WorldWideScience

Sample records for non-redundant thinned-aperture array

  1. Micromorphic continua: non-redundant formulations

    Science.gov (United States)

    Romano, Giovanni; Barretta, Raffaele; Diaco, Marina

    2016-11-01

    The kinematics of generalized continua is investigated and key points concerning the definition of overall tangent strain measure are put into evidence. It is shown that classical measures adopted in the literature for micromorphic continua do not obey a constraint qualification requirement, to be fulfilled for well-posedness in optimization theory, and are therefore termed redundant. Redundancy of continua with latent microstructure and of constrained Cosserat continua is also assessed. A simplest, non-redundant, kinematic model of micromorphic continua, is proposed by dropping the microcurvature field. The equilibrium conditions and the related variational linear elastostatic problem are formulated and briefly discussed. The simplest model involves a reduced number of state variables and of elastic constitutive coefficients, when compared with other models of micromorphic continua, being still capable of enriching the Cauchy continuum model in a significant way.

  2. Wave front engineering from an array of thin aperture antennas.

    Science.gov (United States)

    Kang, Ming; Feng, Tianhua; Wang, Hui-Tian; Li, Jensen

    2012-07-01

    We propose an ultra-thin metamaterial constructed by an ensemble of the same type of anisotropic aperture antennas with phase discontinuity for wave front manipulation across the metamaterial. A circularly polarized light is completely converted to the cross-polarized light which can either be bent or focused tightly near the diffraction limit. It depends on a precise control of the optical-axis profile of the antennas on a subwavelength scale, in which the rotation angle of the optical axis has a simple linear relationship to the phase discontinuity. Such an approach enables effective wave front engineering within a subwavelength scale.

  3. Imaging protoplanets: observing transition disks with non-redundant masking

    CERN Document Server

    Sallum, Steph; Close, Laird M; Hinz, Philip M; Follette, Katherine B; Kratter, Kaitlin; Skemer, Andrew J; Bailey, Vanessa P; Briguglio, Runa; Defrere, Denis; Macintosh, Bruce A; Males, Jared R; Morzinski, Katie M; Puglisi, Alfio T; Rodigas, Timothy J; Spalding, Eckhart; Tuthill, Peter G; Vaz, Amali; Weinberger, Alycia; Xomperio, Marco

    2016-01-01

    Transition disks, protoplanetary disks with inner clearings, are promising objects in which to directly image forming planets. The high contrast imaging technique of non-redundant masking is well posed to detect planetary mass companions at several to tens of AU in nearby transition disks. We present non-redundant masking observations of the T Cha and LkCa 15 transition disks, both of which host posited sub-stellar mass companions. However, due to a loss of information intrinsic to the technique, observations of extended sources (e.g. scattered light from disks) can be misinterpreted as moving companions. We discuss tests to distinguish between these two scenarios, with applications to the T Cha and LkCa 15 observations. We argue that a static, forward-scattering disk can explain the T Cha data, while LkCa 15 is best explained by multiple orbiting companions.

  4. Mining Non-Redundant High Order Correlations in Binary Data.

    Science.gov (United States)

    Zhang, Xiang; Pan, Feng; Wang, Wei; Nobel, Andrew

    2008-08-01

    Many approaches have been proposed to find correlations in binary data. Usually, these methods focus on pair-wise correlations. In biology applications, it is important to find correlations that involve more than just two features. Moreover, a set of strongly correlated features should be non-redundant in the sense that the correlation is strong only when all the interacting features are considered together. Removing any feature will greatly reduce the correlation.In this paper, we explore the problem of finding non-redundant high order correlations in binary data. The high order correlations are formalized using multi-information, a generalization of pairwise mutual information. To reduce the redundancy, we require any subset of a strongly correlated feature subset to be weakly correlated. Such feature subsets are referred to as Non-redundant Interacting Feature Subsets (NIFS). Finding all NIFSs is computationally challenging, because in addition to enumerating feature combinations, we also need to check all their subsets for redundancy. We study several properties of NIFSs and show that these properties are useful in developing efficient algorithms. We further develop two sets of upper and lower bounds on the correlations, which can be incorporated in the algorithm to prune the search space. A simple and effective pruning strategy based on pair-wise mutual information is also developed to further prune the search space. The efficiency and effectiveness of our approach are demonstrated through extensive experiments on synthetic and real-life datasets.

  5. Extra Solar Planet Science With a Non Redundant Mask

    Science.gov (United States)

    Minto, Stefenie Nicolet; Sivaramakrishnan, Anand; Greenbaum, Alexandra; St. Laurent, Kathryn; Thatte, Deeparshi

    2017-01-01

    To detect faint planetary companions near a much brighter star, at the Resolution Limit of the James Webb Space Telescope (JWST) the Near-Infrared Imager and Slitless Spectrograph (NIRISS) will use a non-redundant aperture mask (NRM) for high contrast imaging. I simulated NIRISS data of stars with and without planets, and run these through the code that measures interferometric image properties to determine how sensitive planetary detection is to our knowledge of instrumental parameters, starting with the pixel scale. I measured the position angle, distance, and contrast ratio of the planet (with respect to the star) to characterize the binary pair. To organize this data I am creating programs that will automatically and systematically explore multi-dimensional instrument parameter spaces and binary characteristics. In the future my code will also be applied to explore any other parameters we can simulate.

  6. Ion pairs in non-redundant protein structures

    Indian Academy of Sciences (India)

    B A Gowri Shankar; R Sarani; Daliah Michael; P Mridula; C Vasuki; G Sowmiya; B Vasundhar; P Sudha; J Jeyakanthan; D Velmurugan; K Sekar

    2007-06-01

    Ion pairs contribute to several functions including the activity of catalytic triads, fusion of viral membranes, stability in thermophilic proteins and solvent–protein interactions. Furthermore, they have the ability to affect the stability of protein structures and are also a part of the forces that act to hold monomers together. This paper deals with the possible ion pair combinations and networks in 25% and 90% non-redundant protein chains. Different types of ion pairs present in various secondary structural elements are analysed. The ion pairs existing between different subunits of multisubunit protein structures are also computed and the results of various analyses are presented in detail. The protein structures used in the analysis are solved using X-ray crystallography, whose resolution is better than or equal to 1.5 Å and R-factor better than or equal to 20%. This study can, therefore, be useful for analyses of many protein functions. It also provides insights into the better understanding of the architecture of protein structure.

  7. Dynamics of social contagions with memory of non-redundant information

    CERN Document Server

    Wang, Wei; Zhang, Hai-Feng; Lai, Ying-Cheng

    2015-01-01

    A key ingredient in social contagion dynamics is reinforcement, as adopting a certain social behavior requires verification of its credibility and legitimacy. Memory of non-redundant information plays an important role in reinforcement, which so far has eluded theoretical analysis. We first propose a general social contagion model with reinforcement derived from non-redundant information memory. Then, we develop a unified edge-based compartmental theory to analyze this model, and a remarkable agreement with numerics is obtained on some specific models. Using a spreading threshold model as a specific example to understand the memory effect, in which each individual adopts a social behavior only when the cumulative pieces of information that the individual received from his/her neighbors exceeds an adoption threshold. Through analysis and numerical simulations, we find that the memory characteristic markedly affects the dynamics as quantified by the final adoption size. Strikingly, we uncover a transition pheno...

  8. Non-redundant unique interface structures as templates for modeling protein interactions

    OpenAIRE

    Engin Cukuroglu; Attila Gursoy; Ruth Nussinov; Ozlem Keskin

    2014-01-01

    Non-Redundant Unique Interface Structures as Templates for Modeling Protein Interactions Engin Cukuroglu1, Attila Gursoy1*, Ruth Nussinov2,3, Ozlem Keskin1* 1 Center for Computational Biology and Bioinformatics and College of Engineering, Koc University, Istanbul, Turkey, 2 National Cancer Institute, Cancer and Inflammation Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., National Cancer Institute, Frederick, Maryland, United States of ...

  9. Discovering Non-Redundant Association Rules using MinMax Approximation Rules

    OpenAIRE

    R. Vijaya Prakash; Dr. A. Govardhan3; Prof. SSVN. Sarma

    2012-01-01

    Frequent pattern mining is an important area of data mining used to generate the Association Rules. The extracted Frequent Patterns quality is a big concern, as it generates huge sets of rules and many of them are redundant. Mining Non-Redundant Frequent patterns is a big concern in the area of Association rule mining. In this paper we proposed a method to eliminate the redundant Frequent patterns using MinMax rule approach, to generate the quality Association Rules.

  10. Planetary system, star formation, and black hole science with non-redundant masking on space telescopes

    CERN Document Server

    Sivaramakrishna, Anand; Ireland, Michael; Lloyd, James; Perrin, Marshall; Soummer, Remi; McKernan, Barry; Ford, Saavik

    2009-01-01

    Non-redundant masking (NRM) is a high contrast, high resolution technique relevant to future space missions concerned with extrasolar planetary system and star formation, as well as general high angular resolution galactic and extragalactic astronomy. NRM enables the highest angular resolution science possible given the telescope's diameter and operating wavelength. It also provides precise information on a telescope's optical state. We must assess NRM contrast limits realistically to understand the science yield of NRM in space, and, simultaneously, develop NRM science for planet and star formation and extragalactic science in the UV-NIR, to help steer high resolution space-based astronomy in the coming decade.

  11. Overlap and diversity in antimicrobial peptide databases: compiling a non-redundant set of sequences.

    Science.gov (United States)

    Aguilera-Mendoza, Longendri; Marrero-Ponce, Yovani; Tellez-Ibarra, Roberto; Llorente-Quesada, Monica T; Salgado, Jesús; Barigye, Stephen J; Liu, Jun

    2015-08-01

    The large variety of antimicrobial peptide (AMP) databases developed to date are characterized by a substantial overlap of data and similarity of sequences. Our goals are to analyze the levels of redundancy for all available AMP databases and use this information to build a new non-redundant sequence database. For this purpose, a new software tool is introduced. A comparative study of 25 AMP databases reveals the overlap and diversity among them and the internal diversity within each database. The overlap analysis shows that only one database (Peptaibol) contains exclusive data, not present in any other, whereas all sequences in the LAMP_Patent database are included in CAMP_Patent. However, the majority of databases have their own set of unique sequences, as well as some overlap with other databases. The complete set of non-duplicate sequences comprises 16 990 cases, which is almost half of the total number of reported peptides. On the other hand, the diversity analysis identifies the most and least diverse databases and proves that all databases exhibit some level of redundancy. Finally, we present a new parallel-free software, named Dover Analyzer, developed to compute the overlap and diversity between any number of databases and compile a set of non-redundant sequences. These results are useful for selecting or building a suitable representative set of AMPs, according to specific needs. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. A Frequent Closed Itemsets Lattice-based Approach for Mining Minimal Non-Redundant Association Rules

    CERN Document Server

    Vo, Bay

    2011-01-01

    There are many algorithms developed for improvement the time of mining frequent itemsets (FI) or frequent closed itemsets (FCI). However, the algorithms which deal with the time of generating association rules were not put in deep research. In reality, in case of a database containing many FI/FCI (from ten thousands up to millions), the time of generating association rules is much larger than that of mining FI/FCI. Therefore, this paper presents an application of frequent closed itemsets lattice (FCIL) for mining minimal non-redundant association rules (MNAR) to reduce a lot of time for generating rules. Firstly, we use CHARM-L for building FCIL. After that, based on FCIL, an algorithm for fast generating MNAR will be proposed. Experimental results show that the proposed algorithm is much faster than frequent itemsets lattice-based algorithm in the mining time.

  13. In-focus wavefront sensing using non-redundant mask-induced pupil diversity

    CERN Document Server

    Greenbaum, Alexandra

    2016-01-01

    Wavefront estimation using in-focus image data is critical to many applications. This data is invariant to a sign flip with complex conjugation of the complex amplitude in the pupil, making for a non-unique solution. Information from an in-focus image taken through a non-redundant pupil mask (NRM) can break this ambiguity, enabling the true aberration to be determined. We demonstrate this by priming a full pupil Gerchberg-Saxton phase retrieval with NRM fringe phase information. We apply our method to measure simulated aberrations on the segmented James Webb Space Telescope (JWST) mirror using full pupil and NRM data from its Near Infrared Imager and Slitless Spectrograph (NIRISS).

  14. In-focus phase retrieval using JWST-NIRISS's non-redundant mask

    Science.gov (United States)

    Greenbaum, Alexandra Z.; Gamper, Noah; Sivaramakrishnan, Anand

    2016-07-01

    The James Webb Space Telescope's Near InfraRed Imager and Slitless Spectrograph (NIRISS) contains a 7-hole non-redundant mask (NRM) in its pupil. NIRISS's Aperture Masking Interferometry (AMI) mode is useful both for science as well as wavefront sensing. In-focus science detector NRM and full pupil images of unresolved stars can be used to measure the wavefront without any dedicated wavefront sensing hardware or any moving mirrors. Using routine science operational sequences, these images can be taken before or after any science visit. NRM fringe phases constrain Gerchberg-Saxton phase retrieval to disambiguate the algorithm's two-fold degeneracy. We summarize how consecutive masked and unmasked exposures provide enough information to reconstruct a wavefront with up to ˜1-2 rms radians of error. We present our latest progress on using this approach on laboratory experiments, and discuss those results in the context of contingency for JWST segment phasing. We discuss extending our method to ground-based AO systems and future space telescopes.

  15. Non-redundant patent sequence databases with value-added annotations at two levels.

    Science.gov (United States)

    Li, Weizhong; McWilliam, Hamish; de la Torre, Ana Richart; Grodowski, Adam; Benediktovich, Irina; Goujon, Mickael; Nauche, Stephane; Lopez, Rodrigo

    2010-01-01

    The European Bioinformatics Institute (EMBL-EBI) provides public access to patent data, including abstracts, chemical compounds and sequences. Sequences can appear multiple times due to the filing of the same invention with multiple patent offices, or the use of the same sequence by different inventors in different contexts. Information relating to the source invention may be incomplete, and biological information available in patent documents elsewhere may not be reflected in the annotation of the sequence. Search and analysis of these data have become increasingly challenging for both the scientific and intellectual-property communities. Here, we report a collection of non-redundant patent sequence databases, which cover the EMBL-Bank nucleotides patent class and the patent protein databases and contain value-added annotations from patent documents. The databases were created at two levels by the use of sequence MD5 checksums. Sequences within a level-1 cluster are 100% identical over their whole length. Level-2 clusters were defined by sub-grouping level-1 clusters based on patent family information. Value-added annotations, such as publication number corrections, earliest publication dates and feature collations, significantly enhance the quality of the data, allowing for better tracking and cross-referencing. The databases are available format: http://www.ebi.ac.uk/patentdata/nr/.

  16. Non-redundant patent sequence databases with value-added annotations at two levels

    Science.gov (United States)

    Li, Weizhong; McWilliam, Hamish; de la Torre, Ana Richart; Grodowski, Adam; Benediktovich, Irina; Goujon, Mickael; Nauche, Stephane; Lopez, Rodrigo

    2010-01-01

    The European Bioinformatics Institute (EMBL-EBI) provides public access to patent data, including abstracts, chemical compounds and sequences. Sequences can appear multiple times due to the filing of the same invention with multiple patent offices, or the use of the same sequence by different inventors in different contexts. Information relating to the source invention may be incomplete, and biological information available in patent documents elsewhere may not be reflected in the annotation of the sequence. Search and analysis of these data have become increasingly challenging for both the scientific and intellectual-property communities. Here, we report a collection of non-redundant patent sequence databases, which cover the EMBL-Bank nucleotides patent class and the patent protein databases and contain value-added annotations from patent documents. The databases were created at two levels by the use of sequence MD5 checksums. Sequences within a level-1 cluster are 100% identical over their whole length. Level-2 clusters were defined by sub-grouping level-1 clusters based on patent family information. Value-added annotations, such as publication number corrections, earliest publication dates and feature collations, significantly enhance the quality of the data, allowing for better tracking and cross-referencing. The databases are available format: http://www.ebi.ac.uk/patentdata/nr/. PMID:19884134

  17. An image-plane algorithm for JWST's non-redundant aperture mask data

    CERN Document Server

    Greenbaum, Alexandra Z; Sivaramakrishnan, Anand; Lacour, Sylvestre

    2014-01-01

    The high angular resolution technique of non-redundant masking (NRM) or aperture masking interferometry (AMI) has yielded images of faint protoplanetary companions of nearby stars from the ground. AMI on James Webb Space Telescope (JWST)'s Near Infrared Imager and Slitless Spectrograph (NIRISS) has a lower thermal background than ground-based facilites and does not suffer from atmospheric instability. NIRISS AMI images are likely to have 90 - 95% Strehl ratio between 2.77 and 4.8 micron. In this paper we quantify factors that limit the raw point source contrast of JWST NRM. We develop an analytic model of the NRM point spread function which includes different optical path delays (pistons) between mask holes and fit the model parameters with image plane data. It enables a straightforward way to exclude bad pixels, is suited to limited fields of view, and can incorporate effects such as intra-pixel sensitivity variations. We simulate various sources of noise to estimate their effect on the standard deviation of...

  18. AN IMAGE-PLANE ALGORITHM FOR JWST'S NON-REDUNDANT APERTURE MASK DATA

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, Alexandra Z. [Johns Hopkins University Department of Physics and Astronomy 3400 North Charles, Baltimore, MD 21218 (United States); Pueyo, Laurent; Sivaramakrishnan, Anand [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Lacour, Sylvestre [LESIA, CNRS/UMR-8109, Observatoire de Paris, UPMC, Université Paris Diderot 5 place Jules Janssen, 92195 Meudon (France)

    2015-01-10

    The high angular resolution technique of non-redundant masking (NRM) or aperture masking interferometry (AMI) has yielded images of faint protoplanetary companions of nearby stars from the ground. AMI on James Webb Space Telescope (JWST)'s Near Infrared Imager and Slitless Spectrograph (NIRISS) has a lower thermal background than ground-based facilities and does not suffer from atmospheric instability. NIRISS AMI images are likely to have 90%-95% Strehl ratio between 2.77 and 4.8 μm. In this paper we quantify factors that limit the raw point source contrast of JWST NRM. We develop an analytic model of the NRM point spread function which includes different optical path delays (pistons) between mask holes and fit the model parameters with image plane data. It enables a straightforward way to exclude bad pixels, is suited to limited fields of view, and can incorporate effects such as intra-pixel sensitivity variations. We simulate various sources of noise to estimate their effect on the standard deviation of closure phase, σ{sub CP} (a proxy for binary point source contrast). If σ{sub CP} < 10{sup –4} radians—a contrast ratio of 10 mag—young accreting gas giant planets (e.g., in the nearby Taurus star-forming region) could be imaged with JWST NIRISS. We show the feasibility of using NIRISS' NRM with the sub-Nyquist sampled F277W, which would enable some exoplanet chemistry characterization. In the presence of small piston errors, the dominant sources of closure phase error (depending on pixel sampling, and filter bandwidth) are flat field errors and unmodeled variations in intra-pixel sensitivity. The in-flight stability of NIRISS will determine how well these errors can be calibrated by observing a point source. Our results help develop efficient observing strategies for space-based NRM.

  19. Autonomous control system reconfiguration for spacecraft with non-redundant actuators

    Science.gov (United States)

    Grossman, Walter

    1995-01-01

    The Small Satellite Technology Initiative (SSTI) 'CLARK' spacecraft is required to be single-failure tolerant, i.e., no failure of any single component or subsystem shall result in complete mission loss. Fault tolerance is usually achieved by implementing redundant subsystems. Fault tolerant systems are therefore heavier and cost more to build and launch than non-redundent, non fault-tolerant spacecraft. The SSTI CLARK satellite Attitude Determination and Control System (ADACS) achieves single-fault tolerance without redundancy. The attitude determination system system uses a Kalman Filter which is inherently robust to loss of any single attitude sensor. The attitude control system uses three orthogonal reaction wheels for attitude control and three magnetic dipoles for momentum control. The nominal six-actuator control system functions by projecting the attitude correction torque onto the reaction wheels while a slower momentum management outer loop removes the excess momentum in the direction normal to the local B field. The actuators are not redundant so the nominal control law cannot be implemented in the event of a loss of a single actuator (dipole or reaction wheel). The spacecraft dynamical state (attitude, angular rate, and momentum) is controllable from any five-element subset of the six actuators. With loss of an actuator the instantaneous control authority may not span R(3) but the controllability gramian integral(limits between t,0) Phi(t, tau)B(tau )B(prime)(tau) Phi(prime)(t, tau)d tau retains full rank. Upon detection of an actuator failure the control torque is decomposed onto the remaining active axes. The attitude control torque is effected and the over-orbit momentum is controlled. The resulting control system performance approaches that of the nominal system.

  20. Non-redundant Aperture Masking Interferometry (AMI) and segment phasing with JWST-NIRISS

    Science.gov (United States)

    Sivaramakrishnan, Anand; Lafrenière, David; Ford, K. E. Saavik; McKernan, Barry; Cheetham, Anthony; Greenbaum, Alexandra Z.; Tuthill, Peter G.; Lloyd, James P.; Ireland, Michael J.; Doyon, René; Beaulieu, Mathilde; Martel, André; Koekemoer, Anton; Martinache, Frantz; Teuben, Peter

    2012-09-01

    The Aperture Masked Interferometry (AMI) mode on JWST-NIRISS is implemented as a 7-hole, 15% throughput, non-redundant mask (NRM) that operates with 5-8% bandwidth filters at 3.8, 4.3, and 4.8 microns. We present refined estimates of AMI's expected point-source contrast, using realizations of noise matched to JWST pointing requirements, NIRISS detector noise, and Rev-V JWST wavefront error models for the telescope and instrument. We describe our point-source binary data reduction algorithm, which we use as a standardized method to compare different observational strategies. For a 7.5 magnitude star we report a 10-a detection at between 8.7 and 9.2 magnitudes of contrast between 100 mas to 400 mas respectively, using closure phases and squared visibilities in the absence of bad pixels, but with various other noise sources. With 3% of the pixels unusable, the expected contrast drops by about 0.5 magnitudes. AMI should be able to reach targets as bright as M=5. There will be significant overlap between Gemini-GPI and ESO-SPHERE targets and AMI's search space, and a complementarity with NIRCam's coronagraph. We also illustrate synthesis imaging with AMI, demonstrating an imaging dynamic range of 25 at 100 mas scales. We tailor existing radio interferometric methods to retrieve a faint bar across a bright nucleus, and explain the similarities to synthesis imaging at radio wavelengths. Modest contrast observations of dusty accretion flows around AGNs will be feasible for NIRISS AMI. We show our early results of image-plane deconvolution as well. Finally, we report progress on an NRM-inspired approach to mitigate mission-level risk associated with JWST's specialized wavefront sensing hardware. By combining narrow band and medium band Nyquist-sampled images taken with a science camera we can sense JWST primary mirror segment tip-tilt to lOmas, and piston to a few nm. We can sense inter-segment piston errors of up to 5 coherence lengths of the broadest bandpass filter used

  1. NCBI Reference Sequence (RefSeq): a curated non-redundant sequence database of genomes, transcripts and proteins.

    Science.gov (United States)

    Pruitt, Kim D; Tatusova, Tatiana; Maglott, Donna R

    2005-01-01

    The National Center for Biotechnology Information (NCBI) Reference Sequence (RefSeq) database (http://www.ncbi.nlm.nih.gov/RefSeq/) provides a non-redundant collection of sequences representing genomic data, transcripts and proteins. Although the goal is to provide a comprehensive dataset representing the complete sequence information for any given species, the database pragmatically includes sequence data that are currently publicly available in the archival databases. The database incorporates data from over 2400 organisms and includes over one million proteins representing significant taxonomic diversity spanning prokaryotes, eukaryotes and viruses. Nucleotide and protein sequences are explicitly linked, and the sequences are linked to other resources including the NCBI Map Viewer and Gene. Sequences are annotated to include coding regions, conserved domains, variation, references, names, database cross-references, and other features using a combined approach of collaboration and other input from the scientific community, automated annotation, propagation from GenBank and curation by NCBI staff.

  2. Analysis of knockout mutants reveals non-redundant functions of poly(ADP-ribose)polymerase isoforms in Arabidopsis.

    Science.gov (United States)

    Pham, Phuong Anh; Wahl, Vanessa; Tohge, Takayuki; de Souza, Laise Rosado; Zhang, Youjun; Do, Phuc Thi; Olas, Justyna J; Stitt, Mark; Araújo, Wagner L; Fernie, Alisdair R

    2015-11-01

    The enzyme poly(ADP-ribose)polymerase (PARP) has a dual function being involved both in the poly(ADP-ribosyl)ation and being a constituent of the NAD(+) salvage pathway. To date most studies, both in plant and non-plant systems, have focused on the signaling role of PARP in poly(ADP-ribosyl)ation rather than any role that can be ascribed to its metabolic function. In order to address this question we here used a combination of expression, transcript and protein localization studies of all three PARP isoforms of Arabidopsis alongside physiological analysis of the corresponding mutants. Our analyses indicated that whilst all isoforms of PARP were localized to the nucleus they are also present in non-nuclear locations with parp1 and parp3 also localised in the cytosol, and parp2 also present in the mitochondria. We next isolated and characterized insertional knockout mutants of all three isoforms confirming a complete knockout in the full length transcript levels of the target genes as well as a reduced total leaf NAD hydrolase activity in the two isoforms (PARP1, PARP2) that are highly expressed in leaves. Physiological evaluation of the mutant lines revealed that they displayed distinctive metabolic and root growth characteristics albeit unaltered leaf morphology under optimal growth conditions. We therefore conclude that the PARP isoforms play non-redundant non-nuclear metabolic roles and that their function is highly important in rapidly growing tissues such as the shoot apical meristem, roots and seeds.

  3. NCBI reference sequences (RefSeq): a curated non-redundant sequence database of genomes, transcripts and proteins.

    Science.gov (United States)

    Pruitt, Kim D; Tatusova, Tatiana; Maglott, Donna R

    2007-01-01

    NCBI's reference sequence (RefSeq) database (http://www.ncbi.nlm.nih.gov/RefSeq/) is a curated non-redundant collection of sequences representing genomes, transcripts and proteins. The database includes 3774 organisms spanning prokaryotes, eukaryotes and viruses, and has records for 2,879,860 proteins (RefSeq release 19). RefSeq records integrate information from multiple sources, when additional data are available from those sources and therefore represent a current description of the sequence and its features. Annotations include coding regions, conserved domains, tRNAs, sequence tagged sites (STS), variation, references, gene and protein product names, and database cross-references. Sequence is reviewed and features are added using a combined approach of collaboration and other input from the scientific community, prediction, propagation from GenBank and curation by NCBI staff. The format of all RefSeq records is validated, and an increasing number of tests are being applied to evaluate the quality of sequence and annotation, especially in the context of complete genomic sequence.

  4. A graph-theoretic approach for identifying non-redundant and relevant gene markers from microarray data using multiobjective binary PSO.

    Science.gov (United States)

    Mandal, Monalisa; Mukhopadhyay, Anirban

    2014-01-01

    The purpose of feature selection is to identify the relevant and non-redundant features from a dataset. In this article, the feature selection problem is organized as a graph-theoretic problem where a feature-dissimilarity graph is shaped from the data matrix. The nodes represent features and the edges represent their dissimilarity. Both nodes and edges are given weight according to the feature's relevance and dissimilarity among the features, respectively. The problem of finding relevant and non-redundant features is then mapped into densest subgraph finding problem. We have proposed a multiobjective particle swarm optimization (PSO)-based algorithm that optimizes average node-weight and average edge-weight of the candidate subgraph simultaneously. The proposed algorithm is applied for identifying relevant and non-redundant disease-related genes from microarray gene expression data. The performance of the proposed method is compared with that of several other existing feature selection techniques on different real-life microarray gene expression datasets.

  5. A graph-theoretic approach for identifying non-redundant and relevant gene markers from microarray data using multiobjective binary PSO.

    Directory of Open Access Journals (Sweden)

    Monalisa Mandal

    Full Text Available The purpose of feature selection is to identify the relevant and non-redundant features from a dataset. In this article, the feature selection problem is organized as a graph-theoretic problem where a feature-dissimilarity graph is shaped from the data matrix. The nodes represent features and the edges represent their dissimilarity. Both nodes and edges are given weight according to the feature's relevance and dissimilarity among the features, respectively. The problem of finding relevant and non-redundant features is then mapped into densest subgraph finding problem. We have proposed a multiobjective particle swarm optimization (PSO-based algorithm that optimizes average node-weight and average edge-weight of the candidate subgraph simultaneously. The proposed algorithm is applied for identifying relevant and non-redundant disease-related genes from microarray gene expression data. The performance of the proposed method is compared with that of several other existing feature selection techniques on different real-life microarray gene expression datasets.

  6. Algorithm for Generating Non-Redundant Association Rules%一种无冗余的关联规则发现算法

    Institute of Scientific and Technical Information of China (English)

    高峰; 谢剑英

    2001-01-01

    关联规则是数据挖掘的重要研究内容之一,而传统算法生成的关联规则之间存在着大量的冗余规则.本文提出了一种通用的由最大频繁项目集生成无冗余关联规则的GNRR算法,利用规则之间的冗余关系,按一定顺序挖掘不同的规则,消除了规则之间的冗余性,使发现的规则数目呈指数倍减少.%The discovery of association rules is an important research topic in data mining, but the traditional association rules discovery algorithm produces too many redundant rules. This paper presented a general algorithm for mining non-redundant rules from the largest frequent itemsets using the redundant relationship of rules. The algorithm eliminates the redundancy between the rules and reduces the number of rules exponentially.

  7. GFExtractor:事件序列上有效挖掘无冗余情节规则的算法%GFExtractor:algorithm of mining non-redundant episode rules effectively in event sequence

    Institute of Scientific and Technical Information of China (English)

    袁红娟

    2013-01-01

    事件序列上挖掘情节规则,旨在发现情节之间的因果关系。基于非重叠的最小发生的支持度定义及深度优先搜索策略,提出在事件序列上挖掘无冗余情节规则的GFExtractor算法。利用非生成子情节的剪枝策略,淘汰非生成子情节;利用向前、向后扩展检查,淘汰非闭情节;最终在情节生成子集Gen与频繁闭情节集FCE之间产生无冗余的情节规则。实验结果证实了算法在事件序列上挖掘无冗余情节规则的有效性。%Mining episode rules in event sequence aims to discover the causal relationship between the episodes. To mine non-redundant episode rules in event sequence, the algorithm of GFExtractor is proposed in this paper, based on the support defi-nition of non-overlapping minimal occurrences and the depth-first search strategy. GFExtractor uses the pruning technology to eliminate non-generator episodes, and uses the forward and backward extension check to eliminate non-closed episodes. Non-redundant episode rules are generated between a superset of Gen and FCE. Experimental results confirm the validity of algo-rithm in mining non-redundant episode rules in event sequence.

  8. NARG Algorithm of Extracting Non-redundant Association Rule in Concept Lattice%概念格上无冗余关联规则的提取算法NARG

    Institute of Scientific and Technical Information of China (English)

    苗茹; 沈夏炯; 胡小华

    2009-01-01

    Association roles are the very valuable kind of law in data mining. A large number of rules arc usually generated from database using ordinary mining algorithms. Especially when the minimal support and minimal confidence are reduced, the number of association rules rise rapidly. The key of eliminating redundant association rules is to reduce rules without losing data information. This paper presents a new algorithm called NARG to extract non-redundant association rules based on concept lattice and properties of redundant association rules. This algorithm can gain the minimal non-redundant set of association rules while effectively improve efficiency of extracting rules without losing any information of data.%在数据挖掘中,关联规则是很有价值的一类规律.普通的挖掘算法会产生大量的规则,尤其是当最小支持度和最小可信度减少时,关联规则的数目急剧上升.如何对规则进行约减而又不丢失数据信息是消除冗余关联规则的关键.根据概念格的理论和冗余关联规则的性质,提出在概念格上提取无冗余关联规则的NARG算法.该算法可以得到最小的无冗余的关联规则集,而且不丢失任何信息,可有效提高关联规则生成的效率.

  9. Optimization of diagnostic strategy in non-redundant multi-fault system based on probability threshold%基于概率阈的非冗余多故障系统诊断策略优化

    Institute of Scientific and Technical Information of China (English)

    朱海鹏; 景博; 黄以锋; 苏俊阳

    2012-01-01

    针对传统的单故障假设无法诊断复杂系统多故障并发的情况,提出了一种基于概率阈的非冗余系统多故障诊断策略.首先对系统的相关性模型进行扩展,并删除低于概率阈的故障状态,建立非冗余系统的多故障测试诊断模型;其次在信息熵算法的基础上建立Rollout算法,获得了最优测试序列;然后建立故障诊断树并计算测试代价;最后以某机载电子系统为例验证了该方法的有效性.该方法可以在保证测试费用最小的情况下获得非冗余系统的最优测试序列.%This paper propsoed a multiple fault diagnostic strategy for non-redundant system based on probability threshold. Firstly,it expanded system dependency models, removed fault states which were below probability threshold, and established multiple fault diagnostic models of non-redundant system. Then using entropy algorithm as base algorithm, it presented Rollout algorithm to obtain best test sequence. At last.it built the fault diagnosis tree and calculated test cost. It put forward an airborne electronic system to prove its effectiveness. It can obtain the best test sequence by minimums cost test.

  10. Development of a cDNA array for chicken gene expression analysis

    Directory of Open Access Journals (Sweden)

    Burt David

    2005-02-01

    Full Text Available Abstract Background The application of microarray technology to functional genomic analysis in the chicken has been limited by the lack of arrays containing large numbers of genes. Results We have produced cDNA arrays using chicken EST collections generated by BBSRC, University of Delaware and the Fred Hutchinson Cancer Research Center. From a total of 363,838 chicken ESTs representing 24 different adult or embryonic tissues, a set of 11,447 non-redundant ESTs were selected and added to an existing collection of clones (4,162 from immune tissues and a chicken bursal cell line (DT40. Quality control analysis indicates there are 13,007 useable features on the array, including 160 control spots. The array provides broad coverage of mRNAs expressed in many tissues; in addition, clones with expression unique to various tissues can be detected. Conclusions A chicken multi-tissue cDNA microarray with 13,007 features is now available to academic researchers from genomics@fhcrc.org. Sequence information for all features on the array is in GenBank, and clones can be readily obtained. Targeted users include researchers in comparative and developmental biology, immunology, vaccine and agricultural technology. These arrays will be an important resource for the entire research community using the chicken as a model.

  11. Filter arrays

    Energy Technology Data Exchange (ETDEWEB)

    Page, Ralph H.; Doty, Patrick F.

    2017-08-01

    The various technologies presented herein relate to a tiled filter array that can be used in connection with performance of spatial sampling of optical signals. The filter array comprises filter tiles, wherein a first plurality of filter tiles are formed from a first material, the first material being configured such that only photons having wavelengths in a first wavelength band pass therethrough. A second plurality of filter tiles is formed from a second material, the second material being configured such that only photons having wavelengths in a second wavelength band pass therethrough. The first plurality of filter tiles and the second plurality of filter tiles can be interspersed to form the filter array comprising an alternating arrangement of first filter tiles and second filter tiles.

  12. Global Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamoorthy, Sriram; Daily, Jeffrey A.; Vishnu, Abhinav; Palmer, Bruce J.

    2015-11-01

    Global Arrays (GA) is a distributed-memory programming model that allows for shared-memory-style programming combined with one-sided communication, to create a set of tools that combine high performance with ease-of-use. GA exposes a relatively straightforward programming abstraction, while supporting fully-distributed data structures, locality of reference, and high-performance communication. GA was originally formulated in the early 1990’s to provide a communication layer for the Northwest Chemistry (NWChem) suite of chemistry modeling codes that was being developed concurrently.

  13. Delay Spectrum with Phase-Tracking Arrays: Extracting the HI power spectrum from the Epoch of Reionization

    CERN Document Server

    Paul, Sourabh; Morales, Miguel F; Dwarkanath, K S; Shankar, N Udaya; Subrahmanyan, Ravi; Barry, N; Beardsley, A P; Bowman, Judd D; Briggs, F; Carroll, P; de Oliveira-Costa, A; Dillon, Joshua S; Ewall-Wice, A; Feng, L; Greenhill, L J; Gaensler, B M; Hazelton, B J; Hewitt, J N; Hurley-Walker, N; Jacobs, D J; Kim, Han-Seek; Kittiwisit, P; Lenc, E; Line, J; Loeb, A; McKinley, B; Mitchell, D A; Neben, A R; Offringa, A R; Pindor, B; Pober, J C; Procopio, P; Riding, J; Sullivan, I S; Tegmark, M; Thyagarajan, Nithyanandan; Tingay, S J; Trott, C M; Wayth, R B; Webster, R L; Wyithe, J S B; Cappallo, Roger; Johnston-Hollitt, M; Kaplan, D L; Lonsdale, C J; McWhirter, S R; Morgan, E; Oberoi, D; Ord, S M; Prabu, T; Srivani, K S; Williams, A; Williams, C L

    2016-01-01

    The Detection of redshifted 21 cm emission from the epoch of reionization (EoR) is a challenging task owing to strong foregrounds that dominate the signal. In this paper, we propose a general method, based on the delay spectrum approach, to extract HI power spectra that is applicable to tracking observations using an imaging radio interferometer (Delay Spectrum with Imaging Arrays (DSIA)). Our method is based on modelling the HI signal taking into account the impact of wide field effects such as the $w$-term which are then used as appropriate weights in cross-correlating the measured visibilities. Our method is applicable to any radio interferometer that tracks a phase center and could be utilized for arrays such as MWA, LOFAR, GMRT, PAPER and HERA. In the literature the delay spectrum approach has been implemented for near-redundant baselines using drift scan observations. In this paper we explore the scheme for non-redundant tracking arrays, and this is the first application of delay spectrum methodology to...

  14. Coupling in reflector arrays

    DEFF Research Database (Denmark)

    Appel-Hansen, Jørgen

    1968-01-01

    In order to reduce the space occupied by a reflector array, it is desirable to arrange the array antennas as close to each other as possible; however, in this case coupling between the array antennas will reduce the reflecting properties of the reflector array. The purpose of the present communic...

  15. Clocked combustor can array

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won-Wook; McMahan, Kevin Weston; Srinivasan, Shiva Kumar

    2017-01-17

    The present application provides a clocked combustor can array for coherence reduction in a gas turbine engine. The clocked combustor can array may include a number of combustor cans positioned in a circumferential array. A first set of the combustor cans may have a first orientation and a second set of the combustor cans may have a second orientation.

  16. Axiom turkey genotyping array

    Science.gov (United States)

    The Axiom®Turkey Genotyping Array interrogates 643,845 probesets on the array, covering 643,845 SNPs. The array development was led by Dr. Julie Long of the USDA-ARS Beltsville Agricultural Research Center under a public-private partnership with Hendrix Genetics, Aviagen, and Affymetrix. The Turk...

  17. Clocked combustor can array

    Science.gov (United States)

    Kim, Won-Wook; McMahan, Kevin Weston; Srinivasan, Shiva Kumar

    2017-01-17

    The present application provides a clocked combustor can array for coherence reduction in a gas turbine engine. The clocked combustor can array may include a number of combustor cans positioned in a circumferential array. A first set of the combustor cans may have a first orientation and a second set of the combustor cans may have a second orientation.

  18. Novel optical super-resolution pattern with upright edges diffracted by a tiny thin aperture.

    Science.gov (United States)

    Wu, Jiu Hui; Zhou, Kejiang

    2015-08-24

    In the past decade numerous efforts have been concentrated to achieve optical imaging resolution beyond the diffraction limit. In this letter a thin microcavity theory of near-field optics is proposed by using the power flow theorem firstly. According to this theory, the near-field optical diffraction from a tiny aperture whose diameter is less than one-tenth incident wavelength embedded in a thin conducting film is investigated by considering this tiny aperture as a thin nanocavity. It is very surprising that there exists a kind of novel super-resolution diffraction patterns showing resolution better than λ/80 (λ is the incident wavelength), which is revealed for the first time to our knowledge in this letter. The mechanism that has allowed the imaging with this kind of super-resolution patterns is due to the interaction between the incident wave and the thin nanocavity with a complex wavenumber. More precisely, these super-resolution patterns with discontinuous upright peaks are formed by one or three items of the integration series about the cylindrical waves according to our simulation results. This novel optical super-resolution with upright edges by using the thin microcavity theory presented in the study could have potential applications in the future semiconductor lithography process, nano-size laser-drilling technology, microscopy, optical storage, optical switch, and optical information processing.

  19. Electronic Switch Arrays for Managing Microbattery Arrays

    Science.gov (United States)

    Mojarradi, Mohammad; Alahmad, Mahmoud; Sukumar, Vinesh; Zghoul, Fadi; Buck, Kevin; Hess, Herbert; Li, Harry; Cox, David

    2008-01-01

    Integrated circuits have been invented for managing the charging and discharging of such advanced miniature energy-storage devices as planar arrays of microscopic energy-storage elements [typically, microscopic electrochemical cells (microbatteries) or microcapacitors]. The architecture of these circuits enables implementation of the following energy-management options: dynamic configuration of the elements of an array into a series or parallel combination of banks (subarrarys), each array comprising a series of parallel combination of elements; direct addressing of individual banks for charging/or discharging; and, disconnection of defective elements and corresponding reconfiguration of the rest of the array to utilize the remaining functional elements to obtain the desited voltage and current performance. An integrated circuit according to the invention consists partly of a planar array of field-effect transistors that function as switches for routing electric power among the energy-storage elements, the power source, and the load. To connect the energy-storage elements to the power source for charging, a specific subset of switches is closed; to connect the energy-storage elements to the load for discharging, a different specific set of switches is closed. Also included in the integrated circuit is circuitry for monitoring and controlling charging and discharging. The control and monitoring circuitry, the switching transistors, and interconnecting metal lines are laid out on the integrated-circuit chip in a pattern that registers with the array of energy-storage elements. There is a design option to either (1) fabricate the energy-storage elements in the corresponding locations on, and as an integral part of, this integrated circuit; or (2) following a flip-chip approach, fabricate the array of energy-storage elements on a separate integrated-circuit chip and then align and bond the two chips together.

  20. Array Antenna Limitations

    CERN Document Server

    Jonsson, B L G; Hussain, N

    2013-01-01

    This letter defines a physical bound based array figure of merit that provides a tool to compare the performance of both single and multi-band array antennas with respect to return-loss, thickness of the array over the ground-plane, and scan-range. The result is based on a sum-rule result of Rozanov-type for linear polarization. For single-band antennas it extends an existing limit for a given fixed scan-angle to include the whole scan-range of the array, as well as the unit-cell structure in the bound. The letter ends with an investigation of the array figure of merit for some wideband and/or wide-scan antennas with linear polarization. We find arrays with a figure of merit >0.6 that empirically defines high-performance antennas with respect to this measure.

  1. Carbon nanotube nanoelectrode arrays

    Science.gov (United States)

    Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

    2008-11-18

    The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

  2. Pacific Array (Transportable Broadband Ocean Floor Array)

    Science.gov (United States)

    Kawakatsu, Hitoshi; Ekstrom, Goran; Evans, Rob; Forsyth, Don; Gaherty, Jim; Kennett, Brian; Montagner, Jean-Paul; Utada, Hisashi

    2016-04-01

    Based on recent developments on broadband ocean bottom seismometry, we propose a next generation large-scale array experiment in the ocean. Recent advances in ocean bottom broadband seismometry1, together with advances in the seismic analysis methodology, have enabled us to resolve the regional 1-D structure of the entire lithosphere/asthenosphere system, including seismic anisotropy (azimuthal, and hopefully radial), with deployments of ~15 broadband ocean bottom seismometers (BBOBSs). Having ~15 BBOBSs as an array unit for a 2-year deployment, and repeating such deployments in a leap-frog way or concurrently (an array of arrays) for a decade or so would enable us to cover a large portion of the Pacific basin. Such efforts, not only by giving regional constraints on the 1-D structure beneath Pacific ocean, but also by sharing waveform data for global scale waveform tomography, would drastically increase our knowledge of how plate tectonics works on this planet, as well as how it worked for the past 150 million years. International collaborations is essential: if three countries/institutions participate this endeavor together, Pacific Array may be accomplished within five-or-so years.

  3. Dynamically Reconfigurable Microphone Arrays

    Science.gov (United States)

    2011-05-01

    Static + 2 Wireless Using only a standard computer sound card, a robot is limited to binaural inputs. Even when using wireless microphones, the audio...Abstract—Robotic sound localization has traditionally been restricted to either on-robot microphone arrays or embedded microphones in aware...a microphone array has a significant impact on the mathematics of sound source localization. Arrays, for instance, are commonly designed to

  4. Integrated avalanche photodiode arrays

    Science.gov (United States)

    Harmon, Eric S.

    2015-07-07

    The present disclosure includes devices for detecting photons, including avalanche photon detectors, arrays of such detectors, and circuits including such arrays. In some aspects, the detectors and arrays include a virtual beveled edge mesa structure surrounded by resistive material damaged by ion implantation and having side wall profiles that taper inwardly towards the top of the mesa structures, or towards the direction from which the ion implantation occurred. Other aspects are directed to masking and multiple implantation and/or annealing steps. Furthermore, methods for fabricating and using such devices, circuits and arrays are disclosed.

  5. Focal plane array with modular pixel array components for scalability

    Energy Technology Data Exchange (ETDEWEB)

    Kay, Randolph R; Campbell, David V; Shinde, Subhash L; Rienstra, Jeffrey L; Serkland, Darwin K; Holmes, Michael L

    2014-12-09

    A modular, scalable focal plane array is provided as an array of integrated circuit dice, wherein each die includes a given amount of modular pixel array circuitry. The array of dice effectively multiplies the amount of modular pixel array circuitry to produce a larger pixel array without increasing die size. Desired pixel pitch across the enlarged pixel array is preserved by forming die stacks with each pixel array circuitry die stacked on a separate die that contains the corresponding signal processing circuitry. Techniques for die stack interconnections and die stack placement are implemented to ensure that the desired pixel pitch is preserved across the enlarged pixel array.

  6. Analysis of VCSEL Array Module Using a Simple Microlens Array

    Institute of Scientific and Technical Information of China (English)

    Hen-Wai; Tsao; Shyh-Lin; Tsao

    2003-01-01

    A simple microlens array is designed between VCSEL array and fiber array for integration of array module. We increase the optical coupling efficiency from -32.057 dBm to -0.9054 dBm by using our designed microlens array.

  7. Analysis of VCSEL Array Module Using a Simple Microlens Array

    Institute of Scientific and Technical Information of China (English)

    Wen-Ming Cheng; Hen-Wai Tsao; Shyh-Lin Tsao

    2003-01-01

    A simple microlens array is designed between VCSEL array and fiber array for integration of array module. We increase the optical coupling efficiency from-32.057 dBm to-0.9054 dBm by using our designed microlens array.

  8. Solar array deployment mechanism

    Science.gov (United States)

    Calassa, Mark C.; Kackley, Russell

    1995-05-01

    This paper describes a Solar Array Deployment Mechanism (SADM) used to deploy a rigid solar array panel on a commercial spacecraft. The application required a deployment mechanism design that was not only lightweight, but also could be produced and installed at the lowest possible cost. This paper covers design, test, and analysis of a mechanism that meets these requirements.

  9. Array for detecting microbes

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Gary L.; DeSantis, Todd D.

    2014-07-08

    The present embodiments relate to an array system for detecting and identifying biomolecules and organisms. More specifically, the present embodiments relate to an array system comprising a microarray configured to simultaneously detect a plurality of organisms in a sample at a high confidence level.

  10. Photovoltaic array loss mechanisms

    Science.gov (United States)

    Gonzalez, Charles

    1986-10-01

    Loss mechanisms which come into play when solar cell modules are mounted in arrays are identified. Losses can occur either from a reduction in the array electrical performance or with nonoptimal extraction of power from the array. Electrical performance degradation is caused by electrical mismatch, transmission losses from cell surface soiling and steep angle of reflectance, and electrical losses from field wiring resistance and the voltage drop across blocking diodes. The second type of loss, concerned with the operating points of the array, can involve nonoptimal load impedance and limiting the operating envelope of the array to specific ranges of voltage and current. Each of the loss mechanisms are discussed and average energy losses expected from soiling, steep reflectance angles and circuit losses are calculated.

  11. Microfabricated ion trap array

    Science.gov (United States)

    Blain, Matthew G.; Fleming, James G.

    2006-12-26

    A microfabricated ion trap array, comprising a plurality of ion traps having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale ion traps to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The reduced electrode voltage enables integration of the microfabricated ion trap array with on-chip circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of the microfabricated ion trap array can be realized in truly field portable, handheld microanalysis systems.

  12. Identification of Differentially Expressed Genes During Anther Abortion of Taigu Genic Male Sterile Wheat by Combining Suppression Subtractive Hybridization and cDNA Array

    Institute of Scientific and Technical Information of China (English)

    Qing-Shan Chang; Rong-Hua Zhou; Xiu-Ying Kong; Zeng-Liang Yu; Ji-Zeng Jia

    2006-01-01

    Taigu Genic Male Sterile Wheat (TGMSW; Triticum aestivum L.), a dominant genic male sterile germplasm, is of considerable value in the genetic improvement of wheat because of its stable inherence, complete male abortion, and high cross-fertilization rate. To identify specially transcribed genes in sterile anther, a suppression subtractive hybridization (SSH) library was constructed with sterile anther as the tester and fertile anther as the driver. A total of 2 304 SSH inserts amplified by polymerase chain reaction were arrayed using robotic printing. The cDNA arrays were hybridized with 32P-labeled probes prepared from the RNA of forward- and reverse-subtracted anthers. Ninety-six clones were scored as upregulated in sterile anthers compared with the corresponding fertile anthers and some clones were selected for sequencing and analysis in GenBank. Based on their putative functions, 87 non-redundant clones were classified into the following groups: (i) eight genes involved in metabolic processes; (ii) four material transportation genes;(iii) three signal transduction-associated genes; (iv) four stress response and senescence-associated protein genes; (v) seven other functional protein genes; (vi) five genes with no known function; and (vii)another 56 genes with no match to the databases. To test the hybridization efficiency, eight genes were selected and analyzed by Northern blot. The results of the present study provide a comprehensive overview of the genes and gene products involved in anther abortion in TGMSW.

  13. Introduction to adaptive arrays

    CERN Document Server

    Monzingo, Bob; Haupt, Randy

    2011-01-01

    This second edition is an extensive modernization of the bestselling introduction to the subject of adaptive array sensor systems. With the number of applications of adaptive array sensor systems growing each year, this look at the principles and fundamental techniques that are critical to these systems is more important than ever before. Introduction to Adaptive Arrays, 2nd Edition is organized as a tutorial, taking the reader by the hand and leading them through the maze of jargon that often surrounds this highly technical subject. It is easy to read and easy to follow as fundamental concept

  14. Piezoelectric transducer array microspeaker

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of a piezoelectric micro-speaker. The speaker is an array of micro-machined piezoelectric membranes, fabricated on silicon wafer using advanced micro-machining techniques. Each array contains 2n piezoelectric transducer membranes, where “n” is the bit number. Every element of the array has a circular shape structure. The membrane is made out four layers: 300nm of platinum for the bottom electrode, 250nm or lead zirconate titanate (PZT), a top electrode of 300nm and a structural layer of 50

  15. P systems with array objects and array rewriting rules

    Institute of Scientific and Technical Information of China (English)

    K.G. Subramanian; R. Saravanan; M. Geethalakshmi; P. Helen Chandra; M. Margenstern

    2007-01-01

    Array P systems were introduced by Pǎun Gh. which is linking the two areas of membrane computing and picture grammars. Puzzle grammars were introduced by us for generating connected picture arrays in the two-dimensional plane, motivated by the problem of tiling the plane. On the other hand, incorporating into arrays the developmental type of generation used in the well-known biologically motivated L systems, Siromoney and Siromoney proposed a very general rectangular array generating model, called extended controlled tabled L array system (ECTLAS). In this paper we introduce two variations of the array P system, called BPG array P system and parallel array P system. The former has in the regions array objects and basic puzzle grammar rules (BPG), which are a specific kind of puzzle grammar rules. In the latter, the regions have rectangular array objects and tables of context-free rules. We examine these two types of P systems for their array generative power.

  16. Protein Functionalized Nanodiamond Arrays

    Directory of Open Access Journals (Sweden)

    Liu YL

    2010-01-01

    Full Text Available Abstract Various nanoscale elements are currently being explored for bio-applications, such as in bio-images, bio-detection, and bio-sensors. Among them, nanodiamonds possess remarkable features such as low bio-cytotoxicity, good optical property in fluorescent and Raman spectra, and good photostability for bio-applications. In this work, we devise techniques to position functionalized nanodiamonds on self-assembled monolayer (SAMs arrays adsorbed on silicon and ITO substrates surface using electron beam lithography techniques. The nanodiamond arrays were functionalized with lysozyme to target a certain biomolecule or protein specifically. The optical properties of the nanodiamond-protein complex arrays were characterized by a high throughput confocal microscope. The synthesized nanodiamond-lysozyme complex arrays were found to still retain their functionality in interacting with E. coli.

  17. Using RNA-Seq to assemble a rose transcriptome with more than 13,000 full-length expressed genes and to develop the WagRhSNP 68k Axiom SNP array for rose (Rosa L.

    Directory of Open Access Journals (Sweden)

    Carole F S Koning-Boucoiran

    2015-04-01

    Full Text Available In order to develop a versatile and large SNP array for rose, we set out to mine ESTs from diverse sets of rose germplasm. For this RNA-Seq libraries containing about 700 million reads were generated from tetraploid cut and garden roses using Illumina paired-end sequencing, and from diploid Rosa multiflora using 454 sequencing. Separate de novo assemblies were performed in order to identify single nucleotide polymorphisms (SNPs within and between rose varieties. SNPs among tetraploid roses were selected for constructing a genotyping array that can be employed for genetic mapping and marker-trait association discovery in breeding programs based on tetraploid germplasm, both from cut roses and from garden roses. In total 68,893 SNPs were included on the WagRhSNP Axiom array.Next, an orthology-guided assembly was performed for the construction of a non-redundant rose transcriptome database. A total of 21,740 transcripts had significant hits with orthologous genes in the strawberry (Fragaria vesca L. genome. Of these 13,390 appeared to contain the full-length coding regions. This newly established transcriptome resource adds considerably to the currently available sequence resources for the Rosaceae family in general and the genus Rosa in particular.

  18. Improved array illuminators.

    Science.gov (United States)

    Lohmann, A W; Sinzinger, S

    1992-09-10

    The job of an array illuminator is to provide an array of optical gates or smart pixels with photon power or with synchronous clock signals. So far it has been common to take the power from one big laser and distribute it to perhaps a million gates. An obvious alternative is to assign one private small source to each gate. We favor an in-between approach: a few medium-size sources share the job of providing photons. This hybrid approach has several advantages, such as better homogeneity, less coherent noise, and a distributed risk of source failure. We propose several setups and present some experimental results. Our concept calls for an array of incoherent point sources. We simulate such an array experimentally with a single source, which is virtually expanded into a source array by grating diffraction. Ordinarily these virtual sources are mutually coherent, which is undesirable for our aims. We destroy the mutual coherence by moving the grating during the photographic recording of the output array.

  19. Digital Microrobotics based on bistable modules : Design of a non-redundant digital micropositioning robot.

    OpenAIRE

    Chalvet, Vincent; Zarycki, Artur; Haddab, Yassine; Lutz, Philippe

    2011-01-01

    International audience; High precision manipulation becomes a recurrent need in micro or nanoscale. Microrobots based on active material were designed to perform micromanipulation tasks in various environments such as microrobotic stations or electronic microscopes (SEM, TEM). These active materials are used to generate proportional actuation, but show some drawbacks we want to avoid (non linearity, integration of sensors, . . . ). In this paper we propose a new type of microrobot, called dig...

  20. 2H Singularity-Free Momentum Generation with Non-Redundant Single Gimbaled Control Moment Gyroscopes

    Science.gov (United States)

    2006-12-01

    Authorized licensed use limited to: Naval Postgraduate School. Downloaded on May 29, 2009 at 14:31 from IEEE Xplore . Restrictions apply. Proceedings...from IEEE Xplore . Restrictions apply. 45th IEEE CDC, San Diego, USA, Dec. 13-15, 2006 The Newton-Euler relation relates generated torque to the timed...May 29, 2009 at 14:31 from IEEE Xplore . Restrictions apply. 45th IEEE CDC, San Diego, USA, Dec. 13-15, 2006 20 40 60 80 CMG Skew Angle, ~ Fig. 3

  1. ‘JANE EYRE’:A SIMPLE EXPERIMENT WITH A NON-REDUNDANT BILINGUAL SIMPLIFIED TEXT

    Institute of Scientific and Technical Information of China (English)

    David; Kellogg

    1997-01-01

    What do film subtitles,airport announcements,labels on products for export,simultaneousinterpreters,and vocabulary glosses all have in common?All are bilingual texts,of course,but morethan that they are all redundant,at least for the truly bilingual.Yet there is something irresistiblyseductive about the redundant part of bilingual texts for the language student.To paraphrase OscarWilde,an English student of French can resist almost anything except the temptation to read Englishsubtitles during a French movie or to listen to all four sides of a simultaneously translated argument.Perhaps the temptation lies in our insecurity that we really can understand the original,or in thehopelessly naive quest for the"exact"meaning of language items.With a flick of the eyess.the road

  2. Pentraxin 3, a non-redundant soluble pattern recognition receptor involved in innate immunity.

    Science.gov (United States)

    Mantovani, Alberto; Garlanda, Cecilia; Bottazzi, Barbara

    2003-06-01

    Pentraxin 3 (PTX3) is the first long pentraxin identified. Long pentraxins consist of a C-terminal pentraxin domain, which has sequence similarity to C-reactive protein (CRP) and serum amyloid P (SAP) component (the classic short pentraxins), and of an unrelated N-terminal portion. PTX3 is made by diverse cell types, most prominently endothelial cells, macrophages and dendritic cells, in response to primary inflammatory signals (e.g. interleukin-1 (IL-1), tumour necrosis factor (TNF), lipopolysaccharide (LPS)). It binds diverse ligands, including microbial moieties, C1q and apoptotic cells. Evidence suggests that PTX3 plays a role in the regulation of innate resistance to pathogens, inflammatory reactions, possibly clearance of self-components and female fertility.

  3. GeneCodis3: a non-redundant and modular enrichment analysis tool for functional genomics.

    Science.gov (United States)

    Tabas-Madrid, Daniel; Nogales-Cadenas, Ruben; Pascual-Montano, Alberto

    2012-07-01

    Since its first release in 2007, GeneCodis has become a valuable tool to functionally interpret results from experimental techniques in genomics. This web-based application integrates different sources of information to finding groups of genes with similar biological meaning. This process, known as enrichment analysis, is essential in the interpretation of high-throughput experiments. The frequent feedbacks and the natural evolution of genomics and bioinformatics have allowed the growth of the tool and the development of this third release. In this version, a special effort has been made to remove noisy and redundant output from the enrichment results with the inclusion of a recently reported algorithm that summarizes significantly enriched terms and generates functionally coherent modules of genes and terms. A new comparative analysis has been added to allow the differential analysis of gene sets. To expand the scope of the application, new sources of biological information have been included, such as genetic diseases, drugs-genes interactions and Pubmed information among others. Finally, the graphic section has been renewed with the inclusion of new interactive graphics and filtering options. The application is freely available at http://genecodis.cnb.csic.es.

  4. On the structural basis of non-redundant acquisition: Evidence from Spanish bilingual L3 Portuguese.

    OpenAIRE

    Rothman, Jason; Giancaspro, David; Halloran, Becky

    2014-01-01

    This chapter has two goals: (a) to discuss the Spanish-Portuguese interface in current formal language acquisition research and (b) to highlight the contributions of this language pairing in the emerging field of formal third language acquisition. The authors discuss two L3 acquisition studies (Montrul, Dias, & Santos, 2011; Giancaspro, Halloran, & Iverson, in press) examining Differential Object Marking, a morphological case marker present in Spanish but not in Portuguese, ...

  5. Evaporating metal nanocrystal arrays

    Science.gov (United States)

    Zhang, Xue; Joy, James C.; Zhao, Chenwei; Kim, Jin Ho; Fernandes, Gustavo; Xu, J. M.; Valles, James M., Jr.

    2017-03-01

    Anodic aluminum oxide (AAO) substrates with a self-ordered triangular array of nanopores provide the means to fabricate multiple forms of nano materials, such as nanowires and nanoparticles. This study focuses on nanostructures that emerge in thin films of metals thermally evaporated onto the surface of AAO. Previous work showed that films of different evaporated metals assume dramatically different structures, e.g. an ordered triangular array of nearly monodisperse nanoparticles forms for lead (Pb) while a polycrystalline nanohoneycomb structure forms for silver (Ag). Here, we present investigations of the effects of substrate temperature and deposition angle that reveal the processes controlling the nano particle array formation. Our findings indicate that arrays form provided the grain nucleation density exceeds the pore density and the atomic mobility is high enough to promote grain coalescence. They introduce a method for producing films with anisotropic grain array structure. The results provide insight into the influence of substrate nano-morphology on thin film growth energetics and kinetics that can be harnessed for creating films with other novel nano-structures.

  6. Wireless Josephson Junction Arrays

    Science.gov (United States)

    Adams, Laura

    2015-03-01

    We report low temperature, microwave transmission measurements on a wireless two- dimensional network of Josephson junction arrays composed of superconductor-insulator -superconductor tunnel junctions. Unlike their biased counterparts, by removing all electrical contacts to the arrays and superfluous microwave components and interconnects in the transmission line, we observe new collective behavior in the transmission spectra. In particular we will show emergent behavior that systematically responds to changes in microwave power at fixed temperature. Likewise we will show the dynamic and collective response of the arrays while tuning the temperature at fixed microwave power. We discuss these spectra in terms of the Berezinskii-Kosterlitz-Thouless phase transition and Shapiro steps. We gratefully acknowledge the support Prof. Steven Anlage at the University of Maryland and Prof. Allen Goldman at the University of Minnesota. Physics and School of Engineering and Applied Sciences.

  7. Photovoltaic array performance model.

    Energy Technology Data Exchange (ETDEWEB)

    Kratochvil, Jay A.; Boyson, William Earl; King, David L.

    2004-08-01

    This document summarizes the equations and applications associated with the photovoltaic array performance model developed at Sandia National Laboratories over the last twelve years. Electrical, thermal, and optical characteristics for photovoltaic modules are included in the model, and the model is designed to use hourly solar resource and meteorological data. The versatility and accuracy of the model has been validated for flat-plate modules (all technologies) and for concentrator modules, as well as for large arrays of modules. Applications include system design and sizing, 'translation' of field performance measurements to standard reporting conditions, system performance optimization, and real-time comparison of measured versus expected system performance.

  8. The Submillimeter Array

    CERN Document Server

    Ho, P T P; Lo, K Y; Ho, Paul T.P.; Moran, James M.; Lo, Kwok Yung

    2004-01-01

    The Submillimeter Array (SMA), a collaborative project of the Smithsonian Astrophysical Observatory (SAO) and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), has begun operation on Mauna Kea in Hawaii. A total of eight 6-m telescopes comprise the array, which will cover the frequency range of 180-900 GHz. All eight telescopes have been deployed and are operational. First scientific results utilizing the three receiver bands at 230, 345, and 690 GHz have been obtained and are presented in the accompanying papers.

  9. Wire Array Photovoltaics

    Science.gov (United States)

    Turner-Evans, Dan

    Over the past five years, the cost of solar panels has dropped drastically and, in concert, the number of installed modules has risen exponentially. However, solar electricity is still more than twice as expensive as electricity from a natural gas plant. Fortunately, wire array solar cells have emerged as a promising technology for further lowering the cost of solar. Si wire array solar cells are formed with a unique, low cost growth method and use 100 times less material than conventional Si cells. The wires can be embedded in a transparent, flexible polymer to create a free-standing array that can be rolled up for easy installation in a variety of form factors. Furthermore, by incorporating multijunctions into the wire morphology, higher efficiencies can be achieved while taking advantage of the unique defect relaxation pathways afforded by the 3D wire geometry. The work in this thesis shepherded Si wires from undoped arrays to flexible, functional large area devices and laid the groundwork for multijunction wire array cells. Fabrication techniques were developed to turn intrinsic Si wires into full p-n junctions and the wires were passivated with a-Si:H and a-SiNx:H. Single wire devices yielded open circuit voltages of 600 mV and efficiencies of 9%. The arrays were then embedded in a polymer and contacted with a transparent, flexible, Ni nanoparticle and Ag nanowire top contact. The contact connected >99% of the wires in parallel and yielded flexible, substrate free solar cells featuring hundreds of thousands of wires. Building on the success of the Si wire arrays, GaP was epitaxially grown on the material to create heterostructures for photoelectrochemistry. These cells were limited by low absorption in the GaP due to its indirect bandgap, and poor current collection due to a diffusion length of only 80 nm. However, GaAsP on SiGe offers a superior combination of materials, and wire architectures based on these semiconductors were investigated for multijunction

  10. Selecting Sums in Arrays

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Jørgensen, Allan Grønlund

    2008-01-01

    In an array of n numbers each of the \\binomn2+nUnknown control sequence '\\binom' contiguous subarrays define a sum. In this paper we focus on algorithms for selecting and reporting maximal sums from an array of numbers. First, we consider the problem of reporting k subarrays inducing the k larges...... an algorithm with this running time and by proving a matching lower bound. Finally, we combine the ideas and obtain an O(n· max {1,log(k/n)}) time algorithm that selects a subarray storing the k’th largest sum among all subarrays of length at least l and at most u....

  11. Bandwidth Reconfigurable Metamaterial Arrays

    Directory of Open Access Journals (Sweden)

    Nathanael J. Smith

    2014-01-01

    Full Text Available Metamaterial structures provide innovative ways to manipulate electromagnetic wave responses to realize new applications. This paper presents a conformal wideband metamaterial array that achieves as much as 10 : 1 continuous bandwidth. This was done by using interelement coupling to concurrently achieve significant wave slow-down and cancel the inductance stemming from the ground plane. The corresponding equivalent circuit of the resulting array is the same as that of classic metamaterial structures. In this paper, we present a wideband Marchand-type balun with validation measurements demonstrating the metamaterial (MTM array’s bandwidth from 280 MHz to 2800 MHz. Bandwidth reconfiguration of this class of array is then demonstrated achieving a variety of band-pass or band-rejection responses within its original bandwidth. In contrast with previous bandwidth and frequency response reconfigurations, our approach does not change the aperture’s or ground plane’s geometry, nor does it introduce external filtering structures. Instead, the new responses are realized by making simple circuit changes into the balanced feed integrated with the wideband MTM array. A variety of circuit changes can be employed using MEMS switches or variable lumped loads within the feed and 5 example band-pass and band-rejection responses are presented. These demonstrate the potential of the MTM array’s reconfiguration to address a variety of responses.

  12. Visible Genotype Sensor Array

    Directory of Open Access Journals (Sweden)

    Takashi Imai

    2008-04-01

    Full Text Available A visible sensor array system for simultaneous multiple SNP genotyping has been developed using a new plastic base with specific surface chemistry. Discrimination of SNP alleles is carried out by an allele-specific extension reaction using immobilized oligonucleotide primers. The 3’-ends of oligonucleotide primers are modified with a locked nucleic acid to enhance their efficiency in allelic discrimination. Biotin-dUTPs included in the reaction mixture are selectively incorporated into extending primer sequences and are utilized as tags for alkaline phosphatase-mediated precipitation of colored chemical substrates onto the surface of the plastic base. The visible precipitates allow immediate inspection of typing results by the naked eye and easy recording by a digital camera equipped on a commercial mobile phone. Up to four individuals can be analyzed on a single sensor array and multiple sensor arrays can be handled in a single operation. All of the reactions can be performed within one hour using conventional laboratory instruments. This visible genotype sensor array is suitable for “focused genomics” that follows “comprehensive genomics”.

  13. Extended Array Evaluation Program

    Science.gov (United States)

    1974-01-31

    irregular structure of the Mohorovicic discontinuity (Moho) underneath the NORSAR array. • Time delay anomalies (deviation from plane wave propagation...appears that most of the amplitude vari- ations may be explained by scattering effects due to the irregular structure of the Mohorovicic discontinuity

  14. Array processors in chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Ostlund, N.S.

    1980-01-01

    The field of attached scientific processors (''array processors'') is surveyed, and an attempt is made to indicate their present and possible future use in computational chemistry. The current commercial products from Floating Point Systems, Inc., Datawest Corporation, and CSP, Inc. are discussed.

  15. TANGO Array.. 2. Simulations

    Science.gov (United States)

    Bauleo, P.; Bonifazi, C.; Filevich, A.

    2004-01-01

    The angular and energy resolutions of the TANGO Array were obtained using extensive Monte Carlo simulations performed with a double purpose: (1) to determine the appropriate parameters for the array fitting to the desired range of sensitivity (the knee energy region), and (2) to construct a reliable shower database required for reference in the analysis of experimental data. The AIRES code, with the SIBYLL hadronic collision package, was used to simulate Extended Air Showers produced by primary cosmic rays (assuming protons and iron nuclei), with energies ranging from 10 14 to 10 18 eV. These data were fed into a realistic code which simulates the response of the detectors (water Cherenkov detectors), including the electronics, pickup noise, and the signal attenuation in the connecting cables. The trigger stage was considered in the simulations in order to estimate the trigger efficiency of the array and to verify the accuracy of the reconstruction codes. This paper delineates the simulations performed to obtain the expected behavior of the array, and describes the simulated data. The results of these simulations suggest that we can expect an error in the energy of the primary cosmic-ray of ˜60% of the estimated value and that the error in the measurement of the direction of arrival can be estimated as ˜4°. The present simulations also indicate that unambiguous assignments of the primary energy cannot be obtained because of the uncertainty in the nature of the primary cosmic ray.

  16. TANGO Array. 2. Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Bauleo, P. E-mail: pablo.bauleo@colostate.edu; Bonifazi, C.; Filevich, A

    2004-01-11

    The angular and energy resolutions of the TANGO Array were obtained using extensive Monte Carlo simulations performed with a double purpose: (1) to determine the appropriate parameters for the array fitting to the desired range of sensitivity (the knee energy region), and (2) to construct a reliable shower database required for reference in the analysis of experimental data. The AIRES code, with the SIBYLL hadronic collision package, was used to simulate Extended Air Showers produced by primary cosmic rays (assuming protons and iron nuclei), with energies ranging from 10{sup 14} to 10{sup 18} eV. These data were fed into a realistic code which simulates the response of the detectors (water Cherenkov detectors), including the electronics, pickup noise, and the signal attenuation in the connecting cables. The trigger stage was considered in the simulations in order to estimate the trigger efficiency of the array and to verify the accuracy of the reconstruction codes. This paper delineates the simulations performed to obtain the expected behavior of the array, and describes the simulated data. The results of these simulations suggest that we can expect an error in the energy of the primary cosmic-ray of {approx}60% of the estimated value and that the error in the measurement of the direction of arrival can be estimated as {approx}4 deg. . The present simulations also indicate that unambiguous assignments of the primary energy cannot be obtained because of the uncertainty in the nature of the primary cosmic ray.

  17. The Murchison Widefield Array

    NARCIS (Netherlands)

    Mitchell, Daniel A.; Greenhill, Lincoln J.; Ord, Stephen M.; Bernardi, Gianni

    2010-01-01

    It is shown that the excellent Murchison Radio-astronomy Observatory site allows the Murchison Widefield Array to employ a simple RFI blanking scheme and still calibrate visibilities and form images in the FM radio band. The techniques described are running autonomously in our calibration and imagin

  18. Microelectronic Stimulator Array

    Science.gov (United States)

    2000-08-09

    retinal prosthesis test device. Figure 3b shows an enlarged view of a nano-channel glass (NCG) electrode array. Figure 4 shows a conceptual layout (floor...against a visual cortex. 10 This involves invasive brain surgery through the cranium . From a surgical point of view, the intra ocular approach is

  19. TRMM Solar Array Panels

    Science.gov (United States)

    1998-01-01

    This final report presents conclusions/recommendations concerning the TRMM Solar Array; deliverable list and schedule summary; waivers and deviations; as-shipped performance data, including flight panel verification matrix, panel output detail, shadow test summary, humidity test summary, reverse bias test panel; and finally, quality assurance summary.

  20. Radar techniques using array antennas

    CERN Document Server

    Wirth, Wulf-Dieter

    2013-01-01

    Radar Techniques Using Array Antennas is a thorough introduction to the possibilities of radar technology based on electronic steerable and active array antennas. Topics covered include array signal processing, array calibration, adaptive digital beamforming, adaptive monopulse, superresolution, pulse compression, sequential detection, target detection with long pulse series, space-time adaptive processing (STAP), moving target detection using synthetic aperture radar (SAR), target imaging, energy management and system parameter relations. The discussed methods are confirmed by simulation stud

  1. Timed arrays wideband and time varying antenna arrays

    CERN Document Server

    Haupt, Randy L

    2015-01-01

    Introduces timed arrays and design approaches to meet the new high performance standards The author concentrates on any aspect of an antenna array that must be viewed from a time perspective. The first chapters briefly introduce antenna arrays and explain the difference between phased and timed arrays. Since timed arrays are designed for realistic time-varying signals and scenarios, the book also reviews wideband signals, baseband and passband RF signals, polarization and signal bandwidth. Other topics covered include time domain, mutual coupling, wideband elements, and dispersion. The auth

  2. Atacama Compact Array Antennas

    CERN Document Server

    Saito, Masao; Nakanishi, Kouichiro; Naoi, Takahiro; Yamada, Masumi; Saito, Hiro; Ikenoue, Bungo; Kato, Yoshihiro; Morita, Kou-ichiro; Mizuno, Norikazu; Iguchi, Satoru

    2011-01-01

    We report major performance test results of the Atacama Compact Array (ACA) 7-m and 12-m antennas of ALMA (Atacama Large Millimeter/submillimeter Array). The four major performances of the ACA antennas are all-sky pointing (to be not more than 2.0 arcsec), offset pointing (to be < 0.6 arcsec) surface accuracy (< 25(20) micrometer for 12(7)m-antenna), stability of path-length (15 micrometer over 3 min), and high servo capability (6 degrees/s for Azimuth and 3 degrees/s for Elevation). The high performance of the ACA antenna has been extensively evaluated at the Site Erection Facility area at an altitude of about 2900 meters. Test results of pointing performance, surface performance, and fast motion capability are demonstrated.

  3. The Cherenkov Telescope Array

    Science.gov (United States)

    Connaughton, Valerie

    2014-03-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort dedicated to the design and operation of the next-generation ground-based very high-energy gamma-ray observatory. CTA will improve by about one order of magnitude the sensitivity with respect to the current major arrays (VERITAS, H.E.S.S., and MAGIC) in the core energy range of 100 GeV to 10 TeV, and will extend the viability of the imaging atmospheric Cherenkov technique (IACT) down to tens of GeV and above 100 TeV. In order to achieve such improved performance at both a northern and southern CTA site, four 23m diameter Large Size Telescopes (LST) optimized for low energy gamma rays will be deployed close to the centre of the array. A larger number of Medium Size Telescopes (MST) will be optimized for the core IACT energy range. The southern site will include 25 12m single-mirror MSTs and a US contribution of up to 24 novel dual-mirror design Schwarzschild-Couder (SC) type MSTs with a primary mirror of 9.5m diameter, and will also include an array of Small Size Telescopes (SST) to observe the highest-energy gamma rays from galactic sources. The SSTs can be smaller and more widely separated because more energetic gamma rays produce a larger Cherenkov light pool with many photons. The SSTs achieve a large collection area by covering a wide (10 sq km) footprint on the ground. The CTA project is finishing its preparatory phase, and the pre-production phase will start this year. I will review the status and the expected performance of CTA as well as the main scientific goals for the observatory.

  4. Solar collector array

    Energy Technology Data Exchange (ETDEWEB)

    Hall, John Champlin; Martins, Guy Lawrence

    2015-09-06

    A method and apparatus for efficient manufacture, assembly and production of solar energy. In one aspect, the apparatus may include a number of modular solar receiver assemblies that may be separately manufactured, assembled and individually inserted into a solar collector array housing shaped to receive a plurality of solar receivers. The housing may include optical elements for focusing light onto the individual receivers, and a circuit for electrically connecting the solar receivers.

  5. Photovoltaic cell array

    Science.gov (United States)

    Eliason, J. T. (Inventor)

    1976-01-01

    A photovoltaic cell array consisting of parallel columns of silicon filaments is described. Each fiber is doped to produce an inner region of one polarity type and an outer region of an opposite polarity type to thereby form a continuous radial semi conductor junction. Spaced rows of electrical contacts alternately connect to the inner and outer regions to provide a plurality of electrical outputs which may be combined in parallel or in series.

  6. YBCO Josephson Junction Arrays

    Science.gov (United States)

    1993-07-14

    40, 489 (1961). [8] W. H. Press, B. P. Flannery, S. A. Teukolsky and W. T. Vetterling, Numerical recipes: the art of scientific computing (Cambridge...has recently become a commercial product. He has developed processes for depositing state-of-the art YBCO films on buffered sapphire substrates. His...technology can most improve and on what subsystems would benefit most from the pt.. .imance available from these arrays. Aqppoved f or publicO re󈧎OSI AIR

  7. Pulsar Timing Arrays

    OpenAIRE

    Joshi, Bhal Chandra

    2013-01-01

    In the last decade, the use of an ensemble of radio pulsars to constrain the characteristic strain caused by a stochastic gravitational wave background has advanced the cause of detection of very low frequency gravitational waves significantly. This electromagnetic means of gravitational wave detection, called Pulsar Timing Array(PTA), is reviewed in this article. The principle of operation of PTA, the current operating PTAs and their status is presented along-with a discussion of the main ch...

  8. The TALE Infill Array

    Science.gov (United States)

    Bergman, Douglas

    2009-05-01

    The TALE Infill Array in conjunction with the TALE Tower Detector will provide hybrid coverage of the cosmic ray energy spectrum down to 3x10^16 eV. It will consist of about 100, two square meter scintillators on the surface spaced at 400 m; and 24 buried twelve square meter scintillators. The combination of surface and underground detectors will allow for the determination of the muon content of showers and thus give a handle on cosmic ray composition.

  9. Mir Cooperative Solar Array

    Science.gov (United States)

    Skor, Mike; Hoffman, Dave J.

    1997-01-01

    The Mir Cooperative Solar Array (MCSA), produced jointly by the United States and Russia, was deployed on the Mir Russian space station on May 25, 1996. The MCSA is a photovoltaic electrical power system that can generate up to 6 kW. The power from the MCSA is needed to extend Mir's lifetime and to support experiments conducted there by visiting U.S. astronauts. The MCSA was brought to Mir via the Space Shuttle Atlantis on the STS-74 mission, launched November 12, 1995. This cooperative venture combined the best technology of both countries: the United States provided high-efficiency, lightweight photovoltaic panel modules, whereas Russia provided the array structure and deployment mechanism. Technology developed in the Space Station Freedom Program, and now being used in the International Space Station, was used to develop MCSA's photovoltaic panel. Performance data obtained from MCSA operation on Mir will help engineers better understand the performance of the photovoltaic panel modules in orbit. This information will be used to more accurately predict the performance of the International Space Station solar arrays. Managed by the NASA Lewis Research Center for NASA's International Space Station Program Office in Houston, Texas, the MCSA Project was completed on time and under budget despite a very aggressive schedule.

  10. DSN Array Simulator

    Science.gov (United States)

    Tikidjian, Raffi; Mackey, Ryan

    2008-01-01

    The DSN Array Simulator (wherein 'DSN' signifies NASA's Deep Space Network) is an updated version of software previously denoted the DSN Receive Array Technology Assessment Simulation. This software (see figure) is used for computational modeling of a proposed DSN facility comprising user-defined arrays of antennas and transmitting and receiving equipment for microwave communication with spacecraft on interplanetary missions. The simulation includes variations in spacecraft tracked and communication demand changes for up to several decades of future operation. Such modeling is performed to estimate facility performance, evaluate requirements that govern facility design, and evaluate proposed improvements in hardware and/or software. The updated version of this software affords enhanced capability for characterizing facility performance against user-defined mission sets. The software includes a Monte Carlo simulation component that enables rapid generation of key mission-set metrics (e.g., numbers of links, data rates, and date volumes), and statistical distributions thereof as functions of time. The updated version also offers expanded capability for mixed-asset network modeling--for example, for running scenarios that involve user-definable mixtures of antennas having different diameters (in contradistinction to a fixed number of antennas having the same fixed diameter). The improved version also affords greater simulation fidelity, sufficient for validation by comparison with actual DSN operations and analytically predictable performance metrics.

  11. Spaceborne Processor Array

    Science.gov (United States)

    Chow, Edward T.; Schatzel, Donald V.; Whitaker, William D.; Sterling, Thomas

    2008-01-01

    A Spaceborne Processor Array in Multifunctional Structure (SPAMS) can lower the total mass of the electronic and structural overhead of spacecraft, resulting in reduced launch costs, while increasing the science return through dynamic onboard computing. SPAMS integrates the multifunctional structure (MFS) and the Gilgamesh Memory, Intelligence, and Network Device (MIND) multi-core in-memory computer architecture into a single-system super-architecture. This transforms every inch of a spacecraft into a sharable, interconnected, smart computing element to increase computing performance while simultaneously reducing mass. The MIND in-memory architecture provides a foundation for high-performance, low-power, and fault-tolerant computing. The MIND chip has an internal structure that includes memory, processing, and communication functionality. The Gilgamesh is a scalable system comprising multiple MIND chips interconnected to operate as a single, tightly coupled, parallel computer. The array of MIND components shares a global, virtual name space for program variables and tasks that are allocated at run time to the distributed physical memory and processing resources. Individual processor- memory nodes can be activated or powered down at run time to provide active power management and to configure around faults. A SPAMS system is comprised of a distributed Gilgamesh array built into MFS, interfaces into instrument and communication subsystems, a mass storage interface, and a radiation-hardened flight computer.

  12. TANGO ARRAY II: Simulations

    Science.gov (United States)

    Bauleo, P.; Bonifazi, C.; Filevich, A.

    The angular and energy resolution of the TANGO Array has been obtained using Monte Carlo simulations. The AIRES code, with the SYBILL hadronic collision package, was used to simulate Extended Air Showers produced by primary cosmic rays (protons and iron nuclei), with energies ranging from 1014 eV to 1018 eV. These data were fed into a realistic code which simulates the response of the detector stations (water ˇCerenkov detectors), including the electronics, pick up noise, and the signal attenuation in the connecting cabling. The trigger stage is taken into account in order to produce estimates of the trigger efficiency of the array and to check the accuracy of the reconstruction codes. This paper describes the simulations performed to obtain the expected behavior of the array, and presents the simulated data. These simulations indicate that the accuracy of the cosmic ray primary energy determination is expected to be ˜ 60 % and the precision in the measurement of the direction of arrival can be estimated as ˜ 4 degrees.

  13. Mixed Frequency Ultrasound Phased Array

    Institute of Scientific and Technical Information of China (English)

    香勇; 霍健; 施克仁; 陈以方

    2004-01-01

    A mixed frequency ultrasonic phased array (MPA) was developed to improve the focus, in which the element excitation frequencies are not all the same as in a normal constant frequency phased array. A theoretical model of the mixed frequency phased array based on the interference principle was used to simulate the array's sound distribution. The pressure intensity in the array focal area was enhanced and the scanning area having effective contrast resolution was enlarged. The system is especially useful for high intensity focused ultrasound (HIFU) with more powerful energy and ultrasound imaging diagnostics with improved signal to noise ratios, improved beam forming and more uniform imaging quality.

  14. Compact Transducers and Arrays

    Science.gov (United States)

    2005-05-01

    Soc. Am., 104, pp.64-71 44 25.Decarpigny, J.N., J.C. Debus, B. Tocquet & D. Boucher. 1985. "In-Air Analysis Of Piezoelectric Tonpilz Transducers In A... Transducers and Arrays Final Report May 2005 Contacts: Dr. Robert E. Newnham The Pennsylvania State University, 251 MRL, University Park, PA 16802 phone...814) 865-1612 fax: (814) 865-2326 email: ....c xx.....i.i.....ht.. .u a.p.u..c.e.du. Dr. Richard J. Meyer, Jr. Systems Engineering ( Transducers ), ARL

  15. Nonlinear phased array imaging

    Science.gov (United States)

    Croxford, Anthony J.; Cheng, Jingwei; Potter, Jack N.

    2016-04-01

    A technique is presented for imaging acoustic nonlinearity within a specimen using ultrasonic phased arrays. Acoustic nonlinearity is measured by evaluating the difference in energy of the transmission bandwidth within the diffuse field produced through different focusing modes. The two different modes being classical beam forming, where delays are applied to different element of a phased array to physically focus the energy at a single location (parallel firing) and focusing in post processing, whereby one element at a time is fired and a focused image produced in post processing (sequential firing). Although these two approaches are linearly equivalent the difference in physical displacement within the specimen leads to differences in nonlinear effects. These differences are localized to the areas where the amplitude is different, essentially confining the differences to the focal point. Direct measurement at the focal point are however difficult to make. In order to measure this the diffuse field is used. It is a statistical property of the diffuse field that it represents the total energy in the system. If the energy in the diffuse field for both the sequential and parallel firing case is measured then the difference between these, within the input signal bandwidth, is largely due to differences at the focal spot. This difference therefore gives a localized measurement of where energy is moving out of the transmission bandwidth due to nonlinear effects. This technique is used to image fatigue cracks and other damage types undetectable with conventional linear ultrasonic measurements.

  16. Microplasma generating array

    Energy Technology Data Exchange (ETDEWEB)

    Hopwood, Jeffrey A.; Wu, Chen; Hoskinson, Alan R.; Sonkusale, Sameer

    2016-10-04

    A microplasma generator includes first and second conductive resonators disposed on a first surface of a dielectric substrate. The first and second conductive resonators are arranged in line with one another with a gap defined between a first end of each resonator. A ground plane is disposed on a second surface of the dielectric substrate and a second end of each of the first and second resonators is coupled to the ground plane. A power input connector is coupled to the first resonator at a first predetermined distance from the second end chosen as a function of the impedance of the first conductive resonator. A microplasma generating array includes a number of resonators in a dielectric material substrate with one end of each resonator coupled to ground. A micro-plasma is generated at the non-grounded end of each resonator. The substrate includes a ground electrode and the microplasmas are generated between the non-grounded end of the resonator and the ground electrode. The coupling of each resonator to ground may be made through controlled switches in order to turn each resonator off or on and therefore control where and when a microplasma will be created in the array.

  17. Electromagnetically Clean Solar Arrays

    Science.gov (United States)

    Stem, Theodore G.; Kenniston, Anthony E.

    2008-01-01

    The term 'electromagnetically clean solar array' ('EMCSA') refers to a panel that contains a planar array of solar photovoltaic cells and that, in comparison with a functionally equivalent solar-array panel of a type heretofore used on spacecraft, (1) exhibits less electromagnetic interferences to and from other nearby electrical and electronic equipment and (2) can be manufactured at lower cost. The reduction of electromagnetic interferences is effected through a combination of (1) electrically conductive, electrically grounded shielding and (2) reduction of areas of current loops (in order to reduce magnetic moments). The reduction of cost is effected by designing the array to be fabricated as a more nearly unitary structure, using fewer components and fewer process steps. Although EMCSAs were conceived primarily for use on spacecraft they are also potentially advantageous for terrestrial applications in which there are requirements to limit electromagnetic interference. In a conventional solar panel of the type meant to be supplanted by an EMCSA panel, the wiring is normally located on the back side, separated from the cells, thereby giving rise to current loops having significant areas and, consequently, significant magnetic moments. Current-loop geometries are chosen in an effort to balance opposing magnetic moments to limit far-0field magnetic interactions, but the relatively large distances separating current loops makes full cancellation of magnetic fields problematic. The panel is assembled from bare photovoltaic cells by means of multiple sensitive process steps that contribute significantly to cost, especially if electomagnetic cleanliness is desired. The steps include applying a cover glass and electrical-interconnect-cell (CIC) sub-assemble, connecting the CIC subassemblies into strings of series-connected cells, laying down and adhesively bonding the strings onto a panel structure that has been made in a separate multi-step process, and mounting the

  18. Electrodynamic Arrays Having Nanomaterial Electrodes

    Science.gov (United States)

    Trigwell, Steven (Inventor); Biris, Alexandru S. (Inventor); Calle, Carlos I. (Inventor)

    2013-01-01

    An electrodynamic array of conductive nanomaterial electrodes and a method of making such an electrodynamic array. In one embodiment, a liquid solution containing nanomaterials is deposited as an array of conductive electrodes on a substrate, including rigid or flexible substrates such as fabrics, and opaque or transparent substrates. The nanomaterial electrodes may also be grown in situ. The nanomaterials may include carbon nanomaterials, other organic or inorganic nanomaterials or mixtures.

  19. Combinatorial aspects of covering arrays

    Directory of Open Access Journals (Sweden)

    Charles J. Colbourn

    2004-11-01

    Full Text Available Covering arrays generalize orthogonal arrays by requiring that t -tuples be covered, but not requiring that the appearance of t -tuples be balanced.Their uses in screening experiments has found application in software testing, hardware testing, and a variety of fields in which interactions among factors are to be identified. Here a combinatorial view of covering arrays is adopted, encompassing basic bounds, direct constructions, recursive constructions, algorithmic methods, and applications.

  20. Cascading Constrained 2-D Arrays using Periodic Merging Arrays

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Laursen, Torben Vaarby

    2003-01-01

    We consider a method for designing 2-D constrained codes by cascading finite width arrays using predefined finite width periodic merging arrays. This provides a constructive lower bound on the capacity of the 2-D constrained code. Examples include symmetric RLL and density constrained codes....... Numerical results for the capacities are presented....

  1. The Submillimeter Array Polarimeter

    CERN Document Server

    Marrone, Daniel P

    2008-01-01

    We describe the Submillimeter Array (SMA) Polarimeter, a polarization converter and feed multiplexer installed on the SMA. The polarimeter uses narrow-band quarter-wave plates to generate circular polarization sensitivity from the linearly-polarized SMA feeds. The wave plates are mounted in rotation stages under computer control so that the polarization handedness of each antenna is rapidly selectable. Positioning of the wave plates is found to be highly repeatable, better than 0.2 degrees. Although only a single polarization is detected at any time, all four cross correlations of left- and right-circular polarization are efficiently sampled on each baseline through coordinated switching of the antenna polarizations in Walsh function patterns. The initial set of anti-reflection coated quartz and sapphire wave plates allows polarimetry near 345 GHz; these plates have been have been used in observations between 325 and 350 GHz. The frequency-dependent cross-polarization of each antenna, largely due to the varia...

  2. Diagnosable structured logic array

    Science.gov (United States)

    Whitaker, Sterling (Inventor); Miles, Lowell (Inventor); Gambles, Jody (Inventor); Maki, Gary K. (Inventor)

    2009-01-01

    A diagnosable structured logic array and associated process is provided. A base cell structure is provided comprising a logic unit comprising a plurality of input nodes, a plurality of selection nodes, and an output node, a plurality of switches coupled to the selection nodes, where the switches comprises a plurality of input lines, a selection line and an output line, a memory cell coupled to the output node, and a test address bus and a program control bus coupled to the plurality of input lines and the selection line of the plurality of switches. A state on each of the plurality of input nodes is verifiably loaded and read from the memory cell. A trusted memory block is provided. The associated process is provided for testing and verifying a plurality of truth table inputs of the logic unit.

  3. Array biosensor: recent developments

    Science.gov (United States)

    Golden, Joel P.; Rowe-Taitt, Chris A.; Feldstein, Mark J.; Ligler, Frances S.

    1999-05-01

    A fluorescence-based immunosensor has been developed for simultaneous analyses of multiple samples for 1 to 6 different antigens. A patterned array of recognition antibodies immobilized on the surface of a planar waveguide is used to 'capture' analyte present in samples. Bound analyte is then quantified by means of fluorescent detector molecules. Upon excitation of the fluorescent label by a small diode laser, a CCD camera detects the pattern of fluorescent antigen:antibody complexes on the sensor surface. Image analysis software correlates the position of fluorescent signals with the identity of the analyte. A new design for a fluidics distribution system is shown, as well as results from assays for physiologically relevant concentrations of staphylococcal enterotoxin B (SEB), F1 antigen from Yersinia pestis, and D- dimer, a marker of sepsis and thrombotic disorders.

  4. Automated Solar-Array Assembly

    Science.gov (United States)

    Soffa, A.; Bycer, M.

    1982-01-01

    Large arrays are rapidly assembled from individual solar cells by automated production line developed for NASA's Jet Propulsion Laboratory. Apparatus positions cells within array, attaches interconnection tabs, applies solder flux, and solders interconnections. Cells are placed in either straight or staggered configurations and may be connected either in series or in parallel. Are attached at rate of one every 5 seconds.

  5. The OncoArray Consortium

    DEFF Research Database (Denmark)

    Amos, Christopher I; Dennis, Joe; Wang, Zhaoming

    2017-01-01

    BACKGROUND: Common cancers develop through a multistep process often including inherited susceptibility. Collaboration among multiple institutions, and funding from multiple sources, has allowed the development of an inexpensive genotyping microarray, the OncoArray. The array includes a genome-wi...

  6. Tremor as observed by the Array of Arrays in Cascadia

    Science.gov (United States)

    Ghosh, A.; Vidale, J. E.; Creager, K. C.

    2010-12-01

    We are capturing the intimate details of tremor activity in Cascadia with 8 small-aperture seismic arrays in northwestern Washington. The Array of Arrays (AoA) focuses on the tremor-active megathrust, including the area we previously imaged with a solo seismic array in 2008 [Ghosh et al., GRL, 2009, 2010]. Each array consists of 10 to 20 three-component sensors recording in continuous mode. Since it became operational in June 2009, the AoA has recorded several minor tremor episodes, and the recent episodic tremor and slip (ETS) event in August 2010. During the ETS event, each array was augmented by 10 additional single-channel, vertical-component sensors. We have already started to analyze seismic data for tremor episodes in July 2009, and March 2010. At each array, we apply a beamforming technique to stack the seismic energy at every 0.2 Hz from 2 to 15 Hz. During active tremor, the arrays show stable slowness, and azimuth over time, and up to 15 Hz energy on vertical channels, and 6 Hz on horizontals, with slowness consistent with the P and S waves respectively (Figure 1). Vidale et al. in this meeting provide a detailed description of a weeklong tremor episode in March 2010. The ETS started early second week of August about 60 km south of our arrays, and in a week or so, migrated along-strike to the north passing directly underneath the arrays. Strong tremor is still active about 50 km north of the arrays as we write this abstract. We will imminently analyze this data, and by the time of AGU, have preliminary results to present. Currently, we are developing an algorithm to focus as many arrays as possible to locate the tremor sources. With fine tremor detection capability and good azimuthal coverage, our AoA will better resolve the various confounding features of tremor spatiotemporal distribution (e.g., tremor patches, bands, streaks, rapid tremor reversals, low frequency earthquakes) that have been recently discovered in Cascadia. The AoA is poised to provide

  7. Passive microfluidic array card and reader

    Science.gov (United States)

    Dugan, Lawrence Christopher [Modesto, CA; Coleman, Matthew A [Oakland, CA

    2011-08-09

    A microfluidic array card and reader system for analyzing a sample. The microfluidic array card includes a sample loading section for loading the sample onto the microfluidic array card, a multiplicity of array windows, and a transport section or sections for transporting the sample from the sample loading section to the array windows. The microfluidic array card reader includes a housing, a receiving section for receiving the microfluidic array card, a viewing section, and a light source that directs light to the array window of the microfluidic array card and to the viewing section.

  8. Nanocoax Arrays for Sensing Devices

    Science.gov (United States)

    Rizal, Binod

    We have adapted a nanocoax array architecture for high sensitivity, all-electronic, chemical and biological sensing. Arrays of nanocoaxes with various dielectric annuli were developed using polymer replicas of Si nanopillars made via soft lithography. These arrays were implemented in the development of two different kinds of chemical detectors. First, arrays of nanocoaxes constructed with different porosity dielectric annuli were employed to make capacitive detectors for gaseous molecules and to investigate the role of dielectric porosity in the sensitivity of the device. Second, arrays of nanocoaxes with partially hollowed annuli were used to fabricate three-dimensional electrochemical biosensors within which we studied the role of nanoscale gap between electrodes on device sensitivity. In addition, we have employed a molecular imprint technique to develop a non-conducting molecularly imprinted polymer thin film of thickness comparable to size of biomolecules as an "artificial antibody" architecture for the detection of biomolecules.

  9. Digital electrostatic acoustic transducer array

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of an array of electrostatic acoustic transducers. The array is micromachined on a silicon wafer using standard micro-machining techniques. Each array contains 2n electrostatic transducer membranes, where “n” is the bit number. Every element of the array has a hexagonal membrane shape structure, which is separated from the substrate by 3µm air gap. The membrane is made out 5µm thick polyimide layer that has a bottom gold electrode on the substrate and a gold top electrode on top of the membrane (250nm). The wafer layout design was diced in nine chips with different array configurations, with variation of the membrane dimensions. The device was tested with 90 V giving and sound output level as high as 35dB, while actuating all the elements at the same time.

  10. Chunking of Large Multidimensional Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rotem, Doron; Otoo, Ekow J.; Seshadri, Sridhar

    2007-02-28

    Data intensive scientific computations as well on-lineanalytical processing applications as are done on very large datasetsthat are modeled as k-dimensional arrays. The storage organization ofsuch arrays on disks is done by partitioning the large global array intofixed size hyper-rectangular sub-arrays called chunks or tiles that formthe units of data transfer between disk and memory. Typical queriesinvolve the retrieval of sub-arrays in a manner that accesses all chunksthat overlap the query results. An important metric of the storageefficiency is the expected number of chunks retrieved over all suchqueries. The question that immediately arises is "what shapes of arraychunks give the minimum expected number of chunks over a query workload?"In this paper we develop two probabilistic mathematical models of theproblem and provide exact solutions using steepest descent and geometricprogramming methods. Experimental results, using synthetic workloads onreal life data sets, show that our chunking is much more efficient thanthe existing approximate solutions.

  11. SAQC: SNP Array Quality Control

    Directory of Open Access Journals (Sweden)

    Li Ling-Hui

    2011-04-01

    Full Text Available Abstract Background Genome-wide single-nucleotide polymorphism (SNP arrays containing hundreds of thousands of SNPs from the human genome have proven useful for studying important human genome questions. Data quality of SNP arrays plays a key role in the accuracy and precision of downstream data analyses. However, good indices for assessing data quality of SNP arrays have not yet been developed. Results We developed new quality indices to measure the quality of SNP arrays and/or DNA samples and investigated their statistical properties. The indices quantify a departure of estimated individual-level allele frequencies (AFs from expected frequencies via standardized distances. The proposed quality indices followed lognormal distributions in several large genomic studies that we empirically evaluated. AF reference data and quality index reference data for different SNP array platforms were established based on samples from various reference populations. Furthermore, a confidence interval method based on the underlying empirical distributions of quality indices was developed to identify poor-quality SNP arrays and/or DNA samples. Analyses of authentic biological data and simulated data show that this new method is sensitive and specific for the detection of poor-quality SNP arrays and/or DNA samples. Conclusions This study introduces new quality indices, establishes references for AFs and quality indices, and develops a detection method for poor-quality SNP arrays and/or DNA samples. We have developed a new computer program that utilizes these methods called SNP Array Quality Control (SAQC. SAQC software is written in R and R-GUI and was developed as a user-friendly tool for the visualization and evaluation of data quality of genome-wide SNP arrays. The program is available online (http://www.stat.sinica.edu.tw/hsinchou/genetics/quality/SAQC.htm.

  12. Array gain for a cylindrical array with baffle scatter effects.

    Science.gov (United States)

    Bertilone, Derek C; Killeen, Damien S; Bao, Chaoying

    2007-11-01

    Cylindrical arrays used in sonar for passive underwater surveillance often have sensors surrounding a cylindrical metal baffle. In some operational sonars, the phones in each stave (i.e., each line of phones aligned with the cylinder axis) are hardwired together so that the array is equivalent to a baffled circular array of directional elements, where each element corresponds to a line array of omnidirectional phones steered to broadside. In this paper a model is introduced for computing the array gain of such an array at high frequencies, which incorporates baffle scatter using infinite, rigid cylinder scattering theory, and with ambient noise described by an angular spectral density function. In practice the phones are often offset from the baffle surface, and the acoustic field sampled by the staves is distorted at high frequencies due to interference between the incident and scattered fields. Examples are given to illustrate the resulting array gain degradation, using three noise distributions that are frequently used in sonar performance modeling: three-dimensional isotropic, two-dimensional isotropic, and surface dipole noise.

  13. The Long Wavelength Array

    Science.gov (United States)

    Taylor, G. B.

    2006-08-01

    The Long Wavelength Array (LWA) will be a new, open, user-oriented astronomical instrument operating in the poorly explored window from 20-80 MHz at arcsecond level resolution and mJy level sensitivity. Key science drivers include (1) acceleration, propagation, and turbulence in the ISM, including the space-distribution and spectrum of Galactic cosmic rays, supernova remnants, and pulsars; (2) the high redshift universe, including the most distant radio galaxies and clusters - tools for understanding the earliest black holes and the cosmological evolution of Dark Matter and Dark Energy; (3) planetary, solar, and space science, including space weather prediction and extra-solar planet searches; and (4) the radio transient universe: including the known (e.g., SNe, GRBs) and the unknown. Because the LWA will explore one of the last and least investigated regions of the spectrum, the potential for new discoveries, including new classes of physical phenomena, is high, and there is a strong synergy with exciting new X-ray and Gamma-ray measurements, e.g. for cosmic ray acceleration, transients, and galaxy clusters. Operated by the University of New Mexico on behalf of the South West Consortium (SWC) the LWA will also provide a unique training ground for the next generation of radio astronomers. Students may also put skills learned on the LWA to work in computer science, electrical engineering, and the communications industry, among others. The development of the LWA will follow a phased build, which benefits from lessons learned at each phase. Four university-based Scientific Testing and Evaluation (ST&E) teams with different areas of concentration (1. High resolution imaging and particle acceleration; 2. Wide field imaging and large scale structures; 3. Ionosphere, and 4. RFI suppression and transient detection) will provide the feedback needed to assure that science objectives are met as the build develops. Currently in its first year of construction funding, the LWA

  14. The Cherenkov Telescope Array

    CERN Document Server

    Bigongiari, Ciro

    2016-01-01

    The Cherenkov Telescope Array (CTA) is planned to be the next generation ground based observatory for very high energy (VHE) gamma-ray astronomy. Gamma-rays provide a powerful insight into the non-thermal universe and hopefully a unique probe for new physics. Imaging Cherenkov telescopes have already discovered more than 170 VHE gamma-ray emitters providing plentiful of valuable data and clearly demonstrating the power of this technique. In spite of the impressive results there are indications that the known sources represent only the tip of the iceberg. A major step in sensitivity is needed to increase the number of detected sources, observe short time-scale variability and improve morphological studies of extended sources. An extended energy coverage is advisable to observe far-away extragalactic objects and improve spectral analysis. CTA aims to increase the sensitivity by an order of magnitude compared to current facilities, to extend the accessible gamma-ray energies from a few tens of GeV to a hundred o...

  15. Imaging Properties of Planar Microlens Arrays

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The planar microlens arrays is a two-dimensional array of optical component which is fabricated monolithically available. Imaging properties of planar microlens arrays are described, which provide both image multiplexer and erect, unit magnification images.

  16. Antenna arrays a computational approach

    CERN Document Server

    Haupt, Randy L

    2010-01-01

    This book covers a wide range of antenna array topics that are becoming increasingly important in wireless applications, particularly in design and computer modeling. Signal processing and numerical modeling algorithms are explored, and MATLAB computer codes are provided for many of the design examples. Pictures of antenna arrays and components provided by industry and government sources are presented with explanations of how they work. Antenna Arrays is a valuable reference for practicing engineers and scientists in wireless communications, radar, and remote sensing, and an excellent textbook for advanced antenna courses.

  17. Fundamentals of ultrasonic phased arrays

    CERN Document Server

    Schmerr, Lester W

    2014-01-01

    This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements.?The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and

  18. Fiber Optic Geophysics Sensor Array

    Science.gov (United States)

    Grochowski, Lucjan

    1989-01-01

    The distributed optical sensor arrays are analysed in view of specific needs of 3-D seismic explorations methods. There are compared advantages and disadventages of arrays supported by the sensors which are modulated in intensity and phase. In these systems all-fiber optic structures and their compabilities with digital geophysic formats are discussed. It was shown that the arrays based on TDM systems with the intensity modulated sensors are economically and technically the best matched for geophysic systems supported by a large number of the sensors.

  19. Terahertz superconducting plasmonic hole array

    CERN Document Server

    Tian, Zhen; Han, Jiaguang; Gu, Jianqiang; Xing, Qirong; Zhang, Weili

    2010-01-01

    We demonstrate thermally tunable superconductor hole array with active control over their resonant transmission induced by surface plasmon polaritons . The array was lithographically fabricated on high temperature YBCO superconductor and characterized by terahertz-time domain spectroscopy. We observe a clear transition from the virtual excitation of the surface plasmon mode to the real surface plasmon mode. The highly tunable superconducting plasmonic hole arrays may have promising applications in the design of low-loss, large dynamic range amplitude modulation, and surface plasmon based terahertz devices.

  20. Silicon Heat Pipe Array

    Science.gov (United States)

    Yee, Karl Y.; Ganapathi, Gani B.; Sunada, Eric T.; Bae, Youngsam; Miller, Jennifer R.; Beinsford, Daniel F.

    2013-01-01

    Improved methods of heat dissipation are required for modern, high-power density electronic systems. As increased functionality is progressively compacted into decreasing volumes, this need will be exacerbated. High-performance chip power is predicted to increase monotonically and rapidly with time. Systems utilizing these chips are currently reliant upon decades of old cooling technology. Heat pipes offer a solution to this problem. Heat pipes are passive, self-contained, two-phase heat dissipation devices. Heat conducted into the device through a wick structure converts the working fluid into a vapor, which then releases the heat via condensation after being transported away from the heat source. Heat pipes have high thermal conductivities, are inexpensive, and have been utilized in previous space missions. However, the cylindrical geometry of commercial heat pipes is a poor fit to the planar geometries of microelectronic assemblies, the copper that commercial heat pipes are typically constructed of is a poor CTE (coefficient of thermal expansion) match to the semiconductor die utilized in these assemblies, and the functionality and reliability of heat pipes in general is strongly dependent on the orientation of the assembly with respect to the gravity vector. What is needed is a planar, semiconductor-based heat pipe array that can be used for cooling of generic MCM (multichip module) assemblies that can also function in all orientations. Such a structure would not only have applications in the cooling of space electronics, but would have commercial applications as well (e.g. cooling of microprocessors and high-power laser diodes). This technology is an improvement over existing heat pipe designs due to the finer porosity of the wick, which enhances capillary pumping pressure, resulting in greater effective thermal conductivity and performance in any orientation with respect to the gravity vector. In addition, it is constructed of silicon, and thus is better

  1. The Square Kilometer Array

    Science.gov (United States)

    Cordes, James M.

    2006-06-01

    The SKA is an observatory for m/cm wavelengths that will provide quantum leaps in studies of the early universe, the high-energy universe, and astrobiology. Key science areas include:(1) Galaxy Evolution and Large-Scale Structure, including Dark Energy;(2) Probing the Dark Ages through studies of highly redshifted hydrogen and carbon monoxide;(3) Cosmic magnetism;(4) Probing Gravity with Pulsars and Black Holes; and(5) The Cradle of Life, including real-time images of protoplanetary disks, inventory of organic molecules, and the search for signals from extraterrestrial intelligence.From a phase-space point of view, the SKA will expand enormously our ability to discover new and known phenomena, including transient sources with time scales from nano-seconds to years. Particular examples include coherent emissions from extrasolar planets and gamma-ray burst afterglows, detectable at levels 100 times smaller than currently. Specifications needed to meet the science requirements are technically quite challenging: a frequency range of approximately 0.1 to 25 GHz; wide field of view, tens of square degrees (frequency dependent); high dynamic range and image fidelity; flexibility in imaging on scales from sub-mas to degrees; and sampling the time-frequency domain as demanded by transient objects. Meeting these specifications requires collaboration of a world-wide group of engineers and scientists. For this and other reasons, the SKA will be realized internationally. Initially, several concepts have been explored for building inexpensive collecting area that provides broad frequency coverage. The Reference Design now specifies an SKA based on a large number of small-diameter dish antennas with "smart feeds." Complementary to the dishes is a phased aperture array that will provide very wide-field capability. I will discuss the Reference Design, along with a timeline for developing the technology, building the first 10% of the SKA, and finishing the full SKA, along with the

  2. Fracture characterisation using geoelectric null-arrays

    Science.gov (United States)

    Falco, Pierik; Negro, François; Szalai, Sándor; Milnes, Ellen

    2013-06-01

    The term "geoelectric null-array" is used for direct current electrode configurations yielding a potential difference of zero above a homogeneous half-space. This paper presents a comparative study of the behaviour of three null-arrays, midpoint null-array (MAN), Wenner-γ null-array and Schlumberger null-array in response to a fracture, both in profiling and in azimuthal mode. The main objective is to determine which array(s) best localise fractures or best identify their orientation. Forward modelling of the three null-arrays revealed that the Wenner-γ and Schlumberger null-arrays localise vertical fractures the most accurately, whilst the midpoint null-array combined with the Schlumberger null-array allows accurate orientation of a fracture. Numerical analysis then served as a basis to interpret the field results. Field test measurements were carried out above a quarry in Les Breuleux (Switzerland) with the three null-arrays and classical arrays. The results were cross-validated with quarry-wall geological mapping. In real field circumstances, the Wenner-γ null-array proved to be the most efficient and accurate in localising fractures. The orientations of the fractures according to the numerical results were most efficiently determined with the midpoint null-array, whilst the Schlumberger null-array adds accuracy to the results. This study shows that geoelectrical null-arrays are more suitable than classical arrays for the characterisation of fracture geometry.

  3. CMOS-Based Biosensor Arrays

    CERN Document Server

    Thewes, R; Schienle, M; Hofmann, F; Frey, A; Brederlow, R; Augustyniak, M; Jenkner, M; Eversmann, B; Schindler-Bauer, P; Atzesberger, M; Holzapfl, B; Beer, G; Haneder, T; Hanke, H -C

    2011-01-01

    CMOS-based sensor array chips provide new and attractive features as compared to today's standard tools for medical, diagnostic, and biotechnical applications. Examples for molecule- and cell-based approaches and related circuit design issues are discussed.

  4. Bolometric Arrays for Millimeter Wavelengths

    Science.gov (United States)

    Castillo, E.; Serrano, A.; Torres-Jácome, A.

    2009-11-01

    During last years, semiconductor bolometers using thin films have been developed at INAOE, specifically boron-doped hydrogenated amorphous silicon films. The characteristics shown by these devices made them attractive to be used in astronomical instrumentation, mainly in two-dimentional arrays. These detector arrays used at the Large Millimeter Telescope will make possible to obtain astronomical images in millimeter and sub-millimeter wavelengths. With this in mind, we are developing a method to produce, with enough reliability, bolometer arrays at INAOE. Until now, silicon nitride diaphragm arrays, useful as radiation absorbers, have succesfully been obtained. Sizes going from one to four millimeter by element in a consistent way; however we have not tested thermometers and metallic contact deposition yet. At the same time, we are working on two possible configurations for the readout electronics; one of them using commercial components while the other will be an integrated circuit specifically designed for this application. Both versions will work below 77K.

  5. Next Generation Microshutter Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop the next generation MicroShutter Array (MSA) as a multi-object field selector for missions anticipated in the next two decades. For many...

  6. The Murchison Widefield Array Correlator

    CERN Document Server

    Ord, S M; Emrich, D; Pallot, D; Wayth, R B; Clark, M A; Tremblay, S E; Arcus, W; Barnes, D; Bell, M; Bernardi, G; Bhat, N D R; Bowman, J D; Briggs, F; Bunton, J D; Cappallo, R J; Corey, B E; Deshpande, A A; deSouza, L; Ewell-Wice, A; Feng, L; Goeke, R; Greenhill, L J; Hazelton, B J; Herne, D; Hewitt, J N; Hindson, L; Hurley-Walker, H; Jacobs, D; Johnston-Hollitt, M; Kaplan, D L; Kasper, J C; Kincaid, B B; Koenig, R; Kratzenberg, E; Kudryavtseva, N; Lenc, E; Lonsdale, C J; Lynch, M J; McKinley, B; McWhirter, S R; Mitchell, D A; Morales, M F; Morgan, E; Oberoi, D; Offringa, A; Pathikulangara, J; Pindor, B; Prabu, T; Procopio, P; Remillard, R A; Riding, J; Rogers, A E E; Roshi, A; Salah, J E; Sault, R J; Shankar, N Udaya; Srivani, K S; Stevens, J; Subrahmanyan, R; Tingay, S J; Waterson, M; Webster, R L; Whitney, A R; Williams, A; Williams, C L; Wyithe, J S B

    2015-01-01

    The Murchison Widefield Array (MWA) is a Square Kilometre Array (SKA) Precursor. The telescope is located at the Murchison Radio--astronomy Observatory (MRO) in Western Australia (WA). The MWA consists of 4096 dipoles arranged into 128 dual polarisation aperture arrays forming a connected element interferometer that cross-correlates signals from all 256 inputs. A hybrid approach to the correlation task is employed, with some processing stages being performed by bespoke hardware, based on Field Programmable Gate Arrays (FPGAs), and others by Graphics Processing Units (GPUs) housed in general purpose rack mounted servers. The correlation capability required is approximately 8 TFLOPS (Tera FLoating point Operations Per Second). The MWA has commenced operations and the correlator is generating 8.3 TB/day of correlation products, that are subsequently transferred 700 km from the MRO to Perth (WA) in real-time for storage and offline processing. In this paper we outline the correlator design, signal path, and proce...

  7. Integrated Spatial Filter Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the NASA Earth Science Division need for spatial filter arrays for amplitude and wavefront control, Luminit proposes to develop a novel Integrated Spatial...

  8. Large scale biomimetic membrane arrays

    DEFF Research Database (Denmark)

    Hansen, Jesper Søndergaard; Perry, Mark; Vogel, Jörg

    2009-01-01

    To establish planar biomimetic membranes across large scale partition aperture arrays, we created a disposable single-use horizontal chamber design that supports combined optical-electrical measurements. Functional lipid bilayers could easily and efficiently be established across CO2 laser micro......-structured 8 x 8 aperture partition arrays with average aperture diameters of 301 +/- 5 mu m. We addressed the electro-physical properties of the lipid bilayers established across the micro-structured scaffold arrays by controllable reconstitution of biotechnological and physiological relevant membrane...... peptides and proteins. Next, we tested the scalability of the biomimetic membrane design by establishing lipid bilayers in rectangular 24 x 24 and hexagonal 24 x 27 aperture arrays, respectively. The results presented show that the design is suitable for further developments of sensitive biosensor assays...

  9. Thermopile Area Array Readout Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA/JPL thermopile detector linear arrays, wire bonded to Black Forest Engineering (BFE) CMOS readout integrated circuits (ROICs), have been utilized in NASA...

  10. Tent Shaped Phased Array Tests.

    Science.gov (United States)

    1982-01-01

    AD-A113 191 HARRIS CORP MELBOURNE FL GOVERNMENT COMMUNICATION SY-ETC Fi 20/11TENT SHAPED PHASED ARRAY TESTS.(U JAN 82 C A CHUANG F19628-79-C-T173...821714f1 45 0 +450 SCAN PLANE ARRAY PATTERNS FIG. B-31 B- 31 AD-AL13 191 HARRS CRP PMELBOURNE FLY GOVERNMENT COMMUNICATION ST--ETC F/6 20/14 TENT SHAPED

  11. Flexible solar-array mechanism

    Science.gov (United States)

    Olson, M. C.

    1972-01-01

    One of the key elements of the flexible rolled-up solar array system is a mechanism to deploy, retract, and store the flexible solar-cell arrays. The selection of components, the design of the mechanism assembly, and the tests that were performed are discussed. During 6 months in orbit, all mission objectives were satisfied, and inflight performance has shown good correlation with preflight analyses and tests.

  12. Hemocompatibility of titania nanotube arrays.

    Science.gov (United States)

    Smith, Barbara S; Yoriya, Sorachon; Grissom, Laura; Grimes, Craig A; Popat, Ketul C

    2010-11-01

    Hemocompatibility is a key consideration for the long-term success of blood contacting biomaterials; hence, there is a critical need to understand the physiological response elicited from blood/nano-biomaterial interactions. In this study, we have investigated the adsorption of key blood serum proteins, in vitro adhesion and activation of platelets, and clotting kinetics of whole blood on titania nanotube arrays. Previous studies have demonstrated improved mesenchymal stem cell functionality, osteoblast phenotypic behavior, localized drug delivery, and the production of endothelial cell ECM on titania nanotube arrays. Furthermore, these titania nanotube arrays have elicited minimal levels of monocyte activation and cytokine secretion, thus exhibiting a very low degree of immunogenicity. Titania nanotube arrays were fabricated using anodization technique and the surface morphology was examined through scanning electron microscopy (SEM). The crystalline phases were identified using glancing angled X-ray diffraction (GAXRD). Nanoindentation and scratch tests were used to characterize the mechanical properties of titania nanotube arrays. The adsorption of key blood proteins (albumin, fibrinogen, and immunoglobulin-g) was evaluated using a micro-BCA assay and X-ray photoelectron spectroscopy (XPS). The adhesion and activation of platelets was investigated using live-cell staining, MTT assay, and SEM. Whole blood clotting kinetics was evaluated by measuring the free hemoglobin concentration, and SEM was used to visualize the clot formation. Our results indicate increased blood serum protein adsorption, platelet adhesion and activation, and whole blood clotting kinetics on titania nanotube arrays.

  13. Array imaging system for lithography

    Science.gov (United States)

    Kirner, Raoul; Mueller, Kevin; Malaurie, Pauline; Vogler, Uwe; Noell, Wilfried; Scharf, Toralf; Voelkel, Reinhard

    2016-09-01

    We present an integrated array imaging system based on a stack of microlens arrays. The microlens arrays are manufactured by melting resist and reactive ion etching (RIE) technology on 8'' wafers (fused silica) and mounted by wafer-level packaging (WLP)1. The array imaging system is configured for 1X projection (magnification m = +1) of a mask pattern onto a planar wafer. The optical system is based on two symmetric telescopes, thus anti-symmetric wavefront aberrations like coma, distortion, lateral color are minimal. Spherical aberrations are reduced by using microlenses with aspherical lens profiles. In our system design approach, sub-images of individual imaging channels do not overlap to avoid interference. Image superposition is achieved by moving the array imaging system during the exposure time. A tandem Koehler integrator illumination system (MO Exposure Optics) is used for illumination. The angular spectrum of the illumination light underfills the pupils of the imaging channels to avoid crosstalk. We present and discuss results from simulation, mounting and testing of a first prototype of the investigated array imaging system for lithography.

  14. Instrumentation for multi-detector arrays

    Indian Academy of Sciences (India)

    R K Bhowmik

    2001-07-01

    The new generation of detector arrays require complex instrumentation and data acquisition system to ensure increased reliability of operation, high degree of integration, software control and faster data handling capability. The main features of some of the existing multi-detector arrays like MSU 4 array, Gammasphere and Eurogam are summarized. The instrumentation for the proposed INGA array in India is discussed.

  15. Retrieval of Mir Solar Array

    Science.gov (United States)

    Rutledge, Sharon K.; deGroh, Kim K.

    1999-01-01

    A Russian solar array panel removed in November 1997 from the non-articulating photovoltaic array on the Mir core module was returned to Earth on STS-89 in January 1998. The panel had been exposed to low Earth orbit (LEO) for 10 years prior to retrieval. The retrieval provided a unique opportunity to study the effects of the LEO environment on a functional solar array. To take advantage of this opportunity, a team composed of members from RSC-Energia (Russia), the Boeing Company, and the following NASA Centers--Johnson Space Center, Kennedy Space Center, Langley Research Center, Marshall Space Flight Center, and Lewis Research Center--was put together to analyze the array. After post-retrieval inspections at the Spacehab Facility at Kennedy in Florida, the array was shipped to Lewis in Cleveland for electrical performance tests, closeup photodocumentation, and removal of selected solar cells and blanket material. With approval from RSC-Energia, five cell pairs and their accompanying blanket and mesh material, and samples of painted handrail materials were selected for removal on the basis of their ability to provide degradation information. Sites were selected that provided different sizes and shapes of micrometeoroid impacts and different levels of surface contamination. These materials were then distributed among the team for round robin testing.

  16. Modeling of phased array transducers.

    Science.gov (United States)

    Ahmad, Rais; Kundu, Tribikram; Placko, Dominique

    2005-04-01

    Phased array transducers are multi-element transducers, where different elements are activated with different time delays. The advantage of these transducers is that no mechanical movement of the transducer is needed to scan an object. Focusing and beam steering is obtained simply by adjusting the time delay. In this paper the DPSM (distributed point source method) is used to model the ultrasonic field generated by a phased array transducer and to study the interaction effect when two phased array transducers are placed in a homogeneous fluid. Earlier investigations modeled the acoustic field for conventional transducers where all transducer points are excited simultaneously. In this research, combining the concepts of delayed firing and the DPSM, the phased array transducers are modeled semi-analytically. In addition to the single transducer modeling the ultrasonic fields from two phased array transducers placed face to face in a fluid medium is also modeled to study the interaction effect. The importance of considering the interaction effect in multiple transducer modeling is discussed, pointing out that neighboring transducers not only act as ultrasonic wave generators but also as scatterers.

  17. Wavenumber response of Shanghai Seismic Array

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Seismic array can be traced back to 1950s when it mainly aimed at detecting and distinguishing the signals of nuclear explosion and seismic signals. The research on seismic array includes seismic array techniques and applications of array in geophysics. Array techniques involve array design and data processing methods (Anne, 1990). Nowadays, the continuous development of seismic array¢s theory could relate to many scientific issues in geophysical field (Tormod, 1989; Mykkeltveit, Bungum, 1984). Seismic array is mainly applied to detect weak events. The response characteristic of array is an important indication of array¢s detection ability. Therefore, when we study an array or construct an array, one of the neces-sary works is to calculate the response characteristics of the array (Harjes, 1990). The aperture and layout of array are two dominating geometrical features. The typical aperture of interna-tional array is generally from several to tens kilometers. For instance, arrays with aperture of dozens kilometers aperture are KSA, WRA, YKA, etc, while arrays with several kilometer aperture are ARC, FIN, GEE, etc. Moreo-ver, in the view of array¢s layout, NOR, GER, etc have circle layout, while WRA, YKA, etc have decussating layout. This paper mainly discusses the relation between deployment of array and wavenumber response. With the example of constructing Shanghai Seismic Array, this paper provides one practical solution to search the proper array deployment. In this paper, the simple delay beam technique is adopted to calculate the response characteris-tics of array. Certainly, the different processing methods have different result, but the result from the simple delay beam processing could be enough to reflect the feature of an array.

  18. Mathematical Simulating Model of Phased-Array Antenna in Multifunction Array Radar

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A mathematical simulating model of phased-array antenna in multifunction array radar has been approached in this paper, including the mathematical simulating model of plane phased-array pattern, the mathematical simulating model of directionality factor, the mathematical simulating model of array factor, the mathematical simulating model of array element factor and the mathematical simulating model of beam steering.

  19. Thin, Flexible IMM Solar Array

    Science.gov (United States)

    Walmsley, Nicholas

    2015-01-01

    NASA needs solar arrays that are thin, flexible, and highly efficient; package compactly for launch; and deploy into large, structurally stable high-power generators. Inverted metamorphic multijunction (IMM) solar cells can enable these arrays, but integration of this thin crystalline cell technology presents certain challenges. The Thin Hybrid Interconnected Solar Array (THINS) technology allows robust and reliable integration of IMM cells into a flexible blanket comprising standardized modules engineered for easy production. The modules support the IMM cell by using multifunctional materials for structural stability, shielding, coefficient of thermal expansion (CTE) stress relief, and integrated thermal and electrical functions. The design approach includes total encapsulation, which benefits high voltage as well as electrostatic performance.

  20. 10-kilowatt Photovoltaic Concentrator Array

    Energy Technology Data Exchange (ETDEWEB)

    Donovan, R.L.; Broadbent, S.

    1978-05-01

    Martin Marietta has designed a Photovoltaic Concentrator Array (PCA) for Sandia Laboratories, Kirtland AFB, New Mexico. The PCA is based on the use of an acrylic Fresnel lens to concentrate sunlight on high intensity solar cells. The objective of the development was to obtain economical photovoltaic power generation by replacing relatively high priced solar cells with low cost lenses. Consequently, a major task of the program was to optimize the design for minimum cost per unit power output. Major design aspects considered for optimization were the concentration ratio, size and shape of the Fresnel lens, array size and shape, structure minimization, tracking and control and the practical aspects of operation and maintenance. In addition to design of the complete array, several porototype photovoltaic concentrator module subassemblies were fabricated and delivered to Sandia for evaluation. These prototypes exceed the 9.0% efficiency requirement established for this program.

  1. Optical phased-array ladar.

    Science.gov (United States)

    Montoya, Juan; Sanchez-Rubio, Antonio; Hatch, Robert; Payson, Harold

    2014-11-01

    We demonstrate a ladar with 0.5 m class range resolution obtained by integrating a continuous-wave optical phased-array transmitter with a Geiger-mode avalanche photodiode receiver array. In contrast with conventional ladar systems, an array of continuous-wave sources is used to effectively pulse illuminate a target by electro-optically steering far-field fringes. From the reference frame of a point in the far field, a steered fringe appears as a pulse. Range information is thus obtained by measuring the arrival time of a pulse return from a target to a receiver pixel. This ladar system offers a number of benefits, including broad spectral coverage, high efficiency, small size, power scalability, and versatility.

  2. Coherent magnetic semiconductor nanodot arrays

    Directory of Open Access Journals (Sweden)

    Xiu Faxian

    2011-01-01

    Full Text Available Abstract In searching appropriate candidates of magnetic semiconductors compatible with mainstream Si technology for future spintronic devices, extensive attention has been focused on Mn-doped Ge magnetic semiconductors. Up to now, lack of reliable methods to obtain high-quality MnGe nanostructures with a desired shape and a good controllability has been a barrier to make these materials practically applicable for spintronic devices. Here, we report, for the first time, an innovative growth approach to produce self-assembled and coherent magnetic MnGe nanodot arrays with an excellent reproducibility. Magnetotransport experiments reveal that the nanodot arrays possess giant magneto-resistance associated with geometrical effects. The discovery of the MnGe nanodot arrays paves the way towards next-generation high-density magnetic memories and spintronic devices with low-power dissipation.

  3. EHF multifunction phased array antenna

    Science.gov (United States)

    Solbach, Klaus

    1986-07-01

    The design of a low cost demonstration EHF multifunction-phased array antenna is described. Both, the radiating elements and the phase-shifter circuits are realized on microstrip substrate material in order to allow photolithographic batch fabrication. Self-encapsulated beam-lead PIN-diodes are employed as the electronic switch elements to avoid expensive hermetic encapsulation of the semiconductors or complete circuits. A space-feed using a horn-radiator to illuminate the array from the front-side is found to be the simplest and most inexpensive feed. The phased array antenna thus operates as a reflect-array, the antenna elements employed in a dual role for the collection of energy from the feed-horn and for the re-radiation of the phase-shifted waves (in transmit-mode). The antenna is divided into modules containing the radiator/phase-shifter plate plus drive- and BITE-circuitry at the back. Both drive- and BITE-components use gate-array integrated circuits especially designed for the purpose. Several bus-systems are used to supply bias and logical data flows to the modules. The beam-steering unit utilizes several signal processors and high-speed discrete adder circuits to combine the pointing, frequency and beam-shape information from the radar system computer with the stored phase-shift codes for the array elements. Since space, weight and power consumption are prime considerations only the most advanced technology is used in the design of both the microwave and the digital/drive circuitry.

  4. Airborne electronically steerable phased array

    Science.gov (United States)

    1972-01-01

    The results are presented of the second stage of a program for the design and development of a phased array capable of simultaneous and separate transmission and reception of radio frequency signals at S-band frequencies. The design goals of this stage were the development of three major areas of interest required for the final prototype model. These areas are the construction and testing of the low-weight, full-scale 128-element array of antenna elements, the development of the RF manifold feed system, and the construction and testing of a working module containing diplexer and transmit and receive circuits.

  5. Versatile Flexible Graphene Multielectrode Arrays.

    Science.gov (United States)

    Kireev, Dmitry; Seyock, Silke; Ernst, Mathis; Maybeck, Vanessa; Wolfrum, Bernhard; Offenhäusser, Andreas

    2016-12-23

    Graphene is a promising material possessing features relevant to bioelectronics applications. Graphene microelectrodes (GMEAs), which are fabricated in a dense array on a flexible polyimide substrate, were investigated in this work for their performance via electrical impedance spectroscopy. Biocompatibility and suitability of the GMEAs for extracellular recordings were tested by measuring electrical activities from acute heart tissue and cardiac muscle cells. The recordings show encouraging signal-to-noise ratios of 65 ± 15 for heart tissue recordings and 20 ± 10 for HL-1 cells. Considering the low noise and excellent robustness of the devices, the sensor arrays are suitable for diverse and biologically relevant applications.

  6. Versatile Flexible Graphene Multielectrode Arrays

    Directory of Open Access Journals (Sweden)

    Dmitry Kireev

    2016-12-01

    Full Text Available Graphene is a promising material possessing features relevant to bioelectronics applications. Graphene microelectrodes (GMEAs, which are fabricated in a dense array on a flexible polyimide substrate, were investigated in this work for their performance via electrical impedance spectroscopy. Biocompatibility and suitability of the GMEAs for extracellular recordings were tested by measuring electrical activities from acute heart tissue and cardiac muscle cells. The recordings show encouraging signal-to-noise ratios of 65 ± 15 for heart tissue recordings and 20 ± 10 for HL-1 cells. Considering the low noise and excellent robustness of the devices, the sensor arrays are suitable for diverse and biologically relevant applications.

  7. Substrate integrated antennas and arrays

    CERN Document Server

    Cheng, Yu Jian

    2015-01-01

    Substrate Integrated Antennas and Arrays provides a single source for cutting-edge information on substrate integrated circuits (SICs), substrate integrated waveguide (SIW) feeding networks, SIW slot array antennas, SIC traveling-wave antennas, SIW feeding antennas, SIW monopulse antennas, and SIW multibeam antennas. Inspired by the author's extensive research, this comprehensive book:Describes a revolutionary SIC-based antenna technique with the potential to replace existing antenna technologiesExamines theoretical and experimental results connected to electrical and mechanical performanceExp

  8. Highlights from the Telescope Array

    Science.gov (United States)

    Matthews, J. N.

    2016-11-01

    The Telescope Array measures the properties of ultra high energy cosmic ray induced extensive air showers. We do this using a variety of techniques including an array of scintillator detectors to sample the footprint of the air shower when it reaches the Earth's surface and telescopes to measure the fluorescence and Cerenkov light of the air shower. From this we determine the energy spectrum and chemical composition of the primary particles. We also search for sources of cosmic rays and anisotropy. We have found evidence of a possible source of ultra high energy cosmic rays in the northern sky. The experiment and its most recent measurements will be discussed.

  9. Wicking a confined micropillar array

    CERN Document Server

    Texier, Baptiste Darbois; Stoukatch, Serguei; Dorbolo, Stéphane

    2016-01-01

    This study considers the spreading of a Newtonian and perfectly wetting liquid in a square array of cylindric micropillars confined between two plates. We show experimentally that the dynamics of the contact line follows a Washburn-like law which depends on the characteristics of the micropillar array (height, diameter and pitch). The presence of pillars can either enhanced or slow down the motion of the contact line. A theoretical model based on capillary and viscous forces has been developed in order to rationalize our observations. Finally, the impact of pillars on the volumic flow rate of liquid which is pumped in the microchannel is inspected.

  10. Speckle imaging from an array

    Science.gov (United States)

    Riker, Jim F.; Tyler, Glenn A.; Vaughn, Jeff L.

    2016-09-01

    In this paper, we present two analytic theories developed recently to predict the performance of an imaging system composed of a phased array illuminator and a set of receiver subapertures. The receiver need not coincide with the transmitter. The two theories have been documented separately (ref. 1, 2), and the reader can find more details there - the theories present the analytic phased array irradiance on target in the presence of piston errors, and the resulting speckle pattern-induced imaging noise. The principal results presented here are the Signal to Noise Ratios (SNR) for both the radiometric portion of the problem and the speckle imaging portion of the problem.

  11. Phased arrays: inline flow line hub inspection using phased arrays

    NARCIS (Netherlands)

    Bloom, J.G.P.; Chougrani, K.; Rundberg, H.; Oldenziel, G.; Deleye, X.; Martina, Q.

    2011-01-01

    The feasibility of the inspection of flow line hubs using the phased array technique was investigated to determine the surface area of the seal area degraded by corrosion. A clean model of the hub was simulated to gain insight into the geometrical echoes and to determine the area covered by the ultr

  12. Design Considerations for Array CGH to OligonucleotideArrays

    Energy Technology Data Exchange (ETDEWEB)

    Baldocchi, R.A.; Glynne, R.J.; Chin, K.; Kowbel, D.; Collins, C.; Mack, D.H.; Gray, J.W.

    2005-03-04

    Background: Representational oligonucleotide microarray analysis has been developed for detection of single nucleotide polymorphisms and/or for genome copy number changes. In this process, the intensity of hybridization to oligonucleotides arrays is increased by hybridizing a polymerase chain reaction (PCR)-amplified representation of reduced genomic complexity. However, hybridization to some oligonucleotides is not sufficiently high to allow precise analysis of that portion of the genome. Methods: In an effort to identify aspects of oligonucleotide hybridization affecting signal intensity, we explored the importance of the PCR product strand to which each oligonucleotide is homologous and the sequence of the array oligonucleotides. We accomplished this by hybridizing multiple PCR-amplified products to oligonucleotide arrays carrying two sense and two antisense 50-mer oligonucleotides for each PCR amplicon. Results: In some cases, hybridization intensity depended more strongly on the PCR amplicon strand (i.e., sense vs. antisense) than on the detection oligonucleotide sequence. In other cases, the oligonucleotide sequence seemed to dominate. Conclusion: Oligonucleotide arrays for analysis of DNA copy number or for single nucleotide polymorphism content should be designed to carry probes to sense and antisense strands of each PCR amplicon to ensure sufficient hybridization and signal intensity.

  13. Early Growth Response-1 Plays a Non-redundant Role in the Differentiation of B Cells into Plasma Cells.

    Science.gov (United States)

    Oh, Yeon-Kyung; Jang, Eunkyeong; Paik, Doo-Jin; Youn, Jeehee

    2015-06-01

    Early growth response (Egr)-1 is a Cys2-His2-type zincfinger transcription factor. It has been shown to induce survival and proliferation of immature and mature B cells, respectively, but its role in the differentiation of B cells into plasma cells remains unclear. To examine the effects of Egr-1 deficiency on the activation of B cells, naive B cells from Egr1 (-/-) mice and their wild-type (WT) littermates were activated to proliferate and differentiate, and then assayed by FACS. Proportions of cells undergoing proliferation and apoptosis did not differ between Egr1 (-/-) and WT mice. However, Egr1 (-/-) B cells gave rise to fewer plasma cells than WT B cells. Consistently, Egr1 (-/-) mice produced significantly lower titer of antigen-specific IgG than their WT littermates upon immunization. Our results demonstrate that Egr-1 participates in the differentiation program of B cells into plasma cells, while it is dispensable for the proliferation and survival of mature B cells.

  14. Non-redundant properties of IL-1alpha and IL-1beta during acute colon inflammation in mice

    NARCIS (Netherlands)

    Bersudsky, M.; Luski, L.; Fishman, D.; White, R.M.; Ziv-Sokolovskaya, N.; Dotan, S.; Rider, P.; Kaplanov, I.; Aychek, T.; Dinarello, C.A.; Apte, R.N.; Voronov, E.

    2014-01-01

    OBJECTIVE: The differential role of the IL-1 agonists, IL-1alpha, which is mainly cell-associated versus IL-1beta, which is mostly secreted, was studied in colon inflammation. DESIGN: Dextran sodium sulfate (DSS) colitis was induced in mice globally deficient in either IL-1alpha or IL-1beta, and in

  15. Non-redundant Functions of ATM and DNA-PKcs in Response to DNA Double-Strand Breaks

    Directory of Open Access Journals (Sweden)

    Pierre Caron

    2015-11-01

    Full Text Available DNA double-strand breaks (DSBs elicit the so-called DNA damage response (DDR, largely relying on ataxia telangiectasia mutated (ATM and DNA-dependent protein kinase (DNA-PKcs, two members of the PI3K-like kinase family, whose respective functions during the sequential steps of the DDR remains controversial. Using the DIvA system (DSB inducible via AsiSI combined with high-resolution mapping and advanced microscopy, we uncovered that both ATM and DNA-PKcs spread in cis on a confined region surrounding DSBs, independently of the pathway used for repair. However, once recruited, these kinases exhibit non-overlapping functions on end joining and γH2AX domain establishment. More specifically, we found that ATM is required to ensure the association of multiple DSBs within “repair foci.” Our results suggest that ATM acts not only on chromatin marks but also on higher-order chromatin organization to ensure repair accuracy and survival.

  16. GRIFFIN's Fast-Timing Array

    Science.gov (United States)

    Olaizola, Bruno; Griffin Collaboration

    2016-09-01

    The Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei (GRIFFIN) is the new β-decay spectrometer facility at TRIUMF-ISAC. Consists of an array of 16 large-volume HPGe clover detectors with an unparalleled efficiency of 19% at 1.33 MeV. Its strongest advantage is the versatility of the ancillary detectors that can be coupled to the main array to tag on β particles, neutrons or precisely measure conversion electron spectra. An ancillary array of 8 LaBr3(Ce) detectors for γ-rays and a fast plastic scintillator for β-particles has been optimized for fast-timing experiments with GRIFFIN. The 51 mm x 51 mm cylindrical LaBr3(Ce) crystals are coupled to Hamamatsu R2083 photomultipliers. Timing resolutions as good as FWHM 200 ps and time-walks below +/- 30 ps have been obtained for individual crystals using analog electronics. There is also an ongoing project to develop an active BGO shield for the LaBr3(Ce) crystals. The LaBr3(Ce) array commissioning experiment to measure the 145,146Cs decay to 145,146Ba will test its capabilities over a wide range of lifetimes. Preliminary results on the lifetimes of some of the low-laying states will be presented.

  17. High density arrays of micromirrors

    Energy Technology Data Exchange (ETDEWEB)

    Folta, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Decker, J. Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kolman, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lee, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brase, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1999-02-01

    We established and achieved our goal to (1) fabricate and evaluate test structures based on the micromirror design optimized for maskless lithography applications, (2) perform system analysis and code development for the maskless lithography concept, and (3) identify specifications for micromirror arrays (MMAs) for LLNL's adaptive optics (AO) applications and conceptualize new devices.

  18. Gamma-ray array physics.

    Energy Technology Data Exchange (ETDEWEB)

    Lister, C. J.

    1999-05-25

    In this contribution I am going to discuss the development of large arrays of Compton Suppressed, High Purity Germanium (HpGe) detectors and the physics that has been, that is being, and that will be done with them. These arrays and their science have dominated low-energy nuclear structure research for the last twenty years and will continue to do so in the foreseeable future. John Sharpey Schafer played a visionary role in convincing a skeptical world that the development of these arrays would lead to a path of enlightenment. The extent to which he succeeded can be seen both through the world-wide propagation of ever more sophisticated devices, and through the world-wide propagation of his students. I, personally, would not be working in research if it were not for Johns inspirational leadership. I am eternally grateful to him. Many excellent reviews of array physics have been made in the past which can provide detailed background reading. The review by Paul Nolan, another ex-Sharpey Schafer student, is particularly comprehensive and clear.

  19. The Murchison Widefield Array Correlator

    Science.gov (United States)

    Ord, S. M.; Crosse, B.; Emrich, D.; Pallot, D.; Wayth, R. B.; Clark, M. A.; Tremblay, S. E.; Arcus, W.; Barnes, D.; Bell, M.; Bernardi, G.; Bhat, N. D. R.; Bowman, J. D.; Briggs, F.; Bunton, J. D.; Cappallo, R. J.; Corey, B. E.; Deshpande, A. A.; deSouza, L.; Ewell-Wice, A.; Feng, L.; Goeke, R.; Greenhill, L. J.; Hazelton, B. J.; Herne, D.; Hewitt, J. N.; Hindson, L.; Hurley-Walker, N.; Jacobs, D.; Johnston-Hollitt, M.; Kaplan, D. L.; Kasper, J. C.; Kincaid, B. B.; Koenig, R.; Kratzenberg, E.; Kudryavtseva, N.; Lenc, E.; Lonsdale, C. J.; Lynch, M. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Oberoi, D.; Offringa, A.; Pathikulangara, J.; Pindor, B.; Prabu, T.; Procopio, P.; Remillard, R. A.; Riding, J.; Rogers, A. E. E.; Roshi, A.; Salah, J. E.; Sault, R. J.; Udaya Shankar, N.; Srivani, K. S.; Stevens, J.; Subrahmanyan, R.; Tingay, S. J.; Waterson, M.; Webster, R. L.; Whitney, A. R.; Williams, A.; Williams, C. L.; Wyithe, J. S. B.

    2015-03-01

    The Murchison Widefield Array is a Square Kilometre Array Precursor. The telescope is located at the Murchison Radio-astronomy Observatory in Western Australia. The MWA consists of 4 096 dipoles arranged into 128 dual polarisation aperture arrays forming a connected element interferometer that cross-correlates signals from all 256 inputs. A hybrid approach to the correlation task is employed, with some processing stages being performed by bespoke hardware, based on Field Programmable Gate Arrays, and others by Graphics Processing Units housed in general purpose rack mounted servers. The correlation capability required is approximately 8 tera floating point operations per second. The MWA has commenced operations and the correlator is generating 8.3 TB day-1 of correlation products, that are subsequently transferred 700 km from the MRO to Perth (WA) in real-time for storage and offline processing. In this paper, we outline the correlator design, signal path, and processing elements and present the data format for the internal and external interfaces.

  20. BOLOMETRIC ARRAYS FOR MILLIMETER WAVELENGTHS

    Directory of Open Access Journals (Sweden)

    E. Castillo

    2009-01-01

    Full Text Available During last years, semiconductor bolometers using thin lms have been developed at INAOE, speci cally boron-doped hydrogenated amorphous silicon lms. The characteristics shown by these devices made them attractive to be used in astronomical instrumentation, mainly in two-dimentional arrays. These detector arrays used at the Large Millimeter Telescope will make possible to obtain astronomical images in millimeter and submillimeter wavelengths. With this in mind, we are developing a method to produce, with enough reliability, bolometer arrays at INAOE. Until now, silicon nitride diaphragm arrays, useful as radiation absorbers, have succesfully been obtained. Sizes going from one to four millimeter by element in a consistent way; however we have not tested thermometers and metallic contact deposition yet. At the same time, we are working on two possible con gurations for the readout electronics; one of them using commercial components while the other will be an integrated circuit speci cally designed for this application. Both versions will work below 77K.

  1. Directivity of basic linear arrays

    DEFF Research Database (Denmark)

    Bach, Henning

    1970-01-01

    For a linear uniform array ofnelements, an expression is derived for the directivity as a function of the spacing and the phase constants. The cases of isotropic elements, collinear short dipoles, and parallel short dipoles are included. The formula obtained is discussed in some detail and contour...

  2. TANGO Array. 1. The instrument

    Energy Technology Data Exchange (ETDEWEB)

    Bauleo, P. E-mail: pablo.bauleo@colostate.edu; Bonifazi, C.; Filevich, A.; Reguera, A

    2004-01-11

    TANGO Array is an air shower experiment which has been constructed in Buenos Aires, Argentina. It was commissioned during the year 2000 becoming fully operational in September, 2000. The array consists of four water Cherenkov detectors enclosing a geometrical area of {approx}30,000 m{sup 2} and its design has been optimized for the observation of Extended Air Showers produced by cosmic rays near the 'knee' energy region {approx}4x10{sup 15} eV. Three of the detectors have been constructed using 12,000-l stainless-steel tanks, and the fourth has been mounted in a smaller, 400-l plastic container. The detectors are connected by cables to the data acquisition room, where a very simple system, which takes advantage of the features of a four-channel digital oscilloscope, was set for data collection. This data collection setup allows a fully automatic experiment control which does not require operator intervention. It includes monitoring, data logging, and daily calibration of all detectors. This paper describes the detectors and their associated electronics, and details are given on the data acquisition system, the triggering and calibration procedures, and the operation of the array. Examples of air shower traces, recorded by the array, are presented.

  3. TANGO Array.. 1. The instrument

    Science.gov (United States)

    Bauleo, P.; Bonifazi, C.; Filevich, A.; Reguera, A.

    2004-01-01

    TANGO Array is an air shower experiment which has been constructed in Buenos Aires, Argentina. It was commissioned during the year 2000 becoming fully operational in September, 2000. The array consists of four water Cherenkov detectors enclosing a geometrical area of ˜30,000 m2 and its design has been optimized for the observation of Extended Air Showers produced by cosmic rays near the "knee" energy region ˜4×10 15 eV. Three of the detectors have been constructed using 12,000-l stainless-steel tanks, and the fourth has been mounted in a smaller, 400-l plastic container. The detectors are connected by cables to the data acquisition room, where a very simple system, which takes advantage of the features of a four-channel digital oscilloscope, was set for data collection. This data collection setup allows a fully automatic experiment control which does not require operator intervention. It includes monitoring, data logging, and daily calibration of all detectors. This paper describes the detectors and their associated electronics, and details are given on the data acquisition system, the triggering and calibration procedures, and the operation of the array. Examples of air shower traces, recorded by the array, are presented.

  4. Light weight digital array SAR

    NARCIS (Netherlands)

    Otten, M.; Maas, N.; Bolt, R.; Anitori, L.

    2010-01-01

    A light weight SAR has been designed, suitable for short range tactical UAVs, consisting of a fully digital receive array, and a very compact active transmit antenna. The weight of the complete RF front is expected to be below 3 kg, with a power consumption below 30 W. This X-band system can provide

  5. Photoelectrochemistry of Semiconductor Nanowire Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Mallouk, Thomas E; Redwing, Joan M

    2009-11-10

    This project supported research on the growth and photoelectrochemical characterization of semiconductor nanowire arrays, and on the development of catalytic materials for visible light water splitting to produce hydrogen and oxygen. Silicon nanowires were grown in the pores of anodic aluminum oxide films by the vapor-liquid-solid technique and were characterized electrochemically. Because adventitious doping from the membrane led to high dark currents, silicon nanowire arrays were then grown on silicon substrates. The dependence of the dark current and photovoltage on preparation techniques, wire diameter, and defect density was studied for both p-silicon and p-indium phosphide nanowire arrays. The open circuit photovoltage of liquid junction cells increased with increasing wire diameter, reaching 350 mV for micron-diameter silicon wires. Liquid junction and radial p-n junction solar cells were fabricated from silicon nano- and microwire arrays and tested. Iridium oxide cluster catalysts stabilized by bidentate malonate and succinate ligands were also made and studied for the water oxidation reaction. Highlights of this project included the first papers on silicon and indium phosphide nanowire solar cells, and a new procedure for making ligand-stabilized water oxidation catalysts that can be covalently linked to molecular photosensitizers or electrode surfaces.

  6. Study of stacked microstrip phased arrays

    Science.gov (United States)

    Arts, M. J.; Smolders, A. B.

    1993-06-01

    Two theoretical methods for studying stacked-patch microstrip phased arrays are compared: (1) the element-by-element approach (finite array approach) of Pozar (1986) and Smolders (1992); and (2) the infinite approach of Pozar and Shaubert (1984) and Liu et al. (1988). Both theories were found to give almost the same results for a 7 x 7 stacked microstrip antenna, except for edge array elements and for large scan angles. Edge array elements could only be analyzed properly by using a finite array approach. Coupling measurements were made on a 7 x 7 array with a single patch layer, and the results agreed well with calculations.

  7. Advanced Rainbow Solar Photovoltaic Arrays

    Science.gov (United States)

    Mardesich, Nick; Shields, Virgil

    2003-01-01

    Photovoltaic arrays of the rainbow type, equipped with light-concentrator and spectral-beam-splitter optics, have been investigated in a continuing effort to develop lightweight, high-efficiency solar electric power sources. This investigation has contributed to a revival of the concept of the rainbow photovoltaic array, which originated in the 1950s but proved unrealistic at that time because the selection of solar photovoltaic cells was too limited. Advances in the art of photovoltaic cells since that time have rendered the concept more realistic, thereby prompting the present development effort. A rainbow photovoltaic array comprises side-by-side strings of series-connected photovoltaic cells. The cells in each string have the same bandgap, which differs from the bandgaps of the other strings. Hence, each string operates most efficiently in a unique wavelength band determined by its bandgap. To obtain maximum energy-conversion efficiency and to minimize the size and weight of the array for a given sunlight input aperture, the sunlight incident on the aperture is concentrated, then spectrally dispersed onto the photovoltaic array plane, whereon each string of cells is positioned to intercept the light in its wavelength band of most efficient operation. The number of cells in each string is chosen so that the output potentials of all the strings are the same; this makes it possible to connect the strings together in parallel to maximize the output current of the array. According to the original rainbow photovoltaic concept, the concentrated sunlight was to be split into multiple beams by use of an array of dichroic filters designed so that each beam would contain light in one of the desired wavelength bands. The concept has since been modified to provide for dispersion of the spectrum by use of adjacent prisms. A proposal for an advanced version calls for a unitary concentrator/ spectral-beam-splitter optic in the form of a parabolic curved Fresnel-like prism

  8. 基于量子微粒群的综合孔径圆环阵排列方法%Circular antenna array design method based on quantum particle swarm optimization for aperture synthesis radiometers

    Institute of Scientific and Technical Information of China (English)

    董健; 施荣华; 郭迎; 雷文太

    2012-01-01

    Sparse antenna array design is of great importance in aperture synthesis radiometers. Due to the non-redundant baseline distribution and the simplicity of mechanical structure, the circular antenna array is considered as a promising array configuration of aperture synthesis radiometers. In this paper, a circular antenna array design method based on quantum particle swarm optimization (QPSO) is proposed to improve the UV coverage of the circular antenna array in aperture synthesis radiometers. By introducing quantum mechanics and constructing a novel measure function of UV coverage, this method outperforms the existing methods in terms of the computation complexity and global exploration efficiency, and has a better measurement for the uniformity of UV coverage. Numerical simulations validate the effectiveness of the proposed method.%稀疏天线阵列设计是综合孔径微波辐射计的一个重要研究内容。圆环阵因其可实现(u,v)平面基线零冗余、结构简单以及共形、波束旋转对称等特点而备受关注。针对均匀圆环阵UV覆盖不均匀的问题,提出基于量子微粒群优化(QPSO)的综合孔径圆环阵排列方法,以改善圆环阵的UV覆盖。该方法引入量子行为的搜索机制,并设计一种新的圆环阵优化目标函数;与现有方法相比,该方法在提高全局搜索效率的同时,大大降低计算复杂度,且能更好地度量圆环阵UV覆盖的均匀程度。数值仿真结果验证了本文方法的有效性。

  9. Large Format Uncooled Focal Plane Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Uncooled focal plane arrays have improved dramatically and array sizes of 320x240 elements in a 50-?m pitch are commercially available at affordable cost. Black...

  10. NRAO Very Long Baseline Array (VLBA)

    Data.gov (United States)

    Federal Laboratory Consortium — The Very Long Baseline Array (VLBA) comprises ten radio telescopes spanning 5,351 miles. It's the world's largest, sharpest, dedicated telescope array. With an eye...

  11. Low Cost Phased Array Antenna System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — JEM Engineering proved the technical feasibility of the FlexScan array?a very low-cost, highly-efficient, wideband phased array antenna?in Phase I, and stands ready...

  12. Defect Characterization Using Two-Dimensional Arrays

    Science.gov (United States)

    Velichko, A.; Wilcox, P. D.

    2011-06-01

    2D arrays are able to `view' a given defect from a range of angles leading to the possibility of obtaining richer characterization detail than possible with 1D arrays. In this paper a quantitative comparison of 2D arrays with different element layouts is performed. A technique for extracting the scattering matrix of a defect from the raw 2D array data is also presented. The method is tested on experimental data for characterization of various volumetric defects.

  13. Leakage analysis of crossbar memristor arrays

    KAUST Repository

    Zidan, Mohammed A.

    2014-07-01

    Crossbar memristor arrays provide a promising high density alternative for the current memory and storage technologies. These arrays suffer from parasitic current components that significantly increase the power consumption, and could ruin the readout operation. In this work we study the trade-off between the crossbar array density and the power consumption required for its readout. Our analysis is based on simulating full memristor arrays on a SPICE platform.

  14. Simulations of astronomical imaging phased arrays.

    Science.gov (United States)

    Saklatvala, George; Withington, Stafford; Hobson, Michael P

    2008-04-01

    We describe a theoretical procedure for analyzing astronomical phased arrays with overlapping beams and apply the procedure to simulate a simple example. We demonstrate the effect of overlapping beams on the number of degrees of freedom of the array and on the ability of the array to recover a source. We show that the best images are obtained using overlapping beams, contrary to common practice, and show how the dynamic range of a phased array directly affects the image quality.

  15. Kronecker Product of Two-dimensional Arrays

    Institute of Scientific and Technical Information of China (English)

    Lei Hu

    2006-01-01

    Kronecker sequences constructed from short sequences are good sequences for spread spectrum communication systems. In this paper we study a similar problem for two-dimensional arrays, and we determine the linear complexity of the Kronecker product of two arrays. Our result shows that similar good property on linear complexity holds for Kronecker product of arrays.

  16. Maximum gain of Yagi-Uda arrays

    DEFF Research Database (Denmark)

    Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.

    1971-01-01

    Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....

  17. Subwavelength micropillar array terahertz lasers.

    Science.gov (United States)

    Krall, Michael; Brandstetter, Martin; Deutsch, Christoph; Detz, Hermann; Andrews, Aaron Maxwell; Schrenk, Werner; Strasser, Gottfried; Unterrainer, Karl

    2014-01-13

    We report on micropillar-based terahertz lasers with active pillars that are much smaller than the emission wavelength. These micropillar array lasers correspond to scaled-down band-edge photonic crystal lasers forming an active photonic metamaterial. In contrast to photonic crystal lasers which use significantly larger pillar structures, lasing emission is not observed close to high-symmetry points in the photonic band diagram, but in the effective medium regime. We measure stimulated emission at 4 THz for micropillar array lasers with pillar diameters of 5 µm. Our results not only demonstrate the integration of active subwavelength optics in a terahertz laser, but are also an important step towards the realization of nanowire-based terahertz lasers.

  18. Antenna Arrays and Automotive Applications

    CERN Document Server

    Rabinovich, Victor

    2013-01-01

    This book throws a lifeline to designers wading through mounds of antenna array patents looking for the most suitable systems for their projects. Drastically reducing the research time required to locate solutions to the latest challenges in automotive communications, it sorts and systematizes material on cutting-edge antenna arrays that feature multi-element communication systems with enormous potential for the automotive industry. These new systems promise to make driving safer and more efficient, opening up myriad applications, including vehicle-to-vehicle traffic that prevents collisions, automatic toll collection, vehicle location and fine-tuning for cruise control systems. This book’s exhaustive coverage begins with currently deployed systems, frequency ranges and key parameters. It proceeds to examine system geometry, analog and digital beam steering technology (including "smart" beams formed in noisy environments), maximizing signal-to-noise ratios, miniaturization, and base station technology that ...

  19. Recent Results from Telescope Array

    CERN Document Server

    Fukushima, M

    2015-01-01

    The Telescope Array (TA) is an experiment to observe Ultra-High Energy Cosmic Rays (UHECRs). TA's recent results, the energy spectrum and anisotropy based on the 6-year surface array data, and the primary composition obtained from the shower maximum Xmax are reported. The spectrum demonstrates a clear dip and cutoff. The shape of the spectrum is well described by the energy loss of extra-galactic protons interacting with the cosmic microwave background (CMB). Above the cutoff, a medium-scale (20 degrees radius) flux enhancement was observed near the Ursa-Major. A chance probability of creating this hotspot from the isotropic flux is 4.0 sigma. The measured Xmax is consistent with the primary being proton or light nuclei for energies 10^18.2 eV - 10^19.2 eV.

  20. Sandia concentrator array testing experiences

    Science.gov (United States)

    Gerwin, H. J.; Rogers, C. B.; Beavis, L. C.

    An assortment of PV concentrator modules and arrays have been tested and evaluated at the Sandia outdoor test facility. These test items include actively-cooled parabolic reflector and linear Fresnel lens concentrators, and actively- and passively-cooled point focus collectors. Maximum power efficiencies were measured over a range of sunlight intensities and cell temperatures, then a linear equation relating efficiency to cell temperature and insolation was developed for each module and array by using a multiple linear regression analysis technique on the data. An evaluation of the suitability of Polyvinyl-Butyral (PVB) as a material used to laminate solar cells to glass is presented. Some general observations are made on the accuracy of tracking systems, and the maintenance of these systems.

  1. Invasive tightly coupled processor arrays

    CERN Document Server

    LARI, VAHID

    2016-01-01

    This book introduces new massively parallel computer (MPSoC) architectures called invasive tightly coupled processor arrays. It proposes strategies, architecture designs, and programming interfaces for invasive TCPAs that allow invading and subsequently executing loop programs with strict requirements or guarantees of non-functional execution qualities such as performance, power consumption, and reliability. For the first time, such a configurable processor array architecture consisting of locally interconnected VLIW processing elements can be claimed by programs, either in full or in part, using the principle of invasive computing. Invasive TCPAs provide unprecedented energy efficiency for the parallel execution of nested loop programs by avoiding any global memory access such as GPUs and may even support loops with complex dependencies such as loop-carried dependencies that are not amenable to parallel execution on GPUs. For this purpose, the book proposes different invasion strategies for claiming a desire...

  2. Highlights from the Telescope Array

    Directory of Open Access Journals (Sweden)

    Matthews J.N.

    2016-01-01

    Full Text Available The Telescope Array measures the properties of ultra high energy cosmic ray induced extensive air showers. We do this using a variety of techniques including an array of scintillator detectors to sample the footprint of the air shower when it reaches the Earth’s surface and telescopes to measure the fluorescence and Cerenkov light of the air shower. From this we determine the energy spectrum and chemical composition of the primary particles. We also search for sources of cosmic rays and anisotropy. We have found evidence of a possible source of ultra high energy cosmic rays in the northern sky. The experiment and its most recent measurements will be discussed.

  3. High voltage load resistor array

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, Monty Ray [Smithfield, VA

    2005-01-18

    A high voltage resistor comprising an array of a plurality of parallel electrically connected resistor elements each containing a resistive solution, attached at each end thereof to an end plate, and about the circumference of each of the end plates, a corona reduction ring. Each of the resistor elements comprises an insulating tube having an electrode inserted into each end thereof and held in position by one or more hose clamps about the outer periphery of the insulating tube. According to a preferred embodiment, the electrode is fabricated from stainless steel and has a mushroom shape at one end, that inserted into the tube, and a flat end for engagement with the end plates that provides connection of the resistor array and with a load.

  4. A Systolic Array RLS Processor

    OpenAIRE

    Asai, T.; Matsumoto, T.

    2000-01-01

    This paper presents the outline of the systolic array recursive least-squares (RLS) processor prototyped primarily with the aim of broadband mobile communication applications. To execute the RLS algorithm effectively, this processor uses an orthogonal triangularization technique known in matrix algebra as QR decomposition for parallel pipelined processing. The processor board comprises 19 application-specific integrated circuit chips, each with approximately one million gates. Thirty-two bit ...

  5. Micromirror Arrays for Adaptive Optics

    Energy Technology Data Exchange (ETDEWEB)

    Carr, E.J.

    2000-08-07

    The long-range goal of this project is to develop the optical and mechanical design of a micromirror array for adaptive optics that will meet the following criteria: flat mirror surface ({lambda}/20), high fill factor (> 95%), large stroke (5-10 {micro}m), and pixel size {approx}-200 {micro}m. This will be accomplished by optimizing the mirror surface and actuators independently and then combining them using bonding technologies that are currently being developed.

  6. Nonlinear Ultrasonic Phased Array Imaging

    Science.gov (United States)

    Potter, J. N.; Croxford, A. J.; Wilcox, P. D.

    2014-10-01

    This Letter reports a technique for the imaging of acoustic nonlinearity. By contrasting the energy of the diffuse field produced through the focusing of an ultrasonic array by delayed parallel element transmission with that produced by postprocessing of sequential transmission data, acoustic nonlinearity local to the focal point is measured. Spatially isolated wave distortion is inferred without requiring interrogation of the wave at the inspection point, thereby allowing nonlinear imaging through depth.

  7. Nonlinear ultrasonic phased array imaging

    OpenAIRE

    Potter, J N; Croxford, A.J.; Wilcox, P. D.

    2014-01-01

    This Letter reports a technique for the imaging of acoustic nonlinearity. By contrasting the energy of the diffuse field produced through the focusing of an ultrasonic array by delayed parallel element transmission with that produced by postprocessing of sequential transmission data, acoustic nonlinearity local to the focal point is measured. Spatially isolated wave distortion is inferred without requiring interrogation of the wave at the inspection point, thereby allowing nonlinear imaging t...

  8. Array Imaging of Noisy Materials

    Science.gov (United States)

    Wilcox, P. D.

    2011-06-01

    The ultimate limit on ultrasonic defect detectability is the coherent noise due to material backscatter. A model of such noise in ultrasonic array images is developed based on the single scattering assumption. The implications of the model are discussed and supported with some experimental examples. In the case of a copper specimen, it is shown that an improvement in signal to coherent noise ratio of over 30 dB can be obtained by optimization of imaging parameters.

  9. Nonlinear ultrasonic phased array imaging.

    Science.gov (United States)

    Potter, J N; Croxford, A J; Wilcox, P D

    2014-10-03

    This Letter reports a technique for the imaging of acoustic nonlinearity. By contrasting the energy of the diffuse field produced through the focusing of an ultrasonic array by delayed parallel element transmission with that produced by postprocessing of sequential transmission data, acoustic nonlinearity local to the focal point is measured. Spatially isolated wave distortion is inferred without requiring interrogation of the wave at the inspection point, thereby allowing nonlinear imaging through depth.

  10. Array-based photoacoustic spectroscopy

    Science.gov (United States)

    Autrey, S. Thomas; Posakony, Gerald J.; Chen, Yu

    2005-03-22

    Methods and apparatus for simultaneous or sequential, rapid analysis of multiple samples by photoacoustic spectroscopy are disclosed. A photoacoustic spectroscopy sample array including a body having at least three recesses or affinity masses connected thereto is used in conjunction with a photoacoustic spectroscopy system. At least one acoustic detector is positioned near the recesses or affinity masses for detection of acoustic waves emitted from species of interest within the recesses or affinity masses.

  11. Automated array assembly. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, B.F.

    1977-05-01

    The goal of the ERDA/JPL LSSA program of $0.50/W selling price for array modules in 1986 turns out to have been remarkably appropriate. An extensive and detailed analysis of technologies which could be related to array module manufacturing was completed and a minimum manufacturing cost in a highly automated line of $0.30/W was found assuming the silicon is free. The panels are of a double glass construction and are based on round wafers. Screen printed silver has been used as the metallization with a spray-coated AR layer. The least expensive junction formation technology appears to be ion implantation; however, several other technologies also may be used with very little cost penalty as described. Based on the required investment, a profit of $0.05/W appears reasonable. If silicon wafers are available at a price of $20 to 40/M/sup 2/, a selling price for these array modules of $0.50 to 0.66/W is projected. An analysis of the impact of factory size has been made. For a production level of 500 MW/yr, the price above is derived. For comparison, a factory processing 50 MW/yr using the same technology would sell modules for $0.54/W to $0.70/W. An analysis of the impact of wafer size indicates that with traditional metallization and panel designs there is no advantage in increasing wafer size from 3 in. to 5 in., and, in fact, there is some penalty (10% in $/W) due to increasedmetallization costs and reduced system performance. There is a premium placed on high efficiency due to its impact, not only on array module cost, but on system cost. For the near term goals of this program, wafers cut from single-crystal material seem the most likely sheet configuration.

  12. The Parkes Pulsar Timing Array

    CERN Document Server

    Hobbs, G

    2013-01-01

    The aims of the Parkes Pulsar Timing Array (PPTA) project are to 1) make a direct detection of gravitational waves, 2) improve the solar system planetary ephemeris and 3) develop a pulsar-based time scale. In this article we describe the project, explain how the data are collected and processed and describe current research. Our current data sets are able to place an upper bound on the gravitational wave background that is the most stringent to date.

  13. A distributed array antenna system

    Science.gov (United States)

    Shaw, R.; Kovitz, J.

    1986-01-01

    The Space Station communication system will use microwave frequency radio links to carry digitized information from sender to receiver. The ability of the antenna system to meet stringent requirements on coverage zones, multiple users, and reliability will play an important part in the overall multiple access communication system. This paper will describe the configuration of a multibeam conformal phased array antenna and the individual microwave integrated components incoporated into this antenna system.

  14. A novel method to design sparse linear arrays for ultrasonic phased array.

    Science.gov (United States)

    Yang, Ping; Chen, Bin; Shi, Ke-Ren

    2006-12-22

    In ultrasonic phased array testing, a sparse array can increase the resolution by enlarging the aperture without adding system complexity. Designing a sparse array involves choosing the best or a better configuration from a large number of candidate arrays. We firstly designed sparse arrays by using a genetic algorithm, but found that the arrays have poor performance and poor consistency. So, a method based on the Minimum Redundancy Linear Array was then adopted. Some elements are determined by the minimum-redundancy array firstly in order to ensure spatial resolution and then a genetic algorithm is used to optimize the remaining elements. Sparse arrays designed by this method have much better performance and consistency compared to the arrays designed only by a genetic algorithm. Both simulation and experiment confirm the effectiveness.

  15. Measured Aperture-Array Noise Temperature of the Mark II Phased Array Feed for ASKAP

    CERN Document Server

    Chippendale, A P; Beresford, R J; Hampson, G A; Shaw, R D; Hayman, D B; Macleod, A; Forsyth, A R; Hay, S G; Leach, M; Cantrall, C; Brothers, M L; Hotan, A W

    2015-01-01

    We have measured the aperture-array noise temperature of the first Mk. II phased array feed that CSIRO has built for the Australian Square Kilometre Array Pathfinder telescope. As an aperture array, the Mk. II phased array feed achieves a beam equivalent noise temperature less than 40 K from 0.78 GHz to 1.7 GHz and less than 50 K from 0.7 GHz to 1.8 GHz for a boresight beam directed at the zenith. We believe these are the lowest reported noise temperatures over these frequency ranges for ambient-temperature phased arrays. The measured noise temperature includes receiver electronics noise, ohmic losses in the array, and stray radiation from sidelobes illuminating the sky and ground away from the desired field of view. This phased array feed was designed for the Australian Square Kilometre Array Pathfinder to demonstrate fast astronomical surveys with a wide field of view for the Square Kilometre Array.

  16. The Colorado Lightning Mapping Array

    Science.gov (United States)

    Rison, W.; Krehbiel, P. R.; Thomas, R. J.; Rodeheffer, D.; Fuchs, B.

    2012-12-01

    A fifteen station Lightning Mapping Array (LMA) was installed in northern Colorado in the spring of 2012. While the driving force for the array was to produce 3-dimensional lightning data to support the Deep Convective Clouds and Chemistry (DC3) Experiment (Barth, this conference), data from the array are being used for several other projects. These include: electrification studies in conjunction with the CSU CHILL radar (Lang et al, this conference); observations of the parent lightning discharges of sprites (Lyons et al, this conference); trying to detect upward discharges triggered by wind turbines, characterizing conditions in which aircraft flying through clouds produce discharges which can be detected by the LMA, and other opportunities, such as observations of lightning in pyrocumulus clouds produced by the High Park Fire west of Fort Collins, CO. All the COLMA stations are solar-powered, and use broadband cellular modems for data communications. This makes the stations completely self-contained and autonomous, allowing a station to be installed anywhere a cellular signal is available. Because most of the stations were installed well away from anthropogenic noise sources, the COLMA is very sensitive. This is evidenced by the numerous plane tracks detected in its the vicinity. The diameter, D, of the COLMA is about 100 km, significantly larger than other LMAs. Because the error in the radial distance r is proportional to (r/D)2, and the error in the altitude z is proportional to (z/D)2, the larger array diameter greatly expands the usable range of the COLMA. The COLMA is able to detect and characterize lighting flashes to a distance of about 350 km from the array center. In addition to a web-based display (lightning.nmt.edu/colma), geo-referenced images are produced and updated at one-minute intervals. These geo-referenced images can be used to overlay the real-time lightning data on Google Earth and other mapping software. These displays were used by the DC3

  17. Acoustic array systems theory, implementation, and application

    CERN Document Server

    Bai, Mingsian R; Benesty, Jacob

    2013-01-01

    Presents a unified framework of far-field and near-field array techniques for noise source identification and sound field visualization, from theory to application. Acoustic Array Systems: Theory, Implementation, and Application provides an overview of microphone array technology with applications in noise source identification and sound field visualization. In the comprehensive treatment of microphone arrays, the topics covered include an introduction to the theory, far-field and near-field array signal processing algorithms, practical implementations, and common applic

  18. Beam combining of quantum cascade laser arrays.

    Science.gov (United States)

    Lee, Benjamin G; Kansky, Jan; Goyal, Anish K; Pflügl, Christian; Diehl, Laurent; Belkin, Mikhail A; Sanchez, Antonio; Capasso, Federico A

    2009-08-31

    Wavelength beam combining was used to co-propagate beams from 28 elements in an array of distributed-feedback quantum cascade lasers (DFB-QCLs). The beam-quality product of the array, defined as the product of near-field spot size and far-field divergence for the entire array, was improved by a factor of 21 by using wavelength beam combining. To demonstrate the applicability of wavelength beam combined DFB-QCL arrays for remote sensing, we obtained the absorption spectrum of isopropanol at a distance of 6 m from the laser array.

  19. Silver nanorod arrays for photocathode applications

    Energy Technology Data Exchange (ETDEWEB)

    Vilayurganapathy, Subramanian [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Western Michigan Univ., Kalamazoo MI (United States); Nandasiri, Manjula I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Western Michigan Univ., Kalamazoo MI (United States); Joly, Alan G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); El-Khoury, Patrick Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Varga, Tamas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Coffey, Greg W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schwenzer, Birgit [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pandey, Archana [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kayani, Asghar N. [Western Michigan Univ., Kalamazoo MI (United States); Hess, Wayne P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thevuthasan, Suntharampillai [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-10-16

    In this study, we explore the possibility of using plasmonic Ag nanorod arrays featuring enhanced photoemission as high-brightness photocathode material. Silver nanorod arrays are synthesized by the DC electrodeposition method and their dimensionality, uniformity, crystallinity and oxide/impurity content are characterized. These Ag nanorod arrays exhibit greatly enhanced two-photon photoemission under 400 nm femtosecond pulsed laser excitation. Plasmonic field enhancement in the array produces photoemission hot spots that are mapped using photoemission electron microscopy (PEEM). The relative photoemission enhancement of nanorod array hot spots relative to that of a flat Ag thin film is found to range between 102 and 3 x 103.

  20. Ultrasonic stair case array for NDE

    Science.gov (United States)

    Oliver, K.; Tittmann, B. R.; Kropf, M.

    2006-03-01

    In this paper we present the results on the design of a unique two-dimensional phased array with low channel applications for imaging defects on a metal surface. First, basic transducer calculations will be shown. Followed by the results of important phased array variables, such as focusing, and angle beam sweeping ability, The final design will be given. Next the computer simulation results will be discussed. These results will indicate the performance of the actual array. The second half of the paper will be devoted to a discussion on the phased array testing results with a demonstration phased array.

  1. Coupling Between Waveguide-Fed Slot Arrays

    Science.gov (United States)

    Rengarajan, Sembiam

    2011-01-01

    Coupling between two waveguide-fed planar slot arrays has been investigated using full-wave analysis. The analysis employs the method-of-moments solution to the pertinent coupled integral equations for the aperture electric field of all slots. In order to compute coupling between two arrays, the input port of the first array is excited with a TE(sub 10) mode wave while the second one is match-terminated. After solving the moment method matrix equations, the aperture fields of all slots are obtained and thereby the TE(sub 10) mode wave received at the input port of the second array is determined. Coupling between two arrays is the ratio of the wave amplitude arriving in the second array port to the incident wave amplitude at the first array port. The coupling mechanism has been studied as a function of spacing between arrays in different directions, e.g. the electric field plane, the magnetic field plane, and the diagonal plane. Computed coupling values are presented for different array geometries. This work is novel since it provides a good understanding of coupling between waveguide-fed slot arrays as a function of spacing and orientation for different aperture distributions and array architectures. This serves as a useful tool for antenna design engineers and system engineers.

  2. New fabrication and applications of carbohydrate arrays.

    Science.gov (United States)

    Huang, Gangliang; Chen, Xin; Xiao, Feng

    2014-01-01

    Carbohydrate arrays are used as high-throughput screening platforms to study the carbohydrate-mediated recognition events for glycobiology. The polysaccharide arrays are easy to fabricate by non-covalently or covalently immobilizing polysaccharides onto array surfaces because polysaccharides have hydrophobic interactions. Oligosaccharides must be derived and covalently or non-covalently immobilized onto array surfaces to fabricate oligosaccharide arrays because they have hydrophilic interactions. At the moment, carbohydrate arrays are mainly used to study the carbohydrate-protein interactions and carbohydrate-binding lectins or antibodies, which are possible to be applied to clinics and diagnoses. This review mainly summed up the new fabrication strategies of carbohydrate arrays and their applications in recent four years.

  3. Dynamics and function of compact nucleosome arrays.

    Science.gov (United States)

    Poirier, Michael G; Oh, Eugene; Tims, Hannah S; Widom, Jonathan

    2009-09-01

    The packaging of eukaryotic DNA into chromatin sterically occludes polymerases, recombinases and repair enzymes. How chromatin structure changes to allow their actions is unknown. We constructed defined fluorescently labeled trinucleosome arrays, allowing analysis of chromatin conformational dynamics via fluorescence resonance energy transfer (FRET). The arrays undergo reversible Mg2+-dependent folding similar to that of longer arrays studied previously. We define two intermediate conformational states in the reversible folding of the nucleosome arrays and characterize the microscopic rate constants. Nucleosome arrays are highly dynamic even when compact, undergoing conformational fluctuations on timescales in the second to microsecond range. Compact states of the arrays allow binding to DNA within the central nucleosome via site exposure. Protein binding can also drive decompaction of the arrays. Thus, our results reveal multiple modes by which spontaneous chromatin fiber dynamics allow for the invasion and action of DNA-processing protein complexes.

  4. Delamination Detection Using Guided Wave Phased Arrays

    Science.gov (United States)

    Tian, Zhenhua; Yu, Lingyu; Leckey, Cara

    2016-01-01

    This paper presents a method for detecting multiple delaminations in composite laminates using non-contact phased arrays. The phased arrays are implemented with a non-contact scanning laser Doppler vibrometer (SLDV). The array imaging algorithm is performed in the frequency domain where both the guided wave dispersion effect and direction dependent wave properties are considered. By using the non-contact SLDV array with a frequency domain imaging algorithm, an intensity image of the composite plate can be generated for delamination detection. For the proof of concept, a laboratory test is performed using a non-contact phased array to detect two delaminations (created through quasi-static impact test) at different locations in a composite plate. Using the non-contact phased array and frequency domain imaging, the two impact-induced delaminations are successfully detected. This study shows that the non-contact phased array method is a potentially effective method for rapid delamination inspection in large composite structures.

  5. International ultraviolet explorer solar array power degradation

    Science.gov (United States)

    Day, J. H., Jr.

    1983-01-01

    The characteristic electrical performance of each International Ultraviolet Explorer (IUE) solar array panel is evaluated as a function of several prevailing variables (namely, solar illumination, array temperature and solar cell radiation damage). Based on degradation in the current-voltage characteristics of the array due to solar cell damage accumulated over time by space charged particle radiations, the available IUE solar array power is determined for life goals up to 10 years. Best and worst case calculations are normalized to actual IUE flight data (available solar array power versus observatory position) to accurately predict the future IUE solar array output. It is shown that the IUE solar array can continue to produce more power than is required at most observatory positions for at least 5 more years.

  6. Automated array assembly. Final report

    Energy Technology Data Exchange (ETDEWEB)

    D' Aiello, R.V.

    1977-12-01

    Three main sections are included which describe a general technology assessment and manufacturing cost analysis; a near-term (1982) factory design; and the results of an experimental production study for the large-scale production of flat-panel silicon solar-cell arrays. The results of an extensive study and detailed analysis of technologies which could be related to array module manufacturing are presented. From this study, several manufacturing sequences emerge as candidates for satisfying the ERDA/JPL cost goal of $0.50/W selling price in 1986. A minimum manufacturing cost was found in a highly automated line of $0.30/W assuming the silicon is free. The panels are of a double-glass construction and are based on round wafers. Screen-printed silver has been used as the metallization with a spray-coated antireflection (AR) layer. The least expensive junction-formation technology appears to be ion implantation;however, several other technologies also may be used with very little cost penalty as described. An interim 1982 factory is described for the large-scale production of silicon solar-cell array modules. The boundary conditions for this design are the use of Czochralski silicon crystals and $25/kg polycrystalline silicon. The objective is a large-scale production facility to meet an intermediate ERDA cost goal of $2.00/W in 1982. A 6-month experimental production study of the elements of low-cost solar-cell manufacturing sequences is described as an outgrowth of the cost and manufacturing studies. This program consisted of three parts: an experimental production line study of the major variables associated with the fabrication of 3-in.-diameter silicon solar cells; a study of thick-film screen-printed silver metallization; and panel design and assembly development. (WHK)

  7. Multicolor photonic crystal laser array

    Science.gov (United States)

    Wright, Jeremy B; Brener, Igal; Subramania, Ganapathi S; Wang, George T; Li, Qiming

    2015-04-28

    A multicolor photonic crystal laser array comprises pixels of monolithically grown gain sections each with a different emission center wavelength. As an example, two-dimensional surface-emitting photonic crystal lasers comprising broad gain-bandwidth III-nitride multiple quantum well axial heterostructures were fabricated using a novel top-down nanowire fabrication method. Single-mode lasing was obtained in the blue-violet spectral region with 60 nm of tuning (or 16% of the nominal center wavelength) that was determined purely by the photonic crystal geometry. This approach can be extended to cover the entire visible spectrum.

  8. Sentinel-3 Solar Array Design

    Science.gov (United States)

    Combet, Y.; Reutenauer, X.; Mouret, G.; Guerrere, S.; Ergan, A.; Ferrando, E.; Riva, S.; Hodgetts, P.; Levesque, D.; D'Accolti, G.

    2011-10-01

    Sentinel-3 is primarily a mission to support services relating to the marine environment, with capability to serve numerous land-, atmospheric- and cryospheric- based application areas. The mission's main objective is to determine parameters, such as sea-surface topography, sea- and land-surface temperatures, as well as ocean- and land-surface colours with high-end accuracy and reliability. For this mission, Thales Alenia Space has been selected as the spacecraft prime contractor and is also responsible for the solar array. In this frame, TAS leads a European industrial team, comprising Selex Galileo for the photovoltaic assembly and Patria for the panel substrate.

  9. The collinear coaxial array antenna

    Science.gov (United States)

    Brammer, D. J.; Williams, D.

    1981-03-01

    A design of a coaxial vertical antenna proposed in the ARRL antenna handbook is analyzed. A numerical analysis was carried out using the moment method. A variety of antenna configurations in the 160 MHz design frequency are analyzed and current distribution, gain, polar diagrams and impedances are calculated. The analysis is carried out for simple configurations and extended to a case with 16 repeated center sections. The effects of using lossy cable in the construction is also investigated. A defect in the original ARRL design is rectified. An array of an overall length 5.33 wavelengths is shown to have a gain of 10.69 dB.

  10. rasdaman Array Database: current status

    Science.gov (United States)

    Merticariu, George; Toader, Alexandru

    2015-04-01

    rasdaman (Raster Data Manager) is a Free Open Source Array Database Management System which provides functionality for storing and processing massive amounts of raster data in the form of multidimensional arrays. The user can access, process and delete the data using SQL. The key features of rasdaman are: flexibility (datasets of any dimensionality can be processed with the help of SQL queries), scalability (rasdaman's distributed architecture enables it to seamlessly run on cloud infrastructures while offering an increase in performance with the increase of computation resources), performance (real-time access, processing, mixing and filtering of arrays of any dimensionality) and reliability (legacy communication protocol replaced with a new one based on cutting edge technology - Google Protocol Buffers and ZeroMQ). Among the data with which the system works, we can count 1D time series, 2D remote sensing imagery, 3D image time series, 3D geophysical data, and 4D atmospheric and climate data. Most of these representations cannot be stored only in the form of raw arrays, as the location information of the contents is also important for having a correct geoposition on Earth. This is defined by ISO 19123 as coverage data. rasdaman provides coverage data support through the Petascope service. Extensions were added on top of rasdaman in order to provide support for the Geoscience community. The following OGC standards are currently supported: Web Map Service (WMS), Web Coverage Service (WCS), and Web Coverage Processing Service (WCPS). The Web Map Service is an extension which provides zoom and pan navigation over images provided by a map server. Starting with version 9.1, rasdaman supports WMS version 1.3. The Web Coverage Service provides capabilities for downloading multi-dimensional coverage data. Support is also provided for several extensions of this service: Subsetting Extension, Scaling Extension, and, starting with version 9.1, Transaction Extension, which

  11. Station characteristics of the Singapore Infrasound Array

    Science.gov (United States)

    Perttu, Anna; Taisne, Benoit; Caudron, Corentin; Garces, Milton; Avila Encillo, Jeffrey; Ildefonso, Sorvigenaleon

    2016-04-01

    Singapore, located in Southeast Asia, presents an ideal location for an additional regional infrasound array, with diverse persistent natural and anthropogenic regional infrasound sources, including ~750 active or potentially active volcanoes within 4,000 kilometers. Previous studies have focused on theoretical and calculated regional signal detection capability improvement with the addition of a Singapore array. The Earth Observatory of Singapore installed a five element infrasound array in northcentral Singapore in late 2014, and this station began consistent real-time data transmission mid-2015. The Singapore array uses MB2005s microbarometers and Nanometrics Taurus digitizers. Automated array processing is carried out with the INFrasonic EneRgy Nth Octave (INFERNO) energy estimation suite, and PMCC (Progressive MultiChannel Correlation). The addition of the Singapore infrasound array to the existing International Monitoring System (IMS) infrasound stations in the region has increased regional infrasound detection capability, which is illustrated with the preliminary work on three observed meteor events of various sizes in late 2015. A meteor observed in Bangkok, Thailand in early September, 2015 was picked up by the CTBTO, however, another meteor observed in Bangkok in November was only recorded on the Singapore array. Additionally, another meteor observed over Sumatra was only recorded by one IMS station and the Singapore array. This study uses array processing and Power Spectral Density results for both the Singapore and publicly available regional IMS stations to examine station characteristics and detection capability of the Singapore array in the context of the regional IMS network.

  12. The Ooty Wide Field Array

    Indian Academy of Sciences (India)

    C. R. Subrahmanya; P. K. Manoharan; Jayaram N. Chengalur

    2017-03-01

    We describe here an ongoing upgrade to the legacy Ooty Radio Telescope (ORT). The ORT is a cylindrical parabolic cylinder 530 m × 30 m in size operating at a frequency of 326.5 (or $z \\sim 3.35$ for the HI 21-cm line). The telescope has been constructed on a North–South hill slope whose gradient is equal to the latitude of the hill, making it effectively equatorially mounted. The feed consists of an array of 1056 dipoles. The key feature of this upgrade is the digitization and cross-correlation of the signals of every set of 4-dipoles. This converts the ORT into a 264 element interferometer with a field-of-view of $ 2^{\\circ} \\times 27.4^{\\circ} \\cos(\\delta)$. This upgraded instrument is called the Ooty Wide Field Array (OWFA). This paper briefly describes the salient features of the upgrade, as well as its main science drivers. There are three main science drivers viz. (1) observations of the large scale distribution of HI in the post-reionization era, (2) studies of the propagation of plasma irregularities through the inner heliosphere and (3) blind surveys for transient sources. More details on the upgrade, as well as on the expected science uses can be found in other papers in this special issue.

  13. Stretchable Micro-Electrode Array

    Energy Technology Data Exchange (ETDEWEB)

    Maghribi, M; Hamilton, J; Polla, D; Rose, K; Wilson, T; Krulevitch, P

    2002-03-08

    This paper focuses on the design consideration, fabrication processes and preliminary testing of the stretchable micro-electrode array. We are developing an implantable, stretchable micro-electrode array using polymer-based microfabrication techniques. The device will serve as the interface between an electronic imaging system and the human eye, directly stimulating retinal neurons via thin film conducting traces and electroplated electrodes. The metal features are embedded within a thin ({approx}50 micron) substrate fabricated using poly (dimethylsiloxane) (PDMS), a biocompatible elastomeric material that has very low water permeability. The conformable nature of PDMS is critical for ensuring uniform contact with the curved surface of the retina. To fabricate the device, we developed unique processes for metalizing PDMS to produce robust traces capable of maintaining conductivity when stretched (5%, SD 1.5), and for selectively passivating the conductive elements. An in situ measurement of residual strain in the PDMS during curing reveals a tensile strain of 10%, explaining the stretchable nature of the thin metalized devices.

  14. Optimal array of sand fences.

    Science.gov (United States)

    Lima, Izael A; Araújo, Ascânio D; Parteli, Eric J R; Andrade, José S; Herrmann, Hans J

    2017-03-24

    Sand fences are widely applied to prevent soil erosion by wind in areas affected by desertification. Sand fences also provide a way to reduce the emission rate of dust particles, which is triggered mainly by the impacts of wind-blown sand grains onto the soil and affects the Earth's climate. Many different types of fence have been designed and their effects on the sediment transport dynamics studied since many years. However, the search for the optimal array of fences has remained largely an empirical task. In order to achieve maximal soil protection using the minimal amount of fence material, a quantitative understanding of the flow profile over the relief encompassing the area to be protected including all employed fences is required. Here we use Computational Fluid Dynamics to calculate the average turbulent airflow through an array of fences as a function of the porosity, spacing and height of the fences. Specifically, we investigate the factors controlling the fraction of soil area over which the basal average wind shear velocity drops below the threshold for sand transport when the fences are applied. We introduce a cost function, given by the amount of material necessary to construct the fences. We find that, for typical sand-moving wind velocities, the optimal fence height (which minimizes this cost function) is around 50 cm, while using fences of height around 1.25 m leads to maximal cost.

  15. IRAN: interferometric remapped array nulling

    Science.gov (United States)

    Aristidi, Eric; Vakili, Farrokh; Abe, Lyu; Belu, Adrian; Lopez, Bruno; Lanteri, Henri; Schutz, A.; Menut, Jean-Luc

    2004-10-01

    This paper describes a method of beam-combination in the so-called hypertelescope imaging technique recently introduced by Labeyrie in optical interferometry. The method we propose is an alternative to the Michelson pupil reconfiguration that suffers from the loss of the classical object-image convolution relation. From elementary theory of Fourier optics we demonstrate that this problem can be solved by observing in a combined pupil plane instead of an image plane. The point-source intensity distribution (PSID) of this interferometric "image" tends towards a psuedo Airy disc (similar to that of a giant monolithic telescope) for a sufficiently large number of telescopes. Our method is applicable to snap-shot imaging of extended sources with a field comparable to the Airy pattern of single telescopes operated in a co-phased multi-aperture interferometric array. It thus allows to apply conveniently pupil plane coronagraphy. Our technique called Interferometric Remapped Array Nulling (IRAN) is particularly suitable for high dynamic imaging of extra-solar planetary companions, circumstellar nebulosities or extra-galactic objects where long baseline interferometry would closely probe the central regions of AGNs for instance.

  16. Towards the Long Wavelength Array

    Science.gov (United States)

    Kassim, N. E.; Erickson, W. C.

    2008-08-01

    Nearly three decades ago, the Very Large Array (VLA) opened the cm-wavelength radio sky to high-dynamic range imaging. By developing and exploiting new techniques to mitigate ionospheric phase fluctuations, the VLA 74 MHz system is providing the first sub-arcminute resolution view of the meter-wavelength radio universe. This technical innovation has inspired an emerging suite of much more powerful low-frequency instruments, including the Long Wavelength Array (LWA). The LWA, with its great collecting area (approaching one square kilometer at 20 MHz) and long baselines (up to 400 km), will surpass, by up to 2--3 orders of magnitude, the imaging power of any previous low-frequency interferometer. LWA science goals include Cosmic Evolution, the Acceleration of Relativistic Particles, Plasma Astrophysics, and Ionospheric & Space Weather Science. Because it will explore one of the last and most poorly investigated regions of the spectrum, the potential for unexpected new discoveries is high. For more on the LWA, see http://lwa.unm.edu. The LWA project is led by the University of New Mexico, and includes the Naval Research Laboratory, Applied Research Laboratories of U. Texas, Los Alamos National Laboratory, Virginia Tech, and U. Iowa, with cooperation from the National Radio Astronomy Observatory.

  17. Energy transfer in macromolecular arrays

    Science.gov (United States)

    Andrews, David L.; Jenkins, Robert D.

    2003-11-01

    Macromolecular systems comprised of many light-sensitive centres (the photosynthetic unit, dendrimers, and other highly symmetric multichromophore arrays) are important structures offering challenges to theoreticians and synthetic chemists alike. Here we outline novel photophysical interactions predicted and observed in such arrays. Using the tools of molecular quantum electrodynamics (QED) we present quantum amplitudes for a variety of higher-order resonance energy transfer (RET) schemes associated with well-known nonlinear optical effects such as two- and three-photon absorption. The initial analysis is extended to account for situations where the participant donor species are identical and exist in a highly symmetric environment, leading to the possible formation of excitons. It emerges from the QED theory that such excitons are closely associated with the higher-order RET processes. General results are interpreted by analyzing particular molecular architectures which offer interesting features such as rate enhancement or limitation and exciton pathway quenching. Applications in the areas of photosynthesis, molecular logic gates and low-intensity fluorescence energy transfer are predicted.

  18. One-dimensional Array Grammars and P Systems with Array Insertion and Deletion Rules

    Directory of Open Access Journals (Sweden)

    Rudolf Freund

    2013-09-01

    Full Text Available We consider the (one-dimensional array counterpart of contextual as well as insertion and deletion string grammars and consider the operations of array insertion and deletion in array grammars. First we show that the emptiness problem for P systems with (one-dimensional insertion rules is undecidable. Then we show computational completeness of P systems using (one-dimensional array insertion and deletion rules even of norm one only. The main result of the paper exhibits computational completeness of one-dimensional array grammars using array insertion and deletion rules of norm at most two.

  19. Interferometric Plasmonic Lensing with Nanohole Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yu; Joly, Alan G.; El-Khoury, Patrick Z.; Hess, Wayne P.

    2014-12-18

    Nonlinear photoemission electron microscopy (PEEM) of nanohole arrays in gold films maps propagating surface plasmons (PSPs) launched from lithographically patterned structures. Strong near field photoemission patterns are observed in the PEEM images, recorded following low angle of incidence irradiation of nanohole arrays with sub-15 fs laser pulses centered at 780 nm. The recorded photoemission patterns are attributed to constructive and destructive interferences between PSPs launched from the individual nanoholes which comprise the array. By exploiting the wave nature of PSPs, we demonstrate how varying the array geometry (hole diameter, pitch, and number of rows/columns) ultimately yields intense localized photoemission. Through a combination of PEEM and finite-difference time-domain simulations, we identify the optimal array geometry for efficient light coupling and interferometric plasmonic lensing. We show a preliminary application of inteferometric plasmonic lensing by enhancing the photoemission from the vertex of a gold triangle using nanohole array.

  20. Flexible Ultrasonic Phased-Array Probe

    Institute of Scientific and Technical Information of China (English)

    施克仁; 阙开良; 郭大勇

    2004-01-01

    In ultrasonic phased-array testing, most probes are rigid with fixed elements. However, when testing a cambered piece, a rigid probe cannot be used directly, but an ultrasonic chock or coupling media must be used, which adds cost and reduces the accuracy. The objective of this research was to improve the tests of cambered pieces. A flexible ultrasonic phased-array probe was developed to do the flexible phased-array testing. The key technologies in the flexible phased-array probe include the probe design and the phased-array control. A new method was developed to design the flexible probe according to the curvature of the piece and the test depth. The method includes the calculation of the element's height (he), the relative rotation angle ((e), the distance between the adjoining elements (de), and the element's effective testing range. A flexible ultrasonic phased-array probe has been developed using this method.

  1. Space and power efficient hybrid counters array

    Science.gov (United States)

    Gara, Alan G.; Salapura, Valentina

    2009-05-12

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  2. Anisotropic permeability in deterministic lateral displacement arrays

    CERN Document Server

    Vernekar, Rohan; Loutherback, Kevin; Morton, Keith; Inglis, David

    2016-01-01

    We investigate anisotropic permeability of microfluidic deterministic lateral displacement (DLD) arrays. A DLD array can achieve high-resolution bimodal size-based separation of micro-particles, including bioparticles such as cells. Correct operation requires that the fluid flow remains at a fixed angle with respect to the periodic obstacle array. We show via experiments and lattice-Boltzmann simulations that subtle array design features cause anisotropic permeability. The anisotropy, which indicates the array's intrinsic tendency to induce an undesired lateral pressure gradient, can lead to off-axis flows and therefore local changes in the critical separation size. Thus, particle trajectories can become unpredictable and the device useless for the desired separation duty. We show that for circular posts the rotated-square layout, unlike the parallelogram layout, does not suffer from anisotropy and is the preferred geometry. Furthermore, anisotropy becomes severe for arrays with unequal axial and lateral gaps...

  3. Sky reconstruction for the Tianlai cylinder array

    Science.gov (United States)

    Zhang, Jiao; Zuo, Shi-Fan; Ansari, Reza; Chen, Xuelei; Li, Yi-Chao; Wu, Feng-Quan; Campagne, Jean-Eric; Magneville, Christophe

    2016-10-01

    We apply our sky map reconstruction method for transit type interferometers to the Tianlai cylinder array. The method is based on spherical harmonic decomposition, and can be applied to a cylindrical array as well as dish arrays and we can compute the instrument response, synthesized beam, transfer function and noise power spectrum. We consider cylinder arrays with feed spacing larger than half a wavelength and, as expected, we find that the arrays with regular spacing have grating lobes which produce spurious images in the reconstructed maps. We show that this problem can be overcome using arrays with a different feed spacing on each cylinder. We present the reconstructed maps, and study the performance in terms of noise power spectrum, transfer function and beams for both regular and irregular feed spacing configurations.

  4. The revised solar array synthesis computer program

    Science.gov (United States)

    1970-01-01

    The Revised Solar Array Synthesis Computer Program is described. It is a general-purpose program which computes solar array output characteristics while accounting for the effects of temperature, incidence angle, charged-particle irradiation, and other degradation effects on various solar array configurations in either circular or elliptical orbits. Array configurations may consist of up to 75 solar cell panels arranged in any series-parallel combination not exceeding three series-connected panels in a parallel string and no more than 25 parallel strings in an array. Up to 100 separate solar array current-voltage characteristics, corresponding to 100 equal-time increments during the sunlight illuminated portion of an orbit or any 100 user-specified combinations of incidence angle and temperature, can be computed and printed out during one complete computer execution. Individual panel incidence angles may be computed and printed out at the user's option.

  5. Halbach arrays in precision motion control

    Energy Technology Data Exchange (ETDEWEB)

    Trumper, D.L.; Williams, M.E. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1995-02-01

    The Halbach array was developed for use as an optical element in particle accelerators. Following up on a suggestion from Klaus Halbach, the authors have investigated the utility of such arrays as the permanent magnet structure for synchronous machines in cartesian, polar, and cylindrical geometries. Their work has focused on the design of a novel Halbach array linear motor for use in a magnetic suspension stage for photolithography. This paper presents the details of the motor design and its force and power characteristics.

  6. Mapping Electrical Crosstalk in Pixelated Sensor Arrays

    Science.gov (United States)

    Seshadri, Suresh (Inventor); Cole, David (Inventor); Smith, Roger M (Inventor); Hancock, Bruce R. (Inventor)

    2013-01-01

    The effects of inter pixel capacitance in a pixilated array may be measured by first resetting all pixels in the array to a first voltage, where a first image is read out, followed by resetting only a subset of pixels in the array to a second voltage, where a second image is read out, where the difference in the first and second images provide information about the inter pixel capacitance. Other embodiments are described and claimed.

  7. Big Data Challenges for Large Radio Arrays

    Science.gov (United States)

    Jones, Dayton L.; Wagstaff, Kiri; Thompson, David; D'Addario, Larry; Navarro, Robert; Mattmann, Chris; Majid, Walid; Lazio, Joseph; Preston, Robert; Rebbapragada, Umaa

    2012-01-01

    Future large radio astronomy arrays, particularly the Square Kilometre Array (SKA), will be able to generate data at rates far higher than can be analyzed or stored affordably with current practices. This is, by definition, a "big data" problem, and requires an end-to-end solution if future radio arrays are to reach their full scientific potential. Similar data processing, transport, storage, and management challenges face next-generation facilities in many other fields.

  8. A Study of End-Fed Arrays

    CERN Document Server

    Kondylis, Konstantinos; Zimourtopoulos, Petros

    2010-01-01

    This paper presents a general analysis of end-fed space arrays with application to self-standing linear arrays of parallel dipoles. A number of test array models were simulated, constructed and their radiation pattern was then measured. The experimental and computational results were found to be in good agreement. The developed software applications are available through the Internet as FLOSS Free Libre Open Source Software.

  9. Monostable array-enhanced stochastic resonance.

    Science.gov (United States)

    Lindner, J F; Breen, B J; Wills, M E; Bulsara, A R; Ditto, W L

    2001-05-01

    We present a simple nonlinear system that exhibits multiple distinct stochastic resonances. By adjusting the noise and coupling of an array of underdamped, monostable oscillators, we modify the array's natural frequencies so that the spectral response of a typical oscillator in an array of N oscillators exhibits N-1 different stochastic resonances. Such families of resonances may elucidate and facilitate a variety of noise-mediated cooperative phenomena, such as noise-enhanced propagation, in a broad class of similar nonlinear systems.

  10. SWNT-array resonant MOS transistor

    OpenAIRE

    Arun, A.; Campidelli, S; Filoramo, A.; Derycke, V.; Salet, P.; Ionescu, A. M.; Goffman, M. F.

    2010-01-01

    We show that thin horizontal arrays of single wall carbon nanotubes (SWNTs) suspended above the channel of silicon MOSFETs can be used as vibrating gate electrodes. This new class of nano-electromechanical system (NEMS) combines the unique mechanical and electronic properties of SWNTs with an integrated siliconbased motion detection. Its electrical response exhibits a clear signature of the mechanical resonance of SWNTs arrays (120-150 MHz) showing that these thin horizontal arrays behave as ...

  11. Mapping Electrical Crosstalk in Pixelated Sensor Arrays

    Science.gov (United States)

    Seshadri, Suresh (Inventor); Cole, David (Inventor); Smith, Roger M. (Inventor); Hancock, Bruce R. (Inventor)

    2017-01-01

    The effects of inter pixel capacitance in a pixilated array may be measured by first resetting all pixels in the array to a first voltage, where a first image is read out, followed by resetting only a subset of pixels in the array to a second voltage, where a second image is read out, where the difference in the first and second images provide information about the inter pixel capacitance. Other embodiments are described and claimed.

  12. Big Data Challenges for Large Radio Arrays

    Science.gov (United States)

    Jones, Dayton L.; Wagstaff, Kiri; Thompson, David; D'Addario, Larry; Navarro, Robert; Mattmann, Chris; Majid, Walid; Lazio, Joseph; Preston, Robert; Rebbapragada, Umaa

    2012-01-01

    Future large radio astronomy arrays, particularly the Square Kilometre Array (SKA), will be able to generate data at rates far higher than can be analyzed or stored affordably with current practices. This is, by definition, a "big data" problem, and requires an end-to-end solution if future radio arrays are to reach their full scientific potential. Similar data processing, transport, storage, and management challenges face next-generation facilities in many other fields.

  13. Optical Epitaxial Growth of Gold Nanoparticle Arrays.

    Science.gov (United States)

    Huang, Ningfeng; Martínez, Luis Javier; Jaquay, Eric; Nakano, Aiichiro; Povinelli, Michelle L

    2015-09-09

    We use an optical analogue of epitaxial growth to assemble gold nanoparticles into 2D arrays. Particles are attracted to a growth template via optical forces and interact through optical binding. Competition between effects determines the final particle arrangements. We use a Monte Carlo model to design a template that favors growth of hexagonal particle arrays. We experimentally demonstrate growth of a highly stable array of 50 gold particles with 200 nm diameter, spaced by 1.1 μm.

  14. Airborne Electronically Steerable Phased Array (AESPA) program

    Science.gov (United States)

    1979-01-01

    The basic concept and design of a flatplate-fed transmission array are described and system performance requirements are summarized. Particular emphasis is given to the design of the aperture, the radiating element, the phase shifter, the flatplate feed, and the mechanical support structure. Fabrication and testing techniques are considered. Of the three major parameters of interest in demonstrating the performance capabilities of the transmissive array, beamwidth was shown to be the least sensitive to system amplitude and phase errors. Beam pointing angle was also shown to be relatively insensitive to errors. Close agreement between measured and calculated values was found for array gain. The greatest difference was found for array sidelone level.

  15. Modeling Array Stations in SIG-VISA

    Science.gov (United States)

    Ding, N.; Moore, D.; Russell, S.

    2013-12-01

    We add support for array stations to SIG-VISA, a system for nuclear monitoring using probabilistic inference on seismic signals. Array stations comprise a large portion of the IMS network; they can provide increased sensitivity and more accurate directional information compared to single-component stations. Our existing model assumed that signals were independent at each station, which is false when lots of stations are close together, as in an array. The new model removes that assumption by jointly modeling signals across array elements. This is done by extending our existing Gaussian process (GP) regression models, also known as kriging, from a 3-dimensional single-component space of events to a 6-dimensional space of station-event pairs. For each array and each event attribute (including coda decay, coda height, amplitude transfer and travel time), we model the joint distribution across array elements using a Gaussian process that learns the correlation lengthscale across the array, thereby incorporating information of array stations into the probabilistic inference framework. To evaluate the effectiveness of our model, we perform ';probabilistic beamforming' on new events using our GP model, i.e., we compute the event azimuth having highest posterior probability under the model, conditioned on the signals at array elements. We compare the results from our probabilistic inference model to the beamforming currently performed by IMS station processing.

  16. Microfabricated wire arrays for Z-pinch.

    Energy Technology Data Exchange (ETDEWEB)

    Spahn, Olga Blum; Rowen, Adam M.; Cich, Michael Joseph; Peake, Gregory Merwin; Arrington, Christian L.; Nash, Thomas J.; Klem, John Frederick; Romero, Dustin Heinz

    2008-10-01

    Microfabrication methods have been applied to the fabrication of wire arrays suitable for use in Z. Self-curling GaAs/AlGaAs supports were fabricated as an initial route to make small wire arrays (4mm diameter). A strain relief structure that could be integrated with the wire was designed to allow displacements of the anode/cathode connections in Z. Electroplated gold wire arrays with integrated anode/cathode bus connections were found to be sufficiently robust to allow direct handling. Platinum and copper plating processes were also investigated. A process to fabricate wire arrays on any substrate with wire thickness up to 35 microns was developed. Methods to handle and mount these arrays were developed. Fabrication of wire arrays of 20mm diameter was demonstrated, and the path to 40mm array fabrication is clear. With some final investment to show array mounting into Z hardware, the entire process to produce a microfabricated wire array will have been demonstrated.

  17. Cosmic ray effects in microcalorimeter arrays

    Energy Technology Data Exchange (ETDEWEB)

    Stahle, C.K. E-mail: cak@lheapop.gsfc.nasa.gov; Boyce, K.R.; Brown, G.V.; Cottam, J.; Figueroa-Feliciano, E.; Galeazzi, M.; Kelley, R.L.; McCammon, D.; Porter, F.S.; Szymkowiak, A.E.; Tillotson, W.A

    2004-03-11

    We have identified signals resulting from cosmic rays and environmental gamma rays depositing energy in the pixels and in the silicon frame of the Astro-E2/X-Ray Spectrometer microcalorimeter array. Coincidences between pixels and between the array and an anti-coincidence detector determined the nature of the events. Pulse shapes and amplitudes from the cosmic ray events helped refine the thermal model of the array chip. We discuss how future arrays can be optimized either for the greatest background rejection or for the highest source count rates.

  18. ANTENNAS ARRAY ADJUST WITH ADAPTIVE NEURONAL SYSTEM

    Directory of Open Access Journals (Sweden)

    A. Padrón

    2004-12-01

    Full Text Available In this work an array failure correction for Linear Antenna Array (LAA is presented. This is carried out by means ofan Adaptive Artificial Neural Network (AANN that adjusts the amplitude and phase at beamforming. Theappropriated corrections are given, when one, or two, or three elements have a failure in the antenna linear array.The AANN corrects the corresponding parameters in the radiation pattern obtained due to the failure, when weknow the coefficients of the array factor (AF. This yields a reduction of side lobe level and some interferencesdisappear.

  19. Retroreflector Array for Test Environments (RATE) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Research Support Instruments, Inc. (RSI) proposes to develop the Retroreflector Array for Test Environments (RATE), an innovative technology that will...

  20. Large Format Uncooled Focal Plane Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Black Forest Engineering has identified innovative modifications in uncooled focal plane array (UFPA) architecture and processing that allows development of large...

  1. Enhanced reflection from inverse tapered nanocone arrays

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Xiang-Tian; Dai, Qing, E-mail: daiq@nanoctr.cn [National Center for Nanoscience and Technology, Beijing 100190 (China); Butt, Haider, E-mail: h.butt@bham.ac.uk; Deng, Sunan [School of Mechanical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Yetisen, Ali K.; Cruz Vasconcellos, Fernando da [Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT (United Kingdom); Kangwanwatana, Chuan; Montelongo, Yunuen; Qasim, Malik M.; Wilkinson, Timothy D. [Electrical Engineering Division, Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom)

    2014-08-04

    We computationally and experimentally demonstrate enhanced reflection effects displayed by silicon-based inverted nanocone arrays. A 3D finite element model is used to characterize the optical properties of the nanocone arrays with respect to the change in polarization and incident angles. The nanocone arrays are fabricated by e-beam lithography in hexagonal and triangular geometries with a lattice constant of 300 nm. The fabricated devices show a two-fold increase in reflection compared with bare silicon surface, as well as a strong diffraction within the visible and near-infrared spectra. The nanocone arrays may find a variety of applications from optical devices to energy conservation technologies.

  2. A series array of dc SQUIDs

    Energy Technology Data Exchange (ETDEWEB)

    Welty, R.P. (Colorado Univ., Boulder, CO (United States). Dept. of Electrical Engineering); Martinis, J.M. (Geraghty and Miller, Inc., Reston, VA (United States))

    1991-03-01

    This paper reports on a series array of 100 dc SQUIDs using trilayer Nb-AlO{sub x}-Nb junctions. The SQUIDs are modulated with a common flux bias line and produce an output voltage swing of several millivolts across the array. The large output voltage will allow direct connection to room temperature electronics without the transformer coupling and resulting frequency limitations commonly associated with dc SQUID amplifiers. The authors measured a bandwidth of dc to at least 175 MHz for a 100-SQUID array. The series array will be used as the output stage for a multistage integrated SQUID amplifier.

  3. Design and Realization of Array Signal Processor VLSI Architecture for Phased Array System

    Directory of Open Access Journals (Sweden)

    D. Govind Rao

    2016-08-01

    Full Text Available A method for implementing an array signal processor for phased array radars. The array signal processor can receive planar array antenna inputs and can process it. It is based on the application of Adaptive Digital beam formers using FPGAs. Adaptive filter algorithm used here is Inverse Q-R Decomposition based Recursive Least Squares (IQRD-RLS [1] algorithm. Array signal processor based on FPGAs is suitable in the areas of Phased Array Radar receiver, where speed, accuracy and numerical stability are of utmost important. Using IQRD-RLS algorithm, optimal weights are calculated in much less time compared to conventional QRD-RLS algorithm. A customized multiple FPGA board comprising three Kintex-7 FPGAs is employed to implement array signal processor. The proposed architecture can form multiple beams from planar array antenna elements

  4. Automated calibration of multistatic arrays

    Energy Technology Data Exchange (ETDEWEB)

    Henderer, Bruce

    2017-03-14

    A method is disclosed for calibrating a multistatic array having a plurality of transmitter and receiver pairs spaced from one another along a predetermined path and relative to a plurality of bin locations, and further being spaced at a fixed distance from a stationary calibration implement. A clock reference pulse may be generated, and each of the transmitters and receivers of each said transmitter/receiver pair turned on at a monotonically increasing time delay interval relative to the clock reference pulse. Ones of the transmitters and receivers may be used such that a previously calibrated transmitter or receiver of a given one of the transmitter/receiver pairs is paired with a subsequently un-calibrated one of the transmitters or receivers of an immediately subsequently positioned transmitter/receiver pair, to calibrate the transmitter or receiver of the immediately subsequent transmitter/receiver pair.

  5. AGATA - Advanced Gamma Tracking Array

    CERN Document Server

    Akkoyun, S; Alikhani, B; Ameil, F; de Angelis, G; Arnold, L; Astier, A; Ataç, A; Aubert, Y; Aufranc, C; Austin, A; Aydin, S; Azaiez, F; Badoer, S; Balabanski, D L; Barrientos, D; Baulieu, G; Baumann, R; Bazzacco, D; Beck, F A; Beck, T; Bednarczyk, P; Bellato, M; Bentley, M A; Benzoni, G; Berthier, R; Berti, L; Beunard, R; Bianco, G Lo; Birkenbach, B; Bizzeti, P G; Bizzeti-Sona, A M; Blanc, F Le; Blasco, J M; Blasi, N; Bloor, D; Boiano, C; Borsato, M; Bortolato, D; Boston, A J; Boston, H C; Bourgault, P; Boutachkov, P; Bouty, A; Bracco, A; Brambilla, S; Brawn, I P; Brondi, A; Broussard, S; Bruyneel, B; Bucurescu, D; Burrows, I; Bürger, A; Cabaret, S; Cahan, B; Calore, E; Camera, F; Capsoni, A; Carrió, F; Casati, G; Castoldi, M; Cederwall, B; Cercus, J -L; Chambert, V; Chambit, M El; Chapman, R; Charles, L; Chavas, J; Clément, E; Cocconi, P; Coelli, S; Coleman-Smith, P J; Colombo, A; Colosimo, S; Commeaux, C; Conventi, D; Cooper, R J; Corsi, A; Cortesi, A; Costa, L; Crespi, F C L; Cresswell, J R; Cullen, D M; Curien, D; Czermak, A; Delbourg, D; Depalo, R; Descombes, T; Désesquelles, P; Detistov, P; Diarra, C; Didierjean, F; Dimmock, M R; Doan, Q T; Domingo-Pardo, C; Doncel, M; Dorangeville, F; Dosme, N; Drouen, Y; Duchêne, G; Dulny, B; Eberth, J; Edelbruck, P; Egea, J; Engert, T; Erduran, M N; Ertürk, S; Fanin, C; Fantinel, S; Farnea, E; Faul, T; Filliger, M; Filmer, F; Finck, Ch; de France, G; Gadea, A; Gast, W; Geraci, A; Gerl, J; Gernhäuser, R; Giannatiempo, A; Giaz, A; Gibelin, L; Givechev, A; Goel, N; González, V; Gottardo, A; Grave, X; Grȩbosz, J; Griffiths, R; Grint, A N; Gros, P; Guevara, L; Gulmini, M; Görgen, A; Ha, H T M; Habermann, T; Harkness, L J; Harroch, H; Hauschild, K; He, C; Hernández-Prieto, A; Hervieu, B; Hess, H; Hüyük, T; Ince, E; Isocrate, R; Jaworski, G; Johnson, A; Jolie, J; Jones, P; Jonson, B; Joshi, P; Judson, D S; Jungclaus, A; Kaci, M; Karkour, N; Karolak, M; Kaşkaş, A; Kebbiri, M; Kempley, R S; Khaplanov, A; Klupp, S; Kogimtzis, M; Kojouharov, I; Korichi, A; Korten, W; Kröll, Th; Krücken, R; Kurz, N; Ky, B Y; Labiche, M; Lafay, X; Lavergne, L; Lazarus, I H; Leboutelier, S; Lefebvre, F; Legay, E; Legeard, L; Lelli, F; Lenzi, S M; Leoni, S; Lermitage, A; Lersch, D; Leske, J; Letts, S C; Lhenoret, S; Lieder, R M; Linget, D; Ljungvall, J; Lopez-Martens, A; Lotodé, A; Lunardi, S; Maj, A; van der Marel, J; Mariette, Y; Marginean, N; Marginean, R; Maron, G; Mather, A R; Mȩczyński, W; Mendéz, V; Medina, P; Melon, B; Menegazzo, R; Mengoni, D; Merchan, E; Mihailescu, L; Michelagnoli, C; Mierzejewski, J; Milechina, L; Million, B; Mitev, K; Molini, P; Montanari, D; Moon, S; Morbiducci, F; Moro, R; Morrall, P S; Möller, O; Nannini, A; Napoli, D R; Nelson, L; Nespolo, M; Ngo, V L; Nicoletto, M; Nicolini, R; Noa, Y Le; Nolan, P J; Norman, M; Nyberg, J; Obertelli, A; Olariu, A; Orlandi, R; Oxley, D C; Özben, C; Ozille, M; Oziol, C; Pachoud, E; Palacz, M; Palin, J; Pancin, J; Parisel, C; Pariset, P; Pascovici, G; Peghin, R; Pellegri, L; Perego, A; Perrier, S; Petcu, M; Petkov, P; Petrache, C; Pierre, E; Pietralla, N; Pietri, S; Pignanelli, M; Piqueras, I; Podolyak, Z; Pouhalec, P Le; Pouthas, J; Pugnére, D; Pucknell, V F E; Pullia, A; Quintana, B; Raine, R; Rainovski, G; Ramina, L; Rampazzo, G; La Rana, G; Rebeschini, M; Recchia, F; Redon, N; Reese, M; Reiter, P; Regan, P H; Riboldi, S; Richer, M; Rigato, M; Rigby, S; Ripamonti, G; Robinson, A P; Robin, J; Roccaz, J; Ropert, J -A; Rossé, B; Alvarez, C Rossi; Rosso, D; Rubio, B; Rudolph, D; Saillant, F; Şahin, E; Salomon, F; Salsac, M -D; Salt, J; Salvato, G; Sampson, J; Sanchis, E; Santos, C; Schaffner, H; Schlarb, M; Scraggs, D P; Seddon, D; Şenyiğit, M; Sigward, M -H; Simpson, G; Simpson, J; Slee, M; Smith, J F; Sona, P; Sowicki, B; Spolaore, P; Stahl, C; Stanios, T; Stefanova, E; Stézowski, O; Strachan, J; Suliman, G; Söderström, P -A; Tain, J L; Tanguy, S; Tashenov, S; Theisen, Ch; Thornhill, J; Tomasi, F; Toniolo, N; Touzery, R; Travers, B; Triossi, A; Tripon, M; Tun-Lanoë, K M M; Turcato, M; Unsworth, C; Ur, C A; Valiente-Dobon, J J; Vandone, V; Vardaci, E; Venturelli, R; Veronese, F; Veyssiere, Ch; Viscione, E; Wadsworth, R; Walker, P M; Warr, N; Weber, C; Weisshaar, D; Wells, D; Wieland, O; Wiens, A; Wittwer, G; Wollersheim, H J; Zocca, F; Zamfir, N V; Ziȩbliński, M; Zucchiatti, A

    2011-01-01

    The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation gamma-ray spectrometer. AGATA is based on the technique of gamma-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a gamma ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realization of gamma-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly-segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterization of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorith...

  6. Cherenkov Telescope Array Data Management

    CERN Document Server

    Lamanna, G; Contreras, J L; Knödlseder, J; Kosack, K; Neyroud, N; Aboudan, A; Arrabito, L; Barbier, C; Bastieri, D; Boisson, C; Brau-Nogué, S; Bregeon, J; Bulgarelli, A; Carosi, A; Costa, A; De Cesare, G; Reyes, R de los; Fioretti, V; Gallozzi, S; Jacquemier, J; Khelifi, B; Kocot, J; Lombardi, S; Lucarelli, F; Lyard, E; Maier, G; Massimino, P; Osborne, J P; Perri, M; Rico, J; Sanchez, D A; Satalecka, K; Siejkowski, H; Stolarczyk, T; Szepieniec, T; Testa, V; Walter, R; Ward, J E; Zoli, A

    2015-01-01

    Very High Energy gamma-ray astronomy with the Cherenkov Telescope Array (CTA) is evolving towards the model of a public observatory. Handling, processing and archiving the large amount of data generated by the CTA instruments and delivering scientific products are some of the challenges in designing the CTA Data Management. The participation of scientists from within CTA Consortium and from the greater worldwide scientific community necessitates a sophisticated scientific analysis system capable of providing unified and efficient user access to data, software and computing resources. Data Management is designed to respond to three main issues: (i) the treatment and flow of data from remote telescopes; (ii) "big-data" archiving and processing; (iii) and open data access. In this communication the overall technical design of the CTA Data Management, current major developments and prototypes are presented.

  7. THE AUGER ENGINEERING RADIO ARRAY

    Directory of Open Access Journals (Sweden)

    Klaus Weidenhaupt

    2013-12-01

    Full Text Available The Auger Engineering Radio Array currently measures MHz radio emission from extensive air showers induced by high energy cosmic rays with 24 self-triggered radio detector stations. Its unique site, embedded into the baseline detectors and extensions of the Pierre Auger Observatory, allows to study air showers in great detail and to calibrate the radio emission. In its final stage AERA will expand to an area of approximately 20km2 to explore the feasibility of the radio-detection technique for future cosmic-ray detectors. The concept and hardware design of AERA as well as strategies to enable self-triggered radio detection are presented. Radio emission mechanisms are discussed based on polarization analysis of the first AERA data.

  8. Conformable eddy current array delivery

    Science.gov (United States)

    Summan, Rahul; Pierce, Gareth; Macleod, Charles; Mineo, Carmelo; Riise, Jonathan; Morozov, Maxim; Dobie, Gordon; Bolton, Gary; Raude, Angélique; Dalpé, Colombe; Braumann, Johannes

    2016-02-01

    The external surface of stainless steel containers used for the interim storage of nuclear material may be subject to Atmospherically Induced Stress Corrosion Cracking (AISCC). The inspection of such containers poses a significant challenge due to the large quantities involved; therefore, automating the inspection process is of considerable interest. This paper reports upon a proof-of-concept project concerning the automated NDT of a set of test containers containing artificially generated AISCCs. An Eddy current array probe with a conformable padded surface from Eddyfi was used as the NDT sensor and end effector on a KUKA KR5 arc HW robot. A kinematically valid cylindrical raster scan path was designed using the KUKA|PRC path planning software. Custom software was then written to interface measurement acquisition from the Eddyfi hardware with the motion control of the robot. Preliminary results and analysis are presented from scanning two canisters.

  9. Gold film resistor bolometric array

    Energy Technology Data Exchange (ETDEWEB)

    Yin Fuxian [Academia Sinica, Hefei, AH (China). Inst. of Plasma Physics

    1997-03-01

    A new type of bolometric array diagnostic system has been developed for HT-6M tokamak and HT-7 superconductor tokamak plasma physics experimental research. This system is composed of temperature-sensitive detectors of gold film resistor and phase-sensitive rectifiers of the bridge excited by square waves. With this system, a radiation detection limit of 192.0 {mu}W cm{sup -2} at a spatial resolution of 2.0 cm and a temporal resolution of 1.0 mS. The system features a high temperature baking resistance, ultra high vacuum endurance, sufficient insensitivity to radiation damage, sufficient suppression of electromagnetic interference, good long-term stability, high radiation sensitivity and measurement data reliability. Absolute calibration of the detectors is performed simultaneously and in situ by means of a built-in electronic power pulse. (orig.) 9 refs.

  10. Microlens arrays with integrated pores

    Directory of Open Access Journals (Sweden)

    Shu Yang

    2005-12-01

    Full Text Available Microlenses are important optical components that image, detect, and couple light. But most synthetic microlenses have fixed position and shape once they are fabricated, so their possible range of tunability and complexity is rather limited. By comparison, biology provides many varied, new paradigms for the development of adaptive optical networks. Here, we discuss inspirational examples of biological lenses and their synthetic analogs. We focus on the fabrication and characterization of biomimetic microlens arrays with integrated pores, whose appearance and function are similar to highly efficient optical elements formed by brittlestars. The complex design can be created by three-beam interference lithography. The synthetic lens has strong focusing ability for use as an adjustable lithographic mask and a tunable optical device coupled with the microfluidic system. Replacing rigid microlenses with soft hydrogels provides a way of changing the lens geometry and refractive index continuously in response to external stimuli, resulting in intelligent, multifunctional, tunable optics.

  11. Scanning strategies for imaging arrays

    CERN Document Server

    Kovács, A

    2008-01-01

    Large-format (sub)millimeter wavelength imaging arrays are best operated in scanning observing modes rather than traditional position-switched (chopped) modes. The choice of observing mode is critical for isolating source signals from various types of noise interference, especially for ground-based instrumentation operating under a bright atmosphere. Ideal observing strategies can combat 1/f noise, resist instrumental defects, sensitively recover emission on large scales, and provide an even field coverage -- all under feasible requirements of telescope movement. This work aims to guide the design of observing patterns that maximize scientific returns. It also compares some of the popular choices of observing modes for (sub)millimeter imaging, such as random, Lissajous, billiard, spiral, On-The-Fly (OTF), DREAM, chopped and stare patterns. Many of the conclusions are also applicable other imaging applications and imaging in one dimension (e.g. spectroscopic observations).

  12. Gigapixel imaging with microlens arrays

    Science.gov (United States)

    Orth, Antony; Schonbrun, Ethan

    2016-03-01

    A crucial part of the drug discovery process involves imaging the response of thousands of cell cultures to candidate drugs. Quantitative parameters from these "high content screens", such as protein expression and cell morphology, are extracted from fluorescence and brightfield micrographs. Due to the sheer number of cells that need to imaged for adequate statistics, the imaging time itself is a major bottleneck. Automated microscopes image small fields-of-view (FOVs) serially, which are then stitched together to form gigapixel-scale mosaics. We have developed a microscopy architecture that reduces mechanical overhead of traditional large field-of-view by parallelizing the image capture process. Instead of a single objective lens imaging FOVs one by one, we employ a microlens array for continuous photon capture, resulting in a 3-fold throughput increase. In this contribution, we present the design and imaging results of this microscopy architecture in three different contrast modes: multichannel fluorescence, hyperspectral fluorescence and brightfield.

  13. Wind farm array wake losses

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.W. [Impact Weather, Washougal, WA (United States); McCarthy, E.F. [Wind Economics & Technology, Inc., Martinez, CA (United States)

    1997-12-31

    A wind turbine wake study was conducted in the summer of 1987 at an Altamont Pass wind electric generating facility. The wind speed deficits, turbulence, and power deficits from an array consisting of several rows of wind turbines is discussed. A total of nine different test configurations were evaluated for a downwind spacing ranging from 7 rotor diameters (RD) to 34 RD and a cross wind spacing of 1.3 RD and 2.7 RD. Wake power deficits of 15% were measured at 16 RD and power losses of a few percent were even measurable at 27 RD for the closer cross wind spacing. For several rows of turbines separated by 7-9 RD the wake zones overlapped and formed compound wakes with higher velocity deficits. The wind speed and direction turbulence in the wake was much higher than the ambient turbulence. The results from this study are compared to the findings from other similar field measurements.

  14. Array radars solve communication jams

    Science.gov (United States)

    Lewis, H. D.

    1982-04-01

    The possibilities of incorporating mobile radar units as slave stations in communications relay applications during times of disrupted communications is examined. The limitations on uses of search, tracking, and multifunction radars are examined, noting that employment of the mobile system entails some tracking by the master phased-arrays to keep the mobile units in focus. The tracking patterns and dwell times are outlined, and the possibility of 700-1000 dwell times of 1220 microsec duration/sec is mentioned as opening the opportunity for high quality data transmissions. Signal-to-noise ratios are formulated for jamming situations, with offsetting tactical features for the jamming including the directivity and gain of the master antenna, the master station's power aperture product, on-axis to off-axis gain ratio, and antenna positioning ability. A slave station must be equipped with a transponder for communications, which are best achieved with pseudo-random coded waveforms.

  15. Sputtering in supported cluster arrays

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez-Sáez, J.C., E-mail: jc.jimenez@upm.es [Dept. Física Aplicada a la Ingeniería Aeronáutica y Naval, ETSIAE, Universidad Politécnica de Madrid (UPM), 28040 Madrid (Spain); Pérez-Martín, A.M.C.; Jiménez-Rodríguez, J.J. [Dept. Física Aplicada III, Facultad de Ciencias Físicas, Universidad Complutense de Madrid (UCM), 28040 Madrid (Spain)

    2015-06-01

    Bombardment of periodical arrays formed by Co nanoislands deposited on a Cu(0 0 1) substrate with 1-keV argon ions is simulated by using molecular dynamics. Sputtering yield is analyzed distinguishing between particles sputtered across the supported cluster surface and across the flat substrate surface without nanoparticle above. The dependence of this magnitude on the height and the periodical spacing between nanoislands has been investigated. Results show that this dependence for the sputtering across the nanoislands and across the substrate is different. In the case of the total sputtering, the “substrate” effect prevails since the behavior of this magnitude is approximately analogous to the sputtering across the substrate. The more probable causes are analyzed in this article.

  16. Calculation and analysis of correlation curves between Lanzhou Seismic Array sites and assessment of primary array

    Institute of Scientific and Technical Information of China (English)

    郝春月; 郑重; 周公威

    2003-01-01

    By using the waveform data recorded during the site survey of Lanzhou Seismic Array, the author calculated andanalyzed the correlation of the signal and noise between the site pairs and found that the ideal radii of the twoconcentric rings for Lanzhou Seismic Array were 380 m and 1500 m, respectively. According to the radius limitand other requirements, nine sites were chosen to make a seismic array, and then the detection and location abilityof the array were estimated.

  17. Multipath Array Processing for Co-Prime and Under-Sampled Sensor Arrays

    Science.gov (United States)

    2015-09-30

    freedom than physical sensors present in the array. However, the cost of the achievable degrees of freedom is a loss of approximately half of the array...of degrees of freedom of the array. A co-prime frequency comb is a novel active sonar waveform that achieves range-Doppler performance similar...localization with moving co-prime arrays,” in Acoustics, Speech and Signal Processing (ICASSP), 2015 IEEE International Conference on, 2015. 6 2

  18. Simultaneous use of multiple seismic arrays

    Science.gov (United States)

    Stipčević, J.; Kennett, B. L. N.; Tkalčić, H.

    2017-01-01

    Seismic arrays provide an important means of enhancing seismic signals and determining the directional properties of the wavefield by beam-forming. When multiple arrays are to be used together, the viewpoint needs to be modified from looking outwards from each array to focusing on a specific target area and so constraining the portions of the waveforms to be analysed. Beam-forming for each array is supplemented by the relative time constraints for propagation from the target to each array to provide tight spatial control. Simultaneous multiple array analysis provides a powerful tool for source characterisation, and for structural analysis of scatterers as virtual sources. The multiple array concept allows us to illuminate a specific point in the Earth from many different directions and thus map detailed patterns of heterogeneity in the Earth. Furthermore, illumination of the structure from multiple directions using data from the same event minimizes source effects to provide clearer images of heterogeneity. The analysis is based on a similar concept to the back-projection technique, where a part of the seismic wavetrain is mapped to a specific point in space by ray-tracing. In contrast to classic back-projection where the incoming energy is mapped onto a horizontal plane with limited vertical resolution, the multi-array method controls depth response by combining relative time constraints between the arrays and conventional beam-forming. We illustrate this approach with application to two earthquakes at moderate depth. The results show that the use of simultaneous multiple arrays can provide improvement both in signal quality and resolution, with the additional benefit of being able to accurately locate the source of the incoming energy and map large areas with only a limited number of such arrays.

  19. Diagnostics of the BIOMASS feed array prototype

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Pivnenko, Sergey; Pontoppidan, Kennie Nybo

    2013-01-01

    The 3D reconstruction algorithm is applied to the prototype feed array of the BIOMASS synthetic aperture radar, recently measured at the DTU-ESA Spherical Near-Field Antenna Test Facility in Denmark. Careful analysis of the measured feed array data has shown that the test support structure...

  20. The SKA New Instrumentation: Aperture Arrays

    Science.gov (United States)

    van Ardenne, A.; Faulkner, A. J.; de Vaate, J. G. bij

    The radio frequency window of the Square Kilometre Array is planned to cover the wavelength regime from cm up to a few meters. For this range to be optimally covered, different antenna concepts are considered enabling many science cases. At the lowest frequency range, up to a few GHz, it is expected that multi-beam techniques will be used, increasing the effective field-of-view to a level that allows very efficient detailed and sensitive exploration of the complete sky. Although sparse narrow band phased arrays are as old as radio astronomy, multi-octave sparse and dense arrays now being considered for the SKA, requiring new low noise design, signal processing and calibration techniques. These new array techniques have already been successfully introduced as phased array feeds upgrading existing reflecting telescopes and for new telescopes to enhance the aperture efficiency as well as greatly increasing their field-of-view (van Ardenne et al., Proc IEEE 97(8):2009) by [1]. Aperture arrays use phased arrays without any additional reflectors; the phased array elements are small enough to see most of the sky intrinsically offering a large field of view.

  1. Space Environment Testing of Photovoltaic Array Systems

    Science.gov (United States)

    Phillips, Brandon; Schneider, Todd A.; Vaughn, Jason A.; Wright, Kenneth H.

    2015-01-01

    To successfully operate a photovoltaic (PV) array system in space requires planning and testing to account for the effects of the space environment. It is critical to understand space environment interactions not only on the PV components, but also the array substrate materials, wiring harnesses, connectors, and protection circuitry.

  2. Spherical Horn Array for Wideband Propagation Measurements

    DEFF Research Database (Denmark)

    Franek, Ondrej; Pedersen, Gert Frølund

    2011-01-01

    A spherical array of horn antennas designed to obtain directional channel information and characteristics is introduced. A dual-polarized quad-ridged horn antenna with open flared boundaries and coaxial feeding for the frequency band 600 MHz–6 GHz is used as the element of the array. Matching...

  3. Defect-free atom arrays on demand

    Science.gov (United States)

    Levine, Harry; Bernien, Hannes; Keesling, Alex; Anschuetz, Eric; Senko, Crystal; Vuletic, Vladan; Greiner, Markus; Endres, Manuel; Lukin, Mikhail

    2016-05-01

    Arrays of neutral, trapped atoms have proven to be an extraordinary platform for studying quantum many-body physics and implementing quantum information protocols. Conventional approaches to generate such arrays rely on loading atoms into optical lattices and require elaborate experimental control. An alternative, simpler approach is to load atoms into individual optical tweezers. However, the probabilistic nature of the loading process limits the size of the arrays to small numbers of atoms. Here we present a new method for assembling defect-free arrays of large numbers of atoms. Our technique makes use of an array of tightly focused optical tweezers generated by an acousto-optic deflector. The positions of the traps can be dynamically reconfigured on a sub-millisecond timescale. With single-site resolved fluorescence imaging, we can identify defects in the atom array caused by the probabilistic loading process and rearrange the trap positions in response. This will enable us to generate defect-free atom arrays on demand. We discuss our latest results towards reaching this goal along with schemes to implement long-range interactions between atoms in the array. Now at Caltech.

  4. Array aperture extrapolation using sparse reconstruction

    NARCIS (Netherlands)

    Anitori, L.; Rossum, W.L. van; Huizing, A.G.

    2015-01-01

    In this paper we present some preliminary results on antenna array extrapolation for Direction Of Arrival (DOA) estimation using Sparse Reconstruction (SR). The objective of this study is to establish wether it is possible to achieve with an array of a given physical length the performance (in terms

  5. Polarization tomography of metallic nanohole arrays

    NARCIS (Netherlands)

    Altewischer, E.; Genet, C.; Van Exter, M.P.; Woerdman, J.P.; Alkemade, P.F.A.; Van Zuuk, A.; Van der Drift, E.W.J.M.

    2005-01-01

    We report polarization tomography experiments on metallic nanohole arrays with square and hexagonal symmetry. As a main result we find that a fully polarized input beam is partly depolarized after transmission through a nanohole array. This loss of polarization coherence is found to be anisotropic;

  6. ALMA - the Atacama Large Millimeter Array

    NARCIS (Netherlands)

    Wild, W.; Cunningham, C.

    2002-01-01

    The Atacama Large Millimeter Array (ALMA) is a major ground based project for millimeter and submillimeter astronomy to be realized during this decade. It comprises an array of 64 telescopes of 12 meter diameter, each equipped with 10 receivers bands covering the atmospheric windows from 30 GHz to 9

  7. Difference packing arrays and systematic authentication codes

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    In this paper, a type of combinatorial design (called difference packing array)is proposed and used to give a construction of systematic authentication codes. Taking advantage of this construction, some new series of systematic authentication codes are obtainable in terms of existing difference packing arrays.

  8. Hearing aid comprising an array of microphones

    NARCIS (Netherlands)

    Boone, M.M.; Berkhout, A.J.; Merks, I.L.D.M.

    1999-01-01

    Hearing aid for improving the hearing ability of the hard of hearing, comprising an array of microphones, the electrical output signals of which are fed to at least one transmission path belonging to an ear. Means are provided for deriving two array output signals from the output signals of the micr

  9. Miniaturized Retrodirective Arrays for a Nanosatellite Platform

    Science.gov (United States)

    2012-01-01

    128-134, Jan.2006. [13] T. Brabetz, V. F. Fusco, and S. Karode, "Balanced subharmonic mixers for retrodirective- array applications," IEEE Trans...Murakami, J.D. Roque, S. S. Sung, G. S. Shiroma, R. Y. Miyamoto, and W. A. Shi- roma, "A quadruple subharmonic phase-conjugating array for secure

  10. All Orthogonal Arrays with 18 Runs

    NARCIS (Netherlands)

    Schoen, E.D.

    2009-01-01

    All combinatorially inequivalent orthogonal arrays with 18 runs and eight or less factors are generated. Their potential as practical experimental designs is evaluated by a classification using generalized word-length patterns of the original arrays and those of their projections into less factors.

  11. A microsensor array for biochemical sensing

    NARCIS (Netherlands)

    Van Steenkiste, Filip; Baert, Kris; Debruyker, Dirk; Spiering, Vincent; Schoot, van der Bart; Arquint, Philippe; Born, Reinhard; Schumann, Klaus

    1997-01-01

    A microsensor array to measure chemical properties of biological liquids is presented. A hybrid integration technique is used to mount four sensor chips on a micro flow channel: a pressure, temperature, pH, combined pO2 and pCO2 sensor chip. This results in a microsensor array which is developed to

  12. L3+C air shower array

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    Photo 01: a view of the L3+C air shower array; 50 scintillators on the roof of the SX-hall above L3. Photo 02: view of one of the detectors of the array.Photo 04: detectors seen against the background of the LEP Point 2 facilities.

  13. Si:As BIB detector arrays

    Science.gov (United States)

    Bharat, R.; Petroff, M. D.; Speer, J. J.; Stapelbroek, M. G.

    1986-01-01

    Highlights of the results obtained on arsenic-doped silicon blocked impurity band (BIB) detectors and arrays since the invention of the BIB concept a few years ago are presented. After a brief introduction and a description of the BIB concept, data will be given on single detector performance. Then different arrays that were fabricated will be described and test data presented.

  14. Stochastic Beamforming via Compact Antenna Arrays

    DEFF Research Database (Denmark)

    Alrabadi, Osama; Pedersen, Gert Frølund

    2012-01-01

    The paper investigates the average beamforming (BF) gain of compact antenna arrays when statistical channel knowledge is available. The optimal excitation (precoding vector) and impedance termination that maximize the average BF gain are a compromise between the ones that maximize the array...

  15. Antennas for Frequency Reconfigurable Phased Arrays

    NARCIS (Netherlands)

    Haider, S.N.

    2015-01-01

    Sensors such as phased array radars play a crucial role in public safety. They are unavoidable for surveillance, threat identification and post-disaster management. However, different scenarios impose immensely diverse requirements for these systems. Phased array systems occupy a large space. In add

  16. Redundancy Calibration of Phased Array Stations

    CERN Document Server

    Noorishad, Parisa; van Ardenne, Arnold; van der Hulst, Thijs

    2012-01-01

    Our aim is to assess the benefits and limitations of using the redundant visibility information in regular phased array systems for improving the calibration. Regular arrays offer the possibility to use redundant visibility information to constrain the calibration of the array independent of a sky model and a beam models of the station elements. It requires a regular arrangement in the configuration of array elements and identical beam patterns. We revised a calibration method for phased array stations using the redundant visibility information in the system and applied it successfully to a LOFAR station. The performance and limitations of the method were demonstrated by comparing its use on real and simulated data. The main limitation is the mutual coupling between the station elements, which leads to non-identical beams and stronger baseline dependent noise. Comparing the variance of the estimated complex gains with the Cramer-Rao Bound (CRB) indicates that redundancy is a stable and optimum method for cali...

  17. Development of a monolithic ferrite memory array

    Science.gov (United States)

    Heckler, C. H., Jr.; Bhiwandker, N. C.

    1972-01-01

    The results of the development and testing of ferrite monolithic memory arrays are presented. This development required the synthesis of ferrite materials having special magnetic and physical characteristics and the development of special processes; (1) for making flexible sheets (laminae) of the ferrite composition, (2) for embedding conductors in ferrite, and (3) bonding ferrite laminae together to form a monolithic structure. Major problems encountered in each of these areas and their solutions are discussed. Twenty-two full-size arrays were fabricated and fired during the development of these processes. The majority of these arrays were tested for their memory characteristics as well as for their physical characteristics and the results are presented. The arrays produced during this program meet the essential goals and demonstrate the feasibility of fabricating monolithic ferrite memory arrays by the processes developed.

  18. Analyzing Array Manipulating Programs by Program Transformation

    Science.gov (United States)

    Cornish, J. Robert M.; Gange, Graeme; Navas, Jorge A.; Schachte, Peter; Sondergaard, Harald; Stuckey, Peter J.

    2014-01-01

    We explore a transformational approach to the problem of verifying simple array-manipulating programs. Traditionally, verification of such programs requires intricate analysis machinery to reason with universally quantified statements about symbolic array segments, such as "every data item stored in the segment A[i] to A[j] is equal to the corresponding item stored in the segment B[i] to B[j]." We define a simple abstract machine which allows for set-valued variables and we show how to translate programs with array operations to array-free code for this machine. For the purpose of program analysis, the translated program remains faithful to the semantics of array manipulation. Based on our implementation in LLVM, we evaluate the approach with respect to its ability to extract useful invariants and the cost in terms of code size.

  19. Arrayed Continuous-wave THz Photomixers

    CERN Document Server

    Bauerschmidt, S T; Döhler, G H; Lu, H; Gossard, A C; Preu, S

    2013-01-01

    We present both chip-scale and free space coherent arrays of continuous-wave THz photomixers. By altering the relative phases of the exciting laser signals, the relative THz phase between the array elements can be tuned, allowing for beam steering. The constructive interference of the emission of N elements leads to an increase of the focal intensity by a factor of NxN while reducing the beam width by ~1/N, below the diffraction limit of a single source. Such array architectures strongly improve the THz power distribution for stand-off spectroscopy and imaging systems while providing a huge bandwidth at the same time. We demonstrate this by beam profiles generated by a free space 2x2 and a 4x1 array for a transmission distance of 4.2 meters. Spectra between 70 GHz and 1.1 THz have been recorded with these arrays.

  20. Refracting surface plasmon polaritons with nanoparticle arrays.

    Science.gov (United States)

    Radko, Ilya P; Evlyukhin, Andrey B; Boltasseva, Alexandra; Bozhevolnyi, Sergey I

    2008-03-17

    Refraction of surface plasmon polaritons (SPPs) by various structures formed by a 100-nm-period square lattice of gold nanoparticles on top of a gold film is studied by leakage radiation microscopy. SPP refraction by a triangular-shaped nanoparticle array indicates that the SPP effective refractive index increases inside the array by a factor of approximately 1.08 (for the wavelength 800 nm) with respect to the SPP index at a flat surface. Observations of SPP focusing and deflection by circularly shaped areas as well as SPP waveguiding inside rectangular arrays are consistent with the SPP index increase deduced from the SPP refraction by triangular arrays. The SPP refractive index is found to decrease slightly for longer wavelengths within the wavelength range of 700-860 nm. Modeling based on the Green's tensor formalism is in a good agreement with the experimental results, opening the possibility to design nanoparticle arrays for specific applications requiring in-plane SPP manipulation.

  1. Simultaneous use of multiple seismic arrays

    Science.gov (United States)

    Stipčević, J.; Kennett, B. L. N.; Tkalčić, H.

    2017-05-01

    Seismic arrays provide an important means of enhancing seismic signals and determining the directional properties of the wavefield by beamforming. When multiple arrays are to be used together, the viewpoint needs to be modified from looking outwards from each array to focusing on a specific target area and so constraining the portions of the waveforms to be analysed. Beamforming for each array is supplemented by the relative time constraints for propagation from the target to each array to provide tight spatial control. Simultaneous multiple array analysis provides a powerful tool for source characterization, and for structural analysis of scatterers as virtual sources. The multiple array concept allows us to illuminate a specific point in the Earth from many different directions and thus maps detailed patterns of heterogeneity in the Earth. Furthermore, illumination of the structure from multiple directions using data from the same event minimizes source effects to provide clearer images of heterogeneity. The analysis is based on a similar concept to the backprojection technique, where a part of the seismic wave train is mapped to a specific point in space by ray tracing. In contrast to classic backprojection where the incoming energy is mapped onto a horizontal plane with limited vertical resolution, the multiarray method controls depth response by combining relative time constraints between the arrays and conventional beamforming. We illustrate this approach with application to two earthquakes at moderate depth. The results show that the use of simultaneous multiple arrays can provide improvement both in signal quality and resolution, with the additional benefit of being able to accurately locate the source of the incoming energy and map large areas with only a limited number of such arrays.

  2. Spatial normalization of array-CGH data

    Directory of Open Access Journals (Sweden)

    Brennetot Caroline

    2006-05-01

    Full Text Available Abstract Background Array-based comparative genomic hybridization (array-CGH is a recently developed technique for analyzing changes in DNA copy number. As in all microarray analyses, normalization is required to correct for experimental artifacts while preserving the true biological signal. We investigated various sources of systematic variation in array-CGH data and identified two distinct types of spatial effect of no biological relevance as the predominant experimental artifacts: continuous spatial gradients and local spatial bias. Local spatial bias affects a large proportion of arrays, and has not previously been considered in array-CGH experiments. Results We show that existing normalization techniques do not correct these spatial effects properly. We therefore developed an automatic method for the spatial normalization of array-CGH data. This method makes it possible to delineate and to eliminate and/or correct areas affected by spatial bias. It is based on the combination of a spatial segmentation algorithm called NEM (Neighborhood Expectation Maximization and spatial trend estimation. We defined quality criteria for array-CGH data, demonstrating significant improvements in data quality with our method for three data sets coming from two different platforms (198, 175 and 26 BAC-arrays. Conclusion We have designed an automatic algorithm for the spatial normalization of BAC CGH-array data, preventing the misinterpretation of experimental artifacts as biologically relevant outliers in the genomic profile. This algorithm is implemented in the R package MANOR (Micro-Array NORmalization, which is described at http://bioinfo.curie.fr/projects/manor and available from the Bioconductor site http://www.bioconductor.org. It can also be tested on the CAPweb bioinformatics platform at http://bioinfo.curie.fr/CAPweb.

  3. The Australian Square Kilometre Array Pathfinder: Performance of the Boolardy Engineering Test Array

    Science.gov (United States)

    McConnell, D.; Allison, J. R.; Bannister, K.; Bell, M. E.; Bignall, H. E.; Chippendale, A. P.; Edwards, P. G.; Harvey-Smith, L.; Hegarty, S.; Heywood, I.; Hotan, A. W.; Indermuehle, B. T.; Lenc, E.; Marvil, J.; Popping, A.; Raja, W.; Reynolds, J. E.; Sault, R. J.; Serra, P.; Voronkov, M. A.; Whiting, M.; Amy, S. W.; Axtens, P.; Ball, L.; Bateman, T. J.; Bock, D. C.-J.; Bolton, R.; Brodrick, D.; Brothers, M.; Brown, A. J.; Bunton, J. D.; Cheng, W.; Cornwell, T.; DeBoer, D.; Feain, I.; Gough, R.; Gupta, N.; Guzman, J. C.; Hampson, G. A.; Hay, S.; Hayman, D. B.; Hoyle, S.; Humphreys, B.; Jacka, C.; Jackson, C. A.; Jackson, S.; Jeganathan, K.; Joseph, J.; Koribalski, B. S.; Leach, M.; Lensson, E. S.; MacLeod, A.; Mackay, S.; Marquarding, M.; McClure-Griffiths, N. M.; Mirtschin, P.; Mitchell, D.; Neuhold, S.; Ng, A.; Norris, R.; Pearce, S.; Qiao, R. Y.; Schinckel, A. E. T.; Shields, M.; Shimwell, T. W.; Storey, M.; Troup, E.; Turner, B.; Tuthill, J.; Tzioumis, A.; Wark, R. M.; Westmeier, T.; Wilson, C.; Wilson, T.

    2016-09-01

    We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array's performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.

  4. Sub-array patterns of spherical-section phased array for high intensity focused ultrasound surgery

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaodong; WANG Xufei; LU Mingzhu; WAN Mingxi

    2005-01-01

    The sub-array field patterns of spherical-section phased array were implemented for noninvasive ultrasound surgery of liver-tumor. The sub-array approach included field calculation, pseudo-inverse method and genetic algorithm. The sub-arrays uncovered by ribs according to scanned images normally emitted ultrasound. The results from different sub-arrays demonstrated quite satisfied acoustic performances, which included qualified focus size and intensity level for ultrasound surgery with single-focus and multi-foci patterns. Moreover, the patterns could decrease power accumulation on the ribs, and avoid damaging normal tissues. Thus the sub-array method provides a promising tool for phased array ultrasound propagating through strong obstacles like human rib cage, and it may broaden the therapeutic area, make the surgery safer and more flexible.

  5. Arrays of coupled chemical oscillators

    CERN Document Server

    Forrester, Derek Michael

    2016-01-01

    Oscillating chemical reactions result from complex periodic changes in the concentration of the reactants. In spatially ordered ensembles of candle flame oscillators the fluctuations in the ratio of oxygen atoms with respect to that of carbon, hydrogen and nitrogen produces an oscillation in the visible part of the flame related to the energy released per unit mass of oxygen. Thus, the products of the reaction vary in concentration as a function of time, giving rise to an oscillation in the amount of soot and radiative emission. Synchronisation of interacting dynamical sub-systems occurs as arrays of flames that act as master and slave oscillators, with groups of candles numbering greater than two, creating a synchronised motion in three-dimensions. In a ring of candles the visible parts of each flame move together, up and down and back and forth, in a manner that appears like a "worship". Here this effect is shown for rings of flames which collectively empower a central flame to pulse to greater heights. In ...

  6. Redundant Arrays of IDE Drives

    CERN Document Server

    Sanders, D A; Eschenburg, V; Lawrence, C N; Riley, C P; Summers, D J; Petravick, D L

    2001-01-01

    We report tests of redundant arrays of IDE disk drives for use in offline high energy physics data analysis. Parts costs of total systems using commodity EIDE disks are now at the $4000 per Terabyte level. Disk storage prices have now decreased to the point where they equal the cost per Terabyte of Storage Technology tape silos. The disks, however, offer far better granularity; even small institutions can afford to deploy systems. Our tests include reports on software RAID-5 systems running under Linux 2.4 using Promise Ultra 100 TM disk controllers. RAID-5 protects data in case of a single disk failure by providing parity bits. Tape backup is not required. Journaling file systems are used to allow rapid recovery from crashes. Our data analysis strategy is to encapsulate data and CPU processing power. Analysis for a particular part of a data set takes place on the PC where the data resides. The network is only used to put results together. We explore three methods of moving data between sites; internet transf...

  7. Quantitative ultrasonic phased array imaging

    Science.gov (United States)

    Engle, Brady J.; Schmerr, Lester W., Jr.; Sedov, Alexander

    2014-02-01

    When imaging with ultrasonic phased arrays, what do we actually image? What quantitative information is contained in the image? Ad-hoc delay-and-sum methods such as the synthetic aperture focusing technique (SAFT) and the total focusing method (TFM) fail to answer these questions. We have shown that a new quantitative approach allows the formation of flaw images by explicitly inverting the Thompson-Gray measurement model. To examine the above questions, we have set up a software simulation test bed that considers a 2-D scalar scattering problem of a cylindrical inclusion with the method of separation of variables. It is shown that in SAFT types of imaging the only part of the flaw properly imaged is the front surface specular response of the flaw. Other responses (back surface reflections, creeping waves, etc.) are improperly imaged and form artifacts in the image. In the case of TFM-like imaging the quantity being properly imaged is an angular integration of the front surface reflectivity. The other, improperly imaged responses are also averaged, leading to a reduction in some of the artifacts present. Our results have strong implications for flaw sizing and flaw characterization with delay-and-sum images.

  8. Maintaining Arrays of Contiguous Objects

    Science.gov (United States)

    Bender, Michael A.; Fekete, Sándor P.; Kamphans, Tom; Schweer, Nils

    In this paper we consider methods for dynamically storing a set of different objects (“modules”) in a physical array. Each module requires one free contiguous subinterval in order to be placed. Items are inserted or removed, resulting in a fragmented layout that makes it harder to insert further modules. It is possible to relocate modules, one at a time, to another free subinterval that is contiguous and does not overlap with the current location of the module. These constraints clearly distinguish our problem from classical memory allocation. We present a number of algorithmic results, including a bound of {Θ}(n^2) on physical sorting if there is a sufficiently large free space and sum up NP-hardness results for arbitrary initial layouts. For online scenarios in which modules arrive one at a time, we present a method that requires O(1) moves per insertion or deletion and amortized cost O(m_i lg hat{m}) per insertion or deletion, where m i is the module’s size, hat{m} is the size of the largest module and costs for moves are linear in the size of a module.

  9. Maintaining Arrays of Contiguous Objects

    CERN Document Server

    Bender, Michael A; Kamphans, Tom; Schweer, Nils

    2011-01-01

    In this paper we consider methods for dynamically storing a set of different objects ("modules") in a physical array. Each module requires one free contiguous subinterval in order to be placed. Items are inserted or removed, resulting in a fragmented layout that makes it harder to insert further modules. It is possible to relocate modules, one at a time, to another free subinterval that is contiguous and does not overlap with the current location of the module. These constraints clearly distinguish our problem from classical memory allocation. We present a number of algorithmic results, including a bound of Theta(n^2) on physical sorting if there is a sufficiently large free space and sum up NP-hardness results for arbitrary initial layouts. For online scenarios in which modules arrive one at a time, we present a method that requires O(1) moves per insertion or deletion and amortized cost O(m_i log M) per insertion or deletion, where m_i is the module's size, M is the size of the largest module and costs for ...

  10. Wetting of flexible fibre arrays.

    Science.gov (United States)

    Duprat, C; Protière, S; Beebe, A Y; Stone, H A

    2012-02-23

    Fibrous media are functional and versatile materials, as demonstrated by their ubiquity both in natural systems such as feathers and adhesive pads and in engineered systems from nanotextured surfaces to textile products, where they offer benefits in filtration, insulation, wetting and colouring. The elasticity and high aspect ratios of the fibres allow deformation under capillary forces, which cause mechanical damage, matting self-assembly or colour changes, with many industrial and ecological consequences. Attempts to understand these systems have mostly focused on the wetting of rigid fibres or on elastocapillary effects in planar geometries and on a fibre brush withdrawn from an infinite bath. Here we consider the frequently encountered case of a liquid drop deposited on a flexible fibre array and show that flexibility, fibre geometry and drop volume are the crucial parameters that are necessary to understand the various observations referred to above. We identify the conditions required for a drop to remain compact with minimal spreading or to cause a pair of elastic fibres to coalesce. We find that there is a critical volume of liquid, and, hence, a critical drop size, above which this coalescence does not occur. We also identify a drop size that maximizes liquid capture. For both wetting and deformation of the substrates, we present rules that are deduced from the geometric and material properties of the fibres and the volume of the drop. These ideas are applicable to a wide range of fibrous materials, as we illustrate with examples for feathers, beetle tarsi, sprays and microfabricated systems.

  11. AGATA - Advanced GAmma Tracking Array

    Energy Technology Data Exchange (ETDEWEB)

    Akkoyun, S. [Department of Physics, Faculty of Science, Ankara University, 06100 Tandogan, Ankara (Turkey); Algora, A. [IFIC, CSIC-Universitat de Valencia, E-46980 Paterna (Spain); Alikhani, B. [IKP, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Ameil, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Angelis, G. de [INFN Laboratori Nazionali di Legnaro, IT-35020 Padova (Italy); Arnold, L. [Universite de Strasbourg, IPHC, 23 rue du Loess, 67037 Strasbourg (France); CNRS, UMR 7178, 67037 Strasbourg (France); Astier, A. [CSNSM, CNRS, IN2P3, Universite Paris-Sud, F-91405 Orsay (France); Atac, A. [Department of Physics, Faculty of Science, Ankara University, 06100 Tandogan, Ankara (Turkey); Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); Royal Institute of Technology, SE-10691 Stockholm (Sweden); Aubert, Y. [IPNO, CNRS/IN2P3, Universite Paris-Sud, F-91406 Orsay (France); Aufranc, C. [Universite de Lyon, Universite Lyon 1, CNRS-IN2P3, Institut de Physique Nucleaire de Lyon, F-69622 Villeurbanne (France); Austin, A. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Aydin, S. [INFN Sezione di Padova, IT-35131 Padova (Italy); Azaiez, F. [IPNO, CNRS/IN2P3, Universite Paris-Sud, F-91406 Orsay (France); Badoer, S. [INFN Laboratori Nazionali di Legnaro, IT-35020 Padova (Italy); Balabanski, D.L. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia (Bulgaria); Barrientos, D. [IFIC, CSIC-Universitat de Valencia, E-46980 Paterna (Spain); and others

    2012-03-11

    The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation {gamma}-ray spectrometer. AGATA is based on the technique of {gamma}-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a {gamma} ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realisation of {gamma}-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterisation of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximise its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer.

  12. Large phased-array radars

    Science.gov (United States)

    Brookner, Eli, Dr.

    1988-12-01

    Large phased-array radars can play a very important part in arms control. They can be used to determine the number of RVs being deployed, the type of targeting of the RVs (the same or different targets), the shape of the deployed objects, and possibly the weight and yields of the deployed RVs. They can provide this information at night as well as during the day and during rain and cloud covered conditions. The radar can be on the ground, on a ship, in an airplane, or space-borne. Airborne and space-borne radars can provide high resolution map images of the ground for reconnaissance, of anti-ballistic missile (ABM) ground radar installations, missile launch sites, and tactical targets such as trucks and tanks. The large ground based radars can have microwave carrier frequencies or be at HF (high frequency). For a ground-based HF radar the signal is reflected off the ionosphere so as to provide over-the-horizon (OTH) viewing of targets. OTH radars can potentially be used to monitor stealth targets and missile traffic.

  13. Mass properties survey of solar array technologies

    Science.gov (United States)

    Kraus, Robert

    1991-01-01

    An overview of the technologies, electrical performance, and mass characteristics of many of the presently available and the more advanced developmental space solar array technologies is presented. Qualitative trends and quantitative mass estimates as total array output power is increased from 1 kW to 5 kW at End of Life (EOL) from a single wing are shown. The array technologies are part of a database supporting an ongoing solar power subsystem model development for top level subsystem and technology analyses. The model is used to estimate the overall electrical and thermal performance of the complete subsystem, and then calculate the mass and volume of the array, batteries, power management, and thermal control elements as an initial sizing. The array types considered here include planar rigid panel designs, flexible and rigid fold-out planar arrays, and two concentrator designs, one with one critical axis and the other with two critical axes. Solar cell technologies of Si, GaAs, and InP were included in the analyses. Comparisons were made at the array level; hinges, booms, harnesses, support structures, power transfer, and launch retention mountings were included. It is important to note that the results presented are approximations, and in some cases revised or modified performance and mass estimates of specific designs.

  14. Towards the ASTRI mini-array

    CERN Document Server

    Di Pierro, F; Morello, C; Stamerra, A; Vallania, P; Agnetta, G; Antonelli, L A; Bastieri, D; Bellassai, G; Belluso, M; Billotta, S; Biondo, B; Bonanno, G; Bonnoli, G; Bruno, P; Bulgarelli, A; Canestrari, R; Capalbi, M; Caraveo, P; Carosi, A; Cascone, E; Catalano, O; Cereda, M; Conconi, P; Conforti, V; Cusumano, G; De Caprio, V; De Luca, A; Di Paola, A; Fantinel, D; Fiorini, M; Fugazza, D; Gardiol, D; Ghigo, M; Gianotti, F; Giarrusso, S; Giro, E; Grillo, A; Impiombato, D; Incorvaia, S; La Barbera, A; La Palombara, N; La Parola, V; La Rosa, G; Lessio, L; Leto, G; Lombardi, S; Lucarelli, F; Maccarone, M C; Malaguti, G; Malaspina, G; Mangano, V; Marano, D; Martinetti, E; Millul, R; Mineo, T; Misto, A; Morlino, G; Panzera, M R; Pareschi, G; Rodeghiero, G; Romano, P; Russo, F; Sacco, B; Sartore, N; Schwarz, J; Segreto, A; Sironi, G; Sottile, G; Strazzeri, E; Stringhetti, L; Tagliaferri, G; Testa, V; Timpanaro, M C; Toso, G; Tosti, G; Trifoglio, M; Vercellone, S; Zitelli, V

    2013-01-01

    The Cherenkov Telescope Array (CTA) will consist of an array of three types of telescopes covering a wide energy range, from tens of GeV up to more than 100 TeV. The high energy section (> 3 TeV) will be covered by the Small Size Telescopes (SST). ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is a flagship project of the Italian Ministry of Research and Education led by INAF, aiming at the design and construction of a prototype of the Dual Mirror SST. In a second phase the ASTRI project foresees the installation of the first elements of the SST array at the CTA southern site, a mini-array of 5-7 telescopes. The optimization of the layout of this mini-array embedded in the SST array of the CTA Observatory has been the object of an intense simulation effort. In this work we present the expected mini-array performance in terms of energy threshold, angular and energy resolution and sensitivity.

  15. Transmit TACAN Bearing Information with a Circular Array

    Directory of Open Access Journals (Sweden)

    W. Mark Dorsey

    2015-01-01

    Full Text Available Using TACAN and array fundamentals, we derive an architecture for transmitting TACAN bearing information from a circular array with time-varying weights. We evaluate performance for a simulated example array of Vivaldi elements.

  16. Preparation and characterization of haematite nanowire arrays

    CERN Document Server

    Xue, D S; Liu, Q F; Zhang, L Y

    2003-01-01

    Arrays of alpha-Fe sub 2 O sub 3 nanowires embedded in anodic alumina membranes were obtained after heat-treating beta-FeOOH nanowire arrays fabricated by electrochemical deposition. Haematite polycrystalline nanowires with maximum length of about 7 mu m and average diameter of about 120 nm were characterized by means of x-ray diffraction and transmission electron microscopy. The Morin temperature below 80 K and Neel temperature of about 350 K for the alpha-Fe sub 2 O sub 3 nanowire arrays, far lower than those of bulk material, were measured by Moessbauer spectroscopy and using a Magnetic Property Measurement System.

  17. Resonance spectra of diabolo optical antenna arrays

    Science.gov (United States)

    Guo, Hong; Simpkins, Blake; Caldwell, Joshua D.; Guo, Junpeng

    2015-10-01

    A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.

  18. Resonance spectra of diabolo optical antenna arrays

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Hong; Guo, Junpeng, E-mail: guoj@uah.edu [Department of Electrical and Computer Engineering, University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, AL 35899 (United States); Simpkins, Blake; Caldwell, Joshua D. [Naval Research Laboratory, 4555 Overlook Ave., SW Washington, DC 20375 (United States)

    2015-10-15

    A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.

  19. GENERALIZED SIDELOBE CANCELLER FOR MAGNETOENCEPHALOGRAPHY ARRAYS.

    Science.gov (United States)

    Mosher, John C; Hämäläinen, Matti S; Pantazis, Dimitrios; Hui, Hua Brian; Burgess, Richard C; Leahy, Richard M

    2009-08-07

    In the last decade, large arrays of sensors for magnetoencephalography (MEG) (and electroencephalography (EEG)) have become more commonplace, allowing new opportunities for the application of beamforming techniques to the joint problems of signal estimation and noise reduction. We introduce a new approach to noise cancellation, the generalized sidelobe canceller (GSC), itself an alternative to the linearly constrained minimum variance (LCMV) algorithm. The GSC framework naturally fits within the other noise reduction techniques that employ real or virtual reference arrays. Using expository human subject data with strong environmental and biological artifacts, we demonstrate a straightforward sequence of steps for practical noise filtering, applicable to any large array sensor design.

  20. Performance Analysis of Digital loudspeaker Arrays

    DEFF Research Database (Denmark)

    Pedersen, Bo Rohde; Kontomichos, Fotios; Mourjopoulos, John

    2008-01-01

    An analysis of digital loudspeaker arrays shows that the ways in which bits are mapped to the drivers influence the quality of the audio result. Specifically, a "bit-summed" rather than the traditional "bit-mapped" strategy greatly reduces the number of times drivers make binary transitions per...... period of the input frequency. Detailed simulations compare the results for a 32-loudspeaker array with a similar configuration with analog excitation of the drivers. Ideally, drivers in digital arrays should be very small and span a small area, but that sets limits on the low-frequency response...

  1. Polarization tomography of metallic nanohole arrays

    CERN Document Server

    Altewischer, E; Van Exter, M P; Woerdman, J P; Alkemade, P F A; Van Zuuk, A; Van der Drift, E

    2004-01-01

    We report polarization tomography experiments on metallic nanohole arrays with square and hexagonal symmetry. As a main result, we find that a fully polarized input beam is partly depolarized after transmission through a nanohole array. This loss of polarization coherence is found to be anisotropic, i.e. it depends on the polarization state of the input beam. The depolarization is ascribed to a combination of two factors: i) the nonlocal response of the array due to surface plasmon propagation, ii) the non-plane wave nature of a practical input beam.

  2. Electrochemical Preparation of WO_3 Nanowire Arrays

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results Ordered WO3 nanowires arrays have been fabricated by electrochemical deposition with anodic aluminum oxide (AAO) templates and annealing the W nanowire arrays in air at 400 ℃. The morphology and the chemical composition of WO3 nanowires arrays were characterized by Scanning Electron Microscopy (SEM),Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and X-ray diffraction (XRD). The results show that the diameters of the WO3 nanowires are about 90 nm, which is in go...

  3. Algoritmos array para filtragem de sistemas lineares

    OpenAIRE

    Gildson Queiroz de Jesus

    2007-01-01

    Esta dissertação desenvolve filtro de informação, algoritmos array para estimador do erro médio mínimo quadrático para sistemas lineares sujeitos a saltos Markovianos e algoritmos array rápidos para filtragem de sistemas singulares convencionais. Exemplos numéricos serão apresentados para mostrarem as vantagens dos algoritmos array deduzidos. Parte dos resultados obtidos nesta pesquisa serão publicados no seguinte artigo: Terra et al. (2007). Terra, M. H., Ishihara, J. Y. and Jesus, G. Q. (20...

  4. Avalanche Photodiode Arrays for Optical Communications Receivers

    Science.gov (United States)

    Srinivasan, M.; Vilnrotter, V.

    2001-01-01

    An avalanche photodiode (APD) array for ground-based optical communications receivers is investigated for the reception of optical signals through the turbulent atmosphere. Kolmogorov phase screen simulations are used to generate realistic spatial distributions of the received optical field. It is shown that use of an APD array for pulse-position modulation detection can improve performance by up to 4 dB over single APD detection in the presence of turbulence, but that photon-counting detector arrays yield even greater gains.

  5. Array Biosensor for Toxin Detection: Continued Advances

    Directory of Open Access Journals (Sweden)

    Chris Rowe Taitt

    2008-12-01

    Full Text Available The following review focuses on progress made in the last five years with the NRL Array Biosensor, a portable instrument for rapid and simultaneous detection of multiple targets. Since 2003, the Array Biosensor has been automated and miniaturized for operation at the point-of-use. The Array Biosensor has also been used to demonstrate (1 quantitative immunoassays against an expanded number of toxins and toxin indicators in food and clinical fluids, and (2 the efficacy of semi-selective molecules as alternative recognition moieties. Blind trials, with unknown samples in a variety of matrices, have demonstrated the versatility, sensitivity, and reliability of the automated system.

  6. Large Format Transition Edge Sensor Microcalorimeter Arrays

    Science.gov (United States)

    Chervenak, J. A.; Adams, J. A.; Bandler, S. b.; Busch, S. E.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kilbourne, C. A.; Kelley, R. L.; Porst, J. P.; Porter, F. S.; Ray, C.; Sadleir, J. E.; Smith, S. J.; Wassell, E. J.

    2012-01-01

    We have produced a variety of superconducting transition edge sensor array designs for microcalorimetric detection of x-rays. Designs include kilopixel scale arrays of relatively small sensors (approximately 75 micron pitch) atop a thick metal heat sinking layer as well as arrays of membrane-isolated devices on 250 micron and up to 600 micron pitch. We discuss fabrication and performance of microstripline wiring at the small scales achieved to date. We also address fabrication issues with reduction of absorber contact area in small devices.

  7. Processor arrays with asynchronous TDM optical buses

    Science.gov (United States)

    Li, Y.; Zheng, S. Q.

    1997-04-01

    We propose a pipelined asynchronous time division multiplexing optical bus. Such a bus can use one of the two hardwared priority schemes, the linear priority scheme and the round-robin priority scheme. Our simulation results show that the performances of our proposed buses are significantly better than the performances of known pipelined synchronous time division multiplexing optical buses. We also propose a class of processor arrays connected by pipelined asynchronous time division multiplexing optical buses. We claim that our proposed processor array not only have better performance, but also have better scalabilities than the existing processor arrays connected by pipelined synchronous time division multiplexing optical buses.

  8. Refracting surface plasmon polaritons with nanoparticle arrays

    DEFF Research Database (Denmark)

    Radko, I.P.; Evlyukhin, A.B.; Boltasseva, Alexandra

    2008-01-01

    Refraction of surface plasmon polaritons (SPPs) by various structures formed by a 100-nm-period square lattice of gold nanoparticles on top of a gold film is studied by leakage radiation microscopy. SPP refraction by a triangular-shaped nanoparticle array indicates that the SPP effective refractive...... index increases inside the array by a factor of ~1.08 (for the wavelength 800 nm) with respect to the SPP index at a flat surface. Observations of SPP focusing and deflection by circularly shaped areas as well as SPP waveguiding inside rectangular arrays are consistent with the SPP index increase...

  9. 600 Volt Stretched Lens Array for Solar Electric Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ENTECH, Auburn, NASA, and others have recently developed a new space photovoltaic array called the Stretched Lens Array (SLA), offering unprecedented performance...

  10. Conformal array design on arbitrary polygon surface with transformation optics

    Directory of Open Access Journals (Sweden)

    Li Deng

    2016-06-01

    Full Text Available A transformation-optics based method to design a conformal antenna array on an arbitrary polygon surface is proposed and demonstrated in this paper. This conformal antenna array can be adjusted to behave equivalently as a uniformly spaced linear array by applying an appropriate transformation medium. An typical example of general arbitrary polygon conformal arrays, not limited to circular array, is presented, verifying the proposed approach. In summary, the novel arbitrary polygon surface conformal array can be utilized in array synthesis and beam-forming, maintaining all benefits of linear array.

  11. Conformal array design on arbitrary polygon surface with transformation optics

    Science.gov (United States)

    Deng, Li; Wu, Yongle; Hong, Weijun; Zhu, Jianfeng; Peng, Biao; Li, Shufang

    2016-06-01

    A transformation-optics based method to design a conformal antenna array on an arbitrary polygon surface is proposed and demonstrated in this paper. This conformal antenna array can be adjusted to behave equivalently as a uniformly spaced linear array by applying an appropriate transformation medium. An typical example of general arbitrary polygon conformal arrays, not limited to circular array, is presented, verifying the proposed approach. In summary, the novel arbitrary polygon surface conformal array can be utilized in array synthesis and beam-forming, maintaining all benefits of linear array.

  12. Fiber Optic Pressure Sensor Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — VIP Sensors proposes to develop a Fiber Optic Pressure Sensor Array for measuring air flow pressure at multiple points on the skin of aircrafts for Flight Load Test...

  13. Receptor arrays optimized for natural odor statistics.

    Science.gov (United States)

    Zwicker, David; Murugan, Arvind; Brenner, Michael P

    2016-05-17

    Natural odors typically consist of many molecules at different concentrations. It is unclear how the numerous odorant molecules and their possible mixtures are discriminated by relatively few olfactory receptors. Using an information theoretic model, we show that a receptor array is optimal for this task if it achieves two possibly conflicting goals: (i) Each receptor should respond to half of all odors and (ii) the response of different receptors should be uncorrelated when averaged over odors presented with natural statistics. We use these design principles to predict statistics of the affinities between receptors and odorant molecules for a broad class of odor statistics. We also show that optimal receptor arrays can be tuned to either resolve concentrations well or distinguish mixtures reliably. Finally, we use our results to predict properties of experimentally measured receptor arrays. Our work can thus be used to better understand natural olfaction, and it also suggests ways to improve artificial sensor arrays.

  14. Statistical monitoring of linear antenna arrays

    KAUST Repository

    Harrou, Fouzi

    2016-11-03

    The paper concerns the problem of monitoring linear antenna arrays using the generalized likelihood ratio (GLR) test. When an abnormal event (fault) affects an array of antenna elements, the radiation pattern changes and significant deviation from the desired design performance specifications can resulted. In this paper, the detection of faults is addressed from a statistical point of view as a fault detection problem. Specifically, a statistical method rested on the GLR principle is used to detect potential faults in linear arrays. To assess the strength of the GLR-based monitoring scheme, three case studies involving different types of faults were performed. Simulation results clearly shown the effectiveness of the GLR-based fault-detection method to monitor the performance of linear antenna arrays.

  15. Variable-focus cylindrical liquid lens array

    Science.gov (United States)

    Zhao, Wu-xiang; Liang, Dong; Zhang, Jie; Liu, Chao; Zang, Shang-fei; Wang, Qiong-hua

    2013-06-01

    A variable-focus cylindrical liquid lens array based on two transparent liquids of different refractive index is demonstrated. An elastic membrane divides a transparent reservoir into two chambers. The two chambers are filled with liquid 1 and liquid 2, respectively, which are of different refractive index. The micro-clapboards help liquid 1, liquid 2 and the elastic membrane form a cylindrical lens array. Driving these two liquids to flow can change the shape of the elastic membrane as well as the focal length. In this design, the gravity effect of liquid can be overcome. A demo lens array of positive optical power is developed and tested. Moreover, a potential application of the proposed lens array for autostereoscopic 3D displays is emphasized.

  16. Signal Conditioning For Infrared Staring Arrays

    Science.gov (United States)

    Helfrich, Richard W.

    1981-12-01

    Infrared (IR) staring arrays offer significant performance improvements over mechanically scanned systems, if the signals from these focal planes can be conditioned for use by imaging displays or signal processors. IR staring arrays offer the potential for increased sensitivity, wide dynamic range, and short frame time, if the problems associated with the readout of data from these arrays can be solved in an efficient manner. Some of the func-tions included in this signal conditioning are: nonuniformity compensation, local area gain and brightness control, detector integration time control, and multiple frame composition. Nonuniformity compensation and local area gain and brightness control were covered in earlier papers. 1,2,3 This paper deals with integration time control and the resulting multiple frame composition possible with focal plane arrays.

  17. Array Processing for Radar: Achievements and Challenges

    Directory of Open Access Journals (Sweden)

    Ulrich Nickel

    2013-01-01

    Full Text Available Array processing for radar is well established in the literature, but only few of these algorithms have been implemented in real systems. The reason may be that the impact of these algorithms on the overall system must be well understood. For a successful implementation of array processing methods exploiting the full potential, the desired radar task has to be considered and all processing necessary for this task has to be eventually adapted. In this tutorial paper, we point out several viewpoints which are relevant in this context: the restrictions and the potential provided by different array configurations, the predictability of the transmission function of the array, the constraints for adaptive beamforming, the inclusion of monopulse, detection and tracking into the adaptive beamforming concept, and the assessment of superresolution methods with respect to their application in a radar system. The problems and achieved results are illustrated by examples from previous publications.

  18. Ferrite LTCC based phased array antennas

    KAUST Repository

    Ghaffar, Farhan A.

    2016-11-02

    Two phased array antennas realized in multilayer ferrite LTCC technology are presented in this paper. The use of embedded bias windings in these designs allows the negation of external magnets which are conventionally employed with bulk ferrite medium. This reduces the required magnetostatic field strength by 90% as compared to the traditional designs. The phase shifters are implemented using the SIW technology. One of the designs is operated in the half mode waveguide topology while the other design is based on standard full mode waveguide operation. The two phase shifter designs are integrated with two element patch antenna array and slotted SIW array respectively. The array designs demonstrate a beam steering of 30° and ±19° respectively for a current excitation of 200 mA. The designs, due to their small factor can be easily integrated in modern communication systems which is not possible in the case of bulk ferrite based designs.

  19. ISPA (imaging silicon pixel array) experiment

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    Application components of ISPA tubes are shown: the CERN-developed anode chip, special windows for gamma and x-ray detection, scintillating crystal and fibre arrays for imaging and tracking of ionizing particles.

  20. Probe suppression in conformal phased array

    CERN Document Server

    Singh, Hema; Neethu, P S

    2017-01-01

    This book considers a cylindrical phased array with microstrip patch antenna elements and half-wavelength dipole antenna elements. The effect of platform and mutual coupling effect is included in the analysis. The non-planar geometry is tackled by using Euler's transformation towards the calculation of array manifold. Results are presented for both conducting and dielectric cylinder. The optimal weights obtained are used to generate adapted pattern according to a given signal scenario. It is shown that array along with adaptive algorithm is able to cater to an arbitrary signal environment even when the platform effect and mutual coupling is taken into account. This book provides a step-by-step approach for analyzing the probe suppression in non-planar geometry. Its detailed illustrations and analysis will be a useful text for graduate and research students, scientists and engineers working in the area of phased arrays, low-observables and stealth technology.

  1. Density controlled carbon nanotube array electrodes

    Science.gov (United States)

    Ren, Zhifeng F [Newton, MA; Tu, Yi [Belmont, MA

    2008-12-16

    CNT materials comprising aligned carbon nanotubes (CNTs) with pre-determined site densities, catalyst substrate materials for obtaining them and methods for forming aligned CNTs with controllable densities on such catalyst substrate materials are described. The fabrication of films comprising site-density controlled vertically aligned CNT arrays of the invention with variable field emission characteristics, whereby the field emission properties of the films are controlled by independently varying the length of CNTs in the aligned array within the film or by independently varying inter-tubule spacing of the CNTs within the array (site density) are disclosed. The fabrication of microelectrode arrays (MEAs) formed utilizing the carbon nanotube material of the invention is also described.

  2. Science with the Murchison Widefield Array

    CERN Document Server

    Bowman, Judd D; Kaplan, David L; Murphy, Tara; Oberoi, Divya; Staveley-Smith, Lister; Arcus, Wayne; Barnes, David G; Bernardi, Gianni; Briggs, Frank H; Brown, Shea; Bunton, John D; Burgasser, Adam J; Cappallo, Roger J; Chatterjee, Shami; Corey, Brian E; Coster, Anthea; Deshpande, Avinash; deSouza, Ludi; Emrich, David; Erickson, Philip; Goeke, Robert F; Gaensler, B M; Greenhill, Lincoln J; Harvey-Smith, Lisa; Hazelton, Bryna J; Herne, David; Hewitt, Jacqueline N; Johnston-Hollitt, Melanie; Kasper, Justin C; Kincaid, Barton B; Koenig, Ronald; Kratzenberg, Eric; Lonsdale, Colin J; Lynch, Mervyn J; Matthews, Lynn D; McWhirter, S Russell; Mitchell, Daniel A; Morales, Miguel F; Morgan, Edward H; Ord, Stephen M; Pathikulangara, Joseph; Thiagaraj, Prabu; Remillard, Ronald A; Robishaw, Timothy; Rogers, Alan E E; Roshi, Anish A; Salah, Joseph E; Sault, Robert J; Shankar, N Udaya; Srivani, K S; Stevens, Jamie B; Subrahmanyan, Ravi; Tingay, Steven J; Wayth, Randall B; Waterson, Mark; Webster, Rachel L; Whitney, Alan R; Williams, Andrew J; Williams, Christopher L; Wyithe, J Stuart B

    2012-01-01

    Significant new opportunities for astrophysics and cosmology have been identified at low radio frequencies. The Murchison Widefield Array is the first telescope in the Southern Hemisphere designed specifically to explore the low-frequency astronomical sky between 80 and 300 MHz with arcminute angular resolution and high survey efficiency. The telescope will enable new advances along four key science themes, including searching for redshifted 21 cm emission from the epoch of reionisation in the early Universe; Galactic and extragalactic all-sky southern hemisphere surveys; time-domain astrophysics; and solar, heliospheric, and ionospheric science and space weather. The Murchison Widefield Array is located in Western Australia at the site of the planned Square Kilometre Array (SKA) low-band telescope and is the only low-frequency SKA precursor facility. In this paper, we review the performance properties of the Murchison Widefield Array and describe its primary scientific objectives.

  3. Calibration of a photomultiplier array spectrometer

    Science.gov (United States)

    Bailey, Steven A.; Wright, C. Wayne; Piazza, Charles R.

    1989-01-01

    A systematic approach to the calibration of a photomultiplier array spectrometer is presented. Through this approach, incident light radiance derivation is made by recognizing and tracing gain characteristics for each photomultiplier tube.

  4. Increase in the Array Television Camera Sensitivity

    Science.gov (United States)

    Shakhrukhanov, O. S.

    A simple adder circuit for successive television frames that enables to considerably increase the sensitivity of such radiation detectors is suggested by the example of array television camera QN902K.

  5. Low Cost Phased Array Antenna System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A program is proposed to research the applicability of a unique phased array technology, dubbed FlexScan, to S-band and Ku-band communications links between...

  6. Digital Array Gas Radiometer (DAGR) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The digital array gas radiometer (DAGR) is a new sensor design for accurate measurement and monitoring of trace gases in the boundary layer from space, aircraft, or...

  7. The self-cohering tied-array

    CERN Document Server

    Fridman, P A

    2010-01-01

    Large radio astronomy multi-element interferometers are frequently used as single dishes in a tied-array mode when signals from separate antennas are added. Phase shifts arising during wave propagation through a turbulent atmosphere can significantly reduce the effective area of an equivalent single dish. I aim to give estimates of the impact of the ionosphere and troposphere on the effectiveness of a radio interferometer working in tied-array mode. Statistical estimates of the effective area are calculated and the power-law of turbulent atmosphere irregularities has been used. A simple method of tied-array calibration using optimization techniques is proposed. The impact of phase errors on the effectiveness of tied-arrays are given for low and high frequencies. Computer simulations demonstrate the efficacy of the proposed calibration algorithm.

  8. Thin Flexible IMM Solar Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thin, flexible, and highly efficient solar arrays are needed that package compactly for launch and deploy into large, structurally stable high power generators....

  9. Substrate-supported lipid nanotube arrays.

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A. I.; Poluektov, O. G.; Chemistry; North Carolina State

    2003-07-16

    This Communication describes the self-assembly of phospholipids into lipid nanotubes inside nanoporous anodic aluminum oxide substrate. Orientations of the lipid molecules in such lipid nanoscale structures were verified by high-resolution spin labeling EPR at 95 GHz. The static order parameter of lipids in such nanotube arrays was determined from low-temperature EPR spectra and was found to be exceptionally high, S{sub static} {approx} 0.9. We propose that substrate-supported lipid nanotube arrays have potential for building robust biochips and biosensors in which rigid nanoporous substrates protect the bilayer surface from contamination. The total bilayer surface in the lipid nanotube arrays is much greater than that in the planar substrate-supported membranes. The lipid nanotube arrays seem to be suitable for developing patterned lipid deposition and could be potentially used for patterning of membrane-associated molecules.

  10. Multijunction Ultralight Solar Cells and Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a continuing need within NASA for solar cells and arrays with very high specific power densities (1000-5000 kW/kg) for generating power in a new generation...

  11. Ordered arrays of nanoporous gold nanoparticles

    Directory of Open Access Journals (Sweden)

    Dong Wang

    2012-09-01

    Full Text Available A combination of a “top-down” approach (substrate-conformal imprint lithography and two “bottom-up” approaches (dewetting and dealloying enables fabrication of perfectly ordered 2-dimensional arrays of nanoporous gold nanoparticles. The dewetting of Au/Ag bilayers on the periodically prepatterned substrates leads to the interdiffusion of Au and Ag and the formation of an array of Au–Ag alloy nanoparticles. The array of alloy nanoparticles is transformed into an array of nanoporous gold nanoparticles by a following dealloying step. Large areas of this new type of material arrangement can be realized with this technique. In addition, this technique allows for the control of particle size, particle spacing, and ligament size (or pore size by varying the period of the structure, total metal layer thickness, and the thickness ratio of the as-deposited bilayers.

  12. Slot Coupled Patch Array Antenna Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project is an antenna array whose beam is controlled digitally. The Phase 1 effort will assess the method needed to achieve the gain, bandwidth, and...

  13. Piezoresistive Foam Sensor Arrays for Marine Applications

    CERN Document Server

    Dusek, Jeff E; Lang, Jeffrey H

    2016-01-01

    Spatially-dense pressure measurements are needed on curved surfaces in marine environments to provide marine vehicles with the detailed, real-time measurements of the near-field flow necessary to improve performance through flow control. To address this challenge, a waterproof and conformal pressure sensor array comprising carbon black-doped-silicone closed-cell foam (CBPDMS foam) was developed for use in marine applications. The response of the CBPDMS foam sensor arrays was characterized using periodic hydrodynamic pressure stimuli from vertical plunging, from which a piecewise polynomial calibration was developed to describe the sensor response. Inspired by the distributed pressure and velocity sensing capabilities of the fish lateral line, the CBPDMS foam sensor arrays have significant advantages over existing commercial sensors for distributed flow reconstruction and control. Experimental results have shown the sensor arrays to have sensitivity on the order of 5 Pascal, dynamic range of 50-500 Pascal; are...

  14. Digital Array Gas Radiometer (DAGR) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation proposed here is a digital array gas radiometer (DAGR), a new design for a gas filter correlation radiometer (GFCR) to accurately measure and monitor...

  15. Radiation Hardened Bolometer Linear Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has developed space-based thermal instrument spectrometers based on thermopile detectors linear arrays that are intrinsically radiation hard. Micro-bolometers...

  16. Monolithic Time Delay Integrated APD Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of the proposed program by Epitaxial Technologies is to develop monolithic time delay integrated avalanche photodiode (APD) arrays with sensitivity...

  17. Fiber Optic Pressure Sensor Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — VIP Sensors proposes to develop a Fiber Optic Pressure Sensor Array System for measuring air flow pressure at multiple points on the skin of aircrafts for Flight...

  18. NASA Solar Array Demonstrates Commercial Potential

    Science.gov (United States)

    Creech, Gray

    2006-01-01

    A state-of-the-art solar-panel array demonstration site at NASA's Dryden Flight Research Center provides a unique opportunity for studying the latest in high-efficiency solar photovoltaic cells. This five-kilowatt solar-array site (see Figure 1) is a technology-transfer and commercialization success for NASA. Among the solar cells at this site are cells of a type that was developed in Dryden Flight Research Center s Environmental Research Aircraft and Sensor Technology (ERAST) program for use in NASA s Helios solar-powered airplane. This cell type, now denoted as A-300, has since been transferred to SunPower Corporation of Sunnyvale, California, enabling mass production of the cells for the commercial market. High efficiency separates these advanced cells from typical previously commercially available solar cells: Whereas typical previously commercially available cells are 12 to 15 percent efficient at converting sunlight to electricity, these advanced cells exhibit efficiencies approaching 23 percent. The increase in efficiency is due largely to the routing of electrical connections behind the cells (see Figure 2). This approach to increasing efficiency originated as a solution to the problem of maximizing the degree of utilization of the limited space available atop the wing of the Helios airplane. In retrospect, the solar cells in use at this site could be used on Helios, but the best cells otherwise commercially available could not be so used, because of their lower efficiencies. Historically, solar cells have been fabricated by use of methods that are common in the semiconductor industry. One of these methods includes the use of photolithography to define the rear electrical-contact features - diffusions, contact openings, and fingers. SunPower uses these methods to produce the advanced cells. To reduce fabrication costs, SunPower continues to explore new methods to define the rear electrical-contact features. The equipment at the demonstration site includes

  19. Arrayed-Waveguide Layout for AWG Design

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The key issue of the complex geometry for arrayed-waveguide grating(AWG)is the design of length difference.Conventional-type scheme and improved-type scheme of the ar-rayed -waveguide layout are proposed.For each scheme,the layout rules were given and one ex-ample was presented. At last ,the two schemes were compared with each other.

  20. Dynamic array of dark optical traps

    DEFF Research Database (Denmark)

    Daria, V.R.; Rodrigo, P.J.; Glückstad, J.

    2004-01-01

    A dynamic array of dark optical traps is generated for simultaneous trapping and arbitrary manipulation of multiple low-index microstructures. The dynamic intensity patterns forming the dark optical trap arrays are generated using a nearly loss-less phase-to-intensity conversion of a phase-encode...... optical traps for simultaneous manipulation of hollow "air-filled" glass microspheres suspended in an aqueous medium. (C) 2004 American Institute of Physics....

  1. Generating Milton Babbitt's all-partition arrays

    DEFF Research Database (Denmark)

    Bemman, Brian; Meredith, David

    2016-01-01

    by this algorithm to generate the specific all-partition arrays used in three of Babbitt’s works. Finally, we evaluate the algorithm and the heuristics in terms of how well they predict the sequences of integer partitions used in two of Babbitt’s works. We also explore the effect of the heuristics...... on the performance of the algorithm when it is used in an attempt to generate a novel array....

  2. LOG PERIODIC DIPOLE ARRAY WITH PARASITIC ELEMENTS

    Science.gov (United States)

    The design and measured characteristics of dipole and monopole versions of a log periodic array with parasitic elements are discussed. In a dipole...array with parasitic elements, these elements are used in place of every alternate dipole, thereby eliminating the need of a twisted feed arrangement...for the elements to obtain log periodic performance of the anntenna. This design with parasitic elements lends itself to a monopole version of the

  3. picoArray Technology: The Tool's Story

    CERN Document Server

    Duller, Andrew; Panesar, Gajinder; Gray, Alan; Robbins, Will

    2011-01-01

    This paper briefly describes the picoArray? architecture, and in particular the deterministic internal communication fabric. The methods that have been developed for debugging and verifying systems using devices from the picoArray family are explained. In order to maximize the computational ability of these devices, hardware debugging support has been kept to a minimum and the methods and tools developed to take this into account.

  4. High performance compound semiconductor SPAD arrays

    Science.gov (United States)

    Harmon, Eric S.; Naydenkov, Mikhail; Bowling, Jared

    2016-05-01

    Aggregated compound semiconductor single photon avalanche diode (SPAD) arrays are emerging as a viable alternative to the silicon photomultiplier (SiPM). Compound semiconductors have the potential to surpass SiPM performance, potentially achieving orders of magnitude lower dark count rates and improved radiation hardness. New planar processing techniques have been developed to enable compound semiconductor SPAD devices to be produced with pixel pitches of 11 - 25 microns, with thousands of SPADs per array.

  5. Application of Array Measurement in Blind Identification

    Institute of Scientific and Technical Information of China (English)

    王勇; 孙连明; 刘文江

    2003-01-01

    This paper deals with blind identification and deconvolution algorithm for an arbitrary, possibly white or colored, stationary or nonstationary signal, which is observed through array sensors. By using multiple sensors with their individual outputs sampled at a rate 1/T, one can obtain cyclostationary signals. They can be considered as a single-input multiple-output model with an identical but unknown input signal. With the array measurement, an algorithm for estimating the system transfer function model and its parameters is presented.

  6. Spatiotemporal light localization in infiltrated waveguide arrays

    DEFF Research Database (Denmark)

    Rasmussen, Per Dalgaard; Neshev, D.N-; Sukhorukov, A.A.;

    2008-01-01

    We study light propagation in hexagonal waveguide arrays and show that simultaneous spatiotemporal localisation is possible by combination of engineered anomalous dispersion through selective excitation of Bloch-modes and spatial confinement in a nonlinear defect mode.......We study light propagation in hexagonal waveguide arrays and show that simultaneous spatiotemporal localisation is possible by combination of engineered anomalous dispersion through selective excitation of Bloch-modes and spatial confinement in a nonlinear defect mode....

  7. Multifrequency Arrays: Design and Cost Considerations

    Science.gov (United States)

    1975-07-08

    Alverson, W. K., Pippin, J. E., Simon, J. W., "A Reciprocal TEM Latching Ferrite Phase Shifter," 1966 IEEE-GMTT International Symposium Digest, p 241...of Reciprocal Latching Ferrite Phase Shifters to Lightweight Electronic Scanner Phased Arrays," Proc. IEEE, vol 56, p 1931-1939, Nov 1968. 14...8 Switched -line phase shifter for a two-frequency ratio ... 9 Dual frequency array concept... 10 Phase error effects on side-lobe level... 16

  8. OPTIMAL DESIGN OF SMART ANTENNA ARRAY

    Institute of Scientific and Technical Information of China (English)

    Gao Feng; Liu Qizhong; Shan Runhong; Zhang Hou

    2004-01-01

    This letter investigates an efficient design procedure integrating the Genetic Algorithm (GA) with the Finite Difference Time Domain (FDTD) for the fast optimal design of Smart Antenna Arrays (SAA). The FDTD is used to analyze SAA with mutual coupling. Then,on the basis of the Maximal Signal to Noise Ratio (MSNR) criteria, the GA is applied to the optimization of weighting elements and structure of SAA. Finally, the effectiveness of the analysis is evaluated by experimental antenna arrays.

  9. Time-shared optical tweezers with a microlens array for dynamic microbead arrays.

    Science.gov (United States)

    Tanaka, Yoshio; Wakida, Shin-Ichi

    2015-10-01

    Dynamic arrays of microbeads and cells offer great flexibility and potential as platforms for sensing and manipulation applications in various scientific fields, especially biology and medicine. Here, we present a simple method for assembling and manipulating dense dynamic arrays based on time-shared scanning optical tweezers with a microlens array. Three typical examples, including the dynamic and simultaneous bonding of microbeads in real-time, are demonstrated. The optical design and the hardware setup for our approach are also described.

  10. Acoustic transmission through compound subwavelength slit arrays

    Science.gov (United States)

    Ward, G. P.; Hibbins, A. P.; Sambles, J. R.; Smith, J. D.

    2016-07-01

    The angular dependence of the transmission of sound in air through four types of two-dimensional slit arrays formed of aluminium slats is explored, both experimentally and numerically. For a simple, subwavelength periodic slit array, it is well known that Fabry-Perot-like waveguide resonances, supported by the slit cavities, coupled to diffracted evanescent waves, result in enhanced acoustic transmission at frequencies determined by the length, width, and separation of each slit cavity. We demonstrate that altering the spacing or width of some of the slits to form a compound array (i.e., an array having a basis comprised of more than one slit) results in sharp dips in the transmission spectra, which may have a strong angular dependence. These features correspond to phase resonances, which have been studied extensively in the electromagnetic case. This geometry allows for additional near-field configurations compared to the simple array, whereby the field in adjacent cavities can be out of phase. Several types of compound slit arrays are investigated; one such structure is optimized to minimize the effect of boundary-layer loss mechanisms present in each slit cavity, thereby achieving a deep, sharp transmission minimum in a broad maximum.

  11. Hard Transparent Arrays for Polymer Pen Lithography.

    Science.gov (United States)

    Hedrick, James L; Brown, Keith A; Kluender, Edward J; Cabezas, Maria D; Chen, Peng-Cheng; Mirkin, Chad A

    2016-03-22

    Patterning nanoscale features across macroscopic areas is challenging due to the vast range of length scales that must be addressed. With polymer pen lithography, arrays of thousands of elastomeric pyramidal pens can be used to write features across centimeter-scales, but deformation of the soft pens limits resolution and minimum feature pitch, especially with polymeric inks. Here, we show that by coating polymer pen arrays with a ∼175 nm silica layer, the resulting hard transparent arrays exhibit a force-independent contact area that improves their patterning capability by reducing the minimum feature size (∼40 nm), minimum feature pitch (<200 nm for polymers), and pen to pen variation. With these new arrays, patterns with as many as 5.9 billion features in a 14.5 cm(2) area were written using a four hundred thousand pyramid pen array. Furthermore, a new method is demonstrated for patterning macroscopic feature size gradients that vary in feature diameter by a factor of 4. Ultimately, this form of polymer pen lithography allows for patterning with the resolution of dip-pen nanolithography across centimeter scales using simple and inexpensive pen arrays. The high resolution and density afforded by this technique position it as a broad-based discovery tool for the field of nanocombinatorics.

  12. Terahertz Array Receivers with Integrated Antennas

    Science.gov (United States)

    Chattopadhyay, Goutam; Llombart, Nuria; Lee, Choonsup; Jung, Cecile; Lin, Robert; Cooper, Ken B.; Reck, Theodore; Siles, Jose; Schlecht, Erich; Peralta, Alessandro; Thomas, Bertrand; Mehdi, Imran

    2011-01-01

    Highly sensitive terahertz heterodyne receivers have been mostly single-pixel. However, now there is a real need of multi-pixel array receivers at these frequencies driven by the science and instrument requirements. In this paper we explore various receiver font-end and antenna architectures for use in multi-pixel integrated arrays at terahertz frequencies. Development of wafer-level integrated terahertz receiver front-end by using advanced semiconductor fabrication technologies has progressed very well over the past few years. Novel stacking of micro-machined silicon wafers which allows for the 3-dimensional integration of various terahertz receiver components in extremely small packages has made it possible to design multi-pixel heterodyne arrays. One of the critical technologies to achieve fully integrated system is the antenna arrays compatible with the receiver array architecture. In this paper we explore different receiver and antenna architectures for multi-pixel heterodyne and direct detector arrays for various applications such as multi-pixel high resolution spectrometer and imaging radar at terahertz frequencies.

  13. Testing Microshutter Arrays Using Commercial FPGA Hardware

    Science.gov (United States)

    Rapchun, David

    2008-01-01

    NASA is developing micro-shutter arrays for the Near Infrared Spectrometer (NIRSpec) instrument on the James Webb Space Telescope (JWST). These micro-shutter arrays allow NIRspec to do Multi Object Spectroscopy, a key part of the mission. Each array consists of 62414 individual 100 x 200 micron shutters. These shutters are magnetically opened and held electrostatically. Individual shutters are then programmatically closed using a simple row/column addressing technique. A common approach to provide these data/clock patterns is to use a Field Programmable Gate Array (FPGA). Such devices require complex VHSIC Hardware Description Language (VHDL) programming and custom electronic hardware. Due to JWST's rapid schedule on the development of the micro-shutters, rapid changes were required to the FPGA code to facilitate new approaches being discovered to optimize the array performance. Such rapid changes simply could not be made using conventional VHDL programming. Subsequently, National Instruments introduced an FPGA product that could be programmed through a Labview interface. Because Labview programming is considerably easier than VHDL programming, this method was adopted and brought success. The software/hardware allowed the rapid change the FPGA code and timely results of new micro-shutter array performance data. As a result, numerous labor hours and money to the project were conserved.

  14. Optical properties of titanium dioxide nanotube arrays

    Energy Technology Data Exchange (ETDEWEB)

    Abdelmoula, Mohamed [Department of Physics, Northeastern University, Boston, Massachusetts 02115 (United States); Department of Materials Science, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Sokoloff, Jeffrey; Lu, Wen-Tao; Menon, Latika [Department of Physics, Northeastern University, Boston, Massachusetts 02115 (United States); Close, Thomas; Richter, Christiaan, E-mail: christiaan.richter@rit.edu [Department of Chemical Engineering, Rochester Institute of Technology, Rochester, New York, 14623 (United States)

    2014-01-07

    We present experimental measurements and a theoretical analysis of the near UV to NIR optical properties of free standing titania nanotube arrays. An improved understanding of the optical physics of this type of nanostructure is important to several next generation solar energy conversion technologies. We measured the transmission, reflection, and absorption of the electromagnetic spectrum from 300 nm to 1000 nm (UV to NIR) of titania nanotube arrays. We measured the total, specular, and diffuse reflection and transmission using both single point detection and an integrating sphere spectrometer. We find that the transmission, but not the reflection, of light (UV to NIR) through the nanotube array is well-explained by classic geometric optics using an effective medium model taking into account the conical geometry of the nanotubes. For wavelengths shorter than ∼500 nm, we find the surprising result that the reflection coefficient for light incident on the open side of the nanotube array is greater than the reflection coefficient for light incident on the closed “floor” of the nanotube array. We consider theoretical models based on the eikonal approximation, photonic crystal band theory, and a statistical treatment of scattering to explain the observed data. We attribute the fact that light with wavelengths shorter than 500 nm is more highly reflected from the open than the closed tube side as being due to disorder scattering inside the nanotube array.

  15. Tunable nanoparticle arrays at charged interfaces.

    Science.gov (United States)

    Srivastava, Sunita; Nykypanchuk, Dmytro; Fukuto, Masafumi; Gang, Oleg

    2014-10-28

    Structurally tunable two-dimensional (2D) arrays of nanoscale objects are important for modulating functional responses of thin films. We demonstrate that such tunable and ordered nanoparticles (NP) arrays can be assembled at charged air-water interfaces from nanoparticles coated with polyelectrolyte chains, DNA. The electrostatic attraction between the negatively charged nonhybridizing DNA-coated gold NPs and a positively charged lipid layer at the interface facilitates the formation of a 2D hexagonally closed packed (HCP) nanoparticle lattice. We observed about 4-fold change of the monolayer nanoparticle density by varying the ionic strength of the subphase. The tunable NP arrays retain their structure reasonably well when transferred to a solid support. The influence of particle's DNA corona and lipid layer composition on the salt-induced in-plane and normal structural evolution of NP arrays was studied in detail using a combination of synchrotron-based in situ surface scattering methods, grazing incidence X-ray scattering (GISAXS), and X-ray reflectivity (XRR). Comparative analysis of the interparticle distances as a function of ionic strength reveals the difference between the studied 2D nanoparticle arrays and analogous bulk polyelectrolyte star polymers systems, typically described by Daoud-Cotton model and power law scaling. The observed behavior of the 2D nanoparticle array manifests a nonuniform deformation of the nanoparticle DNA corona due to its electrostatically induced confinement at the lipid interface. The present study provides insight on the interfacial properties of the NPs coated with charged soft shells.

  16. A Review of the Four Dimension Antenna Arrays

    Institute of Scientific and Technical Information of China (English)

    YANG Shi-wen; NIE Zai-ping

    2006-01-01

    The four dimensional (4D) antenna arrays introduce a fourth dimension, time, into conventional antenna arrays to offer greater flexibility in the design of high performance antenna arrays. This paper presents the tutorial on the study of 4D antenna arrays and the review of the recent research findings on 4D antenna arrays. Issues considered include the theory of 4D antenna arrays, different time modulation schemes, numerical simulation results, and some experimental results on their applications to low sidelobe designs. Throughout the discussion, some challenging issues on the study of 4D antenna arrays are highlighted.

  17. Array signal recovery algorithm for a single-RF-channel DBF array

    Science.gov (United States)

    Zhang, Duo; Wu, Wen; Fang, Da Gang

    2016-12-01

    An array signal recovery algorithm based on sparse signal reconstruction theory is proposed for a single-RF-channel digital beamforming (DBF) array. A single-RF-channel antenna array is a low-cost antenna array in which signals are obtained from all antenna elements by only one microwave digital receiver. The spatially parallel array signals are converted into time-sequence signals, which are then sampled by the system. The proposed algorithm uses these time-sequence samples to recover the original parallel array signals by exploiting the second-order sparse structure of the array signals. Additionally, an optimization method based on the artificial bee colony (ABC) algorithm is proposed to improve the reconstruction performance. Using the proposed algorithm, the motion compensation problem for the single-RF-channel DBF array can be solved effectively, and the angle and Doppler information for the target can be simultaneously estimated. The effectiveness of the proposed algorithms is demonstrated by the results of numerical simulations.

  18. SUPERCONDUCTING QUADRUPOLE ARRAYS FOR MULTIPLE BEAM TRANSPORT

    Energy Technology Data Exchange (ETDEWEB)

    Rainer Meinke

    2003-10-01

    The goal of this research was to develop concepts for affordable, fully functional arrays of superconducting quadrupoles for multi-beam transport and focusing in heavy ion fusion (HIF)accelerators. Previous studies by the Virtual National Laboratory (VNL) collaboration have shown that the multi-beam transport system (consisting of alternating gradient quadrupole magnets, a beam vacuum system, and the beam monitor and control system) will likely be one of the most expensive and critical parts of such an accelerator. This statement is true for near-term fusion research accelerators as well as accelerators for the ultimate goal of power production via inertial fusion. For this reason, research on superconducting quadrupole arrays is both timely and important for the inertial fusion energy (IFE) research program. This research will also benefit near-term heavy ion fusion facilities such as the Integrated Research Experiment (IRE)and/or the Integrated Beam Experiment (IBX). We considered a 2-prong approach that addresses the needs of both the nearer and longer term requirements of the inertial fusion program. First, we studied the flat coil quadrupole design that was developed by LLNL; this magnet is 150 mm long with a 50 mm aperture and thus is suitable for near term experiments that require magnets of a small length to aperture ratio. Secondly, we studied the novel double-helix quadrupole (DHQ) design in a small (3 x 3) array configuration; this design can provide an important step to the longer term solution of low-cost, easy to manufacture array constructions. Our Phase I studies were performed using the AMPERES magnetostatic analysis software. Consideration of these results led to plans for future magnet R&D construction projects. The first objective of Phase I was to develop the concept of a superconducting focusing array that meets the specific requirements of a heavy ion fusion accelerator. Detailed parameter studies for such quadrupole arrays were performed

  19. Arrays of magnetic nanoparticles capped with alkylamines

    Indian Academy of Sciences (India)

    P John Thomas; P Saravanan; G U Kulkarni; C N R Rao

    2002-02-01

    Magnetic metal and metal oxide nanoparticles capped with alkylamines have been synthesized and characterized by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray analysis and magnetization measurements. Core-shell Pd–Ni particles with composition, Pd561Ni3000, (diameter ∼ 3.3 nm) are superparamagnetic at 5 K and organize themselves into two-dimensional crystalline arrays. Similar arrays are obtained with Pd561Ni3000Pd1500 nanoparticles containing an additional Pd shell. Magnetic spinel particles of -Fe2O3, Fe3O4 and CoFe2O4 of average diameters in the 4–6 nm range coated with octylamine are all supermagnetic at room temperature and yield close-packed disordered arrays. Relatively regular arrays are formed by dodecylamine-capped Fe3O4 nanoparticles (∼ 8.6 nm diameter) while well-ordered hexagonal arrays were obtained with octylamine-covered Co3O4 nanoparticles (∼ 4.2 nm diameter).

  20. Pipelined Vedic-Array Multiplier Architecture

    Directory of Open Access Journals (Sweden)

    Vaijyanath Kunchigik

    2014-05-01

    Full Text Available In this paper, pipelined Vedic-Array multiplier architecture is proposed. The most significant aspect of the proposed multiplier architecture method is that, the developed multiplier architecture is designed based on the Vedic and Array methods of multiplier architecture. The multiplier architecture is optimized in terms of multiplication and addition to achieve efficiency in terms of area, delay and power. This also gives chances for modular design where smaller block can be used to design the bigger one. So the design complexity gets reduced for inputs of larger number of bits and modularity gets increased. The proposed Vedic-Array multiplier is coded in Verilog, synthesized and simulated using EDA (Electronic Design Automation tool - XilinxISE12.3, Spartan 3E, Speed Grade-4. Finally the results are compared with array and booth multiplier architectures. Proposed multiplier is better in terms of delay and area as compared to booth multiplier and array multiplier respectively. The proposed multiplier architecture can be used for high-speed requirements.

  1. 10-kilowatt photovoltaic concentrator array fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, J.A.; Donovan, R.L.; Broadbent, S.

    1980-12-01

    The PCA is based on the use of an acrylic Fresnel lens to concentrate sunlight on high intensity solar cells. The array with modified heat sinks was fabricated to determine the impact on electrical performance due to lower weight heat sinks and reduced thermal dissipation surfaces. The array with modified heat sinks was fabricated to determine the impact on electrical performance due to lower weight heat sinks and reduced thermal dissipation surfaces. The array fabrication proceeded with normal problems expected of preproduction prototypes. Three major problems occurred in the areas of the dimensional adequacy of the environmental housing for the Photovoltaic Modules, the cell/substrate assembly and the azimuth drive structural integrity. The cost optimization study identified a new lower weight heat sink design that would reduce the heat sink weight by 50% and the array cost by approximately 3.1% for a loss of only 7% in annularized electrical power generation. The production cost estimate provides an indicator that an overall 87% learning curve can be achieved and the cost of the 5000th unit could be $5.30 per watt in 1979 dollars. System level costs were also developed to project a busbar energy cost for a 10 MW system produced at the 500th unit. This system would provide energy at 24 cents per kilowatt hour average over a 30 year projected life. As a result of wind tunnel tests and the fabrication experience, an array has been designed for production. The key elements of the redesign are discussed. (MHR)

  2. Silicon ball grid array chip carrier

    Science.gov (United States)

    Palmer, David W.; Gassman, Richard A.; Chu, Dahwey

    2000-01-01

    A ball-grid-array integrated circuit (IC) chip carrier formed from a silicon substrate is disclosed. The silicon ball-grid-array chip carrier is of particular use with ICs having peripheral bond pads which can be reconfigured to a ball-grid-array. The use of a semiconductor substrate such as silicon for forming the ball-grid-array chip carrier allows the chip carrier to be fabricated on an IC process line with, at least in part, standard IC processes. Additionally, the silicon chip carrier can include components such as transistors, resistors, capacitors, inductors and sensors to form a "smart" chip carrier which can provide added functionality and testability to one or more ICs mounted on the chip carrier. Types of functionality that can be provided on the "smart" chip carrier include boundary-scan cells, built-in test structures, signal conditioning circuitry, power conditioning circuitry, and a reconfiguration capability. The "smart" chip carrier can also be used to form specialized or application-specific ICs (ASICs) from conventional ICs. Types of sensors that can be included on the silicon ball-grid-array chip carrier include temperature sensors, pressure sensors, stress sensors, inertia or acceleration sensors, and/or chemical sensors. These sensors can be fabricated by IC processes and can include microelectromechanical (MEM) devices.

  3. A SQUID series array dc current sensor

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, J; Drung, D [Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, D-10587 Berlin (Germany)], E-mail: joern.beyer@ptb.de, E-mail: dietmar.drung@ptb.de

    2008-09-15

    Superconducting quantum interference device (SQUID) sensors are used to sense changes in various physical quantities, which can be transformed into changes in the magnetic flux threading the SQUID loop. We have developed a novel SQUID array dc current sensor. The device is based on a series array of identical dc SQUIDs. An input signal current to be measured is coupled tightly but non-uniformly to the SQUID array elements. The input signal coupling to the individual array elements is chosen such that a single-valued, non-periodic overall voltage response is obtained. Flux offsets in the individual SQUIDs which would compromise the sensor voltage response are avoided or can be compensated. We present simulations and experimental results on the SQUID Array for Dc (SQUAD) current sensor current sensor performance. A dc current resolution of <1 nA in a measurement bandwidth of 0-25 Hz is achieved for an input inductance of L{sub In}<3 nH.

  4. Research in large adaptive antenna arrays

    Science.gov (United States)

    Berkowitz, R. S.; Dzekov, T.

    1976-01-01

    The feasibility of microwave holographic imaging of targets near the earth using a large random conformal array on the earth's surface and illumination by a CW source on a geostationary satellite is investigated. A geometrical formulation for the illuminator-target-array relationship is applied to the calculation of signal levels resulting from L-band illumination supplied by a satellite similar to ATS-6. The relations between direct and reflected signals are analyzed and the composite resultant signal seen at each antenna element is described. Processing techniques for developing directional beam formation as well as SNR enhancement are developed. The angular resolution and focusing characteristics of a large array covering an approximately circular area on the ground are determined. The necessary relations are developed between the achievable SNR and the size and number of elements in the array. Numerical results are presented for possible air traffic surveillance system. Finally, a simple phase correlation experiment is defined that can establish how large an array may be constructed.

  5. Designing microcapsule arrays that propagate chemical signals

    Science.gov (United States)

    Bhattacharya, Amitabh; Balazs, Anna C.

    2010-08-01

    Using analysis and simulation, we show how ordered arrays of microcapsules in solution can be harnessed to propagate chemical signals in directed and controllable ways, allowing the signals to be transmitted over macroscopic distances. The system encompasses two types of capsules that are localized on an adhesive surface. The “signaling” capsules release inducer molecules, which trigger “targets” to release nanoparticles. The released nanoparticles can bind to the underlying surface and thus, create adhesion gradients, which then propel the signaling capsules to shuttle between neighboring targets. This arrangement acts like a relay, so that triggering target capsules at a particular location in the array also triggers target capsules in adjacent locations. For an array containing two target columns, our simulations and analysis show that steady input signal leads to a sustained periodic output. For an array containing multiple target columns, we show that by introducing a prescribed ratio of nanoparticle release rates between successive target columns, a chemical signal can be propagated along the array without dissipation. We also demonstrate that similar signal transmission cannot be performed via diffusion alone.

  6. Optical absorption enhancement in silicon nanohole arrays for solar photovoltaics.

    Science.gov (United States)

    Han, Sang Eon; Chen, Gang

    2010-03-10

    We investigate silicon nanohole arrays as light absorbing structures for solar photovoltaics via simulation. To obtain the same ultimate efficiency as a standard 300 microm crystalline silicon wafer, we find that nanohole arrays require twelve times less silicon by mass. Moreover, our calculations show that nanohole arrays have an efficiency superior to nanorod arrays for practical thicknesses. With well-established fabrication techniques, nanohole arrays have great potential for efficient solar photovoltaics.

  7. Three-dimensional object representation by array grammars

    Science.gov (United States)

    Wang, Patrick S. P.

    1991-02-01

    A new approach for representing 3-d objects by 3-d array grammar is introduced. The concept of universal array grammar is proposed for 3-d object representation. it uses parallelism for pattern generation. Many interesting 3-d objecis can indeed he represented by this universal 3-d array grammar which paves a ground for 3-d object recognition. description and understanding. Keywords: 3-d array grammars. universal array grammars pattern generation. object representation parallel generation I.

  8. Optimal linear array heading in a directional noise field

    OpenAIRE

    McDonnell, David C.

    1992-01-01

    Approved for public release; distribution is unlimited. This thesis discusses a procedure that optimizes the signal-to-noise ratio (SNR) detected by a linear array in a directional ambient noise field. The SNR can be optimized by minimizing the ambient noise detected by the array. For a given target location, each possible heading of the array centers the ambiguous beam of the array at a different true bearing. Therefore, each heading of the array will receive a different ambient noise lev...

  9. The Australian Square Kilometre Array Pathfinder: System Architecture and Specifications of the Boolardy Engineering Test Array

    CERN Document Server

    Hotan, A W; Harvey-Smith, L; Humphreys, B; Jeffs, B D; Shimwell, T; Tuthill, J; Voronkov, M; Allen, G; Amy, S; Ardern, K; Axtens, P; Ball, L; Bannister, K; Barker, S; Bateman, T; Beresford, R; Bock, D; Bolton, R; Bowen, M; Boyle, B; Braun, R; Broadhurst, S; Brodrick, D; Brooks, K; Brothers, M; Brown, A; Cantrall, C; Carrad, G; Chapman, J; Cheng, W; Chippendale, A; Chung, Y; Cooray, F; Cornwell, T; Davis, E; de Souza, L; DeBoer, D; Diamond, P; Edwards, P; Ekers, R; Feain, I; Ferris, D; Forsyth, R; Gough, R; Grancea, A; Gupta, N; Guzman, JC; Hampson, G; Haskins, C; Hay, S; Hayman, D; Hoyle, S; Jacka, C; Jackson, C; Jackson, S; Jeganathan, K; Johnston, S; Joseph, J; Kendall, R; Kesteven, M; Kiraly, D; Koribalski, B; Leach, M; Lenc, E; Lensson, E; Li, L; Mackay, S; Macleod, A; Maher, T; Marquarding, M; McClure-Griffiths, N; McConnell, D; Mickle, S; Mirtschin, P; Norris, R; Neuhold, S; Ng, A; O'Sullivan, J; Pathikulangara, J; Pearce, S; Phillips, C; Qiao, RY; Reynolds, J E; Rispler, A; Roberts, P; Roxby, D; Schinckel, A; Shaw, R; Shields, M; Storey, M; Sweetnam, T; Troup, E; Turner, B; Tzioumis, A; Westmeier, T; Whiting, M; Wilson, C; Wilson, T; Wormnes, K; Wu, X

    2014-01-01

    This paper describes the system architecture of a newly constructed radio telescope - the Boolardy Engineering Test Array, which is a prototype of the Australian Square Kilometre Array Pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a 6-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least 9 dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.

  10. Terabyte IDE RAID-5 Disk Arrays

    CERN Document Server

    Sanders, D A; Eschenburg, V; Godang, R; Lawrence, C N; Riley, C P; Summers, D J; Petravick, D L

    2003-01-01

    High energy physics experiments are currently recording large amounts of data and in a few years will be recording prodigious quantities of data. New methods must be developed to handle this data and make analysis at universities possible. We examine some techniques that exploit recent developments in commodity hardware. We report on tests of redundant arrays of integrated drive electronics (IDE) disk drives for use in offline high energy physics data analysis. IDE redundant array of inexpensive disks (RAID) prices now are less than the cost per terabyte of million-dollar tape robots! The arrays can be scaled to sizes affordable to institutions without robots and used when fast random access at low cost is important.

  11. Resonance spectra of diabolo optical antenna arrays

    Directory of Open Access Journals (Sweden)

    Hong Guo

    2015-10-01

    Full Text Available A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.

  12. Electronically Steerable Spherical Array capabilities and interfaces

    Science.gov (United States)

    Taylor, T. H., Jr.

    1982-01-01

    The development of the Electronically Steerable Spherical Array (ESSA) was started in 1975. ESSA provides the inertialess antenna needed by user satellites for communication over their large coverage angles towards the Tracking Data Relay Satellite System (TDRSS). The performance of ESSA over large coverage angles is better than the performance provided by phased arrays. The primary difference between the two antenna types is the method of beam forming. The ESSA steers a beam by illuminating a set of elements which point in the desired direction. This set of elements is illuminated by a simple multipole switch called a switching power divider (SPD). Attention is given to details regarding the difference in performance between ESSA and phased arrays, the ESSA block diagram, the performance improvement achieved by phase compensation, power requirements, the four operating modes, multibeam operation, and the data interface.

  13. Modal liquid crystal array of optical elements.

    Science.gov (United States)

    Algorri, J F; Love, G D; Urruchi, V

    2013-10-21

    In this study, a novel liquid crystal array based on modal control principle is proposed and demonstrated. The advanced device comprises a six striped electrode structure that forms a configurable 2D matrix of optical elements. A simulation program based on the Frank-Oseen equations and modal control theory has been developed to predict the device electrooptic response, that is, voltage distribution, interference pattern and unwrapped phase. A low-power electronics circuit, that generates complex waveforms, has been built for driving the device. A combined variation of the waveform amplitude and phase has provided a high tuning versatility to the device. Thus, the simulations have demonstrated the generation of a liquid crystal prism array with tunable slope. The proposed device has also been configured as an axicon array. Test measurements have allowed us to demonstrate that electrooptic responses, simulated and empirical, are fairly in agreement.

  14. Fabrication of patterned polymer nanowire arrays.

    Science.gov (United States)

    Fang, Hao; Yuan, Dajun; Guo, Rui; Zhang, Su; Han, Ray P S; Das, Suman; Wang, Zhong Lin

    2011-02-22

    A method for the large-scale fabrication of patterned organic nanowire (NW) arrays is demonstrated by the use of laser interference patterning (LIP) in conjunction with inductively coupled plasma (ICP) etching. The NW arrays can be fabricated after a short ICP etching of periodic patterns produced through LIP. Arrays of NWs have been fabricated in UV-absorbent polymers, such as PET (polyethylene terephthalate) and Dura film (76% polyethylene and 24% polycarbonate), through laser interference photon ablation and in UV transparent polymers such as PVA (polyvinyl acetate) and PP (polypropylene) through laser interference lithography of a thin layer of photoresist coated atop the polymer surface. The dependence of the structure and morphology of NWs as a function of initial pattern created by LIP and the laser energy dose in LIP is discussed. The absence of residual photoresist atop the NWs in UV-transparent polymers is confirmed through Raman spectroscopy.

  15. Broadband DOA Estimation Based on Nested Arrays

    Directory of Open Access Journals (Sweden)

    Zhi-bo Shen

    2015-01-01

    Full Text Available Direction of arrival (DOA estimation is a crucial problem in electronic reconnaissance. A novel broadband DOA estimation method utilizing nested arrays is devised in this paper, which is capable of estimating the frequencies and DOAs of multiple narrowband signals in broadbands, even though they may have different carrier frequencies. The proposed method converts the DOA estimation of multiple signals with different frequencies into the spatial frequency estimation. Then, the DOAs and frequencies are pair matched by sparse recovery. It is possible to significantly increase the degrees of freedom (DOF with the nested arrays and the number of sources can be more than that of sensor array. In addition, the method can achieve high estimation precision without the two-dimensional search process in frequency and angle domain. The validity of the proposed method is verified by theoretic analysis and simulation results.

  16. Pressure vessel inspections using ultrasonic phased arrays

    Energy Technology Data Exchange (ETDEWEB)

    Moles, M.D.C. [R/D Tech Toronto, Toronto, ON (Canada); Jacques, F.; Dube, N. [R/D Tech Quebec PQ (Canada)

    2003-07-01

    Pressure vessels are used in several industries, including the petrochemical and petroleum industries. Welds in the pressure vessels often produce defects which propagate and fail with time. Many types of pressure vessel weld inspections can now be conducted using automated ultrasonics which offers several advantages over radiography. In terms of phased arrays, custom tailored time-of-flight diffraction (TOFD) and ASME code Section V raster scans, can successfully perform high speed inspections with minimal operator subjectivity. The phased array beams can be steered, scanned, swept and focused electronically. Beam steering can be used to map welds at appropriate angles to optimize probability of defect detection. The main challenge lies with the initial equipment cost, technology awareness, and availability of trained operators. Phased arrays offer great flexibility for different components, defect detection and tailored imaging. 8 refs., 10 figs.

  17. SWNT array resonant gate MOS transistor.

    Science.gov (United States)

    Arun, A; Campidelli, S; Filoramo, A; Derycke, V; Salet, P; Ionescu, A M; Goffman, M F

    2011-02-04

    We show that thin horizontal arrays of single wall carbon nanotubes (SWNTs) suspended above the channel of silicon MOSFETs can be used as vibrating gate electrodes. This new class of nano-electromechanical system (NEMS) combines the unique mechanical and electronic properties of SWNTs with an integrated silicon-based motion detection. Its electrical response exhibits a clear signature of the mechanical resonance of SWNT arrays (120-150 MHz) showing that these thin horizontal arrays behave as a cohesive, rigid and elastic body membrane with a Young's modulus in the order of 1-10 GPa and ultra-low mass. The resonant frequency can be tuned by the gate voltage and its dependence is well understood within the continuum mechanics framework.

  18. SWNT array resonant gate MOS transistor

    Energy Technology Data Exchange (ETDEWEB)

    Arun, A; Salet, P; Ionescu, A M [NanoLab, Ecole Polytechnique Federale de Lausanne, CH-1015, Lausanne (Switzerland); Campidelli, S; Filoramo, A; Derycke, V; Goffman, M F, E-mail: marcelo.goffman@cea.fr [Laboratoire d' Electronique Moleculaire, SPEC (CNRS URA 2454), IRAMIS, CEA, Gif-sur-Yvette (France)

    2011-02-04

    We show that thin horizontal arrays of single wall carbon nanotubes (SWNTs) suspended above the channel of silicon MOSFETs can be used as vibrating gate electrodes. This new class of nano-electromechanical system (NEMS) combines the unique mechanical and electronic properties of SWNTs with an integrated silicon-based motion detection. Its electrical response exhibits a clear signature of the mechanical resonance of SWNT arrays (120-150 MHz) showing that these thin horizontal arrays behave as a cohesive, rigid and elastic body membrane with a Young's modulus in the order of 1-10 GPa and ultra-low mass. The resonant frequency can be tuned by the gate voltage and its dependence is well understood within the continuum mechanics framework.

  19. Redundant Array Configurations for 21 cm Cosmology

    CERN Document Server

    Dillon, Joshua S

    2016-01-01

    Realizing the potential of 21 cm tomography to statistically probe the intergalactic medium before and during the Epoch of Reionization requires large telescopes and precise control of systematics. Next-generation telescopes are now being designed and built to meet these challenges, drawing lessons from first-generation experiments that showed the benefits of densely packed, highly redundant arrays--in which the same mode on the sky is sampled by many antenna pairs--for achieving high sensitivity, precise calibration, and robust foreground mitigation. In this work, we focus on the Hydrogen Epoch of Reionization Array (HERA) as an interferometer with a dense, redundant core designed following these lessons to be optimized for 21 cm cosmology. We show how modestly supplementing or modifying a compact design like HERA's can still deliver high sensitivity while enhancing strategies for calibration and foreground mitigation. In particular, we compare the imaging capability of several array configurations, both ins...

  20. Versatile microfluidic droplets array for bioanalysis.

    Science.gov (United States)

    Hu, Shan-Wen; Xu, Bi-Yi; Ye, Wei-Ke; Xia, Xing-Hua; Chen, Hong-Yuan; Xu, Jing-Juan

    2015-01-14

    We propose a novel method to obtain versatile droplets arrays on a regional hydrophilic chip that is fabricated by PDMS soft lithography and regional plasma treatment. It enables rapid liquid dispensation and droplets array formation just making the chip surface in contact with solution. By combining this chip with a special Christmas Tree structure, the droplets array with concentrations in gradient is generated. It possesses the greatly improved performance of convenience and versatility in bioscreening and biosensing. For example, high throughput condition screening of toxic tests of CdSe quantum dots on HL-60 cells are conducted and cell death rates are successfully counted quickly and efficiently. Furthermore, a rapid biosensing approach for cancer biomarkers carcinoma embryonic antigen (CEA) is developed via magnetic beads (MBs)-based sandwich immunoassay methods.

  1. Receptor arrays optimized for natural odor statistics

    CERN Document Server

    Zwicker, David; Brenner, Michael P

    2016-01-01

    Natural odors typically consist of many molecules at different concentrations. It is unclear how the numerous odorant molecules and their possible mixtures are discriminated by relatively few olfactory receptors. Using an information-theoretic model, we show that a receptor array is optimal for this task if it achieves two possibly conflicting goals: (i) each receptor should respond to half of all odors and (ii) the response of different receptors should be uncorrelated when averaged over odors presented with natural statistics. We use these design principles to predict statistics of the affinities between receptors and odorant molecules for a broad class of odor statistics. We also show that optimal receptor arrays can be tuned to either resolve concentrations well or distinguish mixtures reliably. Finally, we use our results to predict properties of experimentally measured receptor arrays. Our work can thus be used to better understand natural olfaction and it also suggests ways to improve artificial sensor...

  2. Microneedle arrays for biosensing and drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Joseph; Windmiller, Joshua Ray; Narayan, Roger; Miller, Philip; Polsky, Ronen; Edwards, Thayne L.

    2017-08-22

    Methods, structures, and systems are disclosed for biosensing and drug delivery techniques. In one aspect, a^ device for detecting an analyte and/or releasing a biochemical into a biological fluid can include an array of hollowed needles, in which each needle includes a protruded needle structure including an exterior wall forming a hollow interior and an opening at a terminal end of the protruded needle structure that exposes the hollow interior, and a probe inside the exterior wall to interact with one or more chemical or biological substances that come in contact with the probe via the opening to produce a probe sensing signal, and an array of wires that are coupled to probes of the array of hollowed needles, respectively, each wire being electrically conductive to transmit the probe sensing signal produced by a respective probe.

  3. Microneedle arrays for biosensing and drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Joseph; Windmiller, Joshua Ray; Narayan, Roger; Miller, Philip

    2017-08-29

    Methods, structures, and systems are disclosed for biosensing and drug delivery techniques. In one aspect, a device for detecting an analyte and/or releasing a biochemical into a biological fluid can include an array of hollowed needles, in which each needle includes a protruded needle structure including an exterior wall forming a hollow interior and an opening at a terminal end of the protruded needle structure that exposes the hollow interior, and a probe inside the exterior wall to interact with one or more chemical or biological substances that come in contact with the probe via the opening to produce a probe sensing signal, and an array of wires that are coupled to probes of the array of hollowed needles, respectively, each wire being electrically conductive to transmit the probe sensing signal produced by a respective probe.

  4. Turbulent chimeras in large semiconductor laser arrays

    CERN Document Server

    Shena, Joniald; Kovanis, Vassilios; Tsironis, George P

    2016-01-01

    Semiconductor laser arrays have been investigated experimentally and theoretically from the viewpoint of temporal and spatial coherence for the past forty years. In this work, we are focusing on a rather novel complex collective behavior, namely chimera states, where synchronized clusters of emitters coexist with unsynchronized ones. For the first time, we find such states exist in large diode arrays based on quantum well gain media with nearest-neighbor interactions. The crucial parameters are the evanescent coupling strength and the relative optical frequency detuning between the emitters of the array. By employing a recently proposed figure of merit for classifying chimera states, we provide quantitative and qualitative evidence for the observed dynamics. The corresponding chimeras are identified as turbulent according to the irregular temporal behavior of the classification measure. Such studies may be the springboard for designing next generation photonic emitters providing on demand diverse waveforms.

  5. Stochastic synaptic plasticity with memristor crossbar arrays

    KAUST Repository

    Naous, Rawan

    2016-11-01

    Memristive devices have been shown to exhibit slow and stochastic resistive switching behavior under low-voltage, low-current operating conditions. Here we explore such mechanisms to emulate stochastic plasticity in memristor crossbar synapse arrays. Interfaced with integrate-and-fire spiking neurons, the memristive synapse arrays are capable of implementing stochastic forms of spike-timing dependent plasticity which parallel mean-rate models of stochastic learning with binary synapses. We present theory and experiments with spike-based stochastic learning in memristor crossbar arrays, including simplified modeling as well as detailed physical simulation of memristor stochastic resistive switching characteristics due to voltage and current induced filament formation and collapse. © 2016 IEEE.

  6. Plasmonic Properties of Vertically Aligned Nanowire Arrays

    Directory of Open Access Journals (Sweden)

    Hua Qi

    2012-01-01

    Full Text Available Nanowires (NWs/Ag sheath composites were produced to investigate plasmonic coupling between vertically aligned NWs for surface-enhanced Raman scattering (SERS applications. In this investigation, two types of vertical NW arrays were studied; those of ZnO NWs grown on nanosphere lithography patterned sapphire substrate via vapor-liquid-solid (VLS mechanism and Si NW arrays produced by wet chemical etching. Both types of vertical NW arrays were coated with a thin layer of silver by electroless silver plating for SERS enhancement studies. The experimental results show extremely strong SERS signals due to plasmonic coupling between the NWs, which was verified by COMSOL electric field simulations. We also compared the SERS enhancement intensity of aligned and random ZnO NWs, indicating that the aligned NWs show much stronger and repeatable SERS signal than those grown in nonaligned geometries.

  7. The Atacama Large Millimeter/submillimeter Array

    CERN Document Server

    Wootten, Alwyn

    2009-01-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) is an international radio telescope under construction in the Atacama Desert of northern Chile. ALMA is situated on a dry site at 5000 m elevation, allowing excellent atmospheric transmission over the instrument wavelength range of 0.3 to 10 mm. ALMA will consist of two arrays of high-precision antennas. One, of up to 64 12-m diameter antennas, is reconfigurable in multiple patterns ranging in size from 150 meters up to ~15 km. A second array is comprised of a set of four 12-m and twelve 7-m antennas operating in one of two closely packed configurations ~50 m in diameter. The instrument will provide both interferometric and total-power astronomical information on atomic, molecular and ionized gas and dust in the solar system, our Galaxy, and the nearby to high-redshift universe. In this paper we outline the scientific drivers, technical challenges and planned progress of ALMA.

  8. Solid-state curved focal plane arrays

    Science.gov (United States)

    Nikzad, Shouleh (Inventor); Hoenk, Michael (Inventor); Jones, Todd (Inventor)

    2010-01-01

    The present invention relates to curved focal plane arrays. More specifically, the present invention relates to a system and method for making solid-state curved focal plane arrays from standard and high-purity devices that may be matched to a given optical system. There are two ways to make a curved focal plane arrays starting with the fully fabricated device. One way, is to thin the device and conform it to a curvature. A second way, is to back-illuminate a thick device without making a thinned membrane. The thick device is a special class of devices; for example devices fabricated with high purity silicon. One surface of the device (the non VLSI fabricated surface, also referred to as the back surface) can be polished to form a curved surface.

  9. Resolution of Port/Starboard Ambiguity Using a Linear Array of Triplets and a Twin-Line Planar Array

    Science.gov (United States)

    2016-06-01

    Five Octave Research Array) [6] is a mixed towed sonar composed of a linear array of single elements and a linear array of triplets, designed and built...theoretical model and designed specifically to simulate the signals reaching the sensors of a twin-line planar array. The sound -source radiates a...simulations programmed in MATLAB. The simulations make use of a signal generator, designed to assess the performance of the twin-line planar array. The

  10. Optimization of return electrodes in neurostimulating arrays

    Science.gov (United States)

    Flores, Thomas; Goetz, Georges; Lei, Xin; Palanker, Daniel

    2016-06-01

    Objective. High resolution visual prostheses require dense stimulating arrays with localized inputs of individual electrodes. We study the electric field produced by multielectrode arrays in electrolyte to determine an optimal configuration of return electrodes and activation sequence. Approach. To determine the boundary conditions for computation of the electric field in electrolyte, we assessed current dynamics using an equivalent circuit of a multielectrode array with interleaved return electrodes. The electric field modeled with two different boundary conditions derived from the equivalent circuit was then compared to measurements of electric potential in electrolyte. To assess the effect of return electrode configuration on retinal stimulation, we transformed the computed electric fields into retinal response using a model of neural network-mediated stimulation. Main results. Electric currents at the capacitive electrode-electrolyte interface redistribute over time, so that boundary conditions transition from equipotential surfaces at the beginning of the pulse to uniform current density in steady state. Experimental measurements confirmed that, in steady state, the boundary condition corresponds to a uniform current density on electrode surfaces. Arrays with local return electrodes exhibit improved field confinement and can elicit stronger network-mediated retinal response compared to those with a common remote return. Connecting local return electrodes enhances the field penetration depth and allows reducing the return electrode area. Sequential activation of the pixels in large monopolar arrays reduces electrical cross-talk and improves the contrast in pattern stimulation. Significance. Accurate modeling of multielectrode arrays helps optimize the electrode configuration to maximize the spatial resolution, contrast and dynamic range of retinal prostheses.

  11. Integrated Miniature Arrays of Optical Biomolecule Detectors

    Science.gov (United States)

    Iltchenko, Vladimir; Maleki, Lute; Lin, Ying; Le, Thanh

    2009-01-01

    Integrated miniature planar arrays of optical sensors for detecting specific biochemicals in extremely small quantities have been proposed. An array of this type would have an area of about 1 cm2. Each element of the array would include an optical microresonator that would have a high value of the resonance quality factor (Q . 107). The surface of each microresonator would be derivatized to make it bind molecules of a species of interest, and such binding would introduce a measurable change in the optical properties of the microresonator. Because each microresonator could be derivatized for detection of a specific biochemical different from those of the other microresonators, it would be possible to detect multiple specific biochemicals by simultaneous or sequential interrogation of all the elements in the array. Moreover, the derivatization would make it unnecessary to prepare samples by chemical tagging. Such interrogation would be effected by means of a grid of row and column polymer-based optical waveguides that would be integral parts of a chip on which the array would be fabricated. The row and column polymer-based optical waveguides would intersect at the elements of the array (see figure). At each intersection, the row and column waveguides would be optically coupled to one of the microresonators. The polymer-based waveguides would be connected via optical fibers to external light sources and photodetectors. One set of waveguides and fibers (e.g., the row waveguides and fibers) would couple light from the sources to the resonators; the other set of waveguides and fibers (e.g., the column waveguides and fibers) would couple light from the microresonators to the photodetectors. Each microresonator could be addressed individually by row and column for measurement of its optical transmission. Optionally, the chip could be fabricated so that each microresonator would lie inside a microwell, into which a microscopic liquid sample could be dispensed.

  12. Design of a Novel MEMS Gyroscope Array

    OpenAIRE

    Feng Sun; Wei Wang; Xiaoyong Lv

    2013-01-01

    This paper reports a novel four degree-of-freedom (DOF) MEMS vibratory gyroscope. A MEMS gyroscope array is then presented using the novel gyroscope unit. In the design of the proposed 4-DOF MEMS vibratory gyroscope, the elements of the drive-mode are set inside the whole gyroscope architecture, and the elements of sense-mode are set around the drive-mode, which thus makes it possible to combine several gyroscope units into a gyroscope array through sense-modes of all the units. The complete ...

  13. Cell Proliferation Tracking Using Graphene Sensor Arrays

    Directory of Open Access Journals (Sweden)

    Ronan Daly

    2012-01-01

    Full Text Available The development of a novel label-free graphene sensor array is presented. Detection is based on modification of graphene FET devices and specifically monitoring the change in composition of the nutritive components in culturing medium. Micro-dispensing of Escherichia coli in medium shows feasibility of accurate positioning over each sensor while still allowing cell proliferation. Graphene FET device fabrication, sample dosing, and initial electrical characterisation have been completed and show a promising approach to reducing the sample size and lead time for diagnostic and drug development protocols through a label-free and reusable sensor array fabricated with standard and scalable microfabrication technologies.

  14. Astronomical Image Processing with Array Detectors

    CERN Document Server

    Houde, Martin

    2007-01-01

    We address the question of astronomical image processing from data obtained with array detectors. We define and analyze the cases of evenly, regularly, and irregularly sampled maps for idealized (i.e., infinite) and realistic (i.e., finite) detectors. We concentrate on the effect of interpolation on the maps, and the choice of the kernel used to accomplish this task. We show how the normalization intrinsic to the interpolation process must be carefully accounted for when dealing with irregularly sampled grids. We also analyze the effect of missing or dead pixels in the array, and their consequences for the Nyquist sampling criterion.

  15. Graphene array antenna for 5G applications

    Science.gov (United States)

    Sa'don, Siti Nor Hafizah; Kamarudin, Muhammad Ramlee; Ahmad, Fauzan; Jusoh, Muzammil; Majid, Huda A.

    2017-02-01

    Fifth generation (5G) needs to provide better coverage than the previous generation. However, high frequency and millimeter wave experience penetration loss, propagation loss and even more loss in energy for long distance. Hence, a graphene array antenna is proposed for high gain to cover a long distance communications since array antenna enables in providing more directive beams. The investigation is conducted on three types of substrates with gain achieved is more than 7 dBi. The gain obtained is good since it is comparable with other studies. In addition, these antennas consume small numbers of elements to achieve high gain.

  16. The GPS Laser Retroreflector Array Project

    Science.gov (United States)

    Merkowitz, Stephen M.

    2012-01-01

    Systematic co-location in space through the precision orbit determination of GPS satellites via satellite laser ranging will contribute significantly towards improving the accuracy and stability of the international terrestrial reference frame. NASA recently formed the GPS Laser Retroreflector Array Project to develop and deliver retroreflectors for integration on the next generation of GPS satellites. These retroreflectors will be an important contributor to achieving a global accuracy of 1.0 mm and 0.1 mm/year stability in the international terrestrial reference frame. We report here the current status of the GPS Laser Retroreflector Array Project.

  17. Optimal ultrasonic array focusing in attenuative media.

    Science.gov (United States)

    Ganguli, A; Gao, R X; Liang, K; Jundt, J

    2011-12-01

    This paper presents a parametric study on the efficiency of ultrasound focusing in an attenuative medium, using phased arrays. Specifically, an analytical model of ultrasound wave focusing in a homogeneous, isotropic and attenuative fluid with point sources is presented. Calculations based on the model have shown that in an attenuative medium, an optimum frequency exists for the best focusing performance for a particular size of aperture and focal distance. The effect of different f numbers on the focusing performance in the attenuative medium is further investigated. The information obtained from the analytical model provides insights into the design and installation of a phased transducer array for energy efficient wave focusing.

  18. Development of flexible array tactile sensors

    DEFF Research Database (Denmark)

    Drimus, Alin; Marian, Nicolae; Bilberg, Arne

    2010-01-01

    In this paper we describe the development of an array tactile sensor for use in robotic grippers based on a flexible piezoresistive material. We start by comparing different cell structures in terms of output characteristics and we construct an array of cells in a row and columns layout. A real...... time data acquisition system scans all the cells and converts electrical resistance to tactile pressure maps. We validate that this information can be used to improve grasping and perform object recognition. Key words: piezoresistivity, tactile, sensor, pressure, robotics...

  19. The ROSPHERE γ-ray spectroscopy array

    Science.gov (United States)

    Bucurescu, D.; Căta-Danil, I.; Ciocan, G.; Costache, C.; Deleanu, D.; Dima, R.; Filipescu, D.; Florea, N.; Ghiţă, D. G.; Glodariu, T.; Ivaşcu, M.; Lică, R.; Mărginean, N.; Mărginean, R.; Mihai, C.; Negret, A.; Niţă, C. R.; Olăcel, A.; Pascu, S.; Sava, T.; Stroe, L.; Şerban, A.; Şuvăilă, R.; Toma, S.; Zamfir, N. V.; Căta-Danil, G.; Gheorghe, I.; Mitu, I. O.; Suliman, G.; Ur, C. A.; Braunroth, T.; Dewald, A.; Fransen, C.; Bruce, A. M.; Podolyák, Zs.; Regan, P. H.; Roberts, O. J.

    2016-11-01

    The ROmanian array for SPectroscopy in HEavy ion REactions (ROSPHERE) has been designed as a multi-detector setup dedicated to γ-ray spectroscopy studies at the Bucharest 9 MV Tandem accelerator. Consisting of up to 25 detectors (either Compton suppressed HPGe detectors or fast LaBr3(Ce) scintillator detectors) together with a state of the art plunger device, ROSPHERE is a powerful tool for lifetime measurements using the Recoil Distance Doppler Shift (RDDS) and the in-beam Fast Electronic Scintillation Timing (FEST) methods. The array's geometry, detectors, electronics and data acquisition system are described. Selected results from the first experimental campaigns are also presented.

  20. Compound droplet manipulations on fiber arrays

    CERN Document Server

    Weyer, Floriane; Dreesen, Laurent; Vandewalle, Nicolas

    2015-01-01

    Recent works demonstrated that fiber arrays may constitue the basis of an open digital microfluidics. Various processes, such as droplet motion, fragmentation, trapping, release, mixing and encapsulation, may be achieved on fiber arrays. However, handling a large number of tiny droplets resulting from the mixing of several liquid components is still a challenge for developing microreactors, smart sensors or microemulsifying drugs. Here, we show that the manipulation of tiny droplets onto fiber networks allows for creating compound droplets with a high complexity level. Moreover, this cost-effective and flexible method may also be implemented with optical fibers in order to develop fluorescence-based biosensor.

  1. Parasitic antenna arrays for wireless MIMO systems

    CERN Document Server

    Kanatas, Athanasios; Papadias, Constantinos

    2014-01-01

    This  book covers a cross-section of two technologies: parasitic antenna arrays driven via analogue circuits; and MIMO technology for multi-antenna arrays.  The combination of these two technologies results in novel functionality. Relevant technical angles, ranging from theoretic to electromagnetic considerations; from analogue circuit to digital baseband control for signal generation; and from channel modeling to communication theoretic aspects are detailed by the contributors. Potential applications are considered in conjunction with current and upcoming wireless standards is provided.

  2. Acetylcholine molecular arrays enable quantum information processing

    Science.gov (United States)

    Tamulis, Arvydas; Majauskaite, Kristina; Talaikis, Martynas; Zborowski, Krzysztof; Kairys, Visvaldas

    2017-09-01

    We have found self-assembly of four neurotransmitter acetylcholine (ACh) molecular complexes in a water molecules environment by using geometry optimization with DFT B97d method. These complexes organizes to regular arrays of ACh molecules possessing electronic spins, i.e. quantum information bits. These spin arrays could potentially be controlled by the application of a non-uniform external magnetic field. The proper sequence of resonant electromagnetic pulses would then drive all the spin groups into the 3-spin entangled state and proceed large scale quantum information bits.

  3. Demonstration of transparent solar array module design

    Science.gov (United States)

    Pack, G. J.

    1984-01-01

    This report discusses the design, development, fabrication and testing of IR transparent solar array modules. Three modules, consisting of a baseline design using back surface reflector cells, and two modules using gridded back contact, IR transparent cells, were subjected to vacuum thermal balance testing to verify analytical predictions of lower operating emperature and increased efficiency. As a result of this test program, LMSC has verified that a significant degree of IR transparency can be designed into a flexible solar array. Test data correlates with both steady state and transient thermal analysis.

  4. Standard guide for digital detector array radiology

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This standard is a user guide, which is intended to serve as a tutorial for selection and use of various digital detector array systems nominally composed of the detector array and an imaging system to perform digital radiography. This guide also serves as an in-detail reference for the following standards: Practices E2597, , and E2737. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  5. Dynamic Associations in Nonlinear Computing Arrays

    Science.gov (United States)

    Huberman, B. A.; Hogg, T.

    1985-10-01

    We experimentally show that nonlinear parallel arrays can be made to compute with attractors. This leads to fast adaptive behavior in which dynamical associations can be made between different inputs which initially produce sharply distinct outputs. We first define a set of simple local procedures which allow a general computing structure to change its state in time so as to produce classical Pavlovian conditioning. We then examine the dynamics of coalescence and dissociation of attractors with a number of quantitative experiments. We also show how such arrays exhibit generalization and differentiation of inputs in their behavior.

  6. An LTCC 94 GHz Antenna Array

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre, J; Pao, H; Lin, H; Garland, P; O' Neill, D; Horton, K

    2007-12-21

    An antenna array is designed in low-temperature cofired ceramic (LTCC) Ferro A6M{trademark} for a mm-wave application. The antenna is designed to operate at 94 GHz with a few percent bandwidth. A key manufacturing technology is the use of 3 mil diameter vias on a 6 mil pitch to construct the laminated waveguides that form the beamforming network and radiating elements. Measurements for loss in the laminated waveguide are presented. The slot-fed cavity-radiating element is designed to account for extremely tight mutual coupling between elements. The array incorporates a slot-fed multi-layer beamforming network.

  7. The Cherenkov Telescope Array Large Size Telescope

    CERN Document Server

    Ambrosi, G; Baba, H; Bamba, A; Barceló, M; de Almeida, U Barres; Barrio, J A; Bigas, O Blanch; Boix, J; Brunetti, L; Carmona, E; Chabanne, E; Chikawa, M; Colin, P; Conteras, J L; Cortina, J; Dazzi, F; Deangelis, A; Deleglise, G; Delgado, C; Díaz, C; Dubois, F; Fiasson, A; Fink, D; Fouque, N; Freixas, L; Fruck, C; Gadola, A; García, R; Gascon, D; Geffroy, N; Giglietto, N; Giordano, F; Grañena, F; Gunji, S; Hagiwara, R; Hamer, N; Hanabata, Y; Hassan, T; Hatanaka, K; Haubold, T; Hayashida, M; Hermel, R; Herranz, D; Hirotani, K; Inoue, S; Inoue, Y; Ioka, K; Jablonski, C; Kagaya, M; Katagiri, H; Kishimoto, T; Kodani, K; Kohri, K; Konno, Y; Koyama, S; Kubo, H; Kushida, J; Lamanna, G; Flour, T Le; López-Moya, M; López, R; Lorenz, E; Majumdar, P; Manalaysay, A; Mariotti, M; Martínez, G; Martínez, M; Mazin, D; Miranda, J M; Mirzoyan, R; Monteiro, I; Moralejo, A; Murase, K; Nagataki, S; Nakajima, D; Nakamori, T; Nishijima, K; Noda, K; Nozato, A; Ohira, Y; Ohishi, M; Ohoka, H; Okumura, A; Orito, R; Panazol, J L; Paneque, D; Paoletti, R; Paredes, J M; Pauletta, G; Podkladkin, S; Prast, J; Rando, R; Reimann, O; Ribó, M; Rosier-Lees, S; Saito, K; Saito, T; Saito, Y; Sakaki, N; Sakonaka, R; Sanuy, A; Sasaki, H; Sawada, M; Scalzotto, V; Schultz, S; Schweizer, T; Shibata, T; Shu, S; Sieiro, J; Stamatescu, V; Steiner, S; Straumann, U; Sugawara, R; Tajima, H; Takami, H; Tanaka, S; Tanaka, M; Tejedor, L A; Terada, Y; Teshima, M; Totani, T; Ueno, H; Umehara, K; Vollhardt, A; Wagner, R; Wetteskind, H; Yamamoto, T; Yamazaki, R; Yoshida, A; Yoshida, T; Yoshikoshi, T

    2013-01-01

    The two arrays of the Very High Energy gamma-ray observatory Cherenkov Telescope Array (CTA) will include four Large Size Telescopes (LSTs) each with a 23 m diameter dish and 28 m focal distance. These telescopes will enable CTA to achieve a low-energy threshold of 20 GeV, which is critical for important studies in astrophysics, astroparticle physics and cosmology. This work presents the key specifications and performance of the current LST design in the light of the CTA scientific objectives.

  8. Future of phased array radar systems

    Science.gov (United States)

    Bassyouni, Ahmed

    2011-12-01

    This paper spots the light on the future progress of phased array radar systems, presenting two innovative examples on the directions of development. The first example starts with the classic radar range equation to develop the topology of what is called a "Mobile Adaptive Digital Array Radar" (MADAR) system. The second example discusses the possibility to achieve what is called "Entangled Photonic Radar" (EPR) system. The EPR quantum range equation is derived and compared to the classic one to compare the performance. Block diagrams and analysis for both proposed systems are presented.

  9. Fabrication of Polypyrrole Nanowire and Nanotube Arrays

    Directory of Open Access Journals (Sweden)

    Hong Wang

    2005-04-01

    Full Text Available Large area highly uniform and ordered polypyrrole nanowire and nanotubearrays were fabricated by chemical oxidation polymerization with the help of a porousanodic aluminium oxide (AAO template. Under 0.2 moL/L pyrrole (H2O and 0.2 moL/LFeCl3 (H2O pattern, polypyrrole nanowire arrays were obtained after 2.0 hourspolymerization reaction in a two-compartment reaction cell. When the reaction wasstopped after 15 minutes, polypyrrole nanotube arrays have been formed. The diameter,length and density of compositive nanowires and nanotubes could be controlled byparameters of AAO template.

  10. Miniature Sensor Node with Conformal Phased Array

    Directory of Open Access Journals (Sweden)

    W. De Raedt

    2011-12-01

    Full Text Available This paper reports on the design and fabrication of a fully integrated antenna beam steering concept for wireless sensor nodes. The conformal array circumcises four cube faces with a silicon core mounted on each face. Every silicon core represents a 2 by 1 antenna array with an antenna element consisting of a dipole antenna, a balun, and a distributed MEMS phase shifter. All these components are based on a single wafer process and designed to work at 17.2 GHz. Simulations of the entire system and first results of individual devices are reported.

  11. High-resolution SNP array analysis of patients with developmental disorder and normal array CGH results

    Directory of Open Access Journals (Sweden)

    Siggberg Linda

    2012-09-01

    Full Text Available Abstract Background Diagnostic analysis of patients with developmental disorders has improved over recent years largely due to the use of microarray technology. Array methods that facilitate copy number analysis have enabled the diagnosis of up to 20% more patients with previously normal karyotyping results. A substantial number of patients remain undiagnosed, however. Methods and Results Using the Genome-Wide Human SNP array 6.0, we analyzed 35 patients with a developmental disorder of unknown cause and normal array comparative genomic hybridization (array CGH results, in order to characterize previously undefined genomic aberrations. We detected no seemingly pathogenic copy number aberrations. Most of the vast amount of data produced by the array was polymorphic and non-informative. Filtering of this data, based on copy number variant (CNV population frequencies as well as phenotypically relevant genes, enabled pinpointing regions of allelic homozygosity that included candidate genes correlating to the phenotypic features in four patients, but results could not be confirmed. Conclusions In this study, the use of an ultra high-resolution SNP array did not contribute to further diagnose patients with developmental disorders of unknown cause. The statistical power of these results is limited by the small size of the patient cohort, and interpretation of these negative results can only be applied to the patients studied here. We present the results of our study and the recurrence of clustered allelic homozygosity present in this material, as detected by the SNP 6.0 array.

  12. Field computation for two-dimensional array transducers with limited diffraction array beams.

    Science.gov (United States)

    Lu, Jian-Yu; Cheng, Jiqi

    2005-10-01

    A method is developed for calculating fields produced with a two-dimensional (2D) array transducer. This method decomposes an arbitrary 2D aperture weighting function into a set of limited diffraction array beams. Using the analytical expressions of limited diffraction beams, arbitrary continuous wave (cw) or pulse wave (pw) fields of 2D arrays can be obtained with a simple superposition of these beams. In addition, this method can be simplified and applied to a 1D array transducer of a finite or infinite elevation height. For beams produced with axially symmetric aperture weighting functions, this method can be reduced to the Fourier-Bessel method studied previously where an annular array transducer can be used. The advantage of the method is that it is accurate and computationally efficient, especially in regions that are not far from the surface of the transducer (near field), where it is important for medical imaging. Both computer simulations and a synthetic array experiment are carried out to verify the method. Results (Bessel beam, focused Gaussian beam, X wave and asymmetric array beams) show that the method is accurate as compared to that using the Rayleigh-Sommerfeld diffraction formula and agrees well with the experiment.

  13. Wind loads on flat plate photovoltaic array fields

    Science.gov (United States)

    Miller, R. D.; Zimmerman, D. K.

    1981-01-01

    The results of an experimental analysis (boundary layer wind tunnel test) of the aerodynamic forces resulting from winds acting on flat plate photovoltaic arrays are presented. Local pressure coefficient distributions and normal force coefficients on the arrays are shown and compared to theoretical results. Parameters that were varied when determining the aerodynamic forces included tilt angle, array separation, ground clearance, protective wind barriers, and the effect of the wind velocity profile. Recommended design wind forces and pressures are presented, which envelop the test results for winds perpendicular to the array's longitudinal axis. This wind direction produces the maximum wind loads on the arrays except at the array edge where oblique winds produce larger edge pressure loads. The arrays located at the outer boundary of an array field have a protective influence on the interior arrays of the field. A significant decrease of the array wind loads were recorded in the wind tunnel test on array panels located behind a fence and/or interior to the array field compared to the arrays on the boundary and unprotected from the wind. The magnitude of this decrease was the same whether caused by a fence or upwind arrays.

  14. Parallel Syntheses of Peptides on Teflon-Patterned Paper Arrays (SyntArrays).

    Science.gov (United States)

    Deiss, Frédérique; Yang, Yang; Derda, Ratmir

    2016-01-01

    Screening of peptides to find the ligands that bind to specific targets is an important step in drug discovery. These high-throughput screens require large number of structural variants of peptides to be synthesized and tested. This chapter describes the generation of arrays of peptides on Teflon-patterned sheets of paper. First, the protocol describes the patterning of paper with a Teflon solution to produce arrays with solvophobic barriers that are able to confine organic solvents. Next, we describe the parallel syntheses of 96 peptides on Teflon-patterned arrays using the SPOT synthesis method.

  15. Neutron generator for the array borehole logging

    Institute of Scientific and Technical Information of China (English)

    LuHong-Bo; ZhongZhen-Qian; 等

    1998-01-01

    The performance mechanism of the array neutron generator to be used to porosity logging is presented.The neutron generator utilizes a drive-in target ceramic neutron tube,which cursts nerutron with fast-slow period selectively pressure.Regulation of the neutron tube is accomplished by pulse width modulation.The high voltage power supply is poerated at optimum frequency.

  16. Design of a Novel MEMS Gyroscope Array

    Directory of Open Access Journals (Sweden)

    Feng Sun

    2013-01-01

    Full Text Available This paper reports a novel four degree-of-freedom (DOF MEMS vibratory gyroscope. A MEMS gyroscope array is then presented using the novel gyroscope unit. In the design of the proposed 4-DOF MEMS vibratory gyroscope, the elements of the drive-mode are set inside the whole gyroscope architecture, and the elements of sense-mode are set around the drive-mode, which thus makes it possible to combine several gyroscope units into a gyroscope array through sense-modes of all the units. The complete 2-DOF vibratory structure is utilized in both the drive-mode and sense-mode of the gyroscope unit, thereby providing the desired bandwidth and inherent robustness. The gyroscope array combines several gyroscope units by using the unique detection mass, which will increase the gain of sense-mode and improve the sensitivity of the system. The simulation results demonstrate that, compared to a single gyroscope unit, the gain of gyroscope array (n = 6 is increased by about 8 dB; a 3 dB bandwidth of 100 Hz in sense-mode and 190 Hz in drive-mode are also provided. The bandwidths of both modes are highly matched with each other, providing a bandwidth of 100 Hz for the entire system, thus illustrating that it could satisfy the requirements in practical applications.

  17. Design of a novel MEMS gyroscope array.

    Science.gov (United States)

    Wang, Wei; Lv, Xiaoyong; Sun, Feng

    2013-01-28

    This paper reports a novel four degree-of-freedom (DOF) MEMS vibratory gyroscope. A MEMS gyroscope array is then presented using the novel gyroscope unit. In the design of the proposed 4-DOF MEMS vibratory gyroscope, the elements of the drive-mode are set inside the whole gyroscope architecture, and the elements of sense-mode are set around the drive-mode, which thus makes it possible to combine several gyroscope units into a gyroscope array through sense-modes of all the units. The complete 2-DOF vibratory structure is utilized in both the drive-mode and sense-mode of the gyroscope unit, thereby providing the desired bandwidth and inherent robustness. The gyroscope array combines several gyroscope units by using the unique detection mass, which will increase the gain of sense-mode and improve the sensitivity of the system. The simulation results demonstrate that, compared to a single gyroscope unit, the gain of gyroscope array (n = 6) is increased by about 8 dB; a 3 dB bandwidth of 100 Hz in sense-mode and 190 Hz in drive-mode are also provided. The bandwidths of both modes are highly matched with each other, providing a bandwidth of 100 Hz for the entire system, thus illustrating that it could satisfy the requirements in practical applications.

  18. EAS selection in the EMMA underground array

    DEFF Research Database (Denmark)

    Sarkamo, J.; Bezrukov, L.; Enqvist, T.

    2013-01-01

    The first measurements of the Experiment with MultiMuon Array (EMMA) have been analyzed for the selection of the Extensive Air Showers (EAS). Test data were recorded with an underground muon tracking station and a satellite station separated laterally by 10 metres. Events with tracks distributed...

  19. Analysis of Circular Arrays on Cylindrical Surfaces

    NARCIS (Netherlands)

    Gerini, G.; Guglielmi, M.; Rozzi, T.; Zappelli, L.

    2000-01-01

    The analysis of conformal arrays has been deeply developed and many authors have proposed either simplified models, based on single mode theory [1]-[4] or more accurate models but at the cost of a long computation time[5]. In this contribution we use the Multimode Equivalent Network (MEN) formulatio

  20. Design & fabrication of cantilever array biosensors

    DEFF Research Database (Denmark)

    Boisen, Anja; Thundat, T

    2009-01-01

    Surface immobilization of functional receptors on microfabricated cantilever arrays offers a new paradigm for the development of biosensors based on nanomechanics. Microcantilever-based systems are capable of real-time, multiplexed detection of unlabeled disease markers in extremely small volumes...

  1. The Neel IRAM KID Arrays (NIKA)

    NARCIS (Netherlands)

    Monfardini, A.; Benoit, A.; Bideaud, A.; Boudou, N.; Calvo, M.; Camus, P.; Hoffmann, C.; Desert, F. -X.; Leclercq, S.; Roesch, M.; Schuster, K.; Ade, P.; Doyle, S.; Mauskopf, P.; Pascale, E.; Tucker, C.; Bourrion, A.; Macias-Perez, J.; Vescovi, C.; Barishev, A.; Baselmans, J.; Ferrari, L.; Yates, S. J. C.; Cruciani, A.; De Bernardis, P.; Masi, S.; Giordano, C.; Marghesin, B.; Leduc, H. G.; Swenson, L.

    We are developing an instrument based on Kinetic Inductance Detectors (KID) known as the N,el IRAM KID Array (NIKA). Leveraging the experience gained from the first generation NIKA in 2009, an improved, dual-band (150 GHz and 240 GHz) instrument has been designed and tested at the Institut of

  2. Synthesis Array Topology Metrics in Location Characterization

    Science.gov (United States)

    Shanmugha Sundaram, GA

    2015-08-01

    Towards addressing some of the fundamental mysteries in physics at the micro- and macro-cosm level, that form the Key Science Projects (KSPs) for the Square Kilometer Array (SKA; such as Probing the Dark Ages and the Epoch of Reionization in the course of an Evolving Universe; Galaxy Evolution, Cosmology, and Dark Energy; and the Origin and evolution of Cosmic Magnetism) a suitable interfacing of these goals has to be achieved with its optimally designed array configuration, by means of a critical evaluation of the radio imagingcapabilities and metrics. Of the two forerunner sites, viz. Australia and South Africa, where pioneering advancements to state-of-the-art in synthesis array radio astronomy instrumentation are being attempted in the form of pathfinders to the SKA, for its eventual deployment, a diversity of site-dependent topology and design metrics exists. Here, the particular discussion involves those KSPs that relate to galactic morphology and evolution, and explores their suitability as a scientific research goal from the prespective of the location-driven instrument design specification. Relative merits and adaptability with regard to either site shall be presented from invoking well-founded and established array-design and optimization principles designed into a customized software tool.

  3. Synthesis of Phased Cylindrical Arc Antenna Arrays

    Directory of Open Access Journals (Sweden)

    Hussein Rammal

    2009-01-01

    Full Text Available This paper describes a new approach to synthesize cylindrical antenna arrays controlled by the phase excitation, to synthesize directive lobe and multilobe patterns with steered zero. The proposed method is based on iterative minimization of a function that incorporates constraints imposed in each direction. An 8-element cylindrical antenna has been simulated and tested for various types of beam configurations.

  4. Ultrawideband Dipole, Monopole, and Loop Arrays

    Science.gov (United States)

    2017-04-24

    Fenn, PhD, Senior Staff, RF Technology Group, Advanced Technology Division, Lincoln Laboratory, Massachusetts Institute of Technology, Lexington...of external interference (noise), reduction of vehicle scattering effects, and increasing the antenna gain in the direction of the ground...attached to a vehicle. Furthermore, the wavguide supports the array antenna elements, feed cables, RF switching or beamforming network, and protective

  5. Sunflower Array Antenna with Adjustable Density Taper

    NARCIS (Netherlands)

    Viganó, M.C.; Toso, G.; Caille, G.; Mangenot, C.; Lager, I.E.

    2009-01-01

    A deterministic procedure to design a nonperiodic planar array radiating a rotationally symmetric pencil beam pattern with an adjustable sidelobe level is proposed. The elements positions are derived by modifying the peculiar locations of the sunflower seeds in such a way that the corresponding spat

  6. Catalytic enantioselective synthesis of vicinal dialkyl arrays

    NARCIS (Netherlands)

    van Zijl, Anthoni W.; Szymanski, Wiktor; Lopez, Ferrnando; Minnaard, Adriaan J.; Feringa, Ben L.

    2008-01-01

    With a consecutive "asymmetric allylic alkylation (AAA)/cross-metathesis (CM)/conjugate addition (CA)" protocol it is possible to synthesize either stereoisomer of compounds containing a vicinal dialkyl array with excellent stereoselectivity. The versatility of this protocol in natural product synth

  7. Ultrasonic fingerprinting by phased array transducer

    Science.gov (United States)

    Sednev, D.; Kataeva, O.; Abramets, V.; Pushenko, P.; Tverdokhlebova, T.

    2016-06-01

    Increasing quantity of spent nuclear fuel that must be under national and international control requires a novel approach to safeguard techniques and equipment. One of the proposed approaches is utilize intrinsic features of casks with spent fuel. In this article an application of a phased array ultrasonic method is considered. This study describes an experimental results on ultrasonic fingerprinting of austenitic steel seam weld.

  8. Ultrasonic fingerprinting by phased array transducer

    OpenAIRE

    Sednev, Dmitry Andreevich; Kataeva, O.; Abramets, V.; Pushenko, P.; Tverdokhlebova, T.

    2016-01-01

    Increasing quantity of spent nuclear fuel that must be under national and international control requires a novel approach to safeguard techniques and equipment. One of the proposed approaches is utilize intrinsic features of casks with spent fuel. In this article an application of a phased array ultrasonic method is considered. This study describes an experimental results on ultrasonic fingerprinting of austenitic steel seam weld.

  9. Titania nanotube array based photovoltaic cells

    Science.gov (United States)

    Yip, C. T.; Cheung, K. Y.; Djurišić, A. B.; Chan, W. K.

    2007-09-01

    It has been shown that dye sensitized solar cells (DSSCs) based on porous titanium dioxide (titania) layers have efficiencies exceeding 10%. Although porous structure has the advantage of large surface area for light harvesting, electron transport through the random nanoparticle network forming a porous film results in electron mobilities which are two orders of magnitude lower compared to the single crystal materials. Therefore, considerable efforts have been made to fabricate DSSC based on one dimensional nanostructures, such as nanowires or nanotubes. Titania nanotube arrays are typically made by anodization of titanium, followed by annealing to improve crystallinity. In this work, we investigated the influence of annealing temperature and annealing atmosphere on the crystal structure, the electron transport, and the solar cell performance of titania nanotube arrays. The titania nanotube arrays were prepared from electrochemically anodized titanium foils and their morphology and crystal structure were characterized by scanning electron microscopy and transmission electron microscopy. The crystal phases and the compositions of nanotube arrays were further investigated by X-ray diffraction for different annealing temperatures and X-ray photoelectron spectroscopy for different annealing atmospheres. For optimal annealing conditions, the short circuit current density of 4.27 mA/cm2 and power conversion efficiency of 1.30% could be achieved under AM 1.5 simulated solar irradiation for 2 μm long nanotubes.

  10. ISPA (imaging silicon pixel array) experiment

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    On the table, under the scrutiny of some collaboration members, an ISPA tube (upper-left of the table) with some of its application components is shown: they consist of the CERN-developed anode chip, special windows for gamma and x-ray detection, scintillating crystal and fibre arrays for imaging and tracking of ionizing particles.

  11. Interleaved Array Antennas for FMCW Radar Applications

    NARCIS (Netherlands)

    Lager, I.E.; Trampuz, C.; Simeoni, M.; Ligthart, L.P.

    2009-01-01

    An effective and robust strategy for concurrently designing the transmit and receive antennas of a frequency-modulated, continuos-wave radar is discussed. The aperture architecture is based on the use of non-periodic, interleaved sub-arrays. Deterministic element placement is employed for ensuring d

  12. Analysis of Circular Arrays on Cylindrical Surfaces

    NARCIS (Netherlands)

    Gerini, G.; Guglielmi, M.; Rozzi, T.; Zappelli, L.

    2000-01-01

    The analysis of conformal arrays has been deeply developed and many authors have proposed either simplified models, based on single mode theory [1]-[4] or more accurate models but at the cost of a long computation time[5]. In this contribution we use the Multimode Equivalent Network (MEN)

  13. A Large Scale Virtual Gas Sensor Array

    Science.gov (United States)

    Ziyatdinov, Andrey; Fernández-Diaz, Eduard; Chaudry, A.; Marco, Santiago; Persaud, Krishna; Perera, Alexandre

    2011-09-01

    This paper depicts a virtual sensor array that allows the user to generate gas sensor synthetic data while controlling a wide variety of the characteristics of the sensor array response: arbitrary number of sensors, support for multi-component gas mixtures and full control of the noise in the system such as sensor drift or sensor aging. The artificial sensor array response is inspired on the response of 17 polymeric sensors for three analytes during 7 month. The main trends in the synthetic gas sensor array, such as sensitivity, diversity, drift and sensor noise, are user controlled. Sensor sensitivity is modeled by an optionally linear or nonlinear method (spline based). The toolbox on data generation is implemented in open source R language for statistical computing and can be freely accessed as an educational resource or benchmarking reference. The software package permits the design of scenarios with a very large number of sensors (over 10000 sensels), which are employed in the test and benchmarking of neuromorphic models in the Bio-ICT European project NEUROCHEM.

  14. Optical interconnections to focal plane arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rienstra, J.L.; Hinckley, M.K.

    2000-11-01

    The authors have successfully demonstrated an optical data interconnection from the output of a focal plane array to the downstream data acquisition electronics. The demonstrated approach included a continuous wave laser beam directed at a multiple quantum well reflectance modulator connected to the focal plane array analog output. The output waveform from the optical interconnect was observed on an oscilloscope to be a replica of the input signal. They fed the output of the optical data link to the same data acquisition system used to characterize focal plane array performance. Measurements of the signal to noise ratio at the input and output of the optical interconnection showed that the signal to noise ratio was reduced by a factor of 10 or more. Analysis of the noise and link gain showed that the primary contributors to the additional noise were laser intensity noise and photodetector receiver noise. Subsequent efforts should be able to reduce these noise sources considerably and should result in substantially improved signal to noise performance. They also observed significant photocurrent generation in the reflectance modulator that imposes a current load on the focal plane array output amplifier. This current loading is an issue with the demonstrated approach because it tends to negate the power saving feature of the reflectance modulator interconnection concept.

  15. Self-assembled biomimetic superhydrophobic hierarchical arrays.

    Science.gov (United States)

    Yang, Hongta; Dou, Xuan; Fang, Yin; Jiang, Peng

    2013-09-01

    Here, we report a simple and inexpensive bottom-up technology for fabricating superhydrophobic coatings with hierarchical micro-/nano-structures, which are inspired by the binary periodic structure found on the superhydrophobic compound eyes of some insects (e.g., mosquitoes and moths). Binary colloidal arrays consisting of exemplary large (4 and 30 μm) and small (300 nm) silica spheres are first assembled by a scalable Langmuir-Blodgett (LB) technology in a layer-by-layer manner. After surface modification with fluorosilanes, the self-assembled hierarchical particle arrays become superhydrophobic with an apparent water contact angle (CA) larger than 150°. The throughput of the resulting superhydrophobic coatings with hierarchical structures can be significantly improved by templating the binary periodic structures of the LB-assembled colloidal arrays into UV-curable fluoropolymers by a soft lithography approach. Superhydrophobic perfluoroether acrylate hierarchical arrays with large CAs and small CA hysteresis can be faithfully replicated onto various substrates. Both experiments and theoretical calculations based on the Cassie's dewetting model demonstrate the importance of the hierarchical structure in achieving the final superhydrophobic surface states. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Titania nanotube arrays: Interfaces for implantable devices

    Science.gov (United States)

    Smith, Barbara Symie

    For the 8--10% of Americans (20--25 million people) that have implanted biomedical devices, biomaterial failure and the need for revision surgery are critical concerns. The major causes for failure in implantable biomedical devices promoting a need for re-implantation and revision surgery include thrombosis, post-operative infection, immune driven fibrosis and biomechanical failure. The successful integration of long-term implantable devices is highly dependent on the early events of tissue/biomaterial interaction, promoting either implant rejection or a wound healing response (extracellular matrix production and vasculature). Favorable interactions between the implant surface and the respective tissue are critical for the long-term success of any implantable device. Recent studies have shown that material surfaces which mimic the natural physiological hierarchy of in vivo tissue may provide a possible solution for enhancing biomaterial integration, thus preventing infection and biomaterial rejection. Titania nanotube arrays, fabricated using a simple anodization technique, provide a template capable of promoting altered cellular functionality at a hierarchy similar to that of natural tissue. This work focuses on the fabrication of immobilized, vertically oriented and highly uniform titania nanotube arrays to determine how this specific nano-architecture affects skin cell functionality, hemocompatibility, thrombogenicity and the immune response. The results in this work identify enhanced dermal matrix production, altered hemocompatibility, reduced thrombogenicity and a deterred immune response on titania nanotube arrays. This evidences promising implications with respect to the use of titania nanotube arrays as beneficial interfaces for the successful implantation of biomedical devices.

  17. Juno Microwave Radiometer Patch Array Antennas

    Science.gov (United States)

    Chamberlain, N.; Chen, J.; Focardi, P.; Hodges, R.; Hughes, R.; Jakoboski, J.; Venkatesan, J.; Zawadzki, M.

    2009-01-01

    Juno is a mission in the NASA New Frontiers Program with the goal of significantly improving our understanding of the formation and structure of Jupiter. This paper discusses the modeling and measurement of the two patch array antennas. An overview of the antenna architecture, design and development at JPL is provided, along with estimates of performance and the results of measurements.

  18. The Future of Pulsar Timing Arrays

    Science.gov (United States)

    Stappers, B. W.

    Significant advances have been made in the sensitivity of pulsar timing arrays for the detection of gravitational waves in the last decade. This presentation looked forward to consider where the development of pulsar timing arrays might go as we head towards the Square Kilometre Array (SKA) and then beyond. I reviewed where progress needs to be made in terms of sensitivity to gravitational waves, including improvements to existing observing approaches and new telescopes such as MeerKAT and FAST and techniques like LEAP. The dramatic increase in the number of millisecond pulsars is presented and how that might affect progress towards a first detection is discussed. Developments in analytic techniques were also discussed, including the removal of interstellar medium effects, red noise and pulse profile variations. A summary of how the SKA can contribute through an increased millisecond pulsar population and pulsar timing sensitivity was presented. With the likelihood that the SKA will implement some form of Key Science Project approach, some ideas of how will this affect how the International Pulsar Timing Array effort and how it might evolve into a KSP were discussed.

  19. Parallel Array Classes and Lightweight Sharing Mechanisms

    Directory of Open Access Journals (Sweden)

    Steve W. Otto

    1993-01-01

    Full Text Available We discuss a set of parallel array classes, MetaMP, for distributed-memory architectures. The classes are implemented in C++ and interface to the PVM or Intel NX message-passing systems. An array class implements a partitioned array as a set of objects distributed across the nodes – a "collective" object. Object methods hide the low-level message-passing and implement meaningful array operations. These include transparent guard strips (or sharing regions that support finite-difference stencils, reductions and multibroadcasts for support of pivoting and row operations, and interpolation/contraction operations for support of multigrid algorithms. The concept of guard strips is generalized to an object implementation of lightweight sharing mechanisms for finite element method (FEM and particle-in-cell (PIC algorithms. The sharing is accomplished through the mechanism of weak memory coherence and can be efficiently implemented. The price of the efficient implementation is memory usage and the need to explicitly specify the coherence operations. An intriguing feature of this programming model is that it maps well to both distributed-memory and shared-memory architectures.

  20. Self imaging in segmented waveguide arrays

    Science.gov (United States)

    Heinrich, Matthias; Szameit, Alexander; Dreisow, Felix; Pertsch, Thomas; Nolte, Stefan; Tünnermann, Andreas; Suran, Eric; Louradour, Frédéric; Bathélémy, Alain; Longhi, Stefano

    2009-02-01

    Self-imaging in integrated optical devices is interesting for many applications including image transmission, optical collimation and even reshaping of ultrashort laser pulses. However, in general this relies on boundary-free light propagation, since interaction with boundaries results in a considerable distortion of the self-imaging effect. This problem can be overcome in waveguide arrays by segmentation of particular lattice sites, yielding phase shifts which result in image reconstruction in one- as well as two-dimensional configurations. Here, we demonstrate the first experimental realization of this concept. For the fabrication of the segmented waveguide arrays we used the femtosecond laser direct-writing technique. The total length of the arrays is 50mm with a waveguide spacing of 16 μm and 20μm in the one- and two-dimensional case, respectively. The length of the segmented area was 2.6mm, while the segmentation period was chosen to be 16 μm. This results in a complete inversion of the global phase of the travelling field inside the array, so that the evolution dynamics are reversed and the input field is imaged onto the sample output facet. Accordingly, segmented integrated optical devices provide a new and attractive opportunity for image transmission in finite systems.

  1. DETECTION OF BACTERIAL TOXINS WITH MONOSACCHARIDE ARRAYS

    Science.gov (United States)

    Ngundi, Miriam M.; Taitt, Chris R.; McMurry, Scott A.; Kahne, Daniel; Ligler, Frances S.

    2006-01-01

    A large number of bacterial toxins, viruses and bacteria target carbohydrate derivatives on the cell surface to attach to and gain entry into the cell. We report here the use of a monosaccharide-based array to detect protein toxins. The array-based technique provides the capability to perform simultaneous multianalyte analyses. Arrays of N-acetyl galactosamine (GalNAc) and N-acetylneuraminic acid (Neu5Ac) derivatives were immobilized on the surface of a planar waveguide and were used as receptors for protein toxins. These arrays were probed with fluorescently labeled bacterial cells and protein toxins. While Salmonella typhimurium, Listeria monocytogenes, Escherichia coli and staphylococcal enterotoxin B (SEB) did not bind to either of the monosaccharides, both cholera toxin and tetanus toxin bound to GalNAc and Neu5Ac. The results show that the binding of the toxins to the carbohydrates is density dependent and semi-selective. Both toxins were detectable at 100 ng/ml. PMID:15946840

  2. Retina projection using curved lens arrays

    Science.gov (United States)

    Yen, Hao-Ren; Su, Guo-Dung J.

    2016-09-01

    In this paper, we propose a multi-channel imaging system which combines the principles of an insect's compound eye and optical cluster eye. The system consists of two curved structure lens arrays with different pitches. Both of them have the same curvature and the radiuses of the lenses in the arrays are optimized to focus rays on the retina. The optical axes of different channels are tilted to each other in order to reduce the optical system volume and transmit a wide field of view. Each channel of an array of multiple optical system transfers only a part of the field of view. Each partial image passes through each channel and stitches together on the retina to reconstruct a complete image. In order to simulate the image stitching, we also build an eye model. The thickness from the panel to the last surface of lens group is less than 25mm. The panel size is designed to be 4 inch which is the scale of eyeglass. The system can provide a large field of view about 150 degrees which is much wider than the commercial products. By using the 3D printer, we can make a model of lens array to achieve our design.

  3. Piezoresistive Probe Array for High Throughput Applications

    NARCIS (Netherlands)

    Gaitas, A.; French, P.

    2011-01-01

    Microcantilevers are used in a number of applications including atomic-force microscopy (AFM). In this work, piezoresistive deflection-sensing elements are integrated onto micromachined cantilevers to increase sensitivity, and reduce complexity and cost. An array of probes with 5 nm gold ultrathin f

  4. Sparse acoustic imaging with a spherical array

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Xenaki, Angeliki

    2015-01-01

    proposes a plane wave expansion method based on measurements with a spherical microphone array, and solved in the framework provided by Compressed Sensing. The proposed methodology results in a sparse solution, i.e. few non-zero coefficients, and it is suitable for both source localization and sound field...

  5. Compressive sensing with a spherical microphone array

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Xenaki, Angeliki

    2016-01-01

    A wave expansion method is proposed in this work, based on measurements with a spherical microphone array, and formulated in the framework provided by Compressive Sensing. The method promotes sparse solutions via ‘1-norm minimization, so that the measured data are represented by few basis functions...

  6. Performance Analysis of Digital loudspeaker Arrays

    DEFF Research Database (Denmark)

    Pedersen, Bo Rohde; Kontomichos, Fotios; Mourjopoulos, John

    2008-01-01

    An analysis of digital loudspeaker arrays shows that the ways in which bits are mapped to the drivers influence the quality of the audio result. Specifically, a "bit-summed" rather than the traditional "bit-mapped" strategy greatly reduces the number of times drivers make binary transitions per p...

  7. High speed adaptive liquid microlens array

    NARCIS (Netherlands)

    Murade, C.U.; van den Ende, Henricus T.M.; Mugele, Friedrich Gunther

    2012-01-01

    Liquid microlenses are attractive for adaptive optics because they offer the potential for both high speed actuation and parallelization into large arrays. Yet, in conventional designs, resonances of the liquid and the complexity of driving mechanisms and/or the device architecture have hampered a

  8. SNP Array in Hematopoietic Neoplasms: A Review

    Directory of Open Access Journals (Sweden)

    Jinming Song

    2015-12-01

    Full Text Available Cytogenetic analysis is essential for the diagnosis and prognosis of hematopoietic neoplasms in current clinical practice. Many hematopoietic malignancies are characterized by structural chromosomal abnormalities such as specific translocations, inversions, deletions and/or numerical abnormalities that can be identified by karyotype analysis or fluorescence in situ hybridization (FISH studies. Single nucleotide polymorphism (SNP arrays offer high-resolution identification of copy number variants (CNVs and acquired copy-neutral loss of heterozygosity (LOH/uniparental disomy (UPD that are usually not identifiable by conventional cytogenetic analysis and FISH studies. As a result, SNP arrays have been increasingly applied to hematopoietic neoplasms to search for clinically-significant genetic abnormalities. A large numbers of CNVs and UPDs have been identified in a variety of hematopoietic neoplasms. CNVs detected by SNP array in some hematopoietic neoplasms are of prognostic significance. A few specific genes in the affected regions have been implicated in the pathogenesis and may be the targets for specific therapeutic agents in the future. In this review, we summarize the current findings of application of SNP arrays in a variety of hematopoietic malignancies with an emphasis on the clinically significant genetic variants.

  9. Phased array based ultrasound scanning system development

    Science.gov (United States)

    Sagdiev, R. K.; Denisov, E. S.; Evdokimov, Yu K.; Fazlyyyakhmatov, M. G.; Kashapov, N. F.

    2014-12-01

    Multichannel ultrasound scanning system based on phased arrays development is presented in this paper. Substantiation of system parameters is presented. The description of block diagram and hardware development is presented. The combination of the self-developed receiving and a transmitting units and commercially available FPGA unit and Personal Computer can solve our scientific goals, while providing a relatively low device cost.

  10. GaAs optoelectronic neuron arrays

    Science.gov (United States)

    Lin, Steven; Grot, Annette; Luo, Jiafu; Psaltis, Demetri

    1993-01-01

    A simple optoelectronic circuit integrated monolithically in GaAs to implement sigmoidal neuron responses is presented. The circuit integrates a light-emitting diode with one or two transistors and one or two photodetectors. The design considerations for building arrays with densities of up to 10,000/sq cm are discussed.

  11. Analysis of Circular Arrays on Cylindrical Surfaces

    NARCIS (Netherlands)

    Gerini, G.; Guglielmi, M.; Rozzi, T.; Zappelli, L.

    2000-01-01

    The analysis of conformal arrays has been deeply developed and many authors have proposed either simplified models, based on single mode theory [1]-[4] or more accurate models but at the cost of a long computation time[5]. In this contribution we use the Multimode Equivalent Network (MEN) formulatio

  12. Encapsulated thermopile detector array for IR microspectrometer

    NARCIS (Netherlands)

    Wu, H.; Emadi, A.; De Graaf, G.; Wolffenbuttel, R.F.

    2010-01-01

    The miniaturized IR spectrometer discussed in this paper is comprised of: slit, planar imaging diffraction grating and Thermo-Electric (TE) detector array, which is fabricated using CMOS compatible MEMS technology. The resolving power is maximized by spacing the TE elements at an as narrow as possib

  13. Computationally efficient optimisation algorithms for WECs arrays

    DEFF Research Database (Denmark)

    Ferri, Francesco

    2017-01-01

    In this paper two derivative-free global optimization algorithms are applied for the maximisation of the energy absorbed by wave energy converter (WEC) arrays. Wave energy is a large and mostly untapped source of energy that could have a key role in the future energy mix. The collection of this r...

  14. Phase calibration scheme for a ``T'' array

    Science.gov (United States)

    Ramesh, R.; Subramanian, K. R.; Sastry, Ch. V.

    1999-10-01

    A calibration scheme based on closure and redundancy techniques is described for correcting the phase errors in the complex visibilities observed with a T-shaped radio interferometer array. Practical details of the scheme are illustrated with reference to the Gauribidanur radioheliograph (GRH).

  15. CHAMP+: a powerful array receiver for APEX

    NARCIS (Netherlands)

    Kasemann, C.; Güsten, R.; Heyminck, S.; Klein, B.; Klein, T.; Philipp, S.D.; Korn, A.; Schneider, G.; Henseler, A.; Baryshev, A.; Klapwijk, T.M.

    2006-01-01

    CHAMP+, a dual-color 2 × 7 element heterodyne array for operation in the 450 μm and 350 μm atmospheric windows is under development. The instrument, which is currently undergoing final evaluation in the laboratories, will be deployed for commissioning at the APEX telescope in August this year. With

  16. Integration of spintronic interface for nanomagnetic arrays

    Directory of Open Access Journals (Sweden)

    Andrew Lyle

    2011-12-01

    Full Text Available An experimental demonstration utilizing a spintronic input/output (I/O interface for arrays of closely spaced nanomagnets is presented. The free layers of magnetic tunnel junctions (MTJs form dipole coupled nanomagnet arrays which can be applied to different contexts including Magnetic Quantum Cellular Automata (MQCA for logic applications and self-biased devices for field sensing applications. Dipole coupled nanomagnet arrays demonstrate adaptability to a variety of contexts due to the ability for tuning of magnetic response. Spintronics allows individual nanomagnets to be manipulated with spin transfer torque and monitored with magnetoresistance. This facilitates measurement of the magnetic coupling which is important for (yet to be demonstrated data propagation reliability studies. In addition, the same magnetic coupling can be tuned to reduce coercivity for field sensing. Dipole coupled nanomagnet arrays have the potential to be thousands of times more energy efficient than CMOS technology for logic applications, and they also have the potential to form multi-axis field sensors.

  17. CHAMP+: a powerful array receiver for APEX

    NARCIS (Netherlands)

    Kasemann, C.; Güsten, R.; Heyminck, S.; Klein, B.; Klein, T.; Philipp, S.D.; Korn, A.; Schneider, G.; Henseler, A.; Baryshev, A.; Klapwijk, T.M.

    2006-01-01

    CHAMP+, a dual-color 2 × 7 element heterodyne array for operation in the 450 μm and 350 μm atmospheric windows is under development. The instrument, which is currently undergoing final evaluation in the laboratories, will be deployed for commissioning at the APEX telescope in August this year. With

  18. The Neel IRAM KID Arrays (NIKA)

    NARCIS (Netherlands)

    Monfardini, A.; Benoit, A.; Bideaud, A.; Boudou, N.; Calvo, M.; Camus, P.; Hoffmann, C.; Desert, F. -X.; Leclercq, S.; Roesch, M.; Schuster, K.; Ade, P.; Doyle, S.; Mauskopf, P.; Pascale, E.; Tucker, C.; Bourrion, A.; Macias-Perez, J.; Vescovi, C.; Barishev, A.; Baselmans, J.; Ferrari, L.; Yates, S. J. C.; Cruciani, A.; De Bernardis, P.; Masi, S.; Giordano, C.; Marghesin, B.; Leduc, H. G.; Swenson, L.

    2012-01-01

    We are developing an instrument based on Kinetic Inductance Detectors (KID) known as the N,el IRAM KID Array (NIKA). Leveraging the experience gained from the first generation NIKA in 2009, an improved, dual-band (150 GHz and 240 GHz) instrument has been designed and tested at the Institut of RadioA

  19. Mesh Currents and Josephson Junction Arrays

    OpenAIRE

    1995-01-01

    A simple but accurate mesh current analysis is performed on a XY model and on a SIMF model to derive the equations for a Josephson junction array. The equations obtained here turn out to be different from other equations already existing in the literature. Moreover, it is shown that the two models come from an unique hidden structure

  20. Battery Charge Equalizer with Transformer Array

    Science.gov (United States)

    Davies, Francis

    2013-01-01

    High-power batteries generally consist of a series connection of many cells or cell banks. In order to maintain high performance over battery life, it is desirable to keep the state of charge of all the cell banks equal. A method provides individual charging for battery cells in a large, high-voltage battery array with a minimum number of transformers while maintaining reasonable efficiency. This is designed to augment a simple highcurrent charger that supplies the main charge energy. The innovation will form part of a larger battery charge system. It consists of a transformer array connected to the battery array through rectification and filtering circuits. The transformer array is connected to a drive circuit and a timing and control circuit that allow individual battery cells or cell banks to be charged. The timing circuit and control circuit connect to a charge controller that uses battery instrumentation to determine which battery bank to charge. It is important to note that the innovation can charge an individual cell bank at the same time that the main battery charger is charging the high-voltage battery. The fact that the battery cell banks are at a non-zero voltage, and that they are all at similar voltages, can be used to allow charging of individual cell banks. A set of transformers can be connected with secondary windings in series to make weighted sums of the voltages on the primaries.

  1. Laser Dazzling of Focal Plane Array Cameras

    NARCIS (Netherlands)

    Schleijpen, H.M.A.; Dimmeler, A.; Eberle, B; Heuvel, J.C. van den; Mieremet, A.L.; Bekman, H.H.P.T.; Mellier, B.

    2007-01-01

    Laser countermeasures against infrared focal plane array cameras aim to saturate the full camera image. In this paper we will discuss the results of dazzling experiments performed with MWIR lasers. In the “low energy” pulse regime we observe an increasing saturated area with increasing power. The si

  2. Adaptive and mobile ground sensor array.

    Energy Technology Data Exchange (ETDEWEB)

    Holzrichter, Michael Warren; O' Rourke, William T.; Zenner, Jennifer; Maish, Alexander B.

    2003-12-01

    The goal of this LDRD was to demonstrate the use of robotic vehicles for deploying and autonomously reconfiguring seismic and acoustic sensor arrays with high (centimeter) accuracy to obtain enhancement of our capability to locate and characterize remote targets. The capability to accurately place sensors and then retrieve and reconfigure them allows sensors to be placed in phased arrays in an initial monitoring configuration and then to be reconfigured in an array tuned to the specific frequencies and directions of the selected target. This report reviews the findings and accomplishments achieved during this three-year project. This project successfully demonstrated autonomous deployment and retrieval of a payload package with an accuracy of a few centimeters using differential global positioning system (GPS) signals. It developed an autonomous, multisensor, temporally aligned, radio-frequency communication and signal processing capability, and an array optimization algorithm, which was implemented on a digital signal processor (DSP). Additionally, the project converted the existing single-threaded, monolithic robotic vehicle control code into a multi-threaded, modular control architecture that enhances the reuse of control code in future projects.

  3. Wafer-Scale Integration of Systolic Arrays,

    Science.gov (United States)

    1985-10-01

    wafer-scale system, however, all the nearest neighbors of a processor may be dead, and thus the prime advantage of adopting a systolic array...work, however. To the best of our knowledge, the only result of a similar nature is due to Erdos and Renyi 15] who showed that most graphs with N

  4. Optimization of Borehole Heat Exchanger Arrays

    Science.gov (United States)

    Schulte, Daniel; Rühaak, Wolfram; Welsch, Bastian; Oladyshkin, Sergey; Sass, Ingo

    2016-04-01

    Arrays of borehole heat exchangers are an increasingly popular source for renewable energy. Furthermore, they can serve as borehole thermal energy storages for seasonally fluctuating heat sources like solar thermal energy or district heating grids. However, the uncertainty of geological parameters and the nonlinear behavior of the complex system make it difficult to simulate and predict the required design of borehole heat exchanger arrays. As a result, the arrays easily turn out to be over or undersized, which compromises the economic feasibility of these systems. Here, we present a novel optimization strategy for the design of borehole thermal energy storages. The arbitrary polynomial chaos expansion method is used to build a proxy model from a set of numerical training simulations, which allows for the consideration of parameter uncertainties. Thus, the resulting proxy model bypasses the problem of excessive computation time for the numerous function calls required for a mathematical optimization. Additionally, we iteratively refine the proxy model during the optimization procedure using additional numerical simulation runs. With the presented solution, many aspects of borehole heat exchanger arrays can be optimized under geological uncertainty.

  5. Synchronization law for a van der Pol array.

    Science.gov (United States)

    Peles, Slaven; Wiesenfeld, Kurt

    2003-08-01

    We explore the transition to in-phase synchronization in globally coupled oscillator arrays, and compare results for van der Pol arrays with Josephson junction arrays. Our approach yields in each case an analytically tractable iterative map; the resulting stability formulas are simple because the expansion procedure identifies natural parameter groups. A third example, an array of Duffing-van der Pol oscillators, is found to be of the same fundamental type as the van der Pol arrays, but the Josephson arrays are fundamentally different owing to the absence of self-resonant interactions.

  6. Sensors Array Technique for Monitoring Aluminum Alloy Spot Welding

    Institute of Scientific and Technical Information of China (English)

    王蕤; 罗震; 单平; 步贤政; 袁书现; 敖三三

    2010-01-01

    In this paper,the sensors array technique is applied to the quality detection of aluminum alloy spot welding.The sensors array has three forms,i.e.,linear magnetic sensors array,annular magnetic sensors array and cross magnetic sensors array.An algorithm based on principal component analysis is proposed to extract the signal eigenvalues.The three types of magnetic sensors array are used in the experiment of monitoring the signal.After the eigenvalues are extracted,they are used to build a relationship with ...

  7. The ADM-AEOLUS Solar Array

    Science.gov (United States)

    Riva, S.; Ferrando, E.; Contini, R.; Blok, R.; Heijden, R. vd; Caon, A.; Labruyere, G.; Strobl, G.; Koestler, W.; Zimmermann, W.

    2008-09-01

    ADM Aeolus is an Earth Explorer Core Mission of the European Space Agency (ESA). The satellite is provided with a deployable solar array fully equipped with European state of the art Triple Junction (TJ) GaAs solar cells.The structural part and mechanisms of the ADM Aeolus Solar Array (SA) is a derivate of the Dutch Space FRED solar array concept. This FRED type solar array has already been used on Jules Verne (Automated Transfer Vehicle) and Giove-A. Both satellites has been successfully launched and the Solar Arrays are working nominally.The ADM Aeolus spacecraft (S/C) is powered by two deployable wings. Each of them composed by three panels and with a panel size of 1.1×2.2 m2, so that the total area is about 14.5 m2;. European TJ solar cells (27% efficiency class) embodying an integral protection diode were selected to meet the power budget, necessary for the installed payload. The principal one is an Atmospheric LAser Doppler INstrument (ALADIN), a novel system whose development is a strategic goal for ESA.This SA program is a challenging development in terms of solar cell qualification because of the extensive characterisation and qualification campaign performed for the cell and the integral diode components. Especially for protection diode a long duration high temperature test was performed in order to simulate and cover all lifetime stresses.Main drivers for PVA design are the power requirement at the end of life and the requested protection against atomic oxygen erosion.This paper describes : The results achieved during the qualification phase, from bare cell level to the coupon level, The design activity, mainly focused on the prediction of EOL performances, The acceptance phase at panel levels, which has verified the suitability of the design assumption and manufacturing workmanship.

  8. ARRAYS OF BOTTLES OF PLUTONIUM NITRATE SOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Margaret A. Marshall

    2012-09-01

    In October and November of 1981 thirteen approaches-to-critical were performed on a remote split table machine (RSTM) in the Critical Mass Laboratory of Pacific Northwest Laboratory (PNL) in Richland, Washington using planar arrays of polyethylene bottles filled with plutonium (Pu) nitrate solution. Arrays of up to sixteen bottles were used to measure the critical number of bottles and critical array spacing with a tight fitting Plexiglas® reflector on all sides of the arrays except the top. Some experiments used Plexiglas shells fitted around each bottles to determine the effect of moderation on criticality. Each bottle contained approximately 2.4 L of Pu(NO3)4 solution with a Pu content of 105 g Pu/L and a free acid molarity H+ of 5.1. The plutonium was of low 240Pu (2.9 wt.%) content. These experiments were sponsored by Rockwell Hanford Operations because of the lack of experimental data on the criticality of arrays of bottles of Pu solution such as might be found in storage and handling at the Purex Facility at Hanford. The results of these experiments were used “to provide benchmark data to validate calculational codes used in criticality safety assessments of [the] plant configurations” (Ref. 1). Data for this evaluation were collected from the published report (Ref. 1), the approach to critical logbook, the experimenter’s logbook, and communication with the primary experimenter, B. Michael Durst. Of the 13 experiments preformed 10 were evaluated. One of the experiments was not evaluated because it had been thrown out by the experimenter, one was not evaluated because it was a repeat of another experiment and the third was not evaluated because it reported the critical number of bottles as being greater than 25. Seven of the thirteen evaluated experiments were determined to be acceptable benchmark experiments. A similar experiment using uranyl nitrate was benchmarked as U233-SOL-THERM-014.

  9. DNA nanostructure immobilization to lithographic DNA arrays

    Science.gov (United States)

    Negrete, Omar D.

    Although DNA is well known for its genetic role in biology, DNA has also been sought-after as a material for the self-assembly of biological and electronic devices. Examples of DNA nanostructure construction include DNA tiled self-assembly and DNA Origami, where by controlling the sequence and concentration of DNA molecules, the rational design of geometric DNA nanostructures is possible. The assembly of DNA nanostructures takes place in solution and thus they are in disorder and require further organization to construct circuitry or devices. Hence, it is essential for future applications of this technology to develop methods to direct the placement of DNA nanostructures on a surface. To address this challenge my research examines the use of DNA microarrays to capture DNA nanostructures via DNA hybridization. Modern DNA arrays offer a high-density of sequence-specific molecular recognition sites where the addressable placement of DNA nanostructures can be achieved. Using Maskless Array Synthesizer (MAS) technology, I have characterized photolithographic DNA arrays for the hybridization of DNA complexes like large DNA molecules (> 1 kb), DNA-gold nanoparticle conjugates, and DNA Origami. Although modern photolithographic DNA arrays can possess a high-density of sequence (106/cm2), the printed DNA areas are on the order of tens of microns. Thus, I have also developed a method to reduce the DNA array spot size to nanoscale dimensions through the combined use of electron beam lithography with photolithographic DNA synthesis. This work addresses the key elements towards developing a surface patterning technology that takes advantage of DNA base-pairing for both molecular sub-assembly and surface patterning.

  10. Analysis of electrical performances of planar active phased array antennas with distorted array plane

    Institute of Scientific and Technical Information of China (English)

    Wang Congsi; Bao Hong; Zhang Fushun; Feng Xingang

    2009-01-01

    a planar phased array antenna with different distortions grades prove the validity of the model.Therefore,by the method,the antenna designers may set the reasonable requirement on the structural tolerance in manufacturing antenna.

  11. Azimuth DOA Estimation in Y-bend Antenna Array

    Science.gov (United States)

    Sanudin, R.

    2016-11-01

    In smart antenna system, it is extremely crucial to estimate the direction of incoming signals in order to achieve better reception. Reliability of DOA estimation depends on several factors such as the choice of DOA algorithm, size of antenna array as well as array geometry. Therefore, it is particularly desirable to have a configuration of antenna array that could produce an accurate azimuth estimation. In this work, a new planar array is proposed to address the problem of azimuth estimation. This is achieved by having a flexible element position on the x- y plane that improves the steering vector, hence significantly enhances the accuracy of DOA estimation. Besides, a fair distribution of the antenna elements on the x-y plane also helps to eliminates estimation failure in the azimuth range between 240° and 360°. A comparison study between the proposed array and V-shape array is performed in order to gauge the performance of the proposed array in DOA estimation. Simulation results show that the proposed array has acquired better estimation resolution than V-shape array. On top of that, the proposed array has reduced estimation error in V-shape array. It is concluded that the proposed array has shown potential as an excellent choice of antenna array geometry for smart antenna system.

  12. Atacama Compact Array Correlator for Atacama Large Millimeter/submillimeter Array

    CERN Document Server

    Okumura, Sachiko K; Kamazaki, Takeshi; Okuda, Takeshi; Kurono, Yasutaka; Iguchi, Satoru

    2011-01-01

    We have developed a FX-architecture digital spectro-correlator, Atacama Compact Array Correlator for the Atacama Large Millimeter/submillimeter Array. The ACA Correlator processes four pairs of dual polarization signals, whose bandwidth is 2 GHz, from up to sixteen antennas, and calculates auto- and cross-correlation spectra including cross-polarization in all combinations of sixteen antennas. We report the detailed design of the correlator and the verification results of the correlator hardware.

  13. An algorithm for signal processing in multibeam antenna arrays

    Science.gov (United States)

    Danilevskii, L. N.; Domanov, Iu. A.; Korobko, O. V.

    1980-09-01

    A signal processing method for multibeam antenna arrays is presented which can be used to effectively reduce discrete-phasing sidelobes. Calculations of an 11-element array are presented as an example.

  14. [Modeling and simulation of responses from ultrasonic linear phased array].

    Science.gov (United States)

    He, Wenjing; Zhu, Yuanzhong; Wang, Yufeng; He, Lingli; Lai, Siyu

    2012-10-01

    Phased array transducers are very attractive because the beam generated by the arrays can be electronically focused and steered. The present work characterizes far-field 2D properties of phased array system by functions that are deduced from rectangle source, rectangle line array and phased array based on point source. Results are presented for the distribution of ultrasound intensity on plane xoz and on x-axis by simulation using numerical calculation. It is shown that the shape of response of rectangle line array is modulated by the single array element. It is also demonstrated that the delay time of phased array is the key to steer the beam, sacrificing the value of main lobe and increasing the number of side lobes.

  15. SiC Avalanche Photodiodes and Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aymont Technology, Inc. (Aymont) will demonstrate the feasibility of SiC p-i-n avalanche photodiodes (APD) arrays. Aymont will demonstrate 4 x 4 arrays of 2 mm2 APDs...

  16. Time/Wavelength Fiber Bragg Grating Multiplexing Sensor Array

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel time/wavelength-multiplexed fiber Bragg grating sensor array is presented. This type of sensor array has the advantages of more points for multi-point measurement, simple structure and low cost.

  17. CONSTRUCTION OF A NEW CLASS OF ORTHOGONAL ARRAYS

    Institute of Scientific and Technical Information of China (English)

    Shanqi PANG

    2007-01-01

    By using the generalized Hadamard product, difference matrix and projection matrices, we present a class of orthogonal projection matrices and related orthogonal arrays of strength two. A new class of orthogonal arrays are constructed.

  18. Array signal processing in the NASA Deep Space Network

    Science.gov (United States)

    Pham, Timothy T.; Jongeling, Andre P.

    2004-01-01

    In this paper, we will describe the benefits of arraying and past as well as expected future use of this application. The signal processing aspects of array system are described. Field measurements via actual tracking spacecraft are also presented.

  19. 600 Volt Stretched Lens Array for Solar Electric Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the past six years, ENTECH, Auburn, NASA, and other organizations have developed a new space photovoltaic array called the Stretched Lens Array (SLA), which...

  20. Studies on coaxial circular array for underwater transducer applications

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.

    This thesis presents analytical methods to study important aspects of a coaxial circular array for wideband underwater transducer application. It begins with detailed theoretical study of a coaxial circular array of three turns and an analysis...

  1. Photovoltaic Array Space Power flight experiment plus diagnostics (PASP+) modules

    Science.gov (United States)

    Cooley, William T.; Adams, Steven F.; Reinhardt, Kitt C.; Piszczor, Michael F.

    1992-01-01

    The Photovoltaic Array Space Power Plus Diagnostics flight experiment (PASP+) subsumes twelve solar array modules which represent the state of the art in the space photovoltaic array industry. Each of the twelve modules individually feature specific photovoltaic technologies such as advanced semiconductor materials, multi-bandgap structures, lightweight array designs, advanced interconnect technologies, or concentrator array designs. This paper will describe each module in detail including the configuration, components, materials, anticipated on orbit performance, and some of the aspects of each array technology. The layout of each module and the photovoltaic cells or array cross section will be presented graphically. A discussion on the environmental constraints and materials selection will be included as well as a delineation of the differences between the modules and the baseline array configuration in its intended application.

  2. Law of refraction for generalised confocal lenslet arrays

    CERN Document Server

    Oxburgh, Stephen

    2013-01-01

    We derive the law of generalised refraction for generalised confocal lenslet arrays, which are arrays of misaligned telescopes. We have implemented this law of refraction in TIM, a custom open-source ray tracer.

  3. Application of multiplicative array techniques for multibeam sounder systems

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.

    Multiplicative array processing is well known for its narrow beamwidth and low sidelobe level, but the array gain is quite low. The effectiveness of such a system becomes lower, especially when the signal to noise ratio is low. Proposed some...

  4. Silicon Micromachined Microlens Array for THz Antennas

    Science.gov (United States)

    Lee, Choonsup; Chattopadhyay, Goutam; Mehdi, IImran; Gill, John J.; Jung-Kubiak, Cecile D.; Llombart, Nuria

    2013-01-01

    5 5 silicon microlens array was developed using a silicon micromachining technique for a silicon-based THz antenna array. The feature of the silicon micromachining technique enables one to microfabricate an unlimited number of microlens arrays at one time with good uniformity on a silicon wafer. This technique will resolve one of the key issues in building a THz camera, which is to integrate antennas in a detector array. The conventional approach of building single-pixel receivers and stacking them to form a multi-pixel receiver is not suited at THz because a single-pixel receiver already has difficulty fitting into mass, volume, and power budgets, especially in space applications. In this proposed technique, one has controllability on both diameter and curvature of a silicon microlens. First of all, the diameter of microlens depends on how thick photoresist one could coat and pattern. So far, the diameter of a 6- mm photoresist microlens with 400 m in height has been successfully microfabricated. Based on current researchers experiences, a diameter larger than 1-cm photoresist microlens array would be feasible. In order to control the curvature of the microlens, the following process variables could be used: 1. Amount of photoresist: It determines the curvature of the photoresist microlens. Since the photoresist lens is transferred onto the silicon substrate, it will directly control the curvature of the silicon microlens. 2. Etching selectivity between photoresist and silicon: The photoresist microlens is formed by thermal reflow. In order to transfer the exact photoresist curvature onto silicon, there needs to be etching selectivity of 1:1 between silicon and photoresist. However, by varying the etching selectivity, one could control the curvature of the silicon microlens. The figure shows the microfabricated silicon microlens 5 x5 array. The diameter of the microlens located in the center is about 2.5 mm. The measured 3-D profile of the microlens surface has a

  5. Array processors based on Gaussian fraction-free method

    Energy Technology Data Exchange (ETDEWEB)

    Peng, S.; Sedukhin, S. [Aizu Univ., Aizuwakamatsu, Fukushima (Japan); Sedukhin, I.

    1998-03-01

    The design of algorithmic array processors for solving linear systems of equations using fraction-free Gaussian elimination method is presented. The design is based on a formal approach which constructs a family of planar array processors systematically. These array processors are synthesized and analyzed. It is shown that some array processors are optimal in the framework of linear allocation of computations and in terms of number of processing elements and computing time. (author)

  6. Airborne electronically steerable phased array. [steerable antennas - systems analysis

    Science.gov (United States)

    Coats, R.

    1975-01-01

    Results of a study directed to the design of a lightweight high-gain, spaceborne communications array are presented. The array includes simultaneous transmission and receiving, automatic acquisition and tracking of a signal within a 60-degree cone from the array normal, and provides for independent forming of the transmit and receive beams. Application for this array is the space shuttle, space station, or any of the advanced manned (or unmanned) orbital vehicles. Performance specifications are also given.

  7. Acoustic trapping with a high frequency linear phased array

    OpenAIRE

    Zheng, Fan; Ying LI; Hsu, Hsiu-Sheng; Liu, Changgeng; Tat Chiu, Chi; Lee, Changyang; Ham Kim, Hyung; Shung, K. Kirk

    2012-01-01

    A high frequency ultrasonic phased array is shown to be capable of trapping and translating microparticles precisely and efficiently, made possible due to the fact that the acoustic beam produced by a phased array can be both focused and steered. Acoustic manipulation of microparticles by a phased array is advantageous over a single element transducer since there is no mechanical movement required for the array. Experimental results show that 45 μm diameter polystyrene microspheres can be eas...

  8. Plane-wave scattering from half-wave dipole arrays

    DEFF Research Database (Denmark)

    Jensen, Niels E.

    1970-01-01

    A matrix equation for determination of plane-wave scattering from arrays of thin short-circuited dipoles of lengths about half a wavelength is derived. Numerical and experimental results are presented for linear, circular, and concentric circular arrays.......A matrix equation for determination of plane-wave scattering from arrays of thin short-circuited dipoles of lengths about half a wavelength is derived. Numerical and experimental results are presented for linear, circular, and concentric circular arrays....

  9. A new integrated slot element feed array for multibeam systems

    Science.gov (United States)

    Yngvesson, K. Sigfrid; Johansson, Joakim F.; Kollberg, Erik L.

    1986-01-01

    A feed array consisting of constant width slot antennas (CWSA), fed from a block containing fin-line transitions, has been developed. The array has a two-dimensional configuration, with five elements each on five parallel substrates. Beamwidths are compatible with use in f/D = 1.0 multibeam systems, with optimum taper. Array element spacings are close to a factor of two smaller than for other typical arrays, and spillover efficiency is about 65 percent.

  10. Programmable Periodicity of Quantum Dot Arrays with DNA Origami Nanotubes

    Science.gov (United States)

    2010-01-01

    To fabricate quantum dot arrays with programmable periodicity, functionalized DNA origami nanotubes were developed. Selected DNA staple strands were biotin-labeled to form periodic binding sites for streptavidin-conjugated quantum dots. Successful formation of arrays with periods of 43 and 71 nm demonstrates precise, programmable, large-scale nanoparticle patterning; however, limitations in array periodicity were also observed. Statistical analysis of AFM images revealed evidence for steric hindrance or site bridging that limited the minimum array periodicity. PMID:20681601

  11. Phased Antenna Array for Global Navigation Satellite System Signals

    Science.gov (United States)

    Turbiner, Dmitry (Inventor)

    2015-01-01

    Systems and methods for phased array antennas are described. Supports for phased array antennas can be constructed by 3D printing. The array elements and combiner network can be constructed by conducting wire. Different parameters of the antenna, like the gain and directivity, can be controlled by selection of the appropriate design, and by electrical steering. Phased array antennas may be used for radio occultation measurements.

  12. Passive Source Localization Using Compressively Sensed Towed Array

    OpenAIRE

    N. Suresh Kumar; C. Bhattacharya; Unnikrishnan, A

    2013-01-01

    The objective of this work is to estimate the sparse angular power spectrum using a towed acoustic pressure sensor (APS) array. In a passive towed array sonar, any reduction in the analog sensor signal conditioning receiver hardware housed inside the array tube, significantly improves the signal integrity and hence the localization performance. In this paper, a novel sparse acoustic pressure sensor (SAPS) array architecture is proposed to estimate the direction of arrival (DOA) of multiple ac...

  13. Fabrication and characterization of CaP-coated nanotube arrays

    Energy Technology Data Exchange (ETDEWEB)

    Kung, Kuan-Chen; Chen, Jia-Ling [Institute of Oral Medicine, National Cheng Kung University, Tainan 701, Taiwan (China); Liu, Yen-Ting [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Lee, Tzer-Min, E-mail: tmlee@mail.ncku.edu.tw [Institute of Oral Medicine, National Cheng Kung University, Tainan 701, Taiwan (China); Medical Device Innovation Center, National Cheng Kung University, Tainan 701, Taiwan (China); School of Dentistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China)

    2015-03-01

    Modified anodization techniques have been shown to improve the biocompatibility of titanium. This study demonstrated the anodic formation of self-organized nanotube arrays on titanium from an electrolyte solution containing 1 M H{sub 3}PO{sub 4} and 1 wt% hydrofluoric acid (HF). Our aim was to investigate the effects of sputter-deposited CaP on nanotube arrays. SEM images revealed a surface with uniform morphology and an average pore diameter of 29 nm. XRD results indicated that the phase of the nanotube arrays was amorphous. Electron spectroscopy for chemical analysis (ESCA) confirmed that the nanotube arrays were coated with calcium and phosphorus. Cell culture experiments using human osteosarcoma (HOS) cells demonstrated that the CaP/nanotube arrays had a pronounced effect on initial cell attachment as well as on the number of cells at 1, 7, and 14 days. Compared to as-polished titanium, the CaP/nanotube arrays accelerated cell proliferation, attachment, and spreading. Our results demonstrate the pronounced effects of CaP/nanotube arrays on the biological responses of HOS cells. - Highlights: • Self-organized nanotube arrays were anodically formed on titanium. • Surfaces of nanotube arrays exhibited uniform morphology and pore size. • According to ESCA results, Ca and P were successfully coated on nanotube arrays. • CaP/nanotube arrays accelerated the attachment and spreading of cells. • CaP/nanotube arrays were shown to affect biological responses of cells.

  14. PHASIM, an advanced phased array antenna software simulator

    NARCIS (Netherlands)

    Keizer, W.P.M.N.

    2000-01-01

    A sophisticated phased array simulator software package for the design and analysis of planar phased array antennas is presented. This package can accurately simulate the far-field characteristics of a large variety of planar phased array configurations in both the frequency and time domain. The sim

  15. An eigencurrent approach for the analysis of finite antenna arrays

    NARCIS (Netherlands)

    Bekers, D.J.; Eijndhoven, S.J.L. van; Tijhuis, A.G.

    2009-01-01

    An accurate description of typical finite-array behavior such as edge effects and array resonances is essential in the design of various types of antennas. The analysis approach proposed in this paper is essentially based on the concept of eigencurrents and is capable of describing finite-array beha

  16. Submillimeter Array observations of ISM in starburst galaxies

    CERN Document Server

    Sakamoto, K; Kuo, C Y; Mao, R Q; Matsushita, S; Peck, A B; Wiedner, M C; Iono, Daisuke; Kuo, Cheng-Yu; Mao, Rui-Qing; Matsushita, Satoki; Peck, Alison B.; Sakamoto, Kazushi; Wiedner, Martina C.; team, SMA

    2004-01-01

    The Submillimeter Array (SMA) has been under construction at the 4100 m summit of Mauna Kea, Hawaii. The array is going to allow imaging of lines and continuum at sub-arcsecond resolution in submillimeter wavelengths. The status of the array and the results from recent commissioning observations of nearby galaxies are reported.

  17. Receiver architecture of the thousand-element array (THEA)

    NARCIS (Netherlands)

    Kant, G.W.; Kokkeler, A.B.J.; Smolders, A.B.; Gunst, A.W.

    2000-01-01

    As part of the development of a new international radio-telescope SKA (Square Kilometre Array), an outdoor phasedarray prototype, the THousand Element Array (THEA), is being developed at NFRA. THEA is a phased array with 1024 active elements distributed on a regular grid over a surface of approximat

  18. Self-catalysis growth of zinc oxide nanopillar array

    Institute of Scientific and Technical Information of China (English)

    YUAN Zhihao; DUAN Yueqin; WU Yang; BIE Lijian; FAN Shoushan

    2005-01-01

    Zn nanodot array was prepared by using a nano-masking with porous alumina membrane as mask. Based on such a nanodot array, a self-catalysis method was developed for fabricating ZnO nanopillars on Si substrate. The resultant nanopillars show a two-dimensional, and regular array with uniform size and orientation.

  19. Linearly tapered slot antenna circular array for mobile communications

    Science.gov (United States)

    Simons, Rainee N.; Kelly, Eron; Lee, Richard Q.; Taub, Susan R.

    1993-01-01

    The design, fabrication and testing of a conformal K-band circular array is presented. The array consists of sixteen linearly tapered slot antennas (LTSA). It is fed by a 1:16 microstrip line power splitter via electromagnetic coupling. The array has an omni-directional pattern in the azimuth plane. In the elevation plane the beam is displaced above the horizon.

  20. Shared aperture array antennas composed of differently sized

    NARCIS (Netherlands)

    Coman, C.I.

    2006-01-01

    A novel solution for conceiving wide band (multi-band) array antennas is presented. The solution is based on the concept of interleaving sparse, sub-arrays operating at separate frequencies. Sparse array antennas offer two major advantages, namely: they have non-uniformly distributed elements, with