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Sample records for affymetrix genechip arrays

  1. VIZARD: analysis of Affymetrix Arabidopsis GeneChip data

    NASA Technical Reports Server (NTRS)

    Moseyko, Nick; Feldman, Lewis J.

    2002-01-01

    SUMMARY: The Affymetrix GeneChip Arabidopsis genome array has proved to be a very powerful tool for the analysis of gene expression in Arabidopsis thaliana, the most commonly studied plant model organism. VIZARD is a Java program created at the University of California, Berkeley, to facilitate analysis of Arabidopsis GeneChip data. It includes several integrated tools for filtering, sorting, clustering and visualization of gene expression data as well as tools for the discovery of regulatory motifs in upstream sequences. VIZARD also includes annotation and upstream sequence databases for the majority of genes represented on the Affymetrix Arabidopsis GeneChip array. AVAILABILITY: VIZARD is available free of charge for educational, research, and not-for-profit purposes, and can be downloaded at http://www.anm.f2s.com/research/vizard/ CONTACT: moseyko@uclink4.berkeley.edu.

  2. Global Expression Patterns of Three Festuca Species Exposed to Different Doses of Glyphosate Using the Affymetrix GeneChip Wheat Genome Array.

    PubMed

    Cebeci, Ozge; Budak, Hikmet

    2009-01-01

    Glyphosate has been shown to act as an inhibitor of an aromatic amino acid biosynthetic pathway, while other pathways that may be affected by glyphosate are not known. Cross species hybridizations can provide a tool for elucidating biological pathways conserved among organisms. Comparative genome analyses have indicated a high level of colinearity among grass species and Festuca, on which we focus here, and showed rearrangements common to the Pooideae family. Based on sequence conservation among grass species, we selected the Affymetrix GeneChip Wheat Genome Array as a tool for the analysis of expression profiles of three Festuca (fescue) species with distinctly different tolerances to varying levels of glyphosate. Differences in transcript expression were recorded upon foliar glyphosate application at 1.58 mM and 6.32 mM, representing 5% and 20%, respectively, of the recommended rate. Differences highlighted categories of general metabolic processes, such as photosynthesis, protein synthesis, stress responses, and a larger number of transcripts responded to 20% glyphosate application. Differential expression of genes encoding proteins involved in the shikimic acid pathway could not be identified by cross hybridization. Microarray data were confirmed by RT-PCR and qRT-PCR analyses. This is the first report to analyze the potential of cross species hybridization in Fescue species and the data and analyses will help extend our knowledge on the cellular processes affected by glyphosate.

  3. Affymetrix GeneChip microarray preprocessing for multivariate analyses.

    PubMed

    McCall, Matthew N; Almudevar, Anthony

    2012-09-01

    Affymetrix GeneChip microarrays are the most widely used high-throughput technology to measure gene expression, and a wide variety of preprocessing methods have been developed to transform probe intensities reported by a microarray scanner into gene expression estimates. There have been numerous comparisons of these preprocessing methods, focusing on the most common analyses-detection of differential expression and gene or sample clustering. Recently, more complex multivariate analyses, such as gene co-expression, differential co-expression, gene set analysis and network modeling, are becoming more common; however, the same preprocessing methods are typically applied. In this article, we examine the effect of preprocessing methods on some of these multivariate analyses and provide guidance to the user as to which methods are most appropriate.

  4. Using probe secondary structure information to enhance Affymetrix GeneChip background estimates

    PubMed Central

    Gharaibeh, Raad Z.; Fodor, Anthony A.; Gibas, Cynthia J.

    2007-01-01

    High-density short oligonucleotide microarrays are a primary research tool for assessing global gene expression. Background noise on microarrays comprises a significant portion of the measured raw data. A number of statistical techniques have been developed to correct for this background noise. Here, we demonstrate that probe minimum folding energy and structure can be used to enhance a previously existing model for background noise correction. We estimate that probe secondary structure accounts for up to 3% of all variation on Affymetrix microarrays. PMID:17387043

  5. Gene expression in the rat brain during sleep deprivation and recovery sleep: an Affymetrix GeneChip study.

    PubMed

    Terao, A; Wisor, J P; Peyron, C; Apte-Deshpande, A; Wurts, S W; Edgar, D M; Kilduff, T S

    2006-01-01

    Previous studies have demonstrated that macromolecular synthesis in the brain is modulated in association with the occurrence of sleep and wakefulness. Similarly, the spectral composition of electroencephalographic activity that occurs during sleep is dependent on the duration of prior wakefulness. Since this homeostatic relationship between wake and sleep is highly conserved across mammalian species, genes that are truly involved in the electroencephalographic response to sleep deprivation might be expected to be conserved across mammalian species. Therefore, in the rat cerebral cortex, we have studied the effects of sleep deprivation on the expression of immediate early gene and heat shock protein mRNAs previously shown to be upregulated in the mouse brain in sleep deprivation and in recovery sleep after sleep deprivation. We find that the molecular response to sleep deprivation and recovery sleep in the brain is highly conserved between these two mammalian species, at least in terms of expression of immediate early gene and heat shock protein family members. Using Affymetrix Neurobiology U34 GeneChips , we also screened the rat cerebral cortex, basal forebrain, and hypothalamus for other genes whose expression may be modulated by sleep deprivation or recovery sleep. We find that the response of the basal forebrain to sleep deprivation is more similar to that of the cerebral cortex than to the hypothalamus. Together, these results suggest that sleep-dependent changes in gene expression in the cerebral cortex are similar across rodent species and therefore may underlie sleep history-dependent changes in sleep electroencephalographic activity.

  6. Identifying the impact of G-quadruplexes on Affymetrix 3' arrays using cloud computing.

    PubMed

    Memon, Farhat N; Owen, Anne M; Sanchez-Graillet, Olivia; Upton, Graham J G; Harrison, Andrew P

    2010-01-15

    A tetramer quadruplex structure is formed by four parallel strands of DNA/ RNA containing runs of guanine. These quadruplexes are able to form because guanine can Hoogsteen hydrogen bond to other guanines, and a tetrad of guanines can form a stable arrangement. Recently we have discovered that probes on Affymetrix GeneChips that contain runs of guanine do not measure gene expression reliably. We associate this finding with the likelihood that quadruplexes are forming on the surface of GeneChips. In order to cope with the rapidly expanding size of GeneChip array datasets in the public domain, we are exploring the use of cloud computing to replicate our experiments on 3' arrays to look at the effect of the location of G-spots (runs of guanines). Cloud computing is a recently introduced high-performance solution that takes advantage of the computational infrastructure of large organisations such as Amazon and Google. We expect that cloud computing will become widely adopted because it enables bioinformaticians to avoid capital expenditure on expensive computing resources and to only pay a cloud computing provider for what is used. Moreover, as well as financial efficiency, cloud computing is an ecologically-friendly technology, it enables efficient data-sharing and we expect it to be faster for development purposes. Here we propose the advantageous use of cloud computing to perform a large data-mining analysis of public domain 3' arrays.

  7. Rawcopy: Improved copy number analysis with Affymetrix arrays

    PubMed Central

    Mayrhofer, Markus; Viklund, Björn; Isaksson, Anders

    2016-01-01

    Microarray data is subject to noise and systematic variation that negatively affects the resolution of copy number analysis. We describe Rawcopy, an R package for processing of Affymetrix CytoScan HD, CytoScan 750k and SNP 6.0 microarray raw intensities (CEL files). Noise characteristics of a large number of reference samples are used to estimate log ratio and B-allele frequency for total and allele-specific copy number analysis. Rawcopy achieves better signal-to-noise ratio and higher proportion of validated alterations than commonly used free and proprietary alternatives. In addition, Rawcopy visualizes each microarray sample for assessment of technical quality, patient identity and genome-wide absolute copy number states. Software and instructions are available at http://rawcopy.org. PMID:27796336

  8. MADS+: discovery of differential splicing events from Affymetrix exon junction array data

    PubMed Central

    Shen, Shihao; Warzecha, Claude C.; Carstens, Russ P.; Xing, Yi

    2010-01-01

    Motivation: The Affymetrix Human Exon Junction Array is a newly designed high-density exon-sensitive microarray for global analysis of alternative splicing. Contrary to the Affymetrix exon 1.0 array, which only contains four probes per exon and no probes for exon–exon junctions, this new junction array averages eight probes per probeset targeting all exons and exon–exon junctions observed in the human mRNA/EST transcripts, representing a significant increase in the probe density for alternative splicing events. Here, we present MADS+, a computational pipeline to detect differential splicing events from the Affymetrix exon junction array data. For each alternative splicing event, MADS+ evaluates the signals of probes targeting competing transcript isoforms to identify exons or splice sites with different levels of transcript inclusion between two sample groups. MADS+ is used routinely in our analysis of Affymetrix exon junction arrays and has a high accuracy in detecting differential splicing events. For example, in a study of the novel epithelial-specific splicing regulator ESRP1, MADS+ detects hundreds of exons whose inclusion levels are dependent on ESRP1, with a RT-PCR validation rate of 88.5% (153 validated out of 173 tested). Availability: MADS+ scripts, documentations and annotation files are available at http://www.medicine.uiowa.edu/Labs/Xing/MADSplus/. Contact: yi-xing@uiowa.edu PMID:19933160

  9. Development and application of a 6.5 million feature Affymetrix Genechip® for massively parallel discovery of single position polymorphisms in lettuce (Lactuca spp.)

    PubMed Central

    2012-01-01

    Background High-resolution genetic maps are needed in many crops to help characterize the genetic diversity that determines agriculturally important traits. Hybridization to microarrays to detect single feature polymorphisms is a powerful technique for marker discovery and genotyping because of its highly parallel nature. However, microarrays designed for gene expression analysis rarely provide sufficient gene coverage for optimal detection of nucleotide polymorphisms, which limits utility in species with low rates of polymorphism such as lettuce (Lactuca sativa). Results We developed a 6.5 million feature Affymetrix GeneChip® for efficient polymorphism discovery and genotyping, as well as for analysis of gene expression in lettuce. Probes on the microarray were designed from 26,809 unigenes from cultivated lettuce and an additional 8,819 unigenes from four related species (L. serriola, L. saligna, L. virosa and L. perennis). Where possible, probes were tiled with a 2 bp stagger, alternating on each DNA strand; providing an average of 187 probes covering approximately 600 bp for each of over 35,000 unigenes; resulting in up to 13 fold redundancy in coverage per nucleotide. We developed protocols for hybridization of genomic DNA to the GeneChip® and refined custom algorithms that utilized coverage from multiple, high quality probes to detect single position polymorphisms in 2 bp sliding windows across each unigene. This allowed us to detect greater than 18,000 polymorphisms between the parental lines of our core mapping population, as well as numerous polymorphisms between cultivated lettuce and wild species in the lettuce genepool. Using marker data from our diversity panel comprised of 52 accessions from the five species listed above, we were able to separate accessions by species using both phylogenetic and principal component analyses. Additionally, we estimated the diversity between different types of cultivated lettuce and distinguished morphological types

  10. Improvements to previous algorithms to predict gene structure and isoform concentrations using Affymetrix Exon arrays

    PubMed Central

    2010-01-01

    Background Exon arrays provide a way to measure the expression of different isoforms of genes in an organism. Most of the procedures to deal with these arrays are focused on gene expression or on exon expression. Although the only biological analytes that can be properly assigned a concentration are transcripts, there are very few algorithms that focus on them. The reason is that previously developed summarization methods do not work well if applied to transcripts. In addition, gene structure prediction, i.e., the correspondence between probes and novel isoforms, is a field which is still unexplored. Results We have modified and adapted a previous algorithm to take advantage of the special characteristics of the Affymetrix exon arrays. The structure and concentration of transcripts -some of them possibly unknown- in microarray experiments were predicted using this algorithm. Simulations showed that the suggested modifications improved both specificity (SP) and sensitivity (ST) of the predictions. The algorithm was also applied to different real datasets showing its effectiveness and the concordance with PCR validated results. Conclusions The proposed algorithm shows a substantial improvement in the performance over the previous version. This improvement is mainly due to the exploitation of the redundancy of the Affymetrix exon arrays. An R-Package of SPACE with the updated algorithms have been developed and is freely available. PMID:21110835

  11. ExonMiner: Web service for analysis of GeneChip Exon array data

    PubMed Central

    Numata, Kazuyuki; Yoshida, Ryo; Nagasaki, Masao; Saito, Ayumu; Imoto, Seiya; Miyano, Satoru

    2008-01-01

    Background Some splicing isoform-specific transcriptional regulations are related to disease. Therefore, detection of disease specific splice variations is the first step for finding disease specific transcriptional regulations. Affymetrix Human Exon 1.0 ST Array can measure exon-level expression profiles that are suitable to find differentially expressed exons in genome-wide scale. However, exon array produces massive datasets that are more than we can handle and analyze on personal computer. Results We have developed ExonMiner that is the first all-in-one web service for analysis of exon array data to detect transcripts that have significantly different splicing patterns in two cells, e.g. normal and cancer cells. ExonMiner can perform the following analyses: (1) data normalization, (2) statistical analysis based on two-way ANOVA, (3) finding transcripts with significantly different splice patterns, (4) efficient visualization based on heatmaps and barplots, and (5) meta-analysis to detect exon level biomarkers. We implemented ExonMiner on a supercomputer system in order to perform genome-wide analysis for more than 300,000 transcripts in exon array data, which has the potential to reveal the aberrant splice variations in cancer cells as exon level biomarkers. Conclusion ExonMiner is well suited for analysis of exon array data and does not require any installation of software except for internet browsers. What all users need to do is to access the ExonMiner URL . Users can analyze full dataset of exon array data within hours by high-level statistical analysis with sound theoretical basis that finds aberrant splice variants as biomarkers. PMID:19036125

  12. Study on the antiendotoxin action of Pulsatillae Decoction using an Affymetrix rat genome array.

    PubMed

    Hu, Yiyi; Chen, Xi; Lin, Hong; Hu, Yuanliang; Mu, Xiang

    2009-01-01

    A high-throughput and efficient Affymetrix rat genome array was used to investigate the pharmacological mechanism of the traditional Chinese medicine, Pulsatillae Decoction (PD), used for the treatment of diseases induced by lipopolysaccharide (LPS). Rat intestinal microvascular endothelial cells (RIMECs) were challenged with 1mug/ml LPS for 3h, and then treated with PD at a concentration of 1mg/ml for 24h. Total RNA from each treatment group was extracted from cultured RIMECs for detection by the Affymetrix Rat Genome 230 2.0 Array. The results showed that 36 genes were upregulated and 33 genes were downregulated in the LPS group vs. the blank control group; 566 genes were upregulated and 12 genes were downregulated in the PD-treated group vs. the LPS group; and 93 genes were upregulated and 29 genes were downregulated in the PD-treated group vs. the blank control group. The analysis of these data suggested that PD specifically and effectively reduce damage induced by LPS, and improved physiological and biochemical responses to counteract the effects of LPS.

  13. ACNE: a summarization method to estimate allele-specific copy numbers for Affymetrix SNP arrays

    PubMed Central

    Ortiz-Estevez, Maria; Bengtsson, Henrik; Rubio, Angel

    2010-01-01

    Motivation: Current algorithms for estimating DNA copy numbers (CNs) borrow concepts from gene expression analysis methods. However, single nucleotide polymorphism (SNP) arrays have special characteristics that, if taken into account, can improve the overall performance. For example, cross hybridization between alleles occurs in SNP probe pairs. In addition, most of the current CN methods are focused on total CNs, while it has been shown that allele-specific CNs are of paramount importance for some studies. Therefore, we have developed a summarization method that estimates high-quality allele-specific CNs. Results: The proposed method estimates the allele-specific DNA CNs for all Affymetrix SNP arrays dealing directly with the cross hybridization between probes within SNP probesets. This algorithm outperforms (or at least it performs as well as) other state-of-the-art algorithms for computing DNA CNs. It better discerns an aberration from a normal state and it also gives more precise allele-specific CNs. Availability: The method is available in the open-source R package ACNE, which also includes an add on to the aroma.affymetrix framework (http://www.aroma-project.org/). Contact: arubio@ceit.es Supplementaruy information: Supplementary data are available at Bioinformatics online. PMID:20529889

  14. ChIP-on-chip analysis methods for Affymetrix tiling arrays.

    PubMed

    Yoder, Sean J

    2015-01-01

    Although the ChIP-sequencing has gained significant attraction recently, ChIP analysis using microarrays is still an attractive option due to the low cost, ease of analysis, and access to legacy and public data sets. The analysis of ChIP-Chip data entails a multistep approach that requires several different applications to progress from the initial stages of raw data analysis to the identification and characterization of ChIP binding sites. There are multiple approaches to data analysis and there are several applications available for each stage of the analysis pipeline. Each application must be evaluated for its suitability for the particular experiment as well as the investigator's background with computational tools. This chapter is a review of the commonly available applications for Affymetrix ChIP-Chip data analysis, as well as the general workflow of a ChIP-Chip analysis approach. The purpose of the chapter is to allow the researcher to better select the appropriate applications and provide them with the direction necessary to proceed with a ChIP-Chip analysis.

  15. GCOD - GeneChip Oncology Database

    PubMed Central

    2011-01-01

    Background DNA microarrays have become a nearly ubiquitous tool for the study of human disease, and nowhere is this more true than in cancer. With hundreds of studies and thousands of expression profiles representing the majority of human cancers completed and in public databases, the challenge has been effectively accessing and using this wealth of data. Description To address this issue we have collected published human cancer gene expression datasets generated on the Affymetrix GeneChip platform, and carefully annotated those studies with a focus on providing accurate sample annotation. To facilitate comparison between datasets, we implemented a consistent data normalization and transformation protocol and then applied stringent quality control procedures to flag low-quality assays. Conclusion The resulting resource, the GeneChip Oncology Database, is available through a publicly accessible website that provides several query options and analytical tools through an intuitive interface. PMID:21291543

  16. Detection of TMPRSS2-ERG translocations in human prostate cancer by expression profiling using GeneChip Human Exon 1.0 ST arrays.

    PubMed

    Jhavar, Sameer; Reid, Alison; Clark, Jeremy; Kote-Jarai, Zsofia; Christmas, Timothy; Thompson, Alan; Woodhouse, Christopher; Ogden, Christopher; Fisher, Cyril; Corbishley, Cathy; De-Bono, Johann; Eeles, Rosalind; Brewer, Daniel; Cooper, Colin

    2008-01-01

    Translocation of TMPRSS2 to the ERG gene, found in a high proportion of human prostate cancer, results in overexpression of the 3'-ERG sequences joined to the 5'-TMPRSS2 promoter. The studies presented here were designed to test the ability of expression analysis on GeneChip Human Exon 1.0 ST arrays to detect 5'-TMPRSS2-ERG-3' hybrid transcripts encoded by this translocation. Monitoring the relative expression of each ERG exon revealed altered transcription of the ERG gene in 15 of a series of 27 prostate cancer samples. In all cases, exons 4 to 11 exhibited enhanced expression compared with exons 2 and 3. This pattern of expression indicated that the most abundant hybrid transcripts involve fusions to ERG exon 4, and RT-PCR analyses confirmed the joining of TMPRSS2 exon 1 to ERG exon 4 in all 15 cases. The exon expression patterns also indicated that TMPRSS2-ERG fusion transcripts commonly contain deletion of ERG exon 8. Analysis of gene-level data from the arrays allowed the identification of genes whose expression levels significantly correlated with the presence of the translocation. These studies demonstrate that expression analyses using exon arrays represent a valuable approach for detecting ETS gene translocation in prostate cancer, in parallel with analyses of gene expression profiles.

  17. Methods comparison for high-resolution transcriptional analysis of archival material on Affymetrix Plus 2.0 and Exon 1.0 microarrays.

    PubMed

    Linton, Kim; Hey, Yvonne; Dibben, Sian; Miller, Crispin; Freemont, Anthony; Radford, John; Pepper, Stuart

    2009-07-01

    Microarray gene expression profiling of formalin-fixed paraffin-embedded (FFPE) tissues is a new and evolving technique. This report compares transcript detection rates on Affymetrix U133 Plus 2.0 and Human Exon 1.0 ST GeneChips across several RNA extraction and target labeling protocols, using routinely collected archival FFPE samples. All RNA extraction protocols tested (Ambion-Optimum, Ambion-RecoverAll, and Qiagen-RNeasy FFPE) provided extracts suitable for microarray hybridization. Compared with Affymetrix One-Cycle labeled extracts, NuGEN system protocols utilizing oligo(dT) and random hexamer primers, and cDNA target preparations instead of cRNA, achieved percent present rates up to 55% on Plus 2.0 arrays. Based on two paired-sample analyses, at 90% specificity this equalled an average 30 percentage-point increase (from 50% to 80%) in FFPE transcript sensitivity relative to fresh frozen tissues, which we have assumed to have 100% sensitivity and specificity. The high content of Exon arrays, with multiple probe sets per exon, improved FFPE sensitivity to 92% at 96% specificity, corresponding to an absolute increase of ~600 genes over Plus 2.0 arrays. While larger series are needed to confirm high correspondence between fresh-frozen and FFPE expression patterns, these data suggest that both Plus 2.0 and Exon arrays are suitable platforms for FFPE microarray expression analyses.

  18. The comparison of different pre- and post-analysis filters for determination of exon-level alternative splicing events using Affymetrix arrays.

    PubMed

    Whistler, Toni; Chiang, Cheng-Feng; Lin, Jin-Mann; Lonergan, William; Reeves, William C

    2010-04-01

    Understanding the biologic significance of alternative splicing has been impeded by the difficulty in systematically identifying and validating transcript isoforms. Current exon array workflows suggest several different filtration steps to reduce the number of tests and increase the detection of alternative splicing events. In this study, we examine the effects of the suggested pre-analysis filtration by detection above background P value or signal intensity. This is followed post-analytically by restriction of exon expression to a fivefold change between groups, limiting the analysis to known alternative splicing events, or using the intersection of the results from different algorithms. Combinations of the filters are also examined. We find that none of the filtering methods reduces the number of technical false-positive calls identified by visual inspection. These include edge effects, nonresponsive probe sets, and inclusion of intronic and untranslated region probe sets into transcript annotations. Modules for filtering the exon microarray data on the basis of annotation features are needed. We propose new approaches to data filtration that would reduce the number of technical false-positives and therefore, impact the time spent performing visual inspection of the exon arrays.

  19. IGG: A tool to integrate GeneChips for genetic studies.

    PubMed

    Li, M-X; Jiang, L; Ho, S-L; Song, Y-Q; Sham, P-C

    2007-11-15

    To facilitate genetic studies using high-throughput genotyping technologies, we have developed an open source tool to integrate genotype data across the Affymetrix and Illumina platforms. It can efficiently integrate a large amount of data from various GeneChips, add genotypes of the HapMap Project into a specific project, flexibly trim and export the integrated data with different formats of popular genetic analysis tools, and highly control the quality of genotype data. Furthermore, this tool has sufficiently simplified its usage through its user-friendly graphic interface and is independent of third-party databases. IGG has successfully been applied to a genome-wide linkage scan in a Charcot-Marie-Tooth disease pedigree by integrating three types of GeneChips and HapMap project genotypes. PMID:17872914

  20. IGG: A tool to integrate GeneChips for genetic studies.

    PubMed

    Li, M-X; Jiang, L; Ho, S-L; Song, Y-Q; Sham, P-C

    2007-11-15

    To facilitate genetic studies using high-throughput genotyping technologies, we have developed an open source tool to integrate genotype data across the Affymetrix and Illumina platforms. It can efficiently integrate a large amount of data from various GeneChips, add genotypes of the HapMap Project into a specific project, flexibly trim and export the integrated data with different formats of popular genetic analysis tools, and highly control the quality of genotype data. Furthermore, this tool has sufficiently simplified its usage through its user-friendly graphic interface and is independent of third-party databases. IGG has successfully been applied to a genome-wide linkage scan in a Charcot-Marie-Tooth disease pedigree by integrating three types of GeneChips and HapMap project genotypes.

  1. GeneChip profiling of transcriptional responses to soybean cyst nematode, Heterodera glycines, colonization of soybean roots.

    PubMed

    Puthoff, David P; Ehrenfried, Mindy L; Vinyard, Bryan T; Tucker, Mark L

    2007-01-01

    Soybean cyst nematode (SCN) is currently the most devastating pathogen of soybean. SCN penetrates the root and migrates toward the central vascular bundle where it establishes a complex multinucleated feeding structure that provides plant-derived nutrients to support the development and growth of the nematode. To identify host genes that play significant roles in SCN development in susceptible roots, RNA from SCN-inoculated and non-inoculated root pieces were hybridized to the Affymetrix soybean genome GeneChips. RNA was collected at 8, 12, and 16 d post-inoculation from root pieces that displayed multiple swollen female SCN and similar root pieces from non-inoculated roots. Branch roots and root tips were trimmed from the root pieces to minimize the amount of RNA contributed by these organs. Of the 35 593 transcripts represented on the GeneChip, approximately 26,500 were expressed in the SCN-colonized root pieces. ANOVA followed by False Discovery Rate analysis indicated that the expression levels of 4616 transcripts changed significantly (Q-value < or =0.05) in response to SCN. In this set of 4616 transcripts, 1404 transcripts increased >2-fold and 739 decreased >2-fold. Of the transcripts to which a function could be assigned, a large proportion was associated with cell wall structure. Other functional categories that included a large number of up-regulated transcripts were defence, metabolism, and histones, and a smaller group of transcripts associated with signal transduction and transcription. PMID:17977850

  2. A new diagnostic workflow for patients with mental retardation and/or multiple congenital abnormalities: test arrays first.

    PubMed

    Gijsbers, Antoinet C J; Lew, Janet Y K; Bosch, Cathy A J; Schuurs-Hoeijmakers, Janneke H M; van Haeringen, Arie; den Hollander, Nicolette S; Kant, Sarina G; Bijlsma, Emilia K; Breuning, Martijn H; Bakker, Egbert; Ruivenkamp, Claudia A L

    2009-11-01

    High-density single-nucleotide polymorphism (SNP) genotyping technology enables extensive genotyping as well as the detection of increasingly smaller chromosomal aberrations. In this study, we assess molecular karyotyping as first-round analysis of patients with mental retardation and/or multiple congenital abnormalities (MR/MCA). We used different commercially available SNP array platforms, the Affymetrix GeneChip 262K NspI, the Genechip 238K StyI, the Illumina HumanHap 300 and HumanCNV 370 BeadChip, to detect copy number variants (CNVs) in 318 patients with unexplained MR/MCA. We found abnormalities in 22.6% of the patients, including six CNVs that overlap known microdeletion/duplication syndromes, eight CNVs that overlap recently described syndromes, 63 potentially pathogenic CNVs (in 52 patients), four large segments of homozygosity and two mosaic trisomies for an entire chromosome. This study shows that high-density SNP array analysis reveals a much higher diagnostic yield as that of conventional karyotyping. SNP arrays have the potential to detect CNVs, mosaics, uniparental disomies and loss of heterozygosity in one experiment. We, therefore, propose a novel diagnostic approach to all MR/MCA patients by first analyzing every patient with an SNP array instead of conventional karyotyping.

  3. Micro-Analyzer: automatic preprocessing of Affymetrix microarray data.

    PubMed

    Guzzi, Pietro Hiram; Cannataro, Mario

    2013-08-01

    A current trend in genomics is the investigation of the cell mechanism using different technologies, in order to explain the relationship among genes, molecular processes and diseases. For instance, the combined use of gene-expression arrays and genomic arrays has been demonstrated as an effective instrument in clinical practice. Consequently, in a single experiment different kind of microarrays may be used, resulting in the production of different types of binary data (images and textual raw data). The analysis of microarray data requires an initial preprocessing phase, that makes raw data suitable for use on existing analysis platforms, such as the TIGR M4 (TM4) Suite. An additional challenge to be faced by emerging data analysis platforms is the ability to treat in a combined way those different microarray formats coupled with clinical data. In fact, resulting integrated data may include both numerical and symbolic data (e.g. gene expression and SNPs regarding molecular data), as well as temporal data (e.g. the response to a drug, time to progression and survival rate), regarding clinical data. Raw data preprocessing is a crucial step in analysis but is often performed in a manual and error prone way using different software tools. Thus novel, platform independent, and possibly open source tools enabling the semi-automatic preprocessing and annotation of different microarray data are needed. The paper presents Micro-Analyzer (Microarray Analyzer), a cross-platform tool for the automatic normalization, summarization and annotation of Affymetrix gene expression and SNP binary data. It represents the evolution of the μ-CS tool, extending the preprocessing to SNP arrays that were not allowed in μ-CS. The Micro-Analyzer is provided as a Java standalone tool and enables users to read, preprocess and analyse binary microarray data (gene expression and SNPs) by invoking TM4 platform. It avoids: (i) the manual invocation of external tools (e.g. the Affymetrix Power

  4. Micro-Analyzer: automatic preprocessing of Affymetrix microarray data.

    PubMed

    Guzzi, Pietro Hiram; Cannataro, Mario

    2013-08-01

    A current trend in genomics is the investigation of the cell mechanism using different technologies, in order to explain the relationship among genes, molecular processes and diseases. For instance, the combined use of gene-expression arrays and genomic arrays has been demonstrated as an effective instrument in clinical practice. Consequently, in a single experiment different kind of microarrays may be used, resulting in the production of different types of binary data (images and textual raw data). The analysis of microarray data requires an initial preprocessing phase, that makes raw data suitable for use on existing analysis platforms, such as the TIGR M4 (TM4) Suite. An additional challenge to be faced by emerging data analysis platforms is the ability to treat in a combined way those different microarray formats coupled with clinical data. In fact, resulting integrated data may include both numerical and symbolic data (e.g. gene expression and SNPs regarding molecular data), as well as temporal data (e.g. the response to a drug, time to progression and survival rate), regarding clinical data. Raw data preprocessing is a crucial step in analysis but is often performed in a manual and error prone way using different software tools. Thus novel, platform independent, and possibly open source tools enabling the semi-automatic preprocessing and annotation of different microarray data are needed. The paper presents Micro-Analyzer (Microarray Analyzer), a cross-platform tool for the automatic normalization, summarization and annotation of Affymetrix gene expression and SNP binary data. It represents the evolution of the μ-CS tool, extending the preprocessing to SNP arrays that were not allowed in μ-CS. The Micro-Analyzer is provided as a Java standalone tool and enables users to read, preprocess and analyse binary microarray data (gene expression and SNPs) by invoking TM4 platform. It avoids: (i) the manual invocation of external tools (e.g. the Affymetrix Power

  5. Screening and identification of microRNA involved in unstable angina using gene-chip analysis

    PubMed Central

    Li, Si; Sun, Ya-Nan; Zhou, Yun-Tao; Zhang, Chun-Lai; Lu, Feng; Liu, Jia; Shang, Xiao-Ming

    2016-01-01

    Increasing evidence has suggested that microRNA (miRNA) may play a role in the pathogenesis of cardiovascular disease, which has led to a greater understanding of the complex pathophysiological processes underlying unstable angina (UA). The present study aimed to investigate changes in the miRNA expression profiles of patients with UA using gene-chip analysis, in order to further elucidate the pathogenesis of UA. Total RNA was extracted and purified from plasma samples collected from patients with UA and healthy controls. The samples underwent microarray analysis using an Exiqon miRCURY LNA™ microRNA Array. Differentially expressed miRNAs were identified by volcano plot filtering, and were validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). In addition, functional annotation of the differentially expressed miRNAs involved gene ontology analyses. Among the 212 miRNAs differentially expressed between the two groups, 82 were upregulated and 130 were downregulated. Notably, the results of the RT-qPCR were consistent with the gene-chip results. The miRNAs identified in the present study may be potential novel biomarkers for the prevention and early diagnosis of UA. Furthermore, the results of the present study suggested that UA occurs as a result of complex and dynamic processes regulated by numerous factors, including multiple miRNAs. PMID:27703515

  6. GeneChip resequencing of the smallpox virus genome can identify novel strains: a biodefense application.

    PubMed

    Sulaiman, Irshad M; Tang, Kevin; Osborne, John; Sammons, Scott; Wohlhueter, Robert M

    2007-02-01

    We developed a set of seven resequencing GeneChips, based on the complete genome sequences of 24 strains of smallpox virus (variola virus), for rapid characterization of this human-pathogenic virus. Each GeneChip was designed to analyze a divergent segment of approximately 30,000 bases of the smallpox virus genome. This study includes the hybridization results of 14 smallpox virus strains. Of the 14 smallpox virus strains hybridized, only 7 had sequence information included in the design of the smallpox virus resequencing GeneChips; similar information for the remaining strains was not tiled as a reference in these GeneChips. By use of variola virus-specific primers and long-range PCR, 22 overlapping amplicons were amplified to cover nearly the complete genome and hybridized with the smallpox virus resequencing GeneChip set. These GeneChips were successful in generating nucleotide sequences for all 14 of the smallpox virus strains hybridized. Analysis of the data indicated that the GeneChip resequencing by hybridization was fast and reproducible and that the smallpox virus resequencing GeneChips could differentiate the 14 smallpox virus strains characterized. This study also suggests that high-density resequencing GeneChips have potential biodefense applications and may be used as an alternate tool for rapid identification of smallpox virus in the future.

  7. Multicenter Evaluation of Genechip for Detection of Multidrug-Resistant Mycobacterium tuberculosis

    PubMed Central

    Pang, Yu; Xia, Hui; Zhang, Zhiying; Li, Junchen; Dong, Yi; Li, Qiang; Ou, Xichao; Song, Yuanyuan; Wang, Yufeng; O'Brien, Richard; Kam, Kai Man; Chi, Junying; Huan, Shitong; Chin, Daniel P.

    2013-01-01

    Drug-resistant tuberculosis (TB), especially multidrug-resistant TB (MDR-TB), is still one of the most serious threats to TB control worldwide. Early diagnosis of MDR-TB is important for effectively blocking transmission and establishing an effective protocol for chemotherapy. Genechip is a rapid diagnostic method based on molecular biology that overcomes the poor biosafety, time consumption, and other drawbacks of traditional drug sensitivity testing (DST) that can detect MDR-TB. However, the Genechip approach has not been effectively evaluated, especially in limited-resource laboratories. In this study, we evaluated the performance of Genechip for MDR-TB in 1,814 patients in four prefectural or municipal laboratories and compared its performance with that of traditional DST. The results showed that the sensitivity and specificity of Genechip were 87.56% and 97.95% for rifampin resistance and 80.34% and 95.82% for isoniazid resistance, respectively. In addition, we found that the positive grade of the sputum smears influenced the judgment of results by Genechip. The test judged only 75% of the specimens of “scanty” positive grade. However, the positive grade of the specimens showed no influence on the accuracy of Genechip. Overall, the study suggests that, in limited-resource laboratories, Genechip showed high sensitivity and specificity for rifampin and isoniazid resistance, making it a more effective, rapid, safe, and cost-beneficial method worthy of broader use in limited-resource laboratories in China. PMID:23515537

  8. Axiom turkey genotyping array

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. DMET-Analyzer: automatic analysis of Affymetrix DMET Data

    PubMed Central

    2012-01-01

    Background Clinical Bioinformatics is currently growing and is based on the integration of clinical and omics data aiming at the development of personalized medicine. Thus the introduction of novel technologies able to investigate the relationship among clinical states and biological machineries may help the development of this field. For instance the Affymetrix DMET platform (drug metabolism enzymes and transporters) is able to study the relationship among the variation of the genome of patients and drug metabolism, detecting SNPs (Single Nucleotide Polymorphism) on genes related to drug metabolism. This may allow for instance to find genetic variants in patients which present different drug responses, in pharmacogenomics and clinical studies. Despite this, there is currently a lack in the development of open-source algorithms and tools for the analysis of DMET data. Existing software tools for DMET data generally allow only the preprocessing of binary data (e.g. the DMET-Console provided by Affymetrix) and simple data analysis operations, but do not allow to test the association of the presence of SNPs with the response to drugs. Results We developed DMET-Analyzer a tool for the automatic association analysis among the variation of the patient genomes and the clinical conditions of patients, i.e. the different response to drugs. The proposed system allows: (i) to automatize the workflow of analysis of DMET-SNP data avoiding the use of multiple tools; (ii) the automatic annotation of DMET-SNP data and the search in existing databases of SNPs (e.g. dbSNP), (iii) the association of SNP with pathway through the search in PharmaGKB, a major knowledge base for pharmacogenomic studies. DMET-Analyzer has a simple graphical user interface that allows users (doctors/biologists) to upload and analyse DMET files produced by Affymetrix DMET-Console in an interactive way. The effectiveness and easy use of DMET Analyzer is demonstrated through different case studies regarding

  10. Preliminary array analysis reveals novel genes regulated by ovarian steroids in the monkey raphe region.

    PubMed

    Reddy, Arubala P; Bethea, Cynthia L

    2005-06-01

    We hypothesize that ovarian hormones may improve serotonin neuron survival. We sought the effect of estradiol (E) and progesterone (P) on novel gene expression in the macaque dorsal raphe region with Affymetrix array analysis. Nine spayed rhesus macaques were treated with either placebo, E or E+P via Silastic implant for 1 month prior to euthanasia (n=3 per treatment). RNA was extracted from a small block of midbrain containing the dorsal raphe and examined on an Agilent Bioanalyzer. The RNA from each monkey was labeled and hybridized to an Affymetrix HG_U95AV Human GeneChip Array. After filtering and sorting, 25 named genes remained that were regulated by E, and 24 named genes remained that were regulated by supplemental P. These genes further sorted into functional categories that would promote neuronal plasticity, transmitter synthesis, and trafficking, as well as reduce apoptosis. The relative abundance of four pivotal genes was examined in all nine animals with quantitative RT-PCR and normalized by glyceraldehyde 3-phosphate dehydrogenase (GAPDH). E+/-P caused a significant threefold reduction in JNK-1 (a pro-apoptosis gene, p<0.007); and a significant sixfold decrease in kynurenine mono-oxygenase (produces neurotoxic quinolones, p<0.05). GABA-A receptor (alpha3 subunit; benzodiazepine site) and E2F1 (interferes with cytokine signaling) were unaffected by E, but increased sevenfold (p<0.02) and fourfold (p<0.009), respectively, upon treatment with P. In summary, subsets of genes related to tissue remodeling or apoptosis were up- or down-regulated by E and P in a tissue block containing the dorsal raphe. These changes could promote cellular resilience in the region where serotonin neurons originate.

  11. Rapid Array Mapping of Circadian Clock and Developmental Mutations in Arabidopsis1

    PubMed Central

    Hazen, Samuel P.; Borevitz, Justin O.; Harmon, Frank G.; Pruneda-Paz, Jose L.; Schultz, Thomas F.; Yanovsky, Marcelo J.; Liljegren, Sarah J.; Ecker, Joseph R.; Kay, Steve A.

    2005-01-01

    Classical forward genetics, the identification of genes responsible for mutant phenotypes, remains an important part of functional characterization of the genome. With the advent of extensive genome sequence, phenotyping and genotyping remain the critical limiting variables in the process of map-based cloning. Here, we reduce the genotyping problem by hybridizing labeled genomic DNA to the Affymetrix Arabidopsis (Arabidopsis thaliana) ATH1 GeneChip. Genotyping was carried out on the scale of detecting greater than 8,000 single feature polymorphisms from over 200,000 loci in a single assay. By combining this technique with bulk segregant analysis, several high heritability development and circadian clock traits were mapped. The mapping accuracy using bulk pools of 26 to 100 F2 individuals ranged from 0.22 to 1.96 Mb of the mutations revealing mutant alleles of EARLY FLOWERING 3, EARLY FLOWERING 4, TIMING OF CAB EXPRESSION 1, and ASYMMETRIC LEAVES 1. While direct detection of small mutations, such as an ethyl-methane sulfonate derived single base substitutions, is limited by array coverage and sensitivity, large deletions such as those that can be caused by fast neutrons are easily detected. We demonstrate this by resolving two deletions, the 77-kb flavin-binding, kelch repeat, f-box 1 and the 7-kb cryptochrome2-1 deletions, via direct hybridization of mutant DNA to ATH1 expression arrays. PMID:15908595

  12. affyPara-a Bioconductor Package for Parallelized Preprocessing Algorithms of Affymetrix Microarray Data.

    PubMed

    Schmidberger, Markus; Vicedo, Esmeralda; Mansmann, Ulrich

    2009-07-22

    Microarray data repositories as well as large clinical applications of gene expression allow to analyse several hundreds of microarrays at one time. The preprocessing of large amounts of microarrays is still a challenge. The algorithms are limited by the available computer hardware. For example, building classification or prognostic rules from large microarray sets will be very time consuming. Here, preprocessing has to be a part of the cross-validation and resampling strategy which is necessary to estimate the rule's prediction quality honestly.This paper proposes the new Bioconductor package affyPara for parallelized preprocessing of Affymetrix microarray data. Partition of data can be applied on arrays and parallelization of algorithms is a straightforward consequence. The partition of data and distribution to several nodes solves the main memory problems and accelerates preprocessing by up to the factor 20 for 200 or more arrays.affyPara is a free and open source package, under GPL license, available form the Bioconductor project at www.bioconductor.org. A user guide and examples are provided with the package.

  13. Smallpox virus resequencing GeneChips can also rapidly ascertain species status for some zoonotic non-variola orthopoxviruses.

    PubMed

    Sulaiman, Irshad M; Sammons, Scott A; Wohlhueter, Robert M

    2008-04-01

    We recently developed a set of seven resequencing GeneChips for the rapid sequencing of Variola virus strains in the WHO Repository of the Centers for Disease Control and Prevention. In this study, we attempted to hybridize these GeneChips with some known non-Variola orthopoxvirus isolates, including monkeypox, cowpox, and vaccinia viruses, for rapid detection.

  14. Uses of Staphylococcus aureus GeneChips in Genotyping and Genetic Composition Analysis

    PubMed Central

    Dunman, P. M.; Mounts, W.; McAleese, F.; Immermann, F.; Macapagal, D.; Marsilio, E.; McDougal, L.; Tenover, F. C.; Bradford, P. A.; Petersen, P. J.; Projan, S. J.; Murphy, E.

    2004-01-01

    Understanding the relatedness of strains within a bacterial species is essential for monitoring reservoirs of antimicrobial resistance and for epidemiological studies. Pulsed-field gel electrophoresis (PFGE), ribotyping, and multilocus sequence typing are commonly used for this purpose. However, these techniques are either nonquantitative or provide only a limited estimation of strain relatedness. Moreover, they cannot extensively define the genes that constitute an organism. In the present study, 21 oxacillin-resistant Staphylococcus aureus (ORSA) isolates, representing eight major ORSA lineages, and each of the seven strains for which the complete genomic sequence is publicly available were genotyped using a novel GeneChip-based approach. Strains were also subjected to PFGE and ribotyping analysis. GeneChip results provided a higher level of discrimination among isolates than either ribotyping or PFGE, although strain clustering was similar among the three techniques. In addition, GeneChip signal intensity cutoff values were empirically determined to provide extensive data on the genetic composition of each isolate analyzed. Using this technology it was shown that strains could be examined for each element represented on the GeneChip, including virulence factors, antimicrobial resistance determinants, and agr type. These results were validated by PCR, growth on selective media, and detailed in silico analysis of each of the sequenced genomes. Collectively, this work demonstrates that GeneChips provide extensive genotyping information for S. aureus strains and may play a major role in epidemiological studies in the future where correlating genes with particular disease phenotypes is critical. PMID:15365023

  15. High-resolution copy number analysis of paraffin-embedded archival tissue using SNP BeadArrays.

    PubMed

    Oosting, Jan; Lips, Esther H; van Eijk, Ronald; Eilers, Paul H C; Szuhai, Károly; Wijmenga, Cisca; Morreau, Hans; van Wezel, Tom

    2007-03-01

    High-density SNP microarrays provide insight into the genomic events that occur in diseases like cancer through their capability to measure both LOH and genomic copy numbers. Where currently available methods are restricted to the use of fresh frozen tissue, we now describe the design and validation of copy number measurements using the Illumina BeadArray platform and the application of this technique to formalin-fixed, paraffin-embedded (FFPE) tissue. In fresh frozen tissue from a set of colorectal tumors with numerous chromosomal aberrations, our method measures copy number patterns that are comparable to values from established platforms, like Affymetrix GeneChip and BAC array-CGH. Moreover, paired comparisons of fresh frozen and FFPE tissues showed nearly identical patterns of genomic change. We conclude that this method enables the use of paraffin-embedded material for research into both LOH and numerical chromosomal abnormalities. These findings make the large pathological archives available for genomic analysis, which could be especially relevant for hereditary disease where fresh material from affected relatives is rarely available.

  16. A Cross-Platform Comparison of Genome-Wide Expression Changes of Laser Microdissected Lung Tissue of C-Raf Transgenic Mice Using 3′IVT and Exon Array

    PubMed Central

    Londhe, Kishor Bapu; Borlak, Juergen

    2012-01-01

    Microarrays are widely used to study genome-wide gene expression changes in different conditions most notably disease, growth, or to investigate the effects of drugs on entire genomes. While the number and gene probe sequences to investigate individual gene expression changes differs amongst manufactures, the design for all of the probes is biased towards the 3′ region. With the advent of exon arrays, transcripts of any known or predicted exon can be investigated to facilitate the study of genome-wide alternative splicing events. Thus, the use of exon arrays provides unprecedented opportunities in gene expression studies. However, it remains a major challenge to directly compare gene expression data derived from oligonucleotide to exon arrays. In the present study, genome-wide expression profiling of Laser Micro-dissected Pressure Catapulted (LMPC) samples of c-Raf mouse lung adenocarcinoma, dysplasia, unaltered transgenic and non-transgenic tissues was performed using the Affymetrix GeneChip Mouse Genome 430 2.0 Array and whole genome Mouse Exon 1.0 ST Array. Based on individual group comparisons 52 to 83% of regulated genes were similar in direction, but fold changes of regulated genes disagreed when data amongst the two platforms were compared. Furthermore, for 27 regulated genes opposite direction of gene expression was observed when the two platforms were compared pointing to the need to assess alternative splicing events at the 3′ end. Taken collectively, exon arrays can be performed even with laser microdissected samples but fold change gene expression changes differ considerably between 3′IVT array and exon arrays with alternative splicing events contributing to apparent differences in gene expression changes. PMID:22815814

  17. Starr: Simple Tiling ARRay analysis of Affymetrix ChIP-chip data

    PubMed Central

    2010-01-01

    Background Chromatin immunoprecipitation combined with DNA microarrays (ChIP-chip) is an assay used for investigating DNA-protein-binding or post-translational chromatin/histone modifications. As with all high-throughput technologies, it requires thorough bioinformatic processing of the data for which there is no standard yet. The primary goal is to reliably identify and localize genomic regions that bind a specific protein. Further investigation compares binding profiles of functionally related proteins, or binding profiles of the same proteins in different genetic backgrounds or experimental conditions. Ultimately, the goal is to gain a mechanistic understanding of the effects of DNA binding events on gene expression. Results We present a free, open-source R/Bioconductor package Starr that facilitates comparative analysis of ChIP-chip data across experiments and across different microarray platforms. The package provides functions for data import, quality assessment, data visualization and exploration. Starr includes high-level analysis tools such as the alignment of ChIP signals along annotated features, correlation analysis of ChIP signals with complementary genomic data, peak-finding and comparative display of multiple clusters of binding profiles. It uses standard Bioconductor classes for maximum compatibility with other software. Moreover, Starr automatically updates microarray probe annotation files by a highly efficient remapping of microarray probe sequences to an arbitrary genome. Conclusion Starr is an R package that covers the complete ChIP-chip workflow from data processing to binding pattern detection. It focuses on the high-level data analysis, e.g., it provides methods for the integration and combined statistical analysis of binding profiles and complementary functional genomics data. Starr enables systematic assessment of binding behaviour for groups of genes that are alingned along arbitrary genomic features. PMID:20398407

  18. Analysis of discordant Affymetrix probesets casts serious doubt on idea of microarray data reutilization

    PubMed Central

    2014-01-01

    Background Affymetrix microarray technology allows one to investigate expression of thousands of genes simultaneously upon a variety of conditions. In a popular U133A microarray platform, the expression of 37% of genes is measured by more than one probeset. The discordant expression observed for two different probesets that match the same gene is a widespread phenomenon which is usually underestimated, ignored or disregarded. Results Here we evaluate the prevalence of discordant expression in data collected using Affymetrix HG-U133A microarray platform. In U133A, about 30% of genes annotated by two different probesets demonstrate a substantial correlation between independently measured expression values. To our surprise, sorting the probesets according to the nature of the discrepancy in their expression levels allowed the classification of the respective genes according to their fundamental functional properties, including observed enrichment by tissue-specific transcripts and alternatively spliced variants. On another hand, an absence of discrepancies in probesets that simultaneously match several different genes allowed us to pinpoint non-expressed pseudogenes and gene groups with highly correlated expression patterns. Nevertheless, in many cases, the nature of discordant expression of two probesets that match the same transcript remains unexplained. It is possible that these probesets report differently regulated sets of transcripts, or, in best case scenario, two different sets of transcripts that represent the same gene. Conclusion The majority of absolute gene expression values collected using Affymetrix microarrays may not be suitable for typical interpretative downstream analysis. PMID:25563078

  19. AffyTrees: facilitating comparative analysis of Affymetrix plant microarray chips.

    PubMed

    Frickey, Tancred; Benedito, Vagner Augusto; Udvardi, Michael; Weiller, Georg

    2008-02-01

    Microarrays measure the expression of large numbers of genes simultaneously and can be used to delve into interaction networks involving many genes at a time. However, it is often difficult to decide to what extent knowledge about the expression of genes gleaned in one model organism can be transferred to other species. This can be examined either by measuring the expression of genes of interest under comparable experimental conditions in other species, or by gathering the necessary data from comparable microarray experiments. However, it is essential to know which genes to compare between the organisms. To facilitate comparison of expression data across different species, we have implemented a Web-based software tool that provides information about sequence orthologs across a range of Affymetrix microarray chips. AffyTrees provides a quick and easy way of assigning which probe sets on different Affymetrix chips measure the expression of orthologous genes. Even in cases where gene or genome duplications have complicated the assignment, groups of comparable probe sets can be identified. The phylogenetic trees provide a resource that can be used to improve sequence annotation and detect biases in the sequence complement of Affymetrix chips. Being able to identify sequence orthologs and recognize biases in the sequence complement of chips is necessary for reliable cross-species microarray comparison. As the amount of work required to generate a single phylogeny in a nonautomated manner is considerable, AffyTrees can greatly reduce the workload for scientists interested in large-scale cross-species comparisons.

  20. Evaluation of the Affymetrix CytoScan® Dx Assay for Developmental Delay

    PubMed Central

    Webb, Bryn D.; Scharf, Rebecca J.; Spear, Emily A.; Edelmann, Lisa J.; Stroustrup, Annemarie

    2015-01-01

    The goal of molecular cytogenetic testing for children presenting with developmental delay is to identify or exclude genetic abnormalities that are associated with cognitive, behavioral, and/or motor symptoms. Until 2010, chromosome analysis was the standard first-line genetic screening test for evaluation of patients with developmental delay when a specific syndrome was not suspected. In 2010, The American College of Medical Genetics and several other groups recommended chromosomal microarray (CMA) as the first-line test in children with developmental delays, multiple congenital anomalies, and/or autism. This test is able to detect regions of genomic imbalances at a much finer resolution than G-banded karyotyping. Until recently, no CMA testing had been approved by the United States Food and Drug Administration (FDA). This review will focus on the use of the Affymetrix CytoScan® Dx Assay, the first CMA to receive FDA approval for the genetic evaluation of individuals with developmental delay. PMID:25350348

  1. MAAMD: a workflow to standardize meta-analyses and comparison of affymetrix microarray data

    PubMed Central

    2014-01-01

    Background Mandatory deposit of raw microarray data files for public access, prior to study publication, provides significant opportunities to conduct new bioinformatics analyses within and across multiple datasets. Analysis of raw microarray data files (e.g. Affymetrix CEL files) can be time consuming, complex, and requires fundamental computational and bioinformatics skills. The development of analytical workflows to automate these tasks simplifies the processing of, improves the efficiency of, and serves to standardize multiple and sequential analyses. Once installed, workflows facilitate the tedious steps required to run rapid intra- and inter-dataset comparisons. Results We developed a workflow to facilitate and standardize Meta-Analysis of Affymetrix Microarray Data analysis (MAAMD) in Kepler. Two freely available stand-alone software tools, R and AltAnalyze were embedded in MAAMD. The inputs of MAAMD are user-editable csv files, which contain sample information and parameters describing the locations of input files and required tools. MAAMD was tested by analyzing 4 different GEO datasets from mice and drosophila. MAAMD automates data downloading, data organization, data quality control assesment, differential gene expression analysis, clustering analysis, pathway visualization, gene-set enrichment analysis, and cross-species orthologous-gene comparisons. MAAMD was utilized to identify gene orthologues responding to hypoxia or hyperoxia in both mice and drosophila. The entire set of analyses for 4 datasets (34 total microarrays) finished in ~ one hour. Conclusions MAAMD saves time, minimizes the required computer skills, and offers a standardized procedure for users to analyze microarray datasets and make new intra- and inter-dataset comparisons. PMID:24621103

  2. Characterization of Capsicum annuum genetic diversity and population structure based on parallel polymorphism discovery with a 30K unigene Pepper GeneChip.

    PubMed

    Hill, Theresa A; Ashrafi, Hamid; Reyes-Chin-Wo, Sebastian; Yao, JiQiang; Stoffel, Kevin; Truco, Maria-Jose; Kozik, Alexander; Michelmore, Richard W; Van Deynze, Allen

    2013-01-01

    The widely cultivated pepper, Capsicum spp., important as a vegetable and spice crop world-wide, is one of the most diverse crops. To enhance breeding programs, a detailed characterization of Capsicum diversity including morphological, geographical and molecular data is required. Currently, molecular data characterizing Capsicum genetic diversity is limited. The development and application of high-throughput genome-wide markers in Capsicum will facilitate more detailed molecular characterization of germplasm collections, genetic relationships, and the generation of ultra-high density maps. We have developed the Pepper GeneChip® array from Affymetrix for polymorphism detection and expression analysis in Capsicum. Probes on the array were designed from 30,815 unigenes assembled from expressed sequence tags (ESTs). Our array design provides a maximum redundancy of 13 probes per base pair position allowing integration of multiple hybridization values per position to detect single position polymorphism (SPP). Hybridization of genomic DNA from 40 diverse C. annuum lines, used in breeding and research programs, and a representative from three additional cultivated species (C. frutescens, C. chinense and C. pubescens) detected 33,401 SPP markers within 13,323 unigenes. Among the C. annuum lines, 6,426 SPPs covering 3,818 unigenes were identified. An estimated three-fold reduction in diversity was detected in non-pungent compared with pungent lines, however, we were able to detect 251 highly informative markers across these C. annuum lines. In addition, an 8.7 cM region without polymorphism was detected around Pun1 in non-pungent C. annuum. An analysis of genetic relatedness and diversity using the software Structure revealed clustering of the germplasm which was confirmed with statistical support by principle components analysis (PCA) and phylogenetic analysis. This research demonstrates the effectiveness of parallel high-throughput discovery and application of genome

  3. Characterization of Capsicum annuum Genetic Diversity and Population Structure Based on Parallel Polymorphism Discovery with a 30K Unigene Pepper GeneChip

    PubMed Central

    Hill, Theresa A.; Ashrafi, Hamid; Reyes-Chin-Wo, Sebastian; Yao, JiQiang; Stoffel, Kevin; Truco, Maria-Jose; Kozik, Alexander; Michelmore, Richard W.; Van Deynze, Allen

    2013-01-01

    The widely cultivated pepper, Capsicum spp., important as a vegetable and spice crop world-wide, is one of the most diverse crops. To enhance breeding programs, a detailed characterization of Capsicum diversity including morphological, geographical and molecular data is required. Currently, molecular data characterizing Capsicum genetic diversity is limited. The development and application of high-throughput genome-wide markers in Capsicum will facilitate more detailed molecular characterization of germplasm collections, genetic relationships, and the generation of ultra-high density maps. We have developed the Pepper GeneChip® array from Affymetrix for polymorphism detection and expression analysis in Capsicum. Probes on the array were designed from 30,815 unigenes assembled from expressed sequence tags (ESTs). Our array design provides a maximum redundancy of 13 probes per base pair position allowing integration of multiple hybridization values per position to detect single position polymorphism (SPP). Hybridization of genomic DNA from 40 diverse C. annuum lines, used in breeding and research programs, and a representative from three additional cultivated species (C. frutescens, C. chinense and C. pubescens) detected 33,401 SPP markers within 13,323 unigenes. Among the C. annuum lines, 6,426 SPPs covering 3,818 unigenes were identified. An estimated three-fold reduction in diversity was detected in non-pungent compared with pungent lines, however, we were able to detect 251 highly informative markers across these C. annuum lines. In addition, an 8.7 cM region without polymorphism was detected around Pun1 in non-pungent C. annuum. An analysis of genetic relatedness and diversity using the software Structure revealed clustering of the germplasm which was confirmed with statistical support by principle components analysis (PCA) and phylogenetic analysis. This research demonstrates the effectiveness of parallel high-throughput discovery and application of genome

  4. Characterization of Capsicum annuum genetic diversity and population structure based on parallel polymorphism discovery with a 30K unigene Pepper GeneChip.

    PubMed

    Hill, Theresa A; Ashrafi, Hamid; Reyes-Chin-Wo, Sebastian; Yao, JiQiang; Stoffel, Kevin; Truco, Maria-Jose; Kozik, Alexander; Michelmore, Richard W; Van Deynze, Allen

    2013-01-01

    The widely cultivated pepper, Capsicum spp., important as a vegetable and spice crop world-wide, is one of the most diverse crops. To enhance breeding programs, a detailed characterization of Capsicum diversity including morphological, geographical and molecular data is required. Currently, molecular data characterizing Capsicum genetic diversity is limited. The development and application of high-throughput genome-wide markers in Capsicum will facilitate more detailed molecular characterization of germplasm collections, genetic relationships, and the generation of ultra-high density maps. We have developed the Pepper GeneChip® array from Affymetrix for polymorphism detection and expression analysis in Capsicum. Probes on the array were designed from 30,815 unigenes assembled from expressed sequence tags (ESTs). Our array design provides a maximum redundancy of 13 probes per base pair position allowing integration of multiple hybridization values per position to detect single position polymorphism (SPP). Hybridization of genomic DNA from 40 diverse C. annuum lines, used in breeding and research programs, and a representative from three additional cultivated species (C. frutescens, C. chinense and C. pubescens) detected 33,401 SPP markers within 13,323 unigenes. Among the C. annuum lines, 6,426 SPPs covering 3,818 unigenes were identified. An estimated three-fold reduction in diversity was detected in non-pungent compared with pungent lines, however, we were able to detect 251 highly informative markers across these C. annuum lines. In addition, an 8.7 cM region without polymorphism was detected around Pun1 in non-pungent C. annuum. An analysis of genetic relatedness and diversity using the software Structure revealed clustering of the germplasm which was confirmed with statistical support by principle components analysis (PCA) and phylogenetic analysis. This research demonstrates the effectiveness of parallel high-throughput discovery and application of genome

  5. The Affymetrix DMET Plus Platform Reveals Unique Distribution of ADME-Related Variants in Ethnic Arabs

    PubMed Central

    Wakil, Salma M.; Nguyen, Cao; Muiya, Nzioka P.; Andres, Editha; Lykowska-Tarnowska, Agnieszka; Baz, Batoul; Meyer, Brian F.; Morahan, Grant

    2015-01-01

    Background. The Affymetrix Drug Metabolizing Enzymes and Transporters (DMET) Plus Premier Pack has been designed to genotype 1936 gene variants thought to be essential for screening patients in personalized drug therapy. These variants include the cytochrome P450s (CYP450s), the key metabolizing enzymes, many other enzymes involved in phase I and phase II pharmacokinetic reactions, and signaling mediators associated with variability in clinical response to numerous drugs not only among individuals, but also between ethnic populations. Materials and Methods. We genotyped 600 Saudi individuals for 1936 variants on the DMET platform to evaluate their clinical potential in personalized medicine in ethnic Arabs. Results. Approximately 49% each of the 437 CYP450 variants, 56% of the 581 transporters, 56% of 419 transferases, 48% of the 104 dehydrogenases, and 58% of the remaining 390 variants were detected. Several variants, such as rs3740071, rs6193, rs258751, rs6199, rs11568421, and rs8187797, exhibited significantly either higher or lower minor allele frequencies (MAFs) than those in other ethnic groups. Discussion. The present study revealed some unique distribution trends for several variants in Arabs, which displayed partly inverse allelic prevalence compared to other ethnic populations. The results point therefore to the need to verify and ascertain the prevalence of a variant as a prerequisite for engaging it in clinical routine screening in personalized medicine in any given population. PMID:25802476

  6. Oligonucleotide array outperforms SNP array on formalin-fixed paraffin-embedded clinical samples.

    PubMed

    Nasri, Soroush; Anjomshoaa, Ahmad; Song, Sarah; Guilford, Parry; McNoe, Les; Black, Michael; Phillips, Vicky; Reeve, Anthony; Humar, Bostjan

    2010-04-01

    Compromised quality of formalin-fixed paraffin-embedded (FFPE)-derived DNA has compounded the use of archival specimens for array-based genomic studies. Recent technological advances have led to first successes in this field; however, there is currently no general agreement on the most suitable platform for the array-based analysis of FFPE DNA. In this study, FFPE and matched fresh-frozen (FF) specimens were separately analyzed with Affymetrix single nucleotide polymorphism (SNP) 6.0 and Agilent 4x44K oligonucleotide arrays to compare the genomic profiles from the two tissue sources and to assess the relative performance of the two platforms on FFPE material. Genomic DNA was extracted from matched FFPE-FF pairs of normal intestinal epithelium from four patients and were applied to the SNP and oligonucleotide platforms according to the manufacturer-recommended protocols. On the Affymetrix platform, a substantial increase in apparent copy number alterations was observed in all FFPE tissues relative to their matched FF counterparts. In contrast, FFPE and matched FF genomic profiles obtained via the Agilent platform were very similar. Both the SNP and the oligonucleotide platform performed comparably on FF material. This study demonstrates that Agilent oligonucleotide array comparative genomic hybridization generates reliable results from FFPE extracted DNA, whereas the Affymetrix SNP-based array seems less suitable for the analysis of FFPE material.

  7. Lr34-mediated leaf rust resistance in wheat: transcript profiling reveals a high energetic demand supported by transient recruitment of multiple metabolic pathways

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wheat gene Lr34 confers partial resistance to all races of Puccinia triticina, the causal agent of wheat leaf rust. However, the biological basis for the exceptional durability of Lr34 is unclear. We used the Affymetrix GeneChip Wheat Genome Array to compare transcriptional changes of wheat in a...

  8. A new method for class prediction based on signed-rank algorithms applied to Affymetrix® microarray experiments

    PubMed Central

    Rème, Thierry; Hose, Dirk; De Vos, John; Vassal, Aurélien; Poulain, Pierre-Olivier; Pantesco, Véronique; Goldschmidt, Hartmut; Klein, Bernard

    2008-01-01

    Background The huge amount of data generated by DNA chips is a powerful basis to classify various pathologies. However, constant evolution of microarray technology makes it difficult to mix data from different chip types for class prediction of limited sample populations. Affymetrix® technology provides both a quantitative fluorescence signal and a decision (detection call: absent or present) based on signed-rank algorithms applied to several hybridization repeats of each gene, with a per-chip normalization. We developed a new prediction method for class belonging based on the detection call only from recent Affymetrix chip type. Biological data were obtained by hybridization on U133A, U133B and U133Plus 2.0 microarrays of purified normal B cells and cells from three independent groups of multiple myeloma (MM) patients. Results After a call-based data reduction step to filter out non class-discriminative probe sets, the gene list obtained was reduced to a predictor with correction for multiple testing by iterative deletion of probe sets that sequentially improve inter-class comparisons and their significance. The error rate of the method was determined using leave-one-out and 5-fold cross-validation. It was successfully applied to (i) determine a sex predictor with the normal donor group classifying gender with no error in all patient groups except for male MM samples with a Y chromosome deletion, (ii) predict the immunoglobulin light and heavy chains expressed by the malignant myeloma clones of the validation group and (iii) predict sex, light and heavy chain nature for every new patient. Finally, this method was shown powerful when compared to the popular classification method Prediction Analysis of Microarray (PAM). Conclusion This normalization-free method is routinely used for quality control and correction of collection errors in patient reports to clinicians. It can be easily extended to multiple class prediction suitable with clinical groups, and looks

  9. inSilicoDb: an R/Bioconductor package for accessing human Affymetrix expert-curated datasets from GEO.

    PubMed

    Taminau, Jonatan; Steenhoff, David; Coletta, Alain; Meganck, Stijn; Lazar, Cosmin; de Schaetzen, Virginie; Duque, Robin; Molter, Colin; Bersini, Hugues; Nowé, Ann; Weiss Solís, David Y

    2011-11-15

    Microarray technology has become an integral part of biomedical research and increasing amounts of datasets become available through public repositories. However, re-use of these datasets is severely hindered by unstructured, missing or incorrect biological samples information; as well as the wide variety of preprocessing methods in use. The inSilicoDb R/Bioconductor package is a command-line front-end to the InSilico DB, a web-based database currently containing 86 104 expert-curated human Affymetrix expression profiles compiled from 1937 GEO repository series. The use of this package builds on the Bioconductor project's focus on reproducibility by enabling a clear workflow in which not only analysis, but also the retrieval of verified data is supported.

  10. Analysis of the Metabolic Pathways Affected by Poly(γ-glutamic Acid) in Arabidopsis thaliana Based on GeneChip Microarray.

    PubMed

    Xu, Zongqi; Lei, Peng; Feng, Xiaohai; Li, Sha; Xu, Hong

    2016-08-17

    Plant growth is promoted by poly(γ-glutamic acid) (γ-PGA). However, the molecular mechanism underlying such promotion is not yet well understood. Therefore, we used GeneChip microarrays to explore the effects of γ-PGA on gene transcription in Arabidopsis thaliana. Our results revealed 299 genes significantly regulated by γ-PGA. These differently expressed genes participate mainly in metabolic and cellular processes and in stimuli responses. The metabolic pathways linked to these differently expressed genes were also investigated. A total of 64 of the 299 differently expressed genes were shown to be directly involved in 24 pathways such as brassinosteroid biosynthesis, α-linolenic acid metabolism, phenylpropanoid biosynthesis, and nitrogen metabolism, all of which were influenced by γ-PGA. The analysis demonstrated that γ-PGA promoted nitrogen assimilation and biosynthesis of brassinosteroids, jasmonic acid, and lignins, providing a better explanation for why γ-PGA promotes growth and enhances stress tolerance in plants. PMID:27465513

  11. Identification of biomarkers regulated by rexinoids (LGD1069, LG100268 and Ro25-7386) in human breast cells using Affymetrix microarray.

    PubMed

    Seo, Hye-Sook; Woo, Jong-Kyu; Shin, Yong Cheol; Ko, Seong-Gyu

    2015-07-01

    Retinoids possess anti-proliferative properties, which suggests that they possess chemopreventive and therapeutic potential against cancer. In the current study, genes modulated by rexinoids (retinoid X receptor (RXR)-pan agonists, LGD1069 and LG100268; and the RXRα agonist, Ro25-7386) were identified using an Affymetrix microarray in normal and malignant breast cells. It was observed that LGD1069, LG100268 and Ro25-7386 suppressed the growth of breast cells. Secondly, several rexinoid-regulated genes were identified, which are involved in cell death, cell growth/maintenance, signal transduction and response to stimulus. These genes may be associated with the growth-suppressive activity of rexinoids. Therefore, the identified genes may serve as biomarkers and novel molecular targets for the prevention and treatment of breast cancer.

  12. GeneChip expression profiling reveals the alterations of energy metabolism related genes in osteocytes under large gradient high magnetic fields.

    PubMed

    Wang, Yang; Chen, Zhi-Hao; Yin, Chun; Ma, Jian-Hua; Li, Di-Jie; Zhao, Fan; Sun, Yu-Long; Hu, Li-Fang; Shang, Peng; Qian, Ai-Rong

    2015-01-01

    The diamagnetic levitation as a novel ground-based model for simulating a reduced gravity environment has recently been applied in life science research. In this study a specially designed superconducting magnet with a large gradient high magnetic field (LG-HMF), which can provide three apparent gravity levels (μ-g, 1-g, and 2-g), was used to simulate a space-like gravity environment. Osteocyte, as the most important mechanosensor in bone, takes a pivotal position in mediating the mechano-induced bone remodeling. In this study, the effects of LG-HMF on gene expression profiling of osteocyte-like cell line MLO-Y4 were investigated by Affymetrix DNA microarray. LG-HMF affected osteocyte gene expression profiling. Differentially expressed genes (DEGs) and data mining were further analyzed by using bioinfomatic tools, such as DAVID, iReport. 12 energy metabolism related genes (PFKL, AK4, ALDOC, COX7A1, STC1, ADM, CA9, CA12, P4HA1, APLN, GPR35 and GPR84) were further confirmed by real-time PCR. An integrated gene interaction network of 12 DEGs was constructed. Bio-data mining showed that genes involved in glucose metabolic process and apoptosis changed notablly. Our results demostrated that LG-HMF affected the expression of energy metabolism related genes in osteocyte. The identification of sensitive genes to special environments may provide some potential targets for preventing and treating bone loss or osteoporosis. PMID:25635858

  13. GeneChip Expression Profiling Reveals the Alterations of Energy Metabolism Related Genes in Osteocytes under Large Gradient High Magnetic Fields

    PubMed Central

    Wang, Yang; Chen, Zhi-Hao; Yin, Chun; Ma, Jian-Hua; Li, Di-Jie; Zhao, Fan; Sun, Yu-Long; Hu, Li-Fang; Shang, Peng; Qian, Ai-Rong

    2015-01-01

    The diamagnetic levitation as a novel ground-based model for simulating a reduced gravity environment has recently been applied in life science research. In this study a specially designed superconducting magnet with a large gradient high magnetic field (LG-HMF), which can provide three apparent gravity levels (μ-g, 1-g, and 2-g), was used to simulate a space-like gravity environment. Osteocyte, as the most important mechanosensor in bone, takes a pivotal position in mediating the mechano-induced bone remodeling. In this study, the effects of LG-HMF on gene expression profiling of osteocyte-like cell line MLO-Y4 were investigated by Affymetrix DNA microarray. LG-HMF affected osteocyte gene expression profiling. Differentially expressed genes (DEGs) and data mining were further analyzed by using bioinfomatic tools, such as DAVID, iReport. 12 energy metabolism related genes (PFKL, AK4, ALDOC, COX7A1, STC1, ADM, CA9, CA12, P4HA1, APLN, GPR35 and GPR84) were further confirmed by real-time PCR. An integrated gene interaction network of 12 DEGs was constructed. Bio-data mining showed that genes involved in glucose metabolic process and apoptosis changed notablly. Our results demostrated that LG-HMF affected the expression of energy metabolism related genes in osteocyte. The identification of sensitive genes to special environments may provide some potential targets for preventing and treating bone loss or osteoporosis. PMID:25635858

  14. Magnetic arrays

    DOEpatents

    Trumper, David L.; Kim, Won-jong; Williams, Mark E.

    1997-05-20

    Electromagnet arrays which can provide selected field patterns in either two or three dimensions, and in particular, which can provide single-sided field patterns in two or three dimensions. These features are achieved by providing arrays which have current densities that vary in the windings both parallel to the array and in the direction of array thickness.

  15. Magnetic arrays

    DOEpatents

    Trumper, D.L.; Kim, W.; Williams, M.E.

    1997-05-20

    Electromagnet arrays are disclosed which can provide selected field patterns in either two or three dimensions, and in particular, which can provide single-sided field patterns in two or three dimensions. These features are achieved by providing arrays which have current densities that vary in the windings both parallel to the array and in the direction of array thickness. 12 figs.

  16. A Brassica exon array for whole-transcript gene expression profiling.

    PubMed

    Love, Christopher G; Graham, Neil S; O Lochlainn, Seosamh; Bowen, Helen C; May, Sean T; White, Philip J; Broadley, Martin R; Hammond, John P; King, Graham J

    2010-01-01

    Affymetrix GeneChip® arrays are used widely to study transcriptional changes in response to developmental and environmental stimuli. GeneChip® arrays comprise multiple 25-mer oligonucleotide probes per gene and retain certain advantages over direct sequencing. For plants, there are several public GeneChip® arrays whose probes are localised primarily in 3' exons. Plant whole-transcript (WT) GeneChip® arrays are not yet publicly available, although WT resolution is needed to study complex crop genomes such as Brassica, which are typified by segmental duplications containing paralogous genes and/or allopolyploidy. Available sequence data were sampled from the Brassica A and C genomes, and 142,997 gene models identified. The assembled gene models were then used to establish a comprehensive public WT exon array for transcriptomics studies. The Affymetrix GeneChip® Brassica Exon 1.0 ST Array is a 5 µM feature size array, containing 2.4 million 25-base oligonucleotide probes representing 135,201 gene models, with 15 probes per gene distributed among exons. Discrimination of the gene models was based on an E-value cut-off of 1E(-5), with ≤98% sequence identity. The 135 k Brassica Exon Array was validated by quantifying transcriptome differences between leaf and root tissue from a reference Brassica rapa line (R-o-18), and categorisation by Gene Ontologies (GO) based on gene orthology with Arabidopsis thaliana. Technical validation involved comparison of the exon array with a 60-mer array platform using the same starting RNA samples. The 135 k Brassica Exon Array is a robust platform. All data relating to the array design and probe identities are available in the public domain and are curated within the BrassEnsembl genome viewer at http://www.brassica.info/BrassEnsembl/index.html.

  17. Kokkos Array

    SciTech Connect

    Edwards Daniel Sunderland, Harold Carter

    2012-09-12

    The Kokkos Array library implements shared-memory array data structures and parallel task dispatch interfaces for data-parallel computational kernels that are performance-portable to multicore-CPU and manycore-accelerator (e.g., GPGPU) devices.

  18. Systolic arrays

    SciTech Connect

    Moore, W.R.; McCabe, A.P.H.; Vrquhart, R.B.

    1987-01-01

    Selected Contents of this book are: Efficient Systolic Arrays for the Solution of Toeplitz Systems, The Derivation and Utilization of Bit Level Systolic Array Architectures, an Efficient Systolic Array for Distance Computation Required in a Video-Codec Based Motion-Detection, On Realizations of Least-Squares Estimation and Kalman Filtering by Systolic Arrays, and Comparison of Systolic and SIMD Architectures for Computer Vision Computations.

  19. Nanocylinder arrays

    DOEpatents

    Tuominen, Mark; Schotter, Joerg; Thurn-Albrecht, Thomas; Russell, Thomas P.

    2009-08-11

    Pathways to rapid and reliable fabrication of nanocylinder arrays are provided. Simple methods are described for the production of well-ordered arrays of nanopores, nanowires, and other materials. This is accomplished by orienting copolymer films and removing a component from the film to produce nanopores, that in turn, can be filled with materials to produce the arrays. The resulting arrays can be used to produce nanoscale media, devices, and systems.

  20. Nanocylinder arrays

    DOEpatents

    Tuominen, Mark; Schotter, Joerg; Thurn-Albrecht, Thomas; Russell, Thomas P.

    2007-03-13

    Pathways to rapid and reliable fabrication of nanocylinder arrays are provided. Simple methods are described for the production of well-ordered arrays of nanopores, nanowires, and other materials. This is accomplished by orienting copolymer films and removing a component from the film to produce nanopores, that in turn, can be filled with materials to produce the arrays. The resulting arrays can be used to produce nanoscale media, devices, and systems.

  1. Construction of a versatile SNP array for pyramiding useful genes of rice.

    PubMed

    Kurokawa, Yusuke; Noda, Tomonori; Yamagata, Yoshiyuki; Angeles-Shim, Rosalyn; Sunohara, Hidehiko; Uehara, Kanako; Furuta, Tomoyuki; Nagai, Keisuke; Jena, Kshirod Kumar; Yasui, Hideshi; Yoshimura, Atsushi; Ashikari, Motoyuki; Doi, Kazuyuki

    2016-01-01

    DNA marker-assisted selection (MAS) has become an indispensable component of breeding. Single nucleotide polymorphisms (SNP) are the most frequent polymorphism in the rice genome. However, SNP markers are not readily employed in MAS because of limitations in genotyping platforms. Here the authors report a Golden Gate SNP array that targets specific genes controlling yield-related traits and biotic stress resistance in rice. As a first step, the SNP genotypes were surveyed in 31 parental varieties using the Affymetrix Rice 44K SNP microarray. The haplotype information for 16 target genes was then converted to the Golden Gate platform with 143-plex markers. Haplotypes for the 14 useful allele are unique and can discriminate among all other varieties. The genotyping consistency between the Affymetrix microarray and the Golden Gate array was 92.8%, and the accuracy of the Golden Gate array was confirmed in 3 F2 segregating populations. The concept of the haplotype-based selection by using the constructed SNP array was proofed. PMID:26566831

  2. Array2BIO: A Comprehensive Suite of Utilities for the Analysis of Microarray Data

    SciTech Connect

    Loots, G G; Chain, P G; Mabery, S; Rasley, A; Garcia, E; Ovcharenko, I

    2006-02-13

    We have developed an integrative and automated toolkit for the analysis of Affymetrix microarray data, named Array2BIO. It identifies groups of coexpressed genes using two complementary approaches--comparative analysis of signal versus control microarrays and clustering analysis of gene expression across different conditions. The identified genes are assigned to functional categories based on the Gene Ontology classification, and a detection of corresponding KEGG protein interaction pathways. Array2BIO reliably handles low-expressor genes and provides a set of statistical methods to quantify the odds of observations, including the Benjamini-Hochberg and Bonferroni multiple testing corrections. Automated interface with the ECR Browser provides evolutionary conservation analysis of identified gene loci while the interconnection with Creme allows high-throughput analysis of human promoter regions and prediction of gene regulatory elements that underlie the observed expression patterns. Array2BIO is publicly available at http://array2bio.dcode.org.

  3. Thawing Frozen Robust Multi-array Analysis (fRMA)

    PubMed Central

    2011-01-01

    Background A novel method of microarray preprocessing - Frozen Robust Multi-array Analysis (fRMA) - has recently been developed. This algorithm allows the user to preprocess arrays individually while retaining the advantages of multi-array preprocessing methods. The frozen parameter estimates required by this algorithm are generated using a large database of publicly available arrays. Curation of such a database and creation of the frozen parameter estimates is time-consuming; therefore, fRMA has only been implemented on the most widely used Affymetrix platforms. Results We present an R package, frmaTools, that allows the user to quickly create his or her own frozen parameter vectors. We describe how this package fits into a preprocessing workflow and explore the size of the training dataset needed to generate reliable frozen parameter estimates. This is followed by a discussion of specific situations in which one might wish to create one's own fRMA implementation. For a few specific scenarios, we demonstrate that fRMA performs well even when a large database of arrays in unavailable. Conclusions By allowing the user to easily create his or her own fRMA implementation, the frmaTools package greatly increases the applicability of the fRMA algorithm. The frmaTools package is freely available as part of the Bioconductor project. PMID:21923903

  4. Reference genes identified in SH-SY5Y cells using custom-made gene arrays with validation by quantitative polymerase chain reaction.

    PubMed

    Hoerndli, Frédéric J; Toigo, Marco; Schild, Andreas; Götz, Jürgen; Day, Philip J

    2004-12-01

    Transcriptomic methods are widely used as an initial approach to gain a mechanistic insight into physiological and pathological processes. Because differences in gene regulation to be assessed by RNA screening methods (e.g., SAGE, Affymetrix GeneChips) can be very subtle, these techniques require stable reference genes for accurate normalization. It is widely known that housekeeping genes, which are routinely used for normalization, can vary significantly depending on the tissue, and experimental test. In this study, we aimed at identifying stable reference genes for a fibrillar Abeta(42) peptide-treated, human tau-expressing SH-SY5Y neuroblastoma cell line derived to model aspects of Alzheimer's disease in tissue culture. We selected genes exhibiting potential normalization characteristics from public databases to create a custom-made microarray allowing the identification of reference genes for low, intermediate, and abundant mRNAs. A subset of these candidates was subjected to quantitative real-time polymerase chain reaction and was analyzed with geNorm software. By doing so, we were able to identify GAPD, M-RIP, and POLR2F as stable and usable reference genes irrespective of differentiation status and Abeta(42) treatment. PMID:15519568

  5. Microlens arrays

    NASA Astrophysics Data System (ADS)

    Hutley, Michael C.; Stevens, Richard F.; Daly, Daniel J.

    1992-04-01

    Microlenses have been with us for a long time as indeed the very word lens reminds us. Many early lenses,including those made by Hooke and Leeuwenhoek in the 17th century were small and resembled lentils. Many languages use the same word for both (French tilentillelt and German "Linse") and the connection is only obscure in English because we use the French word for the vegetable and the German for the optic. Many of the applications for arrays of inicrolenses are also well established. Lippmann's work on integral photography at the turn of the century required lens arrays and stimulated an interest that is very much alive today. At one stage, lens arrays played an important part in high speed photography and various schemes have been put forward to take advantage of the compact imaging properties of combinations of lens arrays. The fact that many of these ingenious schemes have not been developed to their full potential has to a large degree been due to the absence of lens arrays of a suitable quality and cost.

  6. Global Arrays

    2006-02-23

    The Global Arrays (GA) toolkit provides an efficient and portable “shared-memory” programming interface for distributed-memory computers. Each process in a MIMD parallel program can asynchronously access logical blocks of physically distributed dense multi-dimensional arrays, without need for explicit cooperation by other processes. Unlike other shared-memory environments, the GA model exposes to the programmer the non-uniform memory access (NUMA) characteristics of the high performance computers and acknowledges that access to a remote portion of the sharedmore » data is slower than to the local portion. The locality information for the shared data is available, and a direct access to the local portions of shared data is provided. Global Arrays have been designed to complement rather than substitute for the message-passing programming model. The programmer is free to use both the shared-memory and message-passing paradigms in the same program, and to take advantage of existing message-passing software libraries. Global Arrays are compatible with the Message Passing Interface (MPI).« less

  7. Pacific Array

    NASA Astrophysics Data System (ADS)

    Kawakatsu, H.; Takeo, A.; Isse, T.; Nishida, K.; Shiobara, H.; Suetsugu, D.

    2014-12-01

    Based on our recent results on broadband ocean bottom seismometry, we propose a next generation large-scale array experiment in the ocean. Recent advances in ocean bottom broadband seismometry (e.g., Suetsugu & Shiobara, 2014, Annual Review EPS), together with advances in the seismic analysis methodology, have now enabled us to resolve the regional 1-D structure of the entire lithosphere/asthenosphere system, including seismic anisotropy (both radial and azimuthal), with deployments of ~10-15 broadband ocean bottom seismometers (BBOBSs) (namely "ocean-bottom broadband dispersion survey"; Takeo et al., 2013, JGR; Kawakatsu et al., 2013, AGU; Takeo, 2014, Ph.D. Thesis; Takeo et al., 2014, JpGU). Having ~15 BBOBSs as an array unit for 2-year deployment, and repeating such deployments in a leap-frog way (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, 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 might be sought.

  8. Microdischarge arrays

    NASA Astrophysics Data System (ADS)

    Shi, Wenhui

    Microhollow cathode discharges (MHCDs) are DC or pulsed gas discharges between two electrodes, separated by a dielectric, and containing a concentric hole. The diameter of the hole, in this hollow cathode configuration, is in the hundred-micrometer range. MHCDs satisfy the two conditions necessary for an efficient excimer radiation sources: (1) high energy electrons which are required to provide a high concentration of excited or ionized rare gas atoms; (2) high pressure operation which favors excimer formation (a three-body process). Flat panel excimer sources require parallel operation of MHCDs. Based on the current-voltage characteristics of MHCD discharges, which have positive slopes in the low current (Townsend) mode and in the abnormal glow mode, stable arrays of MHCD discharges in argon and xenon could be generated in these current ranges without ballasting each MHCD separately. In the Townsend range, these arrays could be operated up to pressures of 400 Torr. In the abnormal glow mode, discharge arrays were found to be stable up to atmospheric pressure. By using semi-insulating silicon as the anode material, the stable operation of MHCD arrays could be extended to the current range with constant voltage (normal glow) and also that with negative differential conductance (hollow cathode discharge region). Experiments with a cathode geometry without microholes, i.e. excluding the hollow cathode phase, revealed that stable operation of discharges over an extended area were possible. The discharge structure in this configuration reduces to only the cathode fall and negative glow, with the negative glow plasma serving to conduct the discharge current radially to the circular anode. With decreasing current, a transition from homogenous plasma to self-organized plasma filaments is observed. Array formation was not only studied with discharges in parallel, but also with MHCD discharges in series. By using a sandwich electrode configuration, a tandem discharge was

  9. AMDA 2.13: A major update for automated cross-platform microarray data analysis.

    PubMed

    Kapetis, Dimos; Clarelli, Ferdinando; Vitulli, Federico; de Rosbo, Nicole Kerlero; Beretta, Ottavio; Foti, Maria; Ricciardi-Castagnoli, Paola; Zolezzi, Francesca

    2012-07-01

    Microarray platforms require analytical pipelines with modules for data pre-processing including data normalization, statistical analysis for identification of differentially expressed genes, cluster analysis, and functional annotation. We previously developed the Automated Microarray Data Analysis (AMDA, version 2.3.5) pipeline to process Affymetrix 3' IVT GeneChips. The availability of newer technologies that demand open-source tools for microarray data analysis has impelled us to develop an updated multi-platform version, AMDA 2.13. It includes additional quality control metrics, annotation-driven (annotation grade of Affymetrix NetAffx) and signal-driven (Inter-Quartile Range) gene filtering, and approaches to experimental design. To enhance understanding of biological data, differentially expressed genes have been mapped into KEGG pathways. Finally, a more stable and user-friendly interface was designed to integrate the requirements for different platforms. AMDA 2.13 allows the analysis of Affymetrix (cartridges and plates) and whole transcript probe design (Gene 1.0/1.1 ST and Exon 1.0 ST GeneChips), Illumina Bead Arrays, and one-channel Agilent 4×44 arrays. Relative to early versions, it supports various experimental designs and delivers more insightful biological understanding and up-to-date annotations.

  10. Ancestry informative marker panels for African Americans based on subsets of commercially available SNP arrays.

    PubMed

    Tandon, Arti; Patterson, Nick; Reich, David

    2011-01-01

    Admixture mapping is a widely used method for localizing disease genes in African Americans. Most current methods for inferring ancestry at each locus in the genome use a few thousand single nucleotide polymorphisms (SNPs) that are very different in frequency between West Africans and European Americans, and that are required to not be in linkage disequilibrium in the ancestral populations. Modern SNP arrays provide data on hundreds of thousands of SNPs per sample, and to use these to infer ancestry, using many of the standard methods, it is necessary to choose subsets of the SNPs for analysis. Here we present panels of about 4,300 ancestry informative markers (AIMs) that are subsets respectively of SNPs on the Illumina 1 M, Illumina 650, Illumina 610, Affymetrix 6.0 and Affymetrix 5.0 arrays. To validate the usefulness of these panels, we applied them to samples that are different from the ones used to select the SNPs. The panels provide about 80% of the maximum information about African or European ancestry, even with up to 10% missing data.

  11. Global Arrays

    SciTech Connect

    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.

  12. Inflammatory response of esophageal epithelium in combined-type esophagitis in rats: a transcriptome analysis.

    PubMed

    Naito, Yuji; Kuroda, Masaaki; Uchiyama, Kazuhiko; Mizushima, Katsura; Akagiri, Satomi; Takagi, Tomohisa; Handa, Osamu; Kokura, Satoshi; Yoshida, Norimasa; Ichikawa, Hiroshi; Yoshikawa, Toshikazu

    2006-11-01

    Recent studies have shown that esophageal mucosal inflammatory response is involved in the pathophysiology of gastro-esophageal reflux disease. The aim of the present study was to identify specific gene expression profiles of the esophageal mucosa in a rat model of combined-type chronic reflux esophagitis. Esophagogastroduodenal anastomosis was carried out in male Wistar rats by anastomosing the jejunum to the gastroesophageal junction under diethyl-ether inhalation anesthesia. Esophageal epithelial cells were obtained from esophagi of rats by laser capture microdissection. Preparation of cRNA and target hybridization were performed according to the Affymetrix GeneChip eukaryotic small sample target labeling assay protocol. The gene expression profile was evaluated by the rat toxicology U34 GeneChip. Array data analysis was carried out using Affymetrix GeneChip operating software, ingenuity pathway analysis software, and Gene Springs software. A comparison between esophagitis and sham-operated rats 2 weeks after the operation revealed that 368 probes (36%) were significantly affected, i.e. 185 probes were up-regulated, and 183 probes were down-regulated, both at levels of at least 1.5-fold in the esophagitis rats. Ingenuity signal analysis of 207 affected probes revealed the interleukin-6 signaling pathway as the most significantly affected caronical pathway. In addition, the expression of many genes associated with cytokine and transcription factor was enhanced in the esophagitis rats. This transcriptome approach provided insight into genes and putative genetic pathways thought to be affected by stimulation with gastroduodenal refluxates.

  13. Data analysis considerations for detecting copy number changes in formalin-fixed, paraffin-embedded tissues.

    PubMed

    Jacobs, Sharoni

    2012-11-01

    The Whole Genome Sampling Analysis (WGSA) assay in combination with Affymetrix GeneChip Mapping Arrays is used for copy number analysis of high-quality DNA samples (i.e., samples that have been collected from blood, fresh or frozen tissue, or cell lines). Formalin-fixed, paraffin-embedded (FFPE) samples, however, represent the most prevalent form of archived clinical samples, but they provide additional challenges for molecular assays. FFPE processing usually results in the degradation of FFPE DNA and in the contamination and chemical modification of these DNA samples. In this article, we describe the steps needed to obtain reliable copy number predictions from degraded and contaminated FFPE samples.

  14. Comparison of Nanostring nCounter® Data on FFPE Colon Cancer Samples and Affymetrix Microarray Data on Matched Frozen Tissues.

    PubMed

    Chen, Xi; Deane, Natasha G; Lewis, Keeli B; Li, Jiang; Zhu, Jing; Washington, M Kay; Beauchamp, R Daniel

    2016-01-01

    The prognosis of colorectal cancer (CRC) stage II and III patients remains a challenge due to the difficulties of finding robust biomarkers suitable for testing clinical samples. The majority of published gene signatures of CRC have been generated on fresh frozen colorectal tissues. Because collection of frozen tissue is not practical for routine surgical pathology practice, a clinical test that improves prognostic capabilities beyond standard pathological staging of colon cancer will need to be designed for formalin-fixed paraffin-embedded (FFPE) tissues. The NanoString nCounter® platform is a gene expression analysis tool developed for use with FFPE-derived samples. We designed a custom nCounter® codeset based on elements from multiple published fresh frozen tissue microarray-based prognostic gene signatures for colon cancer, and we used this platform to systematically compare gene expression data from FFPE with matched microarray array data from frozen tissues. Our results show moderate correlation of gene expression between two platforms and discovery of a small subset of genes as candidate biomarkers for colon cancer prognosis that are detectable and quantifiable in FFPE tissue sections. PMID:27176004

  15. CGH arrays compared for DNA isolated from formalin-fixed, paraffin-embedded material.

    PubMed

    Krijgsman, Oscar; Israeli, Danielle; Haan, Josien C; van Essen, Hendrik F; Smeets, Serge J; Eijk, Paul P; Steenbergen, Renske D M; Kok, Klaas; Tejpar, Sabine; Meijer, Gerrit A; Ylstra, Bauke

    2012-04-01

    Formalin-fixed, paraffin-embedded (FFPE) archival tissue is an important source of DNA material. The most commonly used technique to identify copy number aberrations from chromosomal DNA in tumorigenesis is array comparative genomic hybridization (aCGH). Although copy number analysis using DNA from FFPE archival tissue is challenging, several research groups have reported high quality and reproducible DNA copy number results using aCGH. Aim of this study is to compare the commercially available aCGH platforms suitable for high-resolution copy number analysis using FFPE-derived DNA. Two dual channel aCGH platforms (Agilent and NimbleGen) and a single channel SNP-based platform (Affymetrix) were evaluated using seven FFPE colon cancer samples, and median absolute deviation (MAD), deflection, signal-to-noise ratio, and DNA input requirements were used as quality criteria. Large differences were observed between platforms; Agilent and NimbleGen showed better MAD values (0.13 for both) compared with Affymetrix (0.22). On the contrary, Affymetrix showed a better deflection of 0.94, followed by 0.71 for Agilent and 0.51 for NimbleGen. This resulted in signal-to-nose ratios that were comparable between the three commercially available platforms. Interestingly, DNA input amounts from FFPE material lower than recommended still yielded high quality profiles on all platforms. Copy number analysis using DNA derived from FFPE archival material is feasible using all three high-resolution copy number platforms and shows reproducible results, also with DNA input amounts lower than recommended.

  16. Assessment of the functionality of genome-wide canine SNP arrays and implications for canine disease association studies.

    PubMed

    Ke, X; Kennedy, L J; Short, A D; Seppälä, E H; Barnes, A; Clements, D N; Wood, S H; Carter, S D; Happ, G M; Lohi, H; Ollier, W E R

    2011-04-01

    Domestic dogs share a wide range of important disease conditions with humans, including cancers, diabetes and epilepsy. Many of these conditions have similar or identical underlying pathologies to their human counterparts and thus dogs represent physiologically relevant natural models of human disorders. Comparative genomic approaches whereby disease genes can be identified in dog diseases and then mapped onto the human genome are now recognized as a valid method and are increasing in popularity. The majority of dog breeds have been created over the past few hundred years and, as a consequence, the dog genome is characterized by extensive linkage disequilibrium (LD), extending usually from hundreds of kilobases to several megabases within a breed, rather than tens of kilobases observed in the human genome. Genome-wide canine SNP arrays have been developed, and increasing success of using these arrays to map disease loci in dogs is emerging. No equivalent of the human HapMap currently exists for different canine breeds, and the LD structure for such breeds is far less understood than for humans. This study is a dedicated large-scale assessment of the functionalities (LD and SNP tagging performance) of canine genome-wide SNP arrays in multiple domestic dog breeds. We have used genotype data from 18 breeds as well as wolves and coyotes genotyped by the Illumina 22K canine SNP array and Affymetrix 50K canine SNP array. As expected, high tagging performance was observed with most of the breeds using both Illumina and Affymetrix arrays when multi-marker tagging was applied. In contrast, however, large differences in population structure, LD coverage and pairwise tagging performance were found between breeds, suggesting that study designs should be carefully assessed for individual breeds before undertaking genome-wide association studies (GWAS).

  17. Addictions Biology: Haplotype-Based Analysis for 130 Candidate Genes on a Single Array

    PubMed Central

    Hodgkinson, Colin A.; Yuan, Qiaoping; Xu, Ke; Shen, Pei-Hong; Heinz, Elizabeth; Lobos, Elizabeth A.; Binder, Elizabeth B.; Cubells, Joe; Ehlers, Cindy L.; Gelernter, Joel; Mann, John; Riley, Brien; Roy, Alec; Tabakoff, Boris; Todd, Richard D.; Zhou, Zhifeng; Goldman, David

    2008-01-01

    Aims: To develop a panel of markers able to extract full haplotype information for candidate genes in alcoholism, other addictions and disorders of mood and anxiety. Methods: A total of 130 genes were haplotype tagged and genotyped in 7 case/control populations and 51 reference populations using Illumina GoldenGate SNP genotyping technology, determining haplotype coverage. We also constructed and determined the efficacy of a panel of 186 ancestry informative markers. Results: An average of 1465 loci were genotyped at an average completion rate of 91.3%, with an average call rate of 98.3% and replication rate of 99.7%. Completion and call rates were lowered by the performance of two datasets, highlighting the importance of the DNA quality in high throughput assays. A comparison of haplotypes captured by the Addictions Array tagging SNPs and commercially available whole-genome arrays from Illumina and Affymetrix shows comparable performance of the tag SNPs to the best whole-genome array in all populations for which data are available. Conclusions: Arrays of haplotype-tagged candidate genes, such as this addictions-focused array, represent a cost-effective approach to generate high-quality SNP genotyping data useful for the haplotype-based analysis of panels of genes such as these 130 genes of interest to alcohol and addictions researchers. The inclusion of the 186 ancestry informative markers allows for the detection and correction for admixture and further enhances the utility of the array. PMID:18477577

  18. A Quantitative Tool for Producing DNA-Based Diagnostic Arrays

    SciTech Connect

    Tom J. Whitaker

    2008-07-11

    The purpose of this project was to develop a precise, quantitative method to analyze oligodeoxynucleotides (ODNs) on an array to enable a systematic approach to quality control issues affecting DNA microarrays. Two types of ODN's were tested; ODN's formed by photolithography and ODN's printed onto microarrays. Initial work in Phase I, performed in conjunction with Affymetrix, Inc. who has a patent on a photolithographic in situ technique for creating DNA arrays, was very promising but did seem to indicate that the atomization process was not complete. Soon after Phase II work was under way, Affymetrix had further developed fluorescent methods and indicated they were no longer interested in our resonance ionization technique. This was communicated to the program manager and it was decided that the project would continue and be focused on printed ODNs. The method being tested is called SIRIS, Sputter-Initiated Resonance Ionization Spectroscopy. SIRIS has been shown to be a highly sensitive, selective, and quantitative tool for atomic species. This project was aimed at determining if an ODN could be labeled in such a way that SIRIS could be used to measure the label and thus provide quantitative measurements of the ODN on an array. One of the largest problems in this study has been developing a method that allows us to know the amount of an ODN on a surface independent of the SIRIS measurement. Even though we could accurately determine the amount of ODN deposited on a surface, the amount that actually attached to the surface is very difficult to measure (hence the need for a quantitative tool). A double-labeling procedure was developed in which 33P and Pt were both used to label ODNs. The radioactive 33P could be measured by a proportional counter that maps the counts in one dimension. This gave a good measurement of the amount of ODN remaining on a surface after immobilization and washing. A second label, Pt, was attached to guanine nucleotides in the ODN. Studies

  19. Arabidopsis transcriptional responses differentiating closely related chemicals (herbicides) and cross-species extrapolation to Brassica

    EPA Science Inventory

    Using whole genome Affymetrix ATH1 GeneChips we characterized the transcriptional response of Arabidopsis thaliana Columbia 24 hours after treatment with five different herbicides. Four of them (chloransulam, imazapyr, primisulfuron, sulfometuron) inhibit acetolactate synthase (A...

  20. Benchmarking the CATMA Microarray. A Novel Tool forArabidopsis Transcriptome Analysis1[w

    PubMed Central

    Allemeersch, Joke; Durinck, Steffen; Vanderhaeghen, Rudy; Alard, Philippe; Maes, Ruth; Seeuws, Kurt; Bogaert, Tom; Coddens, Kathleen; Deschouwer, Kirsten; Van Hummelen, Paul; Vuylsteke, Marnik; Moreau, Yves; Kwekkeboom, Jeroen; Wijfjes, André H.M.; May, Sean; Beynon, Jim; Hilson, Pierre; Kuiper, Martin T.R.

    2005-01-01

    Transcript profiling is crucial to study biological systems, and various platforms have been implemented to survey mRNAs at the genome scale. We have assessed the performance of the CATMA microarray designed for Arabidopsis (Arabidopsis thaliana) transcriptome analysis and compared it with the Agilent and Affymetrix commercial platforms. The CATMA array consists of gene-specific sequence tags of 150 to 500 bp, the Agilent (Arabidopsis 2) array of 60mer oligonucleotides, and the Affymetrix gene chip (ATH1) of 25mer oligonucleotide sets. We have matched each probe repertoire with the Arabidopsis genome annotation (The Institute for Genomic Research release 5.0) and determined the correspondence between them. Array performance was analyzed by hybridization with labeled targets derived from eight RNA samples made of shoot total RNA spiked with a calibrated series of 14 control transcripts. CATMA arrays showed the largest dynamic range extending over three to four logs. Agilent and Affymetrix arrays displayed a narrower range, presumably because signal saturation occurred for transcripts at concentrations beyond 1,000 copies per cell. Sensitivity was comparable for all three platforms. For Affymetrix GeneChip data, the RMA software package outperformed Microarray Suite 5.0 for all investigated criteria, confirming that the information provided by the mismatch oligonucleotides has no added value. In addition, taking advantage of replicates in our dataset, we conducted a robust statistical analysis of the platform propensity to yield false positive and false negative differentially expressed genes, and all gave satisfactory results. The results establish the CATMA array as a mature alternative to the Affymetrix and Agilent platforms. PMID:15710687

  1. Integrated infrared array technology

    NASA Technical Reports Server (NTRS)

    Goebel, J. H.; Mccreight, C. R.

    1986-01-01

    An overview of integrated infrared (IR) array technology is presented. Although the array pixel formats are smaller, and the readout noise of IR arrays is larger, than the corresponding values achieved with optical charge-coupled-device silicon technology, substantial progress is being made in IR technology. Both existing IR arrays and those being developed are described. Examples of astronomical images are given which illustrate the potential of integrated IR arrays for scientific investigations.

  2. Solar array drive system

    NASA Technical Reports Server (NTRS)

    Berkopec, F. D.; Sturman, J. C.; Stanhouse, R. W.

    1976-01-01

    A solar array drive system consisting of a solar array drive mechanism and the corresponding solar array drive electronics is being developed. The principal feature of the solar array drive mechanism is its bidirectional capability which enables its use in mechanical redundancy. The solar array drive system is of a widely applicable design. This configuration will be tested to determine its acceptability for generic mission sets. Foremost of the testing to be performed is the testing for extended duration.

  3. The development and characterization of a 57K single nucleotide polymorphism array for rainbow trout.

    PubMed

    Palti, Y; Gao, G; Liu, S; Kent, M P; Lien, S; Miller, M R; Rexroad, C E; Moen, T

    2015-05-01

    In this study, we describe the development and characterization of the first high-density single nucleotide polymorphism (SNP) genotyping array for rainbow trout. The SNP array is publically available from a commercial vendor (Affymetrix). The SNP genotyping quality was high, and validation rate was close to 90%. This is comparable to other farm animals and is much higher than previous smaller scale SNP validation studies in rainbow trout. High quality and integrity of the genotypes are evident from sample reproducibility and from nearly 100% agreement in genotyping results from other methods. The array is very useful for rainbow trout aquaculture populations with more than 40 900 polymorphic markers per population. For wild populations that were confounded by a smaller sample size, the number of polymorphic markers was between 10 577 and 24 330. Comparison between genotypes from individual populations suggests good potential for identifying candidate markers for populations' traceability. Linkage analysis and mapping of the SNPs to the reference genome assembly provide strong evidence for a wide distribution throughout the genome with good representation in all 29 chromosomes. A total of 68% of the genome scaffolds and contigs were anchored through linkage analysis using the SNP array genotypes, including ~20% of the genome assembly that has not been previously anchored to chromosomes.

  4. Thermophotovoltaic Array Optimization

    SciTech Connect

    SBurger; E Brown; K Rahner; L Danielson; J Openlander; J Vell; D Siganporia

    2004-07-29

    A systematic approach to thermophotovoltaic (TPV) array design and fabrication was used to optimize the performance of a 192-cell TPV array. The systematic approach began with cell selection criteria that ranked cells and then matched cell characteristics to maximize power output. Following cell selection, optimization continued with an array packaging design and fabrication techniques that introduced negligible electrical interconnect resistance and minimal parasitic losses while maintaining original cell electrical performance. This paper describes the cell selection and packaging aspects of array optimization as applied to fabrication of a 192-cell array.

  5. Allelic imbalance analysis by high-density single-nucleotide polymorphic allele (SNP) array with whole genome amplified DNA

    PubMed Central

    Wong, Kwong-Kwok; Tsang, Yvonne T. M.; Shen, Jianhe; Cheng, Rita S.; Chang, Yi-Mieng; Man, Tsz-Kwong; Lau, Ching C.

    2004-01-01

    Besides their use in mRNA expression profiling, oligonucleotide microarrays have also been applied to single-nucleotide polymorphism (SNP) and loss of heterozygosity (LOH) or allelic imbalance studies. In this report, we evaluate the reliability of using whole genome amplified DNA for analysis with an oligonucleotide microarray containing 11 560 SNPs to detect allelic imbalance and chromosomal copy number abnormalities. Whole genome SNP analyses were performed with DNA extracted from osteosarcoma tissues and patient-matched blood. SNP calls were then generated by Affymetrix® GeneChip® DNA Analysis Software. In two osteosarcoma cases, using unamplified DNA, we identified 793 and 1070 SNP loci with allelic imbalance, respectively. In a parallel experiment with amplified DNA, 78% and 83% of these SNP loci with allelic imbalance was detected. The average false-positive rate is 13.8%. Furthermore, using the Affymetrix® GeneChip® Chromosome Copy Number Tool to analyze the SNP array data, we were able to detect identical chromosomal regions with gain or loss in both amplified and unamplified DNA at cytoband resolution. PMID:15148342

  6. Superconducting Bolometer Array Architectures

    NASA Technical Reports Server (NTRS)

    Benford, Dominic; Chervenak, Jay; Irwin, Kent; Moseley, S. Harvey; Shafer, Rick; Staguhn, Johannes; Wollack, Ed; Oegerle, William (Technical Monitor)

    2002-01-01

    The next generation of far-infrared and submillimeter instruments require large arrays of detectors containing thousands of elements. These arrays will necessarily be multiplexed, and superconducting bolometer arrays are the most promising present prospect for these detectors. We discuss our current research into superconducting bolometer array technologies, which has recently resulted in the first multiplexed detections of submillimeter light and the first multiplexed astronomical observations. Prototype arrays containing 512 pixels are in production using the Pop-Up Detector (PUD) architecture, which can be extended easily to 1000 pixel arrays. Planar arrays of close-packed bolometers are being developed for the GBT (Green Bank Telescope) and for future space missions. For certain applications, such as a slewed far-infrared sky survey, feedhorncoupling of a large sparsely-filled array of bolometers is desirable, and is being developed using photolithographic feedhorn arrays. Individual detectors have achieved a Noise Equivalent Power (NEP) of -10(exp 17) W/square root of Hz at 300mK, but several orders of magnitude improvement are required and can be reached with existing technology. The testing of such ultralow-background detectors will prove difficult, as this requires optical loading of below IfW. Antenna-coupled bolometer designs have advantages for large format array designs at low powers due to their mode selectivity.

  7. Electronic Switch Arrays for Managing Microbattery Arrays

    NASA Technical Reports Server (NTRS)

    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.

  8. High-quality genotyping data from formalin-fixed, paraffin-embedded tissue on the drug metabolizing enzymes and transporters plus array.

    PubMed

    Vos, Hanneke I; van der Straaten, Tahar; Coenen, Marieke J H; Flucke, Uta; te Loo, D Maroeska W M; Guchelaar, Henk-Jan

    2015-01-01

    The Affymetrix Drug Metabolizing Enzymes and Transporters (DMET) Plus array covers 1936 markers in 231 genes involved in drug metabolism and transport. Blood- and saliva-derived DNA works well on the DMET array, but the utility of DNA from FFPE tissue has not been reported for this array. As the ability to use DNA from FFPE tissue on the array could open the potential for large retrospective sample collections, we examined the performance and reliability of FFPE-derived DNA on the DMET Plus array. Germline DNA isolated from archived normal FFPE tissue blocks stored for 3 to 19 years and matched blood or saliva from 16 patients with osteosarcoma were genotyped on the DMET Plus array. Concordance was assessed by calculating agreement and the κ-statistic. We observed high call rates for both the blood- or saliva-derived DNA samples (99.4%) and the FFPE-derived DNA samples (98.9%). Moreover, the concordance among the 16 blood- or saliva-derived DNA and FFPE DNA pairs was high (97.4%, κ = 0.915). This is the first study showing that DNA from normal FFPE tissue provides accurate and reliable genotypes on the DMET Plus array compared with blood- or saliva-derived DNA. This finding provides an opportunity for pharmacogenetic studies in diseases with high mortality rates and prevents a bias in studies where otherwise only alive patients can be included.

  9. Designing linear systolic arrays

    SciTech Connect

    Kumar, V.K.P.; Tsai, Y.C. . Dept. of Electrical Engineering)

    1989-12-01

    The authors develop a simple mapping technique to design linear systolic arrays. The basic idea of the technique is to map the computations of a certain class of two-dimensional systolic arrays onto one-dimensional arrays. Using this technique, systolic algorithms are derived for problems such as matrix multiplication and transitive closure on linearly connected arrays of PEs with constant I/O bandwidth. Compared to known designs in the literature, the technique leads to modular systolic arrays with constant hardware in each PE, few control lines, lexicographic data input/output, and improved delay time. The unidirectional flow of control and data in this design assures implementation of the linear array in the known fault models of wafer scale integration.

  10. Carbon nanotube nanoelectrode arrays

    DOEpatents

    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.

  11. Pacific Array (Transportable Broadband Ocean Floor Array)

    NASA Astrophysics Data System (ADS)

    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.

  12. Phased-array radars

    NASA Astrophysics Data System (ADS)

    Brookner, E.

    1985-02-01

    The operating principles, technology, and applications of phased-array radars are reviewed and illustrated with diagrams and photographs. Consideration is given to the antenna elements, circuitry for time delays, phase shifters, pulse coding and compression, and hybrid radars combining phased arrays with lenses to alter the beam characteristics. The capabilities and typical hardware of phased arrays are shown using the US military systems COBRA DANE and PAVE PAWS as examples.

  13. Integrated avalanche photodiode arrays

    DOEpatents

    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.

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

    DOEpatents

    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.

  15. Solar array deployment mechanism

    NASA Astrophysics Data System (ADS)

    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.

  16. Solar array deployment mechanism

    NASA Technical Reports Server (NTRS)

    Calassa, Mark C.; Kackley, Russell

    1995-01-01

    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.

  17. Array for detecting microbes

    DOEpatents

    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.

  18. ISS Solar Array Management

    NASA Technical Reports Server (NTRS)

    Williams, James P.; Martin, Keith D.; Thomas, Justin R.; Caro, Samuel

    2010-01-01

    The International Space Station (ISS) Solar Array Management (SAM) software toolset provides the capabilities necessary to operate a spacecraft with complex solar array constraints. It monitors spacecraft telemetry and provides interpretations of solar array constraint data in an intuitive manner. The toolset provides extensive situational awareness to ensure mission success by analyzing power generation needs, array motion constraints, and structural loading situations. The software suite consists of several components including samCS (constraint set selector), samShadyTimers (array shadowing timers), samWin (visualization GUI), samLock (array motion constraint computation), and samJet (attitude control system configuration selector). It provides high availability and uptime for extended and continuous mission support. It is able to support two-degrees-of-freedom (DOF) array positioning and supports up to ten simultaneous constraints with intuitive 1D and 2D decision support visualizations of constraint data. Display synchronization is enabled across a networked control center and multiple methods for constraint data interpolation are supported. Use of this software toolset increases flight safety, reduces mission support effort, optimizes solar array operation for achieving mission goals, and has run for weeks at a time without issues. The SAM toolset is currently used in ISS real-time mission operations.

  19. Microfabricated ion trap array

    DOEpatents

    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.

  20. Micromachined electrode array

    DOEpatents

    Okandan, Murat; Wessendorf, Kurt O.

    2007-12-11

    An electrode array is disclosed which has applications for neural stimulation and sensing. The electrode array, in certain embodiments, can include a plurality of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. In other embodiments of the electrode array, the electrodes can be fixed to the substrate. The electrode array can be formed from a combination of bulk and surface micromachining, and can include electrode tips having an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis.

  1. Photovoltaic array loss mechanisms

    NASA Technical Reports Server (NTRS)

    Gonzalez, Charles

    1986-01-01

    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.

  2. High density pixel array

    NASA Technical Reports Server (NTRS)

    Wiener-Avnear, Eliezer (Inventor); McFall, James Earl (Inventor)

    2004-01-01

    A pixel array device is fabricated by a laser micro-milling method under strict process control conditions. The device has an array of pixels bonded together with an adhesive filling the grooves between adjacent pixels. The array is fabricated by moving a substrate relative to a laser beam of predetermined intensity at a controlled, constant velocity along a predetermined path defining a set of grooves between adjacent pixels so that a predetermined laser flux per unit area is applied to the material, and repeating the movement for a plurality of passes of the laser beam until the grooves are ablated to a desired depth. The substrate is of an ultrasonic transducer material in one example for fabrication of a 2D ultrasonic phase array transducer. A substrate of phosphor material is used to fabricate an X-ray focal plane array detector.

  3. Multibeam Phased Array Antennas

    NASA Technical Reports Server (NTRS)

    Popovic, Zoya; Romisch, Stefania; Rondineau, Sebastien

    2004-01-01

    In this study, a new architecture for Ka-band multi-beam arrays was developed and demonstrated experimentally. The goal of the investigation was to demonstrate a new architecture that has the potential of reducing the cost as compared to standard expensive phased array technology. The goals of this specific part of the project, as stated in the yearly statement of work in the original proposal are: 1. Investigate bounds on performance of multi-beam lens arrays in terms of beamwidths, volume (size), isolation between beams, number of simultaneous beams, etc. 2. Design a small-scale array to demonstrate the principle. The array will be designed for operation around 3OGHz (Ka-band), with two 10-degree beamwidth beams. 3. Investigate most appropriate way to accomplish fine-tuning of the beam pointing within 5 degrees around the main beam pointing angle.

  4. Expandable LED array interconnect

    DOEpatents

    Yuan, Thomas Cheng-Hsin; Keller, Bernd

    2011-03-01

    A light emitting device that can function as an array element in an expandable array of such devices. The light emitting device comprises a substrate that has a top surface and a plurality of edges. Input and output terminals are mounted to the top surface of the substrate. Both terminals comprise a plurality of contact pads disposed proximate to the edges of the substrate, allowing for easy access to both terminals from multiple edges of the substrate. A lighting element is mounted to the top surface of the substrate. The lighting element is connected between the input and output terminals. The contact pads provide multiple access points to the terminals which allow for greater flexibility in design when the devices are used as array elements in an expandable array.

  5. Multi Sensor Array

    NASA Technical Reports Server (NTRS)

    Immer, Christopher; Voska, Ned (Technical Monitor)

    2002-01-01

    This paper presents viewgraphs on the Multi Sensor Array. The topics include: 1) MSA Algorithm; 2) Types of Sensors for the MSA; 3) How to test the MSA; 4) Monte Carlo Simulation; and 5) Accelerated Life Tests.

  6. Flexible retinal electrode array

    DOEpatents

    Okandan, Murat; Wessendorf, Kurt O.; Christenson, Todd R.

    2006-10-24

    An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

  7. Glory Solar Array Deployment

    NASA Video Gallery

    The Glory spacecraft uses Orbital Sciences Corporation Space Systems Group's LEOStar-1 bus design, with deployable, four-panel solar arrays. This conceptual animation reveals Glory's unique solar a...

  8. The NMR phased array.

    PubMed

    Roemer, P B; Edelstein, W A; Hayes, C E; Souza, S P; Mueller, O M

    1990-11-01

    We describe methods for simultaneously acquiring and subsequently combining data from a multitude of closely positioned NMR receiving coils. The approach is conceptually similar to phased array radar and ultrasound and hence we call our techniques the "NMR phased array." The NMR phased array offers the signal-to-noise ratio (SNR) and resolution of a small surface coil over fields-of-view (FOV) normally associated with body imaging with no increase in imaging time. The NMR phased array can be applied to both imaging and spectroscopy for all pulse sequences. The problematic interactions among nearby surface coils is eliminated (a) by overlapping adjacent coils to give zero mutual inductance, hence zero interaction, and (b) by attaching low input impedance preamplifiers to all coils, thus eliminating interference among next nearest and more distant neighbors. We derive an algorithm for combining the data from the phased array elements to yield an image with optimum SNR. Other techniques which are easier to implement at the cost of lower SNR are explored. Phased array imaging is demonstrated with high resolution (512 x 512, 48-cm FOV, and 32-cm FOV) spin-echo images of the thoracic and lumbar spine. Data were acquired from four-element linear spine arrays, the first made of 12-cm square coils and the second made of 8-cm square coils. When compared with images from a single 15 x 30-cm rectangular coil and identical imaging parameters, the phased array yields a 2X and 3X higher SNR at the depth of the spine (approximately 7 cm). PMID:2266841

  9. Carbon nanotube array actuators

    NASA Astrophysics Data System (ADS)

    Geier, S.; Mahrholz, T.; Wierach, P.; Sinapius, M.

    2013-09-01

    Experimental investigations of highly vertically aligned carbon nanotubes (CNTs), also known as CNT-arrays, are the main focus of this paper. The free strain as result of an active material behavior is analyzed via a novel experimental setup. Previous test experiences of papers made of randomly oriented CNTs, also called Bucky-papers, reveal comparably low free strain. The anisotropy of aligned CNTs promises better performance. Via synthesis techniques like chemical vapor deposition (CVD) or plasma enhanced CVD (PECVD), highly aligned arrays of multi-walled carbon nanotubes (MWCNTs) are synthesized. Two different types of CNT-arrays are analyzed, morphologically first, and optically tested for their active characteristics afterwards. One type of the analyzed arrays features tube lengths of 750-2000 μm with a large variety of diameters between 20 and 50 nm and a wave-like CNT-shape. The second type features a maximum, almost uniform, length of 12 μm and a constant diameter of 50 nm. Different CNT-lengths and array types are tested due to their active behavior. As result of the presented tests, it is reported that the quality of orientation is the most decisive property for excellent active behavior. Due to their alignment, CNT-arrays feature the opportunity to clarify the actuation mechanism of architectures made of CNTs.

  10. Sample processing considerations for detecting copy number changes in formalin-fixed, paraffin-embedded tissues.

    PubMed

    Jacobs, Sharoni

    2012-11-01

    The Whole Genome Sampling Analysis (WGSA) assay in combination with Affymetrix GeneChip Mapping Arrays is used for copy number analysis of high-quality DNA samples (i.e., samples that have been collected from blood, fresh or frozen tissue, or cell lines). Formalin-fixed, paraffin-embedded (FFPE) samples, however, represent the most prevalent form of archived clinical samples, but they provide additional challenges for molecular assays. FFPE processing usually results in the degradation of FFPE DNA and in the contamination and chemical modification of these DNA samples. Because of these issues, FFPE DNA is not suitable for all molecular assays designed for high-quality DNA samples. Strategies recommended for processing FFPE DNA samples through WGSA and to the Mapping arrays are described here. PMID:23118355

  11. Sample processing considerations for detecting copy number changes in formalin-fixed, paraffin-embedded tissues.

    PubMed

    Jacobs, Sharoni

    2012-11-01

    The Whole Genome Sampling Analysis (WGSA) assay in combination with Affymetrix GeneChip Mapping Arrays is used for copy number analysis of high-quality DNA samples (i.e., samples that have been collected from blood, fresh or frozen tissue, or cell lines). Formalin-fixed, paraffin-embedded (FFPE) samples, however, represent the most prevalent form of archived clinical samples, but they provide additional challenges for molecular assays. FFPE processing usually results in the degradation of FFPE DNA and in the contamination and chemical modification of these DNA samples. Because of these issues, FFPE DNA is not suitable for all molecular assays designed for high-quality DNA samples. Strategies recommended for processing FFPE DNA samples through WGSA and to the Mapping arrays are described here.

  12. Evaluation of genome coverage and fidelity of multiple displacement amplification from single cells by SNP array.

    PubMed

    Ling, Jiawei; Zhuang, Guanglun; Tazon-Vega, Barbara; Zhang, Chenhui; Cao, Baoqiang; Rosenwaks, Zev; Xu, Kangpu

    2009-11-01

    The scarce amount of DNA contained in a single cell is a limiting factor for clinical application of preimplantation genetic diagnosis mainly due to the risk of misdiagnosis caused by allele dropout and the difficulty in obtaining copy number variations in all 23 pairs of chromosomes. Multiple displacement amplification (MDA) has been reported to generate large quantity of products from small amount of templates. Here, we evaluated the fidelity of whole-genome amplification MDA from single or a few cells and determined the accuracy of chromosome copy number assessment on these MDA products using an Affymetrix 10K 2.0 SNP Mapping Array. An average coverage rate (86.2%) from single cells was obtained and the rates increased significantly when five or more cells were used as templates. Higher concordance for chromosome copy number from single cells could be achieved when the MDA amplified product was used as reference (93.1%) than when gDNA used as reference (82.8%). The present study indicates that satisfactory genome coverage can be obtained from single-cell MDA which may be used for studies where only a minute amount of genetic materials is available. Clinically, MDA coupled with SNP mapping array may provide a reliable and accurate method for chromosome copy number analysis and most likely for the detection of single-gene disorders as well. PMID:19671595

  13. Sampled Longest Common Prefix Array

    NASA Astrophysics Data System (ADS)

    Sirén, Jouni

    When augmented with the longest common prefix (LCP) array and some other structures, the suffix array can solve many string processing problems in optimal time and space. A compressed representation of the LCP array is also one of the main building blocks in many compressed suffix tree proposals. In this paper, we describe a new compressed LCP representation: the sampled LCP array. We show that when used with a compressed suffix array (CSA), the sampled LCP array often offers better time/space trade-offs than the existing alternatives. We also show how to construct the compressed representations of the LCP array directly from a CSA.

  14. Microbial Cell Arrays

    NASA Astrophysics Data System (ADS)

    Elad, Tal; Lee, Jin Hyung; Gu, Man Bock; Belkin, Shimshon

    The coming of age of whole-cell biosensors, combined with the continuing advances in array technologies, has prepared the ground for the next step in the evolution of both disciplines - the whole cell array. In the present chapter, we highlight the state-of-the-art in the different disciplines essential for a functional bacterial array. These include the genetic engineering of the biological components, their immobilization in different polymers, technologies for live cell deposition and patterning on different types of solid surfaces, and cellular viability maintenance. Also reviewed are the types of signals emitted by the reporter cell arrays, some of the transduction methodologies for reading these signals, and the mathematical approaches proposed for their analysis. Finally, we review some of the potential applications for bacterial cell arrays, and list the future needs for their maturation: a richer arsenal of high-performance reporter strains, better methodologies for their incorporation into hardware platforms, design of appropriate detection circuits, the continuing development of dedicated algorithms for multiplex signal analysis, and - most importantly - enhanced long term maintenance of viability and activity on the fabricated biochips.

  15. Magnetically actuated microshutter arrays

    NASA Astrophysics Data System (ADS)

    Mott, David B.; Aslam, Shahid; Blumenstock, Kenneth A.; Fettig, Rainer K.; Franz, David E.; Kutyrev, Alexander S.; Li, Mary J.; Monroy, Carlos J.; Moseley, S. Harvey; Schwinger, David S.

    2001-10-01

    Two-dimensional microshutter arrays are being developed at NASA Goddard Space Flight Center (GSFC) for the Next Generation Space Telescope (NGST) for use in the near-infrared region. Functioning as focal plane object selection devices, the microshutter arrays are 2-D programmable masks with high efficiency and high contrast. The NGST environment requires cryogenic operation at 45 K. Arrays are close-packed silicon nitride membranes with a unit cell size of 100x100 micrometer. Individual shutters are patterned with a torsion flexure permitting shutters to open 90 degrees with minimized mechanical stress concentration. The mechanical shutter arrays are fabricated with MEMS technologies. The processing includes a RIE front-etch to form shutters out of the nitride membrane, an anisotropic back-etch for wafer thinning, and a deep RIE (DRIE) back-etch down to the nitride shutter membrane to form frames and to relieve the shutters from the silicon substrate. A layer of magnetic material is deposited onto each shutter. Onto the side-wall of the support structure a metal layer is deposited that acts as a vertical hold electrode. Shutters are rotated into the support structure by means of an external magnet that is swept across the shutter array for opening. Addressing is performed through a scheme using row and column address lines on each chip and external addressing electronics.

  16. Folding of Nucleosome Arrays

    NASA Astrophysics Data System (ADS)

    Howell, Steven; Jimenez-Useche, Isabel; Andresen, Kurt; Yuan, Chongli; Qiu, Xiangyun

    2014-03-01

    Chromatin conformation and dynamics is central to gene functions including packaging, regulation, and repair. At the molecular level, the basic building block of chromatin is a nucleosome core particle (NCP) made of 147 base pairs (bp) of dsDNA wrapped around an octamer of histone proteins. These NCPs are connected by short 10-90 bps of linker DNA as beads on a string. Key factors determining the packaging of NCP arrays to form chromatin include ionic condition, linker DNA length, and epigenetic modifications, especially of the histone tails. We have investigated how the conformations of model tetra-NCP arrays are modulated by these factors using small angle x-ray scattering (SAXS). Here we present recent studies of the effects of ion (KCl and MgCl2), linker length, and histone modification (tail deletions) on NCP arrays. Our SAXS measurement makes it possible to learn about both the global compaction of NCP arrays and local inter-NCP spatial correlations within the same array.

  17. Solar array flight experiment

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Emerging satellite designs require increasing amounts of electrical power to operate spacecraft instruments and to provide environments suitable for human habitation. In the past, electrical power was generated by covering rigid honeycomb panels with solar cells. This technology results in unacceptable weight and volume penalties when large amounts of power are required. To fill the need for large-area, lightweight solar arrays, a fabrication technique in which solar cells are attached to a copper printed circuit laminated to a plastic sheet was developed. The result is a flexible solar array with one-tenth the stowed volume and one-third the weight of comparably sized rigid arrays. An automated welding process developed to attack the cells to the printed circuit guarantees repeatable welds that are more tolerant of severe environments than conventional soldered connections. To demonstrate the flight readiness of this technology, the Solar Array Flight Experiment (SAFE) was developed and flown on the space shuttle Discovery in September 1984. The tests showed the modes and frequencies of the array to be very close to preflight predictions. Structural damping, however, was higher than anticipated. Electrical performance of the active solar panel was also tested. The flight performance and postflight data evaluation are described.

  18. Development and validation of the Axiom(®) Apple480K SNP genotyping array.

    PubMed

    Bianco, Luca; Cestaro, Alessandro; Linsmith, Gareth; Muranty, Hélène; Denancé, Caroline; Théron, Anthony; Poncet, Charles; Micheletti, Diego; Kerschbamer, Emanuela; Di Pierro, Erica A; Larger, Simone; Pindo, Massimo; Van de Weg, Eric; Davassi, Alessandro; Laurens, François; Velasco, Riccardo; Durel, Charles-Eric; Troggio, Michela

    2016-04-01

    Cultivated apple (Malus × domestica Borkh.) is one of the most important fruit crops in temperate regions, and has great economic and cultural value. The apple genome is highly heterozygous and has undergone a recent duplication which, combined with a rapid linkage disequilibrium decay, makes it difficult to perform genome-wide association (GWA) studies. Single nucleotide polymorphism arrays offer highly multiplexed assays at a relatively low cost per data point and can be a valid tool for the identification of the markers associated with traits of interest. Here, we describe the development and validation of a 487K SNP Affymetrix Axiom(®) genotyping array for apple and discuss its potential applications. The array has been built from the high-depth resequencing of 63 different cultivars covering most of the genetic diversity in cultivated apple. The SNPs were chosen by applying a focal points approach to enrich genic regions, but also to reach a uniform coverage of non-genic regions. A total of 1324 apple accessions, including the 92 progenies of two mapping populations, have been genotyped with the Axiom(®) Apple480K to assess the effectiveness of the array. A large majority of SNPs (359 994 or 74%) fell in the stringent class of poly high resolution polymorphisms. We also devised a filtering procedure to identify a subset of 275K very robust markers that can be safely used for germplasm surveys in apple. The Axiom(®) Apple480K has now been commercially released both for public and proprietary use and will likely be a reference tool for GWA studies in apple. PMID:26919684

  19. Identification and validation of copy number variants using SNP genotyping arrays from a large clinical cohort

    PubMed Central

    2012-01-01

    Background Genotypes obtained with commercial SNP arrays have been extensively used in many large case-control or population-based cohorts for SNP-based genome-wide association studies for a multitude of traits. Yet, these genotypes capture only a small fraction of the variance of the studied traits. Genomic structural variants (GSV) such as Copy Number Variation (CNV) may account for part of the missing heritability, but their comprehensive detection requires either next-generation arrays or sequencing. Sophisticated algorithms that infer CNVs by combining the intensities from SNP-probes for the two alleles can already be used to extract a partial view of such GSV from existing data sets. Results Here we present several advances to facilitate the latter approach. First, we introduce a novel CNV detection method based on a Gaussian Mixture Model. Second, we propose a new algorithm, PCA merge, for combining copy-number profiles from many individuals into consensus regions. We applied both our new methods as well as existing ones to data from 5612 individuals from the CoLaus study who were genotyped on Affymetrix 500K arrays. We developed a number of procedures in order to evaluate the performance of the different methods. This includes comparison with previously published CNVs as well as using a replication sample of 239 individuals, genotyped with Illumina 550K arrays. We also established a new evaluation procedure that employs the fact that related individuals are expected to share their CNVs more frequently than randomly selected individuals. The ability to detect both rare and common CNVs provides a valuable resource that will facilitate association studies exploring potential phenotypic associations with CNVs. Conclusion Our new methodologies for CNV detection and their evaluation will help in extracting additional information from the large amount of SNP-genotyping data on various cohorts and use this to explore structural variants and their impact on complex

  20. Synchronizing large systolic arrays

    SciTech Connect

    Fisher, A.L.; Kung, H.T.

    1982-04-01

    Parallel computing structures consist of many processors operating simultaneously. If a concurrent structure is regular, as in the case of systolic array, it may be convenient to think of all processors as operating in lock step. Totally synchronized systems controlled by central clocks are difficult to implement because of the inevitable problem of clock skews and delays. An alternate means of enforcing necessary synchronization is the use of self-timed, asynchronous schemes, at the cost of increased design complexity and hardware cost. Realizing that different circumstances call for different synchronization methods, this paper provides a spectrum of synchronization models; based on the assumptions made for each model, theoretical lower bounds on clock skew are derived, and appropriate or best-possible synchronization schemes for systolic arrays are proposed. This paper represents a first step towards a systematic study of synchronization problems for large systolic arrays.

  1. Wireless Josephson Junction Arrays

    NASA Astrophysics Data System (ADS)

    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.

  2. Solar array subsystems study

    NASA Technical Reports Server (NTRS)

    Richardson, P. W.; Miller, F. Q.; Badgley, M. B.

    1980-01-01

    The effects on life cycle costs of a number of technology areas are examined for a LEO, 500 kW solar array. A baseline system conceptual design is developed and the life cycle costs estimated in detail. The baseline system requirements and design technologies are then varied and their relationships to life cycle costs quantified. For example, the thermal characteristics of the baseline design are determined by the array materials and masses. The thermal characteristics in turn determine configuration, performance and hence life cycle cost.

  3. Automated array assembly

    NASA Technical Reports Server (NTRS)

    Williams, B. F.

    1976-01-01

    Manufacturing techniques are evaluated using expenses based on experience and studying basic cost factors for each step to evaluate expenses from a first-principles point of view. A formal cost accounting procedure is developed which is used throughout the study for cost comparisons. The first test of this procedure is a comparison of its predicted costs for array module manufacturing with costs from a study which is based on experience factors. A manufacturing cost estimate for array modules of $10/W is based on present-day manufacturing techniques, expenses, and materials costs.

  4. Wire Array Photovoltaics

    NASA Astrophysics Data System (ADS)

    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

  5. Soldered solar arrays

    NASA Astrophysics Data System (ADS)

    Allen, H. C.

    1982-06-01

    The ability of soldered interconnects to withstand a combination of long life and severe environmental conditions was investigated. Improvements in joint life from the use of solder mixes appropriate to low temperature conditons were studied. Solder samples were placed in a 150 C oven for 5 weeks (= 12 yr at 80 C, or 24 at 70 C according to Arrhenius's rule). Conventional and high solder melting point array samples underwent 1000 thermal cycles between -186 and 100 C. Results show that conventional and lead rich soldered arrays can survive 10 yr geostationary orbit missions.

  6. Photovoltaic array performance model.

    SciTech Connect

    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.

  7. Array signal processing

    SciTech Connect

    Haykin, S.; Justice, J.H.; Owsley, N.L.; Yen, J.L.; Kak, A.C.

    1985-01-01

    This is the first book to be devoted completely to array signal processing, a subject that has become increasingly important in recent years. The book consists of six chapters. Chapter 1, which is introductory, reviews some basic concepts in wave propagation. The remaining five chapters deal with the theory and applications of array signal processing in (a) exploration seismology, (b) passive sonar, (c) radar, (d) radio astronomy, and (e) tomographic imaging. The various chapters of the book are self-contained. The book is written by a team of five active researchers, who are specialists in the individual fields covered by the pertinent chapters.

  8. Automated array assembly

    NASA Technical Reports Server (NTRS)

    Daiello, R. V.

    1977-01-01

    A general technology assessment and manufacturing cost analysis was presented. A near-term (1982) factory design is described, and the results of an experimental production study for the large-scale production of flat-panel silicon and solar-cell arrays are detailed.

  9. Array processors in chemistry

    SciTech Connect

    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.

  10. TRMM Solar Array Panels

    NASA Technical Reports Server (NTRS)

    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.

  11. The Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    DeBoer, David R.; Welch, William J.; Dreher, John; Tarter, Jill; Blitz, Leo; Davis, Michael; Fleming, Matt; Bock, Douglas; Bower, Geoffrey; Lugten, John; Girmay-Keleta, G.; D'Addario, Larry R.; Harp, Gerry R.; Ackermann, Rob; Weinreb, Sander; Engargiola, Greg; Thornton, Doug; Wadefalk, Niklas

    2004-10-01

    The Allen Telescope Array, originally called the One Hectare Telescope (1hT) [1] will be a large array radio telescope whose novel characteristics will be a wide field of view (3.5 deg-GHz HPBW), continuous frequency coverage of 0.5 - 11 GHz, four dual-linear polarization output bands of 100 MHz each, four beams in each band, two 100 MHz spectral correlators for two of the bands, and hardware for RFI mitigation built in. Its scientific motivation is for deep SETI searches and, at the same time, a variety of other radio astronomy projects, including transient (e.g. pulsar) studies, HI mapping of the Milky Way and nearby galaxies, Zeeman studies of the galactic magnetic field in a number of transitions, mapping of long chain molecules in molecular clouds, mapping of the decrement in the cosmic background radiation toward galaxy clusters, and observation of HI absorption toward quasars at redshifts up to z=2. The array is planned for 350 6.1-meter dishes giving a physical collecting area of about 10,000 square meters. The large number of components reduces the price with economies of scale. The front end receiver is a single cryogenically cooled MIMIC Low Noise Amplifier covering the whole band. The feed is a wide-band log periodic feed of novel design, and the reflector system is an offset Gregorian for minimum sidelobes and spillover. All preliminary and critical design reviews have been completed. Three complete antennas with feeds and receivers are under test, and an array of 33 antennas is under construction at the Hat Creek Radio Observatory for the end of 2004. The present plan is to have a total of about 200 antennas completed by the summer of 2006 and the balance of the array finished before the end of the decade.

  12. The Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Bower, Geoffrey C.; Allen Telescope Array Team

    2010-01-01

    The ATA is a 42-element centimeter wavelength array located in Hat Creek, California and jointly operated by UC Berkeley Radio Astronomy Laboratory and the SETI Institute. Since the ATA dedication in Fall 2007, activities have been focused on commissioning the array, retrofitting a handful of components including the feed, developing an operations model, creation of pipeline processing for correlator imaging data, early science observations, and launching of the major surveys for which the telescope was built. The retrofit of the feed improves feed mechanical robustness as well as high frequency performance. Science programs launched include imaging radio transient and static sky surveys (ATATS and PiGSS), commensal SETI and transient surveys of the Galactic Center, targeted SETI observations of nearby stars, the Fly's Eye transient survey, broadband spectra of nearby star-forming galaxies, polarimetric observations of bright radio sources, observations of hydrogen in nearby galaxies and galaxy groups, molecular line observations in the Galaxy, and observations of Jupiter and the Moon. The baseline Square Kilometer Array (SKA) design, a large-N-small-diameter (LNSD) array with wide-band single-pixel feeds and an offset Gregorian antenna, bears a strong resemblance to the ATA. Additional ATA contributions to the SKA include configuration studies for LNSD arrays, the use of fiber optics for broadband data transmission, the use of flexible FPGA-based digital electronics, passive cooling of antennas, and implementation of commensal observing modes. The ATA is currently used for exploration of calibration and imaging algorithms necessary for the SKA. I will summarize current technical status and performance, the results from early science and surveys, and ATA contributions to SKA development.

  13. Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Bower, Geoffrey

    2007-05-01

    The Allen Telescope Array (ATA) is a pioneering centimeter-wavelength radio telescope that will produce science that cannot be done with any other instrument. The ATA is the first radio telescope designed for commensal observing; it will undertake the most comprehensive and sensitive SETI surveys ever done as well as the deepest and largest area continuum and spectroscopic surveys. Science operations will commence this year with a 42-element array. The ATA will ultimately comprise 350 6-meter dishes at Hat Creek in California, and will make possible large, deep radio surveys that were not previously feasible. The telescope incorporates many new design features including hydroformed antenna surfaces, a log-periodic feed covering the entire range of frequencies from 500 MHz to 11.2 GHz, low noise, wide-band amplifiers with a flat response over the entire band. The full array has the sensitivity of the Very Large Array but with a survey capability that is greater by an order of magnitude due to the wide field of view of the 6-meter dishes. Even with 42 elements, the ATA will be one of the most powerful radio survey telescopes. Science goals include the Five GHz sky survey (FiGSS) to match the 1.4-GHz NRAO VLA Sky Survey (NVSS) and the Sloan Digital Sky Survey within the first year of operation with the 42 element array, and a deep all-sky survey of extragalactic hydrogen to investigate galaxy evolution and intergalactic gas accretion. Transient and variable source surveys, pulsar science, spectroscopy of new molecular species in the galaxy, large-scale mapping of galactic magnetic filaments, and wide-field imaging of comets and other solar system objects are among the other key science objectives of the ATA. SETI surveys will reach sufficient sensitivity to detect an Arecibo planetary radar from 1,000,000 stars to distances of 300 pc.

  14. Detail of array structural elements through axis of array, looking ...

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

    Detail of array structural elements through axis of array, looking north-northeast - Over-the-Horizon Backscatter Radar Network, Columbia Falls Radar Site Receive Sector Two Antenna Array, At the end of Shadagee Ridge Road, Columbia Falls, Washington County, ME

  15. Concurrent array-based queue

    SciTech Connect

    Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2015-01-06

    According to one embodiment, a method for implementing an array-based queue in memory of a memory system that includes a controller includes configuring, in the memory, metadata of the array-based queue. The configuring comprises defining, in metadata, an array start location in the memory for the array-based queue, defining, in the metadata, an array size for the array-based queue, defining, in the metadata, a queue top for the array-based queue and defining, in the metadata, a queue bottom for the array-based queue. The method also includes the controller serving a request for an operation on the queue, the request providing the location in the memory of the metadata of the queue.

  16. Carbon nanotube array based sensor

    DOEpatents

    Lee, Christopher L.; Noy, Aleksandr; Swierkowski, Stephan P.; Fisher, Karl A.; Woods, Bruce W.

    2005-09-20

    A sensor system comprising a first electrode with an array of carbon nanotubes and a second electrode. The first electrode with an array of carbon nanotubes and the second electrode are positioned to produce an air gap between the first electrode with an array of carbon nanotubes and the second electrode. A measuring device is provided for sensing changes in electrical capacitance between the first electrode with an array of carbon nanotubes and the second electrode.

  17. Striped tape arrays

    NASA Technical Reports Server (NTRS)

    Drapeau, Ann L.; Katz, Randy H.

    1992-01-01

    A growing number of applications require high capacity, high throughput tertiary storage systems. How data striping ideas apply to arrays of magnetic tape drives is investigated. Data striping increases throughput and reduces response time for large accesses to a storage system. Striped magnetic tape systems are particularly appealing because many inexpensive magnetic tape drives have low bandwidth; striping may offer dramatic performance improvements for these systems. There are several important issues in designing striped tape systems: the choice of tape drives and robots, whether to stripe within or between robots, and the choice of the best scheme for distributing data on cartridges. One of the most troublesome problems in striped tape arrays is the synchronization of transfers across tape drives. Another issue is how improved devices will affect the desirability of striping in the future. The results of simulations comparing the performance of striped tape systems to non-striped systems are presented.

  18. The Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Deboer, David; Ackermann, Rob; Blitz, Leo; Bock, Douglas; Bower, Geoffrey; Davis, Michael; Dreher, John; Engargiola, Greg; Fleming, Matt; Keleta, Girmay; Harp, Gerry; Lugten, John; Tarter, Jill; Thornton, Doug; Wadefalk, Niklas; Weinreb, Sander; Welch, William J.

    2004-06-01

    The Allen Telescope Array, a joint project between the SETI Institute and the Radio Astronomy Laboratory at the University of California Berkeley, is currently under development and construction at the Hat Creek Radio Observatory in northern California. It will consist of 350 6.1-m offset Gregorian antennas in a fairly densely packed configuration, with minimum baselines of less than 10 m and a maximum baseline of about 900 m. The dual-polarization frequency range spans from about 500 MHz to 11 GHz, both polarizations of which are transported back from each antenna. The first generation processor will provide 32 synthesized beams of 104 MHz bandwidth, eight at each of four tunings, as well as outputs for a full-polarization correlator at two of the tunings at the same bandwidth. This paper provides a general description of the Allen Telescope Array.

  19. Microreactor Array Device

    PubMed Central

    Wiktor, Peter; Brunner, Al; Kahn, Peter; Qiu, Ji; Magee, Mitch; Bian, Xiaofang; Karthikeyan, Kailash; LaBaer, Joshua

    2015-01-01

    We report a device to fill an array of small chemical reaction chambers (microreactors) with reagent and then seal them using pressurized viscous liquid acting through a flexible membrane. The device enables multiple, independent chemical reactions involving free floating intermediate molecules without interference from neighboring reactions or external environments. The device is validated by protein expressed in situ directly from DNA in a microarray of ~10,000 spots with no diffusion during three hours incubation. Using the device to probe for an autoantibody cancer biomarker in blood serum sample gave five times higher signal to background ratio compared to standard protein microarray expressed on a flat microscope slide. Physical design principles to effectively fill the array of microreactors with reagent and experimental results of alternate methods for sealing the microreactors are presented. PMID:25736721

  20. Microreactor Array Device

    NASA Astrophysics Data System (ADS)

    Wiktor, Peter; Brunner, Al; Kahn, Peter; Qiu, Ji; Magee, Mitch; Bian, Xiaofang; Karthikeyan, Kailash; Labaer, Joshua

    2015-03-01

    We report a device to fill an array of small chemical reaction chambers (microreactors) with reagent and then seal them using pressurized viscous liquid acting through a flexible membrane. The device enables multiple, independent chemical reactions involving free floating intermediate molecules without interference from neighboring reactions or external environments. The device is validated by protein expressed in situ directly from DNA in a microarray of ~10,000 spots with no diffusion during three hours incubation. Using the device to probe for an autoantibody cancer biomarker in blood serum sample gave five times higher signal to background ratio compared to standard protein microarray expressed on a flat microscope slide. Physical design principles to effectively fill the array of microreactors with reagent and experimental results of alternate methods for sealing the microreactors are presented.

  1. The TALE Infill Array

    NASA Astrophysics Data System (ADS)

    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.

  2. Array Transposition in SSD

    NASA Technical Reports Server (NTRS)

    Bailey, David H.; Kutler, Paul (Technical Monitor)

    1998-01-01

    One obstacle to running very large two- and three-dimensional codes on the Cray X-MP and Y-MP systems is to efficiently perform array transpositions using SSD storage. This article discusses how such transpositions can be performed by means of algorithms that feature exclusively unit stride, long vector transfers between main memory and SSD, and which only require a single pass through the data (provided sufficient main memory buffers are available).

  3. Photovoltaic cell array

    NASA Technical Reports Server (NTRS)

    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.

  4. Array Transposition in SSD

    NASA Technical Reports Server (NTRS)

    Bailey, David H.; Kutler, Paul (Technical Monitor)

    1989-01-01

    One obstacle to running very large two- and three-dimensional codes on the Cray X-MP and Y-MP systems is to efficiently perform array transpositions using SSD storage. This article discusses how such transpositions can be performed by means of algorithms that feature exclusively unit stride, long vector transfers between main memory and SSD, and which only require a single pass through the data (provided sufficient main memory buffers are available).

  5. Solar collector array

    SciTech Connect

    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.

  6. Infrared Target Array Development

    NASA Astrophysics Data System (ADS)

    McIntire, Thomas O.; Scott, Edward A.

    1982-03-01

    A "life size" thermal target array has been developed to facilitate in-flight testing of airborne weapon systems containing night vision subsystems. This in-flight testing to measure the performance of the night vision subsystem and its effect on overall weapon system performance is essential to the test and evaluation process of the particular weapon under test. This measurement of subsystem performance is called the Modulation Transfer Function, or MTF. In addition, a laser designator subsystem is frequently incorporated in a precision guided munition weapon system. In the test and evaluation of the designator, such quantities as beam quality (energy distribution), beam divergence, and beam wander are of interest. The thermal targets may be used to evaluate armored weapon systems. The capability of providing carefully controlled and variable thermal signatures in a field test environment is considered unique. The thermal target array consists of three targets: A six bar recognition target, a two bar detection target, and a laser designator scoring board (cross-hair). The image dimensions of 2.3 meters by 2.3 meters were derived from an optimized threat envelope. The thermal signatures of the targets are controllable to within 0.3 C about a differential setpoint. This differential setpoint is measured between the active element and the target background (or "ambient"). Several differential temperature settings are available to the test officer: 1.25°C, 3°C, 5°C, 7.5°C, and 10°C. This paper reviews the thermal array test objectives, target array fabrication, methodology of target utilization, and representative results.

  7. The CHARA optical array

    NASA Astrophysics Data System (ADS)

    McAlister, Harold A.

    1992-11-01

    The Center for High Angular Resolution Astronomy (CHARA) was established in the College of Arts and Sciences at Georgia State University in 1984 with the goals of designing, constructing, and then operating a facility for very high spatial resolution astronomy. The interest in such a facility grew out of the participants' decade of activity in speckle interferometry. Although speckle interferometry continues to provide important astrophysical measurements of a variety of objects, many pressing problems require resolution far beyond that which can be expected from single aperture telescopes. In early 1986, CHARA received a grant from the National Science Foundation which has permitted a detailed exploration of the feasibility of constructing a facility which will provide a hundred-fold increase in angular resolution over what is possible by speckle interferometry at the largest existing telescopes. The design concept for the CHARA Array was developed initially with the contractural collaboration of United Technologies Optical Systems, Inc., in West Palm Beach, Florida, an arrangement that expired in August 1987. In late November 1987, the Georgia Tech Research Institute joined with CHARA to continue and complete the design concept study. Very high-resolution imaging at optical wavelengths is clearly coming of age in astronomy. The CHARA Array and other related projects will be important and necessary milestones along the way toward the development of a major national facility for high-resolution imaging--a true optical counterpart to the Very Large Array. Ground-based arrays and their scientific output will lead to high resolution facilities in space and, ultimately, on the Moon.

  8. Mir Cooperative Solar Array

    NASA Technical Reports Server (NTRS)

    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.

  9. Array processor architecture

    NASA Technical Reports Server (NTRS)

    Barnes, George H. (Inventor); Lundstrom, Stephen F. (Inventor); Shafer, Philip E. (Inventor)

    1983-01-01

    A high speed parallel array data processing architecture fashioned under a computational envelope approach includes a data base memory for secondary storage of programs and data, and a plurality of memory modules interconnected to a plurality of processing modules by a connection network of the Omega gender. Programs and data are fed from the data base memory to the plurality of memory modules and from hence the programs are fed through the connection network to the array of processors (one copy of each program for each processor). Execution of the programs occur with the processors operating normally quite independently of each other in a multiprocessing fashion. For data dependent operations and other suitable operations, all processors are instructed to finish one given task or program branch before all are instructed to proceed in parallel processing fashion on the next instruction. Even when functioning in the parallel processing mode however, the processors are not locked-step but execute their own copy of the program individually unless or until another overall processor array synchronization instruction is issued.

  10. Spaceborne Processor Array

    NASA Technical Reports Server (NTRS)

    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.

  11. DSN Array Simulator

    NASA Technical Reports Server (NTRS)

    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.

  12. Solar array construction

    DOEpatents

    Crouthamel, Marvin S.; Coyle, Peter J.

    1982-01-01

    An interconnect tab on each cell of a first set of circular solar cells connects that cell in series with an adjacent cell in the set. This set of cells is arranged in alternate columns and rows of an array and a second set of similar cells is arranged in the remaining alternate columns and rows of the array. Three interconnect tabs on each solar cell of the said second set are employed to connect the cells of the second set to one another, in series and to connect the cells of the second set to those of the first set in parallel. Some tabs (making parallel connections) connect the same surface regions of adjacent cells to one another and others (making series connections) connect a surface region of one cell to the opposite surface region of an adjacent cell; however, the tabs are so positioned that the array may be easily assembled by depositing the cells in a certain sequence and in proper orientation.

  13. Solid state neutron detector array

    DOEpatents

    Seidel, John G.; Ruddy, Frank H.; Brandt, Charles D.; Dulloo, Abdul R.; Lott, Randy G.; Sirianni, Ernest; Wilson, Randall O.

    1999-01-01

    A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors.

  14. Solid state neutron detector array

    DOEpatents

    Seidel, J.G.; Ruddy, F.H.; Brandt, C.D.; Dulloo, A.R.; Lott, R.G.; Sirianni, E.; Wilson, R.O.

    1999-08-17

    A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors. 7 figs.

  15. A genomic approach to myoblast fusion in Drosophila

    PubMed Central

    Estrada, Beatriz; Michelson, Alan M.

    2009-01-01

    Summary We have developed an integrated genetic, genomic and computational approach to identify and characterize genes involved in myoblast fusion in Drosophila. We first used fluorescence activated cell sorting to purify mesodermal cells both from wild-type embryos and from twelve variant genotypes in which muscle development is perturbed in known ways. Then, we obtained gene expression profiles for the purified cells by hybridizing isolated mesodermal RNA to Affymetrix GeneChip arrays. These data were subsequently compounded into a statistical meta-analysis that predicts myoblast subtype-specific gene expression signatures that were later validated by in situ hybridization experiments. Finally, we analyzed the myogenic functions of a subset of these myoblast genes using a double-stranded RNA interference assay in living embryos expressing green fluorescent protein under control of a muscle-specific promoter. This experimental strategy led to the identification of several previously uncharacterized genes required for myoblast fusion in Drosophila. PMID:18979251

  16. Data analysis considerations for detecting copy number changes in formalin-fixed, paraffin-embedded tissues.

    PubMed

    Jacobs, Sharoni

    2012-11-01

    The Whole Genome Sampling Analysis (WGSA) assay in combination with Affymetrix GeneChip Mapping Arrays is used for copy number analysis of high-quality DNA samples (i.e., samples that have been collected from blood, fresh or frozen tissue, or cell lines). Formalin-fixed, paraffin-embedded (FFPE) samples, however, represent the most prevalent form of archived clinical samples, but they provide additional challenges for molecular assays. FFPE processing usually results in the degradation of FFPE DNA and in the contamination and chemical modification of these DNA samples. In this article, we describe the steps needed to obtain reliable copy number predictions from degraded and contaminated FFPE samples. PMID:23118356

  17. Cloning and characterization of the drought-resistance OsRCI2-5 gene in rice (Oryza sativa L.).

    PubMed

    Li, L; Li, N; Song, S F; Li, Y X; Xia, X J; Fu, X Q; Chen, G H; Deng, H F

    2014-01-01

    The genomic expression profile of the super-hybrid rice Liangyoupeijiu female parent Pei'ai 64S in different tissues at different developmental stages under low temperature, drought, and high temperature stresses were detected using an Affymetrix GeneChip Rice Genome Array to screen upregulated and downregulated genes. In this study, we screened the drought-resistant gene OsRCI2-5, after which a constitutive OsRCI2-5 construct was created and transferred into Nipponbare. After polyethylene glycol-6000 and drought treatment, we found that the OsRCI2-5 gene improved the drought resistance of Nipponbare. Gene expression profiling showed that the OsRCI2-5 gene was expressed in the rice leaves, stems, and flower organs. Subcellular localization revealed that the gene was located in the membranes, and hence, we can deduce that a membrane signal peptide was responsible for signal transduction. PMID:24938613

  18. Single-Nucleotide Polymorphism Array-Based Karyotyping of Acute Promyelocytic Leukemia

    PubMed Central

    Gómez-Seguí, Inés; Sánchez-Izquierdo, Dolors; Barragán, Eva; Such, Esperanza; Luna, Irene; López-Pavía, María; Ibáñez, Mariam; Villamón, Eva; Alonso, Carmen; Martín, Iván; Llop, Marta; Dolz, Sandra; Fuster, Óscar; Montesinos, Pau; Cañigral, Carolina; Boluda, Blanca; Salazar, Claudia

    2014-01-01

    Acute promyelocytic leukemia (APL) is characterized by the t(15;17)(q22;q21), but additional chromosomal abnormalities (ACA) and other rearrangements can contribute in the development of the whole leukemic phenotype. We hypothesized that some ACA not detected by conventional techniques may be informative of the onset of APL. We performed the high-resolution SNP array (SNP-A) 6.0 (Affymetrix) in 48 patients diagnosed with APL on matched diagnosis and remission sample. Forty-six abnormalities were found as an acquired event in 23 patients (48%): 22 duplications, 23 deletions and 1 Copy-Neutral Loss of Heterozygocity (CN-LOH), being a duplication of 8(q24) (23%) and a deletion of 7(q33-qter) (6%) the most frequent copy-number abnormalities (CNA). Four patients (8%) showed CNAs adjacent to the breakpoints of the translocation. We compared our results with other APL series and found that, except for dup(8q24) and del(7q33-qter), ACA were infrequent (≤3%) but most of them recurrent (70%). Interestingly, having CNA or FLT3 mutation were mutually exclusive events. Neither the number of CNA, nor any specific CNA was associated significantly with prognosis. This study has delineated recurrent abnormalities in addition to t(15;17) that may act as secondary events and could explain leukemogenesis in up to 40% of APL cases with no ACA by conventional cytogenetics. PMID:24959826

  19. The Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Terzian, Yervant; Lazio, Joseph

    2006-06-01

    The Square Kilometre Array (SKA) is the future centimeter- and meter-wavelength telescope with a sensitivity about 50 times higher than present instruments. Its Key Science Projects are (a) Astrobiology including planetary formation within protoplanetary disks; (b) Testing theories of gravitation using an array of pulsars to search for gravitational waves and relativistic binaries to probe the strong-field regime; (c) The origin and evolution of cosmic magnetism, both within the Galaxy and in intergalactic space, via an all-sky grid of magnetic field measurements; (d) The end of the Dark Ages, involving searches for a neutral hydrogen signature, the first supermassive black holes, and the first metal-rich systems; and (e) A hydrogen census to a redshift z greater than or equal to 1 from which to study the evolution of galaxies, dark matter, and dark energy. The SKA will operate at wavelengths from 1.2 cm to 3 m (0.1-25 GHz), providing milliarcsecond resolution at the shortest wavelengths. Its instantaneous field of view will be about 1° (20 cm wavelength), with many simultaneous beams on the sky. The Reference Design is composed of a large number of small dish antennas, building upon an original US proposal. In order to obtain these capabilities at a reasonable cost, significant engineering investments are being made in antennas, wideband feeds and receivers, and signal processing; aperture arrays (phased feeds) are also being investigated in Europe for the lower frequencies. Candidate sites are in Argentina, Australia, China, and South Africa, with a short list of acceptable sites anticipated late in 2006.

  20. Diode laser array

    NASA Technical Reports Server (NTRS)

    Carlson, Nils W. (Inventor); Evans, Gary A. (Inventor); Kaiser, Charlie J. (Inventor)

    1990-01-01

    A diode laser array comprises a substrate of a semiconductor material having first and second opposed surfaces. On the first surface is a plurality of spaced gain sections and a separate distributed Bragg reflector passive waveguide at each end of each gain section and optically connecting the gain sections. Each gain section includes a cavity therein wherein charge carriers are generated and recombine to generate light which is confined in the cavity. Also, the cavity, which is preferably a quantum well cavity, provides both a high differential gain and potentially large depth of loss modulation. Each waveguide has a wavelength which is preferably formed by an extension of the cavity of the gain sections and a grating. The grating has a period which provides a selective feedback of light into the gain sections to supporting lasing, which allows some of the light to be emitted from the waveguide normal to the surface of the substrate and which allows optical coupling of the gain sections. Also, the grating period provides an operating wavelength which is on the short wavelength side of the gain period of the gain sections required for laser oscillation. An RF pulse is applied so as to maximize the magnitude of the loss modulation and the differential gain in the gain sections. The array is operated by applying a DC bias to all the gain sections at a level just below the threshold of the gain sections to only one of the gain sections which raises the bias in all of the gain sections to a level that causes all of the gain sections to oscillate. Thus, a small bias can turn the array on and off.

  1. UAVSAR Phased Array Aperture

    NASA Technical Reports Server (NTRS)

    Chamberlain, Neil; Zawadzki, Mark; Sadowy, Greg; Oakes, Eric; Brown, Kyle; Hodges, Richard

    2009-01-01

    This paper describes the development of a patch antenna array for an L-band repeat-pass interferometric synthetic aperture radar (InSAR) instrument that is to be flown on an unmanned aerial vehicle (UAV). The antenna operates at a center frequency of 1.2575 GHz and with a bandwidth of 80 MHz, consistent with a number of radar instruments that JPL has previously flown. The antenna is designed to radiate orthogonal linear polarizations in order to facilitate fully-polarimetric measurements. Beam-pointing requirements for repeat-pass SAR interferometry necessitate electronic scanning in azimuth over a range of -20degrees in order to compensate for aircraft yaw. Beam-steering is accomplished by transmit/receive (T/R) modules and a beamforming network implemented in a stripline circuit board. This paper, while providing an overview of phased array architecture, focuses on the electromagnetic design of the antenna tiles and associated interconnects. An important aspect of the design of this antenna is that it has an amplitude taper of 10dB in the elevation direction. This is to reduce multipath reflections from the wing that would otherwise be detrimental to interferometric radar measurements. This taper is provided by coupling networks in the interconnect circuits as opposed to attenuating the output of the T/R modules. Details are given of material choices and fabrication techniques that meet the demanding environmental conditions that the antenna must operate in. Predicted array performance is reported in terms of co-polarized and crosspolarized far-field antenna patterns, and also in terms of active reflection coefficient.

  2. Unravelling the Complexity of Human Olfactory Receptor Repertoire by Copy Number Analysis across Population Using High Resolution Arrays

    PubMed Central

    Veerappa, Avinash M.; Vishweswaraiah, Sangeetha; Lingaiah, Kusuma; Murthy, Megha; Manjegowda, Dinesh S.; Nayaka, Radhika; Ramachandra, Nallur B.

    2013-01-01

    Olfactory receptors (OR), responsible for detection of odor molecules, belong to the largest family of genes and are highly polymorphic in nature having distinct polymorphisms associated with specific regions around the globe. Since there are no reports on the presence of copy number variations in OR repertoire of Indian population, the present investigation in 43 Indians along with 270 HapMap and 31 Tibetan samples was undertaken to study genome variability and evolution. Analysis was performed using Affymetrix Genome-Wide Human SNP Array 6.0 chip, Affymterix CytoScan® High-Density array, HD-CNV, and MAFFT program. We observed a total of 1527 OR genes in 503 CNV events from 81.3% of the study group, which includes 67.6% duplications and 32.4% deletions encompassing more of genes than pseudogenes. We report human genotypic variation in functional OR repertoire size across populations and it was found that the combinatorial effect of both “orthologous obtained from closely related species” and “paralogous derived sequences” provide the complexity to the continuously occurring OR CNVs. PMID:23843967

  3. Next generation genome-wide association tool: Design and coverage of a high-throughput European-optimized SNP array

    PubMed Central

    Hoffmann, Thomas J.; Kvale, Mark N.; Hesselson, Stephanie E.; Zhan, Yiping; Aquino, Christine; Cao, Yang; Cawley, Simon; Chung, Elaine; Connell, Sheryl; Eshragh, Jasmin; Ewing, Marcia; Gollub, Jeremy; Henderson, Mary; Hubbell, Earl; Iribarren, Carlos; Kaufman, Jay; Lao, Richard Z.; Lu, Yontao; Ludwig, Dana; Mathauda, Gurpreet K.; McGuire, William; Mei, Gangwu; Miles, Sunita; Purdy, Matthew M.; Quesenberry, Charles; Ranatunga, Dilrini; Rowell, Sarah; Sadler, Marianne; Shapero, Michael H.; Shen, Ling; Shenoy, Tanushree R.; Smethurst, David; Van den Eeden, Stephen K.; Walter, Larry; Wan, Eunice; Wearley, Reid; Webster, Teresa; Wen, Christopher C.; Weng, Li; Whitmer, Rachel A.; Williams, Alan; Wong, Simon C.; Zau, Chia; Finn, Andrea; Schaefer, Catherine; Kwok, Pui-Yan; Risch, Neil

    2011-01-01

    The success of genome-wide association studies has paralleled the development of efficient genotyping technologies. We describe the development of a next-generation microarray based on the new highly-efficient Affymetrix Axiom genotyping technology that we are using to genotype individuals of European ancestry from the Kaiser Permanente Research Program on Genes, Environment and Health (RPGEH). The array contains 674,517 SNPs, and provides excellent genome-wide as well as gene-based and candidate-SNP coverage. Coverage was calculated using an approach based on imputation and cross validation. Preliminary results for the first 80,301 saliva-derived DNA samples from the RPGEH demonstrate very high quality genotypes, with sample success rates above 94% and over 98% of successful samples having SNP call rates exceeding 98%. At steady state, we have produced 462 million genotypes per week for each Axiom system. The new array provides a valuable addition to the repertoire of tools for large scale genome-wide association studies. PMID:21565264

  4. Copy-Number Variations Measured by Single-Nucleotide–Polymorphism Oligonucleotide Arrays in Patients with Mental Retardation

    PubMed Central

    Wagenstaller, Janine ; Spranger, Stephanie ; Lorenz-Depiereux, Bettina ; Kazmierczak, Bernd ; Nathrath, Michaela ; Wahl, Dagmar ; Heye, Babett ; Gläser, Dieter ; Liebscher, Volkmar ; Meitinger, Thomas ; Strom, Tim M. 

    2007-01-01

    Whole-genome analysis using high-density single-nucleotide–polymorphism oligonucleotide arrays allows identification of microdeletions, microduplications, and uniparental disomies. We studied 67 children with unexplained mental retardation with normal karyotypes, as assessed by G-banded chromosome analyses. Their DNAs were analyzed with Affymetrix 100K arrays. We detected 11 copy-number variations that most likely are causative of mental retardation, because they either arose de novo (9 cases) and/or overlapped with known microdeletions (2 cases). The eight deletions and three duplications varied in size from 200 kb to 7.5 Mb. Of the 11 copy-number variations, 5 were flanked by low-copy repeats. Two of those, on chromosomes 15q25.2 and Xp22.31, have not been described before and have a high probability of being causative of new deletion and duplication syndromes, respectively. In one patient, we found a deletion affecting only a single gene, MBD5, which codes for the methyl-CpG-binding domain protein 5. In addition to the 67 children, we investigated 4 mentally retarded children with apparent balanced translocations and detected four deletions at breakpoint regions ranging in size from 1.1 to 14 Mb. PMID:17847001

  5. A systolic array architecture for the Applebaum-Howells array

    NASA Astrophysics Data System (ADS)

    Ueno, Motoharu; Kawabata, K.; Morooka, Tasuku

    1990-08-01

    A systolic array architecture for the Applebaum-Howells array is derived. The problem to be solved is the elimination of the global signal feedback loop in the conventional Applebaum-Howells array processor. The procedure involved in deriving the architecture consists of two steps: orthogonalization of the input element signals and elimination of the feedback loop. In the first step, the input element signals are orthogonalized with regard to each other by using the Gram-Schmidt processor, placed ahead of the Applebaum-Howells processor. It is shown in the second step that the orthogonality in the Gram-Schmidt processor output signals can remove the global signal feedback loop and that the Applebaum-Howells array can be implemented effectively by using a systolic array with regular structure and local communication. Simulation results also show that the proposed processor features desirable characteristics for the radiation pattern with low sidelobe level common to the Applebaum-Howells array.

  6. The Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Dreher, J.

    2006-12-01

    The ATA will be a massively parallel array of 350 6-m antennas operating from 0.5 GHz to 11.3 GHz. It will be a superb instrument for both surveys and for imaging large, complex sources. By exploiting recent drops in the cost of electronics and by adopting the simplest possible design, the cost of the ATA will be significantly less than that of existing 100-m class telescopes. The ATA offers a very large primary field of view that may be imaged with a spectralline correlator and, at the same time, be studied with 16 dual-polarization pencil beams. The ATA also will have unique capabilities for very high fidelity imaging and for RFI excision. Central to the design is a high performance, yet cost effective, antenna with a Gregorian reflector system, connected to a novel ultrawide- band, log-periodic feed. Analog fiber is used to eliminate most of the electronics that are located at the antennas in more conventional arrays, allowing for a massively parallel signal processing design that offers enormous flexibility. A 42-element version of the ATA will begin observing in 2006.

  7. Electromagnetically Clean Solar Arrays

    NASA Technical Reports Server (NTRS)

    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

  8. Electrode array for neural stimulation

    DOEpatents

    Wessendorf, Kurt O.; Okandan, Murat; Stein, David J.; Yang, Pin; Cesarano, III, Joseph; Dellinger, Jennifer

    2011-08-16

    An electrode array for neural stimulation is disclosed which has particular applications for use in a retinal prosthesis. The electrode array can be formed as a hermetically-sealed two-part ceramic package which includes an electronic circuit such as a demultiplexer circuit encapsulated therein. A relatively large number (up to 1000 or more) of individually-addressable electrodes are provided on a curved surface of a ceramic base portion the electrode array, while a much smaller number of electrical connections are provided on a ceramic lid of the electrode array. The base and lid can be attached using a metal-to-metal seal formed by laser brazing. Electrical connections to the electrode array can be provided by a flexible ribbon cable which can also be used to secure the electrode array in place.

  9. Electrodynamic Arrays Having Nanomaterial Electrodes

    NASA Technical Reports Server (NTRS)

    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.

  10. Active membrane phased array radar

    NASA Technical Reports Server (NTRS)

    Moussessian, Alina; Del Castillo, Linda; Huang, John; Sadowy, Greg; Hoffman, James; Smith, Phil; Hatake, Toshiro; Derksen, Chuck; Lopez, Bernardo; Caro, Ed

    2005-01-01

    We have developed the first membrane-based active phased array in L-band (1.26GHz). The array uses membrane compatible Transmit/Receive (T/R) modules (membrane T/R) for each antenna element. We use phase shifters within each T/R module for electronic beam steering. We will discuss the T/R module design and integration with the membrane, We will also present transmit and receive beam-steering results for the array.

  11. Integrated residential photovoltaic array development

    NASA Astrophysics Data System (ADS)

    Shepard, N. F., Jr.

    1981-12-01

    An advanced, universally-mountable, integrated residential photovoltaic array concept was defined based upon an in-depth formulation and evaluation of three candidate approaches which were synthesized from existing or proposed residential array concepts. The impact of module circuitry and process sequence is considered and technology gaps and performance drivers associated with residential photovoltaic array concepts are identified. The actual learning experience gained from the comparison of the problem areas of the hexagonal shingle design with the rectangular module design led to what is considered an advanced array concept. Building the laboratory mockup provided actual experience and the opportunity to uncover additional technology gaps.

  12. Integrated residential photovoltaic array development

    NASA Technical Reports Server (NTRS)

    Shepard, N. F., Jr.

    1981-01-01

    An advanced, universally-mountable, integrated residential photovoltaic array concept was defined based upon an in-depth formulation and evaluation of three candidate approaches which were synthesized from existing or proposed residential array concepts. The impact of module circuitry and process sequence is considered and technology gaps and performance drivers associated with residential photovoltaic array concepts are identified. The actual learning experience gained from the comparison of the problem areas of the hexagonal shingle design with the rectangular module design led to what is considered an advanced array concept. Building the laboratory mockup provided actual experience and the opportunity to uncover additional technology gaps.

  13. Efficient Array Design for Sonotherapy

    PubMed Central

    Stephens, Douglas N.; Kruse, Dustin E.; Ergun, Arif S.; Barnes, Stephen; Ming Lu, X.; Ferrara, Katherine

    2008-01-01

    New linear multi-row, multi-frequency arrays have been designed, constructed and tested as fully operational ultrasound probes to produce confocal imaging and therapeutic acoustic intensities with a standard commercial ultrasound imaging system. The triple-array probes and imaging system produce high quality B-mode images with a center row imaging array at 5.3 MHz, and sufficient acoustic power with dual therapeutic arrays to produce mild hyperthermia at 1.54 MHz. The therapeutic array pair in the first probe design (termed G3) utilizes a high bandwidth and peak pressure, suitable for mechanical therapies. The second multi-array design (termed G4) has a redesigned therapeutic array pair which is optimized for high time-averaged power output suitable for mild hyperthermia applications. The “thermal therapy” design produces more than 4 Watts of acoustic power from the low frequency arrays with only a 10.5 °C internal rise in temperature after 100 seconds of continuous use with an unmodified conventional imaging system, or substantially longer operation at lower acoustic power. The low frequency arrays in both probe designs were examined and contrasted for real power transfer efficiency with a KLM model which includes all lossy contributions in the power delivery path from system transmitters to tissue load. Laboratory verification was successfully performed for the KLM derived estimates of transducer parallel model acoustic resistance and dissipation resistance, which are the critical design factors for acoustic power output and undesired internal heating respectively. PMID:18591737

  14. Future directions for NICMOS arrays

    NASA Technical Reports Server (NTRS)

    Thompson, R.; Rieke, Marcia J.; Young, Erick T.; Mccarthy, D.; Rasche, Robert; Blessinger, Michael; Vural, Kadri; Kleinhans, William

    1989-01-01

    The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) for the Hubble Space Telescope (HST) requires focal plane arrays of 256x256 pixels for both its cameras and its spectrometers. The new arrays, developed by the Rockwell Corporation for NICMOS, have 40 microns pixels of HgCdTe bump bonded to a switched MOSFET readout. Expected read noise and dark current for the arrays at 60 K are 30 e and 1 e/sec. respectively. The basis for these numbers is previous experience with 128x128 arrays.

  15. Nanoelectrode array for electrochemical analysis

    DOEpatents

    Yelton, William G.; Siegal, Michael P.

    2009-12-01

    A nanoelectrode array comprises a plurality of nanoelectrodes wherein the geometric dimensions of the electrode controls the electrochemical response, and the current density is independent of time. By combining a massive array of nanoelectrodes in parallel, the current signal can be amplified while still retaining the beneficial geometric advantages of nanoelectrodes. Such nanoelectrode arrays can be used in a sensor system for rapid, non-contaminating field analysis. For example, an array of suitably functionalized nanoelectrodes can be incorporated into a small, integrated sensor system that can identify many species rapidly and simultaneously under field conditions in high-resistivity water, without the need for chemical addition to increase conductivity.

  16. In arrayed ranks: array technology in the study of mesothelioma.

    PubMed

    Gray, Steven G; Fennell, Dean A; Mutti, Luciano; O'Byrne, Kenneth J

    2009-03-01

    Mesothelioma is a rare malignancy arising from mesothelial cells lining the pleura and peritoneum. Advances in modern technology have allowed the development of array based approaches to the study of disease allowing researchers the opportunity to study many genes or proteins in a high-throughput fashion. This review describes the current knowledge surrounding array based approaches with respect to mesothelioma research.

  17. Diagnosable structured logic array

    NASA Technical Reports Server (NTRS)

    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.

  18. Solitons in optomechanical arrays.

    PubMed

    Gan, Jing-Hui; Xiong, Hao; Si, Liu-Gang; Lü, Xin-You; Wu, Ying

    2016-06-15

    We show that optical solitons can be obtained with a one-dimensional optomechanical array that consists of a chain of periodically spaced identical optomechanical systems. Unlike conventional optical solitons, which originate from nonlinear polarization, the optical soliton here stems from a new mechanism, namely, phonon-photon interaction. Under proper conditions, the phonon-photon induced nonlinearity that refers to the optomechanical nonlinearity will exactly compensate the dispersion caused by photon hopping of adjacent optomechanical systems. Moreover, the solitons are capable of exhibiting very low group velocity, depending on the photon hopping rate, which may lead to many important applications, including all-optical switches and on-chip optical architecture. This work may extend the range of optomechanics and nonlinear optics and provide a new field to study soliton theory and develop corresponding applications. PMID:27304261

  19. Array biosensor: recent developments

    NASA Astrophysics Data System (ADS)

    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.

  20. Microcavity array IR photodetector

    SciTech Connect

    Esman, A K; Kuleshov, V K; Zykov, G L

    2009-12-31

    An original microcavity array IR photodetector is proposed and the sensitivity and response time of its pixels are calculated. A photosensitive element represents a composite silicon microcavity made of two optically coupled closed waveguides on a dielectric substrate whose resonance wave depends on its temperature. This dependence is used to detect IR radiation which heats an absorbing element and the composite microcavity thermally coupled with this element. It is shown that for a spatial resolution of 45 {mu}m, the time response is 30 ms and the sensitivity is 10{sup -3} K at the IR radiation power of {approx} 4.7 x 10{sup -8} W element{sup -1}. (photodetectors)

  1. Networked Sensor Arrays

    SciTech Connect

    R. J. Tighe

    2002-10-01

    A set of independent radiation sensors, coupled with real-time data telemetry, offers the opportunity to run correlation algorithms for the sensor array as well as to incorporate non-radiological data into the system. This may enhance the overall sensitivity of the sensors and provide an opportunity to project the location of a source within the array. In collaboration with Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories (SNL), we have conducted field experiments to test a prototype system. Combining the outputs of a set of distributed sensors permits the correlation that the independent sensor outputs. Combined with additional information such as traffic patterns and velocities, this can reduce random/false detections and enhance detection capability. The principle components of such a system include: (1) A set of radiation sensors. These may be of varying type and complexity, including gamma and/or neutron detectors, gross count and spectral-capable sensors, and low to high energy-resolution sensors. (2) A set of non-radiation sensors. These may include sensors such as vehicle presence and imaging sensors. (3) A communications architecture for near real-time telemetry. Depending upon existing infrastructure and bandwidth requirements, this may be a radio or hard-wire based system. (4) A central command console to pole the sensors, correlate their output, and display the data in a meaningful form to the system operator. Both sensitivity and selectivity are important considerations when evaluating the performance of a detection system. Depending on the application, the optimization of sensitivity as well as the rejection of ''nuisance'' radioactive sources may or may not be critical.

  2. TRMM Solar Array

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Basic requirement of 978.59 watts per Panel output @ 58.9 volts B.O.L. was met on an average basis per agreement with NASA. Lower grade Cells were used on the shadowed Panel (Boom shadow) to maximize available power to the Spacecraft. The average output @ 58.9 volts was 991 watts. The outputs of the four t4) Panels ranged from 960 to 1,022 watts. The Panels successfully passed environmental testing at TRW to the contract specification and subsequent testing at NASA which involved output measurements at elevated temperatures. As this type of Array had never previously been built by TRW (aluminum Substrate with 4 cm x 4.4 cm GaAs Cells), the TRMM Program was a development effort combined with a Qual and Flight production effort. The most significant technical problem was Cell cracking during Qual thermal cycling. The cracking problem was determined to be generic within our Solar Array factory in the application of GaAs Cells to our designs. As a result, a TRW funded manufacturing process verification panel (known as the Manufacturing Verification Panel) was built to demonstrate our ability to properly apply GaAs Cells. The original Qual Panel comprised three (3) design variations with respect to Coverglass-to-Cell and Cell-to-Substrate adhesives. The intent was to qualify multiple designs in case one or more failed. When two of the three combinations failed due to excessive Cell breakage during thermal cycling, NASA was reluctant to allow Flight production based on the one remaining good Qual Panel Quadrant. This issue was pivotal for continuing the contract. Facts and recommendations are as follows: (1) The cause of the excessive cracking was never determined. and (2) The areas where the excessive cracking occurred utilized DC93-500 glassing adhesive which was NASA approved, and had been widely used by TRW on a multitude of projects.

  3. High Voltage Space Solar Arrays

    NASA Technical Reports Server (NTRS)

    Ferguson, D. C.; Hillard, G. B.; Vayner, B. V.; Galofaro, J. T.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Recent tests performed at the NASA Glenn Research Center and elsewhere have shown promise in the design and construction of high voltage (300-1000 V) solar arrays for space applications. Preliminary results and implications for solar array design will be discussed, with application to direct-drive electric propulsion and space solar power.

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

    NASA Astrophysics Data System (ADS)

    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

  5. Gene Expression and Genetic Variation in Human Atria

    PubMed Central

    Lin, Honghuang; Dolmatova, Elena V.; Morley, Michael P.; Lunetta, Kathryn L.; McManus, David D.; Magnani, Jared W.; Margulies, Kenneth B.; Hakonarson, Hakon; del Monte, Federica; Benjamin, Emelia J.; Cappola, Thomas P.; Ellinor, Patrick T.

    2013-01-01

    Background The human left and right atria have different susceptibilities to develop atrial fibrillation (AF). However, the molecular events related to structural and functional changes that enhance AF susceptibility are still poorly understood. Objective To characterize gene expression and genetic variation in human atria. Methods We studied the gene expression profiles and genetic variations in 53 left atrial and 52 right atrial tissue samples collected from the Myocardial Applied Genomics Network (MAGNet) repository. The tissues were collected from heart failure patients undergoing transplantation and from unused organ donor hearts with normal ventricular function. Gene expression was profiled using the Affymetrix GeneChip Human Genome U133A Array. Genetic variation was profiled using the Affymetrix Genome-Wide Human SNP Array 6.0. Results We found that 109 genes were differentially expressed between left and right atrial tissues. A total of 187 and 259 significant cis-associations between transcript levels and genetic variants were identified in left and right atrial tissues, respectively. We also found that a SNP at a known AF locus, rs3740293, was associated with the expression of MYOZ1 in both left and right atrial tissues. Conclusion We found a distinct transcriptional profile between the right and left atrium, and extensive cis-associations between atrial transcripts and common genetic variants. Our results implicate MYOZ1 as the causative gene at the chromosome 10q22 locus for AF. PMID:24177373

  6. Passive microfluidic array card and reader

    SciTech Connect

    Dugan, Lawrence Christopher; Coleman, Matthew A.

    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.

  7. A systolic array parallelizing compiler

    SciTech Connect

    Tseng, P.S. )

    1990-01-01

    This book presents a completely new approach to the problem of systolic array parallelizing compiler. It describes the AL parallelizing compiler for the Warp systolic array, the first working systolic array parallelizing compiler which can generate efficient parallel code for complete LINPACK routines. This book begins by analyzing the architectural strength of the Warp systolic array. It proposes a model for mapping programs onto the machine and introduces the notion of data relations for optimizing the program mapping. Also presented are successful applications of the AL compiler in matrix computation and image processing. A complete listing of the source program and compiler-generated parallel code are given to clarify the overall picture of the compiler. The book concludes that systolic array parallelizing compiler can produce efficient parallel code, almost identical to what the user would have written by hand.

  8. Loudspeaker line array educational demonstration.

    PubMed

    Anderson, Brian E; Moser, Brad; Gee, Kent L

    2012-03-01

    This paper presents a physical demonstration of an audio-range line array used to teach interference of multiple sources in a classroom or laboratory exercise setting. Software has been developed that permits real-time control and steering of the array. The graphical interface permits a user to vary the frequency, the angular response by phase shading, and reduce sidelobes through amplitude shading. An inexpensive, eight-element loudspeaker array has been constructed to test the control program. Directivity measurements of this array in an anechoic chamber and in a large classroom are presented. These measurements have good agreement with theoretical directivity predictions, thereby allowing its use as a quantitative learning tool for advanced students as well as a qualitative demonstration of arrays in other settings. Portions of this paper are directed toward educators who may wish to implement a similar demonstration for their advanced undergraduate or graduate level course in acoustics.

  9. Integrated residential photovoltaic array development

    NASA Technical Reports Server (NTRS)

    Shepard, N. F., Jr.

    1981-01-01

    Three basic module design concepts were analyzed with respect to both production and installation costs. The results of this evaluation were used to synthesize a fourth design which incorporates the best features of these initial concepts to produce a module/array design approach which offers the promise of a substantial reduction in the installed cost of a residential array. A unique waterproofing and mounting scheme was used to reduce the cost of installing an integral array while still maintaining a high probability that the installed array will be watertight for the design lifetime of the system. This recommended concept will also permit the array to be mounted as a direct or stand-off installation with no changes to the module design.

  10. Massively Parallel MRI Detector Arrays

    PubMed Central

    Keil, Boris; Wald, Lawrence L

    2013-01-01

    Originally proposed as a method to increase sensitivity by extending the locally high-sensitivity of small surface coil elements to larger areas, the term parallel imaging now includes the use of array coils to perform image encoding. This methodology has impacted clinical imaging to the point where many examinations are performed with an array comprising multiple smaller surface coil elements as the detector of the MR signal. This article reviews the theoretical and experimental basis for the trend towards higher channel counts relying on insights gained from modeling and experimental studies as well as the theoretical analysis of the so-called “ultimate” SNR and g-factor. We also review the methods for optimally combining array data and changes in RF methodology needed to construct massively parallel MRI detector arrays and show some examples of state-of-the-art for highly accelerated imaging with the resulting highly parallel arrays. PMID:23453758

  11. PEP solar array definition study

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The conceptual design of a large, flexible, lightweight solar array is presented focusing on a solar array overview assessment, solar array blanket definition, structural-mechanical systems definition, and launch/reentry blanket protection features. The overview assessment includes a requirements and constraints review, the thermal environment assessment on the design selection, an evaluation of blanket integration sequence, a conceptual blanket/harness design, and a hot spot analysis considering the effects of shadowing and cell failures on overall array reliability. The solar array blanket definition includes the substrate design, hinge designs and blanket/harness flexibility assessment. The structural/mechanical systems definition includes an overall loads and deflection assessment, a frequency analysis of the deployed assembly, a components weights estimate, design of the blanket housing and tensioning mechanism. The launch/reentry blanket protection task includes assessment of solar cell/cover glass cushioning concepts during ascent and reentry flight condition.

  12. MIMAS 3.0 is a Multiomics Information Management and Annotation System

    PubMed Central

    Gattiker, Alexandre; Hermida, Leandro; Liechti, Robin; Xenarios, Ioannis; Collin, Olivier; Rougemont, Jacques; Primig, Michael

    2009-01-01

    Background DNA sequence integrity, mRNA concentrations and protein-DNA interactions have been subject to genome-wide analyses based on microarrays with ever increasing efficiency and reliability over the past fifteen years. However, very recently novel technologies for Ultra High-Throughput DNA Sequencing (UHTS) have been harnessed to study these phenomena with unprecedented precision. As a consequence, the extensive bioinformatics environment available for array data management, analysis, interpretation and publication must be extended to include these novel sequencing data types. Description MIMAS was originally conceived as a simple, convenient and local Microarray Information Management and Annotation System focused on GeneChips for expression profiling studies. MIMAS 3.0 enables users to manage data from high-density oligonucleotide SNP Chips, expression arrays (both 3'UTR and tiling) and promoter arrays, BeadArrays as well as UHTS data using MIAME-compliant standardized vocabulary. Importantly, researchers can export data in MAGE-TAB format and upload them to the EBI's ArrayExpress certified data repository using a one-step procedure. Conclusion We have vastly extended the capability of the system such that it processes the data output of six types of GeneChips (Affymetrix), two different BeadArrays for mRNA and miRNA (Illumina) and the Genome Analyzer (a popular Ultra-High Throughput DNA Sequencer, Illumina), without compromising on its flexibility and user-friendliness. MIMAS, appropriately renamed into Multiomics Information Management and Annotation System, is currently used by scientists working in approximately 50 academic laboratories and genomics platforms in Switzerland and France. MIMAS 3.0 is freely available via . PMID:19450266

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

    PubMed

    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.

  14. The Long Wavelength Array

    NASA Astrophysics Data System (ADS)

    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

  15. Solar Array Tracking Control

    1995-06-22

    SolarTrak used in conjunction with various versions of 68HC11-based SolarTrack hardware boards provides control system for one or two axis solar tracking arrays. Sun position is computed from stored position data and time from an on-board clock/calendar chip. Position feedback can be by one or two offset motor turn counter square wave signals per axis, or by a position potentiometer. A limit of 256 counts resolution is imposed by the on-board analog to digital (A/D)more » convertor. Control is provided for one or two motors. Numerous options are provided to customize the controller for specific applications. Some options are imposed at compile time, some are setable during operation. Software and hardware board designs are provided for Control Board and separate User Interface Board that accesses and displays variables from Control Board. Controller can be used with range of sensor options ranging from a single turn count sensor per motor to systems using dual turn-count sensors, limit sensors, and a zero reference sensor. Dual axis trackers oriented azimuth elevation, east west, north south, or polar declination can be controlled. Misalignments from these orientations can also be accommodated. The software performs a coordinate transformation using six parameters to compute sun position in misaligned coordinates of the tracker. Parameters account for tilt of tracker in two directions, rotation about each axis, and gear ration errors in each axis. The software can even measure and compute these prameters during an initial setup period if current from a sun position sensor or output from photovoltaic array is available as an anlog voltage to the control board''s A/D port. Wind or emergency stow to aj present position is available triggered by digital or analog signals. Night stow is also available. Tracking dead band is adjustable from narrow to wide. Numerous features of the hardware and software conserve energy for use with battery powered systems.« less

  16. Planning a Global Array of Broadband Seismic Arrays

    NASA Astrophysics Data System (ADS)

    Koper, Keith D.; Ammon, Charles J.

    2013-08-01

    A diverse group of more than 70 seismologists met for 2 days in Raleigh, N.C., to report on recent innovations in seismic array methods and to discuss the future of seismic arrays in global seismology. The workshop was sponsored by the Incorporated Research Institutions for Seismology (IRIS), with U.S. National Science Foundation funding. Participants included representatives of existing array research groups in Australia, Canada, Germany, Japan, Norway, and the United States, with individuals from academia, government, and industry. The workshop was organized by the authors of this meeting report, Pablo Ampeuro (California Institute of Technology), and Colleen Dalton (Boston University), along with IRIS staff support.

  17. Particle sensor array

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G. (Inventor); Blaes, Brent R. (Inventor); Lieneweg, Udo (Inventor)

    1994-01-01

    A particle sensor array which in a preferred embodiment comprises a static random access memory having a plurality of ion-sensitive memory cells, each such cell comprising at least one pull-down field effect transistor having a sensitive drain surface area (such as by bloating) and at least one pull-up field effect transistor having a source connected to an offset voltage. The sensitive drain surface area and the offset voltage are selected for memory cell upset by incident ions such as alpha-particles. The static random access memory of the present invention provides a means for selectively biasing the memory cells into the same state in which each of the sensitive drain surface areas is reverse biased and then selectively reducing the reversed bias on these sensitive drain surface areas for increasing the upset sensitivity of the cells to ions. The resulting selectively sensitive memory cells can be used in a number of applications. By way of example, the present invention can be used for measuring the linear energy transfer of ion particles, as well as a device for assessing the resistance of CMOS latches to Cosmic Ray induced single event upsets. The sensor of the present invention can also be used to determine the uniformity of an ion beam.

  18. Microshutter Arrays for NIRSpec

    NASA Technical Reports Server (NTRS)

    Silverberg, Robert

    2008-01-01

    A primary science goal of the 6.5 m James Webb Space Telescope is to characterize the epoch of initial galaxy formation, observing the early universe as the first stars and galaxies formed. This program will be accomplished using a combination of multi-band imaging and spectroscopic measurements of large numbers of faint galaxies. Since these objects are in general sparse on the sky, a multi object spectrometer is required to enable this critical scientific investigation. We have developed a microshutter array which is to be used as a high contrast, remotely programmable field selector for the Near Infrared Spectrometer (NIRSpec) on JWST. This device allows slits to be opened at the locations of selected galaxies in the field of view, and blocks sources and background light from the rest of the field. The first flight design devices have been built and were tested. These first generation of devices were used to demonstrate performance and flight readiness. Devices of the same design will be delivered to ESA for installation into the NIRSpec instrument.

  19. Microheater Array Boiling Experiment

    NASA Technical Reports Server (NTRS)

    Kim, Jungho; McQuillen, John; Balombin, Joe

    2002-01-01

    By conducting pool boiling tests in microgravity, the effect of buoyancy on the overall boiling process and the relative magnitude of other phenomena can be assessed. Data from KC-135 and sounding rocket experiments indicate little effect of gravity on boiling heat transfer at wall superheats below 25 C, despite vast differences in bubble behavior between gravity levels. In microgravity, a large primary bubble, surrounded by smaller satellite bubbles, moved over the surface, occasionally causing nucleation. Once formed, the primary bubble size remained constant for a given superheat, indicating evaporation at the bubble base is balanced with condensation on the bubble cap. The primary bubble's size increased with wall superheat. Most heaters under the primary bubble had low heat transfer rates, suggesting liquid dryout. Strong Marangoni convection developed in microgravity, forming a 'jet' into the bulk liquid that forced the bubble onto the heater. An experiment is being designed for the. Microgravity Science Glovebox. This experiment uses two 96 element microheater arrays, 2.7 and 7.0 mm in size. These heaters are individually controlled to operate at a constant temperature, measuring local heat fluxes as a function of time and space. Most boiling experiments operate at constant wall heat flux with larger heaters, allowing only time and space-averaged measurements. Each heater is about the bubble departure size in normal gravity, but significantly smaller than the bubble departure size in reduced gravity.

  20. Offering an Array of Improvements

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Sensors Unlimited, Inc., with SBIR funding from NASA's Langley Research Center, Goddard Space Flight Center, Marshall Space Flight Center, and the Jet Propulsion Laboratory, developed a monolithic focal plane array for near-infrared imaging. The company developed one- (1- D) and two-dimensional (2-D) imaging arrays consisting of a highly reliable InGaAs p-I-n diode as a photodetector for monitoring a variety of applications, including single element device applications in receivers. The InGaAs 1-D and 2-D arrays have many applications. For example, they monitor the performance of dense wavelength division multiplexing (DWDM) systems- the process of packaging many channels into a single fiber-optic cable. Sensors Unlimited commercially offers its LXTM and LYTM Series InGaAs linear arrays for reliable DWDM performance monitoring. The LX and LY arrays enable instrument module designs with no moving parts, which provides for superior uniformity, and fast, linear outputs that remain stable over a wide temperature range. Innovative technologies derived from the monolithic focal plane array have enabled telecommunication companies to optimize existing bandwidth in their fiber-optic networks in order to support a high volume of network traffic. At the same time, the technologies obtained from the array have the potential for reducing costs, while increasing performance from Sensors Unlimited's current product lines.

  1. Replica amplification of nucleic acid arrays

    SciTech Connect

    Church, George M.; Mitra, Robi D.

    2010-08-31

    Disclosed are improved methods of making and using immobilized arrays of nucleic acids, particularly methods for producing replicas of such arrays. Included are methods for producing high density arrays of nucleic acids and replicas of such arrays, as well as methods for preserving the resolution of arrays through rounds of replication. Also included are methods which take advantage of the availability of replicas of arrays for increased sensitivity in detection of sequences on arrays. Improved methods of sequencing nucleic acids immobilized on arrays utilizing single copies of arrays and methods taking further advantage of the availability of replicas of arrays are disclosed. The improvements lead to higher fidelity and longer read lengths of sequences immobilized on arrays. Methods are also disclosed which improve the efficiency of multiplex PCR using arrays of immobilized nucleic acids.

  2. Application specific serial arithmetic arrays

    NASA Technical Reports Server (NTRS)

    Winters, K.; Mathews, D.; Thompson, T.

    1990-01-01

    High performance systolic arrays of serial-parallel multiplier elements may be rapidly constructed for specific applications by applying hardware description language techniques to a library of full-custom CMOS building blocks. Single clock pre-charged circuits have been implemented for these arrays at clock rates in excess of 100 Mhz using economical 2-micron (minimum feature size) CMOS processes, which may be quickly configured for a variety of applications. A number of application-specific arrays are presented, including a 2-D convolver for image processing, an integer polynomial solver, and a finite-field polynomial solver.

  3. Fiber Optic Geophysics Sensor Array

    NASA Astrophysics Data System (ADS)

    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.

  4. Areal array jetting device for ball grid arrays

    SciTech Connect

    Frear, D.R.; Yost, F.G.; Schmale, D.T.; Essien, M.

    1997-08-01

    Package designs for microelectronics devices have moved from through-hole to surface mount technology in order to increase the printed wiring board real estate available by utilizing both sides of the board. The traditional geometry for surface mount devices is peripheral arrays where the leads are on the edges of the device. As the technology drives towards high input/output (I/O) count (increasing number of leads) and smaller packages with finer pitch (less distance between peripheral leads), limitations on peripheral surface mount devices arise. A solution to the peripheral surface mount issue is to shift the leads to the area under the device. This scheme is called areal array packaging and is exemplified by the ball grid array (BGA) package. In a BGA package, the leads are on the bottom surface of the package in the form of an array of solder balls. The current practice of joining BGA packages to printed wiring boards involves a hierarchy of solder alloy compositions. A high melting temperature ball is typically used for standoff. A promising alternative to current methods is the use of jetting technology to perform monolithic solder ball attachment. This paper describes an areal array jetter that was designed and built to simultaneously jet arrays of solder balls directly onto BGA substrates.

  5. Silicon Heat Pipe Array

    NASA Technical Reports Server (NTRS)

    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

  6. Fracture characterisation using geoelectric null-arrays

    NASA Astrophysics Data System (ADS)

    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.

  7. Pipeline feedback array sorter with multi-string sort array and merge tree array

    SciTech Connect

    Chuang, H.Y.H.; He, G.

    1989-01-17

    A pipeline feedback array sorter is described comprising: (a) a multi-string sort array having m inputs and outputs, where m is the width of the array or the number of data strings and is greater than or equal to 2; (b) a merge tree array having q leave nodes connected to the output of one of p buffer memories through a multiplexor for successively merging the columns of a buffer memory to fill subsequent buffer memory columns and having an output from the root node, where q is greater than or equal to 2 and p is greater than or equal to 1; (c) a first buffer memory having m inputs connected to the corresponding m outputs of the multi-string sort array for filling the first buffer memory and q outputs, the first buffer memory having mXq memory units, each of the units for holding one data item, the first buffer memory having two dimensional data movements; (d) p-1 buffer memories in feedback loops and having a single dimensional data movement, each of the p-1 buffer memories having an input connected with the output of the merge tree array and q outputs connected to the q leave nodes of the merge tree array, wherein each of the p buffer memories serve as input buffers to the merge tree array; and (e) a multiplexor for controlling and filling from the first buffer memory and p-1 buffer memories electrically connected to the inputs to the merge tree, whereby merging the columns of the p-th buffer memory a final sort is obtained from the root node of the merge tree array.

  8. Dynamically Reconfigurable Systolic Array Accelerator

    NASA Technical Reports Server (NTRS)

    Dasu, Aravind; Barnes, Robert

    2012-01-01

    A polymorphic systolic array framework has been developed that works in conjunction with an embedded microprocessor on a field-programmable gate array (FPGA), which allows for dynamic and complimentary scaling of acceleration levels of two algorithms active concurrently on the FPGA. Use is made of systolic arrays and a hardware-software co-design to obtain an efficient multi-application acceleration system. The flexible and simple framework allows hosting of a broader range of algorithms, and is extendable to more complex applications in the area of aerospace embedded systems. FPGA chips can be responsive to realtime demands for changing applications needs, but only if the electronic fabric can respond fast enough. This systolic array framework allows for rapid partial and dynamic reconfiguration of the chip in response to the real-time needs of scalability, and adaptability of executables.

  9. Downsampling Photodetector Array with Windowing

    NASA Technical Reports Server (NTRS)

    Patawaran, Ferze D.; Farr, William H.; Nguyen, Danh H.; Quirk, Kevin J.; Sahasrabudhe, Adit

    2012-01-01

    In a photon counting detector array, each pixel in the array produces an electrical pulse when an incident photon on that pixel is detected. Detection and demodulation of an optical communication signal that modulated the intensity of the optical signal requires counting the number of photon arrivals over a given interval. As the size of photon counting photodetector arrays increases, parallel processing of all the pixels exceeds the resources available in current application-specific integrated circuit (ASIC) and gate array (GA) technology; the desire for a high fill factor in avalanche photodiode (APD) detector arrays also precludes this. Through the use of downsampling and windowing portions of the detector array, the processing is distributed between the ASIC and GA. This allows demodulation of the optical communication signal incident on a large photon counting detector array, as well as providing architecture amenable to algorithmic changes. The detector array readout ASIC functions as a parallel-to-serial converter, serializing the photodetector array output for subsequent processing. Additional downsampling functionality for each pixel is added to this ASIC. Due to the large number of pixels in the array, the readout time of the entire photodetector is greater than the time between photon arrivals; therefore, a downsampling pre-processing step is done in order to increase the time allowed for the readout to occur. Each pixel drives a small counter that is incremented at every detected photon arrival or, equivalently, the charge in a storage capacitor is incremented. At the end of a user-configurable counting period (calculated independently from the ASIC), the counters are sampled and cleared. This downsampled photon count information is then sent one counter word at a time to the GA. For a large array, processing even the downsampled pixel counts exceeds the capabilities of the GA. Windowing of the array, whereby several subsets of pixels are designated

  10. Bolometric Arrays for Millimeter Wavelengths

    NASA Astrophysics Data System (ADS)

    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.

  11. Dynamically Reconfigurable Systolic Array Accelorators

    NASA Technical Reports Server (NTRS)

    Dasu, Aravind (Inventor); Barnes, Robert C. (Inventor)

    2014-01-01

    A polymorphic systolic array framework that works in conjunction with an embedded microprocessor on an FPGA, that allows for dynamic and complimentary scaling of acceleration levels of two algorithms active concurrently on the FPGA. Use is made of systolic arrays and hardware-software co-design to obtain an efficient multi-application acceleration system. The flexible and simple framework allows hosting of a broader range of algorithms and extendable to more complex applications in the area of aerospace embedded systems.

  12. Flexible solar-array mechanism

    NASA Technical Reports Server (NTRS)

    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.

  13. Towards Fault Resilient Global Arrays

    SciTech Connect

    Tipparaju, Vinod; Krishnan, Manoj Kumar; Palmer, Bruce J.; Petrini, Fabrizio; Nieplocha, Jaroslaw

    2007-09-03

    The focus of the current paper is adding fault resiliency to the Global Arrays. We extended the GA toolkit to provide a minimal level of capabilities to enable programmer to implement fault resiliency at the user level. Our fault-recovery approach is programmer assisted and based on frequent incremental checkpoints and rollback recovery. In addition, it relies of pool of spare nodes that are used to replace the failing node. We demonstrate usefulness of fault resilient Global Arrays in application context.

  14. Sensor arrays for detecting microorganisms

    NASA Technical Reports Server (NTRS)

    Lewis, Nathan S. (Inventor); Freund, Michael S. (Inventor)

    2000-01-01

    A sensor array for detecting a microorganism comprising first and second sensors electrically connected to an electrical measuring apparatus, wherein the sensors comprise a region of nonconducting organic material and a region of conducting material compositionally that is different than the nonconducting organic material and an electrical path through the regions of nonconducting organic material and the conducting material. A system for identifying microorganisms using the sensor array, a computer and a pattern recognition algorithm, such as a neural net are also disclosed.

  15. A lightweight inflatable solar array

    SciTech Connect

    Malone, P.K.; Williams, G.T.

    1995-12-31

    L`Garde and Phillips Laboratory have developed a light weight deployable solar array wing in the 200-1000 watt range, on the Inflatable Torus Solar Array Technology Demonstration (ITSAT Demo) Project. The power density of a flight unit could be as high as 93 W/kg for a 200 Watt-class wing, including structure and deployment mechanisms. In Phase 1, a proof of concept torus and array was constructed and deployed in the laboratory. During Phase 2, a revised torus and array were constructed and tested at L`Garde and the Naval Research Lab. The qualification tests included random vibration, deployment in a thermal vacuum chamber, natural frequency determination, and thermal cycling. The flight design uses 2 mil thick crystalline Si cells on an AO protected flexible Kapton film substrate folded accordion style for stowage. The support structure is a rectangular frame comprised of two inflated then rigidized cylinders, the array stowage box and its cover. The cylinders, flattened, folded and stored for launch, are deployed by inflating with N{sub 2} and rigidized by straining the cylinder laminate material controllably beyond the elastic limit. The engineering protoflight array was designed for optimum power density but, due to availability, some of the components came from excess production runs. Because of this, the actual power density of the test article was 59 W/kg, or 36% less than the baseline flight array. However, using components as designed, the projected 93 w/kg can be achieved. Due to simple deployment mechanism, the cost of an ITSAT-type solar array is about one-half that of competing systems.

  16. Integrated residential photovoltaic array development

    NASA Astrophysics Data System (ADS)

    Royal, G. C., III

    1981-04-01

    Sixteen conceptual designs of residential photovoltaic arrays are described. Each design concept was evaluated by an industry advisory panel using a comprehensive set of technical, economic and institutional criteria. Key electrical and mechanical concerns that effect further array subsystem development are also discussed. Three integrated array design concepts were selected by the advisory panel for further optimization and development. From these concepts a single one will be selected for detailed analysis and prototype fabrication. The three concepts selected are: (1) An array of frameless panels/modules sealed in a T shaped zipper locking neoprene gasket grid pressure fitted into an extruded aluminum channel grid fastened across the rafters. (2) An array of frameless modules pressure fitted in a series of zipper locking EPDM rubber extrusions adhesively bonded to the roof. Series string voltage is developed using a set of integral tongue connectors and positioning blocks. (3) An array of frameless modules sealed by a silicone adhesive in a prefabricated grid of rigid tape and sheet metal attached to the roof.

  17. Integrated residential photovoltaic array development

    NASA Technical Reports Server (NTRS)

    Royal, G. C., III

    1981-01-01

    Sixteen conceptual designs of residential photovoltaic arrays are described. Each design concept was evaluated by an industry advisory panel using a comprehensive set of technical, economic and institutional criteria. Key electrical and mechanical concerns that effect further array subsystem development are also discussed. Three integrated array design concepts were selected by the advisory panel for further optimization and development. From these concepts a single one will be selected for detailed analysis and prototype fabrication. The three concepts selected are: (1) An array of frameless panels/modules sealed in a T shaped zipper locking neoprene gasket grid pressure fitted into an extruded aluminum channel grid fastened across the rafters. (2) An array of frameless modules pressure fitted in a series of zipper locking EPDM rubber extrusions adhesively bonded to the roof. Series string voltage is developed using a set of integral tongue connectors and positioning blocks. (3) An array of frameless modules sealed by a silicone adhesive in a prefabricated grid of rigid tape and sheet metal attached to the roof.

  18. Genome-wide identification of copy number variations in Holstein cattle from Baja California, Mexico, using high-density SNP genotyping arrays.

    PubMed

    Salomón-Torres, R; González-Vizcarra, V M; Medina-Basulto, G E; Montaño-Gómez, M F; Mahadevan, P; Yaurima-Basaldúa, V H; Villa-Angulo, C; Villa-Angulo, R

    2015-10-02

    Copy number variations (CNVs) are an important source of genomic structural variation, and can be used as markers to investigate phenotypic and economic traits. CNVs also have functional effects on gene expression and can contribute to disease susceptibility in mammals. Currently, single nucleotide polymorphism genotyping arrays (SNP chips) are the technology of choice for identifying CNV variations. Microarray technologies have recently been used to study the bovine genome. The objective of the present study was to develop CNVs in Holstein cows from the Northwest of Mexico using the Affymetrix Axiom Genome-Wide BOS 1 Array, which assays 648,315 SNPs and provides a wide coverage for genome-wide studies. We applied the two most widely used algorithms for the discovery of CNVs (PennCNV and QuantiSNP) and found 56 CNV regions (CNVRs) representing 0.33% of the bovine genome (8.46 Mb). These CNVRs ranged from 1.5 to 970.8 kb with an average length of 151 kb. They involved 103 genes and showed a 28% overlap with CNVRs already reported. Of the 56 CNVRs found, 20 were novel. In this study we present the first genomic analysis of CNVs in Mexican cattle using high-density SNP data. Our results provide a new reference basis for future genomic variation and association studies between CNVs and phenotypes, especially in Mexican cattle.

  19. Biomimetic control for DEA arrays

    NASA Astrophysics Data System (ADS)

    O'Brien, Benjamin; Gisby, Todd; Xie, Sheng Q.; Calius, Emilio; Anderson, Iain

    2010-04-01

    Arrays of actuators are ubiquitous in nature for manipulation, pumping and propulsion. Often these arrays are coordinated in a multi-level fashion with distributed sensing and feedback manipulated by higher level controllers. In this paper we present a biologically inspired multi-level control strategy and apply it to control an array of Dielectric Elastomer Actuators (DEA). A test array was designed consisting of three DEA arranged to tilt a set of rails on which a ball rolls. At the local level the DEA were controlled using capacitive self-sensing state machines that switched the actuator off and on when capacitive thresholds were exceeded, resulting in the steady rolling of the ball around the rails. By varying the voltage of the actuators in the on state, it was possible to control the speed of the ball to match a set point. A simple integral derivative controller was used to do this and an observer law was formulated to track the speed of the ball. The array demonstrated the ability to self start, roll the ball in either direction, and run at a range of speeds determined by the maximum applied voltage. The integral derivative controller successfully tracked a square wave set point. Whilst the test application could have been controlled with a classic centralised controller, the real benefit of the multi-level strategy becomes apparent when applied to larger arrays and biomimetic applications that are ideal for DEA. Three such applications are discussed; a robotic heart, a peristaltic pump and a ctenophore inspired propulsion array.

  20. Design of microstrip disk antenna arrays

    NASA Technical Reports Server (NTRS)

    Bailey, M. C.; Parks, F. G.

    1978-01-01

    The radio frequency characteristics and design parameters for microstrip disk antenna elements and planar arrays are presented. Two C-band model arrays (an 8 element linear and an 8 by 8 planar) were designed, fabricated, and tested to demonstrate the technique of using microstrip elements for array applications. These arrays were designed with a cosine amplitude distribution.

  1. Solar Array Arcing Failure Mode and High Voltage Array Testing

    NASA Astrophysics Data System (ADS)

    Ferguson, Dale C.

    2002-10-01

    In 1998, a new failure mode for space solar arrays was discovered. A flowchart for this failure mode is presented. Since the discovery of this arc failure mode, many tactics have been used to defeat it. The arc thresholds and arc mitigation strategies must be determined in vacuum-plasma tank testing on Earth. Results from these tests must then be extrapolated to the space plasma environment. Thus, the test conditions on Earth must be adequate to reproduce the important aspects of the phenomenon in space. At Glenn Research Center, we have been testing solar arrays for their arc thresholds and sustained arcing thresholds. In this paper, we detail the test conditions for a specific set of tests-those aimed at qualifying the Boeing Solar Tile solar arrays to operate in space at very high voltages (300 V or more).

  2. Characterizing the porcine transcriptional regulatory response to infection by Salmonella: identifying putative new NFkB direct targets through comparative bioinformatics.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have collected data on host response to infection from RNA prepared from mesenteric lymph node of swine infected with either Salmonella enterica serovar Typhimurium (ST) or S. Choleraesuis (SC) using the porcine Affymetrix GeneChip. We identified 848 (ST) and 1,853 (SC) genes with statistical evi...

  3. Surveying expression level polymorphism and single-feature polymorphism in near-isogenic wheat lines differing for the Yr5 stripe rust resistance locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DNA polymorphisms are valuable for several applications including genotyping, molecular mapping and marker-assisted selection. The Affymetrix Wheat GeneChip was used to survey expression level polymorphisms (ELPs) and single-feature polymorphisms (SFPs) between two near-isogenic wheat genotypes (BC...

  4. Surveying expression level polymorphism and single-feature polymorphism in near-isogenic wheat lines differing for the Yr5 stripe rust resistance locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DNA polymorphisms are valuable for several applications including genotyping, molecular mapping and marker-assisted selection. The Affymetrix Wheat GeneChip was used to survey expression level polymorphisms (ELPs) and single-feature polymorphisms (SFPs) between two near-isogenic wheat genotypes (BC7...

  5. Arabidopsis transcriptional responses differentiate between O3 and herbicides

    EPA Science Inventory

    Using published data based on Affymetrix ATH1 Gene-Chips we characterized the transcriptional response of Arabidopsis thaliana Columbia to O3 and a few other major environmental stresses including oxidative stress . A set of 101 markers could be extracted which provided a compo...

  6. Global changes in expression of grapefruit peel tissue in response to the yeast biocontrol agent, Metschnikowia fructicola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To gain a better understanding of the molecular changes taking place in citrus fruit tissue following the application of the yeast biocontrol agent, Metschnikowia fructicola, microarray analysis was performed on grapefruit surface wounds using an Affymetrix Citrus GeneChip. Using a cut off of p<0.0...

  7. STAR: SOFIA terahertz array receiver

    NASA Astrophysics Data System (ADS)

    Graf, Urs U.; Heyminck, Stefan; Rabanus, D.; Jacobs, Karl; Schieder, Rudolf T.; Stutzki, Juergen

    2003-02-01

    We present the concept for KOSMA's 16 element 1.9 THz heterodyne array STAR (SOFIA Terahertz Array Receiver) which is being developed for SOFIA. The instrument will consist of two interleaved sub-arrays of 8 pixels each. Together we will have a 4 × 4 pixel array with a beam spacing on the sky of approximately 1.5 times the beam size of 15 arcsec (FWHM). The receiver is mainly targeted at measuring the fine structure transition of ionized atomic carbon at 1.9 THz (158 microns). STAR's optics setup is modeled after the successful design used in KOSMA's SMART receiver. It will contain a K-mirror type beam rotator, a Martin-Puplett diplexer for LO coupling and an LO multiplexer using imaging Fourier gratings. Complete optical sub-assemblies will be machined monolithically as integrated optics units, to reduce the need for optical alignment. STAR will probably use waveguide mixers with diffusion cooled hot electron bolometers, which are being developed at KOSMA. The receiver backends will be KOSMA Array-AOSs. Local oscillator power will be provided by a backward wave oscillator (BWO), followed by a frequency tripler.

  8. Contact Printing of Arrayed Microstructures

    PubMed Central

    Xu, Wei; Luikart, Alicia M.; Sims, Christopher E.; Allbritton, Nancy L.

    2010-01-01

    A novel contact printing method utilizing a sacrificial layer of polyacrylic acid (PAA) was developed to selectively modify the upper surfaces of arrayed microstructures. The method was characterized by printing polystyrene onto SU-8 microstructures to create an improved substrate for a cell-based microarray platform. Experiments measuring cell growth SU-8 arrays modified with polystyrene and fibronectin demonstrated improved growth of NIH 3T3 (93% vs. 38%), HeLa (97% vs. 77%), and HT1080 (76% vs. 20%) cells relative to that for the previously used coating method. In addition, use of the PAA sacrificial layer permitted the printing of functionalized polystyrene, carboxylate polystyrene nanospheres, and silica nanospheres onto the arrays in a facile manner. Finally, a high concentration of extracellular matrix materials (ECM), such as collagen (5 mg/mL) and gelatin (0.1%), was contact printed onto the array structures using as little as 5 μL of the ECM reagent and without the formation of a continuous film bridge across the microstructures. Murine embryonic stem cells cultured on arrays printed with this gelatin-hydrogel remained in an undifferentiated state indicating an adequate surface gelatin layer to maintain these cells over time. PMID:20425106

  9. Retrieval of Mir Solar Array

    NASA Technical Reports Server (NTRS)

    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.

  10. Integrated Array/Metadata Analytics

    NASA Astrophysics Data System (ADS)

    Misev, Dimitar; Baumann, Peter

    2015-04-01

    Data comes in various forms and types, and integration usually presents a problem that is often simply ignored and solved with ad-hoc solutions. Multidimensional arrays are an ubiquitous data type, that we find at the core of virtually all science and engineering domains, as sensor, model, image, statistics data. Naturally, arrays are richly described by and intertwined with additional metadata (alphanumeric relational data, XML, JSON, etc). Database systems, however, a fundamental building block of what we call "Big Data", lack adequate support for modelling and expressing these array data/metadata relationships. Array analytics is hence quite primitive or non-existent at all in modern relational DBMS. Recognizing this, we extended SQL with a new SQL/MDA part seamlessly integrating multidimensional array analytics into the standard database query language. We demonstrate the benefits of SQL/MDA with real-world examples executed in ASQLDB, an open-source mediator system based on HSQLDB and rasdaman, that already implements SQL/MDA.

  11. Modeling of phased array transducers.

    PubMed

    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.

  12. Vaginal microbiome and epithelial gene array in post-menopausal women with moderate to severe dryness.

    PubMed

    Hummelen, Ruben; Macklaim, Jean M; Bisanz, Jordan E; Hammond, Jo-Anne; McMillan, Amy; Vongsa, Rebecca; Koenig, David; Gloor, Gregory B; Reid, Gregor

    2011-01-01

    After menopause, many women experience vaginal dryness and atrophy of tissue, often attributed to the loss of estrogen. An understudied aspect of vaginal health in women who experience dryness due to atrophy is the role of the resident microbes. It is known that the microbiota has an important role in healthy vaginal homeostasis, including maintaining the pH balance and excluding pathogens. The objectives of this study were twofold: first to identify the microbiome of post-menopausal women with and without vaginal dryness and symptoms of atrophy; and secondly to examine any differences in epithelial gene expression associated with atrophy. The vaginal microbiome of 32 post-menopausal women was profiled using Illumina sequencing of the V6 region of the 16S rRNA gene. Sixteen subjects were selected for follow-up sampling every two weeks for 10 weeks. In addition, 10 epithelial RNA samples (6 healthy and 4 experiencing vaginal dryness) were acquired for gene expression analysis by Affymetrix Human Gene array. The microbiota abundance profiles were relatively stable over 10 weeks compared to previously published data on premenopausal women. There was an inverse correlation between Lactobacillus ratio and dryness and an increased bacterial diversity in women experiencing moderate to severe vaginal dryness. In healthy participants, Lactobacillus iners and L. crispatus were generally the most abundant, countering the long-held view that lactobacilli are absent or depleted in menopause. Vaginal dryness and atrophy were associated with down-regulation of human genes involved in maintenance of epithelial structure and barrier function, while those associated with inflammation were up-regulated consistent with the adverse clinical presentation.

  13. An Integrated ISFET Sensor Array

    PubMed Central

    Nakazato, Kazuo

    2009-01-01

    A monolithically integrated ISFET sensor array and interface circuit are described. A new high-density, low-power source-drain follower was developed for the sensor array. ISFETs were formed by depositing Au/Ti extended-gate electrodes on standard MOSFETs, then thin silicon nitride layers using catalytic chemical vapor deposition and/or SU-8 protective layers were formed on the extended-gate electrodes. Applications for the array include: (1) pH detection by statistical distribution observing time and space fluctuations; (2) DNA detection using thiol-modified or silane-coupled oligonucleotides; (3) bio-image sensing by converting photons to electrons using Photosystem I of Thermosynechococcus elongatus, and sensing the converted electric charges by ISFETs. PMID:22291539

  14. Acoustically driven arrayed waveguide grating.

    PubMed

    Crespo-Poveda, A; Hernández-Mínguez, A; Gargallo, B; Biermann, K; Tahraoui, A; Santos, P V; Muñoz, P; Cantarero, A; de Lima, M M

    2015-08-10

    We demonstrate compact tunable phased-array wavelength-division multiplexers driven by surface acoustic waves (SAWs) in the low GHz range. The devices comprise two couplers, which respectively split and combine the optical signal, linked by an array of single-mode waveguides (WGs). Two different layouts are presented, in which multi-mode interference couplers or free propagating regions were separately employed as couplers. The multiplexers operate on five equally distributed wavelength channels, with a spectral separation of 2 nm. A standing SAW modulates the refractive index of the arrayed WGs. Each wavelength component periodically switches paths between the output channel previously asigned by the design and the adjacent channels, at a fixed applied acoustic power. The devices were monolithically fabricated on (Al,Ga)As. A good agreement between theory and experiment is achieved.

  15. Collective effects in ciliar arrays.

    PubMed

    Lenz, Peter; Ryskin, Andrey

    2006-12-08

    Collective effects in one-dimensional ciliar arrays are studied analytically and numerically. A new phase oscillator description for ciliar motion is introduced which depends only on a single parameter. It allows the systematic study of hydrodynamic interactions between cilia exhibiting arbitrary beating patterns. It is shown that if the hydrodynamic interactions do not alter the beating pattern of the cilia no synchronization of ciliar motion occurs. This is in particular the case in arrays with low ciliar densities. But hydrodynamic interactions can lead to formation of a collective (metachronal) wave which is stable for periodic boundary conditions. In finite arrays free boundaries destroy this collective motion. The dispersion relation for metachronal waves is found to be non-universal, i.e., to depend crucially on the microscopic details of the ciliar beating pattern.

  16. Collective effects in ciliar arrays

    NASA Astrophysics Data System (ADS)

    Lenz, Peter; Ryskin, Andrey

    2006-12-01

    Collective effects in one-dimensional ciliar arrays are studied analytically and numerically. A new phase oscillator description for ciliar motion is introduced which depends only on a single parameter. It allows the systematic study of hydrodynamic interactions between cilia exhibiting arbitrary beating patterns. It is shown that if the hydrodynamic interactions do not alter the beating pattern of the cilia no synchronization of ciliar motion occurs. This is in particular the case in arrays with low ciliar densities. But hydrodynamic interactions can lead to formation of a collective (metachronal) wave which is stable for periodic boundary conditions. In finite arrays free boundaries destroy this collective motion. The dispersion relation for metachronal waves is found to be non-universal, i.e., to depend crucially on the microscopic details of the ciliar beating pattern.

  17. Thin, Flexible IMM Solar Array

    NASA Technical Reports Server (NTRS)

    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.

  18. Chemical gas sensor array dataset.

    PubMed

    Fonollosa, Jordi; Rodríguez-Luján, Irene; Huerta, Ramón

    2015-06-01

    To address drift in chemical sensing, an extensive dataset was collected over a period of three years. An array of 16 metal-oxide gas sensors was exposed to six different volatile organic compounds at different concentration levels under tightly-controlled operating conditions. Moreover, the generated dataset is suitable to tackle a variety of challenges in chemical sensing such as sensor drift, sensor failure or system calibration. The data is related to "Chemical gas sensor drift compensation using classifier ensembles", by Vergara et al. [1], and "On the calibration of sensor arrays for pattern recognition using the minimal number of experiments", by Rodriguez-Lujan et al. [2] The dataset can be accessed publicly at the UCI repository upon citation of: http://archive.ics.uci.edu/ml/datasets/Gas+Sensor+Array+Drift+Dataset+at+Different+Concentrations.

  19. Distributed phased array architecture study

    NASA Technical Reports Server (NTRS)

    Bourgeois, Brian

    1987-01-01

    Variations in amplifiers and phase shifters can cause degraded antenna performance, depending also on the environmental conditions and antenna array architecture. The implementation of distributed phased array hardware was studied with the aid of the DISTAR computer program as a simulation tool. This simulation provides guidance in hardware simulation. Both hard and soft failures of the amplifiers in the T/R modules are modeled. Hard failures are catastrophic: no power is transmitted to the antenna elements. Noncatastrophic or soft failures are modeled as a modified Gaussian distribution. The resulting amplitude characteristics then determine the array excitation coefficients. The phase characteristics take on a uniform distribution. Pattern characteristics such as antenna gain, half power beamwidth, mainbeam phase errors, sidelobe levels, and beam pointing errors were studied as functions of amplifier and phase shifter variations. General specifications for amplifier and phase shifter tolerances in various architecture configurations for C band and S band were determined.

  20. Optical phased-array ladar.

    PubMed

    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.

  1. Innovative Plasma Imaging Array Concept

    NASA Astrophysics Data System (ADS)

    Tobias, Benjamin; Domier, Calvin; Kong, Xiangyu; Liang, Tianran; Luhmann, Neville, Jr.; van de Pol, M. J.; Classen, I. G. J.; Boom, J.; Jaspers, R.; Donne, A. J. H.; Park, Hyeon

    2008-11-01

    A new lens/antenna array concept has been developed for millimeter-wave plasma imaging applications with dramatic increases in RF bandwidth and sensitivity. In this arrangement, an array of tightly coupled miniatured substrate lenses is fabricated such that each antenna has a dedicated substrate lens. The new arrangement exhibits low sidelobe levels over a bandwidth spanning 90 to 140 GHz for use in electron cyclotron emission imaging and microwave imaging reflectometry. An innovative ``vertical zoom'' control is also supported, which the vertical extent of the imaged plasma can be varied from 20 to 30 cm. The first plasma implementation of the new concept will take place on the TEXTOR tokamak in Fall 2008, with systems for DIII-D and ASDEX to follow in 2009. Experimental details regarding the imaging arrays and the new TEXTOR optical design will be presented.

  2. The Deep Space Network Array

    NASA Technical Reports Server (NTRS)

    Gatti, Mark S.

    2006-01-01

    This document is a viewgraph presentation that reviews the costs, and technological processing required to replace the current network of Deep Space Antennas. The concept of using an array for space communications is much less of a concern than the cost of implementing and operating such an array. Within the cost question, the cost uncertainty of the front-end components (repeated n-times) is of most importance. The activities at JPL have focused on both these aspects of the cost. A breadboard array of three antennas at JPL has been the vehicle to perform many investigations into the development of the new DSN. Several pictures of the antennas at JPL are shown.

  3. High voltage solar array experiments

    NASA Technical Reports Server (NTRS)

    Kennerud, K. L.

    1974-01-01

    The interaction between the components of a high voltage solar array and a simulated space plasma is studied to obtain data for the design of a high voltage solar array capable of 15kW at 2 to 16kV. Testing was conducted in a vacuum chamber 1.5-m long by 1.5-m diameter having a plasma source which simulated the plasma conditions existing in earth orbit between 400 nautical miles and synchronous altitude. Test samples included solar array segments pinholes in insulation covering high voltage electrodes, and plain dielectric samples. Quantitative data are presented in the areas of plasma power losses, plasma and high voltage induced damage, and dielectric properties. Limitations of the investigation are described.

  4. Introduction: array technology - an overview.

    PubMed

    Seliger, Hartmut

    2007-01-01

    Microarray technology has its roots in high-throughput parallel synthesis of biomacromolecules, combined with combinatorial science. In principle, the preparation of arrays can be performed either by in situ synthesis of biomacromolecules on solid substrates or by spotting of ex situ synthesized biomacromolecules onto the substrate surface. The application of microarrays includes spatial addressing with target (macro) molecules and screening for interactions between immobilized probe and target. The screening is simplified by the microarray format, which features a known structure of every immobilized library element. The area of nucleic acid arrays is best developed, because such arrays are allowed to follow the biosynthetic pathway from genes to proteins, and because nucleic acid hybridization is a most straightforward screening tool. Applications to genomics, transcriptomics, proteomics, and glycomics are currently in the foreground of interest; in this postgenomic phase they are allowed to gain new insights into the molecular basis of cellular processes and the development of disease.

  5. Integrated residential photovoltaic array development

    NASA Technical Reports Server (NTRS)

    Shepard, N. F., Jr.

    1981-01-01

    The design details of an optimized integrated residential photovoltaic module/array are presented. This selected design features a waterproofing and mounting scheme which was devised to simplify the installation procedures by the avoidance of complex gasketed or caulked joints, while still maintaining a high confidence that the watertight integrity of the integral roofing surface will be achieved for the design lifetime of the system. The production and installation costs for the selected module/array design are reported for a range of annual production rates as a function of the cost of solar cells.

  6. Hybrid Arrays for Chemical Sensing

    NASA Astrophysics Data System (ADS)

    Kramer, Kirsten E.; Rose-Pehrsson, Susan L.; Johnson, Kevin J.; Minor, Christian P.

    In recent years, multisensory approaches to environment monitoring for chemical detection as well as other forms of situational awareness have become increasingly popular. A hybrid sensor is a multimodal system that incorporates several sensing elements and thus produces data that are multivariate in nature and may be significantly increased in complexity compared to data provided by single-sensor systems. Though a hybrid sensor is itself an array, hybrid sensors are often organized into more complex sensing systems through an assortment of network topologies. Part of the reason for the shift to hybrid sensors is due to advancements in sensor technology and computational power available for processing larger amounts of data. There is also ample evidence to support the claim that a multivariate analytical approach is generally superior to univariate measurements because it provides additional redundant and complementary information (Hall, D. L.; Linas, J., Eds., Handbook of Multisensor Data Fusion, CRC, Boca Raton, FL, 2001). However, the benefits of a multisensory approach are not automatically achieved. Interpretation of data from hybrid arrays of sensors requires the analyst to develop an application-specific methodology to optimally fuse the disparate sources of data generated by the hybrid array into useful information characterizing the sample or environment being observed. Consequently, multivariate data analysis techniques such as those employed in the field of chemometrics have become more important in analyzing sensor array data. Depending on the nature of the acquired data, a number of chemometric algorithms may prove useful in the analysis and interpretation of data from hybrid sensor arrays. It is important to note, however, that the challenges posed by the analysis of hybrid sensor array data are not unique to the field of chemical sensing. Applications in electrical and process engineering, remote sensing, medicine, and of course, artificial

  7. SPS large array simulation. [spacetennas

    NASA Technical Reports Server (NTRS)

    Rathjen, S.; Sperber, B. R.; Nalos, E. J.

    1980-01-01

    Three types of computer simulations were developed to study the SPS microwave power transmission system (MPTS). The radially symmetric array simulation is low cost and is utilized to investigate general overall characteristics of the spacetenna at the array level only. "Tiltmain", a subarray level simulation program, is used to study the effects of system errors which modify the far-field pattern. The most recently designed program, "Modmain," takes the detail of simulation down to the RF module level and so to date is the closest numerical model of the reference design.

  8. Mosaic of coded aperture arrays

    DOEpatents

    Fenimore, Edward E.; Cannon, Thomas M.

    1980-01-01

    The present invention pertains to a mosaic of coded aperture arrays which is capable of imaging off-axis sources with minimum detector size. Mosaics of the basic array pattern create a circular on periodic correlation of the object on a section of the picture plane. This section consists of elements of the central basic pattern as well as elements from neighboring patterns and is a cyclic version of the basic pattern. Since all object points contribute a complete cyclic version of the basic pattern, a section of the picture, which is the size of the basic aperture pattern, contains all the information necessary to image the object with no artifacts.

  9. Arabidopsis gene expression patterns during spaceflight

    NASA Astrophysics Data System (ADS)

    Paul, A.-L.; Ferl, R. J.

    The exposure of Arabidopsis thaliana (Arabidopsis) plants to spaceflight environments resulted in the differential expression of hundreds of genes. A 5 day mission on orbiter Columbia in 1999 (STS-93) carried transgenic Arabidopsis plants engineered with a transgene composed of the alcohol dehydrogenase (Adh) gene promoter linked to the β -Glucuronidase (GUS) reporter gene. The plants were used to evaluate the effects of spaceflight on two fronts. First, expression patterns visualized with the Adh/GUS transgene were used to address specifically the possibility that spaceflight induces a hypoxic stress response, and to assess whether any spaceflight response was similar to control terrestrial hypoxia-induced gene expression patterns. (Paul et al., Plant Physiol. 2001, 126:613). Second, genome-wide patterns of native gene expression were evaluated utilizing the Affymetrix ATH1 GeneChip? array of 8,000 Arabidopsis genes. As a control for the veracity of the array analyses, a selection of genes identified with the arrays was further characterized with quantitative Real-Time RT PCR (ABI - TaqmanTM). Comparison of the patterns of expression for arrays of hybridized with RNA isolated from plants exposed to spaceflight compared to the control arrays revealed hundreds of genes that were differentially expressed in response to spaceflight, yet most genes that are hallmarks of hypoxic stress were unaffected. These results will be discussed in light of current models for plant responses to the spaceflight environment, and with regard to potential future flight opportunities.

  10. The Medicago truncatula gene expression atlas web server

    PubMed Central

    2009-01-01

    Background Legumes (Leguminosae or Fabaceae) play a major role in agriculture. Transcriptomics studies in the model legume species, Medicago truncatula, are instrumental in helping to formulate hypotheses about the role of legume genes. With the rapid growth of publically available Affymetrix GeneChip Medicago Genome Array GeneChip data from a great range of tissues, cell types, growth conditions, and stress treatments, the legume research community desires an effective bioinformatics system to aid efforts to interpret the Medicago genome through functional genomics. We developed the Medicago truncatula Gene Expression Atlas (MtGEA) web server for this purpose. Description The Medicago truncatula Gene Expression Atlas (MtGEA) web server is a centralized platform for analyzing the Medicago transcriptome. Currently, the web server hosts gene expression data from 156 Affymetrix GeneChip® Medicago genome arrays in 64 different experiments, covering a broad range of developmental and environmental conditions. The server enables flexible, multifaceted analyses of transcript data and provides a range of additional information about genes, including different types of annotation and links to the genome sequence, which help users formulate hypotheses about gene function. Transcript data can be accessed using Affymetrix probe identification number, DNA sequence, gene name, functional description in natural language, GO and KEGG annotation terms, and InterPro domain number. Transcripts can also be discovered through co-expression or differential expression analysis. Flexible tools to select a subset of experiments and to visualize and compare expression profiles of multiple genes have been implemented. Data can be downloaded, in part or full, in a tabular form compatible with common analytical and visualization software. The web server will be updated on a regular basis to incorporate new gene expression data and genome annotation, and is accessible at: http

  11. Gamma-ray array physics.

    SciTech Connect

    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.

  12. Photoelectrochemistry of Semiconductor Nanowire Arrays

    SciTech Connect

    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.

  13. High density arrays of micromirrors

    SciTech Connect

    Folta, J. M.; Decker, J. Y.; Kolman, J.; Lee, C.; Brase, J. M.

    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.

  14. Array Technology for Terahertz Imaging

    NASA Technical Reports Server (NTRS)

    Reck, Theodore; Siles, Jose; Jung, Cecile; Gill, John; Lee, Choonsup; Chattopadhyay, Goutam; Mehdi, Imran; Cooper, Ken

    2012-01-01

    Heterodyne terahertz (0.3 - 3THz) imaging systems are currently limited to single or a low number of pixels. Drastic improvements in imaging sensitivity and speed can be achieved by replacing single pixel systems with an array of detectors. This paper presents an array topology that is being developed at the Jet Propulsion Laboratory based on the micromachining of silicon. This technique fabricates the array's package and waveguide components by plasma etching of silicon, resulting in devices with precision surpassing that of current metal machining techniques. Using silicon increases the versatility of the packaging, enabling a variety of orientations of circuitry within the device which increases circuit density and design options. The design of a two-pixel transceiver utilizing a stacked architecture is presented that achieves a pixel spacing of 10mm. By only allowing coupling from the top and bottom of the package the design can readily be arrayed in two dimensions with a spacing of 10mm x 18mm.

  15. Solar array flight dynamic experiment

    NASA Technical Reports Server (NTRS)

    Schock, R. W.

    1986-01-01

    The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on space shuttle flight STS-31D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability.

  16. Solar array flight dynamic experiment

    NASA Technical Reports Server (NTRS)

    Schock, Richard W.

    1987-01-01

    The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures' dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on space shuttle flight STS-41D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability.

  17. Low cost silicon solar arrays

    NASA Technical Reports Server (NTRS)

    Goldsmith, J. V.; Cleland, J. W.; Westbrook, R. D.; Davis, H. L.; Wood, R. F.; Lindmayer, J.; Wakefield, G. F.

    1975-01-01

    The economic production of silicon solar cell arrays circumvents p-n junction degradation by nuclear doping, in which the Si-30 transmutes to P-31 after thermal neutron capture. Also considered are chemical purity specifications for improved silicon bulk states, surface induced states, and surface states.

  18. The Auger Engineering Radio Array

    NASA Astrophysics Data System (ADS)

    Fuchs, Benjamin

    2012-11-01

    High and ultra-high energy cosmic rays hitting the Earth's atmosphere cause extensive air showers (EAS). In recent years, these cosmic rays have been extensively studied at the Pierre Auger Observatory in Argentina. The EAS mainly consist of charged particles, especially electrons and positrons, which cause electro-magnetic emission in the MHz range by interaction with the Earth's magnetic field. To measure this radio emission, AERA, the Auger Engineering Radio Array, was deployed in October 2010 and commenced regular data acquisition in April 2011. AERA was designed as an engineering array for technology and methodology development towards future large-scale radio arrays. It will allow studies on the radio emission mechanism and the physics capabilities of the detection technique. AERA's unique site within the surface detector array (SD) of the Pierre Auger Observatory provides the possibility of coincident hybrid and super-hybrid EAS detection especially in overlap with the fluorescence telescopes Coihueco and HEAT. Besides a description of the setup, we present an overview of analyses of commissioning data taken between November 2010 and April 2011. Also, we show the first hybrid and self-triggered events detected with AERA in April 2011.

  19. Progress on the CHARA array

    NASA Astrophysics Data System (ADS)

    McAlister, Harold A.; Bagnuolo, William G.; ten Brummelaar, Theo A.; Hartkopf, W. I.; Shure, Mark A.; Sturmann, Laszlo; Turner, Nils H.; Ridgway, Stephen T.

    1998-07-01

    The Center for High Angular Resolution Astronomy (CHARA) at Georgia State University is building an interferometric array of telescope for high resolution imaging at optical and IR wavelengths. The 'CHARA Array' will initially consist of five 1-m diameter telescopes arranged in a 'Y' shaped configuration with a maximum baseline of approximately 350 m. The facility is being constructed on Mt. Wilson, near Pasadena, California, a site noted for stable atmospheric conditions that often gives rise to exceptional image quality. The Array will be capable of submilliarcsecond imaging and will be devoted to a broad program of science aimed at fundamental stellar astrophysics in the visible and the astrophysics of young stellar objects in the IR spectral regions. This project is being funded in approximately 50/50 percent shares by Georgia State University and the National Science Foundation. The CHARA Array is expected to become operational during 1999. This paper presents a projection status report. An extensive collection of project reports and images are available at our website (http:/www.chara.gsu.edu).

  20. Detector Arrays For Infrared Astronomy

    NASA Technical Reports Server (NTRS)

    Mccreight, C. R.; Mckelvey, M. E.; Goebel, J. H.; Anderson, G. M.; Lee, J. H.

    1988-01-01

    Paper describes status of program for developing integrated infrared detectors for astronomy. Program covers variety of detectors, including extrinsic silicon, extrinsic germanium, and indium antimonide devices with hybrid silicon multiplexers. Paper notes for arrays to reach background noise limit in cryogenic telescope, continued reductions in readout noise and dark current needed.

  1. TANGO Array.. 1. The instrument

    NASA Astrophysics Data System (ADS)

    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.

  2. Design and fabrication of microstrip antenna arrays

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A microstrip array project was conducted to demonstrate the feasibility of designing and fabricating simple, low cost, low sidelobe phased arrays with circular disk microstrip radiating elements. Design data were presented for microstrip elements and arrays including the effects of the protective covers, the mutual interaction between elements, and stripline feed network design. Low cost multilayer laminate fabrication techniques were also investigated. Utilizing this design data two C-band low sidelobe arrays were fabricated and tested: an eight-element linear and a sixty-four element planar array. These arrays incorporated stripline Butler matrix feed networks to produce a low sidelobe broadside beam.

  3. Advanced Rainbow Solar Photovoltaic Arrays

    NASA Technical Reports Server (NTRS)

    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

  4. Bit-level systolic arrays

    SciTech Connect

    De Groot, A.J.

    1989-01-01

    In this dissertation the author considered the design of bit - level systolic arrays where the basic computational unit consists of a simple one - bit logic unit, so that the systolic process is carried out at the level of individual bits. In order to pursue the foregoing research, several areas have been studied. First, the concept of systolic processing has been investigated. Several important algorithms were investigated and put into systolic form using graph-theoretic methods. The bit-level, word-level and block-level systolic arrays which have been designed for these algorithms exhibit linear speedup with respect to the number of processors and exhibit efficiency close to 100%, even with low interprocessor communication bandwidth. Block-level systolic arrays deal with blocks of data with block-level operations and communications. Block-level systolic arrays improve cell efficiency and are more efficient than their word-level counterparts. A comparison of bit-level, word-level and block-level systolic arrays was performed. In order to verify the foregoing theory and analysis a systolic processor called the SPRINT was developed to provide and environment where bit-level, word-level and block-level systolic algorithms could be confirmed by direct implementation rather than by computer simulation. The SPRINT is a supercomputer class, 64-element multiprocessor with a reconfigurable interconnection network. The theory has been confirmed by the execution on the SPRINT of the bit-level, word-level, and block-level systolic algorithms presented in the dissertation.

  5. Microarray profiling of gene expression patterns in glomerular cells of astaxanthin-treated diabetic mice: a nutrigenomic approach.

    PubMed

    Naito, Yuji; Uchiyama, Kazuhiko; Mizushima, Katsura; Kuroda, Masaaki; Akagiri, Satomi; Takagi, Tomohisa; Handa, Osamu; Kokura, Satoshi; Yoshida, Norimasa; Ichikawa, Hiroshi; Takahashi, Jiro; Yoshikawa, Toshikazu

    2006-10-01

    We have demonstrated that astaxanthin reduces glomerular oxidative stress as well as inhibits the increase in urinary albumin in diabetic db/db mice. The aim of the present study was to determine the gene expression patterns in the glomerular cells of the diabetic mouse kidney, and to investigate the effects of astaxanthin on the expression of these genes using a high-density DNA microarray. The diet administered to the astaxanthin-supplementation group was prepared by mixing a control powder with astaxanthin at a concentration of 0.02%. Glomerular cells were obtained from the kidneys of mice by laser capture microdissection. Preparation of cRNA and target hybridization were performed according to the Affymetrix GeneChip eukaryotic small sample target labeling assay protocol. The gene expression profile was evaluated by the mouse expression set 430A GeneChip. Array data analysis was carried out using Affymetrix GeneChip operating and Ingenuity Pathway analysis software. Comparison between diabetic db/db and non-diabetic db/m mice revealed that 779 probes (3.1%) were significantly affected, i.e. 550 probes were up-regulated, and 229 probes were down-regulated, both at levels of >/=1.5-fold in the diabetic mice. Ingenuity signal analysis of 550 up-regulated probes revealed the mitochondrial oxidative phosphorylation pathway as the most significantly affected caronical pathway. The affected genes were associated with complexes I, III, and IV located on the mitochondrial inner membrane, and the expression levels of these genes were decreased in mice treated with astaxanthin as compared to the levels in the control mice. In addition, the expression of many genes associated with oxidative stress, collagen synthesis, and transforming growth factor-beta signaling was enhanced in the diabetic mice, and this enhancement was slightly inhibited in the astaxanthin-treated mice. In conclusion, this genome-wide nutrigenomics approach provided insight into genes and putative

  6. The Allen Telescope Array as Square Kilometer Array Pathfinder

    NASA Astrophysics Data System (ADS)

    Bower, Geoffrey C.

    2007-12-01

    The Allen Telescope Array (ATA) is a new radio interferometer that has begun scientific operations in 2007. Many of the technologies, techniques, and observing modes developed for the ATA are directly applicable to the Square Kilometer Array (SKA). The ATA is a pioneer of the LNSD, which refers to a large number (LN) of small diameter (SD) dishes to create the array. This concept underlies nearly all SKA designs. Other relevant technologies are the offset Gregorian ATA antenna, the ATA wideband log periodic feed, transport of broadband data over fiber optic cables, and flexible digital signal processing electronics. The small dishes of the ATA gives it extraordinary wide-field imaging and survey capability but also require new solutions for calibration and imaging. Real time imaging, rapid response to transients, and thinking telescope technology are also under development. Finally, the ATA is developing commensal observing modes, which enable multiple simultaneous science programs, such as SETI, transient surveys, and HI surveys. Opportunities exist for community members to perform scientific investigations as well as develop techniques and technology for the SKA through use of the ATA.

  7. Arrays of Bolometric Detectors for Submillimeter Astronomy

    NASA Technical Reports Server (NTRS)

    Silverberg, R. F.; Moseley, S. H.; Freund, M.; Allen, C.; Harper, A.; Loewenstein, R.; Dowell, C. D.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Large format two dimensional arrays of bolometric detectors are required for many millimeter and submillimeter applications. We describe the development and testing of such arrays and the plans for using them in both a ground-based and airborne instrument.

  8. Analysis of phased-array diode lasers

    SciTech Connect

    Hardy, A.; Streifer, W.

    1985-07-01

    An improved, more accurate analysis of phased-array diode lasers is presented, which yields results that differ both qualitatively and quantitatively from those previously employed. A numerical example indicating decreased splitting in array mode gains is included.

  9. Breadboard linear array scan imager program

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The performance was evaluated of large scale integration photodiode arrays in a linear array scan imaging system breadboard for application to multispectral remote sensing of the earth's resources. Objectives, approach, implementation, and test results of the program are presented.

  10. Photovoltaic array: Power conditioner interface characteristics

    NASA Technical Reports Server (NTRS)

    Gonzalez, C. C.; Hill, G. M.; Ross, R. G., Jr.

    1982-01-01

    The electrical output (power, current, and voltage) of flat plate solar arrays changes constantly, due primarily to changes in cell temperature and irradiance level. As a result, array loads such as dc-to-ac power conditioners must be capable of accommodating widely varying input levels while maintaining operation at or near the maximum power point of the array. The array operating characteristics and extreme output limits necessary for the systematic design of array load interfaces under a wide variety of climatic conditions are studied. A number of interface parameters are examined, including optimum operating voltage, voltage energy, maximum power and current limits, and maximum open circuit voltage. The effect of array degradation and I-V curve fill factor or the array power conditioner interface is also discussed. Results are presented as normalized ratios of power conditioner parameters to array parameters, making the results universally applicable to a wide variety of system sizes, sites, and operating modes.

  11. Heterodyne arrays for terahertz astronomy

    NASA Astrophysics Data System (ADS)

    Kloosterman, Jenna Lynn

    The clouds of gas and dust that constitute the Interstellar Medium (ISM) within the Milky Way and other galaxies can be studied through the spectral lines of the atoms and molecules. The ISM follows a lifecycle in which each of its phases can be traced through spectral lines in the Terahertz (THz) portion of the electromagnetic spectrum, loosely defined as 0.3--3 THz. Using the high spectral resolution afforded by heterodyne instruments, astronomers can potentially disentangle the large-scale structure and kinematics within these clouds. In order to study the ISM over large size scales, large format THz heterodyne arrays are needed. The research presented in this dissertation focuses on the development of two heterodyne array receiver systems for ISM studies, SuperCam and a Super-THz (>3 THz) receiver. SuperCam is a 64-pixel heterodyne imaging array designed for use on ground-based submillimeter telescopes to observe the astrophysically important CO J=3-2 emission line at 345 GHz. The SuperCam focal plane stacks eight, 1x8 mixer subarrays. Each pixel in the array has its own integrated superconductor-insulator-superconductor (SIS) mixer and Low Noise Amplifier (LNA). In spring 2012, SuperCam was installed on the University of Arizona Submillimeter Telescope (SMT) for its first engineering run with 32 active pixels. A second observing run in May 2013 had 52 active pixels. With the outliers removed, the median double sideband receiver temperature was 104 K. The Super-THz receiver is designed to observe the astrophysically important neutral atomic oxygen line at 4.7448 THz. The local oscillator is a third-order distributed feedback Quantum Cascade Laser operating in continuous wave mode at 4.741 THz. A quasi-optical hot electron bolometer is used as the mixer. We record a double sideband receiver noise temperature of 815 K, which is ˜7 times the quantum noise limit and an Allan variance time of 15 seconds at an effective noise fluctuation bandwidth of 18 MHz

  12. Restructuring for fault-tolerant systolic arrays

    SciTech Connect

    Li, H.F.; Jayakumar, R.; Lam, C.

    1989-02-01

    The problem of restructuring systolic arrays with faulty cells is considered. An approach to derive the required data flow paths and computational sites is proposed. The data skewing requirement, which must be satisfied to find an input schedule, is also discussed. Algorithms to restructure systolic arrays for three different architecture of the processing elements are presented. A systematic method to retime the restructure array using additional programmable delays so that the retimed array satisfies the data skewing requirement is developed.

  13. Method to fabricate hollow microneedle arrays

    DOEpatents

    Kravitz, Stanley H.; Ingersoll, David; Schmidt, Carrie; Flemming, Jeb

    2006-11-07

    An inexpensive and rapid method for fabricating arrays of hollow microneedles uses a photoetchable glass. Furthermore, the glass hollow microneedle array can be used to form a negative mold for replicating microneedles in biocompatible polymers or metals. These microneedle arrays can be used to extract fluids from plants or animals. Glucose transport through these hollow microneedles arrays has been found to be orders of magnitude more rapid than natural diffusion.

  14. Approximate Analysis of Semiconductor Laser Arrays

    NASA Technical Reports Server (NTRS)

    Marshall, William K.; Katz, Joseph

    1987-01-01

    Simplified equation yields useful information on gains and output patterns. Theoretical method based on approximate waveguide equation enables prediction of lateral modes of gain-guided planar array of parallel semiconductor lasers. Equation for entire array solved directly using piecewise approximation of index of refraction by simple functions without customary approximation based on coupled waveguid modes of individual lasers. Improved results yield better understanding of laser-array modes and help in development of well-behaved high-power semiconductor laser arrays.

  15. Arrays of stacked metal coordination compounds

    DOEpatents

    Bulkowski, J.E.

    1986-10-21

    A process is disclosed for preparing novel arrays of metal coordination compounds characterized by arrangement of the metal ions, separated by a linking agent, in stacked order one above the other. The process permits great flexibility in the design of the array. For example, layers of different composition can be added to the array at will. 3 figs.

  16. Arrays of stacked metal coordination compounds

    DOEpatents

    Bulkowski, John E.

    1986-01-01

    A process is disclosed for preparing novel arrays of metal coordination compounds characterized by arrangement of the metal ions, separated by a linking agent, in stacked order one above the other. The process permits great flexibility in the design of the array. For example, layers of different composition can be added to the array at will.

  17. Control of phased-array antennas

    NASA Astrophysics Data System (ADS)

    Samoilenko, V. I.; Shishov, Iu. A.

    Principles and algorithms for the control of phased arrays are described. Particular consideration is given to algorithms for the control of phase distribution, adaptive arrays, beam-steerable arrays, the design of phase shifters, the compensation of beam-pointing errors, and the calibration of high-gain antenna pointing.

  18. Proceedings: EPRI Second Phased Array Inspection Seminar

    SciTech Connect

    2001-11-01

    The Second EPRI Phased Array Inspection Seminar focused on industrial applications of phased array technology that have been achieved to date or are planned for the near future. Presentations were made by developers of inspection techniques, inspection services vendors, and utility personnel who have performed inspections using arrays.

  19. Design of optimal systolic arrays

    SciTech Connect

    Li, G.J.; Wah, B.W.

    1985-01-01

    Conventional design of systolic arrays is based on the mapping of an algorithm onto an interconnection of processing elements in a VLSI chip. This mapping is done in an ad hoc manner, and the resulting configuration usually represents a feasible but suboptimal design. In this paper, systolic arrays are characterized by three classes of parameters: the velocities of data flows, the spatial distributions of data, and the periods of computation. By relating these parameters in constraint equations that govern the correctness of the design, the design is formulated into an optimization problem. The size of the search space is a polynomial of the problem size, and a methodology to systematically search and reduce this space and to obtain the optimal design is proposed. Some examples of applying the method, including matrix multiplication, finite impulse response filtering, deconvolution, and triangular-matrix inversion, are given. 30 references.

  20. Integrated residential photovoltaic array development

    NASA Astrophysics Data System (ADS)

    Shepard, N. F., Jr.

    1981-02-01

    An optimum integrated residential photovoltaic array/module is addressed. Nineteen existing or proposed systems intended for residential applications are described. Each of these systems is rated against a comprehensive set of evaluation criteria in an effort to formulate three module design concepts for further study and analysis. This evaluation led to a number of observations which are enumerated and should be considered in future module and array designs. Three module concepts are presented as baseline design approaches to be further analyzed and optimized. These options include: (1) a rectangular, direct mounted, shingle type module; (2) an integrally mounted module with nonconductive exposed elements; and (3) an aluminum framed, stand off module. Preliminary design drawings are presented for each of these module configurations.

  1. Quantitative detection of protein arrays.

    PubMed

    Levit-Binnun, Nava; Lindner, Ariel B; Zik, Ory; Eshhar, Zelig; Moses, Elisha

    2003-03-15

    We introduce a quantitative method that utilizes scanning electron microscopy for the analysis of protein chips (SEMPC). SEMPC is based upon counting target-coated gold particles interacting specifically with ligands or proteins arrayed on a derivative microscope glass slide by utilizing backscattering electron detection. As model systems, we quantified the interactions of biotin and streptavidin and of an antibody with its cognate hapten. Our method gives quantitative molecule-counting capabilities with an excellent signal-to-noise ratio and demonstrates a broad dynamic range while retaining easy sample preparation and realistic automation capability. Increased sensitivity and dynamic range are achieved in comparison to currently used array detection methods such as fluorescence, with no signal bleaching, affording high reproducibility and compatibility with miniaturization. Thus, our approach facilitates the determination of the absolute number of molecules bound to the chip rather than their relative amounts, as well as the use of smaller samples.

  2. Means of manufacturing annular arrays

    DOEpatents

    Day, R.A.

    1985-10-10

    A method is described for manufacturing an annular acoustic transducer array from a plate of transducer material, which enables production of precision aligned arrays at low cost. The circular plate is sawed along at least two lines that are radial to the axis of the plate. At steps along each radial cut, the plate is rotated first in one direction and then in an opposite direction by a predetermined angle such as slightly less than 90/sup 0/. The cuts result in the forming of several largely ring-shaped lands, each largely ring-shaped land being joined to the other rings of different radii by thin portions of the plate, and each ring being cut into segments. The bridges that join different rings hold the transducer together until it can be mounted on a lens.

  3. High voltage load resistor array

    DOEpatents

    Lehmann, Monty Ray

    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. Recent results from telescope array

    NASA Astrophysics Data System (ADS)

    Fukushima, Masaki

    2015-08-01

    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∘ radius) flux enhancement was observed near the Ursa-Major. A chance probability of creating this hotspot from the isotropic flux is 4.0 σ. The measured ⟨XMAX⟩ is consistent with the primary being proton or light nuclei for energies 1018.2 eV-1019.2 eV.

  5. Anderson attractors in active arrays

    PubMed Central

    Laptyeva, Tetyana V.; Tikhomirov, Andrey A.; Kanakov, Oleg I.; Ivanchenko, Mikhail V.

    2015-01-01

    In dissipationless linear media, spatial disorder induces Anderson localization of matter, light, and sound waves. The addition of nonlinearity causes interaction between the eigenmodes, which results in a slow wave diffusion. We go beyond the dissipationless limit of Anderson arrays and consider nonlinear disordered systems that are subjected to the dissipative losses and energy pumping. We show that the Anderson modes of the disordered Ginsburg-Landau lattice possess specific excitation thresholds with respect to the pumping strength. When pumping is increased above the threshold for the band-edge modes, the lattice dynamics yields an attractor in the form of a stable multi-peak pattern. The Anderson attractor is the result of a joint action by the pumping-induced mode excitation, nonlinearity-induced mode interactions, and dissipative stabilization. The regimes of Anderson attractors can be potentially realized with polariton condensates lattices, active waveguide or cavity-QED arrays. PMID:26304462

  6. Subwavelength micropillar array terahertz lasers.

    PubMed

    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.

  7. Integrated residential photovoltaic array development

    NASA Technical Reports Server (NTRS)

    Shepard, N. F., Jr.

    1981-01-01

    An optimum integrated residential photovoltaic array/module is addressed. Nineteen existing or proposed systems intended for residential applications are described. Each of these systems is rated against a comprehensive set of evaluation criteria in an effort to formulate three module design concepts for further study and analysis. This evaluation led to a number of observations which are enumerated and should be considered in future module and array designs. Three module concepts are presented as baseline design approaches to be further analyzed and optimized. These options include: (1) a rectangular, direct mounted, shingle type module; (2) an integrally mounted module with nonconductive exposed elements; and (3) an aluminum framed, stand off module. Preliminary design drawings are presented for each of these module configurations.

  8. A genome-wide linkage analysis of alcoholism on microsatellite and single-nucleotide polymorphism data, using alcohol dependence phenotypes and electroencephalogram measures.

    PubMed

    Zhang, Chun; Cawley, Simon; Liu, Guoying; Cao, Manqiu; Gorrell, Harley; Kennedy, Giulia C

    2005-01-01

    The Collaborative Study on the Genetics of Alcoholism (COGA) is a large-scale family study designed to identify genes that affect the risk for alcoholism and alcohol-related phenotypes. We performed genome-wide linkage analyses on the COGA data made available to participants in the Genetic Analysis Workshop 14 (GAW 14). The dataset comprised 1,350 participants from 143 families. The samples were analyzed on three technologies: microsatellites spaced at 10 cM, Affymetrix GeneChip Human Mapping 10 K Array (HMA10K) and Illumina SNP-based Linkage III Panel. We used ALDX1 and ALDX2, the COGA definitions of alcohol dependence, as well as electrophysiological measures TTTH1 and ECB21 to detect alcoholism susceptibility loci. Many chromosomal regions were found to be significant for each of the phenotypes at a p-value of 0.05. The most significant region for ALDX1 is on chromosome 7, with a maximum LOD score of 2.25 for Affymetrix SNPs, 1.97 for Illumina SNPs, and 1.72 for microsatellites. The same regions on chromosome 7 (96-106 cM) and 10 (149-176 cM) were found to be significant for both ALDX1 and ALDX2. A region on chromosome 7 (112-153 cM) and a region on chromosome 6 (169-185 cM) were identified as the most significant regions for TTTH1 and ECB21, respectively. We also performed linkage analysis on denser maps of markers by combining the SNPs datasets from Affymetrix and Illumina. Adding the microsatellite data to the combined SNP dataset improved the results only marginally. The results indicated that SNPs outperform microsatellites with the densest marker sets performing the best.

  9. ISO camera array development status

    NASA Technical Reports Server (NTRS)

    Sibille, F.; Cesarsky, C.; Agnese, P.; Rouan, D.

    1989-01-01

    A short outline is given of the Infrared Space Observatory Camera (ISOCAM), one of the 4 instruments onboard the Infrared Space Observatory (ISO), with the current status of its two 32x32 arrays, an InSb charge injection device (CID) and a Si:Ga direct read-out (DRO), and the results of the in orbit radiation simulation with gamma ray sources. A tentative technique for the evaluation of the flat fielding accuracy is also proposed.

  10. Discrete photonics in waveguide arrays.

    PubMed

    Moison, J M; Belabas, N; Minot, C; Levenson, J A

    2009-08-15

    In homogeneous arrays of coupled waveguides, Floquet-Bloch waves are known to travel freely across the waveguides. We introduce a systematic discussion of the built-in patterning of the coupling constant between neighboring waveguides. Key patterns provide functions such as redirecting, guiding, and focusing these waves, up to nonlinear all-optical routing. This opens the way to light control in a functionalized discrete space, i.e., discrete photonics.

  11. PEP solar array definition study

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The power extension package (PEP) is a solar array system that will be used on the space transportation system to augment the power of the Orbiter vehicle and to extend the time the vehicle may stay in orbit. The baseline configuration of the PEP is reviewed. The programmatic aspects of the design covering the development plan, the manufacturing facility plan and the estimated costs and risks are presented.

  12. Automated Camera Array Fine Calibration

    NASA Technical Reports Server (NTRS)

    Clouse, Daniel; Padgett, Curtis; Ansar, Adnan; Cheng, Yang

    2008-01-01

    Using aerial imagery, the JPL FineCalibration (JPL FineCal) software automatically tunes a set of existing CAHVOR camera models for an array of cameras. The software finds matching features in the overlap region between images from adjacent cameras, and uses these features to refine the camera models. It is not necessary to take special imagery of a known target and no surveying is required. JPL FineCal was developed for use with an aerial, persistent surveillance platform.

  13. Multipurpose Communication Satellite solar array

    NASA Astrophysics Data System (ADS)

    Bastard, J. L.; Guyot, Ph.

    Through research and development studies, Aerospatiale has developed with the French National Space Agency (CNES) a new concept of a rigid Solar Array (GSR) which covers a range of power between 1 kW and 10 kW EOL 7 yr. This technology is used by Aerospatiale on the currently running programs:—TELECOM 1, Telecommunication satellite, spinned in transfer; —ARABSAT, Telecommunication satellite, 3-axis stabilized in transfer; —TELE-X and TV-SAT/TDF1, Direct Broadcasting satellites, 3-axis stabilized in transfer. This paper deals with the description and the electrical and mechanical performance of the Multipurpose Communication Satellite Solar Array (M.C.S.). For this satellite, which is expected to be launched in 1984, Aerospatiale has selected the following concept: primary power (1.4 kW EOL 7 yr) will be provided by two separate sun-oriented solar array wings equipped with AEG Telefunken BSR (Back Surface Reflector) solar cells. This solar generator is directly derived from the GSR technology. Owing to the three-axis stabilization of the satellite and the partial deployment of the solar array during the transfer phase it has been necessary to use a primary and a secondary hold-down devices. In the same way the position of the shunt on the solar generator induced an increase of the mass, because of the supplementary hold-down point and of the support structure. Now scribing Laser System leads to the optimization of the solar cells dimensions and allows a better fill factor of the panels and so an increase of the power performance. Beside the M.C.S concept which is fully adapted as regards its mission specifications, it was interesting to present different concepts of solar generators optimized not only as regards mass budget but also power budget. These concepts covering a large range of powers are fully adapted to telecommunication missions.

  14. Nonlinear ultrasonic phased array imaging.

    PubMed

    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.

  15. Array-based photoacoustic spectroscopy

    DOEpatents

    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.

  16. Carbon fibre slotted waveguide arrays

    NASA Astrophysics Data System (ADS)

    Wagner, R.

    Spaceborne SARs call for antennas of large aperture and high structural performance; attention is accordingly given to the slotted waveguide antenna concept, which yields high aperture efficiency, good beam-shaping, and low losses in conjunction with great compactness and high stiffness. A distinctive technology for the manufacture of such waveguides from metallized carbon fiber-reinforced plastics, as well as for the construction of radiating arrays for such waveguides, is presented.

  17. A distributed array antenna system

    NASA Technical Reports Server (NTRS)

    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.

  18. Assessment of algorithms for high throughput detection of genomic copy number variation in oligonucleotide microarray data

    PubMed Central

    Baross, Ágnes; Delaney, Allen D; Li, H Irene; Nayar, Tarun; Flibotte, Stephane; Qian, Hong; Chan, Susanna Y; Asano, Jennifer; Ally, Adrian; Cao, Manqiu; Birch, Patricia; Brown-John, Mabel; Fernandes, Nicole; Go, Anne; Kennedy, Giulia; Langlois, Sylvie; Eydoux, Patrice; Friedman, JM; Marra, Marco A

    2007-01-01

    Background Genomic deletions and duplications are important in the pathogenesis of diseases, such as cancer and mental retardation, and have recently been shown to occur frequently in unaffected individuals as polymorphisms. Affymetrix GeneChip whole genome sampling analysis (WGSA) combined with 100 K single nucleotide polymorphism (SNP) genotyping arrays is one of several microarray-based approaches that are now being used to detect such structural genomic changes. The popularity of this technology and its associated open source data format have resulted in the development of an increasing number of software packages for the analysis of copy number changes using these SNP arrays. Results We evaluated four publicly available software packages for high throughput copy number analysis using synthetic and empirical 100 K SNP array data sets, the latter obtained from 107 mental retardation (MR) patients and their unaffected parents and siblings. We evaluated the software with regards to overall suitability for high-throughput 100 K SNP array data analysis, as well as effectiveness of normalization, scaling with various reference sets and feature extraction, as well as true and false positive rates of genomic copy number variant (CNV) detection. Conclusion We observed considerable variation among the numbers and types of candidate CNVs detected by different analysis approaches, and found that multiple programs were needed to find all real aberrations in our test set. The frequency of false positive deletions was substantial, but could be greatly reduced by using the SNP genotype information to confirm loss of heterozygosity. PMID:17910767

  19. Coupled Array of Superconducting Nanowires

    NASA Astrophysics Data System (ADS)

    Ursache, Andrei

    2005-03-01

    We present experiments that investigate the collective behavior of arrays of superconducting lead nanowires with diameters smaller than the coherence length. The ultrathin (˜15nm) nanowires are grown by pulse electrodeposition into porous self-assembled P(S-b-MMA) diblock copolymer templates. The closely packed (˜24 nm spacing) 1-D superconducting nanowires stand vertically upon a thin normal (Au or Pt) film in a brush-like geometry. Thereby, they are coupled to each other by Andreev reflection at the S-N (Pb-Au) point contact interfaces. Magnetization measurements reveal that the ZFC/FC magnetic response of the coupled array system can be irreversible or reversible, depending on the orientation, perpendicular or parallel, of the applied magnetic field with respect to the coupling plane. As found by electric transport measurements, the coupled array system undergoes an in plane superconducting resistive transition at a temperature smaller than the Tc of an individual nanowire. Current-voltage characteristics throughout the transition region are also discussed. This work was supported by NSF grant DMI-0103024 and DMR-0213695.

  20. Rigid Solar Generator (GSR) solar arrays

    NASA Astrophysics Data System (ADS)

    Martin, G. A.; Laget, R.; Urbain, G.; Bastard, J. L.

    The Telecom, TV-SAT, and ARABSAT solar arrays are described. The Telecom minimal power requirement of 110 W during the spinned transfer phase (solar array stowed on the spacecraft walls) and 1054 W summer solstice on orbit (3 axis stabilized), led to a 3 panels per wing solar array with panel dimensions of 1295.4 x 2047 mm. The TV-SAT and ARABSAT arrays differ from Telecom by their partial deployment in transfer orbit. The arrays contain 14,256 solar cells for primary power and 1560 cells for battery charging. Cells are 180 micron thick back surface reflectors.

  1. Strain responsive concave and convex microlens arrays

    NASA Astrophysics Data System (ADS)

    Chandra, Dinesh; Yang, Shu; Lin, Pei-Chun

    2007-12-01

    We report the fabrication of single-component, strain responsive microlens arrays with real-time tunability. The concave lens array is fabricated by patterning hard oxide layer on a bidirectionally prestretched soft elastomer, poly(dimethylsiloxane) (PDMS) followed by confined buckling upon release of the prestrain. The convex microlens array is replica molded from the concave lenses in PDMS. Due to difference in lens formation mechanisms, the two types of lenses show different tunable range of focal length in response to the applied strain: large focal length change is observed from the concave microlens array, whereas that from the convex microlens array is much smaller.

  2. Status of wake and array loss research

    SciTech Connect

    Elliott, D.L.

    1991-09-01

    In recent years, many projects have evaluated wind turbine wake effects and resultant array losses in both Europe and the United States. This paper examines the status of current knowledge about wake effects and array losses and suggests future research. Single-turbine wake characteristics have been studied extensively and are generally described well by existing theoretical models. Field measurements of wake effects in wind turbine arrays are largely limited to small arrays, with 2 to 4 rows of turbines. Few data have been published on wake effects within large arrays. Measurements of wake deficits downwind of large arrays that deficits are substantially larger and extend farther downwind than expected. Although array design models have been developed, these models have been tested and verified using only limited data from a few rows of wind turbines in complex terrain, whereas some of the largest arrays have more than 40 rows of wind turbines. Planned cooperative efforts with the wind industry will obtain existing data relevant to analyzing energy deficits within large arrays and identifying data sets for potential use in array model verification efforts. Future research being considered include a cooperative research experiment to obtain more definitive data on wake deficits and turbulence within and downwind of large arrays. 16 refs., 9 figs., 1 tab.

  3. Integrating Scientific Array Processing into Standard SQL

    NASA Astrophysics Data System (ADS)

    Misev, Dimitar; Bachhuber, Johannes; Baumann, Peter

    2014-05-01

    We live in a time that is dominated by data. Data storage is cheap and more applications than ever accrue vast amounts of data. Storing the emerging multidimensional data sets efficiently, however, and allowing them to be queried by their inherent structure, is a challenge many databases have to face today. Despite the fact that multidimensional array data is almost always linked to additional, non-array information, array databases have mostly developed separately from relational systems, resulting in a disparity between the two database categories. The current SQL standard and SQL DBMS supports arrays - and in an extension also multidimensional arrays - but does so in a very rudimentary and inefficient way. This poster demonstrates the practicality of an SQL extension for array processing, implemented in a proof-of-concept multi-faceted system that manages a federation of array and relational database systems, providing transparent, efficient and scalable access to the heterogeneous data in them.

  4. Phased Array Inspection of Irregular Surfaces

    NASA Astrophysics Data System (ADS)

    Long, R.; Cawley, P.

    2007-03-01

    The purpose of this project is to research and develop new conformable phased arrays that allow reliable ultrasonic inspection of components with an irregular surface. Two alternative approaches have been considered: flexible contact arrays in which the array itself conforms to the surface and a membrane device in which a standard array is coupled to the surface via a fluid-filled membrane. A linear flexible contact phased array was purchased from CEA France and a conformable membrane device was designed and manufactured at Imperial College. Initial investigations were conducted to evaluate both approaches when coupling to test pieces with machined surfaces representative of typical welded pipes without removal of the weld caps. The research incorporated beam modelling using the CEA CIVA software and comparisons with experimental measurements. It is shown that the conformable membrane approach using a standard array transducer is competitive with the bespoke flexible array.

  5. International ultraviolet explorer solar array power degradation

    NASA Astrophysics Data System (ADS)

    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. Delamination Detection Using Guided Wave Phased Arrays

    NASA Technical Reports Server (NTRS)

    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.

  7. An ANSERLIN array for mobile satellite applications

    NASA Technical Reports Server (NTRS)

    Colomb, F. Y.; Kunkee, D. B.; Mayes, P. E.; Smith, D. W.; Jamnejad, V.

    1990-01-01

    Design, analysis, construction, and test of linear arrays of ANSERLIN (annular sector, radiating line) elements are reported and discussed. Due to feeding simplicity and easy construction as well as good CP performance, a planar array composed of a number of such linear arrays each producing a shaped beam tilted in elevation, is a good candidate as a vehicle-mounted mechanically steered antenna for mobile satellite applications. A single level construction technique was developed that makes this type of array very cost competitive with other low-profile arrays. An asymmetric 19.5 inch long four-element array was fabricated and tested with reasonable performance. A smaller five-element symmetric array (16 inch long) was also designed and tested capable of operating in either sense of circular polarization. Efforts were made to successfully reduce this effect.

  8. The indirect binary n-cube array

    NASA Technical Reports Server (NTRS)

    Pease, M. C.

    1977-01-01

    The array is built from a large number (hundreds or thousands) of microprocessors or microcomputers linked through a switching network into an indirect binary n-cube array. Control is two level, the array operating synchronously, or in lock step, at the higher level, and with the broadcast commands being locally interpreted into rewritable microinstruction streams in the microprocessors and in the switch control units. The key to the design is the switching array. By properly programming it, the array can be made into a wide variety of virtual arrays which are well adapted to a wide range of applications. It is believed that the flexibility of the switching array can be used to obtain fault avoidance, which appears necessary in any highly parallel design.

  9. Imaging phased telescope array study

    NASA Technical Reports Server (NTRS)

    Harvey, James E.

    1989-01-01

    The problems encountered in obtaining a wide field-of-view with large, space-based direct imaging phased telescope arrays were considered. After defining some of the critical systems issues, previous relevant work in the literature was reviewed and summarized. An extensive list was made of potential error sources and the error sources were categorized in the form of an error budget tree including optical design errors, optical fabrication errors, assembly and alignment errors, and environmental errors. After choosing a top level image quality requirment as a goal, a preliminary tops-down error budget allocation was performed; then, based upon engineering experience, detailed analysis, or data from the literature, a bottoms-up error budget reallocation was performed in an attempt to achieve an equitable distribution of difficulty in satisfying the various allocations. This exercise provided a realistic allocation for residual off-axis optical design errors in the presence of state-of-the-art optical fabrication and alignment errors. Three different computational techniques were developed for computing the image degradation of phased telescope arrays due to aberrations of the individual telescopes. Parametric studies and sensitivity analyses were then performed for a variety of subaperture configurations and telescope design parameters in an attempt to determine how the off-axis performance of a phased telescope array varies as the telescopes are scaled up in size. The Air Force Weapons Laboratory (AFWL) multipurpose telescope testbed (MMTT) configuration was analyzed in detail with regard to image degradation due to field curvature and distortion of the individual telescopes as they are scaled up in size.

  10. Sentinel-3 Solar Array Design

    NASA Astrophysics Data System (ADS)

    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.

  11. Electronic switching spherical array antenna

    NASA Technical Reports Server (NTRS)

    Stockton, R.

    1978-01-01

    This work was conducted to demonstrate the performance levels attainable with an ESSA (Electronic Switching Spherical Array) antenna by designing and testing an engineering model. The antenna was designed to satisfy general spacecraft environmental requirements and built to provide electronically commandable beam pointing capability throughout a hemisphere. Constant gain and beam shape throughout large volumetric coverage regions are the principle characteristics. The model is intended to be a prototype of a standard communications and data handling antenna for user scientific spacecraft with the Tracking and Data Relay Satellite System (TDRSS). Some additional testing was conducted to determine the feasibility of an integrated TDRSS and GPS (Global Positioning System) antenna system.

  12. Coated carbon nanotube array electrodes

    DOEpatents

    Ren, Zhifeng; Wen, Jian; Chen, Jinghua; Huang, Zhongping; Wang, Dezhi

    2008-10-28

    The present invention provides conductive carbon nanotube (CNT) electrode materials comprising aligned CNT substrates coated with an electrically conducting polymer, and the fabrication of electrodes for use in high performance electrical energy storage devices. In particular, the present invention provides conductive CNTs electrode material whose electrical properties render them especially suitable for use in high efficiency rechargeable batteries. The present invention also provides methods for obtaining surface modified conductive CNT electrode materials comprising an array of individual linear, aligned CNTs having a uniform surface coating of an electrically conductive polymer such as polypyrrole, and their use in electrical energy storage devices.

  13. Coated carbon nanotube array electrodes

    DOEpatents

    Ren, Zhifeng; Wen, Jian; Chen, Jinghua; Huang, Zhongping; Wang, Dezhi

    2006-12-12

    The present invention provides conductive carbon nanotube (CNT) electrode materials comprising aligned CNT substrates coated with an electrically conducting polymer, and the fabrication of electrodes for use in high performance electrical energy storage devices. In particular, the present invention provides conductive CNTs electrode material whose electrical properties render them especially suitable for use in high efficiency rechargeable batteries. The present invention also provides methods for obtaining surface modified conductive CNT electrode materials comprising an array of individual linear, aligned CNTs having a uniform surface coating of an electrically conductive polymer such as polypyrrole, and their use in electrical energy storage devices.

  14. Double interconnection fuel cell array

    DOEpatents

    Draper, R.; Zymboly, G.E.

    1993-12-28

    A fuel cell array is made, containing number of tubular, elongated fuel cells which are placed next to each other in rows (A, B, C, D), where each cell contains inner electrodes and outer electrodes, with solid electrolyte between the electrodes, where the electrolyte and outer electrode are discontinuous, having two portions, and providing at least two opposed discontinuities which contain at least two oppositely opposed interconnections contacting the inner electrode, each cell having only three metallic felt electrical connectors which contact surrounding cells, where each row is electrically connected to the other. 5 figures.

  15. Double interconnection fuel cell array

    DOEpatents

    Draper, Robert; Zymboly, Gregory E.

    1993-01-01

    A fuel cell array (10) is made, containing number of tubular, elongated fuel cells (12) which are placed next to each other in rows (A, B, C, D), where each cell contains inner electrodes (14) and outer electrodes (18 and 18'), with solid electrolyte (16 and 16') between the electrodes, where the electrolyte and outer electrode are discontinuous, having two portions, and providing at least two opposed discontinuities which contain at least two oppositely opposed interconnections (20 and 20') contacting the inner electrode (14), each cell (12) having only three metallic felt electrical connectors (22) which contact surrounding cells, where each row is electrically connected to the other.

  16. rasdaman Array Database: current status

    NASA Astrophysics Data System (ADS)

    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

  17. Multicolor photonic crystal laser array

    SciTech Connect

    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.

  18. Interleaved array antenna technology development

    NASA Technical Reports Server (NTRS)

    1985-01-01

    This is the third phase of a program to establish an antenna concept for shuttle and free flying spacecraft earth resources experiments using Synthetic Aperture Radar. The feasibility of a plated graphite epoxy waveguide for a space antenna was evaluated. A quantity of flat panels and waveguides were developed, procured, and tested for electrical and mechanical properties. In addition, processes for the assembly of a unique waveguide array were investigated. Finally, trades between various configurations that would allow elevation (range) electronic scanning and that would minimize feed complexity for various RF bandwidths were made.

  19. Sensitivity of an MT Array to 3D Structure Outside the Array Footprint

    NASA Astrophysics Data System (ADS)

    Booker, J. R.; Mackie, R. L.; Burd, A. I.; Pomposiello, M. C.; Favetto, A. B.

    2015-12-01

    Standard data collection strategy in magnetotellurics (MT) is to deploy a profile or array of sites that spans the target of interest. There is no expectation that structure can be imaged outside the area covered by sites. We have inverted two MT arrays for 3D structure under Argentina. The two arrays do not overlap, but serendipitously the 3D model for the northern array overlaps the position of a prominent 3D deep conductive structure seen in the inversion of the southern array. To our surprise this deep southern feature is also imaged by the northern array even though it is well outside the footprint of the northern array. It therefore appears that typical intuition about one's ability to image structure outside the span of the sites is not always true. We present model studies to demonstrate why this is so and under what conditions one can expect a 3D array to be capable of imaging structure outside the array.

  20. Antibacterial activity of ordered gold nanorod arrays.

    PubMed

    Zhu, Yuejing; Ramasamy, Mohankandhasamy; Yi, Dong Kee

    2014-09-10

    Well-packed two- and three-dimensional (2D and 3D) gold nanorod (AuNR) arrays were fabricated using confined convective arraying techniques. The array density could be controlled by changing the concentration of the gold nanorods solution, the velocity of the moving substrate, and the environment air-temperature. The hydrophilic behavior of glass substrates before and after surface modification was studied through contact angle measurements. The affinity and alignment of the AuNR arrays with varying nanorod concentrations and the resulting different array densities were studied using field emission scanning electron microscopy (FE-SEM). Under stable laser intensity irradiation, the photothermal response of the prepared arrays was measured using a thermocouple and the results were analyzed quantitatively. Synthesized AuNR arrays were added to Escherichia coli (E. coli) suspensions and evaluated for photothermal bactericidal activity before and after laser irradiation. The results showed promising bactericidal effect. The severity of pathogen destruction was measured and quantified using fluorescence microscopy, bioatomic force microscopy (Bio-AFM) and flow cytometry techniques. These results indicated that the fabricated AuNR arrays at higher concentrations were highly capable of complete bacterial destruction by photothermal effect compared to the low concentration AuNR arrays. Subsequent laser irradiation of the AuNR arrays resulted in rapid photoheating with remarkable bactericidal activity, which could be used for water treatment to produce microbe-free water. PMID:25148531

  1. Station characteristics of the Singapore Infrasound Array

    NASA Astrophysics Data System (ADS)

    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.

  2. Shielding in ungated field emitter arrays

    SciTech Connect

    Harris, J. R.; Jensen, K. L.; Shiffler, D. A.; Petillo, J. J.

    2015-05-18

    Cathodes consisting of arrays of high aspect ratio field emitters are of great interest as sources of electron beams for vacuum electronic devices. The desire for high currents and current densities drives the cathode designer towards a denser array, but for ungated emitters, denser arrays also lead to increased shielding, in which the field enhancement factor β of each emitter is reduced due to the presence of the other emitters in the array. To facilitate the study of these arrays, we have developed a method for modeling high aspect ratio emitters using tapered dipole line charges. This method can be used to investigate proximity effects from similar emitters an arbitrary distance away and is much less computationally demanding than competing simulation approaches. Here, we introduce this method and use it to study shielding as a function of array geometry. Emitters with aspect ratios of 10{sup 2}–10{sup 4} are modeled, and the shielding-induced reduction in β is considered as a function of tip-to-tip spacing for emitter pairs and for large arrays with triangular and square unit cells. Shielding is found to be negligible when the emitter spacing is greater than the emitter height for the two-emitter array, or about 2.5 times the emitter height in the large arrays, in agreement with previously published results. Because the onset of shielding occurs at virtually the same emitter spacing in the square and triangular arrays, the triangular array is preferred for its higher emitter density at a given emitter spacing. The primary contribution to shielding in large arrays is found to come from emitters within a distance of three times the unit cell spacing for both square and triangular arrays.

  3. Arrays of coupled chemical oscillators

    NASA Astrophysics Data System (ADS)

    Forrester, Derek Michael

    2015-11-01

    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 contrast, situations where the central flames are suppressed are also found. The phenomena leads to in-phase synchronised states emerging between periods of anti-phase synchronisation for arrays with different columnar sizes of candle and positioning.

  4. A millisecond pulsar timing array

    NASA Astrophysics Data System (ADS)

    Hobbs, George; Manchester, Dick; Sarkissian, John; Bailes, Matthew; Bhat, Ramesh; Jenet, Rick; van Straten, Willem; Yardley, Daniel Roger Billing; Burke, Sarah; Oslowski, Stefan; Hotan, Aidan; Champion, David

    2010-10-01

    The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB3, PDFB4) and the baseband system (APSR) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we have achieved the world's best pulsar timing precision, with four pulsars having rms residuals of less than or about 100 ns and 13 less than 1 microsecond. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project.

  5. A millisecond pulsar timing array

    NASA Astrophysics Data System (ADS)

    Hobbs, George; Manchester, Dick; Verbiest, Joris P. W.; Sarkissian, John; Bailes, Matthew; Bhat, Ramesh; Jenet, Rick; Keith, Michael; Burke-Spolaor, Sarah; van Straten, Willem; Yardley, Daniel Roger Billing; Ravi, Vikram; Oslowski, Stefan; Hotan, Aidan; Champion, David; Khoo, Jonathan; Shannon, Ryan; Chaudhary, Ankur

    2012-04-01

    The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB3, PDFB4) and the baseband systems (CPSR2; APSR) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we have achieved the world's best pulsar timing precision. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project. We request continuing status for this project.

  6. A millisecond pulsar timing array

    NASA Astrophysics Data System (ADS)

    Hobbs, George; Manchester, Dick; Sarkissian, John; Bailes, Matthew; Bhat, Ramesh; Keith, Michael; Burke-Spolaor, Sarah; Coles, William; van Straten, Willem; Ravi, Vikram; Oslowski, Stefan; Khoo, Jonathan; Shannon, Ryan; Wang, Jingbo; Levin, Yuri

    2013-10-01

    The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB3, PDFB4) and the baseband systems (CPSR2; APSR) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we have achieved the world's best pulsar timing precision. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project. We request continuing status for this project.

  7. A millisecond pulsar timing array

    NASA Astrophysics Data System (ADS)

    Manchester, Dick; Sarkissian, John; Hobbs, George; Bailes, Matthew; Bhat, Ramesh; Jenet, Rick; van Straten, Willem; Yardley, Daniel Roger Billing; Champion, David; Burke, Sarah; Oslowski, Stefan; Hotan, Aidan

    2009-10-01

    The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB3, PDFB4) and the baseband systems (CPSR2; APSR) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we have achieved the world's best pulsar timing precision, with three pulsars having rms residuals of less than or about 100 ns and more than half less than 1 microsecond. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project.

  8. A millisecond pulsar timing array

    NASA Astrophysics Data System (ADS)

    Hobbs, George; Manchester, Dick; Verbiest, Joris P. W.; Sarkissian, John; Bailes, Matthew; Bhat, Ramesh; Jenet, Rick; Keith, Michael; Burke-Spolaor, Sarah; van Straten, Willem; Yardley, Daniel Roger Billing; Ravi, Vikram; Oslowski, Stefan; Hotan, Aidan; Champion, David; Khoo, Jonathan; Shannon, Ryan; Chaudhary, Ankur

    2011-10-01

    The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB3, PDFB4) and the baseband systems (CPSR2; APSR) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we have achieved the world's best pulsar timing precision. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project. We request continuing status for this project.

  9. A millisecond pulsar timing array

    NASA Astrophysics Data System (ADS)

    Manchester, Dick; Sarkissian, John; Hobbs, George; Bailes, Matthew; Bhat, Ramesh; Hotan, Aidan; Jenet, Rick; van Straten, Willem; Yardley, Daniel Roger Billing; Champion, David; You, Xiaopeng; Burke, Sarah

    2009-04-01

    The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB3, PDFB4) and the baseband systems (CPSR2; APSR) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we have achieved the world's best pulsar timing precision, with three pulsars having rms residuals of less than or about 100 ns and more than half less than 1 microsecond. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project.

  10. A millisecond pulsar timing array

    NASA Astrophysics Data System (ADS)

    Hobbs, George; Manchester, Dick; Sarkissian, John; Bailes, Matthew; Bhat, Ramesh; Keith, Michael; Burke-Spolaor, Sarah; Coles, William; van Straten, Willem; Yardley, Daniel Roger Billing; Ravi, Vikram; Oslowski, Stefan; Khoo, Jonathan; Shannon, Ryan; Wang, Jingbo; Levin, Yuri

    2013-04-01

    The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB3, PDFB4) and the baseband systems (CPSR2; APSR) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we have achieved the world's best pulsar timing precision. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project. We request continuing status for this project.

  11. A millisecond pulsar timing array

    NASA Astrophysics Data System (ADS)

    Hobbs, George; Manchester, Dick; Verbiest, Joris P. W.; Sarkissian, John; Bailes, Matthew; Bhat, Ramesh; Jenet, Rick; Keith, Michael; Burke-Spolaor, Sarah; van Straten, Willem; Ravi, Vikram; Oslowski, Stefan; Hotan, Aidan; Champion, David; Khoo, Jonathan; Shannon, Ryan; Chaudhary, Ankur

    2012-10-01

    The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB3, PDFB4) and the baseband systems (CASPSR; APSR) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we have achieved the world's best pulsar timing precision. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project. We request continuing status for this project.

  12. A millisecond pulsar timing array

    NASA Astrophysics Data System (ADS)

    Manchester, Dick; Verbiest, Joris P. W.; Sarkissian, John; Hobbs, George; Bailes, Matthew; Bhat, Ramesh; Hotan, Aidan; Jenet, Rick; Burke-Spolaor, Sarah; van Straten, Willem; Yardley, Daniel Roger Billing; You, Xiaopeng

    2008-10-01

    The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB2, PDFB3) and the baseband systems (CPSR2; APSR soon) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we are getting the world's best pulsar timing precision, with four pulsars having rms residuals of less than 200 ns and more than half less than 1 microsecond. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project.

  13. A millisecond pulsar timing array

    NASA Astrophysics Data System (ADS)

    Manchester, Dick; Sarkissian, John; Hobbs, George; Bailes, Matthew; Bhat, Ramesh; Jenet, Rick; van Straten, Willem; Yardley, Daniel Roger Billing; Burke, Sarah; Oslowski, Stefan; Hotan, Aidan; Champion, David

    2010-04-01

    The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB3, PDFB4) and the baseband systems (CPSR2; APSR) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we have achieved the world's best pulsar timing precision, with four pulsars having rms residuals of less than or about 100 ns and 13 less than 1 microsecond. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project.

  14. A millisecond pulsar timing array

    NASA Astrophysics Data System (ADS)

    Hobbs, George; Manchester, Dick; Verbiest, Joris P. W.; Sarkissian, John; Bailes, Matthew; Bhat, Ramesh; Jenet, Rick; Keith, Michael; Burke-Spolaor, Sarah; van Straten, Willem; Yardley, Daniel Roger Billing; Oslowski, Stefan; Hotan, Aidan; Champion, David; Khoo, Jonathan; Shannon, Ryan; Chaudhary, Ankur

    2011-04-01

    The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. There are many secondary goals, some astrophysical and some instrumental/technique oriented. Achievement of these ambitious primary goals requires frequent observations of at least 20 MSPs at two or preferably three widely spaced frequencies over several years. We wish to continue observing the PPTA sample at intervals of 2-3 weeks using both the 10/50cm and Multibeam receivers. The digital filterbanks (PDFB3, PDFB4) and the baseband systems (CPSR2; APSR) are used for data recording. With the new instruments and development of an efficient pipeline processing system, we have achieved the world's best pulsar timing precision. We are collaborating with the European and North American pulsar timing array groups (EPTA and NANOGrav, respectively) to obtain more frequent observations and a larger pulsar sample. Because of the high sensitivity and wide bandwidths required, RFI mitigation is an important part of the project. We request continuing status for this project.

  15. Module/array interface study

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Several aspects of module design are evaluated, including glass superstrate and metal substrate module configurations, the potential for hail damage, light absorption in glass superstrates, the economics of glass selection, and electrical design. Also, three alternate glass superstrate module configurations are evaluated by means of finite element computer analyses. Two panel sizes, 1.2 by 2.4 m (4 by 8 ft) and 2.4 by 4.8 m are used to support three module sizes, 0.6 by 1.2 m, 1.2 by 1.2 m, and 1.2 by 2.4 m, for design loadings of + or - 1.7 kPa, + or - 2.4 kPa, and + or - 3.6 kPa. Designs and cost estimates are presented for twenty panel types and nine array configurations at each of the three design loadings. Structural cost sensitivities of combined array configurations and panel cases are presented.

  16. Arrays of coupled chemical oscillators.

    PubMed

    Forrester, Derek Michael

    2015-01-01

    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 contrast, situations where the central flames are suppressed are also found. The phenomena leads to in-phase synchronised states emerging between periods of anti-phase synchronisation for arrays with different columnar sizes of candle and positioning. PMID:26582365

  17. Percolation in dense storage arrays

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Scott; Wilcke, Winfried W.; Garner, Robert B.; Huels, Harald

    2002-11-01

    As computers and their accessories become smaller, cheaper, and faster the providers of news, retail sales, and other services we now take for granted on the Internet have met their increasing computing needs by putting more and more computers, hard disks, power supplies, and the data communications linking them to each other and to the rest of the wired world into ever smaller spaces. This has created a new and quite interesting percolation problem. It is no longer desirable to fix computers, storage or switchgear which fail in such a dense array. Attempts to repair things are all too likely to make problems worse. The alternative approach, letting units “fail in place”, be removed from service and routed around, means that a data communications environment will evolve with an underlying regular structure but a very high density of missing pieces. Some of the properties of this kind of network can be described within the existing paradigm of site or bond percolation on lattices, but other important questions have not been explored. I will discuss 3D arrays of hundreds to thousands of storage servers (something which it is quite feasible to build in the next few years), and show that bandwidth, but not percolation fraction or shortest path lengths, is the critical factor affected by the “fail in place” disorder. Redundancy strategies traditionally employed in storage systems may have to be revised. Novel approaches to routing information among the servers have been developed to minimize the impact.

  18. Stretchable Micro-Electrode Array

    SciTech Connect

    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.

  19. Reduced-vibration tube array

    DOEpatents

    Bruck, Gerald J.; Bartolomeo, Daniel R.

    2004-07-20

    A reduced-vibration tube array is disclosed. The array includes a plurality of tubes in a fixed arrangement and a plurality of damping members positioned within the tubes. The damping members include contoured interface regions characterized by bracing points that selectively contact the inner surface of an associated tube. Each interface region is sized and shaped in accordance with the associated tube, so that the damping member bracing points are spaced apart a vibration-reducing distance from the associated tube inner surfaces at equilibrium. During operation, mechanical interaction between the bracing points and the tube inner surfaces reduces vibration by a damage-reducing degree. In one embodiment, the interface regions are serpentine shaped. In another embodiment, the interface regions are helical in shape. The interface regions may be simultaneously helical and serpentine in shape. The damping members may be fixed within the associated tubes, and damping member may be customized several interference regions having attributes chosen in accordance with desired flow characteristics and associated tube properties.

  20. Energy transfer in macromolecular arrays

    NASA Astrophysics Data System (ADS)

    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.

  1. Arrays of coupled chemical oscillators

    PubMed Central

    Forrester, Derek Michael

    2015-01-01

    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 contrast, situations where the central flames are suppressed are also found. The phenomena leads to in-phase synchronised states emerging between periods of anti-phase synchronisation for arrays with different columnar sizes of candle and positioning. PMID:26582365

  2. Arrays of coupled chemical oscillators.

    PubMed

    Forrester, Derek Michael

    2015-11-19

    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 contrast, situations where the central flames are suppressed are also found. The phenomena leads to in-phase synchronised states emerging between periods of anti-phase synchronisation for arrays with different columnar sizes of candle and positioning.

  3. Sky reconstruction for the Tianlai cylinder array

    NASA Astrophysics Data System (ADS)

    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. Replica amplification of nucleic acid arrays

    DOEpatents

    Church, George M.

    2002-01-01

    A method of producing a plurality of a nucleic acid array, comprising, in order, the steps of amplifying in situ nucleic acid molecules of a first randomly-patterned, immobilized nucleic acid array comprising a heterogeneous pool of nucleic acid molecules affixed to a support, transferring at least a subset of the nucleic acid molecules produced by such amplifying to a second support, and affixing the subset so transferred to the second support to form a second randomly-patterned, immobilized nucleic acid array, wherein the nucleic acid molecules of the second array occupy positions that correspond to those of the nucleic acid molecules from which they were amplified on the first array, so that the first array serves as a template to produce a plurality, is disclosed.

  5. Interferometric Plasmonic Lensing with Nanohole Arrays

    SciTech Connect

    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.

  6. Space and power efficient hybrid counters array

    DOEpatents

    Gara, Alan G.; Salapura, Valentina

    2010-03-30

    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.

  7. Space and power efficient hybrid counters array

    DOEpatents

    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.

  8. Simulations of Array Configurations for the Square Kilometre Array (SKA)

    NASA Astrophysics Data System (ADS)

    Jiménez-Monferrer, Sergio; Lal, Dharam Vir; Lobanov, Andrei P.; Guirado, José Carlos

    The Square Kilometre Array (SKA) is a new generation radio telescope for the next decades, working at metre to centimetre wavelengths. The SKA will be operational at the same time than other new optical, X-ray and Gamma-ray telescopes. It is of extreme importance that the SKA becomes competitive and complementary to those instruments. An extensive study of technologies and possible configurations involved is needed to ensure the SKA will reach the design specifications. To compare imaging capabilities between different SKA configurations or between the SKA and other instruments, we have implemented figures of merit based on several characteristics of these instruments. In this work we are presenting some results of numerical tests based on the Spatial Dynamic Range (SDR), which quantifies the range of spatial scales than can be reconstructed from interferometric data (Lobanov, A.P., SKA Memo 38, 2003).

  9. High-Throughput Quantitative Analysis of the Human Intestinal Microbiota with a Phylogenetic Microarray▿

    PubMed Central

    Paliy, Oleg; Kenche, Harshavardhan; Abernathy, Frank; Michail, Sonia

    2009-01-01

    Gut microbiota carry out key functions in health and participate in the pathogenesis of a growing number of diseases. The aim of this study was to develop a custom microarray that is able to identify hundreds of intestinal bacterial species. We used the Entrez nucleotide database to compile a data set of bacterial 16S rRNA gene sequences isolated from human intestinal and fecal samples. Identified sequences were clustered into separate phylospecies groups. Representative sequences from each phylospecies were used to develop a microbiota microarray based on the Affymetrix GeneChip platform. The designed microbiota array contains probes to 775 different bacterial phylospecies. In our validation experiments, the array correctly identified genomic DNA from all 15 bacterial species used. Microbiota array has a detection sensitivity of at least 1 pg of genomic DNA and can detect bacteria present at a 0.00025% level of overall sample. Using the developed microarray, fecal samples from two healthy children and two healthy adults were analyzed for bacterial presence. Between 227 and 232 species were detected in fecal samples from children, whereas 191 to 208 species were found in adult stools. The majority of identified phylospecies belonged to the classes Clostridia and Bacteroidetes. The microarray revealed putative differences between the gut microbiota of healthy children and adults: fecal samples from adults had more Clostridia and less Bacteroidetes and Proteobacteria than those from children. A number of other putative differences were found at the genus level. PMID:19363078

  10. Big Data Challenges for Large Radio Arrays

    NASA Technical Reports Server (NTRS)

    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.

  11. A simplified solar cell array modelling program

    NASA Technical Reports Server (NTRS)

    Hughes, R. D.

    1982-01-01

    As part of the energy conversion/self sufficiency efforts of DSN engineering, it was necessary to have a simplified computer model of a solar photovoltaic (PV) system. This article describes the analysis and simplifications employed in the development of a PV cell array computer model. The analysis of the incident solar radiation, steady state cell temperature and the current-voltage characteristics of a cell array are discussed. A sample cell array was modelled and the results are presented.

  12. Halbach arrays in precision motion control

    SciTech Connect

    Trumper, D.L.; Williams, M.E.

    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.

  13. Nonvolatile Array Of Synapses For Neural Network

    NASA Technical Reports Server (NTRS)

    Tawel, Raoul

    1993-01-01

    Elements of array programmed with help of ultraviolet light. A 32 x 32 very-large-scale integrated-circuit array of electronic synapses serves as building-block chip for analog neural-network computer. Synaptic weights stored in nonvolatile manner. Makes information content of array invulnerable to loss of power, and, by eliminating need for circuitry to refresh volatile synaptic memory, makes architecture simpler and more compact.

  14. Mapping Electrical Crosstalk in Pixelated Sensor Arrays

    NASA Technical Reports Server (NTRS)

    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.

  15. Performance measurements of hybrid PIN diode arrays

    SciTech Connect

    Shapiro, S.L. ); Arens, J.F.; Jernigan, J.G. . Space Sciences Lab.); Kramer, G. ); Collins, T.; Worley, S. ); Wilburn, C.D. ); Skubic, P. )

    1990-10-01

    We report the successful development of hybrid PIN diode arrays and a series of room-temperature measurements in a high-energy pion beam at FNAL. A PMOS VLSI 256 {times} 256 readout array having 30 {mu}m square pixels was indium-bump bonded to a mating PIN diode detector array. Preliminary measurements on the resulting hybrid show excellent signal-to-noise at room temperature. 3 refs., 5 figs.

  16. Infrared array detectors. [for astronomical observation

    NASA Technical Reports Server (NTRS)

    Arens, J. F.

    1982-01-01

    Arrays of detectors sensitive to infrared radiation will enable astronomical observations to be made with shorter observing times than with discrete detectors and with good relative spatial accuracy. Systems using such arrays are being developed for astronomy in several regions of the electromagnetic spectrum. An example of an infrared system is given here consisting of a 32x32 element bismuth doped silicon charge injection device array that has been used in an astronomical camera.

  17. Modeling Array Stations in SIG-VISA

    NASA Astrophysics Data System (ADS)

    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.

  18. Microfabricated wire arrays for Z-pinch.

    SciTech Connect

    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.

  19. Graphical methods for evaluating covering arrays

    SciTech Connect

    Kim, Youngil; Jang, Dae -Heung; Anderson-Cook, Christine M.

    2015-08-10

    Covering arrays relax the condition of orthogonal arrays by only requiring that all combination of levels be covered but not requiring that the appearance of all combination of levels be balanced. This allows for a much larger number of factors to be simultaneously considered but at the cost of poorer estimation of the factor effects. To better understand patterns between sets of columns and evaluate the degree of coverage to compare and select between alternative arrays, we suggest several new graphical methods that show some of the patterns of coverage for different designs. As a result, these graphical methods for evaluating covering arrays are illustrated with a few examples.

  20. Serial multiplier arrays for parallel computation

    NASA Technical Reports Server (NTRS)

    Winters, Kel

    1990-01-01

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

  1. Airborne Electronically Steerable Phased Array (AESPA) program

    NASA Technical Reports Server (NTRS)

    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.

  2. Nanoelectrode array formation by electrolytic nanoparticle impacts

    NASA Astrophysics Data System (ADS)

    Bartlett, T. R.; Holter, J.; Young, N.; Compton, R. G.

    2016-07-01

    We report the fabrication of functional nanoelectrode arrays by the electrolysis of AgBr nanoparticles (NPs) impacting on a glassy carbon electrode from suspension in aqueous solution. The impacted NPs result in Ag NP deposits of similar size to the originating NP, with the coverage of these arrays easily controlled by the time of the deposition step. The NPs constituting the array are deposited randomly across the surface with little aggregation or agglomeration. The fabricated arrays are themselves electrochemically active, mediating the reduction of hydrogen peroxide, H2O2.

  3. Array algebra estimation in signal processing

    NASA Astrophysics Data System (ADS)

    Rauhala, U. A.

    A general theory of linear estimators called array algebra estimation is interpreted in some terms of multidimensional digital signal processing, mathematical statistics, and numerical analysis. The theory has emerged during the past decade from the new field of a unified vector, matrix and tensor algebra called array algebra. The broad concepts of array algebra and its estimation theory cover several modern computerized sciences and technologies converting their established notations and terminology into one common language. Some concepts of digital signal processing are adopted into this language after a review of the principles of array algebra estimation and its predecessors in mathematical surveying sciences.

  4. Parallel scheduling of recursively defined arrays

    NASA Technical Reports Server (NTRS)

    Myers, T. J.; Gokhale, M. B.

    1986-01-01

    A new method of automatic generation of concurrent programs which constructs arrays defined by sets of recursive equations is described. It is assumed that the time of computation of an array element is a linear combination of its indices, and integer programming is used to seek a succession of hyperplanes along which array elements can be computed concurrently. The method can be used to schedule equations involving variable length dependency vectors and mutually recursive arrays. Portions of the work reported here have been implemented in the PS automatic program generation system.

  5. Enhanced reflection from inverse tapered nanocone arrays

    SciTech Connect

    Kong, Xiang-Tian; Dai, Qing; Butt, Haider Deng, Sunan; Yetisen, Ali K.; Cruz Vasconcellos, Fernando da; Kangwanwatana, Chuan; Montelongo, Yunuen; Qasim, Malik M.; Wilkinson, Timothy D.

    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.

  6. The Very Large Ecological Array

    NASA Astrophysics Data System (ADS)

    Hamilton, M. P.; Dawson, T. E.; Thompson, S. E.

    2011-12-01

    Regional climatic change and variability is expected to alter the boundary conditions to which ecosystems and landscapes are subject. Unambiguously identifying how these changes alter the biophysics of ecosystems or the phenology or behavior of individual organisms, however, remains challenging due to the complexity and heterogeneity of real landscapes. One of the aims of the Very Large Ecological Array (VeLEA) - a landscape-scale distributed wireless environmental monitoring system under deployment at the University of California, Blue Oak Ranch Reserve (Mount Hamilton Range, Santa Clara County, California) - is to allow a sufficiently fine-resolution understanding of spatial and temporal variability in the landscape that such changes can be reliably quantified. The VeLEA is structured around two wireless mesh radio networks, with solar-powered nodes spaced by up to 2 miles. This allows widely distributed arrays of instrumentation to be deployed over hundreds to thousands of hectares. The first network supports ten weather stations (recording barometric pressure, temperature, humidity, wind, rainfall, total solar radiation and leaf wetness), along with sixty nodes measuring humidity and air temperature at 1m above ground. Future deployments will extend the network to include soil moisture, soil temperature, piezometric head and streamflow across the site. The second network supports an array of 10 networked cameras providing real-time viewing and time-lapse recording of animal behavior, vegetation phenology and aquatic variability. An important goal of the VeLEA project is to optimize the deployment of wireless nodes with respect to spatial and temporal variation at the site. Preliminary data obtained from the initial deployments are being used to characterize spatial and temporal variability across the site and to investigate mechanistic and statistical methods for interpolating and up-scaling that data. Observing and characterizing such spatio

  7. Rigorous investigation of the array-tilt aberration for hexagonal, optical phased arrays.

    PubMed

    Hyde, Milo W; Wyman, Jason E; Tyler, Glenn A

    2014-04-10

    An investigation of the array-tilt aberration for hexagonal, optical phased arrays is presented. The investigation begins with theoretical derivations of the far-zone radiated field, the array factor, and the far-field radiated power for the seven-element hexagonal array with array tilt present. Physical insights gained from this analysis are discussed. An analytical treatment of correlation-based array-tilt estimators is also undertaken. Two novel array-tilt estimation techniques are developed from the analysis. The new techniques are shown to be significantly more efficient computationally than the traditional estimation approach. Simulation and experimental results are presented to validate the new array-tilt estimation methods.

  8. On the (Frequency) Modulation of Coupled Oscillator Arrays in Phased Array Beam Control

    NASA Technical Reports Server (NTRS)

    Pogorzelski, R.; Acorn, J.; Zawadzki, M.

    2000-01-01

    It has been shown that arrays of voltage controlled oscillators coupled to nearest neighbors can be used to produce useful aperture phase distributions for phased array antennas. However, placing information of the transmitted signal requires that the oscillations be modulated.

  9. On analytic design of loudspeaker arrays with uniform radiation characteristics

    PubMed

    Aarts; Janssen

    2000-01-01

    Some notes on analytical derived loudspeaker arrays with uniform radiation characteristics are presented. The array coefficients are derived via analytical means and compared with so-called maximal flat sequences known from telecommunications and information theory. It appears that the newly derived array, i.e., the quadratic phase array, has a higher efficiency than the Bessel array and a flatter response than the Barker array. The method discussed admits generalization to the design of arrays with desired nonuniform radiating characteristics.

  10. Remotely Monitored Sealing Array Software

    2012-09-12

    The Remotely Monitored Sealing Array (RMSA) utilizes the Secure Sensor Platform (SSP) framework to establish the fundamental operating capabilities for communication, security, power management, and cryptography. In addition to the SSP framework the RMSA software has unique capabilities to support monitoring a fiber optic seal. Fiber monitoring includes open and closed as well as parametric monitoring to detect tampering attacks. The fiber monitoring techniques, using the SSP power management processes, allow the seals to lastmore » for years while maintaining the security requirements of the monitoring application. The seal is enclosed in a tamper resistant housing with software to support active tamper monitoring. New features include LED notification of fiber closure, the ability to retrieve the entire fiber optic history via translator command, separate memory storage for fiber optic events, and a more robust method for tracking and resending failed messages.« less

  11. Multilayer Ferritin Array for Bionanobattery

    NASA Technical Reports Server (NTRS)

    Chu, Sang-Hyon (Inventor); Choi, Sang H. (Inventor); Kim, Jae-Woo (Inventor); Lillehei, Peter T. (Inventor); Park, Yeonjoon (Inventor); King, Glen C. (Inventor); Elliott, James R., Jr. (Inventor)

    2009-01-01

    A thin-film electrode for a bio-nanobattery is produced by consecutively depositing arrays of a ferritin protein on a substrate, employing a spin self-assembly procedure. By this procedure, a first ferritin layer is first formed on the substrate, followed by building a second, oppositely-charged ferritin layer on the top of the first ferritin layer to form a bilayer structure. Oppositely-charged ferritin layers are subsequently deposited on top of each other until a desired number of bilayer structures is produced. An ordered, uniform, stable and robust, thin-film electrode material of enhanced packing density is presented, which provides optimal charge density for the bio-nanobattery.

  12. Proposed MIDAS II processing array

    SciTech Connect

    Meng, J.

    1982-03-01

    MIDAS (Modular Interactive Data Analysis System) is a ganged processor scheme used to interactively process large data bases occurring as a finite sequence of similar events. The existing device uses a system of eight ganged minicomputer central processor boards servicing a rotating group of 16 memory blocks. A proposal for MIDAS II, the successor to MIDAS, is to use a much larger number of ganged processors, one per memory block, avoiding the necessity of switching memories from processor to processor. To be economic, MIDAS II must use a small, relatively fast and inexpensive microprocessor, such as the TMS 9995. This paper analyzes the use of the TMS 9995 applied to the MIDAS II processing array, emphasizing computational, architectural and physical characteristics which make the use of the TMS 9995 attractive for this application.

  13. UAVSAR Active Electronically Scanned Array

    NASA Technical Reports Server (NTRS)

    Sadowy, Gregory, A.; Chamberlain, Neil F.; Zawadzki, Mark S.; Brown, Kyle M.; Fisher, Charles D.; Figueroa, Harry S.; Hamilton, Gary A.; Jones, Cathleen E.; Vorperian, Vatche; Grando, Maurio B.

    2011-01-01

    The Uninhabited Airborne Vehicle Synthetic Aperture Radar (UAVSAR) is a pod-based, L-band (1.26 GHz), repeatpass, interferometric, synthetic aperture radar (InSAR) used for Earth science applications. Repeat-pass interferometric radar measurements from an airborne platform require an antenna that can be steered to maintain the same angle with respect to the flight track over a wide range of aircraft yaw angles. In order to be able to collect repeat-pass InSAR data over a wide range of wind conditions, UAVSAR employs an active electronically scanned array (AESA). During data collection, the UAVSAR flight software continuously reads the aircraft attitude state measured by the Embedded GPS/INS system (EGI) and electronically steers the beam so that it remains perpendicular to the flight track throughout the data collection

  14. Conformable eddy current array delivery

    NASA Astrophysics Data System (ADS)

    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.

  15. Linear array optical edge sensor

    NASA Technical Reports Server (NTRS)

    Bejczy, Antal K. (Inventor); Primus, Howard C. (Inventor)

    1987-01-01

    A series of independent parallel pairs of light emitting and detecting diodes for a linear pixel array, which is laterally positioned over an edge-like discontinuity in a workpiece to be scanned, is disclosed. These independent pairs of light emitters and detectors sense along intersecting pairs of separate optical axes. A discontinuity, such as an edge in the sensed workpiece, reflects a detectable difference in the amount of light from that discontinuity in comparison to the amount of light that is reflected on either side of the discontinuity. A sequentially sychronized clamping and sampling circuit detects that difference as an electrical signal which is recovered by circuitry that exhibits an improved signal-to-noise capability for the system.

  16. Wind farm array wake losses

    SciTech Connect

    Baker, R.W.; McCarthy, E.F.

    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.

  17. Gigapixel imaging with microlens arrays

    NASA Astrophysics Data System (ADS)

    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.

  18. Photo sensor array technology development

    NASA Technical Reports Server (NTRS)

    Rossman, M. W.; Young, V. F.; Beall, J. R.

    1977-01-01

    The development of an improved capability photo sensor array imager for use in a Viking '75 type facsimile camera is presented. This imager consists of silicon photodiodes and lead sulfide detectors to cover a spectral range from 0.4 to 2.7 microns. An optical design specifying filter configurations and convergence angles is described. Three electronics design approaches: AC-chopped light, DC-dual detector, and DC-single detector, are investigated. Experimental and calculated results are compared whenever possible using breadboard testing and tolerance analysis techniques. Results show that any design used must be forgiving of the relative instability of lead sulfide detectors. A final design using lead sulfide detectors and associated electronics is implemented by fabrication of a hybrid prototype device. Test results of this device show a good agreement with calculated values.

  19. Global Arrays Parallel Programming Toolkit

    SciTech Connect

    Nieplocha, Jaroslaw; Krishnan, Manoj Kumar; Palmer, Bruce J.; Tipparaju, Vinod; Harrison, Robert J.; Chavarría-Miranda, Daniel

    2011-01-01

    The two predominant classes of programming models for parallel computing are distributed memory and shared memory. Both shared memory and distributed memory models have advantages and shortcomings. Shared memory model is much easier to use but it ignores data locality/placement. Given the hierarchical nature of the memory subsystems in modern computers this characteristic can have a negative impact on performance and scalability. Careful code restructuring to increase data reuse and replacing fine grain load/stores with block access to shared data can address the problem and yield performance for shared memory that is competitive with message-passing. However, this performance comes at the cost of compromising the ease of use that the shared memory model advertises. Distributed memory models, such as message-passing or one-sided communication, offer performance and scalability but they are difficult to program. The Global Arrays toolkit attempts to offer the best features of both models. It implements a shared-memory programming model in which data locality is managed by the programmer. This management is achieved by calls to functions that transfer data between a global address space (a distributed array) and local storage. In this respect, the GA model has similarities to the distributed shared-memory models that provide an explicit acquire/release protocol. However, the GA model acknowledges that remote data is slower to access than local data and allows data locality to be specified by the programmer and hence managed. GA is related to the global address space languages such as UPC, Titanium, and, to a lesser extent, Co-Array Fortran. In addition, by providing a set of data-parallel operations, GA is also related to data-parallel languages such as HPF, ZPL, and Data Parallel C. However, the Global Array programming model is implemented as a library that works with most languages used for technical computing and does not rely on compiler technology for achieving

  20. Remotely Monitored Sealing Array Software

    SciTech Connect

    2012-09-12

    The Remotely Monitored Sealing Array (RMSA) utilizes the Secure Sensor Platform (SSP) framework to establish the fundamental operating capabilities for communication, security, power management, and cryptography. In addition to the SSP framework the RMSA software has unique capabilities to support monitoring a fiber optic seal. Fiber monitoring includes open and closed as well as parametric monitoring to detect tampering attacks. The fiber monitoring techniques, using the SSP power management processes, allow the seals to last for years while maintaining the security requirements of the monitoring application. The seal is enclosed in a tamper resistant housing with software to support active tamper monitoring. New features include LED notification of fiber closure, the ability to retrieve the entire fiber optic history via translator command, separate memory storage for fiber optic events, and a more robust method for tracking and resending failed messages.

  1. A Portable Diode Array Spectrophotometer.

    PubMed

    Stephenson, David

    2016-05-01

    A cheap portable visible light spectrometer is presented. The spectrometer uses readily sourced items and could be constructed by anyone with a knowledge of electronics. The spectrometer covers the wavelength range 450-725 nm with a resolution better than 5 nm. The spectrometer uses a diffraction grating to separate wavelengths, which are detected using a 128-element diode array, the output of which is analyzed using a microprocessor. The spectrum is displayed on a small liquid crystal display screen and can be saved to a micro SD card for later analysis. Battery life (2 × AAA) is estimated to be 200 hours. The overall dimensions of the unit are 120 × 65 × 60 mm, and it weighs about 200 g. PMID:27036399

  2. Infrared-Bolometer Arrays with Reflective Backshorts

    NASA Technical Reports Server (NTRS)

    Miller, Timothy M.; Abrahams, John; Allen, Christine A.

    2011-01-01

    Integrated circuits that incorporate square arrays of superconducting-transition- edge bolometers with optically reflective backshorts are being developed for use in image sensors in the spectral range from far infrared to millimeter wavelengths. To maximize the optical efficiency (and, thus, sensitivity) of such a sensor at a specific wavelength, resonant optical structures are created by placing the backshorts at a quarter wavelength behind the bolometer plane. The bolometer and backshort arrays are fabricated separately, then integrated to form a single unit denoted a backshort-under-grid (BUG) bolometer array. In a subsequent fabrication step, the BUG bolometer array is connected, by use of single-sided indium bump bonding, to a readout device that comprises mostly a superconducting quantum interference device (SQUID) multiplexer circuit. The resulting sensor unit comprising the BUG bolometer array and the readout device is operated at a temperature below 1 K. The concept of increasing optical efficiency by use of backshorts at a quarter wavelength behind the bolometers is not new. Instead, the novelty of the present development lies mainly in several features of the design of the BUG bolometer array and the fabrication sequence used to implement the design. Prior to joining with the backshort array, the bolometer array comprises, more specifically, a square grid of free-standing molybdenum/gold superconducting-transition-edge bolometer elements on a 1.4- m-thick top layer of silicon that is part of a silicon support frame made from a silicon-on-insulator wafer. The backshort array is fabricated separately as a frame structure that includes support beams and contains a correspond - ing grid of optically reflective patches on a single-crystal silicon substrate. The process used to fabricate the bolometer array includes standard patterning and etching steps that result in the formation of deep notches in the silicon support frame. These notches are designed to

  3. A unified systolic array for adaptive beamforming

    SciTech Connect

    Bojanczyk, A.W.; Luk, F.T. )

    1990-04-01

    The authors present a new algorithm and systolic array for adaptive beamforming. The authors algorithm uses only orthogonal transformations and thus should have better numerical properties. The algorithm can be implemented on one single p {times} p triangular array of programmable processors that offers a throughput of one residual element per cycle.

  4. Optical transfer function of Starlette retroreflector array

    NASA Technical Reports Server (NTRS)

    Arnold, D. A.

    1975-01-01

    An optical transfer function was computed for the retroreflector array carried by the Starlette satellite (1975 10A). The range correction is given for extrapolating laser range measurements to the center of mass of the satellite. The gain function and active reflecting area of the array are computed for estimating laser-echo signal strengths.

  5. Spectral stability of Taylor's vortex array

    NASA Technical Reports Server (NTRS)

    Lin, S. P.; Tobak, M.

    1986-01-01

    In a global sense it is shown that the two-dimensional Taylor vortex array, an exact solution of the Navier-Stokes equation, is absolutely and monotonically stable with respect to infinitesimal disturbances of all discrete frequencies as long as the viscosity is positive. It is suggested that the Taylor vortex array may also be stable with respect to finite amplitude disturbances.

  6. Dumand-array data-acquisition system

    SciTech Connect

    Brenner, A.E.; Theriot, D.; Dau, W.D.; Geelhood, B.D.; Harris, F.; Learned, J.G.; Stenger, V.; March, R.; Roos, C.; Shumard, E.

    1982-04-01

    An overall data acquisition approach for DUMAND is described. The scheme assumes one array to shore optical fiber transmission line for each string of the array. The basic event sampling period is approx. 13 ..mu..sec. All potentially interesting data is transmitted to shore where the major processing is performed.

  7. Space Environment Testing of Photovoltaic Array Systems

    NASA Technical Reports Server (NTRS)

    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.

  8. Evaluation of space station solar array technology

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The research concerning lightweight solar array assemblies since 1970 is reported. A bibliography of abstracts of documents used for reference during this period is included along with an evaluation of available solar array technology. A list of recommended technology programs is presented.

  9. (Data acquisition for Ge detector arrays)

    SciTech Connect

    Hensley, D.C.

    1989-10-09

    The traveler presented three invited lectures entitled An Overview of Data Acquisition for Ge Detector Arrays,'' Specialized Data Acquisition for Ge Detector Arrays,'' and Gamma-Ray Angular Correlations from Heavy-Ion Inelastic Scattering Measured in the Spin Spectrometer'' and acted as a Study Group Coordinator at the Nuclear Structure in the Era of New Spectroscopy Workshop in Copenhagen, Denmark.

  10. A synthesis array for lunar submillimeter astronomy

    NASA Technical Reports Server (NTRS)

    Mahoney, M. J.

    1990-01-01

    This paper describes a system concept for a synthesis array for lunar submillimeter astronomy (SALSA). It includes a brief discussion of the science objectives and the advantages of a placing such an array on the moon, the system concept, and a top-level discussion of the various subsystems, including the technology drivers associated with each.

  11. JPL Large Advanced Antenna Station Array Study

    NASA Technical Reports Server (NTRS)

    1978-01-01

    In accordance with study requirements, two antennas are described: a 30 meter standard antenna and a 34 meter modified antenna, along with a candidate array configuration for each. Modified antenna trade analyses are summarized, risks analyzed, costs presented, and a final antenna array configuration recommendation made.

  12. An experimental X band phased array

    NASA Astrophysics Data System (ADS)

    Rao, N. P. R.; Limaye, K. U.; Ramalingam, R. P.; Gangadharan, T. S.; Bhandopadhyay, G.; Deshpande, P. A.

    1983-10-01

    The details of an X band experimental 11 x 11 element Phased Array Antenna of phased lens configuration with a monopulse space feed developed at LRDE are presented. The studies carried and the results obtained on collimation, beam steering, pattern variation with scan, array operation in two-dimensional search, dedicated track and track while scan (TWS) are also given.

  13. Defect-free atom arrays on demand

    NASA Astrophysics Data System (ADS)

    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.

  14. Defect-free atom arrays on demand

    NASA Astrophysics Data System (ADS)

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

    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.

  15. MMIC Phased Array Demonstrations with ACTS

    NASA Technical Reports Server (NTRS)

    Raquet, Charles A. (Compiler); Martzaklis, Konstantinos (Compiler); Zakrajsek, Robert J. (Compiler); Andro, Monty (Compiler); Turtle, John P.

    1996-01-01

    Over a one year period from May 1994 to May 1995, a number of demonstrations were conducted by the NASA Lewis Research Center (LeRC) in which voice, data, and/or video links were established via NASA's advanced communications technology satellite (ACTS) between the ACTS link evaluation terminal (LET) in Cleveland, OH, and aeronautical and mobile or fixed Earth terminals having monolithic microwave integrated circuit (MMIC) phased array antenna systems. This paper describes four of these. In one, a duplex voice link between an aeronautical terminal on the LeRC Learjet and the ACTS was achieved. Two others demonstrated duplex voice (and in one case video as well) links between the ACTS and an Army vehicle. The fourth demonstrated a high data rate downlink from ACTS to a fixed terminal. Array antenna systems used in these demonstrations were developed by LeRC and featured LeRC and Air Force experimental arrays using gallium arsenide MMIC devices at each radiating element for electronic beam steering and distributed power amplification. The single 30 GHz transmit array was developed by NASA/LeRC and Texas Instruments. The three 20 GHz receive arrays were developed in a cooperative effort with the Air Force Rome Laboratory, taking advantage of existing Air Force array development contracts with Boeing and Lockheed Martin. The paper describes the four proof-of-concept arrays and the array control system. The system configured for each of the demonstrations is described, and results are discussed.

  16. Dual band QWIP focal plane array

    NASA Technical Reports Server (NTRS)

    Gunapala, Sarath D. (Inventor); Choi, Kwong Kit (Inventor); Bandara, Sumith V. (Inventor)

    2005-01-01

    A quantum well infrared photodetector (QWIP) that provides two-color image sensing. Two different quantum wells are configured to absorb two different wavelengths. The QWIPs are arrayed in a focal plane array (FPA). The two-color QWIPs are selected for readout by selective electrical contact with the two different QWIPs or by the use of two different wavelength sensitive gratings.

  17. Multi-beam Phased Array Antennas

    NASA Technical Reports Server (NTRS)

    Lee, R. Q.; Romisch, S.; Popovic, Z.

    2002-01-01

    Many of NASA's future missions require multiple accesses to work together as a single system. To accomplish these missions, multi-beam phased array antennas are required to communicate between satellites flying in fixed formation. In this paper, a comparison of different multi-beam systems will be given followed by detailed discussions of the lens array architecture and test results.

  18. SEPS solar array design and technology evaluation

    NASA Technical Reports Server (NTRS)

    Elms, R. V., Jr.; Young, L. E.

    1975-01-01

    The technology developments required and a preliminary design of a lightweight 25 kW solar array for the solar electric propulsion stage (SEPS) have been defined. The requirements for a 65 W/Kg SEPS solar array system requires significant component weight reductions over present state-of-the-art flexible solar arrays in both electrical and structural-mechanical designs. A requirement for operation from 0.3 au to 6.0 au presents a wide range of temperature environments as well as severe combined thermal/vacuum/UV radiation environments. Additional requirements are capability for partial array retraction operation, and capability for full retraction and automatic preloading for survival of the Shuttle reentry environment. An assessment of current lightweight flexible solar array technology is made against the SEPS solar array requirements and new technology requirements are defined. A preliminary design and the operating characteristics of a flat-fold solar array system meeting the SEPS requirements is presented. A full-width, 10-ft-tall functional array model, including representative welded electrical modules and a model astromast, was fabricated and tested.

  19. The SKA New Instrumentation: Aperture Arrays

    NASA Astrophysics Data System (ADS)

    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.

  20. Si:As BIB detector arrays

    NASA Technical Reports Server (NTRS)

    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.

  1. Array Of Rockets For Multicrewmember Evacuation

    NASA Technical Reports Server (NTRS)

    Allen, Margaret A.

    1990-01-01

    Emergency egress system undergoing development for aircraft and aerospace vehicles uses fixed array of tractor rockets to eject crewmembers. Crewmembers hook up to tractor rockets and fire them unaided. Positioned as unit in ready-to-use orientation during flight operations. On ground, swung out of way. Rocket array also mounts under exit hatch, serving as egress ramp.

  2. Development of a monolithic ferrite memory array

    NASA Technical Reports Server (NTRS)

    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.

  3. Acoustic positioning using multiple microphone arrays.

    PubMed

    Liu, Hui; Milios, Evangelos

    2005-05-01

    Passive acoustic techniques are presented to solve the localization problem of a sound source in three-dimensional space using off-the-shelf hardware. Multiple microphone arrays are employed, which operate independently, in estimating the direction of arrival of sound, or, equivalently, a direction vector from the array's geometric center towards the source. Direction vectors and array centers are communicated to a central processor, where the source is localized by finding the intersection of the direction lines defined by the direction vectors and the associated array centers. The performance of the method in the air is demonstrated experimentally and compared with a state-of-the-art method that requires centralized digitization of the signals from the microphones of all the arrays. PMID:15957748

  4. Information coding in artificial olfaction multisensor arrays.

    PubMed

    Albert, Keith J; Walt, David R

    2003-08-15

    High-density sensor arrays were prepared with microbead vapor sensors to explore and compare the information coded in sensor response profiles following odor stimulus. The coded information in the sensor-odor response profiles, which is used for odor discrimination purposes, was extracted from the microsensor arrays via two different approaches. In the first approach, the responses from individual microsensors were separated (decoded array) and independently processed. In the second approach, response profiles from all microsensors within the entire array, i.e., the sensor ensemble, were combined to create one response per odor stimulus (nondecoded array). Although the amount of response data is markedly reduced in the second approach, the system shows comparable odor discrimination rates for the two signal extraction methods. The ensemble approach streamlines system resources without decreasing system performance. These signal compression approaches may simulate or parallel information coding in the mammalian olfactory system. PMID:14632130

  5. A multimode electromechanical parametric resonator array

    PubMed Central

    Mahboob, I.; Mounaix, M.; Nishiguchi, K.; Fujiwara, A.; Yamaguchi, H.

    2014-01-01

    Electromechanical resonators have emerged as a versatile platform in which detectors with unprecedented sensitivities and quantum mechanics in a macroscopic context can be developed. These schemes invariably utilise a single resonator but increasingly the concept of an array of electromechanical resonators is promising a wealth of new possibilities. In spite of this, experimental realisations of such arrays have remained scarce due to the formidable challenges involved in their fabrication. In a variation to this approach, we identify 75 harmonic vibration modes in a single electromechanical resonator of which 7 can also be parametrically excited. The parametrically resonating modes exhibit vibrations with only 2 oscillation phases which are used to build a binary information array. We exploit this array to execute a mechanical byte memory, a shift-register and a controlled-NOT gate thus vividly illustrating the availability and functionality of an electromechanical resonator array by simply utilising higher order vibration modes. PMID:24658349

  6. SMEX-Lite Modular Solar Array Architecture

    NASA Technical Reports Server (NTRS)

    Lyons, John W.; Day, John (Technical Monitor)

    2002-01-01

    The NASA Small Explorer (SMEX) missions have typically had three years between mission definition and launch. This short schedule has posed significant challenges with respect to solar array design and procurement. Typically, the solar panel geometry is frozen prior to going out with a procurement. However, with the SMEX schedule, it has been virtually impossible to freeze the geometry in time to avoid scheduling problems with integrating the solar panels to the spacecraft. A modular solar array architecture was developed to alleviate this problem. This approach involves procuring sufficient modules for multiple missions and assembling the modules onto a solar array framework that is unique to each mission. The modular approach removes the solar array from the critical path of the SMEX integration and testing schedule. It also reduces the cost per unit area of the solar arrays and facilitates the inclusion of experiments involving new solar cell or panel technologies in the SMEX missions.

  7. Junction-side illuminated silicon detector arrays

    DOEpatents

    Iwanczyk, Jan S.; Patt, Bradley E.; Tull, Carolyn

    2004-03-30

    A junction-side illuminated detector array of pixelated detectors is constructed on a silicon wafer. A junction contact on the front-side may cover the whole detector array, and may be used as an entrance window for light, x-ray, gamma ray and/or other particles. The back-side has an array of individual ohmic contact pixels. Each of the ohmic contact pixels on the back-side may be surrounded by a grid or a ring of junction separation implants. Effective pixel size may be changed by separately biasing different sections of the grid. A scintillator may be coupled directly to the entrance window while readout electronics may be coupled directly to the ohmic contact pixels. The detector array may be used as a radiation hardened detector for high-energy physics research or as avalanche imaging arrays.

  8. Residential photovoltaic module and array requirements study

    NASA Technical Reports Server (NTRS)

    Nearhoof, S. L.; Oster, J. R.

    1979-01-01

    Design requirements for photovoltaic modules and arrays used in residential applications were identified. Building codes and referenced standards were reviewed for their applicability to residential photovoltaic array installations. Four installation types were identified - integral (replaces roofing), direct (mounted on top of roofing), stand-off (mounted away from roofing), and rack (for flat or low slope roofs, or ground mounted). Installation costs were developed for these mounting types as a function of panel/module size. Studies were performed to identify optimum module shapes and sizes and operating voltage cost drivers. It is concluded that there are no perceived major obstacles to the use of photovoltaic modules in residential arrays. However, there is no applicable building code category for residential photovoltaic modules and arrays and additional work with standards writing organizations is needed to develop residential module and array requirements.

  9. Thermopile Detector Arrays for Space Science Applications

    NASA Technical Reports Server (NTRS)

    Foote, M. C.; Kenyon, M.; Krueger, T. R.; McCann, T. A.; Chacon, R.; Jones, E. W.; Dickie, M. R.; Schofield, J. T.; McCleese, D. J.; Gaalema, S.

    2004-01-01

    Thermopile detectors are widely used in uncooled applications where small numbers of detectors are required, particularly in low-cost commercial applications or applications requiring accurate radiometry. Arrays of thermopile detectors, however, have not been developed to the extent of uncooled bolometer and pyroelectric/ferroelectric arrays. Efforts at JPL seek to remedy this deficiency by developing high performance thin-film thermopile detectors in both linear and two-dimensional formats. The linear thermopile arrays are produced by bulk micromachining and wire bonded to separate CMOS readout electronic chips. Such arrays are currently being fabricated for the Mars Climate Sounder instrument, scheduled for launch in 2005. Progress is also described towards realizing a two-dimensional thermopile array built over CMOS readout circuitry in the substrate.

  10. Analyzing Array Manipulating Programs by Program Transformation

    NASA Technical Reports Server (NTRS)

    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.

  11. Nonlinearities in digital manifold phased arrays

    NASA Astrophysics Data System (ADS)

    Mathews, Bruce D.

    1986-11-01

    In digital beamforming (DBF), the phase shifter is functionally replaced with a receiver and digital phase rotation. A Taylor series expansion of mixer nonlinearities is used to generate receiver intermodulation spectrums respective of the element position and the iso-Doppler wavefront directions of signal arrival across the array. The dominant intermodulation distortion at each element experiences linear phase errors across the array proportional to the harmonic number and the desired steering direction phase gradient. The array distortion signals are reduced relative to the desired signal by the array factor sidelobe isolation when desired collimation directions exceed a few beamwidths of scan off the array normal vector. The result of the nonlinear down conversion analysis is extended to inphase and quadrature imbalances and batch manufacturing tolerances for element receivers.

  12. Astronomical imaging with InSb arrays

    NASA Astrophysics Data System (ADS)

    Pipher, Judith L.

    Ten years ago, Forrest presented the first astronomical images with a Santa Barbara Research Center (SBRC) 32 x 32 InSb array camera at the first NASA-Ames Infrared Detector Technology Work-shop. Soon after, SBRC began development of 58 x 62 InSb arrays, both for ground-based astronomy and for the Space Infrared Telescope Facility (SIRTF). By the time of the 1987 Hilo workshop 'Ground-based Astronomical Observations with Infrared Array Dectectors' astronomical results from cameras based on SBRC 32 x 32 and 58 x 62 InSb arrays, a CE linear InSb array, and a French 32 x 32 InSb charge injection device (CID) array were presented. And at the Tucson 1990 meeting 'Astrophysics with Infrared Arrays', it was clear that this new technology was no longer the province of 'IR pundits', but provided a tool for all astronomers. At this meeting, the first astronomical observations with SBRC's new, gateless passivation 256 x 256 InSb arrays will be presented: they perform spectacularly] In this review, I can only broadly brush on the interesting science completed with InSb array cameras. Because of the broad wavelength coverage (1-5.5 micrometer) of InSb, and the extremely high performance levels throughout the band, InSb cameras are used not only in the near IR, but also from 3-5.5 micrometer, where unique science is achieved. For example, the point-like central engines of active galactic nuclei (AGN) are delineated at L' and M', and Bra and 3.29 micrometer dust emission images of galactic and extragalactic objects yield excitation conditions. Examples of imaging spectroscopy, high spatial resolution imaging, as well as deep, broad-band imaging with InSb cameras at this meeting illustrate the power of InSb array cameras.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Design theory of microphone arrays for teleconferencing

    NASA Astrophysics Data System (ADS)

    Macomber, Dwight Frank

    2001-07-01

    Room reverberation and interfering acoustical noise lower the quality of speech transmission in teleconferencing. Conventional solutions for speech capture that suppress pickup of reverberation and interference typically constrain the motion of the speaker, encumber the speaker physically, or make it difficult for many different speakers to easily participate. These impediments result from cables, radio and headset microphones, or so-called house microphones located at fixed positions. Microphone arrays and matched-filter processing have been proposed as solutions to this sound capture problem. In part because the behavior of arrays in reverberant acoustic spaces has not been well quantified, there have been no guidelines for designing effective teleconference arrays. The principal goal of this work is the development of general design rules for speech acquisition arrays. Expressions for the array performance measures of signal-to-reverberation ratio and signal-to-interference ratio are derived using statistical acoustics, then verified by computer simulation using the image method of geometric room acoustics. The analysis is facilitated by assuming the reverberant sound field to be diffuse. The assumption is valid above approximately 250 Hz. All work assumes omnidirectional sources and sensors mounted on walls with low absorption. Array sensors should be placed close to, and roughly equidistant to the source, yet as far from each other as possible. The aperture of a full-band array should extend into three dimensions. Wall and ceiling mounting of sensors is recommended. Relations specify the number of sensors required for various room volumes, room absorptions, and source-to-sensor distances. A planar ceiling array expands the range of motion for speakers by widening the focal region above 300 Hz. Off-line audition of a 32-sensor array in a 60-cubicmeter room with a reverberation time of .63 second indicates that subjectively good array performance may be obtained

  15. Recent Data from CSMIP Instrumented Downhole Arrays

    NASA Astrophysics Data System (ADS)

    Graizer, V.; Shakal, A.

    2004-12-01

    The California Strong Motion Instrumentation Program (CSMIP) operates 19 downhole geotechnical arrays throughout California, with 8 arrays in Southern and 11 arrays in Northern California. 13 arrays were instrumented with the support and cooperation of the California Department of Transportation (Caltrans). Three more arrays are expected to be instrumented soon. More than 30 low amplitude recordings from earthquakes with 2.4array in Los Angeles area where the freeway collapsed during the Northridge earthquake. This deep soft soil array was instrumented in 1995 with sensors installed at the surface and at depths of 18 m, 100 m and 252 m. The strongest acceleration of 0.5g was recorded at this array during a relatively small earthquake of M4.2 at an epicentral distance of 2.7 km and depth of 7.9 km (almost vertical wave incidence) The downhole array at Treasure Island near San Francisco was installed in 1992 with instruments located at the surface, in fill, alluvium and rock. Transfer functions from the surface to rock (at 104 and 122 m depth) were computed. Both horizontal components demonstrate strong amplifications at: 0.8, 1.9, 3.4, 4.4, 5.8 and 6.8 Hz. The first frequency is associated with the depth to the rock (h = 88 m, average Vs=261 m/s, f = Vs/4h gives 0.74 Hz). During the last year, new low amplitude data were recorded at downhole arrays. An important set of records was obtained during the December 22, 2003 M6.5 San Simeon earthquake at the three arrays: Treasure Island, San Francisco - Bay Bridge, and Hayward - San Mateo Bridge at epicentral distances of 230-260 km. The records from the San Simeon earthquake obtained at different depths demonstrate a similar pattern to that shown during the Hector Mine earthquake: In contrast to accelerations (high frequency part of seismic signal), displacements (relatively low frequency part of seismic signal) demonstrate minimal near-surface site amplification. The one

  16. Miniature quadrupole mass spectrometer array

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)

    1997-01-01

    The present invention provides a minature quadrupole mass spectrometer array for the separation of ions, comprising a first pair of parallel, planar, nonmagnetic conducting rods each having an axis of symmetry, a second pair of planar, nonmagnetic conducting rods each having an axis of symmetry parallel to said first pair of rods and disposed such that a line perpendicular to each of said first axes of symmetry and a line perpendicular to each of said second axes of symmetry bisect each other and form a generally 90 degree angle. A nonconductive top positioning plate is positioned generally perpendicular to the first and second pairs of rods and has an aperture for ion entrance along an axis equidistant from each axis of symmetry of each of the parallel rods, a nonconductive bottom positioning plate is generally parallel to the top positioning plate and has an aperture for ion exit centered on an axis equidistant from each axis of symmetry of each of the parallel rods, means for maintaining a direct current voltage between the first and second pairs of rods, and means for applying a radio frequency voltage to the first and second pairs of rods.

  17. Miniature quadrupole mass spectrometer array

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)

    1998-01-01

    The present invention provides a minature quadrupole mass spectrometer array for the separation of ions, comprising a first pair of parallel, planar, nonmagnetic conducting rods each having an axis of symmetry, a second pair of planar, nonmagnetic conducting rods each having an axis of symmetry parallel to said first pair of rods and disposed such that a line perpendicular to each of said first axes of symmetry and a line perpendicular to each of said second axes of symmetry bisect each other and form a generally 90 degree angle. A nonconductive top positioning plate is positioned generally perpendicular to the first and second pairs of rods and has an aperture for ion entrance along an axis equidistant from each axis of symmetry of each of the parallel rods, a nonconductive bottom positioning plate is generally parallel to the top positioning plate and has an aperture for ion exit centered on an axis equidistant from each axis of symmetry of each of the parallel rods, means for maintaining a direct current voltage between the first and second pairs of rods, and means for applying a radio frequency voltage to the first and second pairs of rods.

  18. CHARA Array Enclosure Control System

    NASA Astrophysics Data System (ADS)

    Hines, Braden E.; ten Brummelaar, Theo A.

    2002-12-01

    The CHARA Array at Mt. Wilson consists of six telescopes spread over hundreds of meters of rugged territory. Making efficient use of such a large physical instrument requires automation and tele-operation of the distributed resources. One system which is key to making daily operations routine is the enclosure control system, which is used to open and close the walls of the enclosure in order to enable quick equilibration of the telescope with its environment in order to minimize ground seeing effects on observations. This paper describes this enclosure control system, which is a distributed hardware/software system consisting of software running on a central control station in the operations room, together with software and hardware installed on six remote computers. The system must be robust in the presence of absent or intermittent nodes or network connections, must provide for both manual or remote control of the enclosures, and must provide for hardware and personnel safety. Remote operation of the system from Atlanta, Georgia has been demonstrated, and the system has proven extremely robust in regular use to date.

  19. Large phased-array radars

    SciTech Connect

    Brookner, D.E.

    1988-12-15

    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.

  20. Automated Array Assembly, Phase 2

    NASA Technical Reports Server (NTRS)

    Carbajal, B. G.

    1979-01-01

    The solar cell module process development activities in the areas of surface preparation are presented. The process step development was carried out on texture etching including the evolution of a conceptual process model for the texturing process; plasma etching; and diffusion studies that focused on doped polymer diffusion sources. Cell processing was carried out to test process steps and a simplified diode solar cell process was developed. Cell processing was also run to fabricate square cells to populate sample minimodules. Module fabrication featured the demonstration of a porcelainized steel glass structure that should exceed the 20 year life goal of the low cost silicon array program. High efficiency cell development was carried out in the development of the tandem junction cell and a modification of the TJC called the front surface field cell. Cell efficiencies in excess of 16 percent at AM1 have been attained with only modest fill factors. The transistor-like model was proposed that fits the cell performance and provides a guideline for future improvements in cell performance.

  1. Nanoscale pillar arrays for separations

    DOE PAGES

    Kirchner, Teresa; Strickhouser, Rachel; Hatab, Nahla; Charlton, Jennifer; Kravchenko, Ivan I.; Lavrik, Nickolay V.; Sepaniak, Michael J.

    2015-04-01

    The work presented herein evaluates silicon nano-pillar arrays for use in planar chromatography. Electron beam lithography and metal thermal dewetting protocols were used to create nano-thin layer chromatography platforms. With these fabrication methods we are able to reduce the size of the characteristic features in a separation medium below that used in ultra-thin layer chromatography; i.e. pillar heights are 1-2μm and pillar diameters are typically in the 200- 400nm range. In addition to the intrinsic nanoscale aspects of the systems, it is shown they can be further functionalized with nanoporous layers and traditional stationary phases for chromatography; hence exhibit broad-rangingmore » lab-on-a-chip and point-of-care potential. Because of an inherent high permeability and very small effective mass transfer distance between pillars, chromatographic efficiency can be very high but is enhanced herein by stacking during development and focusing while drying, yielding plate heights in the nm range separated band volumes. Practical separations of fluorescent dyes, fluorescently derivatized amines, and anti-tumor drugs are illustrated.« less

  2. Nanoscale pillar arrays for separations

    SciTech Connect

    Kirchner, Teresa; Strickhouser, Rachel; Hatab, Nahla; Charlton, Jennifer; Kravchenko, Ivan I.; Lavrik, Nickolay V.; Sepaniak, Michael J.

    2015-04-01

    The work presented herein evaluates silicon nano-pillar arrays for use in planar chromatography. Electron beam lithography and metal thermal dewetting protocols were used to create nano-thin layer chromatography platforms. With these fabrication methods we are able to reduce the size of the characteristic features in a separation medium below that used in ultra-thin layer chromatography; i.e. pillar heights are 1-2μm and pillar diameters are typically in the 200- 400nm range. In addition to the intrinsic nanoscale aspects of the systems, it is shown they can be further functionalized with nanoporous layers and traditional stationary phases for chromatography; hence exhibit broad-ranging lab-on-a-chip and point-of-care potential. Because of an inherent high permeability and very small effective mass transfer distance between pillars, chromatographic efficiency can be very high but is enhanced herein by stacking during development and focusing while drying, yielding plate heights in the nm range separated band volumes. Practical separations of fluorescent dyes, fluorescently derivatized amines, and anti-tumor drugs are illustrated.

  3. Redundant arrays of IDE drives

    SciTech Connect

    D.A. Sanders et al.

    2002-01-02

    The authors 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. The tests include reports on software RAID-5 systems running under Linux 2.4 using Promise Ultra 100{trademark} 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. The 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. They explore three methods of moving data between sites; internet transfers, not pluggable IDE disks in FireWire cases, and DVD-R disks.

  4. Handheld ultrasound array imaging device

    NASA Astrophysics Data System (ADS)

    Hwang, Juin-Jet; Quistgaard, Jens

    1999-06-01

    A handheld ultrasound imaging device, one that weighs less than five pounds, has been developed for diagnosing trauma in the combat battlefield as well as a variety of commercial mobile diagnostic applications. This handheld device consists of four component ASICs, each is designed using the state of the art microelectronics technologies. These ASICs are integrated with a convex array transducer to allow high quality imaging of soft tissues and blood flow in real time. The device is designed to be battery driven or ac powered with built-in image storage and cineloop playback capability. Design methodologies of a handheld device are fundamentally different to those of a cart-based system. As system architecture, signal and image processing algorithm as well as image control circuit and software in this device is deigned suitably for large-scale integration, the image performance of this device is designed to be adequate to the intent applications. To elongate the battery life, low power design rules and power management circuits are incorporated in the design of each component ASIC. The performance of the prototype device is currently being evaluated for various applications such as a primary image screening tool, fetal imaging in Obstetrics, foreign object detection and wound assessment for emergency care, etc.

  5. Endometrial receptivity array: Clinical application.

    PubMed

    Mahajan, Nalini

    2015-01-01

    Human implantation is a complex process requiring synchrony between a healthy embryo and a functionally competent or receptive endometrium. Diagnosis of endometrial receptivity (ER) has posed a challenge and so far most available tests have been subjective and lack accuracy and a predictive value. Microarray technology has allowed identification of the transcriptomic signature of the window of receptivity window of implantation (WOI). This technology has led to the development of a molecular diagnostic tool, the ER array (ERA) for diagnosis of ER. Use of this test in patients with recurrent implantation failure (RIF) has shown that the WOI is displaced in a quarter of these patients and use of a personalized embryo transfer (pET) on the day designated by ERA improves reproductive performance. Our results in the Indian population revealed an endometrial factor in 27.5% RIF patients, which was significantly greater than the non-RIF group 15% (P = 0.04). After pET, the overall ongoing pregnancy rate was 42.4% and implantation rate was 33%, which was at par with our in-vitro fertilization results over 1-year. We also performed ERA in patients with persistently thin endometrium, and it was reassuring to find that the endometrium in 75% of these patients was receptive despite being 6 mm or less. A pregnancy rate of 66.7% was achieved in this group. Though larger studies are required to validate these results ERA has become a useful tool in our diagnostic armamentarium for ER. PMID:26538853

  6. Maintaining Arrays of Contiguous Objects

    NASA Astrophysics Data System (ADS)

    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.

  7. Geochemical Arrays at Woolsey Mound Seafloor Observatory

    NASA Astrophysics Data System (ADS)

    Sleeper, K.; Wilson, R. M.; Chanton, J.; Lapham, L.; Farr, N.; Camilli, R.; Martens, C. S.; Pontbriand, C.

    2011-12-01

    A suite of geochemical monitoring arrays has been developed for the Woolsey Mound Seafloor Observatory in the northern Gulf of Mexico to evaluate the oceanographic and tectonic forcing factors on the formation and stability of gas hydrates. These arrays are designed to collect sustained, time-series data of chemical concentrations, gradients and fluxes from the subsurface to the seafloor and into the near bottom water column. A Pore Fluid Array provides time-series measurements of methane, sulfate and salinity in subsurface pore waters to evaluate microbial activity, hydrate formation and/or hydrate dissociation. A Chimney Sampler Array collects in situ chemical and physical readings at the benthic boundary. The array is designed around a vertical cylinder with a known volume and washout rate for measuring chemical gradients and flux at the seafloor. The Benthic Boundary Layer Array extends into the water column with a package of sensors in a node close to the seafloor and a similar node 20 m above the seafloor to evaluate upward, downward and transversely advecting fluids. The three arrays can be used in concert to evaluate a release of methane by the dissociation of gas hydrates: the Pore Fluid Array identifies the breakdown of gas hydrates in the subsurface, the Chimney Array determines the rate of flux at the seafloor and the Benthic Boundary Layer Array evaluates the fate of the release in the water column. Combining the data from the geochemical arrays with output from the geophysical arrays provides key information to evaluate the specific and relative importance of tectonic and oceanographic triggers for hydrate dissociation. New probes and deployment platforms have been developed for the installation and maintenance of the arrays and new systems are in place and under development for the recovery of the data. Generally, the complete array or its components have to be recovered to download the data. However, this summer 2011, a new optic modem system was

  8. Inductively coupled wireless RF coil arrays.

    PubMed

    Bulumulla, S B; Fiveland, E; Park, K J; Foo, T K; Hardy, C J

    2015-04-01

    As the number of coils increases in multi-channel MRI receiver-coil arrays, RF cables and connectors become increasingly bulky and heavy, degrading patient comfort and slowing workflow. Inductive coupling of signals provides an attractive "wireless" approach, with the potential to reduce coil weight and cost while simplifying patient setup. In this work, multi-channel inductively coupled anterior arrays were developed and characterized for 1.5T imaging. These comprised MR receiver coils inductively (or "wirelessly") linked to secondary or "sniffer" coils whose outputs were transmitted via preamps to the MR system cabinet. The induced currents in the imaging coils were blocked by passive diode circuits during RF transmit. The imaging arrays were totally passive, obviating the need to deliver power to the coils, and providing lightweight, untethered signal reception with easily positioned coils. Single-shot fast spin echo images were acquired from 5 volunteers using a 7-element inductively coupled coil array and a conventionally cabled 7-element coil array of identical geometry, with the inductively-coupled array showing a relative signal-to-noise ratio of 0.86 +/- 0.07. The concept was extended to a larger 9-element coil array to demonstrate the effect of coil element size on signal transfer and RF-transmit blocking. PMID:25523607

  9. Stretched Lens Array Squarerigger (SLASR) Technology Maturation

    NASA Technical Reports Server (NTRS)

    O'Neill, Mark; McDanal, A.J.; Howell, Joe; Lollar, Louis; Carrington, Connie; Hoppe, David; Piszczor, Michael; Suszuki, Nantel; Eskenazi, Michael; Aiken, Dan; Fulton, Michael; Brandhorst, Henry; Schuller, Michael

    2007-01-01

    Since April 2005, our team has been underway on a competitively awarded program sponsored by NASA s Exploration Systems Mission Directorate to develop, refine, and mature the unique solar array technology known as Stretched Lens Array SquareRigger (SLASR). SLASR offers an unprecedented portfolio of performance metrics, SLASR offers an unprecedented portfolio of performance metrics, including the following: Areal Power Density = 300 W/m2 (2005) - 400 W/m2 (2008 Target) Specific Power = 300 W/kg (2005) - 500 W/kg (2008 Target) for a Full 100 kW Solar Array Stowed Power = 80 kW/cu m (2005) - 120 kW/m3 (2008 Target) for a Full 100 kW Solar Array Scalable Array Capacity = 100 s of W s to 100 s of kW s Super-Insulated Small Cell Circuit = High-Voltage (300-600 V) Operation at Low Mass Penalty Super-Shielded Small Cell Circuit = Excellent Radiation Hardness at Low Mass Penalty 85% Cell Area Savings = 75% Lower Array Cost per Watt than One-Sun Array Modular, Scalable, & Mass-Producible at MW s per Year Using Existing Processes and Capacities

  10. Homogeneous LED-illumination using microlens arrays

    NASA Astrophysics Data System (ADS)

    Schreiber, Peter; Kudaev, Serge; Dannberg, Peter; Zeitner, Uwe D.

    2005-08-01

    Efficient homogeneous illumination of rectangular or circular areas with LEDs is a promising application for doublesided microlens arrays. Such illumination schemes employ a primary optics - which can be realized with a concentrator or a collimation lens - and a secondary optics with one or more double-sided microlens arrays and a collection optics for superposing the light from the individual array channels. The main advantage of this design is the achievable short system length compared to integrating lightpipe designs with subsequent relay optics. We describe design rules for the secondary optics derived from simple ABCD-matrix formalism. Based on these rules, sequential raytracing is used for the actual optics system design. Double-sided arrays are manufactured by polymer-on-glass replication of reflow lenses. With cylindrical lens arrays we assembled high-brightness RGB-illumination systems for rectangular areas. Hexagonal packed double-sided arrays of spherical lenslets were applied for a miniaturized circular spotlight. Black matrix polymer apertures attached to the lens array helped to avoid unwanted straylight.

  11. Mass properties survey of solar array technologies

    NASA Technical Reports Server (NTRS)

    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.

  12. Lens-fed multiple beam arrays

    NASA Astrophysics Data System (ADS)

    Archer, D. H.

    1984-09-01

    The lens-fed type of phased array, wherein an entire set of contiguous beams is formed simultaneously, with each beam processing the full gain of the projected array aperture, is described. In this type of phased array, true time delay is used in the beam formation, so the beam-pointing directions in space remain invariant with frequency. Lens-fed multiple beam arrays provide continuous spatial surveillance with high antenna gain and good angular resolution, which makes them attractive for ESM receive applications. When these arrays are not used for ECM transmit applications, relatively low power amplifiers are placed in each of the array element feed lines. Such a distributed amplifier array can be sized to generate any desired level of effective radiated power from a few kilowatts to tens of megawatts. These radiated power levels are available at 100 percent duty cycle over operating bandwidths of 3:1 and can be controlled by direct optimized ECM techniques discretely at multiple threat emitters.

  13. VBG controlled narrow bandwidth diode laser arrays

    NASA Astrophysics Data System (ADS)

    Levy, Joseph; Feeler, Ryan; Junghans, Jeremy

    2012-03-01

    Northrop Grumman Cutting Edge Optronics has developed large kilowatt class lensed laser diode arrays with subnanometer spectral width using Volume Bragg Grating (VBG) reflectors. Using these CW arrays with 100W bars at 885nm, excellent absorption in Nd:YAG is achieved, with lower thermal aberration than can be attained with 808nm pumps. The additional cost of the VBG reflectors and their alignment is partially offset by the much broader wavelength tolerance that is allowed in the unlocked array enhancing bar yield. Furthermore, the center wavelength of the arrays exhibit lower temperature sensitivity allowing the arrays to be operated over a wider current or temperature range than arrays without wavelength control. While there is an efficiency penalty associated with the addition of VBGs of 5-8%, it is more than compensated for by enhanced absorption, especially when used with narrowband absorption lines, such as 885nm in Nd:YAG. An overview of the design and manufacturing issues for arrays that are wavelength-locked with VBGs is presented along with the effect of post-construction hard UV exposure.

  14. Large-scale nanophotonic phased array.

    PubMed

    Sun, Jie; Timurdogan, Erman; Yaacobi, Ami; Hosseini, Ehsan Shah; Watts, Michael R

    2013-01-10

    Electromagnetic phased arrays at radio frequencies are well known and have enabled applications ranging from communications to radar, broadcasting and astronomy. The ability to generate arbitrary radiation patterns with large-scale phased arrays has long been pursued. Although it is extremely expensive and cumbersome to deploy large-scale radiofrequency phased arrays, optical phased arrays have a unique advantage in that the much shorter optical wavelength holds promise for large-scale integration. However, the short optical wavelength also imposes stringent requirements on fabrication. As a consequence, although optical phased arrays have been studied with various platforms and recently with chip-scale nanophotonics, all of the demonstrations so far are restricted to one-dimensional or small-scale two-dimensional arrays. Here we report the demonstration of a large-scale two-dimensional nanophotonic phased array (NPA), in which 64 × 64 (4,096) optical nanoantennas are densely integrated on a silicon chip within a footprint of 576 μm × 576 μm with all of the nanoantennas precisely balanced in power and aligned in phase to generate a designed, sophisticated radiation pattern in the far field. We also show that active phase tunability can be realized in the proposed NPA by demonstrating dynamic beam steering and shaping with an 8 × 8 array. This work demonstrates that a robust design, together with state-of-the-art complementary metal-oxide-semiconductor technology, allows large-scale NPAs to be implemented on compact and inexpensive nanophotonic chips. In turn, this enables arbitrary radiation pattern generation using NPAs and therefore extends the functionalities of phased arrays beyond conventional beam focusing and steering, opening up possibilities for large-scale deployment in applications such as communication, laser detection and ranging, three-dimensional holography and biomedical sciences, to name just a few.

  15. Intracavitary ultrasound phased arrays for thermal therapies

    NASA Astrophysics Data System (ADS)

    Hutchinson, Erin

    Currently, the success of hyperthermia and thermal surgery treatments is limited by the technology used in the design and fabrication of clinical heating devices and the completeness of the thermometry systems used for guidance. For both hyperthermia and thermal surgery, electrically focused ultrasound generated by phased arrays provides a means of controlling localized energy deposition in body tissues. Intracavitary applicators can be used to bring the energy source close to a target volume, such as the prostate, thereby minimizing normal tissue damage. The work performed in this study was aimed at improving noninvasive prostate thermal therapies and utilized three research approaches: (1) Acoustic, thermal and optimization simulations, (2) Design and fabrication of multiple phased arrays, (3) Ex vivo and in vivo experimental testing of the heating capabilities of the phased arrays. As part of this study, a novel aperiodic phased array design was developed which resulted in a 30- 45% reduction in grating lobe levels when compared to conventional phased arrays. Measured acoustic fields generated by the constructed aperiodic arrays agreed closely with the fields predicted by the theoretical simulations and covered anatomically appropriate ranges. The power capabilities of these arrays were demonstrated to be sufficient for the purposes of hyperthermia and thermal surgery. The advantage of using phased arrays in place of fixed focus transducers was shown by demonstrating the ability of electronic scanning to increase the size of the necrosed tissue volume while providing a more uniform thermal dose, which can ultimately reduce patient treatment times. A theoretical study on the feasibility of MRI (magnetic resonance imaging) thermometry for noninvasive temperature feedback control was investigated as a means to improve transient and steady state temperature distributions achieved in hyperthermia treatments. MRI guided ex vivo and in vivo experiments demonstrated

  16. Characterization of pancreatic ductal adenocarcinoma using whole transcriptome sequencing and copy number analysis by single-nucleotide polymorphism array.

    PubMed

    Di Marco, Mariacristina; Astolfi, Annalisa; Grassi, Elisa; Vecchiarelli, Silvia; Macchini, Marina; Indio, Valentina; Casadei, Riccardo; Ricci, Claudio; D'Ambra, Marielda; Taffurelli, Giovanni; Serra, Carla; Ercolani, Giorgio; Santini, Donatella; D'Errico, Antonia; Pinna, Antonio Daniele; Minni, Francesco; Durante, Sandra; Martella, Laura Raffaella; Biasco, Guido

    2015-11-01

    The aim of the current study was to implement whole transcriptome massively parallel sequencing (RNASeq) and copy number analysis to investigate the molecular biology of pancreatic ductal adenocarcinoma (PDAC). Samples from 16 patients with PDAC were collected by ultrasound‑guided biopsy or from surgical specimens for DNA and RNA extraction. All samples were analyzed by RNASeq performed at 75x2 base pairs on a HiScanSQ Illumina platform. Single‑nucleotide variants (SNVs) were detected with SNVMix and filtered on dbSNP, 1000 Genomes and Cosmic. Non‑synonymous SNVs were analyzed with SNPs&GO and PROVEAN. A total of 13 samples were analyzed by high resolution copy number analysis on an Affymetrix SNP array 6.0. RNAseq resulted in an average of 264 coding non‑synonymous novel SNVs (ranging from 146‑374) and 16 novel insertions or deletions (In/Dels) (ranging from 6‑24) for each sample, of which a mean of 11.2% were disease‑associated and somatic events, while 34.7% were frameshift somatic In/Dels. From this analysis, alterations in the known oncogenes associated with PDAC were observed, including Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations (93.7%) and inactivation of cyclin‑dependent kinase inhibitor 2A (CDKN2A) (50%), mothers against decapentaplegic homolog 4 (SMAD4) (50%), and tumor protein 53 (TP53) (56%). One case that was negative for KRAS exhibited a G13D neuroblastoma RAS viral oncogene homolog mutation. In addition, gene fusions were detected in 10 samples for a total of 23 different intra‑ or inter‑chromosomal rearrangements, however, a recurrent fusion transcript remains to be identified. SNP arrays identified macroscopic and cryptic cytogenetic alterations in 85% of patients. Gains were observed in the chromosome arms 6p, 12p, 18q and 19q which contain KRAS, GATA binding protein 6, protein kinase B and cyclin D3. Deletions were identified on chromosome arms 1p, 9p, 6p, 18q, 10q, 15q, 17p, 21q and 19q which involve TP53

  17. Characterization of pancreatic ductal adenocarcinoma using whole transcriptome sequencing and copy number analysis by single-nucleotide polymorphism array.

    PubMed

    Di Marco, Mariacristina; Astolfi, Annalisa; Grassi, Elisa; Vecchiarelli, Silvia; Macchini, Marina; Indio, Valentina; Casadei, Riccardo; Ricci, Claudio; D'Ambra, Marielda; Taffurelli, Giovanni; Serra, Carla; Ercolani, Giorgio; Santini, Donatella; D'Errico, Antonia; Pinna, Antonio Daniele; Minni, Francesco; Durante, Sandra; Martella, Laura Raffaella; Biasco, Guido

    2015-11-01

    The aim of the current study was to implement whole transcriptome massively parallel sequencing (RNASeq) and copy number analysis to investigate the molecular biology of pancreatic ductal adenocarcinoma (PDAC). Samples from 16 patients with PDAC were collected by ultrasound‑guided biopsy or from surgical specimens for DNA and RNA extraction. All samples were analyzed by RNASeq performed at 75x2 base pairs on a HiScanSQ Illumina platform. Single‑nucleotide variants (SNVs) were detected with SNVMix and filtered on dbSNP, 1000 Genomes and Cosmic. Non‑synonymous SNVs were analyzed with SNPs&GO and PROVEAN. A total of 13 samples were analyzed by high resolution copy number analysis on an Affymetrix SNP array 6.0. RNAseq resulted in an average of 264 coding non‑synonymous novel SNVs (ranging from 146‑374) and 16 novel insertions or deletions (In/Dels) (ranging from 6‑24) for each sample, of which a mean of 11.2% were disease‑associated and somatic events, while 34.7% were frameshift somatic In/Dels. From this analysis, alterations in the known oncogenes associated with PDAC were observed, including Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations (93.7%) and inactivation of cyclin‑dependent kinase inhibitor 2A (CDKN2A) (50%), mothers against decapentaplegic homolog 4 (SMAD4) (50%), and tumor protein 53 (TP53) (56%). One case that was negative for KRAS exhibited a G13D neuroblastoma RAS viral oncogene homolog mutation. In addition, gene fusions were detected in 10 samples for a total of 23 different intra‑ or inter‑chromosomal rearrangements, however, a recurrent fusion transcript remains to be identified. SNP arrays identified macroscopic and cryptic cytogenetic alterations in 85% of patients. Gains were observed in the chromosome arms 6p, 12p, 18q and 19q which contain KRAS, GATA binding protein 6, protein kinase B and cyclin D3. Deletions were identified on chromosome arms 1p, 9p, 6p, 18q, 10q, 15q, 17p, 21q and 19q which involve TP53

  18. Comparative gene expression study of the vestibular organ of the Igf1 deficient mouse using whole-transcript arrays.

    PubMed

    Rodríguez-de la Rosa, Lourdes; Sánchez-Calderón, Hortensia; Contreras, Julio; Murillo-Cuesta, Silvia; Falagan, Sandra; Avendaño, Carlos; Dopazo, Joaquín; Varela-Nieto, Isabel; Milo, Marta

    2015-12-01

    The auditory and vestibular organs form the inner ear and have a common developmental origin. Insulin like growth factor 1 (IGF-1) has a central role in the development of the cochlea and maintenance of hearing. Its deficiency causes sensorineural hearing loss in man and mice. During chicken early development, IGF-1 modulates neurogenesis of the cochleovestibular ganglion but no further studies have been conducted to explore the potential role of IGF-1 in the vestibular system. In this study we have compared the whole transcriptome of the vestibular organ from wild type and Igf1(-/-) mice at different developmental and postnatal times. RNA was prepared from E18.5, P15 and P90 vestibular organs of Igf1(-/-) and Igf1(+/+) mice and the transcriptome analysed in triplicates using Affymetrix(®) Mouse Gene 1.1 ST Array Plates. These plates are whole-transcript arrays that include probes to measure both messenger (mRNA) and long intergenic non-coding RNA transcripts (lincRNA), with a coverage of over 28 thousand coding transcripts and over 7 thousands non-coding transcripts. Given the complexity of the data we used two different methods VSN-RMA and mmBGX to analyse and compare the data. This is to better evaluate the number of false positives and to quantify uncertainty of low signals. We identified a number of differentially expressed genes that we described using functional analysis and validated using RT-qPCR. The morphology of the vestibular organ did not show differences between genotypes and no evident alterations were observed in the vestibular sensory areas of the null mice. However, well-defined cellular alterations were found in the vestibular neurons with respect their number and size. Although these mice did not show a dramatic vestibular phenotype, we conducted a functional analysis on differentially expressed genes between genotypes and across time. This was with the aim to identify new pathways that are involved in the development of the vestibular organ

  19. Arrays: The heart and soul of SIRTF

    NASA Technical Reports Server (NTRS)

    Werner, Michael W.; Eisenhardt, Peter R.

    1994-01-01

    This pape describes the status of NASA's Space Infrared Telescope Facility (SIRTF) program. SIRTF will be a cryogenically cooled observatory for infrared astronomy from space and is planned for launch early in the next decade. It will be the first cryogenic space observatory to make extensive use of the powerful infrared detector array technology discussed at this conference. We summarize a newly developed SIRTF mission concept and show how the availability of detector arrays has shaped the scientific rationale for SIRTF, and how the arrays themselves have become part of the definition of the SIRTF mission.

  20. Arrays: The Heart and Soul of SIRTIF

    NASA Technical Reports Server (NTRS)

    Werner, Michael W.; Eisenhardt, Peter R.

    1993-01-01

    This paper describes the status of NASA's Space Infrared Telescope Facility (SIRTF) program. SIRTF will be a cryogenically cooled observatory for infrared astronomy from space and is planned for launch early in the next decade. It will be the first cryogenic observatory to make extensive use of the powerful infrared detector array technology discussed at this conference. We summarize a newly developed SIRTF mission concept and show how the availability of detector arrays has shaped the scientific rationale for SIRTF, and how the arrays themselves have become part of the definition of the SIRTF mission.

  1. Low-background direct readout array performance

    NASA Technical Reports Server (NTRS)

    Goebel, J. H.; Mckelvey, M. E.; Mccreight, C. R.; Anderson, G. M.

    1986-01-01

    The development and evaluation of an integrated array of antimony-doped silicon detectors is described. The spectral range of extrinsic silicon-integrated arrays useful for low-background IR astronomical applications is extended to about 31 microns with this development. The 58 x 62-element array is accessed by a direct readout multiplexer. The device is evaluated with a flexible microcomputer-based drive and readout electronics system in a low-background test dewar. Acceptance testing indicates single-pixel NEPs in the mid-10 to the -18th W/sq rt Hz range, and good global uniformity statistics.

  2. Solid-state phased array (SSPA) performance

    NASA Astrophysics Data System (ADS)

    Kley, Robert C., Jr.; Hull, W. Porter, Jr.; Lamb, Franklin D.

    The solid-state phased-array (SSPA) is an active electronically scanned array (AESA) designed and built for airborne radar applications using transmit/receive module hybrid technology. Details of its subassemblies and results of testing the array and its subassemblies are presented. The SSPA T/R (transmit/receive) modules used a hybrid construction that is labor-intensive and leads to parameter variations. The next generation of modules uses monolithic microwave integrated circuit (MMIC) devices, which will result in more uniform parameters and lower manufacturing cost.

  3. Microminiature molding techniques for cochlear electrode arrays.

    PubMed

    Loeb, G E; Peck, R A; Smith, D W

    1995-12-01

    We provide a general method for producing a variety of small, complex electrode arrays based on injection molds produced using computer-aided drafting and machining (CAD-CAM) procedures and a novel method for connecting to the very fine electrical leads associated with the individual contacts of such arrays. Cat-sized cochlear electrode arrays with up to eight contacts were built according to these methods and their electrical contacts were characterized in vitro by impedance spectroscopy and in vivo by monitoring impedance for over 1 year of intermittent stimulation in chronically instrumented animals. PMID:8788052

  4. Resonance spectra of diabolo optical antenna arrays

    SciTech Connect

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

    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.

  5. Large Format Transition Edge Sensor Microcalorimeter Arrays

    NASA Technical Reports Server (NTRS)

    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.

  6. Giant array faces financial and political challenges

    NASA Astrophysics Data System (ADS)

    Pockley, Peter

    2009-05-01

    The physicist co-ordinating a project to build a €1.5 bn array of radio telescopes has said that the global recession is unlikely to impede plans to begin construction of the Square Kilometer Array (SKA) in 2011. However, Richard Schilizzi, director of the SKA Program Development Office in Manchester, UK, concedes that "we do not know what impact the current economic crisis will have on public spending in general, and on science projects in particular". Meanwhile, political instability in a number of the SKA's potential host countries may also lead to changes in the array's configuration.

  7. LSA Low-cost Solar Array project

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The activities of the Low-Cost Silicon Solar Array Project during the period October through December, 1977 are reported. The LSSA Project is assigned responsibility for advancing silicon solar array technology while encouraging industry to reduce the price of arrays to a level at which photovoltaic electric power systems will be competitive with more conventional power sources early in the next decade. Set forth are the goals and plans with which the Project intends to accomplish this and the progress that was made during the quarter.

  8. High Efficiency Submillimeter-Wave Imaging Array

    NASA Technical Reports Server (NTRS)

    Llombart, Nuria; Skalare, Anders; Gill, John J.; Siegel, Peter H.

    2008-01-01

    The period of a focal array is limited by the angular sampling and the f number of the system. This fact will limit the efficiency of imaging array systems to around 50%. Recently it been demonstrated that the use of a dielectric layer on top of an array of apertures can improve this efficiency limit. In this paper, we describe a similar structure that improves the efficiency in imaging applications and that it is easy to manufacture due to its compatibility with planar lithographic techniques.

  9. Low-cost Solar Array (LSA) project

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The activities of the Low-Cost Solar Array Project are described for the period April through June 1978. The Project is assigned responsibility for advancing solar array technology while encouraging industry to reduce the price of arrays to a level at which photovoltaic electric power systems will be competitive with more conventional power sources early in the next decade. Set forth are the goals and plans with which the Project intends to accomplish this and the progress that was made during the quarter.

  10. Avalanche Photodiode Arrays for Optical Communications Receivers

    NASA Technical Reports Server (NTRS)

    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.

  11. Phased Array Ultrasonic Inspection of Titanium Forgings

    SciTech Connect

    Howard, P.; Klaassen, R.; Kurkcu, N.; Barshinger, J.; Chalek, C.; Nieters, E.; Sun, Zongqi; Fromont, F. de

    2007-03-21

    Aerospace forging inspections typically use multiple, subsurface-focused sound beams in combination with digital C-scan image acquisition and display. Traditionally, forging inspections have been implemented using multiple single element, fixed focused transducers. Recent advances in phased array technology have made it possible to perform an equivalent inspection using a single phased array transducer. General Electric has developed a system to perform titanium forging inspection based on medical phased array technology and advanced image processing techniques. The components of that system and system performance for titanium inspection will be discussed.

  12. Landsat 7 Solar Array Testing Experiences

    NASA Technical Reports Server (NTRS)

    Helfrich, Daniel

    2000-01-01

    This paper covers the extensive Landsat 7 solar array flight qualification testing effort. Details of the mechanical design of the solar array and its retention/release system are presented. A testing chronology is provided beginning with the onset of problems encountered at the subsystem level and carrying through the third and final powered-spacecraft ground deployment test. Design fixes and other changes are explained in the same order as they became necessary to flight-qualify the array. Some interesting lessons learned are included along with key references.

  13. Wireless indoor millimeter-wave beamforming array

    NASA Astrophysics Data System (ADS)

    Tao, Y. M.; Delisle, G. Y.

    1998-11-01

    A practical design of a compact integrated Rotman lens is presented, which will be used as a beamformer of multiple beam antenna arrays in wireless indoor communication network. An improved design equations of integrated Rotman lens is derived to calculate the lens contour and a non-circular focal arc is introduced in beam ports to minimize the phase aberrations on the aperture of array. A log-periodic electromagnetic coupling microstrip patch array is adopted as radiation elements. Both theoretical and experimental results show the designed multiple beam antenna has wide band width performance.

  14. Microfabricated capillary array electrophoresis device and method

    DOEpatents

    Simpson, Peter C.; Mathies, Richard A.; Woolley, Adam T.

    2000-01-01

    A capillary array electrophoresis (CAE) micro-plate with an array of separation channels connected to an array of sample reservoirs on the plate. The sample reservoirs are organized into one or more sample injectors. One or more waste reservoirs are provided to collect wastes from reservoirs in each of the sample injectors. Additionally, a cathode reservoir is also multiplexed with one or more separation channels. To complete the electrical path, an anode reservoir which is common to some or all separation channels is also provided on the micro-plate. Moreover, the channel layout keeps the distance from the anode to each of the cathodes approximately constant.

  15. Microfabricated capillary array electrophoresis device and method

    DOEpatents

    Simpson, Peter C.; Mathies, Richard A.; Woolley, Adam T.

    2004-06-15

    A capillary array electrophoresis (CAE) micro-plate with an array of separation channels connected to an array of sample reservoirs on the plate. The sample reservoirs are organized into one or more sample injectors. One or more waste reservoirs are provided to collect wastes from reservoirs in each of the sample injectors. Additionally, a cathode reservoir is also multiplexed with one or more separation channels. To complete the electrical path, an anode reservoir which is common to some or all separation channels is also provided on the micro-plate. Moreover, the channel layout keeps the distance from the anode to each of the cathodes approximately constant.

  16. Wideband Microstrip Antenna-Feeding Array

    NASA Technical Reports Server (NTRS)

    Huang, John

    1990-01-01

    Special impedance-matching probes help reduce feed complexity. Lightweight array of microstrip antenna elements designed to transmit and illuminate reflector antenna with circularly polarized radiation at 1,545 to 1,550 MHz and to receive circularly polarized radiation at 1,646 to 1,660 MHz. Microstrip array is cluster of 7 subarrays containing total of 28 microstrip patches. Produces cicularly polarized beam with suitable edge taper to illuminate reflector antenna. Teardrop-shaped feed probe provides gradual change of field from coaxial transmission line into microstrip substrate. Intended to be part of larger overlapping-cluster array generating multiple contiguous beams.

  17. Phased Array Ultrasonic Inspection of Titanium Forgings

    NASA Astrophysics Data System (ADS)

    Howard, P.; Klaassen, R.; Kurkcu, N.; Barshinger, J.; Chalek, C.; Nieters, E.; Sun, Zongqi; deFromont, F.

    2007-03-01

    Aerospace forging inspections typically use multiple, subsurface-focused sound beams in combination with digital C-scan image acquisition and display. Traditionally, forging inspections have been implemented using multiple single element, fixed focused transducers. Recent advances in phased array technology have made it possible to perform an equivalent inspection using a single phased array transducer. General Electric has developed a system to perform titanium forging inspection based on medical phased array technology and advanced image processing techniques. The components of that system and system performance for titanium inspection will be discussed.

  18. Flat-plate photovoltaic array design optimization

    NASA Technical Reports Server (NTRS)

    Ross, R. G., Jr.

    1980-01-01

    An analysis is presented which integrates the results of specific studies in the areas of photovoltaic structural design optimization, optimization of array series/parallel circuit design, thermal design optimization, and optimization of environmental protection features. The analysis is based on minimizing the total photovoltaic system life-cycle energy cost including repair and replacement of failed cells and modules. This approach is shown to be a useful technique for array optimization, particularly when time-dependent parameters such as array degradation and maintenance are involved.

  19. Remote environmental sensor array system

    NASA Astrophysics Data System (ADS)

    Hall, Geoffrey G.

    This thesis examines the creation of an environmental monitoring system for inhospitable environments. It has been named The Remote Environmental Sensor Array System or RESA System for short. This thesis covers the development of RESA from its inception, to the design and modeling of the hardware and software required to make it functional. Finally, the actual manufacture, and laboratory testing of the finished RESA product is discussed and documented. The RESA System is designed as a cost-effective way to bring sensors and video systems to the underwater environment. It contains as water quality probe with sensors such as dissolved oxygen, pH, temperature, specific conductivity, oxidation-reduction potential and chlorophyll a. In addition, an omni-directional hydrophone is included to detect underwater acoustic signals. It has a colour, high-definition and a low-light, black and white camera system, which it turn are coupled to a laser scaling system. Both high-intensity discharge and halogen lighting system are included to illuminate the video images. The video and laser scaling systems are manoeuvred using pan and tilt units controlled from an underwater computer box. Finally, a sediment profile imager is included to enable profile images of sediment layers to be acquired. A control and manipulation system to control the instruments and move the data across networks is integrated into the underwater system while a power distribution node provides the correct voltages to power the instruments. Laboratory testing was completed to ensure that the different instruments associated with the RESA performed as designed. This included physical testing of the motorized instruments, calibration of the instruments, benchmark performance testing and system failure exercises.

  20. Microarray analysis of responsible genes in increased growth rate in the subline of HL60 (HL60RG) cells.

    PubMed

    Luan, Yang; Kogi, Mieko; Rajaguru, Palanisamy; Ren, Jin; Yamaguchi, Teruhide; Suzuki, Kazuhiro; Suzuki, Takayoshi

    2012-03-01

    HL60RG, a subline of human promyelocytic leukemia HL60 cells, has a increased growth rate than their parental cells. To gain information of the mechanisms involved in the increased growth rate of HL60RG, we performed a multiplex fluorescence in situ hybridization (M-FISH), standard cytogenetics analysis (G-banding) and genome scan using 10K SNP mapping array on both cell types. Characteristic genomic alterations in HL60RG cells were identified including uniparental disomy (UPD) of chromosome 1, and hemizygous deletion in 10p and 11p. However, no such defects were observed in HL60 cells. Changes in gene expression in HL60RG cells were determined using expression arrays (Affymetrix GeneChip, HU133A). Candidate genes associated with the rapid growth of HL60RG cells were identified. Two tumor necrosis factor receptors, TNFRSF1B (type II tumor necrosis factor-α receptor) and TNFRSF8 (also known as a tumor marker CD30), which are adjacently located on chromosome 1 showed opposing changes in gene expression in HL60RG cells-over-expression of TNFRSF8 and repression of TNFRSF1B. Differences in the DNA methylation status in the transcriptional regulatory regions of both genes between HL60 and HL60RG was detected by a methylation-specific PCR assay. In conclusion, alterations in chromosome and gene expression in HL60RG may be associated with increased growth rate.

  1. Changes in the transcriptome of bovine ovarian cortex during follicle activation in vitro.

    PubMed

    Yang, M Y; Fortune, J E

    2015-12-01

    The signals that regulate activation, a key transition in ovarian follicular development, are still not well understood, especially in nonrodent species. To gain insight into the regulation of this transition in cattle, we combined a microarray approach with an in vitro system in which ovarian cortical pieces cultured in control medium are enriched for primordial follicles, whereas pieces cultured with insulin are enriched for primary follicles. Total RNA was extracted from cultured cortical pieces, and then transcripts were identified and analyzed using the Affymetrix Bovine Genome GeneChip array. Around 65% of the transcripts in the bovine GeneChip were detected in cultured cortical pieces. Comparison between pieces cultured with or without insulin generated 158 differentially expressed transcripts. Compared with controls, 90 transcripts were upregulated and 68 were downregulated by insulin. These transcripts are involved in many biological processes and functions, but most are associated with cellular growth or cell cycle/cell death. The transcript encoding ubiquitin-conjugating enzyme E2C (UBE2C) was significantly upregulated during follicle activation, and Ingenuity Pathways Analysis revealed that UBE2C can interact with the tumor suppressor phosphatase and tensin homolog (PTEN). Both PTEN mRNA and protein were lower in cortical pieces cultured with insulin than in controls. In addition, FOXO3a, a downstream effector of PTEN signaling, underwent nuclear-cytoplasmic shuttling during primordial to primary follicle development in bovine fetal ovaries, further suggesting the involvement of the PTEN pathway in follicle activation in cattle. Genes and pathways identified in this study provide interesting candidates for further investigation of mechanisms underlying follicle activation.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Some results concerning linear iterative (systolic) arrays

    SciTech Connect

    Ibarra, O.H.; Palis, M.A.; Kim, S.M.

    1985-05-01

    The authors have shown some new interesting results concerning the properties, power, and limitations of various types of linear iterative (systolic) arrays. The method they employed consisted of finding sequential machine characterizations of these array models, and then using the characterizations to prove the results. Because of the absence of any concurrency and synchronization problems, the authors obtained simple proofs to results which when proved directly on the arrays would seem very difficult. The characterizations, therefore, provide a novel and promising method which can be used to analyze other systolic systems. In the future they hope to extend this methodology to the study of two-dimensional and multidimensional systolic arrays, and other systolic systems with different interconnection networks.

  4. Systolic arrays - From concept to implementation

    SciTech Connect

    Fortes, J.A.B.; Wah, B.W.

    1987-07-01

    Systolic arrays are the result of advances in semiconductor technology and of applications that require extensive throughput. Their realization requires human ingenuity combined with techniques and tools for algorithm development, architecture design, and hardware implementation. Invariably, the first reaction of people who are exposed to the systolic-array concept is one of admiration for the concept's elegance and for its potential for high performance. However, those who next attempt to implement a systolic array for a specific application soon realize that a wealth of subsumed concepts and engineering solutions must be mastered and understood. This special issue attempts to provide insights into the implementation process and to illustrate the different techniques and theories that contribute to the design of systolic arrays.

  5. Low-cost laser diode array

    DOEpatents

    Freitas, Barry L.; Skidmore, Jay A.

    1999-01-01

    A substrate is used to fabricate a low-cost laser diode array. A substrate is machined from an electrically insulative material that is thermally conductive, or two substrates can be bonded together in which the top substrate is electrically as well as thermally conductive. The substrate thickness is slightly longer than the cavity length, and the width of the groove is wide enough to contain a bar and spring (which secures the laser bar firmly along one face of the groove). The spring also provides electrical continuity from the backside of the bar to the adjacent metalization layer on the laser bar substrate. Arrays containing one or more bars can be formed by creating many grooves at various spacings. Along the groove, many bars can be adjoined at the edges to provide parallel electrical conduction. This architecture allows precise and predictable registration of an array of laser bars to a self-aligned microlens array at low cost.

  6. Low-cost laser diode array

    DOEpatents

    Freitas, B.L.; Skidmore, J.A.

    1999-06-01

    A substrate is used to fabricate a low-cost laser diode array. A substrate is machined from an electrically insulative material that is thermally conductive, or two substrates can be bonded together in which the top substrate is electrically as well as thermally conductive. The substrate thickness is slightly longer than the cavity length, and the width of the groove is wide enough to contain a bar and spring (which secures the laser bar firmly along one face of the groove). The spring also provides electrical continuity from the backside of the bar to the adjacent metalization layer on the laser bar substrate. Arrays containing one or more bars can be formed by creating many grooves at various spacings. Along the groove, many bars can be adjoined at the edges to provide parallel electrical conduction. This architecture allows precise and predictable registration of an array of laser bars to a self-aligned microlens array at low cost. 19 figs.

  7. Signal Conditioning For Infrared Staring Arrays

    NASA Astrophysics Data System (ADS)

    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.

  8. Graphical methods for evaluating covering arrays

    DOE PAGES

    Kim, Youngil; Jang, Dae -Heung; Anderson-Cook, Christine M.

    2015-08-10

    Covering arrays relax the condition of orthogonal arrays by only requiring that all combination of levels be covered but not requiring that the appearance of all combination of levels be balanced. This allows for a much larger number of factors to be simultaneously considered but at the cost of poorer estimation of the factor effects. To better understand patterns between sets of columns and evaluate the degree of coverage to compare and select between alternative arrays, we suggest several new graphical methods that show some of the patterns of coverage for different designs. As a result, these graphical methods formore » evaluating covering arrays are illustrated with a few examples.« less

  9. Increase in the Array Television Camera Sensitivity

    NASA Astrophysics Data System (ADS)

    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.

  10. Discrete photonics resonator in coupled waveguide arrays.

    PubMed

    Plougonven, Nadia Belabas; Minot, Christophe; Bouwmans, Géraud; Levenson, Ariel; Moison, Jean-Marie

    2014-05-19

    We demonstrate both theoretically and experimentally that discrete diffraction resonance can be designed, fabricated, and successfully probed in functionalized - guidonic - coupled waveguide arrays. We evidence that double-barrier patterning of the coupling creates wavelength-independent angular tunnel resonance in the transmitted and the reflected intensity of light beams freely propagating in the plane of the array. Transmission peaks obtained are associated with resonant excitation of the engineered array bound supermodes of the functionalized array, in agreement with accurate and practical numerical modeling based on extended coupled-mode theory. The linear operation of the guidonic resonant tunneling double barrier makes up an original resonator for discrete photonics, suitable for all-optical control of light.

  11. Illustrating Arrays with a Finance Savings Example.

    ERIC Educational Resources Information Center

    Kost, Franklin

    1990-01-01

    Described is a learning activity which incorporates computer programing and the teaching of arrays. Using the newspaper as a source for ideas for programing assignments and classroom examples is emphasized. (KR)

  12. ARRAYS FOR BIOMONITORING ENVIRONMENTAL AND REPRODUCTIVE TOXICOLOGY

    EPA Science Inventory

    DNA arrays are receiving increasing interest as a tool for monitoring the developmental and reproductive impact of xenobiotics and other hazardous materials on human and wildlife populations. The primary tenet of toxicogenomics is that effects of environmental exposure on cellul...

  13. SMEX-Lite Modular Solar Array Architecture

    NASA Technical Reports Server (NTRS)

    Lyons, John

    2002-01-01

    For the most part, Goddard solar arrays have been custom designs that are unique to each mission. The solar panel design has been frozen prior to issuing an RFP for their procurement. There has typically been 6-9 months between RFP release and contract award, followed by an additional 24 months for performance of the contract. For Small Explorer (SMEX) missions, with three years between mission definition and launch, this has been a significant problem. The SMEX solar panels have been sufficiently small that the contract performance period has been reduced to 12-15 months. The bulk of this time is used up in the final design definition and fabrication of flight solar cell assemblies. Even so, it has been virtually impossible to have the spacecraft design at a level of maturity sufficient to freeze the solar panel geometry and release the RFP in time to avoid schedule problems with integrating the solar panels to the spacecraft. With that in mind, the SMEX-Lite project team developed a modular architecture for the assembly of solar arrays to greatly reduce the cost and schedule associated with the development of a mission- specific solar array. In the modular architecture, solar cells are fabricated onto small substrate panels. This modular panel (approximately 8.5" x 17" in this case) becomes the building block for constructing solar arrays for multiple missions with varying power requirements and geometrical arrangements. The mechanical framework that holds these modules together as a solar array is the only mission-unique design, changing in size and shape as required for each mission. There are several advantages to this approach. First, the typical solar array development cycle requires a mission unique design, procurement, and qualification including a custom qualification panel. With the modular architecture, a single qualification of the SMEX-Lite modules and the associated mechanical framework in a typical configuration provided a qualification by

  14. Calibration of a photomultiplier array spectrometer

    NASA Technical Reports Server (NTRS)

    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.

  15. Tomographical imaging using uniformly redundant arrays

    NASA Technical Reports Server (NTRS)

    Cannon, T. M.; Fenimore, E. E.

    1979-01-01

    An investigation is conducted of the behavior of two types of uniformly redundant array (URA) when used for close-up imaging. One URA pattern is a quadratic residue array whose characteristics for imaging planar sources have been simulated by Fenimore and Cannon (1978), while the second is based on m sequences that have been simulated by Gunson and Polychronopulos (1976) and by MacWilliams and Sloan (1976). Close-up imaging is necessary in order to obtain depth information for tomographical purposes. The properties of the two URA patterns are compared with a random array of equal open area. The goal considered in the investigation is to determine if a URA pattern exists which has the desirable defocus properties of the random array while maintaining artifact-free image properties for in-focus objects.

  16. A phased array tracking antenna for vehicles

    NASA Technical Reports Server (NTRS)

    Ohmori, Shingo; Mano, Kazukiko; Tanaka, Kenji; Matsunaga, Makoto; Tsuchiya, Makio

    1990-01-01

    An antenna system including antenna elements and a satellite tracking method is considered a key technology in implementing land mobile satellite communications. In the early stage of land mobile satellite communications, a mechanical tracking antenna system is considered the best candidate for vehicles, however, a phased array antenna will replace it in the near future, because it has many attractive advantages such as a low and compact profile, high speed tracking, and potential low cost. Communications Research Laboratory is now developing a new phased array antenna system for land vehicles based on research experiences of the airborne phased array antenna, which was developed and evaluated in satellite communication experiments using the ETS-V satellite. The basic characteristics of the phased array antenna for land vehicles are described.

  17. An electrically active microneedle array for electroporation

    PubMed Central

    Choi, Seong-O; Kim, Yeu Chun; Park, Jung-Hwan; Hutcheson, Joshua; Gill, Harvinder S.; Yoon, Yong-Kyu; Prausnitz, Mark R.; Allen, Mark G.

    2010-01-01

    We have designed and fabricated a microneedle array with electrical functionality with the final goal of electroporating skin’s epidermal cells to increase their transfection by DNA vaccines. The microneedle array was made of polymethylmethacrylate (PMMA) by micromolding technology from a master PDMS mold, followed by metal deposition, patterning using laser ablation, and electrodeposition. This microneedle array possessed sufficient mechanical strength to penetrate human skin in vivo and was also able to electroporate both red blood cells and human prostate cancer cells as an in vitro model to demonstrate cell membrane permeabilization. A model to predict the effective volume for electroporation with respect to applied voltages was constructed from finite element simulation. This study demonstrates the mechanical and electrical functionalities of the first MEMS-fabricated microneedle array for electroporation, designed for DNA vaccine delivery. PMID:20012696

  18. An electrically active microneedle array for electroporation.

    PubMed

    Choi, Seong-O; Kim, Yeu Chun; Park, Jung-Hwan; Hutcheson, Joshua; Gill, Harvinder S; Yoon, Yong-Kyu; Prausnitz, Mark R; Allen, Mark G

    2010-04-01

    We have designed and fabricated a microneedle array with electrical functionality with the final goal of electroporating skin's epidermal cells to increase their transfection by DNA vaccines. The microneedle array was made of polymethylmethacrylate (PMMA) by micromolding technology from a polydimethylsiloxane (PDMS) mold, followed by metal deposition, patterning using laser ablation, and electrodeposition. This microneedle array possessed sufficient mechanical strength to penetrate human skin in vivo and was also able to electroporate both red blood cells and human prostate cancer cells as an in vitro model to demonstrate cell membrane permeabilization. A computational model to predict the effective volume for electroporation with respect to applied voltages was constructed from finite element simulation. This study demonstrates the mechanical and electrical functionalities of the first MEMS-fabricated microneedle array for electroporation, designed for DNA vaccine delivery. PMID:20012696

  19. Segmented-mirror phased-array lasers

    SciTech Connect

    De Silvestri, S.; Laporta, P.; Magni, V.; Svelto, O.

    1987-11-30

    A scheme for phase-locked laser arrays in both one- and two-dimensional configurations is discussed. The scheme can be applied to any laser and its validity has been proved for the case of a pulsed neodimium laser.

  20. Bionic ommatidia based on microlens array

    NASA Astrophysics Data System (ADS)

    Hao, Liu; Sihai, Chen; Shan, Dong; Xinjian, Yi

    2009-06-01

    A simple method is reported to manufacture a planar compound eye using a microlens array. The compound eye, inspired by insects, consists of a microlens array and a waveguide coupled with it. A microlens array with lenses of 50 μm in diameter is fabricated by melting AZ1500 photoresist and then transferring it onto SU-8. With the self-focus method applied, a waveguide array is formed, and each is exactly coupled to a lens. The formation of the waveguide is simulated using finite difference time domain (FDTD) arithmetic, resembling the ommatidia produced in our experiment. The ommatidia is also testified to astrict beam, just as the natural compound eyes do.

  1. Robustness of the magnetoresistance of nanoparticle arrays

    NASA Astrophysics Data System (ADS)

    Estévez, V.; Bascones, E.

    2011-08-01

    Recent work has found that the interplay between spin accumulation and Coulomb blockade in nanoparticle arrays results in peaky I-V and tunneling magnetoresistance (TMR) curves and in huge values of the TMR. We analyze how these effects are influenced by a polarization asymmetry of the electrodes, the dimensionality of the array, the temperature, resistance, or charge disorder, and long-range interactions. We show that the magnitude and voltage dependence of the TMR do not change with the dimensionality of the array or the presence of junction resistance disorder. A different polarization in the electrodes modifies the peak shape in the I-V and TMR curves but not their order of magnitude. Increasing the temperature or length of the interaction reduces to some extent the size of the peaks, the reduction being due to long-range interactions that are smaller in longer arrays. Charge disorder should be avoided to observe large TMR values.

  2. Multispectral linear array multiband selection device

    NASA Technical Reports Server (NTRS)

    Richard, H. L.

    1986-01-01

    An apparatus for detecting multiple spectral bands, individually or concurrently, using linear detector arrays is described. The system employs a beamsplitter to divide the optical source into two or more optical beams which are directed at the linear detector arrays. Filter trays are positioned in the focal planes of the optical beams so that the beams pass through the filter trays prior to impinging upon the detector arrays. Multiple filters are placed on the filter trays. Linear actuators positioned adjacent the filter trays translate the trays across the focal planes of the optical beams so that individual filters are positioned in the path of beams such that those frequencies of the beams that fall within the spectral ranges of the individual bandpass filter through which it passes may be detected by the detector arrays for further examination and analysis.

  3. Automatic Testing Of Infrared Detector Arrays

    NASA Astrophysics Data System (ADS)

    Jones, David A.

    1982-12-01

    Large scale infrared (IR) detector array production requires highly automated and accurate test equipment with data logging features. At Texas Instruments (TI), five different types of automatic test systems have been developed with a central computer data logging system. Two of these system types test the completed array in various stages of integration into the final assembly. These tests include responsivity, detectivity, and other characteristics. Since direct calibration for responsivity and detectivity is not available, close attention to the applicable formulas, an error budget, and calibration procedures is required. This paper first summarizes the many types of tests and test equipment that are used at TI in constructing a finished "Common Module" detector from raw mercury cadium telluride (MCT), then describes in more detail the test sets for automated testing of the array itself, and the factors affecting array test accuracy and calibration.

  4. Density controlled carbon nanotube array electrodes

    DOEpatents

    Ren, Zhifeng F.; Tu, Yi

    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.

  5. Exploring the Universe with Pulsar Timing Arrays

    NASA Astrophysics Data System (ADS)

    Burke-Spolaor, Sarah

    2016-03-01

    It is an exciting time for pulsar timing arrays, as their upper limits on gravitational radiation are carving into the expected strength of gravitational waves from several source populations in the Universe. Cosmic strings, inflationary gravitational waves, and binary supermassive black holes are all expected contributors to the nanohertz to microhertz band probed by pulsar timing arrays: they might be discovered as bursting sources, as continuously oscillating signals, or as an ensemble population in a stochastic background. This presentation will discuss the predicted intensity and form of these sources, and how the upper limits set by pulsar timing arrays are being used to set unique constraints on source properties, and to measure galaxy evolution in the nearby Universe. Looking to the future, we will explore how pulsar timing arrays can characterize their target source populations, and we will present the prospects for multi-messenger detection.

  6. Gallium arsenide solar array subsystem study

    NASA Technical Reports Server (NTRS)

    Miller, F. Q.

    1982-01-01

    The effects on life cycle costs of a number of technology areas are examined for a gallium arsenide space solar array. Four specific configurations were addressed: (1) a 250 KWe LEO mission - planer array; (2) a 250 KWe LEO mission - with concentration; (3) a 50 KWe GEO mission planer array; (4) a 50 KWe GEO mission - with concentration. For each configuration, a baseline system conceptual design was developed and the life cycle costs estimated in detail. The baseline system requirements and design technologies were then varied and their relationships to life cycle costs quantified. For example, the thermal characteristics of the baseline design are determined by the array materials and masses. The thermal characteristics in turn determine configuration, performance, and hence life cycle costs.

  7. Solid waste drum array fire performance

    SciTech Connect

    Louie, R.L.; Haecker, C.F.; Beitel, J.J.; Gottuck, D.T.; Rhodes, B.T.; Bayier, C.L.

    1995-09-01

    Fire hazards associated with drum storage of radioactively contaminated waste are a major concern in DOE waste storage facilities. This report is the second of two reports on fire testing designed to provide data relative to the propagation of a fire among storage drum arrays. The first report covers testing of individual drums subjected to an initiating fire and the development of the analytical methodology to predict fire propagation among storage drum arrays. This report is the second report, which documents the results of drum array fire tests. The purpose of the array tests was to confirm the analytical methodology developed by Phase I fire testing. These tests provide conclusive evidence that fire will not propagate from drum to drum unless an continuous fuel source other than drum contents is provided.

  8. Substrate-supported lipid nanotube arrays.

    SciTech Connect

    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.

  9. Diamond coated silicon field emitter array

    SciTech Connect

    S. Albin; W. Fu; A. Varghese; A. C. Lavarias; G. R. Myneni

    1999-07-01

    Diamond coated silicon tip arrays, with and without a self-aligned gate, were fabricated, and current-voltage characteristics of 400 tips were measured. Diamond films were grown uniformly on Si tips using microwave plasma after nucleation with 10 nm diamond suspension and substrate bias. An emission current of 57 ?A was obtained at 5 V from the ungated array tips separated from an anode at 2 ?m. In the case of the gated arrays with 1.5 ?m aperture, an emission current of 3.4 ?A was measured at a gate voltage of 80 V for an anode separation of 200 ?m. The turn-on voltages for these two types of devices were 0.2 and 40 V, respectively. Diamond coated Si tip arrays have potential applications in field emission based low voltage vacuum electronic devices and microsensors.

  10. Receptor arrays optimized for natural odor statistics.

    PubMed

    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.

  11. Modeling Charge Collection in Detector Arrays

    NASA Technical Reports Server (NTRS)

    Hardage, Donna (Technical Monitor); Pickel, J. C.

    2003-01-01

    A detector array charge collection model has been developed for use as an engineering tool to aid in the design of optical sensor missions for operation in the space radiation environment. This model is an enhancement of the prototype array charge collection model that was developed for the Next Generation Space Telescope (NGST) program. The primary enhancements were accounting for drift-assisted diffusion by Monte Carlo modeling techniques and implementing the modeling approaches in a windows-based code. The modeling is concerned with integrated charge collection within discrete pixels in the focal plane array (FPA), with high fidelity spatial resolution. It is applicable to all detector geometries including monolithc charge coupled devices (CCDs), Active Pixel Sensors (APS) and hybrid FPA geometries based on a detector array bump-bonded to a readout integrated circuit (ROIC).

  12. Mission applications for advanced photovoltaic solar arrays

    NASA Technical Reports Server (NTRS)

    Stella, Paul M.; West, John L.; Chave, Robert G.; Mcgee, David P.; Yen, Albert S.

    1990-01-01

    The suitability of the Advanced Photovoltaic Solar Array (APSA) for future space missions was examined by considering the impact on the spacecraft system in general. The lightweight flexible blanket array system was compared to rigid arrays and a radio-isotope thermoelectric generator (RTG) static power source for a wide range of assumed future earth orbiting and interplanetary mission applications. The study approach was to establish assessment criteria and a rating scheme, identify a reference mission set, perform the power system assessment for each mission, and develop conclusions and recommendations to guide future APSA technology development. The authors discuss the three selected power sources, the assessment criteria and rating definitions, and the reference missions. They present the assessment results in a convenient tabular format. It is concluded that the three power sources examined, APSA, conventional solar arrays, and RTGs, can be considered to complement each other. Each power technology has its own range of preferred applications.

  13. Stretched Lens Array Photovoltaic Concentrator Technology Developed

    NASA Technical Reports Server (NTRS)

    Piszczor, Michael F., Jr.; O'Neill, Mark J.

    2004-01-01

    Solar arrays have been and continue to be the mainstay in providing power to nearly all commercial and government spacecraft. Light from the Sun is directly converted into electrical energy using solar cells. One way to reduce the cost of future space power systems is by minimizing the size and number of expensive solar cells by focusing the sunlight onto smaller cells using concentrator optics. The stretched lens array (SLA) is a unique concept that uses arched Fresnel lens concentrators to focus sunlight onto a line of high-efficiency solar cells located directly beneath. The SLA concept is based on the Solar Concentrator Array with Refractive Linear Element Technology (SCARLET) design that was used on NASA's New Millennium Deep Space 1 mission. The highly successful asteroid/comet rendezvous mission (1998 to 2001) demonstrated the performance and long-term durability of the SCARLET/SLA solar array design and set the foundation for further improvements to optimize its performance.

  14. NASA Solar Array Demonstrates Commercial Potential

    NASA Technical Reports Server (NTRS)

    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

  15. Implementation and use of systolic array processes

    SciTech Connect

    Kung, H.T.

    1983-01-01

    Major effort are now underway to use systolic array processors in large, real-life applications. The author examines various implementation issues and alternatives, the latter from the viewpoints of flexibility and interconnection topologies. He then identifies some work that is essential to the eventual wide use of systolic array processors, such as the development of building blocks, system support and suitable algorithms. 24 references.

  16. Slotted Polyimide-Aerogel-Filled-Waveguide Arrays

    NASA Technical Reports Server (NTRS)

    Rodriguez-Solis, Rafael A.; Pacheco, Hector L.; Miranda, Felix A.; Meador, Mary Ann B.

    2013-01-01

    This presentation discussed the potential advantages of developing Slotted Waveguide Arrays using polyimide aerogels. Polyimide (PI) aerogels offer great promise as an enabling technology for lightweight aerospace antenna systems. PI aerogels are highly porous solids possessing low density and low dielectric permittivity combined with good mechanical properties. For slotted waveguide array applications, there are significant advantages in mass that more than compensate for the slightly higher loss of the aerogel filled waveguide when compared to state of practice commercial waveguide.

  17. Fault Analysis in Solar Photovoltaic Arrays

    NASA Astrophysics Data System (ADS)

    Zhao, Ye

    Fault analysis in solar photovoltaic (PV) arrays is a fundamental task to increase reliability, efficiency and safety in PV systems. Conventional fault protection methods usually add fuses or circuit breakers in series with PV components. But these protection devices are only able to clear faults and isolate faulty circuits if they carry a large fault current. However, this research shows that faults in PV arrays may not be cleared by fuses under some fault scenarios, due to the current-limiting nature and non-linear output characteristics of PV arrays. First, this thesis introduces new simulation and analytic models that are suitable for fault analysis in PV arrays. Based on the simulation environment, this thesis studies a variety of typical faults in PV arrays, such as ground faults, line-line faults, and mismatch faults. The effect of a maximum power point tracker on fault current is discussed and shown to, at times, prevent the fault current protection devices to trip. A small-scale experimental PV benchmark system has been developed in Northeastern University to further validate the simulation conclusions. Additionally, this thesis examines two types of unique faults found in a PV array that have not been studied in the literature. One is a fault that occurs under low irradiance condition. The other is a fault evolution in a PV array during night-to-day transition. Our simulation and experimental results show that overcurrent protection devices are unable to clear the fault under "low irradiance" and "night-to-day transition". However, the overcurrent protection devices may work properly when the same PV fault occurs in daylight. As a result, a fault under "low irradiance" and "night-to-day transition" might be hidden in the PV array and become a potential hazard for system efficiency and reliability.

  18. Order in vertically aligned carbon nanotube arrays

    SciTech Connect

    Wang, Hsin; Xu, Z; Eres, Gyula

    2006-01-01

    We report the direct measurements on the bulk morphology of vertically aligned multiwalled carbon nanotube (CNT) arrays using small angle neutron scattering (SANS). SANS measurements at different heights of CNT arrays corresponding to different stages of the growth reveal increasing alignment order along the thickness and two distinctly different CNT morphologies. The observations suggest that the evolution of the macroscopic CNT morphologies be driven by competing collective growth and spatial constraints.

  19. Microshutter Arrays for the NGST MOS

    NASA Astrophysics Data System (ADS)

    Woodgate, B. E.; Aslam, S.; Blumenstock, K. A.; Ewin, A.; Fettig, R. K.; Franz, D.; Kotecki, C.; Kutyrev, A. S.; Li, M.; Monroy, C.; Moseley, S. H.; Mott, D. B.; Schwinger, D. S.; Wesenberg, R. P.; Zheng, Y.

    2001-05-01

    Two-dimensional microshutter arrays have been developed at NASA Goddard Space Flight Center for the Next Generation Space Telescope (NGST) for use in the near-infrared region. Functioning as object selection devices, the microshutter arrays are designed for the transmission of light with high efficiency and high contrast. The NGST environment requires cryogenic operation at 45K. Arrays are close-packed silicon nitride membranes with a pixel size of 100μ m x 100 μ m. The mechanical shutter arrays are fabricated with Micro-ElectroMechanical Systems technologies. Individual shutters are patterned with a torsion flexure permitting shutters to open 90 degrees with a minimized mechanical stress concentration. The processing includes a Reactive Ion Etching (RIE) front-etch to form shutters out of the nitride membrane, an anisotropic back-etch for wafer thinning, and a deep RIE (DRIE) back-etch down to the nitride shutter membrane to form frames and to relieve shutters from the silicon substrate. Two schemes for microshutter array actuation and selection are being developed. In the first approach shutters are addressed and selected by a CMOS circuit embedded in the shutter array frame. Actuation is performed by a macro-motion of the whole array support structure utilizing a double-shutter concept. In the second scheme the shutters are coated with a layer of high permeability magnetic material. They are rotated out of the plane by magnetic forcess produced by the interaction of the field produced by an external magnet that is swept across the shutter array and a metal layer on the shutters. To address the shutters a system of transparent electrodes, row and column address lines on each chip and external addressing electronics is used. Vertical walls of the shutter support structure are metallized and act as an electrode to hold selected shutters open at 90 degrees out of the plane. This project is supported by NASA funding.

  20. Large Format Detector Arrays for Astrophysics

    NASA Technical Reports Server (NTRS)

    Moseley, Harvey

    2006-01-01

    Improvements in detector design and advances in fabrication techniques has resulted in devices which can reach fundamental sensitivity limits in many cases. Many pressing astrophysical questions require large arrays of such sensitive detectors. I will describe the state of far infrared through millimeter detector development at NASA/GSFC, the design and production of large format arrays, and the initial deployment of these powerful new tools.