard; Orr, Richard; Williams, Wallace Dan; Collins, Michael; Noreen, Gary

    2006-01-01

    High capacity space communications has been a desire for Human Exploration and Science missions. Current Mars missions operate at data rates of 120 kbps for telemetry downlink and it is desirable to study high rate communication links in the range of 100 Mbps to 1 Gbps data rates from Martian distances. This paper will present some assumed scenarios along with link design assumptions and link analysis for high capacity communications from Mars. The paper will focus on RF subsystems namely antenna and power for the downlink communication from a relay orbiter at Mars. The relay orbiter will communicate with the low orbit spacecrafts at Mars or any Martian surface elements such as robots, and relay the data back to the ground networks on Earth. The study will dive into the spacecraft downlink system design and communication link analysis between the relay orbiter and ground network on Earth for data rates ranging from 100 Mbps to 1 Gbps based on the assumed scenarios and link assumptions. With high rate links at larger distances, there will be a significant impact on the antenna and power requirements and the link design will make an attempt to minimize the mass of the RF subsystem on the spacecraft. The results of this study will be presented for three data rates 1 Gbps, 500 Mbps and 100 Mbps at maximum Mars to Earth distance of 2.67AU. The design will use a Ka-band downlink with 90% link availability, along with various ground network G/T assumptions and possible bandwidth efficient modulations. The paper will conclude with what types of high rate communication links are feasible from Martian distances and also identify a range of requirements for antenna and power technologies for these high capacity communications from Mars.

  20. Atomic short-range order and incipient long-range order in high-entropy alloys

    NASA Astrophysics Data System (ADS)

    Singh, Prashant; Smirnov, A. V.; Johnson, D. D.

    2015-06-01

    Within density-functional theory, we apply an electronic-structure-based thermodynamic theory to calculate short-ranged order (SRO) in homogeneously disordered substitutional N -component alloys, and its electronic origin. Using the geometric properties of an (N -1 ) simplex that describes the Gibbs (compositional) space, we derive the analytic transform of the SRO eigenvectors that provides a unique description of high-temperature SRO in N -component alloys and the incipient low-temperature long-range order. We apply the electronic-based thermodynamic theory and the new general analysis to ternaries (A 1 Cu-Ni-Zn and A 2 Nb-Al-Ti) for validation, and then to quinary Al-Co-Cr-Fe-Ni high-entropy alloys for predictive assessment.

  1. IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 50, NO. 1, JANUARY 2002 31 Iterative Interference Cancellation for High Spectral Efficiency Satellite

    E-print Network

    El-Gamal, Hesham

    Cancellation for High Spectral Efficiency Satellite Communications Bassel F. Beidas, Hesham El Gamal, and Stan feedback, multiuser de- tection, satellite communications. I. INTRODUCTION THE increasingly rapid growth cancellation tech- niques for high spectral efficiency satellite communication sys- tems. We consider two

  2. Short-pulse, high-energy radiation generation from laser-wakefield accelerated electron beams

    NASA Astrophysics Data System (ADS)

    Schumaker, Will

    2013-10-01

    Recent experimental results of laser wakefield acceleration (LWFA) of ~GeV electrons driven by the 200TW HERCULES and the 400TW ASTRA-GEMINI laser systems and their subsequent generation of photons, positrons, and neutrons are presented. In LWFA, high-intensity (I >1019 W /cm2), ultra-short (?L < 1 / (2 ??pe)) laser pulses drive highly nonlinear plasma waves which can trap ~ nC of electrons and accelerate them to ~GeV energies over ~cm lengths. These electron beams can then be converted by a high-Z target via bremsstrahlung into low-divergence (< 20 mrad) beams of high-energy (<600 MeV) photons and subsequently into positrons via the Bethe-Heitler process. By increasing the material thickness and Z, the resulting Ne+ /Ne- ratio can approach unity, resulting in a near neutral density plasma jet. These quasi-neutral beams are presumed to retain the short-pulse (?L < 40 fs) characteristic of the electron beam, resulting in a high peak density of ne- /e+ ~ 1016 cm-3 , making the source an excellent candidate for laboratory study of astrophysical leptonic jets. Alternatively, the electron beam can be interacted with a counter-propagating, ultra-high intensity (I >1021 W /cm2) laser pulse to undergo inverse Compton scattering and emit a high-peak brightness beam of high-energy photons. Preliminary results and experimental sensitivities of the electron-laser beam overlap are presented. The high-energy photon beams can be spectrally resolved using a forward Compton scattering spectrometer. Moreover, the photon flux can be characterized by a pixelated scintillator array and by nuclear activation and (?,n) neutron measurements from the photons interacting with a secondary solid target. Monte-Carlo simulations were performed using FLUKA to support the yield estimates. This research was supported by DOE/NSF-PHY 0810979, NSF CAREER 1054164, DARPA AXiS N66001-11-1-4208, SF/DNDO F021166, and the Leverhulme Trust ECF-2011-383.

  3. proovread: large-scale high-accuracy PacBio correction through iterative short read consensus

    PubMed Central

    Hackl, Thomas; Hedrich, Rainer; Schultz, Jörg; Förster, Frank

    2014-01-01

    Motivation: Today, the base code of DNA is mostly determined through sequencing by synthesis as provided by the Illumina sequencers. Although highly accurate, resulting reads are short, making their analyses challenging. Recently, a new technology, single molecule real-time (SMRT) sequencing, was developed that could address these challenges, as it generates reads of several thousand bases. But, their broad application has been hampered by a high error rate. Therefore, hybrid approaches that use high-quality short reads to correct erroneous SMRT long reads have been developed. Still, current implementations have great demands on hardware, work only in well-defined computing infrastructures and reject a substantial amount of reads. This limits their usability considerably, especially in the case of large sequencing projects. Results: Here we present proovread, a hybrid correction pipeline for SMRT reads, which can be flexibly adapted on existing hardware and infrastructure from a laptop to a high-performance computing cluster. On genomic and transcriptomic test cases covering Escherichia coli, Arabidopsis thaliana and human, proovread achieved accuracies up to 99.9% and outperformed the existing hybrid correction programs. Furthermore, proovread-corrected sequences were longer and the throughput was higher. Thus, proovread combines the most accurate correction results with an excellent adaptability to the available hardware. It will therefore increase the applicability and value of SMRT sequencing. Availability and implementation: proovread is available at the following URL: http://proovread.bioapps.biozentrum.uni-wuerzburg.de Contact: frank.foerster@biozentrum.uni-wuerzburg.de Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25015988

  4. Space Link Extension (SLE) Emulation for High-Throughput Network Communication

    NASA Technical Reports Server (NTRS)

    Murawski, Robert; Tchorowski, Nicole; Golden, Bert

    2014-01-01

    As the data rate requirements for space communications increases, signicant stressis placed not only on the wireless satellite communication links, but also on the groundnetworks which forward data from end-users to remote ground stations. These wide areanetwork (WAN) connections add delay and jitter to the end-to-end satellite communicationlink, eects which can have signicant impacts on the wireless communication link. It isimperative that any ground communication protocol can react to these eects such that theground network does not become a bottleneck in the communication path to the satellite.In this paper, we present our SCENIC Emulation Lab testbed which was developed to testthe CCSDS SLE protocol implementations proposed for use on future NASA communica-tion networks. Our results show that in the presence of realistic levels of network delay,high-throughput SLE communication links can experience signicant data rate throttling.Based on our observations, we present some insight into why this data throttling happens,and trace the probable issue back to non-optimal blocking communication which is sup-ported by the CCSDS SLE API recommended practices. These issues were presented aswell to the SLE implementation developers which, based on our reports, developed a newrelease for SLE which we show xes the SLE blocking issue and greatly improves the pro-tocol throughput. In this paper, we also discuss future developments for our end-to-endemulation lab and how these improvements can be used to develop and test future spacecommunication technologies.

  5. A Short Communication Course for Physicians Improves the Quality of Patient Information in a Clinical Trial | accrualnet.cancer.gov

    Cancer.gov

    This article addresses the question of how to improve the informed consent process. The investigators tested a one-day communications course for physicians and research nurses that included lecture and role-play approaches for its ability to improve the quality of informed consent and the satisfaction of patients who enrolled in a randomized clinical trial of adjuvant treatment for breast cancer.

  6. High repetition-rate and short pulse-width 1064nm laser in a composite crystal device

    NASA Astrophysics Data System (ADS)

    Wang, Zijian; Jin, Guangyong; Yu, Yongji; Zhai, Ruizhi

    2014-12-01

    Compared with lamp pumped solid state laser, laser-diode pumped all-solid-state laser (DPSL) has the characteristic of high efficiency, long life and reliable under the condition of high repetition rate. Therefore, A high repetition rate DPSL has a broad application prospect in the laser detection, laser communication and optoelectronic countermeasure and other fields. Laser-diode (LD) pumped acousto-optic(AO) Q-switch all-solid-state has attractive features, such as compact structure, reliable operation, high repetition rate and short pulse width. Laser crystal is the core component of the laser. Usually composite crystal thermal lens focal length is three times more than traditional crystal, so it can avoid the serious heating effect of the operation material bumping by the traditional method. In this paper, we present a high repetition rate acousto-optic Q-switched Nd:YVO4 laser pumped by 880nm laser diode. By using the 0.25% doping concentration Nd:YVO4 single end composite crystal size of 3*3*(4+16) mm3 , with the 50 W LD pumped power, in order to calculate the laser crystal absorption efficiency of pump light, so that more accurate calculation of light conversion efficiency, first we measured 880 nm pump light absorption, crystal is calculated on the pump light absorption efficiency of 75%; When we put in the cavity mirror to form a flat resonant cavity, we obtained the 1064 nm continuous laser output power of 26 W and 27.1 W, with the output mirror transmittance of 20% and 48%, respectively. 50.7% and 48.7% optical to optical conversion efficiency has been achieved experimentally. When we put in AO Q-switch, with the repetition rate of 50 kHz, 100 kHz and 200 kHz, the 1064 nm laser output power is 21 W, 21.28 W and 20.58 W, and the peak power is 32.9 kW, 17.3 kW, 8.5 kW, respectively. Under the high repetition rate circumstance, the pulse width is limited to 12 ns.

  7. Highly Flexible and Conductive Printed Graphene for Wireless Wearable Communications Applications.

    PubMed

    Huang, Xianjun; Leng, Ting; Zhu, Mengjian; Zhang, Xiao; Chen, JiaCing; Chang, KuoHsin; Aqeeli, Mohammed; Geim, Andre K; Novoselov, Kostya S; Hu, Zhirun

    2015-01-01

    In this paper, we report highly conductive, highly flexible, light weight and low cost printed graphene for wireless wearable communications applications. As a proof of concept, printed graphene enabled transmission lines and antennas on paper substrates were designed, fabricated and characterized. To explore its potentials in wearable communications applications, mechanically flexible transmission lines and antennas under various bended cases were experimentally studied. The measurement results demonstrate that the printed graphene can be used for RF signal transmitting, radiating and receiving, which represents some of the essential functionalities of RF signal processing in wireless wearable communications systems. Furthermore, the printed graphene can be processed at low temperature so that it is compatible with heat-sensitive flexible materials like papers and textiles. This work brings a step closer to the prospect to implement graphene enabled low cost and environmentally friendly wireless wearable communications systems in the near future. PMID:26673395

  8. Highly Flexible and Conductive Printed Graphene for Wireless Wearable Communications Applications

    PubMed Central

    Huang, Xianjun; Leng, Ting; Zhu, Mengjian; Zhang, Xiao; Chen, JiaCing; Chang, KuoHsin; Aqeeli, Mohammed; Geim, Andre K.; Novoselov, Kostya S.; Hu, Zhirun

    2015-01-01

    In this paper, we report highly conductive, highly flexible, light weight and low cost printed graphene for wireless wearable communications applications. As a proof of concept, printed graphene enabled transmission lines and antennas on paper substrates were designed, fabricated and characterized. To explore its potentials in wearable communications applications, mechanically flexible transmission lines and antennas under various bended cases were experimentally studied. The measurement results demonstrate that the printed graphene can be used for RF signal transmitting, radiating and receiving, which represents some of the essential functionalities of RF signal processing in wireless wearable communications systems. Furthermore, the printed graphene can be processed at low temperature so that it is compatible with heat-sensitive flexible materials like papers and textiles. This work brings a step closer to the prospect to implement graphene enabled low cost and environmentally friendly wireless wearable communications systems in the near future. PMID:26673395

  9. Reflectivity of plasmas created by high-intensity, ultra-short laser pulses

    SciTech Connect

    Gold, D.M.

    1994-06-01

    Experiments were performed to characterize the creation and evolution of high-temperature (T{sub e}{approximately}100eV), high-density (n{sub e}>10{sup 22}cm{sup {minus}3}) plasmas created with intense ({approximately}10{sup 12}-10{sup 16}W/cm{sup 2}), ultra-short (130fs) laser pulses. The principle diagnostic was plasma reflectivity at optical wavelengths (614nm). An array of target materials (Al, Au, Si, SiO{sub 2}) with widely differing electronic properties tested plasma behavior over a large set of initial states. Time-integrated plasma reflectivity was measured as a function of laser intensity. Space- and time-resolved reflectivity, transmission and scatter were measured with a spatial resolution of {approximately}3{mu}m and a temporal resolution of 130fs. An amplified, mode-locked dye laser system was designed to produce {approximately}3.5mJ, {approximately}130fs laser pulses to create and nonintrusively probe the plasmas. Laser prepulse was carefully controlled to suppress preionization and give unambiguous, high-density plasma results. In metals (Al and Au), it is shown analytically that linear and nonlinear inverse Bremsstrahlung absorption, resonance absorption, and vacuum heating explain time-integrated reflectivity at intensities near 10{sup 16}W/cm{sup 2}. In the insulator, SiO{sub 2}, a non-equilibrium plasma reflectivity model using tunneling ionization, Helmholtz equations, and Drude conductivity agrees with time-integrated reflectivity measurements. Moreover, a comparison of ionization and Saha equilibration rates shows that plasma formed by intense, ultra-short pulses can exist with a transient, non-equilibrium distribution of ionization states. All targets are shown to approach a common reflectivity at intensities {approximately}10{sup 16}W/cm{sup 2}, indicating a material-independent state insensitive to atomic or solid-state details.

  10. Substantial biases in ultra-short read data sets from high-throughput DNA sequencing

    PubMed Central

    Dohm, Juliane C.; Lottaz, Claudio; Borodina, Tatiana; Himmelbauer, Heinz

    2008-01-01

    Novel sequencing technologies permit the rapid production of large sequence data sets. These technologies are likely to revolutionize genetics and biomedical research, but a thorough characterization of the ultra-short read output is necessary. We generated and analyzed two Illumina 1G ultra-short read data sets, i.e. 2.8 million 27mer reads from a Beta vulgaris genomic clone and 12.3 million 36mers from the Helicobacter acinonychis genome. We found that error rates range from 0.3% at the beginning of reads to 3.8% at the end of reads. Wrong base calls are frequently preceded by base G. Base substitution error frequencies vary by 10- to 11-fold, with A > C transversion being among the most frequent and C > G transversions among the least frequent substitution errors. Insertions and deletions of single bases occur at very low rates. When simulating re-sequencing we found a 20-fold sequencing coverage to be sufficient to compensate errors by correct reads. The read coverage of the sequenced regions is biased; the highest read density was found in intervals with elevated GC content. High Solexa quality scores are over-optimistic and low scores underestimate the data quality. Our results show different types of biases and ways to detect them. Such biases have implications on the use and interpretation of Solexa data, for de novo sequencing, re-sequencing, the identification of single nucleotide polymorphisms and DNA methylation sites, as well as for transcriptome analysis. PMID:18660515

  11. On the choice of electromagnetic model for short high-intensity arcs, applied to welding

    NASA Astrophysics Data System (ADS)

    Choquet, Isabelle; Javidi Shirvan, Alireza; Nilsson, Håkan

    2012-05-01

    We have considered four different approaches for modelling the electromagnetic fields of high-intensity electric arcs: (i) three-dimensional, (ii) two-dimensional axi-symmetric, (iii) the electric potential formulation and (iv) the magnetic field formulation. The underlying assumptions and the differences between these models are described in detail. Models (i) to (iii) reduce to the same limit for an axi-symmetric configuration with negligible radial current density, contrary to model (iv). Models (i) to (iii) were retained and implemented in the open source CFD software OpenFOAM. The simulation results were first validated against the analytic solution of an infinite electric rod. Perfect agreement was obtained for all the models tested. The electromagnetic models (i) to (iii) were then coupled with thermal fluid mechanics, and applied to axi-symmetric gas tungsten arc welding test cases with short arc (2, 3 and 5 mm) and truncated conical electrode tip. Models (i) and (ii) lead to the same simulation results, but not model (iii). Model (iii) is suited in the specific limit of long axi-symmetric arc with negligible electrode tip effect, i.e. negligible radial current density. For short axi-symmetric arc with significant electrode tip effect, the more general axi-symmetric formulation of model (ii) should instead be used.

  12. Evaluating the relationship between breakfast pattern and short-term memory in junior high school girls.

    PubMed

    Ahmadi, A; Sohrabi, Z; Eftekhari, M H

    2009-05-01

    The aim of this study was to evaluate the relationship between breakfast pattern and short-term memory in guidance-school students. Memory improves for subjects who have eaten breakfast. It appears that breakfast consumption influences cognition via several mechanisms. What children eat for breakfast before going to school is very important. A total of 150 junior high school girls were taken from a subject pool in four schools in Shiraz (capital of the Fars Province in Iran). They filled out the socio-economic questionnaires as well as food frequency questionnaires for breakfast and provided two-three day breakfast records in two different seasons and their short-term memories were evaluated by Weksler test socio-economic conditions and dietary intakes were analyzed. The results of the study showed that there was no correlation between parents job, students mean age and their school grades with their memory scores. Dietary analysis demonstrated a negative correlation between local soup consumption in breakfast and memory scores. Food record analysis showed no correlation between fat, cholesterol, protein, vitamin B6, B12, calorie and iodine intake in breakfast and memory scores, but there was a positive correlation between carbohydrate, iron and vitamin B3 intake in breakfast and memory scores, similarly there was a positive correlation between B12 intake in the breakfast and students' average school grades during the year. PMID:19634483

  13. Development of a 1 J short pulse tunable TEA CO2 laser with high energy stability

    NASA Astrophysics Data System (ADS)

    Kumar, Manoj; Reghu, T.; Biswas, A. K.; Bhargav, Pankaj; Pakhare, J. S.; Kumar, Shailesh; Verma, Abrat; Mandloi, Vagesh; Kukreja, L. M.

    2014-12-01

    The design, development and operational characteristics of a 1 J, repetitively pulsed, line tunable TEA CO2 laser producing nearly tail free short pulses (~170 ns) suitable for laser isotope separation is discussed. Tail free short laser pulses were generated by employing a nitrogen lean gaseous active medium. Use of an indigenously developed stable pulsed power supply, uniform and intense UV spark pre-ionization and optimum gas purging with catalytic regeneration to control the deleterious oxygen accumulation helps generate laser pulses with high energy stability. Integration of a sensitive arc detection system allows long term arc-free operation of the laser and protects it from catastrophic failure. Laser pulses in more than 90 lines in 10.6 ?m and 9.6 ?m bands of CO2 laser spectrum with energy about 1 J in as many as 50 lines could be generated with a typical efficiency of about 4%. A typical pulse to pulse energy stability of ±1.4% was obtained during one hour of continuous operation of the TEA CO2 laser at 75 Hz.

  14. Remotely-interrogated high data rate free space laser communications link

    DOEpatents

    Ruggiero, Anthony J. (Livermore, CA)

    2007-05-29

    A system and method of remotely extracting information from a communications station by interrogation with a low power beam. Nonlinear phase conjugation of the low power beam results in a high power encoded return beam that automatically tracks the input beam and is corrected for atmospheric distortion. Intracavity nondegenerate four wave mixing is used in a broad area semiconductor laser in the communications station to produce the return beam.

  15. VERY HIGH-SPEED DRILL STRING COMMUNICATIONS NETWORK

    SciTech Connect

    David S. Pixton

    2002-11-01

    Testing of a high-speed digital data transmission system for drill pipe is described. Passive transmission of digital data through 1000 ft of telemetry drill pipe has been successfully achieved. Data rates of up to 2 Mbit/sec have been tested through the 1000 ft system with very low occurrence of data errors: required error correction effort is very low or nonexistent. Further design modifications have been made to improve manufacturability and high pressure robustness of the transmission line components. Failure mechanisms of previous designs at high pressure and high temperature are described. Present design limitations include high temperature application.

  16. High-dose short-term administration of naringin did not alter talinolol pharmacokinetics in humans.

    PubMed

    Nguyen, M A; Staubach, P; Tamai, I; Langguth, P

    2015-02-20

    Naringin is considered the major causative ingredient of the inhibition of intestinal drug uptake by grapefruit juice. Moreover, it is contained in highly dosed nutraceuticals available on the market. A controlled, open, randomized, crossover study was performed in 10 healthy volunteers to investigate the effect of high-dose naringin on the bioavailability of talinolol, a substrate of intestinal organic anion-transporting polypeptide (OATP)-mediated uptake. Following 6-day supplementation with 3 capsules of 350 mg naringin daily, 100mg talinolol were administered orally with 3 capsules of the same dietary supplement (1050 mg naringin) on the seventh day. This test treatment was compared to 100mg talinolol only (control). The results showed that short-term high-dose naringin supplementation did not significantly affect talinolol pharmacokinetics. Geometric mean ratios of test versus control ranged between 0.90 and 0.98 for talinolol c(max), AUC(0-48 h), AUC(0-?), t(1/2) and A(e(0-48 h)). The high dose may provoke inhibition of the efflux transporter P-glycoprotein (P-gp) which counteracts the uptake inhibition. As disintegration and dissolution processes are required for the solid dosage form, dissolved naringin may arrive at the site of interaction after talinolol is already absorbed. In conclusion, the effect of nutraceuticals on drug pharmacokinetics can deviate from that observed when administered as food component due to the different dose and dosage form. PMID:25486333

  17. Quantification of Shear-Induced Platelet Activation: High Shear Stresses for Short Exposure Time.

    PubMed

    Ding, Jun; Chen, Zengsheng; Niu, Shuqiong; Zhang, Jiafeng; Mondal, Nandan K; Griffith, Bartley P; Wu, Zhongjun J

    2015-07-01

    Thrombosis and thromboembolism are the life-threatening clinical complications for patients supported or treated with prosthetic cardiovascular devices. The high mechanical shear stress within these devices is believed to be the major contributing factor to cause platelet activation (PA) and function alteration, leading to thrombotic events. There have been limited quantitative data on how the high mechanical shear stress causes platelet activation. In this study, shear-induced PA in the ranges of well-defined shear stress and exposure time relevant to cardiovascular devices was quantitatively characterized for human blood using two novel flow-through Couette-type blood shearing devices. Four markers of platelet activation-surface P-selectin (CD62p), platelet-derived microparticles (PMPs), platelet-monocyte aggregation (PMA), and soluble P-selectin-were measured by flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively. The results indicated that PA induced by high shear stresses with short exposure time could be reliably detected with surface P-selectin, and, to a lesser extent, PMPs rather than soluble P-selectin. It was also verified that PMA can be a highly sensitive indirect marker of platelet activation. The quantitative relationship between percentage of activated platelets indicated by surface P-selectin expression and shear stress/exposure time follows well the power law functional form. The coefficients of the power law models of PA based on surface P-selectin expression were derived. PMID:25808300

  18. Short-pulse, high-energy radiation generation using a laser wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Schumaker, W.; Vargas, M.; He, Z.; Chvykov, V.; Hou, B.; Yanovsky, V.; Maksimchuk, A.; Thomas, A. G. R.; Krushelnick, K.; Sarri, G.; Dromey, B.; Zepf, M.

    2012-10-01

    Recent experimental results of laser wakefield acceleration (LWFA) of electrons and their subsequent radiation generation driven by the HERCULES laser with up to 200TW are presented. In LWFA, the plasma ``bubble'' structure forces trapped, off-axis electrons to undergo transverse oscillatory motion during acceleration, resulting in synchrotron-like betatron radiation in the keV X-ray regime. Measurements indicate that the beam source size can be as small as 1 micron and that the radiation exhibits spatial coherence, allowing phase-contrast imaging. Data from Cu K-? generated using an identical geometry are presented to give yield and source size comparisons. Alternatively, the high energy (>200 MeV) electron beam can be subsequently converted via Bremsstrahlung into low-divergence beams of high-energy photons and positrons. These photons are spectrally resolved using a Compton scattering-based, high-energy (30-80 MeV) photon spectrometer. All of these subsequent beams are presumed to retain the short-pulse characteristic of the electron beam, resulting in high peak flux, making the source an excellent candidate for ultrafast pump-probe applications in the keV and MeV photon range.

  19. Enhancement and quenching of high-intensity focused ultrasound cavitation activity via short frequency sweep gaps.

    PubMed

    Hallez, Loïc; Lee, Judy; Touyeras, Francis; Nevers, Aymeric; Ashokkumar, Muthupandian; Hihn, Jean-Yves

    2016-03-01

    This letter reports on the use of frequency sweeps to probe acoustic cavitation activity generated by high-intensity focused ultrasound (HIFU). Unprecedented enhancement and quenching of HIFU cavitation activity were observed when short frequency sweep gaps were applied in negative and positive directions, respectively. It was revealed that irrespective of the frequency gap, it is the direction and frequency sweep rate that govern the cavitation activity. These effects are related to the response of bubbles generated by the starting frequency to the direction of the frequency sweep, and the influence of the sweep rate on growth and coalescence of bubbles, which in turn affects the active bubble population. These findings are relevant for the use of HIFU in chemical and therapeutic applications, where greater control of cavitation bubble population is critical. PMID:26584998

  20. Short pulse, high power microwave radiation source with a laser-induced sheet plasma mirror

    SciTech Connect

    Higashiguchi, Takeshi; Yugami, Noboru

    2009-05-01

    We have demonstrated the short pulse, high power microwave radiation source using an ultraviolet laser-induced sheet plasma mirror in a gas-filled x-band rectangular waveguide from the conventional microwave sources and components. A laser-induced sheet plasma with an overdense plasma acts as a plasma mirror. The long pulse propagating in the gas-filled waveguide was sliced by the sheet plasma mirror at two different points along the waveguide. We observed about twice the power of the pulse by adding the two sliced microwave pulses produced by this scheme. A maximum peak power of 200 kW with a pulse duration of 10 ns (full width at half maximum) from the long microwave pulse source with a pulse duration of 0.8 mus was observed.

  1. Study of short haul high-density V/STOL transportation systems, volume 1

    NASA Technical Reports Server (NTRS)

    Solomon, H. L.

    1972-01-01

    The relative advantages of STOL aircraft concepts were examined by simulating the operations of a short haul high-density intercity STOL system set in two arenas, the California corridor and the Chicago-Detroit-Cleveland triangle, during the 1980 time period. The study was constrained to the use of three aircraft concepts designated as the deflected slipstream turboprop, externally blown flap, and augmentor wing turbofan configurations. The projected demographic, economic, travel demand, and travel characteristics of the representative arenas were identified. The STOL airline operating scenarios were then formulated and through the use of the aerospace modal split simulation program, the traveler modal choices involving alternative STOL concepts were estimated in the context of the total transportation environment for 1980. System combinations that presented the best potential for economic return and traveler acceptance were then identified for each STOL concept.

  2. Epithermal Neutron Source for Neutron Resonance Spectroscopy (NRS) using High Intensity, Short Pulse Lasers

    SciTech Connect

    Higginson, D P; McNaney, J M; Swift, D C; Bartal, T; Hey, D S; Pape, S L; Mackinnon, A; Mariscal, D; Nakamura, H; Nakanii, N; Beg, F N

    2010-04-22

    A neutron source for neutron resonance spectroscopy (NRS) has been developed using high intensity, short pulse lasers. This measurement technique will allow for robust measurements of interior ion temperature of laser-shocked materials and provide insight into equation of state (EOS) measurements. The neutron generation technique uses protons accelerated by lasers off of Cu foils to create neutrons in LiF, through (p,n) reactions with {sup 7}Li and {sup 19}F. The distribution of the incident proton beam has been diagnosed using radiochromic film (RCF). This distribution is used as the input for a (p,n) neturon prediction code which is compared to experimentally measured neutron yields. From this calculation, a total fluence of 1.8 x 10{sup 9} neutrons is infered, which is shown to be a reasonable amount for NRS temperature measurement.

  3. Forward voltage short-pulse technique for measuring high power laser array junction temperature

    NASA Technical Reports Server (NTRS)

    Meadows, Byron L. (Inventor); Amzajerdian, Frazin (Inventor); Barnes, Bruce W. (Inventor); Baker, Nathaniel R. (Inventor)

    2012-01-01

    The present invention relates to a method of measuring the temperature of the P-N junction within the light-emitting region of a quasi-continuous-wave or pulsed semiconductor laser diode device. A series of relatively short and low current monitor pulses are applied to the laser diode in the period between the main drive current pulses necessary to cause the semiconductor to lase. At the sufficiently low current level of the monitor pulses, the laser diode device does not lase and behaves similar to an electronic diode. The voltage across the laser diode resulting from each of these low current monitor pulses is measured with a high degree of precision. The junction temperature is then determined from the measured junction voltage using their known linear relationship.

  4. Estimation of photon dose generated by a short pulse high power laser.

    PubMed

    Hayashi, Y; Fukumi, A; Matsukado, K; Mori, M; Kotaki, H; Kando, M; Chen, L M; Daito, I; Kondo, S; Kanazawa, S; Yamazaki, A; Ogura, K; Nishiuchi, M; Kado, M; Sagisaka, A; Nakamura, S; Li, Z; Orimo, S; Homma, T; Daido, H

    2006-01-01

    The authors obtain a new equation to estimate the forward component of a photon dose generated through the interaction between a target and a short pulse high power laser. As the equation is quite simple, it is useful for calculating the photon dose. The equation shows that the photon dose is proportional to the electron temperature in the range>3 MeV and proportional to the square of the electron temperature in the range<3 MeV. The dose estimated with this method is roughly consistent with the result of Monte Carlo simulation. With some assumptions and corrections, it can reproduce experimental results obtained and the dose result calculated at other laboratories. PMID:16410288

  5. Circular polarization effects in ion acceleration from high intensity, short pulse laser interactions

    NASA Astrophysics Data System (ADS)

    Dollar, F.; Zulick, C.; Bulanov, S. S.; Chvykov, V.; Kalintchenko, G.; Matsuoka, T.; McGuffey, C.; Thomas, A. G. R.; Willingale, L.; Yanovsky, V.; Maksimchuk, A.; Krushelnick, K.; Petrov, G.; Davis, J.

    2011-10-01

    Experiments were performed to investigate ion acceleration effects from circular polarization from thin targets, using a high contrast, ultra-short laser pulse from the HERCULES laser facility at the Univ. of Michigan. Experiments were performed with 50 TW, 35 fs pulses at an intensity of >1021Wcm-2 on Si3N4 and Mylar targets of 30 nm to 1 ?m thickness with contrast <10-13 . Protons with maximum energy 18 MeV and Carbon ions with energies of up to 10 MeV per nucleon were measured. Particle-in-cell simulations demonstrating the acceleration mechanism will be presented as well. Supported by NSF Physics Frontier Center FOCUS (Grant PHY-0114336), Defense Threat Reduction Agency, and Naval Research Laboratory. We acknowledge the OSIRIS consortium for the use of OSIRIS.

  6. High Efficiency Power Combining of Ka-Band TWTs for High Data Rate Communications

    NASA Technical Reports Server (NTRS)

    Wintucky, E. G.; Simons, R. N.; Vaden, K. R.; Lesny, G. G.; Glass, J. L.

    2006-01-01

    Future NASA deep space exploration missions are expected in some cases to require telecommunication systems capable of operating at very high data rates (potentially 1 Gbps or more) for the transmission back to Earth of large volumes of scientific data, which means high frequency transmitters with large bandwidth. Among the Ka band frequencies of interest are the present 500 MHz Deep Space Network (DSN) band of 31.8 to 32.3 GHz and a broader band at 37-38 GHz allocated for space science [1]. The large distances and use of practical antenna sizes dictate the need for high transmitter power of up to 1 kW or more. High electrical efficiency is also a requirement. The approach investigated by NASA GRC is a novel wave guide power combiner architecture based on a hybrid magic-T junction for combining the power output from multiple TWTs [1,2]. This architecture was successfully demonstrated and is capable of both high efficiency (90-95%, depending on frequency) and high data rate transmission (up to 622 Mbps) in a two-way power combiner circuit for two different pairs of Ka band TWTs at two different frequency bands. One pair of TWTs, tested over a frequency range of 29.1 to 29.6 GHz, consisted of two 110-115W TWTs previously used in uplink data transmission evaluation terminals in the NASA Advanced Communications Technology Satellite (ACTS) program [1,2]. The second pair was two 100W TWTs (Boeing 999H) designed for high efficiency operation (greater than 55%) over the DSN frequency band of 31.8 to 32.3 GHz [3]. The presentation will provide a qualitative description of the wave guide circuit, results for power combining and data transmission measurements, and results of computer modeling of the magic-T and alternative hybrid junctions for improvements in efficiency and power handling capability. The power combiner results presented here are relevant not only to NASA deep space exploration missions, but also to other U.S. Government agency programs.

  7. Association between low colonic short-chain fatty acids and high bile acids in high colon cancer risk populations.

    PubMed

    Ou, Junhai; DeLany, James P; Zhang, Ming; Sharma, Sumit; O'Keefe, Stephen J D

    2012-01-01

    We propose that the influence of diet on colon cancer risk is mediated by the microbiota. To investigate how dietary fat influences risk, we compared the colonic contents of 12 adult high-risk African Americans (AAs) and 10 Caucasian Americans (CAs) who consumed a high-fat diet (123 ± 11 g/d and 129 ± 17 g/d, respectively) to 13 native Africans (NAs) who subsisted on a low-fat (38 ± 3.0 g/d) diet, all aged 50-60 yr. The colonic bile acids were measured by LC-MS and the short-chain fatty acids (SCFAs) by GC. The chief secondary colonic bile acids, deoxycholic acid and lithocholic acid, were correlated with fat intake and similar between AAs and CAs, but 3-4 times higher than in AAs (p < 0.05). The major SCFAs were lower in AAs (p < 0.001) and CAs (p < 0.001) compared to AAs, but conversely, the branched chain fatty acids (BFCA) were higher. Our results suggest that the higher risk of colon cancer in Americans may be partly explained by their high-fat and high-protein, low complex carbohydrate diet, which produces colonic residues that promote microbes to produce potentially carcinogenic secondary bile acids and less antineoplastic SCFAs. The role of BCFA in colonic carcinogenesis deserves further study. PMID:22136517

  8. Improving Mathematical Communication Ability and Self Regulation Learning of Junior High Students by Using Reciprocal Teaching

    ERIC Educational Resources Information Center

    Qohar, Abdul; Sumarmo, Utari

    2013-01-01

    This paper presents the findings from a posttest experiment control group design by using reciprocal teaching, conducted in Indonesia University of Education to investigate students' ability in mathematical communication and self regulated learning. Subject of the study were 254 of 9th grade students from three junior high schools of high, medium,…

  9. Developing Students' Literacy Skills Using High-Tech Speech-Generating Augmentative and Alternative Communication Devices

    ERIC Educational Resources Information Center

    Wilkins, Julia; Ratajczak, Amy

    2009-01-01

    This article outlines practical techniques for developing literacy skills in users of high-tech speech-generating augmentative and alternative communication (AAC) devices. The recommended strategies are intended for general classroom teachers who teach literacy skills to students with typical speech. Many students who use high-tech AAC devices…

  10. Communications Strategies on Alcohol and Highway Safety. Volume II. High School Youth. Final Report.

    ERIC Educational Resources Information Center

    Grey Advertising, Inc., New York, NY.

    The second part of a two-part, two volume study deals with high school youth and identifies target populations and communications strategies for encouraging personal action steps to prevent drunk driving. Data, collected from interviews and questionnaires, are summarized and presented in tabular form. One fourth of high schoolers in a…

  11. Solar Cell Short Circuit Current Errors and Uncertainties During High Altitude Calibrations

    NASA Technical Reports Server (NTRS)

    Snyder, David D.

    2012-01-01

    High altitude balloon based facilities can make solar cell calibration measurements above 99.5% of the atmosphere to use for adjusting laboratory solar simulators. While close to on-orbit illumination, the small attenuation to the spectra may result in under measurements of solar cell parameters. Variations of stratospheric weather, may produce flight-to-flight measurement variations. To support the NSCAP effort, this work quantifies some of the effects on solar cell short circuit current (Isc) measurements on triple junction sub-cells. This work looks at several types of high altitude methods, direct high altitude meas urements near 120 kft, and lower stratospheric Langley plots from aircraft. It also looks at Langley extrapolation from altitudes above most of the ozone, for potential small balloon payloads. A convolution of the sub-cell spectral response with the standard solar spectrum modified by several absorption processes is used to determine the relative change from AMO, lscllsc(AMO). Rayleigh scattering, molecular scatterin g from uniformly mixed gases, Ozone, and water vapor, are included in this analysis. A range of atmosph eric pressures are examined, from 0. 05 to 0.25 Atm to cover the range of atmospheric altitudes where solar cell calibrations a reperformed. Generally these errors and uncertainties are less than 0.2%

  12. A high-frequency warm shallow water acoustic communications channel model and measurements.

    PubMed

    Chitre, Mandar

    2007-11-01

    Underwater acoustic communication is a core enabling technology with applications in ocean monitoring using remote sensors and autonomous underwater vehicles. One of the more challenging underwater acoustic communication channels is the medium-range very shallow warm-water channel, common in tropical coastal regions. This channel exhibits two key features-extensive time-varying multipath and high levels of non-Gaussian ambient noise due to snapping shrimp-both of which limit the performance of traditional communication techniques. A good understanding of the communications channel is key to the design of communication systems. It aids in the development of signal processing techniques as well as in the testing of the techniques via simulation. In this article, a physics-based channel model for the very shallow warm-water acoustic channel at high frequencies is developed, which are of interest to medium-range communication system developers. The model is based on ray acoustics and includes time-varying statistical effects as well as non-Gaussian ambient noise statistics observed during channel studies. The model is calibrated and its accuracy validated using measurements made at sea. PMID:18189549

  13. Radiation Hardened, Modulator ASIC for High Data Rate Communications

    NASA Technical Reports Server (NTRS)

    McCallister, Ron; Putnam, Robert; Andro, Monty; Fujikawa, Gene

    2000-01-01

    Satellite-based telecommunication services are challenged by the need to generate down-link power levels adequate to support high quality (BER approx. equals 10(exp 12)) links required for modem broadband data services. Bandwidth-efficient Nyquist signaling, using low values of excess bandwidth (alpha), can exhibit large peak-to-average-power ratio (PAPR) values. High PAPR values necessitate high-power amplifier (HPA) backoff greater than the PAPR, resulting in unacceptably low HPA efficiency. Given the high cost of on-board prime power, this inefficiency represents both an economical burden, and a constraint on the rates and quality of data services supportable from satellite platforms. Constant-envelope signals offer improved power-efficiency, but only by imposing a severe bandwidth-efficiency penalty. This paper describes a radiation- hardened modulator which can improve satellite-based broadband data services by combining the bandwidth-efficiency of low-alpha Nyquist signals with high power-efficiency (negligible HPA backoff).

  14. A Psychometric Evaluation of the Career Decision Self-Efficacy Scale-Short Form in Chinese High School Students

    ERIC Educational Resources Information Center

    Hampton, Nan Zhang

    2006-01-01

    This study explores the reliability and validity of the Career Decision Self-Efficacy Scale-Short Form (CDSES-SF) in Chinese high school students. One hundred and eighty-three high school students from a city in northeastern China participated in the study. The results indicate that scores on the CDSES-SF are reliable (internal consistency…

  15. Thermal sterilization of heat-sensitive products using high-temperature short-time sterilization.

    PubMed

    Mann, A; Kiefer, M; Leuenberger, H

    2001-03-01

    High-temperature short-time (HTST) sterilization with a continuous-flow sterilizer, developed for this study, was evaluated. The evaluation was performed with respect to (a) the chemical degradation of two heat-sensitive drugs in HTST range (140-160 degrees C) and (b) the microbiological effect of HTST sterilization. Degradation kinetics of two heat-sensitive drugs showed that a high peak temperature sterilization process resulted in less chemical degradation for the same microbiological effect than a low peak temperature process. Both drugs investigated could be sterilized with acceptable degradation at HTST conditions. For the evaluation of the microbiological effect, Bacillus stearothermophilus ATCC 7953 spores were used as indicator bacteria. Indicator spore kinetics (D(T), z value, k, and E(a)), were determined in the HTST range. A comparison between the Bigelow model (z value concept) and the Arrhenius model, used to describe the temperature coefficient of the microbial inactivation, demonstrated that the Bigelow model is more accurate in prediction of D(T) values in the HTST range. The temperature coefficient decreased with increasing temperature. The influence of Ca(2+) ions and pH value on the heat resistance of the indicator spores, which is known under typical sterilization conditions, did not change under HTST conditions. PMID:11170021

  16. High Density Lipoproteins for the Systemic Delivery of short interfering RNA

    PubMed Central

    McMahon, Kaylin M.; Thaxton, C. Shad

    2014-01-01

    Introduction RNA interference (RNAi) is a powerful mechanism for gene silencing with the potential to greatly impact the development of new therapies for many human diseases. Short interfering RNAs (siRNAs) may be the ideal molecules for therapeutic RNAi. However, therapeutic siRNAs face significant challenges that must be overcome prior to widespread clinical use. Many efforts have been made to overcome the hurdles associated with systemic administration of siRNA; however, current approaches are still limited. As such, there is an urgent need to develop new strategies for siRNA delivery that have the potential to impact a broad spectrum of systemic diseases. Areas covered This review focuses on the promise of siRNA therapies and highlights current siRNA delivery methods. With an eye toward new strategies, this review first introduces high density lipoproteins (HDL) and their natural functions, and then transitions into how HDLs may provide significant opportunities as next generation siRNA delivery vehicles. Importantly, this review describes how synthetic HDLs leverage the natural ability of HDL to stabilize and deliver siRNAs. Expert Opinion HDLs are natural nanoparticles that are critical to understanding the systemic delivery of therapeutic nucleic acids, like siRNA. Methods to synthesize biomimetic HDLs are being explored and data demonstrate that this type of delivery vehicle may be highly beneficial for targeted and efficacious systemic delivery of siRNAs. PMID:24313310

  17. Development of a resonant laser ionization gas cell for high-energy, short-lived nuclei

    E-print Network

    T. Sonoda; M. Wada; H. Tomita; C. Sakamoto; T. Takatsuka; T. Furukawa; H. Iimura; Y. Ito; T. Kubo; Y. Matsuo; H. Mita; S. Naimi; S. Nakamura; T. Noto; P. Schury; T. Shinozuka; T. Wakui; H. Miyatake; S. Jeong; H. Ishiyama; Y. X. Watanabe; Y. Hirayama; K. Okada; A. Takamine

    2012-10-24

    A new laser ion source configuration based on resonant photoionization in a gas cell has been developed at RIBF RIKEN. This system is intended for the future PArasitic RI-beam production by Laser Ion-Source (PALIS) project which will be installed at RIKEN's fragment separator, BigRIPS. A novel implementation of differential pumping, in combination with a sextupole ion beam guide (SPIG), has been developed. A few small scroll pumps create a pressure difference from 1000 hPa - 10^-3 Pa within a geometry drastically miniaturized compared to conventional systems. This system can utilize a large exit hole for fast evacuation times, minimizing the decay loss for short-lived nuclei during extraction from a buffer gas cell, while sufficient gas cell pressure is maintained for stopping high energy RI-beams. In spite of the motion in a dense pressure gradient, the photo-ionized ions inside the gas cell are ejected with an assisting force gas jet and successfully transported to a high-vacuum region via SPIG followed by a quadrupole mass separator. Observed behaviors agree with the results of gas flow and Monte Carlo simulations.

  18. Development of a resonant laser ionization gas cell for high-energy, short-lived nuclei

    E-print Network

    Sonoda, T; Tomita, H; Sakamoto, C; Takatsuka, T; Furukawa, T; Iimura, H; Ito, Y; Kubo, T; Matsuo, Y; Mita, H; Naimi, S; Nakamura, S; Noto, T; Schury, P; Shinozuka, T; Wakui, T; Miyatake, H; Jeong, S; Ishiyama, H; Watanabe, Y X; Hirayama, Y; Okada, K; Takamine, A

    2012-01-01

    A new laser ion source configuration based on resonant photoionization in a gas cell has been developed at RIBF RIKEN. This system is intended for the future PArasitic RI-beam production by Laser Ion-Source (PALIS) project which will be installed at RIKEN's fragment separator, BigRIPS. A novel implementation of differential pumping, in combination with a sextupole ion beam guide (SPIG), has been developed. A few small scroll pumps create a pressure difference from 1000 hPa - 10^-3 Pa within a geometry drastically miniaturized compared to conventional systems. This system can utilize a large exit hole for fast evacuation times, minimizing the decay loss for short-lived nuclei during extraction from a buffer gas cell, while sufficient gas cell pressure is maintained for stopping high energy RI-beams. In spite of the motion in a dense pressure gradient, the photo-ionized ions inside the gas cell are ejected with an assisting force gas jet and successfully transported to a high-vacuum region via SPIG followed by ...

  19. The Communicative Process of Drug Resistance among High School Students.

    ERIC Educational Resources Information Center

    Alberts, J. K.; And Others

    1992-01-01

    Analyzed 69 narrative accounts of successful and unsuccessful attempts by high school students to say no to drug offers. Found peer pressure applied in approximately 70 percent of offers. Much of pressure was applied after refusal of initial offer. Simple offers were more likely with alcohol; drug offers were more likely to be persuasive and to…

  20. ORIGINAL COMMUNICATION High-throughput classification of clinical populations

    E-print Network

    Munoz, Douglas Perry

    dysfunctions of oculomotor control and attention, including attention deficit hyperactivity disorder (ADHD's disease Á Attention deficits Á Eye tracking Introduction Visual attention and eye movements enable us August 2012 Ó Springer-Verlag 2012 Abstract Many high-prevalence neurological disorders involve

  1. Photography (Graphic Communications). Industrial Arts, Senior High--Level II. North Dakota Senior High Industrial Arts Curriculum Guides.

    ERIC Educational Resources Information Center

    Poehls, Eddie; And Others

    This course guide for a photography course is one of four developed for the graphic communications area in the North Dakota senior high industrial arts education program. (Eight other guides are available for two other areas of Industrial Arts--energy/power and production.) Part 1 provides such introductory information as a definition and…

  2. Design/Drafting (Graphic Communications). Industrial Arts, Senior High--Level II. North Dakota Senior High Industrial Arts Curriculum Guides.

    ERIC Educational Resources Information Center

    Poehls, Eddie; And Others

    This course guide for a design/drafting course is one of four developed for the graphic communications area in the North Dakota senior high industrial arts education program. (Eight other guides are available for two other areas of Industrial Arts--energy/power and production.) Part 1 provides such introductory information as a definition and…

  3. VERY HIGH-SPEED DRILL STRING COMMUNICATIONS NETWORK

    SciTech Connect

    David S. Pixton

    2002-08-01

    Testing of recent upgrades to the drill pipe telemetry system in a 1000-ft vertical well has shown that the new system can achieve at least 1,000 ft passive transmission distance with sufficient bandwidth to accommodate a digital transmission rate of 2 Mbit/sec. Digitized data from a module at the bottom of the well has been successfully transmitted through the transmission line to the top of the well for a period of approximately one month. Manufacture of 30 prototype range 2 drill pipes has demonstrated greater simplicity of manufacturing and greater consistency of electrical characteristics from part to part, as compared to the first production run previously reported. Further work is needed to improve the high pressure capability of the system and to improve the robustness of the system in a high-vibration environment.

  4. Quantum Key Distribution with High Loss: Toward Global Secure Communication

    E-print Network

    W. -Y. Hwang

    2003-05-19

    We propose a decoy-state method to overcome the photon-number-splitting attack for Bennett-Brassard 1984 quantum key distribution protocol in the presence of high loss: A legitimate user intentionally and randomly replaces signal pulses by multi-photon pulses (decoy-states). Then they check the loss of the decoy-states. If the loss of the decoy-states is abnormally less than that of signal pulses, the whole protocol is aborted. Otherwise, to continue the protocol, they estimate loss of signal multi-photon pulses based on that of decoy-states. This estimation can be done with an assumption that the two losses have similar values, that we justify.

  5. Temperature measurement by IR camera of heated device to high temperature during a short time

    NASA Astrophysics Data System (ADS)

    Sonneck-Museux, Nathanaëlle; Vergé, Philippe; Judic, Jean-Pierre; Edard, Pierrick

    2015-04-01

    A device allowing heating a liquid to high temperatures during a very short time has been conceived in our laboratory. The goal of this survey is to find the suitable experimental configurations, so that tested material affected by the temperatures coved between 200 and 750°C. This study is achieved to the Solar Furnace of the DGA in Odeillo. The cavity containing the liquid is a thermocouple sleeve (capillary) in Inconel 600. Its extremity is closed tightly by a removable steel plug permitting the tightness after replenishment. An electromagnet associated to a generator of delay permit to make fall the whole after the solar irradiation in liquid nitrogen in order to stop the reaction of "deterioration" of the tested product. According to capillary dimensions and to heating time, the temperature measurement using a pyrometer is not possible. A second possibility is using thermocouple, but it is not easy to join this captor on Inconel 600. Using by infrared camera allows observing the presence or the absence of inflammation during the solar irradiation and the sleeve fall too. The measures of temperatures by thermocouple show a lot of variability. The measures comparison with those by infrared camera shows a phenomenon of "heat well". Several score of tests to the solar furnace have been achieved in different experimental configurations. Nine experimental configurations have been validated, for variable flux of 100 to 500W/cm². The observation by infrared camera permitted to validate the conceived system and to verify the homogeneity of the sleeve heated.

  6. High-fidelity rotor gap measurements in a short-duration turbine rig

    NASA Astrophysics Data System (ADS)

    Lavagnoli, Sergio; Paniagua, Guillermo; Tulkens, Maxime; Steiner, Alexander

    2012-02-01

    The distance between the tip of rotating airfoils and the stationary casing, i.e., the tip clearance, is a vital parameter to characterize turbomachinery performance. The larger the tip clearance, the lower the turbine efficiency due to the increased loss associated with the hot jet flowing through the gap without generating work. Following the increasing demands in efficiency, these small clearances must be surveyed to avoid mechanical rubbing. The appropriate design of control systems to adjust these small clearances requires a constant monitoring during the whole engine envelope. This paper describes the complete implementation of a high-frequency capacitive sensor on the shroud of a large transonic turbine stage. The presented system and data analysis procedure allow the accurate measurement of the tip clearance of each rotating airfoil. The measurement system performances are first assessed in a simplified test bench and uncertainty analysis is provided. The technique is demonstrated in an aero-propulsion turbine, tested in a short duration rig. The turbine facility has running times of less than 0.5 s, characterized by temperature and rotor speed transients, which requires particular in-situ sensor calibrations. Extensive running tip clearance measurements of the large aero-engine turbine stage validate the system concept and design.

  7. Conflicts and Communication between High-Achieving Chinese American Adolescents and Their Parents

    ERIC Educational Resources Information Center

    Qin, Desiree Baolian; Chang, Tzu-Fen; Han, Eun-Jin; Chee, Grace

    2012-01-01

    Drawing on in-depth interview data collected on 18 high-achieving Chinese American students, the authors examine domains of acculturation-based conflicts, parent and child internal conflicts, and conflict resolution in their families. Their analyses show that well-established negative communication patterns in educational expectations, divergent…

  8. Communication Satisfaction, Organizational Citizenship Behavior and the Relationship to Student Achievement in High Schools

    ERIC Educational Resources Information Center

    Blanchard, Gayle A.

    2012-01-01

    This study used a correlational design that allowed the researcher to examine the relationship among communication satisfaction, organizational citizenship behaviors (OCB) and student achievement. High school teachers were surveyed from a convenience sample of 12 school districts in Arizona. Established instruments were used to survey…

  9. Communication about Contraception and Knowledge of Oral Contraceptives amongst Norwegian High School Students.

    ERIC Educational Resources Information Center

    Hansen, Thomas; Skjeldestad, Finn Egil

    2003-01-01

    Examines communication about contraception and specific knowledge of oral contraceptives (OCs) in a sample of Norwegian high school students. More females than males discussed contraception at least monthly. Discussions were predominantly held with peers and not adults. Females were far more knowledgeable about OCs than males. The most significant…

  10. Attributes of Communication between Clients and Staff of High Capacity Computer Data Processing Centers.

    ERIC Educational Resources Information Center

    Hirsch, Kenneth William; Kimbrough, Kenneth Laslie

    A study was conducted in September 1981 of factors which influence the process of communication between clients and staff at six high-capacity computer facilities in the Sacramento, California, metropolitan area. These included two large government organizations, a medium-sized corporation, two bibliographic database settings, and a computer…

  11. Linux/SimOS -A Simulation Environment for Evaluating High-Speed Communication Systems

    E-print Network

    Lee, Ben

    Linux/SimOS - A Simulation Environment for Evaluating High-Speed Communication Systems Chulho Won presents Linux/SimOS, a Linux operating sys- tem port to SimOS, which is a complete machine simula- tor from Stanford. The motivation for Linux/SimOS is to alleviate the limitations of SimOS, which only

  12. Safety Assurance and Rescue Communication Systems in High-Stress Environments -A Mining

    E-print Network

    New South Wales, University of

    operations in underwater, urban war zones, mountainous terrain, avalanches, underground mine disasters, volcanic eruptions, plane crashes, high-rise building collapses, and nuclear facility mal- functions the potential problems. Third, it explores the design of a wireless sensor network (WSN) based communication

  13. The design of a linear L-band high power amplifier for mobile communication satellites

    NASA Technical Reports Server (NTRS)

    Whittaker, N.; Brassard, G.; Li, E.; Goux, P.

    1990-01-01

    A linear L-band solid state high power amplifier designed for the space segment of the Mobile Satellite (MSAT) mobile communication system is described. The amplifier is capable of producing 35 watts of RF power with multitone signal at an efficiency of 25 percent and with intermodulation products better than 16 dB below carrier.

  14. Brief Communication High temperature pulses decrease indirect chilling injury and elevate ATP levels

    E-print Network

    Lee Jr., Richard E.

    Brief Communication High temperature pulses decrease indirect chilling injury and elevate ATP: Received 20 December 2009 Accepted 8 March 2010 Available online 15 March 2010 Keywords: ATP Energy supply by determining survival rates and ATP levels for flies that had undergone continuous long-term exposure at 0 °C

  15. Communication Strategies Used by High School English Language Learners in Multilingual Classrooms

    ERIC Educational Resources Information Center

    Spromberg, Sarah

    2011-01-01

    In this study, twenty-five high school English language learners were observed in their classrooms in a New York City public school while they worked in small groups. All observations were video recorded or done by the researcher while in the classrooms. The videos were then transcribed. Communication strategies that the participants used were…

  16. Electronic Communication and Its Influence on Parental Involvement in High School

    ERIC Educational Resources Information Center

    Watkins, Aaron

    2013-01-01

    This study investigated the effect of electronic communication has on parent's involvement with their high school child's education. The No Child Left Behind Act of 2001 (NCLB) specifically requires that schools find ways to increase parental involvement; this requirement stemmed from evidence that involvement tends to decline as the students…

  17. EMERGING AIR QUALITY MODELING TECHNOLOGY FOR HIGH PERFORMANCE COMPUTING AND COMMUNICATION ENVIRONMENTS

    EPA Science Inventory

    To demonstrate applications of the HPCC technologies in air quality models, we organized the Specialty Evening Session 1, "Emerging Air Quality Modeling Technologies for High Performance Computing and Communication Environment" as a part of the Twenty First NATO/CCMS Internationa...

  18. InfoMall: An Innovative Strategy for High-Performance Computing and Communications Applications Development.

    ERIC Educational Resources Information Center

    Mills, Kim; Fox, Geoffrey

    1994-01-01

    Describes the InfoMall, a program led by the Northeast Parallel Architectures Center (NPAC) at Syracuse University (New York). The InfoMall features a partnership of approximately 24 organizations offering linked programs in High Performance Computing and Communications (HPCC) technology integration, software development, marketing, education and…

  19. Association between short sleep duration and high incidence of metabolic syndrome in midlife women.

    PubMed

    Choi, Jung-Kyu; Kim, Min-Young; Kim, Jong-Koo; Park, Jong-Ku; Oh, Sung-Soo; Koh, Sang-Baek; Eom, Aeyong

    2011-01-01

    Chronic sleep deprivation is increasingly common in industrialized societies. Short sleep duration has been associated with a number of negative health outcomes. The objectives of this study were to investigate the association between self-reported sleep duration and the presence of metabolic syndrome (combination of central obesity, triglyceride, high density lipoprotein, blood pressure, fasting plasma glucose) in adults during midlife. The Korean Genomic Rural Cohort (KGRC) is a cohort study of aged 40 to 70 years in rural Korea. This study focuses on the prevalence, incidence, and risk factors for chronic degenerative disorders, such as hypertension, diabetes, osteoporosis, respiratory diseases, and metabolic syndrome. The baseline sample of participants in the KGRC study was recruited in 2005-2006 (phase 1). Respondents were followed until 2008-2009 (phase 2). The final sample included 1,107 subjects: 386 males (34.9%) and 721 females (65.1%). The incidence rate of metabolic syndrome in our sample was 18.4% (21.2% for males and 16.9% for females). Subjects sleeping < 6 hours a day (HR: 1.798; 95% CI: 1.06-3.05) were significantly more likely to experience metabolic syndrome than participants sleeping 6 to 7.9 hours a day after controlling for potential covariates (age, body mass index, menopause, smoking, alcohol and physical activity). Shorter sleep duration was associated with the high incidence of metabolic syndrome among females only. In conclusion, shorter sleep duration may be a significant risk factor for the development of metabolic syndrome in women. PMID:22001675

  20. Short time interval for condensation of high-temperature silicates in the solar accretion disk.

    PubMed

    Luu, Tu-Han; Young, Edward D; Gounelle, Matthieu; Chaussidon, Marc

    2015-02-01

    Chondritic meteorites are made of primitive components that record the first steps of formation of solids in our Solar System. Chondrules are the major component of chondrites, yet little is known about their formation mechanisms and history within the solar protoplanetary disk (SPD). We use the reconstructed concentrations of short-lived (26)Al in chondrules to constrain the timing of formation of their precursors in the SPD. High-precision bulk magnesium isotopic measurements of 14 chondrules from the Allende chondrite define a (26)Al isochron with (26)Al/(27)Al = 1.2(±0.2) × 10(-5) for this subset of Allende chondrules. This can be considered to be the minimum bulk chondrule (26)Al isochron because all chondrules analyzed so far with high precision (?50 chondrules from CV and ordinary chondrites) have an inferred minimum bulk initial ((26)Al/(27)Al) ? 1.2 × 10(-5). In addition, mineral (26)Al isochrons determined on the same chondrules show that their formation (i.e., fusion of their precursors by energetic events) took place from 0 Myr to ?2 Myr after the formation of their precursors, thus showing in some cases a clear decoupling in time between the two events. The finding of a minimum bulk chondrule (26)Al isochron is used to constrain the astrophysical settings for chondrule formation. Either the temperature of the condensation zone dropped below the condensation temperature of chondrule precursors at ?1.5 My after the start of the Solar System or the transport of precursors from the condensation zone to potential storage sites stopped after 1.5 My, possibly due to a drop in the disk accretion rate. PMID:25605942

  1. Autonomic Function Predicts Fitness Response to Short-Term High-Intensity Interval Training.

    PubMed

    Kiviniemi, A M; Tulppo, M P; Eskelinen, J J; Savolainen, A M; Kapanen, J; Heinonen, I H A; Hautala, A J; Hannukainen, J C; Kalliokoski, K K

    2015-11-01

    We tested the hypothesis that baseline cardiac autonomic function and its acute response to all-out interval exercise explains individual fitness responses to high-intensity interval training (HIT). Healthy middle-aged sedentary men performed HIT (n=12, 4-6×30?s of all-out cycling efforts with 4-min recovery) or aerobic training (AET, n=9, 40-60?min at 60% of peak workload in exercise test [Loadpeak]), comprising 6 sessions within 2 weeks. Low (LF) and high frequency (HF) power of R-R interval oscillation were analyzed from data recorded at supine and standing position (5+5?min) every morning during the intervention. A significant training effect (p< 0.001), without a training*group interaction, was observed in Loadpeak and peak oxygen consumption (VO2peak). Pre-training supine LF/HF ratio, an estimate of sympathovagal balance, correlated with training outcome in Loadpeak (Spearman's rho [rs]=-0.74, p=0.006) and VO2peak (rs=-?0.59, p=0.042) in the HIT but not the AET group. Also, the mean change in the standing LF/HF ratio in the morning after an acute HIT exercise during the 1(st) week of intervention correlated with training response in Loadpeak (rs=-?0.68, p=0.014) and VO2peak (rs=-0.60, p=0.039) with HIT but not with AET. In conclusion, pre-training cardiac sympathovagal balance and its initial alterations in response to acute HIT exercise were related to fitness responses to short-term HIT. PMID:26140689

  2. Short time interval for condensation of high-temperature silicates in the solar accretion disk

    PubMed Central

    Luu, Tu-Han; Young, Edward D.; Gounelle, Matthieu; Chaussidon, Marc

    2015-01-01

    Chondritic meteorites are made of primitive components that record the first steps of formation of solids in our Solar System. Chondrules are the major component of chondrites, yet little is known about their formation mechanisms and history within the solar protoplanetary disk (SPD). We use the reconstructed concentrations of short-lived 26Al in chondrules to constrain the timing of formation of their precursors in the SPD. High-precision bulk magnesium isotopic measurements of 14 chondrules from the Allende chondrite define a 26Al isochron with 26Al/27Al = 1.2(±0.2) × 10?5 for this subset of Allende chondrules. This can be considered to be the minimum bulk chondrule 26Al isochron because all chondrules analyzed so far with high precision (?50 chondrules from CV and ordinary chondrites) have an inferred minimum bulk initial (26Al/27Al) ? 1.2 × 10?5. In addition, mineral 26Al isochrons determined on the same chondrules show that their formation (i.e., fusion of their precursors by energetic events) took place from 0 Myr to ?2 Myr after the formation of their precursors, thus showing in some cases a clear decoupling in time between the two events. The finding of a minimum bulk chondrule 26Al isochron is used to constrain the astrophysical settings for chondrule formation. Either the temperature of the condensation zone dropped below the condensation temperature of chondrule precursors at ?1.5 My after the start of the Solar System or the transport of precursors from the condensation zone to potential storage sites stopped after 1.5 My, possibly due to a drop in the disk accretion rate. PMID:25605942

  3. Short-range variability of soil pH in a regional geochemical survey, communicating uncertainty to the data user

    NASA Astrophysics Data System (ADS)

    Ander, Louise; Knights, Kate; Lark, Murray

    2015-04-01

    The north of Ireland is well-furnished with geochemical data after completion of the Tellus survey of Northern Ireland and the Tellus Border survey of six northern counties of the Republic of Ireland. These data are of considerable interest to the agricultural sector, in particular the data on soil pH. However, a geochemical survey at regional scale cannot resolve significant variation of soil pH, in particular effects of soil management and fine-scale variation of superficial material. This leads to uncertainties in the mapped soil pH which must be accounted for when making decisions about management interventions, including more detailed local sampling. In this poster we show how uncertainty of predicted soil pH, relative to established threshold values, can be quantified by disjunctive kriging. The uncertainty is expressed in terms of probabilities. We show how this can be communicated to the data user by means of the calibrated phrases of the IPCC, using results from recent research on its efficacy to modify its presentation.

  4. K-band high power latching switch. [communication satellite system

    NASA Technical Reports Server (NTRS)

    Mlinar, M. J.; Piotrowski, W. S.; Raue, J. E.

    1980-01-01

    A 19 GHz waveguide latching switch with a bandwidth of 1400 MHz and an exceptionally low insertion loss of 0.25 dB was demonstrated. The RF and driver ferrites are separate structures and can be optimized individually. This analysis for each structure is separately detailed. Basically, the RF section features a dual turnstile junction. The circulator consists of a dielectric tube which contains two ferrite rods, and a dielectric spacer separating the ferrite parts along the center of symmetry of the waveguide to form two turnstiles. This subassembly is indexed and locked in the center of symmetry of a uniform junction of three waveguides by the metallic transformers installed in the top and bottom walls of the housing. The switching junction and its actuating circuitry met all RF performance objectives and all shock and vibration requirements with no physical damage or performance degradation. It exceeds thermal requirements by operating over a 100 C temperature range (-44 C to +56 C) and has a high power handling capability allowing up to 100 W of CW input power.

  5. Coherent DWDM technology for high speed optical communications

    NASA Astrophysics Data System (ADS)

    Saunders, Ross

    2011-10-01

    The introduction of coherent digital optical transmission enables a new generation of high speed optical data transport and fiber impairment mitigation. An initial implementation of 40 Gb/s coherent systems using Dual Polarization Quadrature Phase Shift Keying (DP-QPSK) is already being installed in carrier networks. New systems running at 100 Gb/s DP-QPSK data rate are in development and early technology lab and field trial phase. Significant investment in the 100 Gb/s ecosystem (optical components, ASICs, transponders and systems) bodes well for commercial application in 2012 and beyond. Following in the footsteps of other telecommunications fields such as wireless and DSL, we can expect coherent optical transmission to evolve from QPSK to higher order modulations schemes such as Mary PSK and/or QAM. This will be an interesting area of research in coming years and poses significant challenges in terms of electro-optic, DSP, ADC/DAC design and fiber nonlinearity mitigation to reach practical implementation ready for real network deployments.

  6. Joint Access Control Based on Access Ratio and Resource Utilization for High-Speed Railway Communications

    NASA Astrophysics Data System (ADS)

    Zhou, Yuzhe; Ai, Bo

    2015-05-01

    The fast development of high-speed rails makes people's life more and more convenient. However, provisioning of quality of service of multimedia applications for users on the high-speed train is a critical task for wireless communications. Therefore, new solutions are desirable to be found to address this kind of problem. Current researches mainly focus on providing seamless broadband wireless access for high-speed mobile terminals. In this paper, an algorithm to calculate the optimal resource reservation fraction of handovers is proposed. A joint access control scheme for high-speed railway communication handover scenario is proposed. Metrics of access ratio and resource utilization ratio are considered jointly in the analysis and the performance evaluation. Simulation results show that the proposed algorithm and the scheme improve quality of service compared with other conventional schemes.

  7. Overview of the Preliminary Design of the Optical Communication Demonstration and High-Rate Link Facility

    NASA Technical Reports Server (NTRS)

    Sandusky, John V.; Jeganathan, M.; Ortiz, G.; Biswas, A.; Lee, S.; Parker, G.; Liu, B.; Johnson, D.; DePew, J.; Lesh, J. R.

    2000-01-01

    Tlis paper presents an overview of the preliminary design of both the flight and ground systems of the Optical Communication Demonstration and High-Rate Link Facility which will demonstrate optical communication from the International Space Station to ground after its deployment in October 2002. The overview of the preliminary design of the Flight System proceeds by contrasting it with the design of the laboratory-model unit, emphasizing key changes and the rationale behind the design choices. After presenting the preliminary design of the Ground System, the timetable for the construction and deployment of the flight and ground systems is outlined.

  8. High bandwidth based on a tapped delay line equalization in visible light communications

    NASA Astrophysics Data System (ADS)

    Zhang, Minglun; Guo, Xujing; Zhu, Hetian; Wang, Chao; Bai, Xiaonan; Zhai, Xiangwen

    2015-08-01

    In the visible light communication, the white LED bandwidth severely limits the transmission rate of information. This paper presents an analog pre-equalization technology to compensate for the bandwidth of white LED. The technology not only can debug according to the actual channel changing, but also avoid the high costs of using FPGA technology. The pre-equalization technology is implemented by an analog circuit of tapped-delay-line, in the circuit we select an appropriate delay line and a digital to analog converter. In our LED visible light communication system, we can achieve a bandwidth of 150MHz which was proved theoretically in the paper.

  9. High Bandwidth Synaptic Communication and Frequency Tracking in Human Neocortex

    PubMed Central

    Testa-Silva, Guilherme; Verhoog, Matthijs B.; Linaro, Daniele; de Kock, Christiaan P. J.; Baayen, Johannes C.; Meredith, Rhiannon M.; De Zeeuw, Chris I.; Giugliano, Michele; Mansvelder, Huibert D.

    2014-01-01

    Neuronal firing, synaptic transmission, and its plasticity form the building blocks for processing and storage of information in the brain. It is unknown whether adult human synapses are more efficient in transferring information between neurons than rodent synapses. To test this, we recorded from connected pairs of pyramidal neurons in acute brain slices of adult human and mouse temporal cortex and probed the dynamical properties of use-dependent plasticity. We found that human synaptic connections were purely depressing and that they recovered three to four times more swiftly from depression than synapses in rodent neocortex. Thereby, during realistic spike trains, the temporal resolution of synaptic information exchange in human synapses substantially surpasses that in mice. Using information theory, we calculate that information transfer between human pyramidal neurons exceeds that of mouse pyramidal neurons by four to nine times, well into the beta and gamma frequency range. In addition, we found that human principal cells tracked fine temporal features, conveyed in received synaptic inputs, at a wider bandwidth than for rodents. Action potential firing probability was reliably phase-locked to input transients up to 1,000 cycles/s because of a steep onset of action potentials in human pyramidal neurons during spike trains, unlike in rodent neurons. Our data show that, in contrast to the widely held views of limited information transfer in rodent depressing synapses, fast recovering synapses of human neurons can actually transfer substantial amounts of information during spike trains. In addition, human pyramidal neurons are equipped to encode high synaptic information content. Thus, adult human cortical microcircuits relay information at a wider bandwidth than rodent microcircuits. PMID:25422947

  10. Short spatial filters with spherical lenses for high-power pulsed lasers

    SciTech Connect

    Burdonov, K F; Soloviev, A A; Shaikin, A A; Potemkin, A K; Egorov, A S

    2013-11-30

    We report possible employment of short spatial filters based on spherical lenses in a pulsed laser source (neodymium glass, 300 J, 1 ns). The influence of the spherical aberration on the quality of output radiation and coefficient of conversion to the second harmonics is studied. The ultra-short aberration spatial filter of length 1.9 m with an aperture of 122 mm is experimentally tested. A considerable shortening of multi-cascade pump lasers for modern petawatt laser systems is demonstrated by the employment of short spatial filters without expensive aspherical optics. (elements of laser systems)

  11. High-power 0.87-micron channel substrate planar lasers for spaceborne communications

    NASA Technical Reports Server (NTRS)

    Connolly, J. C.; Stewart, T. R.; Gilbert, D. B.; Slavin, S. E.; Carlin, D. B.

    1988-01-01

    High-power single-mode channeled-substrate planar AlGaAs diode lasers are being developed for reliable high-power operation for use as sources in spaceborne optical communication systems. The CSP laser structure has been optimized for operation at an emission wavelength of 870 nm. Such devices have exhibited output powers in excess of 80 mW CW at an operating temperature of 80 C.

  12. Development and test of high frequency dc/dc converters for communications satellites

    NASA Astrophysics Data System (ADS)

    Alsbach, W.; Tsuya, N.; Gohnai, T.

    1985-12-01

    The development results of dc/dc converters with high switching frequency for future communications satellites are presented. Two types of dc/dc converters were developed: (1) TWT-EPC A high voltage (3 kV) converter for the Thomson CSF TH3559 TWT, operating at 100 kHz; (2) a low voltage converter for an SSPA-EPC solid state power amplifier, operating at 250 kHz. Evaluation and results of functional, EMC, and frequency tests are presented.

  13. A short timescale for changing oxygen fugacity in the solar nebula revealed by high-resolution 26

    E-print Network

    Manning, Craig

    A short timescale for changing oxygen fugacity in the solar nebula revealed by high-resolution 26 Al­26 Mg dating of CAI rims Justin I. Simon a,*, Edward D. Young a,b , Sara S. Russell c , Eric K of Mineralogy, Natural History Museum, Cromwell Road London, SW7 7BD, UK Received 4 April 2005; received

  14. An Examination of the Structure of the Career Decision Self-Efficacy Scale (Short Form) among Italian High School Students

    ERIC Educational Resources Information Center

    Presti, Alessandro Lo; Pace, Francesco; Mondo, Marina; Nota, Laura; Casarubia, Provvidenza; Ferrari, Lea; Betz, Nancy E.

    2013-01-01

    This study aims to evaluate the factor structure of Career Decision Self-Efficacy scale-short form in a sample of Italian high school adolescents. confirmatory factor analysis (CFA) was used to test the degree to which a one-factor structure and a five-factor structure provided the best fit. In view of available research the five-factor structure…

  15. Testing convective transport on short time scales: Comparisons with mass divergence and ozone anomaly patterns about high

    E-print Network

    Martin, Randall

    the boundary layer to the free troposphere and affect the local rates of ozone and aerosol productionTesting convective transport on short time scales: Comparisons with mass divergence and ozone to construct anomaly patterns of divergence, cloud top frequency, and ozone mixing ratio about the high rain

  16. Eects of Short-term, High Exposure to Chlorine Gas on Morphology and Physiology of Pinus ponderosa and Pseudotsuga menziesii

    E-print Network

    Brewer, Carol

    Eects of Short-term, High Exposure to Chlorine Gas on Morphology and Physiology of Pinus ponderosa morphological and physiological eects of chlorine gas exposure were evaluated on two conifer species was observed only on foliage that was directly exposed to chlorine gas. Necrotic needles of both species

  17. Enhancement of x-ray line emission from plasmas produced by short high-intensity laser double pulses

    E-print Network

    Limpouch, Jiri

    Enhancement of x-ray line emission from plasmas produced by short high-intensity laser double laser-produced plasmas are bright ultrafast line x-ray sources potentially suitable for different onto a solid target into the x-ray emission is significantly enhanced when a laser prepulse precedes

  18. Spectral signature of atmospheric reflection in Hercules X-1/HZ Hercules during low and short high states

    NASA Astrophysics Data System (ADS)

    Abdallah, M. H.; Leahy, D. A.

    2015-11-01

    We analyse RXTE/PCA X-ray spectra of the binary X-ray pulsar Her X-1/HZ Her during short high state and one binary orbit in the preceding low state, just before short high turn-on. The spectrum is well described by two continuum components (absorbed and unabsorbed). The resulting spectral parameters are modulated with orbital phase. During low state, a significant component of the flux, and its spectrum, is consistent with X-ray reflection off the face of the companion star HZ Her. This component has a significantly harder X-ray spectrum than the rest of the flux from the Her X-1 system. A second component in low state is consistent with emission from the accretion disc corona. During short high, a third strong component is present with a softer spectrum, which is associated with the neutron star and accretion disc. Due to this direct emission from the neutron star and accretion disc, the reflected emission is less clear; however, parameters and fluxes modulations during short high state indicate its presence. In low state, the hard X-ray flux (h? > 10 keV) peaks at orbital phase ?orb ? 0.55, which is expected from a simple model of atmospheric reflection from the companion star. The offset indicates an asymmetry in the X-ray illumination of the companion, which could be due to shadowing of the the inner face of HZ Her by the accretion disc and/or stream.

  19. Highly optimized fourth-order short-time approximation for pathintegrals

    SciTech Connect

    Predescu, Cristian

    2006-10-01

    We derive a fourth-order short-time approximation for use in imaginary-time path-integral simulations. The short-time approximation converges for all continuous and bounded from below potentials, attains quartic order of convergence for sufficiently smooth potentials, and utilizes statistically independent random variables for its construction. These properties recommend the approximation as a natural replacement of the trapezoidal Trotter-Suzuki approximation for physical systems with continuous distributions.

  20. Innovative, High-Pressure, Cryogenic Control Valve: Short Face-to-Face, Reduced Cost

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A control valve that can throttle high-pressure cryogenic fluid embodies several design features that distinguish it over conventional valves designed for similar applications. Field and design engineers worked together to create a valve that would simplify installation, trim changes, and maintenance, thus reducing overall cost. The seals and plug stem packing were designed to perform optimally in cryogenic temperature ranges. Unlike conventional high-pressure cryogenic valves, the trim size can be changed independent of the body. The design feature that provides flexibility for changing the trim is a split body. The body is divided into an upper and a lower section with the seat ring sandwiched in between. In order to maintain the plug stem packing at an acceptable sealing temperature during cryogenic service, heat-exchanging fins were added to the upper body section. The body is made of stainless steel. The seat ring is made of a nickel-based alloy having a coefficient of thermal expansion less than that of the body material. Consequently, when the interior of the valve is cooled cryogenically, the body surrounding the seat ring contracts more than the seat ring. This feature prevents external leakage at the body-seat joint. The seat ring has been machined to have small, raised-face sealing surfaces on both sides of the seal groove. These sealing surfaces concentrate the body bolt load over a small area, thereby preventing external leakage. The design of the body bolt circle is different from that of conventional highpressure control valves. Half of the bolts clamp the split body together from the top, and half from the bottom side. This bolt-circle design allows a short, clean flow path, which minimizes frictional flow losses. This bolt-circle design also makes it possible to shorten the face-toface length of the valve, which is 25.5 in. (65 cm). In contrast, a conventional, high-pressure control valve face-to-face dimension may be greater than 40 in. (>1 m) long.

  1. A New Population of High Redshift Short-Duration Gamma-Ray Bursts

    E-print Network

    E. Berger; D. B. Fox; P. A. Price; E. Nakar; A. Gal-Yam; D. E. Holz; B. P. Schmidt; A. Cucchiara; S. B. Cenko; S. R. Kulkarni; A. M. Soderberg; D. A. Frail; B. E. Penprase; A. Rau; E. Ofek; S. J. Bell Burnell; P. B. Cameron; L. L. Cowie; M. A. Dopita; I. Hook; B. A. Peterson; Ph. Podsiadlowski; K. C. Roth; R. E. Rutledge; S. S. Sheppard; A. Songaila

    2007-03-23

    The redshift distribution of the short-duration GRBs is a crucial, but currently fragmentary, clue to the nature of their progenitors. Here we present optical observations of nine short GRBs obtained with Gemini, Magellan, and the Hubble Space Telescope. We detect the afterglows and host galaxies of two short bursts, and host galaxies for two additional bursts with known optical afterglow positions, and five with X-ray positions (1. Our most conservative limit is that at least half of the five hosts without a known redshift reside at z>0.7 (97% confidence level), suggesting that about 1/3-2/3 of all short GRBs originate at higher redshifts than previously determined. This has two important implications: (i) We constrain the acceptable age distributions to a wide lognormal (sigma>1) with tau~4-8 Gyr, or to a power law, P(tau)~tau^n, with -1short GRBs, indicating a large spread in energy release or jet opening angles. Finally, we re-iterate the importance of short GRBs as potential gravitational wave sources and find a conservative Advanced LIGO detection rate of ~2-6 yr^-1.

  2. Short range structure of hadron and nuclear wave functions at high x

    SciTech Connect

    Hoyer, P.; Brodsky, S.J.

    1990-11-01

    We discuss the short-range structure of hadronic and nuclear wave functions expected in QCD. In addition to the extrinsic'' contributions associated with radiation from single partons, there is an intrinsic'' hardness of the high-mass fluctuations of the wave function due to the spatial overlap of two or more partons. We argue that intrinsically-hard partons, having large mass and/or large transverse momentum, will dominate in the region of large Feynman x{sub F}. Their rescattering in nuclear targets is expected to be larger than for extrinsically-hard partons, leading to a suppressed production cross section for hadrons scattering on heavy nuclei. Experimental evidence for this exists for open chars. J/{psi}, and {gamma} production at large x{sub F}. The effects of intrinsic hardness may be particularly striking in nuclear wave functions, where the overlap of partons belonging to different nucleons can give rise to cumulative (x > 1) phenomena. The data on backward cumulative particle production from nuclei supports the existence of an intrinsically-hard component in nuclear wave functions. Partons at large x{sub F} may also be associated with the enhanced subthreshold production of particles observed in hadron-nucleus and nucleus-nucleus collisions. We discuss the evidence for anomalies in the large angle pp {yields} pp cross section near the charm threshold. Arguments are presented that chromium states may bind to nuclei through the QCD Van der Waals force. This would lead to a striking signal in charm production near threshold. 49 refs., 7 figs.

  3. verification & Validation of High-Order Short-Characteristics-Based Deterministic Transport Methodology on Unstructured Grids

    SciTech Connect

    Azmy, Yousry; Wang, Yaqi

    2013-12-20

    The research team has developed a practical, high-order, discrete-ordinates, short characteristics neutron transport code for three-dimensional configurations represented on unstructured tetrahedral grids that can be used for realistic reactor physics applications at both the assembly and core levels. This project will perform a comprehensive verification and validation of this new computational tool against both a continuous-energy Monte Carlo simulation (e.g. MCNP) and experimentally measured data, an essential prerequisite for its deployment in reactor core modeling. Verification is divided into three phases. The team will first conduct spatial mesh and expansion order refinement studies to monitor convergence of the numerical solution to reference solutions. This is quantified by convergence rates that are based on integral error norms computed from the cell-by-cell difference between the code’s numerical solution and its reference counterpart. The latter is either analytic or very fine- mesh numerical solutions from independent computational tools. For the second phase, the team will create a suite of code-independent benchmark configurations to enable testing the theoretical order of accuracy of any particular discretization of the discrete ordinates approximation of the transport equation. For each tested case (i.e. mesh and spatial approximation order), researchers will execute the code and compare the resulting numerical solution to the exact solution on a per cell basis to determine the distribution of the numerical error. The final activity comprises a comparison to continuous-energy Monte Carlo solutions for zero-power critical configuration measurements at Idaho National Laboratory’s Advanced Test Reactor (ATR). Results of this comparison will allow the investigators to distinguish between modeling errors and the above- listed discretization errors introduced by the deterministic method, and to separate the sources of uncertainty.

  4. High-order statistical equalizer for nonlinearity compensation in dispersion-managed coherent optical communications.

    PubMed

    Koike-Akino, Toshiaki; Duan, Chunjie; Parsons, Kieran; Kojima, Keisuke; Yoshida, Tsuyoshi; Sugihara, Takashi; Mizuochi, Takashi

    2012-07-01

    Fiber nonlinearity has become a major limiting factor to realize ultra-high-speed optical communications. We propose a fractionally-spaced equalizer which exploits a trained high-order statistics to deal with data-pattern dependent nonlinear impairments in fiber-optic communications. The computer simulation reveals that the proposed 3-tap equalizer improves Q-factor by more than 2 dB for long-haul transmissions of 5,230 km distance and 40 Gbps data rate. We also demonstrate that the joint use of a digital backpropagation (DBP) and the proposed equalizer offers an additional 1-2 dB performance improvement due to the channel shortening gain. A performance in high-speed transmissions of 100 Gbps and beyond is evaluated as well. PMID:22772267

  5. Dimming-discrete-multi-tone (DMT) for simultaneous color control and high speed visible light communication.

    PubMed

    Sung, Jiun-Yu; Chow, Chi-Wai; Yeh, Chien-Hung

    2014-04-01

    Visible light communication (VLC) using LEDs has attracted significant attention recently for the future secure, license-free and electromagnetic-interference (EMI)-free optical wireless communication. Dimming technique in LED lamp is advantageous for energy efficiency. Color control can be performed in the red-green-blue (RGB) LEDs by using dimming technique. It is highly desirable to employ dimming technique to provide simultaneous color and dimming control and high speed VLC. Here, we proposed and demonstrated a LED dimming control using dimming-discrete-multi-tone (DMT) modulation. High speed DMT-based VLC with simultaneous color and dimming control is demonstrated for the first time to the best of our knowledge. Demonstration and analyses for several modulation conditions and transmission distances are performed, for instance, demonstrating the data rate of 103.5 Mb/s (using RGB LED) with fast Fourier transform (FFT) size of 512. PMID:24718127

  6. Small-bandgap polymer solar cells with unprecedented short-circuit current density and high fill factor.

    PubMed

    Choi, Hyosung; Ko, Seo-Jin; Kim, Taehyo; Morin, Pierre-Olivier; Walker, Bright; Lee, Byoung Hoon; Leclerc, Mario; Kim, Jin Young; Heeger, Alan J

    2015-06-01

    Small-bandgap polymer solar cells (PSCs) with a thick bulk heterojunction film of 340 nm exhibit high power conversion efficiencies of 9.40% resulting from high short-circuit current density (JSC ) of 20.07 mA cm(-2) and fill factor of 0.70. This remarkable efficiency is attributed to maximized light absorption by the thick active layer and minimized recombination by the optimized lateral and vertical morphology through the processing additive. PMID:25899940

  7. A Strategy for WholeA Strategy for Whole--Genome Sequencing and AssemblyGenome Sequencing and Assembly with Highwith High--Throughput, ShortThroughput, Short--Read TechnologiesRead Technologies

    E-print Network

    that is now being used to obtain the entire genetic code of organisms. The predominant technology, Sanger and Assembly with Highwith High--Throughput, ShortThroughput, Short--Read TechnologiesRead Technologies Andreas depth of CovG { 7.5x, 10.0x }. Next, we amplify each of these pieces in clones and randomly sample

  8. The Lunar Laser Communication Demonstration: NASA's First Step Toward Very High Data Rate Support of Science and Exploration Missions

    NASA Astrophysics Data System (ADS)

    Boroson, Don M.; Robinson, Bryan S.

    2014-12-01

    Future NASA missions for both Science and Exploration will have needs for much higher data rates than are presently available, even with NASA's highly-capable Space- and Deep-Space Networks. As a first step towards this end, for one month in late 2013, NASA's Lunar Laser Communication Demonstration (LLCD) successfully demonstrated for the first time high-rate duplex laser communications between a satellite in lunar orbit, the Lunar Atmosphere and Dust Environment Explorer (LADEE), and multiple ground stations on the Earth. It constituted the longest-range laser communication link ever built and demonstrated the highest communication data rates ever achieved to or from the Moon.

  9. High performance drive circuits for integrated microLED/CMOS arrays for visible light communication (VLC) 

    E-print Network

    Mahmood Zuhdi, Ahmad Wafi; Zuhdi, Ahmad

    2015-06-29

    Wireless communication is a form of communication that has been around for over hundreds of years and is the fastest growing segment of the communication industry. Today, wireless communication has become an essential ...

  10. The initial freezing point temperature of beef rises with the rise in pH: a short communication.

    PubMed

    Farouk, M M; Kemp, R M; Cartwright, S; North, M

    2013-05-01

    This study tested the hypothesis that the initial freezing point temperature of meat is affected by pH. Sixty four bovine M. longissimus thoracis et lumborum were classified into two ultimate pH groups: low (<5.8) and high pH (>6.2) and their cooling and freezing point temperatures were determined. The initial freezing temperatures for beef ranged from -0.9 to -1.5°C (?=0.6°C) with the higher and lower temperatures associated with high and low ultimate pH respectively. There was a significant correlation (r=+0.73, P<0.01) between beef pH and freezing point temperature in the present study. The outcome of this study has implications for the meat industry where evidence of freezing (ice formation) in a shipment as a result of high pH meat could result in a container load of valuable chilled product being downgraded to a lower value frozen product. PMID:23410892

  11. Means and method for characterizing high power, ultra short laser pulses in a real time, on line manner

    DOEpatents

    Veligdan, James T. (Manorville, NY)

    1994-01-01

    An ultra short (<10 ps), high power laser pulse is temporally characterized by a system that uses a physical measurement of a wavefront that has been altered in a known manner. The system includes a first reflection switch to remove a portion of a pulse from a beam of pulses, then includes a second reflection switch, operating in a mode that is opposite to the first reflection switch, to slice off a portion of that removed portion. The sliced portion is then directed to a measuring device for physical measurement. The two reflection switches are arranged with respect to each other and with respect to the beam of ultra short pulses such that physical measurement of the sliced portion is related to the temporal measurement of the ultra short pulse by a geometric or trigonometric relationship. The reflection switches are operated by a control pulse that is directed to impinge on each of the reflection switches at a 90.degree. angle of incidence.

  12. Calibration of the effective spring constant of ultra-short cantilevers for a high-speed atomic force microscope

    NASA Astrophysics Data System (ADS)

    Song, Yun-Peng; Wu, Sen; Xu, Lin-Yan; Zhang, Jun-Ming; Dorantes-Gonzalez, Dante J.; Fu, Xing; Hu, Xiao-Dong

    2015-06-01

    Ultra-short cantilevers are a new type of cantilever designed for the next generation of high-speed atomic force microscope (HS-AFM). Ultra-short cantilevers have smaller dimensions and higher resonant frequency than conventional AFM cantilevers. Moreover, their geometry may also be different from the conventional beam-shape or V-shape. These changes increase the difficulty of determining the spring constant for ultra-short cantilevers, and hence limit the accuracy and precision of force measurement based on a HS-AFM. This paper presents an experimental method to calibrate the effective spring constant of ultra-short cantilevers. By using a home-made AFM head, the cantilever is bent against an electromagnetic compensation balance under servo control. Meanwhile the bending force and the cantilever deflection are synchronously measured by the balance and the optical lever in the AFM head, respectively. Then the effective spring constant is simply determined as the ratio of the force to the corresponding deflection. Four ultra-short trapezoid shape cantilevers were calibrated using this method. A quantitative uncertainty analysis showed that the combined relative standard uncertainty of the calibration result is less than 2%, which is better than the uncertainty of any previously reported techniques.

  13. Short Communication: Expression of Transporters and Metabolizing Enzymes in the Female Lower Genital Tract: Implications for Microbicide Research

    PubMed Central

    Zhou, Tian; Hu, Minlu; Cost, Marilyn; Poloyac, Samuel

    2013-01-01

    Abstract Topical vaginal microbicides have been considered a promising option for preventing the male-to-female sexual transmission of HIV; however, clinical trials to date have not clearly demonstrated robust and reproducible effectiveness results. While multiple approaches may help enhance product effectiveness observed in clinical trials, increasing the drug exposure in lower genital tract tissues is a compelling option, given the difficulty in achieving sufficient drug exposure and positive correlation between tissue exposure and microbicide efficacy. Since many microbicide drug candidates are substrates of transporters and/or metabolizing enzymes, there is emerging interest in improving microbicide exposure and efficacy through local modulation of transporters and enzymes in the female lower genital tract. However, no systematic information on transporter/enzyme expression is available for ectocervical and vaginal tissues of premenopausal women, the genital sites most relevant to microbicide drug delivery. The current study utilized reverse transcriptase polymerase chain reaction (RT-PCR) to examine the mRNA expression profile of 22 transporters and 19 metabolizing enzymes in premenopausal normal human ectocervix and vagina. Efflux and uptake transporters important for antiretroviral drugs, such as P-gp, BCRP, OCT2, and ENT1, were found to be moderately or highly expressed in the lower genital tract as compared to liver. Among the metabolizing enzymes examined, most CYP isoforms were not detected while a number of UGTs such as UGT1A1 were highly expressed. Moderate to high expression of select transporters and enzymes was also observed in mouse cervix and vagina. The implications of this information on microbicide research is also discussed, including microbicide pharmacokinetics, the utilization of the mouse model in microbicide screening, as well as the in vivo functional studies of cervicovaginal transporters and enzymes. PMID:23607746

  14. Short communication: expression of transporters and metabolizing enzymes in the female lower genital tract: implications for microbicide research.

    PubMed

    Zhou, Tian; Hu, Minlu; Cost, Marilyn; Poloyac, Samuel; Rohan, Lisa

    2013-11-01

    Topical vaginal microbicides have been considered a promising option for preventing the male-to-female sexual transmission of HIV; however, clinical trials to date have not clearly demonstrated robust and reproducible effectiveness results. While multiple approaches may help enhance product effectiveness observed in clinical trials, increasing the drug exposure in lower genital tract tissues is a compelling option, given the difficulty in achieving sufficient drug exposure and positive correlation between tissue exposure and microbicide efficacy. Since many microbicide drug candidates are substrates of transporters and/or metabolizing enzymes, there is emerging interest in improving microbicide exposure and efficacy through local modulation of transporters and enzymes in the female lower genital tract. However, no systematic information on transporter/enzyme expression is available for ectocervical and vaginal tissues of premenopausal women, the genital sites most relevant to microbicide drug delivery. The current study utilized reverse transcriptase polymerase chain reaction (RT-PCR) to examine the mRNA expression profile of 22 transporters and 19 metabolizing enzymes in premenopausal normal human ectocervix and vagina. Efflux and uptake transporters important for antiretroviral drugs, such as P-gp, BCRP, OCT2, and ENT1, were found to be moderately or highly expressed in the lower genital tract as compared to liver. Among the metabolizing enzymes examined, most CYP isoforms were not detected while a number of UGTs such as UGT1A1 were highly expressed. Moderate to high expression of select transporters and enzymes was also observed in mouse cervix and vagina. The implications of this information on microbicide research is also discussed, including microbicide pharmacokinetics, the utilization of the mouse model in microbicide screening, as well as the in vivo functional studies of cervicovaginal transporters and enzymes. PMID:23607746

  15. A High-Speed Optical Modem Communication System for CORK Seafloor Observatories

    NASA Astrophysics Data System (ADS)

    Farr, N.; Tivey, M.; Ware, J.; Pontbriand, C.; Pelletier, L. P.

    2014-12-01

    High-speed communications underwater is an increasing requirement for data intensive seafloor sensors. Acoustic modems provide dependable long-range communications underwater, but data rates are limited to <57Kbps. Free-water optical modems (OMs) offer high data rate, 10Mbps communications over a range of 200 m - a distance for ROVs, AUVs or wire-lowered packages to communicate without the need to directly plug-in or retrieve the instrument. Over the past 4 years, we have demonstrated the functionality and utility of OM technology using a CORK borehole observatory as a test case. A CORK represents all of the basic components required for a seafloor observatory: a stable environment for long-term continuous measurements of earth and ocean phenomena, access to a unique environment below the seafloor and a standard communication interface. The CORK-OM features a high-bandwidth, low-latency optical system based on LED emitters and PMT receivers and an acoustic command and control system. OM tests established a communication link from 20 to 200 meters range at rates of 1, 5 and 10 Mbps with no bit errors. The seafloor OM was plugged into the CORK's existing underwater wet mateable connector and provided additional power to the CORK to boost the data rate to 1 Hz from the normal 1 minute sample period. To communicate with the seafloor CORK-OM, a number of different modalities were used. One method was an OM mounted to a CTD frame on a lowered wire from a ship with an SDSL link over the conducting wire. Other methods utilized OMs mounted to both ROV Jason and submersible Alvin. We deployed OMs at two CORKs in 2012 in the northeast pacific at sites 857D and 1025C. The CORKs were visited in 2013 by a vessel of opportunity to download data and were put into sleep mode. The CORKs were revisited in 2014, woken up and successfully interrogated for data. ALVIN retrieved the CORK-OMs for corrosion, biofouling and battery performance assessment. We also performed tests of a next generation OM using a deployed seafloor modem and AUV Sentry. A complete lambertian optical field was quantitatively mapped by Sentry and test data was successfully downloaded from 20 to 150 m slant range. The AUV modality demonstrates the capability of 'data-mule' operations to autonomously recover data from a seafloor observatory with minimal human intervention.

  16. Short communication: 3-phenyllactic acid production in milk by Pediococcus pentosaceus SK25 during laboratory fermentation process.

    PubMed

    Yu, Shuhuai; Zhou, Chen; Zhang, Tao; Jiang, Bo; Mu, Wanmeng

    2015-02-01

    3-Phenyllactic acid (PLA) is a broad-spectrum antimicrobial compound, produced by a wide range of lactic acid bacteria. A novel lactic acid bacteria strain with high PLA-producing ability, Pediococcus pentosaceus SK25, was isolated from traditional Chinese pickles. When grown in de Man, Rogosa, Sharpe broth at 30°C for 36h, this strain produced 135.6mg/L of PLA. Using this strain as starter for milk fermentation, 47.2mg/L of PLA was produced after fermentation for 12h. The PLA production was significantly improved by phenylalanine supplement, but was completely inhibited by tyrosine supplement. PMID:25434344

  17. The High-Performance Computing and Communications program, the national information infrastructure and health care.

    PubMed Central

    Lindberg, D A; Humphreys, B L

    1995-01-01

    The High-Performance Computing and Communications (HPCC) program is a multiagency federal effort to advance the state of computing and communications and to provide the technologic platform on which the National Information Infrastructure (NII) can be built. The HPCC program supports the development of high-speed computers, high-speed telecommunications, related software and algorithms, education and training, and information infrastructure technology and applications. The vision of the NII is to extend access to high-performance computing and communications to virtually every U.S. citizen so that the technology can be used to improve the civil infrastructure, lifelong learning, energy management, health care, etc. Development of the NII will require resolution of complex economic and social issues, including information privacy. Health-related applications supported under the HPCC program and NII initiatives include connection of health care institutions to the Internet; enhanced access to gene sequence data; the "Visible Human" Project; and test-bed projects in telemedicine, electronic patient records, shared informatics tool development, and image systems. PMID:7614116

  18. In-situ short-circuit protection system and method for high-energy electrochemical cells

    DOEpatents

    Gauthier, Michel (La Prairie, CA); Domroese, Michael K. (South St. Paul, MN); Hoffman, Joseph A. (Minneapolis, MN); Lindeman, David D. (Hudson, WI); Noel, Joseph-Robert-Gaetan (St-Hubert, CA); Radewald, Vern E. (Austin, TX); Rouillard, Jean (Saint-Luc, CA); Rouillard, Roger (Beloeil, CA); Shiota, Toshimi (St. Bruno, CA); Trice, Jennifer L. (Eagan, MN)

    2003-04-15

    An in-situ thermal management system for an energy storage device. The energy storage device includes a plurality of energy storage cells each being coupled in parallel to common positive and negative connections. Each of the energy storage cells, in accordance with the cell's technology, dimensions, and thermal/electrical properties, is configured to have a ratio of energy content-to-contact surface area such that thermal energy produced by a short-circuit in a particular cell is conducted to a cell adjacent the particular cell so as to prevent the temperature of the particular cell from exceeding a breakdown temperature. In one embodiment, a fuse is coupled in series with each of a number of energy storage cells. The fuses are activated by a current spike capacitively produced by a cell upon occurrence of a short-circuit in the cell, thereby electrically isolating the short-circuited cell from the common positive and negative connections.

  19. In-situ short circuit protection system and method for high-energy electrochemical cells

    DOEpatents

    Gauthier, Michel (La Prairie, CA); Domroese, Michael K. (South St. Paul, MN); Hoffman, Joseph A. (Minneapolis, MN); Lindeman, David D. (Hudson, WI); Noel, Joseph-Robert-Gaetan (St-Hubert, CA); Radewald, Vern E. (Austin, TX); Rouillard, Jean (Saint-Luc, CA); Rouillard, Roger (Beloeil, CA); Shiota, Toshimi (St. Bruno, CA); Trice, Jennifer L. (Eagan, MN)

    2000-01-01

    An in-situ thermal management system for an energy storage device. The energy storage device includes a plurality of energy storage cells each being coupled in parallel to common positive and negative connections. Each of the energy storage cells, in accordance with the cell's technology, dimensions, and thermal/electrical properties, is configured to have a ratio of energy content-to-contact surface area such that thermal energy produced by a short-circuit in a particular cell is conducted to a cell adjacent the particular cell so as to prevent the temperature of the particular cell from exceeding a breakdown temperature. In one embodiment, a fuse is coupled in series with each of a number of energy storage cells. The fuses are activated by a current spike capacitively produced by a cell upon occurrence of a short-circuit in the cell, thereby electrically isolating the short-circuited cell from the common positive and negative connections.

  20. A high-average power tapered FEL amplifier at submillimeter frequencies using sheet electron beams and short-period wigglers

    SciTech Connect

    Bidwell, S.W.; Radack, D.J.; Antonsen, T.M. Jr.; Booske, J.H.; Carmel, Y.; Destler, W.W.; Granatstein, V.L.; Levush, B.; Latham, P.E.; Zhang, Z.X.

    1990-01-01

    A high-average-power FEL amplifier operating at submillimeter frequencies is under development at the University of Maryland. Program goals are to produce a CW, {approximately}1 MW, FEL amplifier source at frequencies between 280 GHz and 560 GHz. To this end, a high-gain, high-efficiency, tapered FEL amplifier using a sheet electron beam and a short-period (superconducting) wiggler has been chosen. Development of this amplifier is progressing in three stages: (1) beam propagation through a long length ({approximately}1 m) of short period ({lambda}{sub {omega}} = 1 cm) wiggler, (2) demonstration of a proof-of-principle amplifier experiment at 98 GHz, and (3) designs of a superconducting tapered FEL amplifier meeting the ultimate design goal specifications. 17 refs., 1 fig., 1 tab.

  1. Short communication: radio frequency dielectric heating of nonfat dry milk affects solubility and whey protein nitrogen index.

    PubMed

    Chen, C; Michael, M; Phebus, R K; Thippareddi, H; Subbiah, J; Birla, S L; Schmidt, K A

    2013-03-01

    The US infant formula market is estimated at over $3.5 billion, of which 75% are dairy-based formulas. Dried dairy powders pose a significant food safety risk, with Cronobacter sakazakii and Salmonella spp. being pathogens of particular concern. Radio frequency dielectric heating (RFDH) can provide rapid, uniform heat treatment of dry powders; thus, it potentially may be used as a postprocess lethality treatment for nonfat dry milk (NDM) or powdered infant formula. Because RFDH is a heat treatment, the functionality of the NDM may be altered and should be evaluated. High heat- and low heat-NDM were RFDH processed at temperatures ranging from 75 to 90°C for 5 to 125 min. Products were then assessed for whey protein nitrogen index (WPNI), solubility, and color. In low heat-NDM, RFDH decreased WPNI and solubility if the process was done at ? 80°C; however, in high heat-NDM, RFDH had a greater effect on solubility than WPNI and some color properties were altered. Further investigation of RFDH is merited to validate its application as a pathogen control process for NDM across processing parameters that result in acceptable functional properties for infant formula and other food products containing NDM. PMID:23332848

  2. Short Communication: Transmitted Drug Resistance and Molecular Epidemiology in Antiretroviral Naive HIV Type 1-Infected Patients in Rhode Island

    PubMed Central

    Tashima, Karen; Cartwright, Charles P.; Gillani, Fizza S.; Mintz, Orli; Zeller, Kimberly; Kantor, Rami

    2011-01-01

    Abstract Transmission of HIV-1 drug resistance has important clinical and epidemiological consequences including earlier treatment failure and forward transmission of resistance strains in high-risk groups. To evaluate the prevalence and molecular epidemiology of transmitted drug resistance in Rhode Island, we collected genotypic, demographic, clinical, and laboratory data from treatment-naive individuals presenting to the largest outpatient HIV clinic in the state from January 2007 to November 2007. Sequences from 35 treatment-naive individuals were available, 83% of whom were men who had sex with men (MSM). All sequences were HIV-1 subtype B. Drug resistance mutations were identified in 7/35 [20%; 95% confidence interval (CI), 0.08–0.37] patients, six of whom had K103N. Two phylogenetic transmission clusters were found, involving 17% (6/35) of individuals, three in each cluster. We did not find an association between belonging to a cluster and age, gender, AIDS-defining illness, CD4 cell count, or viral load. Drug resistance mutations were more commonly observed in transmission clusters (p?=?0.08). Individuals in one cluster all had K103N and were MSM who had attended local bathhouses. Individuals forming clusters were significantly more likely to have visited a bathhouse compared to nonclusters (p?=?0.02). The prevalence of transmitted drug resistance in Rhode Island is high, further justifying genotypic testing on presentation to care and prior to treatment initiation. Molecular epidemiological analysis and association of resistance with phylogenetic networks using data obtained for clinical purposes may serve as useful tools for the prevention of drug resistance transmission and for contact tracing. PMID:20954831

  3. Small-angle stability analysis of a linear control system for a high power communication satellite

    NASA Technical Reports Server (NTRS)

    Omalley, T. A.

    1972-01-01

    A small angle stability analysis is presented for one particular configuration of a high power communication satellite having a linear control system. Both the central body and the solar array are treated as rigid bodies. The control system studied consists of three-axis control of the central body and one-axis control of the solar array rotation relative to the central body. The results yield preliminary indications of the relation of stability to satellite inertias and control gains.

  4. Sustained Silent Reading and Young Adult Short Stories for High School Classes.

    ERIC Educational Resources Information Center

    Jensen, Terry L.; Jensen, Valarie S.

    2002-01-01

    Describes the implementation of a version of Sustained Silent Reading (SSR), called the DEAR (Drop Everything And Read) program, throughout their school. Presents their experience with the program in the KWL format (what we KNOW, what we WANTED to know, and what we LEARNED). Provides a bibliography of 12 young adult short stories used in the…

  5. Study of short haul high-density V/STOL transportation systems. Volume 2: Appendices

    NASA Technical Reports Server (NTRS)

    Solomon, H. L.

    1972-01-01

    Essential supporting data to the short haul transportation study are presented. The specific appendices are arena characteristics, aerospace transportation analysis computer program, economics, model calibration, STOLport siting and services path selection, STOL schedule definition, tabulated California corridor results, and tabulated Midwest arena results.

  6. ScalaTrace: Scalable Compression and Replay of Communication Traces for High Performance Computing

    SciTech Connect

    Noeth, M; Ratn, P; Mueller, F; Schulz, M; de Supinski, B R

    2008-05-16

    Characterizing the communication behavior of large-scale applications is a difficult and costly task due to code/system complexity and long execution times. While many tools to study this behavior have been developed, these approaches either aggregate information in a lossy way through high-level statistics or produce huge trace files that are hard to handle. We contribute an approach that provides orders of magnitude smaller, if not near-constant size, communication traces regardless of the number of nodes while preserving structural information. We introduce intra- and inter-node compression techniques of MPI events that are capable of extracting an application's communication structure. We further present a replay mechanism for the traces generated by our approach and discuss results of our implementation for BlueGene/L. Given this novel capability, we discuss its impact on communication tuning and beyond. To the best of our knowledge, such a concise representation of MPI traces in a scalable manner combined with deterministic MPI call replay are without any precedent.

  7. Short communication: Protease activity measurement in milk as a diagnostic test for clinical mastitis in dairy cows.

    PubMed

    Koop, G; van Werven, T; Roffel, S; Hogeveen, H; Nazmi, K; Bikker, F J

    2015-07-01

    Due to the increasing use of automated milking systems, automated detection of clinical mastitis is becoming more important. Various in- or on-line diagnostic tests are in use, but generally suffer from false mastitis alerts. In this study, we explored a new diagnostic approach based on measurement of protease activity using fluorogenic protease substrates, which can be performed on site, at high speed, and at low costs. Samples from cows with clinical mastitis submitted for bacteriological culture at the University Farm Animal Practice were collected during several months and kept at -20°C until protease activity measurement. A reference set of milk samples from clinically healthy cows were collected on 9 different farms and were tested for protease activity directly and after freezing at -20°C to allow for comparison with the samples from clinical cases. The protease activity in mastitic milk samples was significantly higher than in samples from healthy animals. Based on 71 clinical mastitis samples and 180 milk samples from clinically healthy quarters, the area under the receiver-operating characteristic curve was estimated to be between 0.88 and 0.90, and at a threshold of 38 fluorescence per minute the test had a specificity of 0.99 at a sensitivity of 0.58. Protease activity measured in fresh milk from clinically healthy cows was significantly associated with somatic cell count and parity, but not with electrical conductivity, whereas protease activity in milk that had been frozen was statistically significantly associated with all 3 parameters. This study indicates that protease activity measurement as a stand-alone test can be used for detecting mastitis samples, using milk samples that have been frozen. Because protease activity acts in part on a different biological mechanism than somatic cell count or electrical conductivity, this test may increase the accuracy of mastitis diagnosis in combination with currently available in- or on-line tests in automated milking systems. PMID:25981067

  8. Short communication: Grazing pattern of dairy cows that were selected for divergent residual feed intake as calves.

    PubMed

    Gregorini, P; Waghorn, G C; Kuhn-Sherlock, B; Romera, A J; Macdonald, K A

    2015-09-01

    The aim of this study was to investigate and assess differences in the grazing pattern of 2 groups of mature dairy cows selected as calves for divergent residual feed intake (RFI). Sixteen Holstein-Friesian cows (471±31kg of body weight, 100 d in milk), comprising 8 cows selected as calves (6-8 mo old) for low (most efficient: CSCLowRFI) and 8 cows selected as calves for high (least efficient: CSCHighRFI) RFI, were used for the purpose of this study. Cows (n=16) were managed as a single group, and strip-grazed (24-h pasture allocation at 0800h) a perennial ryegrass sward for 31 d, with measurements taken during the last 21 d. All cows were equipped with motion sensors for the duration of the study, and jaw movements were measured for three 24-h periods during 3 random nonconsecutive days. Measurements included number of steps and jaw movements during grazing and rumination, plus fecal particle size distribution. Jaw movements were analyzed to identify bites, mastication (oral processing of ingesta) during grazing bouts, chewing during rumination, and to calculate grazing and rumination times for 24-h periods. Grazing and walking behavior were also analyzed in relation to the first meal of the day after the new pasture was allocated. Measured variables were subjected to multivariate analysis. Cows selected for low RFI as calves appeared to (a) prioritize grazing and rumination over idling; (b) take fewer steps, but with a higher proportion of grazing steps at the expense of nongrazing steps; and (c) increase the duration of the first meal and commenced their second meal earlier than CSCHighRFI. The CSCLowRFI had fewer jaw movements during eating (39,820 vs. 45,118 for CSCLowRFI and CSCHighRFI, respectively), more intense rumination (i.e., 5 more chews per bolus), and their feces had 30% less large particles than CSCHighRFI. These results suggest that CSCLowRFI concentrate their grazing activity to the time when fresh pasture is allocated, and graze more efficiently by walking and masticating less, hence they are more efficient grazers than CSCHighRFI. PMID:26162793

  9. Performance analysis of communication links based on VCSEL and silicon photonics technology for high-capacity data-intensive scenario.

    PubMed

    Boletti, A; Boffi, P; Martelli, P; Ferrario, M; Martinelli, M

    2015-01-26

    To face the increased demand for bandwidth, cost-effectiveness and simplicity of future Ethernet data communications, a comparison between two different solutions based on directly-modulated VCSEL sources and Silicon Photonics technologies is carried out. Also by exploiting 4-PAM modulation, the transmission of 50-Gb/s and beyond capacity per channel is analyzed by means of BER performance. Applications for optical backplane, very short reach and in case of client-optics networks and intra and inter massive data centers communications (up to 10 km) are taken into account. A comparative analysis based on the power consumption is also proposed. PMID:25835935

  10. First use of high charge states for mass measurements of short-lived nuclides in a Penning trap.

    PubMed

    Ettenauer, S; Simon, M C; Gallant, A T; Brunner, T; Chowdhury, U; Simon, V V; Brodeur, M; Chaudhuri, A; Mané, E; Andreoiu, C; Audi, G; López-Urrutia, J R Crespo; Delheij, P; Gwinner, G; Lapierre, A; Lunney, D; Pearson, M R; Ringle, R; Ullrich, J; Dilling, J

    2011-12-30

    Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to q=8-12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed ? emitter 74Rb (T(1/2)=65??ms). The determination of its atomic mass and an improved Q(EC) value are presented. PMID:22243307

  11. Measurements of plasma-wave generation using a short-pulse high-intensity laser beat wave

    NASA Astrophysics Data System (ADS)

    Walton, B.; Najmudin, Z.; Wei, M. S.; Marle, C.; Kingham, R. J.; Krushelnick, K.; Dangor, A. E.; Clarke, R. J.; Poulter, M. J.; Hernandez-Gomez, C.; Hawkes, S.; Neely, D.; Collier, J. L.; Danson, C. N.; Fritzler, S.; Malka, V.

    2006-01-01

    Experiments to examine the generation of relativistic plasma waves via a high-intensity short-pulse beat-wave scheme are described in detail. The pulse stretcher of the Vulcan chirped-pulse amplification (CPA) laser system was modified to produce two frequency, 3ps pulses focusable to intensities up to 1018Wcm-2. Short high-intensity pulses were used to avoid limitations to the plasma-wave amplitude due to the modulational instability. Two experiments were undertaken, at 3 and 10TW, with the generation of plasma waves diagnosed by measuring the sidebands produced in the spectrum of the forward scattered beam. A resonance in the sideband signal was observed for an initial plasma density higher than expected for the given beat frequency. This resonance shift can be attributed to transverse ponderomotive expulsion of plasma electrons from the laser focal region. A monotonically increasing background was also observed, which was due to nonresonant cross-phase modulation.

  12. First Use of High Charge States for Mass Measurements of Short-Lived Nuclides in a Penning Trap

    SciTech Connect

    Ettenauer, S.; Gallant, A. T.; Dilling, J.; Simon, M. C.; Chaudhuri, A.; Mane, E.; Delheij, P.; Pearson, M. R.; Brunner, T.; Chowdhury, U.; Simon, V. V.; Brodeur, M.; Andreoiu, C.; Audi, G.; Lopez-Urrutia, J. R. Crespo; Ullrich, J.; Gwinner, G.; Lapierre, A.; Lunney, D.; Ringle, R.

    2011-12-30

    Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to q=8-12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed {beta} emitter {sup 74}Rb (T{sub 1/2}=65 ms). The determination of its atomic mass and an improved Q{sub EC} value are presented.

  13. Energy-efficient wireless communication In this chapter we present an energy-efficient highly adaptive network

    E-print Network

    Havinga, Paul J.M.

    Energy-efficient wireless communication In this chapter we present an energy-efficient highly substantial research in the hardware aspects of mobile communications energy-efficiency, such as low-power electronics, power-down modes, and energy efficient modulation. However, due to fundamental physical

  14. Quality of Communication Life in Adolescents with High-Functioning Autism and Asperger Syndrome: A Feasibility Study

    ERIC Educational Resources Information Center

    Burgess, Sloane; Turkstra, Lyn S.

    2010-01-01

    Purpose: This study was designed to evaluate the feasibility of using the American Speech-Language-Hearing Association's Quality of Communication Life Scale (QCL; Paul et al., 2004) for a group of individuals with developmental communication disorders--adolescents with high-functioning autism/Asperger syndrome (HFA/AS). Perceptions of quality of…

  15. The Relative Importance of Selected Communication Skills for Adolescents' Interactions with Their Teachers: High School Teachers' Opinions.

    ERIC Educational Resources Information Center

    Reed, Vicki A.; Spicer, Lynette

    2003-01-01

    High school teachers (n=143) ranked 14 communication skills according to the perceived order of importance for Grade 10 adolescents' communication with them as teachers. Teachers tended to perceive skills associated with discourse management strategies as relatively more important than other skills. Science teachers ranked turn taking higher than…

  16. A High Speed Quantum Communication Testbed Carl J. Williams, Xiao Tang, Mikko Hiekkero, Julie Rouzaud, Richang Lu, Andreas Goedecke,

    E-print Network

    of experience with quantum cryptographic key exchange in a realistic modern network environmentA High Speed Quantum Communication Testbed Carl J. Williams, Xiao Tang, Mikko Hiekkero, Julie of the NIST Quantum Communication Testbed (QCT) facility. QCT is a facility for exploring quantum

  17. Temporal Narrowing of Neutrons Produced by High-Intensity Short-Pulse Lasers.

    PubMed

    Higginson, D P; Vassura, L; Gugiu, M M; Antici, P; Borghesi, M; Brauckmann, S; Diouf, C; Green, A; Palumbo, L; Petrascu, H; Sofia, S; Stardubtsev, M; Willi, O; Kar, S; Negoita, F; Fuchs, J

    2015-07-31

    The production of neutron beams having short temporal duration is studied using ultraintense laser pulses. Laser-accelerated protons are spectrally filtered using a laser-triggered microlens to produce a short duration neutron pulse via nuclear reactions induced in a converter material (LiF). This produces a ?3??ns duration neutron pulse with 10(4)??n/MeV/sr/shot at 0.56 m from the laser-irradiated proton source. The large spatial separation between the neutron production and the proton source allows for shielding from the copious and undesirable radiation resulting from the laser-plasma interaction. This neutron pulse compares favorably to the duration of conventional accelerator sources and should scale up with, present and future, higher energy laser facilities to produce brighter and shorter neutron beams for ultrafast probing of dense materials. PMID:26274423

  18. Temporal Narrowing of Neutrons Produced by High-Intensity Short-Pulse Lasers

    NASA Astrophysics Data System (ADS)

    Higginson, D. P.; Vassura, L.; Gugiu, M. M.; Antici, P.; Borghesi, M.; Brauckmann, S.; Diouf, C.; Green, A.; Palumbo, L.; Petrascu, H.; Sofia, S.; Stardubtsev, M.; Willi, O.; Kar, S.; Negoita, F.; Fuchs, J.

    2015-07-01

    The production of neutron beams having short temporal duration is studied using ultraintense laser pulses. Laser-accelerated protons are spectrally filtered using a laser-triggered microlens to produce a short duration neutron pulse via nuclear reactions induced in a converter material (LiF). This produces a ˜3 ns duration neutron pulse with 104 n /MeV /sr /shot at 0.56 m from the laser-irradiated proton source. The large spatial separation between the neutron production and the proton source allows for shielding from the copious and undesirable radiation resulting from the laser-plasma interaction. This neutron pulse compares favorably to the duration of conventional accelerator sources and should scale up with, present and future, higher energy laser facilities to produce brighter and shorter neutron beams for ultrafast probing of dense materials.

  19. Observation of nuclear dechanneling length reduction for high energy protons in a short bent crystal

    NASA Astrophysics Data System (ADS)

    Scandale, W.; Arduini, G.; Butcher, M.; Cerutti, F.; Garattini, M.; Gilardoni, S.; Lari, L.; Lechner, A.; Losito, R.; Masi, A.; Mereghetti, A.; Metral, E.; Mirarchi, D.; Montesano, S.; Redaelli, S.; Rossi, R.; Schoofs, P.; Smirnov, G.; Bagli, E.; Bandiera, L.; Baricordi, S.; Dalpiaz, P.; Germogli, G.; Guidi, V.; Mazzolari, A.; Vincenzi, D.; Claps, G.; Dabagov, S.; Hampai, D.; Murtas, F.; Cavoto, G.; Iacoangeli, F.; Ludovici, L.; Santacesaria, R.; Valente, P.; Galluccio, F.; Afonin, A. G.; Chesnokov, Yu. A.; Maisheev, V. A.; Sandomirskiy, Yu. E.; Yanovich, A. A.; Yazynin, I. A.; Kovalenko, A. D.; Taratin, A. M.; Gavrikov, Yu. A.; Ivanov, Yu. M.; Lapina, L. P.; Ferguson, W.; Fulcher, J.; Hall, G.; Pesaresi, M.; Raymond, M.; Bolognini, D.; Hasan, S.; Prest, M.; Vallazza, E.

    2015-04-01

    Deflection of 400 GeV/c protons by a short bent silicon crystal was studied at the CERN SPS. It was shown that the dechanneling probability increases while the dechanneling length decreases with an increase of incident angles of particles relative to the crystal planes. The observation of the dechanneling length reduction provides evidence of the particle population increase at the top levels of transverse energies in the potential well of the planar channels.

  20. Incorporating risk communication into highly pathogenic avian influenza preparedness and response efforts.

    PubMed

    Voss, Shauna J; Malladi, Sasidhar; Sampedro, Fernando; Snider, Tim; Goldsmith, Timothy; Hueston, William D; Lauer, Dale C; Halvorson, David A

    2012-12-01

    A highly pathogenic avian influenza (HPAI) outbreak in the United States will initiate a federal emergency response effort that will consist of disease control and eradication efforts, including quarantine and movement control measures. These movement control measures will not only apply to live animals but also to animal products. However, with current egg industry "just-in-time" production practices, limited storage is available to hold eggs. As a result, stop movement orders can have significant unintended negative consequences, including severe disruptions to the food supply chain. Because stakeholders' perceptions of risk vary, waiting to initiate communication efforts until an HPAI event occurs can hinder disease control efforts, including the willingness of producers to comply with the response, and also can affect consumers' demand for the product. A public-private-academic partnership was formed to assess actual risks involved in the movement of egg industry products during an HPAI event through product specific, proactive risk assessments. The risk analysis process engaged a broad representation of stakeholders and promoted effective risk management and communication strategies before an HPAI outbreak event. This multidisciplinary team used the risk assessments in the development of the United States Department of Agriculture, Highly Pathogenic Avian Influenza Secure Egg Supply Plan, a comprehensive response plan that strives to maintain continuity of business. The collaborative approach that was used demonstrates how a proactive risk communication strategy that involves many different stakeholders can be valuable in the development of a foreign animal disease response plan and build working relationships, trust, and understanding. PMID:23402134

  1. FPGA implementation of high-performance QC-LDPC decoder for optical communications

    NASA Astrophysics Data System (ADS)

    Zou, Ding; Djordjevic, Ivan B.

    2015-01-01

    Forward error correction is as one of the key technologies enabling the next-generation high-speed fiber optical communications. Quasi-cyclic (QC) low-density parity-check (LDPC) codes have been considered as one of the promising candidates due to their large coding gain performance and low implementation complexity. In this paper, we present our designed QC-LDPC code with girth 10 and 25% overhead based on pairwise balanced design. By FPGAbased emulation, we demonstrate that the 5-bit soft-decision LDPC decoder can achieve 11.8dB net coding gain with no error floor at BER of 10-15 avoiding using any outer code or post-processing method. We believe that the proposed single QC-LDPC code is a promising solution for 400Gb/s optical communication systems and beyond.

  2. High speed QPPM direct detection optical communication receivers for FSDD intersatellite links

    NASA Technical Reports Server (NTRS)

    Davidson, Frederic M.; Sun, Xiaoli

    1993-01-01

    This final report consists of four separate reports, one for each project involved in this contract. The first report is entitled '325 Mbps QPPM (quaternary pulse position modulation) Direct Detection Free Space Optical Communication Encoder and Receiver,' which was our primary work. The second report is entitled 'Test Results of the 325 Mbps QPPM High Speed Data Transmission GaAs ASICs,' which describes our work in connection with Galaxy Microsystems, Inc. who produced these ASICs for NASA. The third report, 'Receiver Performance Analysis of BPPM Optical Communication Systems Using 1.3 micron Wavelength Transmitter and InGaAs PIN Photodiodes,' was prepared at the request of the NASA/Photonics Branch for their efforts in upgrading the 1773 optical fiber data bus. The fourth report, 'Photomultiplier Tubes for Use at 1.064 micron Wavelength,' was also prepared at the request of the NASA/Photonics Branch as a research project.

  3. Author's personal copy Short communication

    E-print Network

    to estimate the local air pollution in 1863 as 0.17 Æ 0.05 mg mÀ3 (Harrison and Aplin, 2002 from any smoke-induced decrease in air conductivity. Hence, in polluted air, the PG can greatly exceed Keywords: Black carbon Smoke proxy Lord Kelvin Historical pollution Aerosol Atmospheric electricity a b

  4. Author's personal copy Short communication

    E-print Network

    Manga, Michael

    history: Received 5 February 2010 Accepted 13 May 2010 Available online 27 May 2010 Keywords: pumice heat transfer coefficients for natural pumice clasts are reduced by a factor of 2­3 for particles with similar

  5. 4 Gbps direct modulation of 450 nm GaN laser for high-speed visible light communication.

    PubMed

    Lee, Changmin; Zhang, Chong; Cantore, Michael; Farrell, Robert M; Oh, Sang Ho; Margalith, Tal; Speck, James S; Nakamura, Shuji; Bowers, John E; DenBaars, Steven P

    2015-06-15

    We demonstrate high-speed data transmission with a commercial high power GaN laser diode at 450 nm. 2.6 GHz bandwidth was achieved at an injection current of 500 mA using a high-speed visible light communication setup. Record high 4 Gbps free-space data transmission rate was achieved at room temperature. PMID:26193595

  6. Dynamics of short eccentric plain seals with high axial Reynolds number. [for Space Shuttle engine hydrogen fuel turbopump

    NASA Technical Reports Server (NTRS)

    Allaire, P. E.; Lee, C. C.; Gunter, E. J.

    1978-01-01

    Plain seals with high axial flow rates produce large stiffness and damping coefficients that can help stabilize high-speed rotating machinery. When the shaft is eccentric in the seal, a Bernoulli effect low-pressure region occurs on the large-clearance side of the shaft. A fluid-restoring force tends to center the shaft and reduce vibrations. This work extends the previous theory for short plain centered seals to large eccentricities using a perturbation analysis. Surface roughness effects are also included. An analysis of seals used in the Space Shuttle main engine hydrogen fuel turbopump indicates the desirability of plain seals over the labyrinth type. Experimental results confirm this.

  7. High power test of a wideband diplexer with short-slotted metal half mirrors for electron cyclotron current drive system

    SciTech Connect

    Saigusa, M.; Atsumi, K.; Yamaguchi, T.; Nagashima, K.; Oda, Y.; Fukunari, M.; Sakamoto, K.

    2014-02-12

    The wideband high power diplexer has been developed for combining and fast switching of high power millimeter waves generated by a dual frequency gyrotron. The actual diplexer was tested at the frequency band of 170 GHz in low power. After adjusting a resonant frequency of diplexer for the gyrotron frequency, the evacuated wideband diplexer with short-slotted metal half mirrors was tested at an incident power of about 150 kW, a pulse duration of 30 ms and a frequency band of 170.2–170.3 GHz. Any discharge damage was not observed in the diplexer.

  8. Advances in high-throughput speed, low-latency communication for embedded instrumentation ( 7th Annual SFAF Meeting, 2012)

    SciTech Connect

    Jordan, Scott

    2012-06-01

    Scott Jordan on "Advances in high-throughput speed, low-latency communication for embedded instrumentation" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.

  9. Wide-area technologies and services in the Trans-Pacific High Data Rate (HDR) satellite communications experiments

    NASA Technical Reports Server (NTRS)

    Hsu, E.; Hung, C.; Kadowaki, N.; Yoshimura, N.; Takahashi, T.; Shopbell, P.; Walker, G.; Wellnitz, D.; Gary, P.; Clark, G.; Yoshikawa, M.; desJardins, R.; Gill, M.; Tatsumi, H.

    2000-01-01

    This paper describes the technologies and services used in the experiments and demonstrations using the Trans-Pacific high data rate satellite communications infrastructure, and how the environment tasked protocol adaptability, scalability, efficiency, interoperability, and robustness.

  10. Dispersed concentration of high-tech jobs in the new economy : the paradox of new information and communication technologies

    E-print Network

    Kang, Myoung-Gu, 1970-

    2006-01-01

    More high-tech firms are conducting their business over long distances due to the use of new information and communication technologies (ICT). However, regional scientists articulate that geographic proximity is still ...

  11. Advances in high-throughput speed, low-latency communication for embedded instrumentation ( 7th Annual SFAF Meeting, 2012)

    ScienceCinema

    Jordan, Scott [Physik Instrumente

    2013-02-11

    Scott Jordan on "Advances in high-throughput speed, low-latency communication for embedded instrumentation" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.

  12. Changes in corticospinal excitability with short-duration high-frequency electrical muscle stimulation: a transcranial magnetic stimulation study

    PubMed Central

    Miyata, Kazuhiro; Usuda, Shigeru

    2015-01-01

    [Purpose] Afferent input caused by electrical stimulation of a peripheral nerve or a muscle modulates corticospinal excitability. However, a long duration of stimulation is required to induce these effects. The purpose of this study was to investigate the effect of short-duration high-frequency electrical muscle stimulation (EMS) on corticospinal excitability through the measurement of motor evoked potentials (MEP) in young healthy subjects. [Subjects] Eleven healthy right-handed subjects participated in this study. [Methods] EMS was applied to the abductor pollicis brevis (APB) muscle at 100?Hz with a pulse width of 100 ?s for 120 s. The intensity of stimulation was just below the motor threshold. Transcranial magnetic stimulation was applied over the motor cortex, and MEP were recorded from the APB before, and immediately, 10, and 20?min after EMS. [Results] In the APB muscle, the MEP amplitude significantly decreased after EMS, and this effect lasted for 20?min. [Conclusion] The excitability of the corticospinal tract decreased after short-duration high-frequency EMS, and the effect lasted for 20?min. These results suggest that even short duration EMS can change the excitability of the corticospinal tract. PMID:26311936

  13. A highly reliable, autonomous data communication subsystem for an advanced information processing system

    NASA Technical Reports Server (NTRS)

    Nagle, Gail; Masotto, Thomas; Alger, Linda

    1990-01-01

    The need to meet the stringent performance and reliability requirements of advanced avionics systems has frequently led to implementations which are tailored to a specific application and are therefore difficult to modify or extend. Furthermore, many integrated flight critical systems are input/output intensive. By using a design methodology which customizes the input/output mechanism for each new application, the cost of implementing new systems becomes prohibitively expensive. One solution to this dilemma is to design computer systems and input/output subsystems which are general purpose, but which can be easily configured to support the needs of a specific application. The Advanced Information Processing System (AIPS), currently under development has these characteristics. The design and implementation of the prototype I/O communication system for AIPS is described. AIPS addresses reliability issues related to data communications by the use of reconfigurable I/O networks. When a fault or damage event occurs, communication is restored to functioning parts of the network and the failed or damage components are isolated. Performance issues are addressed by using a parallelized computer architecture which decouples Input/Output (I/O) redundancy management and I/O processing from the computational stream of an application. The autonomous nature of the system derives from the highly automated and independent manner in which I/O transactions are conducted for the application as well as from the fact that the hardware redundancy management is entirely transparent to the application.

  14. Short rotation willow coppice in Wales: High production under adverse environmental conditions?

    SciTech Connect

    Slater, F.M.; Hodson, R.W.; Randerson, P.F.

    1995-11-01

    The production of short rotation willow coppice in central Wales was once regarded as a vain hope rather than a distinct possibility. Research at the University of Wales, Cardiff, Field Station at Llysdinam in mid-Wales over the last four years has proven that it is possible to produce a commercially viable crop on very poor upland soils and at an altitude of almost 300m provided that lime and inorganic fertilizers are added. Because of the national need to find new routes for the disposal of sewage sludge, its addition to short rotation coppice serves the dual purpose of disposal and nutrient addition. Over the first two years of the sludging experiment, it was found that the addition of 300 m{sup 3}ha{sup -1} of digested sewage sludge significantly increased crop weight, at least in the first year. Unfortunately, the crop yields did not reach those obtained using inorganic fertilizers at the same site but it is suggested that a repeated application regime might improve overall crop yield.

  15. Communication Cement of high specific heat and high thermal conductivity, obtained by

    E-print Network

    Chung, Deborah D.L.

    conductivity is useful for the thermal insulation of buildings. On the other hand, concrete of high thermal not need thermal insulation. Therefore, concrete of high thermal conductivity is desirable for bridges polymeric admixtures such as latex (which is itself a thermal insulator), silica fume (which introduces

  16. Developments in Acoustic Navigation and Communication for High-Latitude Ocean Research

    NASA Astrophysics Data System (ADS)

    Gobat, J.; Lee, C.

    2006-12-01

    Developments in autonomous platforms (profiling floats, drifters, long-range gliders and propeller-driven vehicles) offer the possibility of unprecedented access to logistically difficult polar regions that challenge conventional techniques. Currently, however, navigation and telemetry for these platforms rely on satellite positioning and communications poorly suited for high-latitude applications where ice cover restricts access to the sea surface. A similar infrastructure offering basin-wide acoustic geolocation and telemetry would allow the community to employ autonomous platforms to address previously intractable problems in Arctic oceanography. Two recent efforts toward the development of such an infrastructure are reported here. As part of an observational array monitoring fluxes through Davis Strait, development of real-time RAFOS acoustic navigation for gliders has been ongoing since autumn 2004. To date, test deployments have been conducted in a 260 Hz field in the Pacific and 780 Hz fields off Norway and in Davis Strait. Real-time navigation accuracy of ~1~km is achievable. Autonomously navigating gliders will operate under ice cover beginning in autumn 2006. In addition to glider navigation development, the Davis Strait array moorings carry fixed RAFOS recorders to study propagation over a range of distances under seasonally varying ice cover. Results from the under-ice propagation and glider navigation experiments are presented. Motivated by the need to coordinate these types of development efforts, an international group of acousticians, autonomous platform developers, high-latitude oceanographers and marine mammal researchers gathered in Seattle, U.S.A. from 27 February -- 1 March 2006 for an NSF Office of Polar Programs sponsored Acoustic Navigation and Communication for High-latitude Ocean Research (ANCHOR) workshop. Workshop participants focused on summarizing the current state of knowledge concerning Arctic acoustics, navigation and communications, developing an overarching system specification to guide community-wide engineering efforts and establishing an active community and steering group to guide long-term engineering efforts and ensure interoperability. This presentation will summarize ANCHOR workshop findings.

  17. Short time scale thermal mechanical shock wave propagation in high performance microelectronic packaging configuration 

    E-print Network

    Nagaraj, Mahavir

    2004-11-15

    The generalized theory of thermoelasticity was employed to characterize the coupled thermal and mechanical wave propagation in high performance microelectronic packages. Application of a Gaussian heat source of spectral profile similar to high...

  18. Sirt1 mediates the effects of a short-term high-fat diet on the heart.

    PubMed

    Villarroya, Joan; Redondo-Angulo, Ibon; Iglesias, Roser; Giralt, Marta; Villarroya, Francesc; Planavila, Anna

    2015-11-01

    High-fat diet leads to development of cardiac dysfunction through molecular mechanisms poorly known. The aim of this study is to elucidate the early events in cardiac dysfunction caused by a high-fat diet, before massive alterations due to obesity and indirect mechanisms of heart damage take place. Moreover, we analyzed the role of Sirt1, a major mediator of cardiac gene regulation, in these effects. Short-term high-fat feeding (5 weeks) caused a similar mild increase in body weight and triglyceridaemia in wild-type (wt) and Sirt1(+/-) mice. The high-fat diet suppressed the expression of lipid catabolism (PPAR? target) gene expression in the hearts of wt mice, but not Sirt1(+/-) mice. Pro-inflammatory genes were induced and estrogen-related receptor-alpha (ERR?) target genes was suppressed in the hearts of wt fed the high-fat diet, but not in Sirt1(+/-) mice. We found the formation of a complex between PPAR? and Sirt1 in wt mice under high-fat diet conditions which might account for suppression of the ERR? pathway. Sirt1 haploinsufficiency impairs the formation of this complex and promotes the binding of PPAR? to the p65 subunit of NF-?B, thereby mediating inhibition of pro-inflammatory pathways and induction of PPAR? target genes. Short-term high-fat diet causes metabolic and inflammatory alterations in heart, and Sirt1 is critical for mediating these cardiac alterations. The capacity of Sirt1 to interact with transcriptional regulators such as NF-?B and PPAR? appears to be involved in the cardiac responsiveness to a high-fat diet. PMID:26359030

  19. A High Speed, Long-Range Mobile Communications Link for use in Polar Regions

    NASA Astrophysics Data System (ADS)

    Chalishazar, N.; Prescott, G.; Braaten, D.

    2003-12-01

    The Polar Radar for Ice Sheet Measurements (PRISM) project has developed a high bandwidth, wireless communications link between an autonomous rover and a manned vehicle deployed on a polar ice sheet to exchange real-time video, timing signals for a bistatic radar, and rover sensory data. The PRISM project is developing advanced intelligent remote sensing technology that involves radar systems, an autonomous rover, and communications systems to measure detailed ice sheet characteristics, and to determine bed conditions (frozen or wet) below active ice sheets in both Greenland and Antarctica. While this wireless communications link is being developed to fill a need within the PRISM Project, the same technology will allow polar researchers separated by moderate distances ( ˜10 km) to exchange data. The communications link is based on a high data rate 802.11b wireless technology, and a prototype system has been tested and evaluated during field experiments conducted at the NorthGRIP ice core drilling camp in Greenland (75° 06\\'\\ N, 42° 20\\'\\ W) from June 23-July 17, 2003. The IEEE 802.11b standard works in the 2.4-2.483 GHz band and has been widely used for high-speed data transfer in a WLAN (Wireless Local Area Network). It typically has a range of a few hundred meters and theoretical data rates on the order of 11 Mbps. It has been used for a number of applications in home and office environments. We modified a 802.11b system to operate up to a maximum distance of about 8 km and investigated the radio propagation environment over the flat terrain of the Greenland ice sheet. We evaluated its performance along three different tracks of 8 km in length, and made throughput measurements at intervals of 0.5 km. We measured the received signal strength and noise level in 2-s intervals along these 8 km tracks. Also we conducted experiments for four different antenna heights (1, 2, 3 and 5 m) for developing a radio propagation model for WLAN communication over the ice sheet. We found that peer-to-peer communication between nodes on the ice had data rates varying from 4.5 Mbps at close range to 2.5 Mbps at a distance of 8 km from the base station. The design, propagation model, throughput and coverage of this peer-to-peer communications system in Greenland are presented in this paper. This WLAN system has numerous applications in polar field camps. We tested the transfer of real-time video segments across this link for our educational outreach efforts in the field. These video segments were subsequently uploaded using an Iridium-based Internet link, and sent back to the University of Kansas. The wireless Internet connectivity was also made available to members of the North Grip camp, who were able to access e-mail and the Internet from their tents and common areas. However, throughput for wireless access to the Internet was limited by the Iridium-based Internet connection that had a maximum bandwidth of 9.6 Kbps.

  20. Demonstration of high-speed multi-user multi-carrier CDMA visible light communication

    NASA Astrophysics Data System (ADS)

    Yang, Chao; Wang, Yuanquan; Wang, Yiguang; Huang, Xingxing; Chi, Nan

    2015-02-01

    We experimentally demonstrated a high-speed multi-user multi-carrier code-division multiple access (MC-CDMA) visible light communication (VLC) system. By employing a commercially available red light emitting diode (LED) and an avalanche photo diode (APD), we achieved a 16-user VLC system enabled by MC-CDMA, pre- and post-equalization, with an overall bit rate of 750 Mb/s over 1.5 m free-space transmission. The measured bit error ratio (BER) of each user is below the 7% pre-forward-error-correction (pre-FEC) threshold of 3.8×10-3.

  1. CTS United States experiments - A progress report. [Communications Technology Satellite for high power broadcasting

    NASA Technical Reports Server (NTRS)

    Robbins, W. H.; Donoughe, P. L.

    1976-01-01

    The Communications Technology Satellite (CTS) is a high-power broadcast satellite launched by NASA on January 17, 1976. CTS is the first satellite to operate at a frequency of 12 gigahertz and incorporates technology making possible new satellite telecommunications services. CTS is a cooperative program of the United States and Canada. This paper presents the results of the United States experimental activity to date. Wide segments of the population are involved in the Experiments Program, including the scientific community, other government agencies, industry, and the education and health entities. The experiments are associated with both technological objectives and the demonstration of new community and social services via satellite.

  2. Circuit for Communication over DC Power Line Using High Temperature Electronics

    NASA Technical Reports Server (NTRS)

    Krasowski, Michael J. (Inventor); Prokop, Norman F. (Inventor)

    2014-01-01

    A high temperature communications circuit includes a power conductor for concurrently conducting electrical energy for powering circuit components and transmitting a modulated data signal, and a demodulator for demodulating the data signal and generating a serial bit stream based on the data signal. The demodulator includes an absolute value amplifier for conditionally inverting or conditionally passing a signal applied to the absolute value amplifier. The absolute value amplifier utilizes no diodes to control the conditional inversion or passing of the signal applied to the absolute value amplifier.

  3. A high-efficiency 59- to 64-GHz TWT for intersatellite communications

    NASA Technical Reports Server (NTRS)

    Wilson, Jeffrey D.; Ramins, Peter; Force, Dale A.; Limburg, Helen C.; Tammaru, Ivo

    1991-01-01

    The design of a 75-W, 59- to 64- GHz TWT with a predicted overall efficiency in excess of 40 percent is described. This intersatellite communications TWT, designated Model 961HA, employs a coupled-cavity slow-wave structure with a two-step velocity taper and an isotropic graphite multistage depressed collector (MDC). Because the RF efficiency of this TWT is less than 8 percent, an MDC design providing a very high collector efficiency was necessary to achieve the overall efficiency goal of 40 percent.

  4. Short Circuits or Superconductors? Effects of Group Composition on High-Achieving Students' Science Assessment Performance.

    ERIC Educational Resources Information Center

    Webb, Noreen M.; Nemer, Kariane Mari; Zuniga, Stephen

    2002-01-01

    Studied the effects of group ability composition (homogeneous versus heterogeneous) on group processes and outcomes for high-ability students completing science assessments. Results for 83 high ability students show the quality of group functioning serves as the strongest predictor of high-ability students' performance and explained much of the…

  5. A Filtering Method to Generate High Quality Short Reads Using Illumina Paired-End Technology

    PubMed Central

    Morrison, Hilary G.; Sogin, Mitchell L.

    2013-01-01

    Consensus between independent reads improves the accuracy of genome and transcriptome analyses, however lack of consensus between very similar sequences in metagenomic studies can and often does represent natural variation of biological significance. The common use of machine-assigned quality scores on next generation platforms does not necessarily correlate with accuracy. Here, we describe using the overlap of paired-end, short sequence reads to identify error-prone reads in marker gene analyses and their contribution to spurious OTUs following clustering analysis using QIIME. Our approach can also reduce error in shotgun sequencing data generated from libraries with small, tightly constrained insert sizes. The open-source implementation of this algorithm in Python programming language with user instructions can be obtained from https://github.com/meren/illumina-utils. PMID:23799126

  6. High detectivity short-wavelength II-VI quantum cascade detector

    SciTech Connect

    Ravikumar, Arvind P. Gmachl, Claire F.; Garcia, Thor A.; Tamargo, Maria C.; Jesus, Joel De

    2014-08-11

    We report on the experimental demonstration of a ZnCdSe/ZnCdMgSe-based short-wavelength photovoltaic Quantum Cascade Detector (QCD). The QCD operates in two spectral bands centered around 2.6??m and 3.6??m. Calibrated blackbody measurements yield a peak responsivity of 0.1?mA/W or 2400?V/W at 80?K, and a corresponding 300?K background radiation limited infrared performance detectivity (BLIP) of ?2.5?×?10{sup 10?}cm ?Hz/W. Comparison of background illuminated and dark current-voltage measurements demonstrates a BLIP temperature of 200?K. The device differential resistance-area product, decreases from about 10{sup 6} ? cm{sup 2} at 80?K to about 8000 ? cm{sup 2} at 300?K, indicative of the ultra-low Johnson noise in the detectors.

  7. High Energy, Short Pulse Fiber Injection Lasers at Lawrence Livermore National Laboratory

    SciTech Connect

    Dawson, J W; Messerly, M J; Phan, H H; Crane, J K; Beach, R J; Siders, C W; Barty, C J

    2008-09-10

    A short pulse fiber injection laser for the Advanced Radiographic Capability (ARC) on the National Ignition Facility (NIF) has been developed at Lawrence Livermore National Laboratory (LLNL). This system produces 100 {micro}J pulses with 5 nm of bandwidth centered at 1053 nm. The pulses are stretched to 2.5 ns and have been recompressed to sub-ps pulse widths. A key feature of the system is that the pre-pulse power contrast ratio exceeds 80 dB. The system can also precisely adjust the final recompressed pulse width and timing and has been designed for reliable, hands free operation. The key challenges in constructing this system were control of the signal to noise ratio, dispersion management and managing the impact of self phase modulation on the chirped pulse.

  8. Means and method for characterizing high power, ultra short laser pulses in a real time, on line manner

    DOEpatents

    Veligdan, J.T.

    1994-03-08

    An ultra short (<10 ps), high power laser pulse is temporally characterized by a system that uses a physical measurement of a wavefront that has been altered in a known manner. The system includes a first reflection switch to remove a portion of a pulse from a beam of pulses, then includes a second reflection switch, operating in a mode that is opposite to the first reflection switch, to slice off a portion of that removed portion. The sliced portion is then directed to a measuring device for physical measurement. The two reflection switches are arranged with respect to each other and with respect to the beam of ultra short pulses such that physical measurement of the sliced portion is related to the temporal measurement of the ultra short pulse by a geometric or trigonometric relationship. The reflection switches are operated by a control pulse that is directed to impinge on each of the reflection switches at a 90[degree] angle of incidence. 8 figures.

  9. Efficacy of acute caffeine ingestion for short-term high-intensity exercise performance: a systematic review.

    PubMed

    Astorino, Todd A; Roberson, Daniel W

    2010-01-01

    Caffeine is the most widely used drug in the world, commonly ingested in coffee, tea, soda, and energy drinks. Its ability to enhance muscular work has been apparent since the early 1900s. Caffeine typically increases endurance performance; however, efficacy of caffeine ingestion for short-term high-intensity exercise is equivocal, which may be explained by discrepancies in exercise protocols, dosing, and subjects' training status and habitual caffeine intake found across studies. The primary aim of this review is to critically examine studies that have tested caffeine's ability to augment performance during exercise dependent on nonoxidative metabolism such as sprinting, team sports, and resistance training. A review of the literature revealed 29 studies that measured alterations in short-term performance after caffeine ingestion. Each study was critically analyzed using the Physiotherapy Evidence Database (PEDro) scale. The mean PEDro score was 7.76 +/- 0.87. Eleven of 17 studies revealed significant improvements in team sports exercise and power-based sports with caffeine ingestion, yet these effects were more common in elite athletes who do not regularly ingest caffeine. Six of 11 studies revealed significant benefits of caffeine for resistance training. Some studies show decreased performance with caffeine ingestion when repeated bouts are completed. The exact mechanism explaining the ergogenic effect of caffeine for short-term exercise is unknown. PMID:19924012

  10. Grand Challenges: High Performance Computing and Communications. The FY 1992 U.S. Research and Development Program.

    ERIC Educational Resources Information Center

    Federal Coordinating Council for Science, Engineering and Technology, Washington, DC.

    This report presents a review of the High Performance Computing and Communications (HPCC) Program, which has as its goal the acceleration of the commercial availability and utilization of the next generation of high performance computers and networks in order to: (1) extend U.S. technological leadership in high performance computing and computer…

  11. Reconfigurable Antennas for High Data Rate Multi-beam Communication Systems

    NASA Technical Reports Server (NTRS)

    Bernhard, Jennifer T.; Michielssen, Eric

    2005-01-01

    High-speed (2-100 Mb/sec) wireless data communication - whether land- or satellite-based - faces a major challenge: high error rates caused by interference and unpredictable environments. A planar antenna system that can be reconfigured to respond to changing conditions has the potential to dramatically improve data throughput and system reliability. Moreover, new planar antenna designs that reduce array size, weight, and cost can have a significant impact on terrestrial and satellite communication system performance. This research developed new individually-reconfigurable planar antenna array elements that can be adjusted to provide multiple beams while providing increased scan angles and higher aperture efficiency than traditional diffraction-limited arrays. These new elements are microstrip spiral antennas with specialized tuning mechanisms that provide adjustable radiation patterns. We anticipate that these new elements can be used in both large and small arrays for inter-satellite communication as well as tracking of multiple mobile surface-based units. Our work has developed both theoretical descriptions as well as experimental prototypes of the antennas in both single element and array embodiments. The technical summary of the results of this work is divided into six sections: A. Cavity model for analysis and design of pattern reconfigurable antennas; B. Performance of antenna in array configurations for broadside and endfire operation; C. Performance of antenna in array configurations for beam scanning operation; D. Simulation of antennas in infinite phased arrays; E. Demonstration of antenna with commercially-available RF MEMS switches; F. Design of antenna MEMS switch combinations for direct simultaneous fabrication.

  12. Isolated short attosecond pulse generated using a two-color laser and a high-order pulse

    SciTech Connect

    Du, Hongchuan; Hu, Bitao; Wang, Huiqiao

    2010-06-15

    An efficient method to generate an isolated short attosecond pulse is investigated theoretically. A broadband extreme ultraviolet supercontinuum harmonics can be generated when a model He{sup +} ion is exposed to the combination of an intense few-cycle laser pulse and a low-frequency field. By properly adding a 27th harmonics pulse to resonantly excite the He{sup +} ion, the intensity of the high-order harmonic generation (HHG) plateau is enhanced by 3-4 orders of magnitude. As a result, an isolated 24-as pulse with a bandwidth of 138 eV can be obtained directly from the supercontinuum around the cutoff of HHG.

  13. High sensitivity to short wavelengths in a lizard and implications for understanding the evolution of visual systems in lizards

    PubMed Central

    Fleishman, Leo J.; Loew, Ellis R.; Whiting, Martin J.

    2011-01-01

    Progress in developing animal communication theory is frequently constrained by a poor understanding of sensory systems. For example, while lizards have been the focus of numerous studies in visual signalling, we only have data on the spectral sensitivities of a few species clustered in two major clades (Iguania and Gekkota). Using electroretinography and microspectrophotometry, we studied the visual system of the cordylid lizard Platysaurus broadleyi because it represents an unstudied clade (Scinciformata) with respect to visual systems and because UV signals feature prominently in its social behaviour. The retina possessed four classes of single and one class of double cones. Sensitivity in the ultraviolet region (UV) was approximately three times higher than previously reported for other lizards. We found more colourless oil droplets (associated with UV-sensitive (UVS) and short wavelength-sensitive (SWS) photoreceptors), suggesting that the increased sensitivity was owing to the presence of more UVS photoreceptors. Using the Vorobyev–Osorio colour discrimination model, we demonstrated that an increase in the number of UVS photoreceptors significantly enhances a lizard's ability to discriminate conspecific male throat colours. Visual systems in diurnal lizards appear to be broadly conserved, but data from additional clades are needed to confirm this. PMID:21389031

  14. A rapidly-tuned, short-pulse-length, high-repetition-rate CO{sub 2} laser for IR dial

    SciTech Connect

    Zaugg, T.; Thompson, D.; Leland, W.T.; Busch, G.

    1997-08-01

    Analysis of noise sources in Differential Absorption LIDAR (DIAL) in the infrared region of the spectrum indicates that the signal-to-noise ratio for direct detection can be improved if multiple-wavelength, short-pulse-length beams are transmitted and received at high repetition rates. Atmospheric effects can be minimized, albedo can be rapidly scanned, and uncorrelated speckle can be acquired at the maximum possible rate. A compact, rugged, RF-excited waveguide laser can produce 15 nanosecond pulses at a 100 kHz rate with sufficient energy per pulse to reach the speckle limit of the signal-to-noise ratio. A high-repetition-rate laser has been procured and will be used to verify these signal and noise scaling relationships at high repetition rates. Current line-tuning devices are mechanical and are capable of switching lines at a rate up to a few hundred Hertz. Acousto-optic modulators, deflectors or tunable filters can be substituted for these mechanical devices in the resonator of a CO{sub 2} laser and used to rapidly line-tune the laser across the 9 and 10 micron bands at a rate as high as 100 kHz. Several configurations for line tuning using acousto-optic and electro-optic devices with and without gratings are presented. The merits of and constraints on each design are also discussed. A pair of large aperture, acousto-optic deflectors has been purchased and the various line-tuning designs will be evaluated in a conventional, glass tube, CO{sub 2} laser, with a view to incorporation into the high-repetition-rate, waveguide laser. A computer model of the dynamics of an RF-excited, short-pulse-length, high-repetition-rate waveguide laser has been developed. The model will be used to test the consequences of various line-tuning designs.

  15. High-performance diamond-based single-photon sources for quantum communication

    E-print Network

    Chun-Hsu Su; Andrew D. Greentree; Lloyd C. L. Hollenberg

    2009-11-10

    Quantum communication places stringent requirements on single-photon sources. Here we report a theoretical study of the cavity Purcell enhancement of two diamond point defects, the nickel-nitrogen (NE8) and silicon-vacancy (SiV) centers, for high-performance, near on-demand single-photon generation. By coupling the centers strongly to high-finesse optical photonic-bandgap cavities with modest quality factor Q = O(10^4) and small mode volume V = O(\\lambda^3), these system can deliver picosecond single-photon pulses at their zero-phonon lines with probabilities of 0.954 (NE8) and 0.812 (SiV) under a realistic optical excitation scheme. The undesirable blinking effect due to transitions via metastable states can also be suppressed with O(10^{-4}) blinking probability. We analyze the application of these enhanced centers, including the previously-studied cavity-enhanced nitrogen-vacancy (NV) center, to long-distance BB84 quantum key distribution (QKD) in fiber-based, open-air terrestrial and satellite-ground setups. In this comparative study, we show that they can deliver performance comparable with decoy state implementation with weak coherent sources, and are most suitable for open-air communication.

  16. GaAs Photonic Integrated Circuit (PIC) development for high performance communications

    SciTech Connect

    Sullivan, C.T.

    1998-03-01

    Sandia has established a foundational technology in photonic integrated circuits (PICs) based on the (Al,Ga,In)As material system for optical communication, radar control and testing, and network switching applications at the important 1.3{mu}m/1.55{mu}m wavelengths. We investigated the optical, electrooptical, and microwave performance characteristics of the fundamental building-block PIC elements designed to be as simple and process-tolerant as possible, with particular emphasis placed on reducing optical insertion loss. Relatively conventional device array and circuit designs were built using these PIC elements: (1) to establish a baseline performance standard; (2) to assess the impact of epitaxial growth accuracy and uniformity, and of fabrication uniformity and yield; (3) to validate our theoretical and numerical models; and (4) to resolve the optical and microwave packaging issues associated with building fully packaged prototypes. Novel and more complex PIC designs and fabrication processes, viewed as higher payoff but higher risk, were explored in a parallel effort with the intention of meshing those advances into our baseline higher-yield capability as they mature. The application focus targeted the design and fabrication of packaged solitary modulators meeting the requirements of future wideband and high-speed analog and digital data links. Successfully prototyped devices are expected to feed into more complex PICs solving specific problems in high-performance communications, such as optical beamforming networks for phased array antennas.

  17. Self-focusing of the high intensity ultra short laser pulse propagating through relativistic magnetized plasma

    NASA Astrophysics Data System (ADS)

    Malekshahi, Moslem; Dorranian, Davoud; Askari, Hassan Ranjbar

    2014-12-01

    In this paper, evolution of the spot size of the ultra short intense laser beam propagating in underdense magnetized cold plasma, taking into account the nonlinearity up to third order and the relativistic effect, has been studied. The plasma embedded in a constant external magnetic field that is set in the plane perpendicular to the electric field vector of the laser beam with different directions. The paraxial wave equation in plasma has been used and the source dependent expansion (SDE) method is employed to solve the equation. Using continuity equation and equation of motion for plasma electrons in the electric field of laser beam a set of equations for the evolution of laser beam structure in plasma is found. Results show that imposing the external magnetic field enhances self-focusing property of the laser beam. Taking into account the relativistic effect increases the effect of the external magnetic field on self-focusing of the laser beam. Increasing the angle between the laser beam magnetic field and external magnetic field will decrease the self-focusing property.

  18. Probiotic supplementation influences faecal short chain fatty acids in infants at high risk for eczema.

    PubMed

    Kim, H K; Rutten, N B M M; Besseling-van der Vaart, I; Niers, L E M; Choi, Y H; Rijkers, G T; van Hemert, S

    2015-12-01

    The composition of the gut microbiota plays a role in the development of allergies. Based on the immunomodulating capacities of bacteria, various studies have investigated the potential role for probiotics in the prevention of childhood eczema. In a previous study we have shown that significantly less children developed eczema after probiotic supplementation (Bifidobacterium bifidum W23, Bifidobacterium animalis subsp. lactis W52 and Lactococcus lactis W58, Ecologic(®)Panda) at three months of age as compared to controls. Here, metabolites in faecal samples of these 3-month old children were measured by (1)H-nuclear magnetic resonance to investigate possible gut metabolic alterations. Lower amounts of short-chain fatty acids (SCFAs), succinate, phenylalanine and alanine were found in faecal samples of children later developing eczema, whereas the amounts of glucose, galactose, lactate and lactose were higher compared to the children not developing eczema. Although these differences were already present at the age of 3 months, eczema did not develop in the majority of children before the age of 1 year. Supplementation of multispecies probiotics seems to induce higher levels of lactate and SCFAs, and lower levels of lactose and succinate when compared with the placebo group. This might explain the temporary preventive effect of probiotics on the development of eczema. These results highlight the role bacterial metabolites may play in development of the immune system, even before clinical manifestations of allergic disease arise. PMID:26565082

  19. High-precision Helical Cutting Using Ultra-short Laser Pulses

    NASA Astrophysics Data System (ADS)

    He, Chao; Zibner, Frank; Fornaroli, Christian; Ryll, Joachim; Holtkamp, Jens; Gillner, Arnold

    The use of a helicaloptics to drill micro holes in fuel injectors and spinning nozzles has already demonstrated great advantages likehigh precision and flexibility. Due to the laser beam rotation on a helical path, the hole-geometry is almost independent from the beam shape. By slightly manipulating the beam path inside the optics, positive and negative tapered as well as straight cylindrical holes can be achieved. If the work-piece is moved relatively to the helical-optics, a helical-cutting process is performed. Compared todirect cutting technologies, helical-cutting can meet higher requirements in terms of roughness and taper of the kerf. By using a helical optics with ultra-short laser pulses, micro cutting experiments on metal and sapphire sheets were performed. As a result of the laser beamhelical movement, the roughness of the cutting kerf in metal isbelow 1 ?m, and a taper less than 1 degree could be achieved with a cutting speed 10 mm/min. Recast layer and heat affected zone around the exits are negligible.

  20. Ventricular structure, function, and mechanics at high altitude: chronic remodeling in Sherpa vs. short-term lowlander adaptation

    PubMed Central

    Ainslie, Philip N.; Hughes, Michael G.; Stöhr, Eric J.; Cotter, James D.; Nio, Amanda Q. X.; Shave, Rob

    2014-01-01

    Short-term, high-altitude (HA) exposure raises pulmonary artery systolic pressure (PASP) and decreases left-ventricular (LV) volumes. However, relatively little is known of the long-term cardiac consequences of prolonged exposure in Sherpa, a highly adapted HA population. To investigate short-term adaptation and potential long-term cardiac remodeling, we studied ventricular structure and function in Sherpa at 5,050 m (n = 11; 31 ± 13 yr; mass 68 ± 10 kg; height 169 ± 6 cm) and lowlanders at sea level (SL) and following 10 ± 3 days at 5,050 m (n = 9; 34 ± 7 yr; mass 82 ± 10 kg; height 177 ± 6 cm) using conventional and speckle-tracking echocardiography. At HA, PASP was higher in Sherpa and lowlanders compared with lowlanders at SL (both P < 0.05). Sherpa had smaller right-ventricular (RV) and LV stroke volumes than lowlanders at SL with lower RV systolic strain (P < 0.05) but similar LV systolic mechanics. In contrast to LV systolic mechanics, LV diastolic, untwisting velocity was significantly lower in Sherpa compared with lowlanders at both SL and HA. After partial acclimatization, lowlanders demonstrated no change in the RV end-diastolic area; however, both RV strain and LV end-diastolic volume were reduced. In conclusion, short-term hypoxia induced a reduction in RV systolic function that was also evident in Sherpa following chronic exposure. We propose that this was consequent to a persistently higher PASP. In contrast to the RV, remodeling of LV volumes and normalization of systolic mechanics indicate structural and functional adaptation to HA. However, altered LV diastolic relaxation after chronic hypoxic exposure may reflect differential remodeling of systolic and diastolic LV function. PMID:24876358